JP2003191440A - Aqueous ink composition control device and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous printing ink composition control device capable of automatically adjusting a control state always to a specified level during an operation, by controlling the volume of water of the aqueous ink composition containing water and alcohol, the volume of alcohol and the volume of a neutralizing agent, and further, adding the water, alcohol and neutralizing agent appropriately during printing/coating. <P>SOLUTION: This aqueous ink composition control device is characterized in that it comprises (1) a conductance (conductivity) detection part, (2) a pH detection part, (3) a temperature detection part and a data processing part (computer). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to management of water-based inks, paints, and coating agents such as adhesives and varnishes (hereinafter referred to as “water-based printing ink compositions”), and particularly water-based printing used for gravure and flexographic printing. The present invention relates to a water-based ink composition management device having a management method and a management detection unit at the time of printing an ink composition.

[0002]

2. Description of the Related Art In recent years, from the viewpoints of conservation of the global environment, effective use of resources, and improvement of working environment, in the coating field of printing inks and paints, adhesives, varnishes, etc., there has been a shift from solvent type to aqueous type. It is being advanced. As an aqueous type, perfect aqueous solution without using an organic solvent is ideal, but from the viewpoint of various required qualities, not only water but also alcohol is often used together. Particularly in gravure printing and flexographic printing, alcohol is used in combination with water-based printing inks in order to improve the drying property (printing speed), the wettability to various plastic films, and the printing effect.

In a water-based printing ink composition containing water and alcohol, since the evaporation rates of water and alcohol are different, the amount of alcohol to water in the water-based ink composition increases as the use time increases during printing. Is getting less. When the amount of alcohol decreases, problems such as a decrease in drying rate and a decrease in wettability with respect to various plastic films and other substrates occur. Therefore, it is necessary to control the amount of alcohol in the aqueous printing ink composition.

In general, when performing gravure printing with solvent-type printing ink, a device that automatically checks the viscosity change of the ink with a diaphragm or the like and automatically adds the solvent that evaporates during the printing operation (ink viscosity controller) It is managed by. An ink viscosity controller is widely used in gravure printing because a printed matter of stable quality can be obtained by using the ink viscosity controller.

[0005]

The ink viscosity controller described above, when applied to a water-based ink composition containing alcohol, causes almost no change in the viscosity of the ink.
Almost no evaporated amount of alcohol is added, and the amount of alcohol in the water-based printing ink composition decreases, which causes a problem that the quality of the printed matter deteriorates.

Further, water-based inks, paints and adhesives,
Aqueous resin used for coating agents such as varnish,
Generally, ammonia, organic amines, etc. are used as a neutralizing agent. In particular, water-based inks used in gravure printing and flexographic printing often use volatile neutralizing agents such as ammonia and low-boiling organic amines in consideration of the water resistance of the dry film. In that case, if the printing work takes a long time and new printing ink is not added, the neutralizing agent will volatilize from the aqueous printing ink during the work and the pH will decrease,
Since the state stability and re-dissolvability of the ink are deteriorated and the printing quality is deteriorated, it is necessary to control the pH in the aqueous printing ink.

From the above points, in the case of printing a water-based printing ink composition containing water and alcohol for a long time, in order to always maintain a good printing effect, the amount of alcohol in the water-based printing ink composition is kept constant, And it is necessary to keep the pH constant.

However, it is impossible to control the amount of alcohol and the pH of the water-based printing ink composition at the time of printing by a commonly used viscosity control device using a viscometer such as a Zahn cup or a viscosity controller. is there.

Further, it is possible to maintain the alcohol amount and the pH at the time of printing to some extent by preparing a correction solvent for correcting the alcohol amount and the neutralizing agent amount in advance and manually adding the correction solvent at regular intervals.

However, the amount of water and alcohol that evaporates depends on the temperature and humidity of the environment in which the work is performed, so it is necessary to change the amount of water and alcohol added depending on the season and day, and workability is also improved. It was complicated.

The present invention manages the amount of water, the amount of alcohol and the amount of neutralizing agent of an aqueous ink composition containing water and alcohol at the time of printing or coating, which cannot be solved by the existing apparatus as described above, It is an object of the present invention to provide a water-based printing ink composition management device capable of automatically adjusting to a constant state during work by adding fresh water, alcohol and a neutralizing agent.

[0012]

The present inventors have arrived at the present invention as a result of extensive studies to solve the above problems.
A first invention is (1) an electric conductivity (conductivity) detector, (2)
A water-based ink composition management device comprising a management device including a pH detection unit, (3) a temperature detection unit, and a data processing unit (computer).

A second invention is provided with a tank capable of storing water, alcohol, a neutralizing agent alone or a mixed liquid (A), and processing from a data processing unit (computer) based on measurement data from the detection unit. The mixed liquid (A) is supplied to the ink pan by the above method, which is the aqueous ink composition management apparatus according to the first invention.

The third aspect of the present invention is (1) electric conductivity (conductivity) detecting section, and (2) p for managing when printing the aqueous ink composition.
Each data obtained from the H detection unit and (3) temperature detection unit is transmitted to the data processing unit (computer), and the data is stored from a tank capable of storing water, alcohol, a neutralizer alone or a mixed liquid (A). The mixed liquid (A) is supplied to the ink pan by the processing from the processing unit (computer),
This is a method for controlling an aqueous ink composition.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The constitution of the present invention will be described in detail below. FIG. 1 shows an example of a schematic configuration diagram of a management apparatus of the present invention.

In FIG. 1, A is a conductivity (conductivity) detector, B is a pH detector, and C is a temperature detector, which are in contact with the tank liquid of K. Further, D is the viscosity measuring section E to G,
Alcohol, water and neutralizer tanks, each with a flow controller I attached. H is a control part, and the detection data from A, B, C and D are sent here. Further, the control data is sent to the flow rate controller I attached to each of E to G. J is a display unit, on which electric conductivity, pH value, temperature, viscosity and the like are displayed. K is a tank for adjusting water-based inks and coating agents, which is connected to, for example, an ink pan of a gravure printing machine, alcohols added from E to G, water and a neutralizing agent are mixed here, and the printing machine is again used. It is designed to return to the ink pan, etc.

In this apparatus, the electric conductivity (conductivity) of the water-based ink and the coating agent in the adjusting tank J is constantly measured by the detecting section A. Similarly, the pH value and liquid temperature are
It is measured by the detectors B and C and stored in the controller. When printing is continuously performed, alcohol evaporates from the water-based ink and the coating agent, and the ratio of water and alcohol is deviated to change the conductivity (conductivity) from the initial setting state. Data is sent from the alcohol tank D and the water tank E to the flow controller I so that the proper amount of alcohol and water are constantly added, and the water-alcohol ratio of the water-based ink and coating agent during printing is maintained. To be done.

At this time, the viscosity of the water-based printing ink composition is measured by the viscosity measuring section D, and it is reflected in the above-mentioned amount data of alcohol and water based on the electric conductivity (conductivity) so that the viscosity is kept constant. It has become so.

The conductivity, pH, and viscosity of the water-based ink and coating agent are affected by the liquid temperature and change. Therefore, the conductivity, pH, and viscosity data can be corrected by the liquid temperature data. ing.

The alcohol used in this control device is a dedicated alcohol compatible with the water-based ink and water-based coating agent used. For example, it is a primary to tertiary alcohol having 1 to 10 carbon atoms, and is methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol. , Neopentanol, 2-pentanol, 3-pentanol, 3-methyl-2-
Butanol, 2-methyl-2-butanol, n-hexanol, isohexanol, 4-methyl-2-pentanol, 2-
Ethyl butanol, n-heptanol, 2-heptanol,
3-heptanol, n-octanol, 2-octanol, 2-
Examples include chain monoalcohols such as ethylhexanol, n-nonanol and 3,3,5-trimethylhexanol, and cyclic monoalcohols such as cyclopentanol, methylcyclopentanol, cyclohexanol, methylcyclohexanol and ethylcyclohexanol. To be When two or more kinds of water-based inks and water-based coating agents are used, it is necessary to set the compounding ratio in advance according to the evaporation rate of each.

Similarly, regarding the pH value, an appropriate amount of the neutralizing agent is always added so that the pH values of the water-based ink and the coating agent during printing can be maintained.

The neutralizing agent used in this control apparatus is a dedicated neutralizing agent compatible with the aqueous ink composition used.
Examples include inorganic basic compounds such as caustic soda and caustic potash, ammonia, alkylamines such as methylamine, ethylamine, monoethanolamine, diethanolamine, triethanolamine, and organic basic compounds such as morpholine. These may be used alone or in combination of two or more.

This ink management device can be used only for viscosity control like the ink viscosity controller generally used when performing gravure printing with solvent type ink, and it is dedicated to the alcohol tank D. The diluent solvent may be added and the viscosity measuring unit D may be operated independently.

[0024]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto. In the examples, "part" means "part by weight", and "%" means "% by weight". Example The apparatus shown in FIG. 1, an aqueous gravure ink for flexible packaging (JW
224 Akwa Ecole 39S Indigo: manufactured by Toyo Ink Mfg. Co., Ltd.). 18μ, 8 lines
Gravure printing was performed continuously for 6 hours at a printing speed of 120 m / min using a solid plate of 0 line / cm, and the ink and printed matter were sampled every hour. Table 1 shows the results of evaluation of the solid content in the ink, the solvent ratio, the print density of the printed matter, the leveling property and the drying property. From the results shown in Table 1, it was confirmed that when the ink management device according to the present invention was used, the printing effect and the drying property of the printed matter were not deteriorated, and the ink was constantly adjusted to a constant state during printing. Comparative Example Using the same water-based ink as the example, the material to be printed, without using the water-based printing ink composition management device, the same printing was performed using a general viscosity controller, and the ink was printed every 1 hour. And prints were sampled. Table 2 shows the results of evaluating the solid content in the ink, the solvent ratio, the print density of the printed matter, the leveling property, and the drying property. The evaluation methods and criteria in Tables 1 and 2 are as follows. Printing density: The density value of the printed matter is measured by a reflection densitometer (X-R
measured at ite 408). Leveling property: The leveling property of printed matter is visually evaluated with an initial value (at the start of printing) as a standard. ⊚: No decrease in leveling property is observed. ◯: A slight decrease in leveling property is recognized. Δ: The leveling property is partially reduced. X: Remarkable leveling property is recognized. Dryability ・ ・ ・ Visually evaluated the degree to which the guide roll of the ink coating of printed matter is taken. ○: Not accepted. Δ: The guide roll was slightly removed. X: Significant removal of the guide roll is recognized.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

INDUSTRIAL APPLICABILITY According to the present invention, the amount of water, the amount of alcohol and the amount of neutralizing agent in water-based inks, paints and coating agents such as adhesives and varnishes containing water and alcohols can be controlled so that the appropriate amount of water, alcohol It is possible to automatically adjust to a constant state during the work by adding a hydrating agent, and especially in gravure printing and flexographic printing for a long time, the printing effect, drying property (printing speed), etc. are kept in a good state. I was able to do it. It has become possible to easily obtain stable print quality and printability.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a management device of the present invention.

[Explanation of symbols]

A: Conductivity detector (detection sensor) B: pH detector (detection sensor) C: Temperature detection unit (detection sensor) D: Viscosity measuring section E: Alcohol tank F: Water tank G: Neutralizer tank H: Control device I: Flow controller J: Display (pH, alcohol amount, temperature, etc.) K: Tank for adjusting ink, coating agent, etc.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koji Otani             2-3-13, Kyobashi, Chuo-ku, Tokyo Toyo             Nki Manufacturing Co., Ltd. (72) Inventor Motoki Miyano             2-3-13, Kyobashi, Chuo-ku, Tokyo Toyo             Nki Engineering Co., Ltd. F-term (reference) 2C250 DA07 DB21 EA23 EB50

Claims (3)

[Claims] 1. A (1) conductivity (conductivity) detector, (2) p
An aqueous ink composition management device comprising an H detection unit, (3) a temperature detection unit, and a data processing unit (computer). 2. A tank which can store water, alcohol, a neutralizing agent alone or a mixed liquid (A), and a mixed liquid (processed by a data processing unit (computer) based on measurement data from a detection unit ( The aqueous ink composition management device according to claim 1, wherein A) is supplied to the ink pan. 3. As a control at the time of printing an aqueous ink composition,
(1) Conductivity (conductivity) detector, (2) pH detector,
(3) Each data obtained from the temperature detection unit is transmitted to the data processing unit (computer), and water, alcohol,
A method for controlling a water-based ink composition, comprising supplying a mixed liquid (A) to an ink pan by a process from a data processing unit (computer) from a tank capable of storing a neutralizer alone or a mixed liquid (A).