JPS606462A - Gravure process printing system - Google Patents

Abstract

PURPOSE:To obtain screen wires of sizes of 6-12mum without cutting by a method in which a plate after forming a resist is subjected to an etching process using an aqueous solution containing 300g/1,000cc or more of cupric chloride and a specific amount of hydrochloric acid. CONSTITUTION:Using an aqueous solution containing 300g/1,000cc or more of cupric chloride and hydrochloric acid in an amount enough to keep cuprous chloride to be chemically changed by the cupric chloride during the processing period in dissolved state in the liquid, a plate after forming a resist is etched. Since the cupric chloride is chamically changed into insoluble cuprous chloride during the processing period, it is necessary to add hydrochloric acid as an aid in order to keep the cuprous chloride in the dissolved state. The etching process used includes Morton Roller touch method, shower spray method, etc., and the preferred temperature of the etching liquid is 25-35 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION <Background of the Invention> Technical Field The present invention relates to a gravure plate-making method in which etching is performed using an aqueous solution of cupric chloride.

Conventional technology Chloride-based etching solutions include an aqueous solution of ferric chloride,
There is also an aqueous solution of cupric chloride.

However, although an aqueous solution of cupric chloride has been used for etching printed wiring boards, it has never been put to practical use for etching gravure printing plates.

However, an aqueous solution of ferric chloride is difficult to process as a liquid (4) and waste liquid, whereas an aqueous solution of cupric chloride is easy to regenerate and treat as a waste liquid. We wanted to put this aqueous solution to practical use in the etching process of gravure printing plates.

For this reason, an aqueous solution of cupric chloride in a concentration range used for etching printed wiring boards was prepared, and an experiment was conducted to determine whether it was suitable as an etching solution that could be used practically for etching gravure printing plates.

This experiment was 1,0OOGC: '! Three types of aqueous solutions containing 100 g, 150 g, and 200 g of cupric chloride, respectively, and 40 g of hydrochloric acid, low concentration, medium concentration, and high concentration, were prepared for 4I, and the test was carried out in three ways.

However, in both cases, it took more than 20 minutes to obtain cells with a depth of 30 microns.

On the other hand, the current etching process using an aqueous solution of ferric chloride takes 3 to 4 minutes to obtain the same cell, so the aqueous solution Iα of cupric chloride is used for etching printed wiring boards. It was found that the concentration given above was not practical.

On the other hand, in order to make the resolution of the shadow part extremely high, it is necessary to increase the dot percentage to 75% to 85%, which requires the bank width to be 6 to 12 microns.

However, since the aqueous solution of ferric chloride has a large side etch, it is very difficult to manage the etching time and set other conditions when increasing the bank width from 6 to 12 microns. If the conditions are set incorrectly, the screen line may often break.

<Object of the Invention> The present invention was devised in view of the above-mentioned points, and is practical because the etching time is almost as short as the aqueous solution of ferric chloride that is currently used. The purpose of the present invention is to provide a gravure plate making method in which etching time management and other conditions can be easily set, and extremely thin screen lines of 6 to 12 microns can be obtained without cutting.

<Structure of the invention> The gravure plate making method of the present invention has a production capacity of 1,0000 (1:3 per
An aqueous solution containing 00g or more of cupric chloride and the necessary amount of hydrochloric acid to maintain the cuprous chloride, which is chemically changed from the cupric chloride during processing, in a dissolved state in the solution. This method is characterized by etching the plate material.

The aqueous solution containing 300 g or more of cupric chloride per 1.000 CC was determined based on the following experiment.

While maintaining the solution to contain 40 g of hydrochloric acid per 1,0 OOC:C, prepare other types of aqueous solutions in which cupric chloride was increased stepwise from 250 g to 25 g, and the solution temperature was maintained at 30 ° C. A plate material with a cell diameter of 25 microns and a test piece (plate material) on TPR with a cell diameter of 38 microns were selected and etched, and f!
! When we investigated the relationship between the concentration of the second chemical solution and the etching time, it was confirmed that an aqueous solution containing 350 g of cupric chloride can perform good etching in 5 to 6 minutes. It was confirmed that good etching could be achieved in 8 to 10 minutes with an aqueous solution containing 300 g of cupric chloride, and that etching did not proceed well even after 15 minutes with aqueous solutions containing 250 g and 275 g of cupric chloride, respectively.
In addition, for an aqueous solution containing 375 g or more of cupric chloride, 350
It was confirmed that the etching time could not be shortened compared to an aqueous solution containing about 500g of copper chloride, and it was confirmed that the saturation point was reached when the etching content was about 500g.From the above results, it was confirmed that the etching time was not shortened compared to an aqueous solution containing more than 300g of cupric chloride. It was confirmed that the gravure plate making method was not practical in terms of time.

In the present invention, an aqueous solution of cupric chloride was selected as the etching solution because the aqueous solution of cupric chloride, which is currently used in the etching process of printed wiring boards, was used in gravure
This is because they wanted to put it to practical use in the 1lii method to facilitate liquid regeneration and waste liquid treatment.

Since cupric chloride is converted into water-insoluble cuprous chloride during processing, it is necessary to include hydrochloric acid as an auxiliary agent to maintain cuprous chloride in a dissolved state. However, the amount of this hydrochloric acid is 1,00. QC: 30 to 40 people per C
Although it is preferable to set it as g, it does not specifically limit. It is sufficient as long as it contains the required amount of hydrochloric acid to be maintained in a dissolved state.

The etching method may be a Molton roller touch method, a shower spray set, a Tobu 18 method, or a Badle method. The temperature of the etching solution is preferably 25°C to 35°C.

For Molton roller touch type and etching, the plate roll rotation speed can be set to 5 ORPM to 140 RPM, and for shower spray type and paddle type, it can be set to 110 PP to 6.
It can be set to 0PPM.

<Operations and Effects of the Invention> The operations and effects of the gravure plate making method of the present invention explained above are as follows.

・In particular, if the etching process takes less than 10 minutes, especially if the aqueous solution contains about 350 g or more of cupric chloride per 1,000 OOCG, it will take 5 to 6 minutes. This is a useful solution with negligible time and workability compared to an aqueous solution.

・Q) Since the second main solution of TJI Chemical is used, it is easy to regenerate the liquid and treat waste liquid.

and) Compared to the conventional method using an aqueous solution of ferric chloride,
The etching effect is small, making it easy to control processing time. In other words, in the conventional method using an aqueous solution of ferric chloride, the etching effect is large, and if the processing time is not controlled, the cells will become too deep and the screen wires will break, but with the present invention, No such thing will occur. In the conventional method using an aqueous solution of ferric chloride, it takes 3 to 4 minutes to form a cell with a depth of 35 microns, but according to the present invention, it takes 3 to 4 minutes to form a cell with a depth of 35 microns.
It took 7 to 8 minutes to create a 5 micron deep cell, and 5 to 6 minutes to create a 25 micron deep cell.

According to the results of experiments described below, the conventional method etches at a speed of about 7 microns per minute, and the method of the present invention etches at a speed of about 4 microns per minute. It was confirmed that it is easy to manage.

Therefore, the present invention also makes it easier in terms of time to obtain cells with a depth of 10 to 25 microns.

・4) Compared to the conventional method using an aqueous solution of ferric chloride, the side etch is extremely small, and therefore not only can bank widths of 6 to 12 microns be obtained with easy time management, but also other conditions It also becomes easier to set up. For this reason, the dot percentage of the most shadow part is set to 75%.
It became easy to increase the resolution to ~85%, which led to a significant increase in the resolution of shadow areas. This was a totally unexpected and favorable result, which led to the fact that good results were obtained even with bank widths of 6 to 12 microns, and the resolution of the shadow area was greatly improved.

Figure 1 shows a gravure plate obtained by etching a plate material with a resist having 175 screen lines per inch and a positive dot percentage of 80% using an aqueous solution containing 350 g of cupric chloride. This is a photograph of the plate viewed with an optical microscope.

The width of the bank was measured and was 8 microns. Furthermore, as can be seen from this photo, it was confirmed that using an aqueous solution of cupric chloride, the bank could be etched well without being cut, even though the width of the bank was extremely small.

Moreover, FIG. 2 is a cross-sectional photograph of the gravure plate shown in FIG. 1, as seen with an optical microscope. As you can see from this photo)
Using an aqueous solution of cupric chloride, it was possible to obtain a cell with no side etching and a hard dot. Therefore, even if the depth is small, the ink transfer to the printed material is good, and the results are in good agreement with etching the cells shallowly.

The inventor had expected to some extent that the use of an aqueous solution of cupric chloride would result in less etching and side etching than in the conventional method, but the ideal cell as shown in the photograph in Figure 2 was obtained. It was completely unexpected.

Compared to the conventional method using an aqueous solution of ferric chloride, the depth preferably varies depending on the cell diameter.

FIG. 3(a) is a diagram showing the experimental results comparing the conventional method and the gravure plate making method of the present invention regarding side etching, where etching was performed for 7 minutes using the conventional method and 7 minutes using the method of the present invention. FIG. 4(a) shows the case where etching was performed for 5 minutes using the conventional method and for 9 minutes using the method of the present invention. The vertical axis shows the etching diameter, and the horizontal axis shows the TP.
The cell diameter on R (name of sensitive material) was calibrated.

Moreover, FIG. 3(b) is a diagram obtained by measuring the depth of the cell corresponding to FIG. 3(a), and FIG. 4(b) is a diagram showing the measured depth of the cell corresponding to FIG.
) is a diagram in which the depth of the cell corresponding to .

In these figures, line 1.3 is the conventional method, line 2.
4 shows the gravure plate making method of the present invention.

Figures 3(a) and 4(a) show that side etching has occurred if the etching diameter is above the straight line inclined at 45 degrees, indicated by the dotted line, and from line 1 and line 2. It can be seen that the gravure plate making method of the present invention causes less side etching.

Further, from 1!3 and line 4, it can be seen that the gravure plate making method of the present invention is better when the cell diameter is 55 microns or less.

・Grain The gravure plate making method of the present invention can be obtained satisfactorily even when the bank width is 6 to 12 microns, so it is extremely effective for health and energy saving for ink drying in the current situation where gravure printing is used in 70% of the food packaging printing industry. Effective.

That is, when the amount of organic solvent remaining in the ink on a package printed using the conventional method was measured using gas chromatography, it was found to be 3 mg, whereas when the same printed image on a package made of the same material was printed using the gravure platemaking method of the present invention, it was found to be 3 mg. After printing and drying under the same conditions, the amount of organic solvent remaining in the ink was measured using gas chromatography, and it was found to be 0.5 mg.
there were.

This is because the gravure plate-making method of the present invention can make the cell depth much shallower than the conventional method, and the packaging itself printed by the gravure plate-making method of the present invention has favorable health results. This is good for health as it reduces nitrogen oxides caused by organic solvents contained in the ink that is discharged into the air during drying.
If we were to reduce the amount of organic solvent remaining in the ink on packaging printed using the conventional method to the amount used in the gravure printing method of the present invention, the drying energy would be proportional to the square of the residual organic solvent, so it would be extremely It saves energy.

[Brief explanation of drawings]

Figure 1 shows a gravure plate obtained by processing a plate material with a resist having 175 screen lines per inch and a positive dot percentage of 80% using the gravure plate making method of the present invention. This is a photo taken with a microscope. FIG. 2 is a cross-sectional photograph of the gravure plate shown in FIG. 1, taken with an optical microscope. FIG. 3(a) is a diagram showing the results of an experiment comparing the conventional method and the gravure plate making method of the present invention regarding side etching. , Fig. 4(a) shows the case of etching for 5 minutes using the conventional method and 9 minutes of etching using the method of the present invention, and Fig. 3(b) shows the measurement of the depth of the cell corresponding to Fig. 3(a). FIG. 4(b) is a diagram of FIG.
It is a figure which measured the depth of the cell corresponding to a). Patent applicant Think Laborad Co., Ltd. 9 - Agent Hiroshi Onuma Patent attorney Hiroshi Onuma - Patent filed on June 28, 1980 II/3 June 27, 1981 Crime 3: Relationship with supplementary table = 1% Patent applicant address: 810-1 Umebayashi, Juyoji, Ai-shi, Chiba Prefecture Name: Think Lahoratory Co., Ltd. CEO Shige 1) Ryuo 4 Agent Postal code: 107 T E L (03)
582-000!3 Spontaneous 6 Number of inventions increased by addition None 7 Drawing 8 attached to the application subject to amendment 8 Details of the amendment I forgot to attach Figure 11ffi and Figure 2 (both photos), so I added it. do.

Claims (1)

[Claims] 1.000C: Contains 300g or more of cupric chloride per C and the necessary amount of hydrochloric acid to maintain the cuprous chloride, which chemically changes from the cupric chloride during processing, in a dissolved state and at IB in the liquid. A gravure plate making method characterized by etching the plate material after resist formation using an aqueous solution.