JPH0210934B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a preset type one-component corrosion method in gravure plate making.

[Technical background of the invention and its problems]

In gravure plate making, the so-called one-component corrosion method is said to be excellent in terms of controlling and simplifying the corrosion process, as it corrodes the gravure printing plate with a single solution of corrosive liquid at a predetermined concentration. . This involves supplying a certain concentration of ferric chloride solution (FeCl ₃ ) as a corrosive liquid to the cylinder surface of the gravure printing plate.
This method attempts to obtain a desired set cell (halftone dot) depth curve by changing the rotational speed of the cylinder.
However, in the conventional one-component corrosion method, the cell depth at two points, the darkest part of the gravure printing plate and another desired part, is detected during the corrosion work, and the cell depth at the desired part matches the intermediate setting value. Each time, the cell depth at the deepest shadow part is measured, and if the cell depth is larger (deeper) than the measured value, the rotation speed of the cylinder is reduced, and if it is smaller (shallower), the rotation speed is increased to reduce the amount of corrosion. It was of the feed pack control type.
In this way, the conventional one-component corrosion method can only control the cell depth at two points, so whether or not the cell depth in the intermediate gradation area matches the desired cell depth curve is determined by the corrosion work. It was difficult to detect unless the process ended.

In addition, since the conventional one-component corrosion method basically uses feedpack control, a cell depth sensor, arithmetic control device, etc. necessary for feedpack control are required, making the structure of the corrosive machine complicated and expensive. There were flaws.

[Purpose of the invention]

In consideration of the above-mentioned points, the present invention calculates in advance the optimum corrosion conditions for the corrosive liquid from the resist penetration characteristics that have a correlation between the test liquid and the corrosive liquid before the corrosion work of the gravure printing plate, and By corroding the gravure printing plate by using a single corrosive solution of a predetermined concentration, the corrosion process operation and corrosion equipment can be simplified, and the image quality of the gravure printing plate can be improved. The purpose of this invention is to provide a preset type one-component corrosion method for gravure plate making.

[Summary of the invention]

In order to achieve the above-mentioned object, the one-component corrosion method for gravure plate making according to the present invention uses a test solution that has excellent correlation with the corrosion solution and reproducibility in terms of resist penetration characteristics, and (i) determines the gradation of the resist. Correlation between resist penetration time of test liquid and resist penetration time of corrosive liquid at each stage of scale, (ii) Correlation between corrosion time of various cylinders and resist penetration time of test liquid for each cylinder rotation speed and corrosion cell depth and (iii) the actual corrosion time of each cylinder and the correlation between the test liquid penetration time and corrosion cell depth for each cylinder rotation speed are determined in advance, and the gradation scale of the resist is determined before the corrosion work is performed. The resist penetration time of one shadow area, one highlight area, and n+2 locations of intermediate gradation (n≧1) was tested using the same test liquid, and the n intermediate gradation locations were determined as the branching point of the corrosion process. The total corrosion time of the corrosion work, the corrosion distribution time in each corrosion period, and the rotation speed of the cylinder are calculated in order so that the n + 2 places inspected have the desired cell depth, and based on this, the corrosion work of the gravure printing plate is carried out. This is done using a preset method.

[Embodiments of the invention]

Embodiments of the invention will be described with reference to the accompanying drawings.

Prior to describing embodiments of the present invention, a method for testing the penetration time of a test liquid into a gelatin resist attached to a copper gravure printing plate will be described. As the test liquid, for example, a non-corrosive or less corrosive conductive solution containing polyhydric alcohol as a main component is used.

In FIG. 1, reference numeral 10 indicates a cylindrical copper gravure printing plate, and a gelatin resist 12 is formed in close contact with the surface of the copper layer of this gravure printing plate 10. In FIG. The resist 12 is made by applying a carbon film coated with photosensitive gelatin or the like to a paper base, exposing it to positive light, pressing it onto the cylinder of the gravure printing plate 10, and transferring it.
It is formed by developing and drying, and a thin resist is formed in the shadow areas and a thick resist is formed in the highlight areas.

Thus, the image to be printed is formed on the resist 12 by development, and the inspection gradation scale is set at one location in the shadow area, one location in the highlight area, and n locations in the middle (n≧1), total n+2. A place is formed. In Figure 1, there are four locations A, B, C, and D.
That is, the case where n=2 will be exemplified.

FIG. 2 shows an inspection device for inspecting the characteristics of the resist 12, and FIG. 3 shows an example of use of the above inspection device. As shown in the figure, the resist electrode 14 is connected to the power supply +V _CC through a resistor R ₁ , and the other resist electrode 16 is grounded through a resistor R ₂ . Further, the potential V _B of the resist electrode 16 is input to the comparator 18 set to the threshold potential V _TH , and the output CM (2
value signal) is input to the AND circuit 20. A clock pulse CP of a predetermined frequency from a pulse oscillator 22 is input to the AND circuit 20. The output of the AND circuit 20 is counted by a counter 24, and the counted value is passed through a decoder 26 and displayed on a display section 28 as penetration time data. Also,
The count value of the counter 24 is cleared by a clear button 30, and the resistance _R3 represents the resistance of the resist 12 as the object to be measured. The resist 12 is grounded via an electrode 32, and the grounding point is the copper layer 33 of the gravure printing plate 10 in the case of FIG.

Then, the inspection operation starts when the power is turned on. In this case, since the resist electrode 16 is grounded via the resistor R ₂ , its potential V _B is
It is 0 (V) as at time Z ₀ to Z ₁ in Figure A,
It is lower than the threshold potential (+V _TH ). Therefore, the output of the comparator 18 is as shown in FIG.
As shown in FIG. 2, the clock pulse CP is a binary signal "0", and since the clock pulse CP is blocked by the AND circuit 20, the counter 24 does not perform counting.

From this state, a conductivity test liquid is dropped onto the resist electrodes 14 and 16 on the resist 12. By dropping this test liquid, the test liquid SL comes into contact with the resist 12 and the resist electrodes 14 and 16, and the current from the power supply (+V _CC ) reaches the above-mentioned dropping point Z ₁
flows from R ₂ and R ₃ through resistor R ₁ . Therefore, the potential V _B becomes a divided voltage value V _M of the combined resistance value of the resistor R ₁ and the resistors R ₂ and R ₃ (see FIG. 4A), which is input to the comparator 18. Since this divided voltage value V _M is larger than the threshold potential (+V _TH ), the output CM of the comparator 18 becomes a binary signal of "1" (see FIG. 4B). As a result, the clock pulse CP is input to the counter 24 through the AND circuit 20, and a counting operation is started. The count value of this counter is converted into time data by the decoder 26, and the elapsed time from the counting start time _Z1 is displayed on the display section 26.

When the test liquid SL is dropped onto the resist 12, the test liquid SL gradually penetrates into the resist 12, so that its resistance _R3 gradually decreases.
Therefore, as shown in FIG. 4A, the potential V _B gradually decreases after time Z ₁ and becomes smaller than the threshold potential V _TH at time Z ₂ . This allows comparator 1
The output CM of 8 becomes "0" again, and the clock pulse CP from the pulse oscillator 22 is output from the AND circuit 20.
The counting operation of the counter 24 is stopped.
In this way, the counter 24 counts from time Z ₁ to Z ₂ , that is, from the time when the test liquid SL is dropped onto the resist 12 until the test liquid SL penetrates to a predetermined depth (corresponding to the value of the threshold potential V _TH ). Count the clock pulses CP from the pulse oscillator 22 until
This is converted into time data by the decoder 26 and then displayed as the resist penetration time of the test liquid. Thereby, the penetration time of the test liquid SL into the resist 12 can be measured. Note that the counter 24
The count value is cleared by pressing the clear button 30.

The measurement by the inspection device is carried out on each part of the gradation scale on the resist 12 in four stages A, B, C, and D (from the positive density shadow side, P _A , P _B , P _C , and P _D ). The penetration time of the resist 12 at each inspection position _PA , _PB , _PC , _PD is inspected.

Here, the set depth y of the cell of the gravure printing plate 10 corresponding to each stage A, B, C, D of the gradation scale of the resist 12 is the positive density P _A , P _B , P _C ,
There is a corresponding relationship with P _D as shown in Figure 5. The corresponding curves shown in FIG. 5 are appropriately selected and determined from experience depending on the type of printed matter and the like.

Further, the set depth y of the cell of the gravure printing plate 10 corresponding to each positive density P _A , P _B , P _C , _PD of the original is as follows:
There is a correlation between the test liquid penetration time x and the resist 12 as shown in FIG. The four stages (inspection points) A, B, C, and D of the inspection gradation scale of the resist 12 are plotted in sequence from the shadow side to the highlight side in FIG. 6 as A, B, C, and D, and the resist thickness becomes gradually thicker from point A to point D.
That is, as the cell setting depth becomes deeper, the resist thickness becomes thinner, and in the opposite case, the resist thickness becomes thicker, resulting in the correlation shown in FIG. 6.

In addition, the test liquid used is a liquid that has excellent correlation with the corrosive liquid and reproducibility in terms of resist penetration characteristics. When the concentration of the etchant is set constant, there is generally a correlation between the resist penetration time x of the test solution SL and the resist penetration time t of the etchant as shown in FIG. In this case, if the concentration of the corrosive liquid is different,
The curves of the relationship curves are also different. According to experiments, the curve of the above relationship curve is cylinder (gravure printing plate)
It was found that it is independent of the rotation speed.

On the other hand, the amount of corrosion on the cylinder surface (copper layer) caused by a corrosive liquid at a certain concentration is affected by the cylinder rotation speed; when the rotation speed is low, the amount of corrosion is small, and conversely, as the rotation speed increases, the amount of corrosion is large. Become.
Further, the amount of corrosion mentioned above is also affected by the corrosion time due to the corrosive liquid. If the rotational speed R of the cylinder or the actual corrosion time θ by the corrosive liquid is kept constant, the resist penetration time x of the test liquid and the cell depth y due to the corrosive liquid are 8th
As shown in the figure and FIG. 9, it was found that there was a certain correlation. Here, the actual corrosion time θ
is the actual corrosion time of the copper surface of the gravure printing plate, which is obtained by subtracting the resist penetration time of the corrosive liquid from the total corrosion time T of the corrosion work, and is in the relationship T=t+θ.

On the other hand, the amount of copper surface corrosion per unit time, that is,
The copper surface corrosion rate Δy of the corrosive liquid has a certain correlation with the resist penetration characteristic x of the test liquid, as shown in FIG. 10, if the cylinder rotational speed R is kept constant.

In this way, the resist penetration characteristics shown in FIG. 6 are determined based on the measurement results by the inspection device shown in FIG.
From the comparison with FIGS. 8, 9, and 10 and the calculation process, the total corrosion time of the corrosion work of the gravure printing plate 10 is determined, and the intermediate gradation inspection positions points B and C in FIG. 6 are determined. is taken as a branching point in the corrosion process, and the corrosion distribution time in each corrosion period and the cylinder rotation speed in each corrosion period are calculated sequentially from the late corrosion (highlight) side.

Next, a specific method of obtaining the data shown in FIGS. 8, 9, and 10 will be described.

First, for multiple types of cylinder rotational speeds (R _a , R _b , R _c ...) for a predetermined test resist,
Total corrosion time T due to corrosion work, resist penetration time of test liquid (time required for test liquid to penetrate through the resist of a specified thickness and reach the surface of the copper layer of the cylinder)
A test is conducted to obtain the relationship between x and cell depth y after copper surface corrosion.

FIG. 11 is a table showing test results at cylinder rotational speed R _a . On the test resist closely adhered to the copper layer of the cylinder, a desired test gradation scale is formed in sections from the shadow area to the highlight area, for example, A, B, C, etc., and each level is There are separate sections for test liquid and corrosive liquid.

For example, for all gradation scales A, B, C, D... of a test resist, a test liquid is dropped into one predetermined section of the resist, and the resist penetration time x _A1 (until it reaches the copper surface of the cylinder) is calculated. x _A2 ,
x _A3 ,... _{x B1 , x B2 ...} After the resist is cured, the resist is removed and the depth of the cells formed in the copper layer below is determined for each section by y _A1 , y _A2 ...y _B1 , y _B2 ...
It is measured. Such measurements are performed not only when the rotational speed of the cylinder is R _a but also when R _b , R _c . . . .

Figure 8 shows that the cylinder rotational speeds are R _a , R _b , R _c
This is a graph of the measurement results in the case of , with the horizontal axis semi-logarithm, and is an example of corrosion time T ₄ . This graph shows the relationship between the resist penetration time x of the test liquid and the cell depth y when the cylinder rotation speeds are R _a , R _b , and R _c . Although graphs of such relationships are not shown, they are also drawn for other corrosion times.

Based on the measurement results in FIG. 11, as shown in FIG. 9, the horizontal axis of the test liquid penetration time x and cell depth _y for each actual corrosion time θ ₁ , θ ₂ , θ _{3 .} . . for the cylinder rotational speed R a Shows a semi-logarithm graph. A graph similar to this graph is also drawn for the cylinder rotational speeds R _b and R _c (not shown).

As described above, the actual corrosion time θ is expressed as T=t+θ (where t is the resist penetration time of the etchant).

Graphs shown in FIGS. 9 to 10 are obtained.
This graph shows the amount of copper surface corrosion per unit actual corrosion time,
In other words, the actual amount of corrosion of the copper surface by the corrosive liquid can be expressed as, for example, the cell depth Δy (μm/μm/minute) by the corrosive liquid per minute.
This is a graph of the test liquid penetration time
It shows R _a , R _b , R _c ....

Further, the relationship between the resist penetration time x of the test liquid and the resist penetration time t of the corrosive liquid is expressed by the graph in FIG. 7 when the concentration of the corrosive liquid is constant. The horizontal axis of this graph is scaled with the penetration time of the test liquid in each gradation part of the resist, and the vertical axis is scaled with the penetration time t in each of the same gradation parts.

Next, the actual corrosion work of gravure printing plates will be explained.

From each graph shown in Figures 6 to 11,
The correlation between the resist penetration characteristics by the test liquid and the cell depth is determined, and this is used as reference data to correspond to the measurement results of the penetration characteristics of the resist 12 of the actual gravure printing plate 10 by the test liquid as described below. The corrosion working conditions can be predetermined before the work actually begins.

[Determination of total corrosion time in corrosion work]

Even if the process of gravure printing plates is strictly controlled in each step of this corrosion work, the properties of the resist will change due to changes in temperature, humidity, etc., so it is necessary to use a test liquid immediately before starting the corrosion work. Assume that it is desirable to test the resist penetration characteristics using the measuring device shown in FIG. 2 described above, and as a result of this test, the resist penetration characteristics shown in FIG. 6 are obtained. This graph is based on the cell depth that each of the test gradation areas A, B, C, and D of the resist in FIG. 1 must have. The relationship between the resist penetration time of the test liquid and the cell depth on the copper layer surface can be obtained. That is, plot point A shown in FIG.
If corrosion is performed under corrosion conditions that satisfy the four points B, C, and D, a cell depth curve as desired can be obtained.

In this sense, the point where the resist penetration characteristic curve 34 shown in FIG. 6 is considered to intersect with the x-axis,
That is, a point P at which the cell depth y=0 is estimated, and the resist penetration time x _P of the test liquid at this point P is first determined. This penetration time x _P can also be determined by other methods. That is, the test liquid penetration time of the resist portion where the cell depth becomes 0 may be actually determined and this may be taken as the resist penetration time _xP . Also, the straight line connecting the point (x _C , y _C ) and the point (x _D , y _D ) in Figure 6 is x
The point that intersects the axis may be approximately set as point P. Alternatively, a point where the tangent to the point (x _D , y _D ) on the resist penetration curve 34 intersects with the x-axis may be determined, and this point may be set as the point P.

The resist penetration time x _P by the test liquid thus obtained is converted using the conversion graph shown in FIG. 7, and the resist penetration time t _P by the corrosive solution is determined.
The resist penetration time t _P by this corrosive liquid is determined as the total corrosion time in the corrosive operation.

[Determination of corrosion distribution time in each corrosion period]

Once the total corrosion time _tP is determined, the two intermediate gradation points B and C are set (estimated) as the corrosion process branching points, and the corrosion work is started from the point of the shadow side intermediate gradation. The period from point B to point C is the first period, the period from point C to the corrosion end point P is the third period, and the corrosion process of the corrosion work is divided into three periods. The corrosion distribution time (ratio to the total corrosion time in the corrosion work) and cylinder rotation speed are detected at each time.

The corrosion work distribution time for each period is the resist penetration time of the test liquid at the branch points B and C, x _B ,
The resist penetration times t _B and t _C of the corrosive liquid corresponding to x _C are determined from the conversion graph in Figure 7, and the corrosion distribution time for each period is determined.

1st period (from corrosion start to point B): t _B 2nd period (from point B to point C): t _C - t _B 3rd period (from point C to point P): t _P - t _C Total corrosion Time: t _P [Determination of cylinder rotational speed in each corrosion stage] The cylinder rotational speed in each corrosion stage is determined in the following steps, starting from the third corrosion stage, starting with the second stage, and working backwards from the first stage. go.

[Calculation of cylinder rotation speed in the third stage of corrosion] If the total corrosion time t _P is now equal to the corrosion time T ₄ , then the test liquid resist for the rotation speed of various cylinders corresponding to the corrosion time T ₄ Curves 36, 38, and 40 in FIG. 8, which are relationship data between penetration time x and cell depth y, are selected and compared with resist penetration curve 34 in FIG. 6. Here, as the cylinder rotation speed in the third stage of corrosion, a rotation speed, for example, R _a (curve 36) having a cell depth y _{C '} closest to the cell set depth y C at point C is selected.
In this case, if detailed data of the cell depths y _C ′, y _C ″, y _C , etc. at point C are collected for each rotational speed R _a , R _b , R _c , etc., the resist shown in FIG. 6 can be obtained. It is possible to select the optimum rotation speed that has the same cell depth as the set depth of the penetration curve.The selected rotation speed R _a of the cylinder is based on point P in FIG.
The rotational speed of the cylinder is such that it satisfies the set depth _yC of the cell at point C and also satisfies the set depth _yD of the cell at point D.

Further, the rotation speed of the cylinder in the third stage of corrosion may be determined by the following method.

That is, the corrosion rate Δ _y of the cylinder copper surface of the corrosive liquid for each cylinder rotational speed at the test liquid penetration time x _C at point C is determined from FIG. Actual corrosion time θ _C
Multiply by to calculate the corrosion cell depth for each cylinder rotation speed. Compare this calculated value with the set cell depth y _C at point C in Fig. 6, select the cylinder rotation speed that is closest to y _C , for example, R _a , and set this rotation speed R _a to the third corrosion stage. The cylinder rotation speed may be determined as the cylinder rotation speed, and any method convenient for calculation processing may be selected. Here, the actual corrosion time θ _C is
It is determined by subtracting the resist penetration time _tC by the corrosive liquid at point C from the total corrosion time _tP .

[Calculation of the cylinder rotation speed in the second corrosion stage] Next, the cylinder rotation speed in the second corrosion stage is calculated.

Before calculating the cylinder rotation speed in the second corrosion period, the ratio of the corrosion cell depth for each period in all three corrosion periods is schematically shown in FIG. From this figure, the dotted line part of the copper layer 33 is the corrosion cell depth under the corrosion conditions of the first corrosion stage, the solid line part is the corrosion cell depth under the corrosion conditions of the second corrosion stage, and the broken line part is the corrosion cell depth under the corrosion conditions of the third corrosion stage. Each represents the corrosion cell depth. In other words, the corrosion of the copper layer 33 is carried out in stages through three stages: the first corrosion stage, the second stage, and the third corrosion stage, but the corrosion cell depth in each stage is as follows:
It also has a correlation with the rotational speed of the cylinder and the actual corrosion time. Therefore, boundary lines (dotted chain lines α, β) are generated between the first and second stages of corrosion, and between the second and third stages due to changes in the cylinder rotational speed.

For example, resist areas where the test liquid penetration time into the resist is longer than the boundary line β are affected only by the cylinder rotation speed in the third stage of corrosion, and resist areas where the test liquid penetration time is between the boundary lines β and α are affected by the corrosion. Both the cylinder rotation speed in the second period and the cylinder rotation speed in the third corrosion period are influential. Furthermore, in the resist portion where the test liquid penetration time is shorter than the boundary line α, the cylinder rotational speeds in the first, second and third stages of corrosion are all affected. Therefore, the calculation method for the rotation speed in the second stage of corrosion is based on the set depth of the cell at point B.
It can be detected by focusing on the cell depth (solid line in Figure 12) obtained by subtracting the cell depth (broken line in Figure 12) due to the rotational speed R _a in the third stage of corrosion from _yB .

Specifically, from this, a new curve is obtained by subtracting the influence of the rotation speed R _a in the third stage of corrosion from the resist penetration characteristic curve 34 in FIG. 6. Therefore, the actual corrosion time θ C at the rotational speed R _a to obtain the set cell depth y _C at the branch point _C as shown in FIG. 13 is determined from FIG. 9 (in this case, θ _C = θ ₂
). As shown in FIG. 14, a curve 42 of actual corrosion time θ _C (θ ₂ ) and rotational speed R _a is subtracted from the resist penetration characteristic curve 34 to obtain a new curve 44 . This curve 44 represents the corrosion conditions before the second stage of corrosion, and the amount of subtraction corresponding to the curve 42 is between point B and point A.
The actual corrosion time θ _C at each resist portion corresponds to the corrosion cell depth under the corrosion condition of rotation speed R _a ,
It may also be determined using FIG. That is, it is obtained by multiplying the cell depth data per unit actual corrosion time of the rotation speed R _a at each resist portion by the actual corrosion time θ _C.

Assuming that the respective subtraction amounts between point B and point A in the registration area are Δy _B ′ and Δy _A ′, and the points on the new curve 44 after the subtraction are B′ and A′ as shown in FIG. The set cell depth y _B ′ at the points B′ and A′,
y _A ′ can be expressed as y _B ′=y _B −Δy _B ′ y _A ′=y _A −Δy _A ′, respectively.

Note that Δy _B ′ and Δy _A ′ indicate the broken line portions at points B and A in FIG.

Furthermore, the points where the curve 44 shown in FIG. 14 intersects with the horizontal axis indirectly indicate the corrosion time t _C required before the second stage of corrosion. That is, this corrosion time t _C
is the time when the corrosive liquid completes permeation into the resist at the resist part ₍ point _C ) corresponding to the _resist permeation time _x −t _C ). and curve 44 as shown in Figure 15.
Using the data of test liquid resist penetration time x versus cell depth y regarding the rotational speed of various cylinders where t _C is the corrosion time, compare as shown in Fig. 16, and calculate the set depth of the cell at point B' y _B ' (= For example _{, R C ( curve} 4
6) is selected. Therefore, the corrosion conditions for the second stage of corrosion are the cylinder rotation speed R _C and the corrosion distribution time t _C
−t _B

[Calculating the cylinder rotation speed in the first stage of corrosion] Finally, calculate the cylinder rotation speed in the first stage of corrosion. This calculation can be performed in exactly the same manner as the method for selecting the cylinder rotation speed in the second stage of corrosion. That is, in Fig. 12, y A ′ was obtained by subtracting the influence of the cylinder rotation speed _R a in the third stage of corrosion Δy _A ′ from the set cell depth y _A in the resist area A where the test liquid penetration time is smaller than the boundary line _α . Similarly, if the influence of the rotational speed R _C in the second stage of corrosion is Δy _A '', then this influence is also subtracted, and a new curve 48 and point A'' are obtained as shown in Figure 17, and this set cell depth is y _A ″ can be expressed as y _A ″=y _A ′−Δy _A ″=y _A −y _A ′−Δy _A ″. This Δy _A ″ indicates the solid line portion at point A in FIG.

Similarly, using the data of test liquid penetration time x versus cell depth y for various rotational speeds where t _B is the corrosion time, the cell setting depth y _A '' (=
It is sufficient to select the rotation speed, for example, R _b , which has the cell depth closest to y _A −Δy _A ′−Δy _A ″). Therefore, the corrosion conditions for the first stage of corrosion are the cylinder rotation speed R _b ,
The corrosion distribution time _tB was calculated, and if this resist is corroded in order from the first corrosion stage under the preset conditions shown below, the corrosion results according to the set cell depth curve can be obtained.

That is, if the total corrosion time is _tP , it is displayed as follows.

Corrosion stage 1: Corrosion distribution time t _b
Cylinder rotation speed R _b 〃 2nd period: 〃 t _C −t _B 〃 R _c 〃 3rd period: 〃 t _P −t _C 〃 R _aThe number of inspection points on the resist gradation scale is the shadow part (point A above) ), one highlight (point D above), and at least one intermediate gradation, the one-component corrosion method according to the present invention can be performed in a preset method by inspecting at least three locations.
When performing corrosion with excellent accuracy closer to the set corrosion curve, corrosion control may be managed by increasing the number of inspection points to two or three or more points in the intermediate gradation, such as points B and C above. In other words, n intermediate gradations (n≧
1) It is possible to inspect a total of n+2 locations at each stage, divide the corrosion into n+1 stages, and calculate the most suitable cylinder rotation speed and corrosion distribution time for each corrosion stage. However, in the case of rough corrosion, for example, when printing a solid plate, it is also possible to inspect two places, a shadow area and a highlight area, and calculate the conditions to allow the corrosion to progress.

Furthermore, if the test liquid is found to have undesirable resist characteristics by testing, if the test liquid is not corrosive, it is sufficient to re-create only the resist, or if the test liquid is slightly corrosive. In the case where the photogravure printing plate material has a certain property, it is sufficient to simply sand the plate material of the gravure printing plate lightly with sandpaper or the like and then re-form the resist thereon. Note that, since the corrosive liquid is usually conductive, when the resist penetration is tested using the corrosive liquid, it is necessary to recreate the gravure printing plate material itself.

In the above embodiments, the amount of corrosion was expressed as cell depth, but if the correlation between cell depth and cell volume is determined in advance, similar results can be obtained using cell volume.

In addition, when setting the above-mentioned corrosion conditions, the computer stores the reference data obtained in advance as shown in FIG. You can also set conditions by doing so. Furthermore, the present invention can be applied not only to the compensatory gravure plate-making method but also to the gravure plate-making method using a mesh positive.

[Specific experimental example]

There are 4 gradation scales (1.7 for positive density, 1.7 for positive density,
1.2, 0.8, 0.4), the resist penetration time of the test solution was measured: 1.6 seconds, 4.7 seconds, 16.0 seconds, 47.5
It was hot in seconds. Then, the cell setting depth of the cylinder copper layer according to this gradation scale is set to 40 μm, 20 μm,
A graph of "resist penetration time of test liquid" versus "cell setting depth" corresponding to FIG. 6 was created with 10 μm and 2 μm.

Next, the resist penetration time of the test liquid at the point where the resist penetration characteristic curve in this graph becomes cell depth = 0.
64 seconds was determined, and the total corrosion time was determined to be 660 seconds (11 minutes) by converting it using the conversion data or functional formula of "test liquid penetration time" versus "corrosion solution penetration time" corresponding to Figure 7. Continuing with the intermediate gradation, positive density 1.2
The two resist areas with a positive concentration of 1.2 and 0.8 were determined as the branching points of the corrosion conditions, and the period from the start of corrosion to just before corrosion started to enter the copper surface of the resist area with a positive concentration of 1.2 was determined as the first corrosion point.
The period up to just before corrosion begins to enter the copper surface of the resist with a positive concentration of 0.8 is the second corrosion period, and the period up to the end of the corrosion is the third corrosion period, and the corrosion distribution time for each period is determined.

The calculation method is as explained in the example, and the resist penetration time of the corrosive liquid is 90 seconds, 90 seconds, and 16.0 seconds, respectively, for the resist test liquids with positive concentrations of 1.2 and 0.8, and 4.7 seconds and 16.0 seconds, respectively.
It turned out to be 230 seconds. Therefore, the corrosion mixing time for each corrosion period is 90 seconds for the first corrosion period, 230-90 = 140 seconds for the second corrosion period, and 660 seconds for the third corrosion period.
230=430 seconds.

In determining the cylinder rotation speed, calculations are made sequentially starting from the third stage of corrosion. First, the rotation speed in the third stage is 16.0 per cent of the test liquid permeation time in the resist area with a positive density of 0.8, based on the data of "test liquid penetration time" vs. "cell depth" when corroding for 660 seconds (11 minutes) at various rotation speeds. Select and determine the rotation speed of 20 rpm that best satisfies the set cell depth of 10 μm in seconds.

Before determining the rotation speed for the second corrosion stage, the resist areas with positive concentrations of 1.7 and 1.2 (i.e., the areas with test solution penetration times of 1.6 seconds and 4.7 seconds) were affected by a rotation speed of 20 rpm and an actual corrosion time of 430 seconds. The cell depth is subtracted by the amount. That is, the corrosion cell depth per unit actual corrosion time is calculated from the data of "test liquid penetration time" versus "copper surface corrosion rate of corrosive liquid" and is multiplied by 430 seconds, resulting in the respective subtracted depths of 25 μm and 16 μm.

Therefore, the rotation speed in the second stage was set at a test liquid penetration time of 4.7 seconds in the resist area with a positive density of 1.2 based on the data of "test liquid penetration time" versus "cell depth" when corroding for 230 seconds at various rotation speeds. Depth 20μm-
Select and determine the rotation speed of 40 rpm that best satisfies 16 μm = 4 μm.

When determining the rotation speed for the first stage of corrosion, as in the previous case, the positive concentration of 1.7, that is, the resist penetration time of the test solution of 1.6 seconds, is determined by the rotation speed of 40 rpm and the cell depth by the amount affected by the actual corrosion time of 140 seconds. Perform the process of subtracting. In other words, the corrosion cell depth per unit actual corrosion time is determined from the data of "testing liquid penetration time" versus "copper surface corrosion rate of corrosive liquid", and this is multiplied by 140 seconds and subtracted to yield a cell depth of 10 μm.

Therefore, the rotation speed of the first stage was set to 1.6 seconds for the test liquid penetration time in the resist area with a positive density of 1.7 based on the data of "test liquid penetration time" vs. "cell depth" when corroding for 90 seconds at various rotation speeds. Cell depth 40μm-
Rotation speed that best satisfies 25μm - 10μm = 5μm
Calculate and determine 50rpm.

Thus, in order to obtain a set cell depth in this resist, one concentration of etchant (in this case
By using 39°Be corrosive liquid), the first stage of corrosion can be suppressed.
The second stage of corrosion was carried out for 90 seconds (1 minute 30 seconds) at a rotation speed of 50 rpm, and the third stage of corrosion was carried out for 430 seconds (7 minutes 10 seconds) at a rotation speed of 40 rpm.
It was found that corrosion could be carried out for a total of 11 minutes at 20 rpm, and corrosion was carried out using the Tatsuchi roller method under these preset conditions. As a result, the cell depth of each scale is
The cell depths were 39 μm, 20 μm, 10 μm, and 2 μm, almost matching the initially set cell depth, and gravure printing plates having good cell depth reproduction curves were obtained.

〔Effect of the invention〕

As mentioned above, in the one-component corrosion method for gravure plate making according to the present invention, a test liquid is used to understand the resist penetration characteristics of the corrosion solution before the corrosion work is performed, and the resist penetration characteristics of the corrosion solution are determined using a corrosion solution suitable for the penetration characteristics. By setting the corrosion conditions (dividing the corrosion process into n+1 stages, cylinder rotation speed and corrosion distribution time for each stage of corrosion), it is possible to carry out corrosion work under the optimum corrosion conditions. Accordingly, cell depth with excellent reproducibility can be obtained without requiring any skill just by controlling the corrosion process, and gravure printing plates with stable quality can be produced.

Since a gravure printing plate with stable quality can be produced, the burden of plate correction of the gravure printing plate in the subsequent process is greatly reduced.

In addition, while it is possible to determine the setting of corrosion conditions such as cylinder rotation speed and corrosion distribution time for each period of corrosion from a graph, it is also possible to determine the setting of corrosion conditions by computer processing by storing test results for determining corrosion conditions in advance in a computer. You can also do that.

Furthermore, in this invention, it is only necessary to carry out corrosion at each stage of corrosion according to the corrosion conditions of the cylinder rotation speed and corrosion distribution time determined before the actual corrosion work of the gravure printing plate, and the corrosive liquid has a predetermined concentration. Since only one liquid needs to be used, the corrosion process operation and corrosion equipment can be simplified, and corrosion work can be performed with higher precision using an inexpensive corrosive machine.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a gravure printing plate cylinder, FIG. 2 is a circuit diagram showing an example of a measurement circuit of a resist inspection device, and FIG. 3 is a diagram partially showing the arrangement relationship between the resist inspection device and the cylinder. , FIG. 4 is a waveform diagram obtained by the measurement circuit of the resist inspection device,
Figure 5 is a graph showing the relationship between the positive density of the original and the cell (halftone dot) setting depth, Figure 6 is a horizontal axis logarithmic graph showing the correlation between the resist penetration time of the test liquid and the cell setting depth, and Figure 7 is a graph showing the relationship between the positive density of the original and the cell (halftone dot) setting depth. The figure is a graph showing the correspondence between the resist penetration time of the test liquid and the resist penetration time of the corrosive liquid. Figure 8 shows the correlation between the resist penetration time of the test liquid and the cell depth when the cylinder rotation speed is changed. 9 is a horizontal axis logarithmic graph showing the relationship between resist penetration time of test liquid and cell depth when the actual corrosion time is changed.
Figure 10 is a horizontal axis logarithmic graph showing the relationship between the resist penetration time of the test liquid and the corrosion rate of the copper surface of the gravure cylinder of the corrosive liquid when the cylinder rotation speed is changed, and Figure 11 is the test result for the test resist. A table showing an example, FIG. 12 is a schematic vertical cross-sectional view of the resist and copper layer of the gravure cylinder,
Figure 13 is a horizontal axis logarithmic graph showing the relationship between the resist penetration time of the test solution and the cell depth while comparing it with the graphs in Figures 6 and 8, and Figure 14 is a comparison between Figures 6 and 9. Horizontal axis logarithmic graph showing the relationship between the resist penetration time of the test solution and the cell depth.
Figure 5 is a horizontal axis logarithmic graph showing the relationship between the resist penetration time of the test liquid and the cell depth when the cylinder rotation speed is changed, similar to Figure 8, and Figure 16 is a logarithmic graph on the horizontal axis showing the relationship between the cell depth and the resist penetration time when the cylinder rotation speed is changed.
17 is a horizontal axis logarithmic graph showing the relationship between the resist penetration time of the test solution and the cell depth while comparing with FIG. It is a horizontal axis logarithmic graph showing the relationship between cell depth and cell depth. 10... Gravure printing plate, 12... Resist, 14,
16... Resist electrode, 33... Copper layer, 34... Resist penetration characteristic curve.

Claims (1)

[Scope of Claims] 1. When a desired resist is closely formed on the surface of the cylinder copper layer of a gravure printing plate and a corrosive liquid of a predetermined concentration is supplied to the surface of the gravure cylinder to form gravure cells on the surface of the cylinder, In the one-component corrosion method in which the corrosion cell depth is adjusted by changing the rotational speed, a) the correlation between the resist penetration time of the test solution and the resist penetration time of the corrosive solution at each stage of the gradation scale of the resist, and b the above. Correlation between the corrosion time of various cylinders at each stage of the resist gradation scale and the resist penetration time of the test liquid for each cylinder rotation speed and the corrosion cell depth, c. The correlation between the corrosion time and the resist penetration time of the test liquid for each cylinder rotation speed and the corrosion cell depth is determined in advance using a gravure cylinder for testing, and d. 1 shadow part, 1 highlight part, halftone n of the resist gradation scale
Detect the relationship between the resist penetration time of the test liquid and the cell setting depth at each stage of n+2 locations (n≧1), and e. calculate the total number of gravure cylinders to be used for printing from the relationship data of steps a and d. Detect the corrosion time, f. Then, each stage of the resist at the n intermediate gradations is set as a branching point in the cylinder corrosion process, and the cylinder corrosion process is divided into n+1 stages, g) the a step, the d step, and the e step. Calculate the corrosion allocation time in each corrosion period from the related data of the and f processes, h) Calculate the cylinder rotation speed in each corrosion period from the related data of the a to g processes from the corrosion n+1 period on the highlighted side to the corrosion 1st period. f Then, while supplying corrosive liquid to the gravure cylinder, the copper layer surface corrosion of each corrosion period is calculated in the order of corrosion period 1, ... n+1 period, and the cylinder rotation speed determined for each corrosion period is calculated. and a one-component corrosion method in gravure plate making, which is characterized by proceeding with corrosion work in a corrosion distribution time.