JPS6049899B2 - Net gravure plate making method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a net gravure plate making method.

The net gravure plate making method is usually (1) one-sheet positive method such as Metuten, Portiel, Angraff, etc., (2) Arco method, (3) two-sheet positive method such as Darzien method, (4) Heliochrysiograph. Carving methods such as this are known.

However, as a net gravure plate making method for publishing, a net gravure plate making method using a net positive for flat plates as an original plate has come to be generally used. An outline of an example of this net gravure plate making method is as follows.

In other words, a direct plate is made by applying copper plating to an iron cylinder, then silver plating is applied to form a release layer, and then a ballad layer is formed on top of this by copper plating, and the surface is polished to create a plate material. Prepare. On the other hand, after a white line gravure screen is printed on the sensitized carbon tissue, a net positive is further printed, and finally, the diffusion sheet and the net positive are sequentially overlapped and printed. The carbon tissue that has been baked three times in this manner is transferred onto the plate material prepared as described above, and then developed. After development, a mesh gravure printing plate is obtained by etching with a ferric chloride solution. In order to improve the printing durability of this printing plate, the plate surface is usually plated with chrome. When revising the printing plate obtained in this way upon completion of printing, the Ballard layer is peeled off and a release layer made of silver plating is applied again to the surface of the direct plate. It requires the work of applying layers.

As mentioned above, in order to produce halftone gravure printing plates, many complicated processes are required to prepare the printing plates, and difficult control of conditions is required, which requires a lot of time and cost. did.

The present invention aims to provide a net gravure plate-making method that does not have the above-mentioned problems, is simpler in plate-making than the conventional example, and also makes revisions easier.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, to explain the manufacturing process of a gravure plate material, in FIG. 1, reference numeral 2 denotes a base material constituting the surface of a gravure cylinder, and pockets 3 of uniform volume are formed on the surface of the base material.

Although various materials can be used for the base material 2, the illustrated embodiment uses a corrosive material that is corroded by a corrosive liquid used in the printing plate manufacturing process. If the corrosive liquid is a typical ferric chloride liquid, the corrosive material is copper. In this way, it is most preferable that the base material is copper;
Any metal or synthetic resin other than copper can also be used as the base material. The pockets 3 are minute recesses uniformly distributed on the surface of the base material in the same arrangement as the halftone dots of a gravure screen in which halftone dots and non-halftone dots are distinct in black and white.

As the gravure screen, a white line screen is typically applied, but other types such as a round dot screen are also applicable.

These pockets 3 can be formed on the surface of the base material 2 by corrosion through a corrosion-resistant resist in which a gravure screen is baked onto the surface of the base material 2. That is, a gravure screen is printed on a continuous tone resist such as carpon chitish, and the screen is transferred and developed onto the smooth surface of the base material 2 to corrode the base material surface, or a photosensitive resin is applied to the cylinder surface and applied to it. After baking the gravure screen, it can be developed and then the base material surface can be corroded. As the above-mentioned continuous tone resist, in addition to using Carpon chitish, for example, Autofilm (trade name, manufactured by Autotype), Chronaviu (trade name, manufactured by DuPont)
It can also be provided by using Roto film (trade name, manufactured by DuPont) or the like.

Note that the pocket can also be made by known physical engraving, but in this case, the shape of the pocket will be different as will be described later.

It has pocket 3 obtained as above. Base material 2
The surface of is then provided with a coating layer of non-corrosive material which is not corroded by the corrosive liquid.

As a result, a non-corrosive material layer 4 is formed on the outer surface of the base material 2 and the inner surface of the pocket 3, as shown in FIG. Assuming that the corrosive liquid is a ferric chloride liquid as described above, the layer 4 is, for example, a chromium layer. This chromium layer 4
is applied by electroplating. On the other hand, layer 4 is also required to be a wear-resistant material that does not wear out due to contact with doctors, paper, etc. during printing, and chromium also satisfies this requirement. In the case of chromium, the non-corrosive material layer 4 has a thickness of about 15 microns, for example. Incidentally, the non-corrosive material layer 4 itself can also be composed of multiple layers.

In this case, at least one layer of the non-corrosive material other than the inner surface of the pocket may be left in the subsequent polishing step. Next, on the non-corrosive material layer 4, as shown in FIG. be done.

This intermediate layer 5 is effective when a non-corrosive material has poor adhesion to a corrosive material. This intermediate layer 5 is typically an electroplated layer of nickel. For the intermediate layer 5, a material is selected that has good adhesion to non-corrosive materials and corrosive materials.
Nickel satisfies this condition in contrast to chromium as a non-corrosive material and copper as a corrosive material. The middle layer 5 is
In the case of nickel, for example, it is about 0.1 micron,
It is considerably thinner than the non-corrosive material layer 4. Note that the intermediate layer 5 itself may be composed of multiple layers. After coating the non-corrosive material layer 4 and the intermediate layer 5 in the above manner, The surface of layer 5 is lightly polished.

As a result, as shown in FIG. 4, the layer 5 on the surface is scraped off, leaving the layer 5 only on the inner wall surface of the pocket 3, and a non-corrosive material layer is formed on the surface other than where the pocket is located. 4 or exposed. Next, a corrosive material is electroplated on the surface of the gravure cylinder in the above condition.

The corrosive material in this embodiment is copper, and by electroplating the pocket is filled with copper, as shown at 6 in FIG. That is, since the intermediate layer 5 made of nickel has good adhesion to copper, the corrosive material 6 precipitates and adheres to the inner wall surface of the layer 5. On the other hand, the non-corrosive material layer 4 made of chromium and exposed in areas other than the pockets does not have very good adhesion to copper, so copper precipitates on the layer 4 as well, but does not adhere. Therefore, a state as shown in FIG. 5 is obtained. The surface of the gravure syring thus obtained is then polished.

As a result, the surface of the corrosive material 6 that was protruding above the surface is scraped off to form the same smooth surface as the non-corrosive material layer 4. As a result, the state shown in FIG. 6 is obtained. The state shown in FIG. 6 is the state of the gravure plate material G1 used in the plate making method of the present invention, in which there are countless minute corrosions between the non-corrosive portions 4 made of non-corrosive material on the surface of the plate material. The transparent portions 6 are uniformly distributed in an array of halftone dots, and both portions 4 and 6 form a smooth surface.

Incidentally, as described above, the gravure plate material G1 shown in FIG.
Among the manufacturing steps, the step shown in FIG. 4, that is, the step of removing the intermediate layer 5 in the portion other than the pocket by polishing, can be omitted.

In this case, the corrosive material 6, ie, copper, is plated in the state shown in FIG. As a result, copper is deposited on the intermediate layer 5 in areas other than the pockets 3, but by polishing the surface, the state shown in FIG. 6 is finally obtained. In this case, the surface of the base material may be smoothed by polishing so as to leave the intermediate layer 5 on the surface of the base material. In order to produce a gravure printing plate using the gravure plate material G1 shown in FIG. 6, the following steps are taken.

In FIG. 7, C is a carpon chittle made up of loose paperboard 7 and carpon chittle emulsion 8, and a lithographic or letterpress net positive 9 is closely printed onto this carpon chittle C. In addition, in the same figure, 9a shows the halftone dot of the halftone positive 9, and the arrow L shows the direction of exposure. When contact baking is performed in this manner, the exposed portion of the emulsion 8 of the carpon chip C becomes a hardened portion 10. After the first baking is performed in this manner, the second baking is performed on the carpon tissue C as shown in FIG.

This secondary baking is performed by sequentially overlapping the diffusion sheet 11 and the net positive 9 on the surface of the emulsion 8 and exposing the emulsion 8 to light in the direction of the arrow L. As the diffusion sheet, a matte film, opal glass, ultrafine ground glass, etc. are used. By baking the net positive 9 through the diffusion sheet 11 in this manner, the light that has passed through the net positive 9 is diffused, and the previously formed cured portion 10 is further exposed, and the cured portion 10 A hardened portion 12 is further formed at the peripheral edge of the hardened portion 12 . As above,
The carpon tissue C that has undergone the first and second baking is transferred onto the previously obtained gravure plate material G1 (Fig. 6) and developed, as shown in Fig. 9. The hardened resists 10 and 12 remain on the printing plate G1.

Next, when the resist is removed by etching with a corrosive liquid such as a ferric chloride solution, the state shown in FIG. 10 is obtained. That is, the corrosive material 6 in the pocket is corroded according to the shape and dimensions of the resist, and the ink cells 13 are formed with a depth and area according to the density gradation of the original image. Since these ink cells 13 are partitioned by bank portions formed by the non-corrosive material layer 4, the halftone dots are not continuous in the shadow areas during printing, and the resulting printing plate is Since the bank portion is covered with a layer 4 of chromium or the like having high printing durability, it can be used for printing as is without chromium plating or the like. In addition,
Instead of the above-mentioned carpon film, use the above-mentioned auto film, Chronaviure, and Roto film (all product names).
A continuous tone resist may also be used.

After printing is completed, in order to revise the printing plate, the printing plate in the state shown in FIG. 10 may be immersed in a storage tank of corrosive liquid such as ferric chloride liquid for a certain period of time.

As a result, the corrosive material 6 such as copper dissolves in the corrosive liquid, but the layer 4 on the surface of the base material and the layer 4 on the inner surface of the cell are made of non-corrosive materials and do not dissolve, and the intermediate layer 5 is also non-corrosive. In the case of a corrosive material, the situation shown in FIG. 4 is again obtained. Thereafter, the plate material shown in FIG. 6 is obtained through the state shown in FIG. 5. Further, when a material that dissolves in a corrosive liquid is used for the intermediate layer 5, the state shown in FIG. 2 is obtained, and thereafter the plate material is obtained through the states shown in FIGS. 3 to 6. In addition,
When a ferric chloride solution is used as a corrosive liquid for the corrosive material copper, the nickel used as the intermediate layer is dissolved by the copper chloride produced by the reaction between copper and ferric chloride.
Similarly, the state shown in FIG. 2 is obtained.

Then, as shown in FIG. 9, when this plate material is corroded through the resist, a new printing plate can be obtained again. When revising the printing plate, after cleaning the ink of the printing plate, the corrosive material 6 in the cells 9 is not removed, but the corrosive material is plated as it is,
The state shown in FIG. 5 may be obtained directly without passing through the state shown in FIG.

In this case, new corrosive material will be deposited on top of the old corrosive material within the cell. FIG. 11 shows an example in which a pocket 3 is formed on a base material 2 by physical engraving.

In this case, due to the nature of the physical engraving, the pocket 3 typically has the shape shown with a pointed bottom. FIG. 12 corresponds to the state shown in FIG. 5, but in this case, the corrosive material 6 is applied without removing the banked part of the intermediate layer 5 coated on the non-corrosive material layer 4 by polishing. Because it is plated, the material is deposited over the entire surface.

Next, when the entire surface is polished and smoothed, the portion of the intermediate layer 5 above the bank is removed, resulting in the gravure plate material G2 of FIG. 13 in which the non-corrosive material layer 4 is exposed on the bank. can get. This state corresponds to the state shown in FIG. After the gravure plate material G2 shown in FIG. 13 is obtained in this manner, corrosion is carried out through the resist in the same manner as shown in FIG. 9 to obtain the printing plate shown in FIG. 14.

To revise the printing plate after printing, the ink is washed and then directly plated with a corrosive material such as copper. If the intermediate layer 5 is dissolved in the corrosive liquid, the intermediate layer 5 is again applied on the non-corrosive material layer 4, and then plated with a corrosive material such as copper. Alternatively, after plating with a corrosive material after immersion in a corrosive liquid, polishing the first
3. Make the plate material as shown in Figure 3. Figures 15 to 22 show a gravure plate material having a surface in which numerous fine corrosive parts are uniformly distributed in an array of halftone dots between non-corrosive parts made of non-corrosive material. Another method of manufacturing is shown.

In this method, a gravure cylinder base material 2a whose surface is smoothed as shown in FIG. 15 is used without forming pockets 3 on the surface of the base material as shown in FIGS. 1 and 11. The base material 2a is made of a corrosive material such as copper. On the surface of the base material 2a, as shown in FIG. 16, a non-corrosive material layer 15, such as a chromium layer, is deposited over the entire surface by plating, and then on the layer 15, as shown in FIG. A synthetic resin layer 16 is applied.

In this case as well, the non-corrosive material layer 15 itself can be multilayered. Next, a gravure screen 1 is placed on the photosensitive resin layer 16 as shown in FIG.
7 is printed and developed.

The gravure screen 17 may be positive or negative, but when using a positive type gravure screen (for example, a white line screen is called positive type), the photosensitive resin 16 should be a photocurable type, or a negative type gravure screen. When using the photosensitive resin 16, a photodissolving type is used. Now, if we use the positive gravure screen 17 and the photocurable resin 16, the part of the resin that is exposed to the light that has passed through the bank forming white line part of the screen 17 will be cured, so by cleaning, the resin shown in FIG. As shown in FIG. 2, a resist 16a remains on the non-corrosive material layer 15.

In this state, when the chromium constituting the non-corrosive material layer 15 is corroded by a corrosive material such as hydrochloric acid (a material that does not corrode copper), the state shown in FIG. 20 is obtained. As is clear from the above, the term "non-corrosive material" as used herein refers to a material that is not corroded by the corrosive solution (i.e., usually a ferric chloride solution) used during printing plate production. Chromium is still referred to as a non-corrosive material even though it is corroded by corrosive materials other than corrosive fluids. Next, in the state shown in FIG. 20, a corrosive material layer 18, that is, copper, having approximately the same thickness as the non-corrosive material layer 15 is deposited on the surface of the base material 2a by plating, as shown in FIG. The state shown is obtained.

Then, after removing the remaining resist 16a and polishing the surface to make it smooth, the gravure plate material G shown in FIG.
3 is obtained. As is clear from the figure, this plate material G3
has a non-corrosive portion 15 made of a non-corrosive material and countless fine corrosive portions 18 uniformly distributed therebetween in an arrangement of halftone dots. Gravure plate material G in Figure 22
In order to produce a gravure printing plate using 3, as explained in FIGS. 7 and 8, two processes are performed: contact baking of the net positive 9 and contact baking of the diffusion sheet 11 and the net positive 9. The prepared carpon chip is transferred to a plate material G3, and resists 10 and 12 are formed by development as shown by imaginary lines in FIG. 23, and the corrosion treatment is performed through this resist.

As a result, ink cells 20 are formed on the surface of the base material 2a. In this case as well, the non-corrosive material layer 15 will not be attacked by the corrosive liquid and will form a bank with printing durability. To carry out the revision, after the printing plate has been cleaned of ink, the printing plate is plated with a corrosive material 21, namely copper.

As a result, the state shown in FIG. 24 is obtained. Next, when the surface of the cylinder is polished, it becomes the state shown in FIG. 25. In this state, the corrosive material constituting the base material 2a and the corrosive material 21 attached by plating are integrally connected, and the
Substantially the same condition as plate material G3 in the figure is obtained. FIGS. 26 to 32 show still another method for producing a gravure plate material that is substantially the same as the gravure plate material G3 shown in FIG. 22.

This method also uses the gravure cylinder base material 2a shown in FIG. 26, which has a smooth surface similar to that shown in FIG. 15.

This base material 2a is also made of a corrosive material such as copper. Masu,
A photosensitive resin 23 is applied to the surface of the base material 2a as shown in FIG. 27. This photosensitive resin may also be of a photocurable type or a photodissolved type. Next, as shown in Figure 28,
A gravure screen 24 is baked on the photosensitive resin 23. When the gravure screen 24 is positive, a photodissolving type of photosensitive resin 23 is used, and when the gravure screen 24 is negative, a photosensitive resin 23 is used. 23 is a photocurable type. By baking and developing the gravure screen 24, as shown in FIG. 29, a resist 23a is formed on the surface of the gravure cylinder base material 2a corresponding to the portion of the gravure screen other than the bank forming line.

Next, as shown in FIG. 30A, a non-corrosive material layer 25 (for example, a chromium layer) is applied to the surface of the base material 2a by plating. The non-corrosive material layer 25 must be a printing-resistant material. Also in this case, the non-corrosive material layer 25
can itself be multi-layered. Next, the base material 2a
When the upper resist 23a is removed, the state shown in FIG.
The hot parts of the resist 23a are filled in by plating, and the surface is polished to make it smooth, resulting in the gravure plate material G shown in FIG.
4 is obtained.

This plate material G4 also has a non-corrosive material portion 25 and a corrosive portion 26 distributed therebetween. The plate material G4 can also be produced from the state shown in FIG. 29 through the states shown in FIGS. 30B and 31B instead of the states shown in FIGS. 30A and 31A1.

That is, in the state shown in FIG. 29, the corrosive liquid is applied to the base material 2a.
As shown in FIG. 30B, a recess 28 due to corrosion is formed between the resists 23a, and the recess 2
8, a non-corrosive material layer 25 (chromium layer) is applied by plating and then polished to remove the resist 23a and make the surface smooth;
After removing a, the surface is polished to make it smooth, and the state shown in FIG. 32 is obtained. A method similar to that shown in FIG. 23 is also used to produce a printing plate from the gravure plate material G4 shown in FIG. 32.

Further, when revising the edition after printing is completed, the same method as explained with reference to FIGS. 24 and 25 can be used. As can be seen from the above description, according to the net gravure plate making method of the present invention, fine corrosive areas are formed on the surface of the non-corrosive material base material by the array of halftone dots on the surface of the non-corrosive material base material before the plate material is first prepared. However, once such a plate material is produced, the subsequent plate-making process involves the process of closely printing the mesh positive onto the carpon chitschule, and It is only necessary to transfer the carpon tissue obtained by sequentially stacking the diffusion sheet and the net positive and baking them in close contact onto the gravure plate material, develop it, and etch it.

That is, in the plate-making method of the present invention, the step of printing a white line gravure screen or the like is not necessary in the printing/printing process of the carpon tissue. This is because the plate material itself has a structure that produces a result equivalent to printing a white line gravure screen. Therefore, the work is shortened by this amount. On the other hand, in the case of conventional mesh gravure plate making, it is necessary to perform chrome plating as the final step of printing plate production to increase printing durability, but the bank structure of the printing plate obtained by the present invention Since the parts are already coated with a layer of non-corrosive material such as press-resistant chrome, subsequent chrome plating is not necessary, which also saves work.

In addition, in conventional net gravure plate making, each time the plate is revised, the Ballard layer is peeled off, and a peeling layer is formed again by silver plating.
Furthermore, a new ballad layer must be formed thereon by copper plating, but by using the plate making method of the present invention, the revision work is simplified.

That is, when revising the printing plate, it is only necessary to wash the printing plate with ink and then plate it with a corrosive material. By this,
Since the inside of the cell is again filled with the corrosive material, a new plate material for plate making can be obtained by simply polishing it as in the conventional case. The present invention also makes it possible to reduce the amount of copper used as a corrosive material compared to the conventional case.

In the conventional case, the thickness of copper plated on the printing plate as a Ballard layer is about 100 to 200 microns, and a corresponding amount of copper is required when making a new printing plate and each time a new printing is made. In contrast, the present invention requires only a corrosive material, ie, copper, approximately equal to the sum of the ink cell volume windows, and the depth of each cell is of course smaller than the thickness of the conventional Ballard layer. , the amount of copper used will be significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a part of the surface of a base material of a gravure cylinder used to produce a gravure plate material in the net gravure plate making method of the present invention, and FIGS. 6 is a cross-sectional view showing the obtained gravure plate material, and FIGS. 7 and 8 are cross-sectional views showing the steps of producing a gravure plate material in the plate making method of the present invention. A diagram showing the baking process, Figure 9 is a cross-sectional view showing the corrosion process of making a printing plate using a carpon chip, Figure 10 is a cross-sectional view of the final printing plate, and Figure 11 is a physical engraving. A sectional view similar to FIG. 1 showing the gravure cylinder base material obtained by
The figure is a cross-sectional view showing the state in the process of making a plate using the base material shown in Fig. 11, Fig. 13 is a cross-sectional view showing the final plate obtained, and Fig. 14 is the plate shown in Fig. 13. FIG. 15 is a cross-sectional view of the printing plate obtained from the process of the present invention, and FIG. 16 to 21 are cross-sectional views sequentially showing the steps of producing the other types of gravure plates mentioned above, FIG. 22 is a cross-sectional view of the resulting gravure plate material, and FIG. 23 is the gravure plate shown in FIG. 22. Figures 24 and 25 are diagrams showing the resist in the corrosion process of making a printing plate using a material in virtual lines, and the final printing plate shown in solid lines. 26 to 31A and 31B are sectional views sequentially showing the revision process; FIGS. 26 to 31A and 31B are sectional views sequentially showing two other processes for producing the other types of gravure plate materials; FIG. 32 is a cross-sectional view showing those steps. FIG. 2 is a cross-sectional view showing a gravure plate material obtained by the method.

Claims (1)

[Claims] 1 The base material surface is made of a non-corrosive material that is not corroded by a corrosive liquid, and the surface is made of a corrosive material that is corroded by a corrosive liquid, and the halftone dot area and the non-halftone dot area are distinct in black and white. Prepare a gravure plate material with countless fine corrosive parts distributed between non-corrosive materials in the same arrangement as the halftone dots of a gravure screen, and on the other hand, place a lithographic or letterpress net positive on the continuous tone resist. The net gravure printing plate is obtained by baking, and then layering a diffusion sheet and the net positive in order and closely baking them, transferring the continuous tone resist thus obtained to the gravure plate material, developing and corroding it, and obtaining a net gravure printing plate. Gravure plate making method.