JPS6318020Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a masking film for exposure used when producing printing plates using a photocurable resin liquid.

Conventional technology Recently, when printing corrugated paperboard and newspapers, urethane-based photocurable liquid resin (manufacturer: Asahi Kasei Corporation), which is liquid in storage but hardens when exposed to external stimulation such as ultraviolet irradiation, has been used to print corrugated paper and newspapers. Product name:
APR) printing plate is used.

The production of this type of printing plate is carried out through the steps shown in FIGS. 8 to 11.

As an example, as shown in Fig. 6, there is a conventional method for producing a printing plate 1 used for printing the mark "AB" on cardboard (the mark appears as a reversed mark 9 on the surface of the printing plate). Explain.

Figure 7 shows negative film 3 used for producing printing plate 1.
A masking film 4 is shown in which a light-transmitting pattern 31 corresponding to the mark 9 is formed on the negative film 3, and the shaded area other than the pattern is a completely light-shielding surface.

The masking film 4 has patterns 31 corresponding to the translucent patterns 31 on the negative film 3.
It has a translucent pattern 41 with a slightly larger outline, and the other shaded areas are completely light-shielding surfaces.

Step a: As shown in FIG. 8, a negative film 3 is placed on a transparent base plate 5, and a protective transparent film 6 is placed over the negative film 3.

Step b: A frame 7 is provided on the outer periphery of the transparent film 6 so as to act as a dam against the liquid resin, and the entire transparent pattern 31 of the negative film 3 is surrounded by the frame 7. A photocurable liquid resin is poured onto the inner transparent film 6 to form a photocurable liquid resin layer 2 (FIG. 8).

Step c: Place the transparent base film 11 on the liquid surface of the photocurable liquid resin layer 2, and
A masking film 4 is placed on top (Fig. 8).

Step d: As shown in FIG. 9, the ultraviolet lamps 51, 51
The liquid resin layer is exposed to light. The exposed portions of the masking film 4 and the negative film 3 begin to harden in correspondence with the patterns 31 and 41, respectively.
The last exposed part remains in the liquid and becomes negative film 3.
The cured resin portion on the side becomes a relief portion 21 that corresponds to the mark 9, and the cured resin portion on the masking film 4 side becomes a mount portion 22 that thickly connects to the relief portion 21 and serves as reinforcement.

Step e: The masking film 4 is removed and the base film 11 is exposed again for a short time from the outside as shown in FIG. 10 to thinly harden the entire upper surface of the resin liquid layer and form the base portion 23 integrally joined to the base film 11.

Step f: Remove the frame 7 and the transparent film 6, and collect the uncured resin liquid.

As shown in FIG. 11, the relief part 21 is reinforced by the mount part 22, and the mount part 22
A printing plate 1 is formed in which the printing plate 1 is connected to a base portion 23 that covers almost the entire surface of the base film 11.

The printing plate 1 has a two-layer structure in which a base film 11 is uniformly covered by a base portion 23. This is cut to an appropriate size including the relief part 21, mount part 22, and alignment mark 12, and as shown in FIG. It is attached removably.

Problems to be solved by the invention Since photocurable liquid resins are expensive, it is necessary to reduce the amount used as much as possible.

However, printing plate 1 produced using the conventional procedure
Since the base portion 23 is formed on the entire surface of the base film 11, the amount of photocurable liquid resin used inevitably increases, resulting in a problem that the implementation cost of the method increases.

Further, in order to correctly position the printing plate 1 on the mounting film 8, it is essential to form the alignment mark 12. Therefore, conventionally, as shown in FIG.
2 and a translucent pattern 42 for forming a mounting part of the matching mark on the masking film 4.
was formed, and the alignment mark 12 was formed at the same time as the relief portion 21. Therefore, the alignment mark 1 was inevitably formed.
2 is formed at the same height as the relief portion 21.

Therefore, after the printing plate 1 is attached to the mounting film 8, the alignment mark 12 must be scraped to be lower than the relief portion 21 in order to prevent printing ink from adhering to the alignment mark 12.

The above operation is time-consuming, and if the relief portion 21 of the printing plate is complicated, the match mark 12 may be overlooked and left unscraped. Alternatively, problems such as the relief portion being accidentally scraped off occurred.

In addition, after positioning the printing plate on the mount film, the conventional method for attaching the printing plate is to adhere an adhesive tape 13 around the periphery of the printing plate while holding it down to fix the base of the printing plate and the mount film, or to attach the printing plate to the mount film. Double-sided adhesive tape was pasted on the back of the mount film, and this was placed on the mounting film and pressed down to adhere.

However, with either method, if the adhesive strength of the adhesive tape is weakened, there is a risk that the printing plate will peel off from the mounting film due to the centrifugal force that acts on the printing plate during high-speed printing. When the surface is cleaned to remove ink and the plate is stored with the plate attached to the mounting film, the cleaning water enters the gap between the plate and the mounting film and remains, and this water flows out during the next printing. There was a risk that the paper would come and stain the printed surface. Attempts have been made to attach the mounting film and printing plate by integrally bonding them together using a high-frequency welder, but the material of the mounting film is polyester, and the surface of the printing plate is uniformly covered with a base of urethane resin. Therefore, high frequency welding could not be carried out.

Means for Solving the Problem The masking film 4 includes a semi-shading film 43 and a completely shielding film 45 on a transparent film 42.
It has a three-layer structure in which each layer is removable.

A cut line is made on a semi-shielding film 43 in an outline slightly larger than the pattern 31 in accordance with the pattern 31 of the negative film 3, and the inner part of the outline is peeled off to form a translucent pattern 44.

The complete light-shielding film 45 is provided with a cut line having an even larger outline than the light-transmitting pattern 44 of the semi-light-shielding film 43, and the inner part of the outline is peeled off to form a light-transmitting pattern 46.

Function and Effect The light-transmitting pattern 44 on the half-light-shielding film 43 side of the masking film 4 is smaller than the light-transmitting pattern 46 on the completely light-shielding film 45 side. Since light passes through the translucent pattern 44 on the side of the semi-light-shielding surface 43a, the mount portion 22 corresponding to the translucent pattern 44 is formed.

However, since only a part of the light shining on the semi-light-shielding surface 43a passes through the semi-light-shielding surface 43a and reaches the resin layer, it hardens thinly and forms the base portion 23 that extends thinly around the mount portion 22. .

On the other hand, the resin layer is cured corresponding to the translucent pattern 31 of the negative film 3, and a relief portion 21 integrally connected to the mount portion 22 is formed.

Mount part 2 extending from the periphery of mount part 22
Since the base portion 11 having a wider area than 2 is bonded to the base film 11 as before, the stability of adhesion to the base film 11 is improved.

Moreover, the completely light-shielding surface 45a of the masking film 4
Since the resin layer corresponding to 2 is not irradiated with light at all, the resin is not cured and no base portion is formed at all.

After exposure, if the uncured liquid resin is removed from the base film and recovered, it can be reused.In the present invention, all of the liquid resin in the portion of the masking film corresponding to the completely light-shielding surface is removed. Since the base film is exposed, the amount of recovered resin increases and resin consumption is saved.

The mount part 22 and the base part 23 can be formed simultaneously by simply covering with a masking film 4 and exposing once, and the manufacturing process is simplified and the efficiency of plate making is improved compared with the conventional method of covering with a masking film, exposing once, removing the masking film and exposing again to form the mount part and the base part in separate processes.

Furthermore, the completely light-shielding surface 45a of the masking film 4
By aligning a part of the light transmitting part 46a with the alignment mark 12 to form a light transmitting part 46a, a part of the light passing through the light transmitting part 46a reaches the resin layer by the semi-light shielding surface 43a, and is transmitted onto the base film 11. The above-mentioned base part 23
It is possible to form the match mark 12 at the same height as .

Since the match mark 12 is formed lower than the relief part 21 representing the mark 9, the match mark 12
There is no risk of printing ink adhering to the print head, and there is no need to scrape off the matching marks as in the past.

Furthermore, as shown in FIG. 2, the printing plate is completed with the base film 11 exposed around the base part 23, so if this is positioned and placed on the mount film and the periphery is welded using a high frequency welder, Since both the mounting film and the base film of the printing plate are made of the same material, polyester,
Since the welding line 80 can be easily welded and integrally connected, and the welding line 80 can be formed around the outer periphery of the printing plate, the conventional problem of cleaning water entering between the printing plate and the mounting film can be solved.

Embodiment Printing Plate FIG. 2 shows the printing plate 1 of the present invention with its edges attached to a mounting film 8 by high frequency welding.

The printing plate 1 has a mark 9 of "AB" embossed by relief portions 21, 21, similar to that described in the conventional example.

The relief part 21 is formed on a mount part 22 having a slightly larger outline than the relief part 21, and the mount part 22 is formed on a base part 23 surrounding it and having a wide area.

The base portion 23 is strongly adhered to the polyester base film 11 by the adhesive force of the resin itself or by the adhesive force of an adhesive applied to the base film if necessary, so that a relief is formed as shown in FIG. The portion 21, the mount portion 22, and the base portion 23 are integrally formed of photocurable resin. In the case of a printing plate for corrugated paper, the thickness h ₁ of the base portion 23 is approximately 2.0 mm.
It is preferable that the thickness h ₂ of the mount portion 22 is approximately 2.5 mm, and the thickness h ₃ of the relief portion 21 is approximately 2 mm.

In the printing plate 1, the base film 11 is exposed on the side where the base part 23 is not formed, and a positioning mark 12 is formed at the same height as the base part 22 in the exposed part of the base film. ing.

To fix the printing plate onto the mount film, use the matching marks on the printing plate to position it on the mount film, and then use a known portable high-frequency welding machine to move the exposed part of the base film of the printing plate onto the mount film. Weld and install as one piece.

Manufacturing process Next, the manufacturing process of the printing plate 1 will be explained.

Figure 1 shows a negative film 3 used to make a printing plate 1.
and masking film 4.

The masking film 4 is a completely light-shielding film 45 on one side of a transparent film 42, and a semi-light-shielding film 43 on the other side of the transparent film 42, which is removably pasted with an adhesive.

The negative film 3 has a completely light-shielding surface, as shown by diagonal lines, except for the translucent pattern 31 corresponding to the mark 9. What should be noted here is that the negative film 3 does not have a transparent part that corresponds to the match mark 12 on the printing plate 1, and only the completely light-shielding surface of the masking film has a transparent part that corresponds to the match mark. Section 46
It was formed by cutting out a.

The semi-shading film 43 is formed by cutting out a translucent pattern 44 having a slightly larger outline than the pattern 31 corresponding to the translucent pattern 31 of the negative film 3, and the completely light-shielding film 45 is formed by cutting out a translucent pattern 44 corresponding to the translucent pattern 31 of the negative film 3. It is formed by cutting out a translucent pattern 46 having an even larger outline than the translucent pattern 44 of 43.

Each of the above-mentioned translucent patterns 44 and 46 is formed on the semi-light-shielding film 43 and the completely light-shielding film 45 with a knife to a depth that reaches the transparent film 42.
It is formed by making a score line corresponding to 6 and peeling off the inside of the score line from the transparent film 42.

The semi-shading film 45 allows about 10 to 15% of the exposed light to pass through.

Incidentally, the masking film 4 is not limited to the above-mentioned one, and for example, the semi-shading film 43 can be removably adhered to the transparent film 42, and the completely light-shielding film 45 can be peeled off onto the semi-shading film 43. It is also possible to attach it to

First step: As shown in FIG. 3, a negative film 3 is placed on a transparent base plate 5, and a transparent film 6 is placed over the negative film 3. Further, a substantially rectangular frame 7 is placed around the outer periphery of the transparent film 6, and a photocurable liquid resin is poured into the frame 7 to form a photocurable liquid resin layer 2 on the transparent film 6.

Second Step: A transparent base film 11 is placed on the upper surface of the photocurable liquid resin layer 2, and a masking film 4 is placed on top of the film 11.

If necessary, a transparent adhesive (not shown) having good adhesion to the photocurable resin is applied to the lower surface of the transparent base film 11 in advance.

Third step As shown in FIG. 4, light from a light source 51 is applied from outside the transparent base plate 5 and masking film 4, and the photocurable resin is exposed for 380 to 400 seconds.

Due to exposure, the lower part of the resin layer becomes a negative film 3.
The portion corresponding to the pattern 31 is hardened to become the relief portion 21.

On the other hand, the cured state of the liquid resin layer 2 on the side of the masking film 4 is as follows:
The portion corresponding to the mount portion 2 has a thick and hardened resin layer and is integrally connected to the relief portion 21.
2, and in the light-transmitting part on the completely light-shielding surface 45a weakened by covering the semi-light-shielding film 43,
The base part 23 is connected to the mount part 22 by thinly hardening the upper part of the resin layer corresponding to the pattern 46.
becomes.

The base portion 23 is firmly bonded to the base film 11 by the adhesive properties of the resin itself or by an adhesive applied to the base film 11 in advance. The order of exposure is to first start exposing the masking film 4 side, and when about 2/3 of the required exposure time has passed, start exposing the negative film 3 side. Stop exposure separately.

As described above, by exposing the masking film 4 side before the exposure from the negative film 3 side, the mount part 22 and base part 23, which serve as the base of the relief part 21, are formed before the relief part 21, The relief part 21 is stably formed integrally with the mount part 22. Although exposure from the negative film 3 side may be started after the exposure from the masking film 4 side is completed, in this case, a time loss occurs.

It goes without saying that the exposure time can be optimally determined depending on the thickness of the printing plate to be formed and the intensity of light.

Fourth step: Masking film 4, frame 7, and transparent film 6 are removed, uncured liquid resin is collected, and printing plate 1 is completed.

[Brief explanation of drawings]

Figure 1 is a perspective view of the negative film and masking film, Figure 2 is a perspective view of the printing plate attached to the masking film, Figures 3, 4, and 5.
The figure is a manufacturing process diagram of a printing plate, and Figure 6 is a perspective view of a conventional printing plate attached to a masking film.
Figure 7 is a perspective view of conventional masking film and negative film, Figures 8, 9, 10, and 1.
FIG. 1 is a manufacturing process diagram of a conventional method. DESCRIPTION OF SYMBOLS 11... Transparent base film, 2... Photocurable liquid resin layer, 21... Relief part, 22... Mount part, 4... Masking film, 42... Transparent film, 43... Semi-shading film, 45... …
Complete blackout film.

Claims (1)

[Claims for Utility Model Registration] A masking film for plate making having a three-layer structure in which a semi-light-shielding film 43 and a complete light-shielding film are each removably provided on a transparent film. A semi-shading film on one side of the transparent film,
A masking film for plate making according to claim 1 of the utility model registration claim, which has a completely light-shielding film adhered to the other surface. The plate making according to claim 1 or 2 of the utility model registration claim, in which a semi-shading film is pasted on one side of the transparent film, and a complete light-shielding film is superimposed and pasted on top of the semi-shading film. masking film. The semi-shading film allows approximately 10 to 15% of the exposed light to pass through.Claim No. 1 for Utility Model Registration
A masking film for plate making according to any one of items 1 to 3.