JPS58143348A - Method for exposing liquid photosensitive resin - Google Patents

Abstract

PURPOSE:To enable a long or wide product to be continuously formed without forming zebra phenomenon, by using a cover film or a base film in place of a negative film for exposure. CONSTITUTION:For example, a cover film 7 is made of a usual plastic film, and desirable letters or patterns are printed with a light-shading ink by a screen printing method, etc. An considerably wide cover film 7 independent of length, can be used by the screen printing method, etc. A photosensitive resin 5 held between a base film 1 and the cover film 7 is exposed to light from a light source 10 while horizontally conveyed. At that time, the film 7 and the resin 5 are in close contact with each other, and since there is no air layer between the 2 layers 7, 5, zebra phenomenon has no danger of occurrence, thus permitting continuous manufacture of long or wide products without causing zebra phenomenon.

Description

[Detailed description of the invention] The present invention particularly relates to a method for exposing liquid photosensitive resin.

BACKGROUND ART In recent years, photosensitive resins have been widely used to produce printing original plates, stamps, masking sheets for engraving by sandblasting, and the like. Liquid photosensitive resins are most commonly used in the production of these materials. Here, in this specification, the liquid photosensitive resin refers to a synthetic resin that is in a viscous liquid state before exposure and undergoes a curing reaction upon exposure. In addition, the above-mentioned masking sheet is a sheet that partitions desired patterns, characters, etc. as through holes or solid parts, and by attaching it to the workpiece and performing sandblasting, it is possible to remove the parts of the workpiece that are not protected by the masking sheet. It is used to carve and carve.

Conventionally, the liquid photosensitive resin was exposed to light by sandwiching the photosensitive resin evenly between a cover film and a base film, and then placing a negative film with desired characters, patterns, etc. on it tightly on a glass plate, and then covering the film. This is done by placing it on the film side and irradiating light through it. here,
The cover film is meant to prevent the photosensitive resin from adhering to the negative film, and is peeled off when the unexposed photosensitive resin is washed away after exposure. Furthermore, the base film refers to a film that functions to hold the photosensitive resin cured by exposure during cleaning.

In particular, when exposing the original printing plate, in addition to leaf exposure on the side of the cover film that forms the image area, which is the printing surface, it is necessary to improve the fixation of the photosensitive resin hardened by exposure to the base film and improve the printability. Back highlight exposure is sometimes performed on the base film side for the purpose of improving the image quality. This backlight exposure is performed by subjecting the base film to halftone dot exposure, and is carried out in exactly the same manner as the relief exposure described above, using a negative film with uniform halftone dots.

However, such conventional exposure methods have the following drawbacks: First, there is a limit to the size of negative film, and it is not possible to make a film that large, so it is difficult to make a long film or film with a continuous pattern. d- It is very difficult to manufacture wide products.

The second problem is that exposure is inevitably done in a batch manner, and it is not possible to completely serialize the sandwiching of the photosensitive resin between the cover film and the base film, the exposure, and the washing. To achieve continuous exposure, the cover film and base film holding the photosensitive resin are moved, and the negative film is also moved in sync with the exposure. It is extremely difficult to move both in synchrony without causing any problems, and this is the biggest bottleneck to continuous exposure. Although this is not much of a problem, it inevitably becomes extremely inefficient when manufacturing large quantities of the same product.

The third problem is that it is a big problem, especially in relief exposure during the production of printing plates.The air between the cover film and the negative film is convected by the radiant heat of the light source, and stripes are created in the image area of the resulting printing plate due to the air convection. This creates a pattern. The occurrence of this striped pattern is called a zebra phenomenon, and causes a decrease in printability.

The present invention solves the above-mentioned conventional drawbacks, and aims to provide a method for exposing photosensitive resins that can continuously produce long or wide products and that is less likely to cause zebra phenomenon. It is something.

In particular, a major feature of the present invention is that it breaks away from the conventional fixed concept that a negative film is always required for exposure, omits the negative film, and performs exposure using the cover film or base film itself instead of the Woneka film. At the point.

Hereinafter, the method of the present invention will be explained in more detail with reference to the drawings.

FIG. 1 shows an example of continuous exposure using the method of the present invention.

In the figure, reference numeral 1 denotes a base film, which is pulled out from the original roll 2 and transported on a line at a constant speed. A photosensitive resin 5 is supplied from a packet 4 onto the base film 1 pulled out from the original roll 2 on a surface plate filter. After the photosensitive resin 5 is leveled to have a uniform thickness, it is covered with a cover film 7 pulled out from the original fabric roll 6, and further transported while being held between the base film 1 and the cover film 7.

The cover film 7 is an ordinary synthetic resin film on which desired characters and patterns have been applied in advance with opaque ink using screen printing or the like. Of course, the cover film 7 is translucent, and the characters and patterns printed on it are printed on the printed part (the part where the ink is attached).
It may be expressed as a non-printing part (a part to which ink is not attached).
Translucency means that at least light can be transmitted through exposure to harden the photosensitive resin 5, and opaqueness means that light can be sufficiently blocked to harden at least the photosensitive resin 5. It means having a sexual nature. Therefore, translucency does not mean that it is colorless and transparent; it is sufficient that it can transmit at least the wavelength of light that cures the photosensitive resin 5, and opacity means that it can transmit light of all wavelengths from infrared to ultraviolet. It is sufficient if it can not only block light but also at least light with a wavelength that hardens the photosensitive resin 5.

The cover film 7 is continuously coated with 1C from the original fabric roll 6 as the base film 1 that has been supplied with the photosensitive resin 5 moves.
It is clear from printing technology that it is possible to print a long piece of paper regardless of its length, and that it is also possible to print a piece with a fairly large width using screen printing or the like.

The photosensitive resin 5 held between the base film 1 and the cover film 7 is exposed by a light source 10 while being horizontally transferred between the base belt 8 and the cover belt 9. The cover belt 9 is translucent, and the light from the light source 10 is irradiated onto the surface of the cover film 7 through the cover belt 9.

At this time, since the cover film 7 is printed as described above, the cover film 7 itself serves as a negative film, and the photosensitive resin 5 is applied along the printed characters, patterns, etc. is exposed. In addition, since the cover film 7 is in close contact with the photosensitive resin 5 and is in a state where there is little risk of blurring, the intensity and irradiation range of the light source 10 are controlled by the photosensitive resin transferred together with the base film 1 and the cover film 7. By adjusting the transfer speed of the plastic resin 5, it is possible to perform continuous exposure without stopping the transfer.

Such continuous exposure can easily cause blurring because the cover film 7, which is closely adhered to the photosensitive resin 5, has become a negative film.
The cover film 7 can be used as a negative film precisely because printed characters and patterns are exposed. As mentioned above, printing has few restrictions regarding the length and width of the printing material, and various characters, patterns, etc. can be applied to the cover film 7 at low cost regardless of whether they are continuous or discontinuous.

Unfortunately, the cover film 7, which also functions as a negative film, and the photosensitive resin 5 are in close contact with each other, and there is no air space between them, so there is no risk of the zebra phenomenon occurring. Of course,
The cover film 7 is tightly adhered to the photosensitive resin 5 without trapping air in order to prevent blurring during exposure and to prevent the zebra phenomenon.

After being exposed as described above, the cover film 7 is wound onto a take-up roll 11 to expose the photosensitive resin 5, and the unexposed portion is washed away by a cleaning liquid sprayed from the nozzle 12, and the film is manufactured into a product. It is something.

The printing pattern applied to the cover film 7 and the base film 1 may be selected as appropriate depending on the need, but if the necessary pattern is printed in halftone dots during the production of the original printing plate, the printed area will be halftone-like. A surface printing original plate having unevenness and good printability is obtained.

In the example shown in FIG. 1, the base film 1 is on the bottom side and the cover film 7 is on the top side, but the top and bottom can also be reversed. When the top and bottom are turned upside down, the photosensitive resin 5 is evenly spread on the cover film 7, and then covered with the base film 1 to guide the light source 10, and the nozzle 12 is placed upward. good.

In addition, in the example shown in FIG. 1, only the side of the film 7 is exposed, but as in the production of printing plates,
When performing light exposure on the base film 1 side, the base film 1 is made translucent, the necessary printing is performed with opaque ink in the same manner as the cover film 7 described above, and the light source 10 is It may be arranged also on the base film 1 side.

Furthermore, in the example shown in FIG.
It is also possible for the take-up lug to unwind the cover film 7 endlessly. , but the cover film 7
If it is made endless, the unexposed photosensitive resin 5 adhering to the cover film 7 must be removed without damaging the cover film 7, which makes the operation somewhat troublesome.

Therefore, in practice, it may be more convenient to make the cover film 7 disposable and fold it as shown in FIG. In this case as well, it is preferable that the unexposed photosensitive resin 5 adhering to the cover film 7 be removed and collected as much as possible and reused.

FIG. 2 is a sectional view showing the state in which the photosensitive resin is sandwiched between the base film and the cover film during exposure.

(a) Id-, the base film 1 and the cover film 7 are in direct contact with the photosensitive resin 5, which is the simplest sandwiched state.

In (b), the base film 1 is in close contact with the photosensitive resin 5 directly, but the cover film 7 is in close contact with the photosensitive resin 5 via the release layer 13.

This peeling layer 1 is for making it easier to separate the cover film 7 from the photosensitive resin 5 after exposure. Specifically, the peeling layer 13 is made of paraffin or cellulose thin film. be.

When paraffin is used, a cover film 7 thinly coated with paraffin may be wound as a raw roll 6; You may also apply a thin layer of paraffin to the surface. If you want to use a cellulose film, attach the cellulose film lightly to the cover film 7 in advance, and then peel off only the cover film 7 from the photosensitive resin 5, leaving the cellulose film id behind. good. in this case,
The cellulose film is preferably a film of water-soluble cellulose derivatives such as carboxymethyl cellulose or hydroxyethyl cellulose so that it can be easily dissolved and removed with a cleaning solution.

In (c), a release layer 16' similar to the release layer 16 explained in (b) is also provided on the base film 1 side.

This is particularly effective when manufacturing masking sheets.

That is, the masking sheet is made into a product by peeling off the cover film 7 and washing it, and then pasting a mount on the washed surface.
This is because, during use, after the mount is peeled off and attached to the workpiece, the base film 1 is also peeled off and sandblasting is performed.

In particular, the release layers 13 and 13' shown in (b+ and (c))
When peeling off the cover film 7 and base film 1
This eliminates the fear that the photosensitive resin 5 that has been cured by exposure may be attached and peeled off, and is particularly effective for high-speed continuous exposure. Further, instead of the release layer 13, 13', a material made of a material that is difficult to adhere to the photosensitive resin 5 to the cover film 7 or the base film 1 may be used.

Although the present invention is particularly suitable for exposing liquid photosensitive resins, it may also be used for exposing solid photosensitive resins. That is, a transparent film printed as described above is applied to a solid photosensitive resin and exposed as a negative film. Especially in the case of solid photosensitive resin, there is no need to worry about the resin adhering to the film.
Continuation can easily be achieved by making the film endless and exposing the film while it is being conveyed while being applied to the photosensitive resin flowing on a conveyor. .

As explained above, according to the present invention, long or wide products can be manufactured continuously, and concerns about the zebra phenomenon can be eliminated9.

[Brief explanation of drawings]

Figure 1 is a diagram showing an example of continuous exposure by the method of the present invention, and Figures 2 (a) to (c) are cross sections showing the sandwiching state of the photosensitive resin of the base film and cover film at the time of exposure, respectively. It is a diagram. 1: Base film, 2: Raw roll, 3: Surface plate, 4:
Packet, 5: Photosensitive resin, 6: Raw roll, 7: Cover film, 8: Base belt, 9: Cover belt, 1
0: Light source, 11: Take-up roll, 12: Nozzle, 13.1
3': Release layer

Claims (1)

[Claims] 1) A liquid photosensitive resin is sandwiched between a base film and a base film, on which at least one or both of the desired prints have been previously printed with opaque ink, and the printed cover film or base film is made into a negative film. A method for exposing liquid photosensitive resin, which is characterized by performing fog light to form a film.