JPH081862Y2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of Invention] (Field of Industrial Application) The present invention relates to the formation of an image, and more specifically, the difference in adhesiveness between the exposed and unexposed areas of the photosensitive layer. The present invention relates to an image forming apparatus using a single-color or multi-color superimposing method, which can obtain a transfer material similar to a printed material as a color proofing prepress proof.

(Prior Art) It has been conventionally known in the printing industry to utilize a prepress proof as a means for confirming the finish, color tone and the like of a finally printed printed matter before printing. This prepress proof has an overlay method and a surprint method, and is used depending on the final image quality and the purpose of use in plate making and printing processes.

In the overlay method, each transparent base film is provided with a photosensitive layer corresponding to each color separation (color separation) image, and each film obtained by irradiation with actinic rays and the developing process is visually checked for the color separation register. Overlap. Although this method is very simple, it has a drawback that it is greatly affected by the reflected light from the film at the time of superposition and the texture of the actual printed matter is very different.

The surprint method is, for example, US Pat. No. 3060023,
As disclosed in JP-A-3060024 and JP-A-3060025, photosensitive layers consisting of several layers are superposed on a single support, and color-separated images are sequentially formed. Coloring includes a simple transfer method and a powder color toner method, but the transfer method has an advantage that the operation is simple. On the other hand, the method using powder color toner requires a consideration in the work environment because it is powder. For the purpose of prepress proof, a copy similar to a printed matter is required, but it is hard to say that the method by transfer is similar to a printed matter in terms of gloss and halftone dot reproducibility. Also, with the method using powder color toner, it is difficult to approximate the actual printed matter because the work is far from printing.

Further, in the transfer method disclosed in US Pat. No. 3060023, etc., a work is disclosed in which the photosensitive layer and the image receptor are planarly pressed and brought into close contact with each other and heated, and then peeled off. However, there is a problem in that stable image reproduction and quickness required for prepress proof are lacking. Also, in peeling after pressure contact, the peeling speed,
There is a work-related drawback that it is difficult to adjust the direction and strength.
That is, when the photosensitive layer and the image receptor are planarly pressed and brought into contact with each other and then peeled off, unless the working conditions such as peeling speed and direction are constant, reproduction of the transferred image becomes unstable,
The unevenness of the reflection density of the transferred image, a fine periodic pattern, and a fine directional pattern are generated, and the accuracy of color reproduction is significantly reduced.

Further, Japanese Patent Publication No. 42326/1987 discloses a sheet comprising a support and a layer which is exposed to ultraviolet rays and a diazo sensitive material, which is transferred onto a single support by using pressure and then subjected to a halftone negative image. Image exposure is carried out, and then a development process is carried out, which can be repeated in sequence on the same support. This method also sequentially forms color-separated images on the same support, but since the development process with a solvent is involved, not only the problem of working environment but also the drawback that the film of the obtained image is brittle Have.

Further, Japanese Patent Laid-Open Nos. 59-97140 and 61-188537 disclose proofing systems which can be used for both the overlay method and the surprint method. In this proofing system, (1) release layer, colored photosensitive layer,
An image receiving film consisting of a color sheet comprising protective layers laminated in sequence and an image receiving layer and a protective film on a polyester support is prepared. (2) The emulsion surface of the color sheet is brought into close contact with the halftone negative image to form an image. The unexposed area is eluted with a mixed solution of sodium carbonate, butyl cellosolve and water. After drying, it is also effective as overlay type proofing.

(3) Proofing as a surprint method
After performing registration by visual inspection or punching on the image-receiving film in the order of ink, cyan, magenta, and yellow at a temperature of 110 ° C, a pressure of 2 bar, and a speed of 60 cm / min, (4) transfer to the receptor that is the transfer target Then, after obtaining a normal image, in order to reduce the reflection gloss of the transfer layer and the colored layer, the film subjected to the matting treatment is transferred to obtain proofing.

This method is characterized in that a release layer is provided between the photosensitive coloring layer and the support, and that this layer does not adversely affect the transfer image quality under conditions of high temperature and high humidity, and thus is closer to printed matter. It can give a texture.

Various proofing methods have been investigated, but most are manual methods or devices. Also known are proofing press methods and devices.

With the manual method, in almost all steps,
It is done manually. Although the transfer process to the image receptor has a significant effect on the quality of the obtained image, it is performed manually, so the quality of the image formation depends on the experience and intuition of the operator. It was hard to say that uniform image formation was always possible.

Furthermore, simple proofing using a letterpress proof printing machine is also known. In other words, this is a method in which an image forming material having a photosensitive layer is used and transfer is performed by a proof printing machine. That is,
A device that holds an image forming material on an impression cylinder with a blanket on its surface and rolls the impression cylinder with this blanket on the image receptor held on a paper surface plate to transfer the image. is there. However, this device is a large and heavy device, and it cannot be said that it is advantageous in terms of location and cost, it takes time to prepare for work, and it is possible to form an image easily and in a short time. I can not say. Furthermore, it is not easy to change the pressure during transfer, and it is difficult to expect that the pressure can be changed to accommodate various conditions.

(Problems to be solved by the invention) Regardless of which method can be used to create a prepress proof, it involves a substantial development process, and the creation process is complicated and the actual printed matter and texture of this machine Since it is different, it has been used mainly for checking the process between plate making and printing. However, even if it was used as a substitute for the actual printed matter, it was recognized that the quality was different.

Therefore, there has been a demand for an apparatus capable of forming a fine image in which the reflection density of the formed image is constant.

The purpose of the present invention is to solve the above-mentioned conventional drawbacks and to solve them. The purpose of the present invention is to effectively use the surprint method, and the final image obtained is similar to the printed image. It is an object of the present invention to provide an apparatus which can obtain the desired quality and can easily form an image of almost constant quality at any time by anyone.

As a result of investigations, the present inventors have found that a uniform image can be easily formed by holding the exposed image forming material on the roller surface and moving the flat base holding the image forming material to transfer the image. It is a thing.

[Constitution of device]

(Means for Solving Problems) In the present invention, an image forming material obtained by forming a photosensitive layer containing a dye and / or a pigment and a photopolymerizable compound on a support is imagewise exposed to form a photosensitive layer in the photosensitive layer. A rotating roller having a mechanism for holding an exposed image forming material on a surface in an image forming apparatus that causes a difference in adhesiveness in transfer between an exposed portion and an unexposed portion and transfers an image to an image receptor such as paper, The present invention relates to an image forming apparatus having a flat base which holds an image receptor and moves the image receptor from the image forming material to the image receptor, and further relates to an image forming apparatus having means for heating the flat platform. .

The present invention is a device that can obtain a color proof that is simple, quick, and stable in the surprint method, with a texture equivalent to that of an actual printed matter. Of course, the device is applicable to the overlay method. That is,
The present invention is an apparatus capable of obtaining a color proof with a stable quality by a dry developing method that does not require a developing solution, that is, a development by peeling, which can obtain a material having almost the same texture as a printed matter of this machine.

The present invention has no swimming in the image forming material due to overheating at the time of transfer, and can be directly transferred to art paper which is an ink receiver of this machine printing, and moreover, the photosensitive layer is transferred in the same state as this machine printing. By going through it, it is possible to obtain a copy extremely close to the actual printed matter. It is also a device that can stably transfer even minute images.

The image forming material according to the present invention usually has a structure of support / colored photosensitive layer / protective film, which will be described below.

As a support, it is stable to heat, chemicals, light, etc.,
Moreover, a material that transmits actinic rays is suitable. For example, it is a film or sheet of cellulose acetate, polystyrene, polyvinyl chloride, polyethylene terephthalate, polycarbonate, polyimide, polypropylene or the like. In particular, polyethylene terephthalate film or sheet is preferable from the viewpoint of transparency, heat stability, dimensional stability and the like.

Further, these supports may be used as they are, but may be subjected to a mold release treatment with an appropriate oil repellent substance. Examples of these oil-repellent substances include silicone resins and fluororesins.

Examples of the cover sheet include, but are not limited to, polyethylene films, polyethylene terephthalate films, and acetate films.

The photosensitive layer according to the present invention includes (a) a photopolymerizable compound and a colorant, and (b) a photopolymerizable compound, a thermoplastic resin, a colorant and the like. The inhibitor is used together.

As the photopolymerizable compound, at least one selected from monomers, oligomers and prepolymers is used.

 Further, other additives can be used together.

The photopolymerizable compound is not particularly limited, but is preferably a compound capable of plasticizing a thermoplastic resin at room temperature.

For the photosensitive layer, a photopolymerizable compound is used so as to be mixed with a dye and / or a pigment and can be cured by exposure.

The photosensitive layer is formed on the support, and a protective sheet (cover sheet) is further provided on the photosensitive layer. The protective film is for preventing stains due to the adhesion of the photosensitive layer to the exposure device when exposing from the support side for image formation. A polyethylene film is preferable, but if it has a considerable performance, etc. It is not limited to this.

Since the photosensitive layer is photopolymerizable, the cured part loses its adhesive force to the image receptor by image exposure, and the moderate internal cohesive force of the unexposed part enables the creation of fine image reproduction and peeling. Has the advantage of facilitating transfer onto an image receptor. Here, having an appropriate internal cohesive force means that the image formed on the image receptor does not transfer at least at all thicknesses. That is,
Delamination (breaking peeling) is performed.

The appropriate internal cohesive force of the photosensitive layer according to the present invention can be variously selected depending on the type and / or the compounding ratio of the photopolymerizable compound, dye or pigment, etc. used in the photosensitive layer. Further, it also varies depending on the type of the image receiving layer or the support.

The film thickness of the photosensitive layer may be about 0.5 to 5 μm, and an appropriate coating amount varies depending on the dye and / or pigment contained, but 0.5 g / m ^{2 to} 10 g / m ² is suitable. The coating of the present invention was carried out using a bar coater or the like.
Of course, for example, a spin coater or a coater similar to this may be used.

Conventionally known dyes and / or pigments contained in the photosensitive layer can be used. In general, dyes and pigments that match the four hues of yellow, magenta, cyan, and black are required, and in addition, metal powder, white pigment, fluorescent pigment, etc. are also used. For color proofing, there are yellow, red, indigo, and black ink, and a pigment or dye that matches these hues may be selected.

There are two types of image exposure methods, one in which the photosensitive layer and the mask are brought into direct contact with each other and the other in which the exposure is performed from the support side.

Furthermore, a protective film is overlaid on the photosensitive layer,
As a material suitable as a protective film, Japanese Patent Laid-Open No. 48-313
As described in No. 23, the polyethylene film has weaker adhesion to the photosensitive layer than that of a base support such as polyethylene terephthalate film and thus serves as a suitable protective film roll. Further, in a photopolymerization system, it is known that the polymerization rate is changed by oxygen in the air. To prevent this, a coating film such as polyvinyl alcohol is formed on the colored photosensitive layer. Either coating with a protective film or both methods are effective, but in the case of forming a coating film, if the film thickness becomes thicker than 5 μ, it adversely affects the transferred image quality. Is more preferably a method of laminating a protective film.

In the present invention, it is preferable to form an image by performing image exposure from the side of the support (most of which is transparent). By this method, the positional relationship such as the orientation of the image is remarkably improved, and a method that does not require a special intermediate image receptor for the purpose of correcting the orientation of the image can be provided.

In the present invention, in the case of an image-forming material having a protective film, the transparent support means, after being pressure-bonded to the image receptor,
The imagewise exposure is from the transparent support side.

The protective film, which is provided as necessary, prevents stains due to the adhesion of the photosensitive layer to the exposure device when exposing the substrate for image formation and reduces the effect of oxygen on the photosensitive layer. is there.

In color proofing work of printed matter to which the present invention is applied, highly accurate image reproduction from a film or the like as an original plate is required. At the same time, it is necessary to shorten the time for the color proofing work. In order to satisfy these requirements and ensure stable quality of finish, the accuracy of the reproduced image position and the correspondence between the front and back sides are determined by a simple work process.
That is, it is preferable to perform the exposure from the transparent support side.

Hereinafter, one example of a process of using the present invention as an image forming material for color proofing will be described step by step.

(1) Register for color separation image mask and image forming material
Register by making holes for the pins. Note that registration other than the pin method may be used. Normally, this registration is performed on the exposure table.

(2) Image exposure, that is, exposure to actinic rays such as ultraviolet rays is performed through the color-separating mask image on the photosensitive layer so that the image-forming material is sufficiently cured.

(3) If the image receptor is paper, etc., make holes for register pins in these image receptors and hold them on a flat base. Of course, registration other than the pin method is also possible.
Note that this step can be performed before the above (2).

(4) Then, the protective film of the image-forming material which has been image-exposed is peeled or fixed without peeling on the roller surface having a holding mechanism, and if the protective film is present,
The protective film is peeled off. The photosensitive layer surface of the image-forming material held on the roller surface and the image receptor are arranged so as to face each other, the roller is rotated, and the flat base is moved with respect to the roller so that the image receptor and the photosensitive layer are separated from each other. Contact and transfer. Usually, transfer is performed under heating.

Since the image forming material is held by the roller, peeling is also performed immediately after the transfer.

(5) If necessary, post-exposure is carried out for the purpose of strengthening the fixation on the entire surface of the transferred image and eliminating the viscosity of the transferred image surface.

In color proofing, the above (1) to (5) are repeated four times (yellow, magenta, cyan, black) to obtain a reproduced image of four colors.

The image receptor in the above is generally art or coated paper as a material used for proof printing, but these examples do not limit the present invention.

In the present invention, as shown in the above step (4), contact, transfer and peeling are quick, unlike in the case of planar pressure contact, that is, when the image forming material and the image receptor are flat. Moreover, the work can be performed stably, and the temperature unevenness when heating is smaller than when using a flat surface.

A schematic side view for explaining the device of the present invention will be described.

FIG. 1 shows a process of image exposure. 1 is an image forming material, 2 is a plate-making film or the like (color separation mask) which is an original for image exposure, 3 is a pin for registering, 4 is an ultraviolet irradiation device which is a light source, and 5 is for exposure Is a table for holding, and may have a mechanism for fixing by suction with a vacuum device, 6 is a roller, 7 is a flat table for holding an image receptor, 8 is an image receptor, and 9 is a light source for post-exposure. Shown respectively. Instead of the pin 3 or together with the pin 3, a registering film may be placed on the plate-making film or the like 2.

FIG. 2 shows the retention on the roller. After the image exposure, the film for plate making 2, etc., and if there is a film for registration, this film is also peeled off and fixed to the roller 6. The roller 6 has a holding mechanism. As this holding mechanism,
There are means using a jaw, vacuum suction, or a combination of these. The holding mechanism is not particularly limited, and any means may be used as long as it does not move or shift during transfer. In FIG. 2, the image forming material 1
It shows a method of fixing the roller to the roller 6 by hand with a jaw. That is, one end of the image forming material 1 is manually fixed to the jaws of the roller 6, and the roller 6 is rotated to hold the image forming material 1. At this stage, the protective film which is usually provided on the image forming material 1 is peeled off.

FIG. 3 shows a transfer process. Transfer is performed by moving the flat base 7 holding the image receptor and rotating the roller 6. The mechanism for holding the image receptor on the flat base 7 may be any of suction by vacuum, fixing with a fingernail, and fixing with a pin.

The contact and transfer between the photosensitive layer and the image receptor during roller rotation and flat plate movement are usually performed by applying pressure and heat.
Only pressure may be applied. In addition, when heating, it is preferable that the image receptor used does not significantly expand and contract. For example, heating the surface temperature of the flat table to 50 to 150 ° C., preferably 70 to 110 ° C. gives preferable results by improving the transfer speed and the accuracy of reproducing fine images.

In FIG. 3, the photosensitive layer and the image receptor are contacted and transferred, and immediately after transfer, they are peeled off. With this device, good transfer can be performed efficiently without causing problems such as ink swimming-like phenomena seen in offset printing or gravure printing due to excessive heating or temperature decrease, and paper shaving. In other words, processing at the roller enables processing at a high speed.

In the present invention, the complicated work of heat treatment before transfer and development by peeling, which is required in the prior art, is eliminated, and an image having a texture very similar to that of a printed matter is reproduced on an image receiving layer such as paper by a simple work.

Hereinafter, the present invention will be described with reference to examples. In the examples, “parts” means “parts by weight” and “%” means “% by weight”.

Example 1 A photosensitive layer liquid having the following composition was prepared.

Diallyl isophthalate prepolymer 21.23 parts (Osaka Soda Co., Ltd. Daiso Isodap Mn45000) Dipentaerythritol hexaacrylate PHA (manufactured by Nippon Kayaku Co., Ltd.) 7.08 parts Addition polymerization initiator benzophenone 0.5 parts 4,4 Bis-diethylaminobenzophenone ( EAB Hodogaya Chemical Co., Ltd. 0.17 parts Hydroquinone 0.001 parts Carbon black MA-7 (Mitsubishi Kasei Co., Ltd.) 5.0
Part Toluene 38.0 parts Methyl ethyl ketone 40.0 parts This photosensitive layer liquid was applied to a biaxially stretched polyethylene terephthalate film (film thickness 12 μm) so that the dry coating film would be 2.4 μm, and then the polyethylene film was applied to the coated surface. , Image forming material was prepared.

This image-forming material is fixed on an exposure table together with a plate-making film and a registering film, and image-exposed from the polyethylene terephthalate film (support) side. After removing the film for plate making and the film for registering, the entire surface is held by a rotating roller with a jaw and the polyethylene film which is the protective sheet is peeled off, and the flat table holding the art paper which is the image receiving layer is moved to the roller. Then, the image receptor and the photosensitive layer are brought into contact with each other at the nip between the roller and the flat base by the device shown in the drawing, transferred, further peeled and post-exposed. Met.

The flatbed feed rate is 50 cm / min and the roller pressure is 5 kg.
/ cm ^2, surface temperature of the flatbed was 100 ° C..

Comparative Example 1 In Example 1, the same image forming material was imagewise exposed to
After peeling off the protective sheet and overlaying it with the art paper, which is the image receiving layer, use a plane transfer machine (Naoprinter Mini, Naomoto Kogyo Co., Ltd.) at a temperature of 100 ° C. and a pressure of 1 Kg / cm ² , Transfer was performed in a flat shape under the condition that the transfer time was 1 minute. When peeled at room temperature, it was impossible to obtain a constant image because the unexposed area was peeled with paper stains.

Comparative Example 2 When the conditions of Comparative Example 1 were changed to a temperature of 100 ° C., a pressure of 5 Kg / cm ² and a transfer time of 1 minute, an experiment was conducted, and it was also found that the paper waste occurred.

Comparative Example 3 The same image forming material as in Example 1 was imagewise exposed,
Peel off the protective sheet, fix it to the blanket cylinder,
Using a flatbed calibrator equipped with a heating device on a paper surface plate on which art paper, which is an image receptor, is placed. Temperature 100 ℃, pressure 8Kg / c
Transfer was performed under the conditions of m ² and transfer time of 1 minute. The transferred image quality was inferior to that of Example 1 because the pressure was higher than usual.

Example 2 In Example 1, only the transfer and peeling conditions were changed.

Feed rate 40 cm / min, pressure 2 Kg / cm ² , roller surface temperature
When the temperature was 90 ° C., almost the same results as in Example 1 were obtained.

Example 3 In Example 1, only the transfer and peeling conditions were changed.

Feed rate 40 cm / min, pressure 4 Kg / cm ² , roller surface temperature
When the temperature was set to 120 ° C., almost the same results as in Example 1 were obtained.

Example 4 Instead of the carbon black of Example 1, Lionol Yellow FG1310, Carmine 7BFG4412, Lionol Blue FG
In 7330, a photosensitive layer liquid was prepared, and an image forming material was obtained in the same manner as in Example 1.

When the image was transferred to the image receptor of Example 1 in an overlapping manner, a color image was formed.

That is, the same operation was repeated for the remaining three color materials to obtain a color proof in which halftone images were formed in the order of black, cyan, magenta, and yellow.

[Brief description of drawings]

The drawing is a schematic side view for explaining the apparatus of the present invention, and FIG. 1 shows a process of image exposure. FIG. 2 shows the retention on the roller. FIG. 3 shows the transfer process. 1 is an image forming material, 2 is a plate-making film or the like which is an original for image exposure, 3 is a pin for registering, 4 is an ultraviolet irradiating device as a light source, 5 is a stand for performing exposure, 6 Is a roller, 7 is a table holding an image receptor, 8 is an image receptor, and 9 is a light source for post-exposure.

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Claims (2)

[Scope of utility model registration request] 1. An image-forming material comprising a support and a photosensitive layer containing a dye and / or a pigment and a photopolymerizable compound formed thereon, which is image-exposed to transfer the exposed and unexposed areas of the photosensitive layer. In an image forming apparatus that causes a difference in adhesiveness in an image transfer device and transfers an image to an image receptor such as paper, a roller that has a mechanism that retains an exposed image forming material on the surface, an image receptor, and the roller. An image forming apparatus comprising: a flat base for transferring an image forming material to an image receptor by moving the image forming material. 2. The image forming apparatus according to claim 1, wherein the utility model registration has means for heating the flatbed.