JPS6217221B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing photosensitive printing plates.
Specifically, a photosensitive printing plate with excellent vacuum adhesion during contact printing can be manufactured without adversely affecting printing characteristics, and maintenance and management during manufacturing is easy, and moreover, it is possible to use inexpensive equipment. The present invention relates to a method for producing a photosensitive printing plate that can easily obtain a photosensitive printing plate of uniform quality by effectively utilizing interleaving paper (insertion paper) used to protect the photosensitive layer of the printing plate.

Conventionally, in order to closely bake a film base plate onto a photosensitive printing plate, a vacuum baking frame was generally used, and the film base plate and photosensitive printing plate were stacked between the glass plate and rubber sheet of the printing frame, and the glass plate and A method (referred to as a vacuum contact method) is used in which the film original plate and the photosensitive printing plate are brought into close contact with each other by creating a vacuum between them and the rubber sheet. In this vacuum adhesion method, various means are known for obtaining sufficient adhesion over the entire surface to be adhered in a short time.

That is, for example, JP-A-50-125805 discloses a photosensitive printing plate provided with a matte layer on its surface. This method improves vacuum adhesion, but the matte layer provided on the surface of the photosensitive layer prevents the developer from penetrating, worsening developability, and some of it remains in the image area after development. The matte layer tends to inhibit the affinity for ink, and furthermore, the matte layer has a strong tendency to dissolve in the developer and fatigue the developer. Also, in Japanese Patent Application Laid-open No. 51-111102,
A photosensitive printing plate having a coating layer provided on its surface in the form of a minute pattern is disclosed. Although this method improves the adverse effect on developability (delay in development) compared to the above-mentioned method of providing a matte layer, the coated layer of the minute pattern is not completely removed when developed with a tired developer, so-called " In addition, a large amount of binder or matting agent is required to obtain sufficient vacuum adhesion, which tends to tire the developer, and the equipment and process for forming the coating layer are complicated. In addition to increasing the coating cost, it may not be possible to coat a coating layer with a minute pattern depending on the composition, thickness, surface properties, etc. of the photosensitive layer. Furthermore, Japanese Patent Application Laid-Open No. 51-98505 discloses a method of applying a wax-like or finely powdered resin having mold releasability in order to solve the problem that the coating layer for improving vacuum adhesion stains the film original plate. Disclosed. However, this coating layer does not adhere firmly to the surface of the photosensitive printing plate and easily falls off, and if it is applied uniformly over the entire surface to achieve strong adhesion, it not only has the disadvantage of impeding the penetration of the developer, but also The disadvantages are that the coating equipment and process for providing the solid or fine powder resin coating layer are complicated, resulting in high coating costs and difficult manufacturing maintenance and management.

On the other hand, there is a method (referred to as powdering) in which a solid powder such as talc is dispersed and adhered to the surface of the photosensitive printing plate by mechanical means before the contact baking process. There are 53 printed magazines
(10), 23 (1970), Inoue, Iino, Printing Information, 33(11),
90 (1973), disclosed in Ishiyama et al. This powdering improves vacuum adhesion by simply applying powder to prevent back transfer of printed matter or commercially available talc with a spray gun or puff, and also solves the developability problem seen in the conventional example. Although it can solve problems such as background stains and manufacturing problems, it also has the following drawbacks. In other words, powdering is generally applied when using photosensitive printing plates, and the powdering operation scatters solid powder into the plate-making work room, polluting the work environment and causing various problems in the plate-making process. Moreover, it is undesirable from the viewpoint of working environment hygiene, and cleaning of peripheral equipment required after the powdering process is a problem that cannot be ignored in terms of efficiency. Furthermore, the solid powder on the powdered photosensitive printing plate is likely to fall off during handling, contaminating the surrounding area, and therefore may not provide the expected vacuum adhesion.

Therefore, the present inventors thought of solving the above-mentioned drawbacks of the conventional powdering method by fixing the powdered solid powder to the surface of the photosensitive printing plate, and fixed the solid powder to the surface of the printing plate. Continued research on heat fusion methods to achieve this goal.
As a result, when hot air or thermal radiation from an infrared heater is used as a method of thermally fusing solid powder to the surface of a printing plate, the entire photosensitive printing plate becomes high temperature due to the heat required for thermal fusing, and the photosensitive layer In addition, from the viewpoint of manufacturing equipment, the heating process equipment is large-scale, which increases manufacturing costs, and maintenance and management during manufacturing is complicated. In this case, the expected vacuum adhesion may not be obtained because the solid powder dispersed and adhered to the surface of the printing plate is scattered by the hot air, or a large amount of solid powder is used for photosensitive printing in anticipation of the scattering by the hot air. It has also been found that if the solid powder is attached to the plate in advance, a larger amount of solid powder than expected may be thermally fused to the surface of the printing plate, which may adversely affect the printing properties. On the other hand, when using heat conduction using a heating roll, etc. as another method for thermally fusing solid powder to the surface of a printing plate, it is only necessary to melt the solid powder and there is no need to heat the entire printing plate. While process equipment becomes cheaper,
Because it is necessary to bring a heating roll that conducts heat to the solid powder into contact with the solid powder, a portion of the heat-molten solid powder is fused to the heating roll, and a uniform amount of solid powder is not thermally fused to the surface of the printing plate. Parts of the photosensitive printing plate where the expected vacuum adhesion could not be obtained were mixed indiscriminately with parts of the photosensitive printing plate where the vacuum adhesion was obtained but the printing properties were adversely affected by the thermal fusion of more solid powder than expected. It has been found that this makes maintenance and control of the heating process extremely difficult.

As mentioned above, it has been found that if the amount of solid powder heat-fused to the surface of the printing plate is too large, it will adversely affect the printing properties, and if the amount is too small, the expected vacuum adhesion properties cannot be obtained. At the same time, it has been found that the printing characteristics and vacuum adhesion are also influenced by the particle size of the solid powder to be heat-sealed.

Based on the above-mentioned knowledge, the present inventors continued their research in order to solve the drawbacks of the conventional vacuum adhesion improvement method described above. 0.005/ ^m2 of fusible fine powder
After feeding and uniformly dispersing and adhering the photosensitive printing plate in an amount of ~0.5 g, the surface side of the photosensitive printing plate is brought into contact with a heating roll having a surface with good mold releasability, and the above heat fusion bond is applied to the surface of the photosensitive printing plate. We have developed a technology to heat-fuse fine powders.

As a result of continuing research even after the development of this new technology, the inventors of the present invention found that in order to continuously produce large quantities of photosensitive printing plates of more perfect uniform quality, the above-mentioned heated roll could be replaced by some method. I learned that it is desirable to clean regularly or constantly.

Conventionally, various cleaning methods have been used in a wide variety of fields, such as spraying a fluid such as air, steam, water, hot water, or an organic solvent, or using a cleaner such as cloth, paper, or a brush. A cleaning method using a wiping method or a combination of these methods is known, but the above-mentioned fluid-based technology has the disadvantage that the surrounding environment is contaminated by the used fluid, and the above-mentioned cleaner-based technology has the disadvantage that There is a drawback that management such as replacing and replenishing the cleaner itself becomes complicated. When the object to be cleaned is fine powder on the micron scale, it is difficult to maintain complete cleaning using the conventional method, and post-treatment of the cleaned fine powder is required. becomes.

Therefore, the first object of the present invention is to firmly heat-seal a solid powder that improves vacuum adhesion to the surface of a photosensitive printing plate so that the powder does not fall off during handling as in the conventional powdering method. It is an object of the present invention to provide a method for producing a photosensitive printing plate free from the above.

A second object of the present invention is to provide a method for producing a photosensitive printing plate that can produce a photosensitive printing plate with excellent vacuum adhesion during contact printing without adversely affecting its printing characteristics. be.

A third object of the present invention is to heat-fuse the solid powder to the surface of a photosensitive printing plate in a uniform amount by combining a specific cleaning technique in the heating process for heat-fusing the solid powder. It is an object of the present invention to provide a method for manufacturing a photosensitive printing plate, which can obtain a printing plate with improved uniform quality.

A fourth object of the present invention is to clean a heating roll used in a heating process for thermally fusing solid powder, as in the conventional cleaning method.
It does not pollute the surrounding environment, does not require complicated management such as replacing or replenishing the cleaner, does not require post-processing of the cleaned solid powder, and complete cleaning can be maintained for a long time. It is an object of the present invention to provide a method for producing a photosensitive printing plate that can obtain a high quality photosensitive printing plate.

The fifth object of the present invention is to obtain high-quality photosensitive printing plates at low cost by effectively utilizing interleaf paper (insertion paper) used to protect the photosensitive layer of photosensitive printing plates in cleaning technology. It is an object of the present invention to provide a method for manufacturing a photosensitive printing plate that can be used.

A sixth object of the present invention is to provide a method for manufacturing a photosensitive printing plate that uses a heating device that is simple and inexpensive from the viewpoint of manufacturing equipment and a cleaning device for the heating device, resulting in low manufacturing costs. It is.

A seventh object of the present invention is that the cleaning method does not adversely affect the thermal management of the heating process during manufacturing, and therefore the thermal management of the heating process is easy, and a large quantity of photosensitive printing with uniform quality can be achieved. An object of the present invention is to provide a method for manufacturing a photosensitive printing plate, which allows plates to be obtained continuously.

The above object of the present invention and other objects mentioned below are such that the surface of a photosensitive printing plate has a uniform direction diameter of 0.5 to 0.5 to 1.
After supplying 0.005 to 0.5 g of heat-adhesive fine powder of 40 μm ^per square meter and uniformly dispersing and adhering it, the front side of the photosensitive printing plate was brought into contact with a heating roll having a surface with good mold release properties. The heat-fusible fine powder is thermally fused to the surface of the photosensitive printing plate, and an interleaving paper for protecting the photosensitive layer of the photosensitive printing plate from being damaged is brought into contact with the heating roll. This is accomplished by polymerizing the cleaned interleaving paper onto the surface of the photosensitive printing plate to which the heat-fusible fine powder has been heat-sealed.

According to a preferred embodiment of the present invention, as shown in the figure, the surface 2 of a photosensitive printing plate 1 running at a constant speed is
(on the side with the photosensitive layer), heat-fusible fine powder with a directional diameter of 0.5 to 40 μ is applied per 1 m ² using the powder feeder 3.
After supplying a fixed amount of 0.005 to 0.5 g and uniformly dispersing and adhering it, it passes between a heating roll 4 having a surface with good mold releasability and a pressure roll 5 having good heat insulation (and good elasticity). and after bringing the printing plate surface 2 into contact with the heating roll 4 during this passage,
Furthermore, it is passed through a roll 6 (suitably one with good heat insulation properties) for bringing the surface 2 into contact with a heating roll 4 (portion A), and then passed between a pair of transport rolls 7 for transport. On the other hand, an interleaving paper (insertion paper) 8 used to prevent the photosensitive layer of the printing plate 1 from being damaged is run at the same constant speed as the printing plate 1, and a roll 9 installed near the heating roll 4, 10 to contact the heating roll 4 to clean the roll 4, and then pass it between the pair of rolls 7 to polymerize on the surface of the printing plate and convey it. In addition, in the figure, 11 indicates the original roll of the interleaf paper 8, and 12 and 13 indicate transport rolls.

According to another preferred embodiment of the invention, before the front surface 2 of the photosensitive printing plate 1 comes into contact with the heating roll 4, the back side of the photosensitive printing plate 1 is heated on a preheating roll 14.
The printing plate is preheated by a method such as bringing it into contact with the printing plate. The preheating step may be performed before the photosensitive printing plate is brought into contact with the heating roll, and may be performed at the same time as the heat-fusible fine powder is uniformly adhered to the surface of the printing plate, or before or after this adhesion. good.

After powdering the heat-fusible fine powder used in the present invention on the surface of the photosensitive layer side of the photosensitive printing plate,
Any material that can be thermally fused to the surface by heat and has a diameter in a fixed direction of 0.5 to 40 microns is sufficient. This heat-sealable fine powder has a first transition point (value measured by a differential scanning calorimeter) lower than the first transition point (value measured by a Koka type flow tester) or a second transition point (a value measured by a differential scanning calorimeter) of the photosensitive layer. A solid powder consisting essentially of a substance or composition, or having a surface layer consisting essentially of the substance or composition, and more preferably a solid powder consisting of a substance or composition having The first-order transition point and the second-order transition point are higher than 40°C, and the first-order transition point or the second-order transition point of the substance or composition is lower than the first-order transition point of the photosensitive layer. be. Furthermore, in the present invention, only the heat-fusible fine powder powdered on the photosensitive layer side surface of the photosensitive printing plate is rapidly heated and melted without heating the entire photosensitive printing plate to a high temperature. It is also possible to use heat-fusible fine powders having a first-order transition point higher than the first-order transition point of the photosensitive layer.

Preferred specific examples include polyvinyl acetate, polyvinylidene chloride, polyethylene oxide, polyethylene oxide, polyethylene glycol, polyacrylic acid, polyacrylamide,
Examples include polyacrylic esters, polystyrene and polystyrene derivatives, copolymers of these monomers, polyvinyl methyl ether, epoxy resins, phenol resins, polyamides, polyvinyl butyral, and the like.

The heat-fusible fine powder used in the present invention is preferably one that is soluble in a developer for photosensitive printing plates. For example, photosensitive printing plates that can be treated with strong alkaline aqueous solutions such as silicates include hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, polyacrylic ester, polystyrene derivatives and acrylic acid. Alternatively, polyacrylic esters, polyacrylamides, copolymers containing polystyrene, phenolic resins, etc. having phenolic or alcoholic hydroxyl groups are preferably applied. Photosensitive printing plates that use developers using organic solvents such as alcohols, glycols, and ketones include cellulose derivatives, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetate, polyvinylidene chloride, polyacrylic acid, and polyacrylamide. , polyacrylic ester, polystyrene, a copolymer consisting of two or more of acrylic acid, acrylamide, acrylic ester, and styrene monomers, epoxy resin, phenolic resin, and the like are preferably used. In addition, matting agents that are widely used to roughen the surface of objects (for example, silica, zinc oxide, titanium oxide, zirconium oxide, alumina, polymethyl methacrylate, polystyrene,
A material in which the surface of a fine solid powder such as a phenol resin is wrapped in the above heat-fusible fine powder material may also be used.

In the present invention, the heat-fusible fine powder supplied to the surface of the photosensitive printing plate is limited to a powder having a diameter in the direction of 0.5 to 40 μm (more preferably a diameter in the direction of 1 to 17 μm). That is, the diameter in the fixed direction is 0.5μ
When the heat-fusible fine powder has a diameter of less than 40 μm, there is almost no improvement in vacuum adhesion, and when the diameter in the fixed direction is larger than 40 μm, the reproducibility of small halftone dots deteriorates.

In order to adjust the particle size of the heat-fusible fine powder used in the present invention within the above-mentioned range, a generally known classification method may be followed. Further, the shape of the heat-fusible fine powder to be used is not particularly limited as long as it has a diameter within the above-mentioned direction, but it may be spherical or the above-mentioned fine powder material that has been pulverized with a ball mill, jet mill, etc. A fixed shape can be used.

In the present invention, the amount of heat-fusible fine powder supplied to the surface of the photosensitive printing plate is 1 m ² of the surface of the photosensitive printing plate.
It is required to be evenly distributed and deposited at 0.005 to 0.5 g per coat. However, if more than 0.5 g of fine powder per 1 m ² is fused to the surface of the printing plate, the reproducibility of small halftone dots deteriorates, and if less than 0.005 g of fine powder is fused to the surface of the printing plate per 1 m ² , the vacuum adhesion is poor. This is because the improvement in performance is not sufficient. According to the method of the present invention, the heat-fusible fine powder uniformly dispersed and adhered to the surface of the printing plate in the above amount is transferred to the printing plate in almost the same amount by contact with a heating roll having good mold releasability. Since it is thermally fused to the surface, it is sufficient to uniformly disperse and adhere it to the surface of the printing plate within the above-mentioned amount range.

In the present invention, in order to uniformly disperse and adhere the heat-fusible fine powder to the printing plate surface in the above amount,
In addition to using the powder feeder, known methods such as JJ Sokol, RC Hendrickson, Plastic Engineering Handbook, P. 426,
P.431 (1976) [JJSokol and RCHendrickson
In addition to the fluidized bed electrostatic spray and electrostatic fluidized bed described in Plastic Eng. Handbook (1976),
A method using air spray, a brush, a puff, etc. may be used.

The heating roll having a releasable surface used in the present invention refers to a printing plate surface on which the heat-fusible fine powder is uniformly dispersed and adhered in the above amount.
Any material may be used as long as it serves to thermally fuse the fine powder to the surface of the printing plate when brought into contact with the roll, and that hardly any of the fine powder adheres to the surface of the heating roll during this heat sealing. Specifically, the surface of a known heating roll is lined with a fluororesin such as Teflon (trade name), the surface of a heating roll is roughened and the roughened surface is impregnated with a fluororesin, A heating roll coated with a heat-shrinkable fluororesin tube such as tetrafluoroethylene-hexafluoropropylene copolymer, or a silicone resin heating roll may be used. The thickness of the resin layer having good mold releasability, such as the above-mentioned fluororesin or silicone resin, is preferably 100 μm or more in order to facilitate control of heat transfer when heat-sealing the above-mentioned fine powder. Also, if it is too thick, it is not preferable from the viewpoint of thermal efficiency. Further, it is desirable that the heating roll having a surface with good mold releasability has a smooth surface.

In the present invention, by bringing the printing plate surface into contact with a heating roll having a surface with good mold releasability, heat-fusible fine powder uniformly dispersed and adhered to the printing plate surface is thermally melted onto the printing plate surface. The process is completed by polymerizing the cleaned interleaving paper, but in the present invention, heat fusion means that the fused fine powder does not easily fall off due to friction during normal plate-making operations. It means that it is fixed to. In particular, when undesirable foreign matter adheres to the surface of the photosensitive printing plate, it is preferable that the fine powder is fixed to such an extent that the fine powder will not be removed along with the foreign matter by wiping the surface with a cloth or the like. . Therefore, the heating temperature by the heating roll may be within a necessary and sufficient temperature range to thermally melt the fine powder and fix it to the printing plate surface to the above degree, and the type of fine powder to be thermally fused, An appropriate temperature is selected depending on the melting point, amount, type of photosensitive printing plate, etc.

In the present invention, the photosensitive printing plate on which the heat-fusible fine powder is fused is basically one in which a photosensitive layer is provided on a support, and includes a lithographic printing plate and a letterpress printing plate. , photosensitive printing plates known to be used for making printing plates such as intaglio printing plates.
As a support, for example, in the case of a photosensitive lithographic printing plate, an aluminum plate, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in Japanese Patent Publication No. 18327/1980, etc. are preferable. Further, in the case of a photosensitive letterpress printing plate, aluminum plates, iron plates, etc. are preferable. The above-mentioned supports include those subjected to known surface treatments, and may also have an undercoat layer.
Furthermore, the photosensitive layer provided on the support may be any known photosensitive material whose solubility or swellability in a developer changes before and after exposure.

Next, the cleaning process in the present invention will be explained. The interleaf paper used in the present invention can be any type of paper as long as it is originally used to protect the photosensitive layer of the photosensitive printing plate from damage.
Those suitable for cleaning heating rolls are preferred. Specifically, pulp paper, synthetic paper, synthetic pulp paper, or those obtained by laminating polyethylene on the surface of these papers are preferably used.

In addition, the contact length of the interleaf paper with the heating roll is
It is preferable to select a range in which the heat-fusible fine powder adhering to the heating roll can be wiped off and the interleaving paper that comes into contact with the heating roll will not be physically deformed. Generally, the contact length is
Although it varies depending on the temperature of the heating roll, the type of interleaf paper, the conveyance speed, etc., it is preferable that the contact length be at least 5 mm or more. If the contact length is less than 5 mm, the cleaning will not be sufficient, and if the contact length is too long, the interleaving paper will dry out too much, causing wrinkles, or in the case of synthetic paper, thermal deformation. may occur.

Hereinafter, specific examples of the present invention will be given, but the embodiments of the present invention are not limited thereto.

Example 1 A styrene-acrylic acid-butyl acrylate (ratio: 45:30:25) copolymer was crushed and classified using a zigzag classifier manufactured by Alpime to produce a thermally fused material with a directional diameter of 0.5 to 40μ. An adherent fine powder was obtained. A known photosensitive printing plate (Sakura PS plate SLP, 0.3mm
Using a powder feeder, the powder was uniformly spread and adhered to the surface of the printing plate (with a thickness of 0.05 g/m ² of the printing plate surface). Thereafter, as shown in the figure, it was passed between a heating roll 4 and a pressure roll 5, and then placed on a roll 6 and conveyed. That is, a heating roll covered with a heat-shrinkable tube made of tetrafluoroethylene-hexafluoropropylene copolymer having a thickness of 0.5 mm is used, and the surface temperature of the heating roll is maintained at 185°C, and the heating roll 4 has a heat-insulating property. The contact pressure with the elastic roll 5 was set to 3 kg per 1 cm of the width of the printing plate, and after passing between the two rolls, the contact length (the length of the part marked A in Fig. 2) was further increased to 70 mm. The fine powder was brought into contact with the heating roll 4 so as to be thermally fused to the surface of the printing plate, and then conveyed through a pair of rolls 7. At the same time, paper 8
(manufactured by Tokushu Paper Industries, TMP) was placed between the rolls 9 and 10 and run at a constant speed of 10 m per minute in the opposite direction to the rotation direction of the heating roll 4, so that the length of contact with the heating roll 4 was After cleaning by contacting with a heated roll to a thickness of 15 mm, the cleaned interleaving paper 8 is introduced between the pair of rolls 7 and polymerized on the surface of the heat-fused photosensitive printing plate 1. A sample according to the present invention was obtained.

The obtained photosensitive printing plate (sample) required 1 minute and 20 seconds for vacuum adhesion during contact baking, whereas the photosensitive printing plate before applying the formulation of the present invention required 2 minutes and 20 seconds. It only took 5 seconds.

The following method was used for the contact baking. That is, a photographic film (500 x 700
mm) and the sample (800 x 1003 mm) were vacuum-adhered using a horizontal vacuum baking frame KD-P1 model manufactured by Kamo Electric Laboratory.

After exposing the above photosensitive printing plate samples of the present invention and the photosensitive printing plate before applying the treatment method of the present invention to a 2KW metal halide lamp from a distance of 11/4 m for 3 minutes, a 1% aqueous solution of trisodium silicate was used. The film was developed by immersing it in water for 45 seconds. The thermally fused fine powder had no effect on development, and a positive image exactly like the original was obtained. The printing performance of each of the above printing plate samples was completely equivalent. That is, no influence was observed on development and printing performance (both image areas and non-image areas) due to the heat-fusible fine powder being fused onto the surface of the electrosensitive printing plate.

Next, in the above embodiment of the present invention, the amount of heat-fusible fine powder to be uniformly dispersed and adhered to the surface of the printing plate was set to 1.
When the same prescription as above was used except that the amount was changed to 0.6g and 0.004g ^per m2, the reproducibility of small halftone dots worsened when the amount was 0.6g ^{per m2} , and 0.004g ^per m2
It was found that the improvement in vacuum adhesion was insufficient in the case of the amount of g.

Next, in the above embodiment of the present invention, the same as above except that the heat-fusible fine powder to be uniformly dispersed and adhered to the printing plate surface had a diameter in the direction of more than 40μ and less than 0.5μ. When formulating, it was found that the reproducibility of small halftone dots deteriorated for samples using fine powder with a diameter larger than 40μ, and the diameter
It was observed that the improvement in vacuum adhesion was insufficient for the sample using fine powder of less than 0.5μ.

Example 2 A photosensitive printing plate sample was prepared in the same manner as in Example 1, but differed from Example 1 in the following points. That is, before uniformly adhering the heat-fusible fine powder to the surface of the printing plate, the back surface of the printing plate (the surface on the support side) was brought into contact with the preheating roll 14 whose surface temperature was heated to 80°C, and the heating The surface temperature of the roll was maintained at 125℃, the contact pressure between the heating roll and the pressure roll was set to 1.2 kg per 1 cm of width of the printing plate, and the contact length of the interleaving paper with the heating roll was set to 20 mm. This is what I did.

The vacuum adhesion of the obtained photosensitive printing plate sample according to the present invention was measured using the same method as in Example 1.
The photosensitive printing plate before applying the formulation of the present invention is 2
The sample of the present invention required 1 minute and 20 seconds.
It only took seconds.

In addition, when exposure and printing were carried out in the same manner as in Example 1, good results similar to those in Example 1 were obtained, and development and
No adverse effects on printing performance were observed.

Furthermore, in this Example 2, when the amount and powder diameter of the heat-fusible fine powder were varied in the same manner as in Example 1, the same results as in Example 1 were observed.

Furthermore, in this Example 2, when the contact length of the interleaf paper with the heating roll was set to 4 mm, cleaning of the heating roll was insufficient. Furthermore, when the contact length was set to 40 mm, wrinkles occurred in the interleaf paper.

[Brief explanation of the drawing]

The figure is a schematic diagram showing an example of the method for manufacturing a photosensitive printing plate according to the present invention (however, the preheating roll portion is shown by imaginary lines). In the figure, 1 is a photosensitive printing plate, 2 is its surface, 3 is a powder feeder, 4 is a heating roll, and 8 is a slip sheet.

Claims (1)

[Claims] 1. After supplying heat-fusible fine powder with a directional diameter of 0.5 to 40μ to the surface of the photosensitive printing plate at a rate of 0.005 to 0.5 g per 1 m ² and uniformly dispersing it, the surface side of the photosensitive printing plate is Contact with a heating roll having a surface with good mold releasability to thermally fuse the heat-fusible fine powder to the surface of the photosensitive printing plate, and protect the photosensitive layer of the photosensitive printing plate from damage. It is characterized by bringing the interleaving paper into contact with the heated roll to clean the roll, and then polymerizing the cleaned interleaving paper onto the surface of the photosensitive printing plate to which the heat-fusible fine powder is heat-fused. A method for producing a photosensitive printing plate.