JP2006137612A - Covering body for guide roller or intermediate cylinder in printing device, and printing device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a covering body for an impression cylinder or an intermediate cylinder in a printer, polluted little with sticking of ink, easy to be cleaned and high in durability, and to provide a printing device. <P>SOLUTION: The covering body for the impression cylinder, the intermediate cylinder or a guide roller is characterized in that a composite covering coat 14 consisting of a porous ceramics thermal sprayed layer 12 or a hard base layer with fine unevenness, and a low surface energy resin layer 13 formed on the surface and in the pore parts of the ceramics thermal sprayed layer, is formed on the surface of a plate-like or sheet-like material. The covering body may be provided in a form of a covering body windable on a roller by forming the composite covering coat on a flexible metal plate, or in a form of a simpler covering body by using an inorganic particle layer composed of ceramics powder, glass beads, or the like instead of the ceramics thermal sprayed layer, and forming a composite covering coat consisting of the inorganic particle layer and the low surface energy resin layer, on a base material such as a synthetic resin film or a waterproofed paper. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a guide roller or intermediate cylinder covering in a printing apparatus, and a printing apparatus using the same.

  The printing technique is a technique for copying a large amount of text and other graphic information as a hard copy (printed material) in which a homogeneous image is formed on the surface of a printing medium such as paper. In such a printing technique, as is well known, as a printing apparatus used to make a printed material by attaching a color material (ink) to a printing plate and then pressure-transferring it to the surface of the printing material, the printing plate type and Depending on the difference in the ink transfer form (direct printing or indirect printing method) from the printing plate to the surface of the printing material, various types such as offset printing machines, letterpress printing machines, flexographic printing machines, gravure printing machines, screen printing machines, etc. is there.

  In these printing apparatuses, there is a difference in whether the printing plate is directly bonded to the printing medium, or an intermediate medium such as a rubber blanket to which the ink attached to the printing plate is once transferred is bonded to the printing medium, The large concept of transferring the ink on the printing element (printing plate or intermediate medium) to the printing medium is the same, and the printing medium is pressure-bonded to the printing element and then transferred. -There are many common configurations for the transfer system.

  FIG. 6 is a diagram showing a schematic configuration of a printing mechanism in an offset printing machine. In an offset printing machine, ink is transferred from a plate cylinder 1 to a rubber cylinder (rubber blanket) 2 and then transferred onto the surface of the printing medium 4 fed between the rubber cylinder 2 and the impression cylinder 3. Then, an ink image (printed material) 5 is formed.

  Conventionally, as an impression cylinder or intermediate cylinder of an offset printing machine, a metal cylinder surface usually finished with chrome plating is used. However, in a printing machine equipped with such an impression cylinder or intermediate cylinder, When double-sided printing is performed, the printing medium 4 after the first-side printing is sent between the rubber cylinder 2 and the impression cylinder 3 having the same configuration as described above as shown in FIG. The first surface of the printing medium on which the ink image 5 is formed is in contact with the impression cylinder 3 side), and the ink image 5 printed on the first surface is transferred as the transfer ink image 6 onto the impression cylinder 3 surface. Then, as a result of the transfer ink image 6 being transferred again to the same surface of the substrate 4 to be sent, the printing surface is contaminated (hereinafter referred to as “back stain”). . If double-sided printing was repeated, this tendency became worse and printing unevenness was generated. These stains occur in the intermediate cylinder as well.

  Therefore, when the double-sided printing as described above is repeated (the intermediate cylinder is soiled even with a single-sided machine), the impression cylinder / intermediate cylinder must be cleaned. The ink adhering to the surface of the impression cylinder / intermediate cylinder is difficult to remove easily, so stop the printing press, reach out to a narrow part in an extremely unstable posture, and use a waste cloth containing an organic solvent. Etc., and it was forced to carry out an extremely dangerous and difficult manual operation of wiping while rotating the impression cylinder and the intermediate cylinder manually.

  In order to solve such problems, Japanese Patent Application Laid-Open No. 62-94392 proposes an impression cylinder in which the surface of a metal cylinder is coated with a specific silicone resin.

  However, when the surface of the metal cylinder is simply coated with a silicone resin, the resulting silicone resin film has a low hardness, so the performance is greatly degraded due to scratches and wear. Thus, it was proved impractical to use as a part that is difficult to replace. In addition, when such a silicone-based resin film is directly formed on the surface of the metal cylinder, the surface property becomes extremely smooth and flat. Since the silicone resin exhibits non-adhesive surface properties with low surface energy, the ink transfer from the printing medium 4 was found to be quite large.

  FIG. 8 is a drawing showing a schematic configuration of a printing and transport mechanism for a printing medium in another offset printing machine. This example is a rotary type using continuous paper wound in a roll shape as the printing material 4, and ink is transferred from the plate cylinder 1 to the rubber cylinder 2 in the same manner as described above. The ink-jet image 5 is formed on the surface of the printing medium 4 fed between the impression cylinders 3 to form an ink image 5. It passes through the apparatus while being redirected by the guide roller 7.

  In a rotary press that continuously prints on a printing medium such as paper or film wound in a roll shape as described above, a large number of guide rollers are provided in the transfer system of the printing medium. The transfer system using such guide rollers is not limited to the above-described offset rotary press (newspaper rotary press, commercial offset rotary press, foam rotary press), but also a gravure printing press, flexographic printing press, letterpress rotary press. A rotary press such as the same is also included.

  As the guide roller 7 for a rotary press, many aluminum alloy pipes are used for weight reduction. Of course, in addition to this, there are also known ones in which the surface of an iron pipe is plated with chrome, or ones using carbon fiber reinforced resin or the like for further weight reduction. Furthermore, in order to prevent the printing material from slipping and ink adhesion, these guide roller surfaces are knurled, taped with a sandpaper-like rough surface, and ceramic sprayed. Are known.

  However, the knurled aluminum alloy pipe has low wear resistance, and the knurled irregularities disappear in a short period of time, and slip easily occurs. Similarly, even when a sandpaper-like rough surface tape was applied to the roller surface, the sand beads were dropped and the tape was peeled off after a short period of use, and could not withstand long-term use. On the other hand, the ceramic sprayed surface has a very high wear resistance and a very good effect in terms of slip resistance, but the following ink adhesion problems become significant. There was a drawback.

  That is, the surface of any conventionally known guide roller is made of a material having a relatively high ink adhesion property. Therefore, even if such a guide roller 7 has a rough surface, When the printing press is operated for a long time, the ink image 5 printed on the surface of the printing medium 4 is transferred as a transfer ink image 8 onto the surface of the guide roller 7 that is in contact with the transfer cylinder 4 as in the case of the impression cylinder described above. A problem similar to that in the above-described impression cylinder, in which the ink image 8 is reversely transferred to the surface of the subsequent printing medium 4 and contamination of the printed matter occurs. For this reason, when operating a rotary press, such guide rollers must be cleaned periodically, interrupting the printing operation for cleaning operations, causing a large cleaning load, and neglecting cleaning. This leads to the occurrence of troubles such as producing defective printed products.

  In particular, in the case where the ceramic sprayed surface is formed, the ink penetrates into and adheres to the concave portion of the sprayed rough surface, so it cannot be easily removed by wiping the surface, and a solvent is used. When washing is performed, the ink dissolved in the solvent is transferred and impregnated into the pores of the ceramic sprayed layer, so that the washing operation is difficult. Further, Japanese Patent Laid-Open No. 63-102940 proposes to wrap a covering material having a silicone resin as a surface layer and having compressibility around the surface of the intermediate cylinder in order to prevent ink smearing on the intermediate cylinder of the printing press. ing. However, as described above, the coating material made of only the silicone resin coating has extremely poor wear resistance and loses the releasing effect in a very short period due to wear contact, so that it can be applied to members used under the wear action. Absent.

  In addition, as a member for preventing ink adhesion to the impression cylinder, feed cylinder, and guide roller of the printing press, Japanese Patent Publication No. 53-7841 and Japanese Utility Model Publication No. 61-31740 are provided on substrates such as kraft paper, synthetic paper and resin film. A technique relating to a coating for preventing ink adhesion, which is coated with glass beads, is generally marketed and is applied to an impression cylinder, a feed cylinder and a guide roller. This technology is based on the idea of preventing ink adhesion by making a point contact effect by bringing the head of glass beads into contact with the printing surface. The material is relatively high in surface energy and has a low repellent property against ink. Inhibiting the effect of preventing ink adhesion. In particular, the valleys (recesses) formed between the glass beads are sharp and easy to remain and solidify, and when operated for a certain period of time, ink, paper dust, etc. adhere and accumulate and contaminate the following paper. There is a drawback. For this reason, it is necessary to periodically stop the machine to clean and remove the adhering contaminants with an organic solvent. In this case as well, it is impossible to continuously operate the printing press for a long time, and the time required for removing the contaminants The effort was quite large. In addition, due to repeated use, residual contaminants such as dried and solidified ink remaining in the valleys increase, and the release effect is lost, and it is necessary to replace with a new covering in a short period of time. .

  Further, in Japanese Examined Patent Publication No. 53-7841, porous beads such as silica gel, alumina, styrene gel or the like are bonded to a sheet-like substrate in place of the glass beads, and moisture is included in the pores of the porous material. Has been disclosed in which the ink is constantly moistened during printing and imparts ink repellent properties. It is stated that hydration in this porous material can be done by spraying or other methods, but if water is sprayed on the sheet surface in use, excess water will adhere to the printing paper surface, causing problems such as color density reduction. Control is very difficult to control. Also, the pores of the porous material are impractical because the ink is clogged and its function is lost in a short time. Furthermore, if the ink repellency effect due to water is lost, as in the case of the sheet with the glass beads adhered, problems due to ink accumulation in the valleys formed between the beads occur, and a large improvement effect is maintained. It was impossible.

  Accordingly, the present invention reduces the contamination of the guide rollers or intermediate cylinders of various printing apparatuses, reduces the work load by reducing the frequency of cleaning, and improves the equipment operation rate. An object of the present invention is to provide a covering for an automobile. Another object of the present invention is to provide a highly durable covering.

  The above-mentioned objects are achieved by the following (1) to (6).

  (1) In a printing apparatus, a printed material is pressure-bonded to a printing element, and is then detachably wound over substantially the entire circumferential surface of a guide roller or intermediate cylinder disposed in a printed material pressure-bonding / transferring system that is subsequently transferred. A hard base layer having fine irregularities on the surface thereof, and a low surface energy resin formed on the surface of the base layer without completely eliminating the irregularities. A coating for a guide roller or intermediate cylinder, wherein a composite coating film comprising a layer is formed, and the surface property thereof is a surface roughness Rmax of 20 to 150 μm and has smooth irregularities.

  (2) The covering according to (1), wherein the low surface energy resin is a silicone resin.

  (3) A hard base layer formed by adhering inorganic fine particles such as ceramic powder or glass beads on a substrate made of a synthetic resin film or water-resistant treated paper, and a low surface energy formed on the surface of the base layer The covering according to (1) or (2), wherein a composite covering film composed of a conductive resin layer is formed.

  (4) The covering according to any one of (1) to (3), wherein the covering is an intermediate cylinder covering for an offset printing press.

  (5) The covering according to any one of (1) to (3), wherein the covering is a guide roller covering for a rotary printing press.

  (6) A composite film comprising a hard base layer having fine irregularities on a flexible substrate and a low surface energy resin layer formed on the surface of the base layer without completely eliminating the irregularities. And having a surface roughness Rmax of 20 to 150 μm and smooth irregularities, having a guide roller or an intermediate cylinder formed by winding the covering according to claim 1. Printing device.

  As described above, the press-bonding / transfer roller to be printed on which the covering of the present invention is wound has a fine surface texture and relatively smooth irregularities, and has excellent wear resistance. Since the substrate surface is coated with a composite coating consisting of a thermal spray layer or inorganic fine particle layer and a low surface energy resin layer such as a silicone resin having a low surface energy, it is difficult for ink to adhere to the surface. is there. For this reason, various rollers disposed in the press-bonding / transfer system of the printing medium in various printing presses, for example, an intermediate cylinder in an offset printing press, or an offset rotary press (news rotary press, commercial offset rotary press, foam rotary press) It can be suitably used as a guide roller in various rotary presses such as gravure printing machines, flexographic printing machines, etc., and it is not necessary to perform a washing operation when performing a printing operation for a large amount or a long time continuously. It is possible to provide a printed matter having a good print quality and excellent durability. In addition, since the ink attached to the surface can be easily removed by dry method, the cleaning operation of the rollers, which has been very dangerous and labor-intensive, has become extremely easy. It also has a very high effect in reducing initial costs. Further, for example, in business form rotary presses, UV ink has been used in order to eliminate the problem of reverse transfer. However, by using the guide roller of the present invention, the ink itself is expensive. In addition, it is possible to achieve the same printing level with ordinary ink without using UV ink, which is complicated and expensive.

  Further, in the coated body of the present invention, in a mode in which a synthetic resin film or water-resistant treated paper is used as a base material, the non-printed body crimping / transfer roller of various sizes of an existing various printing machine is excellent in productivity. However, it can be easily cut and wound into an arbitrary size, and its application range is very wide.

  Furthermore, the roller having such a configuration has the same excellent effect not only in the field of printing presses but also in various fields in other fields for processing a film-like body to which an adhesion transfer substance is applied. It is what you play.

Thus, the guide roller or intermediate cylinder covering according to the present invention is obtained by spraying metal or ceramic on a metal substrate, or ceramic powder or a flexible substrate made of a synthetic resin film or water-resistant treated paper. From a hard base layer having fine irregularities formed on the surface by adhering inorganic fine particles such as glass beads, and a low surface energy resin layer formed on the surface of the base layer without completely eliminating the irregularities The composite coating film is formed, and the surface shape thereof has a surface roughness R _{max of 20 to} 150 μm and has smooth unevenness. FIG. 1 is a diagram schematically showing a cross-sectional structure in one embodiment of the guide roller or intermediate cylinder according to the present invention, and FIG. 2 further shows the cross-sectional structure of the guide roller or intermediate cylinder according to the present invention. FIG. 3 is a diagram schematically showing an enlarged view, and FIG. 3 is a diagram schematically showing a cross-sectional structure in the manufacturing process of the guide roller or the intermediate cylinder according to the present invention. In these drawings, the vertical and horizontal scale ratios are exaggerated.

  Here, when the ceramic sprayed layer 12 is impregnated with a low surface energy resin such as a silicone resin and dried and solidified, for example, as shown in FIGS. A low surface energy resin layer 13 is formed in the portion. As described above, the low surface energy resin 13 has the adhesiveness to the ceramic sprayed layer 12 due to the anchor effect caused by entering the portions because the ceramic sprayed layer 12 has pitch-wave irregularities and is porous. The composite coating is well formed, and the composite coating 14 is constituted by the ceramic sprayed layer 12 and the low surface energy resin layer 13.

Further, the low surface energy resin 13 substantially covers the entire surface of the ceramic sprayed layer 12, but is thick on the undulating undulations and thinly attached to the undulating undulations. For this reason, the surface texture is smoother than the state in which only the ceramic sprayed layer 12 is formed, but the unevenness caused by the ceramic sprayed layer 12 is not completely buried, and the undulating unevenness is generally maintained. A rough surface having smooth irregularities can be formed. The final surface roughness R _max is typically about 20 to 150 μm. Further, it is desirable that the convex portions in the final smooth unevenness (the convex portion of the swell) are uniformly dispersed at a ratio of about 1 per 30 μm × 30 μm square to 60 μm × 60 μm square, for example. The convex portion referred to here is measured by two-dimensionally scanning the surface of the object to be measured over a length of 20 mm × width of 20 mm, and has a height of 70% or more of the height of the highest convex portion in this measurement region. The convex part which has is pointed out.

  For this reason, when the guide roller or the intermediate cylinder according to the present invention is in contact with the printing medium, it is in contact with only the smooth protrusion as described above without contacting the entire roller surface, and the surface is low. Due to the presence of the surface energy resin, the transfer of ink from the substrate is unlikely to occur, and the transferred ink may have a smooth uneven profile because the surface is due to the low surface energy resin. Together, it can be easily removed by lightly touching with a dry cloth material or the like.

  In addition, as described above, since the low surface energy resin layer 13 is combined with the ceramic sprayed layer 12 and applied to the surface, even if it is used for an extremely long period of time, the entire surface is worn away. It does not occur, and only wear occurs at a very small portion, that is, the convex portion of the undulating unevenness. For this reason, the low surface energy of the roll surface is maintained over a long period of time, and the characteristics are hardly deteriorated. The undulations are expressed as “undulations” for comparison with the concavo-convexs of finer pitches. However, the undulations are not visible at all. Therefore, the resin layer 13 on the surface of the projections is not visible. Even if the ceramic sprayed layer 12 is exposed and the ink adheres and reversely shifts at this portion, there is no problem in print quality.

  In the present invention, for example, as shown in FIG. 4, the roller includes a covering body 21 that is detachably wound on the roller body 20, and a metal plate material as a base material of the covering body 21. It is also possible to form a metal coating layer 23 similar to that described above and a composite coating film 26 composed of a ceramic spray layer 24 and a low surface energy resin layer 25 on this, and in this case, excellent as described above. In addition to being able to obtain functions and effects, it is advantageous in terms of cost since only the covering body 21 can be replaced without replacing the roller body 20 even in the event of some trouble on the surface. In the embodiment in which the covering body 21 is formed in this manner, the adhesiveness of the composite covering film 26 to the metal roller base material 10.22 is taken into consideration when bending stress is applied when the roller body 20 is mounted. In order to increase the thickness, it is desirable to form the metal spray layer 23 as much as possible.

  Furthermore, in the case of a covering, an aspect different from that described above may be more preferable depending on the type of roller to be applied. That is, the roller to which the cover according to the first aspect of the second invention as described above, or the roller of the first invention is applied, has a very high ink adhesion preventing effect and high durability when used in an actual machine. Has practically very great value. However, when applied to the impression cylinder, intermediate cylinder, guide roller, etc. of an existing printing press, the work is complicated and the cost is high, such as replacement of the roller and modification of the plate detaching mechanism. It also has a side. In the case of the covering according to the first aspect of the second invention, a metal plate material is used as the base material. The metal plate material has vertical and horizontal dimensions, hole processing for mounting, bending according to the shape of the roller to be mounted. After processing or the like is performed in advance, it is necessary to perform ceramic spraying and low surface energy resin coating, which inevitably requires batch processing with a cut plate, resulting in high costs. And as a roller to which such a covering is applied, there are many low-load rollers that do not apply printing pressure.

  From such a viewpoint, as a coating material for a roller whose conditions such as printing pressure and friction are mainly low, for example, as shown in FIG. In addition, as a hard base layer replacing the ceramic sprayed layer 23, a composite coating formed by adhering a plurality of inorganic fine particles such as ceramic powder and glass beads and comprising the inorganic fine particle layer 33 and the low surface energy resin layer 34 is provided. The thing of the 2nd aspect formed with the membrane | film | coat 35 can be considered. In the figure, reference numeral 36 denotes an adhesive layer for attaching inorganic fine particles to the base material 32.

  In the case of the covering according to the second aspect, although it is inferior to the covering according to the first aspect in terms of durability, it can be easily cut to a desired size using a scissors, a cutter or the like, and is bent for winding. This is advantageous in terms of workability and cost.

  The cover according to the second aspect is particularly advantageous as a cover for a low-load roller as described above. Furthermore, there is another point to be noted. That is, in a conventional printing apparatus using, for example, a blasted chrome-plated roller or the like in a high load portion (for example, a chrome-plated roller as an impression cylinder of an offset printing machine), the roller is contaminated during operation of the printing apparatus. Remarkably, it is necessary to frequently stop the operation and perform manual cleaning of the roller, and the roller of the low load portion has not been a problem because it is also cleaned at this time. In the case of a printing apparatus using as a high load portion a roller formed by winding the roller according to the first aspect of the present invention or the cover according to the second aspect of the present invention, the following low load portion roller is chrome plated on a general iron roller. If a conventional coating body such as a glass bead coating body is pasted on these, the fouling frequency of the high load roller will be significantly reduced. Contamination of the low-load portion roller becomes a problem, and there is a situation in which the operation must be stopped for cleaning the low-load portion roller or replacing the adhered cover. In the printing apparatus having a configuration in which the roller wound with the covering according to the first aspect is provided in the high load portion, the operability is extremely excellent by winding the covering according to the second aspect around the roller of the low load portion. This means that a printing apparatus can be provided.

  As described above, the covering of the present invention includes a hard base layer having fine irregularities on the surface and a low surface formed on the surface of the base layer without completely eliminating the irregularities on the flexible substrate. What is formed by a composite coating film comprising an energetic resin layer is widely included.

  Hereinafter, the present invention will be described in more detail based on embodiments.

First, a ceramic sprayed layer is formed on the surface of the flexible substrate by using a known ceramic spraying method such as a plasma jet spraying method. Ceramic materials include Al ₂ O ₃ , TiO ₂ , Al ₂ O ₃ —TiO ₂ , Cr ₂ O ₃ , ZrO ₂ , WC, WC—Co, Cr ₃ C ₂ , TiC and the like, or a mixture thereof, and further conductive. Examples thereof include composite coatings and cermets obtained by simultaneous thermal spraying of ceramics and metal in order to provide properties, but are not limited thereto. The ceramic material is selected from the following: adhesion strength with flexible substrate or sprayed metal, wear resistance, and the resulting ceramic sprayed layer has fine pores (continuous pores) of several μm to several tens μm with a porosity of 5-20. %, And the surface roughness is about R _max 30 to 150 μm. In general, white alumina (W—Al ₂ O ₃ ), gray alumina (G—Al ₂ O ₃ ) (Al ₂ O ₃ —TiO ₂ ), chromia (Cr ₂ O ₃ ), and the like are desirable.

In addition, it is desirable that the ceramic sprayed layer has fine pores (continuous pores) of several μm to several tens of μm with a porosity of 5 to 20%. When the porosity is less than 5%, the surface active resin may not sufficiently enter the ceramic sprayed layer, and the peelability may be increased. On the other hand, the porosity exceeds 20%. This is because the strength of the ceramic sprayed layer that becomes the skeleton structure of the composite coating may be lowered. Further, it is desired that the surface roughness has a R _{max of} about 30 to 50 μm when the low surface energy resin as described later is deposited on the surface of the ceramic sprayed layer. This is because it is in a range in which smooth irregularities having a necessary and sufficient size are easily formed.

  Further, the thickness of the ceramic sprayed layer is desirably about 30 to 200 μm, more preferably about 40 to 80 μm. That is, if the average film thickness is less than 30 μm, there is a possibility that a sprayed layer having uniform properties such as adhesion, strength and abrasion resistance cannot be obtained, while the average film thickness exceeds 200 μm. This is disadvantageous in terms of cost.

The surface roughness of the ceramic sprayed layer is generally desired to be about R _{max 30 to} 50 μm as described above, but the optimum surface roughness required for the final product varies depending on the type of roller.

  When the ceramic sprayed layer is formed in this way, the low surface energy resin is impregnated and coated from the upper part by a method such as spraying, dipping, brushing, roller coating, etc., and dried and solidified at a predetermined temperature, A low surface energy resin layer is formed on the surface of the thermal spray layer and in the pores. The low surface energy resin is not particularly limited as long as it has a low wettability with respect to the ink used and can form a film that is stable against a chemical used in the ink composition, preferably a high hardness film. However, usually, a silicone resin and a fluorine atom-containing resin are desirable, and a silicone resin is more desirable in terms of its hardness, workability, chemical stability, and the like.

  Silicone resins have a skeletal structure mainly composed of Si-O-Si bonds and organic groups, preferably methyl groups and / or phenyl groups, and more preferably methyl groups, after polymerizing and three-dimensionally after construction. And what is necessary is just to be able to form a stable cured film. The more methyl groups as the side chain, the lower the wettability with respect to the ink. However, from the viewpoint of improving the hardness, it is possible to increase the content of the cross-linked structure due to functional groups such as phenyl groups or vinyl groups. desired.

  In addition, the form at the time of construction is not particularly limited, for example, liquids such as oligomers and monomers, or solutions in which a resinous material is dissolved in an appropriate solvent, such as silicone varnish and silicone rubber Various known compositions that are classified and marketed can be appropriately selected and used. For example, a composition marketed as a varnish-type silicone release agent, or a composition similar thereto is available. Many are preferable from the viewpoints of workability and obtained film properties. As the silicone release agent, for example, a silicone mold or copolymer having a structure represented by the general formula (I) as a main component can be obtained as a commercial product.

(In the formula, each R independently represents a hydroxyl group, alkyl, aryl, alkenyl, halogen-substituted alkyl, halogen-substituted aryl, halogen-substituted alkenyl, preferably a methyl group, and n is 1 to 30000.)
However, as a matter of course, the silicone resin composition to be used is not limited to such a silicone release agent.

  Further, in such a silicone-based resin composition, if necessary, a filler such as silica fine particles for increasing the film hardness can be blended. It is necessary to have a particle size that can penetrate sufficiently.

  In addition, as the fluorine atom-containing resin, a thermoplastic fluorine atom-containing resin such as polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride or the like is used, which is applied after being suspended or swollen in an appropriate solvent and heated to a melting temperature or higher. It is also possible to use a dispersion processing method such as forming a film, but in order to form a film more reliably on the surface of the ceramic sprayed layer and in the pores, a small amount of hydroxyl groups and carboxylic acid groups are formed in the molecular chain. Thermosetting fluorine atom-containing resins that have functional groups such as, can be applied in liquid form, and are cured at room temperature or by crosslinking are desirable. For example, co-polymerization of fluoroethylene with acrylic acid and methacrylic acid Examples include coalescence.

  The thickness of the low surface energy resin layer to be formed on the surface of the ceramic sprayed layer is thicker on the wavy undulations of the ceramic sprayed layer as described above, while it is thinly attached to the wavy undulations of the ceramic sprayed layer. It is difficult to specify as However, it is desirable that the entire surface of the thermal spray layer be deposited at a thickness of about 0.5 to 20 μm so as to cover the entire surface substantially and maintain the undulations of the ceramic thermal spray layer.

  Therefore, the roller of the present invention can be suitably used as various rollers disposed on an impression cylinder or an intermediate cylinder in various printing machines. Specifically, for example, an impression cylinder / intermediate cylinder or an offset wheel in an offset printing machine. It can be suitably used as a guide roller in various rotary presses such as rotary presses (newspaper rotary presses, commercial offset rotary presses, foam rotary presses), gravure printing presses, flexographic printing presses, letterpress rotary presses, and the like.

  Next, the covering of the second invention will be described in detail. The covering according to the second invention is formed on a flexible substrate with a hard base layer having fine irregularities on the surface and a low surface energy property formed on the surface of the base layer without completely eliminating the irregularities. A composite coating film composed of a resin layer is formed.

  When relatively stressing pressure resistance, durability, etc. as a flexible substrate, it is necessary to use a metal plate such as an aluminum alloy plate or stainless steel plate, and when emphasizing ease of construction, price, etc. These include shrinkage due to absorption of water, solvent, etc., small expansion and contraction due to heat, some degree of flexibility to adhere well to the roller surface, and some degree of tearing, strength to withstand tension, and cutter From the viewpoint of easy cutting with a knife, scissors or the like, the use of a synthetic resin film or water-resistant treated paper is exemplified, but it is of course not limited thereto. Synthetic resin films include olefin-based films such as polyethylene and polypropylene, polyurethane-based films, polyester-based films, polyvinyl chloride or polyvinylidene chloride-based films, polyamide-based films, etc., and water-resistant treated paper includes resin-impregnated paper. , Water-resistant kraft paper, or other water-resistant non-woven paper is included, but it is of course not limited thereto.

  The thickness of the flexible substrate depends on the type of plate material or the type of roller, and is not particularly limited, but is about 0.1 to 0.5 mm, for example. Can be used.

  Examples of such a hard base layer having fine irregularities on the surface formed on the flexible substrate include a ceramic sprayed layer as described above or a coating layer formed of a plurality of inorganic fine particles. Further, as the low surface energy resin layer formed on the surface of the base layer without completely eliminating the unevenness, the above-described silicone resin or the like is used.

  Here, when a metal plate material is used as the flexible substrate and a ceramic sprayed layer is used as the hard base layer (first embodiment), the case relating to the roller of the first aspect of the invention and the metal product to be constructed are used. Since the roller base material is merely replaced with a metal plate material, the manufacturing method, manufacturing conditions, material and characteristic values of each layer are substantially the same, and detailed description thereof will be omitted. To outline only the manufacturing method, a metal plate material is first degreased and blasted by a well-known method to roughen the surface, and then a metal or metal alloy sprayed layer is formed as necessary. By using the ceramic spraying method, a ceramic sprayed layer is formed, and a low surface energy resin is impregnated and coated from the upper part, dried and solidified at a predetermined temperature, and a low surface is formed on the surface of the ceramic sprayed layer and in the pores. An energetic resin layer is formed to form a composite coating film layer.

  Next, the case where an inorganic fine particle layer is formed as a hard base layer will be described. As the inorganic fine particles to be used, various ceramic powders, glass beads, hard metal particles and the like are used, and various ceramic powders and glass beads are preferable. The size of these fine particles is not particularly limited, but those having an average particle size of about 30 to 200 μm and having a narrow particle size distribution are preferable, and the shape thereof is spherical or spherical. Is preferably from the viewpoint of not damaging the printing paper and the printing surface. These fine particles may be porous or substantially nonporous. In the case of a porous material, the adhesion of a low surface energy resin to be described later is good, but on the other hand, it is often weak in strength and expensive in price. In the case of a non-porous material, the adhesion of the low surface energy resin is reduced, but it is advantageous in terms of strength and price. Therefore, what is necessary is just to select suitably whether it is a porous thing or a non-porous according to the use conditions etc. of the roller in which the said covering body is constructed.

  In general, an adhesive is used to adhere such inorganic fine particles to a flexible substrate, in particular, a top of a substrate such as a synthetic resin film or water-resistant treated paper. The adhesive used has sufficient water resistance and solvent resistance, and has good adherence or wettability with the substrate and inorganic fine particles used and the low surface energy resin applied to the upper part. A thing is appropriately selected and used. Although not particularly limited, for example, acrylic adhesive, epoxy adhesive, chloroprene adhesive, cyanoacrylate adhesive, urethane adhesive, SBR adhesive, butyl rubber adhesive, SBS / SIS adhesive An adhesive or the like can be used. Further, when the base material is a thermoplastic synthetic resin film, a mode of direct adhesion by thermal welding of inorganic fine particles (partial melting of the synthetic resin film) is also conceivable.

When attaching such inorganic fine particles to the upper part of the substrate, the inorganic fine particles are attached so that the surface roughness after the attachment is an appropriate value, for example, R _max 30 to 150 μm, with the heads of the inorganic fine particles exposed. There is a need. That is, if the inorganic fine particles are completely buried in the adhesive layer or the like, the function as a covering for imparting a rough surface to the roller cannot be achieved. In addition, the inorganic fine particles adhered on the base material may be in a state of being laminated in two layers or more as long as they are uniformly adhered to the whole, but only one layer as shown in FIG. This is more preferable because it is less likely to cause defects such as peeling of fine particles and exhibits stable characteristics.

  After the inorganic fine particle layer is formed in this manner, a low surface energy resin layer is formed on the upper part of the inorganic fine particle layer by using a silicone resin or the like in the same manner as described above to obtain a composite coating film. The thickness of the low-energy resin layer on the inorganic fine particle layer is thin on the exposed head of the inorganic fine particles, while it is relatively thick on the valley formed between the particles. It is necessary to have a state in which smooth irregularities are left without completely eliminating the irregularities formed in the valleys. For example, it is desirable that the inorganic fine particles be attached to the head portion with a thickness of about 2 μm and to the valley portion with a thickness of about 5 to 10 μm. In addition, the kind of specific low energy resin, its application | coating method, etc. are the same as that of the above. In order to improve the adherence between the low-energy resin and the inorganic fine particles (and the adhesive or base material partially exposed as the valleys), for example, chemical pretreatment using a known coupling agent or the like Various physical pretreatments can also be performed.

The covering according to the second aspect of the second invention thus obtained also has smooth irregularities in the final surface properties, but the surface roughness R _max is about 20 to 150 μm. It is desirable.

  In the case of the covering according to the second aspect of the second aspect of the present invention, a synthetic resin film or water-resistant treated paper can be used as the base material. For example, for a long base material wound in a roll shape, It can be said that inorganic fine particle coating and low energy resin coating are performed, and high production efficiency can be achieved. Then, it can be easily cut and applied to a necessary size for each of the pressure cylinder, intermediate cylinder, guide roller and the like to be wound.

  As a method of attaching the covering of the second invention to the roller body, a method using screwing or adhesion, or a method in which the roller body is provided with a clamping device or a winding device having a winding shaft can be employed. In the case of the covering according to the second embodiment, it can be easily attached using a double-sided adhesive tape or the like.

  The structure of the roller formed by winding the covering of the second invention as described above or the structure of the covering is not limited to the field of printing presses, but is similar to the ink in printed matter as described above. It is obvious that a roller or a surface coating body for treating a film-like body to which a substance has been applied on its surface can be suitably used as a roller that is not easily contaminated by these adhesive transfer substances and has high durability. is there. Examples of applications other than the impression cylinder, intermediate cylinder, or guide roller in a printing machine include, for example, rollers in a pressure-bonding / transfer system of a printing object in various copying machines, but of course, the invention is not limited thereto. Absent.

  In a printing machine using an impression cylinder or an intermediate cylinder formed by winding the covering of the second invention, it is preferable to have a cleaning device for these impression cylinders or the intermediate cylinder. Such a cleaning device only needs to have a cleaning body that can come into contact with the surface of the impression cylinder or the intermediate cylinder in a portion that does not interfere with the transfer path of the printing medium or other apparatus configuration. The cleaning body may be configured to be in contact with the roller surface only at the end of printing, or may be configured to be appropriately contacted / separated during printing work. The cleansing body can provide a sufficient cleaning effect even if it is dry, but in order to obtain a higher cleaning effect, a wet body impregnated with a solvent is desired. In addition, a cleaning body can be comprised with flexible and absorptive materials, such as felt, a nonwoven fabric, a cloth material, and a paper material. Further, it is possible to adopt a configuration in which the roller surface is fixedly contacted or rotationally contacted.

  Hereinafter, the present invention will be described more specifically with reference to examples.

Reference example 1
The surface of a metal plate made of SUS304 having a thickness of 0.3 mm was roughened by degreasing and blasting. At this time, the surface roughness R _max was about 10 μm.

Thereafter, a Ni—Cr alloy having a powder particle size of 10 to 55 μm is used, and a Ni—Cr sprayed layer having a film thickness of about 30 μm is formed on the cylinder surface by plasma spraying, followed by G-Al having a powder particle size of 10 to 44 μm. Plasma spraying was similarly performed using ₂ O ₃ to form a ceramic sprayed layer having a thickness of about 70 μm. The surface roughness R _max of this ceramic sprayed layer was about 40 μm, and was a rough surface wavy with very sharp protrusions as shown in FIG. The ceramic sprayed layer had pores with a size of 0.1 to several tens of micrometers, and the porosity was about 16%. The coated body thus obtained was wound around the surface of a ductile cast iron metal cylinder to obtain an impression cylinder. This impression cylinder was subjected to the following printing test.

Example 1
After performing the same procedure as in Reference Example 1, 100 parts of a silicone-based resin release agent (KS776L manufactured by Shin-Etsu Chemical Co., Ltd.), 300 parts of toluene and a curing catalyst (Shin-Etsu Chemical ( A solution obtained by mixing and stirring 1 part of CAT-PL8 manufactured by Co., Ltd. was impregnated and applied by a spray method, and then dried and solidified in a drying furnace at 150 ° C. for 1 hour to form a silicone resin film on the surface of the ceramic sprayed layer. This silicone-based resin film completely closes the communicating pores of the ceramic sprayed layer, and on the surface of the sprayed layer, it adheres thickly to the concave portions of the wavy undulations and thinly covers the convex portions and completely covers the entire surface. The film thickness was in the range of 2 to 20 μm although it varied depending on each part. The surface roughness R _max after the formation of the silicone-based resin film was about 30 μm, and was a rough surface having smooth irregularities as shown in FIG. 1 or FIG. The impression cylinder thus obtained was subjected to the following printing test in the same manner as in Reference Example 1 and further to the following scratch resistance test.

Printing test 1
The impression cylinder created in Reference Example 1 and Example 1 above is attached to an offset printing machine (manufactured by Komori Corporation, Kikuzen Duplex Machine), and red ink (manufactured by Toyo Ink Co., Ltd., High Plus) is used. Thus, double-sided printing was performed on 30,000 coated papers. For comparison purposes, a similar printing test was also performed using an ordinary impression cylinder polished after chromium plating. As a result, when the impression cylinder of Reference Example 1 was used, the ink stain on the impression cylinder surface compared to a normal chrome-plated impression cylinder because the impression cylinder surface had a grainy uneven shape. Although the number of paper passes increases, the stain becomes more and more serious, and when it exceeds about 3000 sheets, the back stain of the printed matter due to the ink stain on this impression cylinder becomes noticeable, and it turns out that it cannot be used practically. did. In addition, by removing the ink on the solid part of the printed matter with the sharp protrusions on the surface of the ceramic sprayed layer, countless fine voids (white spots) of several μm can be obtained, and the clearness of the printing is clearly visible even visually. It was inferior.

  On the other hand, in the case of the impression cylinder of Example 1, even after printing 30,000 sheets, only a very small amount of ink is adhered to the fine convex portions on the impression cylinder surface. Further, even if the number of sheets passed through was increased, there was almost no change and the ink adhesion did not grow. Furthermore, ink is hardly transferred to the protrusions on the surface of the impression cylinder even at the part that contacts the solid part of the printed matter, and the amount of missing ink is very small and small, so that there is almost no obstacle to the print quality of the printed matter. Good prints could be obtained.

  Further, after the printing test was completed, an attempt was made to remove the ink adhering to the surface of the impression cylinder. In the case of Example 1, the ink slightly adhered could be completely removed by lightly wiping with a dry cloth. In the case of the control chrome-plated impression cylinder, it is difficult to remove it by such treatment, and it cannot be removed unless it is washed with white kerosene. Even if an organic solvent is used, the ink that has entered the fine recesses on the surface cannot be completely removed, and the ink that has dissolved in the solvent and has flowed into the pores is difficult to clean. It was.

Scratch resistance test When the surface hardness of the impression cylinder obtained in Example 1 was examined by a pencil hardness test, it was 4H. Moreover, even if the iron tool (driver) was strongly pressed and rubbed, it was once placed on the impression cylinder. Has a metal-colored scratch mark, but when it was wiped with a fingertip, the mark disappeared cleanly. That is, the surface of the impression cylinder of Example 1 was not scratched, but the tool was shaved and the wrinkles adhered to the impression cylinder. This means that only the fine projections on the surface of the impression cylinder are in contact with the tool, and this projection has an extremely thin silicone-based resin film on the ceramic sprayed layer with high wear resistance. This is considered to be because the influence of the hardness of the sprayed layer is strongly generated. In this projection, the silicone-based resin film is in direct contact with the tool, but it is only in contact as a very fine point and not as a surface. The silicone resin film is only worn and removed only at the protrusions, and the silicone resin film is not peeled off as a surface.

  On the other hand, for comparison, the silicone resin used in Example 1 or some silicone resins disclosed in Japanese Patent Application Laid-Open No. 62-94392 are applied to the cast iron cylinder surface having a smooth surface property before blasting. When the surface hardness of the test body obtained by direct coating was examined by a pencil hardness test, it was B to 2H, and it was easily scratched only by lightly rubbing with a hard tool or the like.

Reference example 2
The surface of the roller made of an aluminum alloy pipe was degreased and blasted to roughen the surface. At this time, the surface roughness R _max was about 35 μm. Thereafter, a Ni—Cr alloy having a powder particle size of 10 to 55 μm is used, and a Ni—Cr sprayed layer having a film thickness of about 30 μm is formed on the cylinder surface by plasma spraying, followed by G-Al having a powder particle size of 10 to 44 μm. Plasma spraying was similarly performed using ₂ O ₃ to form a ceramic sprayed layer having a thickness of about 70 μm. The surface roughness R _max of this ceramic sprayed layer was about 40 μm, and was a rough surface wavy with very sharp protrusions as shown in FIG. The ceramic sprayed layer had pores with a size of 0.1 to several tens of micrometers, and the porosity was about 16%. The guide roller thus obtained was subjected to the following printing test.

Example 2
After performing the same procedure as in Reference Example 2, 100 parts of a silicone-based resin release agent (KS776L manufactured by Shin-Etsu Chemical Co., Ltd.), 300 parts of toluene and a curing catalyst (Shin-Etsu Chemical ( A solution obtained by mixing and stirring 1 part of CAT-PL8 manufactured by Co., Ltd. was impregnated and applied by a spray method, and then dried and solidified in a drying furnace at 150 ° C. for 1 hour to form a silicone resin film on the surface of the ceramic sprayed layer. This silicone-based resin film completely closes the communicating pores of the ceramic sprayed layer, and on the surface of the sprayed layer, it adheres thickly to the concave portions of the wavy undulations and thinly covers the convex portions and completely covers the entire surface. The film thickness was in the range of 2 to 20 μm although it varied depending on each part. The surface roughness R _max after the formation of the silicone resin film was about 30 μm, and was a rough surface having smooth irregularities as shown in FIG. The guide roller thus obtained was subjected to the following printing test in the same manner as in Reference Example 2.

Printing test 2
The guide rollers created in Reference Example 2 and Example 2 above are each mounted on a foam press (MVF18, manufactured by Miyakoshi Co., Ltd.), and color pictures are printed with black, indigo, red and yellow process inks. On the other hand, continuous 40 hours were performed. For comparison, a similar printing test was also performed using a knurled roll with a normal aluminum alloy roll as a guide roller.

  As a result, when the guide roller of Reference Example 2 was used, good slip resistance was obtained, and the surface was a grainy uneven shape, so that a comparative knurled aluminum alloy guide was used. Compared with the roller, the ink stain was less and the cleaning frequency was about 1/2. However, as the number of papers passed increased, the stain became more serious, and when it exceeded about 10 hours, it was caused by the ink stain on this guide roller. As a result, it was found that the printed matter was noticeably soiled and could not be used practically.

  On the other hand, in the case of the guide roller of Example 2, even after 40 hours of printing, only a very small amount of ink adheres to the fine convex portions on the surface. Even if the number of sheets was increased, there was almost no change and the ink adhesion did not grow. For this reason, the stain of the printed matter that can be confirmed with the naked eye does not occur even after 40 hours of continuous operation, and a printed matter with good print quality can be obtained without cleaning the guide roller in the middle.

  In addition, after the printing test was completed, an attempt was made to remove the ink adhering to the surface of the guide roller. In the case of Example 1, the ink slightly adhering to the inside of the printing apparatus could be completely removed by simply wiping with a dry cloth. It was suggested that a dry type cleaning device for the guide roller provided in the above is sufficient. On the other hand, in the case of the comparative control, it is difficult to remove by such treatment, and it cannot be removed without washing with white kerosene, and the cleaning device provided in the printing apparatus also uses an organic solvent. It was confirmed that a wet cleaning device was necessary. Further, in the case of the guide roller of Reference Example 2, when washing is performed using such an organic solvent, the ink that has dissolved in the solvent and has flowed infiltrates into the pores, so that the cleaning is very difficult to perform. It was concluded that a sufficient cleaning effect could not be obtained even with a conventional wet cleaning apparatus using an organic solvent.

Example 3
A low surface energy resin film is mixed and stirred with 100 parts of a silicone-based resin release agent (KNS316 manufactured by Shin-Etsu Chemical Co., Ltd.), 100 parts of toluene and 3 parts of a curing catalyst (CAT-PL56 manufactured by Shin-Etsu Chemical Co., Ltd.). An impression cylinder was produced in the same manner as in Example 1 except that it was formed using the prepared solution, and a printing test and a scratch resistance test were conducted in the same manner as described above. As a result, excellent results were obtained as in Example 1.

Examples 4-7
KR2046 (Example 4), X-40-2141 (Example 5), X-41-9710H (Example 6) or X-40-201 (Example) 7) Except for using 7 (made by Shin-Etsu Chemical Co., Ltd.), an impression cylinder was prepared in the same manner as in Example 1, and a printing test was performed in the same manner as described above. Although there was a slight difference in the degree of soiling on the impression cylinder surface after the printing test, good printing quality was maintained as in Example 1 and the impression cylinder after completion of printing. The soil was completely removable by a dry method.

Reference example 3
A test piece was prepared by coating a synthetic resin film (polypropylene) having a thickness of 100 μm with a silicone resin release agent (KNS316, manufactured by Shin-Etsu Chemical Co., Ltd.) to a thickness of 3 μm.

Reference example 4
A glass bead having an average particle diameter of 200 μm is bonded to the same synthetic resin film as in Reference Example 3 with an adhesive (acrylic) so that the glass bead covers the entire surface of the film and the glass bead is evenly dispersed. Produced. The surface roughness of the obtained test piece was R _max 140 μm.

Example 8
After the glass beads were adhered to the film surface by the same method as in Reference Example 4, the same silicone release agent as used in Reference Example 3 was coated from the top of the glass bead layer. Silicone mold release agent is relatively thin, about 2 μm at the head of the glass beads, while it is relatively thick, about 5-10 μm, at the valley between the glass beads. R _{max was} 133 μm.

  The test pieces of Reference Examples 3 and 4 and Example 8 thus obtained were subjected to the following gum tape peeling test and printing test.

Gum Tape Peeling Test In order to confirm the adhesion of the test piece surfaces of Reference Examples 3, 4 and Example 8, a commercially available gum tape (width 25 mm × length 100 mm) was applied to the test piece surface and peeled off. The required force was measured.

  As a result, in the initial stage, Example 8 and Reference Example 3 were in a state where the gum tape hardly adhered (peeling force less than 5 g), but Reference Example 4 required a force of 110 g. The peel strength of the comparative polypropylene resin film itself was 480 g.

  Next, in order to examine the change with time of the peeling force due to surface wear, each test piece was attached to a roll having a diameter of 100 mm with a double-sided adhesive tape so that the silicone resin layer or the glass bead layer faced the surface side. The coated paper was attached with a winding angle of 90 ° and a tension force of 200 g / cm, the coated paper side was fixed, and the roller was rotated to perform a sliding wear test. In addition, the paper which apply | coated the ink regularly was used for the coated paper surface. And the above-mentioned gum tape peeling test was implemented for every predetermined rotation speed. FIG. 9 shows the relationship between the cumulative number of rotations obtained for each test piece and the peel force.

  As is clear from the results shown in FIG. 9, the test piece of Reference Example 3 has significantly less peeling force than that of Reference Example 4 while the silicone-based resin release agent is present on the surface, but it has less cumulative rotation. The release agent wears and drops at a few (about 1000 revolutions), and the peel force increases rapidly (that is, the stain resistance performance decreases). In addition, the reference example 4 has an effect of forming an uneven surface with glass beads in the initial stage compared to the resin film only as a comparison, and the peel force is small, but the cumulative rotational speed is large. As a result, ink and paper powder adhere to and accumulate on the concave surface, and the peeling force increases (decrease in stain resistance). On the other hand, in the case of Example 8, when the peel force is almost zero in the initial stage, the peel force increases slightly as the cumulative rotational speed increases, but the increase is very gradual, and the anti-contamination performance over a long period of time. To maintain. This is because the release of the release agent is only the convex part of the glass beads, and the release agent in the concave part is not worn off and remains as it is, so that ink and paper powder do not adhere and accumulate in the concave part. It seems that this does not lead to a decrease in the anti-contamination performance as in the case of.

Printing test 3
The test pieces prepared in Reference Examples 3 and 4 and Example 8 were wound on the intermediate cylinder of a JP-40 double-sided printing machine manufactured by Akiyama Printing Co., Ltd. using double-sided adhesive tape and operated on the actual machine. A comparative test was performed. The paper used was coated paper, the ink was made by Toyo Ink Co., Ltd., High Plus, and the plate was printed on a test plate with a pattern with many solid parts.

  As a result, when the sample of Reference Example 3 was used, the surface was naturally high in ink repellency at the initial stage, but because of the high friction coefficient of the surface, the paper separation between the intermediate cylinder surface and the paper surface was very good. Absent. For this reason, when paper is transferred from the first intermediate cylinder to the second intermediate cylinder to the impression cylinder, a slight misalignment occurs between the intermediate cylinder and the paper. The print surface was scratched and smudged. In addition, with this test piece, the surface silicone release agent layer was worn and dropped as the number of printed copies increased, and the ink adhesion to the sheet surface suddenly increased in about one month, and the scratches and smudges on the printed matter were also extremely high. It became conspicuous and did not endure practical use.

  Moreover, when the thing of the reference example 4 is used, since an intermediate | middle cylinder becomes considerably dirty by printing about 5000-10000 sheets, and this becomes a double of a printed matter and dirt, it is impossible to operate a long-lasting printing press continuously, It is necessary to stop the machine and clean it with gasoline. This test piece is effective in terms of reducing the friction with the paper because the contact with the printing surface is a point contact, but the glass beads themselves have almost no ink repellency, especially the ink deposited and deposited in the recesses.・ Contaminants such as paper dust are very difficult to clean. The time and labor required for these cleaning removals accounted for a large proportion of the printing process. Also, dirt that could not be removed by each washing was accumulated in the recesses and the ink repellency was further lowered, so that a new sheet had to be replaced in 1 to 3 months. Further, deterioration of the sheet due to the solvent used for cleaning was a matter that cannot be ignored.

  On the other hand, when the sample of Example 8 was used, the stain on the intermediate cylinder surface was very small, and even with continuous printing of 60,000 sheets per day, the printed matter was not stained or doubled due to the intermediate cylinder stain. Slightly adhering ink stains could be easily removed by wiping with a cloth soaked in cleaning oil, and the residue on the recesses was very small. In other words, there is a great effect in reducing the occurrence of defective prints due to smearing of the intermediate cylinder, improving productivity by reducing the frequency of washing, and reducing the work load. It has become possible.

The figure which shows typically the cross-sectional structure in one embodiment of the impression body or intermediate | middle cylinder covering which concerns on this invention, The figure which further expands and schematically shows the cross-sectional structure of the impression cylinder or intermediate cylinder covering according to the present invention, The figure which shows typically the cross-section in the manufacturing process of the impression cylinder or intermediate | middle cylinder covering which concerns on this invention, Sectional drawing which shows typically the state which winds the 1st embodiment of the coating body for impression cylinders or intermediate | middle cylinders which concerns on this invention to the to-be-printed body pressurization and transfer roller, The figure which shows typically the cross-sectional structure of the 2nd embodiment of the intermediate | middle cylinder or guide-roller covering body which concerns on this invention, The figure which shows the schematic structure of the printing mechanism in an offset printing machine, Schematic diagram explaining ink stains on the impression cylinder during double-sided printing in offset printing, The figure which shows schematic structure of the printing and transfer mechanism of the to-be-printed body in another offset printing machine (rotary press), The graph which shows the time-dependent change of the adhesion characteristic of the various coating body surfaces obtained in the Example of this invention.

Explanation of symbols

1 ... plate cylinder,
2 ... Rubber body,
3 ... impression cylinder,
4 ... Substrate,
5 ... Ink image,
6, 8 ... transfer ink image,
7 ... Guide roller
10, 22 ... metal roller base material,
11, 23 ... Metal sprayed layer,
12, 24 ... Ceramic sprayed layer,
13, 25, 34 ... low surface energy resin layer,
14, 26, 35 ... composite coating film,
20 ... Roller body,
21 ... covered body,
32 ... Base material (synthetic resin film or water-resistant treated paper),
33 ... inorganic fine particle layer,
36: Adhesive layer.

Claims (6)

  In a printing apparatus, a cover that is detachably wound around substantially the entire circumferential surface of a guide roller or an intermediate cylinder that is arranged in a press-bonding / transfer system for a print-subject that is to be pressed against a printing element and then transferred. A hard base layer having fine irregularities on a surface of a flexible substrate and a low surface energy resin layer formed on the surface of the base layer without completely eliminating the irregularities A guide roller or intermediate cylinder covering, wherein a composite covering film is formed, and the surface texture thereof has a surface roughness Rmax of 20 to 150 μm and has smooth unevenness.   The covering according to claim 1, wherein the low surface energy resin is a silicone-based resin.   A hard base layer formed by adhering inorganic fine particles such as ceramic powder or glass beads on a substrate made of a synthetic resin film or water-resistant treated paper, and a low surface energy resin layer formed on the surface of the base layer The covering according to claim 1 or 2, wherein a composite covering film comprising:   The covering according to claim 1, wherein the covering is an intermediate cylinder covering for an offset printing press.   The covering according to claim 1, wherein the covering is a guide roller covering for a rotary printing press.   A composite coating comprising a hard base layer having fine irregularities on the surface and a low surface energy resin layer formed on the surface of the base layer without completely eliminating the irregularities is formed on the flexible substrate. The surface texture is a surface roughness Rmax of 20 to 150 μm and has smooth unevenness. 6. A printing comprising a guide roller or an intermediate cylinder wound with a covering according to claim 1. apparatus.

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