JP2001287334A - Method and apparatus for stencil printing and original plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel method and a novel apparatus for stencil printing by dispensing with a preparation and a discard of thermal stencil paper by providing a recyclable stencil printing original plate. SOLUTION: The stencil printing original plate comprises a many finely perforated part formed in a sectional direction of a polymer material contracted in response to an electrical stimulus or a film containing, for example, a polypyrrole, a polythiophene or a polyaniline as a main component. The method for stencil printing comprises the steps of selectively extending a perforated part by giving the electrical stimulus so as to reproduce a desired image on a surface of the original plate, and transferring an image forming material onto a recording medium by passing the forming material from the extended perforated part. Thus, the stencil paper can be discarded from a rotary stencil printer by constituting an outer peripheral surface of a plate cylinder of the printer of the original plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing method and apparatus, and more particularly, to a stencil printing method and a stencil printing method using a novel master having a large number of fine perforations which expand or narrow in response to an electrical stimulus. Related to the device.

[0002]

2. Description of the Related Art Using a heating means such as a thermal head for generating dot-like heat in accordance with character image information converted into an electric signal, a thermoplastic resin film of a heat-sensitive stencil sheet is melt-punched to form a stencil. 2. Description of the Related Art A printing device that winds around a plate cylinder and allows ink to pass through a perforated portion to transfer to printing paper has already been widely used as a high-speed printing and low running cost digital printing machine.

However, such a conventional digital printing machine needs to include a heat-sensitive stencil sheet storing member, a conveying member, and a plate discharging member. In addition, when printing a new document, it is necessary to discard the used base paper. Usually, the used stencil is temporarily stored in a plate discharge box provided in the printing press, and is discarded when the plate discharge box is full. It took time and effort. That is, in the conventional stencil printing, the stencil sheet used as the stencil cannot be recycled or reused.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reproducible stencil printing plate, which eliminates the need for preparing and discarding a heat-sensitive stencil sheet, and solves the above-mentioned problems of the prior art. It is an object of the present invention to provide a stencil printing method and apparatus.

[0005]

According to the present invention, the object is to form a large number of fine perforations in a cross-sectional direction of a film made of a polymer material which contracts in response to an electric stimulus,
The stimulus is applied to the film so as to reproduce a desired image, the perforated portion is selectively expanded, and the image forming material is transferred from the expanded perforated portion onto a recording medium to transfer the image forming material onto a recording medium. And a stencil printing method.

That is, in the printing method of the present invention, a stencil printing plate is a film made of a polymer material which contracts in response to an electric stimulus, and a large number of fine perforations are previously formed in the cross-sectional direction thereof. Prepare the original, make the original plate by applying the stimulus so as to reproduce the desired image on the film and selectively expand the perforated part, and make the image forming material from the perforated part of the perforated original plate , And transferred onto a recording medium.

Thus, according to another aspect of the present invention, there is provided a stencil having a number of fine perforations formed in a cross-sectional direction of a film made of a polymer material which contracts in response to an electric stimulus. A printing master is provided.

[0008] The film constituting the stencil printing plate of the present invention has a property of contracting in response to an electrical stimulus when applied thereto. Therefore, in response to the stimulus, the surface of the film contracts and the perforated portion expands, so that the image forming material can be easily passed. The size of the perforated portion may be a size that does not allow the image forming material to easily pass in a state where the stimulus is not given, and specifically, such as the viscosity of the image forming material such as printing ink. It can be appropriately selected according to the physical properties.

Further, the polymer material constituting the film of the stencil printing plate of the present invention may have a property of expanding in response to the removal of the electrical stimulus or the decrease in the degree of the electrical stimulus. preferable. In this case, the surface of the film expands and narrows the perforated portion, thereby impeding the passage of the image forming material. Accordingly, it is advantageous in that the passage of the image forming material can be prevented irrespective of physical properties such as viscosity.

As described above, the film perforated portion of the original plate of the present invention has a state in which ink can be reversibly passed and a state in which ink cannot be passed by repeating application and removal of an electrical stimulus.
In other words, an open state and a closed state are possible.
Therefore, once the original plate is made and used for printing, all the perforated portions can be closed to prepare for the next printing, that is, it can be reproduced. To close the perforated part of the original and regenerate it,
The electrical stimulus that causes the polymer material constituting the film to contract may be removed or the degree of the electrical stimulus may be reduced.

As described above, in the present invention, the original plate can be used repeatedly, so that the conventional disposable heat-sensitive stencil sheet is not required. Accordingly, if the original plate of the present invention is applied to a plate cylinder of a rotary copying machine, any apparatus for handling a stencil sheet from a conventional rotary copying machine with a plate making function can be eliminated.

Thus, according to still another aspect of the present invention, there is provided an ink-permeable cylindrical plate cylinder provided with the stencil printing plate of the present invention on its outer peripheral surface and driven to rotate around its own central axis, Plate making means for applying an electric stimulus to the original so as to reproduce a desired image to selectively expand a perforated portion of the original, and provided in contact with an inner peripheral surface of the plate cylinder; Squeegee means for extruding the image forming material supplied to the outside of the plate cylinder; and at least one of the plate cylinder and the print sheet in a state in which the print sheet moves in synchronization with the rotation of the plate cylinder. There is provided a stencil printing apparatus comprising: a pressing mechanism for pressing one of the plates to bring them into close contact with each other and transferring the image forming material from the inside of the plate cylinder to the printing paper via the expanded perforated portion of the original plate. The stencil printing apparatus further applies an electrical stimulus to the original to narrow the expanded perforations of the original by expanding the polymer material of the original to facilitate reproduction of the original. Means may be provided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The polymer material constituting the film of the original plate of the present invention can be selected from materials that contract reversibly when an electric stimulus is applied, and examples thereof include polypyrrole, polythiophene, and polyaniline. . These polymer materials can be synthesized by a method such as oxidation polymerization, electrolytic polymerization, or polycondensation. For example, polypyrrole can be obtained by electrolytic polymerization of a pyrrole monomer in an aqueous solution of tetraethylammonium perchlorate. The polymer material may be composed of the above-mentioned polymer component alone or may be a mixture thereof.
Or it may be a copolymer.

Further, the polymer material may be mixed with another polymer or may be a copolymer in order to improve the electrical stimulus responsiveness and the expansion and contraction rates. For example, a polar polymer such as polyvinylpyrrolidone, Ethylene-vinyl alcohol copolymer, polydioxolan, polyvinyl acetal,
Polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinyl acetate, melamine resin, polyamide, polyimide, polyacrylamide, polyacrylonitrile,
Polyethylene imine, polyester, polycarbonate, polyurethane, polysulfoxide, polyphenylene sulfide, polyoxazoline, polyvinyl carbazole, and the like may be used.

The polymer material may include an inorganic compound,
Organic compounds, metal powders, metal oxides, pigments, dyes and the like may be contained, for example, carbon black, titanium oxide, calcium carbonate, silicon carbide, anthraquinone pigments, phthalocyanine pigments, azo pigments, cyanine dyes, Polymethine dyes are preferably used.

The original plate film of the present invention can be formed by a known method using the above-mentioned polymer material. For example, a method of dissolving a polymer which is a main component of the film in a solvent, applying the composition onto a non-adhesive support, and drying it, a method of producing by polymerizing a monomer on the non-adhesive support, A method of producing a polymer film by a stretching device is exemplified. The thickness of the film is 0.5
１０００1000 μm, preferably 1-500 μm. If the thickness of the film is less than 0.5 μm, the handleability and strength are inferior. If the thickness exceeds 1000 μm, a large amount of electric energy is required for opening and closing the perforated portion, and the image forming material may be difficult to pass. .

The fine perforations formed in the film of the present invention can be formed by using a perforation device such as an excimer laser irradiation device or an electron beam irradiation device so that the image forming material used for stencil printing does not substantially pass through. Can be provided in a state in which the hole is previously penetrated in the cross-sectional direction of the film. The pore size when the film shrinks, that is, when the perforated portion is opened is usually in the range of 0.1 μm to 500 μm. When the thickness is less than 0.1 μm, the image-forming material hardly passes through, and when the thickness is 500 μm or more, a printed image obtained on a recording medium has low resolution, resulting in an unclear image.

The original plate of the present invention may be constituted by the above-mentioned film alone, but may be constituted by laminating the film on a porous support in order to maintain mechanical strength. Examples of the porous support include Manila hemp, pulp, mitsumata, mulberry,
Thin paper, nonwoven fabric, screen gauze, and the like using natural fibers such as Japanese paper, synthetic fibers such as polyester, nylon, vinylon, and acetate, metal fibers, and glass fibers alone or in combination.

The original plate of the present invention can be made by applying an electrical stimulus to the film. The reproduction of the plate-making master can be achieved, for example, by removing the electrical stimulus applied to the film or reducing the degree of the electrical stimulus.

The plate making of the original plate of the present invention can be performed, for example, by the following method. That is, the original plate is sandwiched between the two electrodes such that one surface of the film is brought into contact with the needle-like electrode and the other surface of the film is brought into contact with the planar electrode such as a metal plate. Next, when a current is applied to the electrode, the film near the electrode shrinks, and as a result, the size of the hole in the perforated portion near the electrode is enlarged, so that plate making can be performed.

According to the present invention, after the original plate is made as described above, printing can be performed according to a general stencil printing method. For example, an image forming material such as ink is placed on one surface of the original plate, a recording medium such as printing paper is superimposed on the other surface, and the image forming material is pressed, depressurized, a pressing mechanism such as a squeegee. With the help of a mechanism that generates electrostatic force, magnetic force, and the like, the image forming material can be transferred from the expanded perforated portion of the original plate to the recording medium with the aid of a press.

The image forming material includes a liquid printing ink, a solid powder, an image forming precursor, and the like. Examples of the liquid ink include oil-based inks, aqueous inks, water-in-oil emulsion inks, oil-in-water emulsion inks, and heat-meltable inks. Solid powders include powder toners, magnetic powders, and the like. Examples of the image forming precursor include a reactive dye and a chelate color former.

Examples of the recording medium include printing paper, plastic sheets, plate materials such as wood and metal plates, and a substance containing a reactant of the image forming precursor.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on specific examples with reference to the drawings, but the present invention is not limited to these specific examples.

FIG. 1 is a schematic perspective view showing an original plate used in the present invention in a state where a perforated portion is closed. Numeral 1 denotes the original plate, and the original plate is a polymer that contracts in response to an electric stimulus. It is composed of a single film made of a material, and has a large number of fine perforations 1a formed in its cross-sectional direction. In this state, the opening of the perforated portion 1a has a sufficiently small size to prevent the passage of the image forming material.

FIG. 2 is a schematic perspective view showing a state where the electric stimulus is continuously applied to the surface of the original 1 in FIG. 1 or immediately after the electric stimulus is applied. In this state, the periphery of the perforated portion 1b is shown. The perforated portion 1b opens because the film surface shrinks,
The image forming material can pass through the perforated portion 1b.
Therefore, the image forming material is placed on one surface of the original 1 and the recording medium is brought into contact with the other surface, and in this state, the image forming material is passed in the direction of the recording medium, so that the perforated portion 1b is formed.
The image forming material can be transferred to the recording medium via the. Thus, it is clear that the stencil printing plate precursor of the present invention can be used in various stencil printing machines instead of the stencil sheet conventionally used by selectively opening and closing the perforated portion in accordance with a desired image. The original plate 1 is fixed by stretching each side to a frame or fixed to a plate cylinder of a rotary copying machine by an appropriate fixing means so that the dimensions do not change due to contraction and expansion of the polymer material. Is preferred.

Further, when the electrical stimulus of the original 1 of FIG. 2 is removed or the degree of the electrical stimulus is reduced, the original 1 returns to the state of FIG. 1 and the image forming material passes through the perforated portion 1a. Is prevented, and the original 1 is reproduced. As described above, since the original plate 1 can reversibly repeat contraction and return, the perforated portion opens and closes reversibly, and can be used repeatedly for plate making and printing.

FIG. 3 is a schematic cross-sectional view showing an example of a rotary stencil printing machine for carrying out the method of the present invention, which is provided with a cylindrical plate cylinder 2 driven to rotate about its own central axis. . The plate cylinder 2 is provided on the outer peripheral surface of an ink-permeable cylindrical porous member similar to that used in a conventional apparatus, as shown in FIG.
And an original 1 as shown in FIG. Further, a squeegee roller 3 is provided inside the plate cylinder 2 so as to be in sliding contact with the inner surface of the cylindrical porous member, and is driven to rotate in the same direction as the plate cylinder 2 during printing.

Further, the apparatus shown in FIG. 3 includes an electric stimulus applying means 5 arranged in contact with the original 1 on the outer peripheral surface of the plate cylinder 2. The electrical application means 5 is configured such that one electrode is a needle-shaped electrode and the other electrode is in contact with the inner surface of the plate cylinder 2 while sliding. Since the electrical stimulus applying means 5 is disposed so as to be movable in parallel with the central axis of the plate cylinder 2, the electrical stimulus is applied to the original 1 so as to reproduce the image in accordance with the image information previously converted into an electrical signal. Can be given.

In order to perform printing with the apparatus shown in FIG. 3, first, a DC voltage is applied to the electrical stimulus applying means 5 so as to reproduce a desired image on the original 1 while rotating the plate cylinder 2 appropriately. Then, since the image-corresponding portion of the original 1 to which the electric stimulus has been applied contracts, a perforated portion around it is opened, and the printing ink 6 supplied into the plate cylinder 2 can pass through the perforated portion. And the plate making of the master 1 is performed. Here, when the printing paper 7 is conveyed while being pressed against the original plate 1 by the press roller 4 while being synchronized with the rotation of the plate cylinder 2, the printing ink 6 is pushed out of the plate cylinder 2 by the squeegee roller 3 and opened. Since the image passes through the original plate 1 and is transferred onto the printing paper 7 through the perforated portion, a printed image 8 can be obtained. In the apparatus shown in FIG. 3, an electric stimulus is applied to the original 1 in a pulsed manner from the electric stimulus applying means 5, and as a result, the perforated portion is instantaneously opened.
Start closing with the rotation of. Therefore, in this example, the rotation speed of the plate cylinder 2 may be adjusted such that the original plate 1 and the printing paper 7 are in contact with each other while the perforated portion is sufficiently opened to allow the printing ink 6 to pass therethrough. Then, after printing,
With the rotation of the plate cylinder 2, the perforated portion gradually closes,
Next, when reaching the position of the electrical stimulus applying means 5, it may be controlled so as to be substantially closed. In this way, when performing the next print, if the same electrical stimulus is applied to the same image information as the previous print, a printed matter of the same image can be obtained, while an image different from the previous print is obtained. When an electrical stimulus corresponding to the information is given, printed matter of a different image can be obtained.

[0031]

According to the present invention, a reproducible stencil printing plate which can be repeatedly made and printed is provided, so that stencils can be discarded from a stencil printing apparatus.
Members conventionally required for storing, transporting, and disposing of base paper are not required, so that the printing apparatus can be downsized and the generation of waste can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a stencil printing plate of the present invention with a perforated portion closed.

FIG. 2 is a schematic perspective view showing the stencil printing plate of the present invention in a state where a perforated portion is opened.

FIG. 3 is a schematic cross-sectional view showing an example of a stencil printing machine having a plate cylinder provided with the stencil printing plate of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 original plate 1 a closed perforated portion 1 b open perforated portion 2 plate cylinder 3 squeegee roller 4 press roller 5 electrical stimulation applying means 6 printing ink 7 printing paper 8 print image

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) B41N 3/00 B41N 3/00 F term (reference) 2H084 AA21 AA36 AA38 AE05 BB04 BB13 CC09 2H113 AA01 AA02 AA03 BA09 BB02 BB08 BB10 BB18 BC01 BC02 DA21 DA41 DA47 DA49 DA52 DA57 DA58 DA60 FA22 FA48 2H114 AB23 AB34 BA00 BA10 DA41 EA01 EA06 EA10 FA06 GA11 GA29

Claims (7)

[Claims] 1. A large number of fine perforations are formed in a cross-sectional direction of a film made of a polymer material which contracts in response to an electric stimulus, and the stimulus is applied to the film so as to reproduce a desired image. A stencil printing method, wherein the perforated portion is selectively expanded, and the image forming material is transferred from the expanded perforated portion onto a recording medium. 2. The stencil printing method according to claim 1, wherein the polymer material is mainly composed of a polymer selected from polypyrrole, polythiophene, and polyaniline. 3. A stencil printing plate comprising a plurality of fine perforations formed in a cross-sectional direction of a film made of a polymer material which contracts in response to an electric stimulus. 4. The stencil printing plate according to claim 3, wherein the polymer material is mainly composed of a polymer selected from polypyrrole, polythiophene and polyaniline. 5. An ink-permeable cylindrical plate cylinder which is provided with an original plate according to claim 3 on its outer peripheral surface and is driven to rotate around its own central axis, so that an electric stimulus is applied to said original plate to reproduce a desired image. And a plate making means for selectively expanding the perforated portion of the original plate and an image forming material provided inside the plate cylinder and supplied to the inside of the plate cylinder. Squeegee means for extruding the printing paper and, in a state where the printing paper moves in synchronization with the rotation of the printing drum, presses at least one of the printing cylinder and the printing paper to bring them into close contact with each other, and A stencil printing apparatus comprising: a pressing mechanism for transferring the printing medium from the inside of the plate cylinder to the printing paper via the expanded perforated portion of the original. 6. The original according to claim 5, further comprising means for applying an electrical stimulus to the original to narrow the expanded perforated portion of the original by expanding the polymer material of the original. Stencil printing machine. 7. The stencil printing machine according to claim 5, wherein the original plate comprises a film mainly composed of a polymer selected from polypyrrole, polythiophene and polyaniline.