JP3678655B2 - Method for reinforcing stencil sheet and stencil sheet making apparatus - Google Patents

Description

（実施例４）
実施例１において、印刷用紙としてはがきを用いた以外は実施例１と全く同様にして印刷を行った。
【００６４】
（比較例１）
実施例１において、反応硬化性樹脂によって孔版原紙を処理しなかった以外は実施例１と全く同様にして印刷を行った。
【００６５】
（比較例２）
実施例４において、反応硬化性樹脂によって孔版原紙を処理しなかった以外は実施例４と全く同様にして印刷を行った。
【００６６】
（印刷伸びの評価）
実施例１〜３および比較例１の印刷物における天地方向の任意の２点間の距離を測定し、印刷1000枚目、印刷3000枚目の印刷１枚目に対する変化率を求め、次の基準で評価を行った。
【００６７】
◎：極めて良好（変化率0.1％未満）
○：良好（変化率0.1％以上0.4％未満）
△：実用上使えるレベル（変化率0.4％以上0.8％未満）
×：実用上使用不可レベル（変化率0.8％以上）
【００６８】
（印刷しわの評価）
実施例１〜４、比較例１，２において、3000枚印刷後に、印刷ドラムの原紙の様子を目視判定し、次の基準で評価した。
【００６９】
○：しわの発生なし
△：微妙なしわの発生は認められるが実用上使えるレベル
×：しわの発生があり画像鮮明度が悪く、実用上使用不可レベル
結果を表２に示す。
【００７０】
【表２】

表２から明らかなように、従来の処理をしなかった孔版原紙（比較例１）は、3000枚の連続印刷により大きな伸びやしわの発生が認められ、また、はがきのように端面に大きな圧がかかるような印刷用紙においては、500枚 の連続印刷ではがきの端面に相当する孔版原紙部分に切れが認められた。
【００７１】
一方、本発明の処理を行った孔版原紙（実施例１〜３）は伸びに強く、しわの発生も全く認められなかった。また、はがき印刷では、3000枚の連続印刷を行ってもはがきの端面に相当する孔版原紙には切れが発生せず、従来の処理をしなかった孔版原紙に比べて飛躍的に耐久性が向上した。さらに、印刷画像は印刷用紙にかかわらず極めて鮮明であった。
【図面の簡単な説明】
【図１】 本発明の一つの実施の形態を示す孔版印刷装置の概略模式図
【図２】 塗工手段の別の配置を示す孔版印刷装置の一部概略模式図
【図３】 塗工手段のさらに別の配置を示す孔版印刷装置の一部概略模式図
【図４】 塗工手段のロールコータと孔版原紙の拡大図
【図５】 孔版原紙の補強を段階を追って示す模式図
【符号の説明】
１ 塗工手段
２ 製版手段
３ 除去手段
４ 硬化手段
15 反応硬化性樹脂
100 孔版原紙
101 フィルム
102 多孔性支持体
103 インキ
104 穿孔
105 非穿孔部
Ａ 非穿孔部分
Ｂ 穿孔部分[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stencil sheet for stencil printing, and more particularly to reinforcement of a stencil sheet.
[0002]
[Prior art]
A method is known in which a heat-sensitive stencil sheet is used, and a plate is produced by thermally perforating desired characters and figures on the film surface of the stencil sheet to perform stencil printing. This method has advantages such as low printing cost when printing a large number of sheets and high-speed printing as compared with electrostatic copying (PPC).
[0003]
Conventionally, as a method for making a heat-sensitive stencil sheet, for example, a manuscript in which characters and the like are handwritten with a writing instrument containing carbon such as a pencil, a toner image original copied by an electrophotographic method, and a heat-sensitive stencil sheet are superimposed, and a flash lamp This method is used in accordance with image information obtained by converting the character image or the like into an electric signal by heating the thermoplastic film of the heat-sensitive stencil sheet that is in contact with the original character portion or image portion with heat from an infrared lamp or the like. In order to reproduce the above, there is known a method of using a thermal head that generates dot-like heat and melt-perforating the thermoplastic resin film of the stencil sheet by bringing the thermal head into contact with the heat-sensitive stencil sheet. In particular, the latter method of digital plate making using a thermal head is rapidly spreading because it has the convenience of being able to directly print document data and image data produced by a word processor or graphic software on paper.
[0004]
[Problems to be solved by the invention]
In general, a heat-sensitive stencil sheet is made of a thermoplastic film such as a polyester film, a vinylidene chloride film, or a polypropylene film, and a porous support made of a thin paper made of natural fibers or synthetic fibers, a nonwoven fabric, a screen wrinkle, or the like directly or Since the above-mentioned digital plate making method has a strong demand for high-speed plate making, the thickness of the film is reduced because it is necessary to improve the heat-melt punchability of the heat-sensitive stencil sheet to be used. Attempts have been made to use a film made of a material having a low melting point, a high heat shrinkage rate, or a low crystallinity.
[0005]
However, in general, such high-sensitivity films have low physical strength, so if you print a large number of sheets continuously, the base paper will stretch, or the base paper will be perforated or the part corresponding to the end face of the base print paper. Problems such as cutting and wrinkling of the base paper are likely to occur.
[0006]
In order to solve such problems, the physical strength is increased by a method of increasing the thickness of the base paper itself, but this cannot meet the demand for high-speed plate making and clear images.
[0007]
The present invention has been made in view of the above circumstances, and a stencil sheet capable of dramatically improving durability while satisfying requirements for high-speed plate making such as punchability and a clear image, and such a stencil sheet. It is an object of the present invention to provide a method for reinforcing a stencil sheet for producing a stencil sheet and a stencil sheet making apparatus.
[0008]
[Means for Solving the Problems]
The method for reinforcing a stencil sheet of the present invention includes impregnating a reactive curable resin into the porous support of a stencil sheet formed by laminating a resin film and a porous support, and perforating plate making to the resin film. The reaction curable resin in the perforated portion of the stencil sheet is selectively removed from the perforated portion of the stencil sheet formed by the plate making by replacing the printing ink by a printing operation, and remains in the non-perforated portion of the pre-made stencil sheet. The reaction curable resin is cured.
[0009]
Impregnation with the reaction curable resin and perforating plate making of the resin film means that the impregnation of the reaction curable resin is perforated when perforating plate making after impregnating the reaction curable resin in the porous support. When it is carried out at the same time as the plate making, it means that any of the cases in which perforation plate making is carried out before impregnating the porous support with the reaction curable resin may be used.
[0010]
The perforated portion of the stencil paper means a perforated resin film and a porous support laminated on the perforated. The non-perforated portion of the stencil sheet means a porous support laminated on the non-perforated portion of the resin film.
[0011]
The reaction curable resin is preferably an ultraviolet curable resin. It is preferable that the viscosity and yield value of the reaction curable resin are adjusted to be equal to or less than the viscosity and yield value of the printing ink.
[0012]
The stencil sheet making apparatus of the present invention comprises a coating means for impregnating a reactive curable resin in the porous support of a stencil sheet obtained by laminating a resin film and a porous support, and the resin film. Plate making means for perforating plate making, removing means for selectively removing the reaction curable resin in the perforated portion of the stencil base paper from the perforation of the resin film formed by plate making by replacing printing ink by printing operation, and the plate making And a curing means for curing the reaction curable resin remaining in the non-perforated portion of the stencil sheet.
[0013]
The reaction curable resin is preferably an ultraviolet curable resin. It is preferable that the viscosity and yield value of the reaction curable resin are adjusted to be equal to or less than the viscosity and yield value of the printing ink.
[0014]
【The invention's effect】
The method for reinforcing a stencil sheet of the present invention includes impregnating a reactive curable resin into a porous support of a stencil sheet obtained by laminating a resin film and a porous support, and perforating the resin film. The reactive curable resin in the perforated portion of the stencil sheet is selectively removed by replacing the printing ink by printing operation from the perforation of the resin film formed by the plate making, and the reaction hardening remaining in the non-perforated portion of the pre-made stencil paper Since the curable resin is cured and reinforced, the reaction curable resin impregnated in the porous support on the non-perforated resin film is cured. For this reason, the non-perforated portion of the stencil sheet is reinforced by the curing of the reaction curable resin while the perforation property of the resin film is good, so that the stencil has high durability while satisfying high-speed perforation and a clear image. It can be a base paper.
[0015]
That is, conventionally, in order to improve the durability of the stencil sheet, a method of increasing the thickness of the resin film, using a strong resin film, or increasing the thickness of the porous support has been employed. In addition, even if the durability of the stencil sheet is improved, it has been difficult to realize high-speed perforation and a clear image.
[0016]
However, according to the stencil sheet reinforcing method and stencil sheet making apparatus of the present invention, the resin film and the porous support itself can be used after the stencil, even if a thin film that can realize high-speed perforation and a clear image is used. Since the strength of the stencil sheet can be increased by curing the reaction curable resin impregnated in the porous support, it is possible to provide a stencil sheet excellent in durability while being high-speed perforated and a clear image It is something that can be done.
[0017]
When an ultraviolet curable resin is used as the reactive curable resin, the reaction is fast, so that the resin film is hardly damaged and the economic burden is reduced. Furthermore, in thermosensitive plate making, when using a thermosetting resin, it is not possible to apply a reactive curable resin until after plate making, but in the case of an ultraviolet curable resin, even before plate making, Since there is no problem even at the same time as the plate making, the coating place of the apparatus is not restricted.
[0018]
Further, in the stencil sheet making apparatus, the reaction curable resin is removed from the perforated portion of the stencil sheet by replacing the printing ink using the printing operation of the stencil printing apparatus, so that a new apparatus must be added as a removing means. However, since the printing drum of the conventional stencil printing apparatus can be used, the economic burden of capital investment can be reduced.
[0019]
In this case, the reaction curable resin and the printing ink can be replaced more smoothly by adjusting the viscosity and the yield value of the reactive curable resin to be equal to or less than the viscosity and the yield value of the printing ink used for printing. It becomes.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
Although the stencil sheet making apparatus of the present invention may perform only the stencil sheet making, the conventionally used stencil printing apparatus has only one stencil sheet making means and printing means. Is incorporated into the mainstream, and if such a stencil printing apparatus is used, the reaction curable resin in the perforated portion of the stencil sheet can be removed using the printing operation of the stencil printing apparatus. Therefore, hereinafter, the stencil printing apparatus in which the stencil sheet making apparatus of the present invention and the printing apparatus are integrated will be described.
[0021]
FIG. 1 is a schematic diagram of a stencil printing apparatus showing one embodiment of the present invention, FIG. 2 is a partial schematic diagram of a stencil printing apparatus showing another arrangement of the coating part, and FIG. It is a partial schematic diagram of a stencil printing apparatus showing yet another arrangement.
[0022]
The stencil printing apparatus 10 of the present invention is formed by coating means 1 for impregnating a reactive curable resin in a porous support of stencil base paper, plate making means 2 for perforating plate making on a resin film, and plate making. A removal means 3 for selectively removing the reaction curable resin in the perforated portion of the stencil sheet from the perforation of the resin film, and a curing means 4 for curing the reaction curable resin remaining in the non-perforated portion of the stencil sheet after making the plate. And a printing paper supply means 5 and a printed paper storage means 6.
[0023]
The coating means 1 includes a tank 11 for storing the reactive curable resin 15, a container 12 for immersing the reactive curable resin 15 in a roll coater, and a pump 13 for transferring the reactive curable resin 15 from the tank 11 to the container 12. And a roll coater 14 that impregnates the stencil sheet with the reaction curable resin 15. Here, a roll coater is used as a means for impregnating a stencil sheet with a reactive curable resin. However, as long as a stencil sheet can be impregnated with a reactive curable resin, various types such as a gravure coater, a blade coater, and a bar coater can be used. A coater may be used, and without using a coater, the stencil sheet may be impregnated by a method of directly immersing the stencil sheet in a resin pool or a method of spraying a resin on the stencil sheet using a spray or an ink jet.
[0024]
Further, the coating means 1 shown in FIG. 1 is provided at a position before the plate making, but as long as the stencil sheet is set, the coating means 1 is applied simultaneously with the plate making as shown in FIG. As shown in FIG. 3, it may be provided at the lower part of the plate making means 2 or may be provided during the transporting process from plate making to plate making as shown in FIG.
[0025]
Next, the operation of the stencil printing apparatus 10 will be described. The roll-shaped stencil sheet 100 set in the holder is fed to the coating means 1 by a feed roller. In the coating means 1, the stencil paper 100 is impregnated with the reactive curable resin 15 by the roll coater 14. An enlarged view of the roll coater and stencil sheet of the coating means 1 is shown in FIG. When the stencil sheet 100 moves in the conveying direction indicated by the arrow, the reactive curable resin 15 impregnated in the roll coater 14 moves to the stencil sheet 100, and the excess reactive curable resin 15 impregnated in the stencil sheet 100 is removed by the scraper 16. Scraped.
[0026]
On the other hand, when a printed document is set on a reading means (not shown) of the printing apparatus, the reading sensor reads the shading corresponding to the figure or character of the document as a digital signal, and the signal is sent to the thermal head 21 of the plate making means 2. . The stencil sheet 100 impregnated with the reaction curable resin 15 is sent to the plate making means 2 by a feed roller, and is punched and made by heating the thermal head 21. Here, a thermal head whose plate making means is thermal perforation is described, but a thermal perforation using flash or infrared as a heat source may be used, or mechanical perforation such as a file plate, a needle, a punch, or the like. May be.
[0027]
The stencil sheet 100 that has been made is squeezed by the clamp 32 of the printing drum 31 and wound around the printing drum 31 in the feeding direction. The ink 103 is pushed out from the inside of the printing drum 31, is pierced through the stencil sheet 100 wound around the printing drum 31, and is transferred to the printing paper supplied from the printing paper supply means 5. At this time, the reaction curable resin is also transferred from the perforations together with the ink 103, whereby the reaction curable resin is removed from the perforated portions. After confirming the transfer of the ink 103 to the printing paper, external energy is irradiated from the curing section 41 of the curing means 4 toward the printing drum 31 around which the stencil sheet 100 is wound, and remains in the non-perforated section of the stencil sheet 100 The reactive curable resin is cured to complete the reinforcement of the stencil paper 100. After curing, printing can be continuously performed on the printing paper supplied in synchronization with the rotation of the printing drum 31.
[0028]
FIG. 5 uses the printing operation of the stencil printing apparatus to selectively remove the reactive curable resin in the perforated portion of the stencil paper and harden the reactive curable resin in the non-perforated portion of the stencil paper to reinforce the stencil paper 100. It is a schematic diagram which shows a mode that it does step by step.
[0029]
In the removing means for selectively removing the reaction curable resin in the perforated portion of the stencil sheet, as shown in FIG. 5 (a), the ink 103 pushed out from the printing drum is applied on the stencil sheet 100 which has been made, Under the stencil sheet 100, the printing paper 51 is supplied from the printing paper supply means.
[0030]
The stencil sheet 100 is composed of a film 101 perforated by plate making and a porous support 102 impregnated with a reactive curable resin, and the ink 103 is gradually pushed out by the repeated rotation of the printing drum to make it porous. It passes through the support 102 and further passes through the perforations 104 of the film 101 and is transferred to the printing paper 51. At this time, the reaction curable resin impregnated in the perforated portion B of the porous support 102 just above the perforations 104 is gradually pushed out when the ink 103 infiltrates and transferred to the printing paper 51 together with the ink 103. (FIG. 5B). This transfer occurs first from the reaction curable resin impregnated in the perforated portion B of the porous support 102. When the ink 103 is transferred to the printing paper 51, the perforated portion B of the porous support 102 is impregnated. The reactive curable resin is completely replaced with the ink 103. Therefore, it can be seen that the reaction curable resin impregnated in the perforated portion B of the porous support 102 is completely removed by transferring the ink 103 to the printing paper 51. In FIG. 5, the description of the infiltration of the ink 103 in the non-perforated portion A is omitted for easy understanding of the curing of the reaction curable resin.
[0031]
When it is confirmed that the reaction curable resin has been completely removed from the perforated portion B of the porous support 102, that is, the ink has been transferred to the printing paper 51, the porosity just above the non-perforated portion 105 of the film 101 is obtained. The reaction curable resin impregnated in the non-perforated portion A of the support 102 is cured by irradiating the external energy of the curing unit 41 (FIG. 5C).
[0032]
The external energy irradiated from the curing unit 41 differs depending on what is selected for the reactive curable resin.For example, when a thermosetting resin, an infrared curable resin, a thermoplastic resin, or paraffins is selected, radiant heat, A heat source such as infrared is used as external energy. When a photocurable resin is selected, light such as visible light or ultraviolet light is used as external energy. Further, when a resin curable by a high frequency radio wave, various electron beams, radiation, or the like is selected as the reaction curable resin, these may be used as external energy. Further, here, the curing means is described as being incorporated in the stencil printing apparatus, but it is not necessary to be incorporated in the stencil printing apparatus as long as a handy type can be used for the curing part.
[0033]
When external energy is irradiated from the curing portion 41, the reaction curable resin impregnated in the non-perforated portion A of the porous support 102 is cured. On the other hand, since the reaction curable resin is completely removed in the perforated portion B of the porous support 102, curing does not occur (FIG. 5 (d)). As a result, the stencil sheet 100 is reinforced with the reaction curable resin.
[0034]
Next, the stencil paper and reaction curable resin that can be used in the present invention will be described.
As the stencil sheet, a film generally used in the past can be used, but the film itself needs to be unchanged while transmitting external energy emitted from the cured portion, for example, thermoplasticity. A resin film or the like can be used.
[0035]
The thermoplastic resin film is not particularly limited as long as it can be heat-sensitive stenciled with a thermal head or the like. For example, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate, polybutylene terephthalate, polynaphthalene terephthalate, Polysulfone sulfide, polystyrene, polyurethane, polycarbonate, polyvinyl acetate, acrylic resin, silicone resin and the like are used. These resin components may be used alone or in combination, or used as a copolymer thermoplastic resin film. The thermoplastic resin film may be white.
[0036]
In addition, for thermoplastic resin films, if necessary, flame retardants, thermal stability, antioxidants, ultraviolet absorbers, antistatic agents, pigments, dyes, fatty acid esters, organic lubricants such as waxes, polysiloxanes, etc. An antifoaming agent can be contained.
[0037]
The thickness of the thermoplastic resin film is preferably in the range of 0.5 to 50 μm, more preferably 1 to 20 μm. If the film thickness is less than 0.5 μm, the handleability and strength are inferior, and if it exceeds 50 μm, a large amount of heat energy is required for drilling, which is not economical.
[0038]
The porous support is not particularly limited as long as it is a porous support through which ink passes, and examples thereof include thin paper, paper-making paper, non-woven fabric, woven fabric, screen wrinkles, and continuous pores, so-called sponge sheets. The constituent fibers of thin paper and papermaking paper include natural fibers such as manila hemp, mulberry, mitsumata and pulp, or synthetic fibers such as polyester, vinylon and nylon, and these may be used alone or in combination of two or more. Can do. In the case of non-woven fabrics, woven fabrics, and screen wrinkles, the above fibers can be appropriately selected and used. Examples of the continuous pores include synthetic resin foams such as natural rubber, synthetic rubber-based sponge rubber, polyurethane foam, polystyrene foam, and polyethylene foam.
[0039]
The porous support may be subjected to chemical treatment such as acid or alkali, corona discharge, low-temperature plasma treatment, etc., on the surface of the fiber to be constituted as necessary in order to impart affinity with ink.
[0040]
These porous supports have a basis weight of 1-20g / m ² Is preferable, more preferably 5 to 15 g / m ² Range. 1g / m ² If it is less than 20 g / m ² Exceeding this may result in poor ink passage during printing. Further, the thickness of the porous support is preferably in the range of 5 to 100 μm, more preferably in the range of 10 to 50 μm. When the thickness is less than 5 μm, the strength as a base paper is weakened, and when it exceeds 100 μm, the ink permeability during printing may be deteriorated.
[0041]
The heat-sensitive stencil sheet can be obtained by laminating and integrating the thermoplastic resin film and the porous support. Lamination of the thermoplastic resin film and the porous support can be performed by either a method of adhering using an adhesive under conditions that do not reduce the perforation sensitivity of the film or a method of heat adhering without using an adhesive.
[0042]
As the adhesive, vinyl acetate-based, acrylic-based, vinyl chloride-vinyl acetate copolymer system, polyester-based, urethane-based, etc. can be used. Also, as the ultraviolet curable adhesive, polyester-based acrylate, urethane-based acrylate, A mixture of an epoxy acrylate or the like and a photopolymerization initiator can be used.
[0043]
The thermal bonding is usually performed by thermocompression bonding in which the thermoplastic resin film and the porous support are directly bonded together while heating. The method of thermocompression bonding is not particularly limited, but thermocompression bonding with a heating roll is preferable from the viewpoint of processability. The adhesion temperature is usually preferably in the range of 80 to 170 ° C, more preferably in the range of 100 to 150 ° C.
[0044]
From the viewpoint of image clarity of the printed matter, it is preferable to directly fix the thermoplastic resin film and the porous support by thermal bonding without using an adhesive.
[0045]
A release agent is generally applied to the film surface of the stencil printing paper to prevent sticking during perforation by a thermal head. However, it is preferable to apply a release agent also to the stencil paper of the present invention. As the release agent, conventionally known ones such as silicone oil, silicone resin, fluorine resin, and surfactant can be used. Moreover, you may mix various additives, such as an antistatic agent, a heat resistant agent, antioxidant, an organic particle, an inorganic particle, and a pigment, in a mold release agent.
[0046]
The reaction curable resin of the present invention is preferably one that has a flexibility to withstand an impact during printing after curing, a high elasticity that does not cause elongation, and a tensile strength, and has such properties. If it is, it will not specifically limit, For example, the resin etc. which harden | cure with an ultraviolet curable resin, an infrared curable resin, a thermosetting resin, a thermoplastic resin, paraffins, a high frequency electric wave, various electron beams, etc. are used. Can do. Further, in addition to the reaction curable resin, a photoinitiator, a viscosity modifier, and a polymerization initiator may be appropriately included.
[0047]
However, when the plate making is by thermal perforation, the coating means is provided at a position before the plate making (in the case of FIG. 1), or the coating is performed simultaneously with the plate making (in the case of FIG. 2). However, since heat is applied during plate making, a thermosetting resin cannot be used as a reactive curable resin.
[0048]
More preferably, the reaction curable resin is composed of an ultraviolet curable resin oligomer or monomer, a photoinitiator, a viscosity modifier, a polymerization initiator, and the like. Since such a reaction curable resin is close to the configuration in which the colorant is removed from the ultraviolet curable ink, there are few adverse effects when used in a printing apparatus, and problems such as curing inhibition due to the ultraviolet absorption of the colorant do not occur. Further, even when the plate making is thermal plate making, it can be used regardless of the position where the coating means and the plate making means are provided.
[0049]
As the ultraviolet curable resin, it is preferable to use, for example, various oligomers and monomers of urethane-based, epoxy-based, polyester-based, and polyol-based (meth) acrylic acid-modified resins.
[0050]
As the oligomer, for example, epoxy acrylate, epoxy oil acrylate, urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl acrylate and the like can be preferably used, and monomers include dicyclopentenyl ethyl acrylate, isobornyl Monofunctional acrylates such as acrylate, phenol / ethylene oxide modified acrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol A diglycidyl ether diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, Pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaene A polyfunctional acrylate such as lithitol hexaacrylate can be preferably used.
[0051]
As the photoinitiator, commercially available products can be used. For example, Irgacure 651, Irgacure 184, Darocur 1173, Irgacure 907, Irgacure 369 (above, manufactured by Ciba Geigy), or Kayacure DETX, Kayacure ITX (manufactured by Nippon Kayaku Co., Ltd.), Sorvathrone BIPE, Sorbastron BIBE (manufactured by Kurokin Kasei), Lucyrin TPO (manufactured by BASF), benzophenone, acetophenone, 4,4'-bisdiethylaminobenzophenone, benzyl , Benzoin, benzoin ethyl ether, etc. can be used alone or in admixture of two or more. Further, as a sensitizer, an aliphatic amine such as n-butylamine, triethylamine, ethyl p-dimethylaminobenzoate may be used in combination. In general, the photoinitiator is preferably added in an amount of 1 to 20% by weight based on the total amount of the ultraviolet curable resin alone (without additives).
[0052]
When using the printing operation of a stencil printing machine as a means for removing reactive curable resin, the viscosity should be adjusted to the same or preferably lower viscosity or yield value as printing ink so that it can be easily replaced with printing ink. It is desirable to use a viscosity modifier for adjusting viscosity and yield value.
[0053]
As a viscosity modifier, powders such as organic bentonite, organic hectorite, various waxes, calcium carbonate, silica, starch, metal soap, quartz, glass, polytetrafluoroethylene (trade name Teflon) can be preferably used. If necessary, a commercially available gelling agent may be used in combination. The viscosity modifier is preferably 30% by weight or less based on the total amount of the reaction curable resin alone (excluding additives).
[0054]
In order to prevent gelation of the reaction curable resin during storage, a polymerization inhibitor is preferably used, and hydroquinone, a nitroso compound, or the like can be preferably used as the polymerization inhibitor.
[0055]
Furthermore, you may contain various additives, such as a well-known photoinitiator, a light stabilizer, surfactant, antioxidant, antiseptic | preservative, antifungal agent, silicone oil, an antifoamer, as needed.
[0056]
The reaction curable resin is adjusted by stirring and mixing components such as the reaction curable resin and then mixing them with a kneading machine such as a three-roll machine. The prepared reaction curable resin is stored in a container that can shield ultraviolet rays, sunlight, and the like.
Examples are shown below.
[0057]
【Example】
(Example 1)
Epoxy acrylate oligomer (manufactured by Harima Chemicals Co., Ltd.) 9% by weight, dipentaerythritol hexaacrylate (DPHA: manufactured by Toagosei Co., Ltd.) 38.2% by weight, phenol / ethylene oxide modified acrylate (manufactured by Toagosei Co., Ltd.) 38.2% by weight %, Irgacure 369 (manufactured by Ciba Geigy) as photoinitiator, 3.5% by weight as viscosity modifier, 10% by weight of Benton 38 (manufactured by RHEOX), 1% by weight as Solsperse S24000GR (manufactured by Geneca), polymerization inhibitor As a mixture, 0.1% by weight of hydroquinone was stirred and mixed with a stirrer, and then mixed with a three-roll mixer to prepare a reaction curable resin.
[0058]
A roll coater for impregnating reactive curable resin is installed in the plate making means of the stencil printing machine (Rithograph SR7400: Riso Kagaku Kogyo Co., Ltd.), and the handy UV irradiation device (ORC: Handy UV-500) is used as the paper feeding means. installed.
[0059]
A roll-shaped stencil sheet (manufactured by Riso Kagaku Kogyo Co., Ltd.) was set in the holder, conveyed to a plate-making coating means by a feed roller, and impregnated with a reactive curable resin at the same time as thermal plate-making. For the plate making, a lattice pattern was used as a manuscript. This stencil sheet was wound around a printing drum to which ink (HD ink (black)) was supplied in advance, and a printing operation was performed while supplying printing paper (A3 size: Riso Kagaku Kogyo Co., Ltd.). At the 10th printed sheet, the transferred colorless reaction curable resin turned into a black image, and the reaction curable resin in the perforated portion of the stencil sheet was completely removed.
[0060]
While irradiating the printing drum with ultraviolet rays from the UV irradiation device, the printing drum was rotated three times at 20 rpm to complete the reinforcement of the stencil sheet. The UV printing was stopped and 3000 sheets were printed as usual.
[0061]
(Example 2)
Printing was performed in the same manner as in Example 1 except that the reaction curable resin was formulated as shown in Table 1.
[0062]
(Example 3)
Printing was performed in the same manner as in Example 1 except that the reaction curable resin was formulated as shown in Table 1.
[0063]
[Table 1]

(Example 4)
In Example 1, printing was performed in exactly the same manner as in Example 1 except that a postcard was used as the printing paper.
[0064]
(Comparative Example 1)
In Example 1, printing was performed in exactly the same manner as in Example 1 except that the stencil sheet was not treated with a reactive curable resin.
[0065]
(Comparative Example 2)
In Example 4, printing was performed in exactly the same manner as in Example 4 except that the stencil paper was not treated with a reactive curable resin.
[0066]
(Evaluation of printing elongation)
The distance between any two points in the vertical direction in the printed materials of Examples 1 to 3 and Comparative Example 1 is measured, and the rate of change with respect to the first print of the 1000th print and the 3000th print is obtained. Evaluation was performed.
[0067]
A: Very good (change rate less than 0.1%)
○: Good (change rate 0.1% or more and less than 0.4%)
Δ: Practical level (change rate: 0.4% or more and less than 0.8%)
×: Unusable for practical use (change rate 0.8% or more)
[0068]
(Evaluation of printing wrinkles)
In Examples 1 to 4 and Comparative Examples 1 and 2, after printing 3000 sheets, the state of the base paper of the printing drum was visually determined and evaluated according to the following criteria.
[0069]
○: No wrinkle
Δ: Slight wrinkles are observed but practically usable
×: Wrinkles occurred, image clarity was poor, and practically unusable level
The results are shown in Table 2.
[0070]
[Table 2]

As is apparent from Table 2, the stencil sheet (Comparative Example 1) that had not been subjected to the conventional treatment was found to generate large stretches and wrinkles due to continuous printing of 3000 sheets, and a large pressure on the end face such as a postcard. In such a printing paper, cutting of the stencil paper corresponding to the end face of the postcard was recognized in the continuous printing of 500 sheets.
[0071]
On the other hand, the stencil sheets (Examples 1 to 3) subjected to the treatment of the present invention were strong in elongation and no wrinkles were observed. In postcard printing, the stencil paper corresponding to the end face of the postcard does not break even after 3000 sheets of continuous printing, and the durability is dramatically improved compared to the stencil paper that was not processed in the past. did. Furthermore, the printed image was very clear regardless of the printing paper.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a stencil printing apparatus showing an embodiment of the present invention.
FIG. 2 is a partial schematic diagram of a stencil printing apparatus showing another arrangement of coating means.
FIG. 3 is a partial schematic diagram of a stencil printing apparatus showing still another arrangement of coating means.
[Fig. 4] Enlarged view of roll coater and stencil sheet of coating means
FIG. 5 is a schematic diagram showing reinforcement of a stencil sheet step by step.
[Explanation of symbols]
1 Coating method
2 Plate making means
3 removal means
4 Curing means
15 Reaction curable resin
100 stencil paper
101 films
102 Porous support
103 ink
104 drilling
105 Non-perforated part
A Non-perforated part
B Perforated part

Claims (6)

A resin film formed by plate making by impregnating the porous support of a stencil base paper formed by laminating a resin film and a porous support with a reactive curable resin and perforating the resin film. The reaction curable resin in the perforated portion of the stencil sheet is selectively removed by replacing the printing ink by a printing operation, and the reaction curable resin remaining in the non-perforated portion of the stencil stencil sheet is cured. A stencil paper reinforcing method characterized by the above. Reinforcing method of the stencil sheet according to claim 1, wherein the reactive curable resin is an ultraviolet curable resin. The method for reinforcing a stencil sheet according to claim 2 , wherein a viscosity and a yield value of the reaction curable resin are adjusted to be equal to or less than a viscosity and a yield value of the printing ink. A coating means for impregnating a reactive curable resin into the porous support of a stencil sheet obtained by laminating a resin film and a porous support, a plate making means for perforating plate making to the resin film, and plate making Removing means for selectively removing the reactive curable resin in the perforated portion of the stencil sheet from the perforated portion of the stencil sheet formed by the printing ink replacement by a printing operation; And a stencil sheet making apparatus, comprising: a curing means for curing the reactive curable resin. 5. The stencil sheet making apparatus according to claim 4, wherein the reaction curable resin is an ultraviolet curable resin. 6. The stencil sheet making apparatus according to claim 5 , wherein a viscosity and a yield value of the reaction curable resin are adjusted to be equal to or less than a viscosity and a yield value of the printing ink.

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