JP4633278B2 - Master for heat-sensitive stencil printing and method for producing the same - Google Patents

Description

【００８２】
【表２】

【００８３】
実施例及び比較例の評価
実施例１：穿孔感度はやや低めであるが印刷濃度安定性は高く、使用上問題が無い
実施例２：本発明の標準的なサンプル、印刷性、耐刷性、搬送性、何れにも問題が無い
実施例３：印刷濃度安定性はやや低めであるが穿孔感度は良好で、使用上問題は無い
比較例１：印刷濃度安定性は高いが穿孔感度が悪い
実施例４：印刷濃度安定性はやや低目であるが穿孔感度は高く、使用上問題は無い
実施例５：機能性薄層の効果でＦ−Ｐ接着強度が高い
実施例６：多孔性樹脂層の付着量を減らして多孔性繊維膜を積層させたことで印刷濃度安定性が高い
実施例７：多孔性樹脂膜の付着量を減らして多孔性繊維膜を積層させたことで印刷濃度安定性が高い
実施例８：多孔性樹脂膜の付着量を減らしたが多孔性繊維膜を積層させていないので耐刷性がやや低いものの、問題は無い
実施例９：飽和ポリエステルの接着力が低いので耐刷性と搬送性がやや劣るものの、使用上問題は無い
実施例１０：請求項９の製法によるマスター。印刷性、耐刷性、搬送性、何れにも問題は無い
実施例１１：印刷品質に問題は無く、耐刷試験後にフィルムと多孔性樹脂膜、及び多孔性樹脂膜と多孔性繊維膜の間にそれぞれ若干のハガレが見られたものの、使用上問題は無い
比較例２：印刷濃度安定性は高いが穿孔感度が低く、画像に白抜けが多い
実施例１２：フィルムと多孔性樹脂膜の接着強度が低いためややハガレが見られたものの、使用上問題は無い
【００８４】
【発明の効果】
請求項１に記載の発明によれば、穿孔感度の良好なマスターが得られる。
請求項２に記載の発明によれば、良好な穿孔感度と優れた耐刷性を兼ね備えたマスターが得られる。
請求項３に記載の発明によれば、良好な穿孔感度と優れた耐刷性を兼ね備えたマスターが得られる。
請求項４に記載の発明によれば、多孔性樹脂膜と熱可塑性樹脂フィルムの接着が良好なマスターが得られる。機能性薄層はその成分により、マスターのカール、剛度、強度などを改善する効果が期待できる。
請求項５に記載の発明によれば、積層する多孔性繊維膜によって耐刷性が確保されるので、多孔性繊維膜を積層しない場合よりも多孔性樹脂膜を構成する樹脂の選択肢が広がり、また、マスターの搬送性や耐刷性に問題を生じることなく、多孔性樹脂膜の樹脂付着量を少なくできるので、高インキ通過性と印刷濃度安定性を両立でき、インキ通過性の高い多孔性樹脂膜を形成させやすいマスターが得られる。
請求項６に記載の発明によれば、製版時や印刷時にハガレのないマスターが得られる。
請求項７に記載の発明によれば、製版時や印刷時にハガレのないマスターが得られる。
請求項８に記載の発明によれば、良好な印刷画像品質を損なうことなく、多孔性樹脂膜と多孔性繊維膜の間に十分な接着強度を与えることができるマスターが得られる。
請求項９に記載の発明は、多孔性樹脂膜を形成する樹脂の溶解度の異なる複数の溶剤（良溶媒と貧溶媒）が互いによく溶ける場合に用いられる。有機溶媒は互いによく溶けることが多いので溶媒の選択肢が広く、結果的に樹脂の選択範囲も広くなる。また、任意に溶剤の混合比を変更することによって容易に糸瓜状の多孔性樹脂膜が形成され、更にエーテルやアセトンなど、蒸発の速い溶剤を選択して生産性を高められる。
請求項１０に記載の発明は、互いに混ざり合わない良溶媒と貧溶媒を選びエマルションを形成させる。請求項９の方法と比べ、樹脂の溶解度に依存しないので温度や湿度の影響を受けにくく、形成される膜形状の再現性が高く、処方の自由度が高く、多孔性樹脂膜の形成できる範囲が広いので、油相水相の比率や樹脂濃度、樹脂分子量などで塗布液の粘度を調整しやすい。また、本請求項の発明は一般に固形分濃度が同じならば、請求項９の方法よりも塗布液が高粘度になる。
【図面の簡単な説明】
【図１】本発明の感熱孔版印刷用マスターの一例の模式断面図である。
【符号の説明】
１ 熱可塑性樹脂フィルム
２ 多孔性樹脂膜
３ 多孔性繊維膜
４ 多孔性樹脂膜樹脂部
５ 多孔性樹脂膜空隙部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat-sensitive stencil printing master that is pierced with a halogen lamp, a xenon lamp, a flash bulb, etc., pulsed irradiation with infrared light, laser light, or the like, or a thermal head or the like, and a method for manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a thermal stencil printing master in which a porous thin paper made of natural fiber or synthetic fiber alone or mixed with an adhesive is used as an ink-permeable support on a thermoplastic film has been used. However, a heat-sensitive stencil master using a porous thin paper made of such fibers as a support has the following problems.
(1) By laminating the porous thin paper and the film using an adhesive, the adhesive accumulates between the fibers of the porous thin paper like a bird's web, and it is difficult for the thermal head to perforate at that portion. The passage of ink is obstructed, and uneven printing tends to occur.
(2) The porous thin paper fibers themselves prevent the passage of ink, and printing unevenness is likely to occur.
(3) The smoothness of the film surface is lowered due to the fiber pattern of the porous thin paper, the adhesion with the thermal head is poor, and an unperforated portion is formed, and printing unevenness occurs.
[0003]
Several proposals have been made to improve these problems, but no one has yet been satisfied. For example, Japanese Patent Laid-Open No. 3-193445 proposes to use a thin paper made of synthetic fibers having a fineness of 1 denier or less as a porous support, but it is not sufficient for solving the above problems.
[0004]
Japanese Patent Application Laid-Open No. Sho 62-198459 proposes a method for forming a porous support on a thermoplastic resin film by using a printing method such as gravure, offset, flexo, etc., with a radiation curable resin pattern having a substantially closed shape. Has been. However, with this printing method, it is difficult to reduce the line width of the resin pattern to 50 μm or less, and the printing portion cannot be perforated, resulting in uneven printing.
[0005]
Japanese Patent Application Laid-Open No. 3-240596 discloses a low-viscosity ink jet ink in which a dispersion composed of a water-dispersible polymer and colloidal silica is applied to the surface of a thermoplastic resin film, dried, and provided with a porous support. A printing method has been proposed. However, in this method, the pore diameter of the porous layer is small, and the ink used for stencil printing used in the past does not pass through the ink, and a sufficient printing density cannot be obtained.
[0006]
On the other hand, Japanese Patent Application Laid-Open No. 54-33117 proposes a heat-sensitive stencil printing master that is substantially composed only of a thermoplastic resin film without using a porous support. This method has a high heat shrinkage rate, and films having a film thickness of 3 μm or less have good punchability by a thermal head and excellent printing quality, but have a problem that they are weak and cannot be conveyed by a printing press. If a thick film is used to improve the transportability, the punchability by the thermal head is lowered and printing unevenness occurs.
[0007]
The present inventors have previously proposed a thermosensitive stencil printing master in which a porous resin film is provided on one side of a thermoplastic resin film (Japanese Patent Laid-Open Nos. 8-332785 and 10-24667). However, the porous resin film formed by applying the fluid on the thermoplastic resin film and drying is lower in strength than the thin paper used for pasting with the conventional film, and the printing durability of the master There was a problem that there was a shortage. In particular, in order to obtain good perforation sensitivity, when the porosity of the porous resin film is high and the trunk is narrowed, the porous resin film becomes brittle, the master stretches during printing, and the porous resin film collapses. There was a problem of a decrease in printing density due to breakage.
[0008]
In order to make up for the lack of strength of the porous resin film, the present inventors disclosed in Japanese Patent Application Laid-Open Nos. 10-147075 and 10-236011 from a resin on one surface of a thermoplastic resin film. Has proposed a heat-sensitive stencil printing master having a porous resin film and a laminated porous fiber film made of a fibrous material on the surface, and has improved the elongation of the master during printing. Even in these masters, the problem of a decrease in printing density during printing has not been completely solved.
[0009]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described prior art, and is a thermosensitive stencil printing master having a porous resin film made of a resin on one surface of a thermoplastic resin film. An object of the present invention is to provide a master for heat-sensitive stencil printing excellent in both printing resistance and printing durability, and a method for producing the same.
[0010]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, according to the present invention, the following thermal stencil printing master and a method for producing the same are provided.
(1) In a heat-sensitive stencil printing master having at least a porous resin film formed by applying and drying a fluid on a thermoplastic resin film, the void area ratio of the porous resin film observed from the film side is Is larger than the void area ratio of the porous resin film observed from the opposite side, a master for heat-sensitive stencil printing.
(2) The void area ratio of the porous resin film observed from the film side is 1.05 to 1.5 times the void area ratio of the porous resin film observed from the side opposite to the film side. The heat-sensitive stencil printing master of (1) above.
(3) The heat-sensitive stencil printing master of (1) to (2), wherein the void area ratio of the porous resin film observed from the film side is 40 to 80%.
(4) The master for heat-sensitive stencil printing according to (1) to (3), wherein a functional thin layer is provided between the thermoplastic resin film and the porous resin film.
(5) The heat sensitive as described in (1) to (4) above, wherein a porous fiber film made of a fibrous material is laminated on the surface of the porous resin film provided on one surface of the thermoplastic resin film. Master for stencil printing.
(6) The master for thermosensitive stencil printing of (1) to (5), wherein the adhesive strength between the thermoplastic resin film and the porous resin film is 1.4 N / m or more.
(7) The heat sensitivity of (5) above, wherein the adhesive strength between the thermoplastic resin film and the porous resin film and the adhesive strength between the porous resin film and the porous fiber film are each 1.4 N / m or more. Master for stencil printing.
(8) The heat-sensitive stencil printing master according to (5) above, wherein the porous resin film and the porous fiber film are bonded with a polyurethane-based adhesive.
(9) The synthetic resin is mixed with a plurality of solvents having different solubilities, solubilized, coated on the thermoplastic resin film at a constant thickness, and dried to produce the thermosensitive stencil master of (1) above. Method.
(10) A method for producing a heat-sensitive stencil printing master according to (1) above, wherein a water-in-oil emulsion containing a dissolved synthetic resin is applied on a thermoplastic resin film with a constant thickness and dried.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
The heat-sensitive stencil printing master of the present invention is a heat-sensitive stencil printing master having at least a porous resin film formed by applying and drying a fluid on a thermoplastic resin film. The void area ratio is larger than the void area ratio of the porous resin film observed from the side opposite to the film side.
[0012]
In order to increase the sensitivity of the master, the porous resin film has a high porosity and a thinner trunk is preferable. However, if this is done, the film strength will decrease and problems such as the elongation of the master during printing and the decrease in print image density will occur. Is likely to occur. Further, the effect of controlling the ink passing amount by the porous resin film is lost, and the set-off is worsened.
[0013]
The present inventor found that the porosity of the porous resin film on the film side is high and advantageous in perforation sensitivity, but the porosity of the porous resin film on the side opposite to the film side is low and the printing durability of the porous film is reduced. It has been found that the above-mentioned technical problems can be solved by using a heat-sensitive stencil printing master that achieves both high perforation sensitivity and high printing durability by adopting a shape that is advantageous for controlling the properties and the ink passage amount.
[0014]
In the present invention, the film side of the porous membrane and the opposite side thereof are observed, and the ratio of the total void area in the measured area of the porous resin film (void area ratio) is obtained. Value.
[0015]
Void area ratio
In order to prevent the elongation of the master during printing and the decrease in printing density, it is preferable to increase the strength by lowering the porosity of the porous resin film. On the other hand, it is preferable to increase the porosity for good perforation sensitivity. In order to satisfy these contradictory characteristics at the same time, the present inventor has been able to achieve this by a technique in which the porosity of the portion in contact with the film of the porous resin film is higher than the opposite side. That is, a means for increasing the porosity at the portion in contact with the film to obtain good perforation sensitivity and at the same time increasing the film strength at a portion having a low porosity on the side opposite to the film side was adopted.
[0016]
Even if the porosity of the porous resin film in contact with the film is increased, there is a film on the film side of the porous resin film, so the decrease in strength due to the increase in the porosity on the film side is within the scope of achieving the object of the present invention. Although it does not become a problem, it is preferable that the void area ratio of the porous resin film observed from the film side is 1.05 to 1.5 times that observed from the film-free side. When the ratio is less than 1.05 times, the void ratio in the porous resin film is often lowered, and perforation by the thermal head is likely to be hindered. On the other hand, if it exceeds 1.5 times, the strength of the porous resin film in contact with the film is weakened, and the porous film is crushed during printing, and the printing density is liable to decrease during printing.
[0017]
The void area ratio observed from the film side is preferably 40 to 80%. If it is less than 40%, the resin part of the porous film tends to hinder the perforation of the film by the thermal head, and the ink permeability tends to be insufficient during printing. If it exceeds 80%, the strength of the porous resin film in contact with the film becomes weak, and the porous film is crushed during printing, so that the print density during printing tends to decrease.
[0018]
the film
As the thermoplastic resin film in the present invention, conventionally known ones such as polyester, polyamide, polypropylene, polyethylene, polyvinyl chloride, polyvinylidene chloride or a copolymer thereof are used, and polyester film is particularly preferable from the viewpoint of perforation sensitivity. Preferably used. Preferred examples of the polyester used for the polyester film include polyethylene terephthalate, a copolymer of ethylene terephthalate and ethylene isophthalate, and a copolymer of hexamethylene terephthalate and cyclohexanedimethylene terephthalate. In order to improve the perforation sensitivity, particularly preferred are a copolymer of ethylene terephthalate and ethylene isophthalate, a copolymer of hexamethylene terephthalate and cyclohexanedimethylene terephthalate, and the like.
[0019]
For the thermoplastic resin film in the present invention, if necessary, flame retardant, heat stabilizer, antioxidant, ultraviolet absorber, antistatic agent, pigment, dye, fatty acid ester, wax or other organic lubricant or polysiloxane, etc. An antifoaming agent or the like can be blended.
Furthermore, easy slipperiness can be imparted if necessary. The slipperiness imparting method is not particularly limited. For example, inorganic particles such as clay, mica, titanium oxide, calcium carbonate, kaolin, talc, wet or dry silica, organic particles containing acrylic acid, styrene, or the like as constituent components. Etc., a method using internal particles, a method of applying a surfactant, and the like.
[0020]
The thickness of the thermoplastic resin film in the present invention is usually preferably 0.1 to 5.0 μm, and more preferably 0.1 to 3.0 μm. When the thickness exceeds 5.0 μm, the piercing property may be deteriorated. When the thickness is less than 0.1 μm, the film forming stability may be deteriorated or the printing durability may be deteriorated.
[0021]
Functional thin layer
The functional thin layer referred to in the present invention refers to a thin layer having a function having at least one of the following functions, for example.
1. Function to improve adhesion between thermoplastic resin film and porous resin film.
2. A feature that improves curl.
3. A function that improves the rigidity of the master.
4). When drilling a master with a thermal head, it does not impede drilling sensitivity or even improves drilling performance.
5. Function to improve the strength of the film.
[0022]
Examples of the resin material include polyvinyl resins such as polyvinyl acetate, polyvinyl butyral, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, styrene-acrylonitrile copolymer, polybutylene, nylon and the like. Polyamide, polyphenylene oxide, (meth) acrylic acid ester, polycarbonate, polyester resin, polyether resin, polyurethane resin, copolymers thereof, mixtures, modified products and the like are used.
[0023]
When a biaxially stretched polyester is used as the film and a butyral resin is used as the porous film, polyester, a reaction product of polyol and isocyanate, an isocyanate polymer, or the like can be suitably used as the thin layer.
[0024]
Furthermore, various fillers, antistatic agents, anti-sticking agents, surfactants, preservatives, antifoaming agents, plasticizers, modifiers and the like can be used in combination as long as the effects of the present invention are not impaired.
[0025]
Moreover, in order to improve the adhesiveness between the thermoplastic resin film and the porous resin film, it is preferable to use polyisocyanate in combination. It is particularly preferable to use a polyester polyol, a polyether polyol, a polyurethane resin and a polyisocyanate in combination. In order to improve the piercing property in the thermal head, it is preferable to use polyester polyol, polyether polyol, polyurethane resin and isocyanate having a softening point of 40 to 150 ° C. in combination. Here, the molar ratio of OH group / NCO group is 1 / 0.1 to 1/20, but may be appropriately selected according to the required characteristics.
Furthermore, in order to lower the softening point of the functional thin layer, a resin having a low softening point may be used, or a plasticizer or the like may be added.
[0026]
The thickness of the functional thin layer after drying is preferably 0.01 to 2.0 μm, more preferably 0.1 to 1.0 μm. If it is thinner than 0.01 μm, the effect of improving adhesiveness, stiffness and curl is small, and if it exceeds 2.0 μm, the thermal perforation sensitivity is adversely affected. The material of the functional thin layer, the thickness after drying, is actually determined by several experiments.
[0027]
Interface thin layer
The porous resin film may have a thin layer having no void at the interface with the film. In the present invention, the void of the porous resin film is measured regardless of the presence or absence of this thin layer. The same applies when a functional thin film is present between the porous resin film and the film.
When observing with an optical microscope, especially when viewed from the film side, there may be a part that does not directly affect the perforation sensitivity of the master due to the depth of field of the microscope. A thin layer portion that does not directly affect the perforation sensitivity as described above is ignored, and the pore diameter of the porous resin film is measured as a void visible on the surface of the porous resin film.
[0028]
Porous resin membrane
The porous resin film in the present invention only needs to have a structure having a large number of voids inside and on the surface thereof, and the voids are continuous in the thickness direction in the porous resin film from the viewpoint of ink permeability. A structure is desirable.
In the present invention, the average pore diameter of the porous resin film is generally 2 to 50 μm, desirably 5 to 30 μm. When the average pore diameter is less than 2 μm, ink permeability is poor. For this reason, if low-viscosity ink is used in order to obtain a sufficient amount of ink passing, a phenomenon occurs in which printing ink oozes out from the side portion of the printing drum or the back end of the wound master during printing or printing. On the other hand, when the average pore diameter exceeds 50 μm, the ink suppression effect by the porous resin film is reduced, and the ink between the printing drum and the film is excessively pushed out during printing, causing problems such as back stains and blurring. To do. That is, if the average pore size is too small or too large, good print quality cannot be obtained.
In particular, when the average pore diameter of the voids in the porous resin film is 20 μm or less, the thicker the porous resin film layer, the more difficult it is for the printing ink to pass, so the thickness of this layer controls the amount of ink transferred to the printing paper can do. If the thickness of the layer is not uniform, printing unevenness may occur. Therefore, it is desirable that the thickness is uniform.
[0029]
The thickness of the porous resin film of the present invention is 2 to 100 μm, preferably 5 to 50 μm. When the thickness is less than 2 μm, the porous resin film hardly remains behind the perforated portion after perforation by the thermal head, and the backside of the printed matter tends to occur without controlling the ink transfer amount. Further, the effect of suppressing the ink transfer amount of the porous resin film is larger as the film is thicker, and the amount of ink transferred onto the paper during printing can be adjusted by the thickness of the porous resin film.
[0030]
The density of the porous resin film is usually 0.01 to 1 g / cm. ^Three And preferably 0.1 to 0.7 g / cm ^Three It is. Density is 0.01g / cm ^Three If it is less, the strength of the film is insufficient, and the film itself is fragile. 0.7 g / cm ^Three Exceeding the ink deteriorates the ink permeability during printing. The adhesion amount of the porous resin film is 0.1 to 35 g / m. ² , Preferably 0.5 to 25 g / m ² , Particularly preferably 1 to 11 g / m ² It is. 0.1 g / m ² If it is less than 1, it becomes difficult to control the ink transfer amount, and conversely 35 g / m ² If it exceeds, the passage of ink is hindered and the image is deteriorated.
[0031]
Examples of the resin material constituting the porous resin film include polyvinyl resins such as polyvinyl acetate, polyvinyl butyral, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, styrene-acrylonitrile copolymer, and the like. And polyamide derivatives such as polybutylene and nylon, polyphenylene oxide, (meth) acrylic acid ester, polycarbonate, polyurethane, acetylcellulose, acetylbutylcellulose, cellulose derivatives such as acetylpropylcellulose, and the like.
Each of the above resins may be used in combination of two or more.
[0032]
In order to adjust the formation, strength, pore size, etc. of the porous resin film, it is desirable to add an additive such as a filler to the porous resin film as necessary. Here, the filler is a concept including pigments, powders and fibrous substances. Among them, a needle-like filler is particularly preferable. Specific examples thereof include magnesium silicate, sepiolite, potassium titanate, wollastonite, zonotlite, gypsum fiber and other mineral needle fillers, non-oxide needle whiskers, oxide whiskers, and complex oxides. Artificial mineral needle fillers such as whiskers and plate fillers such as mica, glass flakes, and talc can be mentioned.
As the pigment, not only inorganic pigments but also organic pigments, organic polymer particles such as polyvinyl acetate, polyvinyl chloride, and polymethyl acrylate, and zinc oxide, titanium dioxide, calcium carbonate, and silica can be used.
The addition amount of these additives is preferably 5 to 200% with respect to the resin.
If it is less than 5%, the bending rigidity by adding an additive does not increase. On the other hand, if it exceeds 200%, the adhesion to the film is deteriorated.
[0033]
The porous resin film of the present invention can be used in combination with an antistatic agent, an anti-stick agent, a surfactant, a preservative, an antifoaming agent and the like within a range that does not impair the effects of the present invention.
[0034]
Precipitation method
Next, the formation method of the porous resin film of the master for heat-sensitive stencil printing is demonstrated.
The first porous resin film is formed by applying a coating solution obtained by dissolving and / or dispersing in a mixed solvent of a good solvent and a poor solvent of a resin that dissolves well together, and forming the porous film in a drying process. To form. At this time, the good solvent needs a combination that is relatively easy to evaporate at a lower temperature than the poor solvent. When one good solvent and one poor solvent are used, the boiling point of the good solvent must be relatively lower than the boiling point of the poor solvent. The selection of the good solvent and the poor solvent is arbitrary, but in general, a porous resin film having desired characteristics is easily formed when the difference in boiling points is 15 to 40 ° C. When the difference in boiling points is less than 10 ° C., the difference in evaporation time between the two solvents is small, and the formed film is unlikely to have a porous structure. When the boiling point of the poor solvent is too high, drying takes time and the productivity is poor, so the boiling point of the poor solvent is desirably 150 ° C. or lower.
[0035]
The resin concentration in the coating solution is 5 to 30% (by weight) although it varies depending on the material used. If it is less than 5%, the opening diameter becomes too large, or the thickness of the porous resin film tends to be uneven. Conversely, if it exceeds 30%, it is difficult to form a porous resin film, or even if it is formed, the pore diameter becomes small and it is difficult to obtain desired characteristics.
[0036]
The size of the average pore diameter of the porous resin film is affected by the poor solvent in the atmosphere. Generally, the higher the ratio to the good solvent, the larger the amount of condensation and the larger the average pore diameter. Since the addition ratio of the poor solvent varies depending on the resin and the solvent, it is necessary to determine appropriately by experiment. Generally, the pore diameter of the porous resin film increases as the amount of the poor solvent added increases. If the amount of the poor solvent added is too large, the resin will precipitate and the coating solution will become unstable.
[0037]
The ratio of the void area ratio of the porous resin film observed from the film side and the void area ratio of the porous resin film observed from the opposite side to the film side can be controlled as follows.
[0038]
When it takes time to dry the porous resin film-forming coating solution, the growth of voids on the side closer to the film proceeds, and the void area ratio on the film side increases. Further, even when the viscosity of the coating solution is low, the gap on the film side is large and the void area ratio tends to be high.
[0039]
The drying time of the coating solution is controlled by the atmospheric temperature at the time of drying, the amount of wind blown, and the like. The viscosity of the coating solution is determined by the formulation such as the solid content concentration and the molecular weight of the resin.
[0040]
Emulsion method
As a method for forming the second porous resin film, a fluid mainly composed of a W / O emulsion is used when the good solvent and the poor solvent of the resin forming the porous resin film do not mix well with each other. It is formed by applying and drying on a thin layer (for example, Japanese Patent Application Laid-Open No. 11-235895), and mainly water portions become pores through which ink passes after drying, and resin in the solvent (filler, emulsifier, etc.) In which the additive may be contained) is a method of forming a structure. Also in this method, in order to adjust the formation, strength, pore size, stiffness, etc. of the porous resin film, an additive such as the filler is added to the porous film as necessary in addition to the hollow filler. be able to. Of these, needle-like, plate-like, or fibrous fillers are particularly preferred.
[0041]
For the formation of a W / O type emulsion, a surfactant having a relatively strong lipophilicity and having an HLB (Hydrophiric-Lyophiric Balance) of 4 to 6 is effective, but the surfactant having an HLB of 8 to 20 is also used in the aqueous layer. Can be used to obtain a more stable and uniform W / O emulsion. The use of a polymeric surfactant is also one method for obtaining a more stable and uniform emulsion. In addition, the addition of a thickener such as polyvinyl alcohol or polyacrylic acid is effective for stabilizing the emulsion in the aqueous system.
[0042]
The ratio of the void area ratio observed from the film side of the porous resin film to the void area ratio observed from the film-free side can be controlled as follows.
[0043]
When the viscosity of the coating liquid for forming a porous resin film is low or the stability of the emulsion is low, the void area ratio observed from the film side tends to be higher than that observed from the side without the film.
When the W / O emulsion is dried with the film facing down, the aqueous phase having a large particle size tends to settle and gather near the film, and the aqueous phase having a small particle size tends to gather upward.
[0044]
When the viscosity of the coating solution is low, the movement of the aqueous phase is facilitated, and the pore diameter observed from the film side tends to be larger than the pore diameter observed from the side without the film. As a result, the void area ratio on the film side increases. When the stability of the emulsion is low, the aqueous phase is likely to coalesce in the emulsion, and the aqueous phase having a large particle size due to the coalescence is likely to settle. As a result, the pore diameter observed from the film side is large and the void area ratio tends to be high. (Normally, as the pore diameter increases, the void area ratio also increases, and as a result, the void area ratio can be controlled.)
[0045]
The viscosity of the coating solution is determined by the formulation, such as the solid content concentration, the molecular weight of the resin, and the ratio of water phase to oil phase. The stability of the coating solution can be controlled by the formulation, particularly the type and amount of surfactant, in addition to the emulsification method.
However, the method for forming the porous resin film of the present invention is not limited to the method exemplified above.
[0046]
Coating method
As a method of applying the coating liquid for forming the porous resin film of the present invention to the thermoplastic resin film, conventionally used coating methods such as blades, transfer rolls, wire bars, reverse rolls, gravure and dies are used. There is no particular limitation.
[0047]
Porous fiber membrane
In order to stabilize the printed image density in printing using the master of the present invention, it is effective to reduce the porosity of the porous resin film or reduce the porosity, but this will deteriorate the ink permeability of the master. As a result, the print image density is lowered. Therefore, if the adhesion amount of the porous resin film is reduced, the thickness of the porous resin film becomes small and it is difficult to be crushed during printing, and the change in the printing density is reduced. However, since there is a possibility that a problem may occur in the transportability and printing durability of the master as it is, it is preferable to laminate a porous fiber film on the porous resin film.
A master on which a porous fiber film is laminated can be a means for achieving both high ink permeability and printing density stability.
[0048]
Examples of the porous fiber membrane in the present invention include (1) mineral fibers such as glass, sepiolite, various metals, (2) animal fibers such as wool and silk, (3) natural materials such as cotton, Manila hemp, Kozo, Mitsumata, and pulp. Recycled fibers such as fibers, (4) recycled fibers such as soot and rayon, (5) synthetic fibers such as polyester, polyvinyl alcohol and acrylic, (6) semi-synthetic fibers such as carbon fibers, and (7) inorganic fibers having a whisker structure Is mentioned.
[0049]
The thickness of the fibrous substance needs to be selected appropriately depending on the perforation diameter of the thermoplastic resin film, the thickness of the film, etc., but the diameter is 20 μm or less, preferably 1 to 10 μm. If the diameter is smaller than 1 μm, the tensile strength is weak, and if it is larger than 20 μm, ink passage is hindered, and so-called white spots due to fibers appear in the image. The length of the fibrous substance is preferably about 0.1 to 10 mm, more preferably about 1 to 6 mm. If it is shorter than 0.1 mm, the tensile strength becomes weak, and if it is longer than 10 mm, it becomes difficult to uniformly disperse.
[0050]
The basis weight of the porous fiber layer in the present invention is preferably preferably 3 to 20 g / m. ² More preferably, it is 5-15 g / m ² It is. Basis weight is 20g / m ² If it exceeds 1, the ink permeability is lowered and the image sharpness is lowered. The basis weight is 3g / m ² If it is less, sufficient strength as a support may not be obtained.
[0051]
The porous fiber layer made of a fibrous substance in the present invention may be a paper-making paper made of short fibers, a non-woven fabric or a woven fabric, a screen wrinkle, etc. Papermaking paper is preferably used from the viewpoint of cost.
[0052]
The adhesive strength between the thermoplastic resin film and the porous resin film of the heat-sensitive stencil printing master of the present invention, and when the porous fiber film is provided, the adhesive strength between the porous resin film and the porous fiber film is respectively It is desirable that it is 1.4 N / m or more, more preferably 2.8 N / m or more. When the adhesive strength is less than 1.4 N / m, peeling occurs during handling and conveyance, causing not only wrinkles but also problems such as elongation, peeling, and tearing during printing. The upper limit of the adhesive strength is not particularly limited as long as ink passage is not inhibited.
[0053]
In the present invention, the adhesive used when laminating the porous fiber membrane is preferably in a high-viscosity state so as not to block the pores of the porous resin film from the ink-permeable surface, preferably an adhesive. The viscosity until completely cured is 100 cps or more, and more preferably 300 cps or more.
[0054]
According to the present invention, as a method for producing a heat-sensitive stencil master for laminating a porous fiber layer, a coating liquid for forming a porous resin film is applied on one surface of a thermoplastic resin film. It is desirable that at least after the outermost surface layer of the porous resin film is dried and formed into a film, it is bonded to the porous fiber layer coated with an adhesive. If the porous fiber film is laminated before the porous resin film is formed, formation of the porous resin film is hindered and a desirable porous film cannot be obtained. In addition, since the adhesive may block the pores of the porous resin film, it is desirable to apply it to the porous fiber film.
[0055]
In order to form a porous resin film having excellent ink permeability, which is the object of the present invention, a thermoplastic resin is preferably used. In this case, if a solvent-type adhesive is used as the adhesive, the porous resin film is eroded and closes the pores, so there should be no solvent at least when the porous resin film and the porous fiber film are laminated. From this aspect, a solventless adhesive and an aqueous / emulsion adhesive are preferably used.
[0056]
In order to obtain the adhesive strength of the present invention and to satisfy the above conditions, a polyurethane-based adhesive is used. As the polyurethane-based adhesive of the present invention, a solventless polyurethane adhesive capable of obtaining desired adhesive strength with a low adhesion amount is used. In addition, since porous fiber membranes containing inexpensive natural fibers are preferably used, the aqueous fiber type polyurethane adhesive causes expansion and contraction of the porous fiber layer at the time of coating, from the aspect of deteriorating curl and the like. Also, a solventless polyurethane adhesive is used.
[0057]
Solventless polyurethane adhesives include one-component moisture-curing urethane prepolymers obtained by the reaction of polyol components such as polyether polyols and polyester polyols having hydroxyl groups at both ends with isocyanate components, and polyol components and isocyanate components. A separate two-part curable adhesive may be mentioned, but is not particularly limited. As the isocyanate component, hexamethylene diisocyanate (HMDI), 2,4-diisocyanate-1-methylcyclohexane, 2,6-diisocyanate-1-methylcyclohexane, diisocyanate cyclobutane, tetramethylene diisocyanate, o-, m-, and p- Xylylene diisocyanate (XDI), dicyclohexylmethane diisocyanate, dimethyldicyclohexylmethane diisocyanate, hexahydrometaxylidene diisocyanate (HXDI), and lysine diisocyanate alkyl esters (the alkyl portion of the alkyl ester has 1 to 6 carbon atoms) Aliphatic or cycloaliphatic diisocyanates such as toluylene-2,4-diisocyanate (TD1), toluylene-2, -Diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), 3-methyldiphenylmethane-4,4'-diisocyanate, m- and p-phenylene diisocyanate, chlorophenylene-2,4-diisocyanate, naphthalene 1,5-diisocyanate Aromatic diisocyanates such as, diphenyl-4,4′-diisocyanate, 3,3′-dimethyldiphenyl-4,4′-diisocyanate, 1,3,5-triisopropylbenzene-2,4-diisocyanate and diphenyl ether diisocyanate: Mixtures of these are used.
[0058]
The adhesive application method may be any method such as blade coating method, reverse roll coating method, gravure coating method, knife coating method, spray coating method, offset gravure coating method, kiss coating method, bar coating method, etc., and is not particularly limited. .
The surface to which the adhesive is applied may be applied to either the porous resin film or the porous fiber film, but in order not to block the opening of the porous resin film, it is better to apply to the porous fiber film. .
[0059]
When a solventless polyurethane adhesive is applied to a porous fiber membrane, if the viscosity is too high, the fibers will fall off and a coating failure will occur. Therefore, by heating the roll, the viscosity is reduced to 3000 cps or less. preferable. More preferably, the coating is preferably performed between 300 and 1500 cps. If the viscosity is less than 300 cps, the opening may be blocked after being bonded to the porous resin film, and ink permeability may be impaired. If the viscosity exceeds 3000 cps, fiber loss of the porous fiber layer tends to occur.
[0060]
When a solventless adhesive is used, curing is preferably performed for the purpose of promoting the reaction of the heat-sensitive stencil master wound in a roll. The curing temperature is preferably 50 ° C. or lower, and more preferably 40 ° C. or lower. If the temperature exceeds 50 ° C., the thermoplastic resin film shrinks and a curling problem occurs. The curing time is not particularly limited as long as the target adhesive force is obtained.
[0061]
As an application method of the adhesive of the present invention, there is a method in which a coating liquid diluted with an organic solvent such as ethyl acetate is applied to the porous fiber layer and dried, and then bonded to the porous resin film. In view of the problem of surface and residual solvent, a method of coating without solvent is preferred.
[0062]
Unlike the conventional heat-sensitive stencil printing master (laminated product of thermoplastic resin film and porous fiber film), it is not necessary to consider the influence of perforation inhibition as the adhesion amount of the adhesive described above, Although it will not specifically limit if the desired adhesive strength is obtained, What is necessary is just the range which does not obstruct | occlude the hole of a porous resin membrane and a porous fiber membrane, Preferably it is 0.05-5.0 g / m. ² More preferably, 0.1 to 3.0 g / m ² Range.
[0063]
ASL
The heat-sensitive stencil printing master of the present invention has a silicone oil, a silicone resin, a fluorine resin, a surfactant, an antistatic agent, a heat resistance to prevent fusion at the time of perforation on one side of the film to be in contact with the thermal head. It is desirable to provide a thin layer comprising an agent, an antioxidant, organic particles, inorganic particles, a pigment, a dispersion aid, an antiseptic, an antifoaming agent, and the like.
The thickness of the anti-fusing thin layer is preferably 0.005 to 0.4 [mu] m, more preferably 0.01 to 0.4 [mu] m.
[0064]
The method for providing a thin layer for preventing fusion in the heat-sensitive stencil master of the present invention is not particularly limited, but a solution diluted with water, a solvent, or the like is applied using a roll coater, gravure coater, reverse coater, bar coater or the like. It is preferable to dry.
[0065]
(Characteristic measurement method)
Porous resin film void area ratio
Observe the master porous resin film from the film side and the side without the film with an optical microscope (Olympus BX60 magnification 200 times, illumination is reflected light, level 9. Use the polarizing filter at the most effective position), computer Import images to. Focus is adjusted to each surface of the porous resin film. (The sample is gradually brought closer to the eyepiece of the optical microscope, and the first focused part of the porous resin film)
The image is binarized using image processing software “WinROOF” (manufactured by Mitani Shoji Co., Ltd.) to obtain the void area ratio.
The binarization procedure is as follows. Gray imaging, density conversion (default), automatic binarization (P tile method, default), hole filling, deletion (100 or less), measurement (shape feature-area).
In the case of a master in which a porous fiber film is laminated on a porous resin film, photography from the side without the film is completed before the porous fiber film is laminated in the master preparation stage.
[0066]
Adhesive strength
(1) Adhesive strength between thermoplastic resin film and porous resin film
When the heat-sensitive stencil printing master of the present invention has a porous fiber film, only the porous fiber film is peeled off from the master. If the master does not have a porous fiber membrane, this work is unnecessary.
Next, a cellophane tape is affixed to the surface opposite to the porous resin film so that air does not enter, and measurement is performed by a 90-degree peel test in accordance with JIS K6854-1. At this time, the porous resin film to which the cellophane tape is attached is fixed, the thermoplastic resin film is pulled, and measurement is performed. When only the porous fiber membrane cannot be peeled off, the cellophane tape is not attached, and the laminate of the porous fiber membrane and the porous resin membrane is fixed and measured.
Even when a functional thin film exists between the thermoplastic resin film and the porous resin film, the adhesive strength between the thermoplastic resin film and the porous resin film is increased by the above method without worrying about the presence of the functional thin film. It shall be measurable.
[0067]
(2) Adhesive strength between porous resin film and porous fiber film
(Only when the heat-sensitive stencil printing master of the present invention has a porous fiber membrane)
Only the thermoplastic resin film is peeled off from the master for heat-sensitive stencil printing of the present invention, and a cellophane tape is pasted on the surface of the porous resin film from which the thermoplastic resin film has been peeled off so as not to enter air, in accordance with JIS K6854-1. Measured by the 90 degree peel test. At this time, the porous resin film to which the cellophane tape is attached is fixed, and the porous fiber film is subjected to tensile measurement. When only the thermoplastic resin film cannot be peeled off, the cellophane tape is not attached, and the laminate of the thermoplastic resin film and the porous fiber film is fixed and measured.
[0068]
2) Evaluation of printability
The prepared master was supplied to “Preport JP4000” (thermal head resolution 400 dpi) manufactured by Ricoh Co., Ltd., and 100 sheets were printed at a standard speed by using a thermal head type plate making method using a black solid of 50 mm × 50 mm. .
Perforation sensitivity: A film portion of the master that is completely perforated by a thermal head and has a large perforation diameter ◎, a film that is completely perforated ○, and a film that is perforated but has a small perforation diameter △ Those which are not partially perforated are indicated by x.
Image quality: By visually judging the printed matter, the solid white portion where the white spots were conspicuous was evaluated as “x”, and the intermediate level between “◯” and “x” was evaluated as “Δ”.
Set-off: The case where there was no set-off was evaluated as “◯”, the set-off set at a level that could not withstand double-sided printing was evaluated as “X”, and the level that could be used practically in the middle was evaluated as “Δ”.
[0069]
3) Evaluation of printing durability
Stretch, peel
The prepared master was supplied to “Preport JP4000” manufactured by Ricoh Co., Ltd., and was subjected to plate making and printing by using a thermal head type plate making method using a manuscript having 6-point characters and 50 mm × 50 mm solid black. The standard printing speed was 3000 sheets.
If an abnormal image such as image stretching occurs x, no defect is seen in the image, but if the master is peeled off or the porous fiber film is peeled after printing, the master is completely abnormal The case where no was seen was marked as ◯.
Image density change
In the print of the printing durability test, the value obtained by dividing the image density of the 3000th sheet by the image density of the 50th sheet is less than 0.95, x if 0.95 or more and less than 0.98, Δ, 0.98. If it is above 0.99 and less than 0.99, it is marked as ◯, and if it is 0.99 and below 1.01, it is marked as.
[0070]
4) Evaluation of transportability
When performing the above evaluations 2) and 3), those that could be transported without problems were marked with ○, those that were wrinkled during transportation, and those that were wrinkled during transportation but did not affect the image. Evaluated as △.
[0071]
【Example】
EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. All parts shown below are based on weight.
[0072]
Reference example 1-4, 8, Comparative Example 1
Polyvinyl acetal resin
(Sekisui Chemical Co., Ltd. S-REC KS-1) 3.2
Talc (Nihon Talc Co., Ltd. Microace LG) 2.4
Sorbitan fatty acid ester
(Nikko Chemicals Corporation SO-10) 0.1
Modified silicone oil
(Shin-Etsu Chemical KF6012) 0.1
Acrylic polymer O / W emulsion
(Johnson Polymer Co., Ltd. Joncryl-711) 0.2
The above solution was dissolved and dispersed in ethyl acetate, and water (HEC (hydroxyethylcellulose) 1% solution) was slowly added to the solution while stirring to obtain a cloudy porous film-forming coating solution. The amount of ethyl acetate and water (HEC 1% solution) depends on the solid content concentration of each coating solution shown in Table 1, and the ratio of both is 1.0 for water (HEC 1% solution) to 1.5 for ethyl acetate. there were. Each of the above coating solutions was applied in a die head on a biaxially stretched polyester film having a thickness of 2.0 μm in an atmosphere of 20 ° C. and 50% RH so that the adhesion amount after drying would be the value shown in Table 1. It dried in 50 degreeCRH atmosphere, formed the porous resin film, and wound up in roll shape.
Anti-fusing agent coating liquid formulation
Silicone oil (SF8422 manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5
Surfactant (Pricesurf A208 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5
Toluene 100.0
Next, the above anti-fusing agent was applied and dried on the surface of the thermoplastic resin film opposite to the porous resin film using a bar coater to obtain a heat-sensitive stencil printing master. The prepared thermosensitive stencil printing master was evaluated by the above-described evaluation method. The results are shown in Table 2.
[0073]
Reference example 5
Functional thin layer coating solution
Polyester resin 30% ethyl acetate solution
(Toyobo Co., Ltd. Byron 50AS) 25.0
Ethyl acetate 185
A polyester resin ethyl acetate solution (Toyobo Co., Ltd. Byron 50AS) was diluted with ethyl acetate to obtain a functional thin layer coating solution. The functional thin layer coating solution was applied onto a biaxially stretched polyester film having a thickness of 2.0 μm and dried at 50 ° C. to obtain a functional thin layer having a thickness of 0.05 μm. Furthermore, the coating amount of the porous film forming coating solution used in Example 2 was 6.0 g / m after drying with a die head in an atmosphere of 20 ° C. and 50% RH. ² Then, it was applied and dried in an atmosphere of 50 ° C. and 50% RH to form a porous resin film and wound up into a roll. Then Reference example 1. Apply and dry the anti-fusing agent 1 on the surface of the thermoplastic resin film opposite to the porous resin film using a bar coater. , Feeling A master for hot stencil printing was obtained. The prepared thermosensitive stencil printing master was evaluated by the above-described evaluation method. The results are shown in Table 2.
[0074]
Example 6
Reference example The coating solution for forming a porous film used in No. 2 was dried on a biaxially stretched polyester film having a thickness of 2.0 μm by a die head in an atmosphere of 20 ° C. and 50% RH, and the adhesion amount was 3.0 g / m ² Then, it was applied and dried in an atmosphere of 50 ° C. and 50% RH to form a porous resin film and wound up into a roll. Subsequently, paper made of 100% natural fiber as a porous fiber membrane (basis weight 10 g / m ² And a thickness of 33 μm) using a roll coater heated to 100 ° C., a one-component urethane adhesive (Takenate A260 manufactured by Takeda Pharmaceutical Company Limited) is applied in an amount of 0.2 g / m. ² After rolling, coating was performed so that the porous resin film surface of the previously prepared roll was laminated. The viscosity of the adhesive at the time of application was about 1000 cps. Then Reference example The anti-fusing agent coating solution used in 1 was applied to the surface of the thermoplastic resin film opposite to the porous resin film using a bar coater, dried, wound up, and cured at 30 ° C. for 3 days. A master for thermal stencil printing of the present invention was obtained. The prepared thermosensitive stencil printing master was evaluated by the above-described evaluation method. The results are shown in Table 2.
[0075]
Example 7
Reference example The coating solution for forming a porous film used in No. 2 was dried on a biaxially stretched polyester film having a thickness of 2.0 μm by a die head in an atmosphere of 20 ° C. and 50% RH, and the adhesion amount was 3.0 g / m ² Then, it was applied and dried in an atmosphere of 50 ° C. and 50% RH to form a porous resin film and wound up into a roll. Subsequently, a paper made of two types of polyester fibers having a fineness of 0.2 denier and 1.1 denier as a porous fiber membrane (basis weight: 8 g / m ² , Thickness 25 μm) using a roll coater heated to 70 ° C. with a two-component reactive urethane adhesive (Polyol component: Takelac A230, isocyanate component: A30, mixing ratio 10: 8, manufactured by Takeda Pharmaceutical Company Limited) as an adhesive. Application amount is 0.7g / m ² After rolling, coating was performed so that the porous resin film surface of the previously prepared roll was laminated. The viscosity of the adhesive at the time of application was about 800 cps. Then Reference example The anti-fusing agent coating solution used in 1 was applied to the surface of the thermoplastic resin film opposite to the porous resin film using a bar coater, dried, wound up, and cured at 30 ° C. for 3 days. A master for thermal stencil printing of the present invention was obtained. The prepared thermosensitive stencil printing master was evaluated by the above-described evaluation method. The results are shown in Table 2.
[0076]
Reference example 9
Reference example The porous film-forming coating solution 2 used in No. 2 was dried on a biaxially stretched polyester film having a thickness of 2.0 μm by a die head in an atmosphere of 20 ° C. and 50% RH, and the adhesion amount was 3.0 g / m. ² Then, it was applied and dried in an atmosphere of 50 ° C. and 50% RH to form a porous resin film and wound up into a roll.
Saturated polyester adhesive (UE3500, manufactured by Unitika) 15.0
Toluene 75.0
The coating amount obtained by dissolving and mixing the above using a direct gravure coater is 0.2 g / m after drying. ² Paper made of 100% natural fiber (basis weight 10g / m) ² , A thickness of 33 μm), and was superposed on the porous resin film surface of the previously prepared roll, followed by drying at 50 ° C. Then Reference example Apply and dry the anti-fusing agent coating solution used in 1 on the surface of the thermoplastic resin film opposite to the porous resin film using a bar coater. , Feeling A master for hot stencil printing was obtained. The prepared thermosensitive stencil printing master was evaluated by the above-described evaluation method. The results are shown in Table 2.
[0077]
Reference example 10
Polyvinyl butyral
(PVB3000-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) 8.0
Ethyl alcohol 73.0
Water 19.0
After dissolving polyvinyl butyral in ethyl alcohol, water was added dropwise with stirring and mixed to obtain a porous film-forming coating solution. This liquid was dried by a die head in an atmosphere of 20 ° C. and 50% RH, and the adhesion amount was 6.0 g / m. ² Then, it was applied and dried in an atmosphere of 20 ° C. and 50% RH to form a porous resin film and wound up into a roll. Then Reference example 1. Apply and dry the anti-fusing agent 1 on the surface of the thermoplastic resin film opposite to the porous resin film using a bar coater. , Feeling A master for hot stencil printing was obtained. The prepared thermosensitive stencil printing master was evaluated by the above-described evaluation method. The results are shown in Table 2.
[0078]
Example 11
Polyvinyl butyral
(PVB3000-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) 8.0
Ethyl alcohol 69.0
Water 23.0
After dissolving polyvinyl butyral in ethyl alcohol, water was added dropwise with stirring and mixed to obtain a porous film-forming coating solution. This liquid was dried by a die head in an atmosphere of 20 ° C. and 50% RH, and the adhesion amount was 6.0 g / m. ² Then, it was applied and dried in an atmosphere of 20 ° C. and 50% RH to form a porous resin film and wound up into a roll. Subsequently, paper made of 100% natural fiber as a porous fiber membrane (basis weight 10 g / m ² And a thickness of 33 μm) using a roll coater heated to 100 ° C., a one-component urethane adhesive (Takenate A260 manufactured by Takeda Pharmaceutical Co., Ltd.) is applied in an amount of 0.05 g / m. ² After rolling, coating was performed so that the porous resin film surface of the previously prepared roll was laminated. The viscosity of the adhesive at the time of application was about 1000 cps. Then Reference example The anti-fusing agent coating solution used in 1 was applied to the surface of the thermoplastic resin film opposite to the porous resin film using a bar coater, dried, wound up, and cured at 30 ° C. for 3 days. A heat-sensitive stencil printing master of the present invention was obtained. The prepared thermosensitive stencil printing master was evaluated by the above-described evaluation method. The results are shown in Table 2.
[0079]
Comparative Example 2
Polyvinyl butyral
(PVC3000-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) 12.0
Ethyl alcohol 71.0
Water 17.0
After dissolving polyvinyl butyral in ethyl alcohol, water was added dropwise with stirring and mixed to obtain a porous film-forming coating solution. This liquid was dried by a die head in an atmosphere of 20 ° C. and 50% RH, and the adhesion amount was 6.0 g / m. ² Then, it was applied and dried in an atmosphere of 50 ° C. and 50% RH to form a porous resin film and wound up into a roll. Then Reference example The anti-fusing agent 1 was applied and dried on the surface of the thermoplastic resin film opposite to the porous resin film using a bar coater to obtain a heat-sensitive stencil printing master of a comparative example. The prepared thermosensitive stencil printing master was evaluated by the above-described evaluation method. The results are shown in Table 2.
[0080]
Reference example 12
Polyvinyl butyral
(PVB3000-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) 8.0
Ethyl alcohol 67.0
Water 25.0
After dissolving polyvinyl butyral in ethyl alcohol, water was added dropwise with stirring and mixed to obtain a porous film-forming coating solution. This liquid was dried by a die head in an atmosphere of 20 ° C. and 50% RH, and the adhesion amount was 6.0 g / m. ² Then, it was applied and dried in an atmosphere of 20 ° C. and 50% RH to form a porous resin film and wound up into a roll. Then Reference example Apply and dry 1 anti-fusing agent on the surface of the thermoplastic resin film opposite to the porous resin film using a bar coater. , Feeling A master for hot stencil printing was obtained. The prepared thermosensitive stencil printing master was evaluated by the above-described evaluation method. The results are shown in Table 2.
[0081]
[Table 1]

[0082]
[Table 2]

[0083]
Evaluation of Examples and Comparative Examples
Example 1: Perforation sensitivity is slightly low, but printing density stability is high, and there is no problem in use.
Example 2: There is no problem in any of the standard sample of the present invention, printability, printing durability, and transportability.
Example 3: Print density stability is slightly lower, but perforation sensitivity is good, and there is no problem in use.
Comparative Example 1: High printing density stability but poor perforation sensitivity
Example 4: Print density stability is slightly low, but perforation sensitivity is high, and there is no problem in use.
Example 5: FP adhesive strength is high due to the effect of the functional thin layer
Example 6: Print density stability is high by reducing the adhesion amount of the porous resin layer and laminating the porous fiber film.
Example 7: Printing density stability is high by reducing the adhesion amount of the porous resin film and laminating the porous fiber film
Example 8: Although the adhesion amount of the porous resin film was reduced but the porous fiber film was not laminated, the printing durability was slightly low, but there was no problem
Example 9: Although the printing durability and transportability are slightly inferior due to the low adhesive strength of saturated polyester, there is no problem in use.
Example 10: Master according to the process of claim 9. There are no problems with printability, printing durability, and transportability.
Example 11: There was no problem in printing quality, and although some peeling was observed between the film and the porous resin film and between the porous resin film and the porous fiber film after the printing durability test, there was no problem in use.
Comparative Example 2: Printing density stability is high, but the perforation sensitivity is low, and the image has many white spots
Example 12: There was no problem in use although some peeling was observed due to the low adhesive strength between the film and the porous resin film.
[0084]
【The invention's effect】
According to the first aspect of the present invention, a master having good perforation sensitivity can be obtained.
According to the second aspect of the present invention, a master having both good perforation sensitivity and excellent printing durability can be obtained.
According to the invention described in claim 3, a master having both good perforation sensitivity and excellent printing durability can be obtained.
According to invention of Claim 4, the master with favorable adhesion | attachment of a porous resin film and a thermoplastic resin film is obtained. The functional thin layer can be expected to improve the curl, stiffness, strength, etc. of the master due to its components.
According to the invention described in claim 5, since the printing durability is ensured by the porous fiber film to be laminated, the choice of the resin constituting the porous resin film is wider than the case where the porous fiber film is not laminated, In addition, the amount of resin adhesion of the porous resin film can be reduced without causing problems in the transportability and printing durability of the master, so that both high ink permeability and printing density stability can be achieved, and high ink permeability A master that can easily form a resin film is obtained.
According to the invention described in claim 6, a master free from peeling during plate making or printing can be obtained.
According to the seventh aspect of the present invention, a master free from peeling during plate making or printing can be obtained.
According to the invention described in claim 8, a master capable of giving sufficient adhesive strength between the porous resin film and the porous fiber film without deteriorating good print image quality can be obtained.
The invention according to claim 9 is used when a plurality of solvents (good solvent and poor solvent) having different solubility of the resin forming the porous resin film are well dissolved. Since organic solvents are often soluble in each other, the choice of solvent is wide, and as a result, the selection range of the resin is widened. Further, by arbitrarily changing the mixing ratio of the solvent, a string-like porous resin film can be easily formed, and a solvent having a high evaporation rate such as ether or acetone can be selected to increase productivity.
In the invention described in claim 10, a good solvent and a poor solvent that do not mix with each other are selected to form an emulsion. Compared with the method of claim 9, since it does not depend on the solubility of the resin, it is not easily affected by temperature and humidity, the reproducibility of the formed film shape is high, the degree of freedom of formulation is high, and the range in which a porous resin film can be formed Therefore, it is easy to adjust the viscosity of the coating liquid by the ratio of the oil phase and the water phase, the resin concentration, the resin molecular weight, and the like. Further, in the invention of this claim, generally, if the solid content concentration is the same, the coating liquid becomes higher in viscosity than the method of claim 9.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an example of a heat-sensitive stencil master according to the present invention.
[Explanation of symbols]
1 Thermoplastic resin film
2 Porous resin membrane
3 Porous fiber membrane
4 Porous resin membrane resin part
5 Porous resin film void

Claims (8)

In the thermal stencil printing master having at least a porous resin film formed by applying and drying a fluid on a thermoplastic resin film, the void area ratio of the porous resin film observed from the film side is opposite to the film side Larger than the void area ratio of the porous resin film observed from
Laminating a porous fiber film made of a fibrous material on the surface of the porous resin film provided on one surface of the thermoplastic resin film,
The porous resin film and the porous fiber film are bonded with a solventless polyurethane adhesive ,
The adhesive strength between the thermoplastic resin film and the porous resin film is 1.4 N / m or more and 3.2 N / m or less,
A master for heat-sensitive stencil printing , wherein an adhesive strength between the porous resin film and the porous fiber film is 15.8 N / m to 29.4 N / m .   2. The void area ratio of the porous resin film observed from the film side is 1.05 to 1.5 times the void area ratio of the porous resin film observed from the side opposite to the film side. The master for thermal stencil printing described.   The heat-sensitive stencil printing master according to claim 1 or 2, wherein the void area ratio of the porous resin film observed from the film side is 40 to 80%.   The master for heat-sensitive stencil printing according to any one of claims 1 to 3, further comprising a functional thin layer between the thermoplastic resin film and the porous resin film. The solventless polyurethane adhesive is either a one-component urethane adhesive having a viscosity of 100 cps at application of 1000 cps or a two-component urethane adhesive having a viscosity of 75 cps and 800 cps at application. The master for heat-sensitive stencil printing according to any one of the above. Adhesion amount of solvent-free polyurethane adhesive is, 0.05 to 5.0 g / ^{m 2} and is claim 1 according to any one of the 5 thermal stencil master.   The method for producing a heat-sensitive stencil printing master according to claim 1, wherein the synthetic resin is mixed in a plurality of solvents having different solubilities, solubilized, coated on the thermoplastic resin film at a constant thickness, and dried.   The method of manufacturing the master for heat-sensitive stencil printing of Claim 1 by apply | coating the water-in-oil type emulsion containing the melt | dissolved synthetic resin with a fixed thickness on a thermoplastic resin film, and drying it.

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