Double-layer water-based black film and digital resin plate

Abstract

The invention belongs to a washing resin plate for digital imaging, and particularly relates to a double-layer water-based black film and a digital resin plate. Comprising a moisture-resistant layer; the moisture-resistant layer is formed by coating moisture-resistant coating liquid; the moisture-resistant coating liquid is prepared from the following substances: a photo-crosslinkable vinyl-containing polymer, fluorine-containing resin and an acrylate monomer. The method can effectively solve the problems that the plate absorbs moisture or generates fingerprints in the storage or operation process, oxygen is blocked in the exposure process, the influence of oxygen on plate imaging is reduced, sand grains are formed on the surface of the plate without influencing the characteristics of the plate, and the ink transfer performance of the plate and the reduction of high-definition screen dots are improved.

Description

Technical Field

[0001] The invention belongs to the field of water-washable resin plates for digital imaging, and relates to a double-layer water-based black film and a digital resin plate. Background Art

[0002] Washable resin plates are mainly used for rotary letterpress printing, self-adhesive label printing, bills, security printing, hot stamping, hot molds and glazing, etc. They are widely used in the printing of trademarks, hoses, pipes, seals, metal sheets and other fields, and can reach a high screen count of more than 150lpi.

[0003] There are two types of water-washable resin plates: conventional plates and digital plates. The main difference lies in the differences in the plate-making process. The digital plate has higher precision. During the plate-making process, the conventional plate will attach the film with patterns or texts to the photosensitive resin layer, and the digital plate will directly use a laser engraving machine to engrave the image on the surface of the plate. The key to the digital water-washable resin plate is that it contains a black film layer, also called a laser-ablative mask layer. The working method is: the computer controls the laser to ablate the black film layer into images and texts. Under the action of ultraviolet light, the initiator decomposes to produce free radicals, which triggers the cross-linking reaction of resin molecules and monomers; the resin monomers of the printed image part are polymerized and cured. There is a relatively large solubility difference between the cured and uncured polymers. After development, drying and post-processing, a relief printing plate is made. The prepared plate is fixed on the roller of the printing press and is ready for printing.

[0004] The water-based black film in the digital resin plate is required to be easily peeled off or dissolved in water during water development, that is, the water-based black film has good water solubility. Similarly, the water-based black film is easy to absorb moisture when exposed to the air, or it is easy to cause fingerprints when the hand presses the surface of the water-based black film, affecting the imaging quality of the plate.

[0005] Research has found that the existing technology has done a lot of work on digital resin plates. Technicians have done a lot of research on water-based black films from the aspects of scratch resistance, oxygen barrier, imaging, transfer, etc. However, how to improve the moisture resistance of water-based black films is mainly reflected in the selection of resins, and there are no other effective means. For research on improving ink transfer, most of them are to improve ink transfer and wear resistance by adding some small particles.

[0006] Patent US2006 / 00087291A1 discloses a process for making a digital water-washable resin plate. The patent evaluates the invention effect of the black film from three aspects: first, the scratch resistance of the laser-ablated black film; second, the transfer and diffusion problem between the photosensitive resin layer and the laser-ablated layer; and third, the problem of image restoration sharpness. The water-based moisture resistance is not involved.

[0007] Patent US2012156514A1 also discloses digital water-washable resin plate technology. The unique structure of the plate is that a protective layer is set between the photosensitive resin layer and the laser ablation layer. The protective layer contains 20-80% polyvinyl alcohol, 15-60% plasticizer, and 5-40% water-dispersible latex. The plate surface does not produce wrinkles, no laser damage, and has good oxygen barrier properties. The plate surface does not produce coarsening. Moisture resistance is not involved.

[0008] The patent US6020108A highlights the preparation of laser ablation black film, and the laser spot diameter is 0.02mm. The present invention only improves the restoration of fine dots. Moisture resistance is not involved.

[0009] To improve the ink transfer and wear resistance of digital resin plates, patent US11137683B2 uses a method of adding inorganic particles with small particle size and a certain curvature to photosensitive elastomers to improve the wear resistance and excellent ink transfer of the plate relief surface. This method is relatively complicated in plate production, which will affect the light transmittance and haze of the plate, and is not conducive to the restoration of high-definition dots.

[0010] Patent CN107969149A introduces a method of setting an oxygen barrier layer between the laser ablation black film and the photosensitive resin layer, and using the oxygen barrier layer and the average particle size of 2-6μm silicon dioxide or silicate particles in the layer to press onto the surface of the flexible resin plate, a flat-top dot plate with a self-textured texture is formed to improve the wear resistance and ink transfer of the plate. The inorganic particles of this technology remain on the surface of the plate, and long-term printing will wear away the inorganic particles, but it will affect the quality of the subsequent printed products.

[0011] In summary, the key problem with digital resin plates is that it is difficult for the laser ablated black film to be both easy to remove in water development and moisture-resistant. In addition, in order to improve the wear resistance and ink transfer of the printing plate, inorganic or organic particles are added to the plate surface. During long-term printing, the particles disappear due to wear, affecting the surface stability of the printing plate. Summary of the invention

[0012] The present application provides a double-layer water-based black film and a digital resin plate, which can effectively solve the problem of moisture absorption or fingerprints during storage or operation of the plate, block oxygen during exposure and reduce the influence of oxygen on plate imaging, form sand grains on the surface of the plate without affecting the characteristics of the plate itself, and improve the ink transfer of the plate and the restoration of high-definition dots.

[0013] In order to achieve the above technical purpose, the technical solution adopted in the present application is a double-layer water-based black film, comprising a moisture-proof layer; the moisture-proof layer is formed by coating a moisture-proof coating liquid;

[0014] The moisture-proof coating liquid comprises the following substances in parts by weight:

[0015] 7.0-7.5 parts by weight of a photo-crosslinkable vinyl polymer

[0016] 2.0-3.0 parts by weight of fluorine-containing resin

[0017] 1.5-2.5 parts by weight of acrylic acid ester monomers.

[0018] As an improved technical solution of the present application, the photo-crosslinkable vinyl polymer is double-bond modified polyvinyl alcohol.

[0019] As an improved technical solution of the present application, the fluorine-containing resin is one of polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyperfluoroethylene propylene, tetrafluoroethylene-ethylene copolymer, or multiple thereof in any weight ratio.

[0020] As an improved technical solution of the present application, the acrylic ester monomer refers to one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, glycidyl methacrylate, polyethylene glycol acrylate, ethylene glycol dimethacrylate, and 2-acryloylethoxysuccinate in any weight ratio.

[0021] As an improved technical solution of the present application, the moisture-proof layer coating liquid also includes an initiator in an amount of 0.3 parts by weight.

[0022] As an improved technical solution of the present application, it also includes a matte layer, which is formed by applying a matte layer coating liquid to the moisture-proof layer; the matte layer coating liquid includes microparticles in an amount of 0.5 parts by weight; the microparticles are pretreated; the pretreatment refers to introducing hydrophilic groups on the surface of the microparticles to achieve the physical property of not easily generating coagulants in water.

[0023] As an improved technical solution of the present application, the microparticles refer to one or more of zinc oxide, silicon dioxide, titanium dioxide, aluminum oxide, calcium carbonate, and aluminum nitride in any weight ratio; the size of the microparticles is 0.1-5 μm.

[0024] As an improved technical solution of the present application, the matte layer coating liquid further comprises at least one of ethylene or polyethylene copolymer resin, water-soluble adhesive, carbon black, and surfactant;

[0025] Wherein, the amount of ethylene or polyethylene copolymer resin is 7-8 parts by weight,

[0026] 1.5 parts by weight of water-soluble adhesive,

[0027] 1.8-2.0 parts by weight of carbon black,

[0028] 0.2 parts by weight of surfactant,

[0029] Wherein, the ethylene or polyethylene copolymer resin is at least one of polyvinyl alcohol, ethylene and vinyl alcohol copolymer, polyvinyl pyrrolidone, and polyvinyl butyral;

[0030] The water-soluble adhesive is at least one of starch, dextrin, polyvinyl alcohol, carboxymethyl cellulose, water-based polyamide, and modified polyether polyurethane;

[0031] The surfactant is at least one of anionic, nonionic, cationic, zwitterionic, anionic-nonionic, and cationic-nonionic.

[0032] As an improved technical solution of the present application, the thickness of the upper moisture-resistant film layer of the water-based black film is 1-3 μm; the thickness of the lower matte film layer is 1-5 μm; and the thickness of the double-layer water-based black film is 2-6 μm.

[0033] Another technical purpose of the present application is to provide a digital resin plate containing the aforementioned double-layer water-based black film.

[0034] Beneficial Effects

[0035] This application adopts a double-layer structure of a moisture-proof layer and a matte layer. The technical logic is that the moisture-proof layer can solve the problem of moisture absorption by the black film layer, preventing the black film from absorbing moisture and causing damage to the black film during platemaking operations, affecting the quality of platemaking; the matte layer can form a tiny grain structure on the plate surface without changing the inherent characteristics of the plate surface. The effect achieved is to eliminate loopholes in the manual operation process during platemaking and form grains with a stable structure on the surface of the printing plate. Compared with the existing technology, it has better performance in terms of moisture resistance, excellent ink transfer and stability.

[0036] The moisture-proof layer of the present application adopts an upper layer containing a photo-crosslinkable vinyl polymer, a fluorine-containing film-forming resin and a fluorine-containing auxiliary agent, which has better moisture-proof properties and can thus achieve a moisture-proof effect for the film layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a 500-fold 3D magnification of 1% dots of the digital resin printing plate 175lpi produced in Example 1: Figure 1 The top left is a top view of the front of the dot. Figure 1 The lower left is a side stereogram of the dots. Figure 1 On the right is the dot outline.

[0038] Figure 2 This is a 500-fold 3D magnification of the digital resin printing plate produced in Example 1.

[0039] Figure 3 This is a 5000-fold 3D magnification of the digital resin printing plate produced in Example 1. DETAILED DESCRIPTION

[0040] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that this embodiment is only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Technical personnel skilled in the art can make some non-essential improvements and adjustments based on the above-mentioned contents of the present invention.

[0041] A double-layer water-based black film includes a moisture-proof layer and an imaging layer (which can be described as a matte layer or a laser engraved imaging layer). The moisture-proof layer contains a moisture-proof fluorine-containing resin; the moisture-proof layer also contains photo-crosslinkable vinyl polymers and acrylate monomers; under the action of light during plate making, the photo-crosslinkable vinyl polymers and acrylate monomers are triggered to undergo polymerization reactions, reducing water solubility; the presence of the two types of substances can improve the moisture-proof effect of the moisture-proof layer. The imaging layer contains surface-modified microparticles with a certain hydrophilicity. During development, sand grains will be formed on the surface of the plate material but will not remain on the surface of the plate material, thereby improving the printing ink transfer of the plate material without affecting the characteristics of the plate material itself.

[0042] Specifically, the purpose of the moisture-proof layer is to solve the problem that the black film itself is damp or the workers' hands are wet during the plate making process, and the workers' improper operation damages the black film on the surface of the plate, causing the black film to form light leakage points, affecting the quality of the plate. The moisture-proof layer is formed by coating with a moisture-proof coating liquid.

[0043] Another object of the present application is to provide a digital resin plate, containing the aforementioned double-layer water-based black film. Specifically, a digital resin plate includes, from bottom to top, a support (A), an adhesive layer (B), a photosensitive resin layer (C), a water-based black film (D) and a protective film base (E). The structure is basically consistent with the layer structure of the digital resin plate of the prior art, the main difference being the water-based black film. The black film layer (water-based black film) of the present invention includes a moisture-proof layer and a rough surface layer (imaging layer, the imaging layer is located between the moisture-proof layer and the photosensitive resin layer), while the existing plate material has only one black film layer or an imaging layer + a transition layer (the imaging layer is located between the protective film base and the transition layer). Different structures lead to different effects.

[0044] A method for making a digital resin plate is that an adhesive layer is pre-coated on a support body and rolled up for use, a photosensitive resin layer (C) is coated to form a film, a water-based black film is pre-coated on a protective film base, and the composite film is rolled up for use, and the three layers are then composited into a digital resin plate with a complete structure.

[0045] Among them, the support (A)

[0046] In the present invention, the support substrate of the digital resin plate can be a plastic film such as polyester, polyetherimide, polystyrene, triacetate, etc., or a metal substrate such as stainless steel sheet, iron sheet, aluminum sheet, tinplate, etc. The substrate thickness can be 0.10mm-0.40mm, and the commonly used thickness is 0.25mm, 0.27mm and 0.30mm.

[0047] In order to improve the adhesion of the support surface, the support can be treated by corona, plasma, chemical corrosion, grinding, adding a primer, etc.

[0048] Adhesive layer (B)

[0049] In the present invention, the adhesive used in the adhesive layer of the digital resin plate can be one or more of water-soluble, hot-melt, solvent-based, emulsion-based, and solvent-free types, such as starch, dextrin, polyvinyl alcohol, carboxymethyl cellulose, etc. using water as a solvent, polyurethane, polystyrene, polyacrylate, ethylene-vinyl acetate copolymer, etc. used after the adhesive is melted by heating, shellac, butyl rubber, polyester, polyurethane, etc. dissolved in a certain solvent, vinyl acetate resin, acrylic resin, chlorinated rubber, etc. in a suspended state, and epoxy resin in a viscous liquid state at room temperature.

[0050] The specific adhesive layer B adopts the WD-NF adhesive layer developed by Lucky Huaguang Printing Technology Co., Ltd. The formula is as follows:

[0051] The following components are used, the total mass of the components is 100g, and the unit mass is g:

[0052]

[0053]

[0054] The thickness of the adhesive layer can be 5-20 μm, and the optimal thickness is 10-20 μm.

[0055] The bonding layer also needs to have an anti-halation function, which can be achieved by utilizing the characteristics of the adhesive itself or by adding fluorescent powder or dye to produce the anti-halation function.

[0056] Photosensitive resin layer (C)

[0057] The thickness of the photosensitive resin layer can be 0.4-2.0 mm, with 0.43 mm, 0.65 mm and 2.0 mm being commonly used.

[0058] It is necessary to provide the specific formula of the photosensitive resin layer C or the model and manufacturer of the finished product.

[0059] The specific formula of the photosensitive resin layer C is as follows:

[0060]

[0061] The photosensitive resin layer generally uses a water-soluble polymer material as the main resin, and the main resin can be water-soluble polyamide, water-based polyurethane, modified poly (styrene-butadiene copolymer) and its derivatives, modified polyvinyl alcohol, ethylene and vinyl alcohol copolymer, etc.

[0062] Water-based polymer materials are added with acrylic monomers, plasticizers, cross-linking agents, photoinitiators, inhibitors, dyes, etc. to form photosensitive resins.

[0063] The acrylate monomer in the photosensitive resin layer can be 1,4-butanediol diacrylate, propoxylated glycerol triacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (200) dimethacrylate, neopentyl glycol diacrylate, diethyl phthalate diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, ethoxylated 1,6-hexanediol diacrylate, polyethylene glycol (600) diacrylate, 2-methyl-1,3-propanediol diacrylate, At least one of ester, ethylene glycol dimethacrylate, propoxylated glycerol triacrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane trimethacrylate, ethoxylated polyethylene glycol o-phenylphenol acrylate, methoxy polyethylene glycol (400) diacrylate, phenoxydiethylene glycol acrylate, 2-acryloylethoxysuccinate, polyethylene glycol (1000) diacrylate, 1.9-nonanediol diacrylate, and tricyclodecane dimethanol diacrylate.

[0064] The plasticizer in the photosensitive resin layer can be at least one of sorbitol, ethylene glycol, diethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, glycerol, trimethylolpropane, N-butylbenzenesulfonamide, lauryl methacrylate, polyethylene glycol, magnesium chloride, urea / triethanolamine, ethylene glycolamine, triethanolamine, and dibutyl maleate.

[0065] The photoinitiator and its initiation system in the photosensitive layer can be at least one of benzophenone, thioxanthone, benzoin and its derivatives, acetophenone derivatives or acylphosphine oxide photosensitive initiators, benzophenones such as benzophenone, 2,4-dihydroxybenzophenone, 4-chlorobenzophenone, 4-phenylbenzophenone, 4,4'-di(diethylamino)benzophenone, etc.; thioxanthone such as 2-isopropylthioxanthone, 2,4-diethylthioxanthone, etc.; benzoin and its derivatives such as benzoin, benzoin dimethyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, etc.; acetophenone derivatives such as diphenylacetophenone, 2,2-dimethoxy-1,2-diphenylacetophenone, etc.; acylphosphine oxides such as aromatic acylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, etc.

[0066] The photosensitive layer also contains water-based dyes and other additives, and other additives are leveling agents, defoamers, stabilizers and antioxidants. Such auxiliary dyes include Solvent Red 149, Solvent Red 179, Red Base 543, Solvent Red 135, Solvent Red 235, Neozapon Red 346, Valifast Red 3306, Basic Red T (CI50240), Rhodamine Blue, Neutral Red (CI50040), Solvent Orange 107, etc. The defoamer can be a mineral oil, silicone, amide, fatty acid and fatty acid ester, alcohol, polyether, phosphate, polyether modified polysiloxane defoamer. The stabilizer can be IRGANOX 1010, BHT, 168, IRGANOX 1076, etc.

[0067] Water-based black film (D)

[0068] A double-layer water-based black film has two layers, the upper layer contains photo-crosslinkable vinyl polymers, fluorine-containing film-forming resins and fluorine-containing additives, and the prepared coating liquid dries to form a moisture-resistant film layer (moisture-resistant layer); the lower layer contains water-based microparticles of 0.1-5μm in size, and the prepared coating liquid dries to form a matte film layer (matte layer) that can be laser ablated for imaging.

[0069] The moisture-proof coating liquid (forming a moisture-proof layer) described in this application includes the following substances in parts by weight:

[0070] 7.0-7.5 parts by weight of a photo-crosslinkable vinyl polymer

[0071] 2.0-3.0 parts by weight of fluorine-containing resin

[0072] 1.5-2.5 parts by weight of acrylic acid ester monomer;

[0073] Definition: The photo-crosslinkable vinyl polymer is a double-bond modified polyvinyl alcohol, that is, the photo-crosslinkable vinyl polymer is a polymer containing unsaturated double bonds and can be crosslinked under light conditions.

[0074] Among them, the photocrosslinkable vinyl polymer is a polyvinyl alcohol that is double-bond modified, and the modification can be modification on the main chain or side chain of the molecule; Definition: Modification on the main chain refers to the direct introduction of unsaturated double bonds into PVA during the preparation process, and the product can be obtained by alcoholysis, hydrolysis or oxidation-reduction method, such as the modified PVA FS-10 of Chongqing Chuanwei Chemical Co., Ltd. and the modified PVARS-1717 of Kuraray Co., Ltd.; Modification on the side chain refers to the use of hydroxyl groups on the side chain of PVA to carry out etherification, esterification or acetalization, and grafting unsaturated double bond-containing groups that can be photocrosslinked, such as the modified PVA-G of Lucky Huaguang Printing Technology Co., Ltd.

[0075] The purpose of the photo-crosslinkable vinyl polymer is to undergo a crosslinking reaction with the acrylic ester monomer under light to reduce hydrophilicity. The technical effect achieved is to reduce the water solubility of the moisture-proof layer and improve the moisture-proof effect. The dosage range is controlled to be 7.0-7.5 parts by weight, in order to fully undergo a crosslinking reaction with the acrylic ester monomer. Excessive or insufficient amounts will result in insufficient reaction and poor moisture resistance.

[0076] The fluorine-containing resin is one of polytetrafluoroethylene, polytrifluorochloroethylene, polyvinylidene fluoride, polyperfluoroethylene propylene, tetrafluoroethylene-ethylene copolymer or multiple thereof in any weight ratio. The purpose of its existence is to reduce the moisture absorption of the moisture-proof layer, and the technical effect achieved is to improve the moisture resistance of the moisture-proof layer. The dosage range is controlled to be 2.0-3.0 parts by weight, and the purpose is to improve the moisture resistance of the moisture-proof layer without affecting the film-forming property of the moisture-proof film and the solubility of the film in water. Excessive or small amounts will result in poor film-forming property, poor moisture-proof effect or insolubility in water.

[0077] The acrylic ester monomer refers to one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, glycidyl methacrylate, polyethylene glycol acrylate, ethylene glycol dimethacrylate, and 2-acryloylethoxysuccinate in any weight ratio. Its purpose is to undergo a cross-linking reaction with a photo-crosslinkable vinyl polymer, and the technical effect achieved is to reduce the water solubility of the moisture-proof layer and improve the moisture-proof effect. The dosage range is controlled to be 1.5-2.5 parts by weight, in order to fully undergo a cross-linking reaction with the acrylic ester monomer. Excessive or small amounts will result in insufficient reaction and poor moisture resistance.

[0078] Wherein, the moisture-proof layer coating liquid also includes an initiator; the amount of the initiator is 0.3 parts by weight.

[0079] When used specifically, the initiator can be 184 photoinitiator, benzoin dimethyl ether, diphenyl acetone, dibenzophenone, etc., and its function is to initiate a cross-linking reaction between modified polyvinyl alcohol and acrylate monomers to form a high molecular structure that does not absorb moisture or has low moisture absorption.

[0080] The moisture-proof coating liquid also includes a surfactant, mainly a fluorinated surfactant, with a dosage range of 0.2, such as DuPont's FS-50, 3M's Fc-4430, etc. Its function is to adjust the surface tension of the fluorinated resin so that it can be evenly dispersed in the coating liquid.

[0081] In order to improve the technical effect of plate printing ink transfer, the laser engraving imaging layer has a certain matte effect, which is formed by applying the laser engraving imaging layer coating liquid (matte layer coating liquid) to the moisture-proof layer; the matte layer coating liquid includes microparticles, and the microparticles are pretreated; pretreatment refers to the introduction of hydrophilic groups on the surface of the microparticles to achieve the physical property of not easily generating condensates in water. The specific dosage is 0.5 parts by weight. Existing commercially available products include modified silicon dioxide HC-220 of Shanghai Jiaquan Industrial Co., Ltd. and modified titanium dioxide T-1170 of Shanghai Evonik Special Chemical Co., Ltd.

[0082] The microparticles are one or more of zinc oxide, silicon dioxide, titanium dioxide, aluminum oxide, calcium carbonate, and aluminum nitride in any weight ratio. The particle size of the microparticles is 0.1-5 μm.

[0083] Its purpose is to form uniform sand grains on the surface of the plate. The technical effect achieved is that the ink transferability of the plate is improved and the surface structure is stable. The dosage range is controlled at 0.5 parts by weight. The purpose is to form dense and uniform sand grains on the surface of the plate. Excessive or insufficient amount will affect the film-forming property of the rough surface layer or result in fewer and uneven sand grains on the surface of the plate.

[0084] The matte layer coating liquid also includes

[0085] Contains 7-8 parts by weight of ethylene or polyethylene copolymer resin,

[0086] 1.5 parts by weight of water-soluble adhesive,

[0087] Carbon black (carbon black particles) 1.8-2.0 parts by weight,

[0088] 0.2 parts by weight of surfactant,

[0089] Water 88 parts by weight.

[0090] Among them, the ethylene or polyethylene copolymer resin can be at least one of polyvinyl alcohol, ethylene and vinyl alcohol copolymer (EVOH), polyvinyl pyrrolidone, and polyvinyl butyral.

[0091] Containing ethylene or polyethylene copolymer resin, the purpose of its existence is to make the hair surface layer have good film-forming property and good water solubility, and the technical effect achieved is good film-forming property. The dosage range is controlled at 7-8 parts by weight, the purpose is to have good film-forming property and the black density of the hair surface film meets the requirements. Excessive or small amounts will result in poor imaging performance or poor film-forming property of the hair surface layer. Containing polyethylene copolymer resin can be selected from PVA-205 of Kuraray Co., Ltd., polyvinyl pyrrolidone K100 of Shanghai Kain Chemical Co., Ltd., modified PVA FS-10 (Sichuan Wei Petrochemical Engineering Co., Ltd.), modified PVA RS-1717 (Kuraray Co., Ltd.), extramolecular modified PVA-G (Lucky Huaguang Printing Technology Co., Ltd.), and modified PVA FS-10 (Sichuan Wei Petrochemical Engineering Co., Ltd.).

[0092] The synthetic formula of PVA-G is as follows:

[0093] The following components are used, the total mass of the components is 100g, and the unit mass is g:

[0094]

[0095] Deionized water, PVA 205, tetrabutylammonium bromide and BHT were added to the reaction bottle in sequence according to the above ratio, and stirred at 80°C. After all the materials in the reaction bottle were dissolved, glycidyl methacrylate was added, and the temperature was maintained at 80°C for 2h. Heating was stopped to obtain a PVA-G solution.

[0096] The water-soluble adhesive can be at least one of starch, dextrin, polyvinyl alcohol, carboxymethyl cellulose, water-based polyamide, and modified polyether polyurethane. The water-based polyamide HT series of Beijing Runbo Hengtong Technology Co., Ltd. is selected to increase the interface force between the laser engraving imaging layer and the photosensitive resin layer, which is conducive to the transfer of the black film layer to the photosensitive resin layer during the later plate making. The modified polyether polyurethane is epoxy-modified, and commercially available products include WF-77-244 (Jining Yiyue Polymer Materials Co., Ltd.), YY100WSC (Jining Yiyue Polymer Materials Co., Ltd.), 7145P AA (Jiangrui New Materials Technology (Shanghai) Co., Ltd.), AH-2322 (Anda Huatai New Materials Co., Ltd.), etc.

[0097] The surfactants were DF-664 (Dongguan Defeng Defoamer Co., Ltd.), Z6-10 (Kangru Technology Co., Ltd.), and SY-9131 (Xi'an Sanye New Materials Co., Ltd.).

[0098] The matte coating liquid also contains carbon black particles; the purpose of its existence is to enable laser engraving and imaging. The technical effect achieved is that the electronic image is transferred to the plate in a 1:1 ratio. The dosage range is controlled at 1.8-2.0 parts by weight, and the purpose is to form a film layer that can be laser imaged. Excessive or insufficient amounts will result in poor film formation, light leakage points, and low interface strength with the photosensitive resin layer.

[0099] Among them, water and isopropyl alcohol are only solvents and are used only as solvents to dissolve the polyvinyl alcohol resin, binder resin, etc.

[0100] Based on the moisture-proof effect of the black film and the appropriate laser engraving energy purpose, the thickness of the upper moisture-proof film layer of the water-based black film is 1-3μm; the thickness of the lower rough film layer is 1-5μm; and the thickness of the water-based black film layer is 2-6μm.

[0101] Protective film base (E)

[0102] The purpose of the protective film base is to protect the digital resin plate. The protective film base can be removed, and when it is removed, the water-based black film is completely transferred to the photosensitive resin layer before the next step of laser engraving. The removable protective film base material can be PET or PE film with a thickness of 80-150μm, commonly 100μm or 125μm, and the average roughness value (Ra) is controlled at 0.1-0.5μm. This film material can be transparent, translucent or opaque. In order to facilitate the distinction between the two sides of the resin plate, the protective film base generally has a certain degree of haze.

[0103] When making plates, first remove the protective film base, use a laser engraving machine to engrave the image and text, and then under the action of ultraviolet light UVA, the initiator decomposes to produce free radicals, which trigger the cross-linking reaction between the resin molecules and the monomers to form a network structure polymer that is insoluble in water developer. After post-processing such as water washing, development, post-baking or detackification, the relief printing plate is made. The influence of oxygen is effectively blocked during the exposure process, which is conducive to the restoration of high-definition dots. During development, the microparticles are carried away by water and form sand grains on the surface of the plate, which effectively improves the ink transfer of the plate.

[0104] The following examples are intended to further illustrate the content of the present invention, but do not limit the scope of protection of the present invention. This patent is a double-layer water-based black film based on a digital resin plate. The other structural layers of the digital resin plate, such as the support (A), adhesive layer (B), photosensitive resin layer (C) and protective film base (E) are omitted and only a unified description is given.

[0105] It should be noted that the following examples of the structure of the support (A), adhesive layer (B), photosensitive resin layer (C) and protective film base (E) are intended to verify or evaluate the implementation effect of the double-layer black film (D) in the present invention, but do not limit the scope of application of the present invention. The double-layer water-based black film in the present invention can also be used on water-based resin plates of other companies, such as Torelief Co., Ltd. Series, Toyobo Co., Ltd. Printight Flint Group WS-S series and other water-based resin plates.

[0106] Support (A) + Adhesive layer (B)

[0107] The following components are used, the total mass of the components is 100g, and the unit mass is g:

[0108]

[0109] According to the above ratio, ethyl acetate and dioxolane were weighed, polyester 670, adhesion promoter LTH and BR95 resin were added in sequence, and stirred at 60°C for 2 hours to dissolve. After all dissolved, glycerol acrylic epoxy resin DA-314, photoinitiator 651 and 2,6-di-tert-butyl-p-cresol were added in sequence, and stirring was continued at 60°C for 0.5 hours. After the solid was dissolved, curing agent N3300 was added, and stirring was continued for 0.5 hours to prepare the adhesive layer coating liquid.

[0110] The polyester support body uses PET (full name: PG series produced by Hefei Lucky Technology Industry Co., Ltd.) with a thickness of 0.30 mm, which has been treated with polyester primer. The formulated adhesive layer coating liquid is applied to the PET support body with a wire rod, and dried in an oven at 120°C for 5 minutes to obtain an adhesive layer with a coating thickness of 10 μm for standby use.

[0111] The steel support body is made of 0.28mm thick T4 tinplate (Dongguan Hangzhan Steel Co., Ltd.), which is treated with chemical corrosion to remove oil and sand grain. The prepared adhesive coating liquid is applied to the treated tinplate with a wire rod, and dried in an oven at 150°C for 5 minutes to obtain an adhesive layer with a coating thickness of 20μm. If necessary, 2 or more coatings can be used for standby.

[0112] Photosensitive resin layer (C)

[0113] The following components are used, the total mass of the components is 100.01 g, and the unit mass is g: including solvent, a total of 100.01 g.

[0114]

[0115]

[0116] Pre-dissolve the modified PVA H-G4# and sorbitol in water and ethanol at 65°C, and stir for 4 hours to completely dissolve. 651 photoinitiator and 2,6-di-tert-butyl-p-cresol are pre-added to the mixed monomers, stirred at 65°C for 20 minutes to dissolve, and then added to the solution of modified PVA H-G4# and sorbitol, and continued to stir for 0.5 hours. Finally, add water-based blue dye and SY-9131 defoamer, and continue to stir for 1 hour to obtain the photosensitive resin layer coating liquid. The photosensitive resin layer coating liquid is placed in a beaker, sealed with plastic wrap, and left to defoam in an oven at 40°C for more than 4 hours. Take out the photosensitive resin layer coating liquid from the oven, apply it to the plate with a doctor blade coater while it is hot, dry it in an oven at 60°C for 3 hours, and dry it at 70°C for 1 hour to obtain a photosensitive resin layer with a dry coating thickness of 0.65 mm, and set it aside. If necessary, 2 or more coatings can be used.

[0117] Protective film base (E)

[0118] The protective film base is a PET film (Lucky Film Co., Ltd.) with a thickness of 125 μm. The film base is translucent and the grain Ra value is controlled at 0.2-0.3 μm.

[0119] The water-based black film (D) is selected according to the following example.

[0120] Example 1

[0121] In the embodiment of the water-based black film, it is divided into an upper layer and a lower layer, and the two layers use the following components respectively, with a total weight of 100g for each component, and the unit mass is g:

[0122]

[0123]

[0124] The above components were mixed at 65° C. for 4 hours to be completely mixed, and then allowed to stand and cool to room temperature to prepare an upper moisture-proof film coating solution for use.

[0125] Lower level

[0126]

[0127] The above-mentioned PVA-205 and water-based polyamide were mixed in water at 65°C for 3 hours until they were completely mixed, and then allowed to stand and cool to room temperature. Modified silica HC-220, carbon black and surfactant DF-664 were then added, and the mixture was continued to be mixed at room temperature for 1 hour to prepare a lower wool mask coating liquid for use.

[0128] The prepared moisture-proof film coating liquid was applied to the protective film substrate with a wire rod, and dried in an oven at 100°C for 5 minutes. The coating thickness was 2-3μm. Then the prepared fur film coating liquid was applied to the upper film, and dried in an oven at 90°C for 3 minutes. The coating thickness was 2-3μm. The total coating thickness of the final double-layer water-based black film was 4-5μm.

[0129] Plate production and evaluation

[0130] The photosensitive resin layer is coated with a wetting liquid on one side with a wire rod to wet the surface, and then the support with an adhesive layer is laminated. Then, the other side of the photosensitive resin layer is coated with a wetting liquid on the other side with a wire rod to wet the surface, and the prepared double-layer water-based black film is laminated. The laminated plate is placed in an oven, dried at 60°C for 10 minutes, and cooled to room temperature to complete the plate production.

[0131] The manufactured digital resin plate was stored openly under natural conditions for more than 6 months, and no significant change was found in the weight of the plate, and the moisture absorption rate was ≤0.1%. Remove the protective film base of the digital resin plate and press the surface of the plate with your fingers, and no fingerprints will be left on the surface of the plate.

[0132] The evaluation document was laser engraved on a CRON laser engraver, and the plate was exposed for 4 minutes using a UVA light source from a Kemao exposure machine (LED lamp exposure has the same effect), developed for 3 minutes in 30°C warm water using a Kemao flatbed plate washer, dried for 10 minutes at 60°C, and post-exposed with UVA and de-sticked with UVC for 3 minutes to complete the plate making.

[0133] Without adding a correction curve, the plate can achieve 1% dot restoration of 175lpi, and the dot restoration is complete. Using a 500x 3D magnifying glass to observe the solid part of the plate, some micro pits can be observed without other particles. The dyne value of the solid part of the plate tested by a dyne pen can reach 36 (the dyne value is tested using a dyne pen and judged based on the spreading effect. The dyne pen only has resins such as 34 / 36 / 38. Because the test results show that both 36 and 38 can be spread, it is judged to be 36-38). The ink affinity is good. See the relevant test pictures. Figure 1-Figure 3 .

[0134] Example 2

[0135] In the embodiment of the water-based black film, it is divided into an upper layer and a lower layer, and the two layers use the following components respectively, with a total weight of 100g for each component, and the unit mass is g:

[0136] upper layer

[0137]

[0138] The above components were mixed at 65° C. for 4 hours to be completely mixed, and then allowed to stand and cool to room temperature to prepare an upper moisture-proof film coating solution for use.

[0139] Lower level

[0140]

[0141] The above-mentioned PVA-205 and water-based polyamide were mixed in water at 65°C for 3 hours until they were completely mixed, and then allowed to stand and cool to room temperature. Modified silica HC-220, carbon black and surfactant DF-664 were then added, and the mixture was continued to be mixed at room temperature for 1 hour to prepare a lower wool mask coating liquid for use.

[0142] Plate production and evaluation

[0143] The prepared moisture-proof film coating liquid was applied to the protective film substrate with a wire rod, and dried in an oven at 100°C for 5 minutes. The coating thickness was 2-3μm. Then the prepared fur film coating liquid was applied to the upper film, and dried in an oven at 90°C for 3 minutes. The coating thickness was 2-3μm. The total coating thickness of the final double-layer water-based black film was 4-5μm.

[0144] The manufactured digital resin plate was stored openly under natural conditions for more than 6 months, and no significant change was found in the weight of the plate, and the moisture absorption rate was ≤0.1%. Remove the protective film base of the digital resin plate and press the surface of the plate with your fingers, and no fingerprints will be left on the surface of the plate.

[0145] Without adding a correction curve, the plate can achieve 1% dot restoration of 175lpi, and the dot restoration is complete. Using a 500x 3D magnifying glass to observe the solid part of the plate, some micro pits can be observed without other particles. The dyne pen tests the solid part of the plate, and the dyne value can reach 36, which has good ink affinity.

[0146] Example 3

[0147] In the embodiment of the water-based black film, it is divided into an upper layer and a lower layer, and the two layers use the following components respectively, with a total weight of 100g for each component, and the unit mass is g:

[0148] upper layer

[0149]

[0150] The above components were mixed at 65° C. for 4 hours to be completely mixed, and then allowed to stand and cool to room temperature to prepare an upper moisture-proof film coating solution for use.

[0151] Lower level

[0152]

[0153]

[0154] The above-mentioned PVA-205 and water-based polyamide were mixed in water at 65°C for 3 hours until they were completely mixed, and then allowed to stand and cool to room temperature. Modified silica HC-220, carbon black and surfactant DF-664 were then added, and the mixture was continued to be mixed at room temperature for 1 hour to prepare a lower wool mask coating liquid for use.

[0155] Plate production and evaluation

[0156] The prepared moisture-proof film coating liquid was applied to the protective film substrate with a wire rod, and dried in an oven at 100°C for 5 minutes. The coating thickness was 2-3μm. Then the prepared fur film coating liquid was applied to the upper film, and dried in an oven at 90°C for 3 minutes. The coating thickness was 2-3μm. The total coating thickness of the final double-layer water-based black film was 4-5μm.

[0157] The manufactured digital resin plate was stored openly under natural conditions for more than 6 months, and no significant change was found in the weight of the plate, and the moisture absorption rate was ≤0.1%. Remove the protective film base of the digital resin plate and press the surface of the plate with your fingers, and no fingerprints will be left on the surface of the plate.

[0158] Without adding a correction curve, the plate can achieve 1% dot restoration of 175lpi, and the dot restoration is complete. Using a 500x 3D magnifying glass to observe the solid part of the plate, some micro pits can be observed without other particles. The dyne pen tests the solid part of the plate, and the dyne value can reach 36, which has good ink affinity.

[0159] Example 4

[0160] In the embodiment of the water-based black film, it is divided into an upper layer and a lower layer, and the two layers use the following components respectively, with a total weight of 100g for each component, and the unit mass is g:

[0161] upper layer

[0162]

[0163] The above components were mixed at 65° C. for 4 hours to be completely mixed, and then allowed to stand and cool to room temperature to prepare an upper moisture-proof film coating solution for use.

[0164] Lower level

[0165]

[0166]

[0167] The above-mentioned PVA-205 and polyvinyl pyrrolidone K100 were mixed in water at 65°C for 3 hours until they were completely mixed, and then allowed to stand and cool to room temperature. Modified titanium dioxide T-1170, carbon black and surfactant DF-664 were then added, and the mixture was continued to mix at room temperature for 1 hour to prepare a lower wool mask coating liquid for use.

[0168] The prepared moisture-proof film coating liquid was applied to the protective film substrate with a wire rod, and dried in an oven at 100°C for 5 minutes. The coating thickness was 2-3μm. Then the prepared fur film coating liquid was applied to the upper film, and dried in an oven at 90°C for 3 minutes. The coating thickness was 2-3μm. The total coating thickness of the final double-layer water-based black film was 4-5μm.

[0169] Plate production and evaluation

[0170] The photosensitive resin layer is coated with a wetting liquid on one side with a wire rod to wet the surface, and then the support with an adhesive layer is laminated. Then, the other side of the photosensitive resin layer is coated with a wetting liquid on the other side with a wire rod to wet the surface, and the prepared double-layer water-based black film is laminated. The laminated plate is placed in an oven, dried at 60°C for 10 minutes, and cooled to room temperature to complete the plate production.

[0171] The prepared digital resin plate was stored openly under natural conditions for more than 6 months, and no significant change was found in the weight of the plate, and the moisture absorption rate was ≤0.1%. Remove the protective film base of the digital resin plate, press the surface of the plate with your fingers, and no fingerprints will be left on the surface of the plate. The evaluation file was laser engraved on the Koray laser engraving machine, and the UVA light source of the Kemao exposure machine was used for exposure for 4 minutes (LED lamp bead exposure has the same effect), and the Kemao flatbed plate washer was used for development in 30℃ warm water for 3 minutes, dried at 60℃ for 10 minutes, and UVA post-exposure and UVC detackification for 3 minutes to complete the printing plate making.

[0172] Without adding a correction curve, the plate can achieve 1% dot restoration of 175lpi, and the dot restoration is complete. Using a 500x 3D magnifying glass to observe the solid part of the plate, some micro-pits can be observed without other particles (micro-pits are good, which is conducive to the control of peeling force). The dyne pen tests the solid part of the plate, and the dyne value can reach 36, which has good ink affinity.

[0173] Example 5

[0174] In the embodiment of the water-based black film, it is divided into an upper layer and a lower layer, and the two layers use the following components respectively, with a total weight of 100g for each component, and the unit mass is g:

[0175] upper layer

[0176]

[0177] The above components were mixed at 65° C. for 4 hours to be completely mixed, and then allowed to stand and cool to room temperature to prepare an upper moisture-proof film coating solution for use.

[0178] Lower level

[0179]

[0180] The above-mentioned PVA-205 and water-based polyamide were mixed in water at 65°C for 3 hours until they were completely mixed, and then allowed to stand and cool to room temperature. Modified silica HC-220, carbon black and surfactant DF-664 were then added, and the mixture was continued to be mixed at room temperature for 1 hour to prepare a lower wool mask coating liquid for use.

[0181] The prepared moisture-proof film coating liquid was applied to the protective film substrate with a wire rod, and dried in an oven at 100°C for 5 minutes. The coating thickness was 2-3μm. Then the prepared fur film coating liquid was applied to the upper film, and dried in an oven at 90°C for 3 minutes. The coating thickness was 2-3μm. The total coating thickness of the final double-layer water-based black film was 4-5μm.

[0182] Plate production and evaluation

[0183] The photosensitive resin layer is coated with a wetting liquid on one side with a wire rod to wet the surface, and then the support with an adhesive layer is laminated. Then, the other side of the photosensitive resin layer is coated with a wetting liquid on the other side with a wire rod to wet the surface, and the prepared double-layer water-based black film is laminated. The laminated plate is placed in an oven, dried at 60°C for 10 minutes, and cooled to room temperature to complete the plate production.

[0184] The manufactured digital resin plate was stored openly under natural conditions for more than 6 months, and no significant change was found in the weight of the plate, and the moisture absorption rate was ≤0.1%. Remove the protective film base of the digital resin plate and press the surface of the plate with your fingers, and no fingerprints will be left on the surface of the plate.

[0185] The evaluation document was laser engraved on a CRON laser engraver, and the plate was exposed for 4 minutes using a UVA light source from a Kemao exposure machine (LED lamp exposure has the same effect), developed for 3 minutes in 30°C warm water using a Kemao flatbed plate washer, dried for 10 minutes at 60°C, and post-exposed with UVA and de-sticked with UVC for 3 minutes to complete the plate making.

[0186] Without adding a correction curve, the plate can achieve 1% dot restoration of 175lpi, and the dot restoration is complete. Using a 500x 3D magnifying glass to observe the solid part of the plate, some micro pits can be observed without other particles. The dyne pen tests the solid part of the plate, and the dyne value can reach 36, which has good ink affinity.

[0187] Comparative Example 1

[0188] In the embodiment of the water-based black film, it is divided into an upper layer and a lower layer, and the two layers use the following components respectively, with a total weight of 100g for each component, and the unit mass is g:

[0189] upper layer

[0190]

[0191] The above components were mixed at 65° C. for 4 hours to be completely mixed, and then allowed to stand and cool to room temperature to prepare an upper moisture-proof film coating solution for use.

[0192] Lower level

[0193]

[0194] The above-mentioned PVA-205 and water-based polyamide were mixed in water at 65°C for 3 hours until they were completely mixed, and then allowed to stand and cool to room temperature. Modified silica HC-220, carbon black and surfactant DF-664 were then added, and the mixture was continued to be mixed at room temperature for 1 hour to prepare a lower wool mask coating liquid for use.

[0195] The prepared moisture-proof film coating liquid was applied to the protective film substrate with a wire rod, and dried in an oven at 100°C for 5 minutes. The coating thickness was 2-3μm. Then the prepared fur film coating liquid was applied to the upper film, and dried in an oven at 90°C for 3 minutes. The coating thickness was 2-3μm. The total coating thickness of the final double-layer water-based black film was 4-5μm.

[0196] Plate production and evaluation

[0197] The photosensitive resin layer is coated with a wetting liquid on one side with a wire rod to wet the surface, and then the support with an adhesive layer is laminated. Then, the other side of the photosensitive resin layer is coated with a wetting liquid on the other side with a wire rod to wet the surface, and the prepared double-layer water-based black film is laminated. The laminated plate is placed in an oven, dried at 60°C for 10 minutes, and cooled to room temperature to complete the plate production.

[0198] The prepared digital resin plate was stored in the open for more than 6 months under natural conditions, and the weight of the plate did not change significantly, and the moisture absorption rate was 0.13%. The protective film base of the digital resin plate was removed, and the surface of the plate was pressed with fingers, and obvious fingerprints were found on the surface of the plate.

[0199] The evaluation document was laser engraved on a CRON laser engraver, and the plate was exposed for 4 minutes using a UVA light source from a Kemao exposure machine (LED lamp exposure has the same effect), developed for 3 minutes in 30°C warm water using a Kemao flatbed plate washer, dried for 10 minutes at 60°C, and post-exposed with UVA and de-sticked with UVC for 3 minutes to complete the plate making.

[0200] Without adding a correction curve, the plate can achieve 2% dot reduction at 175lpi. Using a 500x 3D magnifying glass to observe the solid part of the plate, some micro pits can be observed without other particles. The dyne value of the solid part of the plate tested by a dyne pen can reach 36, indicating good ink affinity.

[0201] Comparative Example 2

[0202] In the embodiment of the water-based black film, it is divided into an upper layer and a lower layer, and the two layers use the following components respectively, with a total weight of 100g for each component, and the unit mass is g:

[0203] upper layer

[0204]

[0205] The above components were mixed at 65° C. for 4 hours to be completely mixed, and then allowed to stand and cool to room temperature to prepare an upper moisture-proof film coating solution for use.

[0206] Lower level

[0207]

[0208] The above-mentioned PVA-205 and water-based polyamide were mixed in water at 65°C for 3 hours until they were completely mixed, and then allowed to stand and cool to room temperature. Modified silica HC-220, carbon black and surfactant DF-664 were added, and the mixture was continued to be mixed at room temperature for 1 hour to prepare a lower wool mask coating liquid for use.

[0209] The prepared moisture-proof film coating liquid was applied to the protective film substrate with a wire rod, and dried in an oven at 100°C for 5 minutes. The coating thickness was 2-3μm. Then the prepared fur film coating liquid was applied to the upper film, and dried in an oven at 90°C for 3 minutes. The coating thickness was 2-3μm. The total coating thickness of the final double-layer water-based black film was 4-5μm.

[0210] Plate production and evaluation

[0211] The photosensitive resin layer is coated with a wetting liquid on one side with a wire rod to wet the surface, and then the support with an adhesive layer is laminated. Then, the other side of the photosensitive resin layer is coated with a wetting liquid on the other side with a wire rod to wet the surface, and the prepared double-layer water-based black film is laminated. The laminated plate is placed in an oven, dried at 60°C for 10 minutes, and cooled to room temperature to complete the plate production.

[0212] The manufactured digital resin plate was stored in the open for more than 6 months under natural conditions, and the weight of the plate did not change significantly, and the moisture absorption rate was 0.15%. The protective film base of the digital resin plate was removed, and the surface of the plate was pressed with fingers. There were obvious fingerprints on the surface of the plate, and the local black film was taken away to cause light leakage points.

[0213] The evaluation document was laser engraved on a CRON laser engraver, and the plate was exposed for 4 minutes using a UVA light source from a Kemao exposure machine (LED lamp exposure has the same effect), developed for 3 minutes in 30°C warm water using a Kemao flatbed plate washer, dried for 10 minutes at 60°C, and post-exposed with UVA and de-sticked with UVC for 3 minutes to complete the plate making.

[0214] Without adding a correction curve, the plate can achieve 2% dot restoration at 175lpi, and 2% dot partial dropout. Using a 500x 3D magnifying glass to observe the solid part of the plate, some micro pits can be observed without other particles. The dyne pen tests the solid part of the plate, and the dyne value can reach 36, indicating good ink affinity.

[0215] Comparative Example 3

[0216] In the embodiment of the water-based black film, it is divided into an upper layer and a lower layer, and the two layers use the following components respectively, with a total weight of 100g for each component, and the unit mass is g:

[0217] upper layer

[0218]

[0219] The above components were mixed at 65° C. for 4 hours to be completely mixed, and then allowed to stand and cool to room temperature to prepare an upper moisture-proof film coating solution for use.

[0220] Lower level

[0221]

[0222] The above-mentioned PVA-205 and water-based polyamide were mixed in water at 65°C for 3 hours until they were completely mixed, and then allowed to stand and cool to room temperature. Modified silica, carbon black and surfactant DF-664 were then added, and the mixture was continued to be mixed at room temperature for 1 hour to prepare a lower wool mask coating liquid for use.

[0223] The prepared moisture-proof film coating liquid was applied to the protective film substrate with a wire rod, and dried in an oven at 100°C for 5 minutes. The coating thickness was 2-3μm. Then the prepared fur film coating liquid was applied to the upper film, and dried in an oven at 90°C for 3 minutes. The coating thickness was 2-3μm. The total coating thickness of the final double-layer water-based black film was 4-5μm.

[0224] Plate production and evaluation

[0225] The photosensitive resin layer is coated with a wetting liquid on one side with a wire rod to wet the surface, and then the support with an adhesive layer is laminated. Then, the other side of the photosensitive resin layer is coated with a wetting liquid on the other side with a wire rod to wet the surface, and the prepared double-layer water-based black film is laminated. The laminated plate is placed in an oven, dried at 60°C for 10 minutes, and cooled to room temperature to complete the plate production.

[0226] The manufactured digital resin plate was stored openly under natural conditions for more than 6 months, and no significant change was found in the weight of the plate, and the moisture absorption rate was ≤0.1%. Remove the protective film base of the digital resin plate and press the surface of the plate with your fingers, and no fingerprints will be left on the surface of the plate.

[0227] The evaluation document was laser engraved on a CRON laser engraver, and the plate was exposed for 4 minutes using a UVA light source from a Kemao exposure machine (LED lamp exposure has the same effect), developed for 3 minutes in 30°C warm water using a Kemao flatbed plate washer, dried for 10 minutes at 60°C, and post-exposed with UVA and de-sticked with UVC for 3 minutes to complete the plate making.

[0228] Without adding a correction curve, the plate can achieve 1% dot restoration of 175lpi, and the dot restoration is complete. Use a 500x 3D magnifying glass to observe the solid part of the plate, and the solid part is flat. The dyne pen tests the solid part of the plate, and the dyne value can reach 34, and the ink affinity is average.

Claims

1. A double-layer water-based black film, characterized in that: It comprises a moisture-proof layer; the moisture-proof layer is formed by coating a moisture-proof coating liquid; The moisture-proof coating liquid comprises the following substances in parts by weight: 7.0-7.5 parts by weight of a photo-crosslinkable vinyl polymer 2.0-3.0 parts by weight of fluorine-containing resin 1.5-2.5 parts by weight of acrylic acid ester monomers.

2. A double-layer water-based black film according to claim 1, characterized in that: The photo-crosslinkable vinyl-containing polymer is double-bond-modified polyvinyl alcohol.

3. A double-layer water-based black film according to claim 1, characterized in that: The fluorine-containing resin is one of polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyperfluoroethylene-propylene, and tetrafluoroethylene-ethylene copolymer, or multiple thereof in any weight ratio.

4. A double-layer water-based black film according to claim 1, characterized in that: The acrylic acid ester monomer refers to one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, glycidyl methacrylate, polyethylene glycol acrylate, ethylene glycol dimethacrylate, and 2-acryloylethoxysuccinate in any weight ratio.

5. A double-layer water-based black film according to claim 1, characterized in that: The moisture-proof layer coating liquid also includes an initiator in an amount of 0.3 parts by weight.

6. A double-layer water-based black film according to claim 1, characterized in that: It also includes a matte layer, which is formed by applying a matte layer coating liquid to the moisture-proof layer; the matte layer coating liquid includes microparticles in an amount of 0.5 parts by weight; the microparticles are pretreated; the pretreatment refers to introducing hydrophilic groups on the surface of the microparticles to achieve the physical property of not easily generating coagulants in water.

7. A double-layer water-based black film according to claim 6, characterized in that: The microparticles are one or more of zinc oxide, silicon dioxide, titanium dioxide, aluminum oxide, calcium carbonate, and aluminum nitride in any weight ratio; the size of the microparticles is 0.1-5 μm.

8. A double-layer water-based black film according to claim 6, characterized in that: The matte layer coating liquid also includes at least one of ethylene or polyethylene copolymer resin, water-soluble adhesive, carbon black, and surfactant; Among them, the amount of ethylene or polyethylene copolymer resin is 7-8 parts by weight. 1.5 parts by weight of water-soluble adhesive, 1.8-2.0 parts by weight of carbon black, 0.2 parts by weight of surfactant, Wherein, the ethylene or polyethylene copolymer resin is at least one of polyvinyl alcohol, ethylene and vinyl alcohol copolymer (EVOH), polyvinyl pyrrolidone, and polyvinyl butyral; The water-soluble adhesive is at least one of starch, dextrin, polyvinyl alcohol, carboxymethyl cellulose, water-based polyamide, and modified polyether polyurethane; The surfactant is at least one of anionic, nonionic, cationic, zwitterionic, anionic-nonionic, and cationic-nonionic.

9. A double-layer water-based black film according to claim 6, characterized in that: The thickness of the upper moisture-proof film layer of the water-based black film is 1-3 μm; the thickness of the lower matte film layer is 1-5 μm; and the thickness of the double-layer water-based black film is 2-6 μm.

10. A digital resin plate, characterized in that: Contains the double-layer water-based black film according to any one of claims 1 to 9.

Images