A photosensitive resin layer of a water-developable transfer photosensitive resin plate, a preparation method thereof, and a transfer photosensitive resin plate containing the same

Abstract

The present invention provides a photosensitive resin layer of a water-developable transfer photosensitive resin plate, a preparation method thereof, and a transfer photosensitive resin plate comprising the same. A photosensitive resin layer of a water-developable transfer photosensitive resin plate, the raw materials including: (A) the main resin is modified polyvinyl alcohol, and the modified polyvinyl alcohol: contains vinyl groups on the main chain, contains a hydrophobic formyl group on the side chain, and also contains a photocrosslinkable vinyl group on the side chain; (B) a highly flexible active water-soluble monomer; (C) a plasticizer; (D) a photoinitiator and its initiation system; (E) a water-based dye and other additives; the other additives at least include at least one of an antifoaming agent and a stabilizer; (F) other polymerizable vinyl monomers except the modified polyvinyl alcohol in (A). Plate making can be directly developed with water, and the water rinsing time is short. The made printing plate has a low hardness, good resilience, and good ink transfer property, and can achieve the reduction of graphics, dots, and lines.

Description

Technical Field

[0001] The present invention relates to a water-developable transfer photosensitive resin plate, in particular to a photosensitive resin layer of a water-developable transfer photosensitive resin plate that can be directly developed with pure water and can be directly used for printing on a printing machine, a preparation method thereof, and a transfer photosensitive resin plate including the same. This application belongs to the green printing materials in the sub-direction of 3.19 ecological environment materials under the key direction of 3.1 new functional materials industry in the strategic emerging industry catalog. Background Art

[0002] With the continuous development of science and technology, the advantages of flexographic printing in the printing industry have gradually emerged, and the related technologies have also emerged accordingly, being widely loved by industry insiders. Flexographic printing is widely used in the printing of easily deformed or relatively soft substrates such as cartons, flexible packaging, and labels.

[0003] Since the development of flexographic printing to date, according to the developing method, it can be divided into several methods such as solvent development, water development, and heat development. Among them, water development has become the second major mainstream after solvent development. The water-developable resin plate has a very fast plate-making speed, greatly shortening the plate-making process, and the accuracy can reach 150 - 200 line / inch high screen line. Coupled with the more environmentally friendly developing advantage, it is highly praised by users because of these advantages. The water-washed resin plate is mainly used for rotary letterpress printing, self-adhesive label printing, bills, security printing, hot stamping, hot die, and glazing, etc., and is widely used in the printing of trademarks, hoses, pipes, seals, metal sheets, etc.

[0004] Generally, a film with patterns or characters is adhered to the photosensitive layer or the graphic and text are directly transferred to the black film layer of the photosensitive layer. Under the action of ultraviolet light, the initiator decomposes to generate free radicals, which initiate the cross-linking reaction of resin molecules and monomers. The resin monomers in the printed graphic and text parts polymerize and solidify. There is a relatively large solubility difference between the solidified and non-solidified polymers. After development, drying, and post-treatment, etc., a relief printing plate is made. The made plate is fixed on the drum of the flexographic printing machine and can be prepared for printing.

[0005] U.S. Patent US4517277A uses polyvinyl alcohol and an acylating reagent such as methacrylic anhydride / acrylic anhydride to react in an aprotic solvent to generate polyvinyl alcohol with vinyl double bonds that can be cross-linked on the side chains, and adds cross-linking monomers, initiators, dyes, etc. to make a water-washed resin plate. However, the made water-washed resin plate has a relatively high hardness, is prone to cracking in winter, and has poor resilience.

[0006] Chinese Patent CN106814540A modifies polyvinyl alcohol with isocyanate, grafts photo-crosslinkable vinyl double bonds on the side chains, and adds self-emulsifying active monomers, plasticizers, cross-linking monomers, initiators, etc. to make a water-washed relief plate. After making the printing plate, the hardness is also relatively high, it is prone to cracking in winter, and the resilience is poor. Summary of the Invention

[0007] The present invention provides a photosensitive resin layer of a water-developable transfer photosensitive resin plate, a preparation method thereof, and a transfer photosensitive resin plate comprising the same. The plate-making can be directly developed with water, and the water rinsing time is short. The made printing plate has low hardness, good resilience, and excellent ink transfer property, and can realize the reduction of graphics, texts, dots, and lines.

[0008] The object of the present invention is achieved by the following technical solutions, which are not limited to the following:

[0009] A photosensitive resin layer of a water-developable transfer photosensitive resin plate, the raw materials including: (A) The main resin is modified polyvinyl alcohol, and the modified polyvinyl alcohol: contains vinyl on the main chain, formyl group as a hydrophobic group on the side chain, and also contains a photocrosslinkable vinyl group on the side chain; (B) A highly flexible active water-soluble monomer; (C) A plasticizer; (D) A photoinitiator and its initiation system; (E) A water-based dye and other additives; the other additives at least include at least one of an antifoaming agent and a stabilizer; (F) Other polymerizable vinyl monomers except the modified polyvinyl alcohol in (A).

[0010] The above materials are placed on a PET sheet base or a metal substrate with a certain thickness and a bonding layer by means of metering feeding, mixing, coating and drying by a screw extruder or twin-screw extrusion, and an oxygen barrier and anti-sticking layer and a protective film layer are covered to make a usable water-washable flexible resin plate.

[0011] For the photosensitive resin layer of the water-developable transfer photosensitive resin plate, by weight,

[0012] (A) The modified polyvinyl alcohol: contains vinyl on the main chain, formyl group as a hydrophobic group on the side chain, and also contains a photocrosslinkable vinyl group on the side chain, accounting for 40-70% of the total mass of the photosensitive layer;

[0013] (B) The highly flexible active water-soluble monomer accounts for 10-20% of the total mass of the photosensitive layer;

[0014] (C) The plasticizer accounts for 10-20% of the total mass of the photosensitive layer;

[0015] (D) The photoinitiator and its initiation system account for 1-5% of the total mass of the photosensitive layer;

[0016] (E) The water-based dye and other additives account for 1-5% of the total mass of the photosensitive layer.

[0017] (F) Other polymerizable vinyl monomers except the modified polyvinyl alcohol in (A) account for 5-10% of the total mass of the photosensitive layer.

[0018] Here, the total mass of the photosensitive layer does not include the solvent, because when the photosensitive layer is finally formed, the solvent is completely evaporated.

[0019] The structure of the modified polyvinyl alcohol (A) is as follows: Formula (II):

[0020]

[0021] In Formula (II), m is an integer from 500 to 1000, and n is an integer from 100 to 500; the structure of the photocrosslinkable vinyl group R is as follows: Formula (III):

[0022]

[0023] Formula (III), where a is an integer from 4 to 7, and a + b is an integer from 16 to 25.

[0024] The preparation method of the modified polyvinyl alcohol (A) is as follows: Polyvinyl alcohol with vinyl groups on the main chain and formyl groups (hydrophobic groups) on the side chain is prepared into the modified polyvinyl alcohol in Formula (III) by grafting groups containing photocrosslinkable vinyl groups on the side chain.

[0025] The structure of polyvinyl alcohol with vinyl groups on the main chain and formyl groups (hydrophobic groups) on the side chain is as follows: Formula (I):

[0026]

[0027] In Formula (I), m is an integer from 500 to 1000, n is an integer from 100 to 500, and the average molecular weight of polyvinyl alcohol is from 25,000 to 80,000.

[0028] The water-developable photosensitive resin layer in the present invention contains one or more kinds of modified polyvinyl alcohol.

[0029] The high-flexibility active water-soluble monomer in the present invention is at least one of polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, or polypropylene glycol dimethacrylate, and polyethylene glycol (1000) diacrylate is preferably selected.

[0030] The plasticizer in the present invention can be at least one of glycerol, ethylene glycol, diethylene glycol, N-butylbenzenesulfonamide, lauryl methacrylate, trimethylolpropane, or nylon plasticizer.

[0031] The photoinitiator and its initiating system in the present invention are one of cleavage-type, hydrogen-abstraction type, or mixed-type photoinitiators, and cleavage-type photoinitiators are preferred.

[0032] The water-based dyes and other additives in the present invention, the water-based dyes are at least one of blue, red, or green, and the other additives are defoamers, stabilizers, leveling agents, antioxidants, etc.

[0033] The preparation method of the photosensitive resin layer of the water-developable transfer photosensitive resin plate is to mix the raw materials of the photosensitive resin layer and obtain the photosensitive resin layer with the required thickness by means of coating and drying or twin-screw extrusion.

[0034] A water-developable transfer photosensitive resin plate includes a laser ablation black film, a photosensitive resin layer and a support; the photosensitive resin layer is the above-mentioned photosensitive resin layer. After applying a bonding layer on the support, the photosensitive resin layer is applied, and then an upper film with a laser ablation layer is applied, and a complete water-developable resin plate is obtained after slightly applying pressure.

[0035] The substrate of the support of the present invention can be polybutylene terephthalate, poly(ethylene naphthalene-2,6-dicarboxylate), polyvinyl chloride, polyethylene terephthalate, polypropylene, polycarbonate, aluminum sheet, stainless steel sheet, copper sheet, iron sheet, etc., preferably a PET sheet base or a magnetic stainless steel sheet, with a thickness of 0.2-0.5 mm. The PET sheet base support can be pre-corona treated, and the magnetic steel support can be pre-treated by surface treatment such as water washing, degreasing, and graining. The bonding layer of the present invention is prepared by pre-configuring one or more of polyester, polyurethane or other copolymer adhesives into a solution, and coating the above components on the support such as by an anilox roll or a doctor blade coating method, and drying to form a film for standby, with a coating thickness of 2-10 μm.

[0036] The substrate of the laser ablation black film of the present invention can be a PET or PE film, with a thickness of 0.1-0.3 mm. The ablation black film contains carbon black nanoparticles, and also contains polyvinyl alcohol or polyvinyl alcohol / ethylene glycol graft copolymer, polyvinylpyrrolidone, hydroxypropyl cellulose ester, etc., plus a dispersant and other components are mixed into a coating solution, and the coating solution is coated on the protective film sheet base by a doctor blade coating or an anilox roll coating method, and dried for standby, with a dry coating thickness of 1-2 μm.

[0037] The photosensitive layer, that is, the photosensitive resin layer material of the present invention can be metered and fed, kneaded, and melt-extruded onto a support pre-coated with a bonding layer, or the above composition is dissolved in a certain proportion of water and solvent, and is cast and coated on a support pre-coated with a bonding layer with a certain thickness, and the water and solvent are evaporated to obtain a photosensitive elastomer layer of a water-washable flexographic plate, and the thickness of the photosensitive elastomer layer is 0.1-2.0 mm. Then it is laminated on the laser ablation black film of the present invention to prepare a water-washable transfer resin plate.

[0038] The water-developable transfer resin plate of the present invention is subjected to processing steps such as graphic engraving, UV-A light source exposure, development, and drying to obtain a transfer plate that can be directly mounted on a printing machine. The transfer resin plate of the present invention has good water development effect, good reduction of graphics, dots, and screen lines, and the plate material has high flexibility and good ink transferability. Specific embodiments

[0039] The present invention will be specifically described below in conjunction with specific embodiments. It is necessary to point out here that these embodiments are only used to further illustrate the present invention and should not be construed as limiting the protection scope of the present invention. Those skilled in the art can make some non-essential improvements and adjustments based on the content of the present invention above.

[0040] The photosensitive resin layer of the water-developable transfer photosensitive resin plate, the raw materials include: (A) The main resin is modified polyvinyl alcohol, and the modified polyvinyl alcohol: contains vinyl on the main chain, contains formyl as a hydrophobic group on the side chain, and also contains a photocrosslinkable vinyl group on the side chain; (B) A highly flexible active water-soluble monomer; (C) A plasticizer; (D) A photoinitiator and its initiation system; (E) A water-based dye and other additives; the other additives include at least one of a defoaming agent and a stabilizer.

[0041] (A) The main resin is modified polyvinyl alcohol:

[0042] The structure of polyvinyl alcohol containing vinyl on the main chain and formyl as a hydrophobic group on the side chain is as shown in (I), and it can be at least one of HR-3010, RS-2117, AQ-4104, RS-1717, etc. in the modified PVA of Kuraray, Japan.

[0043]

[0044] In formula (I), m is an integer from 500 to 1000, n is an integer from 100 to 500, and the average molecular weight of polyvinyl alcohol is 25,000 to 80,000.

[0045] The main resin in the photosensitive layer, that is, the photosensitive resin layer, is polyvinyl alcohol containing vinyl on the main chain, formyl as a hydrophobic group on the side chain, and also a photocrosslinkable vinyl group on the side chain: graft a group containing a photocrosslinkable vinyl group on the side chain in the structural formula (I), and the structure is as follows formula (II), and the structure of the photocrosslinkable vinyl group R is as follows formula (III):

[0046]

[0047]

[0048] In formula (III), a is an integer from 4 to 7, and a + b is an integer from 16 to 25.

[0049] The highly flexible active water-soluble monomer in the photosensitive layer is at least one of polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, etc.

[0050] Other polymerizable vinyl monomers in the photosensitive layer may be at least one of tripropylene glycol diacrylate, trimethylolpropane triacrylate, 3,3,5-trimethylcyclohexyl acrylate, ethoxyethoxyethyl acrylate, lauryl acrylate, stearyl acrylate, isodecyl acrylate, isodecyl methacrylate, 2-phenoxyethyl methacrylate, lauryl methacrylate, benzyl acrylate, dipropylene glycol diacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, diethanol phthalate diacrylate, etc., 2-phenoxyethyl acrylate, tripropylene glycol diacrylate, ethoxylated 1,6-hexanediol diacrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, di-trimethylolpropane tetraacrylate, ethoxypolyethylene glycol o-phenylphenol acrylate, phenoxydiethylene glycol acrylate, 2-acryloyloxyethyl succinate, isostearyl acrylate, 2-hydroxy-3-acryloxymethacryloxypropane, propoxylated ethoxylated bisphenol A diacrylate, 2-methyl-1,3-propanediol diacrylate, ethylene glycol dimethacrylate, ethoxylated bisphenol A dimethacrylate, pentaerythritol triacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, ethoxylated isocyanuric acid triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, tripropylene glycol diacrylate, ethoxylated glycerol triacrylate, dimethoxypropane tetraacrylate, tetramethoxymethane tetraacrylate, dipentaerythritol hexaacrylate, etc.

[0051] The plasticizer in the photosensitive layer may be at least one of aliphatic dibasic acid esters, phthalic acid esters (including phthalic acid esters, terephthalic acid esters), benzene polycarboxylic acid esters, benzoic acid esters, polyols, alkanolamines, chlorinated hydrocarbons, epoxies, citric acid esters, nylons, polyesters, composites, etc.

[0052] The photoinitiator and its initiating system in the photosensitive layer can be at least one of benzophenone-based, thioxanthone-based, benzoin and its derivatives, acetophenone derivatives or acylphosphine oxide-based photosensitive initiators. Benzophenone-based ones such as benzophenone, 2,4-dihydroxybenzophenone, 4-chlorobenzophenone, 4-phenylbenzophenone, 4,4'-bis(diethylamino)benzophenone, etc.; thioxanthone-based ones 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 diphenylacetone, 2,2-dimethoxy-1,2-diphenylethanone, etc.; acylphosphine oxide-based ones such as aromatic acylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, etc.

[0053] The photosensitive layer also contains water-soluble dyes and other additives. The other additives are at least one of defoamers, stabilizers, leveling agents and antioxidants, etc. Such dyes as Red Base 543, Neozapon Red 346, Valifast Red3306, Solvent Red 135, Solvent Red149, Solvent Red 179, Solvent Red 235, Neutral Red (C.I.50040), Basic Red T (C.I.50240), Rhodamine Blue, Solvent Orange 107, etc. The defoamer can be mineral oil-based, alcohol-based, fatty acid and fatty acid ester-based, amide-based, phosphate ester-based, silicone-based, polyether-based, polyether-modified polysiloxane-based defoamers. The stabilizer can be BHT, IRGANOX 1010, IRGANOX 1076, 168, etc.

[0054] The leveling agent is the leveling agent used in the conventional photosensitive layer. The antioxidant is the antioxidant used in the conventional photosensitive layer.

[0055] The water-developable transfer photosensitive resin plate comprises a laser ablation black film, the above-mentioned photosensitive resin layer and a support.

[0056] The support substrate of the transfer resin plate can be polybutylene terephthalate, poly(ethylene naphthalate)-2,6-dicarboxylate, polyvinyl chloride, polyethylene terephthalate, polypropylene, polycarbonate, aluminum sheet, stainless steel sheet, copper sheet, iron sheet, etc., with common thicknesses of 0.27mm and 0.30mm. The PET sheet support can be pre-corona treated, and the magnetic steel support can be pre-surface treated such as water washing, degreasing, sanding, etc. For the adhesive layer described in the present invention, one or more of polyester-based, polyurethane-based or other copolymer adhesives are pre-configured into a solution, and the above components are coated on the support by means of a gravure roll or a doctor blade coating method and dried into a film for standby.

[0057] The laser ablation black film substrate of the transfer resin plate can be a PET or PE film. The ablation black film contains carbon black nanoparticles, and also contains polyvinyl alcohol or polyvinyl alcohol / ethylene glycol graft copolymer, polyvinylpyrrolidone, hydroxypropyl cellulose ester, etc., plus a dispersant and other components are mixed into a coating solution, which is coated on the protective film substrate by methods such as blade coating or gravure coating, and dried for later use.

[0058] The photosensitive layer material of the transfer resin plate can be metered and fed, kneaded, and melt-extruded onto a support body pre-coated with an adhesive layer, or the above composition is dissolved in a certain proportion of water and solvent, and is cast and coated on a support body pre-coated with an adhesive layer with a certain thickness, and the water and solvent are evaporated to obtain a photosensitive elastomer layer of a water-washable flexographic plate, with a common thickness of 0.65 mm. Then it is laminated on the laser ablation black film of the present invention to prepare a water-washable transfer resin plate. An offset plate that can be directly used for printing can be obtained. The graphics, dots, and screen lines of the offset plate are restored well, and the plate material has high flexibility and good ink transferability.

[0059] The following examples are intended to further illustrate the content of the present invention, but do not limit the protection scope of the present invention.

[0060] Example 1

[0061] Preparation of the support body: The substrate is PET with a thickness of 0.30 mm, and the surface of the substrate is treated with a ZLD-2 type experimental plasma processor (Hangzhou Shangqiang Intelligent Technology) for later use. 75 g of ethyl acetate, 15 g of unsaturated polyester (Lucky Huaguang), 5 g of adhesion promoter LTH (Shanghai Kayin Chemical Industry), 3 g of pentaerythritol triacrylate (Taiwan Changxing), 2 g of initiator 651, and stirred at 60 °C for 1 hour to prepare a coating solution. The prepared coating solution is coated on the treated PET with a 40# wire bar, and dried in an oven at 90 °C for 5 min to obtain a support body with a coating thickness of 4 μm for later use.

[0062] Preparation of the laser ablation black film: The substrate is selected as 0.1 mm frosted PET with a sand grain size of about 0.10 μm. 30 g of polyvinyl alcohol AZF8035W (Kuraray, Japan), 20 g of carbon black, 10 g of PVI (Panchim Company), 180 g of deionized water, 0.5 g of Le-202 (Guangzhou Lier Chemical), mixed evenly, and coated on a 0.100 mm PET sheet base protective film using a gravure roll, and dried at 90 °C for 10 min to obtain a black film with a coating thickness of 2 μm for later use.

[0063] Synthesis of the main resin in the photosensitive layer, i.e., the photosensitive resin plate layer: Add 100 g of polyvinyl alcohol RS1717 (Kuraray, Japan) and 150 g of dimethyl sulfoxide (DMSO) into a 500 ml three-necked flask, stir and dissolve at 90 °C for 1 h; when the temperature drops to 60 °C, dropwise add a mixture of 80 g of epoxy polybutadiene JP-100 (Nippon Soda, Japan) and 2 g of dibutyltin dilaurate (DBTDL), complete the dropwise addition in 0.5 h, continue stirring for 6 h, cool to a low temperature of 5 °C and perform suction filtration, and vacuum-dry the wet reactants on the filter for 24 h to obtain modified polyvinyl alcohol PVA1# with vinyl double bonds in the side chain.

[0064] Photosensitive elastomer component:

[0065] 40 g of modified PVA1#

[0066] 5 g of polyethylene glycol (1000) diacrylate (Taiwan Changxing)

[0067] 15 g of polyethylene glycol (200) diacrylate (Taiwan Changxing)

[0068] 5 g of 2-hydroxyethyl methacrylate

[0069] 5 g of glycerol acrylate epoxy resin DA-314 (Nagase, Japan)

[0070] 20 g of glycerol

[0071] 5 g of 651 photoinitiator (Jingjiang Hongtai Chemical Industry)

[0072] 2 g of 2,6-di-tert-butyl-p-cresol (Nanjing Jiulong Chemical Industry)

[0073] Neozapon ® 0.02 g of Red 395 (BASF)

[0074] 1 g of silicon dioxide

[0075] 60 g of water

[0076] 20 g of ethanol

[0077] 2 g of SY-9131 defoamer (Xi'an Sanye)

[0078] After mixing the above components at 90 °C for 6 h to mix them completely evenly, let them stand and cool to room temperature, coat them in a mold with a prepared support at the bottom, level them with a wire rod, and perform gradient heating and vacuum drying in an oven, drying at 40 °C for 12 h and at 60 °C for 8 h to obtain a resin plate with a total thickness of 1.70 mm.

[0079] Wipe the surface of the dried resin plate above with a gently damp cloth, then apply the prepared laser ablation black film, and dry it in an oven at 50 °C for 0.5 h to obtain a water-developable transfer resin plate with a thickness of 1.70 mm.

[0080] Example 2

[0081] Preparation of the support: The same as in Example 1.

[0082] Preparation of the laser ablation black film: The same as in Example 1.

[0083] Synthesis of the main resin of the photosensitive layer: The same as in Example 1

[0084] Photosensitive elastomer components:

[0085] Modified PVA1# 50 g

[0086] Polyethylene glycol (600) dimethacrylate (Taiwan Changxing) 18 g

[0087] Polypropylene glycol epoxy acrylate DA-931 (Japan Nagase) 1 g

[0088] Acetylated trimethylolpropane triacrylate (Taiwan Changxing) 2 g

[0089] 2-Hydroxyethyl methacrylate 5 g

[0090] Glycerol 15 g

[0091] 651 photoinitiator (Jingjiang Hongtai Chemical Industry) 4 g

[0092] 2,6-Di-tert-butyl-p-cresol (Nanjing Jiulong Chemical Industry) 1 g

[0093] Neozapon ® Red 395 (BASF) 0.02 g

[0094] Silica 1 g

[0095] Water 60 g

[0096] Ethanol 20 g

[0097] SY-9131 defoamer (Xi'an Sanye) 3 g

[0098] After mixing the above components at 90 °C for 6 h until completely mixed evenly, let it stand and cool to room temperature, coat it in a mold with the prepared support placed at the bottom, level it with a wire bar, and dry it by gradient heating and vacuum drying in an oven, dry it at 40 °C for 12 h and at 60 °C for 8 h to obtain a resin plate with a total thickness of 1.70 mm.

[0099] Wipe the surface of the dried resin plate above with a gently damp cloth, then apply the prepared laser ablation black film, and dry it in an oven at 50 °C for 0.5 h to obtain a water-developable transfer resin plate with a thickness of 1.70 mm.

[0100] Example 3

[0101] Preparation of the support: The same as in Example 1.

[0102] Preparation of the laser ablation black film: The same as in Example 1.

[0103] Synthesis of the main resin of the photosensitive layer: The same as in Example 1

[0104] Photosensitive elastomer components:

[0105] Modified PVA1# 60 g

[0106] Polyethylene glycol (600) dimethacrylate (Changxing, Taiwan) 16 g

[0107] Polypropylene glycol epoxy acrylate DA-931 (Nagase, Japan) 2 g

[0108] 2-Hydroxyethyl methacrylate 4 g

[0109] Trimethylolpropane 14 g

[0110] 651 photoinitiator (Jingjiang Hongtai Chemical Industry) 3 g

[0111] Neozapon ® Red 395 (BASF) 0.02 g

[0112] Water 60 g

[0113] Ethanol 20 g

[0114] SY-9131 defoamer (Xi'an Sanye) 1 g

[0115] After mixing the above components at 90 °C for 6 h until completely mixed evenly, let it stand and cool to room temperature, coat it in a mold with the prepared support placed at the bottom, level it with a wire rod, and dry it under vacuum with gradient heating in an oven, dry it at 40 °C for 12 h and at 60 °C for 8 h to obtain a resin plate with a total thickness of 1.70 mm.

[0116] Wipe the surface of the dried resin plate above with a gently damp cloth, then apply the prepared laser ablation black film, and dry it in an oven at 50 °C for 0.5 h to obtain a water-developable transfer resin plate with a thickness of 1.70 mm.

[0117] Example 4

[0118] Preparation of the support: The same as in Example 1.

[0119] Preparation of the laser ablation black film: The same as in Example 1.

[0120] Synthesis of the photosensitive layer matrix resin: The same as in Example 1

[0121] Photosensitive elastomer components:

[0122] Modified PVA1# 70 g

[0123] Polyethylene glycol (600) diacrylate (Taiwan Changxing) 10 g

[0124] Acetylated trimethylolpropane triacrylate (Taiwan Changxing) 3 g

[0125] 2-Hydroxyethyl methacrylate 2 g

[0126] Trimethylolpropane 10 g

[0127] 651 photoinitiator (Jingjiang Hongtai Chemical Industry) 1 g

[0128] 2,6-Di-tert-butyl-p-cresol (Nanjing Jiulong Chemical Industry) 1 g

[0129] Neozapon ® Red 395 (BASF) 0.02 g

[0130] Silica 1 g

[0131] Water 60 g

[0132] Ethanol 20 g

[0133] SY-9131 defoamer (Xi'an Sanye) 3 g

[0134] After mixing the above components at 90 °C for 6 h until completely and evenly mixed, let it stand and cool to room temperature, coat it in a mold with the prepared support placed at the bottom, level it with a wire bar, and dry it under vacuum with gradient heating in an oven, drying for 12 h at 40 °C and 8 h at 60 °C to obtain a resin plate with a total thickness of 1.70 mm.

[0135] Gently wipe the surface of the dried resin plate above with a damp cloth, then apply the prepared laser ablation black film, and dry it in an oven at 50 °C for 0.5 h to obtain a water-developable transfer resin plate with a thickness of 1.70 mm.

[0136] Example 5

[0137] Preparation of the support: The same as in Example 1.

[0138] Preparation of the laser ablation black film: The same as in Example 1.

[0139] Synthesis of the photosensitive layer main resin: Add 125 g of polyvinyl alcohol RS2117 (Kuraray, Japan) and 150 g of dimethyl sulfoxide (DMSO) into a 500 ml three-necked flask, stir and dissolve at 90 °C for 1 h; when the temperature drops to 60 °C, dropwise add a mixture of 55 g of epoxy polybutadiene JP-100 (Nippon Soda, Japan) and 1.8 g of dibutyltin dilaurate (DBTDL), complete the dropwise addition in 0.5 h, continue stirring for 6 h, cool to a low temperature of 5 °C and perform suction filtration, and vacuum dry the wet reactants on the filter for 24 h to obtain modified polyvinyl alcohol PVA2# with vinyl double bonds in the side chain.

[0140] 30 g of modified PVA1#

[0141] 20 g of modified PVA2#

[0142] 9 g of polyethylene glycol (1000) diacrylate (Taiwan Changxing)

[0143] 9 g of polyethylene glycol (400) diacrylate (Taiwan Changxing)

[0144] 3 g of 2-hydroxyethyl methacrylate

[0145] 4 g of glycerol acrylate epoxy resin DA-314 (Nippon Nagase, Japan)

[0146] 16 g of glycerol

[0147] 4 g of 651 photoinitiator (Jingjiang Hongtai Chemical Industry)

[0148] 2 g of 2,6-di-tert-butyl-p-cresol (Nanjing Jiulong Chemical Industry)

[0149] Neozapon ® 0.02 g of Red 395 (BASF)

[0150] 1 g of silicon dioxide

[0151] 60 g of water

[0152] 20 g of ethanol

[0153] 2 g of SY-9131 defoamer (Xi'an Sanye)

[0154] After mixing the above components at 90 °C for 6 h to mix them completely evenly, let them stand and cool to room temperature, coat them in a mold with a prepared support at the bottom, scrape them flat with a wire bar, and perform gradient heating and vacuum drying in an oven, drying at 40 °C for 12 h and at 60 °C for 8 h to obtain a resin plate with a total thickness of 1.70 mm.

[0155] Wipe the surface of the dried resin plate above with a slightly damp cloth, then apply the prepared laser ablation black film, and dry it in an oven at 50 °C for 0.5 h to obtain a water-developable transfer resin plate with a thickness of 1.70 mm.

[0156] Comparative Example 1

[0157] Preparation of the support: The same as in Example 1.

[0158] Preparation of the laser ablation black film: The same as in Example 1.

[0159] Photosensitive elastomer component:

[0160] Polyvinyl alcohol RS1717 (Kuraray, Japan) 40 g

[0161] Polyethylene glycol (1000) diacrylate (Changxing, Taiwan) 5 g

[0162] Polyethylene glycol (200) diacrylate (Changxing, Taiwan) 15 g

[0163] 2-Hydroxyethyl methacrylate 5 g

[0164] Glycerol acrylate epoxy resin DA-314 (Nagase, Japan) 5 g

[0165] Glycerol 20 g

[0166] 651 photoinitiator (Jingjiang Hongtai Chemical Industry) 5 g

[0167] 2,6-Di-tert-butyl-p-cresol (Nanjing Jiulong Chemical Industry) 2 g

[0168] Neozapon ® Red 395 (BASF) 0.02 g

[0169] Silica 1 g

[0170] Water 60 g

[0171] Ethanol 20 g

[0172] SY-9131 defoamer (Xi'an Sanye) 2 g

[0173] After mixing the above components at 90 °C for 6 h until completely mixed evenly, let it stand and cool to room temperature, coat it in a mold with the prepared support placed at the bottom, level it with a wire bar, and dry it under vacuum with gradient heating in an oven, dry it at 40 °C for 12 h and at 60 °C for 8 h to obtain a resin plate with a total thickness of 1.70 mm.

[0174] Wipe the surface of the dried resin plate above with a damp cloth gently, then apply the prepared laser ablation black film, and dry it in an oven at 50 °C for 0.5 h to obtain a water-developable transfer resin plate with a thickness of 1.70 mm.

[0175] Comparative Example 2

[0176] Preparation of the support: The same as in Example 1.

[0177] Preparation of the laser ablation black film: The same as in Example 1.

[0178] Synthesis of the main resin of the photosensitive layer: Add 100 g of PVA-217 (Kuraray, Japan) and 150 g of dimethyl sulfoxide (DMSO) to a 500 ml three-necked flask, stir and dissolve at 90 °C for 1 h; lower the temperature to 60 °C, and dropwise add a mixture of 80 g of epoxy polybutadiene JP-100 (Nippon Soda, Japan) and 2 g of dibutyltin dilaurate (DBTDL). The dropping is completed in 0.5 h, and continue to stir for 6 h. Cool to a low temperature of 5 °C and perform suction filtration. The wet reactants on the filter are dried in vacuo for 24 h to obtain modified polyvinyl alcohol PVA3# with vinyl double bonds in the side chain.

[0179] Photosensitive elastomer components:

[0180] PVA3# 40 g

[0181] Polyethylene glycol (1000) diacrylate (Changxing, Taiwan) 5 g

[0182] Polyethylene glycol (200) diacrylate (Changxing, Taiwan) 15 g

[0183] 2-Hydroxyethyl methacrylate 5 g

[0184] Glycerol acrylate epoxy resin DA-314 (Nagase, Japan) 5 g

[0185] Glycerol 20 g

[0186] 651 photoinitiator (Jingjiang Hongtai Chemical Industry) 5 g

[0187] 2,6-Di-tert-butyl-p-cresol (Nanjing Jiulong Chemical Industry) 2 g

[0188] Neozapon ® Red 395 (BASF) 0.02 g

[0189] Silica 1 g

[0190] Water 60 g

[0191] Ethanol 20 g

[0192] SY-9131 defoamer (Xi'an Sanye) 2 g

[0193] After mixing the above components at 90 °C for 6 h until completely and evenly mixed, let it stand and cool to room temperature, coat it in a mold with a prepared support at the bottom, scrape it flat with a wire bar, and perform gradient heating and vacuum drying in an oven, drying for 12 h at 40 °C and 8 h at 60 °C to obtain a resin plate with a total thickness of 1.70 mm.

[0194] Gently wipe the surface of the dried resin plate above with a damp cloth, then apply the prepared laser ablation black film, and dry it in an oven at 50 °C for 0.5 h to obtain a water-developable transfer resin plate with a thickness of 1.70 mm.

[0195] Comparative Example 3

[0196] Preparation of the support: The same as in Example 1.

[0197] Preparation of the laser ablation black film: The same as in Example 1.

[0198] Synthesis of the main resin of the photosensitive layer: The same as in Example 1.

[0199] Modified PVA1# 40 g

[0200] Triacetylated trimethylolpropane triacrylate (Changxing, Taiwan) 10 g

[0201] 2-Hydroxyethyl methacrylate 15 g

[0202] Glycerol acrylate epoxy resin DA-314 (Nagase, Japan) 5 g

[0203] Glycerol 20 g

[0204] 651 photoinitiator (Jingjiang Hongtai Chemical Industry) 5 g

[0205] 2,6-Di-tert-butyl-p-cresol (Nanjing Jiulong Chemical Industry) 2 g

[0206] Neozapon ® Red 395 (BASF) 0.02 g

[0207] Silica 1 g

[0208] Water 60 g

[0209] Ethanol 20 g

[0210] SY-9131 defoamer (Xi'an Sanye) 2 g

[0211] After mixing the above components at 90 °C for 6 h until completely and evenly mixed, let it stand and cool to room temperature, coat it in a mold with a prepared support placed at the bottom, scrape it flat with a wire rod, and dry it under vacuum with gradient heating in an oven, drying for 12 h at 40 °C and 8 h at 60 °C to obtain a resin plate with a total thickness of 1.70 mm.

[0212] Gently wipe the surface of the dried resin plate above with a damp cloth, then apply the prepared laser ablation black film, and dry it in an oven at 50 °C for 0.5 h to obtain a water-developable transfer resin plate with a thickness of 1.70 mm.

[0213] Place the 1.70-mm-thick water-developable transfer resin plates obtained in the examples and comparative examples in the dark at room temperature for 7 days. Remove the protective base film, laser engrave it on a high-precision digital flexographic plate-making machine HDI-900S / 900H (Hangzhou Kele Electromechanical), with a laser energy of 3500 J and a focal length of 1.70 mm, transfer the test file to the plate material, then expose it on a high-definition dot platemaker A3L (Dongguan Xinyie Printing Equipment) for 10 min, wash the plate in warm water at 30 °C for 5 min, dry it at 60 °C for 20 min, remove tackiness with UV-C for 5 min, and post-expose it with UV-A for 5 min to obtain a printing plate that can be directly used on the press, and evaluate the imaging performance.

[0214] The performance evaluation results of the water-developable transfer resin plates of Examples 1-3 and Comparative Examples 1-3 are shown in Table 1.

[0215] Table 1 Performance evaluation results

[0216]

[0217] It can be seen from the data in Table 1 that the water-developable transfer resin plate of the present invention can be directly laser imaged, can be water-washed, is suitable for high-definition halftone imaging, has good resilience and good ink transfer property, and can be used for printing. In Comparative Example 2, there is no vinyl group on the modified polyvinyl alcohol main chain, so the resilience is poor and the printing is poor; in Comparative Example 3, it does not contain monomers with good flexibility, the plate material is hard, and the resilience is also very poor. The above are only the preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. It should be pointed out that for those skilled in the art and anyone familiar with the technical field of the present invention, without departing from the overall concept of the present invention, according to the technical solution of the present invention and its inventive concept, equivalent replacements or changes are made, and several changes and improvements are made, and these should also be regarded as the protection scope of the present invention.

Claims

1. The photosensitive resin layer of a water-developable transfer photosensitive resin plate, characterized in that: The raw materials include: (A) The main resin is modified polyvinyl alcohol. The modified polyvinyl alcohol has vinyl groups on the main chain, formyl groups (hydrophobic groups) on the side chains, and photocrosslinkable vinyl groups on the side chains; (B) A highly flexible active water-soluble monomer, which is at least one of polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, or polypropylene glycol dimethacrylate; (C) A plasticizer; (D) A photoinitiator; (E) An aqueous dye and other additives; The other additives include at least one of an antifoaming agent and a stabilizer; (F) Other polymerizable vinyl monomers other than the modified polyvinyl alcohol in (A).

2. The photosensitive resin layer of the water-developable transfer photosensitive resin plate according to claim 1, wherein: By weight, (A) The modified polyvinyl alcohol accounts for 40 - 70% of the total mass of the photosensitive layer; (B) The highly flexible active water-soluble monomer accounts for 10 - 20% of the total mass of the photosensitive layer; (C) The plasticizer accounts for 10 - 20% of the total mass of the photosensitive layer; (D) The photoinitiator accounts for 1 - 5% of the total mass of the photosensitive layer; (E) The aqueous dye and other additives account for 1 - 5% of the total mass of the photosensitive layer; (F) Other polymerizable vinyl monomers other than the modified polyvinyl alcohol in (A) account for 5 - 10% of the total mass of the photosensitive layer.

3. The photosensitive resin layer of the water-developable transfer photosensitive resin plate according to claim 1, wherein: The structure of the modified polyvinyl alcohol in (A) is as follows (Formula II): In Formula (II), m is an integer from 500 to 1000, and n is an integer from 100 to 500; The structure of the photocrosslinkable vinyl group R is as follows (Formula III): In Formula (III), where a is an integer from 4 to 7, and a + b is an integer from 16 to 25.

4. The photosensitive resin layer of the water-developable transfer photosensitive resin plate according to claim 3, wherein: The preparation method of the modified polyvinyl alcohol is: Polyvinyl alcohol with vinyl groups on the main chain and formyl groups (hydrophobic groups) on the side chains is prepared into the modified polyvinyl alcohol in the structural formula (II) by grafting groups containing photocrosslinkable vinyl groups on the side chains.

5. The photosensitive resin layer of the water-developable transfer photosensitive resin plate according to claim 4, characterized in that: The structure of polyvinyl alcohol with vinyl groups on the main chain and formyl groups (hydrophobic groups) on the side chains is as follows (Formula I): In Formula (I), where m is an integer from 500 to 1000, n is an integer from 100 to 500, and the average molecular weight of polyvinyl alcohol is 25,000 - 80,000.

6. The photosensitive resin layer of the water-developable transfer photosensitive resin plate according to claim 1, wherein: The photosensitive resin layer contains at least one of the modified polyvinyl alcohols; The photoinitiator is one of a cleavage type, a hydrogen abstraction type, or a mixed type initiator.

7. The photosensitive resin layer of the water-developable transfer photosensitive resin plate according to claim 6, characterized in that: The highly flexible active water-soluble monomer is polyethylene glycol (1000) diacrylate; The photoinitiator is a cleavage type initiator.

8. The photosensitive resin layer of the water-developable transfer photosensitive resin plate according to claim 1, characterized in that: The plasticizer is at least one of glycerol, ethylene glycol, diethylene glycol, N-butylbenzenesulfonamide, lauryl methacrylate, trimethylolpropane, or a nylon plasticizer; The aqueous dye is at least one of blue, red, or green.

9. The method for preparing the photosensitive resin layer of the water-developable transfer photosensitive resin plate according to any one of claims 1-8, characterized in that: Mix the raw materials of the photosensitive resin layer, and obtain the photosensitive resin layer with the required thickness by means of coating and drying or twin-screw extrusion.

10. A water-developable transfer photosensitive resin plate, characterized in that: It includes a laser ablation black film, a photosensitive resin layer and a support; the photosensitive resin layer is the photosensitive resin layer described in any one of claims 1-9, the support is PET or a metal substrate. After applying an adhesive layer on the support, the photosensitive resin layer is applied, and then the laser ablation black film is applied. After slightly applying pressure, a complete water-developable transfer photosensitive resin plate is obtained.

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