A kind of treatment-free thermal sensitive plate and preparation method thereof

Abstract

The invention provides a treatment-free thermal plate and a preparation method thereof, so that the plate material treated by hot melt has good scratch resistance, and the plate material has excellent imaging performance and is green and environmentally friendly. A treatment-free thermal plate comprises a substrate and an imaging layer, wherein the imaging layer comprises a thermal resin A, a thermal resin B, a thermal initiator, and a dye; the thermal resin A is nano-micron resin particles existing in a discrete form, and the thermal resin B is a functional film-forming resin.

Description

Technical Field

[0001] The invention belongs to the technical field of lithography, and in particular relates to a treatment-free thermal-sensitive plate and a preparation method thereof. Background Art

[0002] The printing industry is a key pillar industry supporting economic development. For a long time, from the film and developer, fixer, and washing water in the plate-making process to the solvent-based ink, alcohol fountain solution, and car wash water in the printing process, to the coating and oil-based glazing processes that are still widely used in post-printing finishing, green printing refers to the use of environmentally friendly materials and process technologies to reduce pollution generated during the printing process. The development of green and environmentally friendly printing consumables, especially green and environmentally friendly printing plates, is the top priority in the development of green printing.

[0003] At present, thermal CTP plates have been widely used in the printing industry, from the first generation of preheating negative thermal plates to the second generation of widely used mature preheating-free positive thermal plates. The development goal of the third generation of thermal plate technology is environmentally friendly and processing-free thermal plates.

[0004] There are many technical routes for developing green, environmentally friendly and processing-free CTP plates, which can be divided into thermal ablation technology, phase change technology and hot melt technology, etc. Thermal ablation technology refers to the use of infrared laser energy to ablate the oleophilic coating, exposing the hydrophilic surface of the aluminum plate to form a hydrophilic area; phase change technology refers to the use of laser energy to convert the polymer into hydrophilic and oleophilic, thereby achieving ink-water separation; hot melt technology refers to the use of laser energy to melt the thermoplastic polymer particles dispersed in the cross-linked hydrophilic layer, changing from hydrophilic to hydrophobic and oleophilic.

[0005] Process-free CTP plates can be divided into two categories: (1) Completely process-free CTP plates. These are CTP plates that can be directly printed on the machine after being imaged on the platemaking equipment. According to the different imaging methods, they can be mainly divided into ablative process-free CTP plates and thermo-polar process-free CTP plates. (2) Low chemical development process-free CTP plates. This means that after the CTP plate is exposed and imaged on the platemaking machine, it must be developed before printing on the machine. This process does not require chemical developers, and can be developed by washing with clean water or by applying glue to the printing plate; or after the CTP plate is exposed and imaged on the platemaking machine, it is developed on the printing press using the wetting effect of the fountain solution to remove the film on the non-image part.

[0006] At present, environmentally friendly thermal plates are divided into two types: double-layer plates and single-layer plates. Double-layer environmentally friendly thermal plates generally use a double-bond free radical imaging mechanism. In order to reduce the inhibitory effect of oxygen on free radical reactions, the plate is provided with an oxygen barrier protective layer. Its advantage is that the plate has high printing resistance. Its disadvantage is that it requires double-layer coating, high production process control requirements, low product yield rate, and the treatment of defective products produced during the production process will cause environmental pollution, which indirectly increases environmental pressure. Single-layer environmentally friendly thermal plates generally use a non-oxygen inhibition imaging mechanism. The plate does not need to be provided with an oxygen barrier protective layer. Its advantage is single-layer coating, simple plate production process, high yield rate, and high printing resistance. Its disadvantage is that it requires high imaging ability of imaging materials. Insufficient imaging ability of imaging materials often affects the environmental performance and printing resistance of thermal plates.

[0007] Development of chemical-free CTP plate technology: EP0980754 introduces decarboxylation to achieve hydrophilic-hydrophobic conversion technology, but the printing resistance is poor. WO94 / 23954 introduces hot melt micro-gel technology, but it is easy to get dirty; US4004924 introduces a mixture of thermoplastic hydrophobic particles and hydrophilic binder, which is also not printing-resistant; EP 2006-5-24 06114475.4 introduces a hot-melt thermoplastic particle, which is easy to contaminate the fountain solution; US 2005-8-3 11 / 196,124 introduces a one-dimensional linear structure hydrophilic adhesive, which has low printing resistance; US 2006-7-27 11 / 494,235 introduces a printing plate precursor containing hydrophilic groups and esterified allyl groups, but the ester group is not resistant to ink erosion.

[0008] At present, there is a technical difficulty in non-developer-developable, processing-free plates, which is the platemaking contrast problem. The developer-developable plates can achieve contrast presentation through development, which is conducive to the printing operator to check the plate with the naked eye to detect the image defects of the printing plate. At the same time, modern highly intelligent printing presses automatically locate and identify through the cross image positioning line of the plate, realizing automatic intelligent plate loading. Non-developer-type processing-free plates cannot achieve contrast presentation through development, so it is impossible to realize the early stage of the naked eye plate proofing to find image defects, and it is also impossible to automatically locate and identify through the image positioning line to realize automatic intelligent plate loading. Therefore, it is necessary to solve the problem of the presentation of contrast in the platemaking of non-developer-developable, processing-free thermal plates.

[0009] Hot melt technology is widely used in the field of imaging. Laser energy melts thermoplastic polymer particles, changing from hydrophilic to hydrophobic and oleophilic. However, the film-forming property of the dispersed particles is extremely poor, which greatly reduces the scratch resistance of the raw plate. This problem also needs to be solved urgently.

[0010] In order to solve the above problems, the purpose of the present invention is to further improve the performance of the processing-free thermal CTP plate, especially to improve the platemaking contrast of the plate, improve the scratch resistance of the plate, and at the same time the plate has excellent imaging performance. Summary of the invention

[0011] In order to solve the above problems, the present invention provides a treatment-free thermal plate and a preparation method thereof, so that the hot-melt treated plate has good scratch resistance, and at the same time the plate has excellent imaging performance and is green and environmentally friendly.

[0012] The object of the present invention is achieved in the following manner: a processing-free thermal plate comprises a substrate and an imaging layer, wherein the imaging layer comprises a thermal resin A, a thermal resin B, a thermal initiator, and a dye; the thermal resin A is nano-micron resin particles existing in a discrete form, and the thermal resin B is a functional film-forming resin.

[0013] The dye is a thermochromic dye.

[0014] The structure of the thermochromic dye is one of the following:

[0015]

[0016] (Structural formula D1)

[0017] or:

[0018]

[0019] (Structural formula D2).

[0020] By weight percentage, the thermosensitive resin A accounts for 40-80% of the total solid content of the composition, the thermosensitive resin B accounts for 10-50% of the total solid content of the composition, the thermal initiator accounts for 1-10% of the total solid content of the composition, and the thermochromic dye accounts for 1-10% of the total solid content of the composition.

[0021] The heat-sensitive resin A is a ternary free radical copolymer of monomer a: methyl methacrylate, monomer b: allyl polyoxyethylene ether and monomer c: 3,4-epoxycyclohexyl methacrylate; by weight percentage, the proportion of methyl methacrylate in a is 40-80%, the proportion of allyl polyoxyethylene ether in b is 10-30%, and the proportion of monomer c in c is 10-30%.

[0022] The thermosensitive resin B is a ternary free radical copolymer of monomer a: methyl methacrylate, monomer b: 2-acrylamide-2-methylpropane sulfonic acid and monomer c: glycidyl methacrylate; by weight percentage, the proportion a of methyl methacrylate is 40-80%, the proportion b of 2-acrylamide-2-methylpropane sulfonic acid is 10-30%, and the proportion c of glycidyl methacrylate is 10-30%.

[0023] The thermal initiator is selected from onium salts; suitable onium salts include sulfonium salts, oxysulfonium salts, oxosulfonium salts, sulfonium salts, diazonium salts and halogen onium salts; suitable onium salts may specifically be: diphenyliodonium chloride, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, [4-[(2-hydroxytetradecyl-oxy]-phenyl]phenyliodonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium iodonium octyl sulfate, hexafluorophosphate-2-methoxy-4-aminophenyldiazonium or hexafluoroantimonate phenoxyphenyldiazonium.

[0024] The thermal initiator is selected from at least one of iodonium salt and sulfonium salt which can simultaneously undergo homolysis and heterolysis, and its thermal decomposition temperature is 150-200°C.

[0025] The weight average molecular weight of the thermosensitive resin A is 4000-150000, the glass transition temperature is 110-130°C, and the particle size is controlled at 85-250nm; the weight average molecular weight of the thermosensitive resin B is 4000-150000, and the glass transition temperature is 110-130°C; the substrate is an aluminum plate substrate that has been electrolytically roughened, anodized, and sealed.

[0026] The method for preparing the treatment-free thermal plate comprises the following steps: (1) treating the hydrophilic carrier of the aluminum plate; and (2) coating the imaging layer on the treated hydrophilic carrier of the aluminum plate.

[0027] Compared with the prior art, the imaging layer of the present invention contains thermosensitive resin A and thermosensitive resin B. The thermosensitive resin A has a nano-micron morphology and can realize laser thermal melting imaging; the thermosensitive resin B mainly acts as an adhesive, which can fix the particle-shaped thermosensitive resin A and improve the scratch resistance of the plate. The treatment-free thermal plate of the present application is a single-layer plate and does not require an oxygen barrier layer.

[0028] Thermosensitive resin A contains epoxy and polyethoxy groups, and thermosensitive resin B contains epoxy and sulfonic acid groups. Both thermosensitive resin A and thermosensitive resin B contain epoxy groups, which can realize epoxy cross-linking imaging and improve the imaging performance of the plate; the polyethoxy groups of thermosensitive resin A and the sulfonic acid groups of thermosensitive resin B can both realize the infiltration of fountain solution, and the non-exposed part can be quickly taken away by the plate-passing paper to expose the hydrophilic aluminum plate base, and finally complete the green printing process. The treatment-free thermosensitive plate of the present application can realize network cationic polymerization, and has excellent imaging ability and printing durability. DETAILED DESCRIPTION

[0029] A treatment-free thermosensitive plate comprises a substrate and an imaging layer, wherein the imaging layer comprises a thermosensitive resin A, a thermosensitive resin B, a thermal initiator, and a dye; the thermosensitive resin A is nano-micron resin particles existing in a discrete form, and the thermosensitive resin B is a functional film-forming resin. The dye may be a thermochromic dye.

[0030] First, the heat-sensitive resin A in the image forming layer will be described.

[0031] Thermo Fuse technology is widely used in the field of imaging. It uses the principle that the melting point of nano-micron particles decreases sharply due to the size effect. Laser energy melts the water-in-oil thermoplastic particles, changing them from hydrophilic to hydrophobic and lipophilic.

[0032] The heat-sensitive resin A in the heat-sensitive layer of the plate material of the present invention is a kind of resin particles existing in a discrete form, which is a ternary free radical self-emulsifying copolymer of monomer a: methyl methacrylate, monomer b: allyl polyoxyethylene ether and monomer c: 3,4-epoxycyclohexyl methacrylate (CAS: 64630-63-3), wherein the proportion of methyl methacrylate a is 40-80% (weight percentage), the proportion of allyl polyoxyethylene ether b is 10-30% (weight percentage), and the proportion of 3,4-epoxycyclohexyl methacrylate c is 10-30% (weight percentage).

[0033] The thermosensitive resin A contains methyl methacrylate structural units, which have good lipophilicity, thermoplasticity and rigidity, and can improve the ink-holding and wear resistance of the plate. The weight percentage content of the methyl methacrylate copolymer unit a in the copolymer is 40-80% (weight percentage).

[0034] Thermosensitive resin A contains allyl polyoxyethylene ether hydrophilic structural unit b. After infrared laser scanning imaging, the molecular weight of the thermosensitive layer increases sharply, making the coating more solid. The coating after laser thermal exposure is difficult to be removed by water and ink. The excess coating in the unexposed blank area is easily infiltrated by the fountain solution and removed by the plate paper due to the presence of ether bond groups. The exposed blank area is the hydrophilic aluminum plate base, achieving the environmental protection purpose of no pollution discharge in the plate making process. The weight percentage content of allyl polyoxyethylene ether b in the copolymer is 10-30% (weight percentage), and the weight average molecular weight of allyl polyoxyethylene ether is preferably 600-2400.

[0035] The thermosensitive resin A designed by the present invention contains epoxy bonds on the cyclohexyl group, and has the ability of efficient cationic crosslinking. The laser heat energy is transferred to the thermal initiator through the thermosensitive dye, and the thermal initiator generates cations by heterolysis, so that the epoxy bonds on the cyclohexyl group in the thermosensitive resin A and the epoxy bonds in the thermosensitive resin B are crosslinked and polymerized. The epoxy bonds on the cyclohexyl group contained in the thermosensitive resin A of the present invention have the ability of ultra-high cationic crosslinking, and the cyclohexyl group has a certain rigidity, which can increase the wear resistance of the plate coating and improve the printing resistance of the plate. The weight percentage content of the epoxy bond copolymer unit c: 3,4-epoxycyclohexyl methacrylate in the multi-polymer is 10-30% (weight percentage).

[0036] The synthesis of the heat-sensitive resin A of the present invention adopts an emulsion copolymerization method, and the copolymerization reaction can be selected from random copolymerization or block copolymerization, preferably random copolymerization. The polymerization initiator includes peroxides such as di-tert-butyl peroxide, benzoyl peroxide, persulfates such as potassium persulfate, ammonium persulfate, and azo compounds such as azobisisobutyronitrile.

[0037] The reaction solvent that can be selected is a mixture of water and methanol, ethanol, n-propanol, isopropanol, butanol, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, dimethylacetamideacetone, methyl ethyl ketone, cyclohexane, ethylene dichloride, toluene, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol dimethyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, acetylacetone, diacetone alcohol, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol isopropyl ether, ethylene glycol butyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dimethyl sulfoxide, methyl lactate and ethyl lactate. The copolymerization temperature is preferably 40-100°C, and most preferably 60-90°C.

[0038] The weight average molecular weight of the heat-sensitive resin A of the present invention is 4000-150000, the glass transition temperature is 110-130° C., and the particle size is optimally controlled between 85-250 nm.

[0039] The heat-sensitive resin A designed in the present invention accounts for 40-80% of the total solid weight of the heat-sensitive layer.

[0040] Next, the heat-sensitive resin B in the image forming layer will be described.

[0041] Hot melt technology is widely used in the field of imaging. Laser energy melts thermoplastic polymer particles, changing from hydrophilic to hydrophobic and lipophilic. However, the film-forming property of the dispersed particles is extremely poor, which greatly reduces the scratch resistance of the plate. An important binder, namely a functional film-forming resin, is required in the thermosensitive coating. The resin can form a film after the coating liquid is dried, so that the thermosensitive coating is attached to the hydrophilic carrier. The thermosensitive resin B described in the present invention plays the role of anti-scratch binder, and it is also a functional resin. The resin contains functional groups and plays a special functional role. The thermosensitive resin B is a ternary free radical copolymer of monomer a: methyl methacrylate, monomer b: 2-acrylamide-2-methylpropane sulfonic acid and monomer c: glycidyl methacrylate, wherein the proportion a of methyl methacrylate is 40-80% (weight percentage), the proportion b of 2-acrylamide-2-methylpropane sulfonic acid is 10-30% (weight percentage), and the proportion c of glycidyl methacrylate is 10-30% (weight percentage). It is a polymer resin. As a reactive adhesive, it has a larger molecular weight than low molecular prepolymers and a high glass transition temperature, which can improve the scratch resistance of the raw plate (unexposed imaging printing plate).

[0042] Thermosensitive resin B also contains thermoplastic methyl methacrylate structural units, has good lipophilicity, thermoplasticity and rigidity, can improve the ink pick-up and wear resistance of the plate, and thermosensitive resin B and thermosensitive resin A simultaneously use methyl methacrylate copolymer units, which can increase the compatibility of the hot melt layer of the plate and improve the printing endurance of the plate. The weight percentage content of methyl methacrylate a in the copolymer is 40-80% (weight percentage).

[0043] Thermosensitive resin B also contains hydrophilic structural units, using 2-acrylamide-2-methylpropanesulfonic acid, which can provide excellent hydrophilicity. The hydrophilic group action principle is the same as that of thermosensitive resin A. The excess coating in the unexposed area is easily infiltrated by the fountain solution and removed through the plate paper due to the hydrophilic group, and the blank area is exposed as the hydrophilic aluminum plate. The weight percentage of 2-acrylamide-2-methylpropanesulfonic acid in the copolymer is 10-30% (weight percentage).

[0044] The thermosensitive resin B designed in the present invention has both adhesive and imaging functions, so an epoxy bond is also designed in the thermosensitive resin B. The thermosensitive resin B contains a glycidyl methacrylate copolymer unit, which has the ability of efficient cationic crosslinking. The laser heat energy is transferred to the thermal initiator through the thermosensitive dye, and the thermal initiator is heterolytically cleaved to generate cations, so that the epoxy bond on the cyclohexyl group in the thermosensitive resin A and the epoxy bond in the thermosensitive resin B are crosslinked and polymerized; the glycidyl methacrylate copolymer unit has a lower cost advantage. The glycidyl methacrylate copolymer unit c: the weight percentage content in the multi-polymer is 10-30% (weight percentage).

[0045] The thermosensitive resin B of the present invention is synthesized by solution copolymerization, and the copolymerization reaction can be random copolymerization or block copolymerization, preferably random copolymerization. The polymerization initiator includes peroxides such as di-tert-butyl peroxide, benzoyl peroxide, persulfates such as potassium persulfate, ammonium persulfate, and azo compounds such as azobisisobutyronitrile.

[0046] The reaction solvent that can be selected is methanol, ethanol, n-propanol, isopropanol, butanol, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, dimethylacetamideacetone, methyl ethyl ketone, cyclohexane, ethylene dichloride, toluene, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol dimethyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, acetylacetone, diacetone alcohol, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol isopropyl ether, ethylene glycol butyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dimethyl sulfoxide, methyl lactate and ethyl lactate, etc. The copolymerization temperature is preferably 40-100°C, and most preferably 60-90°C.

[0047] The heat-sensitive resin B of the present invention has a weight average molecular weight of 4000-150000 and a glass transition temperature of 110-130°C.

[0048] The heat-sensitive resin B designed in the present invention accounts for 10-50% of the total solid weight of the heat-sensitive layer.

[0049] The thermal initiator in the heat-sensitive layer of the plate is described in detail below.

[0050] The plate material has free radical polymerization imaging capability, and the thermal initiator is selected from onium salts, such as sulfonium salts, iodonium salts, etc. Suitable onium salts include sulfonium salts, oxysulfonium salts, oxysulfonium salts, sulfoxide salts, diazonium salts and halogen onium salts such as iodonium salts. Specific examples of suitable onium salts include diphenyliodonium chloride, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, [4-[(2-hydroxytetradecyl-oxy]-phenyl]phenyliodonium hexafluoroantimonate, triphenylsulfonium iodonium tetrafluoroborate, triphenylsulfonium iodonium octylsulfate, 2-methoxy-4-aminophenyldiazonium hexafluorophosphate, phenoxyphenyldiazonium hexafluoroantimonate, and the like. The cationic initiator of the present invention is selected from one or more iodonium salts and sulfonium salts that can undergo homolysis and heterolysis at the same time. Its thermal decomposition temperature is 150-200° C. The thermal initiator accounts for 1-10% of the total weight of the solids of the thermal sensitive layer in the thermal sensitive layer.

[0051] The components in the heat-sensitive layer of the heat-sensitive plate of the present invention are described in detail below: Thermochromic dye.

[0052] In conventional thermal plates, the thermal dye mainly plays the role of energy transfer. The heat of the infrared laser transfers the laser energy to the thermal initiator through the thermal dye, and the thermal initiator acts on the thermal resin to achieve thermal imaging. The maximum absorption wavelength range of the thermal dye is 750-1100nm, and it is selected from carbon black, azo dyes, triarylamine dyes, indolium dyes, oxonol dyes, cyanine dyes, merocyanine dyes, indocyanine dyes, phthalocyanine dyes, polythiophene dyes, pyrazoline azo dyes, oxazine dyes, naphthoquinone dyes, anthraquinone dyes, quinone imine dyes, methine dyes, porphyrin dyes, etc.

[0053] However, there is a technical difficulty in the non-developer-developable, processing-free plates, which is the platemaking contrast problem. The developer-developable plates can achieve contrast presentation through development, which is conducive to the printing operator to check the plate with the naked eye to detect the image defects of the printing plate. At the same time, modern highly intelligent printing presses automatically locate and identify the cross-line images at the four corners of the plate, realizing automatic intelligent plate loading. The non-developer-developable, processing-free plates cannot achieve contrast presentation through development, and the image needs to be presented during platemaking, so the contrast of the non-developer-developable, processing-free platemaking needs to be improved, which is also the difficulty in the development of direct printing, processing-free thermal plates.

[0054] The imaging layer of the present invention also includes a special thermochromic dye, which is synthesized by China Aerospace Science and Technology Group Lucky Huaguang Printing Technology Co., Ltd. It is an azamethine dye, which has the functions of both infrared dye and laser thermochromic. The thermochromic dye is a thermochromic dye of structural formula D1 or one of structural formulas D1. The following is a detailed introduction to the thermochromic dye of structural formula D1 and the thermochromic dye of structural formula D2:

[0055]

[0056] Structural formula D1

[0057] The maximum absorption peak of D1 is at 794nm. Under the action of laser heat, it can undergo a closed-loop reaction, transforming from structural formula D1 to structural formula II, and undergoing a color change from very light light green to dark blue. Moreover, this color change is irreversible, realizing non-developing contrast presentation of the plate material, which is beneficial for printing operators to proofread the plate with the naked eye to detect image defects of the printing plate. At the same time, it can realize automatic intelligent plate loading through automatic positioning and recognition of modern highly intelligent printing presses.

[0058]

[0059] Structural formula after color change Ⅰ

[0060] The structure of the D2 thermochromic dye is as follows:

[0061]

[0062] Structural formula D2

[0063] The maximum absorption peak of D2 is at 800nm. Under the action of laser heat, it can also undergo a closed-ring reaction, transforming from structural formula D2 to structural formula II, and undergoing a color change from very light green to dark blue. This color change is also irreversible.

[0064]

[0065] Structural formula after color change Ⅱ

[0066] The thermochromic dye accounts for 1-10% of the total solid weight of the thermosensitive layer in the photosensitive coating.

[0067] Finally, the hydrophilic carrier of the heat-sensitive plate of the present invention is described in detail.

[0068] The heat-sensitive plate composition of the present invention needs to be coated on a heat-sensitive plate hydrophilic carrier, and the heat-sensitive plate carrier includes a metal plate base such as a copper plate base, an aluminum plate base, etc. The hydrophilic carrier selected in the present invention is an aluminum plate base that has been subjected to electrolytic roughening, anodization, and sealing treatments.

[0069] The average centerline roughness of the aluminum substrate is 0.3-0.6um, and it is made by electrolytic roughening. The aluminum substrate is more than 99% aluminum, 0.1% -0.5% iron, 0.03% -0.3% silicon, 0.003% -0.03% copper, and 0.01% -0.1% titanium. The electrolytic roughening electrolyte can be an aqueous solution of acid, alkali or salt. First, place the aluminum plate in an aqueous solution of 1% - 30% sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, etc., and chemically corrode it at a temperature of 20-80°C for 5-250 seconds. Then neutralize it in 10% -30% nitric acid or sulfuric acid at a temperature of 20-70°C to remove the ash. At a temperature of 10-60°C, use a rectangular wave, a mezzanine wave or a sine wave with alternating positive and negative polarity at 5-100A / dm 2 The current density is 10-300 seconds in a nitric acid or hydrochloric acid electrolyte. Then anodizing is performed. Anodizing is usually done by sulfuric acid method, with a sulfuric acid concentration of 5-30% and a current density of 1-15A / dm 2 The oxidation temperature is 20-60°C and the oxidation time is 5-250 seconds to form 1-10g / m 2 The oxide film is then sealed. Various methods can be used to seal the pores, preferably sealing 50-80% of the volume of the oxide film micropores. Finally, polyvinylphosphonic acid is coated on the aluminum plate treated as above with a thickness of 3 mg / m 2 .

[0070] The preparation method of the thermal plate of the present application comprises the following steps: (1) treating the hydrophilic carrier of the aluminum plate; and (2) coating the imaging layer on the treated hydrophilic carrier of the aluminum plate.

[0071] The thermosensitive composition in the imaging layer of the present invention may also be added with some other necessary additives during production, such as solvents, room temperature thermal polymerization inhibitors, surfactants, etc. The solvent is mainly used to prepare the thermosensitive coating photosensitive liquid from the thermosensitive composition, including: alcohols, ketones, esters, ethers, amides, aromatic solvents, ethylene dichloride, tetrahydrofuran, etc. The solvent can be used in pure form or in a mixture; the room temperature thermal polymerization inhibitor is used to prevent the plate from polymerizing at room temperature and improve the room temperature stability of the plate. Thermal polymerization inhibitors include: hydroquinone, nitroxide piperidinol, p-methoxyphenol, di-tert-butyl-p-cresol, pyrogallol, tert-butyl catechol, benzoquinone, 4,4'-thiobis-(3-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-16-tert-butylphenol), and primary cerium salt of N-nitrosophenylhydroxylamine, etc. The addition of layer colorants is to increase the image density of the thermal plate after platemaking, which is convenient for visual inspection or image analysis of the thermal plate after platemaking. Analytical measuring equipment is used to measure the properties of the plate, which include: methyl violet, ethyl violet, crystal violet, crystal violet, Victoria blue, oil green, oil blue, oil yellow, rhodamine B, methyl violet, malachite green, methylene blue, triazines, etc.; surfactants need to be added to the coating, and non-ionic surfactants, amphoteric surfactants, silicon-containing surfactants, fluorine-containing surfactants, etc. can be selected, such as betaines, stearic acid glyceryl esters, sorbic acid palm oil esters, polysiloxanes, and polyfluoroalkyl ethers.

[0072] The heat-sensitive compositions of the present invention are generally applied by techniques known in the art (e.g., knife coating, blade coating, bar coating, roller coating, press coating, etc.).

[0073] After being scanned and exposed by a thermal CTP plate-making machine, the thermal plate provided by the invention can be directly mounted on a printing machine, soaked with a printing machine fountain solution, passed through the plate, and then printed.

[0074] 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.

[0075] The following are synthesis examples of the present invention, but the present invention is not limited to the following examples.

[0076] The main raw materials can be obtained from the following companies: methyl methacrylate MMA, 2-acrylamide-2-methylpropanesulfonic acid AMPS, and isopropyl alcohol are from Shanghai Bailingwei Technology; allyl polyoxyethylene ether (APEG600, APEG1000 APEG1200APEG1500 APEG2400) are from Liaoning Kelong Fine Chemical Co., Ltd.; glycidyl methacrylate GMA and 3,4-epoxycyclohexyl methacrylate CMA are from Mitsubishi Rayon Chemical of Japan; ethylene glycol methyl ether MC: Lanzhou Petrochemical, azobisisobutyl cyanide AIBN: Tianjin Fuchen Chemical Reagent; benzoyl peroxide BPO: Laiwu Kangxin Reagent; thermochromic dyes D1 and D2 are both provided by China Lucky Group.

[0077] Part 1: Synthesis Examples A1-A10 of Thermosensitive Resin A (Code A)

[0078] Thermosensitive resin A1: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 75 g of deionized water, 250 g of isopropanol, 80 g (80 wt%) of methyl methacrylate, 10 g (10 wt%) of allyl polyoxyethylene ether (APEG600), 10 g (10 wt%) of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0079] Thermosensitive resin A2: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 75 g of deionized water, 250 g of isopropanol, 70 g (80 wt%) of methyl methacrylate, 15 g (15 wt%) of allyl polyoxyethylene ether (APEG600), 15 g (15 wt%) of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0080] Thermosensitive resin A3: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 75 g of deionized water, 250 g of isopropanol, 60 g (60 wt%) of methyl methacrylate, 20 g (20 wt%) of allyl polyoxyethylene ether (APEG1000), 20 g (20 wt%) of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0081] Thermosensitive resin A4: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 75 g of deionized water, 250 g of isopropanol, 50 g (50 wt%) of methyl methacrylate, 25 g (25 wt%) of allyl polyoxyethylene ether (APEG1000), 25 g (25 wt%) of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0082] Thermosensitive resin A5: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 75 g of deionized water, 250 g of isopropanol, 40 g (40 wt%) of methyl methacrylate, 30 g (30 wt%) of allyl polyoxyethylene ether (APEG1200), 30 g (30 wt%) of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0083] Thermosensitive resin A6: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 75 g of deionized water, 250 g of isopropanol, 70 g (70 wt%) of methyl methacrylate, 10 g (10 wt%) of allyl polyoxyethylene ether (APEG1200), 20 g (20 wt%) of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0084] Thermosensitive resin A7: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 75 g of deionized water, 250 g of isopropanol, 70 g (70 wt%) of methyl methacrylate, 20 g (20 wt%) of allyl polyoxyethylene ether (APEG1500), 10 g (10 wt%) of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0085] Thermosensitive resin A8: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 75 g of deionized water, 250 g of isopropanol, 60 g (60 wt%) of methyl methacrylate, 15 g (15 wt%) of allyl polyoxyethylene ether (APEG1500), 25 g (25 wt%) of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0086] Thermosensitive resin A9: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 75 g of deionized water, 250 g of isopropanol, 60 g (60 wt%) of methyl methacrylate, 25 g (25 wt%) of allyl polyoxyethylene ether (APEG2400), 15 g (15 wt%) of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0087] Thermosensitive resin A10: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 75 g of deionized water, 250 g of isopropanol, 50 g (50 wt%) of methyl methacrylate, 30 g (30 wt%) of allyl polyoxyethylene ether (APEG2400), 20 g (20 wt%) of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70 °C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0088] Part II: Synthesis Examples B1-B10 of Thermosensitive Resin B (Code B)

[0089] Thermosensitive resin B1: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 325 g of ethylene glycol methyl ether, 80 g (80 wt%) of methyl methacrylate, 10 g (10 wt%) of 2-acrylamide-2-methylpropanesulfonic acid, 10 g (10 wt%) of glycidyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0090] Thermosensitive resin B2: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 325 g of ethylene glycol methyl ether, 70 g (70 wt%) of methyl methacrylate, 15 g (15 wt%) of 2-acrylamide-2-methylpropanesulfonic acid, 15 g (15 wt%) of glycidyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0091] Thermosensitive resin B3: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 325 g of ethylene glycol methyl ether, 60 g (60 wt%) of methyl methacrylate, 20 g (20 wt%) of 2-acrylamide-2-methylpropanesulfonic acid, 20 g (20 wt%) of glycidyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0092] Thermosensitive resin B4: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 325 g of ethylene glycol methyl ether, 50 g (50 wt%) of methyl methacrylate, 25 g (25 wt%) of 2-acrylamide-2-methylpropanesulfonic acid, 25 g (25 wt%) of glycidyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0093] Thermosensitive resin B5: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 325 g of ethylene glycol methyl ether, 40 g (40 wt%) of methyl methacrylate, 30 g (30 wt%) of 2-acrylamide-2-methylpropanesulfonic acid, 30 g (30 wt%) of glycidyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0094] Thermosensitive resin B6: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 325 g of ethylene glycol methyl ether, 70 g (70 wt%) of methyl methacrylate, 10 g (10 wt%) of 2-acrylamide-2-methylpropanesulfonic acid, 20 g (20 wt%) of glycidyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0095] Thermosensitive resin B7: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 325 g of ethylene glycol methyl ether, 70 g (70 wt%) of methyl methacrylate, 20 g (20 wt%) of 2-acrylamide-2-methylpropanesulfonic acid, 10 g (10 wt%) of glycidyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0096] Thermosensitive resin B8: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 325 g of ethylene glycol methyl ether, 60 g (60 wt%) of methyl methacrylate, 15 g (15 wt%) of 2-acrylamide-2-methylpropanesulfonic acid, 25 g (25 wt%) of glycidyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0097] Thermosensitive resin B9: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 325 g of ethylene glycol methyl ether, 60 g (60 wt%) of methyl methacrylate, 25 g (25 wt%) of 2-acrylamide-2-methylpropanesulfonic acid, 15 g (15 wt%) of glycidyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70°C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0098] Thermosensitive resin B10: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 325 g of ethylene glycol methyl ether, 50 g (50 wt%) of methyl methacrylate, 30 g (30 wt%) of 2-acrylamide-2-methylpropanesulfonic acid, 20 g (20 wt%) of glycidyl methacrylate, and 1 g of azobisisobutyronitrile, stir evenly, react at 70 °C for 8 hours, cool down to terminate the reaction, and use the reaction stock solution directly.

[0099] Comparative Examples 1-5 (Synthesis of similar Agfa polymers F1-F5):

[0100] According to Agfa patent EP 2006-5-24 06114475.4, a polymer similar to Agfa is synthesized by solution polymerization, but the polymer does not contain hydrophilic groups. The polymer structure is:

[0101]

[0102] Basic operation: add 400 g methyl ethyl ketone and 5 g sodium dodecyl sulfate to a 1000 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, and add 60 g (60 wt%) ST (styrene), 40 g (40 wt%) AN (acrylonitrile) and 0.7 g AIBN (azobisisobutyronitrile) dropwise at 80°C for 0.5 hour. After reacting for 7.5 hours, add 0.3 g AIBN (azobisisobutyronitrile) and continue to react for another 12 hours before ending.

[0103] According to Table 1, the feed ratio and reaction concentration were changed to synthesize similar Agfa polymers F1-F5.

[0104] Comparative Examples 6-10 (Synthesis of similar Kodak polymers K1-K5):

[0105] According to Kodak patent US 2005-8-3 11 / 196, a polymer similar to Agfa is synthesized by solution polymerization. The polymer contains hydrophilic groups but no epoxy groups. The polymer structure is:

[0106]

[0107] Basic operation: add 400g of methyl ethyl ketone to a 1000ml four-necked flask equipped with temperature control heating, mechanical stirring, condensation reflux and nitrogen protection device, and add 20g (20 wt%) ST (styrene), 70g (70 wt%) AN (acrylonitrile), 20g0.7g (20 wt%) PEGMA (polyethoxy methacrylate), AIBN (azobisisobutyronitrile) dropwise at 80°C for 0.5 hour. After reacting for 7.5 hours, add 0.3g AIBN (azobisisobutyronitrile) and continue to react for another 12 hours before ending.

[0108] According to Table 1, the feed ratio and reaction concentration were changed to synthesize similar Kodak polymers K1-K5.

[0109] Example 1

[0110] Preparation of the plate base: A1050 rolled aluminum plate with a purity of 99.5% and a thickness of 0.3 mm was etched in a 5% sodium hydroxide aqueous solution at 70°C for 20 seconds, rinsed with running water, and immediately neutralized with a 1% nitric acid aqueous solution. Then, in a 1% hydrochloric acid aqueous solution, a sine wave AC current of 50 A / dm was used at 40°C. 2 The surface was electrolytically roughened at a current density of 15A / dm for 16 seconds, then neutralized with a 5% sodium hydroxide aqueous solution at 40°C for 10 seconds and washed with water. Finally, a 20% sulfuric acid aqueous solution was used at 30°C with a current density of 15A / dm 2 The current density was 20 seconds for anodization and then washed with water. The holes were sealed with a 5% sodium silicate aqueous solution at 80°C for 18 seconds, washed with water and dried. The average center line roughness of the plate obtained was 0.5 μm and the oxide film weight was 3.0 g / dm 2 .

[0111] Photosensitive layer coating: Extrusion-coat the following photosensitive solution on the hydrophilized substrate, and then dry at 100°C for 60 seconds. Obtain a coating dry weight of 10 mg / dm2. The photosensitive solution uses the following components (each component is by weight):

[0112] Thermosensitive resin A1 80

[0113] Thermosensitive resin B1 10

[0114] Diaryl iodonium hexafluorophosphate salt 5

[0115] Thermosensitive dye (Structural formula Ⅰ) 5

[0116] Surfactant (BYK306) 0.5

[0117] 1-Methoxy-2-propanol 700

[0118] Embodiment 2-20

[0119] The plate base and photosensitive layer were prepared in the same manner as above, the surfactant and solvent remained unchanged, and the thermosensitive composition was changed according to Table 2 to prepare printing plates 2-15, and their properties are listed in the following Table 3. The photosensitive layer in the embodiment of the present application is the imaging layer of the present application.

[0120] Comparative Examples 1-10

[0121] The substrate and photosensitive layer were prepared in the same manner as in Example 1. The photosensitive coating solution used the following components:

[0122] Polymer F1-F5, K1-K5 70

[0123] Pentaerythritol triacrylate 25

[0124] Diaryl iodonium hexafluorophosphate salt 2.5

[0125] Thermosensitive dye ADS830 1

[0126] Nitrogen oxide free radical piperidinol 0.5

[0127] Basic Brilliant Blue 0.5

[0128] Surfactant (BYK306) 0.5

[0129] Methyl Ethyl Ketone 200

[0130] 1-Methoxy-2-propanol 700

[0131] Here, for Comparative Examples 1-10, polymers F1-F5, K1-K5 70 means that Comparative Examples 1-10 respectively use only polymers F1, F2, F3, F4, F5, K1, K2, K3, K4, K5, and the weight proportions of other components are the same.

[0132] Comparative Example 1-10 also requires oxygen barrier coating: the following oxygen barrier solution is extrusion coated on the photosensitive layer obtained above, and then dried at 110° C. for 60 seconds to obtain a coating dry weight of 10 mg / dm2 (each component is by weight).

[0133] Oxygen barrier layer formula (components by weight)

[0134] Polyvinyl alcohol PVA-205 (Japan Kuraray) 17

[0135] Polyvinylpyrrolidone PVPK30 (BASF, Germany) 3

[0136] Emulsifier OP-10 (Helm, Germany) 0.45

[0137] Deionized water 480

[0138] Test and analysis of plate materials:

[0139] 1. Dot reproduction: All the above plates were exposed to 120 mJ / cm2 energy on a Kodak Thermal CTP plate-making machine, and their image dot reproduction values ​​were measured. The performance is listed in Table 3 below.

[0140] 2. Contrast value △E: It is the density at 120mJ / cm2 minus the density of the unexposed plate. Its performance is listed in Table 3 below.

[0141] 3. Number of sheets of paper passed through the plate: This is the number of sheets of paper consumed before printing on a Beiren 4-color 4-size printing press with uniform ink flow and normal printed images. Its performance is listed in Table 3 below.

[0142] 4. Scratch resistance: Use Lucky Thermal Plate Scratch Resistance Tester to test its scratch resistance. The basic principle is the scratch pressure value of standard scratch paper on thermal plate under different weight pressures. The unit is: gram. The larger the gram number, the better the scratch resistance of the thermal plate. Its performance is listed in Table 3 below.

[0143] 5. Printing life: Printing was performed on a Beiren 4-color 4-size printing press to test the total number of normal printed products printed on the thermal plate. The performance is listed in Table 3 below.

[0144] The detection application results in Table 3 show that, compared with other treatment-free plates, the high-contrast, scratch-resistant treatment-free thermal plate designed by the present invention can realize network cationic polymerization, and has excellent imaging ability and printing durability; the functional polymer adhesive improves the scratch resistance of the raw plate; the use of thermochromic dyes with both infrared absorption and thermochromic functions greatly improves the platemaking contrast of the plate, and solves the problems of manual plate proofreading and computer automatic plate recognition and plate mounting; at the same time, the plate contains hydrophilic units, which can realize green and environmentally friendly printing.

[0145] Table 1 Comparative Example Polymer Synthesis Feed Table

[0146]

[0147] Table 2 Example plate material feeding table (unit: grams)

[0148]

[0149] Table 3 Plate application performance table

[0150]

[0151] The above description is only a preferred embodiment 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 any technician familiar with the technical field, without departing from the overall concept of the present invention, the technical solution and the inventive concept of the present invention are equivalently replaced or changed, and several changes and improvements are made, which should also be regarded as the protection scope of the present invention.

Claims

1. A treatment-free thermal plate, characterized in that: The invention comprises a substrate and an imaging layer, wherein the imaging layer comprises a thermosensitive resin A, a thermosensitive resin B, a thermal initiator and a thermosensitive dye; the thermosensitive resin A is nano-micron resin particles existing in a discrete form, and the thermosensitive resin A is a ternary free radical copolymer of methyl methacrylate, allyl polyoxyethylene ether and 3,4-epoxycyclohexyl methacrylate; the thermosensitive resin B is a functional film-forming resin, and the thermosensitive resin B is a ternary free radical copolymer of methyl methacrylate, 2-acrylamide-2-methylpropane sulfonic acid and glycidyl methacrylate.

2. The process-free thermal plate according to claim 1, characterized in that: Thermosensitive dyes are thermochromic dyes.

3. The process-free thermal plate according to claim 2, characterized in that: The structure of the thermochromic dye is one of the following: (Structural formula D1) (Structural formula D2).

4. The process-free thermal plate according to claim 2 or 3, characterized in that: By weight percentage, the thermosensitive resin A accounts for 40-80% of the total solid content of the composition, the thermosensitive resin B accounts for 10-50% of the total solid content of the composition, the thermal initiator accounts for 1-10% of the total solid content of the composition, and the thermochromic dye accounts for 1-10% of the total solid content of the composition.

5. The process-free thermal plate according to any one of claims 1 to 3, characterized in that: In the heat-sensitive resin A, by weight percentage, methyl methacrylate accounts for 40-80%, allyl polyoxyethylene ether accounts for 10-30%, and 3,4-epoxycyclohexyl methacrylate accounts for 10-30%.

6. The process-free thermal plate according to any one of claims 1 to 3, characterized in that: In the heat-sensitive resin B, by weight percentage, methyl methacrylate accounts for 40-80%, 2-acrylamide-2-methylpropanesulfonic acid accounts for 10-30%, and glycidyl methacrylate accounts for 10-30%; The thermal initiator is selected from one or more of iodonium salts and sulfonium salts, and has a decomposition temperature of 150-200°C.

7. The process-free thermal plate according to claim 1, characterized in that: The thermal initiator is an onium salt; onium salts include sulfonium salts, oxysulfonium salts, oxosulfonium salts, sulfoxide salts, diazonium salts and halogen onium salts.

8. The process-free thermal plate according to claim 7, characterized in that: The onium salt is: diphenyliodonium chloride, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, [4-[(2-hydroxytetradecyl-oxy]-phenyl]phenyliodonium hexafluoroantimonate, triphenylsulfonium iodonium tetrafluoroborate, triphenylsulfonium iodonium octylsulfate, 2-methoxy-4-aminophenyldiazonium hexafluorophosphate or phenoxyphenyldiazonium hexafluoroantimonate.

9. The process-free thermal plate according to claim 7, characterized in that: The thermal initiator is selected from at least one of iodonium salt and sulfonium salt which can simultaneously undergo homolysis and heterolysis, and its thermal decomposition temperature is 150-200°C.

10. The process-free thermal plate according to claim 1, characterized in that: The weight average molecular weight of the thermosensitive resin A is 4000-150000, the glass transition temperature is 110-130°C, and the particle size is controlled at 85-250nm; the weight average molecular weight of the thermosensitive resin B is 4000-150000, and the glass transition temperature is 110-130°C; the substrate is an aluminum plate substrate that has been electrolytically roughened, anodized, and sealed.

11. The method for preparing a treatment-free thermal plate according to any one of claims 1 to 10, characterized in that: The steps are: (1) treating the hydrophilic carrier of the aluminum plate; and (2) coating the imaging layer on the treated hydrophilic carrier of the aluminum plate.

Images