Super-hydrophilic cross-linked resin, application thereof and treatment-free thermo-sensitive plate containing super-hydrophilic cross-linked resin

Abstract

The invention provides super-hydrophilic cross-linked resin, application thereof and a treatment-free thermosensitive plate containing the super-hydrophilic cross-linked resin. The super-hydrophilic cross-linked resin has three characteristics of super-hydrophilicity, thermosensitive cross-linking property and solvent resistance. The processing-free thermosensitive plate is provided with the middle layer, the middle layer contains the super-hydrophilic cross-linked resin, meanwhile, the thermosensitive layer is not designed to be super-hydrophilic any more, the inking property of the plate is better, and the problem that the on-press development (DOP) capacity, the pressrun and the inking property of the processing-free thermosensitive plate contradict is effectively solved through the middle layer.

Description

Technical Field

[0001] The invention belongs to the technical field of advanced lithography, and in particular relates to a super-hydrophilic cross-linked resin and an application thereof and a treatment-free thermal plate containing the same. Background Art

[0002] Thermal plates are widely used in the printing industry. Thermal plates are a type of offset printing plate that uses computer-controlled infrared laser imaging, can be operated in a bright room, and has high imaging quality.

[0003] Thermal plate technology is constantly improving and developing around the world. One of the current technological development directions is to develop processing-free thermal plates to reduce the damage to the environment caused by the use of developer in the platemaking process.

[0004] There are many technical routes for process-free thermal plates. From the perspective of imaging mechanism, they can be divided into thermal ablation technology, phase change technology, hot melt technology, etc.; from the perspective of development method, process-free thermal plates can be divided into two categories: one is a low-chemical development type process-free thermal plate: for example, Agfa patent EP 2006-5-24 06114475.4 discloses a styrene acrylic emulsion that can achieve low-chemical development in an arabic gum aqueous solution and then print on a machine. However, there is still waste development liquid, so the low-chemical development type process-free thermal plate has been gradually eliminated, and replaced by the second type of process-free thermal plate: on-press development (develop on press, referred to as DOP) process-free thermal plate, such as Kodak patent CN201280042411.6 for on-press development of lithographic printing plate precursors. After the plate is imaged, it can be directly put on the machine and developed and printed under the action of the printing press fountain solution.

[0005] The development of process-free thermal plates, especially the development of process-free thermal plate precursors, is a hot topic in the world today. The process-free thermal plate precursor refers to the precursor for manufacturing process-free thermal plates, and generally refers to the necessary materials and technologies required before manufacturing process-free thermal plates.

[0006] There are many technologies used in the processing-free thermal plates. One of the mainstream technologies is to use infrared absorbers to transfer the thermal energy of the laser to the thermal initiator. The thermal initiator triggers the chemical reaction of the thermal sensitive layer to achieve laser imaging.

[0007] In the process of continuous advancement of the process-free thermal plate technology, technicians have found that there is a contradiction between the on-press developability (DOP) of the process-free thermal plate and its press durability and ink affinity, and it is difficult to balance the contradiction between the two.

[0008] Specifically, the carrier of the treatment-free thermal plate generally adopts a porous and multi-grit aluminum plate base treated with electrochemical roughening. The porous and multi-grit aluminum plate base can make the blank part of the aluminum plate base hydrophilic, and the porous and multi-grit aluminum plate base can firmly grasp the oleophilic image layer, and then realize offset printing according to the principle of oil-water separation. On-press development (DOP) requires that the non-laser exposed part of the treatment-free thermal plate can be well infiltrated by the fountain solution, and then removed by the paper to expose the porous and multi-grit aluminum plate base, while the exposed imaging part of the plate needs to be firmly attached to the aluminum plate base, and the imaging layer needs to have good ink affinity to better absorb the ink. This will lead to a contradiction: if the thermal layer is very hydrophilic, the unexposed part can be easily removed, and the on-press development (DOP) ability is very good, but it will cause the exposed imaging layer to be easily swollen by the fountain solution during the printing process due to its good hydrophilicity, and the adhesion and wear resistance will decrease. In addition, if the thermal layer is too hydrophilic, it will also cause the ink affinity of the plate to decrease, affecting the ink absorption of the plate.

[0009] The purpose of the present invention is to solve the contradiction between the on-press developing (DOP) capability, press run and ink affinity of the treatment-free thermal plate, improve the image quality and further enhance the performance of the treatment-free thermal plate. Summary of the invention

[0010] In order to solve the above problems, the present invention provides a super-hydrophilic cross-linked resin and its application and a treatment-free thermal plate containing the same. The super-hydrophilic cross-linked resin has three major characteristics: super-hydrophilicity, thermal-sensitive cross-linking and solvent resistance. The treatment-free thermal plate of the present invention is provided with an intermediate layer, and the intermediate layer contains the super-hydrophilic cross-linked resin described in the present invention. The super-hydrophilic cross-linked resin has super-hydrophilicity and can be easily removed from the grain pores by the fountain solution. Even if there is a trace amount of residue, due to its super-hydrophilicity, it does not affect its ink repellency and will not cause dirt on the non-image part; the plate is designed with an intermediate layer between the plate base and the imaging layer, and the thermal layer of the plate no longer contacts the grained porous aluminum plate base, but contacts the intermediate layer, so it is easier to remove the unexposed thermal layer from the plane intermediate layer than from the grains of the aluminum plate base, so the thermal layer does not need to be designed to be super-hydrophilic. Influencing the ink acceptability of the image layer after imaging, the thermal layer only needs to be swollen with the wettability of the fountain solution. The swollen unexposed thermal layer is easily carried by the paper, and the fountain solution further removes the middle layer to make the blank part hydrophilic; under the action of the laser, the exposed part undergoes a cation reaction between the middle layer and the imaging layer to achieve laser thermal fusion, and at the same time the middle layer solidifies and firmly adheres to the aluminum base, greatly improving the printing resistance of the plate; at the same time, the thermal layer is no longer designed to be super hydrophilic, and the plate has better ink acceptability. Through the middle layer, the contradiction between the on-machine development (DOP) ability and the printing resistance and ink affinity of the treatment-free thermal plate is effectively solved.

[0011] The object of the present invention is achieved in the following manner: a super-hydrophilic cross-linked resin, the super-hydrophilic cross-linked resin is a ternary free radical copolymer of monomer a: phosphate monomer, monomer b: 3,4-epoxycyclohexyl methacrylate, and monomer c: 2-acrylamide-2-methylpropane sulfonic acid, wherein a: phosphate monomer has the following structure: R1 and R3 are H or CH3, R2 is a covalent bond, a methoxy group or an acyloxy group, and n is an integer of 0-45.

[0012] In the super-hydrophilic cross-linked resin, by weight percentage, monomer a: phosphate monomer accounts for 10-20% by weight, monomer b: 3,4-epoxycyclohexyl methacrylate accounts for 10-20% by weight, and monomer c: 2-acrylamide-2-methylpropane sulfonic acid accounts for 60-80% by weight.

[0013] The reaction adopts solution polymerization, the reaction is a random free radical polymerization reaction, the reaction catalyst is an azo catalyst, and the reaction temperature is 60-90°C.

[0014] Application of the super hydrophilic cross-linked resin.

[0015] The application of the super-hydrophilic cross-linked resin in a treatment-free heat-sensitive plate.

[0016] A treatment-free heat-sensitive plate comprises a carrier, an intermediate layer and a heat-sensitive layer from bottom to top. The heat-sensitive layer contains a heat-sensitive resin, a cross-linkable prepolymer, a thermal initiator and an infrared absorber, and the intermediate layer comprises the super-hydrophilic cross-linking resin and the thermal initiator.

[0017] The thermosensitive resin accounts for 60-80% of the total solid content of the thermosensitive layer composition, the crosslinkable prepolymer accounts for 10-30% of the total solid content of the thermosensitive layer composition, the thermal initiator of the thermosensitive layer accounts for 1-5% of the total solid content of the thermosensitive layer composition, and the infrared absorber accounts for 1-5% of the total solid content of the thermosensitive layer composition; The thermal initiator contained in the middle layer is an iodonium salt; The carrier is an aluminum plate that has been electrolytically roughened and anodized.

[0018] The heat-sensitive resin in the heat-sensitive layer is a branched polyolefin resin containing hydrophilic groups and epoxy groups; the cross-linkable prepolymer is a multi-double-bond acrylic monomer or a multi-double-bond polyurethane acrylic monomer; the thermal initiator is an iodonium salt; and the infrared absorber is a cyanine dye with an absorption peak at 750-850nm.

[0019] The thermosensitive resin is a polyolefin resin obtained by quaternary copolymerization of styrene, acrylonitrile, polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), and 3,4-epoxycyclohexyl methacrylate; calculated by weight percentage, styrene accounts for 70-80%, acrylonitrile accounts for 10-20%, polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000) accounts for 5-10%, and 3,4-epoxycyclohexyl methacrylate accounts for 5-10%, and the thermosensitive resin is in an emulsion state.

[0020] A protective layer is also provided on the heat-sensitive layer; After being scanned and exposed by a thermal CTP plate-making machine, the thermal plate can be directly loaded onto a printing press and developed and printed with the printing press fountain solution.

[0021] Compared with the prior art, the present invention provides a super-hydrophilic cross-linked resin and its application and a treatment-free thermal plate containing the same. The super-hydrophilic cross-linked resin has three major characteristics: super-hydrophilicity, thermal-sensitive cross-linking and solvent resistance. The treatment-free thermal plate of the present invention is provided with an intermediate layer, and the intermediate layer contains the super-hydrophilic cross-linked resin of the present invention. Since the super-hydrophilic cross-linked resin has very good hydrophilicity and good metal cleaning ability, the super-hydrophilic cross-linked resin has super-hydrophilicity and can be easily removed from the grain pores by the fountain solution, thereby improving the on-machine development (DOP) ability of the treatment-free thermal plate; the plate is designed with an intermediate layer between the plate base and the imaging layer, and the plate thermal layer no longer contacts the grained porous aluminum plate base, but contacts the intermediate layer, so the unexposed thermal layer is removed more easily from the planar intermediate layer than from the grains of the aluminum plate base. It is easier to remove, so the thermal layer does not need to be designed to be super-hydrophilic, which will affect the ink-adhesion of the image layer after imaging. The thermal layer only needs to be swollen with the wettability of the fountain solution. The swollen unexposed thermal layer is easily carried by the paper. The fountain solution further removes the middle layer to make the blank part hydrophilic. Under the action of the laser, the exposed part reacts with the cationic reaction of the middle layer and the imaging layer to achieve cationic cross-linking. At the same time, the middle layer solidifies and firmly adheres to the aluminum base, greatly improving the printing resistance of the plate. The super-hydrophilic cross-linked resin also contains rigid cyclohexyl and solvent-resistant amide groups, giving the plate excellent solvent resistance. At the same time, the thermal layer is no longer designed to be super-hydrophilic, and the plate has better ink-adhesion. Through the middle layer, the contradiction between the on-machine development (DOP) ability and the printing resistance and ink affinity of the treatment-free thermal plate is effectively solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the treatment-free thermal plate of the present invention. Figure 1 .

[0023] Figure 2 This is a schematic diagram of the structure of the treatment-free thermal plate of the present invention. Figure 2 .

[0024] Among them, 1 is the carrier, 2 is the intermediate layer, 3 is the heat-sensitive layer, and 4 is the protective layer. DETAILED DESCRIPTION

[0025] The following first describes the superhydrophilic cross-linked resin: A super-hydrophilic cross-linked resin, the super-hydrophilic cross-linked resin is a ternary free radical copolymer of monomer a: phosphate monomer, monomer b: 3,4-epoxycyclohexyl methacrylate, and monomer c: 2-acrylamide-2-methylpropane sulfonic acid, wherein a: phosphate monomer has the following structure: R1 and R3 are H or CH3, R2 is a covalent bond, a methoxy group or an acyloxy group, and n is an integer of 0-45; that is, monomer a contains a terminal double-bond ethoxy phosphate.

[0026] Monomer a: Phosphate monomer contains phosphate structural units, which have good metal affinity and can improve the adhesion of the film after laser cross-linking; Monomer a preferably contains ethoxy units (when n is an integer of 1-45), and the thermosensitive layer of the present invention also contains ethoxy units, which have similar structural units and can be well fused under the action of laser heat. Monomer a: terminal double-bond ethoxy phosphate compounds having the above structure can be exemplified as follows: a1 (n=0, R2 is a covalent bond): a2 (n=1, R2 is acyloxy): a3 (n is an integer of 1-45, R2 is an acyloxy group): a4 (n is an integer of 1-45, R2 is an acyloxy group): a5 (n is an integer of 1-45, R2 is a methoxy group): In the super-hydrophilic cross-linked resin, the weight proportion of monomer a: phosphate monomer is 10-20%.

[0027] The super-hydrophilic cross-linked resin of the present invention further contains monomer b: 3,4-epoxycyclohexyl methacrylate, the structure of which is as follows: It contains epoxy bonds on the cyclohexyl group, has the ability of efficient cationic cross-linking, can undergo a cross-linking reaction with the heat-sensitive layer and adhere firmly together; at the same time, 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.

[0028] In the super-hydrophilic cross-linked resin, the weight proportion of monomer b is 10-20%.

[0029] The super-hydrophilic cross-linked resin of the present invention further contains monomer c: 2-acrylamide-2-methylpropanesulfonic acid, the structure of which is as follows: It has amide and sulfonic acid groups, which give the super-hydrophilic cross-linked resin very good hydrophilicity and good metal cleaning ability, so that it can be quickly removed from the pores of the plate base sand. In addition, the amide group has excellent solvent resistance and can resist the corrosion of hydrocarbon compounds in the ink, thereby improving the printing durability.

[0030] In the super-hydrophilic cross-linked resin, the weight proportion of monomer c is 60-80%.

[0031] The synthesis reaction of the intermediate layer tree adopts solution polymerization, the reaction is a random free radical polymerization reaction, the reaction catalyst is an azo or peroxide catalyst, preferably an azo catalyst, and the reaction temperature is 60-90°C; The middle layer includes a super-hydrophilic cross-linked resin and a thermal initiator. The middle layer has three characteristics: super-hydrophilicity, thermal cross-linking and solvent resistance. The super-hydrophilic cross-linked resin has very good hydrophilicity and good metal cleaning ability, which enables it to be quickly removed from the pores of the plate base sand grains, improving the on-machine development (DOP) ability of the treatment-free thermal plate; the middle layer includes a super-hydrophilic cross-linked resin and a thermal initiator. The super-hydrophilic cross-linked resin contains epoxy bonds on the cyclohexyl group and has the ability of efficient cationic cross-linking under the action of laser heat. The thermal resin in the thermal layer also contains epoxy bonds on the cyclohexyl group. The middle layer and the thermal layer undergo a cross-linking reaction to improve the printability; the super-hydrophilic cross-linked resin also contains rigid cyclohexyl and solvent-resistant amide groups, giving the plate excellent solvent resistance. After the plate is designed with an intermediate layer, the thermal layer is no longer designed to be super-hydrophilic, and the plate has better ink absorption. Through the transition of the intermediate layer, the contradiction between the on-machine development (DOP) ability of the treatment-free thermal plate and the printability and ink affinity is effectively solved.

[0032] Applications of the super-hydrophilic cross-linked resin include, but are not limited to: the super-hydrophilic cross-linked resin is applied to various reactions, various substances, various structures and their preparation.

[0033] The application of the super-hydrophilic cross-linked resin in the treatment-free thermal plate includes all the treatment-free thermal plates of the super-hydrophilic cross-linked resin used.

[0034] like Figure 1As shown, a processing-free thermal plate includes a carrier 1, an intermediate layer 2, and a thermal layer 3 from bottom to top. The thermal layer contains a thermal resin, a cross-linkable prepolymer, a thermal initiator and an infrared absorber, and the intermediate layer includes the super-hydrophilic cross-linking resin and the thermal initiator.

[0035] Firstly, the thermal initiator contained in the intermediate layer is preferably an onium salt thermal initiator, preferably an iodonium salt.

[0036] Next, the heat-sensitive layer of the process-free heat-sensitive plate is described.

[0037] The heat-sensitive layer comprises a heat-sensitive resin, a cross-linkable prepolymer, a thermal initiator and an infrared absorber, which are described in order below: The thermosensitive resin in the thermosensitive layer is a photocrosslinked resin, which is a branched polyolefin resin containing a hydrophilic group and an epoxy group. The hydrophilic group can be a carboxyl group, an amino group, an amide group, a sulfonic acid group, a phosphoric acid group, a polyether group and its salt, etc. The epoxy group can be an epoxy group connected to a fatty chain or an epoxy group connected to an aromatic ring.

[0038] Furthermore, the heat-sensitive resin heat-sensitive layer of the treatment-free heat-sensitive plate of the present invention comprises a polyolefin resin obtained by quaternary copolymerization of styrene, acrylonitrile, polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), and 3,4-epoxycyclohexyl methacrylate; calculated by weight percentage, styrene accounts for 70-80%, acrylonitrile accounts for 10-20%, polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000) accounts for 5-10%, and 3,4-epoxycyclohexyl methacrylate accounts for 5-10%, and the heat-sensitive resin is in an emulsion state. The heat-sensitive resin in the heat-sensitive layer accounts for 60-80% of the total solid content of the composition. The sum of the lipophilic components styrene and acrylonitrile is higher than that of the previous patent, and the hydrophilic component polyethylene glycol methyl ether methacrylate is significantly lower, which improves the ink affinity of the plate material, and also contains active epoxy groups, which can be cross-linked with the intermediate layer, improve the printing resistance, ink pick-up, and dot quality, and reduce the number of plate-passing papers.

[0039] The crosslinkable prepolymer in the heat-sensitive layer can be a monomer capable of free radical polymerization or a monomer capable of cationic polymerization, etc. The monomer capable of free radical polymerization is generally an acrylic monomer containing a double bond, and the monomer capable of cationic polymerization is generally a monomer containing an epoxy group. The crosslinkable prepolymer in the heat-sensitive layer of the present invention is a multifunctional acrylic monomer or a multifunctional polyurethane acrylic monomer, where multifunctionality means that it contains multiple double bonds. Multifunctional acrylic monomers such as 1,6-hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, trimethylolpropane triacrylate, hydroxypropyl glyceryl triacrylate, hydroxyethyl trimethylolpropane triacrylate, polyethylene glycol dimethacrylate, dipentaerythritol hexaacrylate, etc.; multifunctional polyurethane acrylic monomers are condensation products of isocyanate and multifunctional acrylic esters, such as condensation products of isocyanate with hydroxyethyl acrylate and pentaerythritol triacrylate, etc.; or are condensation products of double-bonded isocyanates such as methacryloyloxyisocyanate and polyhydroxy compounds such as pentaerythritol. The crosslinkable prepolymer in the heat-sensitive layer is preferably a multi-double-bond acrylic monomer or a multi-double-bond polyurethane acrylic monomer, which accounts for 10-30% of the total solid content of the composition by weight percentage.

[0040] The thermal initiator in the heat-sensitive layer is selected from onium salts, such as sulfonium salts, iodonium salts, etc. Onium salts undergo homolysis and heterolysis simultaneously under the action of heat. The homolysis of onium salts produces free radicals, which trigger free radical polymerization of double bonds in the imaging layer. The heterolysis of onium salts produces cations, which trigger cationic polymerization of epoxy bonds in the imaging layer. Therefore, the treatment-free heat-sensitive plate made with the precursor of the present invention has dual imaging capabilities of free radical polymerization and cationic polymerization. The plate material has excellent imaging capabilities, and the curing of the influence layer can form a network cross-linked structure with high wear resistance. Suitable onium salts include sulfonium salts, oxysulfonium salts, oxysulfonium salts, sulfoxide onium 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 tetrafluoroborate, triphenylsulfonium octylsulfate, 2-methoxy-4-aminophenyldiazonium hexafluorophosphate, phenoxyphenyldiazonium hexafluoroantimonate, and the like. The thermal initiator of the present invention is selected from iodonium salts that can undergo homolysis and heterolysis at the same time, and its thermal decomposition temperature is 150-200° C. The thermal initiator accounts for 1-5% of the total weight of the solids of the thermal sensitive layer in the thermal sensitive layer.

[0041] The infrared absorber in the thermosensitive layer mainly plays the role of energy transfer. The heat of the infrared laser transfers the laser energy to the thermal initiator through the infrared absorber. The thermal initiator is cracked to produce active groups to make the hydrophilic thermosensitive resin and the cross-linkable prepolymer undergo three-dimensional network polymerization to achieve thermal imaging. The maximum absorption wavelength range of the infrared absorber is 750-1100nm, and it is selected from carbon black, azo dyes, triarylamine dyes, indolium dyes, oxocyanol 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. In order to improve the platemaking contrast, it is beneficial for the printing operator to check the plate with the naked eye to detect the image defects of the printing plate, and it is also beneficial for modern highly intelligent printing machines to realize automatic intelligent plate loading through the automatic positioning and recognition of the cross-line images at the four corners of the plate. The selected infrared absorber can be an infrared absorber with a color-changing function, and the presentation of high-contrast images can be achieved through laser cracking. The infrared absorber in the imaging layer of the present invention is preferably a cyanine dye with an absorption peak at 750-850 nm. The infrared absorber in the heat-sensitive layer accounts for 1-5% of the total solid content of the composition by weight percentage.

[0042] Finally, the support for the process-free thermal plate is described.

[0043] The carrier includes a metal substrate such as a steel substrate, a copper substrate, an aluminum substrate, etc. The carrier selected in the present invention is an aluminum substrate that has been roughened by electrolysis and anodized.

[0044] The aluminum substrate is made by electrolytic roughening, and the average center line roughness is 0.3-0.6um. The aluminum substrate is made of 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 1%-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, with a current of 5-100A / dm 2 The electrolytic roughening of the aluminum substrate is then anodized. Anodization is usually carried out using sulfuric acid, with a concentration of 5-30% sulfuric acid 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 oxide film.

[0045] like Figure 2As shown, the manufacturing steps of the treatment-free thermal plate of the present invention at least include carrier treatment, intermediate layer coating, and thermal layer coating. A protective layer 4 can be optionally coated or not. A protective layer 4 is coated on the imaging layer to reduce the inhibitory effect of oxygen on the performance of the thermal plate imaging layer, and the imaging layer is not polluted or scratched by the external environment. The protective layer can be made of a water-soluble polymer compound with relatively good crystallinity, such as polyvinyl alcohol, polyvinyl pyrrolidone, hydroxypropyl cellulose, gelatin, gum arabic, polyacrylic acid and other water-soluble polymers.

[0046] When using the treatment-free thermal plate of the present invention for manufacturing, some other necessary additives may be added, such as solvents, room temperature thermal polymerization inhibitors, surfactants, layer colorants, etc. The solvent is mainly used to prepare the thermal composition into a thermal coating photosensitive liquid, including: alcohols, ketones, esters, ethers, amides, aromatic solvents, ethylene dichloride, tetrahydrofuran, etc. The solvent can be used in pure or mixed forms; the room temperature thermal polymerization inhibitor is 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.

[0047] The treatment-free heat-sensitive plate of the present invention is usually prepared by coating using known techniques in the art, such as knife coating, scraper coating, strip coating, roller coating, pressure coating, spray coating, etc.

[0048] The treatment-free thermal plate of the present invention is scanned and exposed by a thermal CTP plate-making machine, and then directly mounted on a printing machine, developed with a printing machine fountain solution, and printed.

[0049] 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.

[0050] The following are synthesis examples of the present invention, but the present invention is not limited to the following examples.

[0051] Part 1: Synthesis Example of Super Hydrophilic Cross-linked Resin (Code: M) The main raw materials can be obtained from the following companies: Phosphate monomers: Example compounds a1-a5, all from Merck Chemicals; monomer b: 3,4-epoxycyclohexyl methacrylate, from Mitsubishi Chemical Corporation; monomer c: 2-acrylamide-2-methylpropanesulfonic acid, from Merck Chemicals; azobisisobutyronitrile and azobisisoheptanenitrile, from Tianjin Fuchen Chemical Reagents.

[0052] Synthesis of M1: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, 10 g of monomer a1, 10 g of monomer b, 80 g of monomer c, 1 g of azobisisobutyronitrile and 100 g of deionized water were added, and the mixture was stirred and reacted at 60°C for 5 hours. 1 g of azobisisobutyronitrile was added, and the mixture was reacted for another 5 hours, then the temperature was lowered to terminate the reaction, and the target product M1 was synthesized. The reaction stock solution containing the target product obtained by the above reaction can be used directly. The amount of the target product M1 is the solid content in the reaction stock solution, and the solid content of the reaction stock solution is 50.5%.

[0053] Synthesis of M2: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 10 g of monomer a2, 15 g of monomer b, 75 g of monomer c, 1 g of azobisisoheptanonitrile and 150 g of deionized water, stir and react at 70°C for 4.5 hours, add 1 g of azobisisoheptanonitrile, react for another 5 hours, then cool down to terminate the reaction, and then synthesize the target product M2. The reaction stock solution containing the target product obtained by the above reaction can be used directly. The amount of the target product M2 is the solid content in the reaction stock solution, and the solid content of the reaction stock solution is 40.5%.

[0054] Synthesis of M3: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, 15 g of monomer a3 (n=45), 15 g of monomer b, 70 g of monomer c, 1 g of azobisisobutyronitrile and 130 g of deionized water were added, and the mixture was stirred and reacted at 80°C for 4 hours. 1 g of azobisisobutyronitrile was added, and the mixture was reacted for another 5 hours, then the temperature was lowered to terminate the reaction, and then the target product M3 was synthesized. The reaction stock solution containing the target product obtained by the above reaction can be used directly. The amount of the target product M3 is the solid content in the reaction stock solution, and the solid content of the reaction stock solution is 44.0%.

[0055] Synthesis of M4: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, 20 g of monomer a4 (n=20), 15 g of monomer b, 65 g of monomer c, 1 g of azobisisobutyronitrile and 120 g of deionized water were added, and the mixture was stirred and reacted at 90°C for 4 hours. 1 g of azobisisobutyronitrile was added, and the mixture was reacted for another 4 hours, then the temperature was lowered to terminate the reaction, and then the target product M4 was synthesized. The reaction stock solution containing the target product obtained by the above reaction can be used directly. The amount of the target product M4 is the solid content in the reaction stock solution, and the solid content of the reaction stock solution is 45.6%.

[0056] Synthesis of M5: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, 20 g of monomer a5 (n=20), 20 g of monomer b, 60 g of monomer c, 1 g of azobisisoheptanonitrile and 140 g of deionized water were added, and the mixture was stirred and reacted at 90°C for 4 hours. 1 g of azobisisoheptanonitrile was added, and the mixture was reacted for another 5 hours, then the temperature was lowered to terminate the reaction, and then the target product M5 was synthesized. The reaction stock solution containing the target product obtained by the above reaction can be used directly. The amount of the target product M5 is the solid content in the reaction stock solution, and the solid content of the reaction stock solution is 42.1%.

[0057] Synthesis of M6: In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, 15 g of monomer a3 (n=8), 15 g of monomer b, 70 g of monomer c, 1 g of azobisisobutyronitrile and 160 g of deionized water were added, and the mixture was stirred and reacted at 80°C for 4 hours. 1 g of azobisisobutyronitrile was added, and the mixture was reacted for another 5 hours, then the temperature was lowered to terminate the reaction, and the target product M6 was synthesized. The reaction stock solution containing the target product obtained by the above reaction can be used directly. The amount of the target product M6 is the solid content in the reaction stock solution, and the solid content of the reaction stock solution is 38.9%.

[0058] Part 2: Synthesis example of hydrophilic thermosensitive resin (code R).

[0059] The main raw materials can be obtained from the following companies: styrene St from Qilu Petrochemical, acrylonitrile AN from Tianjin Fuchen, polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000) from Merck Chemical, 3,4-epoxycyclohexyl methacrylate from Mitsubishi Chemical Corporation, isopropanol: J&K Reagents, azobisisobutylcyanide AIBN: Tianjin Fuchen Chemical Reagents.

[0060] Hydrophilic thermosensitive resin R1: In a 500 ml beaker, 200 g of deionized water, 50 g of isopropanol, 70 g of styrene, 10 g of acrylonitrile, 10 g of polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), 10 g of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile were added, and then reacted at 80°C for 8 hours. After adding 1 g of azobisisobutyronitrile and continuing the reaction for another 8 hours, the temperature was lowered to terminate the reaction, and a hydrophilic thermosensitive resin R1 was synthesized. The obtained liquid was the reaction stock solution, and the amount of the hydrophilic thermosensitive resin was the solid content in the reaction stock solution. The hydrophilic thermosensitive resin can be used directly according to the solid content of the reaction stock solution, and the solid content of the reaction stock solution is 28.9%.

[0061] Hydrophilic thermosensitive resin R2: In a 500 ml beaker, 200 g of deionized water, 60 g of isopropanol, 80 g of styrene, 10 g of acrylonitrile, 5 g of polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), 5 g of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile were added, and then reacted at 80°C for 8 hours. After adding 1 g of azobisisobutyronitrile and continuing the reaction for another 8 hours, the temperature was lowered to terminate the reaction, and a hydrophilic thermosensitive resin R2 was synthesized. The obtained liquid was a reaction stock solution, and the amount of the hydrophilic thermosensitive resin was the solid content in the reaction stock solution. The hydrophilic thermosensitive resin can be used directly according to the solid content of the reaction stock solution, and the solid content of the reaction stock solution is 28.2%.

[0062] Hydrophilic thermosensitive resin R3: In a 500 ml beaker, 210 g of deionized water, 65 g of isopropanol, 75 g of styrene, 10 g of acrylonitrile, 10 g of polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), 5 g of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile were added, and then reacted at 80°C for 8 hours. After adding 1 g of azobisisobutyronitrile and continuing the reaction for another 8 hours, the temperature was lowered to terminate the reaction, and a hydrophilic thermosensitive resin R3 was synthesized. The obtained liquid was a reaction stock solution, and the amount of the hydrophilic thermosensitive resin was the solid content in the reaction stock solution. The hydrophilic thermosensitive resin can be used directly according to the solid content of the reaction stock solution, and the solid content of the reaction stock solution is 27.1%.

[0063] Hydrophilic thermosensitive resin R4: In a 500 ml beaker, 210 g of deionized water, 75 g of isopropanol, 70 g of styrene, 20 g of acrylonitrile, 5 g of polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), 5 g of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile were added, and then reacted at 80°C for 8 hours. After adding 1 g of azobisisobutyronitrile and continuing the reaction for another 8 hours, the temperature was lowered to terminate the reaction, and a hydrophilic thermosensitive resin R4 was synthesized. The obtained liquid was the reaction stock solution, and the amount of the hydrophilic thermosensitive resin was the solid content in the reaction stock solution. The hydrophilic thermosensitive resin can be used directly according to the solid content of the reaction stock solution, and the solid content of the reaction stock solution is 26.4%.

[0064] Hydrophilic thermosensitive resin R5: In a 500 ml beaker, 220 g of deionized water, 75 g of isopropanol, 70 g of styrene, 15 g of acrylonitrile, 10 g of polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), 5 g of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile were added, and then reacted at 80°C for 8 hours. After adding 1 g of azobisisobutyronitrile and continuing the reaction for another 8 hours, the temperature was lowered to terminate the reaction, and a hydrophilic thermosensitive resin R5 was synthesized. The obtained liquid was the reaction stock solution, and the amount of the hydrophilic thermosensitive resin was the solid in the reaction stock solution. The hydrophilic thermosensitive resin can be used directly according to the solid content of the reaction stock solution, and the solid content of the reaction stock solution is 25.7%.

[0065] Hydrophilic thermosensitive resin R6: In a 500 ml beaker, 220 g of deionized water, 80 g of isopropanol, 75 g of styrene, 10 g of acrylonitrile, 5 g of polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), 10 g of 3,4-epoxycyclohexyl methacrylate, and 1 g of azobisisobutyronitrile were added, and then reacted at 80°C for 8 hours. After adding 1 g of azobisisobutyronitrile and continuing the reaction for another 8 hours, the temperature was lowered to terminate the reaction, and a hydrophilic thermosensitive resin R6 was synthesized. The obtained liquid was a reaction stock solution, and the amount of the hydrophilic thermosensitive resin was the solid content in the reaction stock solution. The hydrophilic thermosensitive resin could be used directly according to the solid content of the reaction stock solution, and the solid content of the reaction stock solution was 25.4%.

[0066] The present invention achieves a comprehensive effect through the interaction between the super-hydrophilic cross-linked resin and the hydrophilic thermosensitive resin. In order to more clearly illustrate the effect of the present invention, the following comparative example resin is specially synthesized.

[0067] The resin (codenamed m) that replaces the super-hydrophilic cross-linked resin used in the interlayer in the embodiment of the present application in the comparative example is synthesized as follows: m1 resin: Based on M1 resin, monomer b is removed and the resin does not contain epoxy bonds.

[0068] In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 10 g of monomer a1, 80 g of monomer c, 0.9 g of azobisisobutyronitrile and 90 g of deionized water, stir and react at 60°C for 5 hours, add 0.9 g of azobisisobutyronitrile, react for another 5 hours, then cool down to terminate the reaction, and then synthesize the target product m1 resin. The reaction stock solution containing the target product obtained by the above reaction can be used directly. The amount of the target product m1 resin is the solid content in the reaction stock solution, and the solid content of the reaction stock solution is 50.5%.

[0069] m2 resin: Based on M2 resin, monomer a and monomer b are removed. The resin does not contain phosphate groups and epoxy bonds, but is only a super hydrophilic homopolymer of 2-acrylamide-2-methylpropane sulfonic acid.

[0070] In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 100 g of monomer C, 1 g of azobisisoheptanonitrile and 100 g of deionized water, stir and react at 70°C for 4.5 hours, add 1 g of azobisisoheptanonitrile, react for another 5 hours, then cool down to terminate the reaction, and then synthesize the target product m2 resin. The reaction stock solution containing the target product obtained by the above reaction can be used directly. The amount of the target product m2 resin is the solid content in the reaction stock solution, and the solid content of the reaction stock solution is 50.5%.

[0071] m3 resin: Based on M3 resin, monomer b and monomer c are removed. The resin does not contain super-hydrophilic sulfonic acid groups, amide groups and epoxy bonds, and is only a polyethoxy phosphate homopolymer.

[0072] In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 100 g of monomer a3 (n=45), 1 g of azobisisobutyronitrile and 100 g of deionized water, stir and react at 80°C for 4 hours, add 1 g of azobisisobutyronitrile, react for another 5 hours, then cool down to terminate the reaction, and then synthesize the target product m3 resin. The reaction stock solution containing the target product obtained by the above reaction can be used directly. The amount of the target product m3 resin is the solid content in the reaction stock solution, and the solid content of the reaction stock solution is 50.5%.

[0073] m4 resin: Based on M4 resin, monomer a is removed and the resin does not contain phosphate and ethoxy groups.

[0074] In a 500 ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, condensation reflux and nitrogen protection device, add 15 g of monomer b, 65 g of monomer c, 0.8 g of azobisisobutyronitrile and 80 g of water, stir and react at 90°C for 4 hours, add 0.8 g of azobisisobutyronitrile, react for another 4 hours, then cool down to terminate the reaction, and then synthesize the target product m2 resin. The reaction stock solution containing the target product obtained by the above reaction can be used directly. The amount of the target product m4 resin is the solid content in the reaction stock solution, and the solid content of the reaction stock solution is 50.5%.

[0075] Comparative Example Synthesis of hydrophilic thermosensitive resin (code name: r): R1 resin: Based on the hydrophilic thermosensitive resin R1, the epoxy copolymer unit is removed.

[0076] In a 500 ml beaker, 180 g of deionized water, 50 g of isopropanol, 70 g of styrene, 10 g of acrylonitrile, 10 g of polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), and 0.9 g of azobisisobutyronitrile were added, and then reacted at 80°C for 8 hours. After adding 0.9 g of azobisisobutyronitrile and continuing to react for another 8 hours, the temperature was lowered to terminate the reaction and R1 resin was synthesized. The obtained liquid was the reaction stock solution. The amount of R1 resin was the solid content in the reaction stock solution. R1 resin could be used directly according to the solid content of the reaction stock solution. The solid content of the reaction stock solution was 28.5%.

[0077] R2 resin: Based on the hydrophilic thermosensitive resin R1, the hydrophilic component polyethylene glycol methyl ether methacrylate is added.

[0078] In a 500 ml beaker, add 200 g of deionized water, 50 g of isopropanol, 70 g of styrene, 10 g of acrylonitrile, 20 g of polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), and 1 g of azobisisobutyronitrile, then react at 80°C for 8 hours, add 1 g of azobisisobutyronitrile and continue to react for another 8 hours, then cool down to terminate the reaction and synthesize R2 resin. The obtained liquid is the reaction stock solution, and the amount of R2 resin is the solid content in the reaction stock solution. The R2 resin can be used directly according to the solid content of the reaction stock solution, and the solid content of the reaction stock solution is 29.0%.

[0079] R3 resin: Based on the hydrophilic thermosensitive resin R1, the hydrophilic component polyethylene glycol methyl ether methacrylate is reduced.

[0080] In a 500 ml beaker, 170 g of deionized water, 50 g of isopropanol, 70 g of styrene, 10 g of acrylonitrile, 5 g of polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), and 0.85 g of azobisisobutyronitrile were added, and then reacted at 80°C for 8 hours. After adding 0.85 g of azobisisobutyronitrile and continuing to react for another 8 hours, the temperature was lowered to terminate the reaction and R3 resin was synthesized. The obtained liquid was the reaction stock solution. The amount of R3 resin was the solid content in the reaction stock solution. The R3 resin could be used directly according to the solid content of the reaction stock solution. The solid content of the reaction stock solution was 28.3%.

[0081] The following are implementation examples of the present invention, but the present invention is not limited to the following examples.

[0082] Source of raw materials for the heat-sensitive layer: Infrared absorbers that meet the requirements of the present invention can be obtained from Dye Chemical or Merck. The infrared absorber (IR820) in the example is Merck's product Sigma-Adrich543365, chemical name: 2-[2-[2-chloro-3-[[1,3-dihydro-1,1-dimethyl-3-(4-sulfonic acid butyl)-2H-benzo[e]indol-2-ylidene]-ethylidene]-1-cyclohexene-1-yl]-vinyl]-1,1-dimethyl-3-(4-sulfonic acid butyl)-1H-benzo[e]indolium hydroxide inner salt; multifunctional acrylate: SR399 is dipentaerythritol pentaacrylate, from Sartomer; multifunctional polyurethane Ester acrylate: PU100 is polyurethane acrylate, which is a condensation product of Covestro's Desmodurn100, hydroxyethyl acrylate and pentaerythritol triacrylate, obtained from Shenyang Institute of Chemical Industry; thermal initiator: diphenyliodonium tetrafluoroborate (code: B1) and 4,4-di-tert-butyldiphenyliodonium hexafluorophosphate (code: B2) are from J&K, surfactant BYK306 is from BYK; 1-methoxy-2-propanol is from Union Carbide Chemical; polyvinyl alcohol PVA-205 is from Kuraray Co., Ltd. of Japan; polyvinyl pyrrolidone PVPK30 is from BASF of Germany; emulsifier OP-10 is from Hamm of Germany.

[0083] Example 1 Step 1: 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. 2The surface was electrolytically roughened for 16 seconds at a current density of 10A / dm, 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 at a current density of 15A / dm 2 The current density was 20 seconds for anodization and then washed with water. The average center line thickness of the plate obtained was 0.5 μm and the oxide film weight was 3.0 g / dm 2 .

[0084] Step 2: Apply the middle layer on the substrate. The middle layer uses the following coating solution: 98g M1 resin, 2g initiator B1, 500g water, 400g methyl ethyl ketone, and the coating thickness is 3mg / m 2 .

[0085] Step 3: Coating the heat-sensitive layer on the middle layer Thermal layer raw materials (specific raw materials and amounts are shown in Table 1): Hydrophilic thermosensitive resin R1 80 Cross-linkable prepolymer SR399 14 Thermal initiator B1 5 Infrared absorber (IR820) 1 The above raw materials were added with 0.5 g of surfactant BYK306 and 700 g of 1-methoxy-2-propanol to prepare a heat-sensitive layer coating solution, which was dried at 100°C for 60 seconds. 2 Dry weight of coating.

[0086] Example 2 Step 1: Same as Example 1.

[0087] Step 2: Apply an intermediate layer on the substrate. The intermediate layer uses the following coating solution: 98g M2 resin, 2g initiator B1, 500g water, 400g methyl ethyl ketone, and the coating thickness is 3mg / m 2 .

[0088] Step 3: Coating the heat-sensitive layer on the middle layer Thermal layer raw materials (specific raw materials and amounts are shown in Table 1): Hydrophilic thermosensitive resin R2 60 Cross-linkable prepolymer PU100 30 Thermal initiator B2 5 Infrared absorber (IR820) 5 The above raw materials were added with 0.5 g of surfactant BYK306 and 700 g of 1-methoxy-2-propanol to prepare a heat-sensitive layer coating solution, which was dried at 100°C for 60 seconds. 2 Dry weight of coating.

[0089] Example 3 Step 1: Same as Example 1.

[0090] Step 2: Apply an intermediate layer on the substrate. The intermediate layer uses the following coating solution: 98g M3 resin, 2g initiator B1, 500g water, 400g methyl ethyl ketone, and the coating thickness is 3mg / m 2 .

[0091] Step 3: Coating the heat-sensitive layer on the middle layer Thermal layer raw materials (specific raw materials and amounts are shown in Table 1): Hydrophilic thermosensitive resin R3 70 Cross-linkable prepolymer PU100 20 Thermal initiator B1 5 Infrared absorber (IR820) 5 The above raw materials were added with 0.5 g of surfactant BYK306 and 700 g of 1-methoxy-2-propanol to prepare a heat-sensitive layer coating solution, which was dried at 100°C for 60 seconds. 2 Dry weight of coating.

[0092] Example 4 Step 1: Same as Example 1.

[0093] Step 2: Apply an intermediate layer on the substrate. The intermediate layer uses the following coating solution: 98g M4 resin, 2g initiator B2, 500g water, 400g methyl ethyl ketone, and the coating thickness is 3mg / m 2 .

[0094] Step 3: Coating the heat-sensitive layer on the middle layer Thermal layer raw materials (specific raw materials and amounts are shown in Table 1): Hydrophilic thermosensitive resin R4 70 Cross-linkable prepolymer PU100 20 Thermal initiator B1 5 Infrared absorber (IR820) 5 The above raw materials were added with 0.5 g of surfactant BYK306 and 700 g of 1-methoxy-2-propanol to prepare a heat-sensitive layer coating solution, which was dried at 100°C for 60 seconds. 2 Dry weight of coating.

[0095] Example 5 Step 1: Same as Example 1.

[0096] Step 2: Apply the middle layer on the substrate. The middle layer uses the following coating solution: 98g M5 resin, 2g initiator B1, 500g water, 400g methyl ethyl ketone, and the coating thickness is 3mg / m 2 .

[0097] Step 3: Coating the heat-sensitive layer on the middle layer Thermal layer raw materials (specific raw materials and amounts are shown in Table 1): Hydrophilic thermosensitive resin R5 80 Cross-linkable prepolymer SR99 10 Thermal initiator B2 5 Infrared absorber (IR820) 5 The above raw materials were added with 0.5 g of surfactant BYK306 and 700 g of 1-methoxy-2-propanol to prepare a heat-sensitive layer coating solution, which was dried at 100°C for 60 seconds. 2 Dry weight of coating.

[0098] Example 6 Step 1: Same as Example 1.

[0099] Step 2: Apply an intermediate layer on the substrate. The intermediate layer uses the following coating solution: 98g M6 resin, 2g initiator B1, 500g water, 400g methyl ethyl ketone, and the coating thickness is 3mg / m 2 .

[0100] Step 3: Coating the heat-sensitive layer on the middle layer Thermal layer raw materials (specific raw materials and amounts are shown in Table 1): Hydrophilic thermosensitive resin R6 75 Cross-linkable prepolymer SR99 20 Thermal initiator B2 2.5 Infrared absorber (IR820) 2.5 The above raw materials were added with 0.5 g of surfactant BYK306 and 700 g of 1-methoxy-2-propanol to prepare a heat-sensitive layer coating solution, which was dried at 100°C for 60 seconds. 2 Dry weight of coating.

[0101] Example 7 Steps 1, 2 and 3 are the same as those in Example 1.

[0102] Step 4: The following protective layer was extrusion coated on the heat-sensitive layer, and then dried at 110°C for 60 seconds. 2 Dry weight of coating.

[0103] Protective layer formula: Polyvinyl alcohol PVA-205 (Japanese Kuraray) 17g Polyvinylpyrrolidone PVPK30 (BASF, Germany) 3g Emulsifier OP-10 (Helm, Germany) 0.45g Deionized water 480g Comparative Example 1: Same as Example 1, except that the super-hydrophilic cross-linked resin M1 is replaced by m1.

[0104] Comparative Example 2: Same as Example 2, except that the super-hydrophilic cross-linked resin M2 is replaced by m2.

[0105] Comparative Example 3: Same as Example 3, except that the super-hydrophilic cross-linked resin M3 is replaced by m3.

[0106] Comparative Example 4: Same as Example 4, except that the super-hydrophilic cross-linked resin M4 is replaced by m4.

[0107] Comparative Example 5: Same as Example 1, except that the water-based thermosensitive resin R1 is replaced by r1.

[0108] Comparative Example 6: Same as Example 1, except that the water-based thermosensitive resin R1 is replaced by r2.

[0109] Comparative Example 7: Same as Example 1, except that the water-based thermosensitive resin R1 is replaced by r3.

[0110] Comparative Example 8: Same as Example 1, except that step 2 is changed to: sealing with a 5% by mass sodium silicate aqueous solution at 80°C for 18 seconds, washing with water, and drying.

[0111] The test analysis of the plate material, the performance of the thermal plates of the embodiments and comparative examples are listed in Table 1 below.

[0112] 1. Sensitivity: Sensitivity is characterized by the laser energy value required for imaging. The lower the triggering efficiency, the higher the energy required for laser imaging. All the plates just produced above were placed on a Kodak Thermal CTP platemaking machine at 5 mJ / cm 2 The progressive amount is between 80-200mJ / cm 2 The plate was exposed within an energy range of , and the initial sensitivity was measured. Its performance is listed in Table 1 below.

[0113] 2. Dot quality: Dot quality is characterized by whether 1-99% of the dots can be restored after laser imaging. For example, 1-99% means that 1% to 99% of the dots can be restored, which is the best value. 2-98% means that only 2-98% of the dots can be restored, and 1% and 99% of the dots cannot be restored, which is slightly worse, and so on. All the above plates were exposed on the Kodak Trendy thermal CTP platemaking machine with the best sensitivity energy, and the initial dot restoration value of the image was measured. Its performance is listed in Table 1 below.

[0114] 3. Number of paper passes: An important evaluation index for on-press development of processing-free thermal plates is the on-press developing ability, which is measured by the number of paper passes. The number of paper passes is the number of papers wasted in on-press development before normal printing. The smaller the value, the better the on-press developing ability.

[0115] 4. Inkability: All the newly produced plates were placed on a Kodak Thermal CTP plate-making machine at 1 mJ / cm 2 The progressive amount is 1-20mJ / cm 2 Exposure was performed within an energy range to form scale bars, which were then printed on a Heidelberg-XL754C printing press to test the inking properties of the scale bars. The values ​​ranged from 1 to 20, with 1 being the worst, 20 being the best, and 14 being a pass.

[0116] 5. Printing life: If the thermal layer and the base are not firmly bonded, the printing life of the plate will be reduced. Use Heidelberg-XL754C printing press to print and test the total number of normal prints printed by the thermal plate. Its performance is listed in Table 2 below.

[0117] The test application results in Table 1 show that the five performance indicators of sensitivity, dot quality, number of plates, inking property, and printing resistance of Comparative Examples 1-8 are contradictory, and one indicator cannot meet the requirements. Compared with the comparative example of the untreated plate, the five performance indicators of sensitivity, dot quality, number of plates, inking property, and printing resistance of Examples 1-7 are improved. Therefore, the untreated thermal plate of the present invention is a green and environmentally friendly thermal plate with on-machine development capability, and has excellent imaging performance, on-machine development capability, and printing resistance. This is because the untreated thermal plate of the present invention is provided with an intermediate layer, and the intermediate layer contains the super-hydrophilic cross-linked resin of the present invention. The super-hydrophilic cross-linked resin has super-hydrophilicity and can be easily removed from the pores of the sand mesh by the fountain solution; under the action of the laser, the intermediate layer and the imaging layer react with cations to achieve laser thermal fusion, and the intermediate layer solidifies and firmly adheres to the aluminum plate base, greatly improving the printing resistance of the plate; at the same time, the thermal layer is no longer designed to be super-hydrophilic, and the plate has better inking property. The invention effectively solves the contradiction between the on-press development (DOP) capability, printing durability and ink affinity of the treatment-free thermal plate material through the intermediate layer.

[0118] Table 1 Plate application performance table Compared with Example 1, since the epoxy-containing monomer b cross-linked with the heat-sensitive layer is removed from the intermediate resin, the press run is greatly reduced, the sensitivity is slightly reduced, the dot quality and ink-taking properties are slightly reduced, and the number of plate passes is slightly increased.

[0119] Compared with Example 2, since the monomer b containing an epoxy group cross-linked with the heat-sensitive layer and the monomer a containing a phosphate group and an ethoxy group having a similar structural unit to that in the heat-sensitive layer are removed from the intermediate resin, the printing endurance of Comparative Example 2 is greatly reduced, which is lower than that of Comparative Example 1. In addition, the dot quality and inking properties are slightly reduced. Furthermore, since the content of hydrophilic components in the intermediate resin is increased compared with Example 2, the number of passed papers is further reduced.

[0120] Compared with Example 3, since the monomer b containing epoxy group cross-linked with the heat-sensitive layer and the monomer c containing super-hydrophilic sulfonic acid group and amide group are removed from the intermediate resin, the printing endurance of Comparative Example 3 is greatly reduced, the number of plates is greatly increased, and the dot quality and ink-taking properties are slightly reduced.

[0121] In Comparative Example 4, compared with Example 4, since the monomer a containing a phosphate group and an ethoxy group having a structural unit similar to that in the heat-sensitive layer is removed from the intermediate resin, the printing endurance is reduced and the dot quality is slightly reduced. Furthermore, since the content of the hydrophilic component in the intermediate resin is increased compared with Example 4, the number of passed plates is further reduced.

[0122] Compared with Example 1, since the epoxy copolymer unit is removed from the hydrophilic thermosensitive resin, the cross-linking property with the intermediate layer is poor, and the relatively hydrophilic content of the hydrophilic thermosensitive resin is increased, so the ink-taking property is slightly reduced, the number of plate passes is increased, the dot quality and sensitivity are reduced, and the printing endurance is greatly reduced.

[0123] Compared with Example 1, since the epoxy copolymer unit is removed from the hydrophilic thermosensitive resin and the content of the hydrophilic component polyethylene glycol methyl ether methacrylate is increased, the crosslinking property with the intermediate layer is poor, and the hydrophilic content in the hydrophilic thermosensitive resin is increased, the ink-taking property is greatly reduced, the number of plates is increased, the dot quality and sensitivity are reduced, and the printing endurance is greatly reduced.

[0124] Compared with Comparative Example 5, the hydrophilic component in the hydrophilic thermosensitive resin in Comparative Example 6 is increased, which can slightly resist the corrosion of oily ink, so the printing durability is slightly increased.

[0125] Compared with Example 1, since the epoxy copolymer unit is removed from the hydrophilic thermosensitive resin and the content of the hydrophilic component polyethylene glycol methyl ether methacrylate is reduced, the crosslinking property with the intermediate layer is poor, the printing endurance is greatly reduced, the hydrophilic content in the hydrophilic thermosensitive resin is reduced, the hydrophilicity is poor, the fountain solution cannot be developed, the on-machine developing ability is poor, the number of plates passed increases, the inking property increases, and the dot quality and sensitivity are reduced.

[0126] Compared with Comparative Examples 5 and 6, in Comparative Example 7, the hydrophilic component in the hydrophilic thermosensitive resin is reduced, the hydrophilicity is poor, the fountain solution cannot be developed, the on-machine developing ability is poor, the number of plate passes increases, and the inking property increases.

[0127] Comparative Example 8: After sealing, but without an intermediate layer, the biggest impact is that the resin of the thermal layer will be hidden in the holes of the plate base, and the number of paper passes will increase dramatically. The inking property and printing durability are basically not affected, but the number of paper passes is too high and does not meet the requirements.

[0128] 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 super hydrophilic cross-linked resin, characterized in that: The super-hydrophilic cross-linked resin is a ternary free radical copolymer of monomer a: phosphate monomer, monomer b: 3,4-epoxycyclohexyl methacrylate, and monomer c: 2-acrylamide-2-methylpropane sulfonic acid, wherein a: phosphate monomer has the following structure: R1 and R3 are H or CH3, R2 is a covalent bond, a methoxy group or an acyloxy group, and n is an integer of 0-45.

2. The super hydrophilic cross-linked resin according to claim 1, characterized in that: In the super-hydrophilic cross-linked resin, by weight percentage, monomer a: phosphate monomer accounts for 10-20% by weight, monomer b: 3,4-epoxycyclohexyl methacrylate accounts for 10-20% by weight, and monomer c: 2-acrylamide-2-methylpropane sulfonic acid accounts for 60-80% by weight.

3. The method for preparing a super hydrophilic cross-linked resin according to claim 1 or 2, characterized in that: The reaction adopts solution polymerization, the reaction is a random free radical polymerization reaction, the reaction catalyst is an azo catalyst, and the reaction temperature is 60-90°C.

4. Use of the super hydrophilic cross-linked resin according to any one of claims 1 to 3.

5. Use of the super-hydrophilic cross-linked resin according to any one of claims 1 to 3 in a treatment-free heat-sensitive plate.

6. A treatment-free thermal plate, comprising from bottom to top a carrier, an intermediate layer, and a thermal layer, wherein the thermal layer comprises a thermal resin, a cross-linkable prepolymer, a thermal initiator, and an infrared absorber, characterized in that: The middle layer comprises the super-hydrophilic cross-linking resin described in any one of claims 1 to 3 and a thermal initiator.

7. The process-free thermal plate according to claim 6, characterized in that: The thermosensitive resin accounts for 60-80% of the total solid content of the thermosensitive layer composition, the crosslinkable prepolymer accounts for 10-30% of the total solid content of the thermosensitive layer composition, the thermal initiator of the thermosensitive layer accounts for 1-5% of the total solid content of the thermosensitive layer composition, and the infrared absorber accounts for 1-5% of the total solid content of the thermosensitive layer composition; The thermal initiator contained in the middle layer is an iodonium salt; The carrier is an aluminum plate that has been electrolytically roughened and anodized.

8. The process-free thermal plate according to claim 6, characterized in that: The heat-sensitive resin in the heat-sensitive layer is a branched polyolefin resin containing hydrophilic groups and epoxy groups; the cross-linkable prepolymer is a multi-double-bond acrylic monomer or a multi-double-bond polyurethane acrylic monomer; the thermal initiator is an iodonium salt; and the infrared absorber is a cyanine dye with an absorption peak at 750-850nm.

9. The process-free thermal plate according to claim 8, characterized in that: The thermosensitive resin is a polyolefin resin obtained by quaternary copolymerization of styrene, acrylonitrile, polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000), and 3,4-epoxycyclohexyl methacrylate; calculated by weight percentage, styrene accounts for 70-80%, acrylonitrile accounts for 10-20%, polyethylene glycol methyl ether methacrylate (number average molecular weight Mn=2000) accounts for 5-10%, and 3,4-epoxycyclohexyl methacrylate accounts for 5-10%, and the thermosensitive resin is in an emulsion state.

10. The process-free thermal plate according to claim 6, characterized in that: A protective layer is also provided on the heat-sensitive layer; After being scanned and exposed by a thermal CTP plate-making machine, the thermal plate can be directly loaded onto a printing press and developed and printed with the printing press fountain solution.

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