An aluminum-containing substrate, uses thereof, and a processless thermal plate precursor and processless thermal plate comprising the same and uses thereof

Abstract

The present application provides an aluminum-containing substrate and its application, and a processing-free thermal plate precursor containing the same, a processing-free thermal plate and its application. The present application can effectively solve the problems of easy pollution and difficult treatment of pollution waste when a hydrophilic polymer is used as a hydrophilic layer for the aluminum-containing substrate. The hydrophilic layer obtained by using a non-polymer hydrophilic compound, which is a sugar alcohol or oligosaccharide, or a chemically modified sugar alcohol or oligosaccharide, is not easy to cause pollution, and the pollution waste is easy to be degraded by microorganisms, so it is more environmentally friendly. A processing-free thermal plate precursor uses the above aluminum-containing substrate, has excellent on-press development capability, and can improve the adhesion of the thermal layer. The processing-free thermal plate manufactured by the precursor can solve the problems of pollution of the printing plate to the fountain system of the printing machine and environmental pollution, and the plate material has excellent imaging performance, on-press development capability and UV ink printing resistance.

Description

Technical Field

[0001] This invention belongs to the field of advanced offset printing technology, specifically relating to an aluminum-containing substrate and its application, a pre-treatment-free thermal plate containing the same, a pre-treatment-free thermal plate, and its application. Background Technology

[0002] Traditional PS plates and ordinary computer-to-plate (CTP) developing processes generate large amounts of highly alkaline waste liquid containing various toxic organic compounds and heavy metal ions. Improper treatment can severely pollute water bodies, and the volatile organic compounds (VOCs) in the developing solution affect workshop air quality and endanger the health of operators. Process-free thermal CTP plates are a product of the advanced stage of CTP technology. This process-free technology simplifies the plate-making process from "exposure → development → washing → drying → printing" to "exposure → direct printing," increasing efficiency by more than 30%. Its core feature is that after laser imaging, no chemical development or washing is required before printing, minimizing the environmental impact of pre-press plate making. The global printing industry is promoting a green printing strategy, with high-end environmentally friendly printing materials listed as a key development area, supporting the research and development of process-free plates. Process-free thermal plates achieve performance differences between image and non-image areas through infrared laser irradiation (typically 830nm). There are three main technical routes: 1. Thermal Ablation: The principle is that laser energy instantly heats the coating on the surface of the printing plate to over 1000°C, directly ablating away the coating in non-image areas to expose the hydrophilic aluminum base. However, it has problems with dust pollution and printability, which limits its commercial application.

[0003] 2. Thermal Polar Conversion: The principle is that laser energy changes the chemical properties of the coating, making the image area change from hydrophilic to ink-philic, or ink-philic to hydrophilic, without removing the coating. Although this solves the dust problem, it is difficult to ensure that the polarity conversion is complete, and ultimately it is difficult to guarantee high printing durability and accurate dot reproduction.

[0004] 3. Thermal Fusion: The principle is that laser energy melts the coating in the image area and penetrates into the hydrophilic aluminum plate base layer to form a stable ink-receptive area. The non-image area retains its hydrophilic properties. The printing press dampening solution and ink automatically complete the slight cleaning of the non-image area during the start-up phase, without the need for additional treatment. This is currently a feasible technical approach.

[0005] During the development of heat-melting technology for processing-free thermal plates, technicians discovered that the aluminum base abrasive layer has a very strong adsorption capacity, particularly adsorbing hydrophilic thermal resin in a discrete particle state. The thermal layer in the non-image areas that are not melted by the laser is not easily removed by the paper, resulting in a decrease in the water retention function of the alumina pores in the aluminum base abrasive layer, making it difficult to repel ink, causing dirt to accumulate in the blank non-image areas, reducing on-machine development ability, and affecting image reproduction quality.

[0006] To address the aforementioned issues, some technicians have considered applying one or more hydrophilic polymers as a coating to the abrasive layer of the aluminum plate base. This would facilitate the removal of the heat-sensitive layer in non-image areas. However, the hydrophilic polymers are not discrete particles and are not easily removed by the paper. After detachment, they thicken and contaminate the dampening solution, even causing it to become a hydrogel, polluting the operating system of high-precision printing presses and affecting in-machine development (DOP). Furthermore, the treatment of dampening solution wastewater containing hydrophilic polymers is challenging, as the polymers are not easily decomposed by microorganisms, impacting the environment. Additionally, the hydrophilic polymers affect the adhesion between the image area and the abrasive layer, leading to a decrease in printing durability. This is especially problematic when using UV inks, where acrylic monomers in UV inks and solvents in UV ink printing wash water can penetrate the coating, damaging the adhesion between the coating and the plate base, resulting in a significant reduction in printing durability. A comprehensive approach addressing both the substrate and coating aspects is necessary to resolve this problem. Summary of the Invention

[0007] The technical problem this invention aims to solve is that the hydrophilic polymer coating on the abrasive layer of an aluminum plate base is not discrete granular, making it difficult to remove from the paper. After detachment, it thickens and contaminates the dampening solution, affecting in-machine development (DOP). The hydrophilic polymer also affects the adhesion between the image area and the abrasive layer, resulting in decreased printing durability, especially when using UV inks, where printing durability drops significantly. To solve these problems, this invention provides an aluminum-containing substrate and its applications, as well as a pre-prepared, treatment-free thermal plate containing the same substrate, a treatment-free thermal plate, and its applications. The aluminum-containing substrate is obtained by roughening and anodizing an aluminum plate base, followed by coating it with a hydrophilic layer containing one or more non-polymer hydrophilic compounds. These non-polymer hydrophilic compounds are sugar alcohols or oligosaccharides, or chemically modified sugar alcohols or oligosaccharides. Sugar alcohols or oligosaccharides in non-image areas, or chemically modified sugar alcohols or oligosaccharides, are non-polymers and are less likely to contaminate the dampening solution after detachment. Waste dampening solution can be decomposed by microorganisms, reducing the difficulty of environmental treatment. Through chemical modification, sugar alcohols or oligosaccharides can improve the adhesion between the hydrophilic layer of the image area and the aluminum substrate and imaging layer under laser thermal action. Combined with aluminum substrate treatment technology with at least two layers of abrasive structure, it can significantly improve the in-machine development ability, printing durability and image performance of treatment-free thermal plates. Treatment-free thermal plates containing such aluminum substrates use solvent-resistant thermal layers and can undergo thermal cross-linking with sugar alcohols or oligosaccharides on the aluminum substrate, or chemically modified sugar alcohols or oligosaccharides, under laser thermal action, which can significantly improve the printing durability of the plate when printing with UV inks.

[0008] The object of the present invention is achieved in the following manner: an aluminum-containing substrate, which is obtained by roughening and anodizing an aluminum plate base and covering it with a hydrophilic layer containing one or more non-polymer hydrophilic compounds, wherein the non-polymer hydrophilic compounds are sugar alcohols or oligosaccharides, or chemically modified sugar alcohols or oligosaccharides, and are non-polymers.

[0009] The aluminum substrate undergoes electrolytic roughening and anodizing to form a structural mesh. The average centerline thickness of the mesh is 0.2-0.6 μm, and the average diameter of the micropores inside the mesh is 10-60 nm. The oxide film formed by anodizing weighs 1-10 g / dm². The dry weight of the hydrophilic layer covering the mesh is 0.001-0.1 g / m². 2 ; The sugar alcohol is xylitol, sorbitol, or maltitol, and the oligosaccharide is xylitol or xylooligosaccharide; Chemically modified sugar alcohols or oligosaccharides are those that, after chemical modification, contain at least a phosphate group, a double bond, or an epoxy group within their molecules.

[0010] The chemical modification methods for sugar alcohols or oligosaccharides are as follows: sugar alcohols or oligosaccharides react with phosphoric acid to form phosphate groups within the molecule; sugar alcohols or oligosaccharides react with acrylic anhydride or isocyanate acrylates to form double bonds within the molecule; sugar alcohols or oligosaccharides react with epichlorohydrin or glycidyl ester to form epoxy groups within the molecule.

[0011] The application of the aluminum-containing substrate in a heat-sensitive plate that requires no treatment.

[0012] A treatment-free thermal plate precursor includes an aluminum-containing substrate and a thermally sensitive layer. The thermally sensitive layer includes a hydrophilic thermally sensitive resin, a crosslinkable prepolymer, a thermal initiator, and an infrared absorber. The aluminum-containing substrate is the aforementioned aluminum-containing substrate, with the side coated with the hydrophilic layer of a non-polymer hydrophilic compound being the front side. The thermally sensitive layer is located on the front side of the aluminum-containing substrate.

[0013] The thermosensitive layer, by weight percentage, comprises 45-80% hydrophilic thermosensitive resin, 10-40% crosslinkable prepolymer, 5-10% thermal initiator, and 1-5% infrared absorber.

[0014] The hydrophilic thermosensitive resin is a polyolefin resin containing comonomers with polyalkoxy branches, comonomers with epoxy side groups, and comonomers with urethane amide side groups. A protective layer is also provided on the heat-sensitive layer.

[0015] The hydrophilic thermosensitive resin contains polyalkoxy-branched comonomers of polyethylene glycol monomethyl ether methacrylate or 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate or mixtures thereof; the copolymer containing epoxy side groups is 3,4-epoxycyclohexyl methacrylate or epoxy polyethylene glycol acrylate or mixtures thereof; the comonomer containing carbamate side groups is 4-[[2-(methacryloyloxy)ethyl]carbamate]benzamide or 4-[(prop-2-en-1-yloxy)carbonyl]aminobenzamide or mixtures thereof; The crosslinkable prepolymer is a multifunctional acrylic monomer or a multifunctional polyurethane acrylic monomer or a multifunctional silicone acrylate, or a mixture thereof; The thermal initiator is iodonium salt, and the decomposition temperature is 150-220℃; The infrared absorber is a cyanine dye with an absorption peak at 750-850 nm.

[0016] A process-free thermal plate is prepared from the aforementioned process-free thermal plate precursor.

[0017] The aforementioned application of the heat-sensitive plate involves scanning and exposing the heat-sensitive plate using a thermal CTP plate-making machine, followed by water rinsing and development before mounting it onto a printing press for printing, or directly mounting it onto a printing press and developing it with dampening solution before printing.

[0018] Compared to existing technologies, this invention effectively solves the problems of pollution and difficult-to-treat waste caused by using hydrophilic polymers as hydrophilic layers on aluminum-containing substrates. This invention uses a hydrophilic layer obtained from non-polymer hydrophilic compounds, which are sugar alcohols or oligosaccharides, or chemically modified sugar alcohols or oligosaccharides. Because they are low-molecular-weight compounds, they are less likely to cause pollution, and the waste is easily degraded by microorganisms, making it more environmentally friendly. A treatment-free thermal plate precursor, using the aforementioned aluminum-containing substrate, exhibits excellent in-machine developability and improves the adhesion of the thermal layer. Treatment-free thermal plates manufactured using this precursor can solve the problems of printing plate contamination of printing press damping systems and environmental pollution. The plate material also possesses excellent imaging performance, in-machine developability, and UV ink printing durability. Detailed Implementation

[0019] Before going into further detail, let's refer to the following terms: 1. Polymer: According to the "Glossary of Basic Terms in Polymer Science" published by the International Union of Pure and Applied Chemistry ("IUPAC"), Pure Appl. Chem. 68, 2287-2311 (1996), a polymer is a substance composed of macromolecules.

[0020] 2. Macromolecule (polymer molecule): According to the IUPAC 1996 "Basic Glossary of Polymer Science" (Pure and Applied Chemistry, 1996, 68, 2287) and the "IUPAC Golden Book of Chemical Terminology" (… IUPAC Gold Book(Entry number: M03667) A macromolecule is a molecule with a high relative molecular mass, whose structure is essentially composed of multiple repeating units, which are actually or conceptually derived from molecules of low relative molecular mass.

[0021] 3. Chemical Modification: IUPAC defines chemical modification as a chemical process that alters the chemical structure, composition, or properties of a substance by breaking and forming chemical bonds, without changing the fundamental chemical identity of the bulk material in a way that results in a new chemical compound classification.

[0022] 3. Oligomer: According to the IUPAC definition, an oligomer is a substance composed of molecules of intermediate relative molecular mass, whose molecular structure essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecular mass. Note: Oligomer molecules have a small number of repeating units (typically 2 ≤ DP ≤ 10), and adding or removing even one repeating unit will significantly change its properties. Note: A molecule of an oligomer contains a small number of repeat units (typically 2≤DP≤10), and the properties of the oligomer varysignificantly with the addition or removal of one repeat unit.).

[0023] 4. Copolymer: A polymer derived from two or more monomers with different structures, whose macromolecules contain a significant amount of structural units derived from each monomer, and these units are connected by chemical bonds to form a main chain or side chain.

[0024] 5. Polysaccharide Alcohol: Polysaccharide alcohol (also known as polyglycitols, hydrogenated polysaccharides, polyglycitols / polyglucitols) refers to polyol compounds obtained by reducing polysaccharides with a degree of polymerization (DP) ≥ 10 through a reduction reaction (usually hydrogenation). In this process, the aldehyde or ketone group of each monosaccharide unit in the molecule is reduced to a hydroxyl group, while retaining the original glycosidic bond linkage.

[0025] 6. Oligosaccharide Alcohol: Oligosaccharides composed of 3 to 9 monosaccharide units, which are reduced to hydroxyl groups by catalytic hydrogenation, retaining the original glycosidic bond linkage.

[0026] 7. Polymer side groups refer to atoms or groups of atoms that are attached to the backbone atoms of the polymer main chain, do not participate in the formation of covalent bonds in the main chain, and exist only as substituent groups. Simply put, the core of a polymer molecule is a continuous long chain (i.e., the main chain) formed by the polymerization reaction of monomers, and side groups are the various groups "attached" to this main chain.

[0027] 8. Polymer branch: A polymer branch is a shorter polymer chain that branches off from the main polymer chain backbone. Essentially, it is a "branch" of the main chain.

[0028] The invention is described in detail below: An aluminum-containing substrate, characterized in that: the aluminum-containing substrate is obtained by roughening and anodizing an aluminum plate base, and then covering it with a hydrophilic layer containing one or more non-polymer hydrophilic compounds, wherein the non-polymer hydrophilic compounds are sugar alcohols or modified sugar alcohols, and are non-polymers.

[0029] The aluminum-containing substrate is an aluminum plate base that has been roughened and anodized. Its surface contains a large amount of sand, making it highly susceptible to ink adsorption and contamination in non-image areas. One or more hydrophilic compounds can be applied to improve the ink repellency of these non-image areas. The hydrophilic compounds can be polymeric or non-polymeric; however, polymers easily cause contamination of the dampening system, posing a significant environmental hazard. This invention uses non-polymeric hydrophilic compounds, which are less likely to cause dampening system contamination and are environmentally friendly.

[0030] There are many non-polymer hydrophilic compounds, which will not be listed in detail. The non-polymer hydrophilic compounds used in this invention are sugar alcohols or oligosaccharides, or chemically modified sugar alcohols or oligosaccharides.

[0031] Sugar alcohols are polyols formed by the reduction of the carbonyl group of monosaccharides or oligosaccharides. They can be classified into four main categories based on their degree of polymerization (DP): 1. Monosaccharide alcohols (degree of polymerization DP=1): These are produced by the reduction of a single monosaccharide. The molecules contain 3 to 6 hydroxyl groups. They are the most common type of sugar alcohol, such as sorbitol, mannitol, xylitol, erythritol, arabitol, and ribitol. 2. Disaccharides (degree of polymerization DP=2): such as maltitol, lactitol, isomalt, and trehalitol; 3. Oligosaccharide alcohols (degree of polymerization 3≤DP≤9): maltodextrin, isomaltodextrin; 4. Polysaccharide alcohols (degree of polymerization DP≥10): hydrogenated starch hydrolysate (HSH), hydrogenated cellulose, hydrogenated chitosan.

[0032] Oligosaccharides, also known as oligosaccharides, generally refer to carbohydrate polymers formed by 2 to 10 monosaccharides linked by glycosidic bonds. They are classified according to their degree of polymerization as follows: Disaccharides (two monosaccharides), such as sucrose, lactose, maltose, trehalose, etc. Trisaccharides: such as raffinose and maltotriose; Four sugars: such as stachyose; Five sugars or more (≤10): such as xylooligosaccharides, fructooligosaccharides, galactooligosaccharides, isomaltooligosaccharides, etc.

[0033] Based on the above-mentioned terminology, it should be noted that: 1. Monosaccharide alcohols and disaccharide alcohols are not polymers, much less copolymers; 2. Oligosaccharide alcohols and oligosaccharides are not polymers or copolymers, but oligomers; 3. Polysaccharide alcohols may fall under the category of polymers.

[0034] The sugar alcohols of this invention are non-polymeric sugar alcohols or oligosaccharides, specifically monosaccharides, disaccharides, oligosaccharides, or oligosaccharides. Before chemical modification, the sugar alcohols or oligosaccharides used are not polysaccharides; they can be monosaccharides, disaccharides, oligosaccharides, or oligosaccharides. The sugar alcohols or oligosaccharides of this invention, or the chemically modified sugar alcohols or oligosaccharides, must be non-polymeric.

[0035] The sugar alcohols used in this invention are preferably xylitol, sorbitol, or maltitol, and the oligosaccharides are preferably xylooligosaccharides.

[0036] The chemically modified sugar alcohols or oligosaccharides of the present invention are sugar alcohols or oligosaccharides that, after chemical modification, contain at least phosphate ester groups, double bonds, or epoxy groups in their molecules, and the modified sugar alcohols are non-polymers.

[0037] The specific methods for chemical modification of sugar alcohols or oligosaccharides are as follows: Phosphate ester groups can be formed within sugar alcohol or oligosaccharide molecules through dehydration condensation between the hydroxyl groups (-OH) in the sugar alcohol or oligosaccharide molecule and the hydroxyl groups (-OH) in the phosphoric acid. Double bonds can be formed within sugar alcohol or oligosaccharide molecules through ring-opening esterification reactions between the sugar alcohol or oligosaccharide and acrylic anhydride, or through amino esterification reactions between the sugar alcohol or oligosaccharide and isocyanate acrylates. Epoxy groups can be formed within sugar alcohol or oligosaccharide molecules by directly grafting small molecules containing epoxy functional groups onto the hydroxyl groups of the sugar alcohol or oligosaccharide backbone. This can be achieved using epichlorohydrin grafting, epichlorohydrin grafting, or glycidyl ether grafting.

[0038] The aluminum-containing substrate of this invention uses an aluminum plate base with aluminum accounting for more than 99%, iron accounting for 0.1%-0.5%, silicon accounting for 0.03%-0.3%, copper accounting for 0.003%-0.03%, and titanium accounting for 0.01%-0.1%. The aluminum plate base needs to be roughened, anodized, and then coated with a hydrophilic layer containing one or more non-polymer hydrophilic compounds. The non-polymer hydrophilic compounds are sugar alcohols or oligosaccharides, or chemically modified sugar alcohols or oligosaccharides, and are non-polymers.

[0039] Methods for roughening aluminum plate substrates include mechanical grinding and electrolytic roughening, with electrolytic roughening being preferred. The electrolyte for electrolytic roughening can be an aqueous solution of acid, alkali, or salt. First, the aluminum plate is placed in a 1%-30% aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, etc., and chemically etched at 20-80℃ for 5-250 seconds. Then, it is neutralized in 10%-30% nitric acid or sulfuric acid at 20-70℃ to remove ash. Finally, at 10-60℃, a rectangular wave, a trapezoidal wave, or a sine wave with alternating positive and negative polarities is applied at 5-100 A / dm². 2 Electrolysis is performed for 10-300 seconds in an electrolyte of nitric acid or hydrochloric acid at a given current density. This is followed by anodic oxidation, typically using a sulfuric acid method with a sulfuric acid concentration of 5-30% and a current density of 1-15 A / dm³. 2 The oxidation temperature is 20-60℃, and the oxidation time is 5-250 seconds, to form 1-10 g / m³ 2 The oxide film. Electrolytic roughening and anodizing can be performed multiple times to form a multi-layered sand texture on one side of the aluminum substrate.

[0040] The multi-structured sand mesh control parameters described in this invention are as follows: average centerline roughness of the sand mesh is 0.2-0.6 μm; average diameter of internal micropores is 10-60 nm; and the weight of the oxide film formed by anodic oxidation is 1-10 g / dm². 2 Finally, a hydrophilic layer containing one or more non-polymer hydrophilic compounds is applied over the sand grains. The non-polymer hydrophilic compounds are sugar alcohols or chemically modified sugar alcohols, and are non-polymeric, with a dry weight of 0.001-0.1 g / m³. 2 .

[0041] The aluminum-containing substrate described in this invention can be used in fields such as offset printing plate manufacturing, and is mainly used in the manufacturing of environmentally friendly offset printing plates such as heat-sensitive plates that do not require treatment.

[0042] A treatment-free thermal plate precursor includes an aluminum-containing substrate and a thermally sensitive layer, characterized in that: the thermally sensitive layer includes a hydrophilic thermally sensitive resin, a crosslinkable prepolymer, a thermal initiator, and an infrared absorber; the aluminum-containing substrate is the aluminum-containing substrate described in this invention, with the side coated with the non-polymer hydrophilic layer being the front side; the thermally sensitive layer is located on the front side of the aluminum-containing substrate.

[0043] Process-free thermal imaging requires a thermally sensitive layer containing a hydrophilic thermally sensitive resin. This resin is typically a polymer with functional groups. Besides film-forming properties to ensure the coating adheres to the carrier after drying, this resin must also possess specific functions such as hydrophilicity, thermal sensitivity, abrasion resistance, and solvent resistance. Following chemical theories and principles, based on the resin's hydrophilicity, hydrophilic groups such as carboxyl, sulfonic acid, phosphate, hydroxyl, and ether bonds can be incorporated into the resin structure. For the resin's thermal sensitivity, thermally crosslinking or thermally decomposable groups can be added. Alternatively, thermal sensitivity can be achieved through physical properties, such as utilizing the size effect or tunneling effect of micro / nanomaterials. The most typical example is utilizing the rapid decrease in the melting point of micro / nanomaterials, employing laser scanning to melt and image them.

[0044] The hydrophilic thermosensitive resin of the present invention is a polyolefin resin containing a comonomer with polyalkoxy side chains, a comonomer with epoxy side groups, and a comonomer with urethane amide side groups.

[0045] The hydrophilic thermosensitive resin of this invention achieves its hydrophilicity through polyalkoxy branching, which is achieved by copolymerization using comonomers containing polyalkoxy branching. Comonomers containing polyalkoxy branching include nonionic monomers such as polyethylene glycol methyl ether acrylate, polypropylene glycol methyl ether acrylate, polyethylene glycol methyl ether methacrylate, and polypropylene glycol methyl ether methacrylate; they also include comonomers containing polyalkoxy anionic branching. The core of these monomers is a molecule possessing both polymerizable active sites (such as carbon-carbon double bonds, epoxy groups, etc.) and polyalkoxy chains such as polyethylene oxide (PEO) / polypropylene oxide (PPO), with the polyalkoxy chain terminal being an alkoxy anion (-O). - M + M + (Cat), such as acrylic acid / methacrylic acid polyalkoxy anionic comonomers, which are generated by reacting polyether alcohols with acrylic acid / methacrylic acid esters and then treating with an alkali to produce anionic compounds. The double bonds can be free radical polymerized, such as potassium polyoxyethylene methacrylate (PEO-MA-K). + ), polyoxyethylene methacrylate sulfonate (PEO-MA-SO3) + ), Sodium polyoxypropylene ether acrylate (PPO-AA-Na) + ), polyoxyethylene methacrylate-polyoxypropylene ether ammonium salt (PEO-PPO-MA-NH4) + This also includes allyl polyalkoxy anionic comonomers, such as sodium allyl polyoxyethylene ether (APEO-Na). + ), allyl polyoxypropylene ether potassium salt (APPO-K) +It also includes epoxy-based polyalkoxy anionic copolymer monomers, whose molecules contain epoxy groups and can undergo ring-opening polymerization. The terminal anions of the polyether chains have both initiation and crosslinking effects, making them suitable for preparing crosslinked polyether-ionic copolymers, such as polyoxyethylene ether glycidyl ether lithium salt (PEO-GE-Li). + ), polyoxypropylene ether glycidyl ether cesium salt (PPO-GPE-Cs) + It also includes vinylpyridine-based polyalkoxy anionic comonomers, containing a vinylpyridine ring, which can ionicly bond with polyether anions to form copolymers with both coordination ability and ionic properties, such as 4-vinylpyridine polyoxyethylene ether complexes (4-VP-PEO-O). - Na + The hydrophilic thermosensitive resin of the present invention contains polyalkoxy-branched comonomers such as polyethylene glycol monomethyl ether methacrylate (CAS: 26915-72-0) or 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate (CAS: 184719-88-8).

[0046] The hydrophilic thermosensitive resin of this invention contains a comonomer with epoxy side groups. These epoxy side groups enable thermosensitive cross-linking imaging and can cross-link with sugar alcohols or oligosaccharides, or chemically modified sugar alcohols or oligosaccharides, on the surface of aluminum-containing substrates under laser thermal action. This improves the bonding strength of the thermosensitive layer in the imaging area and enhances the printing durability of UV inks on the printing plate. Comonomers containing epoxy side groups are a type of special bifunctional monomer. Their molecular structure simultaneously contains acrylate double bonds (capable of free radical polymerization) and epoxy groups (capable of ring-opening addition and cross-linking reactions), possessing both polymerization activity and functional modification capabilities. Examples of comonomers containing epoxy side groups include glycidyl methacrylate (GMA), glycidyl acrylate, 3,4-epoxycyclohexyl methacrylate, epoxy-based polyethylene glycol acrylate, etc. The hydrophilic thermosensitive resin of this invention contains 3,4-epoxycyclohexyl methacrylate or epoxy-based polyethylene glycol acrylate as its comonomer with epoxy side groups. 3,4-epoxycyclohexyl methacrylate has epoxy bonds on its cyclohexyl groups. It exhibits high epoxy activity, which can improve the dot reproduction quality of the thermal imaging plate. Simultaneously, it possesses good rigidity, imparting good abrasion resistance to the film layer. Epoxy-based polyethylene glycol acrylate has epoxy bonds with long-chain end groups, which helps improve the winding properties of the wound film layer. Furthermore, the long polyether chains possess flexibility and hydrophilicity; after polymerization, they can improve the toughness and hydrophilicity of the film layer, thus contributing to improved abrasion resistance and in-machine development capability of the plate.

[0047] The hydrophilic thermosensitive resin of this invention also contains a carbamate amide side-group comonomer, the main function of which is to improve the plate material's resistance to UV ink and solvents in UV ink printing wash water. UV ink contains acrylic reactive monomers, and UV ink printing wash water also contains solvent oil, which easily corrodes the imaging layer. The corrosion of acrylic reactive monomers can be resisted by improving the film layer's resistance to solvent corrosion. The carbamate amide side-group comonomer is an excellent chemically resistant comonomer containing strong polar hydrogen bonds. It is an amide monomer containing carbamate groups (-O-CO-NH-) and amide groups (-CO-NH-). Its core characteristic is that it simultaneously possesses two functional groups within the molecule and contains polymerizable active carbon-carbon double bonds, such as 4-[[2-(2-methylprop-2-enoyloxy)ethyl]carbamate]benzamide, with a methacrylic acid double bond at one end of the molecule, a carbamate bond in the middle, and a benzamide group at the end. The active double bond can participate in free radical polymerization, and the urethane and benzamide bonds provide hydrogen bonding, improving the polymer's solvent resistance and mechanical properties. Allyl urethane amide monomers, with allyl double bonds as polymerization sites, exhibit mild reactivity. The -O-CO-NH- linking to the caprolactam ring-opening amide structure combines flexibility and rigidity. The lactam ring of the amide group can be further crosslinked after ring opening. It contains aromatic amide groups, resulting in greater rigidity and combining abrasion resistance and UV ink erosion resistance. The hydrophilic thermosensitive resin of this invention contains urethane amide side-group comonomers of 4-[[2-(methacryloyloxy)ethyl]carbamoylamino]benzamide or 4-[(allyloxycarbonyl)amino]benzamide (English name: 4-[(prop-2-en-1-yloxy)carbonyl]aminobenzamide) or mixtures thereof.

[0048] The hydrophilic thermosensitive resin described in this invention is synthesized using free radical polymerization, which can be homogeneous or heterogeneous, such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion copolymerization. The copolymerization product can be random copolymer or block copolymer. The polymerization initiators include thermally decomposable initiators, redox initiators, and photoinitiators. Thermally decomposable initiators include azo compounds (such as azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, etc.), peroxides (such as di-tert-butyl peroxide, benzoyl peroxide, persulfates such as potassium persulfate, ammonium persulfate, lauroyl peroxide, etc.), redox initiators (such as persulfate-sulfite (KPS-Na2SO3), persulfate-ferrous salt (KPS-FeSO4), persulfate-alcohol / amine (KPS-ethanol / triethanolamine), benzoyl peroxide-tert-amine (BPO-N,N-dimethylaniline), di-tert-butyl peroxide-alkylaluminum (DTBP-Al(C2H5)3), and photoinitiators such as benzoin methyl ether (MMF), α-hydroxy ketone (1173), benzophenone dimethyl ketal, benzophenone (BP) + triethanolamine, thioxanone + amine, etc.). Emulsion polymerization is the preferred copolymerization method. The reaction solvents that can be used include water, alcohols, ketones, esters, ethers, or mixtures thereof. The copolymerization reaction temperature is preferably 40-100℃, and optimally 60-90℃. The hydrophilic thermosensitive resin in the imaging layer of this invention accounts for 45-80% of the total solids of the composition by weight.

[0049] The crosslinkable prepolymer in the thermosensitive layer is described below.

[0050] The crosslinkable prepolymer in the thermosensitive layer of this invention can be a monomer capable of free radical polymerization or a monomer capable of cationic polymerization, etc. Monomers capable of free radical polymerization are generally acrylic monomers containing double bonds, while monomers capable of cationic polymerization are generally monomers containing epoxy groups. The crosslinkable prepolymer in the thermosensitive layer of this invention is a multifunctional acrylic monomer, a multifunctional polyurethane acrylic monomer, or a multifunctional silicone-containing acrylate, or a mixture thereof. Here, multifunctionality means that it contains multiple double bonds. Multifunctional acrylic monomers include 1,6-hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, trimethylolpropane triacrylate, hydroxypropyl glycerol triacrylate, hydroxyethyl trimethylolpropane triacrylate, polyethylene glycol dimethacrylate, dipentaerythritol hexaacrylate, etc.; multifunctional polyurethane acrylic monomers are products of the condensation of isocyanates and multifunctional acrylates, such as products of the condensation of isocyanates with hydroxyethyl acrylates and pentaerythritol triacrylates; or products of the condensation of isocyanates containing double bonds, such as methacryloyloxyisocyanates, and polyhydroxy compounds such as pentaerythritol; multifunctional silicone acrylates include bis(methacryloyloxypropyl)tetramethyldisiloxane, pentaerythritol triacrylate-isocyanate silane adducts, cage-like silsesquioxanes, etc. The crosslinkable prepolymer in the imaging layer of this invention can improve the crosslinking ability of the plate, improve the imaging performance of the plate, and enhance the adaptability of UV ink printing. It accounts for 10-40% of the total solids of the composition by weight percentage.

[0051] The thermal initiator in the thermistor layer is described below.

[0052] The thermal initiator in the heat-sensitive layer of the printing plate described in this invention is a substance that releases active ingredients under thermal action, initiating the polymerization or cross-linking of the active components in the heat-sensitive layer. There are many types of thermal initiators, which will not be listed here. The thermal initiator described in this invention is selected from iodonium salts, specifically those containing diaryliodonium cations (Ar₂I₃). +Organic iodides composed of inorganic / organic anions are high-performance cationic photoinitiators. Iodonium salts are thermally stable at room temperature, but undergo thermal decomposition only when heated to a specific temperature. Under heat, iodonium salts undergo both homolytic and heterolytic cleavage. Homolytic cleavage of the iodonium salt generates free radicals, which initiate free radical polymerization of double bonds in the thermosensitive layer. Heterolytic cleavage of the iodonium salt generates cations, which initiate cationic polymerization of epoxy bonds in the thermosensitive layer. Therefore, the treatment-free thermosensitive plate manufactured using the precursor of this 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 examples of onion salts include: diphenyliodonium chloride, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, and [4-[(2-hydroxytetradecyl-oxy]phenyl]phenyliodonium hexafluoroantimonate. The initiator used in this application is bis(4-tert-butylphenyl)iodonium tetraphenylborate (CAS: 131725-16-1, code in the examples: IB). The thermal initiator described in this invention is selected from iodonium salts, with a thermal decomposition temperature of 150-200°C, and the thermal initiator accounts for 5-10% of the total solid weight of the thermosensitive layer.

[0053] The infrared absorber in the thermosensitive layer is described below.

[0054] The infrared absorber contained in the thermosensitive layer of this invention primarily functions as an energy absorber, capable of absorbing light and heat energy in the infrared band. The infrared absorber absorbs the heat of the infrared laser, transferring the laser energy to the thermal initiator. Under the influence of heat, the initiator undergoes decomposition, generating active groups that cause the hydrophilic thermosensitive resin and crosslinkable prepolymer to undergo three-dimensional network polymerization, achieving infrared laser thermosensitive imaging. The maximum absorption peak wavelength range of the infrared absorber is 750-1100 nm, and can be selected from carbon black, azo dyes, triarylamine dyes, indolon dyes, oxacyanine dyes, anthocyanin dyes, phthalocyanine dyes, polythiophene dyes, pyrazoline azo dyes, oxazine dyes, naphthoquinone dyes, anthraquinone dyes, quinone imine dyes, methylene dyes, porphyrin dyes, etc. To improve plate contrast and facilitate visual inspection of printing plate defects by prepress operators, and because modern highly intelligent printing presses require positioning crosshairs at the four corners of the plate, automatic image recognition software and devices are used to automatically locate and identify these crosshairs, achieving automated intelligent plate mounting. Therefore, high contrast between the image and text is necessary for this automated intelligent plate mounting. Infrared absorbers with color-changing functions can be used, and high-contrast images are achieved through laser fragmentation. The infrared absorber in the imaging layer of this invention is preferably a cyanine dye with a wavelength of 750-850 nm. The infrared absorber in the imaging layer of this invention accounts for 1-5% of the total solid content of the constituent components by weight.

[0055] The heat-sensitive plate precursor described in this invention may have a protective layer optionally applied to its imaging layer to provide oxygen barrier and protection. The protective layer can be a water-soluble polymer compound with good crystallinity, such as polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropyl cellulose, gelatin, gum arabic, polyacrylic acid, etc. While the protective layer provides oxygen barrier and protection, it increases the difficulty of in-machine development. Therefore, it is not recommended to use a protective layer unless an additional protective layer is applied to the plate material in harsh environments such as high temperature or easy abrasion to prevent the imaging layer from being oxidized, contaminated, or scratched by the external environment.

[0056] When manufacturing a treatmentless thermal plate using the treatmentless thermal plate precursor of the present invention, other necessary additives may be added, such as solvents, room-temperature thermal polymerization inhibitors, surfactants, coating colorants, etc. Solvents are mainly used to formulate the thermally sensitive composition into a thermally sensitive coating photosensitive liquid, including: alcohols, ketones, esters, ethers, amides, aromatic solvents, as well as vinyl dichloride, tetrahydrofuran, etc. Solvents can be used in pure or mixed forms; room-temperature thermal polymerization inhibitors are used to prevent polymerization of the plate at room temperature and improve the room-temperature stability of the plate. Thermal polymerization inhibitors include: hydroquinone, nitroxide free radical piperidinol, p-methoxyphenol, di-tert-butyl-p-cresol, pyrogallol, tert-butylcatechol, benzoquinone, 4,4'-thiobis-(3-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-16-tert-butylphenol), and cerium salts of N-nitrosophenylhydroxylamine, etc. Adding layer colorants increases the image density after thermal plate making, facilitating visual inspection or measurement of plate properties using image analysis and measurement equipment. These include: Methyl violet, ethyl violet, crystal violet, crystal inner violet, Victoria blue, oil green, oil blue, oil yellow, rhodamine B, methyl violet, malachite green, methylene blue, triazine, etc., can also be added. Coloring is achieved by Lewis acid reactions, such as the decomposition of iodonium salts to produce cations. Surfactants can be added to the coating, including nonionic surfactants, amphoteric surfactants, silicone surfactants, fluorinated surfactants, etc., such as betaine derivatives, glyceryl stearate derivatives, palm oil sorbate derivatives, polysiloxanes, and polyfluoroalkyl ethers.

[0057] The process-free thermal plates prepared using the process-free thermal plate precursor of the present invention are typically coated using techniques known in the art (such as doctor blade coating, roller coating, cast coating, etc.).

[0058] The process-free thermal plate manufactured using the process-free thermal plate precursor of the present invention is scanned and exposed using a thermal CTP plate-making machine, and then rinsed and developed with water or directly mounted on a printing press for development and printing with printing press dampening solution.

[0059] The present invention will now be described in detail with reference to specific embodiments. It should be noted that these embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments based on the above description of the present invention.

[0060] The following are examples of the synthesis of the present invention, but the present invention is not limited to the following examples.

[0061] The main raw materials can be obtained from the following companies: Xylitol, sorbitol, maltitol: from Merck Chemicals; xylooligosaccharides from Shandong Pingju Biotechnology Co., Ltd.; ethyl isocyanate acrylate (AOI, CAS: 13641-96-8), ethyl isocyanate methacrylate (CAS: 30674-80-7, code MOI) from Showa Denko Corporation, Japan; methylimidazole, triethylenediamine, sodium hydroxide, epichlorohydrin, glycidol, azobisisobutyronitrile from Bailingwei Technology; isopropanol from Shanghai LianCarbon Chemicals; polyethylene glycol monomethyl ether methacrylate (CAS: 26915-72-0) from Merck Chemicals; 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate (CAS: 184719-88-8) from ADEKA, Japan; glycidyl methacrylate, epoxy polyethylene glycol acrylate from Mitsubishi Rayon; 4- [[2-(methacryloyloxy)ethyl]carbamoylamino]benzamide and 4-[(prop-2-en-1-yloxy)carbonyl]aminobenzamide are from the Research Institute of China Lucky Group Co., Ltd.; 3,4-epoxycyclohexyl methacrylate is from Mitsubishi Rayon, Japan.

[0062] Part 1: Examples of Chemically Modified Sugar Alcohol Synthesis I. Examples of chemically modified sugar alcohols that form intramolecular phosphate groups: 1. Add 152g xylitol and 245g phosphoric acid to a 1000ml four-necked flask equipped with temperature-controlled heating, strong mechanical stirring, reflux condenser and nitrogen protection device. Stir at 60℃ for 30 minutes and cool down to stop the reaction to obtain the target product XP.

[0063] 2. Add 414g xylooligosaccharide and 490g phosphoric acid to a 1000ml four-necked flask equipped with temperature-controlled heating, strong mechanical stirring, reflux condenser and nitrogen protection device. Stir at 60℃ for 40 minutes and cool down to stop the reaction to obtain the target product XO-P.

[0064] 3. Add 182g of sorbitol and 490g of phosphoric acid to a 1000ml four-necked flask equipped with temperature-controlled heating, strong mechanical stirring, reflux condenser and nitrogen protection device. Stir at 90℃ for 60 minutes and cool down to stop the reaction to obtain the target product SP.

[0065] 4. Add 342g of maltitol and 588g of phosphoric acid to a 1000ml four-necked flask equipped with temperature-controlled heating, strong mechanical stirring, reflux condenser and nitrogen protection device. Stir at 80℃ for 20 minutes, then cool to stop the reaction and obtain the target product MP.

[0066] II. Examples of chemical modification of sugar alcohols to form intramolecular double bonds: 1. Add 152g xylitol, 154g methacrylic anhydride, 1g methylimidazole, and 0.1g nitric oxide free radical piperidinol to a 1000ml four-necked flask equipped with temperature-controlled heating, strong mechanical stirring, reflux condensation and nitrogen protection devices. Stir at 80℃ for 120 minutes and cool to stop the reaction to obtain the target product XD.

[0067] 2. Add 414g xylooligosaccharide, 141g ethyl isocyanate acrylate (AOI), 1g triethylenediamine, and 0.1g nitric oxide free radical piperidinol to a 1000ml four-necked flask equipped with temperature-controlled heating, strong mechanical stirring, reflux condensation, and nitrogen protection. Stir at 60℃ for 30 minutes, then cool to stop the reaction to obtain the target product XO-D.

[0068] 3. Add 182g sorbitol, 252g acrylic anhydride, 2g methylimidazole, and 0.2g nitric oxide free radical piperidine alcohol to a 1000ml four-necked flask equipped with temperature-controlled heating, strong mechanical stirring, reflux condensation and nitrogen protection devices. Stir at 60℃ for 30 minutes, cool down to stop the reaction, and obtain the target product SD.

[0069] 4. Add 342g maltitol, 310g isocyanate methacrylate (MOI), 2g triethylenediamine, and 0.2g nitric oxide free radical piperidine alcohol to a 1000ml four-necked flask equipped with temperature-controlled heating, strong mechanical stirring, reflux condensation and nitrogen protection device. Stir at 80℃ for 60 minutes, then cool to stop the reaction to obtain the target product MD.

[0070] III. Chemical modification of sugar alcohols, examples of intramolecular epoxide bond / group synthesis: 1. In a 2000 ml four-necked flask equipped with a temperature-controlled heating system, a powerful mechanical stirrer, a reflux condenser, and a nitrogen protection device, add 152 g xylitol, 200 g isopropanol, 300 g deionized water, and 100 g sodium hydroxide. Slowly add 308 g epichlorohydrin dropwise. Stir at 50 °C for 5 hours. Cool down to stop the reaction, neutralize the pH to neutral, filter out the salt, and remove residual epichlorohydrin, isopropanol, and water under reduced pressure to obtain the target product XE.

[0071] 2. In a 2000 ml four-necked flask equipped with temperature-controlled heating, strong mechanical stirring, reflux condenser, and nitrogen protection, add 414 g xylooligosaccharide, 300 g isopropanol, 450 g deionized water, and 0.5 g sodium hydroxide. Slowly add 370 g glycidol. Stir at 50 °C for 5 hours. Cool down to stop the reaction, neutralize the pH to neutral, filter out the salt, and remove glycidol, isopropanol, and water under reduced pressure to obtain the target product XO-E.

[0072] 3. In a 2000 ml four-necked flask equipped with a temperature-controlled heating system, a powerful mechanical stirrer, a reflux condenser, and a nitrogen protection device, add 182 g of sorbitol, 200 g of isopropanol, 300 g of deionized water, and 100 g of sodium hydroxide. Slowly add 282 g of glycidyl methacrylate. Stir at 50 °C for 5 hours, cool to stop the reaction, neutralize the pH to neutral, filter the salt, and remove glycidyl methacrylate, isopropanol, and water under reduced pressure to obtain the target product SE.

[0073] 4. In a 2000 ml four-necked flask equipped with temperature-controlled heating, strong mechanical stirring, reflux condenser, and nitrogen protection, add 342 g of maltitol, 400 g of isopropanol, 600 g of deionized water, and 150 g of sodium hydroxide. Slowly add 460 g of epichlorohydrin. Stir at 50 °C for 5 hours. Cool down to stop the reaction, neutralize the pH to neutral, filter out the salt, and remove residual epichlorohydrin, isopropanol, and water under reduced pressure to obtain the target product ME.

[0074] Part Two: Examples of Hydrophilic Thermosensitive Numerical Synthesis Hydrophilic thermosensitive resin A1: Add 100g deionized water, 15g polyethylene glycol monomethyl ether methacrylate, 15g 3,4-epoxycyclohexyl methacrylate, 70g 4-[[2-(methacryloyloxy)ethyl]carbamoylamino]benzamide, and 1g azobisisobutyronitrile to a 500ml beaker, and emulsify under high-speed shear at 800 rpm to prepare a pre-emulsion.

[0075] Add 200g of deionized water to a 500ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, reflux condensation, and nitrogen protection. Heat to 80℃ and begin adding the above pre-emulsion dropwise over 60 minutes. Then react at 80℃ for 8 hours. Add 0.5g of azobisisobutyronitrile and continue reacting for another 8 hours. Finally, cool down to stop the reaction. Use the original reaction solution directly according to its solid content.

[0076] Hydrophilic thermosensitive resin A2: Add 100g deionized water, 15g 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate, 15g epoxy-based polyethylene glycol acrylate, 70g 4-[(prop-2-en-1-yloxy)carbonyl]aminobenzamide, and 1g azobisisobutyronitrile to a 500ml beaker, and emulsify under high-speed shear at 800 rpm to prepare a pre-emulsion.

[0077] Add 200g of deionized water to a 500ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, reflux condensation, and nitrogen protection. Heat to 80℃ and begin adding the above pre-emulsion dropwise over 60 minutes. Then react at 80℃ for 8 hours. Add 0.5g of azobisisobutyronitrile and continue reacting for another 8 hours. Cool down to end the reaction. Use the original reaction solution directly according to its solid content.

[0078] Hydrophilic thermosensitive resin A3: Add 100g deionized water, 15g polyethylene glycol monomethyl ether methacrylate, 15g epoxy polyethylene glycol acrylate, 70g 4-[(prop-2-en-1-yloxy)carbonyl]aminobenzamide, and 1g azobisisobutyronitrile to a 500ml beaker and emulsify under high-speed shear at 800 rpm to prepare a pre-emulsion.

[0079] Add 200g of deionized water to a 500ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, reflux condensation, and nitrogen protection. Heat to 80℃ and begin adding the above pre-emulsion dropwise over 60 minutes. Then react at 80℃ for 8 hours. Add 0.5g of azobisisobutyronitrile and continue reacting for another 8 hours. Cool down to end the reaction. Use the original reaction solution directly according to its solid content.

[0080] Hydrophilic thermosensitive resin A4: Add 100g of deionized water, 15g of 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate, 15g of 3,4-epoxycyclohexyl methacrylate, 70g of 4-[(prop-2-en-1-yloxy)carbonyl]aminobenzamide, and 1g of azobisisobutyronitrile to a 500ml beaker, and emulsify under high-speed shear at 800 rpm to prepare a pre-emulsion.

[0081] Add 200g of deionized water to a 500ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, reflux condensation, and nitrogen protection. Heat to 80℃ and begin adding the above pre-emulsion dropwise over 60 minutes. Then react at 80℃ for 8 hours. Add 0.5g of azobisisobutyronitrile and continue reacting for another 8 hours. Cool down to end the reaction. Use the original reaction solution directly according to its solid content.

[0082] Hydrophilic thermosensitive resin A5: Add 100g of deionized water, 15g of 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate, 15g of epoxy-based polyethylene glycol acrylate, 70g of 4-[[2-(methacryloyloxy)ethyl]carbamoylamino]benzamide, and 1g of azobisisobutyronitrile to a 500ml beaker, and emulsify under high-speed shear at 800 rpm to prepare a pre-emulsion.

[0083] Add 200g of deionized water to a 500ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, reflux condensation, and nitrogen protection. Heat to 80℃ and begin adding the above pre-emulsion dropwise over 60 minutes. Then react at 80℃ for 8 hours. Add 0.5g of azobisisobutyronitrile and continue reacting for another 8 hours. Cool down to end the reaction. Use the original reaction solution directly according to its solid content.

[0084] Hydrophilic thermosensitive resin A6: Add 100g deionized water, 10g polyethylene glycol monomethyl ether methacrylate, 5g 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate, 15g 3,4-epoxycyclohexyl methacrylate, 70g 4-[[2-(methacryloyloxy)ethyl]carbamoylamino]benzamide, and 1g azobisisobutyronitrile to a 500ml beaker, and emulsify under high-speed shear at 800 rpm to prepare a pre-emulsion.

[0085] Add 200g of deionized water to a 500ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, reflux condensation, and nitrogen protection. Heat to 80℃ and begin adding the above pre-emulsion dropwise over 60 minutes. Then react at 80℃ for 8 hours. Add 0.5g of azobisisobutyronitrile and continue reacting for another 8 hours. Cool down to end the reaction. Use the original reaction solution directly according to its solid content.

[0086] Hydrophilic thermosensitive resin A7: Add 100g deionized water, 15g polyethylene glycol monomethyl ether methacrylate, 10g 3,4-epoxycyclohexyl methacrylate, 5g epoxy polyethylene glycol acrylate, 70g 4-[[2-(methacryloyloxy)ethyl]carbamoylamino]benzamide, and 1g azobisisobutyronitrile to a 500ml beaker, and emulsify under high-speed shear at 800 rpm to prepare a pre-emulsion.

[0087] Add 200g of deionized water to a 500ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, reflux condensation, and nitrogen protection. Heat to 80℃ and begin adding the above pre-emulsion dropwise over 60 minutes. Then react at 80℃ for 8 hours. Add 0.5g of azobisisobutyronitrile and continue reacting for another 8 hours. Cool down to end the reaction. Use the original reaction solution directly according to its solid content.

[0088] Hydrophilic thermosensitive resin A8: Add 100g deionized water, 15g 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate, 15g epoxy polyethylene glycol acrylate, 35g 4-[[2-(methacryloyloxy)ethyl]carbamoylamino]benzamide, 35g 4-[(prop-2-en-1-yloxy)carbonyl]aminobenzamide, and 1g azobisisobutyronitrile to a 500ml beaker, and emulsify under high-speed shear at 800 rpm to prepare a pre-emulsion.

[0089] Add 200g of deionized water to a 500ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, reflux condensation, and nitrogen protection. Heat to 80℃ and begin adding the above pre-emulsion dropwise over 60 minutes. Then react at 80℃ for 8 hours. Add 0.5g of azobisisobutyronitrile and continue reacting for another 8 hours. Cool down to end the reaction. Use the original reaction solution directly according to its solid content.

[0090] Hydrophilic thermosensitive resin A9: Add 100g deionized water, 10g polyethylene glycol monomethyl ether methacrylate, 5g 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate, 10g 3,4-epoxycyclohexyl methacrylate, 5g epoxy polyethylene glycol acrylate, 35g 4-[[2-(methacryloyloxy)ethyl]carbamoylamino]benzamide, 35g 4-[(prop-2-en-1-yloxy)carbonyl]aminobenzamide, and 1g azobisisobutyronitrile to a 500ml beaker and emulsify under high-speed shear at 800 rpm to prepare a pre-emulsion.

[0091] Add 200g of deionized water to a 500ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, reflux condensation, and nitrogen protection. Heat to 80℃ and begin adding the above pre-emulsion dropwise over 60 minutes. Then react at 80℃ for 8 hours. Add 0.5g of azobisisobutyronitrile and continue reacting for another 8 hours. Cool down to end the reaction. Use the original reaction solution directly according to its solid content.

[0092] Comparative example hydrophilic layer: The aluminum substrate is covered with a hydrophilic polymer, which is polyacrylic acid (PAA), the AC-10S product from TOAGOSEI.

[0093] Synthesis of comparative hydrophilic thermosensitive resin: According to Kodak patent US 2005-8-3 11 / 196, Kodak polymer K was synthesized. The polymer contains hydrophilic polyether groups but does not contain epoxy groups. The polymer structure is as follows:

[0094] Basic procedure: Add 75g of deionized water and 250g of n-propanol to a 1000ml four-necked flask equipped with temperature-controlled heating, mechanical stirring, reflux condenser, and nitrogen protection. At 80℃, add 20g (20 wt%) St (styrene), 70g (70 wt%) AN (acrylonitrile), 10g (10 wt%) PEGMA (polyethoxymethyl methacrylate), and AIBN (azobisisobutyronitrile) dropwise over 0.5 hours. After reacting for another 7.5 hours, add 0.3g of AIBN (azobisisobutyronitrile) and continue reacting for another 12 hours. Example

[0095] Preparation of aluminum-containing substrates: A1050 rolled aluminum plate with a purity of 99.5% and a thickness of 0.3 mm was etched in a 4.5% sodium hydroxide aqueous solution at 75°C for 25 seconds. After rinsing with running water, it was immediately neutralized with a 0.9% nitric acid aqueous solution at 40°C. Then, it was etched in a 0.75% hydrochloric acid aqueous solution at 40°C with a sinusoidal alternating current of 42 A / dm². 2 The surface was roughened by electrolysis at a current density of 12.4 seconds, followed by neutralization at 40°C with a 4% sodium hydroxide aqueous solution at 40°C for 13 seconds, and then washed with water. Finally, it was roughened at 30°C with a 17% sulfuric acid aqueous solution at 10.6 A / dm³. 2 The current density was set, anodizing was performed for 18.6 seconds, followed by water washing, and then a 0.1% xylitol aqueous solution was applied with a coating amount of 0.001 g / m². 2 After drying, the resulting substrate has an average centerline thickness of 0.2 μm, an average internal micropore diameter of 10 nm, and an oxide film weight of 1.0 g / dm².2 The dry weight of xylitol, a non-polymer hydrophilic compound, was 0.001 g / m³. 2 .

[0096] Imaging layer material: Infrared absorbers that meet the requirements of this invention can be obtained from Dye Chemical or Merck. In the example, the infrared absorber IR820 is Merck's Sigma-Adrich 543365, chemical name: 2-[2-[2-chloro-3-[[1,3-dihydro-1,1-dimethyl-3-(4-sulfonate butyl)-2H-benzo[e]indol-2-ethylene]-1-cyclohexen-1-yl]-vinyl]-1,1-dimethyl-3-(4-sulfonate butyl)-1H -Benzo[e]indoline hydroxide inner salt, abbreviated as IR in Table 2; Multifunctional acrylates: SR is pentaerythritol pentaacrylate, from Sartoma (SR399); Multifunctional polyurethane acrylates: PU is polyurethane acrylate, a condensation polymer of Covestro Desmodurn 100 and hydroxyethyl acrylate and pentaerythritol triacrylate, obtained from Shenyang Chemical Research Institute (product number PU100); Trifunctional silicone-modified acrylate LC (trade number LuCure 8852) is from Guangzhou Runao Chemical Materials Co., Ltd.; Thermal initiator bis(4-tert-butylphenyl)iodonium tetraphenylborate (code: IB), surfactant BYK306 is from BYK Company; 1-methoxy-2-propanol is from Union Carbide Chemicals; Polyvinyl alcohol PVA-205 is from Kuraray Co., Ltd. of Japan; Polyvinylpyrrolidone PVPK30 is from BASF of Germany; Emulsifier OP-10 is from Hamm of Germany.

[0097] Imaging layer materials (specific materials and quantities are shown in Table 2): Hydrophilic thermosensitive resin 80 Crosslinkable prepolymer 14 Thermal initiator 5 Infrared absorber (IR820) 1 The above raw materials were mixed with 0.5g of surfactant BYK306 and 700g of 1-methoxy-2-propanol to prepare an imaging layer coating solution. This coating solution was then applied to the hydrophilically treated substrate by extrusion and drying at 100°C for 60 seconds. A solution of 15 mg / dm³ was obtained. 2 The dry weight of the coating.

[0098] Alternatively, a protective layer can be extruded and coated onto the imaging layer, followed by drying at 110°C for 60 seconds. This yields a solution of 10 mg / dm³. 2 The dry weight of the coating.

[0099] Protective layer formulation: Polyvinyl alcohol (PVA-205) (Kuraray, Japan) 17g Polyvinylpyrrolidone (PVPK30) (BASF, Germany) 3g Emulsifier OP-10 (Häm, Germany) 0.45g 480g of deionized water Referring to the manufacturing method of Example 1, thermal plates of other examples and comparative examples were manufactured according to the following requirements.

[0100] 1. By changing the electrolytic roughening and anodizing parameters, the average centerline roughness of the sand mesh is obtained to be 0.2-0.6 μm, the average diameter of the micropores inside the sand mesh is 10-60 nm, and the weight of the oxide film formed by anodizing is 1-10 g / dm. 2 An aluminum plate base is formed, and then a hydrophilic layer is applied over the aluminum plate base with a dry weight of 0.001-0.1 g / m². 2 The parameters of the aluminum-containing substrate are shown in Table 1.

[0101] 2. Preparation of different thermal plates: Based on the data given in Table 2, the imaging layer formulation was modified to prepare thermal plates 2-22 and comparative examples 1-8. Only Example 1 had a protective layer coated; the other examples did not. The performance of the thermal plates of the examples and comparative examples is listed in Table 3 below.

[0102] Testing and analysis of printing plates: 1. Sensitivity Evaluation: Sensitivity is characterized by the laser energy value required for imaging. The plate is placed on a Kodak Allwinner thermal CTP plate-making machine at 5 mJ / cm². 2 The progressive amount is between 80-200 mJ / cm 2 Exposure was performed within the energy range, and the initial sensitivity of the plate was measured according to the Pantone LIVE color digital workflow (unit: mJ / cm). 2 Its performance is listed in Table 3 below.

[0103] 2. Dot Quality Evaluation: Dot quality is characterized by whether 1%-99% of the dots can be reproduced after laser imaging. For example, 1-99% means that 1% to 99% of the dots can be reproduced, which is the optimal value. 2-98% means that only 2-98% of the dots can be reproduced, and 1% and 99% of the dots cannot be reproduced, which is slightly worse. And so on. All the above plates were exposed on the Kodak Allwinner thermal CTP plate-making machine with the optimal sensitivity energy. According to the Pantone LIVE color digital workflow, the initial dot reproduction value of the image was measured. The performance is listed in Table 3 below.

[0104] 3. Evaluation of In-Machine Development Capability (DOP): The laser imaging printing plate was directly mounted on the Komori Lithrone G40 Advance (H-UV / LED-UV) printing press for in-machine development. The thermal plate was tested using TOYO INK FD K-HS series H-UV special ink, the dampening solution was Sakata UV dampening solution 2136 (WACHOI), the Japanese Fujikura Wizard UV blanket was used, the paper was Taiyo 200g coated paper, and the printing speed was 9,000 sheets / hour. The number of sheets of printed paper in which no ink transfer was observed in the non-imaged areas (unit: sheets) was used to characterize the in-machine development capability (DOP). Its performance is listed in Table 3 below.

[0105] 4. UV ink printing durability (UV-K) S Evaluation: The total number of normal prints (unit: 10,000 impressions) printed using the Komori Lithrone G40 advance (H-UV / LED-UV) printing press was tested using TOYO INK FD K-HS series H-UV special inks on thermal plates. The performance is listed in Table 3 below.

[0106] 6. Total Print Runs (UV-K) Index of the Dampening System of the Printing Press t Evaluation: The printing plates were used on a Komori Lithrone G40 Advance (H-UV / LED-UV) printing press, with TOYO INK FD K-HS series H-UV special inks and Sakata UV dampening solution 2136 (WACHOI). If the dampening system is contaminated, the printed matter will appear dirty. The total number of prints of qualified products that have been printed due to dampening contamination (contamination accumulates to a certain level and cannot be printed normally) was monitored (unit: 10,000 prints). Its performance is listed in Table 3 below.

[0107] 7. Environmental Pollution Assessment: Hydrophilic compounds on the aluminum-containing substrate will enter the dampening water system of the printing press during the printing process, forming industrial wastewater. This invention does not conduct verification tests and evaluations on the industrial wastewater generated during the use of the embodiments and comparative examples of this invention. It can be directly verified according to the "List of Toxic and Hazardous Water Pollutants (First Batch)" promulgated by the Ministry of Ecology and Environment of the People's Republic of China in 2019. Polyacrylic acid industrial wastewater is listed as a recalcitrant pollutant that is easily accumulated in the environment, has high concentrations of biological toxicity, and is difficult to degrade. Sugar alcohols such as xylitol and sorbitol are not listed and are non-toxic and easily biodegradable organic compounds. Therefore, the technology of this invention is more environmentally friendly.

[0108] The test results in Table 3 show that, compared with the comparative example of treatment-free printing plates, the thermal plate manufactured using the treatment-free thermal plate precursor of this invention can solve the problems of printing plate contamination of the printing press damping system and wastewater environmental pollution. The plate also exhibits excellent imaging performance, in-machine development capability, and UV ink printing durability. This is because the aluminum-containing substrate of this treatment-free thermal plate uses a non-polymer hydrophilic layer, which has better in-machine development capability than polymer hydrophilic layers, is less likely to contaminate the damping system, and generates more environmentally friendly industrial wastewater. The hydrophilic thermal resin in the thermal layer of the plate contains anti-solvent copolymer components and epoxy crosslinking groups, resulting in excellent in-machine development capability in non-imaging areas and laser-induced crosslinking between the imaging areas and the hydrophilic layer of the aluminum-containing substrate, significantly improving UV ink printing durability. This thermal plate can be directly printed and is a green and environmentally friendly thermal plate material.

[0109] Table 1 Parameters of Aluminum-containing Substrates

[0110] Note: H1 is a mixture of SP (50% by mass) and SD (50% by mass), and H2 is a mixture of xylitol (40% by mass), MD (30% by mass), and SE (30% by mass).

[0111] Table 2 Manufacturing parameters for the plates of the examples and comparative examples

[0112] Table 3 Application Performance Table of Printing Plates

[0113] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. It should be noted that for those skilled in the art and any person skilled in the art, any equivalent substitutions or changes made to the technical solution and inventive concept of the present invention without departing from the overall concept of the present invention, as well as any changes and improvements made, should also be considered within the scope of protection of the present invention.

Claims

1. An aluminum-containing substrate, characterized in that: The aluminum-containing substrate is obtained by roughening and anodizing an aluminum plate base, and then covering it with a hydrophilic layer containing one or more non-polymer hydrophilic compounds. The non-polymer hydrophilic compounds are sugar alcohols or oligosaccharides, or chemically modified sugar alcohols or oligosaccharides.

2. The aluminum-containing substrate according to claim 1, characterized in that: The aluminum substrate undergoes electrolytic roughening and anodizing to form a structural mesh. The average thickness of the centerline of the mesh is 0.2-0.6 μm, and the average diameter of the micropores inside the mesh is 10-60 nm. The oxide film formed by anodizing weighs 1-10 g / dm³. 2 The dry weight of the hydrophilic layer covering the sand grains is 0.001-0.1 g / m³. 2 ; The sugar alcohol is xylitol, sorbitol, or maltitol, and the oligosaccharide is xylooligosaccharide; Chemically modified sugar alcohols or oligosaccharides are those that, after chemical modification, contain at least a phosphate group, a double bond, or an epoxy group within their molecules.

3. The aluminum-containing substrate according to claim 1, characterized in that: The chemical modification methods for sugar alcohols or oligosaccharides are as follows: sugar alcohols or oligosaccharides react with phosphoric acid to form phosphate groups within the molecule; sugar alcohols or oligosaccharides react with acrylic anhydride or isocyanate acrylates to form double bonds within the molecule; sugar alcohols or oligosaccharides react with epichlorohydrin or glycidyl ester to form epoxy groups within the molecule.

4. The application of the aluminum-containing substrate according to any one of claims 1-3 in a heat-sensitive plate without treatment.

5. A preform for a heat-sensitive plate that requires no processing, comprising an aluminum-containing substrate and a heat-sensitive layer, characterized in that: The thermosensitive layer comprises a hydrophilic thermosensitive resin, a crosslinkable prepolymer, a thermal initiator, and an infrared absorber; the aluminum-containing substrate is the aluminum-containing substrate as described in any one of claims 1-3, and the side coated with the hydrophilic layer of the non-polymer hydrophilic compound is the front side; the thermosensitive layer is located on the front side of the aluminum-containing substrate.

6. The process-free thermal plate precursor according to claim 5, characterized in that: The thermosensitive layer, by weight percentage, comprises 45-80% hydrophilic thermosensitive resin, 10-40% crosslinkable prepolymer, 5-10% thermal initiator, and 1-5% infrared absorber.

7. The process-free thermal plate precursor according to claim 5, characterized in that: The hydrophilic thermosensitive resin is a polyolefin resin containing comonomers with polyalkoxy branches, comonomers with epoxy side groups, and comonomers with urethane amide side groups. A protective layer is also provided on the heat-sensitive layer.

8. The process-free thermal plate precursor according to claim 7, characterized in that: The hydrophilic thermosensitive resin contains polyalkoxy-branched comonomers of polyethylene glycol monomethyl ether methacrylate or 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate or mixtures thereof; the copolymer containing epoxy side groups is 3,4-epoxycyclohexyl methacrylate or epoxy polyethylene glycol acrylate or mixtures thereof; the comonomer containing carbamate side groups is 4-[[2-(methacryloyloxy)ethyl]carbamate]benzamide or 4-[(prop-2-en-1-yloxy)carbonyl]aminobenzamide or mixtures thereof; The crosslinkable prepolymer is a multifunctional acrylic monomer or a multifunctional polyurethane acrylic monomer or a multifunctional silicone acrylate, or a mixture thereof; The thermal initiator is iodonium salt, and the decomposition temperature is 150-220℃; The infrared absorber is a cyanine dye with an absorption peak at 750-850 nm.

9. A heat-sensitive plate that requires no processing, characterized in that: It is prepared from the heat-sensitive precursor without processing as described in any one of claims 5-8.

10. The application of the processing-free thermal plate according to claim 9, characterized in that: After being scanned and exposed using a thermal CTP plate-making machine, the thermal plate is rinsed and developed with water before being mounted on a printing press for printing, or it can be directly mounted on a printing press and developed and printed using the printing press's dampening solution.

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