An amphiphilic modified compound and its preparation method, an aqueous black film with excellent flexibility, a digital aqueous photosensitive resin plate and its preparation method

Abstract

This invention provides an amphiphilic modified compound and its preparation method, an aqueous black film with excellent flexibility, a digital aqueous photosensitive resin plate and its preparation method. The amphiphilic modified compound provided in this application simultaneously achieves amphiphilicity, high flexibility, and rigidity, controls the hygroscopicity in high humidity environments, and effectively blocks the diffusion of small molecule oxygen without affecting the imaging of the photosensitive resin layer.

Description

Technical Field

[0001] This invention belongs to the field of letterpress printing technology and relates to a water-washable resin plate capable of digital imaging. Specifically, it relates to an amphiphilic modified compound and its preparation method, a water-based black film with excellent flexibility, and a digital water-based photosensitive resin plate and its preparation method. Background Technology

[0002] Letterpress printing is a long-established printing method. Its principle is that the image area is significantly raised above the blank area. During printing, ink is applied to the image surface, and pressure is used to transfer the ink to the substrate. The letterpress plate (also called a resin plate) is the core component that determines the print quality. Current plate-making uses computer-to-plate (CTP) technology, which uses lasers to create a digital image on the plate surface, followed by exposure and development steps to create the letterpress plate.

[0003] Currently, mainstream letterpress developing methods still have significant shortcomings: Solvent-developed plates use organic solvents (such as tetrachloroethylene and n-butanol) as developers, forming images by dissolving the unexposed resin portions. While this technology is mature and offers high image resolution, organic solvents generally have drawbacks such as high volatility, high toxicity, and flammability / explosiveness. Alkaline-developed plates use dilute alkaline solutions (such as sodium carbonate solution). However, alkaline waste liquid still requires neutralization and is highly corrosive to the sidewalls of certain fine images, easily causing dot distortion and reduced edge sharpness, affecting print quality. Thermal developing technology does not require liquid developers, but the equipment is expensive and requires extremely high temperature and pressure control, resulting in uneven image depth and difficulty in removing plate residues, thus preventing its widespread adoption.

[0004] This invention relates to a novel letterpress printing plate and its preparation method, specifically designed for digital plate making, using water as the developing medium, and combining environmental friendliness with high imaging quality, to overcome the aforementioned shortcomings of existing technologies. It is primarily used for rotary letterpress printing, self-adhesive label printing, ticket printing, security printing, hot stamping, thermal molding, and varnishing, achieving high screen rulings of 175 lpi or higher.

[0005] The digital water-based resin plate making process involves different environments: low temperature and dryness in winter, and high temperature and high humidity in summer. Water-based black films may crack and become brittle if stored for a long time in low-temperature environments or when bent. In high-humidity environments, they are also prone to absorbing moisture. In addition, collisions or pressures may occur during the cutting, moving, and bending of the plate, leaving traces of external force on the plate surface, which affects the imaging quality of the plate.

[0006] Research has found that several foreign companies have done extensive work on digital resin plates. Technicians have focused their research on water-based black films primarily on scratch resistance, oxygen barrier properties, imaging, and transfer capabilities. However, improving the moisture resistance of water-based black films mainly relies on resin selection, with no other effective methods. Research on improving ink transfer performance largely involves adding small particles to enhance both ink transfer and abrasion resistance.

[0007] Patent US2006 / 00087291A1 discloses a process for manufacturing a digital water-washable resin plate. This patent improves three aspects—scratch resistance of the black film, inhibition of interlayer material transfer, and treatment of developing waste—by introducing a cross-linked structure or hydrophobic component into the thermal mask layer. While the patent mentions a water-insoluble design of the mask layer to prevent interlayer material transfer, it does not consider the plasticizing effect of water molecules on the film layer in high-humidity environments or during water washing and developing. Its formulation system does not effectively control water absorption, and there is still a risk of swelling and decreased adhesion after long-term storage under humid conditions or after water developing.

[0008] Patent WO2023026724A1 describes a photosensitive resin printing plate with excellent scratch resistance in its infrared sensing layer. The infrared sensing layer utilizes polyvinyl alcohol (PVA) with a saponification degree of 60–100 mol% and a polymerization degree of 300–3000 as the film-forming resin, further enhanced with carbon black containing carboxyl and / or sulfonyl groups. However, this technology uses only PVA as the main resin, making it prone to cracking when bent in low-temperature environments, affecting the engraving and reproduction of the image on the plate.

[0009] Patent CN113453910A describes a water-developable photosensitive resin printing plate. The printing plate is covered with a light-shielding layer containing carbon black and vinyl polymer in a mass ratio of 80 / 20 to 30 / 70. It uses an alcohol-soluble vinyl polymer with hydroxyl groups, combined with polyvinyl alcohol, water-based polyamide, etc. to form a water-based black film, which has good flexibility and resistance to low temperature and high humidity. However, the black film made with this technology has poor water solubility during plate making, and will form flocculent particles that float in water and easily stick to the brush surface, affecting the number of times the developing solution can be used and the life of the brush.

[0010] Patent JP2023139417A discloses a laser-ablated black film or related photosensitive resin composition. This patent document primarily focuses on improving the optical density (OD value) of the black film or enhancing its dispersion / dissolution rate in the developer. The disclosed formulations often employ a rigid resin structure (such as a specific proportion of aromatic polyurethane or high-Tg acrylic resin). In practical applications, when the printing plate is wound around a printing cylinder for laser engraving, the black film layer lacks sufficient flexible segments, preventing the release of internal stress and making it highly susceptible to microcracks. These cracks can lead to laser blocking failure and printing smudges, indicating a technical blind spot in its crack resistance under dynamic flexural conditions. Summary of the Invention

[0011] To address the aforementioned problems, this invention provides an amphiphilic modified compound and its preparation method, an aqueous black film with excellent flexibility, a digital aqueous photosensitive resin plate and its preparation method. The amphiphilic modified compound provided in this application simultaneously achieves amphiphilicity, high flexibility, and rigidity, controls hygroscopicity in high-humidity environments, and effectively blocks the diffusion of small molecule oxygen without affecting the imaging of the photosensitive resin layer.

[0012] The object of the present invention is achieved in the following manner: an amphiphilic modified compound, wherein the main chain of the amphiphilic modified compound contains at least two imide groups and at least two ether groups, and the terminal suspending hydroxyl groups or contains polyethylene glycol side chains.

[0013] The structural formula of the amphiphilic modified compound is:

[0014] (I) In formula (I), R1 is a suspended hydroxyl group or a polyethylene glycol side chain, R2 is a segment containing at least one ether group, and R3 is a segment containing an aromatic ring, a methyl group, or bisphenol A.

[0015] The preparation method of the amphiphilic modified compound adopts a two-step synthesis method. First, polyamic acid is synthesized, and then polyimide is obtained by imidization. Using a hydroxyl-containing or polyethylene glycol-structured compound as a hydrophilic source, an ether-based segment compound as a flexible chain, and an acid anhydride as a connecting bridge, the amphiphilic modified compound is finally obtained through low-temperature solution polycondensation and heated imidization.

[0016] An aqueous black film with excellent flexibility comprises (A) an amphiphilic modified compound, (B) an aqueous binder, (C) carbon black, (D) a modifier, and (E) a wetting agent; the amphiphilic modified compound is the amphiphilic modified compound of claim 1 or 2 or the amphiphilic modified compound prepared by the method of claim 3.

[0017] Aqueous black film is formed by coating with black film coating liquid and then drying; The black film coating liquid comprises the following raw materials in parts by weight: (A) 5-6 parts by weight of the amphiphilic modified compound; (B) 0.5-1 parts by weight of water-based adhesive; (C) 2-3 parts by weight of carbon black; (D) Modifier 1-1.5 parts by weight; (E) 0.5 parts by weight of wetting agent; (F) 88-91 parts by weight of solvent; the solvent is composed of water and ethanol; the weight ratio of water to ethanol is 3-5:1.

[0018] (B) The waterborne adhesive is at least one of polyvinyl alcohol, carboxyethyl cellulose, polyvinylpyrrolidone, esterified starch, dextrin, waterborne polyurethane, and hydroxypropyl methylcellulose; (C) Carbon black is a nanoparticle with a particle size range of 100-300 nm; (D) The modifier is at least one of the following: polymer modifier, small molecule anionic modifier, coupling modifier, surface oxidation modifier, and in-situ coating modifier; (E) The wetting agent is at least one of the following: acetylenic diol, organosilicon, phosphate ester, and polymer.

[0019] The thickness of the water-based black film is 2-5 μm.

[0020] The digital waterborne resin plate includes, from top to bottom, a protective film base (1), a waterborne black film (2), a photosensitive resin layer (3), an adhesive layer (4), and a support (5); wherein the waterborne black film is the aforementioned waterborne black film.

[0021] (1) The protective substrate is a matte PET substrate with a thickness between 100-125 μm; (2) The water-based black film is a black film layer that can be laser-etched at wavelengths of 1064nm and 830nm; (3) The photosensitive resin layer is a composite film layer with a thickness of 400-2000μm containing a photocrosslinkable waterborne resin, acrylate unsaturated monomers, plasticizers, photoinitiators, stabilizers and dyes; (4) The adhesive layer is an adhesive coating with a thickness of 20-40 μm; (5) The support is a PET sheet or metal sheet with a thickness of 250-300μm.

[0022] The method for preparing the digital hydrosensitive photosensitive resin plate, A water-based ablation black film coating solution is coated onto a protective substrate and dried to obtain a water-based ablation black film with a protective substrate. The adhesive coating liquid is applied to the support and dried to obtain a support with an adhesive layer; The photosensitive resin layer is applied to a support with an adhesive layer by extrusion or casting and then dried. A water-based ablation black film with a protective film base is then laminated to the other side of the photosensitive resin layer to obtain a digital water-based photosensitive resin plate.

[0023] Compared with the prior art, the amphiphilic modified compound provided in this application simultaneously achieves amphiphilicity, high flexibility, rigidity, control of hygroscopicity in high humidity environments, and effective blocking of the diffusion of small molecule oxygen without affecting the imaging of the photosensitive resin layer.

[0024] The aqueous black film uses the amphiphilic modified compound of this invention, which is beneficial for controlling the magnitude of the two interfacial forces between the protective film substrate and the aqueous black film, and between the aqueous black film and the photosensitive resin layer. This ensures that there is a sufficiently large interfacial force between the protective film substrate and the aqueous black film, and that the interfacial force between the aqueous black film and the photosensitive resin layer is much greater than that between the protective film substrate and the aqueous black film, so that the black film can be effectively transferred into the photosensitive resin layer.

[0025] The resin plate provided by this invention has high flexibility. Under low temperature bending operation, the black film is resistant to cracking and brittleness. At the same time, the black film is resistant to moisture absorption and water solubility in high humidity environment. It has excellent temperature and humidity adaptability and resistance to external force during the plate making process, and the plate material has a wide range of environmental tolerance. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a digital hydrosensitive photoresist plate.

[0027] The components include: 1. Protective film base; 2. Water-based black film; 3. Photosensitive resin layer; 4. Adhesive layer; and 5. Support. Detailed Implementation

[0028] 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.

[0029] An amphiphilic modified compound, wherein the main chain of the amphiphilic modified compound contains at least two imide groups and at least two ether groups, and the terminal suspending hydroxyl groups or contains polyethylene glycol side chains.

[0030]

[0031] (I) In formula (I), R1 is a suspended hydroxyl group or a polyethylene glycol side chain, R2 is a segment containing at least one ether group, and R3 is a segment containing an aromatic ring, a methyl group, or bisphenol A.

[0032] The amphiphilic modified compound contains at least two imide groups and at least two ether segments in its main chain. The ether segments provide high flexibility, while the presence of at least two imide groups and at least two ether segments retains the rigidity of the imide groups while also exhibiting high flexibility. The carbonyl polar group in the imide group can control the water absorption rate, thereby controlling hygroscopicity in high-humidity environments. The terminal suspending hydroxyl groups or the presence of polyethylene glycol side chains introduce hydrophilic segments. Furthermore, the carbonyl oxygen on the imide group acts as a hydrogen bond acceptor, forming a dense physical cross-link with the hydroxyl group, effectively blocking the diffusion of small molecule oxygen without affecting the imaging of the photosensitive resin layer. The amphiphilic modified compound provided in this application simultaneously achieves amphiphilicity, high flexibility, rigidity, control of hygroscopicity in high-humidity environments, and effective blocking of the diffusion of small molecule oxygen without affecting the imaging of the photosensitive resin layer.

[0033] The preparation method of the amphiphilic modified compound adopts a two-step synthesis method. First, polyamic acid is synthesized, and then polyimide is obtained by imidization. The amphiphilic modified compound is finally obtained by using a hydroxyl-containing or polyethylene glycol-structured compound as a hydrophilic source, an ether-based chain segment compound as a flexible chain, and an acid anhydride as a connecting bridge, through low-temperature solution polycondensation and heated imidization.

[0034] Specifically, hydroxyl-containing or polyethylene glycol-structured compounds and ether-based segment compounds are dissolved in an organic solvent, and then 4,4'-oxophthalic anhydride or bisphenol A type diether dianhydride is added. The reaction is carried out at a temperature below 10°C (the low-temperature reaction is a nucleophilic addition-ring-opening strongly exothermic reaction after the addition of anhydride or dianhydride, which prevents molecular chain crosslinking or even gelation caused by local overheating, and also prevents the anhydride or dianhydride from reacting with the trace amounts of water remaining in the system at high temperatures to form acid). After the reaction is completed, the temperature is naturally raised to room temperature, and the reaction is stirred at room temperature for 20-24 hours under nitrogen protection (the 20-hour reaction at room temperature is to complete chain growth; at low temperatures, the monomer activity is high, and a large amount of oligomers are rapidly generated, but at this time the system viscosity is high, and the molecular chain movement is hindered, so it is necessary to raise the temperature to room temperature to improve the chain segment diffusion ability and promote the reaction to tend to be complete). After the reaction is completed, a pale yellow viscous solution is obtained; then an organic solvent is added for dilution, and then acetic anhydride and pyridine are added, and the temperature is raised to 80°C to carry out an imidization reaction to obtain an amphiphilic modified compound.

[0035] Compounds containing hydroxyl groups or polyethylene glycol structures can be amino-terminated polyvinyl alcohol, 2,2-bis(3-amino-4-hydroxyphenyl)propane, or 3,3'-dihydroxybenzidine; ether-based compounds can be 4,4'-diaminodiphenyl ether.

[0036] Another object of this application is to provide a waterborne black film with excellent flexibility and a digital waterborne resin plate comprising the same, wherein the waterborne black film with excellent flexibility contains the aforementioned amphiphilic modified compound. Figure 1As shown, the digital water-based resin plate includes, from top to bottom, a protective film base (1), a water-based black film (2), a photosensitive resin layer (3), an adhesive layer (4), and a support (5).

[0037] The preparation method of digital water-based photosensitive resin plate is as follows: an aqueous ablation black film is pre-coated on a protective film base and dried for later use; an adhesive layer is pre-coated on a support and dried for later use; a photosensitive resin layer is coated onto a support with an adhesive layer by extrusion or casting and dried for later use; and a protective film base with an aqueous ablation black film is laminated to the other side of the photosensitive resin layer to complete the production of digital water-based photosensitive resin plate.

[0038] Among them, (1) protect the substrate The purpose of the protective film is to protect the digital water-based resin plate from external damage or environmental influences to the surface of the water-based black film or photosensitive resin layer. The protective film needs to be removed during plate making. When removed, the water-based black film is completely transferred to the photosensitive resin layer, and then laser engraving is performed to transfer the electronic graphics to the plate surface at a 1:1 scale.

[0039] The protective film base material can be PET or PE film with a thickness of 80-150μm, and a commonly used thickness of 100-125μm. This film material can be transparent, semi-transparent or opaque. To facilitate the differentiation of the two sides of the resin plate, matte PET film base is commonly used.

[0040] (2) Water-based black film The water-based black film can be laser-engraved at wavelengths of 1064nm and 830nm, enabling a 1:1 replication of electronic graphics to the plate surface. The required parts of the black film are cleanly ablated, while the unwanted parts remain covered by the black film. Furthermore, it can be completely washed away during the water development process.

[0041] A flexible aqueous black film comprises (A) an amphiphilic modified compound, (B) an aqueous binder, (C) carbon black, (D) a modifier, and (E) a wetting agent. The aqueous black film is formed by coating with a black film coating solution and then drying. Wherein: (A) The amphiphilic modified compound is at least one of the compounds A1-A8 synthesized in Part I. The amphiphilic modified compound is present in 5-6 parts by weight in the black film coating solution.

[0042] (B) The water-based binder is at least one of polyvinyl alcohol, carboxyethyl cellulose, polyvinylpyrrolidone, esterified starch, dextrin, water-based polyurethane, and hydroxypropyl methylcellulose. The water-based binder in the black film coating solution is 0.5-1 parts by weight.

[0043] (C) Carbon black is a nanoparticle with a particle size range of 100-300 nm. By weight, carbon black accounts for 2-3 parts by weight in the black film coating solution.

[0044] (D) The modifier is at least one of the following: high molecular weight polymer modifier, small molecule anionic modifier, coupling modifier, surface oxidation modifier, and in-situ coating modifier. The modifier in the black film coating solution is 1-1.5 parts by weight.

[0045] (E) The wetting agent is at least one of the following: acetylenic diol, organosilicon, phosphate ester, and polymer. The wetting agent in the black film coating solution is 0.5 parts by weight.

[0046] The black film coating solution also includes a solvent with a solvent weight ratio of water:ethanol 3-5:1. By weight, the solvent in the black film coating solution is 88-91 parts by weight.

[0047] Photosensitive resin layer The photosensitive resin layer is a crucial component of the digital photosensitive plate. Its formulation must contain a host resin capable of photocrosslinking, monomers with unsaturated double bonds, plasticizers, photoinitiators, and water-based dyes. The components in the formulation can form emulsions or dissolve in an aqueous system, enabling washability. Under UVA irradiation, the resin components in the resin layer crosslink with the unsaturated monomers to form a water-insoluble network structure. The portions not exposed to UVA are washed away by water, thus revealing the image. The revealed image is then transferred to the printed material using ink, achieving printing. The thickness of the photosensitive resin layer can range from 400 to 2000 μm, with 430 μm, 650 μm, and 2000 μm being commonly used.

[0048] The main resin of the photosensitive resin layer is generally a water-soluble polymer material, such as water-soluble polyamide, waterborne polyurethane, modified poly(styrene-butadiene copolymer) and its derivatives, modified polyvinyl alcohol, ethylene and vinyl alcohol copolymer, etc.; the modified polyvinyl alcohol can be isocyanate-modified polyvinyl alcohol containing vinyl double bonds.

[0049] The unsaturated monomers in the photosensitive resin layer can be at least one of the following: polyethylene glycol (200) diacrylate, polyethylene glycol (200) dimethacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (400) dimethacrylate, polyethylene glycol (600) diacrylate, polyethylene glycol (600) dimethacrylate, polyethylene glycol (1000) diacrylate, glycidyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, pentaerythritol triacrylate, ethoxylated 1,6-hexanediol diacrylate, ethoxylated polyethylene glycol o-phenylphenol acrylate, ethoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, propoxylated glycerol triacrylate, 2-acryloylethoxysuccinate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, and 2-methyl-1,3-propanediol diacrylate.

[0050] The plasticizer in the photosensitive resin layer can be at least one of urea / triethanolamine, ethylene glycolamine, triethanolamine, sorbitol, ethylene glycol, diethylene glycol, glycerol, trimethylolpropane, N-butylbenzenesulfonamide, lauryl methacrylate, polyethylene glycol, magnesium chloride, and dibutyl maleate.

[0051] The photoinitiator in the photosensitive resin layer can be at least one of benzoin and its derivatives, such as benzoin, benzoin dimethyl ether 651, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, benzophenone, 2,4-dihydroxybenzophenone, 4-chlorobenzophenone, 4-phenylbenzophenone, 4,4'-di(diethylamino)benzophenone, 2-isopropylthioxanthraphenone, 2,4-diethylthioxanthraphenone, diphenyl ethyl ketone, 2,2-dimethoxy-1,2-diphenyl ethyl ketone, aromatic phosphine oxide, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0052] The aqueous dye in the photosensitive resin layer can be at least one of Sudan Red, Neutral Red, Aqueous Green, Aqueous Yellow, Aqueous Blue, Basic Magenta, Rhodamine B, and Rhodamine Blue.

[0053] The photosensitive resin layer may also contain defoamers, stabilizers, and other additives. The defoamer can be at least one of the following: mineral oils, organosilicones, amides, fatty acids and fatty acid esters, alcohols, polyethers, phosphate esters, and polyether-modified polysiloxane defoamers. The stabilizer can be at least one of the following: polyphenol 1010, 2,6-di-tert-butyl-p-cresol BHT, 168, asymmetric phenol 1136, bisphenol 2245, dilauryl thiodipropionate, distearate thiodipropionate, and IRGANOX 1076.

[0054] (4) Adhesive layer The adhesive layer of the digital water-based resin plate firmly bonds the support and the photosensitive resin layer together, ensuring that the photosensitive resin layer does not detach from the support during plate making and printing. The type of adhesive layer must meet the bonding requirements and can be one of the following: photocurable, hot melt adhesive, thermocurable, or pressure-sensitive. The main adhesive type is one or more of polyester, polyurethane, epoxy resin, phenolic resin, acrylate, polyimide, polyamide, vinyl acetate resin, chlorinated rubber, or other copolymer adhesives. The adhesive layer described in this invention is pre-prepared as a solution and applied to the support using an anilox roller or doctor blade coating method, then dried into a film for later use. The coating thickness is generally 20-40 μm.

[0055] (5) Support The support structure of the digital water-based resin plate provides support for the entire plate and protects the back of the plate from external damage. It also serves to connect with the printing roller during printing. The support structure can be a plastic film, such as polyester, polyetherimide, polystyrene, or triacetate, or a metal material, such as stainless steel, iron, aluminum, or tinplate. The support structure thickness can range from 250μm to 300μm, with 270μm and 300μm being commonly used. To improve the adhesion of the support structure surface, methods such as plasma etching, corona treatment, polishing, chemical etching, and the addition of a primer coating can be used.

[0056] During plate making, the protective film base is first removed, and the graphics are engraved using a laser engraving machine. Under UVA light, the initiator decomposes to generate free radicals, which trigger a cross-linking reaction between resin molecules and monomers, forming a water-insoluble network polymer structure. After post-treatment such as washing, developing, baking, or de-adhesion, an embossed printing plate is produced. During the plate making process, the digital water-based resin plate exhibits high flexibility. Under low-temperature bending operations, the black film is resistant to cracking and brittleness. At the same time, the black film is resistant to moisture absorption and water solubility in high-humidity environments. It has excellent temperature and humidity adaptability and resistance to external forces during the plate making process. The plate material has a high tolerance for the usage environment, ensuring the quality of the plate material.

[0057] The digital waterborne resin plate provided in this application uses a protective film base typically made of PET. PET has low surface energy, is relatively inert, and smooth. Polyimide also exhibits similar inertness, making it difficult for polyimide to effectively wet PET, resulting in poor adhesion. Using only polyimide compounds in the waterborne black film causes the protective film base to detach directly from the black film during cutting, transportation, and movement, thus losing its protective function. By employing the amphiphilic modified compound of this invention, with hydroxyl groups or polyethylene glycol side chains suspended at the ends, the black film can achieve water rinsing functionality and effectively improve the interfacial force between the waterborne black film and the protective film base. The hydroxyl groups or polyethylene glycol side chains suspended at the ends can form effective intermolecular hydrogen bonds with the waterborne compound-modified PVA or waterborne nylon in the photosensitive resin layer, enabling a strong and effective interfacial force between the waterborne black film and the photosensitive resin layer. While water-based compounds in water-based black films can create strong and effective interfacial forces between the water-based black film and the photosensitive resin layer, they can also result in significant interfacial forces between the water-based black film and the protective substrate. If the sandblasting or corona treatment intensity of the protective substrate is not properly controlled, the interfacial force between the water-based black film and the protective substrate can easily become only slightly smaller than the interfacial force between the water-based black film and the photosensitive resin layer, hindering the transfer of the black film to the surface of the photosensitive resin layer. Using the compounds of this invention in water-based black films allows for better control of the interfacial forces between the protective substrate and the water-based black film, and between the water-based black film and the photosensitive resin layer. This ensures both a sufficiently large interfacial force between the protective substrate and the water-based black film, and a much larger interfacial force between the water-based black film and the photosensitive resin layer than the interfacial force between the protective substrate and the water-based black film, enabling effective transfer of the black film into the photosensitive resin layer.

[0058] Part 1: Synthesis of amphiphilic modified compound A (A1-A8).

[0059] The main raw materials can be obtained from the following companies: 4,4'-oxophthalic anhydride, bisphenol A type diether dianhydride, and 4,4'-diaminodiphenyl ether are all from Sigma Chemical Reagent Co., Ltd.; amino-terminated polyvinyl alcohol 2000 and 3,3'-dihydroxybenzidine are both from Zhengzhou Alpha Chemical Co., Ltd.; 2,2-bis(3-amino-4-hydroxyphenyl)propane is from Shanghai Xianding Biotechnology Co., Ltd.; methanol, pyridine, and N-methylpyrrolidone are all from Beijing Bailingwei Technology Co., Ltd.; nitrogen is from Henan Kejing Chemical Products Co., Ltd.; and acetic anhydride is from Shandong Hualu Hengsheng Chemical Co., Ltd.

[0060] Compound A1: Dry-treated 4A molecular sieves were sealed and soaked in N-methylpyrrolidone for at least 48 hours to remove moisture from the solvent. 50 ml of the dehydrated N-methylpyrrolidone was placed in a 250 ml four-necked flask. 1.4 g of 4,4'-diaminodiphenyl ether and 6 g of amino-terminated polyvinyl alcohol 2000 were added to the flask. Stirring was started, and nitrogen gas was introduced for protection. The mixture was kept in an ice-water bath at 0-5°C and stirred until completely dissolved for 30 minutes. 3.1 g of 4,4'-oxydiphthalic anhydride was added to the flask in five batches, 15 minutes apart, with the reaction temperature maintained below 10°C throughout. The ice bath was removed, and the mixture was allowed to warm naturally to room temperature. Under nitrogen protection, the mixture was stirred at room temperature for 20 hours until a pale yellow viscous solution was obtained.

[0061] The yellow viscous solution obtained from the above reaction was diluted with 30 ml of N-methylpyrrolidone. 5 g of acetic anhydride and 5 g of pyridine were slowly added dropwise at room temperature. The mixture was heated to 80 °C and stirred for 12 h. 10 g of toluene was added to azeotropically to remove the water produced. The final reactant was slowly poured into 200 ml of methanol to precipitate the product. The mixture was stirred until precipitation was complete, allowed to stand, filtered, and washed three times with 20 ml of methanol each time. The product was then dried under vacuum at 60 °C to obtain compound A1.

[0062] Compound A2: Dry-treated 4A molecular sieves were sealed and soaked in N-methylpyrrolidone for at least 48 hours to remove moisture from the solvent. 50 ml of the dehydrated N-methylpyrrolidone was placed in a 250 ml four-necked flask. 1.4 g of 4,4'-diaminodiphenyl ether and 6 g of terminal amino-terminated polyvinyl alcohol 2000 were added to the flask. Stirring was started, and nitrogen gas was introduced for protection. The mixture was kept in an ice-water bath at 0-5°C and stirred until completely dissolved for 30 minutes. 5.2 g of bisphenol A type diether dianhydride was added to the flask in five batches, 15 minutes apart, with the reaction temperature maintained below 10°C throughout. The ice bath was removed, and the mixture was allowed to warm naturally to room temperature. Under nitrogen protection, the mixture was stirred at room temperature for 20 hours until a pale yellow viscous solution was obtained.

[0063] The yellow viscous solution obtained from the above reaction was diluted with 30 ml of N-methylpyrrolidone. 5 g of acetic anhydride and 5 g of pyridine were slowly added dropwise at room temperature. The mixture was heated to 80 °C and stirred for 12 h. 10 g of toluene was added to azeotropically to remove the water produced. The final reactant was slowly poured into 200 ml of methanol to precipitate the product. The mixture was stirred until precipitation was complete, allowed to stand, filtered, and washed three times with 20 ml of methanol each time. The product was then dried under vacuum at 60 °C to obtain compound A2.

[0064] Compound A3: Dry-treated 4A molecular sieves were sealed and soaked in N-methylpyrrolidone for at least 48 hours to remove moisture from the solvent. 50 ml of the dehydrated N-methylpyrrolidone was placed in a 250 ml four-necked flask. 1.4 g of 4,4'-diaminodiphenyl ether and 0.8 g of 2,2-bis(3-amino-4-hydroxyphenyl)propane were added to the flask. Stirring was started, and nitrogen gas was introduced for protection. The mixture was kept in an ice-water bath at 0-5°C and stirred until completely dissolved for 30 minutes. 3.1 g of 4,4'-oxydiphthalic anhydride was added to the flask in five batches, 15 minutes apart, with the reaction temperature maintained below 10°C throughout. The ice bath was removed, and the mixture was allowed to warm naturally to room temperature. Under nitrogen protection, the mixture was stirred at room temperature for 21 hours until a pale yellow viscous solution was obtained.

[0065] The yellow viscous solution obtained from the above reaction was diluted with 30 ml of N-methylpyrrolidone. 5 g of acetic anhydride and 5 g of pyridine were slowly added dropwise at room temperature. The mixture was heated to 80 °C and stirred for 12 h. 10 g of toluene was added to azeotropically to remove the water produced. The final reactant was slowly poured into 200 ml of methanol to precipitate the product. The mixture was stirred until precipitation was complete, allowed to stand, filtered, and washed three times with 20 ml of methanol each time. The product was then dried under vacuum at 60 °C to obtain compound A3.

[0066] Compound A4: The dried 4A molecular sieve was sealed and soaked in N-methylpyrrolidone for at least 48 hours to remove moisture from the solvent. 50 ml of the dehydrated N-methylpyrrolidone was placed in a 250 ml four-necked flask. 1.4 g of 4,4'-diaminodiphenyl ether and 0.6 g of 3,3'-dihydroxybenzidine were added to the flask. Stirring was started, and nitrogen gas was introduced for protection. The mixture was kept in an ice-water bath at 0-5°C and stirred until completely dissolved for 30 minutes. 3.1 g of 4,4'-oxydiphthalic anhydride was added to the flask in five batches, 15 minutes apart, with the reaction temperature maintained below 10°C throughout. The ice bath was removed, and the mixture was allowed to warm naturally to room temperature. Under nitrogen protection, the mixture was stirred at room temperature for 21 hours until a pale yellow viscous solution was obtained.

[0067] The yellow viscous solution obtained from the above reaction was diluted with 30 ml of N-methylpyrrolidone. 5 g of acetic anhydride and 5 g of pyridine were slowly added dropwise at room temperature. The mixture was heated to 80 °C and stirred for 12 h. 10 g of toluene was added to azeotropically to remove the water produced. The final reactant was slowly poured into 200 ml of methanol to precipitate the product. The mixture was stirred until precipitation was complete, allowed to stand, filtered, and washed three times with 20 ml of methanol each time. The product was then dried under vacuum at 60 °C to obtain compound A4.

[0068] Compound A5: Dry-treated 4A molecular sieves were sealed and soaked in N-methylpyrrolidone for at least 48 hours to remove moisture from the solvent. 50 ml of the dehydrated N-methylpyrrolidone was placed in a 250 ml four-necked flask. 1.2 g of 4,4'-diaminodiphenyl ether and 8 g of amino-terminated polyvinyl alcohol 2000 were added to the flask. Stirring was started, and nitrogen gas was introduced for protection. The mixture was kept in an ice-water bath at 0-5°C and stirred until completely dissolved for 30 minutes. 3.1 g of 4,4'-oxydiphthalic anhydride was added to the flask in five batches, 15 minutes apart, with the reaction temperature maintained below 10°C throughout. The ice bath was removed, and the mixture was allowed to warm naturally to room temperature. Under nitrogen protection, the mixture was stirred at room temperature for 22 hours until a pale yellow viscous solution was obtained.

[0069] The yellow viscous solution obtained from the above reaction was diluted with 30 ml of N-methylpyrrolidone. 5 g of acetic anhydride and 5 g of pyridine were slowly added dropwise at room temperature. The temperature was raised to 80 °C, and the reaction was continued with stirring for 12 h. 10 g of toluene was added to azeotropically to remove the water produced. The final reactant was slowly poured into 200 ml of methanol to precipitate, and the mixture was stirred until precipitation was complete. After standing, the mixture was filtered and washed three times with 20 ml of methanol each time. The precipitate was then dried under vacuum at 60 °C to obtain compound A5.

[0070] Compound A6: Dry-treated 4A molecular sieves were sealed and soaked in N-methylpyrrolidone for at least 48 hours to remove moisture from the solvent. 50 ml of the dehydrated N-methylpyrrolidone was placed in a 250 ml four-necked flask. 1.6 g of 4,4'-diaminodiphenyl ether and 4 g of terminal amino-terminated polyvinyl alcohol 2000 were added to the flask. Stirring was started, and nitrogen gas was introduced for protection. The mixture was cooled to 0-5°C in an ice-water bath and stirred for 30 minutes until completely dissolved. 3.1 g of 4,4'-oxydiphthalic anhydride was added to the flask in five batches, 15 minutes apart, with the reaction temperature maintained below 10°C throughout. The ice bath was removed, and the mixture was allowed to warm naturally to room temperature. Under nitrogen protection, the mixture was stirred at room temperature for 22 hours until a pale yellow viscous solution was obtained.

[0071] The yellow viscous solution obtained from the above reaction was diluted with 30 ml of N-methylpyrrolidone. 5 g of acetic anhydride and 5 g of pyridine were slowly added dropwise at room temperature. The mixture was heated to 80 °C and stirred for 12 h. 10 g of toluene was added to azeotropically to remove the water produced. The final reactant was slowly poured into 200 ml of methanol to precipitate the product. The mixture was stirred until precipitation was complete, allowed to stand, filtered, and washed three times with 20 ml of methanol each time. The product was then dried under vacuum at 60 °C to obtain compound A6.

[0072] Compound A7: Dry-treated 4A molecular sieves were sealed and soaked in N-methylpyrrolidone for at least 48 hours to remove moisture from the solvent. 50 ml of the dehydrated N-methylpyrrolidone was placed in a 250 ml four-necked flask. 1.8 g of 4,4'-diaminodiphenyl ether and 0.3 g of 2,2-bis(3-amino-4-hydroxyphenyl)propane were added to the flask. Stirring was started, and nitrogen gas was introduced for protection. The mixture was kept in an ice-water bath at 0-5°C and stirred until completely dissolved for 30 minutes. 3.1 g of 4,4'-oxydiphthalic anhydride was added to the flask in five batches, 15 minutes apart, with the reaction temperature maintained below 10°C throughout. The ice bath was removed, and the mixture was allowed to warm naturally to room temperature. Under nitrogen protection, the mixture was stirred at room temperature for 23 hours until a pale yellow viscous solution was obtained.

[0073] The yellow viscous solution obtained from the above reaction was diluted with 30 ml of N-methylpyrrolidone. 5 g of acetic anhydride and 5 g of pyridine were slowly added dropwise at room temperature. The mixture was heated to 80 °C and stirred for 12 h. 10 g of toluene was added to azeotropically to remove the water produced. The final reactant was slowly poured into 200 ml of methanol to precipitate the product. The mixture was stirred until precipitation was complete, allowed to stand, filtered, and washed three times with 20 ml of methanol each time. The product was then dried under vacuum at 60 °C to obtain compound A7.

[0074] Compound A8: Dry-treated 4A molecular sieves were sealed and soaked in N-methylpyrrolidone for at least 48 hours to remove moisture from the solvent. 50 ml of the dehydrated N-methylpyrrolidone was placed in a 250 ml four-necked flask. 1.5 g of 4,4'-diaminodiphenyl ether and 1.3 g of 2,2-bis(3-amino-4-hydroxyphenyl)propane were added to the flask. Stirring was started, and nitrogen gas was introduced for protection. The mixture was kept in an ice-water bath at 0-5°C and stirred until completely dissolved for 30 minutes. 3.1 g of 4,4'-oxydiphthalic anhydride was added to the flask in five batches, 15 minutes apart, with the reaction temperature maintained below 10°C throughout. The ice bath was removed, and the mixture was allowed to warm naturally to room temperature. Under nitrogen protection, the mixture was stirred at room temperature for 24 hours until a pale yellow viscous solution was obtained.

[0075] The yellow viscous solution obtained from the above reaction was diluted with 30 ml of N-methylpyrrolidone. 5 g of acetic anhydride and 5 g of pyridine were slowly added dropwise at room temperature. The mixture was heated to 80 °C and stirred for 12 h. 10 g of toluene was added to azeotropically to remove the water produced. The final reactant was slowly poured into 200 ml of methanol to precipitate the product. The mixture was stirred until precipitation was complete, allowed to stand, filtered, and washed three times with 20 ml of methanol each time. The product was then dried under vacuum at 60 °C to obtain compound A8.

[0076] The feed solution for the highly flexible aqueous black film was prepared according to the methods described in the following examples and comparative examples. Example 1

[0077] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Compound A1 5 PVA-205 (Kuraray Co., Ltd.) 0.5 Waterborne polyamide HT (Beijing Runbo Hengtong Technology Co., Ltd.) 0.5 Carbon black BK919 (Zhongke Huacai Technology Development Co., Ltd.) 2.5 Tego Dispers 650 (Evonik Industries AG, Germany) 1 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 18% ethanol Water 72 Compound A1, PVA-205, and waterborne polyamide HT were dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours, the solution was completely dissolved. The temperature was then lowered to 40°C, and carbon black BK919, Tego Dispers 650, and Tego Wet260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. It was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating weight of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Example 2

[0078] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Compound A2 6 Waterborne polyamide HT (Beijing Runbo Hengtong Technology Co., Ltd.) 1 Carbon Black BK919 (Zhongke Huacai Technology Development Co., Ltd.) 3 Tego Dispers 650 (Evonik Industries AG, Germany) 1.5 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 Ethanol 17.6 Water 70.4 Compound A2 and waterborne polyamide HT were dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours, the solution was completely dissolved. The temperature was then lowered to 40°C, and carbon black BK919, Tego Dispers 650, and Tego Wet 260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. It was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating amount of 20g / m². 2Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Example 3

[0079] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Compound A3 5 Polyvinylpyrrolidone K100 (Shanghai Kaiyin Chemical Co., Ltd.) 1 Carbon Black ET-TS (Zhejiang Nami New Materials Co., Ltd.) 2 Tego Dispers 650 (Evonik Industries AG, Germany) 1 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 Ethanol 18.1 Water 72.4 Compound A3 and polyvinylpyrrolidone K100 were dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours, the solution was completely dissolved. The temperature was then lowered to 40°C, and carbon black ET-TS, Tego Dispers 650, and Tego Wet 260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. It was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating amount of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Example 4

[0080] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Compound A4 5.2 Polyvinylpyrrolidone K100 (Shanghai Kaiyin Chemical Co., Ltd.) 0.3 PVA-205 (Kuraray Co., Ltd.) 0.5 Carbon black ET-TS (Zhejiang Nami New Materials Co., Ltd.) 2.5 Tego Dispers 650 (Evonik Industries AG, Germany) 1 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 18% ethanol Water 72 Compound A4, polyvinylpyrrolidone K100, and PVA-205 were dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours of complete dissolution, the solution was cooled to 40°C, and carbon black ET-TS, Tego Dispers 650, and TegoWet 260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. The solution was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating weight of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Example 5

[0081] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Compound A5 6 PVA-205 (Kuraray Co., Ltd.) 0.6 Waterborne polyamide HT (Beijing Runbo Hengtong Technology Co., Ltd.) 0.4 Carbon black BK919 (Zhongke Huacai Technology Development Co., Ltd.) 2.5 Tego Dispers 650 (Evonik Industries AG, Germany) 1 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 Ethanol 17.8 Water 71.2 Compounds A5, PVA-205, and waterborne polyamide HT were dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours of complete dissolution, the solution was cooled to 40°C, and carbon black BK919, Tego Dispers 650, and Tego Wet260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. The solution was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating weight of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Example 6

[0082] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Compound A6 5 PVA-205 (Kuraray Co., Ltd.) 0.5 Waterborne polyamide HT (Beijing Runbo Hengtong Technology Co., Ltd.) 0.5 Carbon black BK919 (Zhongke Huacai Technology Development Co., Ltd.) 2.8 Tego Dispers 650 (Evonik Industries AG, Germany) 1.2 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 Ethanol 17.9 Water 71.6 Compounds A6, PVA-205, and waterborne polyamide HT were dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours, the solution was completely dissolved. The temperature was then lowered to 40°C, and carbon black BK919, Tego Dispers 650, and Tego Wet260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. The solution was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating weight of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Example 7

[0083] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Compound A7 5.2 Polyvinylpyrrolidone K100 (Shanghai Kaiyin Chemical Co., Ltd.) 0.8 Carbon Black ET-TS (Zhejiang Nami New Materials Co., Ltd.) 3 Tego Dispers 650 (Evonik Industries AG, Germany) 1.5 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 Ethanol 17.8 Water 71.2 Compound A7 and polyvinylpyrrolidone K100 were dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours, the solution was completely dissolved. The temperature was then lowered to 40°C, and carbon black ET-TS, Tego Dispers 650, and Tego Wet 260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. It was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating amount of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Example 8

[0084] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Compound A8 6 Polyvinylpyrrolidone K100 (Shanghai Kaiyin Chemical Co., Ltd.) 1 Carbon black ET-TS (Zhejiang Nami New Materials Co., Ltd.) 2.5 Tego Dispers 650 (Evonik Industries AG, Germany) 1.5 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 Ethanol 17.7 Water 70.8 Compound A8 and polyvinylpyrrolidone K100 were dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours, the solution was completely dissolved. The temperature was then lowered to 40°C, and carbon black ET-TS, Tego Dispers 650, and Tego Wet 260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. It was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating amount of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Comparative Example 1

[0085] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: PVA-205 (Kuraray Co., Ltd.) 5.5 Waterborne polyamide HT (Beijing Runbo Hengtong Technology Co., Ltd.) 0.5 Carbon black BK919 (Zhongke Huacai Technology Development Co., Ltd.) 2.5 Tego Dispers 650 (Evonik Industries AG, Germany) 1 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 18% ethanol Water 72 PVA-205 and waterborne polyamide HT were dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours, the solution was completely dissolved. The temperature was then lowered to 40°C, and carbon black BK919, Tego Dispers 650, and Tego Wet 260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. The solution was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating weight of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Comparative Example 2

[0086] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Polyvinylpyrrolidone K100 (Shanghai Kaiyin Chemical Co., Ltd.) 6 Carbon Black ET-TS (Zhejiang Nami New Materials Co., Ltd.) 2 Tego Dispers 650 (Evonik Industries AG, Germany) 1 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 Ethanol 18.1 Water 72.4 Polyvinylpyrrolidone K100 was dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours, the solution was completely dissolved. The temperature was then lowered to 40°C, and carbon black ET-TS, Tego Dispers 650, and Tego Wet 260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. The solution was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating weight of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Comparative Example 3

[0087] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Polyvinylpyrrolidone K100 (Shanghai Kaiyin Chemical Co., Ltd.) 5.5 PVA-205 (Kuraray Co., Ltd.) 0.5 Carbon black ET-TS (Zhejiang Nami New Materials Co., Ltd.) 2.5 Tego Dispers 650 (Evonik Industries AG, Germany) 1 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 18% ethanol Water 72 Polyvinylpyrrolidone K100 and PVA-205 were dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours, the solution was completely dissolved. The temperature was then lowered to 40°C, and carbon black ET-TS, Tego Dispers 650, and Tego Wet 260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to defoam. The solution was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating amount of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use. Comparative Example 4

[0088] The total weight of the components is 100g, and the number of portions per unit mass (g) is as follows: Compound A1 6 Carbon black BK919 (Zhongke Huacai Technology Development Co., Ltd.) 2.5 Tego Dispers 650 (Evonik Industries AG, Germany) 1 Tego Wet 260 (Evonik Industries AG, Germany) 0.5 18% ethanol Water 72 Compound A1 was dissolved in a mixed solvent of water and ethanol at 65°C with stirring. After 4 hours, the solution was completely dissolved. The temperature was then lowered to 40°C, and carbon black BK919, Tego Dispers 650, and Tego Wet 260 were added sequentially. Stirring was continued for another 4 hours to prepare an aqueous black film coating solution. The coating solution was sealed and allowed to stand at 30°C for at least 8 hours to remove bubbles. The solution was then coated onto a 125μm thick matte PET substrate using a wire rod, with a coating weight of 20g / m². 2 Dry in an oven at 100℃ for 5 minutes to obtain an aqueous black film for later use.

[0089] Plate making and evaluation: (I) Plate preparation (1) Photosensitive resin layer The photosensitive resin layer uses WD-95C resin layer developed by Lucky Huaguang Printing Technology Co., Ltd., and the specific formula of the photosensitive resin layer is as follows: The following components are used, with a total mass of 100g and a number of parts per unit mass (g): Modified PVA H-95# (Polyvinyl alcohol A1 modified with isocyanate containing vinyl double bonds, prepared in Example 1 of Patent CN106814540A) 38 Glycidyl methacrylate (Shinnakamura Chemical Industry Co., Ltd.) 6 Polyethylene glycol (200) dimethacrylate (Taiwan Chang Hsing Chemical Industry Co., Ltd.) 4 Ethylene oxide trimethylolpropane triacrylate (Chang Hsing Chemical Industry Co., Ltd., Taiwan) 3 Hydroxyethyl acrylate (Chang Hsing Chemical Industry Co., Ltd., Taiwan) 2.5 Pentaerythritol triacrylate (Shinnakamura Chemical Industry Co., Ltd.) 1.5 Sorbitol 3 Photoinitiator 651 1.5 BHT 0.4 Neutral red dye (Kunshan Zhongxing Dyestuff & Chemical Co., Ltd.) 0.1 Water 40 Modified PVA H-95# and sorbitol were dissolved in water at 65℃ and stirred for 4 hours until completely dissolved. All monomers were weighed, and photoinitiator 651 and BHT were added to the mixed monomers. The mixture was stirred at 65℃ for 20 minutes to dissolve. After dissolution, the solution was added to the aqueous solution of modified PVA H-95# and sorbitol while stirring, and stirring was continued for 0.5 hours. Finally, neutral red dye was added, and stirring was continued for 1 hour to obtain the photosensitive resin coating solution. The photosensitive resin coating solution was placed in a beaker, sealed with plastic wrap, and allowed to stand in an oven at 40℃ for at least 4 hours to defoam. The photosensitive resin coating solution was removed from the oven and coated onto a printing plate while still hot using a doctor blade coater. The plate was dried in an oven at 60℃ for 3 hours and then at 70℃ for 1 hour to obtain a photosensitive resin layer with a dry coating thickness of 0.65 mm, which was then set aside.

[0090] (2) Preparation of a support with an adhesive layer The adhesive layer consists of the following components, with a total mass of 100g and a unit mass fraction of g: VYLON 240 (Toyobo Co., Ltd.) 10 PR-53724 (Nantong Sumitomo Bakelite Co., Ltd.) 2.5 712 epoxy resin (Guangzhou Taiji New Materials Co., Ltd.) 3 Glycidyl methacrylate (Shinnakamura Chemical Industry Co., Ltd.) 2.5 Hardener N3300 (Bayer Chemicals AG) 3.6 Photoinitiator 651 0.4 Ethyl acetate 60 Dioxane 18 According to the above proportions, weigh ethyl acetate and dioxane, then add VYLON 240, PR-53724, and 712 epoxy resin sequentially, and stir at 60°C for 2 hours to dissolve. After complete dissolution, add glycidyl methacrylate and photoinitiator 651 sequentially, and continue stirring at 60°C for 0.5 hours. After the solid dissolves, add curing agent N3300, and stir for another 0.5 hours to prepare the adhesive coating solution.

[0091] The polyester support is made of 270μm thick PET (PG series produced by Hefei Lucky Technology Industry Co., Ltd.), and a polyester base coat has been applied at the factory. The prepared adhesive coating solution is applied to the PET support using a wire rod and dried in an oven at 120℃ for 5 minutes to obtain an adhesive layer with a coating thickness of 20μm, which is then ready for use.

[0092] (3) Composite One side of the photosensitive resin layer was moistened with water using a wire rod, and a support with an adhesive layer was then laminated onto it. The other side of the photosensitive resin layer was then moistened with water using a wire rod. This process was repeated to laminate the prepared water-based black films from Examples 1-8 and Comparative Examples 1-4, respectively, to obtain the plates for Examples 1-8 and Comparative Examples 1-4. The laminated plates were placed in an oven and dried at 60°C for 10 minutes, then cooled to room temperature, completing the plate fabrication.

[0093] (ii) Performance testing Performance under freezing treatment: The prepared plate is cut into 200*400mm size, the protective film is removed, it is wrapped in a cylindrical tube with a diameter of 400mm, and stored in an oven at -16℃ for more than 24 hours. Observe whether the surface of the black film cracks or becomes brittle.

[0094] High temperature and humidity performance: After the printing plate is made, remove the protective film and place it in a constant temperature and humidity chamber (40℃, 60%) for at least 24 hours. Remove the printing plate and observe whether the black film surface has absorbed moisture and bulged. Gently press a finger on an area of ​​the black film where there is no bulging, and observe whether fingerprints or damage remain. If the black film is resistant to high temperature and humidity, does not easily absorb moisture, and has no bulging, pressing a finger on an area of ​​the black film where there is no bulging will not leave a mark (this pressing should not be too forceful; it simulates an accidental press by a worker during plate making, with a force of approximately 0.5 kg / cm²). 2 If the black film is not resistant to high temperature and humidity and easily absorbs moisture, pressing the black film with your finger will leave a fingerprint or damage the black film.

[0095] Bending performance: After the plate is made, remove the protective film base, bend it 120° and repeat 50 times, and check whether cracks appear on the surface of the black film.

[0096] Black film transfer: Remove the protective film base of the digital resin plate and observe the black film transfer.

[0097] Black film transfer and image reproduction performance: The protective film base of the digital resin plate was removed, and the black film transfer was observed. After the protective film base was removed, the plate was subjected to freezing, high temperature and high humidity, and bending treatment. The evaluation document was then laser-engraved on a Kele laser engraving machine. The plate was then exposed to UVA light for 4 minutes using a Kele exposure machine (LED light bead exposure has the same effect). The plate was then developed in 30℃ warm water for 3 minutes and dried at 60℃ for 10 minutes using a Kele flatbed plate washer. After UVA post-exposure and UVC de-adhesion for 3 minutes, the plate was completed, and the image reproduction performance of the plate was evaluated.

[0098] Table 1 shows the evaluation results of the printing plates made using the aqueous black films of Examples 1-8 and Comparative Examples 1-4.

[0099] Table 1. Evaluation Results Details As can be seen from the data in Table 1, the water-based black film with excellent flexibility and the digital water-based resin plate containing it of the present invention have high flexibility. When bending operations are performed in low temperature environments, the black film is resistant to cracking and brittleness. At the same time, the black film has the properties of moisture absorption and water solubility in high humidity environments. It has excellent temperature and humidity adaptability and resistance to external forces during the plate-making process. The plate material has a high tolerance for the use environment and is particularly suitable for printing.

[0100] 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 amphiphilic modified compound, characterized in that: The amphiphilic modified compound contains at least two imide groups and at least two ether groups on its main chain, with suspended hydroxyl groups at the ends or containing polyethylene glycol side chains.

2. The amphiphilic modified compound according to claim 1, characterized in that: The structural formula of the amphiphilic modified compound is: （I） In formula (I), R1 is a suspended hydroxyl group or a polyethylene glycol side chain, R2 is a segment containing at least one ether group, and R3 is a segment containing an aromatic ring, a methyl group, or bisphenol A.

3. The method for preparing the amphiphilic modified compound according to claim 1 or 2, characterized in that: The synthesis adopts a two-step method: first, polyamic acid is synthesized, and then polyimide is obtained by imidization; using hydroxyl-containing or polyethylene glycol-structured compounds as hydrophilic sources, ether-based chain segments as flexible chains, and acid anhydrides as connecting bridges, the amphiphilic modified compounds are finally obtained through low-temperature solution polycondensation and heated imidization.

4. A water-based black film with excellent flexibility, characterized in that: The mixture includes (A) an amphiphilic modified compound, (B) an aqueous binder, (C) carbon black, (D) a modifier, and (E) a wetting agent; the amphiphilic modified compound is the amphiphilic modified compound described in claim 1 or 2 or the amphiphilic modified compound prepared by the method described in claim 3.

5. The waterborne black film with excellent flexibility according to claim 4, characterized in that: Aqueous black film is formed by coating with black film coating liquid and then drying; The black film coating liquid comprises the following raw materials in parts by weight: (A) 5-6 parts by weight of the amphiphilic modified compound; (B) 0.5-1 parts by weight of water-based adhesive; (C) 2-3 parts by weight of carbon black; (D) Modifier 1-1.5 parts by weight; (E) 0.5 parts by weight of wetting agent; (F) 88-91 parts by weight of solvent; the solvent is composed of water and ethanol; the weight ratio of water to ethanol is 3-5:

1.

6. The waterborne black film with excellent flexibility according to claim 4, characterized in that: (B) The waterborne adhesive is at least one of polyvinyl alcohol, carboxyethyl cellulose, polyvinylpyrrolidone, esterified starch, dextrin, waterborne polyurethane, and hydroxypropyl methylcellulose; (C) Carbon black is a nanoparticle with a particle size range of 100-300 nm; (D) The modifier is at least one of the following: polymer modifier, small molecule anionic modifier, coupling modifier, surface oxidation modifier, and in-situ coating modifier; (E) The wetting agent is at least one of the following: acetylenic diol, organosilicon, phosphate ester, and polymer.

7. The waterborne black film with excellent flexibility according to claim 4, characterized in that: The thickness of the water-based black film is 2-5 μm.

8. A digital water-based resin plate, characterized in that: From top to bottom, it includes a protective substrate (1), an aqueous black film (2), a photosensitive resin layer (3), an adhesive layer (4), and a support (5); wherein the aqueous black film is the aqueous black film described in any one of claims 4-7.

9. The digital hydrosensitive photosensitive resin plate according to claim 8, characterized in that: (1) The protective substrate is a matte PET substrate with a thickness between 100-125 μm; (2) The water-based black film is a black film layer that can be laser-etched at wavelengths of 1064nm and 830nm; (3) The photosensitive resin layer is a composite film layer with a thickness of 400-2000μm containing a photocrosslinkable waterborne resin, acrylate unsaturated monomers, plasticizers, photoinitiators, stabilizers and dyes; (4) The adhesive layer is an adhesive coating with a thickness of 20-40 μm; (5) The support is a PET sheet or metal sheet with a thickness of 250-300μm.

10. The method for preparing a digital hydrosensitive photosensitive resin plate according to claim 8 or 9, characterized in that: A water-based ablation black film coating solution is coated onto a protective substrate and dried to obtain a water-based ablation black film with a protective substrate. The adhesive coating liquid is applied to the support and dried to obtain a support with an adhesive layer; The photosensitive resin layer is applied to a support with an adhesive layer by extrusion or casting and then dried. A water-based ablation black film with a protective film base is then laminated to the other side of the photosensitive resin layer to obtain a digital water-based photosensitive resin plate.

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