Multifunctional mercaptoalcohol compound and colored photosensitive resin composition

Abstract

The application provides a multi-functional mercapto alcohol compound and a colored photosensitive resin composition, and relates to the technical field of photoelectric display materials. The multi-functional mercapto alcohol compound is selected from any one of a compound M1, a compound M2 or a compound M3. The multi-functional mercapto alcohol compound has both mercapto and hydroxyl groups; the mercapto is used for regulating internal stress caused by molecular weight reduction; and the hydroxyl group promotes a cross-linking reaction in a low-temperature environment below 90 DEG C. This promotes the system to build a dense and tough three-dimensional network at low temperature, completely solves the problem of poor low-temperature curing, significantly improves the chemical resistance and adhesion of the material, eliminates development residues, and ensures that a fine line pattern has an ideal tilt angle and no lateral etching defects.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic display materials technology, and more specifically, to a composition of a multifunctional mercaptool compound and a coloring photosensitive resin. Background Technology

[0002] With the continuous development of display technology, organic light-emitting diodes (OLEDs) have gradually become the mainstream technology in the display field due to their significant advantages such as thinness, high brightness, low power consumption, and the ability to achieve flexible displays. In OLED and other display devices, color filter components are usually required to achieve full-color display and improve visual contrast, and the coloring photosensitive resin composition is the basic material for preparing the core coloring layer of the color filter.

[0003] In current OLED manufacturing processes, the technique of directly fabricating color filters on the thin-film encapsulation layer (COE) is widely used, which can significantly reduce screen thickness and improve flexibility. Unlike traditional liquid crystal displays (LCDs) that undergo high-temperature curing at temperatures above 200 degrees Celsius on a glass substrate, when forming color filters directly on the thin-film encapsulation layer, the thermal curing process of the color layer must be carried out in a relatively low-temperature environment (usually below 90 degrees Celsius) due to the strict limitations on the heat resistance of the underlying components.

[0004] However, existing coloring photosensitive resin compositions face significant technical bottlenecks when adapting to the aforementioned low-temperature thermosetting process. To improve the physical properties of the polymer film, existing technologies typically add conventional monofunctional thiol-based chain transfer agents to the system, aiming to reduce microscopic internal stress by controlling the molecular weight distribution. However, under limited low-temperature heating conditions, conventional chain transfer agents can only play a limited regulatory role and are difficult to effectively participate in or promote the construction of a sufficiently dense and tough three-dimensional cross-linked network, resulting in an unsatisfactory overall curing degree of the resin composition.

[0005] The aforementioned problems of poor cross-linking network construction ability and insufficient low-temperature curing have resulted in multiple defects in the existing technology. Specifically, poor curing significantly reduces the chemical resistance and adhesion of the color filter to the substrate, and easily generates development residue during the development process. In addition, due to the lack of sufficient support for the internal network structure at low temperatures, existing compositions cannot guarantee strict process morphology requirements when forming fine line patterns, easily leading to undesirable tilt angles and lateral etching defects, which seriously restricts the yield and reliability of high-end display panels.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a multifunctional mercaptool compound and a coloring photosensitive resin composition. The multifunctional mercaptool compound, through the synergistic effect of thiol group regulating molecular weight and hydroxyl group participating in low-temperature crosslinking, constructs a dense three-dimensional crosslinking network below 90°C, thereby achieving excellent chemical resistance, adhesion, no developing residue, and perfect pattern morphology.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In a first aspect, the present invention provides a multifunctional thiol compound, wherein the structure of the multifunctional thiol compound is selected from any one of compound M1, compound M2, or compound M3; wherein the chemical structures of compound M1, compound M2, and compound M3 are as follows: , and .

[0009] Secondly, the present invention provides a method for preparing a multifunctional thiol compound as described in the foregoing embodiments, comprising: A multifunctional epoxy compound was reacted with thioacetic acid to obtain an intermediate product. The intermediate product is hydrolyzed with an alkali to obtain the multifunctional mercaptool compound.

[0010] In some embodiments, the method for preparing the multifunctional thiol compound satisfies at least one of the following conditions: A. The reaction between the polyfunctional epoxy compound and thioacetic acid is carried out in the presence of a catalyst; B. The reaction temperature between the polyfunctional epoxy compound and thioacetic acid is 0℃~23℃; C. The reaction time between the polyfunctional epoxy compound and thioacetic acid is 3h~5h; D. The reaction temperature of the hydrolysis reaction is 0℃~23℃; E. The reaction time of the hydrolysis reaction is 1h~4h; F. The alkali includes sodium hydroxide; G. The multifunctional epoxy compound includes at least one of glycidyl ether, 2-[[1-[2,3-bis(epoxy-2-methoxy)propoxy]-3-(epoxy-2-methoxy)propenyl-2-]epoxymethyl]epoxyalkane and 2-[1,2,4,5,6-penta(epoxy-2-methoxy)hexyl-3-epoxymethyl]epoxyalkane.

[0011] Thirdly, the present invention provides a coloring photosensitive resin composition comprising a multifunctional mercaptool compound as described in the foregoing embodiments, as well as an alkali-soluble resin, a colorant, a photopolymerizable compound, a photopolymerization initiator, an additive, and a solvent.

[0012] In some embodiments, the alkali-soluble resin and / or the additive contains at least one active crosslinking group selected from isocyanate groups, blocked isocyanate groups, and epoxy groups.

[0013] In some embodiments, the alkali-soluble resin includes a first alkali-soluble resin; wherein the polymerizing monomer of the first alkali-soluble resin includes an acrylate monomer containing a pyrazole group. Preferably, the acrylate monomer containing the pyrazol group is 2-[(3,5-dimethyl-1-H-pyrazolyl)carboxyamino]ethyl acrylate; Preferably, the polymerization monomers of the first alkali-soluble resin further include alkyl methacrylate monomers, hydroxyalkyl methacrylate monomers, and methacrylic acid; Preferably, the alkali-soluble resin further includes a second alkali-soluble resin; wherein the polymerization monomers of the second alkali-soluble resin include polycycloalkyl acrylate monomers, benzyl methacrylate monomers, alkyl methacrylate monomers, vinyl double bond monomers containing epoxy groups, and acrylic acid.

[0014] In some embodiments, the coloring photosensitive resin composition satisfies at least one of the following conditions: A. The additive includes a crosslinking agent containing epoxy groups; B. The photopolymerizable compound includes acrylate monomers containing multiple functional groups, preferably dipentaerythritol hexaacrylate; C. The photopolymerization initiator includes oxime ester photoinitiators.

[0015] In some embodiments, based on the total weight of the colored photosensitive resin composition, the content of the alkali-soluble resin is 1% to 35%, the content of the colorant is 15% to 55%, the content of the photopolymerizable compound is 0.5% to 5%, the content of the photopolymerization initiator is 0.5% to 5%, the content of the additive is 0.5% to 10%, and the content of the additionally added solvent is 35% to 75%.

[0016] Fourthly, the present invention provides a color filter comprising a coloring layer formed by curing a coloring photosensitive resin composition as described in any of the foregoing embodiments; Preferably, the coloring layer is formed by heating and curing the coloring photosensitive resin composition at a temperature below 90°C; Preferably, the color difference ΔEab* value of the color filter before and after the chemical resistance test is 0.48~3.

[0017] Fifthly, the present invention provides a display device including a color filter as described in the foregoing embodiments; Preferably, the display device is an OLED display device; Preferably, the color filter is disposed on the thin-film encapsulation layer of the OLED display device.

[0018] In a sixth aspect, the present invention provides an electronic device including a display device as described in the foregoing embodiments.

[0019] Compared with existing technologies, the multifunctional mercapto alcohol compounds provided by this invention simultaneously and densely introduce multiple active mercapto groups and hydroxyl groups into a specific molecular backbone. These two groups endow the substance with unique dual functions. Among them, the mercapto groups can act as efficient chain transfer agents, effectively controlling the relative molecular mass and its uniformity of distribution of the polymer during free radical polymerization, reducing the free volume between molecular chains and maintaining consistent shrinkage and expansion behaviors, thereby significantly reducing the micro-stress inside the polymer and improving the overall structural stability.

[0020] Compared to conventional thiol-based compounds, the hydroxyl groups introduced in this compound possess crucial cross-linking activity. In environments where low-temperature heating below 90°C is necessary due to the heat resistance limitations of the underlying components, the hydroxyl groups in this compound can overcome the low-temperature reaction barrier and actively participate in cross-linking reactions with other active groups (such as isocyanate groups and epoxy groups) within the system. This synergistic effect of thiol regulation and hydroxyl cross-linking overcomes the bottleneck of conventional monofunctional compounds failing to fully solidify at low temperatures, greatly promoting the construction of a highly dense and robust three-dimensional cross-linked network.

[0021] Thanks to this dense and robust low-temperature cross-linking network, this compound fundamentally overcomes multiple performance defects caused by existing low-temperature curing processes. It imparts exceptional chemical resistance and strong adhesion to the substrate to the film-formed material, completely eliminating development residue issues. Simultaneously, the robust internal network structure provides ample support for fine-line patterns, ensuring ideal tilt angles at the pattern edges and effectively preventing lateral etching, fully meeting the demanding manufacturing requirements of high-end display panels under limited process conditions. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a synthetic reaction route diagram for step one of the preparation of the multifunctional mercaptool compound M1 in the embodiments of this application; Figure 2 This is a synthetic reaction route diagram for step two of the preparation of the multifunctional mercaptool compound M1 in the embodiments of this application; Figure 3 This is a synthetic reaction route diagram for step one of the preparation of the multifunctional mercaptool compound M2 in the embodiments of this application; Figure 4 This is a synthetic reaction route diagram for step two of the preparation of the multifunctional mercaptool compound M2 in the embodiments of this application; Figure 5 This is a synthetic reaction route diagram for step one of the preparation of the multifunctional mercaptool compound M3 in the embodiments of this application; Figure 6 This is a synthetic reaction route diagram for step two of the preparation of the multifunctional mercaptool compound M3 in the embodiments of this application; Figure 7 This is a schematic diagram indicating the taper angle of the micro-line pattern of the coloring layer in the embodiments of this application. Detailed Implementation

[0024] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0025] This application provides a multifunctional mercaptool compound, wherein the structure of the multifunctional mercaptool compound is selected from any one of compound M1, compound M2 or compound M3; The details are shown in Table 1: Table 1. Structures of multifunctional thiol compounds

[0026] The multifunctional mercaptool compounds described in this application have outstanding and substantial characteristics in their molecular structure, with multiple thiol groups (-SH) and multiple hydroxyl groups (-OH) introduced into their molecular skeleton. This specific multifunctional structure endows the compounds with a dual synergistic effect in photosensitive resin systems.

[0027] On the one hand, the thiol group in the compound acts as a highly efficient chain transfer agent, enabling the transfer of chain-growing free radicals during free radical polymerization, thereby precisely controlling the relative molecular mass of the polymer. This regulatory effect not only improves the uniformity of the polymer's molecular weight distribution and increases the effective entanglement and interaction between molecular chains, but also promotes a more uniform distribution of free volume between molecular chains. Consequently, the shrinkage and expansion behavior of the material tends to be consistent during subsequent processing, effectively releasing and reducing microscopic internal stress, greatly reducing the probability of coating cracking, and laying the foundation for the stability of the overall structure.

[0028] On the other hand, the hydroxyl group in the compound serves as a highly active crosslinking site, overcoming the limitation of conventional chain transfer agents having only one function. In low-temperature heating processes at 90°C and below, this hydroxyl group can overcome the low-temperature reaction barrier and undergo deep chemical crosslinking reactions with isocyanate groups or epoxy groups coexisting in the system.

[0029] Through the synergistic effect of the molecular weight regulation of thiol groups and the low-temperature crosslinking effect of hydroxyl groups, the multifunctional thiol compounds of this application can promote the construction of an extremely dense and tough three-dimensional crosslinked network in confined low-temperature curing environments (such as the color filter manufacturing process on OLED thin-film encapsulation layers). The formation of this crosslinked network fundamentally solves the technical problem of poor low-temperature curing, resulting in a film layer with excellent chemical resistance and adhesion to the substrate, effectively avoiding the generation of development residues, and providing strong structural support for micro-fine line patterns. This ensures that the patterns have a good tilt angle and no lateral etching defects, meeting the manufacturing requirements of high-precision display devices.

[0030] This application provides a method for preparing a multifunctional thiol compound as described in the foregoing embodiments. This method features mild reaction conditions, high conversion rate, and easily purified product. The preparation method includes: Step S1: The multifunctional epoxy compound is reacted with thioacetic acid to obtain an intermediate product.

[0031] In this step, a ring-opening reaction is carried out to synthesize the intermediate product. Specifically, a multifunctional epoxy compound is mixed and reacted with thioacetic acid.

[0032] In this reaction, thioacetic acid acts as a nucleophile, its highly reactive sulfur atom attacking the epoxy group in the multifunctional epoxy compound, promoting a nucleophilic ring-opening reaction of the epoxy ring. Through this ring-opening process, the epoxy group is converted into a hydroxyl group, while the thioacetic acid group is attached to the molecular backbone through a thioether bond, thereby constructing an intermediate product containing both a hydroxyl group and a thioester (-S-CO-CH3) structure in one step.

[0033] This step offers extremely high atom economy by pre-introducing the hydroxyl sites and thiol precursors required for cross-linking into the target product. To ensure a smooth ring-opening reaction and improve yield, this step can be carried out in the presence of a catalyst and at a suitable reaction time (e.g., 3–5 hours) under a non-high-temperature environment such as 0–23°C.

[0034] Step S2 involves hydrolyzing the intermediate product with an alkali to obtain the multifunctional mercaptool compound.

[0035] This step involves an alkaline hydrolysis reaction to release the target product. Specifically, the intermediate product containing hydroxyl and thioester structures obtained in the above steps is hydrolyzed with an alkali.

[0036] Under alkaline conditions, the thioester bonds on the intermediate product skeleton break (i.e., deprotection process), cleaving away the acetyl group and reducing the protected sulfur atom to a highly reactive free thiol group (-SH). The byproducts of cleavage (such as acetate) dissolve in the aqueous phase. Through this hydrolysis step, the polyfunctional thiol compound containing multiple hydroxyl and thiol groups on the same molecular skeleton is finally obtained.

[0037] This hydrolysis step can also be carried out under mild conditions, such as treating with an aqueous solution of a strong alkali like sodium hydroxide at a temperature of 0~23°C for 1~4 hours. After the reaction is complete, water-soluble impurities can be easily removed by conventional water washing and layering to obtain the target compound with high purity.

[0038] In a preferred embodiment of this application, in order to further improve the synthesis yield and final purity of the multifunctional mercapto alcohol compound, the first reaction (ring-opening reaction) and the second reaction (hydrolysis reaction) in the above preparation method are carried out under specific mild conditions and with preferred raw materials.

[0039] In some embodiments, the method for preparing the multifunctional thiol compound satisfies at least one of the following conditions: A. The reaction between the polyfunctional epoxy compound and thioacetic acid is carried out in the presence of a catalyst.

[0040] Specifically, in the step of preparing intermediate products, it is preferable to carry out the reaction of the multifunctional epoxy compound with thioacetic acid in the presence of a catalyst to reduce the activation energy of the reaction and accelerate the nucleophilic ring-opening process.

[0041] B. The reaction temperature between the polyfunctional epoxy compound and thioacetic acid is 0℃~23℃. For example, it can be 0℃, 2℃, 5℃, 8℃, 12℃, 15℃, 18℃, 20℃, 22℃, 23℃, etc.

[0042] C. The reaction time between the polyfunctional epoxy compound and thioacetic acid is 3h to 5h; for example, it can be 3h, 3.2h, 3.5h, 3.8h, 4h, 4.2h, 4.5h, 4.8h, 5h, etc.

[0043] Since the ring-opening reaction is exothermic, to suppress side reactions and avoid self-polymerization of the epoxy skeleton, the temperature of the reaction system is preferably strictly controlled within the range of 0℃ to 23℃. Under this low-temperature or ambient-temperature environment, the reaction system is maintained for 3 to 5 hours to ensure that all reaction sites on the multifunctional epoxy compound can undergo sufficient and complete ring-opening transformation with thioacetic acid, thereby obtaining an intermediate product with high conversion rate.

[0044] D. The reaction temperature of the hydrolysis reaction is 0℃~23℃; for example, it can be 0℃, 2℃, 5℃, 8℃, 12℃, 15℃, 18℃, 20℃, 22℃, 23℃, etc.

[0045] E. The reaction time of the hydrolysis reaction is 1h to 4h; for example, it can be 1h, 1.5h, 2h, 2.2h, 2.5h, 3h, 3.5h, 3.8h, 4h, etc.

[0046] F. The alkali includes sodium hydroxide; In the hydrolysis step, sodium hydroxide is preferably used as the alkaline hydrolysis reagent to efficiently release the intermediate product into the target product without destroying the formed molecular structure. Sodium hydroxide can efficiently cleave thioester bonds, and the byproducts generated in the reaction (such as sodium acetate) are highly soluble in water and can be completely removed by conventional water washing, thus greatly simplifying the post-processing purification process. To prevent the highly reactive free thiol groups from oxidizing or coupling at high temperatures, the hydrolysis reaction is also preferably carried out at a mild temperature of 0℃ to 23℃, and the reaction time is controlled within 1h to 4h. The low-temperature and controllable process conditions throughout the entire process synergistically ensure that the prepared multifunctional thiol alcohol compound possesses extremely high chemical purity and functional group activity, providing a reliable material basis for its subsequent application in photosensitive resin compositions.

[0047] G. The multifunctional epoxy compound includes at least one of glycidyl ether, 2-[[1-[2,3-bis(epoxy-2-methoxy)propoxy]-3-(epoxy-2-methoxy)propenyl-2-]epoxymethyl]epoxyalkane and 2-[1,2,4,5,6-penta(epoxy-2-methoxy)hexyl-3-epoxymethyl]epoxyalkane.

[0048] As the aforementioned multifunctional epoxy compounds, it is preferable to use specific skeletal compounds containing multiple epoxy groups in their structure, specifically including at least one of glycidyl ether, 2-[[1-[2,3-bis(epoxy-2-methoxy)propoxy]-3-(epoxy-2-methoxy)propenyl-2-]epoxymethyl]epoxide, and 2-[1,2,4,5,6-penta(epoxy-2-methoxy)hexyl-3-epoxymethyl]epoxide. Using the above-mentioned specific compounds as precursors ensures that the final multifunctional mercaptool compound has an ideal molecular skeleton with sufficient crosslinking active sites densely distributed thereon.

[0049] This application provides a coloring photosensitive resin composition with a rationally designed formulation system that can meet the requirements of low-temperature curing processes under extremely harsh conditions. Specifically, the coloring photosensitive resin composition comprises: a multifunctional mercaptool compound as described in the foregoing embodiments, as well as an alkali-soluble resin, a colorant, a photopolymerizable compound, a photopolymerization initiator, additives, and a solvent.

[0050] In this composition system, the components exhibit a high degree of synergistic effect. The colorant is uniformly dispersed throughout the system to provide the required optical transmittance; the solvent is used to adjust the system viscosity to ensure excellent coating uniformity; the photopolymerization initiator absorbs light energy during the exposure process, releasing active free radicals that initiate rapid cross-linking polymerization of the photopolymerizable compounds, thereby constructing the initial physical network resisting the developer and completing the depiction of fine patterns. Simultaneously, the alkali-soluble resin provides the film-forming matrix and the necessary alkaline developing ability, ensuring that unexposed areas can be cleanly washed away without residue.

[0051] It is worth emphasizing that the aforementioned multifunctional mercapto alcohol compound introduced into the system in this application embodiment produces a key low-temperature synergistic curing effect with other components in the composition. During the photolithography stage, the mercapto groups in this compound act as chain transfer agents, effectively regulating the molecular weight distribution during crosslinking of the photopolymerizable compound, significantly reducing internal micro-stress, thereby ensuring the structural stability of fine lines and effectively avoiding lateral etching defects during the development process. In the subsequent low-temperature thermal curing stage (e.g., heating below 90°C), the free hydroxyl groups in this compound act as highly active reaction sites, actively forming deep chemical bonds with the latent active groups on the alkali-soluble resin (such as heat-unsealed isocyanate structures) and additives (such as epoxy thermal crosslinking agents).

[0052] In some embodiments, the alkali-soluble resin and / or the additive contains at least one active crosslinking group selected from isocyanate groups, blocked isocyanate groups, and epoxy groups.

[0053] It should be noted that, in order to achieve deep crosslinking with the multifunctional mercapto alcohol compound at low temperatures, the system of this application must contain active target groups (such as isocyanate groups, blocked isocyanate groups, or epoxy groups) capable of reacting with it. These active groups can be mounted on the polymer side chains of a specific alkali-soluble resin as described in the following examples, or they can exist as independent crosslinking agents in the additive. This invention does not impose strict limitations on this; as long as the coloring photosensitive resin composition system meets the above-mentioned crosslinking target requirements, excellent low-temperature curing effects can be achieved through the synergistic network construction of mercapto and hydroxyl groups.

[0054] Through the dual effects of photocuring and the aforementioned low-temperature thermal crosslinking mediated by thiol and hydroxyl groups, this colored photosensitive resin composition overcomes the technical bottleneck of traditional materials that require high temperatures for full curing. It can form a highly dense and tough three-dimensional polymer crosslinking network at extremely low heating temperatures, not only completely eliminating development residues and imparting excellent tilt angle morphology to the fine patterns, but also resulting in a colored layer that exhibits superior resistance to chemical solvents and strong adhesion to the substrate. This makes it extremely suitable for the manufacture of advanced display devices (such as OLED thin-film encapsulation layers) where processing temperatures are limited.

[0055] In some embodiments, in order to achieve excellent development performance, long-term storage stability and efficient low-temperature crosslinking and curing, the alkali-soluble resin is preferably a composite resin system copolymerized from different functional monomers.

[0056] Specifically, the alkali-soluble resin includes a first alkali-soluble resin; wherein the polymerizing monomer of the first alkali-soluble resin includes an acrylate monomer containing a pyrazole group.

[0057] Furthermore, the acrylate monomer containing the pyrazol group is 2-[(3,5-dimethyl-1-H-pyrazolyl)carboxyamino]ethyl acrylate.

[0058] Furthermore, the polymerization monomers of the first alkali-soluble resin also include alkyl methacrylate monomers, hydroxyalkyl methacrylate monomers, and methacrylic acid.

[0059] The first alkali-soluble resin is an alkali-soluble polymer containing heat-latent crosslinking groups. Its monomers include at least an acrylate monomer containing a pyrazole group, preferably 2-[(3,5-dimethyl-1-H-pyrazole)carboxyamino]ethyl acrylate. This specific monomer introduces a blocked isocyanate structure onto the resin side chain. During room temperature storage or coating drying, the isocyanate groups are protected by the pyrazole ring, preventing premature crosslinking within the system, thus giving the composition excellent storage stability. In subsequent heat curing processes, even at low temperatures below 90°C, the pyrazole blocked groups can effectively dissociate, releasing highly active isocyanate groups. To adjust film-forming properties and developability, the monomers of the first alkali-soluble resin also include alkyl methacrylate monomers, hydroxyalkyl methacrylate monomers, and methacrylic acid to provide the necessary alkali solubility.

[0060] Furthermore, the alkali-soluble resin further includes a second alkali-soluble resin; wherein the polymerization monomers of the second alkali-soluble resin include polycycloalkyl acrylate monomers, benzyl methacrylate monomers, alkyl methacrylate monomers, vinyl double bond monomers containing epoxy groups, and acrylic acid.

[0061] The second alkali-soluble resin is an alkali-soluble polymer containing epoxy active groups. Its monomers include polycycloalkyl acrylate monomers, benzyl methacrylate monomers, alkyl methacrylate monomers, vinyl double-bonded monomers containing epoxy groups (e.g., glycidyl methacrylate), and acrylic acid. This combination of monomers not only endows the second alkali-soluble resin with suitable heat resistance and excellent alkaline development tolerance, effectively preventing lateral etching of the fine pattern bottom by the developer, but also provides abundant reaction sites for subsequent thermosetting with the epoxy groups on the side chains.

[0062] During the low-temperature heating treatment (e.g., 85°C~90°C) after development, the isocyanate groups released by the thermal desealing of the first alkali-soluble resin undergo a deep synergistic crosslinking reaction with the hydroxyl groups on the multifunctional mercapto alcohol compounds in the composition system, as well as the epoxy groups contained in the second alkali-soluble resin and additives. This construction of a multi-layered crosslinking network allows the resin composition of this application to achieve full curing even under limited low-temperature conditions. The resulting colored layer has a dense physical structure, exhibiting comprehensive technical effects such as no development residue, excellent pattern tilt angle, and excellent chemical resistance and substrate adhesion.

[0063] In a preferred embodiment of this application, in order to further improve the precision of the coloring photosensitive resin composition during the photolithography stage and the crosslinking density during the low-temperature thermosetting stage, in some embodiments, the coloring photosensitive resin composition satisfies at least one of the following conditions: A. The additives include crosslinking agents containing epoxy groups.

[0064] When a crosslinking agent containing epoxy groups is introduced into the additive, the crosslinking agent can produce an excellent synergistic effect of thermal crosslinking with the free hydroxyl groups on the multifunctional mercapto alcohol compounds in the system. During the low-temperature heating process (e.g., below 90°C) after development, the epoxy groups are highly susceptible to nucleophilic attack by the hydroxyl groups, resulting in ring-opening polymerization. This deep low-temperature thermal crosslinking effectively compensates for the incomplete curing defects of conventional systems under limited temperatures, enabling the final colored layer to construct an extremely dense three-dimensional network, thereby exhibiting excellent resistance to chemical solvents and strong adhesion to the substrate.

[0065] B. The photopolymerizable compound includes acrylate monomers containing multiple functional groups, preferably dipentaerythritol hexaacrylate.

[0066] In the photolithography exposure stage, acrylate monomers containing multiple functional groups are preferred as photopolymerizable compounds, especially dipentaerythritol hexaacrylate (DPHA). These multifunctional monomers, due to the multiple polymerization sites within a single molecule, can form a high-density anti-development physical network extremely rapidly under light irradiation. Simultaneously, the thiol groups on the multifunctional mercaptool compounds in the system act as efficient chain transfer agents, effectively mitigating and releasing the microscopic shrinkage stress caused by high-density crosslinking. The synergistic effect of these two factors results in micro-line patterns with extremely high strength after development, effectively avoiding bottom lateral etching and imparting smooth edges and ideal tilt angles to the pattern.

[0067] C. The photopolymerization initiator includes oxime ester photoinitiators.

[0068] To ensure efficient activation of the aforementioned photopolymerization reaction, oxime ester photoinitiators are preferably used. Oxime ester photoinitiators possess extremely high light absorption efficiency and sensitivity, and can undergo efficient cleavage and release a large number of highly reactive free radicals during ultraviolet light exposure. This not only ensures complete photocuring of the deep layers of the coating and improves the resolution of the photolithographic pattern, but also fundamentally eliminates the problem of developing residue caused by the peeling off of incompletely cured portions in the developing solution, fully meeting the stringent material requirements of high-precision display device manufacturing processes.

[0069] In the coloring photosensitive resin composition of this application, the proportions of each component in the system are precisely controlled to achieve an optimal balance between optical properties, development properties, and final physical properties in a limited low-temperature curing environment (e.g., below 90°C). Specifically, based on the total weight of the coloring photosensitive resin composition, refer to Table 2: Table 2. Components and Contents in the Coloring Photosensitive Resin Composition

[0070] It should be noted that the percentage content of each component involved in this application (as shown in Table 2 and the weight percentages described in the aforementioned schemes) is calculated based on the total macroscopic weight of the raw materials added when preparing the coloring photosensitive resin composition. Specifically, when the 'colorant' is added to the system in the form of a pre-prepared 'colorant dispersion composition' (containing pigments, dispersants, solvents, etc.), the 'colorant content (15%~55%)' refers to the total weight percentage of the colorant dispersion composition added; similarly, if the alkali-soluble resin is added in the form of a resin solution, its content also refers to the total weight percentage of the resin solution added. The 'solvent' content refers to the weight percentage of the solvent added separately to adjust the viscosity of the system, in addition to the above-mentioned dispersion composition or resin solution.

[0071] The specific weight percentage range mentioned above is the basis for the synergistic effect of each component. Specifically, controlling the alkali-soluble resin at 1% to 35% ensures both an excellent film-forming framework and sufficient alkali development capability, while avoiding poor coating due to excessive viscosity. The colorant content is as high as 15% to 55%, meeting the stringent requirements of advanced display devices for high color saturation and high contrast. Simultaneously, to overcome the masking effect of high-concentration colorant on the exposure light source, this application precisely controls the content of both the photopolymerizable compound and the photopolymerization initiator within the range of 0.5% to 5%. This specific dosage of the photopolymerization system, combined with the unique multifunctional mercaptool compound of this application, effectively avoids the "light shielding" phenomenon caused by excessive surface curing, allowing for sufficient cross-linking even in the deeper layers of the coating. This results in a residue-free, perfectly fine line pattern with excellent tilt angles and no lateral etching after development.

[0072] Furthermore, the additive content is limited to 0.5%~10%. Within this range, the thermal crosslinking agent containing active ingredients such as epoxy groups can fully and appropriately undergo a deep low-temperature thermal crosslinking reaction with the free hydroxyl groups on the multifunctional mercapto alcohol compounds in the system. This secondary thermal crosslinking triggered under a specific concentration window allows the final coloring layer to construct an extremely dense three-dimensional network without damaging the underlying components with poor heat resistance, thus endowing the coating with excellent chemical resistance and substrate adhesion. Meanwhile, the solvent content of 35%~75% provides ideal leveling and coating adaptability for the entire system, ensuring the yield of industrial processing of the product.

[0073] This application also provides a color filter, which is particularly suitable for high-precision optoelectronic display devices (such as organic light-emitting diode display panels with thin-film encapsulation layers) with strict limitations on process temperature. Specifically, the color filter includes a coloring layer formed by curing a coloring photosensitive resin composition as described in any of the foregoing embodiments.

[0074] The coloring layer can be a cured film with a specific microstructure formed by coating the aforementioned coloring photosensitive resin composition onto a substrate and then sequentially undergoing exposure, development, and heat curing processes.

[0075] Furthermore, the coloring layer is formed by heating and curing the coloring photosensitive resin composition at a temperature below 90°C. For example, it can be 60°C, 65°C, 70°C, 75°C, 80°C, 82°C, 85°C, 88°C, 89°C, 90°C, etc.

[0076] During the formation of the coloring layer, thanks to the efficient synergy of specific components in the coloring photosensitive resin composition, the heat curing process can be completed below 90°C. The underlying mechanism lies in the fact that the multifunctional mercaptool compounds contained in the system possess highly active free hydroxyl groups. Under low-temperature heating below 90°C, these hydroxyl groups can undergo deep chemical bonding with the isocyanate groups on the alkali-soluble resin that are deactivated by heat, as well as the epoxy groups in the additives. This low-temperature synergistic crosslinking mechanism breaks through the technical barrier of traditional color filters that require 230°C for curing, perfectly avoiding damage to the underlying fragile light-emitting components from high temperatures while thoroughly achieving high-density crosslinking film formation.

[0077] Furthermore, the color difference ΔEab* value of the color filter before and after the chemical resistance test is 0.48~3. For example, it can be 0.48, 0.5, 0.8, 1.0, 1.3, 1.8, 2.0, 2.4, 2.8, 3, etc.

[0078] Due to the extremely dense three-dimensional polymer network constructed at low temperatures and free of microscopic stress defects, the color filter exhibits exceptional resistance to chemical solvents. Objective measurements show that after rigorous chemical resistance testing (immersing the cured color layer in a specific chemical solvent for a certain period), the color difference ΔEab* value before and after the test remains consistently within an extremely low range of 0.48 to 3. This excellent color difference parameter confirms that solvents have extremely difficulty penetrating and damaging the internal structure of the color layer, ensuring that the color filter maintains perfect optical transmittance and color fidelity during the complex chemical processes of subsequent panel manufacturing.

[0079] This application also provides a display device including a color filter as described in the foregoing embodiments. This display device incorporates the aforementioned color filter and can achieve excellent color display effects.

[0080] Furthermore, the display device is an OLED display device.

[0081] Specifically, the display device is preferably an organic light-emitting diode (OLED) display device. In order to meet the development needs of modern smart devices for ultra-thin and flexible screens, the display device of this application adopts an advanced substrate-free packaging structure, that is, the color filter is directly disposed on the thin film encapsulation layer of the OLED display device (i.e., COE technology architecture).

[0082] Furthermore, the color filter is disposed on the thin-film encapsulation layer of the OLED display device.

[0083] While building the color filter layer directly onto the thin-film encapsulation layer can significantly improve screen contrast and outdoor visibility, traditional color filter manufacturing processes often require thermal curing at temperatures exceeding 200°C. This directly leads to irreversible thermal degradation and failure of the heat-sensitive OLED organic light-emitting components beneath the thin-film encapsulation layer.

[0084] The display device provided in this application perfectly overcomes the aforementioned technical bottlenecks. Because the coloring layer used in this application is formed from a photosensitive resin composition containing specific multifunctional mercaptool compounds, this composition possesses extremely excellent low-temperature thermal crosslinking characteristics, allowing the heat curing process of the color filter to be strictly controlled below 90°C. This specific low-temperature curing mechanism ensures the formation of a dense and robust polymer crosslinking network within the color filter layer while achieving zero thermal damage to the underlying OLED light-emitting components.

[0085] Furthermore, thanks to the excellent chemical solvent resistance and strong adhesion to the substrate exhibited by the cured resin composition of this application, the coloring layer directly attached to the thin-film encapsulation layer not only avoids peeling or swelling during subsequent panel processing (such as cleaning and etching), but also serves as a robust optical and physical composite protective layer, further isolating the internal encapsulation structure from external chemical substances. Simultaneously, the excellent tilt angle and absence of development residue in the microscopic fine line pattern of this coloring layer fundamentally eliminates panel light leakage and pixel crosstalk issues, thereby comprehensively ensuring the high image quality and long-term reliability of this novel OLED display device.

[0086] This application also provides an electronic device, including the display device described in the foregoing embodiments. The display device in the electronic device is mainly used to provide high-quality image or video information display and a visual interactive interface.

[0087] Thanks to the built-in display device prepared using the specific coloring photosensitive resin composition of this application, the overall performance of this electronic device is significantly improved. Specifically, since the underlying coloring layer has been successfully cured at a low temperature below 90°C and can be directly integrated onto the thin-film encapsulation layer of the organic light-emitting diode, the traditional heavy glass substrate has been eliminated, enabling the overall structure of this electronic device to achieve an extremely thin and light design, making it particularly suitable for novel flexible or foldable electronic device forms with extremely stringent space and weight requirements.

[0088] Meanwhile, due to the formation of an extremely dense and micro-defect-free three-dimensional cross-linked network inside the coloring layer, its excellent resistance to chemical solvents and strong substrate adhesion not only fundamentally eliminates the problems of light leakage and color bleeding inside the panel, giving electronic devices extremely high contrast and color saturation, but also effectively enhances the structural stability of internal core components, and significantly improves the service life and reliability of the entire electronic device in various complex application scenarios.

[0089] In specific embodiments of this application, the electronic device can be any intelligent terminal, industrial equipment, or large intelligent transportation vehicle with display functionality, including but not limited to: smartphones, tablets, laptops, personal digital assistants (PDAs), portable media players, smart wearable devices (such as smartwatches, virtual reality headsets, augmented reality headsets, etc.), smart TVs, and intelligent display terminals for various medical or industrial control instruments. Furthermore, the electronic device can also be a transportation vehicle with display functionality, such as new energy vehicles, intelligent connected vehicles, ships, and aircraft that include in-vehicle central control displays, electronic instrument panels, or head-up display systems (HUDs). Those skilled in the art can combine the display device with conventional power modules, main control chips, and housing components (or vehicle / ship structures) according to actual product requirements to assemble a complete electronic device.

[0090] The present invention will be further illustrated below with specific embodiments. However, it should be understood that these embodiments are merely for the purpose of more detailed illustration and should not be construed as limiting the present invention in any way.

[0091] I. Example of raw material preparation: Before preparing the coloring photosensitive resin composition of this application, the synthesis and preparation of each core raw material component are carried out first.

[0092] 1. Synthesis of mercapto alcohol compounds as chain transfer agents: Preparation Example 1 (Synthesis of mercaptool compound M1) Preparation method: Step 1: Place a 1L four-necked reactor equipped with a thermometer and mechanical stirrer in an ice-water bath. Add 200 parts by weight of N,N-dimethylformamide as a solvent, 26 parts by weight of glycidyl ether, 25.1 parts by weight of thioacetic acid, and triethylamine equivalent to 20% by weight of thioacetic acid as a catalyst. Stir under a nitrogen atmosphere and react at 0°C for 4 hours. Measure the FT-IR. When the characteristic peak of the epoxy group is 1000~1200cm... -1 The reaction was terminated when the N,N-dimethylformamide completely disappeared. The product was washed three times or more with 0.1 mol / L dilute hydrochloric acid, and N,N-dimethylformamide was removed by rotary evaporation to obtain intermediate M1' with a hydroxythioester structure. The specific reaction route can be seen as follows: Figure 1 As shown.

[0093] Step 2: Place a 1L four-necked reactor equipped with a thermometer and mechanical stirrer in an ice-water bath. Add 300 parts by mass of methanol and 60 parts by mass of water as solvents, 48.4 parts by mass of M1', and 12 parts by mass of sodium hydroxide. Stir under a nitrogen atmosphere and react at 0°C for 2 hours. Wash the product three times or more with 0.1 mol / L dilute hydrochloric acid and extract with ethyl acetate. Remove excess solvent by rotary evaporation to obtain the mercapto alcohol compound M1. The specific reaction route can be seen as follows: Figure 2 As shown.

[0094] Structural characterization: 1 H NMR (CDCl3, 500MHz): δ ppm: M1: 5.37 (3H), 4.18 (6H), 4.00 (3H), 3.82 (3H), 3.58 (5H), 2.17 (6H).

[0095] Preparation Example 2 (Synthesis of thiol compound M2) Preparation method: Step 1: Under the same conditions as in Step 1 above, 39 parts by mass of 2-[[1-[2,3-bis(epoxy-2-methoxy)propoxy]-3-(epoxy-2-methoxy)propenyl-2-]epoxymethyl]epoxide was reacted with 33.5 parts by mass of thioacetic acid to obtain intermediate product M2'. The specific reaction route can be as follows: Figure 3 As shown.

[0096] Step Two: Under the same conditions as in Step Two above, use 300 parts by mass of methanol, 80 parts by mass of water, 66.4 parts by mass of M2', and 16 parts by mass of sodium hydroxide to react. After extraction and rotary evaporation, the mercapto alcohol compound M2 is obtained. The specific reaction route can be as follows: Figure 4 As shown.

[0097] Structural characterization: 1 H NMR (CDCl3, 500MHz): δ ppm: M2: 5.37 (4H), 4.18 (4H), 4.00 (8H), 3.82 (4H), 3.58 (10H), 2.17 (8H).

[0098] Preparation Example 3 (Synthesis of mercaptool compound M3) Preparation method: Step 1: Under the same conditions as in Step 1 above, 51.8 parts by mass of 2-[1,2,4,5,6-penta(epoxy-2-methoxy)hexyl-3-epoxymethyl]epoxide is reacted with 50.2 parts by mass of thioacetic acid to obtain intermediate product M3'. The specific reaction route can be as follows: Figure 5 As shown.

[0099] Step Two: Under the same conditions as in Step Two above, use 300 parts by mass of methanol, 120 parts by mass of water, 97.4 parts by mass of M3', and 24 parts by mass of sodium hydroxide to react. After extraction and rotary evaporation, the mercapto alcohol compound M3 is obtained. The specific reaction route can be as follows: Figure 6 As shown.

[0100] Structural characterization: 1 H NMR (CDCl3, 500MHz): δ ppm: M3: 5.37 (6H), 4.45 (2H), 4.18 (12H), 4.00 (8H), 3.82 (6H), 3.66 (4H), 2.17 (12H).

[0101] 2. Synthesis of alkali-soluble resins: Preparation Example 4 (Synthesis of Alkali-Soluble Resin B1) Preparation method: 45 parts by weight of isooctyl methacrylate, 30 parts by weight of 2-[(3,5-dimethyl-1-H-pyrazolyl)carboxyamino]ethyl acrylate, 11 parts by weight of methacrylic acid, and 14 parts by weight of hydroxyethyl methacrylate were added, along with 7% by weight of azobisisobutyronitrile and 272 parts by weight of propylene glycol monomethyl ether acetate. The mixture was reacted at 70°C for 8 hours under a nitrogen atmosphere to obtain alkali-soluble resin B1 with a weight-average molecular weight of 11500 and an acid value of 34.3 mg•KOH / g.

[0102] Preparation Example 5 (Synthesis of Alkali-Soluble Resin B2) Preparation method: Ten parts by mass of tricyclodecanediethanol dimethacrylate, 29.5 parts by mass of benzyl methacrylate, 20 parts by mass of isooctyl methacrylate, and 40.5 parts by mass of acrylic acid were added, along with 7 wt% azobisisobutyronitrile and 302 parts by mass of propylene glycol monomethyl ether acetate. The mixture was reacted at 70°C for 6 hours under a nitrogen atmosphere. After cooling to room temperature, 15 parts by mass of glycidyl methacrylate, 0.07 wt% hydroquinone, and 0.1 wt% 2,4,6-tris(dimethylaminomethyl)phenol were added, and the mixture was heated to 90°C and reacted for 5 hours to obtain alkali-soluble resin B2 with a weight-average molecular weight of 9700 and an acid value of 93 mg•KOH / g.

[0103] 3. Preparation of the colorant dispersion composition: Preparation Example 6 (Colorant A1) Preparation method: 13 parts of PR254, 11 parts of PY150, 69 parts of PMA, and 7 parts of DISPERBYK-2001 were dispersed in a bead mill for 12 hours.

[0104] Preparation Example 7 (Colorant A2) Preparation method: 3.8 parts PG36, 3 parts PB15:6, 3.3 parts PY150, 1.3 parts PY185, 4.4 parts PY139, 75.9 parts PMA, and 8.3 parts DISPERBYK-2001 were dispersed in a bead mill for 12 hours.

[0105] Preparation Example 8 (Colorant A3) Preparation method: 8.4 parts PB15:6, 3 parts PB16, 1.4 parts PV23, 78.2 parts PMA, and 9 parts DISPERBYK-2001 were dispersed in a bead mill for 12 hours.

[0106] II. Examples and Comparative Examples of the Compositions: Example 1 This embodiment provides a coloring photosensitive resin composition, mainly examining the overall performance of the composition when a mercapto alcohol compound M1 is added as a chain transfer agent to a basic formulation using colorant A1 and a specific photoinitiator system.

[0107] Preparation method: Mix 43.74 parts by weight of pigment dispersion composition A1, 2.44 parts by weight of alkali-soluble resin B1, 9.23 parts by weight of alkali-soluble resin B2, 1.67 parts by weight of DPHA, 0.53 parts by weight of YJP-05, 0.13 parts by weight of leveling agent EFS-801, 0.8 parts by weight of mercapto alcohol compound M1, 3.34 parts by weight of crosslinking agent EHPE-3150, 0.16 parts by weight of adhesion promoter KBM-503M, 0.16 parts by weight of adhesion promoter KBM-603, and 37.8 parts by weight of PGMEA to prepare a photosensitive resin composition.

[0108] Example 2 This embodiment provides a coloring photosensitive resin composition, mainly examining the overall performance when the chain transfer agent is replaced with mercaptool compound M2 in the same formulation system as in Example 1. Formulation method: The formulation is the same as in Example 1, except that 0.8 parts by mass of mercaptool compound M1 is replaced with 0.8 parts by mass of mercaptool compound M2.

[0109] Example 3 This embodiment provides a coloring photosensitive resin composition, mainly examining the comprehensive performance of adding mercapto alcohol compound M3 as a chain transfer agent in a system with adjusted resin B2 and photoinitiator ratios. Preparation method: Mix 43.74 parts by weight of A1, 2.44 parts by weight of B1, 2.21 parts by weight of B2, 1.67 parts by weight of DPHA, 0.89 parts by weight of YJP-05, 0.13 parts by weight of EFS-801, 0.8 parts by weight of mercapto alcohol compound M3, 3.34 parts by weight of EHPE-3150, 0.16 parts by weight of KBM-503M, 0.16 parts by weight of KBM-603, and 37.8 parts by weight of PGMEA.

[0110] Example 4 This embodiment provides a coloring photosensitive resin composition, mainly examining the comprehensive performance of adding mercapto alcohol compound M1 as a chain transfer agent in a system using colorant A2 and composite photoinitiators (DFI-020 and YJP-05). Preparation method: Mix 44.8 parts by weight of A2, 7.91 parts by weight of B1, 9.23 parts by weight of B2, 1.19 parts by weight of DPHA, 0.89 parts by weight of DFI-020, 0.3 parts by weight of YJP-05, 0.13 parts by weight of EFS-801, 0.71 parts by weight of mercapto alcohol compound M1, 3.96 parts by weight of EHPE-3150, 0.16 parts by weight of KBM-503M, 0.16 parts by weight of KBM-603, and 30.56 parts by weight of PGMEA.

[0111] Example 5 This embodiment provides a coloring photosensitive resin composition, mainly examining the overall performance when the chain transfer agent is replaced with mercaptool compound M2 in the same formulation system as in Example 4. Preparation method: The formulation is the same as in Example 4, except that 0.71 parts by mass of mercaptool compound M1 is replaced with 0.71 parts by mass of mercaptool compound M2.

[0112] Example 6 This embodiment provides a coloring photosensitive resin composition, mainly examining the overall performance when the chain transfer agent is replaced with mercaptool compound M3 in the same formulation system as in Example 4. Preparation method: The formulation is the same as in Example 4, except that 0.71 parts by mass of mercaptool compound M1 is replaced with 0.71 parts by mass of mercaptool compound M3.

[0113] Example 7 This embodiment provides a coloring photosensitive resin composition, mainly examining the comprehensive performance of adding mercapto alcohol compound M1 as a chain transfer agent in a system using colorant A3 and three composite photoinitiators. Preparation method: Mix 24.78 parts by weight of A3, 5.14 parts by weight of B1, 14.56 parts by weight of B2, 1.64 parts by weight of DPHA, 0.25 parts by weight of DFI-020, 0.14 parts by weight of TR-PBG-345, 0.82 parts by weight of YJP-05, 0.13 parts by weight of EFS-801, 0.41 parts by weight of mercapto alcohol compound M1, 5.47 parts by weight of EHPE-3150, 0.16 parts by weight of KBM-503M, 0.16 parts by weight of KBM-603, and 46.34 parts by weight of PGMEA.

[0114] Example 8 This embodiment provides a coloring photosensitive resin composition, mainly examining the overall performance when the chain transfer agent is replaced with mercaptool compound M2 in the same formulation system as in Example 7. Formulation method: The formulation is the same as in Example 7, except that 0.41 parts by mass of mercaptool compound M1 is replaced with 0.41 parts by mass of mercaptool compound M2.

[0115] Example 9 This embodiment provides a coloring photosensitive resin composition, mainly examining the overall performance when the chain transfer agent is replaced with mercaptool compound M3 in the same formulation system as in Example 7. Formulation method: The formulation is the same as in Example 7, except that 0.41 parts by mass of mercaptool compound M1 is replaced with 0.41 parts by mass of mercaptool compound M3.

[0116] Comparative Example 1 This comparative example provides a coloring photosensitive resin composition as a control for Examples 1-3, mainly examining the performance of the basic formulation when the specific mercapto alcohol compound of this application is absent as a chain transfer agent. Preparation method: Based on Example 1, 0.8 parts by weight of mercapto alcohol compound M1 were removed, and PGMEA solvent was added to adjust the composition to 38.6 parts by weight. The remaining components and contents were the same as in Example 1.

[0117] Comparative Example 2 This comparative example provides a coloring photosensitive resin composition as a control for Examples 4-6, mainly examining the performance of the formulation using colorant A2 without the specific mercapto alcohol compound of this application. Preparation method: Based on Example 4, 0.71 parts by mass of mercapto alcohol compound M1 were removed, and PGMEA solvent was added to adjust the composition to 31.27 parts by mass. The remaining components and contents were the same as in Example 4.

[0118] Comparative Example 3 This comparative example provides a coloring photosensitive resin composition as a control for Examples 7-9, mainly examining the performance of the formulation using colorant A3 without the specific mercapto alcohol compound of this application. Preparation method: Based on Example 7, 0.41 parts by mass of mercapto alcohol compound M1 were removed, and PGMEA solvent was added to adjust the composition to 46.75 parts by mass. The remaining components and contents were the same as in Example 7.

[0119] Comparative Example 4 This comparative example provides a coloring photosensitive resin composition as a control for Examples 1-3, mainly examining the advantages of the specific thiol compound of this application as a chain transfer agent compared to conventional thiol compounds, and the performance of various aspects of the basic formulation. Preparation method: Based on Example 1, 0.8 parts by weight of thiol compound M1 were replaced with 0.8 parts by weight of pentaerythritol tetrakis(3-mercaptopropionate) PETMP, while the remaining components and contents remained the same as in Example 1.

[0120] III. Performance Evaluation Experiments and Results: 1. Manufacturing of photosensitive resin films (color filters): The compositions of Examples 1-9 and Comparative Examples 1-3 were coated onto glass substrates (2 μm film thickness after drying). After vacuum drying (reducing to 65 Pa within 90 seconds), they were pre-baked on a hot plate at 85°C for 140 seconds. Exposure was performed with or without a mask (50 μm spacing between lines / micropores) using a high-pressure mercury lamp (330 nm filter, 80 mJ / cm²). 2 Expose the sample to a solution of KOH at pH 10.5 for 2 minutes, rinse with distilled water, dry with nitrogen, and finally cure in an oven at 85°C for 60 minutes to obtain the test filter.

[0121] 2. Evaluation methods: film thickness and color: The film thickness, xy chromaticity coordinates, and tristimulus value Y were measured before and after the experiment using a film thickness measuring device and a colorimeter.

[0122] (1) Chemical resistance evaluation: The entire coating was immersed in a solvent (propylene glycol monomethyl ether: PGMEA = 7:3) for 8 minutes. The color difference ΔEab and film thickness retention ΔTpr before and after the test were evaluated.

[0123] Judgment criteria: A: ΔEab < 3 or ΔTpr > 90%; B: 3 < ΔEab* < 6 or 80% < ΔTpr < 90%; C: ΔEab* > 6 or ΔTpr < 80%.

[0124] (2) Evaluation of development residue: Microscopic observation of 30μm micropore pattern.

[0125] Judgment criteria: A: No residue inside or around; B: No residue inside, transparent matter around; C: Colored residue around.

[0126] (3) Evaluation of the fine line pattern morphology (Taper Angle and Undercut): The cross-section was observed using an electron microscope. Tilt angle θ (refer to...) Figure 7 (The indicated angle) Judgment criteria: A: 15° < θ < 70°; B: 70° < θ < 90°; C: θ > 90°.

[0127] It should be noted that the aforementioned tapered angle refers to the angle formed between the sidewall surface of the pattern and the surface of the underlying substrate in the cross-section of the micro-line pattern formed after the coloring photosensitive resin composition has been coated, exposed, developed, and heat-cured to form a micro-line pattern. In the manufacturing of high-end optoelectronic display panels, in order to ensure the step coverage of subsequent film layers and reduce interlayer stress, the ideal tapered angle is usually a trapezoidal morphology (i.e., a tapered angle less than 90°, preferably between 15° and 70°). The resin composition of this application, through the internal stress release effect of a specific chain transfer agent, can ensure that the formed pattern has an excellent and smooth tapered angle.

[0128] It should be noted that the aforementioned undercut refers to the excessive lateral erosion that occurs during the developing process at the interface between the exposed and cured pattern and the underlying substrate (i.e., the bottom of the pattern). Undercut can cause an inwardly recessed "hollowing out" or "mushroom-like" structure at the bottom of the pattern cross-section. This defect severely weakens the contact area and interfacial adhesion between the color layer and the substrate, making it highly susceptible to the collapse or peeling of fine patterns. The resin composition of this application can form an extremely dense cross-linked network during both the exposure and the restricted low-temperature thermal curing stages, thereby completely resisting the lateral intrusion of the developing solution and effectively avoiding the occurrence of undercut defects.

[0129] (4) Undercut (lateral etching) judgment criteria: A: No lateral etching occurred at the bottom; C: Lateral etching occurred.

[0130] The above rating criteria can be interpreted or expressed as: A (excellent), B (good), C (poor).

[0131] 3. Summary of Experimental Data and Results: Based on the original test data provided in the disclosure document, the specific values ​​and the grading evaluation results are summarized as follows: Table 3. Main parameters and performance evaluation of the coloring patterns in each experimental group

[0132] 4. Experimental conclusions: The experimental results above show that, under the limited low-temperature thermosetting process conditions of 85°C, the comparative composition without the chain transfer agent of this invention exhibits extremely poor adhesion, accompanied by severe lateral etching (undercut) and poor chemical resistance. In contrast, after adding a chain transfer agent (M1, M2, or M3) with a multifunctional thiol structure to the photosensitive resin composition formulation of this application, the color filters prepared in Examples 1-9 exhibited extremely excellent chemical resistance (ΔEab* as low as 0.48), strong adhesion, and no developing residue in all evaluation dimensions. Furthermore, even under low-temperature molding conditions, their micro-line patterns still maintain perfect morphology (good tape angle and no undercut). This fully demonstrates that the multifunctional thiol compound can significantly improve the low-temperature crosslinking film quality of the resin composition.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multifunctional mercapto alcohol compound, characterized in that, The structure of the multifunctional thiol compound is selected from any one of compound M1, compound M2, or compound M3; wherein the chemical structures of compound M1, compound M2, and compound M3 are as follows: , and .

2. A method for preparing the multifunctional thiol compound as described in claim 1, characterized in that, include: A multifunctional epoxy compound was reacted with thioacetic acid to obtain an intermediate product. The intermediate product is hydrolyzed with an alkali to obtain the multifunctional mercaptool compound.

3. The method for preparing the multifunctional thiol compound as described in claim 2, characterized in that, At least one of the following conditions must be met: A. The reaction between the polyfunctional epoxy compound and thioacetic acid is carried out in the presence of a catalyst; B. The reaction temperature between the polyfunctional epoxy compound and thioacetic acid is 0℃~23℃; C. The reaction time between the polyfunctional epoxy compound and thioacetic acid is 3h~5h; D. The reaction temperature of the hydrolysis reaction is 0℃~23℃; E. The reaction time of the hydrolysis reaction is 1h~4h; F. The alkali includes sodium hydroxide; G. The multifunctional epoxy compound includes at least one of glycidyl ether, 2-[[1-[2,3-bis(epoxy-2-methoxy)propoxy]-3-(epoxy-2-methoxy)propenyl-2-]epoxymethyl]epoxyalkane and 2-[1,2,4,5,6-penta(epoxy-2-methoxy)hexyl-3-epoxymethyl]epoxyalkane.

4. A coloring photosensitive resin composition, characterized in that, It includes the multifunctional mercapto alcohol compound as described in claim 1, as well as alkali-soluble resins, colorants, photopolymerizable compounds, photopolymerization initiators, additives, and solvents.

5. The coloring photosensitive resin composition according to claim 4, characterized in that, The alkali-soluble resin and / or the additive contain at least one active crosslinking group selected from isocyanate groups, blocked isocyanate groups, and epoxy groups.

6. The coloring photosensitive resin composition according to claim 5, characterized in that, The alkali-soluble resin includes a first alkali-soluble resin; wherein the polymer monomer of the first alkali-soluble resin includes an acrylate monomer containing a pyrazole group. Preferably, the acrylate monomer containing the pyrazol group is 2-[(3,5-dimethyl-1-H-pyrazolyl)carboxyamino]ethyl acrylate; Preferably, the polymerization monomers of the first alkali-soluble resin further include alkyl methacrylate monomers, hydroxyalkyl methacrylate monomers, and methacrylic acid; Preferably, the alkali-soluble resin further includes a second alkali-soluble resin; wherein the polymerization monomers of the second alkali-soluble resin include polycycloalkyl acrylate monomers, benzyl methacrylate monomers, alkyl methacrylate monomers, vinyl double bond monomers containing epoxy groups, and acrylic acid.

7. The coloring photosensitive resin composition according to claim 5, characterized in that, The coloring photosensitive resin composition satisfies at least one of the following conditions: A) the additive includes a crosslinking agent containing epoxy groups; B) the photopolymerizable compound includes an acrylate monomer containing polyfunctional groups, preferably dipentaerythritol hexaacrylate; C) the photopolymerization initiator includes an oxime ester photoinitiator; and / or, Based on the total weight of the coloring photosensitive resin composition, the content of the alkali-soluble resin is 1% to 35%, the content of the colorant is 15% to 55%, the content of the photopolymerizable compound is 0.5% to 5%, the content of the photopolymerization initiator is 0.5% to 5%, the content of the additive is 0.5% to 10%, and the content of the additionally added solvent is 35% to 75%.

8. A color filter, characterized in that, It includes a coloring layer, said coloring layer being formed by curing the coloring photosensitive resin composition as described in any one of claims 4-7; Preferably, the coloring layer is formed by heating and curing the coloring photosensitive resin composition at a temperature below 90°C; Preferably, the color difference ΔEab* value of the color filter before and after the chemical resistance test is 0.48~3.

9. A display device, characterized in that, Includes the color filter as described in claim 8; Preferably, the display device is an OLED display device; Preferably, the color filter is disposed on the thin-film encapsulation layer of the OLED display device.

10. An electronic device, characterized in that, Includes the display device as described in claim 9.

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