Flexible display device and dual-curing photosensitive material

Abstract

The invention discloses a flexible display device and a photosensitive material or a compound suitable for forming patterns of an insulating film or a protective film in flexible display manufacturing, and the compound is shown as a structural formula (I). The photosensitive material has the advantages of low curing temperature, high elastic recovery rate and high light transmittance; the technical contradiction of a traditional insulating film material is overcome, and the problem of color development of diazonaphthoquinone is solved.

Description

Technical Field

[0001] This invention relates to a photosensitive material, and more particularly to a photosensitive material suitable for forming insulating or protective film patterns in the manufacture of flexible displays. Background Technology

[0002] Flexible displays are display devices made of soft materials that can be deformed and bent. Compared with traditional screens, flexible screens have obvious advantages. They are not only thinner and lighter in size, but also consume less power than the original devices, which helps to improve the device's battery life. At the same time, based on their bendable and flexible characteristics, their durability is also much higher than that of previous screens, reducing the probability of accidental damage to the device.

[0003] Nokia's Kinetic technology provided a reference for the design of flexible screen products, and since then, the development of flexible display devices has entered a fast track: In 2013, Samsung launched the YOUM flexible organic light-emitting diode (OLED) screen to replace glass screens, and LG Display mass-produced flexible OLED panels for smartphones for the first time; in 2014, Royole Technology released a color flexible display with a thickness of 0.01 mm and a bending radius of 1 mm, and the Japan Innovation High-Tech Semiconductor Energy Laboratory demonstrated a 5.9-inch flexible foldable OLED display; in June 2018, Royole Technology put into operation the world's first mass production line for fully flexible screens, and launched the third-generation Cicada Wing fully flexible screen in 2020; BYD announced an invention patent for "folding device and mobile terminal for flexible screen" in 2021, involving the optimization of the hinge structure; Visionox's metal-free mask technology enables a pixel density of over 1700 PPI, which is applied to foldable screen phones and wearable devices.

[0004] Flexible displays require the formation of a bendable insulating film on substrates such as PET / COP. Currently used insulating films include low-temperature (≤80℃) curing resins and high-elasticity resins. Low-temperature curing resins exhibit excellent adhesion to flexible substrates (5B), but their elastic recovery rate is only 55–80%, which cannot meet the requirements for repeated bending. While high-elasticity resins can achieve an elastic recovery rate of ≥80%, they require curing at 230℃, a high curing temperature that can easily damage the heat-sensitive substrate. Furthermore, the resins used in traditional insulating films employ diazonaphthoquinone for color development, which can lead to insufficient light transmittance. Summary of the Invention

[0005] This invention provides a flexible display device and a photosensitive material suitable for forming insulating or protective film patterns in the manufacture of flexible displays. It has a low curing temperature, high elastic recovery rate, and high light transmittance, overcoming the technical limitations of traditional insulating film materials.

[0006] The first aspect of this application is to provide a compound as shown in structural formula (I): (I) Among them, R1, R2, R3, R4, and Y are each independently selected from divalent organic groups; Among them, R5, R6, R7, and R8 are each independently selected from H or a monovalent organic group. Wherein, X is selected from divalent organic groups containing epoxy groups.

[0007] In a preferred embodiment, R1, R2, R3, and R4 can be alkylene groups selected independently from C1-C6 (e.g., C1, C2, C3, C4, C5, C6), heteroatom-containing alkylene groups from C1-C6 (e.g., C1, C2, C3, C4, C5, C6), non-aromatic cyclic structures from C3-C12 (e.g., C4, C5, C6, C7, C8, C9, C10, C11), or heteroatom-containing C One or more combinations of the following: non-aromatic ring structures of 3-C12 (such as C4, C5, C6, C7, C8, C9, C10, C11), aromatic ring structures of C5-C18 (such as C6, C7, C8, C9, C10, C12, C14, C15), and aromatic ring structures of C5-C18 (such as C6, C7, C8, C9, C10, C12, C14, C15) containing heteroatoms.

[0008] In a preferred embodiment, R5, R6, R7, and R8 are each independently selected from H, halogen atoms (such as Cl, F, or Br), C1-C6 (such as C1, C2, C3, C4, C5, C6) alkyl groups, C1-C6 (such as C1, C2, C3, C4, C5, C6) alkyl groups containing heteroatoms, and non-aromatic cyclic structures of C3-C12 (such as C4, C5, C6, C7, C8, C9, C10, C11). One or more combinations of non-aromatic ring structures of C3-C12 (such as C4, C5, C6, C7, C8, C9, C10, C11) containing heteroatoms, aromatic ring structures of C5-C18 (such as C6, C7, C8, C9, C10, C12, C14, C15) containing heteroatoms, and aromatic ring structures of C5-C18 (such as C6, C7, C8, C9, C10, C12, C14, C15).

[0009] In a preferred embodiment, Y is selected from one or more combinations of C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9) alkylene groups, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9) alkylene groups containing heteroatoms, divalent organic groups containing aromatic rings, divalent organic groups containing aromatic rings with heteroatoms, divalent organic groups containing non-aromatic rings, and divalent organic groups containing non-aromatic rings with heteroatoms.

[0010] In a preferred embodiment, the aromatic ring in Y is an aromatic ring of C5-C20 (such as C6, C8, C10, C12, C14, C16, C18).

[0011] In a preferred embodiment, the non-aromatic ring in Y is a non-aromatic ring of C3-C20 (such as C3, C4, C5, C6, C7, C8, C10, C12, C14, C16, C18).

[0012] In a preferred embodiment, the aromatic ring in Y can be one or more of a monocyclic, cyclic, or fused ring.

[0013] In a preferred embodiment, the non-aromatic ring in Y can be one or more combinations of monocyclic rings, fused rings, spirocyclic rings, and bridged rings.

[0014] In a preferred embodiment, the aromatic or non-aromatic rings in Y can also be independently linked by alkylene groups, for example, by C1-C6 (such as C2, C3, C4, C5) alkylene groups. For example, the alkylene groups linking the aromatic or non-aromatic rings in Y can be one or more combinations of -CH2-, -CH2-CH2-, -CH(CH3)-, -C(CH3)2-, -CH(CH3)-CH2-, -CH(CH3)-CH(CH3)-, -CH2-C(CH3)2-, and -CH2-C(CH3)2-CH2-.

[0015] In a preferred embodiment, the heteroatoms in R1, R2, R3, R4, R5, R6, R7, R8, and Y can each be independently one or more combinations of O, N, S, Si, and P.

[0016] In a preferred embodiment, the heteroatoms in R1, R2, R3, R4, R5, R6, R7, R8, and Y can each be independently located between C atoms or form side groups. For example, the heteroatoms in R1, R2, R3, R4, R5, R6, R7, R8, and Y can each independently form one or more combinations of -O-, -S-, -CO-, -COO-, -NH-, -C=N-, -CO-NH-, and -SiH2-, or the side groups formed by the heteroatoms can be one or more combinations of -OH, -SH, -CHO, -COOH, -CN, -NH2, -Cl, -F, and -Br.

[0017] In a preferred embodiment, the non-aromatic ring structures among R1, R2, R3, R4, R5, R6, R7, R8, and Y can be one or more combinations of monocyclic, fused, tandem, bridged, and helical ring structures.

[0018] In a preferred embodiment, the aromatic ring structures in R1, R2, R3, R4, R5, R6, R7, R8, and Y can be one or more combinations of monocyclic, fused, and cyclic structures.

[0019] In a preferred embodiment, R1, R2, R3, and R4 can be independently selected from H, halogen atoms, -CH2-, -CH2-CH2-, -CH2-CH2-CH2-, -CH(CH3)-CH2-, -CH(CH3)-CH(CH3)-, -CH2-C(CH3)2-CH2-, and so on. , , , , , , , , , , , , , , , One or more combinations of them.

[0020] In a preferred embodiment, R5, R6, R7, and R8 can be independently selected from H, -CH3, -CH2-CH3, -CH(CH3)-CH3, -C(CH3)2-CH3, -C(CH3)3, -CH2-CH2-CH3, -CH2-CH(CH3)-CH3, -CH2-C(CH3)2-CH3, and -CH2-C(CH3)3. , , , , , , , , , , , , , One or more combinations of them.

[0021] In a preferred embodiment, Y may be selected from: -CH2-, -CH2-CH2-, -CH2-CH2-CH2-, -CH(CH3)-CH2-, -CH2-CH2-CH2-CH2-, -CH(CH3)-CH(CH3)-, -CH2-C(CH3)2-CH2-, -CH2-CH2-CH2-CH2-CH2-, -CH2-CH2-CH2-CH2-CH2-CH2-, , , , , , , , , , , One or more combinations of them.

[0022] In a preferred embodiment, the epoxy group in X may be located on a side group or on the main chain, and preferably on a side group; more preferably, the epoxy group contains... The group, preferably selected from: , , , , One or more combinations of them.

[0023] In a preferred embodiment, X may contain one or more (preferably 2-6, such as 2, 3, 4, 5, or 6) epoxy groups. When there is more than one epoxy group, the epoxy groups may be the same or different.

[0024] In a preferred embodiment, X can be -A (-BT). n Wherein, T is the epoxy group, B is selected from one or more of single bonds, -O-, -S-, -CO-, -C=N-, -COO-, -NH-, -CO-NH-, C1-C5 alkylene groups, A is an organic group containing an aromatic ring, and n is the number of epoxy groups (preferably 2-6, such as 2, 3, 4, 5, 6).

[0025] In a preferred embodiment, B may be one or more combinations selected from single bonds, -O-, -S-, -CO-, -C=N-, -COO-, -NH-, -CO-NH-, -CH2-, -O-CH2-, -O-CH2-CH2-, -CH2-O-CH2-, -CH2-O-CH2-, and -CH2-O-CH2-CH2-.

[0026] In a preferred embodiment, A is an organic group of C5-C30 (preferably C6-C26, more preferably C6-C22, more preferably C6-C20, more preferably C6-C18, more preferably C6-C15, such as C7, C8, C9, C10, C12, C14, etc.). More preferably, A may contain heteroatoms, and the heteroatoms in A may be one or more combinations of O, S, N, P, and Si.

[0027] In a preferred embodiment, A may contain both aromatic rings and non-aromatic rings.

[0028] In a preferred embodiment, the aromatic ring and the non-aromatic ring in A can be independently formed, or the aromatic ring and the non-aromatic ring can form one or more combinations of monocyclic, fused, and combined ring structures.

[0029] In a preferred embodiment, the structure of A can be selected from: , , , , , , , , , , , , , , , , , , , , , , One or more combinations thereof, wherein D can be any one or more selected from C, O, S, Se, Si, N, P, and preferably any one or more selected from C, O, S, Se, Si, and more preferably any one or more selected from O, S, Se.

[0030] In a preferred embodiment, X can be selected from: , , , , , , , , , , , , , , , , , , , , , , , One or more combinations of them.

[0031] In a preferred embodiment, the weight-average molecular weight of the above-mentioned compound is preferably 1,000-100,000, more preferably 2,000-80,000, and even more preferably 5,000-50,000, such as 3,000, 4,000, 6,000, 8,000, 10,000, 20,000, 30,000, 40,000, 60,000, etc.

[0032] A second aspect of the present invention is to provide a photosensitive resin composition comprising the above-described compound, photoinitiator, and epoxy curing agent.

[0033] In a preferred embodiment, the photoinitiator is a compound that can absorb the energy of waves in the ultraviolet, infrared, or visible light regions to generate free radicals, cations, anions, etc., thereby initiating the polymerization of vinyl monomers.

[0034] In a preferred embodiment, the photoinitiator may be one or a combination of free radical polymeric photoinitiators and cationic polymeric photoinitiators.

[0035] In a preferred embodiment, the photoinitiator may be one or more combinations selected from benzoyl photoinitiators, benzoin, benzoin ether, alkyl phenyl ketone photoinitiators, acyl phosphorus oxides, benzophenone photoinitiators, thioxanthone photoinitiators, diazonium salts, diaryliodomonium salts, triarylthiomonium salts, alkylthiomonium salts, iron aromatic salts, sulfonyloxy ketones, and triarylsiloxanes.

[0036] In a preferred embodiment, the photoinitiator may be selected from diphenyl ethyl ketone, benzophenone, 2,4-dihydroxybenzophenone, michidone, α,α-dimethoxy-α-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropanone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, and 2-dimethylamino-2-benzyl-1-[4-(4-morpholinyl)phenyl]-1-butanone. The following are combinations of one or more of the following: α,α-diethoxyacetophenone, α-hydroxyalkylacetophenone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, α-aminealkylacetophenone, benzoin, benzoin dimethyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, thiopropoxythione, isopropylthione, methyl benzoylformate, and diphenyltitanium fluoride.

[0037] In a preferred embodiment, the photoinitiator is 0.01-10% of the weight of the compound, more preferably 0.05-8%, even more preferably 0.1-6%, such as 0.5%, 1%, 2%, 3%, 4%, 5%, etc.

[0038] In a preferred embodiment, the epoxy curing agent is a compound that initiates a reaction of epoxy groups to form a polymer.

[0039] In a preferred embodiment, the epoxy curing agent may be one or more of acidic epoxy curing agents, basic epoxy curing agents, and addition-type epoxy curing agents. More preferably, it may be one or more of amines (such as cyanamide, aliphatic diamine, aliphatic polyamine, aromatic polyamine, etc., wherein the polyamine is at least a triamine), acid anhydrides, organic acids, and boron trifluoride.

[0040] In a preferred embodiment, the epoxy curing agent may be selected from one or more of ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, diethylaminopropylamine, dicyandiamide, melamine, boron trinitride ethylamine, maleic anhydride, and phthalic anhydride diazo.

[0041] In a preferred embodiment, the epoxy curing agent is 0.1-10% of the weight of the compound, more preferably 0.2-8%, even more preferably 0.3-6%, such as 0.4%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, etc.

[0042] In a preferred embodiment, the photosensitive resin composition may further include a photosensitizer.

[0043] In a preferred embodiment, the photosensitizer is 1-50% of the weight of the compound, more preferably 5-45%, even more preferably 10-40%, such as 20%, 30%, etc.

[0044] In a preferred embodiment, the photosensitizer may be a compound containing an azole structure, a compound containing a diazo structure, a compound containing a phenol structure, a compound containing a quinone structure, etc., and is particularly preferred to be a compound containing a diazo structure. Preferably, the photosensitizer may be one or more selected from: 1-phenyl-5-mercaptotetrazole, 1,2-diazidonaphthoquinone-5-sulfonate, 2-diazo-1-naphthoquinone-5-sulfonyl chloride, 2,3,4-trihydroxybenzophenone, 1,4-naphthoquinone, 1,2-naphthoquinone, and 2-amino-3-chloro-1,4-naphthoquinone.

[0045] In a preferred embodiment, the photosensitive resin composition may further include a crosslinking agent.

[0046] In a preferred embodiment, the crosslinking agent comprises at least a compound containing a thiol-olefin click reaction group. In a more preferred embodiment, the crosslinking agent may be a combination of one or more of the following: o-carborane-9-thiol, m-carborane-thiol, alkyl thiols (such as methyl thiol, mercaptoethanol), thiophenol, pentaerythritol tetra(3-mercaptopropionate), cysteine, 1,6-hexanedithiol, and 1-thioglycerol.

[0047] In a preferred embodiment, the crosslinking agent may further include a compound containing a non-conjugated C=C group, such as one or more combinations of tetraallyl ether, trimethylolpropane triacrylate, 1,6-ethylene glycol diacrylate, and 1,4-butanediol diacrylate.

[0048] In a preferred embodiment, the crosslinking agent is 0.1-20% of the weight of the compound, more preferably 0.5-22%, more preferably 0.8-20%, more preferably 1-15%, more preferably 3-12%, and more preferably 5-10%.

[0049] In a preferred embodiment, the molar ratio of the compound containing the thiol-olefin click reactive group to the compound containing the non-conjugated C=C group in the crosslinking agent is preferably 1:(0.1-5), more preferably 1:(0.3-4), and even more preferably 1:(0.5-4), such as 1:0.8, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, etc.

[0050] In a preferred embodiment, the photosensitive resin composition may further include fillers, particularly reinforcing fillers.

[0051] In a preferred embodiment, the particle size of the filler is preferably 1-200nm, more preferably 3-180nm, more preferably 5-150nm, more preferably 8-120nm, more preferably 10-100nm, more preferably 20-80nm, more preferably 30-70nm, such as 40nm, 50nm, 60nm.

[0052] In a preferred embodiment, the filler is 0.01-10% of the weight of the compound, more preferably 0.05-8%, more preferably 0.08-7%, more preferably 0.1-5%, more preferably 0.5-4%, more preferably 0.8-2%, such as 1% or 1.5%.

[0053] In a preferred embodiment, the filler may be any one or more selected from metal oxides, metal hydroxides, silicon oxides, carbonates, silicates, sulfates, phosphates, nitrides, carbides, and polymer materials. For example, the filler may be a combination of one or more selected from silica, diatomaceous earth, quartz, silica fume, calcium carbonate, calcium sulfate, barium sulfate, barium carbonate, kaolin, attapulgite, mica, silicon carbide, carbon black, magnesium hydroxide, carbon nanotubes, alumina, asbestos, corundum, clay, calcium silicate, titanium dioxide, zinc oxide, antimony trioxide, polyamide, polyimide, carbon nanotubes, aramid, and carbon fiber.

[0054] In a preferred embodiment, the filler surface can also be surface modified, and the surface modifier can be silane M(CH2). m SiL3, where m is a positive integer; M is selected from one or more of alkenyl, amino, epoxy, methacryloyloxy, mercapto, and urea groups; L is selected from hydrolyzable groups, such as halogen atoms (Cl, Br, etc.), alkoxy groups (such as methoxy, ethoxy, methoxyethoxy), alkyl acyloxy groups (such as acetoxy), etc.

[0055] Examples include butadienetriethoxysilane, vinyltriperoxide tert-butylsilane, γ-methacryloyloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane, and isobutyltriethoxysilane.

[0056] In a preferred embodiment, the photosensitive resin composition may further include a solvent.

[0057] In a preferred embodiment, the solvent may be one or more of alcohols, ethers, hydrocarbons (aromatic hydrocarbons, aliphatic hydrocarbons, cycloalkanes, etc.), halogenated hydrocarbons, heterocyclic compounds, amides, esters, ketones, aldehydes, phenols, and sulfones. For example, it may be one or more of methanol, ethanol, propanol, glycerol, diethyl ether, petroleum ether, benzene, toluene, xylene, dichloromethane, chloroform, carbon tetrachloride, benzyl chloride, chlorobenzene, N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, cyclohexanone, cyclobutanone, acetone, propylene glycol methyl ether acetate, ethyl acetate, butyl acetate, tetrahydrofuran, and petroleum ether.

[0058] In a preferred embodiment, the photosensitive resin composition may further include an additive selected from one or more combinations of silane coupling agents, leveling agents, defoamers, antioxidants, preservatives, flame retardants, waterproofing agents, bactericides, and lubricants.

[0059] In a preferred embodiment, the adjuvant is 0.01-10% of the weight of the compound, more preferably 0.05-8%, more preferably 0.08-7%, more preferably 0.1-5%, more preferably 0.5-4%, more preferably 0.8-2%, such as 1% or 1.5%.

[0060] In a preferred embodiment, the additive contains a silane coupling agent. Preferably, the silane coupling agent is 0.01-5% of the weight of the compound, more preferably 0.03-4.5%, more preferably 0.05-4%, more preferably 0.08-3.5%, more preferably 0.1-3%, more preferably 0.5-2.5%, such as 1%, 1.5%, 2%.

[0061] In a preferred embodiment, the additive contains a leveling agent, preferably 0.01-4% of the weight of the compound, more preferably 0.03-3.5%, more preferably 0.05-3%, more preferably 0.08-2.5%, more preferably 0.1-2%, more preferably 0.5-1.5%, such as 0.8%, 1%, 1.2%.

[0062] The present invention also provides a method for preparing the photosensitive resin composition, comprising: Dissolve the compound in a solvent; Add epoxy curing agent, photoinitiator, or one or more combinations of photosensitizer and crosslinking agent; The photosensitive resin composition is obtained by adding filler and ultrasonically dispersing.

[0063] In a preferred embodiment, the power of the ultrasonic dispersion is 200-500W.

[0064] In a preferred embodiment, the frequency of the ultrasonic dispersion is 20-40 kHz.

[0065] In a preferred embodiment, the ultrasonic dispersion time is 30-60 minutes.

[0066] The present invention also provides a flexible display device comprising a film prepared from the photosensitive resin composition.

[0067] In a preferred embodiment, the photosensitive resin composition is cured into a film at 80-100°C.

[0068] In a preferred embodiment, the curing time of the photosensitive resin composition is preferably ≤30 minutes.

[0069] In a preferred embodiment, the elastic modulus of the membrane is ≥85%.

[0070] In a preferred embodiment, the light transmittance of the membrane is ≥95%.

[0071] The compounds and photosensitive resin compositions provided by this invention, by integrating low-temperature curing, high-elasticity photosensitive resin compositions and innovative dynamic crosslinking / nano-reinforcement technology, can achieve low-temperature curing and have high elastic recovery rate and light transmittance. The industrial feasibility has been verified through 5 examples and is suitable for the manufacture of insulating films for flexible OLED touch screens. Attached Figure Description

[0072] Figure 1 This is an example of a load deformation curve. Detailed Implementation

[0073] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0074] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or apparatuses.

[0075] Synthesis example 1: After preparing a flask equipped with a mechanical stirrer, thermometer, and cooling jacket, 240 g of propylene glycol monomethyl ether and 100 g of the compound represented by chemical formula 1-1 were added under a nitrogen gas flow. The mixture was heated to 40°C and stirred. 0.288 g of dibutyltin dilaurate was added to the reaction mixture, and the reactor temperature was increased to 65°C. While continuing to stir the reaction mixture, 36.98 g of 4,4'-diphenylmethane diisocyanate was added. The absorption spectrum of the isocyanate group (~2280 cm⁻¹) was confirmed by infrared absorption spectroscopy. -1 )disappear.

[0076] (1-1) Add 315.2 g of epichlorohydrin to the reaction solution and heat to 100 °C while stirring for 1 hour.

[0077] Add 33.8g of methacrylic acid to the reaction solution and raise the temperature to 110℃ to allow the reaction to proceed for 3 hours.

[0078] The reaction product was then dissolved in tetrahydrofuran (THF), the precipitate was obtained by water and then dissolved in dichloromethane, and finally in hexane to obtain 20g of a light yellow precipitate.

[0079] 100g of propylene glycol methyl ether acetate was added to the light yellow precipitate to dissolve it, and the mixture was heated to 140°C. After 1 hour, 5.3g of pyromellitic anhydride and 2.1g of maleic anhydride were added dropwise, and the mixture was reacted for 5 hours to obtain a high molecular weight resin [LB-1] with a solid content of 20% and a weight average molecular weight of 6,500.

[0080] Synthesis example 2: After preparing a flask equipped with a mechanical stirrer, thermometer, and cooling jacket, add 240g of propylene glycol monomethyl ether and 110g of the compound represented by chemical formula 1-2 under a nitrogen gas flow, and heat to 40°C while stirring.

[0081] (1-2) After adding 0.285 g of dibutyltin dilaurate to the reaction solution, the reactor temperature was increased to 65 °C. While continuing to stir the reaction solution, 37.02 g of 4,4'-diphenylmethane diisocyanate was added. The absorption spectrum of the isocyanate group (~2280 cm⁻¹) was confirmed by infrared absorption spectroscopy. -1 )disappear.

[0082] Epichlorohydrin 316.1 was added to the reaction solution and heated to 100°C while stirring for 1 hour.

[0083] Add 34.3% methacrylic acid to the reaction solution and raise the temperature to 110°C to allow the reaction to proceed for 3 hours.

[0084] The reaction product was then dissolved in tetrahydrofuran, precipitated with water, and then dissolved in dichloromethane, followed by hexane to obtain 23g of a pale yellow precipitate. 100g of propylene glycol methyl ether acetate was added to the pale yellow precipitate to dissolve it, and the mixture was heated to 140°C. After 1 hour, 5.5g of pyromellitic anhydride and 2.2g of maleic anhydride were added dropwise, and the reaction was carried out for 5 hours to obtain a high molecular weight resin [LB-2] with a solid content of 22% and an average molecular weight of 7,300.

[0085] Synthesis example 3: After preparing a flask equipped with a mechanical stirrer, thermometer, and cooling jacket, 240 g of propylene glycol monomethyl ether and 100 g of the compound represented by chemical formula 1-1 were added under a nitrogen gas flow. The mixture was heated to 40°C and stirred. 0.293 g of dibutyltin dilaurate was added to the reaction mixture, and the reactor temperature was increased to 65°C. While continuing to stir the reaction mixture, 70.9 g of trimethylhexamethylene diisocyanate was added. The absorption spectrum of the isocyanate group (~2280 cm⁻¹) was confirmed by infrared absorption spectroscopy. -1 )disappear.

[0086] (1-1) Add 315.0 g of epichlorohydrin to the reaction solution and heat to 100 °C while stirring for 1 hour.

[0087] Add 33.8g of methacrylic acid to the reaction solution and raise the temperature to 110℃ to allow the reaction to proceed for 3 hours.

[0088] The reaction product was then dissolved in tetrahydrofuran (THF), the precipitate was obtained by water, and then dissolved in dichloromethane, followed by hexane to obtain 21.5 g of a pale yellow precipitate.

[0089] 100g of propylene glycol methyl ether acetate was added to the light yellow precipitate to dissolve it, and the mixture was heated to 140°C. After 1 hour, 5.1g of pyromellitic anhydride and 2.0g of maleic anhydride were added dropwise, and the mixture was reacted for 5 hours to obtain a polymer resin [PB-1] with a solid content of 22% and a weight average molecular weight of 5,100.

[0090] Synthesis example 4: After preparing a flask equipped with a mechanical stirrer, thermometer, and cooling jacket, 240 g of propylene glycol monomethyl ether and 100 g of the compound represented by chemical formulas 1-4 were added under a nitrogen gas flow. The mixture was heated to 40°C and stirred. 0.295 g of dibutyltin dilaurate was added to the reaction mixture, and the reactor temperature was increased to 65°C. While continuing to stir the reaction mixture, 70.3 g of trimethylhexamethylene diisocyanate was added. The absorption spectrum of the isocyanate group (~2280 cm⁻¹) was confirmed by infrared absorption spectroscopy. -1 )disappear.

[0091] (1-4) Add 315.5g of epichlorohydrin to the reaction solution and heat to 100°C while stirring for 1 hour.

[0092] Add 34.2 g of methacrylic acid to the reaction solution and raise the temperature to 110 °C to allow the reaction to proceed for 3 hours.

[0093] The reaction product was then dissolved in tetrahydrofuran (THF), the precipitate was obtained by water, and then dissolved in dichloromethane, followed by hexane to obtain 22.8 g of a pale yellow precipitate.

[0094] 100g of propylene glycol methyl ether acetate was added to the light yellow precipitate to dissolve it, and the mixture was heated to 140°C. After 1 hour, 5.2g of pyromellitic anhydride and 2.2g of maleic anhydride were added dropwise, and the mixture was reacted for 5 hours to obtain a high molecular weight resin [PB-2] with a solid content of 21% and a weight average molecular weight of 5,900.

[0095] Example 1 Add 100 parts by weight (based on solids) of the resin [LB-1] solution obtained in Synthesis Example 1 and 100 parts by weight of the solvent propylene glycol monomethyl ether to a mixing tank equipped with an ultraviolet blocking membrane and a stirrer, and stir at 60°C for 1 hour to mix evenly.

[0096] Then, add 25 parts by weight of photosensitizer 1,2-diazidonaphthoquinone sulfonate, 3 parts by weight of epoxy curing agent dicyandiamide, 1 part by weight of photoinitiator 2-hydroxy-2-methylphenylacetone, and 5 parts by weight of dynamic crosslinking agent (tetraallyl ether: 3-mercaptopropionate = 1:1 molar ratio). Each time a component is added, stir for 1 hour before adding another component.

[0097] Then, 1 part by weight of silane coupling agent γ-glycidoxypropyltrimethoxysilane and 0.5 parts by weight of leveling agent BYK-333 were added as additives, and the mixture was stirred for 0.5 hours. Next, 1 part by weight of nano-reinforcing filler γ-silane (γ-methacryloyloxypropyltrimethoxysilane) was added to modify SiO2, and the mixture was sonicated at 300 W and 30 kHz for 40 minutes. Stirring continued, and propylene glycol monomethyl ether was added as solvent. The amount of solvent was adjusted to achieve a viscosity of 15 cPs, and the mixture was then filtered through a 0.2 μm microporous filter to prepare the photosensitive resin composition.

[0098] Example 2 Add 100 parts by weight (based on solids) of the resin [PB-1] solution obtained in Synthesis Example 3 and 100 parts by weight of the solvent propylene glycol monomethyl ether to a mixing tank equipped with an ultraviolet blocking membrane and a stirrer, and stir at 60°C for 1 hour to mix evenly.

[0099] Then, add 25 parts by weight of photosensitizer 1,2-diazidonaphthoquinone sulfonate, 3 parts by weight of epoxy curing agent dicyandiamide, 1 part by weight of photoinitiator 2-hydroxy-2-methylphenylacetone, and 10 parts by weight of dynamic crosslinking agent (tetraallyl ether: 3-mercaptopropionate = 1:1 molar ratio). Each time a component is added, stir for 1 hour before adding another component.

[0100] Then, 1 part by weight of silane coupling agent γ-glycidoxypropyltrimethoxysilane and 0.5 parts by weight of leveling agent BYK-333 were added as additives, and the mixture was stirred for 0.5 hours. Next, 3 parts by weight of nano-reinforcing filler γ-silane-modified SiO2 were added, and the mixture was sonicated at 300 W and 30 kHz for 40 minutes. Stirring continued, and propylene glycol monomethyl ether was added as solvent. The amount of solvent was adjusted to achieve a viscosity of 15 cPs, and then the mixture was filtered through a 0.2 μm microporous filter to prepare the photosensitive resin composition.

[0101] Example 3 The resin [LB-1] solution obtained in Synthesis Example 1 and the resin [PB-1] solution obtained in Synthesis Example 3 were mixed at a weight ratio of 1:1 to obtain a mixed resin solution.

[0102] Add 100 parts by weight (based on solids) of the mixed resin solution and 100 parts by weight of the solvent propylene glycol monomethyl ether to a mixing tank equipped with an ultraviolet blocking membrane and a stirrer, and stir at 60°C for 1 hour to mix evenly.

[0103] Then, add 30 parts by weight of photosensitizer 1,2-diazidonaphthoquinone sulfonate, 3 parts by weight of epoxy curing agent dicyandiamide, 1 part by weight of photoinitiator 2-hydroxy-2-methylphenylpropionone, and 8 parts by weight of dynamic crosslinking agent (tetraallyl ether: 3-mercaptopropionate = 1:1 molar ratio). Each time a component is added, stir for 1 hour before adding another component.

[0104] Then, 1 part by weight of silane coupling agent γ-glycidoxypropyltrimethoxysilane and 0.5 parts by weight of leveling agent BYK-333 were added as additives, and the mixture was stirred for 0.5 hours. Next, 2 parts by weight of nano-reinforcing filler γ-silane-modified SiO2 were added, and the mixture was sonicated at 300 W and 30 kHz for 40 minutes. Stirring continued, and propylene glycol monomethyl ether was added as solvent. The amount of solvent was adjusted to achieve a viscosity of 15 cPs, and then the mixture was filtered through a 0.2 μm microporous filter to prepare the photosensitive resin composition.

[0105] Example 4 Add 100 parts by weight (based on solids) of the resin [LB-2] solution obtained in Synthesis Example 2 and 100 parts by weight of the solvent propylene glycol monomethyl ether to a mixing tank equipped with an ultraviolet blocking membrane and a stirrer, and stir at 60°C for 1 hour to mix evenly.

[0106] Then, add 20 parts by weight of photosensitizer 1,2-diazidonaphthoquinone sulfonate, 3 parts by weight of epoxy curing agent dicyandiamide, 1 part by weight of photoinitiator 2-hydroxy-2-methylphenylacetone, and 12 parts by weight of dynamic crosslinking agent (tetraallyl ether: 3-mercaptopropionate = 1:1 molar ratio). Stir for 1 hour after each addition of one component before adding the next component.

[0107] Then, 1 part by weight of silane coupling agent γ-glycidoxypropyltrimethoxysilane and 0.5 parts by weight of leveling agent BYK-333 were added as additives, and the mixture was stirred for 0.5 hours. Next, 4 parts by weight of nano-reinforcing filler γ-silane-modified SiO2 were added, and the mixture was sonicated at 300 W and 30 kHz for 40 minutes. Stirring continued, and propylene glycol monomethyl ether was added as solvent. The amount of solvent was adjusted to achieve a viscosity of 15 cPs, and the mixture was then filtered through a 0.2 μm microporous filter to prepare the photosensitive resin composition.

[0108] Example 5 Add 100 parts by weight (based on solids) of the resin [PB-2] solution obtained in Synthesis Example 4 and 100 parts by weight of the solvent propylene glycol monomethyl ether to a mixing tank equipped with an ultraviolet blocking membrane and a stirrer, and stir at 60°C for 1 hour to mix evenly.

[0109] Then, add 35 parts by weight of photosensitizer 1,2-diazidonaphthoquinone sulfonate, 3 parts by weight of epoxy curing agent dicyandiamide, 1 part by weight of photoinitiator 2-hydroxy-2-methylphenylacetone, and 15 parts by weight of dynamic crosslinking agent (tetraallyl ether: 3-mercaptopropionate = 1:1 molar ratio). Each time a component is added, stir for 1 hour before adding another component.

[0110] Then, 1 part by weight of silane coupling agent γ-glycidoxypropyltrimethoxysilane and 0.5 parts by weight of leveling agent BYK-333 were added as additives, and the mixture was stirred for 0.5 hours. Next, 5 parts by weight of nano-reinforcing filler γ-silane-modified SiO2 were added, and the mixture was sonicated at 300 W and 30 kHz for 40 minutes. Stirring continued, and propylene glycol monomethyl ether was added as solvent. The amount of solvent was adjusted to achieve a viscosity of 15 cPs, and the mixture was then filtered through a 0.2 μm microporous filter to prepare the photosensitive resin composition.

[0111] Comparative Example 1: Add 100 parts by weight (based on solids) of the resin [LB-1] solution obtained in Synthesis Example 1 and 100 parts by weight of the solvent propylene glycol monomethyl ether to a mixing tank equipped with an ultraviolet blocking membrane and a stirrer, and stir at 60°C for 1 hour to mix evenly.

[0112] Then, add 25 parts by weight of photosensitizer 1,2-diazidonaphthoquinone sulfonate, 3 parts by weight of epoxy curing agent dicyandiamide, and 1 part by weight of photoinitiator 2-hydroxy-2-methylphenylacetone in sequence. Stir for 1 hour after each addition of a component before adding another component.

[0113] Then add 1 part by weight of silane coupling agent γ-epoxypropoxypropyltrimethoxysilane and 0.5 parts by weight of leveling agent BYK-333 as one of the additives, and stir for 0.5 hours.

[0114] Add propylene glycol monomethyl ether as solvent, adjust the amount of solvent to make the viscosity of the composition 15 cPs, and then filter it with a microporous filter with a pore size of 0.2 μm to prepare a photosensitive resin composition.

[0115] Comparative Example 2: Add 100 parts by weight (based on solids) of the resin [PB-2] solution obtained in Synthesis Example 4 and 100 parts by weight of the solvent propylene glycol monomethyl ether to a mixing tank equipped with an ultraviolet blocking membrane and a stirrer, and stir at 60°C for 1 hour to mix evenly.

[0116] Then, add 25 parts by weight of photosensitizer 1,2-diazidonaphthoquinone sulfonate, 3 parts by weight of epoxy curing agent dicyandiamide, and 1 part by weight of photoinitiator 2-hydroxy-2-methylphenylacetone in sequence. Stir for 1 hour after each addition of a component before adding another component.

[0117] Then, add 1 part by weight of silane coupling agent γ-glycidoxypropyltrimethoxysilane and 0.5 parts by weight of leveling agent BYK-333 as additives, and stir for 0.5 hours. Add propylene glycol monomethyl ether solvent to adjust the amount of solvent so that the viscosity of the composition is 15 cPs, and then filter it through a microporous filter with a pore size of 0.2 μm to prepare the photosensitive resin composition.

[0118] Forming an insulating film pattern After spin-coating or slit-coating the photosensitive resin composition solutions of Examples 1 to 5 and Comparative Examples 1 and 2 onto one side of a transparent substrate, the coated surface is heated (pre-dried) to form a thin film.

[0119] The transparent substrate used for pattern formation is a glass substrate. After coating with the composition, it is pre-dried at 80°C for 90 seconds, and then the formed film is exposed through a photomask with a 15 μm pattern. After exposure, it is developed with a 0.042% (by weight) aqueous solution of potassium hydroxide at 25°C for 60 seconds, rinsed with pure water for 1 minute, and heated in an oven to form the pattern. The required curing temperature and time vary for the resin compositions of different embodiments and comparative examples, as shown in Tables 1-2 below.

[0120] Table 1. Resin composition components (parts by weight) and curing conditions for Examples 1-5 Components Example 1 Example 2 Example 3 Example 4 Example 5 Resin type LB-1 PB-1 LB-1+PB-1 LB-2 PB-2 Resin Mw 6,500 5,100 8,000 7,300 5,900 Photosensitive agent 25 25 30 20 35 Photoinitiator 1 1 1 1 1 Epoxy curing agent 3 3 3 3 3 Crosslinking agent 5 10 8 12 15 <![CDATA[Nanometer SiO2]]> 1 3 2 4 5 Leveling agent 0.5 0.5 0.5 0.5 0.5 Silane coupling agents 1 1 1 1 1 Curing conditions (°C, 30 min) 80 100 80 90 100 Table 2. Resin composition (parts by weight) and curing conditions for Comparative Examples 1-2 Components Comparative Example 1 Comparative Example 2 Resin type LB-1 PB-2 Resin Mw 6,500 5,900 Photosensitive agent 25 25 Photoinitiator 1 1 Epoxy curing agent 3 3 Leveling agent 0.5 0.5 Silane coupling agents 1 1 Crosslinking agent No additions No additions <![CDATA[Nanometer SiO2]]> No additions No additions Curing conditions (°C, 30 min) 80 230 The following aspects of the photosensitive resin compositions prepared in the Examples and Comparative Examples were then evaluated.

[0121] Testing standards: Elastic recovery rate: The obtained insulating film pattern was subjected to a load of 20 mN using a micro-pressure testing machine (product name DUH-W201, manufactured by Shimadzu Corporation) through a 50 μm diameter flat indenter. The load was held for 5 seconds and then removed. Load deformation curves under load and unload were then generated (e.g., ...). Figure 1 (As shown). Let L2 be the deformation when the load is 20mN and L1 be the deformation when the load is removed. The elastic recovery rate can be calculated by elastic recovery rate (%) = L1×100 / L2.

[0122] A good deformation is achieved when the deformation L2 reaches 1.0 μm or more and L1 reaches 0.8 μm or more, and the elastic recovery rate reaches 60% or more.

[0123] Transmittance: The transmittance of the cured film at a wavelength of 400 nm was measured using a UV-Vis spectrometer. A transmittance of 95% or higher is considered good, while a transmittance below 95% is considered poor.

[0124] Adhesion: The adhesion between the cured film and the flexible substrate was tested using a cross-cut test. Following the ATSM-D3359 method, 100 checkerboard marks were formed on the cured film using a corner cutter, followed by peeling with 3M tape. An adhesion of 5B across the 100 peel marks was considered good. The benchmarks are shown in Table 3 below.

[0125] Table 3, Adhesion Benchmark Number of items that cannot be peeled 100 ≥80 ≥60 ≥40 ≥20 ≥0 Classification 5B 4B 3B 2B 1B 0 determination excellent bad bad bad bad bad Performance test results Table 4, Performance test results of Examples 1-5 Example 1 Example 2 Example 3 Example 4 Example 5 Elastic recovery rate (%) 85.2 87.6 90.1 88.3 92.5 Light transmittance (%, 400nm) 96.5 95.8 97.2 95.1 98.0 Adhesion 5B 5B 5B 5B 5B Table 5. Performance test results of Comparative Examples 1-2 Comparative Example 1 Comparative Example 2 Elastic recovery rate (%) 55.3 81.85 Light transmittance (%, 400nm) 95 Untested Adhesion none PET substrate deformation A comparison of Examples 1-5 with Comparative Example 2 shows that the present invention achieves a dual breakthrough in elastic recovery rate (92.5% vs 81.85%) and light transmittance (98% vs 95%) under low-temperature curing, making it suitable for roll coating (slot coating process) and roll-to-roll production (continuous processing of flexible substrates). This is because the thiol-olefin bonds in the crosslinking agent undergo reversible breakage / reorganization during bending, thereby significantly improving the elastic recovery rate, while the low-temperature curing time is also greatly shortened by 60%. The nanofiller of the present invention has good dispersibility, which can improve light transmittance, and the ultrasonic dispersion power of the present invention can avoid the agglomeration of nanofiller. Moreover, the present invention also solves the color development problem of diazonaphthoquinone in the traditional technology.

[0126] The specific embodiments of the present invention have been described in detail above, but they are merely examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, all equivalent transformations and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention.

Claims

1. A compound, characterized in that, The compound is shown in structural formula (I): （I） Among them, R1, R2, R3, R4, and Y are each independently selected from divalent organic groups; Among them, R5, R6, R7, and R8 are each independently selected from H or a monovalent organic group. Wherein, X is selected from divalent organic groups containing epoxy groups.

2. The compound according to claim 1, characterized in that, R1, R2, R3, and R4 are each independently selected from one or more combinations of C1-C6 alkylene, C1-C6 alkylene containing heteroatoms, C3-C12 non-aromatic cyclic structures, C3-C12 non-aromatic cyclic structures containing heteroatoms, C5-C18 aromatic cyclic structures, and C5-C18 aromatic cyclic structures containing heteroatoms. R5, R6, R7, and R8 are each independently selected from one or more combinations of H, halogen atoms, C1-C6 alkyl groups, C1-C6 alkyl groups containing heteroatoms, C3-C12 non-aromatic cyclic structures, C3-C12 non-aromatic cyclic structures containing heteroatoms, C5-C18 aromatic cyclic structures, and C5-C18 aromatic cyclic structures containing heteroatoms. Y is selected from one or more combinations of C1-C10 alkylene groups, C1-C10 alkylene groups containing heteroatoms, divalent organic groups containing aromatic rings, divalent organic groups containing aromatic rings with heteroatoms, divalent organic groups containing non-aromatic rings, and divalent organic groups containing non-aromatic rings with heteroatoms.

3. The compound according to claim 2, characterized in that, R1, R2, R3, and R4 are independently selected from H, halogen atoms, -CH2-, -CH2-CH2-, -CH2-CH2-CH2-, -CH(CH3)-CH2-, -CH(CH3)-CH(CH3)-, and -CH2-C(CH3)2-CH2-, respectively. , , , , , , , , , , , , , , , One or more combinations of them; R5, R6, R7, and R8 are each independently selected from H, -CH3, -CH2-CH3, -CH(CH3)-CH3, -C(CH3)2-CH3, -C(CH3)3, -CH2-CH2-CH3, -CH2-CH(CH3)-CH3, -CH2-C(CH3)2-CH3, and -CH2-C(CH3)3, respectively. , , , , , , , , , , , , , One or more combinations of them; Y is selected from: -CH2-, -CH2-CH2-, -CH2-CH2-CH2-, -CH(CH3)-CH2-, -CH2-CH2-CH2-CH2-, -CH(CH3)- CH(CH3)-, -CH2-C(CH3)2-CH2-, -CH2-CH2-CH2-CH2-CH2-, -CH2-CH2-CH2-CH2-CH2-CH2-, , , , , , , , , , , One or more combinations thereof.

4. The compound according to claim 1, characterized in that, X contains one or more of the epoxy groups.

5. The compound according to claim 1, characterized in that, X is -A (-BT) n Wherein, T is the epoxy group, B is selected from one or more of single bonds, -O-, -S-, -CO-, -C=N-, -COO-, -NH-, -CO-NH-, and C1-C5 alkylene groups, A is an organic group containing an aromatic ring, and n is the number of epoxy groups.

6. The compound according to claim 5, characterized in that, X is selected from , , , , , , , , , , , , , , , , , , , , , , , One or more combinations thereof.

7. A photosensitive resin composition, characterized in that, Includes the compound described in claim 1, a photoinitiator, and an epoxy curing agent.

8. The photosensitive resin composition according to claim 7, characterized in that, The photoinitiator is 0.01-10% of the weight of the compound; the epoxy curing agent is 0.1-10% of the weight of the compound.

9. The photosensitive resin composition according to claim 7, characterized in that, The photosensitive resin composition further includes a photosensitizer, said photosensitizer being 1-50% by weight of the compound; and / or The photosensitive resin composition further includes a crosslinking agent, which comprises at least a compound containing a thiol-olefin click-reactive group, and the crosslinking agent is 0.1-20% by weight of the compound; and / or The photosensitive resin composition further includes a filler having a particle size of 1-200 nm and being 0.01-10% of the weight of the compound.

10. A method for preparing the photosensitive resin composition of claim 9, characterized in that, include: Dissolve the compound in a solvent; Add epoxy curing agent, photoinitiator, or one or more combinations of photosensitizer and crosslinking agent; The photosensitive resin composition is obtained by adding filler and ultrasonically dispersing.

11. A flexible display device, characterized in that, The film includes the photosensitive resin composition of claim 7.

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