A photosensitive resin composition containing two oligomers, a photosensitive spacer

Abstract

The application belongs to the technical field of photosensitive resin and specifically relates to a photosensitive resin composition containing two oligomers and a photosensitive spacer. One of the two oligomers is an acrylic resin oligomer I containing an epoxy group, and the other is a grafted acrylic resin oligomer II. The light-cured and heat-cured resin composition containing the two oligomers is prepared from the following components in parts by weight: oligomer I 3-8 parts, oligomer II 1-5 parts, leveling agent 0.2-0.5 parts, photoinitiator 0.5-1.2 parts, curing agent 3-8 parts, coupling agent 0.5-3 parts, active monomer 5-10 parts, and organic solvent 70-88 parts. The oligomer has good crosslinking capacity and good compatibility with a developing solution. When the oligomer is applied to a lithography process, the demand for high-resolution patterning can be met, and the oligomer can be used to prepare a PS spacer in a liquid crystal display for supporting.

Description

Technical Field

[0001] This invention belongs to the field of photosensitive resin technology, specifically relating to a photosensitive resin composition comprising two oligomers and a photosensitive interstitial material. Background Technology

[0002] Display is the process of converting electrical signals (data information) into visible light (visual information), and the interface that completes the display is the human-machine interface. Flat panel displays (FPDs) are currently the most popular type of display device. Liquid crystal displays (LCDs) are the earliest developed and most popular type of flat panel display. In LCDs, such as thin-film transistor liquid crystal displays (TFT-LCDs), the black matrix (BM), spacers, color filter layers (RGB), alignment layers (PI), organic planarization layers (OC), and other polymers form the foundation for the TFT-LCD to complete the display. The frame adhesive is a photocurable adhesive. These materials are as important to the TFT-LCD as hands and feet are to the human body; if any part has a problem, the entire TFT-LCD will malfunction or become paralyzed.

[0003] To prevent image blurring caused by uneven liquid crystal layer thickness, liquid crystal displays (LCDs) typically use spacers to maintain a certain thickness of the liquid crystal layer. These spacers are generally classified as granular or columnar. Currently, LCDs use two types of spacers: silicon spheres for the bezel and plastic spheres for the center, with selectable particle sizes. These spacers are electrostatically sprayed onto the surface of an aligned alignment agent. However, this method of coating spacers is prone to movement under pressure and can damage the alignment agent under vibration. Furthermore, controlling the uniformity of distribution during spraying is difficult, leading to speckled areas in the LCD. This is gradually being replaced by columnar spacers, which are less prone to movement, have a larger contact area, and can be controlled through photolithography. These photo-etched spacers can be fixed to the matrix metallization (BM) with a mask, increasing the light emission efficiency of the LCD and preventing speckled areas. Although a photoresist composition composed of oligomers can also form spacers of a specified size, the lack of cross-linking with the active monomers causes serrated murex structures to easily form on the top of the subPS during development. These structures are prone to breakage under stress, failing to provide adequate support and causing the display to malfunction. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a photosensitive resin composition comprising two oligomers and a photosensitive spacer, wherein the photosensitive resin oligomer II can be well crosslinked with the active monomer, completely encapsulating the oligomer I which is not a photosensitive resin, and is not washed away by the developer during development, thereby improving the development pattern effect on the top of the subPS.

[0005] The present invention solves the above problems through the following technical solutions:

[0006] This invention provides a photosensitive resin composition comprising oligomer I and oligomer II; oligomer I is an acrylic resin containing epoxy groups, comprising repeating units containing epoxy groups, repeating units containing hydroxyl groups, repeating units containing alicyclic or aromatic hydrocarbon groups, and repeating units containing carboxyl groups, and having a structure as shown in Formula I; oligomer II is a grafted acrylic resin, having a structure as shown in Formula II.

[0007]

[0008] In Formula I, R1 is methyl or hydrogen, R2 contains an epoxy group, R3 contains a group with a hydroxyl group, and R4 contains an alicyclic hydrocarbon group or an aromatic hydrocarbon group; in Formula II, R1 is methyl or hydrogen, and the repeating unit containing R2 is derived from at least one of cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate, rosin methacrylate, and phenoxyethyl methacrylate.

[0009] Furthermore, the weight ratio of oligomer I to oligomer II is 3-8:1-5.

[0010] Furthermore, in the oligomer I, the molar percentage of epoxy groups is 50-80%, the molar percentage of hydroxyl groups is 5-15%, and the molar percentage of aromatic hydrocarbon groups or alicyclic hydrocarbon groups is 15-35%.

[0011] Furthermore, the epoxy-containing repeating units in oligomer I are derived from at least one of glycidyl (meth)acrylate, tetrahydrofuran (meth)acrylate, (3-ethyloxetane-3-yl)methyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolane-4-yl)methyl (meth)acrylate, cyclic trimethylolpropane acetal (meth)acrylate, 2-[(2-tetrahydropyranyl)oxy)ethyl (meth)acrylate, and 1,3-dioxane-(meth)acrylate; the hydroxyl-containing repeating units are derived from (methyl)... The ester contains at least one of 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 6-hydroxyhexyl acrylate, 8-hydroxyoctyl acrylate, 10-hydroxydecyl acrylate, and 12-hydroxylaurate acrylate; and contains an alicyclic or aromatic cyclic repeating unit derived from at least one of phenyl acrylate, benzyl acrylate, cyclohexyl acrylate, or a bridging cycloalkyl acrylate having 8-20 carbon atoms.

[0012] Furthermore, the acid value of the oligomer I is controlled at 30-80 mg KOH / g, preferably 40-60 mg KOH / g, and the number average molecular weight is controlled at 3000-7000.

[0013] Furthermore, the acid value of oligomer II is controlled at 60-180 mgKOH / g, preferably 70-120 mgKOH / g, and the number average molecular weight is controlled at 2000-6000, preferably 3000-5000.

[0014] The present invention provides a resin composition comprising the two oligomers mentioned above, and may further include a photoinitiator, a curing agent, a solvent and other additives.

[0015] Furthermore, the photosensitive resin composition comprises the following components in parts by weight:

[0016] Oligomer I: 3-8 parts

[0017] Oligomer II: 1-5 parts

[0018] Coupling agent: 0.5-3 parts

[0019] Leveling agent: 0.2-0.5 parts

[0020] Hardener: 3-8 parts

[0021] Photoinitiator: 0.5-1.2 parts

[0022] Active monomer: 5-10 parts

[0023] PMA: 70-88 copies.

[0024] Furthermore, the curing agent is preferably a latent curing agent, such as a blocked amine, melamine resin, anhydride blocked amine, organic hydrazide, modified imidazole, etc., and more preferably melamine resin.

[0025] Furthermore, the coupling agent is a silane coupling agent, preferably γ-glycidoxypropyltrimethoxysilane, such as KH560 or Dow Corning's Z6040.

[0026] Furthermore, the leveling agent is selected from, but not limited to, at least one of the following: polyether-modified polydimethylsiloxane solution, polyester-modified polydimethylsiloxane solution, polyether-modified polysiloxane solution, polyester-modified polymethylalkylsiloxane solution, polyether-modified polydimethylsiloxane solution, polyether-modified polydimethylsiloxane solution, polyacrylate solution, and fluorocarbon copolymer solution.

[0027] Furthermore, the coupling agent is selected from, but not limited to, one or more of N′-β′-aminoethyl-N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane, N′-β′-aminoethyl-N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N′-β′-aminoethyl-N-β-aminoethyl-γ-aminopropyltriethoxysilane, N′-β′-aminoethyl-N-β-aminoethyl-α-aminomethyltriethoxysilane, γ-cyclohexylaminopropyltriethoxysilane and methyl, γ-cyclohexylaminopropyldimethoxysilane, and γ-chloropropyltriethoxysilane (γ2); preferably BYK333, BYK378, BYK306, etc.

[0028] Furthermore, the solvent is a moderately polar solvent, which can be any solvent suitable for dissolving the aforementioned components without causing a chemical reaction; for example, methyl ethyl ketone, ethylene glycol dimethyl ether, 2-ethoxypropanol, 1,4-dioxane, cyclopentanone, propylene glycol methyl ether acetate, propylene glycol monomethyl ether, methyl cellulose acetate, γ-butyrolactone, or butyl acetate; amide solvents such as one or more of dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, or dimethyl sulfoxide; the selected solvent should be able to dissolve the other components in the composition well and give the composition good coatability and appropriate drying speed, so a boiling point between 100°C and 250°C can also be selected, preferably between 120°C and 180°C.

[0029] Furthermore, the active monomer can be any compound that can react with photosensitive grafted oligomer II; examples include aromatic vinyl monomers such as styrene, α-methylstyrene, α-chloromethylstyrene, vinyltoluene, divinylbenzene, and diallyl phthalate; polycarboxylic acid monomers such as vinyl acetate and vinyl adipate; and one or more of the following: methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; preferably pentaerythritol tetraacrylate or dipentaerythritol hexaacrylate.

[0030] Furthermore, the photoinitiator can be any known compound used in photocuring by active light such as ultraviolet light. Specific examples of photopolymerization initiators include, for instance, 2,4,6-tris(trichloromethyl)-triazine, 2-methyl-4,6-bis(trichloromethyl)-triazine, 2-[2-(5-methylfuran-2-yl)vinyl]-4,6-bis(trichloromethyl)-triazine, 2-[2-(furan-2-yl)vinyl]-4,6-bis(trichloromethyl)-triazine, 2-[2-(4-diethylamino-2-methylphenyl)vinyl]-4,6-bis(trichloromethyl)-triazine, 2-[2-(3,4-dimethoxyphenyl)vinyl]-4,6-bis(trichloromethyl)-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-triazine, 2-(4-ethoxystyryl)-4,6-bis(trichloromethyl)-triazine, and 2-(4-butoxyphenyl) -4,6-bis(trichloromethyl)-triazine and other triazine compounds containing a halomethyl group; examples also include, for instance, 1-[4-(phenylthio)phenyl]-1,2-octanedione-2-(o-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl] acetone-1-(o-acetyl oxime), 1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranyl)methoxy] [[benzoyl]-9H-carbazole-3-yl]-1-(o-acetyloxime) ethyl ketone, 1-[9-ethyl-6-(2-methyl-4-(2,2-dimethyl-1,3-dioxane-1,3-dioxane-6-(2-methyl-4-(2,2-dimethyl ...

[0031] In this invention, the resin composition containing the aforementioned two oligomers can also be cured to form a coating film.

[0032] Furthermore, the curing process is either photocuring or thermal curing, preferably photocuring first to crosslink the double bonds, followed by thermal curing to open the epoxy ring and form strength.

[0033] The present invention also provides photosensitive spacers prepared using photosensitive resin compositions.

[0034] Furthermore, photosensitive spacers can be manufactured through steps such as pre-baking, developing, and post-baking.

[0035] The beneficial effects of this invention are as follows: In this invention, photosensitive resin oligomer II can effectively crosslink with the active monomer, completely encapsulating oligomer I, which is not a photosensitive resin. It is not washed away by the developing solution during development and exhibits good compatibility with the developing solution, improving the development pattern effect on the top of the subPS. When applied to lithography processes, it can meet the current high-resolution patterning requirements. When the aforementioned two oligomers and their combinations are used as PS spacers, they can be used to prepare spacers that provide support in liquid crystal displays, allowing liquid crystal cells to replace spacers made of styrene polymers and silicon, improving the display effect and increasing the yield rate of liquid crystal displays. Attached Figure Description

[0036] Figure 1 : A photographic image of a photosensitive space containing oligomer II.

[0037] Figure 2 : A photographic image of a photosensitive spacer that does not contain oligomer II. Detailed Implementation

[0038] The present invention will be further described below with reference to specific embodiments and accompanying drawings, but the present invention is not limited thereto. Unless otherwise specified, all reagents involved in the present invention can be obtained through ordinary commercial channels.

[0039] Determination of number-average molecular weight:

[0040] Using a Waters PL-GPC220 instrument, a Polymer Laboratories PLgel MIX-B 300mm column was used at an evaluation temperature of 40°C. Tetrahydrofuran was used as the solvent, and the flow rate was 1 mL / min. Samples were prepared at a concentration of 10 mg / 10 mL, with a single injection volume of 200 μL. The Mn value could be determined using a calibration curve formed from polystyrene standards. Nine molecular weights of polystyrene standards were used in this invention:

[0041] 2000 / 10000 / 30000 / 70000 / 200000 / 700000 / 2000000 / 4000000 / 10000000.

[0042] In this invention, the acid value of the photosensitive graft polymer is the number of mg of potassium hydroxide required to neutralize 1g of photosensitive resin. A certain amount of the reaction solution is weighed and dissolved in a toluene-ethanol mixed solvent, and then measured using a potentiometric titrator from Metrohm, Switzerland, with a potassium hydroxide ethanol standard titrant.

[0043] The common Chinese names of the raw materials used in the following examples are as follows:

[0044] GMA: Glycidyl methacrylate

[0045] HEMA: β-hydroxyethyl methacrylate

[0046] CHMA: Encyclohexyl methacrylate

[0047] AIBN: 2,2′-Azobisisobutyronitrile

[0048] MAA: Methacrylic acid

[0049] PMA: Propylene glycol monomethyl ether acetate

[0050] 1. Synthesis of Oligomer I

[0051] Synthesis example 1:

[0052] Add 29.85g GMA (epoxy equivalent 95.54), 1.96g HEMA (hydroxyl value 0.019), and 12.66g CHMA (molar percentage of GMA:HEMA:CHMA = 70%:5%:25%), 4.50g MAA, 1.73g AIBN, 1.73g α-methylstyrene dimer, and 50g PMA to a 250ml three-necked flask. Start stirring and purge with nitrogen to remove oxygen for half an hour. Simultaneously, add 100g of PMA to a 500ml four-necked flask, install the condenser, thermometer, and stirrer, purge with nitrogen to remove oxygen, and raise the temperature to 85℃. Once the temperature in the 500ml flask reaches 85℃, pour 250ml of the slurry into a constant pressure funnel and begin dropwise addition. Control the addition time to 2.5-3 hours, and maintain the reaction temperature at 85±1℃. After the addition is complete, continue the reaction for 2 hours. Sample and analyze with GPC. Stop the reaction once no more monomer peaks appear in the chromatogram.

[0053] According to GPC testing, the number average Mn was 4360, PDI was 1.73, and the measured acid value was 59.54 mg KOH / g.

[0054] Synthesis example 2:

[0055] Add 25.59g GMA (epoxy equivalent 81.89), 5.88g HEMA (hydroxyl value 0.057), and 12.66g CHMA (molar percentage of GMA:HEMA:CHMA = 60%:15%:25%), 4.90g MAA, 1.73g AIBN, 1.73g α-methylstyrene dimer, and 50g PMA to a 250ml three-necked flask. Start stirring and purge with nitrogen to remove oxygen for half an hour. Simultaneously, add 100g of PMA to a 500ml four-necked flask, install the condenser, thermometer, and stirrer, purge with nitrogen to remove oxygen, and raise the temperature to 85℃. Once the temperature in the 500ml flask reaches 85℃, pour 250ml of the slurry into a constant pressure funnel and begin dropwise addition. Control the addition time to 2.5-3 hours, and maintain the reaction temperature at 85±1℃. After the addition is complete, continue the reaction for 2 hours. Sample and analyze with GPC. Stop the reaction once no more monomer peaks appear in the chromatogram.

[0056] According to GPC testing, the number average Mn was 4100, PDI was 1.67, and the measured acid value was 65.70 mg KOH / g.

[0057] Synthesis example 3:

[0058] Add 25.59g GMA (epoxy equivalent 81.89), 7.84g HEMA (hydroxyl value 0.076), and 10.13g CHMA (molar percentage of GMA:HEMA:CHMA = 60%:20%:20%), 4.85g MAA, 1.73g AIBN, 1.73g α-methylstyrene dimer, and 50g PMA to a 250ml three-necked flask. Start stirring and purge with nitrogen to remove oxygen for half an hour. Simultaneously, add 100g of PMA to a 500ml four-necked flask, install the condenser, thermometer, and stirrer, purge with nitrogen to remove oxygen, and raise the temperature to 85℃. Once the temperature in the 500ml flask reaches 85℃, pour 250ml of the slurry into a constant pressure funnel and begin dropwise addition. Control the addition time to 2.5-3 hours, and maintain the reaction temperature at 85±1℃. After the addition is complete, continue the reaction for 2 hours. Sample and analyze with GPC. Stop the reaction once no more monomer peaks appear in the chromatogram.

[0059] According to GPC testing, the number average Mn was 4150, PDI was 1.62, and the measured acid value was 65.23 mg KOH / g.

[0060] Synthesis example 4:

[0061] Add 21.33g GMA (epoxy equivalent 68.24), 9.8g HEMA (hydroxyl value 0.095), and 12.66g CHMA (molar percentage of GMA:HEMA:CHMA = 50%:25%:25%), 4.85g MAA, 1.73g AIBN, 1.73g α-methylstyrene dimer, and 50g PMA to a 250ml three-necked flask. Start stirring and purge with nitrogen to remove oxygen for half an hour. Simultaneously, add 100g of PMA to a 500ml four-necked flask, install the condenser, thermometer, and stirrer, purge with nitrogen to remove oxygen, and raise the temperature to 85℃. Once the temperature in the 500ml flask reaches 85℃, pour 250ml of the slurry into a constant pressure funnel and begin dropwise addition. Control the addition time to 2.5-3 hours, and maintain the reaction temperature at 85±1℃. After the addition is complete, continue the reaction for 2 hours. Sample and analyze with GPC. Stop the reaction once no more monomer peaks appear in the chromatogram.

[0062] According to GPC testing, the number average Mn was 4360, PDI was 1.74, and the measured acid value was 64.90 mg KOH / g.

[0063] Synthesis example 5:

[0064] Add 29.85g GMA (epoxy equivalent 95.54), 1.96g HEMA (hydroxyl value 0.057), and 7.6g CHMA (molar percentage of GMA:HEMA:CHMA = 70%:15%:15%), 4.50g MAA, 1.73g AIBN, 1.73g α-methylstyrene dimer, and 50g PMA to a 250ml three-necked flask. Start stirring and purge with nitrogen to remove oxygen for half an hour. Simultaneously, add 100g of PMA to a 500ml four-necked flask, install the condenser, thermometer, and stirrer, purge with nitrogen to remove oxygen, and raise the temperature to 85℃. Once the temperature in the 500ml flask reaches 85℃, pour 250ml of the slurry into a constant pressure funnel and begin dropwise addition. Control the addition time to 2.5-3 hours, and maintain the reaction temperature at 85±1℃. After the addition is complete, continue the reaction for 2 hours. Sample and analyze with GPC. Stop the reaction once no more monomer peaks appear in the chromatogram.

[0065] According to GPC testing, the number average Mn was 4520, PDI was 1.68, and the measured acid value was 66.70 mg KOH / g.

[0066] Comparative Example 1:

[0067] Add 36.25g GMA (epoxy equivalent 116), 1.96g HEMA (hydroxyl value 0.019), and 12.66g CHMA (molar percentage of GMA:HEMA:CHMA = 85%:5%:25%), 3.10g MAA, 1.73g AIBN, 1.73g α-methylstyrene dimer, and 50g PMA to a 250ml three-necked flask. Start stirring and purge with nitrogen to remove oxygen for half an hour. Simultaneously, add 100g of PMA to a 500ml four-necked flask, install the condenser, thermometer, and stirrer, purge with nitrogen to remove oxygen, and raise the temperature to 85℃. Once the temperature in the 500ml flask reaches 85℃, pour 250ml of the slurry into a constant pressure funnel and begin dropwise addition. Control the addition time to 2.5-3 hours, and maintain the reaction temperature at 85±1℃. After the addition is complete, continue the reaction for 2 hours. Sample and analyze with GPC. Stop the reaction once no more monomer peaks appear in the chromatogram.

[0068] According to GPC testing, the number average Mn was 4420, PDI was 1.64, and the measured acid value was 37.42 mg KOH / g.

[0069] Comparative Example 2:

[0070] Add 17.06g GMA (epoxy equivalent 54.59), 1.96g HEMA (hydroxyl value 0.019), 27.85g CHMA (molar percentage of GMA:HEMA:CHMA = 40%:5%:55%), 8.7g MAA, 1.73g AIBN, 1.73g α-methylstyrene dimer and 50g PMA to a 250ml three-necked flask. Start stirring and purge with nitrogen to remove oxygen for half an hour. Simultaneously, add 100g of PMA to a 500ml four-necked flask, install the condenser, thermometer, and stirrer, purge with nitrogen to remove oxygen, and raise the temperature to 85℃. Once the temperature in the 500ml flask reaches 85℃, pour 250ml of the slurry into a constant pressure funnel and begin dropwise addition. Control the addition time to 2.5-3 hours, and maintain the reaction temperature at 85±1℃. After the addition is complete, continue the reaction for 2 hours. Sample and analyze with GPC. Stop the reaction once no more monomer peaks appear in the chromatogram.

[0071] According to GPC testing, the number average Mn was 4810, PDI was 1.78, and the measured acid value was 103.30 mg KOH / g.

[0072] 2. Synthesis of Oligomer II

[0073] 100 g of propylene glycol methyl ether acetate as a solvent was added to a 250 ml four-necked flask equipped with a stirrer, condenser, thermometer, and nitrogen inlet tube. The mixture was stirred while being purged with nitrogen, and the temperature was raised to 85°C. Next, 5 g of tert-butyl peroxide (2-ethylhexanoate) and 1.5 g of n-dodecyl mercaptan were added to the 250 ml flask, and nitrogen was purged for oxygen removal for 15 min. The mixture was then added to a 150 ml constant-pressure funnel and added dropwise to the flask over 2 hours. The reaction was further stirred at 120°C for 2 hours. Heating and stirring were stopped when no monomer remained in the reaction solution, as monitored by GPC. A grafted oligomer with a solid acid value of 130.33 mg KOH / g and a number-average molecular weight of 3320 was obtained.

[0074] Next, the air inside the flask was replaced, and then 5.35 parts by weight of glycidyl methacrylate, 0.05 parts by weight of tetrabutylammonium bromide, and 0.02 parts by weight of p-methoxyphenol were added. The reaction was carried out at 100°C for 5 hours. The reaction was stopped when the peak of GMA in the reaction solution disappeared, monitored by GPC. The number-average molecular weight of the polymer was 3840, and the acid value of the solid component was 88.09 mg KOH / g.

[0075] 3. Photosensitive resin composition

[0076] The photosensitive resin compositions of Examples 1-5 and Comparative Examples 1-4 were prepared according to the formulations in the table below.

[0077] The composition is prepared by conventional mixing and stirring.

[0078]

[0079] 4. After curing the photosensitive resin compositions in the table above into curable coatings according to the following methods, conduct relevant tests.

[0080] Preparation of the curable coating: The above-mentioned raw materials were weighed into a 20ml brown sample bottle using an analytical balance. The mixture was homogenized using a JOANLAB Roller Mixer for 3 hours. Then, the coating was spin-coated onto a 10×10cm RGB glass film (sample 1) using an EZ6-5 vacuum spin coater. Simultaneously, a 10×10cm transparent glass film was also spin-coated (sample 2). Solvent was extracted for 180s using a Lichen vacuum drying oven. The film was then pre-dried at 90℃ for 2 minutes in a Lichen drying oven, and finally dried at 230℃ for 30 minutes in a Lichen hot air drying oven until a dry film thickness of 3.0µm was achieved. This sample was used as the test sample.

[0081] 5. Performance testing methods and results

[0082] Hardness test:

[0083] Sharpen about 5-6mm of wood off one end of a pencil (Mitsubishi, Japan) with a specified hardness. Hold the pencil vertically and move it back and forth on the sandpaper at a 90° angle. Smooth the lead at a right angle, continuing to move the pencil until the cross-section is a smooth, round shape with no debris or nicks at the edges. Place the Airipu QHQ-A (500g) pencil hardness tester (Quzhou Aipu Measurement Instrument Co., Ltd.) on a pad, insert the pencil into the 45° hole, and secure it with the locking screw. Place the sample to be tested on a stable surface. Remove the pad and place the instrument on the sample, ensuring the pencil lead contacts the sample coating. Immediately push the roller to move the instrument at a speed of 0.5-1mm / s for at least 7mm. Wipe all pencil lead debris off the coating surface with a lint-free cloth and observe under a microscope. If the membrane has scratches, it indicates the pencil does not meet the specified hardness; if there are no scratches, the membrane meets the specified hardness. A hardness ≥4H is acceptable, and a hardness <4H is unacceptable.

[0084] Response rate test:

[0085] Use the Anton Paar Step 300 recovery rate tester to perform the test according to the test conditions in the table below:

[0086]

[0087] Response rate calculation method:

[0088] One press: Resilience rate = (hmax1 - hp1) / hmax * 100%

[0089] Press twice: Recovery rate = (hmax² - hp²) / hmax * 100%

[0090] Press 3 times: Recovery rate = (hmax3 - hp3) / hmax * 100%

[0091] ...

[0092] Press N times: Recovery rate = (hmaxN - hpN) / hmax * 100%

[0093] A response rate of ≥85% is considered acceptable; a response rate of <85% is considered unacceptable.

[0094] The test results for hardness and recovery rate are shown in the table below:

[0095] Sample Name hardness Response rate % Example 1 5H 86.8 Example 2 5H 87.0 Example 3 5H 88.2 Example 4 5H 87.4 Example 5 4H 87.6 Comparative Example 1 3H 78.2 Comparative Example 2 3H 75.4 Comparative Example 3 2H 65.8 Comparative Example 4 2H 67.8

[0096] 6. Photosensitive interstitial material

[0097] This invention provides a photosensitive spacer prepared using a photosensitive resin composition. The photosensitive spacer can be manufactured by steps such as pre-baking, developing, and post-baking, which are conventional manufacturing methods in the art.

[0098] For example, the surface pattern of the test sample (a test piece with a 4-step film formation) is observed using an L2030-7045T metallographic microscope, and then photographed. Figure 1 and Figure 2 As shown. Figure 1 The sample prepared in Example 1 Figure 2 The sample prepared for Comparative Example 3.

[0099] from Figure 2 As can be seen, although a photoresist composition composed of one type of oligomer I can form spacers of a specified size, due to the lack of cross-linking with the active monomer, serrated MURAs easily form on the top of the sub-PS during development. These MURAs are prone to breakage under stress and fail to provide the necessary support, causing the display to malfunction. When the aforementioned two oligomers and their compositions are used as PS spacers, they can replace spacers made of styrene polymers and silicon in the liquid crystal cell, improving the display effect and increasing the yield rate of the liquid crystal display.

[0100] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Any person skilled in the art should be able to make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the appended claims.

Claims

1. A photosensitive resin composition, characterized in that, This includes oligomer I and oligomer II; oligomer I is an acrylic resin containing epoxy groups, comprising epoxy-containing repeating units, hydroxyl-containing repeating units, alicyclic hydrocarbon-containing repeating units, and carboxyl-containing repeating units, and has the structure shown in Formula I; oligomer II is a grafted acrylic resin, and has the structure shown in Formula II. Formula I Formula II In Formula I, R1 is methyl or hydrogen, R2 contains an epoxy group, R3 contains a hydroxyl group, and R4 contains an alicyclic hydrocarbon group; in Formula II, R1 is methyl or hydrogen, and the repeating unit containing R2 is derived from at least one of cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate, rosin methacrylate, and phenoxyethyl methacrylate. In the oligomer I, the epoxy repeating unit is derived from glycidyl methacrylate, the hydroxy repeating unit is derived from 2-hydroxyethyl methacrylate, and the alicyclic hydrocarbon repeating unit is derived from cyclohexyl methacrylate. The oligomer I contains 50-80% epoxy groups, 5-15% hydroxyl groups, and 15-35% alicyclic hydrocarbon groups. The acid value of oligomer I is 30-80 mg KOH / g.

2. The photosensitive resin composition according to claim 1, characterized in that, The weight ratio of oligomer I to oligomer II is 3-8:1-5.

3. The photosensitive resin composition according to claim 1, characterized in that, The number average molecular weight of oligomer I is 3000-7000.

4. The photosensitive resin composition according to claim 1, characterized in that, The oligomer II has an acid value of 70-180 mg KOH / g and a number-average molecular weight of 2000-6000.

5. A photosensitive resin composition according to any one of claims 1-4, characterized in that, By weight, it includes 3-8 parts of oligomer I, 1-5 parts of oligomer II, 0.2-0.5 parts of leveling agent, 0.5-1.2 parts of photoinitiator, 3-8 parts of curing agent, 0.5-3 parts of coupling agent, 5-10 parts of active monomer, and 70-88 parts of organic solvent.

6. The photosensitive resin composition according to claim 5, characterized in that, The curing agent is a latent curing agent, and the coupling agent is a siloxane coupling agent.

7. A curable coating, characterized in that, It is prepared from the photosensitive resin composition according to any one of claims 5-6.

8. A photosensitive spacer, characterized in that, It is prepared from the photosensitive resin composition according to any one of claims 5-6.

Images