Positive photosensitive resin composition

Abstract

Disclosed is a positive photosensitive resin composition and a manufacturing method using the same. The positive photosensitive resin composition comprises: a polymer resin comprising i) 5 to 95 wt% of a polyimide precursor having a structural unit represented by Chemical Formula 1, ii) 5 to 95 wt% of a polyimide having a structural unit represented by Chemical Formula 2, and iii) 0 to 20 wt% of a polyimide precursor having a structural unit represented by Chemical Formula 3; a quinonediazide compound comprising 5 to 50 parts by weight per 100 parts by weight of the polymer resin; and a solvent comprising 100 to 2,000 parts by weight per 100 parts by weight of the polymer resin.

Description

TECHNICAL FIELD

[0001] The present application relates to a positive photosensitive resin composition, and more particularly, to a positive photosensitive resin composition used in a display device. BACKGROUND

[0002] In recent markets, an organic light emitting diode (OLED) display device, particularly an active matrix OLED (AMOLED) display device, is favored for various reasons.

[0003] Generally, an organic light emitting diode (OLED) element includes an organic insulating film, and a polyimide photosensitive resin composition is generally used in forming the organic insulating film. In a polyimide precursor used in a conventional polyimide photosensitive resin composition, a technology of using an alkyl-substituted polyamic acid ester is applied, but the alkyl-substituted polyamic acid ester has a problem of difficulty in adjusting solubility and low sensitivity, and thus a solution related thereto is urgently needed. SUMMARY

[0004] TECHNICAL PROBLEM

[0005] Therefore, the present application aims to provide a positive photosensitive resin composition having easy solubility adjustment and significantly improved sensitivity.

[0006] METHOD FOR SOLVING TECHNICAL PROBLEM

[0007] To achieve the above object, the present application provides a positive photosensitive resin composition including: a polymer resin including i) 5 to 95 wt% of a polyimide precursor having a structural unit represented by the following Chemical Formula 1, ii) 5 to 95 wt% of a polyimide precursor having a structural unit represented by the following Chemical Formula 2, and iii) 0 to 20 wt% of a polyimide precursor having a structural unit represented by the following Chemical Formula 3; a quinonediazide compound including 5 to 50 parts by weight with respect to 100 parts by weight of the polymer resin; and a solvent including 100 to 2,000 parts by weight with respect to 100 parts by weight of the polymer resin.

[0008] [Chemical Formula 1]

[0009]

[0010] [Chemical Formula 2]

[0011]

[0012] [Chemical Formula 3]

[0013]

[0014] In the Chemical Formula 1 to Chemical Formula 3, R1 and R2 are each independently an organic group having a carbon number of 5 to 30, in which hydrogen can be substituted with hydroxyl (OH), methyl, or fluorine, methylene can be substituted with oxygen or nitrogen, and R3 can be a substituent derived from an epoxy group.

[0015] Further, the present application provides a display element including a driving circuit, a planarization layer, a first electrode, an insulating layer, a light emitting layer, and a second electrode on a substrate, at least one of the planarization layer and the insulating layer being formed using the positive photosensitive resin composition.

[0016] The positive photosensitive resin composition according to the present application is easy to adjust the solubility and can improve the sensitivity, chemical resistance, adhesion, and the like when forming a pattern of a display element such as an organic light emitting diode (OLED), and can also suppress the generation of scum and cracks. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram illustrating a state in which a pattern film is formed on an indium tin oxide (ITO) substrate on which a pattern is formed and electroluminescent lighting (EL) is deposited according to an embodiment of the present application. DETAILED DESCRIPTION

[0018] Next, the present application will be described in more detail.

[0019] In the present specification, "*" represents a moiety connected to the same or different yard or chemical formula.

[0020] The positive photosensitive resin composition according to the present application includes a polymer resin, a quinonediazide compound, and a solvent.

[0021] The polymer resin used in the present application can function to form a polyimide film by polymerization, and can include 5 to 95 wt% of a polyimide precursor having a structural unit represented by the following Chemical Formula 1, specifically, 10 to 90 wt%, 5 to 95 wt% of a polyimide having a structural unit represented by the following Chemical Formula 2, specifically, 50 to 90 wt%, and 0 to 20 wt% of a polyimide precursor having a structural unit represented by the following Chemical Formula 3, specifically, 0 to 15 wt%.

[0022] [Chemical Formula 1]

[0023]

[0024] [Chemical Formula 2]

[0025]

[0026] [Chemical Formula 3]

[0027]

[0028] In the Chemical Formula 1 to Chemical Formula 3, R1and R2are each independently an organic group having a carbon number of 5 to 30, specifically, an organic group having a carbon number of 5 to 20. Hydrogen in the organic group can be substituted with a hydroxyl group (OH), a methyl group, or a fluorine, and a methylene group can be substituted with oxygen or nitrogen. R3is a substituent derived from an epoxy group, specifically, a substituent represented by the following Chemical Formula 4.

[0029] [Chemical Formula 4]

[0030]

[0031] In the Chemical Formula 4, R4is a linear, branched, or cyclic alkyl group having a carbon number of 1 to 12, hydrogen of the alkyl group can be substituted with 1 to 3 fluorines, a hydroxyl group, a methylene group can be substituted with an alkenyl group, oxygen, nitrogen, an ester group (COO), or a carboxyl group (C=O).

[0032] As a substituent represented by the aforementioned chemical formula 4, R3 is specifically derived from a compound selected from the group consisting of epoxycyclohexylmethyl methaacrylate (ECMMA), 1,2-epoxy-4-vinylcyclohexane, 3,4-(epoxycyclohexane)methyl-3',4'-epoxycyclohexylcarboxylate, and 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate modified epsilon-caprolactone. In particular, when 1,2-epoxy-4-vinylcyclohexane or similar cyclohexane is used as the terminal substituent for cyclohexane and has an alkyl or alkynyl group, it exhibits superior thermal stability compared to carboxylate and can therefore be used as an insulating film for organic light-emitting diodes (OLEDs), but is not limited thereto.

[0033] The polymer resin is manufactured by polymerizing aromatic dianhydrides and diamine structural components, for example, in a molar ratio of 1:0.6 to 1:1.4. When the molar ratio of the aromatic dianhydrides and diamine structural components is exceeded, the mechanical and thermal properties may be weakened because the molecular weight of the resin drops below 3,000.

[0034] As a structural component of the aromatic dianhydride, one or more compounds represented by the following chemical formulas R1-1 to R1-7 may be selected, in which case the structure of R1 in the polymer resin is derived from the structure of the following aromatic dianhydrides.

[0035] [Chemical formula R1-1]

[0036]

[0037] [Chemical formula R1-2]

[0038]

[0039] [Chemical formula R1-3]

[0040]

[0041] [Chemical Formula R1-4]

[0042]

[0043] [Chemical Formula R1-5]

[0044]

[0045] [Chemical Formula R1-6]

[0046]

[0047] [Chemical Formula R1-7]

[0048]

[0049] As the structural component of the diamine, one or more of the compounds represented by the following Chemical Formulas R2-1 to R2-10, for example, can be selected, and an aromatic diamine can be preferably used. The structure of R2 in the polymer resin is derived from the following diamine.

[0050] [Chemical Formula R2-1]

[0051]

[0052] [Chemical Formula R2-2]

[0053]

[0054] [Chemical Formula R2-3]

[0055]

[0056] [Chemical Formula R2-4]

[0057]

[0058] [Chemical Formula R2-5]

[0059]

[0060] [Chemical Formula R2-6]

[0061]

[0062] [Chemical Formula R2-7]

[0063]

[0064] [Chemical Formula R2-8]

[0065]

[0066] [Chemical Formula R2-9]

[0067]

[0068] [Chemical Formula R2-10]

[0069]

[0070] In the polyimide precursor having the structural unit represented by Chemical Formula 1, the content of the structural unit represented by Chemical Formula 1 is not particularly limited as long as the development speed of the composition can be improved, for example, 0.1 to 100 mol% with respect to the number of all repeating units, and specifically, can be 5 to 100 mol%.

[0071] In the polyimide precursor having the structural unit represented by Chemical Formula 1, by using a substituent derived from an epoxy group as R3, a substance in which a hydroxyl group (OH) is substituted into R3 of the polyamic acid ester can be manufactured. In the case of using the polyimide precursor having the structural unit represented by Chemical Formula 1 including the polyamic acid ester structure in which the hydroxyl group (OH) is substituted as a photosensitive resin composition, the sensitivity thereof can be improved compared to a conventional photosensitive resin composition without a hydroxyl group. As an example, in the case of applying a positive photosensitive resin composition to an organic light emitting diode (OLED) substrate and irradiating light after volatilizing the solvent by soft baking, a quinonediazide substance is converted from hydrophobicity to hydrophilicity, and in this case, in the case in which the structural unit represented by Chemical Formula 1 includes a hydroxyl group (OH), the development speed can be further improved and thereby the sensitivity can be improved.

[0072] The weight average molecular weight (Mw) of the polyimide precursor having the structural unit represented by Chemical Formula 1 is 3,000 to 20,000, and specifically, can be 3,500 to 10,000. In the case in which the molecular weight of the polyimide precursor is too low, there can be a problem in that the mechanical and thermal characteristics after curing of the resin composition do not satisfy the organic light emitting diode (OLED), and in the case in which the molecular weight is too high, there can be a problem in that the production cost of the organic light emitting diode (OLED) is increased due to the excessively high amount of light irradiation required, that is, the excessively low sensitivity.

[0073] The polyimide having the structural unit represented by Chemical Formula 2 can control the sensitivity. In the structure of Chemical Formula 2, the sensitivity can be controlled to be improved when R2 is substituted with a hydroxyl group, and the sensitivity can be controlled to be reduced when R2 is substituted with a fluorine. In the structural unit represented by Chemical Formula 2, R1 and R2 are the same as described above.

[0074] The weight average molecular weight (Mw) of the polyimide having the structural unit represented by the Chemical Formula 2 is 4,000 to 20,000, and specifically, can be 3,500 to 10,000. In the case where the molecular weight of the polyimide is too low, there can be a problem in that mechanical and thermal properties after curing of the resin composition do not satisfy the organic light emitting diode (OLED), and in the case where the molecular weight is too high, there can be a problem in that the production cost of the organic light emitting diode (OLED) is increased due to the high amount of light exposure required, i.e., low sensitivity.

[0075] The polyimide precursor having the structural unit represented by the Chemical Formula 3 is a polyamic acid structure including a carboxyl group, and like the polyimide precursor having the structural unit represented by the Chemical Formula 1, in the case where a hydroxyl group (OH) is included, the development speed can be further increased and thereby the sensitivity can be increased. However, in the case where 20% by weight or more of the structural unit represented by the Chemical Formula 3 is used in the resin polymer composition, there can be a problem in that the photosensitive function is lost due to the small difference in development between the exposed portion and the non-exposed portion, i.e., the contrast. In the structural unit represented by the Chemical Formula 3, R1 and R2 are the same as described above.

[0076] The weight average molecular weight (Mw) of the polyimide having the structural unit represented by the Chemical Formula 3 is 3,000 to 20,000, and specifically, can be 3,500 to 10,000. In the case where the molecular weight of the polyimide precursor is too low, there can be a problem in that mechanical and thermal properties after curing of the resin composition do not satisfy the organic light emitting diode (OLED), and in the case where the molecular weight is too high, there can be a problem in that the production cost of the organic light emitting diode (OLED) is increased due to the high amount of light exposure required, i.e., low sensitivity.

[0077] The content of the polyimide precursor having the structural unit represented by the Chemical Formula 1 is 5 to 95% by weight, and specifically, can be 10 to 90% by weight, the content of the polyimide precursor having the structural unit represented by the Chemical Formula 2 is 5 to 95% by weight, and specifically, can be 50 to 90% by weight, and the content of the polyimide precursor having the structural unit represented by the Chemical Formula 3 is 0 to 20% by weight, and specifically, can be 0 to 15% by weight, among all the polymers.

[0078] The polymer resin can include, as a main component, a polyimide precursor having a structural unit represented by Chemical Formula 1 and a polyimide having a structural unit represented by Chemical Formula 2, and in all of the polymer resin, when the content of the polyimide precursor having a structural unit represented by the Chemical Formula 1 or the polyimide having a structural unit represented by Chemical Formula 2 is less than 5 wt%, it can cause a problem of easily occurring scum and cracks in the photoresist or a decrease in coating properties of the photoresist such as chemical resistance, and when it exceeds 95 wt%, it can cause a problem of an increase in sensitivity and occurrence of cracks.

[0079] The polymer resin can include, as a main component, a polyimide having a structural unit represented by Chemical Formula 2, for example, 50 to 95 wt% of the structure of Chemical Formula 2 can be included in all of the polymer resin, and specifically, 60 to 95 wt% can be included, thereby exhibiting coating properties such as chemical resistance or effects such as crack prevention.

[0080] The quinonediazide compound is a photosensitive substance that is changed from hydrophobic to hydrophilic before and after irradiation of light, and is a necessary compound for forming a photosensitive resin composition. In particular, it can be effectively used to control sensitivity. The quinonediazide compound can be obtained by the reaction of a phenolic compound including a compound represented by Chemical Formula 4-1 to Chemical Formula 4-3 below with a naphthoquinone diazide sulfonic acid halogen compound.

[0081] [Chemical Formula 4-1]

[0082]

[0083] [Chemical Formula 4-2]

[0084]

[0085] [Chemical Formula 4-3]

[0086]

[0087] In the Chemical Formula 4-1 to Chemical Formula 4-3, R 31 to R 36 each independently is hydrogen, halogen, hydroxyl, an alkyl group having a carbon number of 1 to 4, or an alkenyl group having a carbon number of 1 to 4, R 37 and R 38 each independently is hydrogen, halogen, or an alkyl group having a carbon number of 1 to 4, R 39 is hydrogen or an alkyl group having a carbon number of 1 to 4.

[0088] The content of the quinonediazide compound is 5 to 30 parts by weight, specifically, 10 to 40 parts by weight, relative to 100 parts by weight of the polymer resin. When the content of the quinonediazide compound is too low, the problem of excessive increase in sensitivity can occur, and when the content is too high, the problem of easy occurrence of scum and crack or decrease in coating properties of the resist such as decrease in chemical resistance can occur.

[0089] The solvent can affect the mura and dispersion of the coating thickness when the polymer resin and the quinonediazide compound are coated on the substrate with excessively high viscosity. In order to reduce the mura and dispersion of the coating thickness as described above, it is necessary to maintain an appropriate viscosity by mixing the solvent with the polymer resin and the quinonediazide compound. The boiling point of the solvent is preferably 230°C or less, and the solubility of the polymer resin and the quinonediazide compound should be excellent. As the solvent, γ-butyrolactone (GBL), N-methylpyrrolidone (NMP), propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether (PGME), ethyl lactate (EL), methyl-3-methoxypropionate (MMP), and a mixture thereof, etc. can be used. For example, γ-butyrolactone (GBL): methyl-3-methoxypropionate (MMP): propylene glycol methyl ether (PGME) = 24:20:56 in molar ratio can be used in mixture.

[0090] The content of the solvent is 100 to 2,000 parts by weight, specifically, 250 to 1,500 parts by weight, relative to 100 parts by weight of the polymer resin. When the content of the solvent is too low, the problem of precipitation of solid substances when the resin composition is stored for a long time can occur, and when the content is too high, the problem of failure to form an appropriate thickness when coating is performed using the resin composition to form an insulating film can occur.

[0091] The positive photosensitive resin composition including the polymer resin including the polyimide precursor having the structural unit represented by Chemical Formula 1, the polyimide having the structural unit represented by Chemical Formula 2, and the polyimide precursor having the structural unit represented by Chemical Formula 3, the quinonediazide compound, and the solvent can be coated on the substrate to maintain the insulating properties between the metal films in the substrate, but in order to perfect the properties of the insulating film, one or more of additives such as a thermal crosslinking agent, a thermal acid generator, an ultraviolet (UV) absorber, and a thermal base generator, etc. can be further included.

[0092] The thermal crosslinking agent can function to improve the chemical resistance of the photosensitive resin composition by undergoing a crosslinking reaction with the polymer resin. The thermal crosslinking agent can be a phenol compound including the following Chemical Formula a, and in particular, can include a functional group represented by the following Chemical Formula 5.

[0093] [Chemical Formula a]

[0094]

[0095] [Chemical Formula 5]

[0096]

[0097] In the Chemical Formula 5, A is the Chemical Formula a below, and in the Chemical Formula a, n is an integer of 1 to 6, and Ra is an alkyl group having a carbon number of 1 to 3.

[0098] The thermal crosslinking agent preferably includes a structure in which 1 to 4 functional groups represented by the Chemical Formula 5 are combined, and in particular, can include compounds represented by the following Chemical Formula 5-1 to Chemical Formula 5-4.

[0099] [Chemical Formula 5-1]

[0100]

[0101] [Chemical Formula 5-2]

[0102]

[0103] [Chemical Formula 5-3]

[0104]

[0105] [Chemical Formula 5-4]

[0106]

[0107] In the Chemical Formula 5-1 to Chemical Formula 5-4, A is as described above.

[0108] The content of the thermal crosslinking agent is 10 to 50 parts by weight, and in particular, 10 to 30 parts by weight, with respect to 100 parts by weight of the polyimide polymer. In the case where the amount of the thermal crosslinking agent is too small, there can be a problem in that there is no chemical resistance effect, and in the case where the amount is too large, there can be a problem in that it is not possible to form a polymer resin of a certain height or more due to a severe reduction in the film when developing after soft baking the photosensitive resin composition coated on a substrate.

[0109] The thermal acid generator can function to generate an acid at a certain temperature or higher, and can promote the cross-linking reaction of the thermal cross-linking agent with the polymer resin. The content of the thermal acid generator is preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the polyimide polymer. In the case where the amount of the thermal acid generator is too small, there can be a problem in that no effect is obtained, and in the case where the amount is too large, there can be a problem in that scum occurs.

[0110] In the case where the photosensitive resin composition according to the present application is applied to a substrate to be used as an insulating film, in order to prevent a phenomenon of deterioration upon exposure to external light for a long time, an ultraviolet (UV) absorber such as a benzophenone-based compound and a benzotriazole-based compound can be further added. As the ultraviolet (UV) absorber, for example, 2-(2H-benzotriazol-2-yl)-phenol or the like can be used. The content of the ultraviolet (UV) absorber is preferably 0.01 to 2.0 parts by weight with respect to 100 parts by weight of the polymer resin. In the case where the amount of the ultraviolet (UV) absorber is too small, there can be a problem in that no effect is obtained, and in the case where the amount is too large, there can be a problem in that the heat resistance is reduced.

[0111] The present application provides an insulating film manufacturing method using a positive photosensitive resin composition. The insulating film can be applied to a display element such as an organic light emitting diode (OLED), and has excellent high-sensitivity pattern development, and effects of reduction in occurrence of scum and cracks upon pattern formation, improvement in chemical resistance, and improvement in adhesion.

[0112] The insulating film manufacturing method includes a step of drying after applying the positive photosensitive resin composition to a substrate, and a step of forming a polyimide film by curing after exposing and developing the substrate to which the photosensitive resin composition is applied. As a method of applying the photosensitive resin composition, a method known in the art can be used without limitation, for example, a method such as spin coating, dip coating, roll coating, screen coating, spray coating, and screen printing can be used. As the developing solution, an aqueous alkali solution can be used without limitation. The thickness of the insulating film according to the present application can be changed according to the purpose, and is preferably 1.0 to 15 μm, but is not limited thereto.

[0113] Further, the present application provides a display element including a driving circuit, a planarization layer, a first electrode, an insulating layer, a light-emitting layer, and a second electrode on a substrate, at least one of the planarization layer and the insulating layer being formed using the positive photosensitive resin composition.

[0114] Next, the present application will be described in more detail with reference to Examples, but the present application is not limited by the following Examples.

[0115] [Synthesis Example 1] Synthesis of polyimide precursor (Chemical Formula 1)

[0116] Into a 1000 mL beaker, γ-butyrolactone (GBL, 313 g) was charged, and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (bis-APAF, 71.8 g, 0.196 mol) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (SiDA, 0.99 g, 0.04 mol) were dissolved at 50°C. To this, 3,3',4,4'-oxydiphthalic dianhydride (ODPA, 46.5 g, 0.15 mol) was added and after stirring for 25 hours at 70°C, phthalic anhydride (14.8 g, 0.1 mol) was charged and reacted for 2 hours. Next, dimethylformamide dimethyl acetal (DFA, 17.8 g, 0.15 mol) was added thereto and after stirring for 4 hours at 70°C, the reaction was terminated, thereby synthesizing a polyimide precursor.

[0117] [Synthesis Example 2] Synthesis of polyimide precursor (Chemical Formula 1)

[0118] Into a 1000 mL beaker, γ-butyrolactone (GBL, 309 g) was charged, and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (bis-APAF, 68.1 g, 0.1860 mol), 4,4,'-diphenylamine (2.0 g, 0.01 mol), and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (SiDA, 0.99 g, 0.04 mol) were dissolved at 50°C. To this, 3,3',4,4'-oxydiphthalic dianhydride (ODPA, 47.8 g, 0.154 mol) was added and after stirring for 25 hours at 70°C, phthalic anhydride (13.63 g, 0.092 mol) was charged and reacted for 2 hours. Next, dimethylformamide dimethyl acetal (DFA, 18.3 g, 0.154 mol) was added thereto and after stirring for 4 hours at 70°C, the reaction was terminated, thereby synthesizing a polyimide precursor.

[0119] [Synthesis Example 3] Synthesis of polyimide precursor (Chemical Formula 1)

[0120] Into a 1000 mL beaker, γ-butyrolactone (GBL, 329 g) was charged and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (bis-APAF, 71.8 g, 0.196 mol) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (SiDA, 0.99 g, 0.04 mol) were dissolved at 50°C. To this, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (ODPA, 32.3 g, 0.104 mol) and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA, 22.2 g, 0.05 mol) were added and after stirring at 70°C for 25 hours, o-phthalic anhydride (13.6 g, 0.092 mol) was charged and reacted for 2 hours. Next, dimethylformamide dimethyl acetal (DFA, 18.3 g, 0.154 mol) was added and after stirring at 70°C for 4 hours, the reaction was terminated, thereby synthesizing a polyimide precursor.

[0121] [Synthesis Example 4] Synthesis of polyimide precursor (Chemical Formula 1)

[0122] A polyimide precursor was synthesized in the same manner as in the Synthesis Example 1, except that 1,2-epoxy-4-vinylcyclohexane (37.35 g, 0.3 mol) and triethylamine (0.81 g, 0.008 mol) were charged instead of dimethylformamide dimethyl acetal, and the reaction was terminated after stirring for 48 hours, thereby synthesizing a polyimide precursor.

[0123] [Synthesis Example 5] Synthesis of polyimide precursor (Chemical Formula 1)

[0124] A polyimide precursor was synthesized in the same manner as in the Synthesis Example 2, except that 1,2-epoxy-4-vinylcyclohexane (38.25 g, 0.308 mol) and triethylamine (0.81 g, 0.008 mol) were charged instead of dimethylformamide dimethyl acetal, and the reaction was terminated after stirring for 48 hours, thereby synthesizing a polyimide precursor.

[0125] [Synthesis Example 6] Synthesis of polyimide precursor (Chemical Formula 1)

[0126] A polyimide precursor was synthesized in the same manner as in the Synthesis Example 3, except that 1,2-epoxy-4-vinylcyclohexane (38.25 g, 0.308 mol) and triethylamine (0.81 g, 0.008 mol) were charged instead of dimethylformamide dimethyl acetal, and the reaction was terminated after stirring for 48 hours, thereby synthesizing a polyimide precursor.

[0127] [Synthesis Example 7] Synthesis of polyimide (Chemical Formula 2)

[0128] Into a 1000 mL beaker, γ-butyrolactone (GBL, 313 g) was charged and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (bis-APAF, 71.79 g, 0.196 mol) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (SiDA, 0.99 g, 0.04 mol) were dissolved at 50°C. To this, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (ODPA, 46.5 g, 0.15 mol) was added and after stirring for 4 hours at 70°C, 3-aminophenol (13.1 g, 0.12 mol) was charged and reacted for 2 hours. Next, 60 mL of toluene was charged and after reacting for 2 hours at 150°C and 2 hours at 180°C, the reaction was terminated, thereby synthesizing a polyimide.

[0129] [Synthesis Example 8] Synthesis of polyimide (Chemical Formula 2)

[0130] Into a 1000 mL beaker, γ-butyrolactone (GBL, 313 g) was charged and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (bis-APAF, 71.79 g, 0.196 mol) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (SiDA, 0.99 g, 0.04 mol) were dissolved at 50°C. To this, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (ODPA, 46.5 g, 0.15 mol) was added and after stirring for 4 hours at 70°C, 3-aminophenol (13.1 g, 0.12 mol) was charged and reacted for 2 hours. Next, 60 mL of toluene was charged and after reacting for 2 hours at 150°C and 2 hours at 180°C, the reaction was terminated, thereby synthesizing a polyimide.

[0131] [Synthesis Example 9] Synthesis of polyimide precursor (Chemical Formula 1)

[0132] Into a 1000 mL beaker, γ-butyrolactone (GBL, 321 g) was charged and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (bis-APAF, 71.8 g, 0.196 mol) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (SiDA, 0.99 g, 0.04 mol) were dissolved at 50°C. To this, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA, 22.21 g, 0.05 mol), 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (13.21 g, 0.05 mol), and 2,3,3',4'-biphenyltetracarboxylic dianhydride (20.6 g, 0.07 mol) were added and after stirring at 70°C for 25 hours, phthalic anhydride (8.89 g, 0.06 mol) was charged and the reaction was further carried out for 2 hours. Next, after raising the temperature of the reactor to 130°C and carrying out the reaction for 30 hours, the temperature was lowered to 70°C. To this, 2-epoxy-4-vinylcyclohexane (19.9 g, 0.16 mol) and triethylamine (0.81 g, 0.008 mol) were added and after stirring at 70°C for 48 hours, the reaction was terminated, thereby synthesizing a polyimide precursor.

[0133] [Synthesis Example 10] Synthesis of polyimide precursor (Chemical Formula 1)

[0134] Into a 1000 mL beaker, γ-butyrolactone (GBL, 321 g) was charged and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (bis-APAF, 71.8 g, 0.196 mol) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (SiDA, 0.99 g, 0.04 mol) were dissolved at 50°C. To this, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA, 22.21 g, 0.05 mol), 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (13.21 g, 0.05 mol), and 2,3,3',4'-biphenyltetracarboxylic dianhydride (20.6 g, 0.07 mol) were added and after stirring at 70°C for 25 hours, phthalic anhydride (8.89 g, 0.06 mol) was charged and the reaction was further carried out for 2 hours. Next, after raising the temperature of the reactor to 130°C and carrying out the reaction for 30 hours, the temperature was lowered to 70°C. To this, 2-epoxy-4-vinylcyclohexane (19.9 g, 0.16 mol) and triethylamine (0.81 g, 0.008 mol) were added and after stirring at 70°C for 48 hours, the reaction was terminated, thereby synthesizing a polyimide precursor.

[0135] [Synthesis Example 11] Synthesis of polyimide precursor (Chemical Formula 1)

[0136] Into a 1000 mL beaker, γ-butyrolactone (GBL, 327 g) was charged and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (bis-APAF, 71.79 g, 0.196 mol) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (SiDA, 0.99 g, 0.04 mol) were dissolved at 50°C. To this, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA, 22.21 g, 0.05 mol), 2,3,3',4'-biphenyltetracarboxylic dianhydride (14.7 g, 0.05 mol), and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (ODPA, 21.7 g, 0.07 mol) were added and after stirring at 70°C for 25 hours, phthalic anhydride (8.89 g, 0.06 mol) was charged and the reaction was additionally carried out for 2 hours. Next, the temperature of the reactor was raised to 130°C and the reaction was carried out for 30 hours, after which the temperature was lowered to 70°C. To this, 2-epoxy-4-vinylcyclohexane (19.9 g, 0.16 mol) and triethylamine (0.81 g, 0.008 mol) were added and after stirring at 70°C for 48 hours, the reaction was terminated, thereby synthesizing a polyimide precursor.

[0137] [Synthesis Example 12] Synthesis of polyimide precursor (Chemical Formula 3)

[0138] Into a 1000 mL beaker, γ-butyrolactone (GBL, 327 g) was charged and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (bis-APAF, 71.79 g, 0.196 mol) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (SiDA, 0.99 g, 0.04 mol) were dissolved at 50°C. To this, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA, 22.21 g, 0.05 mol), 2,3,3',4'-biphenyltetracarboxylic dianhydride (14.7 g, 0.05 mol), and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (ODPA, 21.7 g, 0.07 mol) were added and after stirring at 70°C for 25 hours, phthalic anhydride (8.89 g, 0.06 mol) was charged and the reaction was additionally carried out for 2 hours, thereby synthesizing a polyamic acid.

[0139] [Examples 1 to 26 and Comparative Examples 1 to 11] Manufacture of photosensitive resin composition

[0140] The polyimides and polyimide precursors synthesized by Synthesis Examples 1 to 12 were mixed in the proportions described in Table 1 below, thereby producing a photosensitive resin composition. Specifically, after confirming the solid content in the polyimides and polyimide precursors synthesized by Synthesis Examples 1 to 12, the contents of the quinonediazide and thermal crosslinking agent were mixed in the proportions shown in Table 1 below, with respect to 100 parts by weight of the polymer resin. Next, using a solvent in which γ-butyrolactone (GBL): methyl-3-methoxypropionate (MMP): propylene glycol methyl ether (PGME) = 24:20:56 were mixed in molar proportions, a photosensitive resin composition in which the solid content was 13% was produced.

[0141] In Table 1 below, Tris-TPPA used as the quinonediazide compound is a compound represented by Chemical Formula 4-1-1 below, and Tris-THAP is a compound represented by Chemical Formula 4-2-1 below. Furthermore, in the case of using a thermal crosslinking agent having the structure of Chemical Formula 5-2 or Chemical Formula 5-3, A is a thermal crosslinking agent in which n in Chemical Formula a is 1 and Ra is a methyl group.

[0142] [Chemical Formula 4-1-1]

[0143]

[0144] [Chemical Formula 4-2-1]

[0145]

[0146] [Table 1]

[0147]

[0148]

[0149]

[0150]

[0151] (unit: parts by weight)

[0152] [Experimental Example] Physical property evaluation

[0153] The photosensitive resin compositions of Comparative Examples 1 to 10 and Examples 1 to 26 synthesized in the proportions described in Table 1 were coated onto a substrate. Next, after coating a thin film on a glass substrate using a spin coater, a film having a thickness of 2.0㎛ was formed by drying at 120℃ for 2 minutes in a hot plate, and the physical properties of the photoresist such as sensitivity, scum, crack, chemical resistance, adhesion, organic light emitting diode (OLED) reliability, etc. were measured using the manufactured substrate, and the result values are described in Table 2 below.

[0154] 1. Sensitivity measurement

[0155] After irradiating the ultraviolet rays having an intensity of 20mW / cm 2 of Broadband at a 5㎛ contact hole critical dimension (CD) using a pattern mask on the manufactured substrate, development was performed using a 2.38 parts by weight aqueous solution of tetramethylammonium hydroxide at 23℃ for 1 minute, and then washing was performed using ultrapure water for 1 minute. Next, curing was performed in an oven at 250℃ for 60 minutes, thereby obtaining a pattern film having a contact hole critical dimension (CD) of 5㎛. The appropriate sensitivity result value was 50 to 150mJ / ㎝ 2 .

[0156] 2. Scum measurement

[0157] The inside of the pattern formed at the time of sensitivity measurement was observed using a scanning electron microscope (SEM), and whether or not there was scum in the line and space and contact hole was confirmed. In the case where there was development scum, it was marked with an X, in the case where there was development scum only at the pattern boundary portion, it was marked with a Δ, and in the case where there was no scum, it was marked with an O.

[0158] 3. Crack measurement

[0159] The manufactured substrate was visually inspected and observed under a microscope at 100 times, and in the case where a crack was observed, it was marked with an X, in the case where a crack was observed only at the coating edge portion, it was marked with a Δ, and in the case where no crack was observed, it was marked with an O.

[0160] 4. Chemical resistance measurement

[0161] The manufactured substrate was immersed in methylpyrrolidone (NMP) at 60°C for 120 seconds and the change in the cured film thickness before and after immersion was measured, and marked as O in the case where the change was less than 10%, marked as O in the case where the change was 10% or more but less than 50%, marked as Δ in the case where the change was 50% or more but less than 100%, and marked as X in the case where the change was 100% or more.

[0162] 5. Adhesion measurement

[0163] A pattern film was formed in the same manner as in the sensitivity measurement, and the adhesion at different drying temperatures was compared with the case where the line width was 10 μm and the slit width was 1:1. At this time, the case where the adhesion could be ensured when pre-drying at 90°C to 100°C was marked as O, the case where the adhesion could be ensured when pre-drying at 105°C to 115°C was marked as Δ, and the case where the adhesion could be ensured when pre-drying at 120°C or more or other cases were marked as X.

[0164] 6. Organic light emitting diode (OLED) reliability measurement

[0165] A pattern film was formed in the same manner as in the sensitivity measurement, Figure 1 is a schematic diagram illustrating a state where an indium tin oxide (ITO) on which a pattern is formed is substantially formed into a pattern film and deposition of electroluminescent lighting (EL) is performed. As shown below Figure 1 , an encapsulation process is performed after deposition of Al as a cathode in the upper portion. The time (T 97 ) until the luminance decreases by 3% in the element on state was measured with 85°C, 85% RH as a reference. The case where 1000 hours or more could be ensured was marked as O, and the case where less than 1000 hours was marked as X.

[0166] [Table 2]

[0167]

[0168] ​​​​As shown in Table 2 above, Comparative Examples 1 to 3 are polyimide precursors of Synthetic Examples 1 to 3, which include a structure in which R3 is an alkyl group in the structural unit represented by the stated Chemical Formula 1. In contrast, Examples 1 to 3 are polyimide precursors of Synthetic Examples 4 to 6, which include a structure in which R3 in the structural unit represented by the stated Chemical Formula 1 is derived from an epoxy compound. A comparison shows that the sensitivity of Examples 1 to 3 is improved by about 10%, and physical properties such as scum, crack, chemical resistance, adhesion, and OLED reliability are also improved. As shown in Comparative Examples 4 to 7, when only a polyimide precursor having a structural unit represented by Chemical Formula 1 or a polyimide synthetic polymer resin having a structural unit represented by Chemical Formula 2 is used, or when less than 5% by weight of a polyimide precursor having a structural unit represented by the aforementioned Chemical Formula 1 or a polyimide synthetic polymer resin having a structural unit represented by the aforementioned Chemical Formula 2 is used, the physical properties such as scum, crack, chemical resistance, adhesion, and organic light-emitting diode (OLED) reliability are worse compared to Examples 1 to 3.

[0169] As shown in Comparative Examples 8 to 11, when the content of the photosensitive substance, quinone diazide, compared to the polymer resin is less than 5% by weight, the sensitivity becomes very high (Comparative Examples 8 and 9). Conversely, when the content of quinone diazide compared to the polymer resin exceeds 50% by weight, the sensitivity decreases, and compared to Examples 1 to 3, physical properties such as scum, crack, chemical resistance, adhesion, and OLED reliability are poor.

[0170] As described in Examples 1 to 21, the sensitivity, scum, crack, chemical resistance, adhesion and reliability of organic light-emitting diode (OLED) substrates are relatively excellent, especially in Examples 22 to 26 which use thermal crosslinking agents, the chemical resistance is very excellent.

[0171] [Symbol Explanation]

[0172] 1: Indium Tin Oxide (ITO)

[0173] 2: Insulator

[0174] 3: Electroluminescent Lighting & Aluminum (EL & Al)

Claims

1. A positive photosensitive resin composition comprising: a polymer resin including i) 5 to 95 wt% of a polyimide precursor having a structural unit represented by the following Chemical Formula 1, ii) 5 to 95 wt% of a polyimide precursor having a structural unit represented by the following Chemical Formula 2, and iii) 0 to 20 wt% of a polyimide precursor having a structural unit represented by the following Chemical Formula 3; a quinonediazide compound including 5 to 50 parts by weight with respect to 100 parts by weight of the polymer resin; and a solvent including 100 to 2,000 parts by weight with respect to 100 parts by weight of the polymer resin: [Chemical Formula 1] [Chemical Formula 2] [Chemical Formula 3] In the Chemical Formula 1 to Chemical Formula 3, R1 and R2 are each independently an organic group having a carbon number of 5 to 30, a hydrogen in the organic group can be substituted with a hydroxyl (OH), a methyl, or a fluorine, a methylene can be substituted with an oxygen or a nitrogen, and R3 is a substituent represented by the following Chemical Formula 4: [Chemical Formula 4] In the Chemical Formula 4, R4 is a linear, branched, or cyclic alkyl group having a carbon number of 1 to 12, a hydrogen of the alkyl group can be substituted with 1 to 3 fluorines, a hydroxyl, a methylene of the alkyl group can be substituted with an alkenyl, an oxygen, a nitrogen, an ester group (COO), or a carbonyl group (C=O).

2. The positive photosensitive resin composition according to claim 1, the R3 is derived from a compound selected from the group consisting of an epoxy cyclohexylmethyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, 3,4-(epoxycyclohexane)methyl-3',4'- epoxycyclohexylcarboxylate, and 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate modified ε-caprolactone.

3. The positive photosensitive resin composition according to claim 1, the polyimide precursor having a structural unit represented by the Chemical Formula 1, the polyimide precursor having a structural unit represented by the Chemical Formula 2, and the polyimide precursor having a structural unit represented by the Chemical Formula 3 each have a weight average molecular weight of 3,500 to 20,000.

4. The positive photosensitive resin composition according to claim 1, the polymer resin includes 50 to 95 wt% of a polyimide having a structural unit represented by the Chemical Formula 2.

5. The positive photosensitive resin composition according to claim 1, the quinonediazide compound is obtained by a reaction of a phenolic compound selected from the group consisting of the following Chemical Formulae 4-1 to 4-3 and a naphthoquinone diazide sulfonic acid halogen compound: [Chemical Formula 4-1] [Chemical Formula 4-2] [Chemical Formula 4-3] 6. The positive photosensitive resin composition according to claim 1, the solvent is selected from the group consisting of γ-butyrolactone (GBL), N-methyl pyrrolidone (NMP), propylene glycol methyl ether acetate (PGMEA), ethyl lactate (EL), methyl-3-methoxypropionate (MMP), propylene glycol methyl ether (PGME), and a mixture thereof.

7. The positive photosensitive resin composition according to claim 1, ​ ​ ​ In the Chemical Formula 4-1 to Chemical Formula 4-3, R 31 to R 36 each independently is hydrogen, halogen, hydroxyl, alkyl having a carbon number of 1 to 4, or alkenyl having a carbon number of 2 to 4, R 37 and R 38 each independently is hydrogen, halogen, or alkyl having a carbon number of 1 to 4, R 39 is hydrogen or alkyl having a carbon number of 1 to 4. ​ ​ ​ The positive photosensitive resin composition further includes an additive selected from the group consisting of a thermal crosslinking agent, a thermal acid generator, a ultraviolet (UV) absorber, and a mixture thereof.

8. The positive photosensitive resin composition according to claim 7, The thermal crosslinking agent includes a functional group represented by the following Chemical Formula 5: [Chemical Formula 5] In the Chemical Formula 5, A is the following Chemical Formula a, and in the following Chemical Formula a, n is an integer of 1 to 6, and Ra is an alkyl group having a carbon number of 1 to 3: [Chemical Formula a] 9. The positive photosensitive resin composition according to claim 7, The thermal crosslinking agent is selected from the group consisting of compounds represented by the following Chemical Formula 5-1 to Chemical Formula 5-4: [Chemical Formula 5-1] [Chemical Formula 5-2] [Chemical Formula 5-3] [Chemical Formula 5-4] In the Chemical Formula 5-1 to Chemical Formula 5-4, A is the following Chemical Formula a, and in the following Chemical Formula a, n is an integer of 1 to 6, and Ra is an alkyl group having a carbon number of 1 to 3: [Chemical Formula a] 10. The positive photosensitive resin composition according to claim 7, 10 to 50 parts by weight of the thermal crosslinking agent is contained with respect to 100 parts by weight of the polymer resin.

11. A display element, including a driving circuit, a planarization layer, a first electrode, an insulating layer, a light emitting layer, and a second electrode on a substrate, at least one of the planarization layer and the insulating layer being formed using the positive photosensitive resin composition according to claim 1.

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