Cured film, photosensitive resin composition forming the same, and display device

Abstract

A cured film is provided that derives new parameters to improve device reliability. One embodiment of the present invention provides a cured film obtained by curing a photosensitive resin composition, the photosensitive resin composition including an alkali-soluble resin and a photoactive compound (PAC), wherein the cured film has a phenolic gas content of 30% (v / v) or less in total outgassing measured by Purge & Trap analysis at 250°C for 60 minutes.

Description

[Technical Field]

[0001] The present invention relates to a cured film, a photosensitive resin composition for forming the same, and a display device. [Background technology]

[0002] Photosensitive resin compositions are representative functional polymer materials that have been put to practical use in the production of various precision electronics products and are currently being used extensively in the high-tech industry, particularly in the production of semiconductors and displays. Generally, a photosensitive resin composition refers to a composition in which a chemical change in molecular structure occurs in a short period of time upon irradiation with light, resulting in changes in physical properties such as solubility in a specific solvent, coloration, and hardening. Photosensitive resin compositions enable fine precision processing, significantly reduce energy and raw materials compared to thermal reaction processes, and enable rapid and accurate work in a small installation space. As a result, they are widely used in various precision electronics industries, including advanced printing, semiconductor production, display production, and photocurable surface coating materials.

[0003] Such photosensitive resin compositions can be broadly classified into negative-type and positive-type, with negative-type photosensitive resin compositions being insoluble in a developer when exposed to light, and positive-type photosensitive resin compositions being soluble in a developer when exposed to light.Recently, as electronic devices have become highly integrated and finer-patterned, positive-type photosensitive resin compositions have become more popular because they can minimize defect rates and improve processing efficiency and resolution.

[0004] In particular, organic light-emitting displays (OLEDs) have attracted attention in the display industry due to their excellent resolution. OLEDs are characterized by their self-luminous nature, which means they do not require a backlight, unlike liquid crystal displays (LCDs). As a result, OLEDs can be thinned, are lightweight, provide clear readability even outdoors, and have excellent contrast ratios and color reproduction. Meanwhile, a pixel-defining layer (PDL) can be disposed on the sidewalls of the light-emitting layer of such OLED devices. This partition can be defined as, for example, a cured film (or insulating film) made from a photosensitive resin composition. When the photosensitive resin composition contains a phenolic additive that improves sensitivity to a developer, the phenolic gas emitted from the cured film can affect the light-emitting layer, causing the OLED device to turn black and reducing the reliability of the OLED. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a cured film that has excellent sensitivity to a developer and leaves no residue after development. Another object of the present invention is to provide a cured film that has excellent adhesion to a substrate, excellent chemical resistance, and also excellent reliability of elements.

[0006] It is yet another object of the present invention to provide a novel parameter relating to outgassing of a cured film that achieves the above performance. A further object of the present invention is to provide a photosensitive resin composition that forms the cured film. It is still another object of the present invention to provide a display device including the cured film.

[0007] The objects of the present invention are not limited to those mentioned above, and other objects and advantages of the present invention not mentioned above will be understood from the following description and will become more clearly understood by the examples of the present invention. Furthermore, it will be easily understood that the objects and advantages of the present invention can be realized by the means and combinations thereof as claimed. [Means for solving the problem]

[0008] To achieve the above object, according to a first aspect of the present invention, there is provided a cured film obtained by curing a photosensitive resin composition, wherein the cured film has a phenolic gas content of 30% (v / v) or less in total outgassing as measured by Purge & Trap analysis at 250°C for 60 minutes.

[0009] According to a second aspect of the present invention, in the first aspect, the content of the phenol-based gas in the total outgas of the cured film measured by the Purge & Trap analysis method may be 0.1 to 10% (v / v).

[0010] According to a third aspect of the present invention, in the first or second aspect, the photosensitive resin composition can contain an alkali-soluble resin and a photoactive compound (PAC).

[0011] According to a fourth aspect of the present invention, in the third aspect, the alkali-soluble resin may be any one selected from the group consisting of polyimide resins, polyamic acids, polyamic esters, polyhydroxystyrenes, and copolymers thereof. According to a fifth aspect of the present invention, in the fourth aspect, the polyimide resin may have an imidization index of 50 to 100%.

[0012] According to a sixth aspect of the present invention, in the fourth or fifth aspect, the polyimide resin can include a structure derived from a diamine containing a hydroxy group.

[0013] According to a seventh aspect of the present invention, in any one of the third to sixth aspects, the photoactive compound may be produced by reacting a phenolic compound with a quinone diazide compound.

[0014] According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the content of unreacted phenol monomers may be less than 1.0% by weight based on the total weight of the photosensitive resin composition.

[0015] According to a ninth aspect of the present invention, in any one of the first to eighth aspects, the content of unreacted phenolic compounds relative to the total weight of the photosensitive resin composition is less than 1.0 wt %, and the unreacted phenolic compounds can contain a phenol structure as a ballast. According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the photosensitive resin composition may contain no phenol-based additives.

[0016] According to an eleventh aspect of the present invention, in any one of the first to tenth aspects, the content of alcohol-based gas in total outgas in the cured film measured by the Purge & Trap analysis method may be 20% (v / v) or less, and the alcohol-based gas may consist of methanol and ethanol. According to a twelfth aspect of the present invention, in any one of the third to eleventh aspects, the photosensitive resin composition can further contain a thermal crosslinking agent.

[0017] According to a thirteenth aspect of the present invention, in the twelfth aspect, the thermal crosslinking agent can include a first thermal crosslinkable compound and a second thermal crosslinkable compound different from the first thermal crosslinkable compound.

[0018] According to a 14th aspect of the present invention, in the 13th aspect, the first thermally crosslinkable compound may contain 1 to 2 functional groups represented by the following chemical formula 1-1, and the second thermally crosslinkable compound may contain 3 to 5 functional groups represented by the following chemical formula 1-1.

[0019] According to a fifteenth aspect of the present invention, there is provided a photosensitive resin composition that forms a cured film according to any one of the first to fourteenth aspects. According to a sixteenth aspect of the present invention, there is provided a display device including the cured film according to any one of the first to fourteenth aspects.

[0020] The above summary of the invention is not an exhaustive list of the features of the invention, and the various features and advantages thereof will be more fully understood with reference to the following specific examples. [Effects of the Invention]

[0021] According to some embodiments of the present invention, by specifying a parameter related to the content of phenolic gas in the total outgassing of the cured film, it is possible to realize a cured film that not only has excellent sensitivity to a developer and is free of residue after development, but also has excellent adhesion to a substrate, excellent chemical resistance, and excellent device reliability.

[0022] In addition to the above-mentioned effects, specific effects of the present invention will be described below while explaining specific details for carrying out the invention. [Brief explanation of the drawings]

[0023] [Figure 1] 1 shows a plan view of an OLED according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, each configuration of the present invention will be described in more detail so that a person having ordinary skill in the art to which the present invention pertains can easily implement the present invention. However, this is merely an example, and the scope of the present invention is not limited by the following content.

[0025] One embodiment of the present invention provides a cured film obtained by curing a photosensitive resin composition, wherein the cured film has a phenolic gas content of 30% (v / v) or less in total outgassing as measured by purge and trap analysis at 250° C. for 60 minutes. According to one embodiment of the present invention, by specifying a parameter related to the phenolic gas content in total outgassing of the cured film, it is possible to realize a cured film that not only has excellent sensitivity to a developer and no residue after development, but also has excellent adhesion to a substrate, excellent chemical resistance, and excellent device reliability. The configuration of the present invention will be described in more detail below.

[0026] 1. Cured film and photosensitive resin composition for forming the same One embodiment of the present invention provides a cured film prepared from a photosensitive resin composition, wherein the photosensitive resin composition according to the present invention may include an alkali-soluble resin that is soluble in alkali. Specifically, the alkali-soluble resin may be any one selected from the group consisting of polyimide-based resins, polyamic acids, polyamic esters, polyhydroxystyrenes, and copolymers thereof, and may be a polyimide-based resin produced by a condensation polymerization reaction between an anhydride and a diamine compound.

[0027] According to one embodiment of the present invention, the imidization index of the polyimide resin may be 50 to 100%, specifically 60 to 98%, and more specifically 60 to 90%. The imidization index of the polyimide resin can be adjusted by varying the synthesis temperature and synthesis time during the synthesis of the polyimide resin. For example, the synthesis temperature and synthesis time of the polyimide resin may be 100 to 180°C and 2 to 6 hours. If the imidization index of the polyimide resin exceeds the above range, the polyimide resin may have excellent heat resistance and be able to control sources that induce outgassing, but may have problems such as reduced sensitivity to a developer and reduced solubility, which can lead to precipitation. If the imidization index of the polyimide resin is below the above range, the solubility is relatively high, which prevents precipitation, but the heat resistance may be reduced and it may be difficult to control sources that induce outgassing. The imidization index of the polyimide resin can be measured by checking the peak of the polyimide resin using a Fourier transform infrared spectroscopy (FTIR, Bruker IFS-66 / S).

[0028] Monomers for synthesizing the polyimide-based resin according to the present invention may include a diamine containing a hydroxy group, which increases sensitivity and solubility in a developer. For example, the diamine containing a hydroxy group may be 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (bis-APAF). That is, the polyimide-based resin according to the present invention may include a repeating unit derived from the diamine containing a hydroxy group. In addition, the polyimide-based resin may further include a repeating unit derived from various dianhydrides commercially available in the art. For example, the dianhydride may include one or more selected from the group consisting of ODPA (4,4'-Oxydiphthalic Anhydride), P6FDA (1,4-bis(trifluoromethyl)-2,3,5,6-benzenetetracarboxylic dianhydride), BPDA (4,4-biphthalic anhydride), and 6FDA (4,4-hexafluoroisopropylidenediphthalic dianhydride).

[0029] According to one embodiment of the present invention, by using the hydroxyl group-containing diamine as a monomer for the polyimide resin, the imidization index of the polyimide resin increases, which can effectively prevent reduced sensitivity to a developer or reduced solubility, resulting in precipitation. The content of the hydroxyl group-containing diamine may be 10 to 95 mol %, specifically 30 to 95 mol %, based on 100 mol % of the total monomers. Specifically, the molar ratio of the repeating units derived from the hydroxyl group-containing diamine to the repeating units derived from the dianhydride may be 10:90 to 95:5 or 30:70 to 95:5. When the content of the hydroxyl group-containing diamine or the molar percentage of the repeating units is within the above range, optimal sensitivity and solubility in a developer can be achieved.

[0030] The photosensitive resin composition according to the present invention may contain a photoactive compound (PAC) that is activated by light irradiation. Specifically, the photoactive compound generates an acid by photoreaction, thereby increasing the solubility of the light-irradiated portion in an alkaline developer. The photoactive compound may be produced by reacting a phenolic compound with a quinone diazide compound. The phenolic compound may be any one selected from the group consisting of 4,4'-(1-(4-(1-(4-hydroxyphenyl)-1-methylethyl)phenyl)ethylidene)bisphenol; 2,3,4-trihydroxybenzophenone; 2,3,4,4'-tetrahydroxybenzophenone; 2,4-dihydroxybenzophenone; 2,3,4,3',4',5'-hexahydroxybenzophenone; bisphenol-A; methyl gallate; and propyl gallate. The quinone diazide compound may be, for example, 5-naphthoquinone diazide sulfonic acid chloride. Since a phenolic compound is used to synthesize the photoactive compound, the content of phenolic gases in the total outgassing of the cured film can be changed depending on the degree to which the photoactive compound is decomposed.

[0031] According to another embodiment of the present invention, the content of unreacted phenolic compounds may be less than 1.0 wt %, specifically less than 0.5 wt %, based on the total weight of the photosensitive resin composition. The unreacted phenolic compounds are compounds that remain in the cured film without reacting with the quinone diazide compound used in synthesizing the photoactive compound and contain at least one hydroxy group (—OH) directly bonded to a benzene ring. When the content of the unreacted phenolic compounds satisfies the above numerical range, the content of phenolic gases in the total outgassing can be appropriately adjusted, thereby achieving a cured film that has excellent sensitivity to a developer and no residue after development, as well as excellent adhesion to a substrate, excellent chemical resistance, and excellent device reliability. The content of the unreacted phenolic compounds can be appropriately adjusted depending on the synthesis process of the photoactive compound, the content of the photoactive compound, etc., to effectively control the source of phenolic outgassing. The unreacted phenolic compounds may have a structure containing a phenol structure as a ballast. The ballast may include, for example, one or more of the compounds represented by the following chemical formulas 1 to 9: [C1] JPEG2025528051000002.jpg65170[2] JPEG2025528051000003.jpg40170[3] JPEG2025528051000004.jpg48170[C4] JPEG2025528051000005.jpg75170[5] JPEG2025528051000006.jpg74170[6] JPEG2025528051000007.jpg37170[7] JPEG2025528051000008.jpg53170[8] JPEG2025528051000009.jpg38170[9] JPEG2025528051000010.jpg50170

[0032] In the above chemical formulas 1 to 9, R4, R6, R8 to R 13 may each independently represent a hydrogen atom (H), an alkyl group having 1 to 4 carbon atoms, or an alkenyl group having 2 to 4 carbon atoms, and R4, R6, R8 to R9 in each chemical formula may each independently represent a hydrogen atom (H), an alkyl group having 1 to 4 carbon atoms, or an alkenyl group having 2 to 4 carbon atoms. 13 If all of R4, R6 and R8 to R9 are hydrogen atoms (H), there may be problems with chemical resistance and reliability. 13 Preferably, R5 and R7 each contain at least one alkyl group or alkenyl group. Specifically, each of the chemical formulas 1 to 9 can contain one or more alkyl groups having 1 to 4 carbon atoms or alkenyl groups having 2 to 4 carbon atoms. Furthermore, R5 and R7 are each independently a hydrogen atom (H) or an alkyl group having 1 to 4 carbon atoms.

[0033] According to another embodiment of the present invention, the content of unreacted phenol monomer may be less than 1.0 wt %, specifically less than 0.5 wt %, based on the total weight of the photosensitive resin composition. The unreacted phenol monomer is a monomer containing a phenol structure that can be used in synthesizing an alkali-soluble resin. The presence of such unreacted phenol monomer can cause phenolic outgassing. When the content of the unreacted phenol monomer satisfies the above numerical range, the content of phenolic gases in the total outgassing can be appropriately controlled, resulting in a cured film that has excellent sensitivity to a developer, no residue after development, excellent adhesion to a substrate, excellent chemical resistance, and excellent device reliability. The content of the unreacted phenol monomer can be appropriately controlled within the above numerical range depending on the conditions (e.g., monomer content, temperature conditions) used in synthesizing the alkali-soluble resin, thereby effectively controlling the source of phenolic outgassing.

[0034] The content of the photoactive compound may be more than 20 and less than 35 parts by weight, specifically 20 to 30 parts by weight, 21 to 29 parts by weight, 22 to 28 parts by weight, 23 to 27 parts by weight, 24 to 26 parts by weight, or 25 to 26 parts by weight, based on 100 parts by weight of the alkali-soluble resin. If the content of the photoactive compound is less than the above range, the adhesive strength of the cured film to the substrate or the chemical resistance may be reduced, whereas if the content exceeds the above range, the reliability of the device may be reduced.

[0035] The photosensitive resin composition according to the present invention may be free of a phenol-based additive that improves sensitivity to a developer. Specifically, the phenol-based additive may be any one selected from the group consisting of compounds represented by the following chemical formulas A to T and mixtures thereof: JPEG2025528051000011.jpg206170JPEG2025528051000012.jpg89170

[0036] A partition may be disposed on the sidewall of an emitting layer of an OLED device, and such a partition may be defined as, for example, a cured film made of a photosensitive resin composition. When the photosensitive resin composition forming the cured film contains a phenol-based additive that improves sensitivity to a developer, the emitting layer may be affected by phenol-based gases emitted from the cured film, resulting in a problem of reduced reliability of the OLED. The photosensitive resin composition according to one embodiment of the present invention does not contain the phenol-based additive, thereby reducing the amount of phenol-based gases in the total outgassing emitted from the cured film. This significantly reduces the amount of phenol-based gases that affect the emitting layer of an OLED device, resulting in significantly improved reliability of the OLED.

[0037] According to one embodiment of the present invention, the content of phenolic gases in the total outgassing of the cured film, as measured by purge and trap analysis, may be 30% (v / v) or less, specifically 0.1 to 30% (v / v), more specifically 0.1 to 20% (v / v), and even more specifically 0.1 to 10% (v / v). If the content of phenolic gases in the total outgassing of the cured film exceeds the above range, the phenolic gases emitted from the cured film may affect the light-emitting layer of the OLED, causing the OLED device to turn black, which may reduce the reliability of the OLED.

[0038] According to another embodiment of the present invention, the content of alcohol-based gases in the total outgassing of the cured film, as measured by the purge and trap analysis method, may be 20% (v / v) or less, specifically 0.1 to 15% (v / v). If the content of the alcohol-based gases in the total outgassing of the cured film exceeds this range, the reliability of the OLED may be reduced, similar to that of phenol-based gases. Specifically, the alcohol-based gas may be composed of methanol and ethanol, and the alcohol-based gas may be generated during the imidization process. The content of the alcohol-based gas may be low since the imidization index of the polyimide-based resin satisfies 50% or more.

[0039] The purge and trap analysis method according to the present invention may be a method of analyzing the cured film at 180 to 250° C. for 30 to 120 minutes, specifically, a method of analyzing the cured film at 250° C. for 60 minutes. Specifically, the purge and trap analysis method may be performed during a hard bake process in the step of forming a patterned film from the photosensitive resin composition.

[0040] The photosensitive resin composition according to another embodiment of the present invention may further include a solvent, which may be any one selected from the group consisting of gamma-butyrolactone (GBL), N-methylpyrrolidone (NMP), propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate (EL), methyl 3-methoxypropionate (MMP), propylene glycol monomethyl ether (PGME), diethylene glycol ethyl methyl ether (MEDG), diethylene glycol butyl methyl ether (MBDG), diethylene glycol dimethyl ether (DMDG), diethylene glycol diethyl ether (DEDG), and mixtures thereof. For example, the content of the solvent may be 50 to 95% by weight based on the total weight of the photosensitive resin composition.

[0041] The photosensitive resin composition according to the present invention may further contain an additive, if necessary, which may be any one selected from the group consisting of a thermal crosslinker, a thermal acid generator, a UV absorber, and combinations thereof.

[0042] According to another embodiment of the present invention, the photosensitive resin composition may further include a thermal crosslinking agent that undergoes a crosslinking reaction with the alkali-soluble resin by heat, thereby effectively preventing the cured film from losing its original pattern due to heat and flowing off.

[0043] The thermal crosslinking agent contained in the photosensitive resin composition of the present invention may include two or more thermal crosslinking compounds having different numbers of functional groups, i.e., the thermal crosslinking agent may include a first thermal crosslinking compound and a second thermal crosslinking compound different from the first thermal crosslinking compound.

[0044] Specifically, the thermal crosslinking agent can include a first thermal crosslinking compound containing 1 to 2 functional groups represented by the following chemical formula 1-1, and a second thermal crosslinking compound containing 3 to 5 functional groups represented by the following chemical formula 1-1. [Case 1-1] JPEG2025528051000013.jpg34170[Ka2-1] JPEG2025528051000014.jpg16170

[0045] In the above chemical formula 1-1, R 1 are each independently hydrogen, a substituent represented by the above chemical formula 2-1, or an organic group having 1 to 30 carbon atoms, and R 1 At least one of the groups is a substituent represented by the above-mentioned chemical formula 2-1, and R 2 are each independently hydrogen, a hydroxy group, or an organic group having 1 to 30 carbon atoms. In the above chemical formula 2-1, m is an integer of 1 to 27, and R 3 is an alkyl group having 1 to 3 carbon atoms.

[0046] R in the above Chemical Formula 1-1 1 At least one of the groups is a substituent represented by the chemical formula 2-1, which means that one to two substituents of the chemical formula 2-1 in the chemical formula 1-1 are substituted. When m in the chemical formula 2-1 is 1 to 2, the curing rate of the photosensitive resin composition can be excellent. In particular, when m in the chemical formula 2-1 is 1 to 2 and R 3 When R is a methyl group, an excellent curing rate can be achieved. 3 When methyl groups are contained in 90 mol % or more of the positions, the curing rate of the photosensitive resin composition can be particularly excellent, and 100 mol % is most ideal.

[0047] According to yet another embodiment of the present invention, the weight ratio of the first thermally crosslinkable compound to the second thermally crosslinkable compound (first thermally crosslinkable compound:second thermally crosslinkable compound) may be 5:95 to 80:20. Within this weight ratio range, the photosensitive resin composition can achieve excellent sensitivity and a low film residual rate, while also achieving excellent adhesion, chemical resistance, heat resistance, sunlight resistance, and driving reliability. By finely adjusting the weight ratio of the first thermally crosslinkable compound to the second thermally crosslinkable compound as the thermally crosslinkable compounds, the sunlight resistance, moisture absorption, and driving reliability of the photosensitive resin composition can be significantly improved. Specifically, the weight ratio of the first thermally crosslinkable compound to the second thermally crosslinkable compound may be 30:70 to 60:40.

[0048] The thermal crosslinking agent according to the present invention may be included in an amount of 5 to 50 parts by weight, specifically 10 to 30 parts by weight, based on 100 parts by weight of the alkali-soluble resin. If the content of the thermal crosslinking agent is less than the above range, the alkali-soluble resin may not be sufficiently thermally crosslinked, and if it exceeds the above range, problems may occur such as reduced moisture absorption and reduced driving reliability.

[0049] The first thermally crosslinkable compound is a compound containing 1 to 2 functional groups represented by the chemical formula 1-1, and can include, for example, one or more of the compounds represented by the following chemical formulas 3-1 to 15-1. JPEG2025528051000015.jpg123170

[0050] In addition, the second thermally crosslinkable compound is a compound containing 3 to 5 functional groups represented by the chemical formula 1-1, and can include, for example, one or more of the compounds represented by the following chemical formulas 16-1 to 24-1. JPEG2025528051000016.jpg100170JPEG2025528051000017.jpg163170

[0051] In the chemical formulas 3-1 to 24-1, R 4are each independently a substituent represented by the above chemical formula 2-1, an alkyl group having 2 to 30 carbon atoms, or hydrogen, and at least one R 4 is a substituent represented by the above chemical formula 2-1.

[0052] The ratio of the substituents contained in the thermally crosslinkable compound can also affect the crosslinkability of the resin composition. Specifically, it is preferred that the first thermally crosslinkable compound and the second thermally crosslinkable compound each contain one to two substituents represented by the chemical formula 2-1 in the phenolic hydroxy group structure of the chemical formula 1-1. The substituent of the alkoxyalkyl structure represented by the chemical formula 2-1 is R 1 However, the substituent represented by Chemical Formula 2-1 does not necessarily have to be included in Chemical Formula 1. In the thermally crosslinkable compound, when the number of substituents represented by Chemical Formula 2-1 in the structure of Chemical Formula 1-1 having the phenolic hydroxy group is in the range of 1 to 2, the crosslinking reaction may have a much better chemical resistance effect, and the content of phenol gas and / or alcohol-based gas in the outgas may be reduced.

[0053] According to yet another embodiment of the present invention, the sensitivity of the cured film is 120 mJ / cm 2 Specifically, factors affecting the sensitivity of the cured film may include the presence or absence of a phenolic additive and the content of a photoactive compound. For example, the photosensitive resin composition forming the cured film must be free of a phenolic additive and the content of the photoactive compound must be within an appropriate range in order for the cured film to have excellent sensitivity. In yet another embodiment of the present invention, a photosensitive resin composition for forming the cured film may be provided. A description that is the same as that described above will be omitted.

[0054] 2.Display device Yet another embodiment of the present invention can provide a display device including the cured film. The display device according to the present invention may be, for example, an OLED. The cured film constituting the display device may be a barrier rib (or insulating film) disposed on a sidewall of an emission layer. According to one embodiment of the present invention, by patterning the barrier rib with a cured film prepared from the photosensitive resin composition, the content of phenolic gases that affect the emission layer constituting the OLED device is significantly reduced, resulting in significantly improved reliability of the OLED. [Example]

[0055] Hereinafter, the embodiments of the present invention will be described in detail so that a person having ordinary skill in the art to which the present invention pertains can easily implement the present invention. However, this is merely an example, and the scope of the present invention is not limited by the following content.

[0056] [Synthesis Example 1: Synthesis of polyamic acid] Under a dry nitrogen stream, diamines 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (bis-APAF; 0.2 mol) and 1,3-bis(3-aminophenoxy)benzene (APB; 0.02 mol) were dissolved in gamma-butyrolactone and stirred. 4,4'-oxydiphthalic anhydride (ODPA; 0.1 mol) was added to the stirred mixture and dissolved, followed by stirring at 70°C for 4 hours. Then, phthalic anhydride (PA; 0.1 mol) was added to the stirred mixture and stirred at 70°C for 2 hours to terminate the reaction and synthesize polyamic acid.

[0057] [Synthesis Example 2: Synthesis of Polyimide] Polyamic acid was synthesized in the same manner as in Synthesis Example 1, and then the mixture was stirred at 100° C. for an additional 4 hours to synthesize polyimide (imidization index: 60%).

[0058] [Synthesis Example 3: Synthesis of Polyimide] Polyimide was synthesized in the same manner as in Synthesis Example 2, but the synthesized polyamic acid was stirred at 120°C for 4 hours instead of at 100°C for 4 hours (imidization index: 70%).

[0059] [Synthesis Example 4: Synthesis of Polyimide] Polyimide was synthesized in the same manner as in Synthesis Example 2, but the synthesized polyamic acid was stirred at 130°C for 4 hours instead of at 100°C for 4 hours (imidization index: 75%).

[0060] [Synthesis Example 5: Synthesis of Polyimide] Polyimide was synthesized in the same manner as in Synthesis Example 2, but the synthesized polyamic acid was stirred at 140°C for 4 hours instead of at 100°C for 4 hours (imidization index: 80%).

[0061] [Synthesis Example 6: Synthesis of Polyimide] Polyimide was synthesized in the same manner as in Synthesis Example 2, but the synthesized polyamic acid was stirred at 150°C for 4 hours instead of at 100°C for 4 hours (imidization index: 87%).

[0062] [Synthesis Example 7: Synthesis of polyimide] Polyimide was synthesized in the same manner as in Synthesis Example 2, except that 0.02 mol of 4,4'-oxydianiline (ODA) was used instead of 0.02 mol of 1,3-bis(3-aminophenoxy)benzene (APB), and the synthesized polyamic acid was stirred at 160°C for 4 hours instead of at 100°C for 4 hours (imidization index: 90%).

[0063] [Synthesis Example 8: Synthesis of Polyimide] A polyimide was synthesized in the same manner as in Synthesis Example 7, except that 0.02 mol of 1,3-bis(4-aminophenoxy)benzene (TPE-R) was used instead of 0.02 mol of 4,4'-oxydianiline (ODA) (imidization index: 90%).

[0064] [Synthesis Example 9: Synthesis of Polyimide] Polyimide was synthesized in the same manner as in Synthesis Example 2, but the synthesized polyamic acid was stirred at 160°C for 4 hours instead of at 100°C for 4 hours (imidization index: 90%).

[0065] [Synthesis Example 10: Synthesis of Polyimide] A polyimide was synthesized in the same manner as in Synthesis Example 7, except that 0.02 mol of 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenylether (6FODA) was used instead of 0.02 mol of 4,4'-oxydianiline (ODA) (imidization index: 90%).

[0066] [Synthesis Example 11: Synthesis of Polyimide] A polyimide was synthesized in the same manner as in Synthesis Example 10, except that the content of phthalic anhydride (PA; 0.1 mol) was changed to 0.2 mol (imidization index: 90%).

[0067] [Synthesis Example 12: Synthesis of Polyimide] A polyimide was synthesized in the same manner as in Synthesis Example 9, except that 0.1 mol of 1,4-bis(trifluoromethyl)-2,3,5,6-benzenetetracarboxylic dianhydride (P6FDA) was used instead of 0.1 mol of 4,4'-oxydiphthalic anhydride (ODPA) (imidization index: 90%).

[0068] [Synthesis Example 13: Synthesis of polyimide] A polyimide was synthesized in the same manner as in Synthesis Example 9, except that 0.1 mol of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was used instead of 0.1 mol of 4,4'-oxydiphthalic anhydride (ODPA) (imidization index: 90%).

[0069] [Synthesis Example 14: Synthesis of polyimide] Polyimide was synthesized in the same manner as in Synthesis Example 2, but the synthesized polyamic acid was stirred at 170°C for 4 hours instead of at 100°C for 4 hours (imidization index: 93%).

[0070] [Synthesis Example 15: Synthesis of polyimide] Polyimide was synthesized in the same manner as in Synthesis Example 2, but the synthesized polyamic acid was stirred at 180°C for 4 hours instead of at 100°C for 4 hours (imidization index: 95%).

[0071] [Synthesis Example 16: Synthesis of polyimide using bis-APHP as diamine] A polyimide was synthesized in the same manner as in Synthesis Example 9, except that 0.2 mol of 2,2-bis(3-aminophenyl)hexafluoropropane (bis-APHP) was used instead of 0.2 mol of 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (bis-APAF) (imidization index: 90%).

[0072] [Synthesis Example 17: Synthesis of photoactive compound] Under dry nitrogen gas (N2), the parent (ballast) 4,4'-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol (1 mol) and 5-naphthoquinone diazide sulfonic acid chloride (2 mol) were dissolved in 1,4-dioxane at room temperature. Triethylamine was added dropwise to the solution so that the temperature did not exceed 35°C, and the resulting mixture was stirred at 40°C for 2 hours. The triethylamine salt was filtered, and the filtrate was poured into water. The precipitate was filtered and washed with aqueous hydrochloric acid (1% HCl (aq)). After washing with water three times, the precipitate was dried in a vacuum dryer to synthesize the quinone diazide compound.

[0073] [Production Example 1: Production of photosensitive resin composition] Photosensitive resin compositions were prepared as shown in Tables 1 to 5 below. Polyimides were synthesized using the diamine, dianhydride, and anhydride monomers shown in Tables 1 to 5 according to the methods of the above Synthesis Examples. In Comparative Examples 2 to 25, the compounds represented by the above chemical formulas A to S (phenolic additives) were used as additives. The quinone diazide compound synthesized in Synthesis Example 17 was used as the PAC, and 1,000 parts by weight of a mixed solvent of propylene glycol monomethyl ether (PGME) and gamma-butyrolactone (GBL) (mixing weight ratio 5:5) was used as the solvent, based on 100 parts by weight of the alkali-soluble resin of the above Synthesis Example, and 15 parts by weight of two thermal crosslinking agents were used.

[0074] The two types of thermal crosslinking agents used were a first thermal crosslinking compound represented by the following chemical formula A-1 and a second thermal crosslinking compound represented by the following chemical formula B-1. Specifically, a thermal crosslinking agent in which the first thermal crosslinking compound and the second thermal crosslinking compound were mixed in a weight ratio of 1:2 was used. [Chemical A-1] JPEG2025528051000018.jpg35170[KaB-1] JPEG2025528051000019.jpg38170

[0075] [Table 1] JPEG2025528051000021.jpg111170

[0076] [Table 2]

[0077] [Table 3] JPEG2025528051000024.jpg110170

[0078] [Table 4] JPEG2025528051000026.jpg110170

[0079] [Table 5]

[0080] [Experimental example: physical property evaluation] The photosensitive resin composition of Preparation Example 1 was applied onto a glass substrate using a slit coater, and then subjected to a vacuum drying process at a pressure of 40 Pa. The resulting coating was then pre-baked on a hot plate at 120°C for 2 minutes to form a pre-cured film having a thickness of 3.0 μm. A predetermined pattern mask was used to apply a photosensitive resin composition to the pre-cured film at an intensity of 20 mW / cm. 2 After irradiating with ultraviolet light (a dose based on the critical dimension of a 2.5 μm contact hole), the film was soaked in a tetramethylammonium hydroxide solution (N(CH3)4 + OH - The resulting product was developed with 2.38 wt % of the resist at 23°C for 1 minute and then washed with ultrapure water for 1 minute. The washed product was then cured in an oven at 250°C for 60 minutes to form a patterned film (or cured film) with a thickness of 3.0 μm.

[0081] 1) Analysis of phenols and alcohols in outgassing The patterned film was analyzed for outgassing at 250°C for 60 minutes using a Purge & Trap device (JAI JTD-505III). Based on the total volume of outgassing, the phenol gas content was marked with "◎" if it was 10% (v / v) or less, "O" if it was more than 10% but not more than 20% (v / v), "△" if it was more than 20% but not more than 30% (v / v), "X" if it was more than 30% (v / v), "O" if it was alcohol-based gas (methanol + ethanol) content was 20% (v / v) or less, and "X" if it was not. These results are shown in Tables 6 to 8.

[0082] 2) The sensitivity The sensitivity for the patterned film is 120 mJ / cm 2 The following cases are marked with "O" and other cases are marked with "X" as shown in Tables 6 to 8 below.

[0083] 3) Scum (residue) The inside of the pattern film was observed with a SEM (scanning electron microscope), and the presence of scum (residue) after development was marked with "X" and the absence of scum was marked with "O" in Tables 6 to 8 below.

[0084] 4) Adhesive strength The adhesive strength of the pattern film to the substrate was evaluated based on the minimum critical dimension of the dot pattern. Specifically, when the adhesive strength of the pattern film to the substrate was secured with a dot pattern CD of 5 μm, it was given an "O" rating, and when peeling occurred due to insufficient adhesive strength, it was given an "X" rating, as shown in Tables 6 to 8 below.

[0085] 5) Chemical resistance The pattern film was immersed in N-methylpyrrolidone (NMP) at 60°C for 120 seconds, and the thickness change rate of the pattern film before and after immersion was measured. The thickness change rate of 300 Å or less was marked as "O", and the thickness change rate of more than 300 Å was marked as "X", as shown in Tables 6 to 8 below.

[0086] 6) OLED reliability FIG. 1 shows a plan view of an OLED according to one embodiment of the present invention. As shown in Figure 1, a patterned film (insulating film) was formed on an ITO (indium tin oxide) substrate (anode electrode) in the same manner as in the sensitivity analysis method, and then an organic light-emitting layer (EL; luminescent material: TADF) was deposited. An aluminum thin film (Al) was formed on top as a cathode electrode, and an encapsulation process was carried out to manufacture an OLED device. The time (T) at which the OLED device's brightness drops by 3% when it is on was measured at 85°C and 85% RH. 97 ) was evaluated. The results are shown in Tables 6 to 8 below, with an "O" if 1000 hours or more was secured, a "△" if 800 hours or more but less than 1000 hours was secured, and an "X" if less than 800 hours was secured.

[0087] [Table 6]

[0088] [Table 7]

[0089] [Table 8]

[0090] In Tables 6-8, comparing Comparative Example 1, which uses polyamic acid as the binder resin, with Examples using polyimide-based resins as the binder resin, it can be inferred that using a polyimide-based resin as the binder resin improves chemical resistance and OLED reliability. Comparing Comparative Examples 2-25, which use a phenolic additive to improve developer sensitivity, with Examples that do not contain a phenolic additive, it can be inferred that the absence of a phenolic additive in the Examples reduces the amount of phenolic gas released from the cured film, thereby improving OLED reliability and chemical resistance. Furthermore, comparing Comparative Examples 26-30 with Examples, when the content of the photoactive compound (PAC) is more than 20 but less than 35 parts by weight based on 100 parts by weight of the alkali-soluble resin, the adhesion of the cured film to the substrate, chemical resistance, developer sensitivity, and OLED reliability are all improved. Comparing Comparative Example 31 with the Examples, it can be inferred that the use of a hydroxyl-containing diamine monomer (bis-APAF) to synthesize a polyimide resin used as a binder resin can increase the imidization index of the polyimide resin, thereby reducing its sensitivity to a developer or its solubility, thereby effectively preventing precipitation.

[0091] Comparing Example 8 with Reference Examples 1 and 2 in Tables 6 and 8, it can be seen that when the content of unreacted phenol monomers, which correspond to monomers containing a phenol structure that can be used in synthesizing an alkali-soluble resin, is less than 1 wt % based on the total weight of the photosensitive resin composition, and the content of unreacted phenolic compounds that do not react with the quinone diazide compound is less than 1.0 wt %, and the content of phenolic gases in the total outgassing is appropriately adjusted, it is possible to obtain a cured film that not only has excellent sensitivity to a developer and is free of residue after development, but also has excellent adhesion to a substrate, excellent chemical resistance, and excellent device reliability.

[0092] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

Claims

1. A cured film obtained by curing a photosensitive resin composition, the content of phenolic gases in the total outgas of the cured film measured by purge and trap analysis at 250°C for 60 minutes is 30% (v / v) or less; Cured film.

2. The content of the phenol-based gas in the total outgas of the cured film measured by the Purge & Trap analysis method is 0.1 to 10% (v / v). The cured film according to claim 1.

3. The photosensitive resin composition comprises an alkali-soluble resin; and a photoactive compound (PAC), The cured film according to claim 1 .

4. The alkali-soluble resin is any one selected from the group consisting of polyimide resins, polyamic acids, polyamic esters, polyhydroxystyrenes, and copolymers thereof; The cured film according to claim 3.

5. The imidization index of the polyimide resin is 50 to 100%. The cured film according to claim 4.

6. The polyimide resin is containing a repeating unit derived from a diamine containing a hydroxy group, The cured film according to claim 4.

7. The photoactive compound is It is produced by reacting a phenolic compound with a quinone diazide compound. The cured film according to claim 3.

8. The content of unreacted phenol monomer is less than 1.0 wt % based on the total weight of the photosensitive resin composition. The cured film according to claim 1.

9. The content of unreacted phenolic compounds is less than 1.0 wt % based on the total weight of the photosensitive resin composition; The unreacted phenolic compound contains a phenol structure as a base (ballast). The cured film according to claim 1.

10. The photosensitive resin composition comprises Contains no phenolic additives The cured film according to claim 1.

11. The content of alcohol-based gas in the total outgas of the cured film measured by the Purge & Trap analysis method is 20% (v / v) or less; The alcohol-based gas is consisting of methanol and ethanol, The cured film according to claim 1.

12. The photosensitive resin composition comprises a thermal crosslinker; The cured film according to claim 1 .

13. The thermal crosslinking agent is a first thermally crosslinkable compound; a second thermally crosslinkable compound different from the first thermally crosslinkable compound, The cured film according to claim 12.

14. The first thermally crosslinkable compound is Contains 1 to 2 functional groups represented by the following chemical formula 1-1: The second thermally crosslinkable compound is Contains 3 to 5 functional groups represented by the following chemical formula 1-1: The cured film according to claim 13: [Chemical formula 1-1] [Chemical formula 2-1] In the above chemical formula 1-1, R １ are each independently hydrogen, a substituent represented by the above chemical formula 2-1, or an organic group having 1 to 30 carbon atoms, and R １ At least one of the groups is a substituent represented by the chemical formula 2-1, and R ２ are each independently a hydrogen atom, a hydroxy group, or an organic group having 1 to 30 carbon atoms, In the above chemical formula 2-1, m is an integer from 1 to 27, and R ３ is an alkyl group having 1 to 3 carbon atoms.

15. The photosensitive resin composition for forming a cured film according to any one of claims 1 to 14.

16. A display device comprising the cured film according to any one of claims 1 to 14.

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