Method of preparing polymer film, polymer film, substrate for display device, and optical device using the same

Abstract

The present invention relates to a method for manufacturing a polymer resin film capable of realizing excellent heat resistance and optical properties, a polymer resin film, a substrate for a display device using the same, and an optical device.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a polymer resin film capable of realizing excellent heat resistance and optical properties, a polymer resin film, a substrate for a display device using the same, and an optical device. Background Technology

[0002] The display device market is rapidly shifting toward Flat Panel Displays (FPDs), which facilitate large-area applications and enable thin and lightweight designs. These flat panel displays include Liquid Crystal Displays (LCDs), Organic Light Emitting Displays (OLEDs), and Electrophoretic Displays (EPDs).

[0003] Rigid type displays are manufactured using a glass substrate. Flexible type displays are manufactured using a plastic substrate.

[0004] However, as plastic substrates are applied to flexible displays, problems such as image restoration occur. Additionally, plastic substrates have lower heat resistance, thermal conductivity, and electrical insulation compared to glass substrates.

[0005] Nevertheless, research is actively underway to apply plastic substrates, which have the advantages of being lightweight, flexible, and manufacturable via continuous processes, to mobile phones, laptop PCs, TVs, and the like, as a replacement for glass substrates.

[0006] Polyimide resins possess the advantages of being easy to synthesize, capable of being manufactured into thin films, and applicable to high-temperature processes. In line with the trend toward lighter and more precise electronic devices, polyimide resins are widely used as integration materials in semiconductors. In particular, much research is being conducted to apply polyimide resins to flexible plastic display boards, which require lightweight and flexible properties. The problem to be solved

[0007] The present invention relates to a method for manufacturing a polymer resin film capable of realizing excellent heat resistance and optical properties.

[0008] In addition, the present invention is intended to provide a polymer resin film manufactured according to the method for manufacturing the polymer resin film, a substrate for a display device using the same, and an optical device. means of solving the problem

[0009] To solve the above problem, the present specification provides a method for manufacturing a polymer resin film, comprising the steps of: applying a polymer resin composition, comprising a polyimide-based resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms, to a substrate to form a coating film; drying the coating film; and curing the dried coating film by heat treating it at a heating rate of 4 ℃ / min or more.

[0011] The present specification also provides a polymer resin film having a coefficient of thermal expansion of 23 ppm / ℃ or less at a temperature of 100 ℃ or more and 400 ℃ or less, and a transmittance of 80% or more for a wavelength of 380 nm to 780 nm.

[0012] In addition to the above, a substrate for a display device comprising the polymer resin film is provided.

[0013] The present specification also provides an optical device comprising the polymer resin film.

[0014] A method for manufacturing a polymer resin film according to a specific embodiment of the invention, a polymer resin film, a substrate for a display device using the same, and an optical device will be described in more detail below.

[0016] Unless explicitly stated otherwise in this specification, technical terms are used merely to refer to specific embodiments and are not intended to limit the invention.

[0017] The singular forms used in this specification include plural forms unless the phrases clearly indicate otherwise.

[0018] As used in this specification, the meaning of 'includes' specifies certain characteristics, regions, integers, steps, actions, elements, and / or components, and does not exclude the existence or addition of other specific characteristics, regions, integers, steps, actions, elements, components, and / or groups.

[0019] Also, in this specification, terms including ordinal numbers such as 'first' and 'second' are used for the purpose of distinguishing one component from another and are not limited by said ordinal numbers. For example, within the scope of the present invention, the first component may also be named the second component, and similarly, the second component may be named the first component.

[0020] In this specification, the term (co)polymer includes both polymers and copolymers, wherein the polymer refers to a homopolymer composed of a single repeating unit, and the copolymer refers to a composite polymer containing two or more repeating units.

[0021] In this specification, examples of substituents are described below, but are not limited thereto.

[0022] In this specification, the term "substitution" means that another functional group is bonded in place of a hydrogen atom in a compound, and the substitution site is not limited to the site where the hydrogen atom is substituted, that is, the site where the substituent can be substituted, and in the case of two or more substitutions, the two or more substituents may be the same or different from each other.

[0023] In this specification, the term “substituted or unsubstituted” means that it is substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium; halogen group; cyano group; nitro group; hydroxyl group; carbonyl group; ester group; imide group; amide group; primary amino group; carboxyl group; sulfonic acid group; sulfonamide group; phosphine oxide group; alkoxy group; aryloxy group; alkyl thioxy group; aryl thioxy group; alkyl sulfoxy group; aryl sulfoxy group; silyl group; boron group; alkyl group; cycloalkyl group; alkenyl group; aryl group; aralkyl group; aralkenyl group; alkyl aryl group; alkoxysilylalkyl group; aryl phosphine group; or heterocyclic groups comprising one or more of N, O, and S atoms, or is substituted or unsubstituted with two or more of the exemplified substituents connected. For example, “substituents connected with two or more substituents” may be a biphenyl group. That is, the biphenyl group can be an aryl group, or it can be interpreted as a substituent in which two phenyl groups are connected.

[0024] In this specification, , or means a bond connected to another substituent, and a direct bond means a case where there is no separate atom in the part indicated by L.

[0025] In this specification, aromatic is a characteristic that satisfies Huckels' rule, and according to Huckels' rule, a case that satisfies all three of the following conditions can be defined as aromatic.

[0026] 1) There must be 4n+2 electrons that are completely conjugated by empty p-orbitals, unsaturated bonds, unpaired electron pairs, etc.

[0027] 2) The 4n+2 electrons must form a planar isomer and form a ring structure.

[0028] 3) All atoms in the ring must be able to participate in conjugation.

[0029] In this specification, a multivalent functional group is a residue in which a plurality of hydrogen atoms bonded to any compound have been removed, such as a divalent functional group, a trivalent functional group, or a tetravalent functional group. As an example, a tetravalent functional group derived from cyclobutane refers to a residue in which any four hydrogen atoms bonded to cyclobutane have been removed.

[0030] In this specification, the aryl group is a monovalent functional group derived from an arene, and while not particularly limited, it is preferably 6 to 20 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. As a monocyclic aryl group, the aryl group may be a phenyl group, a biphenyl group, a terphenyl group, etc., but is not limited thereto. As a polycyclic aryl group, the aryl group may be a naphthyl group, anthracenyl group, phenanthryl group, pyrenyl group, perylenyl group, chrysenyl group, fluorenyl group, etc., but is not limited thereto. The aryl group may be substituted or unsubstituted, and in the case of substitution, examples of substituents are as described above.

[0031] In this specification, a direct bond or single bond means that no atoms or atomic groups exist at the corresponding positions and are connected by a bonding line. Specifically, it means the case where no separate atoms exist in the parts indicated by L1 and L2 in the chemical formula.

[0032] In this specification, the weight-average molecular weight refers to the weight-average molecular weight equivalent to polystyrene measured by the GPC method. In the process of measuring the weight-average molecular weight equivalent to polystyrene measured by the GPC method, commonly known analytical devices, detectors such as a refractive index detector, and analytical columns may be used, and commonly applied temperature conditions, solvents, and flow rates may be applied. As a specific example of the above measurement conditions, a Waters PL-GPC220 instrument is used with a Polymer Laboratories PLgel MIX-B 300 mm long column, the evaluation temperature is 160 ℃, 1,2,4-trichlorobenzene is used as the solvent, the flow rate is 1 mL / min, the sample is prepared at a concentration of 10 mg / 10 mL and supplied in an amount of 200 μL, and the value of Mw can be obtained using a calibration curve formed using a polystyrene standard. Nine types of polystyrene standards were used, with molecular weights of 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000.

[0033] The present invention will be described in more detail below.

[0035] According to one embodiment of the invention, a method for manufacturing a polymer resin film may be provided, comprising the steps of: applying a polymer resin composition comprising a polyimide-based resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms to a substrate to form a coating film; drying the coating film; and curing the dried coating film by heat treating it at a heating rate of 4°C / min or more.

[0036] The inventors confirmed through experiments that, as in the method for manufacturing a polymer resin film of the above embodiment, a nitrogen-containing polycyclic compound having 10 or more carbon atoms is included, and the nitrogen-containing polycyclic compound having 10 or more carbon atoms acts as a catalyst to promote the imidization of the polyimide resin, thereby effectively aligning the polymer of the polyimide resin within the polymer resin composition and removing moisture before the solvent volatilizes, and thus the phenomenon of film lifting of the polymer resin film in the final optical device can be minimized, and thus completed the invention.

[0037] In addition, by undergoing a curing process with a heating rate of 4 ℃ / min or higher, the action of the nitrogen-containing polycyclic compound having 10 or more carbon atoms is optimized, and the final polymer resin film produced does not exhibit delamination on the inorganic film deposition substrate, and optical properties such as yellow index or transmittance do not change significantly even after undergoing a high-temperature process of 430 ℃ or higher, and there is no significant deformation of the shape of individual layers or the shape of the laminated structure, and there is no significant change in physical properties, the invention was completed by confirming through experiments.

[0038] Specifically, according to one embodiment of the invention, a method for manufacturing a polymer resin film may be provided, comprising the steps of: applying a polymer resin composition comprising a polyimide-based resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms to a substrate to form a coating film (Step 1); drying the coating film (Step 2); and heat-treating the dried coating film at a heating rate of 4 ℃ / min or more to cure it (Step 3).

[0040] Step 1 above is a step of forming a coating film by applying a polymer resin composition, comprising a polyimide-based resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms, to a substrate. The method of applying the polymer resin composition, comprising a polyimide-based resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms, to a substrate is not particularly limited, and methods such as screen printing, offset printing, flexographic printing, and inkjet printing may be used.

[0041] In addition, the polymer resin composition comprising the above-mentioned polyimide resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms may be dissolved or dispersed in an organic solvent. In the case of such a form, for example, when the polyimide resin is synthesized in an organic solvent, the solution may be the reaction solution obtained itself, or it may be the reaction solution diluted with another solvent. Also, when the polyimide resin is obtained as a powder, it may be dissolved in an organic solvent to form a solution.

[0043] The polymer resin composition comprising the above-mentioned polyimide-based resin and a nitrogen-containing multi-ring compound having 10 or more carbon atoms may contain a solid content in an amount that has an appropriate viscosity, taking into account processability such as applicability during the film formation process. For example, the content of the composition may be adjusted so that the total resin content is 5% by weight or more and 25% by weight or less, or 5% by weight or more and 20% by weight or less, or 5% by weight or more and 15% by weight or less.

[0044] In addition, the polymer resin composition comprising the above-mentioned polyimide resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms may additionally include other components in addition to the organic solvent. As a non-limiting example, when the resin composition containing the above-mentioned polyimide resin is applied, a compound capable of improving the uniformity of film thickness or surface smoothness, improving adhesion to a substrate, changing dielectric constant or conductivity, or increasing density may be additionally included. Examples of such compounds include surfactants, silane compounds, dielectric or crosslinking compounds, etc.

[0046] More specifically, in the method for manufacturing a polymer resin film of the above embodiment, the polymer resin composition may include a nitrogen-containing polycyclic compound having 10 or more carbon atoms. The nitrogen-containing polycyclic compound having 10 or more carbon atoms is included in the polymer resin composition and acts as a catalyst to promote the imidization of the polyimide-based resin. As the polymer alignment and moisture removal of the polyimide-based resin within the polymer resin composition occur effectively before the solvent volatilizes, the film lifting phenomenon of the polymer resin film in the final optical device can be minimized.

[0048] In addition, the polymer resin composition may contain a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms in an amount of 0.001% by weight or less, 0.0001% by weight or less, or 0.00001% by weight or less, based on the total weight of the polymer resin composition.

[0049] The fact that the above polymer resin composition contains 0.001 weight% or less of a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms may mean that the above polymer resin composition does not contain a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms.

[0050] Nitrogen-containing polycyclic compounds with 9 or fewer carbon atoms, such as quinoline and isoquinoline, are designated as hazardous chemicals under domestic regulations (NCIS). Therefore, to replace them, it was confirmed through experiments that an excellent polymer resin film without lifting can be manufactured by adding a nitrogen-containing polycyclic compound with 10 or more carbon atoms. The invention was completed.

[0052] The types of nitrogen-containing polycyclic compounds having 10 or more carbon atoms are not significantly limited, but may include, for example, nitrogen-containing heterocyclic compounds having 10 or more carbon atoms. In this specification, a heterocyclic compound refers to a cyclic compound containing one or more of the heteroatoms O, N, Si, and S.

[0054] More specifically, the nitrogen-containing polycyclic compound having 10 or more carbon atoms may include a nitrogen-containing heterocyclic aromatic compound having 10 or more carbon atoms. In this specification, a heterocyclic aromatic compound refers to a cyclic aromatic compound containing one or more of the heteroatoms O, N, Si, and S. Examples of heterocyclic aromatic compounds include, but are not limited to, thiophene, furan, pyrrole, imidazole, thiazole, oxazole, oxadiazole, triazole, pyridyl group, bipyridine, pyrimidine, triazine, acridine pyridazine, pyrazine, quinoline, quinazolin, quinoxaline, phthalazine, pyridopyrimidine, pyridopyrazine, pyrazinopyrazine, isoquinoline, indole, carbazole, benzoxazole, benzimidazole, benzothiazole, benzocarbazole, benzothiophene, dibenzothiophene, benzofuranyl group, phenanthroline, isooxazole, thiadiazole, phenothiazine, and dibenzofuran. The above heterocyclic aromatic compounds may be mixed or unsubstituted.

[0055] The above nitrogen-containing heterocyclic aromatic compounds having 10 or more carbon atoms may include, for example, 4-methylquinoline (Lepidine).

[0057] The above nitrogen-containing polycyclic compound having 10 or more carbon atoms may be included in an amount of 0.1% by weight or more and 10% by weight or less with respect to the total weight of the polymer resin composition.

[0058] If the nitrogen-containing polycyclic compound with 10 or more carbon atoms is included in an amount of less than 1% by weight relative to the total weight of the polymer resin composition, technical problems such as film peeling may occur during the curing process due to insufficient inclusion of the nitrogen-containing polycyclic compound with 10 or more carbon atoms, and if the nitrogen-containing polycyclic compound with 10 or more carbon atoms is included in an amount exceeding 10% by weight relative to the total weight of the polymer resin composition, technical problems such as deterioration of the heat resistance and optical properties of the polymer may occur due to excessive inclusion of the nitrogen-containing polycyclic compound with 10 or more carbon atoms.

[0060] In addition, the polymer resin composition may contain the nitrogen-containing polycyclic compound having 10 or more carbon atoms in an amount of 0.1 to 20 parts by weight, 1 to 20 parts by weight, 5 to 20 parts by weight, or 5 to 15 parts by weight, based on 100 parts by weight of the polyimide-based resin solid content.

[0061] If the above nitrogen-containing polycyclic compound with 10 or more carbon atoms is included in an amount of less than 0.1 parts by weight per 100 parts by weight of solid content of the polyimide-based resin, the above nitrogen-containing polycyclic compound with 10 or more carbon atoms is not sufficiently included, and a technical problem may occur in which the film in the inorganic film lifts up. If it is included in an amount exceeding 20 parts by weight, the above nitrogen-containing polycyclic compound with 10 or more carbon atoms is included in an excessive amount, and a technical problem may occur in which the overall polymer properties are degraded.

[0063] Meanwhile, the above polyimide-based resin means that it includes polyimide and its precursor polymers, such as polyamic acid and polyamic acid ester. That is, the above polyimide-based polymer may include one or more selected from the group consisting of polyamic acid repeating units, polyamic acid ester repeating units, and polyimide repeating units. That is, the above polyimide-based polymer may include one type of polyamic acid repeating unit, one type of polyamic acid ester repeating unit, one type of polyimide repeating unit, or a copolymer in which two or more of these repeating units are mixed.

[0064] One or more repeating units selected from the group consisting of the above-mentioned polyamic acid repeating units, polyamic acid ester repeating units, and polyimide repeating units can form the main chain of the above-mentioned polyimide-based polymer.

[0065] The above polyimide-based resin film may include a cured product of the polyimide-based resin. The above cured product of the polyimide-based resin refers to a product obtained through a curing process of the above polyimide-based resin.

[0066] Specifically, the polyimide-based resin film may include a polyimide resin containing aromatic imide repeating units.

[0067] The above aromatic imide repeating unit can be implemented in a tetracarboxylic acid or its anhydride and a diamine compound used as monomers in the synthesis of a polyimide-based resin, wherein the tetracarboxylic acid or its anhydride comprises an aromatic group, the diamine compound comprises an aromatic group, or both the tetracarboxylic acid or its anhydride and the diamine compound comprise an aromatic group.

[0068] More specifically, the polyimide-based resin film may comprise a polyimide resin containing aromatic imide repeating units.

[0069] The above aromatic imide repeating unit can be implemented in a tetracarboxylic acid or its anhydride and a diamine compound used as monomers in the synthesis of a polyimide-based resin, wherein the tetracarboxylic acid or its anhydride comprises an aromatic group, the diamine compound comprises an aromatic group, or both the tetracarboxylic acid or its anhydride and the diamine compound comprise an aromatic group.

[0071] In particular, the above polyimide-based resin may include a polyimide repeating unit represented by the following chemical formula 1.

[0072] [Chemical Formula 1]

[0073]

[0074] In the above chemical formula 1, X1 is an aromatic tetravalent functional group, and Y1 is an aromatic divalent functional group having 6 to 10 carbon atoms.

[0075] Specifically, in the above chemical formula 1, Y1 is an aromatic divalent functional group substituted with at least one fluorine-based functional group, and may be a functional group derived from a diamine compound used in the synthesis of polyimide resins.

[0076] As fluorine-based functional groups, such as the highly electronegative trifluoromethyl group (-CF3), are substituted, the effect of suppressing the formation of CTCs (charge transfer complexes) of Pi-electrons present within the polyimide resin chains is increased, thereby enabling enhanced transparency. In other words, packing within the polyimide structure or between chains can be reduced, and electrical interactions between chromogenic sources are weakened due to steric hindrance and electrical effects, allowing for high transparency in the visible light region.

[0077] Specifically, the aromatic divalent functional group to which at least one fluorine-based functional group of the above Y1 is substituted may include a functional group represented by the following chemical formula 3-1.

[0078] [Chemical Formula 3-1]

[0079]

[0080] In the above chemical formula 3-1,

[0081] P is an integer between 0 and 5, preferably between 0 and 2.

[0083] More specifically, in the polyimide resin, a bond can be formed between the nitrogen atom of the amino group and the carbon atom of the anhydride group through the reaction of the terminal anhydride group (-OC-O-CO-) of a tetracarboxylic acid dianhydride and the terminal amino group (-NH2) of an aromatic diamine substituted with at least one fluorine-based functional group.

[0084] The above polyimide-based resin can be prepared by reacting two or more different diamine compounds with a tetracarboxylic acid dianhydride compound, and a random copolymer can be synthesized by adding the two diamine compounds simultaneously, or a block copolymer can be synthesized by adding them sequentially.

[0086] In the above chemical formula 1, X1 is a functional group derived from a tetracarboxylic acid dianhydride compound used in the synthesis of polyimide resins.

[0087] Specifically, the above X1 may be a tetravalent functional group represented by the following chemical formula 5.

[0088] [Chemical Formula 5]

[0089]

[0090] In the above chemical formula 5, R1 to R6 are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms, L1 and L2 are identical or different from each other and are each independently one of -COO- or -OCO-, and L3 is a single bond, -O-, -CO-, -COO-, -S-, -SO-, -SO2-, -CR7R8-, -(CH2) t -, -O(CH2) t O-, -COO(CH2) t It is any one selected from the group consisting of OCO-, -CONH-, phenylene, or a combination thereof, wherein R7 and R8 are each independently one of hydrogen, an alkyl group having 1 to 10 carbon atoms, or a haloalkyl group having 1 to 10 carbon atoms, and t is an integer from 1 to 10.

[0091] The above polyimide-based resin can be prepared by reacting two or more different tetracarboxylic acid dianhydride compounds with a diamine compound, and a random copolymer can be synthesized by adding the two tetracarboxylic acid dianhydride compounds simultaneously, or a block copolymer can be synthesized by adding them sequentially.

[0093] More specifically, the above X1 may include one or more tetravalent functional groups selected from the group consisting of tetravalent functional groups represented by the following chemical formulas 2-1 to 2-4.

[0094] [Chemical Formula 2-1]

[0095]

[0096] [Chemical Formula 2-2]

[0097]

[0098] [Chemical Formula 2-3]

[0099]

[0100] [Chemical Formula 2-4]

[0101] .

[0103] Specific examples of the above aromatic tetracarboxylic acid dianhydrides include 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (4,4'-(hexafluoroispropylidene)diphthalic anhydride (6FDA), and pyromellitic dianhydride (PMDA).

[0105] The weight-average molecular weight (GPC measurement) of the above polyimide-based resin is not significantly limited, but, for example, it may be 1000 g / mol or more and 200000 g / mol or 10000 g / mol or more and 200000 g / mol or less.

[0107] The polyimide-based resin according to the present invention can exhibit excellent colorless and transparent properties while maintaining characteristics such as heat resistance and mechanical strength due to its rigid structure, and can be used in various fields such as substrates for devices, cover substrates for displays, optical films, integrated circuit (IC) packages, adhesive films, multilayer flexible printed circuits (FRC), tapes, touch panels, and protective films for optical discs, and is particularly suitable for cover substrates for displays.

[0109] Step 2 above is a step of drying a coating film formed by applying the polyimide-based resin and a nitrogen-containing multi-ring compound having 10 or more carbon atoms to a substrate.

[0110] The drying step of the above coating film can be carried out by a heating means such as a hot plate, a hot air circulation furnace, or an infrared furnace, and can be performed at a temperature of 50°C or higher and 150°C or lower, or 50°C or higher and 100°C or lower.

[0111] Step 3 above is a step of curing the dried coating film by heat treatment. At this time, the heat treatment may be carried out by a heating means such as a hot plate, a hot air circulation furnace, or an infrared furnace.

[0112] Specifically, the above step 3 can be heat-treated at a heating rate of 4 ℃ / min or more, 4 ℃ / min or more and 10 ℃ / min or less, and 4 ℃ / min or more and 7 ℃ / min or less.

[0113] As the above step 3 is heat-treated at a rapid heating rate of 4 ℃ / min or more, the promotion of imidization of the nitrogen-containing polycyclic compound having 10 or more carbon atoms described above is accelerated, and rapid imidization of the polyimide resin occurs. Consequently, optical properties such as transmittance are not degraded due to increased polymer orientation, and excellent heat resistance properties can be achieved even in high-temperature processes of 400 ℃ or higher.

[0114] If the heating rate in step 3 above is less than 4 ℃ / min, the aforementioned nitrogen-containing polycyclic chemical with 10 or more carbon atoms volatilizes in the low-temperature range before acting as an imide promoter, and is not effective in improving permeability and heat resistance properties.

[0116] Meanwhile, the step of curing the dried film by heat treating it at a heating rate of 4 ℃ / min or more may include the step of curing the dried film by heat treating it at a heating rate of 4 ℃ / min or more from an initial temperature of 50 ℃ or more and 100 ℃ or less to a final temperature of 400 ℃ or more and 500 ℃ or less.

[0118] Meanwhile, according to another embodiment of the invention, a polymer resin film may be provided having a coefficient of thermal expansion of 23 ppm / ℃ or less at a temperature of 100 ℃ or more and a transmittance of 80% or more for a wavelength of 380 nm to 780 nm.

[0119] The above polymer resin film can be manufactured according to the method for manufacturing a polymer resin film described above.

[0120] That is, the polymer resin film may include a polyimide-based resin and a nitrogen-containing multi-ring compound having 10 or more carbon atoms.

[0121] The description of the above polyimide-based resin and nitrogen-containing multi-ring compounds with 10 or more carbon atoms includes all of the aforementioned contents.

[0123] Meanwhile, the polymer resin film may contain a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms in an amount of 0.001% by weight or less, 0.0001% by weight or less, or 0.00001% by weight or less relative to the total weight of the polymer resin film.

[0124] The fact that the above polymer resin film contains 0.001 weight% or less of a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms may mean that the above polymer resin film does not contain a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms.

[0125] Nitrogen-containing polycyclic compounds with 9 or fewer carbon atoms, such as quinoline and isoquinoline, which have been widely used in the past, are designated as hazardous chemicals under domestic regulations (NCIS). Therefore, to replace them, a nitrogen-containing polycyclic compound with 10 or more carbon atoms can be added to produce an excellent polymer resin film without delamination.

[0128] According to the method for manufacturing the polymer resin film described above, the polymer resin film has a coefficient of thermal expansion of 23 ppm / ℃ or less at a temperature of 100 ℃ or more and 400 ℃ or less, and can satisfy a transmittance of 80% or more for wavelengths of 380 nm to 780 nm.

[0130] The thickness of the above polyimide-based resin film is not significantly limited, but can be freely adjusted, for example, within a range of 0.01 μm or more and 1000 μm or less. When the thickness of the above polyimide-based resin film increases or decreases by a specific amount, the physical properties measured in the polyimide-based resin film can also change by a certain amount.

[0132] In addition, the polymer resin film of the above embodiment may have a transmittance of 80% or more, 90% or less, or 80% or more and 90% or less for a wavelength of 380 nm to 780 nm.

[0133] The method for measuring the transmittance above is not significantly limited, but, for example, it can be measured using UV-vis spectroscopy. More specifically, it may be transmittance measured for light of a wavelength of 450 nm using a UV-vis spectroscopy device.

[0134] Since the transmittance of the polymer resin film of the above embodiment for a wavelength of 380 nm to 780 nm is 80% or more, excellent optical properties can be realized.

[0136] A substrate for a display device comprising a polymer resin film of the above-described other embodiment may be provided. The details regarding the polymer resin film may include all the details described above in the above-described embodiment.

[0137] The display device including the above substrate may be a liquid crystal display device (LCD), an organic light emitting diode (OLED), a flexible display, or a rollable display or foldable display, but is not limited thereto.

[0138] The above display device may have various structures depending on the application field and specific form, and may include, for example, a structure including a cover plastic window, a touch panel, a polarizer, a barrier film, a light-emitting element (OLED element, etc.), a transparent substrate, etc.

[0139] The polymer resin film of the other embodiment described above can be used for various purposes, such as a substrate, an external protective film, or a cover window in these various display devices, and more specifically, can be applied as a substrate.

[0140] For example, the substrate for the display device may have a structure in which a device protection layer, a transparent electrode layer, a silicon oxide layer, a polyimide-based resin film, a silicon oxide layer, and a hard coating layer are sequentially laminated.

[0141] The above transparent polyimide substrate may include a silicon oxide layer formed between a transparent polyimide-based resin film and a cured layer to further improve solvent resistance, moisture permeability, and optical properties, and the silicon oxide layer may be formed by curing polysilazane.

[0142] Specifically, the silicon oxide layer may be formed by coating and drying a solution containing polysilazane before the step of forming a coating layer on at least one surface of a transparent polyimide-based resin film, and then curing the coated polysilazane.

[0143] A substrate for a display device according to the present invention can provide a transparent polyimide cover substrate having excellent bending characteristics and impact resistance, as well as solvent resistance, optical characteristics, moisture permeability, and scratch resistance by including the above-described device protection layer.

[0145] Meanwhile, according to another embodiment of the invention, an optical device comprising a polymer resin film of the other embodiment may be provided. The details regarding the polymer resin film may include all the details described above in the first embodiment.

[0146] The above optical device may include all types of devices utilizing properties realized by light, such as display devices. Specific examples of the above display devices include, but are not limited to, liquid crystal display devices (LCDs), organic light emitting diodes (OLEDs), flexible displays, or rollable or foldable displays.

[0147] The above optical device may have various structures depending on the application field and specific form, and may include, for example, a structure including a cover plastic window, a touch panel, a polarizer, a barrier film, a light-emitting element (OLED element, etc.), a transparent substrate, etc.

[0148] The polymer resin film of the other embodiment described above can be used for various purposes, such as a substrate, an external protective film, or a cover window in these various optical devices, and more specifically, can be applied to a substrate. Effects of the invention

[0150] According to the present invention, a polymer resin composition capable of realizing excellent heat resistance and optical properties, a method for manufacturing a polymer resin film, a polymer resin film, a substrate for a display device using the same, and an optical device may be provided. Specific details for implementing the invention

[0151] The invention is described in more detail in the following examples. However, the following examples are merely illustrative of the invention, and the scope of the invention is not limited by the following examples.

[0153] <Examples and Comparative Examples: Preparation of Polyimide Compositions and Polyimide Films>

[0154] Example 1

[0155] (1) Preparation of a polyimide composition

[0156] After filling 155 g of N,N-diethylacetamide (DEAc) into a stirrer with a nitrogen stream, 27.62 g (0.09 mol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) was added and dissolved at the same temperature while maintaining the reactor temperature at 25 ℃. 5.07 g (0.02 mol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3.95 g (0.02 mol) of 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), and 13.14 g (0.06 mol) of pyromellitic dianhydride (PMDA) were added to the above solution at the same temperature and stirred for 24 hours. At this time, the polyimide solid content was found to be 15 g out of a total of 180 g of the prepared polyimide precursor composition.

[0157] Subsequently, 1.35 g of Lepidine (4-methylquinoline) was added at 5% by weight relative to the total solid content and stirred to prepare a polyimide precursor composition.

[0158] (2) Preparation of polyimide film

[0159] The above polyimide precursor composition was spin-coated onto a glass substrate. The glass substrate coated with the polyimide precursor composition was heat-treated from 80°C to 460°C at a heating rate of 4°C / min and a curing process was carried out for 200 minutes to produce a polyimide film with a thickness of 10 μm (including ±1 μm error) on the glass substrate.

[0161] Example 2

[0162] A polyimide precursor composition and a polyimide film were prepared in the same manner as in Example 1, except that 2.7 g of Lepidine (4-methylquinoline) was added at 10% by weight based on the total solid content.

[0164] Example 3

[0165] A polyimide precursor composition and a polyimide film were prepared in the same manner as in Example 1, except that 8.1 g of Lepidine (4-methylquinoline) was added at 30% by weight of the total solid content.

[0167] Example 4

[0168] A polyimide precursor composition and a polyimide film were prepared in the same manner as in Example 1, except that when preparing the polyimide film, a glass substrate coated with a polyimide precursor composition was heat-treated from 80°C to 460°C at a heating rate of 7°C / min and a curing process was carried out for 120 minutes.

[0170] Example 5

[0171] A polyimide precursor composition and a polyimide film were prepared in the same manner as in Example 1, except that 2.7 g of lepidine (4-methylquinoline) was added at 10 wt% of the total solid content, and during the preparation of the polyimide film, a glass substrate coated with the polyimide precursor composition was heat-treated from 80 ℃ to 460 ℃ at a heating rate of 7 ℃ / min and a curing process was carried out for 120 minutes.

[0173] Example 6

[0174] A polyimide precursor composition and a polyimide film were prepared in the same manner as in Example 1, except that 8.1g of Lepidine (4-methylquinoline) was added at 30% by weight relative to the total solid content, and a curing process was carried out for 120 minutes by heat treating a glass substrate coated with the polyimide precursor composition from 80°C to 460°C at a heating rate of 5°C / min during the preparation of the polyimide film.

[0176] Comparative Example 1

[0177] A polyimide precursor composition and a polyimide film were prepared in the same manner as in Example 1, except that lepidine (4-methylquinoline) was not added.

[0179] Comparative Example 2

[0180] A polyimide precursor composition and a polyimide film were prepared in the same manner as in Example 1, except that lepidine (4-methylquinoline) was not added, and when preparing the polyimide film, a glass substrate coated with the polyimide precursor composition was heat-treated from 80°C to 460°C at a heating rate of 2.5°C / min and a curing process was carried out for 180 minutes.

[0182] Comparative Example 3

[0183] A polyimide precursor composition and a polyimide film were prepared in the same manner as in Example 1, except that lepidine (4-methylquinoline) was not added, and when preparing the polyimide film, a glass substrate coated with the polyimide precursor composition was heat-treated from 80°C to 460°C at a heating rate of 7°C / min and a curing process was carried out for 120 minutes.

[0185] Comparative Example 4

[0186] A polyimide precursor composition and a polyimide film were prepared in the same manner as in Example 1, except that 1.35 g of quinoline was added at 5% by weight of the total solid content instead of lepidine (4-methylquinoline).

[0188] Comparative Example 5

[0189] A polyimide precursor composition and a polyimide film were prepared in the same manner as in Example 1, except that 1.35 g of isoquinoline was added at 5% by weight of the total solid content instead of lepidine (4-methylquinoline).

[0191] <Experimental Example: Measurement of Physical Properties of Polyimide Precursor Compositions and Polyimide Films Obtained in Examples and Comparative Examples>

[0192] The physical properties of the polyimide precursor compositions and polyimide films obtained in the above examples and comparative examples were measured by the following methods, and the results are shown in Tables 1 to 3.

[0194] 1. CTE

[0195] Using a TMA (TA Q400), the temperature was raised to 180°C at a heating rate of 5°C / min, maintained at that temperature for 10 minutes, then cooled down to 50°C at a rate of 5°C / min, and then raised again to 400°C at a heating rate of 5°C / min to measure the CTE during the heating process.

[0197] 2. Transmittance

[0198] The transmittance (T) for light at a wavelength of 450 nm was measured using a UV-vis spectroscopy (Agilent, UV 8453) device.

[0201] Measurement results of experimental examples in Examples 1-3 division Example 1 Example 2 Example 3 Lepidine (weight%) 5 10 30 Solid content (%) 15 15 15 CTE (ppm / ℃) 23 23 20 T (Transmittance) (%) @450 nm 82 83 82

[0202] Measurement results of experimental examples 4-6 division Example 4 Example 5 Example 6 Lepidine (weight%) 5 10 30 Solid content (%) 15 15 15 CTE (ppm / ℃) 11.5 4.6 6.0 T (Transmittance) (%) @450 nm 82 82 82

[0203] Measurement results of experimental examples in Comparative Examples 1-5 division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Lepidine (weight%) - - - - - Quinoline (weight%) - - - 5 - Isoquinoline (weight%) - - - - 5 Solid content (%) 15 15 15 15 15 CTE (ppm / ℃) 25 15.1 12.9 34 24 T (Transmittance) (%) @450 nm 83 75 76 84 77

[0204] As shown in Tables 1 and 2 above, the polymer resin film of the example was found to have excellent heat resistance and optical properties, with a CTE of 6.0 ppm / ℃ or higher and 23 ppm / ℃ or lower, and a light transmittance of 82% or higher.

[0205] On the other hand, in the case of Comparative Examples 1-5, as shown in Table 3, it was confirmed that the heat resistance was poor with a CTE of 24 ppm / ℃ or higher, or the optical properties were poor with a light transmittance of 77% or lower.

Claims

Claim 1 A method for manufacturing a polymer resin film, comprising the steps of: forming a coating film by applying a polymer resin composition comprising a polyimide-based resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms to a substrate; drying the coating film; and curing the dried coating film by heat treating it at a heating rate of 4 ℃ / min or higher, wherein the nitrogen-containing polycyclic compound having 10 or more carbon atoms is a nitrogen-containing heterocyclic aromatic compound including 4-methylquinoline, and the polymer resin composition comprises 0.1 parts by weight or more and 20 parts by weight or less of the nitrogen-containing polycyclic compound having 10 or more carbon atoms per 100 parts by weight of the polyimide-based resin solid content. Claim 2 A method for manufacturing a polymer resin film according to claim 1, wherein the step of curing the dried film by heat treatment at a heating rate of 4 ℃ / min or more comprises the step of curing the dried film by heat treatment at a heating rate of 4 ℃ / min or more from an initial temperature of 50 ℃ or more and 100 ℃ or less to a final temperature of 400 ℃ or more and 500 ℃ or less. Claim 3 A method for manufacturing a polymer resin film according to claim 1, wherein the polymer resin composition comprises 0.001 weight% or less of a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms with respect to the total weight of the polymer resin composition. Claim 4 delete Claim 5 A method for manufacturing a polymer resin film according to claim 1, wherein the nitrogen-containing polycyclic compound having 10 or more carbon atoms is included in an amount of 1% or more and 10% or less with respect to the total weight of the polymer resin composition. Claim 6 delete Claim 7 A method for manufacturing a polymer resin film according to claim 1, wherein the polyimide resin comprises a polyimide resin containing aromatic imide repeating units. Claim 8 A method for manufacturing a polymer resin film according to claim 1, wherein the polyimide-based resin comprises a polyimide repeating unit represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, X1 is an aromatic tetravalent functional group, and Y1 is an aromatic divalent functional group having 6 to 10 carbon atoms. Claim 9 In claim 8, a method for manufacturing a polymer resin film wherein X1 comprises a tetravalent functional group represented by the following chemical formula 5: [Chemical Formula 2] . Claim 10 A polymer resin film having a coefficient of thermal expansion of 23 ppm / ℃ or less at a temperature of 100 ℃ or more and 400 ℃ or less, and a transmittance of 80% or more for a wavelength of 380 nm to 780 nm, comprising a polyimide-based resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms, wherein the nitrogen-containing polycyclic compound having 10 or more carbon atoms is a nitrogen-containing heterocyclic aromatic compound including 4-methylquinoline, and comprising 0.1 parts by weight or more and 20 parts by weight or less of the nitrogen-containing polycyclic compound having 10 or more carbon atoms per 100 parts by weight of solid content of the polyimide-based resin. Claim 11 delete Claim 12 In claim 10, the polymer resin film comprises a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms in an amount of 0.001% by weight or less relative to the total weight of the polymer resin film. Claim 13 A substrate for a display device comprising the polymer resin film of claim 10. Claim 14 An optical device comprising the polymer resin film of claim 10.

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