Method for manufacturing a polymer resin film, polymer resin film and a substrate for a display device using the same, and an optical device

Abstract

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

Description

Technical Field

[0001] Cross-reference with related application(s) This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0063559 filed on May 24, 2022, and all the contents disclosed in the document of the Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a method for manufacturing a polymer resin film capable of realizing physical properties of excellent heat resistance and optical properties, a polymer resin film, a substrate for a display device using the same, and an optical device.

Background Art

[0003] The display device market is rapidly changing mainly with flat panel displays (FPDs) that are easy to have a large area and can be thinned and lightened. Such flat panel displays include liquid crystal displays (LCDs), organic light emitting displays (OLEDs), or electrophoretic displays (EPDs).

[0004] Rigid type displays are manufactured using a glass substrate as a base material. Flexible type displays are manufactured using a substrate of a plastic material as a base material.

[0005] However, when a substrate of a plastic material is applied to a flexible type display, problems such as residual image appear. And the substrate of the plastic material has problems in that its heat resistance, thermal conductivity, and electrical insulation are lower than those of a glass substrate.

[0006] Nevertheless, research is actively underway to apply plastic substrates, which are lighter, more flexible, and can be manufactured in a continuous process, as an alternative to glass substrates, to mobile phones, laptops, TVs, and other devices.

[0007] Polyimide resins have the advantages of being easy to synthesize, being able to be manufactured as thin films, and being applicable to high-temperature processes. With the trend towards lighter and more precise electronic devices, polyimide resins are widely used as integrated materials in semiconductor materials. In particular, much research is being conducted to apply polyimide resins to flexible plastic display boards, where lightness and flexibility are required. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The object of the present invention is to provide a method for manufacturing a polymer resin film that can embody excellent heat resistance and optical properties.

[0009] Furthermore, an object of the present invention is to provide a polymer resin film manufactured by the method for manufacturing the polymer resin film described above, a substrate for a display device utilizing the same, and an optical device. [Means for solving the problem]

[0010] To solve the aforementioned problems, this specification provides a method for producing a polymer resin film, comprising the steps of: applying a polymer resin composition containing a polyimide 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 heat-treating the dried coating film at a heating rate of 4°C / min or higher to cure it.

[0011] This specification also provides a polymer resin film having a coefficient of thermal expansion of 23 ppm / °C or less at temperatures between 100°C and 400°C, and a transmittance of 80% or more for wavelengths between 380 nm and 780 nm.

[0012] This specification also provides a substrate for a display device, comprising the polymer resin film.

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

[0014] The following describes in more detail a method for manufacturing a polymer resin film according to specific embodiments of the invention, the polymer resin film and a substrate for a display device using the same, and an optical device.

[0015] Unless otherwise expressly stated herein, technical terms are used solely to refer to specific embodiments and are not intended to limit the invention.

[0016] As used herein, the singular form includes the plural form unless the context explicitly indicates the opposite.

[0017] As used herein, "includes" embodies a particular characteristic, domain, integer, stage, operation, element and / or component, and does not exclude the presence or addition of other particular characteristics, domains, integers, stages, operations, elements, components and / or groups.

[0018] Furthermore, 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 the ordinal numbers. For example, within the scope of the rights of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0019] In this specification, (co)polymer means all polymers or copolymers, wherein polymer means a homopolymer consisting of a single repeating unit, and copolymer means a composite polymer containing two or more repeating units.

[0020] Examples of substituents in this specification are given below, but are not limited to them.

[0021] In this specification, the term "substituted" means that another functional group is bonded in place of a hydrogen atom in a compound, and the position where substitution occurs is not limited as long as it is the position where a hydrogen atom is substituted, that is, the position where a substituent can be substituted. When two or more substitutions occur, the two or more substituents may be the same or different from each other.

[0022] In this specification, the term "substituted or unsubstituted" means being substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium; a halogen group; a cyano group; a nitro group; a hydroxy group; a carbonyl group; an ester group; an imide group; an amide group; a primary amino group; a carboxy group; a sulfonic acid group; a sulfonamide group; a phosphine oxide group; an alkoxy group; an aryloxy group; an alkylthioxy group; an arylthioxy group; an alkylsulfinyl group; an arylsulfinyl group; a silyl group; a boron group; an alkyl group; a cycloalkyl group; an alkenyl group; an aryl group; an aralkyl group; an aralkenyl group; an alkylaryl group; an alkoxysilylalkyl group; an arylphosphine group; or a heterocyclic group containing one or more of N, O, and S atoms, or being substituted or unsubstituted with two or more of the above-exemplified substituents linked together. For example, a "substituent with two or more substituents linked together" can be a biphenyl group. That is, a biphenyl group may be an aryl group and may also be interpreted as a substituent in which two phenyl groups are linked together.

[0023] In this specification

Chemical formula

[0024] In this specification, aromaticity is a property that satisfies Hückel's rule, and according to Hückel's rule, those that satisfy all of the following three conditions can be defined as aromatic.

[0025] 1) There must be 4n + 2 electrons that are fully conjugated by vacant p-orbitals, unsaturated bonds, hole electron pairs, etc. 2) The 4n + 2 electrons must form planar isomers and a ring structure. 3) All atoms of the ring must be able to participate in conjugation.

[0026] As used herein, a multivalent functional group is a residue in a form in which a plurality of hydrogen atoms bonded to an arbitrary compound are removed, and examples thereof include divalent, trivalent, and tetravalent functional groups. As an example, a tetravalent functional group derived from cyclobutane means a residue in a form in which any four hydrogen atoms bonded to cyclobutane are removed.

[0027] As used herein, an aryl group is a monovalent functional group derived from an arene, and although not particularly limited, preferably has 6 to 20 carbon atoms and can be a monocyclic aryl group or a polycyclic aryl group. Examples of the monocyclic aryl group include, but are not limited to, a phenyl group, a biphenyl group, and a terphenyl group. Examples of the polycyclic aryl group include, but are not limited to, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a chrysenyl group, and a fluorenyl group. The aryl group may be substituted or unsubstituted, and when substituted, examples of the substituent are as described above.

[0028] As used herein, a direct bond or a single bond means that there are no atoms or atomic groups at that position and they are connected by a bond line. Specifically, in a chemical formula, it means that there are no separate atoms in the portions represented by L1 and L2.

[0029] In this specification, weight-average molecular weight refers to the weight-average molecular weight in polystyrene terms, measured by the GPC method. In the process of measuring the weight-average molecular weight in polystyrene terms measured by the GPC method, commonly known analytical instruments, detectors such as differential index detectors, and analytical columns can be used, and commonly applied temperature conditions, solvents, and flow rates can be applied. A specific example of the measurement conditions is as follows: using a 300 mm long column of Polymer Laboratories PLgel MIX-B with a Waters PL-GPC220 instrument, an evaluation temperature of 160°C, 1,2,4-trichlorobenzene as the solvent, a flow rate of 1 mL / min, and a sample prepared to a concentration of 10 mg / 10 mL supplied in 200 μL quantities; the Mw value can then be determined 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, and 10,000,000.

[0030] The present invention will be described in more detail below.

[0031] According to one embodiment of the invention, a method for producing a polymer resin film can be provided, comprising the steps of: applying a polymer resin composition containing a polyimide 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 heat-treating the dried coating film at a heating rate of 4°C / min or more to cure it.

[0032] The inventors have completed their invention by experimentally confirming that, as in the method for producing a polymer resin film according to one embodiment described above, by including a nitrogen-containing polycyclic compound having 10 or more carbon atoms, the nitrogen-containing polycyclic compound acting as a catalyst to promote the imidation of the polyimide resin, thereby effectively aligning the polymers of the polyimide resin within the polymer resin composition and removing moisture before the solvent evaporates, thereby minimizing the floating phenomenon of the polymer resin film in the final optical device.

[0033] Furthermore, by optimizing the action of the nitrogen-containing multi-ring compound with 10 or more carbon atoms as it undergoes a curing process with a heating rate of 4°C / min or more, the invention was completed through experiments confirming that the final polymer resin film produced does not exhibit lifting phenomena on the inorganic film deposition substrate, and at the same time, even after going through a process at high temperatures of 430°C or more, its optical properties such as yellowness and light transmittance do not change significantly, the deformation of the individual layer morphology and the laminated structure morphology is not large, and the physical properties do not change significantly.

[0034] Specifically, according to one embodiment of the invention, a method for manufacturing a polymer resin film can be provided, comprising the steps of: applying a polymer resin composition containing a polyimide 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°C / min or more to cure it (Step 3).

[0035] Step 1 is a step of forming a coating film by applying a polymer resin composition, which comprises a polyimide resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms, to a substrate. The method of applying the polymer resin composition, which comprises a polyimide resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms, to the substrate is not particularly limited, and methods such as screen printing, offset printing, flexographic printing, and inkjet printing can be used.

[0036] Furthermore, the polymer resin composition containing the polyimide resin and the nitrogen-containing polycyclic compound having 10 or more carbon atoms may be dissolved or dispersed in an organic solvent. In such a form, for example, if the polyimide resin is synthesized in an organic solvent, the solution may be the resulting reaction solution itself, or it may be this reaction solution diluted with another solvent. Also, if the polyimide resin is obtained as a powder, it may be dissolved in an organic solvent to form a solution.

[0037] The polymer resin composition, comprising the polyimide resin and a nitrogen-containing multi-ring compound having 10 or more carbon atoms, may contain solids in an amount that provides an appropriate viscosity, taking into consideration processability such as applicability during the film formation process. For example, the composition can 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.

[0038] Furthermore, the polymer resin composition containing the polyimide resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms may contain additional components other than organic solvents. As a non-limiting example, the resin composition containing the polyimide resin may contain additional compounds that improve the uniformity of film thickness and surface smoothness, improve adhesion to the substrate, alter dielectric constant and conductivity, or increase density when the resin composition is applied. Examples of such compounds include surfactants, silane compounds, dielectrics, or crosslinking compounds.

[0039] More specifically, in the method for producing a polymer resin film according to the above embodiment, the polymer resin composition may contain 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 imidation of the polyimide resin, thereby effectively aligning the polymers of the polyimide resin within the polymer resin composition and removing moisture before the solvent evaporates, thereby minimizing the floating phenomenon of the polymer resin film in the final optical device.

[0040] Furthermore, the polymer resin composition may contain 0.001% by weight or less, 0.0001% by weight or less, or 0.00001% by weight or less of a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms, relative to the total weight of the polymer resin composition.

[0041] The fact that the polymer resin composition contains 0.001% by weight or less of a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms may mean that the polymer resin composition does not contain a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms.

[0042] Nitrogen-containing polycyclic compounds with 9 or fewer carbon atoms, such as quinoline and isoquinoline, are designated as hazardous chemicals under the National Control Information System (NCIS) in Korea. Therefore, through experiments, we confirmed that a superior polymer resin film without budding can be produced by adding nitrogen-containing polycyclic compounds with 10 or more carbon atoms as a substitute, thus completing the invention.

[0043] The types of nitrogen-containing polycyclic compounds having 10 or more carbon atoms are not particularly limited, but for example, nitrogen-containing heterocyclic compounds having 10 or more carbon atoms may be included. In this specification, a heterocyclic compound means a cyclic compound containing one or more heteroatoms from among O, N, Si, and S.

[0044] More specifically, the nitrogen-containing polycyclic compound having 10 or more carbon atoms may include nitrogen-containing heterocyclic aromatic compounds having 10 or more carbon atoms. In this specification, a heterocyclic aromatic compound means a cyclic aromatic compound containing one or more heteroatoms from 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, quinazoline, quinoxaline, phthalazine, pyridopyrimidine, pyridopyrazine, pyrazinopyrazine, isoquinoline, indole, carbazole, benzoxazole, benzimidazole, benzothiazole, benzocarbazole, benzothiophene, dibenzothiophene, benzofuranyl group, phenanthroline, isoxazole, thiadiazole, phenothiazine, and dibenzofuran. The heterocyclic aromatic compound may be substituted or unsubstituted.

[0045] The nitrogen-containing heterocyclic aromatic compound having 10 or more carbon atoms may include, for example, 4-methylquinoline (lepidine).

[0046] The nitrogen-containing polycyclic compound having 10 or more carbon atoms may be included in the polymer resin composition in an amount of 0.1% to 10% by weight relative to the total weight of the polymer resin composition.

[0047] If the nitrogen-containing polycyclic compound having 10 or more carbon atoms is present in less than 1% by weight of the total weight of the polymer resin composition, the nitrogen-containing polycyclic compound having 10 or more carbon atoms is not sufficiently present, which may cause technical problems such as film lifting during the curing process. If the nitrogen-containing polycyclic compound having 10 or more carbon atoms is present in more than 10% by weight of the total weight of the polymer resin composition, the nitrogen-containing polycyclic compound having 10 or more carbon atoms is present in an excessive amount, which may cause technical problems such as a decrease in the heat resistance and optical properties of the polymer.

[0048] Furthermore, the polymer resin composition may contain, per 100 parts by weight of the polyimide resin solids, 0.1 parts by weight to 20 parts by weight, 1 part by weight to 20 parts by weight, 5 parts by weight to 20 parts by weight, or 5 parts by weight to 15 parts by weight of the nitrogen-containing multi-ring compound having 10 or more carbon atoms.

[0049] If the nitrogen-containing polycyclic compound having 10 or more carbon atoms is present in an amount of less than 0.1 parts by weight per 100 parts by weight of the polyimide resin solids, the nitrogen-containing polycyclic compound having 10 or more carbon atoms may not be sufficiently present, which may cause technical problems such as the film lifting in the inorganic film. If it is present in an amount exceeding 20 parts by weight, the nitrogen-containing polycyclic compound having 10 or more carbon atoms may be present in an excessive amount, which may cause technical problems such as a decrease in the overall polymer properties.

[0050] On the other hand, the polyimide resin means one that includes polyimide and its precursor polymers, polyamic acid and polyamic acid ester. In other words, the polyimide 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. In other words, the polyimide 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.

[0051] One or more repeating units selected from the group consisting of polyamic acid repeating units, polyamic acid ester repeating units, and polyimide repeating units can form the main chain of the polyimide polymer.

[0052] The polyimide resin film may include a cured polyimide resin. The cured polyimide resin refers to the product obtained through the curing process of the polyimide resin.

[0053] Specifically, the polyimide resin film may include a polyimide resin containing aromatic imide repeating units.

[0054] The aforementioned aromatic imide repeating unit can be embodied in tetracarboxylic acids or their anhydrides and diamine compounds used as monomers in the synthesis of polyimide resins, where the tetracarboxylic acid or its anhydride contains an aromatic group, the diamine compound contains an aromatic group, or all of the tetracarboxylic acid or its anhydride and the diamine compound contain an aromatic group.

[0055] More specifically, the polyimide resin film may include a polyimide resin containing aromatic imide repeating units.

[0056] The aforementioned aromatic imide repeating unit can be embodied in tetracarboxylic acids or their anhydrides and diamine compounds used as monomers in the synthesis of polyimide resins, where the tetracarboxylic acid or its anhydride contains an aromatic group, the diamine compound contains an aromatic group, or all of the tetracarboxylic acid or its anhydride and the diamine compound contain an aromatic group.

[0057] In particular, the polyimide resin may contain polyimide repeating units represented by the following chemical formula 1. [Chemical formula 1] [ka] In the above chemical formula 1, X1 is an aromatic tetravalent activator, and Y1 is an aromatic divalent activator having 6 to 10 carbon atoms.

[0058] Specifically, in the above chemical formula 1, Y1 is an aromatic divalent working group substituted with at least one fluorine-based working group, and may be a working group derived from a diamine compound used in the synthesis of polyimide resins.

[0059] By substituting fluorine-based active groups such as trifluoromethyl groups (-CF3), which have high electronegativity, the effect of suppressing the formation of charge transfer complexes (CTCs) of Pi electrons present in the polyimide resin chain is increased, thereby ensuring improved transparency. In other words, packing within or between the polyimide structure can be reduced, and electrical interactions between color sources can be weakened due to steric hindrance and electrical effects, resulting in high transparency in the visible light region.

[0060] Specifically, the aromatic divalent active group in which at least one fluorine-based active group of Y1 is substituted may include the active group represented by the following chemical formula 3-1. [Chemical formula 3-1] [ka] In the aforementioned chemical formula 3-1, P is an integer between 0 and 5, preferably between 0 and 2.

[0061] More specifically, the polyimide resin may form a bond between the nitrogen atom of the amino group and the carbon atom of the anhydride group through a reaction between the terminal anhydride group (-OC-O-CO-) of a tetracarboxylic dianhydride and the terminal amino group (-NH2) of an aromatic diamine substituted with at least one fluorine-based active group.

[0062] The polyimide resin can be produced by reacting a tetracarboxylic dianhydride compound with two or more different diamine compounds. A random copolymer can be synthesized by adding the two diamine compounds simultaneously, or a block copolymer can be synthesized by adding them sequentially.

[0063] In the aforementioned chemical formula 1, X1 is an active group derived from a tetracarboxylic dianhydride compound used in the synthesis of polyimide resins.

[0064] Specifically, X1 may be a tetravalent active group represented by the following chemical formula 5. [Chemical formula 5] [ka]

[0065] In the aforementioned chemical formula 5, R1 to R6 are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms, L1 and L2 may be the same 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 The element is selected from the group consisting of OCO-, -CONH-, phenylene, or combinations thereof, where 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.

[0066] The polyimide resin can be produced by reacting a diamine compound with two or more different tetracarboxylic dianhydride compounds. A random copolymer can be synthesized by simultaneously adding the two tetracarboxylic dianhydride compounds, or a block copolymer can be synthesized by adding them sequentially.

[0067] More specifically, X1 may contain one or more tetravalent activators selected from the group consisting of tetravalent activators represented by the following chemical formulas 2-1 to 2-4. [Chemical formula 2-1] [ka] [Chemical formula 2-2] [ka] [Chemical formula 2-3] [ka] [Chemical formula 2-4] [ka]

[0068] Specific examples of the aforementioned aromatic tetracarboxylic dianhydrides include 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), 4,4'-(hexafluoroispropylidene)diphthalic anhydride (FDA), and pyromellitic dianhydride (PMDA).

[0069] The weight-average molecular weight (measured by GPC) of the aforementioned polyimide resin is not significantly limited, but may be, for example, between 1,000 g / mol and 200,000 g / mol, or between 10,000 g / mol and 200,000 g / mol.

[0070] The polyimide resin according to the present invention exhibits excellent colorless and transparent properties while maintaining properties such as heat resistance and mechanical strength due to its rigid structure. Therefore, it can be used in a wide range of fields, such as substrates for devices, cover substrates for displays, optical films, integrated circuit (IC) packages, adhesive films, multilayer FRCs (flexible printed circuits), tapes, touch panels, and protective films for optical discs, and is particularly suitable for cover substrates for displays.

[0071] Step 2 is a step of drying the coating film formed by applying the polyimide resin and the nitrogen-containing polycyclic compound having 10 or more carbon atoms to the substrate.

[0072] The drying step of the coating can be carried out by 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 to 150°C, or 50°C to 100°C.

[0073] Step 3 is a step in which the dried coating film is heat-treated to harden it. At this time, the heat treatment can be carried out by heating means such as a hot plate, a hot air circulation furnace, or an infrared furnace.

[0074] Specifically, step 3 can be heat-treated at heating rates of 4°C / min or more, 4°C / min or more and 10°C / min or less, and 4°C / min or more and 7°C / min or less.

[0075] By performing the heat treatment in step 3 at a rapid heating rate of 4°C / min or more, the promotion of imidization of the nitrogen-containing multi-ring compound with 10 or more carbon atoms is accelerated, resulting in rapid imidization of the polyimide resin. As a result, optical properties such as transmittance do not decrease due to increased polymer orientation, and at the same time, excellent heat resistance properties can be achieved even in high-temperature processes of 400°C or higher.

[0076] If the heating rate in step 3 is less than 4°C / min, the nitrogen-containing polycyclic compound with 10 or more carbon atoms mentioned above will volatilize in the low-temperature range before it can act as an imide promoter, and will not be effective in improving permeability and heat resistance.

[0077] On the other hand, the step of heat-treating the dried coating film at a heating rate of 4°C / min or more to cure it may include a step of heat-treating the dried coating film from an initial temperature of 50°C to 100°C to a final temperature of 400°C to 500°C at a heating rate of 4°C / min or more to cure it.

[0078] On the other hand, according to yet another embodiment of the invention, a polymer resin film can be provided that has a thermal expansion coefficient of 23 ppm / °C or less at a temperature of 100°C to 400°C and a transmittance of 80% or more for wavelengths of 380 nm to 780 nm.

[0079] The polymer resin film can be manufactured by the method for manufacturing the polymer resin film described above.

[0080] In other words, the polymer resin film may contain a polyimide resin and a nitrogen-containing multi-cyclic compound having 10 or more carbon atoms.

[0081] The description of the polyimide resin and the nitrogen-containing polycyclic compounds having 10 or more carbon atoms includes all of the above-mentioned information.

[0082] On the other hand, the polymer resin film may contain 0.001% by weight or less, 0.0001% by weight or less, or 0.00001% by weight or less of a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms, relative to the total weight of the polymer resin film.

[0083] The fact that the polymer resin film contains 0.001% by weight or less of nitrogen-containing polycyclic compounds having 9 or fewer carbon atoms may mean that the polymer resin film does not contain nitrogen-containing polycyclic compounds having 9 or fewer carbon atoms.

[0084] Conventional nitrogen-containing polycyclic compounds with 9 or fewer carbon atoms, such as quinoline and isoquinoline, which have been widely used, are designated as hazardous chemicals under the National Control Information System (NCIS) in Korea. Therefore, to replace them, nitrogen-containing polycyclic compounds with 10 or more carbon atoms can be added as a post-addition to produce polymer resin films with excellent buoyancy and no floating phenomenon.

[0085] The aforementioned polymer resin film, manufactured by the aforementioned method for producing the polymer resin film, has a thermal expansion coefficient of 23 ppm / °C or less at temperatures between 100°C and 400°C, and can satisfy a transmittance of 80% or more for wavelengths between 380 nm and 780 nm.

[0086] The thickness of the polyimide resin film is not strictly limited, but can be freely adjusted within a range of, for example, 0.01 μm to 1000 μm. When the thickness of the polyimide resin film increases or decreases by a specific amount, the physical properties measured on the polyimide resin film can also change by a certain amount.

[0087] Furthermore, the polymer resin film of the above embodiment may have a transmittance of 80% to 90% or 80% to 90% for wavelengths of 380 nm to 780 nm.

[0088] The method for measuring the transmittance is not significantly limited, but it can be measured using, for example, UV-vis spectroscopy. More specifically, it can be the transmittance measured for light with a wavelength of 450 nm using a UV-vis spectroscopy device.

[0089] Since the polymer resin film of the above embodiment has a transmittance of 80% or more for wavelengths of 380 nm to 780 nm, it can exhibit excellent optical properties.

[0090] A substrate for a display device including the polymer resin film of the other embodiment described above may be provided. The details relating to the polymer resin film can include all of the details described above in the first embodiment.

[0091] The display device including the substrate may include, but is not limited to, a liquid crystal display device (LCD), an organic light-emitting diode (OLED), a flexible display, or a rollable display or foldable display.

[0092] The aforementioned display device can have a variety of structures depending on the application field and specific form, and may include, for example, a cover plastic window, a touch panel, a polarizing plate, a barrier film, a light-emitting element (such as an OLED element), a transparent substrate, and so on.

[0093] The polymer resin films of the other embodiments described above can be used in a variety of applications in such diverse display devices, such as substrates, external protective films, or cover windows, and more specifically, they can be applied to substrates.

[0094] For example, the substrate for the display device may have a structure in which an element protection layer, a transparent electrode layer, a silicon oxide layer, a polyimide resin film, a silicon oxide layer, and a hard coating layer are sequentially laminated.

[0095] The transparent polyimide substrate may include a silicon oxide layer formed between a transparent polyimide resin film and a cured layer, from the standpoint of being able to further improve solvent resistance or moisture permeability and optical properties, and the silicon oxide layer may be produced by curing polysilazane.

[0096] Specifically, the silicon oxide layer may be formed by coating and drying a solution containing polysilazane on at least one surface of a transparent polyimide resin film prior to the step of forming a coating layer on that surface, and then curing the coated polysilazane.

[0097] The substrate for a display device according to the present invention has excellent warp resistance and impact resistance by including the aforementioned element protection layer, and also provides a transparent polyimide cover substrate that has solvent resistance, optical properties, moisture permeability, and scratch resistance.

[0098] On the other hand, according to yet another embodiment of the invention, an optical device including the polymer resin film of the other embodiment may be provided. The details relating to the polymer resin film may include all of the details described above in the first embodiment.

[0099] The aforementioned optical devices may include all types of devices that utilize properties embodied by light, such as display devices. Specific examples of such 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.

[0100] The optical device can have a variety of structures depending on the application field and specific form, and may include, for example, a cover plastic window, a touch panel, a polarizing plate, a barrier film, a light-emitting element (such as an OLED element), a transparent substrate, and so on.

[0101] The polymer resin films of the other embodiments described above can be used in a variety of applications in such diverse optical devices, such as substrates, external protective films, or cover windows, and more specifically, they can be applied to substrates. [Effects of the Invention]

[0102] According to the present invention, a polymer resin composition that can embody excellent heat resistance and optical properties, a method for manufacturing a polymer resin film, a polymer resin film and a substrate for a display device utilizing the same, and an optical device can be provided. [Modes for carrying out the invention]

[0103] The invention will be described in more detail by the following embodiments. However, the following embodiments are merely illustrative of the present invention, and the content of the present invention is not limited by the following embodiments.

[0104] <Examples and Comparative Examples: Production of Polyimide Compositions and Polyimide Films>

[0105] Example 1

[0106] (1) Production of polyimide compositions After filling a stirrer with a nitrogen stream with 155 g of N,N-diethylacetamide (DEAc), 27.62 g (0.09 mol) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) was added at the same temperature while maintaining the reactor temperature at 25°C and dissolved. To the aforementioned solution, 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 at the same temperature and stirred for 24 hours. At this time, of the total 180 g of the prepared polyimide precursor composition, the polyimide solid content was 15 g.

[0107] Subsequently, 1.35 g of lepidine (4-methylquinoline) was added at a concentration of 5% by weight relative to the total solid content, and the mixture was stirred to produce a polyimide precursor composition.

[0108] (2) Manufacturing of polyimide film The 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 cured for 200 minutes to produce a polyimide film with a thickness of 10 μm (including an error of ±1 μm) on the glass substrate.

[0109] Example 2 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 a concentration of 10% by weight relative to the total solid content.

[0110] Example 3 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 a concentration of 30% by weight relative to the total solid content.

[0111] Example 4 The polyimide precursor composition and polyimide film were manufactured in the same manner as in Example 1, except that during the production of the polyimide film, the 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, followed by a curing process for 120 minutes.

[0112] Example 5 Lepidine (4-methylquinoline) was added at a concentration of 10% by weight (2.7 g) relative to the total solid content. The polyimide precursor composition and polyimide film were produced in the same manner as in Example 1, except that during the production of the polyimide film, the 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 for 120 minutes to perform a curing step.

[0113] Example 6 Lepidine (4-methylquinoline) was added at a concentration of 30% by weight (8.1 g) relative to the total solid content. The polyimide precursor composition and polyimide film were produced in the same manner as in Example 1, except that during the production of the polyimide film, the glass substrate coated with the polyimide precursor composition was heat-treated from 80°C to 460°C at a heating rate of 5°C / min for 120 minutes to perform a curing step.

[0114] Comparative Example 1 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.

[0115] Comparative Example 2 A polyimide precursor composition and a polyimide film were produced in the same manner as in Example 1, except that lepidine (4-methylquinoline) was not added, and during the production of the polyimide film, the 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 cured for 180 minutes.

[0116] Comparative Example 3 A polyimide precursor composition and a polyimide film were produced in the same manner as in Example 1, except that lepidine (4-methylquinoline) was not added, and during the production of the polyimide film, the 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 cured for 120 minutes.

[0117] Comparative Example 4 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 (5% by weight relative to the total solid content) was added instead of lepidine (4-methylquinoline).

[0118] Comparative Example 5 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 (5% by weight) relative to the total solid content was added instead of lepidine (4-methylquinoline).

[0119] <Experimental Example: Measurement of physical properties of polyimide precursor compositions and polyimide films obtained in the examples and comparative examples> The physical properties of the polyimide precursor compositions and polyimide films obtained in the above examples and comparative examples were measured by the following method, and the results are shown in Tables 1 to 3.

[0120] 1. CTE Using a TMA (TA Corporation Q400), the temperature was increased to 180°C at a heating rate of 5°C / min, maintained at that temperature for 10 minutes, then cooled again to 50°C at a rate of 5°C / min, and then increased again to 400°C at a heating rate of 5°C / min. The CTE during the heating process was then measured.

[0121] 2. Translucency The transmittance (T) to light at a wavelength of 450 nm was measured using a UV-vis spectroscopy (Agillent, UV 8453) instrument.

[0122] [Table 1] [Table 2] [Table 3]

[0123] As shown in Tables 1 and 2 above, the polymer resin films of the examples were found to have excellent heat resistance and optical properties, with a CTE of 6.0 ppm / °C to 23 ppm / °C and a light transmittance of 82% or more.

[0124] On the other hand, in the case of Comparative Examples 1-5, as shown in Table 3, it was possible to confirm that the heat resistance was poor, as indicated by a CTE of 24 ppm / °C or higher, or that the optical properties were poor, as indicated by a light transmittance of 77% or lower.

Claims

1. It contains a polyimide resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms. The nitrogen-containing polycyclic compound having 10 or more carbon atoms is formed by applying a polymer resin composition containing 4-methylquinoline to a substrate to form a coating film; A step of drying the aforementioned coating film; The process includes a step of heat-treating the dried coating film at a heating rate of 4°C / min or more to cure it. The above polymer resin composition contains 5 to 20 parts by weight of 4-methylquinoline per 100 parts by weight of polyimide resin solids, and is a method for producing a polymer resin film.

2. The step of heat-treating the dried coating film at a heating rate of 4°C / min or more to cure it is: A method for producing a polymer resin film according to claim 1, comprising the step of heat-treating the dried coating film from an initial temperature of 50°C to 100°C to a final temperature of 400°C to 500°C at a heating rate of 4°C / min or more to cure it.

3. The method for producing a polymer resin film according to claim 1, wherein the polymer resin composition contains 0.001% by weight or less of a nitrogen-containing multi-ring compound having 9 or fewer carbon atoms based on the total weight of the polymer resin composition.

4. The method for producing a polymer resin film according to claim 1, wherein the nitrogen-containing polycyclic compound having 10 or more carbon atoms is contained in an amount of 1% by weight or more and 10% by weight or less based on the total weight of the polymer resin composition.

5. The aforementioned polyimide resin is A method for producing a polymer resin film according to claim 1, comprising a polyimide resin containing aromatic imide repeating units.

6. The aforementioned polyimide resin is A method for producing a polymer resin film according to claim 1, comprising polyimide repeating units represented by the following chemical formula 1. [Chemical formula 1] 【Chemistry 1】 (In the above chemical formula 1, X １ It is an aromatic tetravalent active group, Y １ (This refers to a divalent aromatic active group with 6 to 10 carbon atoms.)

7. The aforementioned X １ The method for producing a polymer resin film according to claim 6, wherein the polymer resin film comprises a tetravalent active group represented by the following chemical formula 2. [Chemical formula 2] 【Chemistry 2】

8. The coefficient of thermal expansion is 23 ppm / °C or less at temperatures between 100°C and 400°C. The transmittance for wavelengths from 380 nm to 780 nm is 80% or higher. It contains a polyimide resin and a nitrogen-containing polycyclic compound having 10 or more carbon atoms. The nitrogen-containing polycyclic compound having 10 or more carbon atoms includes 4-methylquinoline. A polymer resin film comprising 5 to 20 parts by weight of 4-methylquinoline per 100 parts by weight of the polyimide resin solids.

9. The polymer resin film according to claim 8, wherein the polymer resin film contains 0.001% by weight or less of a nitrogen-containing polycyclic compound having 9 or fewer carbon atoms, based on the total weight of the polymer resin film.

10. A substrate for a display device, comprising the polymer resin film described in claim 8.

11. An optical device comprising the polymer resin film described in claim 8.

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