KR20240054654A - Polyimide-based polymer film, laminate, substrate for display device, circuit board, optical device and electronic device using the same - Google Patents

Abstract

The present invention has a peeling strength of 0.09 N/cm or more when peeling the polyimide-based resin film at a peeling speed of 50 mm/min and a peeling angle of 90 degrees for a sample in which an inorganic layer is laminated on a polyimide-based resin film, and JIS A polyimide resin film with a saturation voltage of 1.18 kV or more as measured under the L 1094 standard measurement conditions, a saturation voltage half-life of 180 seconds or more as measured under the JIS L 1094 standard measurement conditions, and a Td 1% of 570 ℃ or more, and It relates to laminates, display device substrates, circuit boards, optical devices, and electronic devices using this.

Description

Polyimide resin film and laminates using the same, substrates for display devices, circuit boards, optical devices and electronic devices {POLYIMIDE-BASED POLYMER FILM, LAMINATE, SUBSTRATE FOR DISPLAY DEVICE, CIRCUIT BOARD, OPTICAL DEVICE AND ELECTRONIC DEVICE USING THE SAME}

The present invention relates to a polyimide-based resin film that has improved adhesion to inorganic films and can realize excellent insulating properties and heat resistance, and a laminate using the same, a substrate for a display device, a circuit board, an optical device, and an electronic device.

The display device market is rapidly changing, focusing on flat panel displays (FPDs) that are easy to use in large areas and can be thin and lightweight. Such flat panel displays include liquid crystal displays (LCD), organic light emitting displays (OLED), and electrophoretic displays (EPD).

Rigid type displays are manufactured using a glass substrate as a substrate. Flexible type displays are manufactured using a plastic substrate as a substrate.

However, as flexible type displays use plastic substrates, problems such as restoration afterimages appear. Additionally, plastic substrates have problems with poorer heat resistance, thermal conductivity, and electrical insulation compared to glass substrates.

Nevertheless, research is being actively conducted to replace glass substrates by applying plastic substrates, which are light, flexible, and can be manufactured through a continuous process, to mobile phones, laptop PCs, TVs, etc.

Polyimide resin is easy to synthesize, can be manufactured into a thin film, and has the advantage of being applicable to high temperature processes. In line with the trend toward lightness and precision in various electronic devices, polyimide resin is widely used as an integration material in semiconductor materials. In particular, much research is being conducted to apply polyimide resin to flexible plastic display boards that require light and flexible properties.

In addition, substrate materials such as polyimide resin are supplied in solution form, which is a composition containing polyimide resin. Solvents such as methylpyrrolidone used as the main solvent are hazardous compounds, so there is no substitute for them. There is a continuous need for development of compositions utilizing solvents.

The present invention relates to a polyimide-based resin film that has improved adhesion to inorganic films and can realize excellent insulating properties and heat resistance.

Additionally, the present invention relates to a laminate, a substrate for a display device, a circuit board, an optical device, and an electronic device using the polyimide resin film.

In order to solve the above problem, in this specification, when peeling the polyimide resin film at a peeling speed of 50 mm/min and a peeling angle of 90 degrees for a sample in which an inorganic material layer is laminated on a polyimide resin film, the peeling strength is It is 0.09 N/cm or more, the saturation voltage measured under the JIS L 1094 standard measurement conditions is 1.18 kV or more, the saturation voltage half-life measured under the JIS L 1094 standard measurement conditions is 180 seconds or more, and Td 1% is 570 ℃. The above polyimide resin film is provided.

Also in this specification, a first polyimide resin layer; a first inorganic material layer formed on the first polyimide resin layer; a second polyimide resin layer formed on the first inorganic material layer; and a second inorganic material layer formed on the second polyimide resin layer, wherein the first polyimide resin layer or the second polyimide resin layer includes the polyimide-based resin film.

Also provided in this specification is a substrate for a display device comprising either the polyimide-based resin film or the laminate.

Also provided in this specification is a circuit board comprising either the polyimide-based resin film or the laminate.

Also provided in this specification is an optical device comprising either the polyimide-based resin film or the laminate.

Also provided in this specification is an electronic device comprising either the polyimide-based resin film or the laminate.

Hereinafter, a polyimide-based resin film, a laminate using the same, a substrate for a display device, a circuit board, an optical device, and an electronic device according to specific embodiments of the invention will be described in more detail.

Unless explicitly stated herein, terminology is intended to refer only to specific embodiments and is not intended to limit the invention.

As used herein, singular forms include plural forms unless phrases clearly indicate the contrary.

As used herein, the meaning of 'comprise' is to specify a specific characteristic, area, integer, step, operation, element and/or component, and to specify another specific property, area, integer, step, operation, element, component and/or group. It does not exclude the existence or addition of .

Additionally, in this specification, terms including ordinal numbers such as 'first' and 'second' are used for the purpose of distinguishing one component from another component and are not limited by the ordinal numbers. For example, within the scope of the present invention, a first component may also be referred to as a second component, and similarly, the second component may be referred to as a first component.

In this specification, (co)polymer refers to both polymers or copolymers. The polymer refers to a homopolymer composed of a single repeating unit, and the copolymer refers to a complex polymer containing two or more types of repeating units.

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

In this specification, the term "substitution" means bonding with another functional group in place of a hydrogen atom in a compound, and the position to be substituted is not limited as long as it is the position where the hydrogen atom is substituted, that is, a position where the substituent can be substituted, and if two or more substitutions are made, , two or more substituents may be the same or different from each other.

As used herein, the term “substituted or unsubstituted” refers to 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; Alkylthioxy group; Arylthioxy group; Alkyl sulphoxy group; Aryl sulfoxy group; silyl group; boron group; Alkyl group; Cycloalkyl group; alkenyl group; Aryl group; Aralkyl group; Aralkenyl group; Alkylaryl group; Alkoxysilylalkyl group; Arylphosphine group; or substituted or unsubstituted with one or more substituents selected from the group consisting of heterocyclic groups containing one or more of N, O and S atoms, or substituted or unsubstituted with two or more of the above-exemplified substituents linked. . For example, “a substituent group in which two or more substituents are connected” may be a biphenyl group. That is, the biphenyl group may be an aryl group, or it may be interpreted as a substituent in which two phenyl groups are connected.

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

In the present specification, aromatic is a characteristic that satisfies the Huckels Rule. According to the Huckels Rule, a case that satisfies all of the following three conditions can be defined as aromatic.

1) There must be 4n+2 electrons that are fully conjugated by empty p-orbitals, unsaturated bonds, and unpaired electron pairs.

2) 4n+2 electrons must form a planar isomer and form a ring structure.

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

In the present specification, a multivalent functional group is a residue in which a plurality of hydrogen atoms bonded to any compound have been removed, and examples include a divalent functional group, a trivalent functional group, and a tetravalent functional group. For example, a tetravalent functional group derived from cyclobutane refers to a residue in which any four hydrogen atoms bonded to cyclobutane have been removed.

In the present specification, the alkyl group is a monovalent functional group derived from an alkane and may be straight-chain or branched, and the number of carbon atoms of the straight-chain alkyl group is not particularly limited, but is preferably 1 to 20. Additionally, the branched chain alkyl group has 3 to 20 carbon atoms. Specific examples of alkyl groups include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n. -pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl , n-heptyl, 1-methylhexyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl- Propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, 2,6-dimethylheptan-4-yl, etc., but are not limited to these. The alkyl group may be substituted or unsubstituted, and when substituted, examples of the substituent are as described above.

In the present specification, the aryl group is a monovalent functional group derived from arene, and is not particularly limited, but preferably has 6 to 20 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. The aryl group may be a monocyclic aryl group, such as a phenyl group, biphenyl group, or terphenyl group, but is not limited thereto. The polycyclic 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 when substituted, examples of the substituent are as described above.

In this specification, a direct bond or single bond means that no atom or atomic group exists at the corresponding position and is connected by a bond line. Specifically, it refers to the case where no separate atoms exist in the portions represented by L ₁ and L ₂ in the chemical formula.

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

Hereinafter, the present invention will be described in more detail.

1. Polyimide resin film

According to one embodiment of the invention, when the polyimide-based resin film is peeled at a peeling speed of 50 mm/min and a peeling angle of 90 degrees for a sample in which an inorganic material layer is laminated on a polyimide-based resin film, the peeling strength is 0.09 N/ cm or more, the saturation voltage measured under the JIS L 1094 standard measurement conditions is 1.18 kV or more, the saturation voltage half-life measured under the JIS L 1094 standard measurement conditions is 180 seconds or more, and a Td 1% of 570 ℃ or more. A resin film may be provided.

The present inventors peeled the polyimide-based resin film at a peeling speed of 50 mm/min and a peeling angle of 90 degrees for a sample in which an inorganic material layer was laminated on a polyimide-based resin film, such as the polyimide-based resin film of the above embodiment. The invention was completed after confirming through experiments that when the peel strength satisfies 0.09 N/cm or more, durability can be improved in a laminate of an inorganic film and a polyimide resin film as the adhesion to the inorganic film increases. .

In addition, like the polyimide resin film of the above embodiment, the saturation voltage measured under the JIS L 1094 standard measurement conditions is 1.18 kV or more, and the saturation voltage half-life measured under the JIS L 1094 standard measurement conditions satisfies 180 seconds or more. When this is done, it was confirmed through experiments that the static electricity attenuation characteristics slow down and the polyimide-based resin film has high surface resistance characteristics and thus the insulation characteristics can be improved, and the invention was completed.

In addition, the polyimide-based resin film of the above-mentioned embodiment has a Td of 1% of 570°C or higher, so that deterioration of optical properties or deformation of shape occurs even in processes where high temperatures of 400°C or higher are applied, especially in the manufacturing process of a substrate for a display device. It is not large, and the surface resistance is high, so it is possible to prevent afterimages on the display panel and malfunction of the panel unit from occurring, thereby providing a high-quality optical device.

The polyimide-based resin film of one embodiment has a technical advantage in that adhesion durability, insulation, and heat resistance are simultaneously improved.

Specifically, the polyimide-based resin film of one embodiment is peeled when the polyimide-based resin film is peeled off at a peeling speed of 50 mm/min and a peeling angle of 90 degrees with respect to a sample in which an inorganic material layer is laminated on the polyimide-based resin film. The lower numerical limit of strength may be greater than or equal to 0.09 N/cm, or greater than or equal to 0.10 N/cm, or greater than or equal to 0.25 N/cm, greater than or equal to 0.30 N/cm, greater than or equal to 0.35 N/cm, or greater than or equal to 0.40 N/cm. Additionally, the upper numerical limit of the peel strength may be 0.55 N/m or less, 0.50 N/cm or less, and 0.45 N/cm or less. In addition, the numerical range between the lower limit and the upper limit can also be satisfied by combining the upper and lower numerical ranges. As an example of the numerical range between the lower limit and the upper limit, the polyimide-based resin film of one embodiment is peeled off at a peeling speed of 50 mm/min and a peeling angle of 90 degrees for a sample in which an inorganic material layer is laminated on a polyimide-based resin film. When peeling the polyimide-based resin film, the peeling strength may be 0.09 N/cm to 0.55 N/m.

Accordingly, as the adhesion to the inorganic film increases, the durability of the laminate of the inorganic film and the polyimide-based resin film can be improved.

The example of the method of measuring the peel strength is not greatly limited, but for example, using a texture analyzer (TA-XP plus/SMS) equipment, a polyimide resin film is measured under the conditions of a peel speed of 50 mm/min and a peeling direction of 90 degrees. can be peeled off.

The inorganic material layer includes one or more inorganic materials selected from the group consisting of silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiON), aluminum oxide (AlO), and aluminum oxynitride (AlON). can do. More specifically, silicon dioxide (SiO ₂ ) may be used as the inorganic layer.

The thickness of the inorganic layer is not greatly limited and can be applied without limitation within the range of 1000 Å to 7000 Å. However, as a limited example, the first inorganic layer may have a thickness of 100 nm or more, or 400 nm or more, or 700 nm or less, or 100 nm to 700 nm, or 400 nm to 700 nm.

For the formation of the inorganic layer, conventional inorganic film formation methods in the technical field to which the present invention pertains, such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), may be applied. In particular, the specific method of the chemical vapor deposition method is not greatly limited, but for example, plasma chemical vapor deposition (PECVD) or high density plasma chemical vapor deposition (HDPCVD) can be applied.

The thickness of the polyimide resin film used to measure the peel strength is not greatly limited, but for example, a film with a thickness of 10 ㎛, or 9 ㎛ to 11 ㎛ can be used.

When the peel strength of the polyimide-based resin film from the above-mentioned inorganic layer is excessively reduced to less than 0.09 N/cm, the adhesion to the inorganic layer decreases, resulting in poor durability in the laminate of the inorganic layer and the polyimide-based resin film. can do.

In addition, the polyimide-based resin film of one embodiment may have a lower limit of the saturation voltage voltage measured under the JIS L 1094 standard measurement conditions of 1.18 kV or more, 1.2 kV or more, 1.21 kV or more, 1.22 kV or more, and 1.23 kV or more. Additionally, the upper limit of the saturation voltage may be 1.5 kV or less, 1.4 kV or less, 1.3 kV or less, and 1.25 kV or less. In addition, the numerical range between the lower limit and the upper limit can also be satisfied by combining the upper and lower numerical ranges. As an example of the numerical range between the lower limit and the upper limit, the polyimide-based resin film of one embodiment may have a saturation voltage of 1.18 kV to 1.5 kV as measured under the JIS L 1094 standard measurement conditions.

In addition, the polyimide-based resin film of the above embodiment may have a numerical lower limit of the saturation voltage half-life measured under the JIS L 1094 standard measurement conditions of 180 seconds or more, 190 seconds or more, 200 seconds or more, 210 seconds or more, or 220 seconds or more. Additionally, the upper limit of the saturation voltage half-life may be 250 seconds or less, 240 seconds or less, or 230 seconds or less. In addition, the numerical range between the lower limit and the upper limit can also be satisfied by combining the upper and lower numerical ranges. As an example of the numerical range between the lower limit and the upper limit, the polyimide-based resin film of one embodiment may have a saturation voltage half-life of 180 to 250 seconds as measured under the JIS L 1094 standard measurement conditions.

The saturation voltage half-life can be measured under the JIS L 1094 standard using a Honestmeter device on polyimide-based resin film specimens with a thickness of 5 ㎛ to 15 ㎛, or 5 ㎛ to 10 ㎛. If the saturation voltage half-life of the polyimide resin film decreases to less than 180 seconds, it is difficult to implement low dielectric properties.

Specifically, the polyimide-based resin film of one embodiment has a saturation voltage of 1.18 kV or more and a half-life time of 180 seconds or more, as measured using a charging discharge method using corona discharge, so that the insulation properties are significantly improved. A substrate can be provided.

In the case of polymer substrate materials, surface charge accumulation occurs due to the electric field applied due to the formation of a carrier within the polymer due to the molecular structure of the polymer material and the presence of impurities mixed during manufacturing. Leakage current may occur and affect the electrical characteristics of the TFT device. The present invention minimizes the influence of this outflow current by increasing the surface charge density due to surface charge accumulation, thereby enabling stable operation of the TFT device.

It is possible to measure the electrostatic properties of a sample using the characteristic that the saturation voltage and half-life increase as the electrical insulation of the polymer film increases.

At this time, the half-life refers to the time at which the saturation voltage becomes 1/2 after the power is cut off, and this can be used as an indicator of the electrostatic attenuation characteristics of the sample. For example, static electricity attenuation characteristics can be defined as being slower as the saturation voltage is greater and the half-life time is longer, and materials with slower static electricity attenuation characteristics can exhibit higher surface insulation characteristics.

The saturation charge voltage and half-life time of the polyimide-based resin film of the above embodiment can be measured using a charge-discharge meter. According to one embodiment, the direct current voltage during charging by the corona discharge may be 5 kV to 20 kV, for example, 8 kV to 15 kV, or 8 kV to 12 kV, or 9 kV to 11 kV. Corona discharge can be generated by applying .

When direct current voltage is applied to the polyimide resin film in the form of corona discharge, the detected voltage value reaches a saturation value where there is no further change at a certain voltage, and at this point, the voltage is cut off. This saturation voltage is called “saturation voltage.” After the voltage is cut off, the potential attenuation state of the film is continuously detected, and the point at which the detected potential becomes 1/2 of the saturation voltage is defined as “half-life.”

A longer half-life means that the attenuation of the static charge accumulated in the polyimide-based resin film occurs more slowly during charging, which may mean that the polyimide-based resin film has high insulating properties.

In the case of a polyimide-based resin film with a large saturation voltage, the amount of static charge accumulation increases during charging, resulting in delayed static charge attenuation after charging, and thus the half-life increases. On the other hand, in the case of a polyimide-based resin film with a low surface resistance, static charge attenuation occurs during charging, which causes static charge attenuation to occur quickly after charging, thereby reducing the half-life.

In addition, the polyimide resin film of the above embodiment has a Td (Decomposition Temperature) of 1% of 570°C or higher, or 574°C or higher, or 650°C or lower, or 600°C or lower, or 570°C to 650°C, 574°C. It may be ℃ to 650 ℃, 570 ℃ to 600 ℃, 574 ℃ to 600 ℃.

The Td 1% may refer to the temperature (°C) at which the weight loss rate is 1% based on the mass of the sample at 100°C. The method of measuring Td 1% is not greatly limited, but may be measured using, for example, TGA equipment. More specifically, it can be measured using Discovery TGA equipment from TA instruments.

As the Td of the polyimide resin film of the above embodiment is 570°C or higher, it exhibits excellent heat resistance and is not deformed even at high temperatures, ensuring mechanical properties and dimensional stability. Specifically, when manufacturing a flexible display, the deformation and denaturation of the resin layer can be significantly reduced even if it goes through a process at a high temperature of 430°C or higher.

The thickness of the polyimide resin film used to measure Td 1% is not greatly limited, but for example, a film with a thickness of 10 ㎛, or 9 ㎛ to 11 ㎛ can be used.

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

The polyimide-based resin film is manufactured from the polymer resin composition described above, and can be manufactured according to the polyimide-based resin film manufacturing method described later.

Specifically, forming a coating film by applying the polymer resin composition to a substrate (step 1); Drying the coating film (step 2); The polyimide-based resin film can be manufactured through a method for manufacturing a polyimide-based resin film, which includes curing the dried coating film by heat treatment (step 3).

More specifically, Step 1 is a step of forming a coating film by applying a resin composition containing the above-described polyimide resin to a substrate. The method of applying the resin composition containing the polyimide resin to the substrate is not particularly limited, and for example, methods such as screen printing, offset printing, flexographic printing, and inkjet can be used.

Additionally, the resin composition containing the polyimide resin may be dissolved or dispersed in an organic solvent. When it has this form, for example, when a polyimide resin is synthesized in an organic solvent, the solution may be the obtained reaction solution itself, or this reaction solution may be diluted with another solvent. Additionally, when the polyimide resin is obtained as a powder, it may be dissolved in an organic solvent to form a solution.

The organic solvent may be a solvent that satisfies Equation 1 as described above.

The resin composition containing the polyimide resin may contain solid content in an amount to have an appropriate viscosity in consideration of processability such as applicability during the film forming process. For example, the content of 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. .

Additionally, the resin composition containing the polyimide resin may further include other components in addition to the organic solvent. As a non-limiting example, when the resin composition containing the polyimide resin is applied, it improves the uniformity of film thickness or surface smoothness, improves adhesion to the substrate, or changes dielectric constant or conductivity. Alternatively, compounds that can increase density may be additionally included. Examples of such compounds may include surfactants, silane-based compounds, dielectrics, or crosslinking compounds.

Step 2 is a step of drying the coating film formed by applying the resin composition containing the polyimide resin to the substrate.

The drying step of the coating film may be performed by a heating means such as a hot plate, hot air circulation furnace, or infrared furnace, and may be performed at a temperature of 50°C or more and 150°C or less, or 50°C or more and 100°C or less.

Step 3 is a step of curing the dried coating film by heat treatment. At this time, the heat treatment may be performed by a heating means such as a hot plate, a hot air circulation furnace, or an infrared furnace, and may be performed at a temperature of 200 ℃ or higher, or 200 ℃ or higher and 300 ℃ or lower.

Meanwhile, the polymer resin composition may include polyimide-based resin. The polyimide-based resin means that it includes both polyimide and its precursor polymers, polyamic acid and polyamic acid ester. That is, the polyimide-based polymer may include one or more types selected from the group consisting of polyamic acid repeating units, polyamic acid ester repeating units, and polyimide repeating units. That is, the 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 types of these repeating units are mixed.

One or more repeating units selected from the group consisting of polyamic acid repeating units, polyamic acid ester repeating units, and polyimide repeating units may form the main chain of the polyimide-based polymer.

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

Specifically, the polyimide-based resin film may include a polyimide-based resin containing an aromatic imide repeating unit.

The aromatic imide repeating unit refers to tetracarboxylic acid or its anhydride and diamine compound used as monomers in polyimide resin synthesis, where tetracarboxylic acid or its anhydride contains an aromatic group, or the diamine compound contains an aromatic group. Alternatively, both tetracarboxylic acid or its anhydride and diamine compound may be implemented as including an aromatic group.

More specifically, the polyimide-based resin film may include a polyimide-based resin containing an aromatic imide repeating unit.

The aromatic imide repeating unit refers to tetracarboxylic acid or its anhydride and diamine compound used as monomers in polyimide resin synthesis, where tetracarboxylic acid or its anhydride contains an aromatic group, or the diamine compound contains an aromatic group. Alternatively, both tetracarboxylic acid or its anhydride and diamine compound may be implemented as including an aromatic group.

In particular, the polyimide-based resin may include a polyimide repeating unit represented by the following formula (1).

[Formula 1]

In Formula 1, X ₁ is an aromatic tetravalent functional group, and Y ₁ is an aromatic divalent functional group having 6 to 10 carbon atoms.

In Formula 1, X ₁ is an aromatic tetravalent functional group, and X ₁ is a functional group derived from a tetracarboxylic dianhydride compound used in polyimide resin synthesis.

More specifically, the X ₁ tetravalent functional group may include a tetravalent functional group represented by the following formula (2).

[Formula 2]

Specific examples of the functional group represented by Formula 2 include a functional group represented by Formula 2-1 below derived from biphenyltetracarboxylic dianhydride (3,3,4,4-Biphenyltetracarboxylic dianhydride, BPDA).

[Formula 2-1]

Meanwhile, in Formula 1, Y ₁ is an aromatic divalent functional group having 6 to 10 carbon atoms, and Y ₁ may be a functional group derived from polyamic acid, polyamic acid ester, or a diamine compound used in polyimide synthesis.

The aromatic divalent functional group having 6 to 10 carbon atoms may include a phenylene group. More specifically, the aromatic divalent functional group having 6 to 10 carbon atoms of Y ₁ may include a functional group represented by Formula 3 below.

[Formula 3]

Specific examples of the functional group represented by the following formula (3) include a functional group represented by the following formula (3-1) derived from p-phenylenediamine (1,4-phenylenediamine, p-PDA).

[Formula 3-1]

.

When the functional group represented by Formula 3-1 is included in Y ₁ , a region in which molecules are arranged in a linear form is formed, thereby increasing the rigidity of the polyimide resin and realizing excellent thermal stability.

The polyimide-based resin may include a combination of aromatic tetracarboxylic dianhydride and aromatic diamine having 6 to 10 carbon atoms.

The aromatic tetracarboxylic dianhydride is a compound in which an anhydride group (-OC-O-CO-) is introduced at both ends of the aromatic tetravalent functional group described above, and the description of the aromatic tetravalent functional group is as described above.

Specific examples of the aromatic tetracarboxylic dianhydride include 3,3,4,4-biphenyltetracarboxylic dianhydride (BPDA).

The aromatic diamine having 6 to 10 carbon atoms is a compound in which an amino group (-NH ₂ ) is introduced at both ends of the aromatic divalent functional group having 6 to 10 carbon atoms. The description of the aromatic divalent functional group having 6 to 10 carbon atoms is described above. It is the same as what was said.

Specific examples of the aromatic diamine having 6 to 10 carbon atoms include p-phenylenediamine (1,4-phenylenediamine, p-PDA).

More specifically, the polyimide resin is an amino group formed through a reaction between the terminal anhydride group (-OC-O-CO-) of the aromatic tetracarboxylic dianhydride and the terminal amino group (-NH ₂ ) of the aromatic diamine having 6 to 10 carbon atoms. A bond may be formed between the nitrogen atom and the carbon atom of the anhydride group.

The weight average molecular weight (GPC measurement) of the polyimide resin is not greatly limited, but may be, for example, 1000 g/mol or more and 200,000 g/mol or less, or 10,000 g/mol or more and 200,000 g/mol or less.

The polyimide resin according to the present invention can exhibit excellent colorless and transparent properties while maintaining properties such as heat resistance and mechanical strength due to its rigid structure, and can be used as a substrate for devices, cover substrates for displays, and optical films. It can be used in various fields such as IC (integrated circuit) package, adhesive film, multi-layer FRC (flexible printed circuit), tape, touch panel, protective film for optical disk, etc. It can be especially suitable for display cover substrate. there is.

Meanwhile, the polyimide-based resin film may include a cured product of a polymer resin composition containing a polyimide-based resin and a solvent that satisfies the following equation (1). The cured product of the polymer resin composition refers to a product obtained through a curing process of the polymer resin composition. The polyimide-based resin is the same as the polyimide-based resin containing the aromatic imide repeating unit described above.

[Equation 1]

Log P > 0

In Equation 1, P is the partition coefficient of the solvent at 25°C.

That is, in the polyimide-based resin film of the above embodiment, by using a solvent with a positive Log P value, inorganic film adhesion and insulating properties can be improved while maintaining heat resistance.

Specifically, the solvent may satisfy Equation 2 below.

[Equation 2]

0.001 ≤ Log P < 5.000

In Equation 2, P is the partition coefficient of the solvent at 25°C.

More specifically, in Equations 1 and 2, the Log P of the solvent may be 0.001 or more, 0.05 or more, 0.1 or more, 0.15 or more, 0.2 or more, 0.25 or more, less than 5.000, 0.32 or less, 0.3 or less, 0.25 or less, and 0.2 or less. .

The distribution coefficient can be calculated, for example, using the ACD/LogP module of ACD/Labs' ACD/Percepta platform, and the ACD/LogP module is based on QSPR (Quantitative Structure-Property Relationship) methodology using the 2D structure of the molecule. uses the algorithm.

A solvent that satisfies the Log P value of Equation 1 above may mean that it is a hydrophobic solvent.

Specifically, when the Log P is a positive number, the water absorption of the solvent is low and the affinity with the polyimide resin is high. Conversely, when Log P is a negative number, the water absorption of the solvent is high and the affinity with the polyimide resin is low.

Therefore, by using a specific solvent that satisfies Equation 1 above, the inflow of moisture into the polyamic acid solution can be suppressed, and even when applying a large amount of solvent dilution process, it does not cause a reversible reaction of the polyamic acid polymer through moisture in the solution. It is possible to suppress the decomposition of polyamic acid polymers that occurs due to moisture inflow.

In addition, when polar fine foreign substances are introduced into the polyimide-based resin composition, in the polyimide-based resin composition containing a polar solvent with a negative distribution coefficient Log P, sporadic coating is caused by the polar foreign substances based on the location of the foreign substances. Cracks or changes in thickness may occur, but when using a hydrophobic solvent with a positive partition coefficient Log P, the occurrence of thickness changes due to cracks in the coating can be reduced or suppressed even when polar fine foreign substances are introduced. .

Specifically, the solvent may include a tertiary amine functional group in which at least one alkyl group of 2 or more carbon atoms or 2 to 5 carbon atoms in the molecule is bonded to nitrogen. The tertiary amine refers to a structure in which three organic functional groups (excluding hydrogen) are bonded to one nitrogen atom. That is, at least one of the three organic functional groups bonded to the nitrogen atom of the tertiary amine is an alkyl group having 2 or more carbon atoms, or 2 to 5 carbon atoms.

The alkyl group having 2 or more carbon atoms may be an alkyl group having 2 to 5 carbon atoms, and more specifically, may be an ethyl group. As at least 1 or more of the alkyl group having 2 or more carbon atoms is bonded to nitrogen, the effect of increasing the positive LogP value can be achieved compared to the case of an alkyl group having 1 carbon number.

Additionally, the tertiary amine functional group may include a linear tertiary amine functional group or a cyclic tertiary amine functional group.

The solvent compound containing the linear tertiary amine functional group may include a compound represented by the following formula (4).

[Formula 4]

In Formula 4, R ₁ is hydrogen or an alkyl group having 1 to 10 carbon atoms, and R ₂ and R ₃ are each independently an alkyl group having 2 or more carbon atoms or 2 to 5 carbon atoms. Specific examples of the compound represented by Formula 4 include N,N-diethylformamide and N,N-diethylacetamide.

The solvent compound containing the cyclic tertiary amine functional group may include a compound represented by the following formula (5).

[Formula 5]

In Formula 5, R ₄ is an alkyl group having 2 or more carbon atoms or 2 to 5 carbon atoms, and n is an integer of 1 to 3. Specific examples of the compound represented by Formula 5 include N-ethylpyrrolidone.

That is, the solvent may include one or more compounds selected from the group consisting of N,N-diethylformamide, N,N-diethylacetamide, and N-ethylpyrrolidone. That is, the solvent may include one type of N,N-diethylformamide, one type of N,N-diethylacetamide, one type of N-ethylpyrrolidone, or a mixture of two or more types thereof.

Meanwhile, the polymer resin composition may further include a lactone-based compound. The lactone-based compound may be a compound represented by the following formula (6).

[Formula 6]

In Formula 6, R ₅ is an alkyl group having 1 to 10 carbon atoms, and m is an integer from 0 to 3.

The solvent and the lactone-based compound may have a boiling point of 150°C or higher. That is, the solvent and the lactone-based compound exist in a liquid state at room temperature between 20°C and 30°C and may be included in the polymer resin composition of the above embodiment in the form of a solvent.

More specifically, the compound represented by Formula 6 may include a compound represented by Formula 6-1 below.

[Formula 6-1]

.

As the solvent and lactone-based compound are listed as existing chemical substances in national regulations (NCIS), the polymer resin composition of the above embodiment containing them is designated as an N-hazardous chemical substance, unlike the conventional polymer resin composition. A polymer resin composition that can replace methylpyrrolidone (NMP) may be provided.

Meanwhile, the polymer resin composition may simultaneously include the solvent and the lactone-based compound.

Specifically, the polymer resin composition contains 99 parts by weight or less, 50 to 99 parts by weight, 50 to 90 parts by weight, or 50 to 80 parts by weight, based on 100 parts by weight of the solvent. It may contain 50 parts by weight or more and 75 parts by weight or less, 60 parts by weight or more and 75 parts by weight or less, and 60 parts by weight or more and 70 parts by weight or less.

If the polymer resin composition contains more than 99 parts by weight of the lactone-based compound based on 100 parts by weight of the solvent, polymer formation may be reduced due to a decrease in the degree of polymerization.

Meanwhile, the polymer resin composition may further include a nitrogen-containing multi-ring compound having 5 or more carbon atoms. The nitrogen-containing multicyclic compound having 5 or more carbon atoms is included in the polymer resin composition and acts as a catalyst to promote imidization of the polyimide resin, thereby aligning the polymer and removing moisture of the polyimide resin in the polymer resin composition before the solvent is volatilized. As this occurs effectively, the film lifting phenomenon of the polymer resin film in the final manufactured optical device can be minimized.

The type of the nitrogen-containing multi-ring compound having 5 or more carbon atoms is not greatly limited, but may include, for example, a nitrogen-containing heterocyclic compound having 5 or more carbon atoms. In the present specification, a heterocyclic compound refers to a ring compound containing one or more of O, N, Si, and S as heteroatoms. The nitrogen-containing heterocyclic compound having 5 or more carbon atoms may include, for example, 1,4-diazabicyclo[2.2.2]octane (DABCO) or Lepidine (4-methylquinoline).

More specifically, the nitrogen-containing multicyclic compound having 5 or more carbon atoms may include a nitrogen-containing heterocyclic aromatic compound having 5 or more carbon atoms. In the present specification, a heterocyclic aromatic compound refers to a ring aromatic compound containing one or more of O, N, Si, and S as a heteroatom. Examples of heterocyclic aromatic compounds include thiophene, furan, pyrrole, imidazole, thiazole, oxazole, oxadiazole, triazole, pyridyl group, bipyridine, pyrimidine, triazine, acridine, pyridazine, pyrazine, Quinoline, quinazoline, quinoxaline, phthalazine, pyrido pyrimidine, pyrido pyrazine, pyrazino pyrazine, isoquinoline, indole, carbazole, benzooxazole, benzoimidazole, benzothiazole, benzocarbazole, benzoyl Thiophene, dibenzothiophene, benzofuranyl group, phenanthroline, isoxazole, thiadiazole, phenothiazine, and dibenzofuran, etc., but are not limited to these. The heterocyclic aromatic compound may be substituted or unsubstituted.

The nitrogen-containing heterocyclic aromatic compound having 5 or more carbon atoms may include, for example, 4-methylquinoline (Lepidine).

The nitrogen-containing multi-ring compound having 5 or more carbon atoms may be included in an amount of 0.1% by weight or more and 10% by weight or less based on the total weight of the polymer resin composition.

If the nitrogen-containing multi-ring compound having 5 or more carbon atoms is included in less than 1% by weight based on the total weight of the polymer resin composition, the nitrogen-containing multi-ring compound having 5 or more carbon atoms is not sufficiently contained, and technical problems such as film detachment during the curing process may occur. When the nitrogen-containing multi-ring compound having 5 or more carbon atoms is included in an amount of more than 10% by weight based on the total weight of the polymer resin composition, the nitrogen-containing multi-ring compound having 5 or more carbon atoms is included in an excessive amount, thereby deteriorating the heat resistance and optical properties of the polymer. Technical problems may arise.

In addition, the polymer resin composition contains 0.1 to 20 parts by weight, 1 to 20 parts by weight, or 3 to 20 parts by weight of the nitrogen-containing multicyclic compound having 5 or more carbon atoms, based on 100 parts by weight of polyimide resin solid content. It may contain less than or equal to 5 parts by weight and less than or equal to 20 parts by weight.

When the nitrogen-containing multicyclic compound having 5 or more carbon atoms is included in less than 0.1 parts by weight based on 100 parts by weight of the solid content of the polyimide resin, the nitrogen-containing multicyclic compound having 5 or more carbon atoms is not sufficiently contained, causing a technical problem in that the film in the inorganic film is lifted. may occur, and if it is included in excess of 20 parts by weight, the nitrogen-containing multicyclic compound having 5 or more carbon atoms may be included in excessive amounts, which may cause a technical problem of deteriorating the overall polymer properties.

2. Laminate

According to another embodiment of the invention, a first polyimide resin layer; a first inorganic material layer formed on the first polyimide resin layer; a second polyimide resin layer formed on the first inorganic material layer; and a second inorganic material layer formed on the second polyimide resin layer, wherein the first polyimide resin layer or the second polyimide resin layer includes the polyimide-based resin film of the embodiment. It can be.

The present inventors composed the polyimide layer as a double layer of a first polyimide resin layer and a second polyimide resin layer, inserted a first inorganic layer between the first polyimide resin layer and the second polyimide resin layer, A second inorganic layer is also introduced on the second polyimide resin layer, so that the first inorganic layer is inserted between the first polyimide resin layer and the second polyimide resin layer, and the second layer is formed on the second polyimide resin layer. The inorganic material layer is used to strengthen the encapsulation ability of the polyimide resin layer, which has stronger moisture permeability and hygroscopicity than glass, and the second inorganic material layer formed on the second polyimide resin layer serves as the second polyimide water in the display TFT structure. By acting as an insulating film applied on the ground layer, electrical influence on the second polyimide resin layer can be reduced.

The laminate may include a first polyimide resin layer. By including the first polyimide resin layer, high resistance characteristics are realized due to the wide polymer chain spacing of the first polyimide resin layer, and the electrical influence is reduced, improving afterimage when applied as a substrate to a display device or flexible display device. It can be helpful.

Additionally, the laminate may include a first inorganic material layer formed on the first polyimide resin layer. The first inorganic material layer is located between the first polyimide resin layer and the second polyimide resin layer to block air and moisture, thereby providing a laminate with excellent device stability.

The first inorganic material layer is one or more inorganic materials selected from the group consisting of silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiON), aluminum oxide (AlO), and aluminum oxynitride (AlON). may include. More specifically, silicon dioxide (SiO ₂ ) may be used as the first inorganic layer.

The thickness of the first inorganic material layer is not greatly limited and can be applied without limitation within the range of 1000 Å to 7000 Å. However, as a limited example, the first inorganic layer may have a thickness of 100 nm or more, or 400 nm or more, or 700 nm or less, or 100 nm to 700 nm, or 400 nm to 700 nm.

For the formation of the first inorganic layer, conventional inorganic film formation methods in the technical field to which the present invention pertains, such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), may be applied. In particular, the specific method of the chemical vapor deposition method is not greatly limited, but for example, plasma chemical vapor deposition (PECVD) or high density plasma chemical vapor deposition (HDPCVD) can be applied.

Additionally, the laminate may include a second polyimide resin layer formed on the first inorganic material layer. The composition of the second polyimide resin layer is the same as that of the first polyimide resin layer.

Meanwhile, the thickness of the first polyimide resin layer may be greater than the thickness of the second polyimide resin layer. Specifically, based on the thickness of 1 ㎛ of the first polyimide resin layer, the thickness ratio of the second polyimide resin layer may be 0.3 ㎛ to 0.7 ㎛. Accordingly, structural stability during lamination is improved in terms of physical strength due to thickness, and moisture permeation prevention can also be improved. If the thickness ratio of the second polyimide resin layer is excessively reduced to less than 0.3 ㎛ based on the thickness of 1 ㎛ of the first polyimide resin layer, the structural stability and moisture resistance by the second polyimide resin layer cannot be sufficiently implemented. It is difficult, and if the thickness ratio of the second polyimide resin layer is excessively increased to more than 0.7 ㎛ based on the thickness of 1 ㎛ of the first polyimide resin layer, the permeability decreases and membrane detachment increases due to the increase in the thickness of the polyimide resin layer. problems may arise.

For example, in the above embodiment, the first polyimide resin layer has a thickness of 1 ㎛ to 15 ㎛, or 2 ㎛ to 15 ㎛, or 6 ㎛ to 15 ㎛, or 1 ㎛ to 10 ㎛, or 2 ㎛ to 10 ㎛. , or has a thickness of 6 ㎛ to 10 ㎛, and the second polyimide resin layer may have a thickness of 0.5 ㎛ to 6 ㎛, or 1 ㎛ to 6 ㎛, or 3 ㎛ to 6 ㎛.

Additionally, the laminate may include a second inorganic material layer formed on the second polyimide resin layer. The second inorganic material layer is located on the second polyimide resin layer to block air and moisture, thereby realizing excellent device stability, and by minimizing the electrical effect caused by the thin film transistor, it can be used as a high-quality display device or flexible device. A laminate suitable for a display device can be provided.

That is, the second inorganic layer acts as an insulating film applied over the second polyimide resin layer in the display TFT structure, thereby reducing electrical influence on the second polyimide resin layer.

The second inorganic material layer is one or more inorganic materials selected from the group consisting of silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiON), aluminum oxide (AlO), and aluminum oxynitride (AlON). may include. More specifically, silicon dioxide (SiO ₂ ) may be used as the second inorganic layer.

For the formation of the second inorganic layer, conventional inorganic film formation methods in the technical field to which the present invention pertains, such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), may be applied. In particular, the specific method of the chemical vapor deposition method is not greatly limited, but for example, plasma chemical vapor deposition (PECVD) or high density plasma chemical vapor deposition (HDPCVD) can be applied.

The thickness of the second inorganic layer is not greatly limited and can be applied without limitation within the range of 1000 Å to 7000 Å. However, as a limited example, the thickness of the first inorganic material layer may be greater than the thickness of the second inorganic material layer. Specifically, based on the thickness of 1 ㎛ of the first inorganic material layer, the thickness ratio of the second inorganic material layer may be 0.3 ㎛ to 0.9 ㎛. This is due to differences in the structure in which the first inorganic material layer is laminated between the first polyimide resin layer and the second polyimide resin layer, and the second inorganic material layer is laminated only on the second polyimide resin layer. will be.

For example, the first inorganic layer may have a thickness of 100 nm or more, or 400 nm or more, or 700 nm or less, or 100 nm to 700 nm, or 400 nm to 700 nm. Additionally, the second inorganic layer may have a thickness of 100 nm or more, or 700 nm or less, or 600 nm or less, or 100 nm to 700 nm, or 100 nm to 600 nm.

The laminate according to the present invention can exhibit excellent colorless and transparent properties while maintaining the properties such as heat resistance and mechanical strength due to the rigid structure, and can be used for device substrates, display cover substrates, optical films, and circuits. It can be used in various fields such as substrates, integrated circuit (IC) packages, adhesive films, multi-layer flexible printed circuits (FRCs), tapes, touch panels, and protective films for optical disks.

Meanwhile, the laminate may further include a base layer. The base layer can be used as a support substrate layer for a large-area flexible display. To this end, the base layer may have various thicknesses ranging from 0.01 ㎛ to 1000 ㎛.

The base layer may be formed under the first polyimide resin layer. That is, the base layer, the first polyimide resin layer, the first inorganic material layer, the second polyimide resin layer, and the second inorganic material layer may be laminated in that order.

Examples of the base layer are not greatly limited, and glass substrates, wafer substrates, flexible substrates, or mixtures thereof may be used without limitation. The flexible substrate may include any polymer known to be generally applicable to substrates of flexible devices, etc., without any particular limitation. Specific examples include polyethersulfone, polyethylene naphthalate, polyethylene terephthalate, polycarbonate, polyimide, polyetherimide, polyamideimide, polyester, polyetheramide imide, polyester amide imide, and polyarylate. It may contain one or more types of polymer resin selected from, and more preferably, it may contain a polyimide-based resin, and the type of polyimide is not particularly limited.

3. Substrate for display device

Meanwhile, according to another embodiment of the invention, a substrate for a display device including either the polyimide-based resin film of one embodiment or the laminate of another embodiment may be provided. Content regarding the polyimide-based resin film may include all of the information described above in the embodiment. The content regarding the laminate may include all of the content described above in the other embodiments.

The display device including the 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. ), etc., but are not limited thereto.

The display device may have various structures depending on the field of application and specific form, etc., and may include, for example, a cover plastic window, a touch panel, a polarizer, a barrier film, a light-emitting device (OLED device, etc.), a transparent substrate, etc. there is.

The polyimide resin film of one embodiment or the laminate of another embodiment may be used for various purposes such as a substrate, external protective film, or cover window in various display devices, and more specifically, may be applied as a substrate.

For example, the substrate for the display device has a structure in which a device protection layer, a transparent electrode layer, a silicon oxide layer, a polyimide resin film of the above embodiment or a laminate of the other embodiment, a silicon oxide layer, and a hard coating layer are sequentially stacked. can be provided.

The transparent polyimide substrate may include a silicon oxide layer formed between the transparent polyimide-based resin film and the cured layer in terms of improving solvent resistance, moisture permeability, and optical properties, and the silicon oxide layer is poly. It may be produced by curing silazane.

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

The substrate for a display device according to the present invention can provide a transparent polyimide cover substrate having excellent bending properties and impact resistance, solvent resistance, optical properties, moisture permeability, and scratch resistance by including the above-described device protection layer. there is.

4. Circuit board

Meanwhile, according to another embodiment of the invention, a circuit board including either the polyimide-based resin film of one embodiment or the laminate of another embodiment may be provided. The content regarding the polyimide resin film may include all of the content described above in the embodiment. Content regarding the laminate may include all of the content described above in the other embodiments.

The polyimide-based resin film of one embodiment or the laminate of another embodiment may be used for various purposes such as a substrate, external protective film, or cover window in various electronic devices, and more specifically, may be applied as a substrate.

For example, the polyimide-based resin film of one embodiment or the laminate of another embodiment may be applied as an insulating material such as a protective film for a circuit board, a base film of a circuit board, or an interlayer insulating film of a circuit board within the circuit board, without limitation. can do.

The configuration and manufacturing method of the circuit board may utilize techniques known in the art, except that the polyimide-based resin film of one embodiment or the laminate of the other embodiment is used for the above-described purpose.

5. Optics

Meanwhile, according to another embodiment of the invention, an optical device including either the polyimide-based resin film of one embodiment or the laminate of another embodiment may be provided. Content regarding the polyimide-based resin film may include all of the information described above in the embodiment. Content regarding the laminate may include all of the content described above in the other embodiments.

The optical device may include all kinds of devices that utilize properties realized by light, and may include, for example, a display device. Specific examples of the display device include a liquid crystal display device (LCD), an organic light emitting diode (OLED), a flexible display, or a rollable display or foldable display. These may include, but are not limited to these.

The optical device may have various structures depending on the field of application and specific form, and may include, for example, a cover plastic window, a touch panel, a polarizer, a barrier film, a light-emitting device (OLED device, etc.), a transparent substrate, etc. there is.

The polyimide-based resin film of one embodiment or the laminate of another embodiment may be used for various purposes such as a substrate, external protective film, or cover window in various optical devices, and more specifically, may be applied to a substrate.

6. Electronic devices

Meanwhile, according to another embodiment of the invention, an electronic device including either the polyimide-based resin film of one embodiment or the laminate of another embodiment may be provided. Content regarding the polyimide-based resin film may include all of the information described above in the embodiment. The content regarding the laminate may include all of the content described above in the other embodiments.

The electronic device may include all kinds of devices that utilize properties implemented by electrical signals, and examples include semiconductor devices, communication equipment such as mobile phones, and lighting devices. In particular, a preferred example of the electronic device is a high-speed electronic device capable of realizing high-frequency, high-speed communication. Specific examples of the high-speed electronic devices include 5G antennas.

In the electronic device, the polyimide-based resin film of one embodiment or the laminate of another embodiment may be used for various purposes, such as a substrate, an interlayer insulating film, a solder resist, an external protective film, or a cover window, and may be used in the configuration of the electronic device. And the manufacturing method may use techniques known in the art, except that the polyimide-based resin film of one embodiment or the laminate of the other embodiment is used for the above-described purpose.

According to the present invention, a polyimide resin film capable of improving adhesion to inorganic films and realizing excellent insulation properties and heat resistance, and a laminate using the same, a substrate for a display device, a circuit board, an optical device, and an electronic device will be provided. You can.

The invention is explained in more detail in the following examples. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

<Example: Production of polyimide film>

Example 1

After filling 154.8 g of N,N-diethylformamide (DEF) in a stirrer with a nitrogen stream, p-phenylenediamine (1,4- phenylenediamine (p-PDA) was added and dissolved at the same temperature. 3,3',4,4'-Biphenyltetracarboxylic dianhydride (BPDA) was added to the solution at the same temperature and stirred for 24 hours. At this time, the polyimide solid content was 25 g out of a total of 180 g of the prepared polyimide precursor composition.

Afterwards, 5% by weight of 1.26 g of Lepidine (4-methylquinoline) based on the total solid content was added and stirred to prepare a polyimide precursor composition.

The polyimide precursor composition was spin-coated on a glass substrate. A curing process is carried out by maintaining the glass substrate coated with the polyimide precursor composition at 80°C for 10 to 30 minutes and 60 minutes at 460°C, thereby forming polyimide with a thickness of 10 ㎛ (including ±1 ㎛ error) on the glass substrate. A mid film was prepared. After completing the curing process, the glass substrate was immersed in water, the film formed on the glass substrate was removed, and dried in an oven at 100°C to prepare a polyimide film with a thickness of 10 ㎛ (including ±1 ㎛ error).

Example 2

The same method as Example 1, except that N,N-diethylacetamide (DEAc) was added instead of N,N-diethylformamide (DEF). A polyimide film was manufactured.

Example 3

The same method as Example 1, except that N-ethyl-2-pyrrolidone (NEP) was added instead of N,N-diethylformamide (DEF). A polyimide film was manufactured.

<Comparative example: production of polyimide film>

Comparative Example 1

The same method as Example 1, except that N-methyl-2-pyrrolidone (NMP) was added instead of N,N-diethylformamide (DEF). A polyimide film was manufactured.

Comparative example 2

A polyimide film was prepared in the same manner as Example 1, except that dimethylacetamide (DMAc) was added instead of N,N-diethylformamide (DEF).

Comparative example 3

Except that 3-methoxy-N,N-dimethylpropanamide (DMPA) was added instead of N,N-diethylformamide (DEF). , a polyimide film was manufactured in the same manner as in Example 1.

<Experimental Example: Measurement of physical properties of polyimide films obtained in Examples and Comparative Examples>

The physical properties of the polyimide films obtained in the above examples and comparative examples were measured by the following method, and the results are shown in Table 1.

1. Adhesion

The polyimide film prepared in the above examples and comparative examples was cut to 100 mm in length and 10 mm in width, and an inorganic layer (a-Si, thickness 5,000 Å) was formed on the polyimide film by plasma chemical vapor deposition to prepare a sample. Manufactured.

Afterwards, the lower part of the sample was fixed using double-sided tape, and one end of the sample was peeled off from the polyimide film using tape and then fixed to the upper grip for measurement at a 90-degree angle. After manually pulling the fixed sample to make it taut, the polyimide film was peeled using a texture analyzer (TA-XP plus/SMS) at a peel speed of 50 mm/min and a peeling direction of 90 degrees, and the peel strength was measured. It was measured and evaluated as adhesion.

2. Saturation voltage and half-life

A polyimide film sample with a thickness of 6㎛ was prepared using the polyimide film prepared in the above examples and comparative examples. Afterwards, to measure the saturation voltage and half-life, SHISHIDO ELECTROSTATIC's H-0110 Honestmeter was used to measure the saturation voltage and half-life under the conditions of a measurement temperature of 25°C and humidity of 40-50% according to the JIS L 1094 standard measurement method.

Specifically, the applied voltage to each manufactured polyimide film was 10 kV, the distance from the tip of the needle electrode of the application unit to the surface of the rotating table was 20 mm, and the distance from the electrode plate of the power receiving unit to the surface of the rotating table was 15 mm. Adjusted. An applied voltage of 10 kV was started while rotating the rotating table, and the application was completed after 100 seconds. When the saturation value was reached, the saturation voltage was measured.

Afterwards, the application of high pressure was cut off, and the half-life was obtained by rotating the rotary plate and measuring the time from when the high pressure application was cut off until the potential value decreased by 50% of the saturation voltage value.

3. Heat resistance (Td 1%, ℃)

The temperature (°C) when the weight loss rate of the polyimide resin layer specimen was 1% was measured under a nitrogen atmosphere using Discovery TGA equipment from TA Instruments.

Specifically, the temperature was maintained isothermally at 50°C for 5 minutes, then raised to 200°C and then maintained isothermally for 30 minutes. Afterwards, it was stabilized by cooling to 50°C, and then the temperature was raised to 600°C at a rate of 10°C/min. After stabilization, the temperature at which the weight loss rate was 1% was calculated based on the mass at 100°C.

Experimental measurement results of examples and comparative examples division Example 1 Example 2 Example 3 Comparative Example 1 Comparative example 2 Comparative Example 3 Solvent (partition coefficient [logP] @ 25℃) DEF
(0.05) DEAc
(0.32) NEP
(0.22) NMP
(-0.28) DMAc
(-0.75) DMF
(-1.01) Diamine molar ratio (%) 100(p-PDA) 100(p-PDA) 100(p-PDA) 100(p-PDA) 100(p-PDA) 100(p-PDA) Anhydride molar ratio (%) 100(BPDA) 100(BPDA) 100(BPDA) 100(BPDA) 100(BPDA) 100(BPDA) Adhesion (N/cm) 0.41 0.10 0.09 0.09 0.08 0.09 Saturation voltage (Kv) 1.23 1.21 1.19 1.15 1.16 1.17 Half-life (seconds) 220 200 180 170 168 180 Td 1% (℃) 574 574 570 573 572 568

As shown in Table 1, it was confirmed that the polyimide film of the example exhibited excellent adhesion, insulation, and heat resistance compared to the polyimide film of the comparative example.

Claims (19)

When peeling the polyimide-based resin film at a peeling speed of 50 mm/min and a peeling angle of 90 degrees for a sample in which an inorganic layer is laminated on a polyimide-based resin film, the peeling strength is 0.09 N/cm or more,
The saturation voltage measured under the JIS L 1094 standard measurement conditions is 1.18 kV or more,
The saturation voltage half-life measured under the JIS L 1094 standard measurement conditions is more than 180 seconds,
A polyimide-based resin film with Td 1% of 570°C or higher.
According to paragraph 1,
The polyimide-based resin film is a polyimide-based resin film comprising a polyimide-based resin containing an aromatic imide repeating unit.
According to paragraph 2,
The polyimide resin is,
A polyimide-based resin film comprising a polyimide repeating unit represented by the following formula (1):
[Formula 1]

In Formula 1 above,
X ₁ is an aromatic tetravalent functional group,
Y ₁ is an aromatic divalent functional group having 6 to 10 carbon atoms.
According to paragraph 3,
Wherein X ₁ is a polyimide-based resin film comprising a tetravalent functional group represented by the following formula (2):
[Formula 2]
.
According to paragraph 3,
The Y ₁ is a polyimide-based resin film containing a divalent functional group represented by the following formula (3):
[Formula 3]
.
According to paragraph 1,
The polyimide-based resin film,
A polyimide-based resin film comprising a cured product of a polymer resin composition containing a polyimide-based resin and a solvent that satisfies Equation 1 below:
[Equation 1]
Log P > 0
In Equation 1, P is the partition coefficient of the solvent at 25°C.
According to clause 6,
The solvent is a polyimide-based resin film that satisfies the following equation 2:
[Equation 2]
0.001 ≤ Log P < 5.000
In Equation 2, P is the partition coefficient of the solvent at 25°C.
According to clause 6,
The solvent is a polyimide-based resin film containing a tertiary amine functional group in which at least one alkyl group having 2 or more carbon atoms in the molecule is bonded to nitrogen.
According to clause 8,
The polyimide-based resin film wherein the alkyl group having 2 or more carbon atoms is an alkyl group having 2 to 5 carbon atoms.
According to clause 8,
A polyimide-based resin film, wherein the tertiary amine functional group includes a linear tertiary amine functional group or a cyclic tertiary amine functional group.
According to clause 10,
The solvent compound containing the linear tertiary amine functional group is a polyimide-based resin film including a compound represented by the following formula (4):
[Formula 4]

In Formula 4, R ₁ is hydrogen or an alkyl group having 1 to 10 carbon atoms, and R ₂ and R ₃ are each independently an alkyl group having 2 or more carbon atoms.
According to clause 10,
The solvent compound containing the cyclic tertiary amine functional group is a polyimide-based resin film including a compound represented by the following formula (5):
[Formula 5]

In Formula 5, R ₄ is an alkyl group having 2 or more carbon atoms, and n is an integer of 1 to 3.
According to clause 6,
The solvent is a polyimide-based resin film comprising at least one compound selected from the group consisting of N,N-diethylformamide, N,N-diethylacetamide, and N-ethylpyrrolidone.
According to clause 6,
The polymer resin composition is a polyimide-based resin film further comprising a nitrogen-containing multicyclic compound having 5 or more carbon atoms.
First polyimide resin layer;
a first inorganic material layer formed on the first polyimide resin layer;
a second polyimide resin layer formed on the first inorganic material layer; and
It includes a second inorganic material layer formed on the second polyimide resin layer,
A laminate in which the first polyimide resin layer or the second polyimide resin layer includes the polyimide-based resin film of claim 1.
A substrate for a display device comprising either the polyimide-based resin film of claim 1 or the laminate of claim 15.
A circuit board comprising either the polyimide resin film of claim 1 or the laminate of claim 15.
An optical device comprising either the polyimide resin film of claim 1 or the laminate of claim 15.
An electronic device comprising either the polyimide resin film of claim 1 or the laminate of claim 15.