KR20230148093A - Polyimide precursor - Google Patents

Abstract

The present application provides a polyimide precursor that is environmentally friendly, has excellent adhesion, surface flatness, and durability, and can produce polyimide with a high imidization rate, a method for producing the polyimide precursor and a polyimide film including a cured product of the polyimide precursor.

Description

Polyimide precursor {Polyimide precursor}

This application relates to a polyimide precursor, a method for producing the polyimide precursor, and a polyimide film containing a cured product of the polyimide precursor.

In general, polyimide (PI) is a polymer of imide monomers formed by solution polymerization of dianhydride and diamine or diisocyanate, and has excellent strength, chemical resistance, weather resistance, and heat resistance based on the chemical stability of the imide ring. It has mechanical properties such as: In addition, polyimide is attracting attention as a highly functional polymer material that can be applied to a wide range of industrial fields such as electronics, communications, and optics due to its excellent electrical properties such as insulating properties and low dielectric constant.

Here, polyimide refers to a highly heat-resistant resin produced by solution polymerizing dianhydride monomer and diamine monomer to produce polyamic acid, and then imidizing it by ring-closure dehydration at high temperature.

This application covers a polyimide precursor that is environmentally friendly, has excellent adhesion, surface flatness, and durability, and can produce polyimide with a high imidization rate, a method for producing the polyimide precursor, and a cured product of the polyimide precursor. Provides a polyimide film that

This application relates to polyimide precursors. For example, the polyimide precursor may be a polyimide varnish that is applied to a coating object and then imidized by heat curing. As the polyimide precursor contains the composition described below, it is possible to provide environmentally friendly polyimide with high adhesion, surface flatness, and excellent durability.

Exemplary polyimide precursors according to the present application include polyamic acids containing dianhydride monomers and diamine monomers as polymerized units; N,N-diethylacetamide (DEAc), N,N-diethylformamide (DEF), N-ethylpyrrolidone (NEP), An organic solvent containing at least one selected from the group consisting of dimethylpropionamide (DMPA) and diethylpropionamide (DEPA); A silicon-containing additive containing at least one functional group; and a phosphorus-based additive having an aromatic ring group.

In addition, the weight average molecular weight of the polyamic acid may be in the range of 40,000 to 100,000 g/mol, 45,000 to 90,000 g/mol, 48,000 to 80,000 g/mol, 50,000 to 75,000 g/mol, or 51,000 to 70,000 g/mol. In this application, the term weight average molecular weight refers to the converted value for standard polystyrene measured by GPC (Gel permeation Chromatograph).

The polyimide precursor according to the present invention may be a polyamic acid solution containing polyamic acid, an organic solvent, a silicon-containing additive, and a phosphorus-based additive. In the present invention, polyimide precursor, polyamic acid solution, and polyimide varnish are interpreted to have the same meaning.

The polyamic acid may be prepared through a polymerization reaction of a dianhydride monomer and a diamine monomer in the presence of the organic solvent, and may be a mixture of a silicon-containing additive and a phosphorus-based additive in the polymer. As the polyamic acid of the present invention is polymerized in the organic solvent, the weight average molecular weight increases and can satisfy the above-mentioned numerical range.

In the present invention, the silicon-containing additive may be a silane-based compound or a siloxane-based compound. In addition, as the silicon-containing additive is mixed with the polyamic acid after the polymerization reaction is completed, it may not be included in the polymerization unit of the polyamic acid, but instead interacts with the polyamic acid or polyimide through a functional group to achieve high adhesion, surface flatness, and It can contribute to creating polyimide with excellent durability. Additionally, as the phosphorus-based additive is mixed with the polyamic acid after the polymerization reaction is completed, it can contribute to increasing the imidization rate and durability during curing of the polyamic acid.

When mixed with polyamic acid polymerized in the presence of the organic solvent, polyimide can be provided with high adhesion, surface flatness, and durability when cured.

In one embodiment, the organic solvent may have a negative octanol/water partition coefficient (Log P) calculated by Equation 1 below.

[Equation 1]

Log P = Log (Kow)

Kow　=Co/Cw

In Equation 1, Co is the concentration of the solute in octanol, and Cw is the concentration of the solute in water.

The distribution coefficient can be calculated using the ACD/LogP module of the ACD/Percepta platform of ACD/Labs under a temperature condition of 25°C. At this time, the ACD/LogP module uses the 2D structure of the molecule to calculate QSPR (Quantitative Structure) -Property Relationship) methodology-based algorithm can be used. However, since the distribution coefficient is an experimental value, the possibility that it is measured as a positive value cannot be ruled out depending on the measurement method or algorithm used.

The organic solvent having a negative distribution coefficient is N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), or N,N-dimethylpropionamide ( Examples include DMPA).

Considering environmentally friendly aspects, the organic solvent may be N,N-dimethylpropionamide (DMPA). The DMPA is an environmentally friendly organic solvent that can be processed without a separate purification process after the polymerization reaction, thereby reducing cost. In addition, during the polymerization reaction of the polyamic acid in the DMPA solvent, the weight average molecular weight of the polyamic acid is as described above. It can be adjusted within the numerical range. Meanwhile, in the case of polyamic acid polymerized in a DMPA solvent, it may exhibit a low imidation rate upon curing, but the polyimide precursor according to the present invention contains a phosphorus-based additive, thereby improving the low imidation rate.

Additionally, the organic solvent may not contain N-methyl-2-pyrrolidone (NMP). Polyamic acid polymerized in the presence of N-methyl-2-pyrrolidone may not satisfy the weight average molecular weight within the above-mentioned numerical range. In addition, since NMP is classified as a hazardous substance, additional costs for purification are required, and it may cause environmental pollution problems during the processing process.

In one embodiment, the content of the silicon-containing additive may be 0.0001 to 1% by weight based on the total polyimide precursor. For example, the content of the silicon-containing additive is 0.0001 to 0.9% by weight, 0.0001 to 0.8% by weight, 0.0001 to 0.7% by weight, 0.0001 to 0.6% by weight, 0.0001 to 0.5% by weight, 0.0001 to 0.4% by weight, based on the total polyimide precursor. Weight %, 0.0001 to 0.3 weight %, 0.0001 to 0.2 weight %, 0.0001 to 0.1 weight %, 0.0001 to 0.09 weight %, 0.0001 to 0.08 weight %, 0.0001 to 0.07 weight %, 0.0001 to 0.06 weight %, 0.0001 to 0 .05% by weight , 0.0001 to 0.04% by weight, 0.0001 to 0.03% by weight, 0.0001 to 0.02% by weight, 0.0001 to 0.01% by weight, 0.001 to 0.9% by weight, 0.001 to 0.8% by weight, 0.001 to 0.7% by weight, 0.001 to 0.6% by weight, 0.001 to 0.5% by weight, 0.001 to 0.4% by weight, 0.001 to 0.3% by weight, 0.001 to 0.2% by weight, 0.001 to 0.1% by weight, 0.001 to 0.09% by weight, 0.001 to 0.08% by weight, 0.001 to 0.07% by weight, 0.001 to 0.06 Weight %, 0.001 to 0.05 weight %, 0.001 to 0.04 weight %, 0.001 to 0.03 weight %, 0.001 to 0.02 weight %, 0.001 to 0.01 weight %, 0.01 to 0.9 weight %, 0.01 to 0.8 weight %, 0.01 to 0.7 weight % , 0.01 to 0.6% by weight, 0.01 to 0.5% by weight, 0.01 to 0.4% by weight, 0.01 to 0.3% by weight, 0.01 to 0.2% by weight, 0.01 to 0.1% by weight, 0.01 to 0.09% by weight, 0.01 to 0.08% by weight, 0.01 It may range from 0.07% by weight, 0.01 to 0.06% by weight, 0.01 to 0.05% by weight, 0.01 to 0.04% by weight, 0.01 to 0.03% by weight, or 0.01 to 0.02% by weight. A silicon-containing additive having a content within the above range can be mixed with polymerized polyamic acid to provide polyimide with high adhesion upon curing, excellent surface flatness, and durability.

The functional group of the silicon-containing additive may be an amine group, carboxyl group, alcohol, alkoxy group, mercapto group, epoxy group, or isocyanate. The silicon-containing additive may be a monomer or polymer containing at least one of the functional groups, for example, a compound of the following formula (1).

[Formula 1]

R ₁ R ₂ R ₃ Si-RR ₄

In Formula 1 above,

At least one of R ₁ to R ₃ is an alkoxy group, and the remainder is an organic group,

R is a single bond or a divalent organic group,

R ₄ is an organic group having one or more functional groups selected from amine group, carboxyl group, alcohol, alkoxy group, mercapto group, epoxy group, or isocyanate.

When the above functional group is an amine group, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminopropyltrimethoxysilane, Ethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethylsilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-( N-phenylamino)propyltrimethoxysilane, γ-(N-phenylamino)propylmethyldimethoxysilane, γ-(N-methylamino)propyltrimethoxysilane, γ-(N-methylamino)propylmethyldime Toxysilane, γ-(N-ethylamino)propyltrimethoxysilane, γ-(N-ethylamino)propylmethyldimethoxysilane, or N-[3-(trimethoxysilyl)propyl]aniline may be mentioned. .

When the functional group is mercapto, examples include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, or γ-mercaptopropylmethyldimethoxysilane.

When the functional group is an epoxy group, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-(2,3-epoxycyclohexyl)propyltrimethoxysilane, or γ-glycidoxysilane. Doxypropyltrimethoxysilane, etc. can be mentioned.

Examples of the silicon-containing additive in which the functional group is an epoxy group and is a polymer include X-12-984S (manufactured by Shin-Etsu Chemical Industry).

In addition, the silicon-containing additive whose functional group is an isocyanate group and is a monomer may include, for example, 3-isocyanatopropyltriethoxysilane.

In one embodiment, the content of the phosphorus-based additive may be 0.001 to 2% by weight based on the total polyimide precursor. For example, the content of the phosphorus additive is 0.001 to 1.9% by weight, 0.001 to 1.8% by weight, 0.001 to 1.7% by weight, 0.001 to 1.6% by weight, 0.001 to 1.5% by weight, 0.001 to 1.4% by weight, based on the total polyimide precursor. %, 0.001 to 1.3% by weight, 0.001 to 1.2% by weight, 0.001 to 1.1% by weight, 0.001 to 1% by weight, 0.001 to 0.9% by weight, 0.001 to 0.8% by weight, 0.001 to 0.7% by weight, 0.001 to 0.6% by weight, 0.001 to 0.5% by weight, 0.001 to 0.4% by weight, 0.001 to 0.3% by weight, 0.001 to 0.2% by weight, 0.001 to 0.1% by weight, 0.01 to 1.9% by weight, 0.01 to 1.8% by weight, 0.01 to 1.7% by weight, 0.01 to 1.6% by weight, 0.01 to 1.5% by weight, 0.01 to 1.4% by weight, 0.01 to 1.3% by weight, 0.01 to 1.2% by weight, 0.01 to 1.1% by weight, 0.01 to 1% by weight, 0.01 to 0.9% by weight, 0.01 to 0.8% by weight %, 0.01 to 0.7% by weight, 0.01 to 0.6% by weight, 0.01 to 0.5% by weight, 0.01 to 0.4% by weight, 0.01 to 0.3% by weight, 0.01 to 0.2% by weight, 0.01 to 0.1% by weight, 0.02 to 1.9% by weight, 0.02 to 1.8% by weight, 0.02 to 1.7% by weight, 0.02 to 1.6% by weight, 0.02 to 1.5% by weight, 0.02 to 1.4% by weight, 0.02 to 1.3% by weight, 0.02 to 1.2% by weight, 0.02 to 1.1% by weight, 0.02 to 1.4% by weight 1% by weight, 0.02 to 0.9% by weight, 0.02 to 0.8% by weight, 0.02 to 0.7% by weight, 0.02 to 0.6% by weight, 0.02 to 0.5% by weight, 0.02 to 0.4% by weight, 0.02 to 0.3% by weight, 0.02 to 0.2% by weight %, 0.02 to 0.1% by weight, 0.03 to 1.9% by weight, 0.03 to 1.8% by weight, 0.03 to 1.7% by weight, 0.03 to 1.6% by weight, 0.03 to 1.5% by weight, 0.03 to 1.4% by weight, 0.03 to 1.3% by weight, 0.03 to 1.2% by weight, 0.03 to 1.1% by weight, 0.03 to 1% by weight, 0.03 to 0.9% by weight, 0.03 to 0.8% by weight, 0.03 to 0.7% by weight, 0.03 to 0.6% by weight, 0.03 to 0.5% by weight, 0.03 to 0.03% by weight It may be in the range of 0.4% by weight, 0.03 to 0.3% by weight, 0.03 to 0.2% by weight, and 0.03 to 0.1% by weight. The phosphorus-based additive having a content within the above range can be mixed with polyamic acid polymerized with a silicon-containing additive to achieve a high imidization rate and durability during curing.

In one example, the phosphorus-based additive may have an aromatic ring group. For example, the phosphorus-based additive may have 1 or more, 2 or more, or 3 or more aromatic ring groups, preferably 3 aromatic ring groups, and more preferably, the phosphorus-based additive may have triphenyl phosphate or tri. It may be phenylphosphine.

In one embodiment, the dianhydride monomer may be aromatic tetracarboxylic dianhydride. For example, the dianhydride monomer includes at least one compound represented by the following formula (2).

[Formula 2]

In the above formula (2), It is connected to the ring constituent atoms of a cyclic group, aromatic ring group, or heteroaromatic ring group,

The aliphatic ring group, the heteroaliphatic ring group, the aromatic ring group, or the heteroaromatic ring group

is a monocyclic ring;

conjugated to each other to form a polycyclic ring; or

Single bond, substituted or unsubstituted alkylene group, substituted or unsubstituted alkylidene group, substituted or unsubstituted alkenylene group, substituted or unsubstituted alkynylene group, substituted or unsubstituted arylene group, -O-, are connected by a linking group containing one or more divalent substituents selected from the group consisting of -S-, -C(=O)-, -S(=O) ₂ - and -Si(R _b ) _2- , where R _b is hydrogen or an alkyl group.

Preferably, X is phenyl, biphenyl, or an aliphatic ring group,

The M includes at least one from the group including a single bond, an alkylene group, an alkylidene group, -O-, -S-, -C(=O)-, and -S(=O) ₂ -.

As used herein, the term “aliphatic ring group” may refer to an aliphatic ring group having 3 to 30 carbon atoms, 4 to 25 carbon atoms, 5 to 20 carbon atoms, or 6 to 16 carbon atoms, unless otherwise specified. Specific examples of the tetravalent aliphatic ring group include, for example, cyclohexane ring, cycloheptane ring, cyclodecane ring, cyclododecane ring, norbornane ring, isobornane ring, adamantane ring, and cyclododecane. Examples include groups in which four hydrogen atoms have been removed from a ring, such as a ring or a dicyclopentane ring.

As used herein, the term “aromatic ring group” may refer to an aromatic ring group having 4 to 30 carbon atoms, 5 to 25 carbon atoms, 6 to 20 carbon atoms, or 6 to 16 carbon atoms, unless otherwise specified. may be a single ring or a fused ring. Examples of the tetravalent aromatic hydrocarbon ring group include groups obtained by removing four hydrogen atoms from a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, or pyrene ring.

As used herein, the term “arylene group” may refer to a divalent organic group derived from the aromatic ring group.

As used herein, the term “heterocyclic group” includes a heteroaliphatic ring group and a heteroaromatic ring group.

As used herein, the term “hetero aliphatic ring group” may refer to a ring group in which at least one carbon atom of the aliphatic ring group is replaced with one or more heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur, and phosphorus.

As used herein, the term "hetero aromatic ring group", unless specifically defined otherwise, refers to a ring group in which at least one carbon atom of the aromatic ring group is replaced with one or more heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur, and phosphorus. It can mean. The heteroaromatic ring group may be a single ring or a condensed ring.

The aliphatic ring group, the heteroaliphatic ring group, the aromatic ring group, or the heteroaromatic ring group are each independently halogen, a hydroxy group, a carboxyl group, an alkyl group of 1 to 4 carbon atoms substituted or unsubstituted by halogen, and a carbon number of 1. It may be substituted with one or more substituents selected from the group consisting of alkoxy groups of to 4.

As used herein, the term “single bond” may mean a bond connecting both atoms without any atoms. For example, X in Formula 2 is , where M is a single bond, and both aromatic rings can be directly connected to each other.

In this specification, unless otherwise specified, the term “alkyl group” refers to a group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. It may mean an alkyl group of. The alkyl group may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, a polar functional group such as one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, unless otherwise specified, the term “alkenyl group” refers to a group having 2 to 30 carbon atoms, 2 to 25 carbon atoms, 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 8 carbon atoms. It may mean an alkenyl group of 4. The alkenyl group may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, a polar functional group such as one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, unless otherwise specified, the term “alkynyl group” refers to a group having 2 to 30 carbon atoms, 2 to 25 carbon atoms, 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 8 carbon atoms. It may mean an alkynyl group of 4. The alkynyl group may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, a polar functional group such as one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, unless otherwise specified, the term “alkylene group” refers to a group having 2 to 30 carbon atoms, 2 to 25 carbon atoms, 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 10 carbon atoms, or 2 to 10 carbon atoms. It may mean 2 to 8 alkylene groups. The alkylene group is a divalent organic group in which two hydrogens have been removed from different carbon atoms, and may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, a polar functional group such as one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, the term “alkylidene group” refers to a group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, or It may refer to an alkylidene group having 1 to 8 carbon atoms. The alkylidene group is a divalent organic group in which two hydrogens are removed from one carbon atom and may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, a polar functional group such as one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, unless otherwise specified, the term “alkoxy group” refers to a group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 8 carbon atoms. It may refer to the alkoxy group of 4. The alkoxy group may have a straight-chain, branched-chain, or cyclic alkyl group, and the alkyl group may be optionally substituted with one or more substituents. The substituent may be, for example, one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, the term “alkylamine group” includes monoalkylamine (-NHR) or dialkylamine (-NR ₂ ), where R each independently has 1 to 30 carbon atoms, unless otherwise specified. It may mean an alkyl group having 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, the term “alkylamide” includes monoalkylamide (-C(O)NHR) or dialkylamide (-C(O)NR ₂ ), unless otherwise specified, where R is each It may independently mean an alkyl group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, the term “thiol ether group” or “sulfide” means -SR, unless otherwise specified, where R each independently has 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, and 1 to 20 carbon atoms. It may mean an alkyl group having 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, the term “sulfoxide” means -S(O)R, unless otherwise specified, where R each independently has 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, and 1 carbon number. It may refer to an alkyl group having 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, the term "carbonyl", unless specifically defined otherwise, includes -C(O)R, where R each independently has 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, and 1 carbon atom. It may refer to an alkyl group having 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

In this specification, the term “ester”, unless specifically defined otherwise, includes -C(O)OR or -OC(O)R, where R each independently has 1 to 30 carbon atoms, 1 to 25 carbon atoms, and 1 to 25 carbon atoms. It may mean an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a straight-chain, branched-chain, or cyclic structure, and may be optionally substituted with one or more substituents. The substituent may be, for example, one or more substituents consisting of halogen, hydroxy group, alkoxy group, thiol group, or thiol ether group.

Aliphatic tetracarboxylic dianhydride satisfying Formula 2 is 1,2,4,5-cyclohexane tetracarboxylic dianhydride (or HPMDA), bicyclo[2.2.2]octane-2,3, 5,6-tetracarboxylic 2:3,5:6-dianhydride (BODA), 1,2,3,4-cyclohexane tetracarboxylic dianhydride (CHMDA), bicyclo[2.2.1 ]heptane-2,3,5,6-tetracarboxylic 2:3,5:6-dianhydride (BHDA), butane-l,2,3,4-tetracarboxylic dianhydride (BTD) , bicyclo-[2.2.2]oct-7-en-2-exo,3-exo,5-exo,6-exo-2,3:5,6-dianhydride (BTA), 1,2, 3,4-Tetraclobutane tetracarboxylic dianhydride (CBDA), bicyclo[4.2.0]octane-3,4,7,8-tetracarboxylic dianhydride (OTD), norbonane-2 -spiro-α-cyclohexanone-α'-spiro-2"-norbonane-5,5",6,6"- tetracarboxylic dianhydride (ChODA), cyclopentanone bis-spironorbonane tetra Carboxylic dianhydride (CpODA), bicyclo[2.2.1]heptane-2,3,5-tricarboxyl-5-acetic dianhydride (BSDA), dicyclohexyl-3,3',4 ,4'-tetracarboxylic dianhydride (DCDA), dicyclohexyl-2,3'3,4'-tetracarboxylic dianhydride (HBPDA), 5,5'-oxybis (hexahydro- 1,3-isobenzofurandione) (HODPA), 5,5'-methylenebis(hexahydro-1,3-isobenzofurandione) (HMDPA), 3,3'-(1,4-piperazidione 1) Bis[dihydro-2,5-furandione] (PDSA), 5-(2,5-dioxotetrahydrofurfuryl)-3-methyl-3-cyclohexane-1,2-dicarboxylic Anhydride (DOCDA), 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride (TDA), 3,4-dicarboxy-1,2,3, 4-Tetrahydro-6-methyl-1-naphthalene succinic dianhydride (MTDA), 3,4-dicarboxy-1,2,3,4-tetrahydro-6-fluoro-1-naphthalene succinic dianhydride hydride (FTDA), 3,3,3',3'-tetramethyl-1,1'-spirobisindan-5,5',6,6'-tetracarboxylic anhydride (SBIDA), 4 ,4,4',4'-tetramethyl-3,3',4,4'-tetrahydro-2,2'-spirobi[furo[3,4-g]chromen]-6,6', 8,8'-tetraone (SBCDA), or 9,10-difluoro-9,10-bis(trifluoromethyl)-9,10-dihydroanthracene-2,3,6,7-tetra Examples include carboxylic acid dianhydride (6FDA).

Aromatic tetracarboxylic dianhydride satisfying Formula 2 includes pyromellitic dianhydride (or PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (or BPDA), 2,3,3',4'-Biphenyltetracarboxylic dianhydride (or a-BPDA), oxydiphthalic dianhydride (or ODPA), diphenylsulfone-3,4,3',4' -Tetracarboxylic dianhydride (or DSDA), bis(3,4-dicarboxyphenyl)sulfide dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3 ,3,3-Hexafluoropropane dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic Dianhydride (or BTDA), bis(3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, p-phenylenebis( Trimellitic monoester acid anhydride), p-biphenylenebis (trimellitic monoester acid anhydride), m-terphenyl-3,4,3',4'-tetracarboxylic dianhyde p-terphenyl-3,4,3',4'-tetracarboxylic dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 2,2-bis[(3,4-dicarboxyphenoxy) C) phenyl] propane dianhydride (BPADA), 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, or 4,4' Examples include -(2,2-hexafluoroisopropylidene)diphthalic acid dianhydride (6-FDA).

The compound represented by Formula 2 is preferably aromatic tetracarboxylic dianhydride, especially 3,3',4,4'-biphenyltetracarboxylic dianhydride (or BPDA), or 2,3, It may include 3',4'-biphenyltetracarboxylic dianhydride (or a-BPDA).

As an example, the diamine monomer may include at least one compound represented by the following formula (3).

[Formula 3]

In Formula 3, any one of B ₁ to B ₅ is an amino group, and the others are hydrogen; halogen; hydroxyl group; Carboxyl group; Or it represents an alkyl group substituted or unsubstituted with halogen.

In addition, diamine monomers that can be used to prepare polyamic acid solutions are aromatic diamines, and examples can be classified as follows.

1) 1,4-diaminobenzene (or paraphenylenediamine, PPD), 1,3-diaminobenzene, 2,4-diaminotoluene, 2,6-diaminotoluene, or 3,5-diamino A diamine having one benzene nucleus in structure, such as benzoic acid (or DABA), and having a relatively rigid structure;

2) Diaminodiphenyl ether such as 4,4'-diaminodiphenyl ether (or oxydianiline, ODA), 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane (methylenediamine), 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl )-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane , 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, bis(4-aminophenyl)sulfide, 4,4'-diaminobenzanilide, 3,3' -Dichlorobenzidine, 3,3'-dimethylbenzidine (or o-tolidine), 2,2'-dimethylbenzidine (or m-tolidine), 3,3'-dimethoxybenzidine, 2,2'-dimethoxy Benzidine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4' -diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone , 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diamino-4,4'-dichlorobenzophenone, 3,3'-diamino-4,4' -Dimethoxybenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2-bis(3- Aminophenyl)propane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodi Diamines having two benzene nuclei in structure, such as phenyl sulfoxide or 4,4'-diaminodiphenyl sulfoxide;

3) 1,3-bis(3-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(3-aminophenyl)benzene, 1,4-bis(4-amino) Phenyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene (or TPE-Q), 1,4-bis(4-aminophenoxy) Benzene (or TPE-Q), 1,3-bis(3-aminophenoxy)-4-trifluoromethylbenzene, 3,3'-diamino-4-(4-phenyl)phenoxybenzophenone, 3 ,3'-diamino-4,4'-di(4-phenylphenoxy)benzophenone, 1,3-bis(3-aminophenyl sulfide)benzene, 1,3-bis(4-aminophenyl sulfide) Benzene, 1,4-bis (4-aminophenyl sulfide) benzene, 1,3-bis (3-aminophenyl sulfone) benzene, 1,3-bis (4-aminophenyl sulfone) benzene, 1,4-bis ( 4-aminophenylsulfone)benzene, 1,3-bis[2-(4-aminophenyl)isopropyl]benzene, 1,4-bis[2-(3-aminophenyl)isopropyl]benzene, or 1,4 -Diamines having three benzene nuclei in structure, such as bis[2-(4-aminophenyl)isopropyl]benzene;

4) 3,3'-bis(3-aminophenoxy)biphenyl, 3,3'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, bis[3-(3-aminophenoxy)phenyl]ether, bis[3-(4-aminophenoxy)phenyl]ether, bis[4- (3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, bis[3-(3-aminophenoxy)phenyl]ketone, bis[3-(4-aminophenok) Cy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[3-(3-aminophenoxy)phenyl]sulfide , bis[3-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[3- (3-aminophenoxy)phenyl]sulfone, bis[3-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy) Cy)phenyl]sulfone, bis[3-(3-aminophenoxy)phenyl]methane, bis[3-(4-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl 〕Methane, bis[4-(4-aminophenoxy)phenyl]methane, 2,2-bis[3-(3-aminophenoxy)phenyl]propane, 2,2-bis[3-(4) -aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane ( BAPP), 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[3-(4-) aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3 , 3,3-hexafluoropropane, or 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, etc. A diamine with four benzene nuclei in its structure.

The diamine monomer may be used alone or in combination of two or more types, as needed, for example, 1,4-diaminobenzene (PPD), 1,3-diaminobenzene (MPD), 2,4- It may include diaminotoluene, 2,6-diaminotoluene, or 4,4'-methylenediamine (MDA), and preferably the compound represented by Formula 2 includes 1,4-diaminobenzene (PPD). can do.

In one example, the dianhydride monomer may be included in the range of 90 to 102 mol% based on 100 mol% of the diamine monomer. For example, the dianhydride monomer is 91 to 102 mol%, 92 to 102 mol%, 93 to 102 mol%, 94 to 102 mol%, 95 to 102 mol%, 96 to 102 mol% based on 100 mol% of diamine monomer. %, 97 to 102 mol%, 98 to 102 mol%, 90 to 101 mol%, 90 to 100 mol%, or 90 to 99 mol%.

In one specific example, the polyimide precursor may include 5 to 40% by weight, 10 to 30% by weight, or 15 to 20% by weight of solid content based on the total weight. By adjusting the solid content of the polyimide precursor, the present application can control the increase in viscosity and prevent the increase in manufacturing cost and process time that requires removal of a large amount of solvent during the curing process.

The polyimide precursor of the present application may contain a high molecular weight polyamic acid and at the same time have low viscosity characteristics. The polyimide precursor of the present application has a viscosity measured at a temperature of 23°C and a shear rate of 1 s ^-1 of 50,000 cP or less, 40,000 cP or less, 30,000 cP or less, 20,000 cP or less, 10,000 cP or less, 9,000 cP or less, 5,000 cP. It may be below 4,000 cP or below 3,000 cP. The lower limit is not particularly limited, but may be 500 cP or more or 1000 cP or more. In one embodiment, the polyimide precursor of the present application may range from 500 to 10,000 cp. For example, the viscosity may be measured using Haake's MARS40 at a temperature of 23°C. By adjusting the viscosity range, the present application can provide a polyimide precursor with excellent processability and easy product application.

This application relates to a method for producing polyamic acid. The manufacturing method can provide a polyamic acid with a high weight average molecular weight by polymerizing the polyamic acid under a specific solvent, and by mixing the polymerized polyamic acid with a silicon-containing additive and a phosphorus-based additive, it is environmentally friendly, has high adhesion, and has excellent adhesive strength. It is possible to provide polyimide that has surface flatness and durability while exhibiting a high imidization rate.

Specifically, the production method is N,N-diethylacetamide (DEAc), N,N-diethylformamide (DEF), N-ethylpyrrolidone ( Dianhydride monomer and diamine monomer are polymerized in an organic solvent containing at least one selected from the group consisting of N-ethylpyrrolidone (NEP), dimethylpropionamide (DMPA), and diethylpropionamide (DEPA). Polymerization step of producing polyamic acid; And a manufacturing step of preparing a polyimide precursor by mixing the prepared polyamic acid with a silicon-containing additive containing at least one functional group and a phosphorus-based additive having an aromatic ring group.

As the phosphorus-based additive is mixed with the polyamic acid after the polymerization reaction, it can contribute to increasing the imidization rate and durability during curing.

A detailed description of each of the compositions above will be omitted below since it overlaps with the above-described content.

The present application also relates to a polyimide film comprising a cured product of the above-described polyimide precursor. The polyimide film may be produced in a film form by imidizing a polyimide precursor through thermal curing. Thermal curing conditions are not particularly limited, but may be performed within a temperature range of 100 to 400°C. The polyimide film may be attached to the bottom of the substrate of the display device.

Accordingly, the thickness of the film can be formed to be thin enough to be suitable for attachment to a product, for example, the thickness is 1 to 100㎛, 5 to 90㎛, 5 to 80㎛, 5 to 70㎛, 10㎛. It may range from 100 ㎛ to 100 ㎛, 10 to 90 ㎛, 10 to 80 ㎛, 10 to 70 ㎛, 10 to 60 ㎛ or 10 to 50 ㎛.

In addition, the film may be capable of controlling various physical properties within the numerical range below by adjusting the material and content ratio of the polyimide precursor composition described above.

For example, the polyimide film has an elongation measured using a UTM (Universal Testing Machine) device of 100% or less, 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less. , may be 65% or less, 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, or 25% or less, and the tensile strength is 700Mpa or less, 650Mpa or less, 600Mpa or less. , may be 550Mpa or less, 500Mpa or less, 450Mpa or less, 400Mpa or less, 350Mpa or less, 300Mpa or less, 250Mpa or less, 200Mpa or less, or 150Mpa or less, and the modulus is 12Gpa or less, 11Gpa or less, 10Gpa or less, 9Gpa or less, 8 Below Gpa, below 7Gpa, It may be 6Gpa or less, 5Gpa or less, 4Gpa or less, or 3Gpa or less. The measurement can be made with a UTM device under the conditions of a width of 20 mm, a grip distance of 50 mm, and a crosshead speed of 20 min/min.

In addition, the 1% thermal decomposition temperature (td) of the polyimide film measured using a TGA (Thermo Gravimetric analysis) device is 300 to 600 ℃, 350 to 600 ℃, 400 to 600 ℃, 450 to 600 ℃, 500 to 600 °C or may be in the range of 540 to 600°C. The 1% thermal decomposition temperature (td) can be measured by removing moisture in the film at a temperature of 150°C using a TGA device and then heating it to 600°C at a temperature increase rate of 10°C/min.

In one example, the polyimide film has an adhesive force to a polyimide substrate of 0.05 to 0.5 N/cm, 0.05 to 0.45 N/cm, 0.05 to 0.4 N/cm, 0.05 to 0.35 N/cm, 0.05 to 0.3 N/cm. cm, 0.05 to 0.25 N/cm, 0.05 to 0.2 N/cm or 0.05 to 0.15 N/cm. The adhesive strength was measured on a polyimide substrate and polyimide film of 100x10mm in size using INSTRON's UTM 5546 model at ^90o Peel mode and Cross Head Speed of 50mm/min.

The present application also relates to a display device. For example, the device may include a substrate; and the above-described polyimide film attached to the lower portion of the substrate. The type of the display device is not particularly limited and can be applied to various types without limitation. The display device may have excellent heat resistance, light resistance, and electrical properties as the above-described polyimide film is attached to the bottom of the substrate.

This application discloses a polyimide precursor capable of producing environmentally friendly polyimide with high adhesion, excellent surface flatness, and durability, a method for manufacturing the polyimide precursor, a polyimide film containing a cured product of the polyimide precursor, and the polyimide precursor. A display device in which a mid film is attached to the bottom of a substrate is provided.

The present application will be described in detail through examples below, but the scope of the present application is not limited by the examples below.

Example 1

N,N-dimethylpropionamide (DMPA) as an organic solvent was added to a 500 mL glass reaction vessel equipped with a stirrer and nitrogen gas introduction and discharge pipes, and 100 mol% of 1,4-diaminobenzene (PPD) was added. And 100 mol% of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was added. Then, polymerization was performed at 25°C to prepare a polyamic acid solution with a solid content of 15%, and 0.01% by weight of glycidoxypropyltrimethoxysilane (silicon-containing additive) and 0.03% by weight were added to the total polyamic acid solution prepared above. Triphenyl phosphate (TPP), a phosphorus-based additive, was added and stirred at room temperature for 12 hours to prepare a polyimide precursor.

In addition, the polyimide precursor was heat-cured from 100°C to 460°C at a temperature increase rate of 5°C/min to prepare a polyimide film with a thickness of 10 μm.

Examples 2 to 4

A polyimide precursor was prepared in the same manner as in Example 1, except that the composition shown in Table 1 below was used.

Comparative Examples 1 to 5

A polyamic acid solution was prepared in the same manner as in Example 1, except that the composition shown in Table 1 below was used.

division diamine
(mol%)(PPD) Dianhydride (mol%) (BDPA) Silicon-containing additives
(weight%) phosphorus additive
(weight%) menstruum Example 1 100 100 0.01 0.03 DMPA Example 2 100 100 0.01 0.05 DMPA Example 3 100 100 0.01 0.08 DMPA Example 4 100 100 0.01 0.10 DMPA Comparative Example 1 100 100 - - NMP Comparative Example 2 100 100 - - DMPA Comparative Example 3 100 100 0.01 - DMPA Comparative Example 4 100 100 - 1.0 DMPA Comparative Example 5 100 100 - 0.5 DMPA PPD: 1,4-diaminobenzene
BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride
DMPA: N,N-dimethylpropionamide
NMP: N-methyl-2-pyrrolidone

Experimental Example 1 - Surface Flatness

The surface of the polyimide film prepared in Examples and Comparative Examples was visually observed to determine whether bubbles were generated to evaluate surface flatness, and the results are shown in Table 2 according to the criteria below.

O: No bubbles generated (excellent surface flatness)

△: Few bubbles (normal surface flatness)

X: Many bubbles are generated (poor surface flatness)

Experimental Example 2- 1% thermal decomposition temperature (1% Td)

TA's thermogravimetric analysis Q50 model was used, and the polyimide film was heated to 150°C at a rate of 10°C/min under a nitrogen atmosphere and then maintained isothermally for 30 minutes to remove moisture. Afterwards, the temperature was raised to 600°C at a rate of 10°C/min to measure the temperature at which 1% weight loss occurred, and the results are shown in Table 2 below.

Experimental Example 3- Adhesion

The adhesion of the polyimide films prepared in Examples and Comparative Examples to polyimide-coated substrates was measured.

The adhesive strength was measured on a polyimide substrate and polyimide film of 100x10mm in size using INSTRON's UTM 5546 model at ^90o Peel mode and Cross Head Speed of 50mm/min.

nine Example
Comparative example
division One 2 3 4 One 2 3 4 5 Exterior ○ ○ ○ ○ ○ x ○ △ △ 1%TD(℃) 574 575 574 576 570 563 563 575 569 Adhesion (N/cm) 0.08 0.07 0.07 0.06 0.10 0.03 0.11 0.04 0.04

As shown in Table 2, the examples including silicon-containing additives and phosphorus-based additives were confirmed to have excellent appearance (excellent surface flatness) without bubbles, and also showed high adhesion.

On the other hand, NMP in Comparative Example 1 was classified as a hazardous substance, so additional costs were required for purification, and there was a problem of causing environmental pollution during the processing process.

In addition, in Comparative Example 2, which used DMPA as an organic solvent but did not include silicon-containing additives or phosphorus-based additives, it was confirmed that bubbles were generated and the appearance was not excellent (surface flatness was average or poor), and the adhesion was also improved by silicon-containing additives. and it was confirmed that it was inferior to the examples containing phosphorus additives.

On the other hand, in the case of Comparative Example 3, which included only silicon-containing additives and no phosphorus-based additives, the adhesion was excellent, but the thermal decomposition temperature was confirmed to be 1% lower than the examples including phosphorus-based additives due to the low imidization rate. It was confirmed that Comparative Examples 4 and 5, which further included a phosphorus-based additive, had a higher 1% thermal decomposition temperature than Comparative Example 2, which did not contain either a silicon-containing additive or a phosphorus-based additive due to the high imidization rate.

The higher the 1% pyrolysis temperature, the better the durability. Therefore, from the above results, it was confirmed that the phosphorus-based additive had a superior effect on improving the durability of polyimide compared to the silicon-containing additive.

Claims (16)

Polyamic acid containing dianhydride monomer and diamine monomer as polymerized units;
N,N-diethylacetamide (DEAc), N,N-diethylformamide (DEF), N-ethylpyrrolidone (NEP), An organic solvent containing at least one selected from the group consisting of dimethylpropionamide (DMPA) and diethylpropionamide (DEPA);
A silicon-containing additive containing at least one functional group; and
A polyimide precursor containing a phosphorus-based additive having an aromatic ring group. The polyimide precursor of claim 1, wherein the organic solvent is N,N-dimethylpropionamide (DMPA). The polyimide precursor of claim 1, wherein the content of the silicon-containing additive is 0.0001 to 1% by weight based on the total polyimide precursor. The polyimide precursor according to claim 1, wherein the functional group of the silicon-containing additive is an amine group, carboxyl group, alcohol, alkoxy group, mercapto group, epoxy group, or isocyanate. The polyimide precursor according to claim 1, wherein the content of the phosphorus-based additive is 0.001 to 2% by weight based on the total polyimide precursor. The polyimide precursor according to claim 1, wherein the phosphorus-based additive is triphenylphosphate or triphenylphosphine. The polyimide precursor of claim 1, wherein the dianhydride monomer includes at least one compound represented by the following formula (2):
[Formula 2]

In the above formula (2), It is connected to the ring constituent atoms of a cyclic group, aromatic ring group, or heteroaromatic ring group,
The aliphatic ring group, the heteroaliphatic ring group, the aromatic ring group, or the heteroaromatic ring group
is a monocyclic ring;
conjugated to each other to form a polycyclic ring; or
Single bond, substituted or unsubstituted alkylene group, substituted or unsubstituted alkylidene group, substituted or unsubstituted alkenylene group, substituted or unsubstituted alkynylene group, substituted or unsubstituted arylene group, -O-, are connected by a linking group containing one or more divalent substituents selected from the group consisting of -S-, -C(=O)-, -S(=O) ₂ - and -Si(R _b ) _2- , where R _b is hydrogen or an alkyl group. According to claim 7,
Wherein X is phenyl, biphenyl, or an aliphatic ring group,
Wherein M is a polyethylene containing at least one of the group consisting of a single bond, an alkylene group, an alkylidene group, -O-, -S-, -C(=O)-, and -S(=O) ₂ -. Mead precursor. The polyimide precursor of claim 7, wherein the compound represented by Formula 2 includes 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA). The polyimide precursor of claim 1, wherein the diamine monomer includes at least one compound represented by the following formula (3):
[Formula 3]

In Formula 3, any one of B ₁ to B ₅ is an amino group, and the others are hydrogen; halogen; hydroxyl group; Carboxyl group; Or it represents an alkyl group substituted or unsubstituted with halogen. The polyimide precursor of claim 10, wherein the compound represented by Formula 3 includes 1,4-diaminobenzene (PPD). N,N-diethylacetamide (DEAc), N,N-diethylformamide (DEF), N-ethylpyrrolidone (NEP), A polymerization step of preparing polyamic acid by polymerizing a dianhydride monomer and a diamine monomer in an organic solvent containing at least one selected from the group consisting of dimethylpropionamide (DMPA) and diethylpropionamide (DEPA). ; and
A method for producing a polyimide precursor, comprising the step of preparing a polyimide precursor by mixing the prepared polyamic acid with a silicon-containing additive containing at least one functional group and a phosphorus-based additive having an aromatic ring group. A polyimide film comprising a cured product of the polyimide precursor of claim 1. The polyimide film according to claim 13, wherein the thickness is in the range of 1 to 100㎛. 14. The polyimide film according to claim 13, wherein the adhesive force to the polyimide substrate is in the range of 0.05 to 0.5 N/cm. The polyimide film according to claim 13, wherein the 1% thermal decomposition temperature (td) is in the range of 300 to 600°C.