KR20230001765A - Aqueous polyamic acid composition - Google Patents

Abstract

The present application provides an aqueous polyamic acid composition capable of polymerizing polyamic acid in water rather than an organic solvent by using a water-based catalyst having a small amount of polydentate structure and performing imidization into polyimide having an amorphous structure during curing.

Description

Polyamic acid aqueous solution composition {AQUEOUS POLYAMIC ACID COMPOSITION}

The present application relates to a polyamic acid aqueous solution composition, a method for preparing polyamic acid, and a method for preparing polyimide.

With the advent of the 5G mobile communication and Internet of Things (IoT) era, multifunctional, miniaturized, and highly integrated functional materials are required, and polyimide polymers are attracting attention as highly heat-resistant materials for electrical and electronic applications.

Polyimide is a polymer with high thermal stability. It has excellent mechanical strength, chemical resistance, weather resistance, and heat resistance as a material, and has physical property stability in a wide range of temperatures (-273 ℃ ~ 400 ℃). In particular, it has electrical insulation, flexibility, and incombustibility, so its use in the electronic and optical fields is increasing.

Typically, polyimide synthesis is obtained by dehydration of polyamic acid obtained by condensation polymerization of aromatic dianhydride and aromatic diamine in an organic solvent. This synthesis process may not be easy to synthesize due to the hydrolysis of aromatic dianhydride, which is vulnerable to moisture, during condensation polymerization in a solvent. As a result, polyamic acid synthesized in an organic system is a major problem in controlling the crosslinking reaction by molecular weight control and initial rapid reaction, and the contamination problem of the organic solvent used and the expensive treatment cost problem to solve it are still problems to be solved. .

In addition, polyimide has a crystal structure, and this crystal structure has a problem of deteriorating the uniformity of insulating and dielectric properties of the film.

The present application provides an aqueous polyamic acid composition capable of polymerizing polyamic acid in water rather than an organic solvent using an aqueous catalyst having a small amount of polydentate structure, and providing polyimide having an amorphous structure upon curing.

This application relates to a polyamic acid aqueous solution composition. More specifically, the present application relates to an aqueous polyamic acid composition capable of being polymerized in water (water-based polymerization) and providing a polyimide having an amorphous structure upon curing.

An exemplary aqueous polyamic acid composition may include a polyamic acid containing a diamine monomer and a dianhydride monomer as polymerized units; and an aqueous catalyst, wherein the cured product is an amorphous polymer. In this application, an aqueous solution composition means a composition containing water as a solvent, and other solvents are not allowed. The cured material may be polyimide. Polyimide having such an amorphous structure (or amorphous structure) has an advantage of improving the uniformity of insulating and dielectric properties of a film compared to polyimide having a general crystalline structure.

In the present specification, an amorphous polymer means one that does not have a crystalline structure and has the characteristics of an XRD pattern described below.

For example, an XRD pattern of a cured product may have an amorphous peak at 2θ=21°. On the other hand, the XRD pattern of the cured product does not have crystalline peaks at 2θ=19.3° and 2θ=25.4°. The XRD pattern can be measured by various known devices and methods, and is not particularly limited.

The water-based catalyst may have a polydentate structure in which at least two or more tertiary amines are connected with aliphatic or aromatic hydrocarbons. As the present application uses a water-based catalyst having a polydentate structure in which at least two or more tertiary amines are connected by aliphatic or aromatic hydrocarbons, uniform polymerization of polyamic acid in water is possible. On the other hand, when one tertiary amine, for example, an aliphatic tertiary amine such as triethylamine (TEA) is used as a water-based catalyst, it may be difficult to synthesize polyamic acid.

Specifically, the water-based catalyst is a polyamic acid aqueous solution composition comprising at least one or more of the compounds represented by Formulas 1 to 4:

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

The R ₁ to R ₆ are each independently an alkyl group having 1 to 4 carbon atoms;

A ₁ to A ₃ are each independently an oxygen, a carbonyl group, an alkylcarbonyl group, an alkyl group, an alkylene group, or an alkylidene group. The alkylene group or alkylidene group may be unsubstituted or substituted with at least one substituent. The substituent may be, for example, an alkyl group, an alkenyl group or an alkynyl group, but is not limited thereto. The alkyl group, alkenyl group or alkynyl group may be straight chain, branched chain or cyclic, and may have 1 to 30 carbon atoms or 1 to 10 carbon atoms. The lower limit of the number of carbon atoms may be 1, 2, 3, or 4, and the upper limit may be 30, 25, 20, 15, 10, or 8 or less.

In this specification, the term "alkyl group", unless otherwise specified, has 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.

In this specification, the term "alkenyl group", unless otherwise specified, has 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. 4 may mean an alkenyl group. 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.

In this specification, the term "alkynyl group", unless otherwise specified, has 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. 4 may mean an alkynyl group. 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.

In this specification, the term "alkylene group", unless otherwise specified, has 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 an alkylene group of 2 to 8. The alkylene 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.

In this specification, the term "alkylidene group", unless otherwise specified, has 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 It may mean an alkylidene group having 2 to 8 carbon atoms. The alkylidene 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.

The composition of the present application may be made of polyimide having an amorphous structure upon curing by using at least one compound of Chemical Formulas 1 to 4 as an aqueous catalyst as described above.

In the specific example of the present application, the water-based catalyst may be within the range of 0.5 to 2.0 times the equivalent of 1 equivalent of the carboxyl group in the polyamic acid. In one example, the water-based catalyst may be 0.55-fold equivalent or more, 0.6-fold equivalent or more, 0.7-fold equivalent or more, 0.8-fold equivalent or more, 0.83-fold equivalent or more, or 0.93-fold equivalent or more with respect to 1 equivalent of the carboxyl group in the polyamic acid, In addition, the upper limit is 1.9 times equivalent or less, 1.8 times equivalent or less, 1.7 times equivalent or less, 1.6 times equivalent or less, 1.5 times equivalent or less, 1.4 times equivalent or less, 1.3 times equivalent or less, 1.2 times equivalent or less, 1.15 times equivalent or less, or 1.05 times. It may be less than twice the equivalent.

In the present specification, "equivalent to carboxyl group in polyamic acid", which defines the amount of water-based catalyst, may mean the number (moles) of water-based catalyst or metal ion used for one carboxyl group in polyamic acid.

In one specific example, the polyamic acid composition may include 1 to 50% by weight of the solid content based on the total weight, for example, 1 to 45% by weight, 1 to 40% by weight, or 1 to 35% by weight. can do. In the present application, by controlling the solid content of the polyamic acid composition, it is possible to prevent an increase in manufacturing cost and process time in which a large amount of solvent must be removed during a curing process while controlling an increase in viscosity.

The aqueous polyamic acid composition of the present application is a composition subjected to water-based polymerization, and may not substantially contain an organic solvent. In the present specification, substantially not included may mean that the organic solvent is included in less than 5% by weight, less than 3% by weight, less than 1% by weight, or 0% to 0.5% by weight. A water-based polymerizable polyamic acid composition may be advantageous in terms of process and environment.

In this specification, the terms polyamic acid composition, polyamic acid solution, polyamic acid aqueous solution composition, and polyimide precursor composition may be used in the same meaning. Also, in this specification, the terms curing and imidization may be used in the same meaning.

The dianhydride monomer that can be used for preparing the polyamic acid solution may be an aromatic tetracarboxylic dianhydride. For example, the dianhydride monomer includes at least one compound represented by Formula 5 below.

[Formula 5]

또는 알릭사이클릭이고,Wherein X is phenyl, biphenyl,

or an aliccyclic;

Wherein M includes at least one from the group containing a single bond, an alkylene group, an alkylidene group, a carbonyl group, an alkylcarbonyl group, an alkoxy group, and a sulfonyl group, and M is at least one from the group containing fluorine and an alkyl group. It is unsubstituted or substituted with one or more. M in Formula 5 may be an alkylene group having at least one fluorine-substituted alkyl group as a substituent. As an example, an alkyl group having 1 to 6 carbon atoms substituted with at least one fluorine may be a perfluoroalkyl group, specifically, a perfluoromethyl group. In another example, the dianhydride monomer component may include at least one dianhydride monomer substituted with at least one fluorine.

In this specification, the term "single bond" may mean a bond connecting both atoms without any atoms. For example, when M in Formula 5 is a single bond, both aromatic rings may be directly connected to each other.

The aromatic tetracarboxylic dianhydride satisfying Formula 5 is 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 ric 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 diane Hydride, 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-dicarboxy Phenoxy) phenyl] propane dianhydride (BPADA), 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4' -(2,2-hexafluoroisopropylidene) diphthalic acid dianhydride (6-FDA), etc. are exemplified.

The dianhydride monomers may be used alone or in combination of two or more, if necessary, but the present application considers bond dissociation energy, for example, pyromellitic dianhydride (PMDA), 3,3' , 4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) or 2,3,3', 4'-biphenyltetracarboxylic dianhydride (a-BPDA) may be included. .

In addition, the diamine monomers that can be used in preparing the polyamic acid solution are aromatic diamines, and can be classified and exemplified as follows.

1) 1,4-diaminobenzene (or para-phenylenediamine, PDA), 1,3-diaminobenzene, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,5-diaminobenzo diamines having a relatively rigid structure as diamines having one benzene nucleus in structure, such as acid acid (or DABA);

2) 4,4'-diaminodiphenyl ether (or oxydianiline, ODA), diaminodiphenyl ether such as 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' -Diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone , 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'-diaminodiphenylsulfoxide, 3,4'-diaminodi diamines having two benzene nuclei in their structure, such as phenyl sulfoxide, 4,4'-diaminodiphenyl sulfoxide and the like;

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-aminophenylsulfide)benzene, 1,3-bis(4-aminophenylsulfide) Benzene, 1,4-bis(4-aminophenylsulfide)benzene, 1,3-bis(3-aminophenylsulfone)benzene, 1,3-bis(4-aminophenylsulfone)benzene, 1,4-bis( 4-aminophenylsulfone)benzene, 1,3-bis[2-(4-aminophenyl)isopropyl]benzene, 1,4-bis[2-(3-aminophenyl)isopropyl]benzene, 1,4- diamines having three benzene nuclei in their 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-aminophenoxy) 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, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, etc. A diamine with four phase benzene nuclei.

The said diamine monomer can be used individually or in combination of 2 or more types as needed.

The polyamic acid composition of the present application may be a composition having low viscosity. The polyamic acid composition of the present application may have a viscosity of 20,000 cps or less, 10,000 cps or less, or 6,000 cps or less when measured under conditions of a temperature of 25 °C and a shear rate of 30 s ^-1 . The lower limit is not particularly limited, but may be 10 cps or more, 15 cps or more, 30 cps or more, 100 cps or more, 300 cps or more, 500 cps or more, or 1000 cps or more. The viscosity may be measured using, for example, Haake's VT-550, and may be measured under conditions of a shear rate of 30/s, a temperature of 25°C, and a plate gap of 1 mm. The present application can provide a precursor composition having excellent processability by adjusting the above viscosity range.

In one example, the polyamic acid composition may have a logarithmic viscosity of 0.1 or more or 0.2 or more measured at a temperature of 30° C. and a concentration of 0.5 g/100 mL (dissolved in water) based on its solid content concentration. The upper limit is not particularly limited, but may be 5 or less, 3 or less, or 2.5 or less. In the present application, by adjusting the logarithmic viscosity, an appropriate amount of polyamic acid molecular weight can be controlled and fairness can be secured.

In one embodiment, the polyamic acid composition of the present application has a weight average molecular weight after curing of 10,000 to 200,000 g/mol, 15,000 to 80,000 g/mol, 18,000 to 70,000 g/mol, 20,000 to 60,000 g/mol, 25,000 to 55,000 g /mol or within the range of 30,000 to 50,000 g/mol. In this application, the term weight average molecular weight means a value in terms of standard polystyrene measured by gel permeation chromatograph (GPC).

When the aqueous polyamic acid composition of the present application is prepared as a cured product, the cured product may exhibit excellent physical properties such as mechanical strength and heat resistance by satisfying various physical properties described below. In the present application, the cured product of the polyamic acid aqueous solution composition means polyimide.

In one example, the cured product of the aqueous polyamic acid composition has a tensile elongation of 15 to 50%, 15 to 45%, 15 to 40%, 15 to 35%, 20 to 50%, 20 to 45% according to ASTM D882, It may be in the range of 20 to 40% or 20 to 35%. As the cured product of the present application has an amorphous structure, tensile elongation is adjusted to the above range, and thus exhibits excellent mechanical properties.

In addition, the cured product of the polyamic acid aqueous solution composition has a 5% thermal decomposition temperature (Td) of 450 to 700 ℃, 500 to 700 ℃, 550 to 700 ℃ measured using a thermogravimetric analyzer (TGA, TA instrument 2950, USA) or within the range of 600 to 700 °C.

In addition, the cured product of the polyamic acid aqueous solution composition may have a coefficient of thermal expansion (CTE) measured using a mechanical analysis method (TMA, TA Instrument Co.) in the range of 1 to 15 ppm/°C. The lower limit of the thermal expansion coefficient may be, for example, 1 ppm/°C or more, 2 ppm/°C or more, 3 ppm/°C or more, 4 ppm/°C or more, 5 ppm/°C or more, or 6 ppm/°C or more. And the upper limit of the thermal expansion coefficient may be, for example, 14 ppm/°C or less, 13 ppm/°C or less, 12 ppm/°C or less, 11 ppm/°C or less, or 10 ppm/°C or less.

In another example, the cured product of the polyamic acid aqueous solution composition may have a dielectric constant of 3 to 3.5. For example, the lower limit of the permittivity may be 3.05 or more, 3.1 or more, 3.15 or more, or 3.2 or more, and the upper limit of the permittivity may be 3.45 or less, 3.4 or less, 3.35 or 3.3 or less.

This application also relates to a method for producing a polyamic acid. In one example, the method for preparing the aqueous polyamic acid composition may include preparing polyamic acid using an aqueous catalyst having a polydentate structure in which at least two or more tertiary amines are linked with aliphatic or aromatic hydrocarbons. The production method of the present application can prepare polyamic acid imidized with polyimide having an amorphous structure and water-based polymerization by using the water-based catalyst. A detailed description of the water-based catalyst is omitted because it overlaps with the above description.

This application relates to a method for producing polyimide. The polyimide production method includes preparing polyamic acid using an aqueous catalyst having a polydentate structure in which at least two or more tertiary amines are connected by aliphatic or aromatic hydrocarbons; and preparing polyimide by thermally curing the polyamic acid at 200° C. or higher. For example, the above step may be thermally cured at 350° C. or less. The production method of the present application may provide amorphous polyimide by thermally curing polyamic acid prepared using a water-based catalyst having a specific structure.

This application also relates to polyimides. The polyimide may be derived from the above-described polyamic acid aqueous solution composition. As the polyimide has an amorphous structure, the cured product has uniform insulation and dielectric properties, and thus can be applied to various materials for electric and electronic applications.

The polyamic acid aqueous solution composition according to the present application can polymerize the polyamic acid in water instead of an organic solvent using an aqueous catalyst having a small amount of polydentate structure, and can provide polyimide having an amorphous structure upon curing.

1 is a polyimide XRD pattern graph for Examples 1 and 4 and Comparative Examples 1 and 2.
Figure 2 is a graph of the solution viscosity measurement results for Examples 1 and 4 and Comparative Examples 1 and 2.
3 is a graph of tensile elongation measurement results for Examples 1 and 4 and Comparative Examples 1 and 2.
4 is a graph of 5% thermal decomposition temperature measurement results for Examples 1 and 4 and Comparative Examples 1 and 2.
5 and 6 are graphs of thermal expansion coefficient measurement results for Examples 1 and 4 and Comparative Examples 1 and 2.
7 is a graph of permittivity measurement results for Examples 1 and 4 and Comparative Examples 1 and 2.

Hereinafter, the present application will be described in more detail through examples according to the present application, but the scope of the present application is not limited to the examples to be presented below.

Example 1

65 g of distilled water was added as a solvent to a reactor equipped with a temperature controller and filled with nitrogen. After adding 1.0814 g (0.01 mol) of p-phenylenediamine (pPDA) and 3.2557 g (2.5 equivalents compared to the carboxyl group) of N, N, N ', N'-tetramethyl-1,3-propane diamine, the mixture was heated at 25 ° C. The mixture was dissolved using a mechanical stirrer for 1 hour. Thereafter, 2.9422 g (0.01 mol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) was added, and the mixture was stirred at 70°C for 18 hours to effect polymerization. Proceeding to prepare a water-soluble polyamic acid.

Thereafter, the obtained polyamic acid was cast on a glass substrate with a bar coater, and after defoaming and drying for 2 hours at 25° C. in a vacuum oven, thermal curing was performed at 300° C. to 350° C. for 30 minutes to prepare a polyimide film having a thickness of 25 μm. did

Hereinafter, polyamic acid aqueous solution compositions and polyimide films of various Examples and Comparative Examples were prepared in the same manner as in Example 1 according to the compositions shown in Table 1.

[Table 1]

Comparative Example 1 is an example in which polyamic acid was polymerized in an organic solvent, Comparative Example 2 was synthesized in the presence of a high content of a water-based catalyst, and Comparative Example 3 was not polymerized with polyamic acid. On the other hand, in Examples 2 to 12, it was confirmed that the aqueous polymerization of polyamic acid was carried out even with a small amount of the aqueous catalyst.

In addition, the solid content of the polyamic acid composition prepared in the above Examples and Comparative Examples was 10wt%, and for these, the physical properties of the composition and the film were evaluated in the experimental example of the following method, and the results are shown in Table 1 .

Additionally, FIG. 1 is a polyimide XRD pattern graph for Examples 1 and 4 and Comparative Examples 1 and 2. Referring to FIG. 1, it was confirmed that the amorphous peak 2θ = 21 ° was observed in the polyimide XRD patterns of Examples 1 and 4, whereas the crystalline peaks 2θ = 19.3 ° and 2θ = 25.4 ° were not observed. . This suggests that the polyimide films of Examples 1 and 4 have an amorphous structure. On the other hand, crystalline peaks were observed in Comparative Examples 1 and 2, suggesting that the polyimide films of Comparative Examples 1 and 2 had a crystalline structure.

1. Solution Viscosity Measurement

The polyamic acid compositions prepared in Examples and Comparative Examples were measured under conditions of a shear rate of 30/s, a temperature of 25° C., and a plate gap of 1 mm using Haake's VT-550. Additionally, Figure 2 is a graph of the solution viscosity measurement results for Examples 1 and 4 and Comparative Examples 1 and 2.

2. Logarithmic Viscosity

The polyamic acid compositions prepared in Examples and Comparative Examples were diluted to a concentration of 0.5 g/dl (solvent: water) based on the solid content concentration. The flow time (T ₁ ) of the diluent was determined using a Cannon-Fenske viscometer No. 30 at 30 °C. It was measured using 100. The logarithmic viscosity was calculated by the following formula using the flow time (T ₀ ) of the blank water.

Logarithmic viscosity = {ln(T ₁ /T ₀ )}/0.5

3. Tensile Elongation

After cutting the polyimide film into a width of 10 mm and a length of 70 mm, modulus and tensile strength were measured using an Instron 5564 UTM device by the ASTM D-882 method. Cross head speed at this time was measured under the condition of 5 mm/min. Additionally, Figure 3 is a graph of the tensile elongation measurement results for Examples 1 and 4 and Comparative Examples 1 and 2.

4. 5% pyrolysis temperature

TA's thermogravimetric analysis Q50 model was used, and the polyimide film was heated up to 800 °C at a nitrogen rate of 10 °C/min, and the temperature at which a weight loss of 5% occurred was measured.

Additionally, FIG. 4 is a graph of 5% thermal decomposition temperature measurement results for Examples 1 and 4 and Comparative Examples 1 and 2.

5. Coefficient of thermal expansion

It was measured using a thermomechanical analysis method (TMA, Perkin Elmer Co., Ltd.), the measurement temperature range was 50 ~ 250 ° C, the temperature increase rate was 5 ° C / min, and the film pulling force was set to 0.05 N. Additionally, FIGS. 5 and 6 are graphs of 5% thermal expansion coefficient measurement results for Examples 1 and 4 and Comparative Examples 1 and 2. In detail, FIG. 5 is a graph showing the result of quantitatively measuring length change with respect to temperature change. FIG. 6 is a result value calculated as an average slope of the 50-250° C. section of FIG. 5 as a coefficient of thermal expansion (CTE).

6. Permittivity

MIN (metal-insulator-metal) capacitors are fabricated by aluminum deposition on both sides of polyimide film. After measuring the capacitance and dielectric loss (tanδ) according to the frequency change from 20 Hz to 2 MHz using an LCR-meter (Agilent E4980A, USA) from the manufactured MIM capacitor, the dielectric constant was calculated using the following formula got the value

[formula]

는 필름 주변 유전 상수이며,

는 필름 유전 상수이고, A는 알루미늄 증착 면적이며, d는 필름 두께이다. 도 7은 실시예 1, 4 비교예 1, 2에 대한 유전율 측정 결과 그래프이다. 도 7은 상기 계산식의 변수에 아래 수치를 각각 대입하여 측정한 결과이다.In the above calculation formula, C is the capacitor capacitance,

is the dielectric constant around the film,

is the film dielectric constant, A is the aluminum deposition area, and d is the film thickness. 7 is a graph of permittivity measurement results for Examples 1 and 4 and Comparative Examples 1 and 2. 7 is a measurement result by substituting the following values into the variables of the above formula.

=8.854 ⅹ10^-12 F/m

=8.854 ⅹ10 ^-12 F/m

d = 40 to 55 µm

A = 210 to 240 mm ²

Claims (13)

Polyamic acid containing a diamine monomer and a dianhydride monomer as polymerized units; and an aqueous catalyst;
A polyamic acid aqueous solution composition wherein the cured product is an amorphous polymer. The aqueous polyamic acid composition according to claim 1, wherein the XRD pattern of the cured product has an amorphous peak at 2θ=21°. The polyamic acid aqueous solution composition according to claim 1, wherein the XRD pattern of the cured product does not have crystalline peaks at 2θ = 19.3 ° and 2θ = 25.4 °. The aqueous polyamic acid composition according to claim 1, wherein the aqueous catalyst comprises at least one of the compounds represented by the following Chemical Formulas 1 to 4:
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

The R ₁ to R ₆ are each independently an alkyl group having 1 to 4 carbon atoms;
A ₁ to A ₃ are each independently oxygen, a carbonyl group, an alkylcarbonyl group, an alkyl group, an alkylene group, or an alkylidene group. The aqueous polyamic acid composition according to claim 1, wherein the water-based catalyst is in the range of 0.5 to 2.0 times equivalent to 1 equivalent of the carboxyl group in the polyamic acid. The polyamic acid aqueous solution composition according to claim 1, wherein the dianhydride monomer comprises at least one compound represented by Formula 5 below:
[Formula 5]

Wherein X is phenyl, biphenyl,

or an aliccyclic;
Wherein M includes at least one from the group containing a single bond, an alkylene group, an alkylidene group, a carbonyl group, an alkylcarbonyl group, an alkoxy group, and a sulfonyl group, and M is at least one from the group containing fluorine and an alkyl group. It is unsubstituted or substituted with one or more. [Claim 7] The aqueous solution composition of polyamic acid according to claim 6, wherein M is an alkylene group having at least one fluorine-substituted alkyl group as a substituent. The aqueous solution composition of polyamic acid according to claim 1, wherein the solid content is in the range of 1 to 50% by weight. The aqueous polyamic acid composition according to claim 1, wherein the cured product of the aqueous polyamic acid composition has a tensile elongation in the range of 15 to 50% according to ASTM DD882. The method of claim 1, wherein the cured product of the polyamic acid aqueous solution composition has a 5% thermal decomposition temperature (Td) measured using a thermogravimetric analyzer (TGA, TA instrument 2950, USA) in the range of 450 to 700 ° C., the polyamic acid aqueous solution composition. The polyamic acid aqueous solution composition according to claim 1, wherein the cured product of the polyamic acid aqueous solution composition has a coefficient of thermal expansion (CTE) measured using a mechanical analysis method (TMA, TA instrument) in the range of 1 to 15 ppm/℃. A method for producing polyamic acid, comprising preparing polyamic acid using an aqueous catalyst having a polydentate structure in which at least two or more tertiary amines are linked by aliphatic or aromatic hydrocarbons. preparing a polyamic acid using a water-based catalyst having a polydentate structure in which at least two or more tertiary amines are linked by aliphatic or aromatic hydrocarbons; and
Comprising the step of preparing a polyimide by thermally curing the polyamic acid at 200 ° C. or higher, a polyimide manufacturing method.

Images