KR102164458B1 - Polyimide Film Having Low Permittivity and Low Hygroscopicity And Manufacturing Method thereof - Google Patents

Abstract

The present invention is an aliphatic polyimide resin; Aromatic polyimide resin; And microspheres having pores, wherein the aliphatic polyimide resin includes at least one of a chain aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group, providing a polyimide film.

Description

Polyimide Film Having Low Permittivity and Low Hygroscopicity And Manufacturing Method thereof

The present invention relates to a polyimide film having a low dielectric constant and low hygroscopicity, and a method of manufacturing the same.

In recent years, the introduction of advanced information transmission technology to network these electronic devices along with the high performance and high functionality of computers and communication devices is rapidly progressing, and as part of this, information on such electronic devices or communication devices constituting the network High-frequency signals are in progress for high-speed processing and transmission technology according to an increase in transmission amount.

Conventionally, high-frequency signals of 1 MHz or higher have been mainly used for limited wireless communication purposes such as aircraft or satellite communication, but recently they are also used in electronic devices such as mobile phones and wireless LANs, and due to the demand for faster operation speed and communication speed, 10 GHz The development of electronic devices for high-speed transmission capable of high-speed communication with the above high-frequency signals has been actively made.

In order to realize such high-frequency, high-speed communication, it is required to overcome the problems of signal delay and transmission loss that occur in components of electronic equipment (eg, high-speed transmission circuit boards) mounted in communication equipment. The signal delay (RC delay) is expressed as the product of the capacitance (C) and the wiring resistance (R) between metal wires, which increases in proportion to the square root of the dielectric constant of the insulator. According to the trend of high integration, there is a problem that the entire signal transmission is further delayed due to propagation delay or crosstalk noise. In addition, transmission loss is divided into conductor loss and dielectric loss, which is proportional to dielectric constant and dielectric loss tangent of an insulator, and tends to increase as the frequency increases.

That is, since the high-frequency characteristics of the electronic device for high-speed transmission are closely related to the dielectric characteristics of the insulating layer, in particular, the use of an insulating material having a very low dielectric constant is required for high-frequency high-speed communication. Conventionally, a substrate made of fluorine resin (PTFE), which is known to have the best high-frequency properties among polymer materials, was standardized in MIL (Military Specifications and Standards) in 1975 and was used for aviation, space, and military purposes. Since it is a thermoplastic resin with a glass transition temperature, it lacks dimensional stability against heat, has poor mechanical strength and thermal conductivity, requires a special plating pretreatment process, and has problems with moldability (high temperature above 350 ℃) and workability. There was.

Therefore, in recent years, the possibility of utilizing polyimide resins for high-speed transmission electronic devices has been studied.

In general, a polyimide resin is a highly heat-resistant resin prepared by solution polymerization of an aromatic dianhydride and an aromatic diamine or an aromatic diisocyanate to prepare a polyamic acid derivative, and then imidization by ring closure dehydration at a high temperature. Together, it is a polymer material that has the highest level of heat resistance, chemical resistance, electrical insulation, chemical resistance, and weather resistance among organic materials based on an imide ring with excellent chemical stability. In particular, the dielectric constant is relatively stable in the entire frequency range. Since it has a high dielectric breakdown voltage, it is in the spotlight as an insulating material for high-speed communication electronic devices.

However, since polyimide itself has a high moisture absorption rate due to the characteristics of the material, there are certain limitations to the expression of low dielectric constant despite the excellent physical properties. To overcome this, in recent years, high performance of polyimide, especially high frequency Research on low dielectric constant and low dielectric loss tangent as corresponding electrical characteristics is being actively conducted.

For example, as an attempt to reduce the dielectric constant of a polyimide resin, an aromatic obtained from an aromatic tetracarboxylic acid component containing biphenyltetracarboxylic acids as main components and an aromatic diamine component in the presence of a surfactant compound having a fluorine atom in the fluorine resin powder. A fluororesin-containing polyimide composition, characterized in that polyimide is uniformly dissolved in an organic polar solvent capable of dissolving the aromatic polyimide, and a method for producing the same have been proposed, but polyimide containing a fluorine-containing surfactant, etc. The dielectric constant and dielectric loss tangent can be reduced to some extent due to the effect of the fluorine-based resin, but surfactants and dispersants containing fluorine generally increase the dielectric constant and dielectric loss tangent, and it is difficult to sufficiently improve the electrical properties. There is a limit.

On the other hand, in order to reduce the dielectric constant, a method for producing a polyimide film in which specific particles are dispersed in a polyimide resin precursor solution and then imidized to obtain a polyimide resin has been proposed. Not only is there a problem, but the polyimide film produced therefrom only exhibits a dielectric constant of 2.5 to 3.0 at 1 GHz, so there is a certain limit to achieving the desired low dielectric constant in a higher frequency band (e.g., 10 GHz or more). There is.

In addition, even if these particles are once dispersed in a solvent, there is a problem in that input and storage stability are poor, such as layer separation from the polyimide resin precursor during storage of the solution due to the difference in specific gravity.

Accordingly, there is a need to develop a polyimide film that has excellent input and storage stability and can realize a low dielectric constant in a higher frequency band than that of a conventional polyimide film.

An object of the present invention is to provide a polyimide film having excellent input and storage stability, and relatively low dielectric constant and moisture absorption coefficient, and a method for manufacturing the same.

According to an aspect of the present invention, a polyimide film is prepared to contain an aliphatic polyimide resin each containing at least one of a chain aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group and microspheres having pores.

In this aspect, the aliphatic polyimide resin can function usefully in suppressing the dielectric constant and hygroscopicity, can implement a polyimide film having a lower dielectric constant through microspheres having pores, and a polyimide having improved input and storage stability A method of manufacturing a film can be provided.

According to another aspect of the present invention, the electronic device for high-speed transmission including the polyimide film may implement high-speed communication at a high frequency of 10 GHz based on a relatively low dielectric constant of the polyimide film.

As a result, according to one aspect of the present invention, the prior problems can be solved.

Accordingly, the present invention has a practical purpose to provide specific examples thereof.

In order to achieve the above object, the present invention,

Aliphatic polyimide resin;

Aromatic polyimide resin; And

It includes microspheres having pores,

The aliphatic polyimide resin may provide a polyimide film including at least one of a chain aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group.

The present invention also,

Polymerizing an aliphatic diamine monomer and an aliphatic dianhydride monomer in an organic polar solvent to prepare an aliphatic polyamic acid solution;

Polymerizing an aromatic diamine monomer and an aromatic dianhydride monomer in an organic polar solvent to prepare an aromatic polyamic acid solution;

Preparing an aliphatic polyamic acid microsphere dispersion by adding microspheres to the aliphatic polyamic acid solution;

Preparing a precursor composition by mixing an aromatic polyamic acid solution with the aliphatic polyamic acid microsphere dispersion; And

A polyimide film comprising the step of preparing a polyimide film in which the polyamic acid precursor is imidized by forming a film on a support and drying the precursor composition to prepare a gel film, followed by heat treatment at a temperature of 200°C to 450°C It can provide a manufacturing method of.

The present invention can also provide an electronic device for high-speed transmission including the polyimide film.

Hereinafter, embodiments of the present invention will be described in more detail in the order of "polyimide film" and "manufacturing method of polyimide film" according to the present invention.

Prior to this, terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

Therefore, the configuration of the embodiments described in the present specification is only one of the most preferred embodiments of the present invention, and does not represent all of the technical spirit of the present invention, and various equivalents and modifications that can replace them at the time of application It should be understood that there may be examples.

In the present specification, expressions in the singular include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise", "include" or "have" are intended to designate the presence of implemented features, numbers, steps, components, or a combination thereof, and one or more other features or It is to be understood that the possibility of the presence or addition of numbers, steps, elements, or combinations thereof is not preliminarily excluded.

In the present specification, "dianhydride (dianhydride)" is intended to include its precursor or derivative, which may not be technically dianhydride, but nevertheless react with diamine to form polyamic acid. And this polyamic acid can be converted back to polyimide.

In the present specification "diamine" is intended to include precursors or derivatives thereof, which may not technically be diamines, but nevertheless will react with dianhydride to form polyamic acid, and this polyamic The acid can be converted back to polyimide.

Where an amount, concentration, or other value or parameter herein is given as an enumeration of a range, a preferred range, or a preferred upper and lower preferred value, any pair of any upper range limits, or It is to be understood that the preferred values and any lower range limits or all ranges that may be formed with preferred values are specifically disclosed. When a range of numerical values is referred to herein, unless stated otherwise, the range is intended to include its endpoints and all integers and fractions within that range. It is intended that the scope of the invention is not limited to the specific values recited when defining the range.

Polyimide film

The polyimide film according to the present invention,

Aliphatic polyimide resin;

Aromatic polyimide resin; And

It includes microspheres having pores,

The aliphatic polyimide resin is characterized in that it contains at least one of a chain aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group.

Here, the aliphatic polyimide resin is derived from an aliphatic polyamic acid in which an aliphatic diamine monomer and an aliphatic dianhydride monomer are polymerized,

The aromatic polyimide resin is derived from an aromatic polyamic acid in which an aromatic diamine monomer and an aromatic dianhydride monomer are polymerized,

It may be prepared by imidizing a precursor composition including the aliphatic polyamic acid, aromatic polyamic acid, and microspheres having pores.

As an example, this polyimide film may have (a) a dielectric constant of 3.0 or less, and (b) a moisture absorption of 1.5% or less at 10 GHz.

In this regard, in the case of the polyimide film according to the present invention that satisfies both the conditions of (a) dielectric constant and (b) moisture absorption rate, it can be used as an insulating film used for high-speed transmission electronic devices, and Even if it is used as an electrical signal transmission circuit that transmits signals at high frequency, signal delay and transmission loss can be minimized based on excellent insulation stability.

Hereinafter, the two conditions will be described in detail.

<Dielectric constant>

Permittivity is an important characteristic value representing the electrical characteristics of a dielectric (or insulator), that is, a non-conductor. Permittivity does not represent the electrical characteristics of DC current, but is directly related to the characteristics of AC current, especially AC electromagnetic waves. It is known.

In an insulator (for example, a polyimide film), the + and-moment components, which are usually scattered in random directions, are aligned according to the alternating current of the electromagnetic field applied from the outside. That is, the moment components change according to the change direction of the electromagnetic field, so that it is possible to propagate the electromagnetic wave inside while being a non-conductor.

The degree to which the moment inside the material reacts sensitively to such changes in the external electromagnetic field can be expressed as the dielectric constant, and the high dielectric constant means that the electric energy is well transferred, so an insulator such as a polyimide film has a dielectric constant. The lower the more preferable.

That is, while a typical polyimide film has a dielectric constant higher than a level capable of maintaining sufficient insulation for high-frequency communication, the polyimide film according to the present invention, as an example, may have a dielectric constant of 3.0 or less at 10 GHz. And, preferably, it may be 2.6 or less, and its lower limit may be at least 2.2. It can be seen that the polyimide film exhibits an ideal dielectric constant as an insulator, considering that the engineering properties of the polyimide film are at the highest level.

On the other hand, even if all conductors are separated from each other, capacitive coupling by an electric field always exists between them, so even if the layers of the multilayer substrate are electrically separated from each other, it is an open circuit for direct current. In reality, it can be seen that a capacitor of a certain value is connected between them.

In this case, the capacitor has a property of lowering the impedance as the frequency of the current or voltage at both ends thereof increases, and the value can be expressed as follows.

-Impedance = 1/(2*π*f*C); Where f is the frequency and C=capacitance.

-C = e*S/d; Where e is the dielectric constant, S is the area of the conductor, and d is the distance.

In general, at a scale that can be seen and handled with bare hands, it is difficult for the capacitance value (farad) between the two conductors to deviate from the pico unit no matter how close they are, and the C between layers is similar to the general PCB. Because it is so small, insulation between layers can be maintained even if the circuit operates at a certain high frequency, but in the case of a high-speed transmission electronic device operating at a high frequency of 10 GHz or higher, for example, a GIGA unit frequency, as in the above equation. Insulation may be difficult to maintain because impedance is very low due to high frequency values. When selecting an insulator, use a material with a low dielectric constant, that is, a material with a low dielectric constant, to minimize electrostatic coupling and capacitance (i.e., impedance). shall.

Accordingly, the polyimide film according to the present invention has a relatively low dielectric constant as described above by containing an aliphatic polyimide resin and microspheres having pores. Specifically, the aliphatic polyimide resin has a very low dielectric constant, since the probability of forming a specific gravity, molecular density, polarity, and charge transfer complex is lower than that of an aromatic polyimide resin, and microspheres having pores have a very low dielectric constant. The dielectric constant can be further reduced by using the electrical characteristics.

Accordingly, the polyimide film of the present invention has the advantage of being easy to maintain insulation even in electronic devices for high-speed transmission that operate at a frequency of a giga (GIGA) unit, for example, a high frequency of 10 GHz or more.

<Moisture absorption rate>

The moisture absorption rate is a ratio showing the amount of moisture absorbed by the material. In general, it is known that the dielectric constant increases when the moisture absorption rate is high, and water has a dielectric constant of 100 or more when it is in a solid state, about 80 when it is in a liquid state, and 1.0059 when it is in a gaseous state.

Accordingly, water in the vapor state of the polyimide film does not substantially affect the dielectric constant of the polyimide film, but when water is absorbed in the polyimide film in a liquid state, the dielectric constant may increase dramatically. That is, even with only a small amount of moisture absorption, there is a concern that the dielectric constant of the polyimide film is rapidly changed and the dielectric constant is remarkably increased.

Therefore, it can be seen that the low moisture absorption rate is a physical property that is necessarily required for the polyimide film to be used as an insulating film.

As an example, the polyimide film according to the present invention has a moisture absorption rate of 1.5% or less, and its lower limit may be at least 0.8, the achievement of which is due to the constitutional characteristics of the polyimide film according to the present invention.

This will be described in more detail later, but due to the fact that the polyimide film according to the present invention contains an aliphatic polyimide resin containing at least one of a non-polar chain aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group in its molecular structure. Is predicted.

As described above, since the polyimide film according to the present invention satisfies all of the above two conditions, insulation stability is ensured even at high frequencies, and thus signal delay and transmission loss can be minimized.

This will be demonstrated in more detail through'specific details for carrying out the invention', but it is assumed that the polyimide resin and microspheres exist in the polyimide film in at least one state selected from the following.

(A) a first state in which microspheres are coated on the surface;

(B) a second state in which the microspheres are physically bound to the polymer chain of the polyimide resin;

(C) The third state in which microspheres are chemically bound to the polymer chain of the polyimide resin.

The first state may be a result of inhibiting layer separation by facilitating mixing and/or dispersion of the aliphatic polyamic acid and microspheres. This structure provides an advantage of achieving a low dielectric constant in a high frequency region since pores of the microspheres are evenly dispersed in the polyimide film to uniformly reduce the dielectric constant.

The second state may be that the microspheres are physically entangled with the polymer chain of the polyimide resin. This structure may provide an advantage similar to that of the first state, since the microspheres may be fixed to the polymer chain of the polyimide resin.

Likewise, the third state is that microspheres are chemically bound to at least a part of the polymer chain of the polyimide resin, and may provide an advantage similar to that of the first state or the second state.

Meanwhile, as described above, the aliphatic polyimide resin may include at least one of a chain aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group.

As an example, the chain aliphatic hydrocarbon group C ₁ to C ₃₀ alkyl group, C ₂ to C ₃₀ alkenyl group, C ₂ to C ₃₀ alkynyl group, C ₁ to C ₃₀ alkylene group, C ₂ to C ₃₀ alkenylene group , And C ₂ to C ₃₀ alkynylene group comprising at least one aliphatic organic group selected from the group consisting of,

The cyclic aliphatic hydrocarbon group C ₃ to C ₃₀ cycloalkyl group, C ₃ to C ₃₀ cycloalkenyl group, C ₃ to C ₃₀ cycloalkynyl group, C ₃ to C ₃₀ cycloalkylene group, C ₆ to C ₃₀ cycloalkenylene group , And C ₃ to C ₃₀ It may include at least one alicyclic organic group selected from the group consisting of cycloalkynylene groups.

As an example, the aliphatic diamine monomer containing the chain aliphatic hydrocarbon group or cyclic aliphatic hydrocarbon group is, for example, cyclohexanediamine (CHDA), 1,4-cyclohexanebis(methylamine), 2,2- Bis[(4-aminophenoxy)phenyl]propane (BAPP), 2,2-bis[4-(4-aminophenoxyphenyl)]hexafluoropropane (HFBAPP), 4,4'-methylenebiscyclohexyl Amine (MCA), 4,4'-methylenebis (2-methylcyclohexylamine) (MMCA), 1,3-diaminoadamantane (DAA), 3,3'-diamino-1,1'-dia Damantan (DADA), isophorone diamine, 4,4'-diaminodicyclohexyl methane, 3,3'-dimethyl-4,4'-diamino Dicyclohexyl methane (3,3'-Dimethyl-4,4'-Diaminodicyclohexyl methane) and 3,3',5,5' tetramethyl -4,4'-diaminodicyclohexyl methane (3,3', 5,5'-Tetramethyl-4,4'-diaminodicyclohexyl methane) may be at least one selected from the group consisting of, in detail, may be cyclohexanediamine (CHDA).

More specifically, the cyclohexanediamine (CHDA) is, for example, 1,2-cyclohexanediamine (1,2-Cyclohexanediamine), 1,3-cyclohexanediamine (1,3-Cyclohexanediamine), 1,4 -Cyclohexanediamine (1,4-Cyclohexanediamine), N,N'-dimethyl-1,2-cyclohexanediamine (N,N'-Dimethyl-1,2-Cyclohexanediamine), 4-methyl-1,3-cyclo Hexanediamine (4-Methyl-1,3-Cyclohexanediamine), (1R,2R)-N,N,N',N'-tetramethyl-1,2-cyclohexanediamine ((1R,2R)-N,N ,N',N'-Tetramethyl-1,2-Cyclohexanediamine) and N,N'-dipropyl cyclohexanediamine (N,N'-Dipropyl Cyclohexanediamine) may be at least one selected from the group consisting of.

As described above, the polyimide film of the present invention comprising an aliphatic polyimide resin prepared from a diamine monomer and a dianhydride monomer including at least one of a chain aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group and microspheres is described above. Based on one advantage, it can have low dielectric constant and hygroscopicity even at high frequencies.

However, in spite of the above advantages, it is not preferable to contain too much aliphatic polyimide resin in an amount outside the range limited in the present invention.

Specifically, when the content of the aliphatic polyimide resin is within the range limited in the present invention, the above advantages may be expressed, but if it is out of this, the mechanical strength or heat resistance of the polyimide film may be rapidly deteriorated in terms of physical properties, and In terms of fairness, film forming properties such as surface defects, thermal wrinkles, and poor film forming may be deteriorated in the film forming step.

Accordingly, in the present invention, the aliphatic polyamic acid may be included in an amount of 5 to 30% by weight, specifically 10 to 20% by weight, based on the total weight of the solids of the aliphatic polyamic acid and the aromatic polyamic acid.

If it is less than the above range, the dielectric constant and moisture absorption are not reduced to the desired level, and on the contrary, if it exceeds the above range, fairness such as film forming properties may be degraded due to a low glass transition degree. Can not do it.

Further, the aliphatic polyamic acid may have a viscosity of 2,000 to 20,000 cP, specifically 3,000 to 15,000 cP, and more specifically 5,000 to 10,000 cP.

When the viscosity of the aliphatic polyamic acid is less than the above range, layer separation with microspheres may occur, so it is not preferable in terms of input and storage stability, and on the contrary, when it exceeds the above range, miscibility with microspheres and /Or dispersion may not be easy.

Meanwhile, the microspheres having pores may be included in an amount of 3 to 10% by weight, specifically 5 to 7% by weight, based on the total weight of the solids of the aliphatic polyamic acid and the aromatic polyamic acid.

If it is less than the above range, the voids formed in the polyimide film by microspheres are reduced, so that the electrical properties of the air are not sufficiently implemented, and thus the desired level of low dielectric constant cannot be achieved. If it exceeds, the microspheres may aggregate and cause defects on the film surface, and excessively contained microspheres may negatively affect the mechanical properties of the polyimide film.

As an example, the microspheres may have an average particle diameter of 1 to 20 µm, specifically 10 to 20 µm, and more specifically 16 to 20 µm.

When the average particle diameter is less than the above range, it is very difficult to produce particles having pores, which is not preferable due to poor fairness. On the contrary, when exceeding the above range, it occurs according to the content range of the preceding microspheres. Problems can arise.

Microspheres having such pores may contain, for example, at least one selected from the group consisting of silica, alumina, titania, zeolite, boron oxide, and glass, and in detail, may be borosilicate glass, but limited to this. It does not become.

Meanwhile, the aromatic polyimide resin may be prepared by a polymerization reaction of at least one aromatic diamine monomer and at least one aromatic dianhydride monomer in an organic solvent.

The aromatic diamine monomer is 4-phenylenediamine (PPD), 4,4'-oxydianiline (ODA), 3,4'-oxydianiline, 4,4'-methylenedianiline (MDA), and 1 ,3-bis(4-aminophenoxy)benzene (TPE-R) may be at least any one selected from the group consisting of, these may be used alone or in combination of two or more as desired.

In addition, the aromatic dianhydride monomer is pyromellitic dianhydride (PMDA), biphenyltetracarboxylic dianhydride (BPDA), oxydiphthalic anhydride (ODPA), and benzophenone tetracarboxylic dianhydride. It may be at least any one selected from the group consisting of hydride (BTDA), and these may be used singly or in combination of two or more as desired.

Manufacturing method of polyimide film

The polyimide film of the present invention is obtained from a solution of aliphatic polyamic acid and aromatic polyamic acid, which are precursors of polyimide.

The polyamic acid solution is a diamine monomer and a dianhydride monomer dissolved in an organic solvent in a substantially equimolar amount of a monomer compound and the obtained polyamic acid organic solvent solution under controlled temperature conditions, the aromatic dianhydride monomer and the aromatic diamine It is prepared by stirring until polymerization of the monomer is complete.

As an example, the polyamic acid solution is usually obtained in a concentration of 5 to 35% by weight, preferably 10 to 30% by weight of solid content. In the case of a concentration in this range, the polyamic acid solution obtains an appropriate molecular weight and solution viscosity.

The solvent for synthesizing the polyamic acid solution is not particularly limited, and any solvent may be used as long as it dissolves the polyamic acid, but it is preferably an amide solvent. Specifically, the solvent may be an organic polar solvent, in detail, an aprotic polar solvent, for example, N,N-dimethylformamide (DMF), N,N- It may be at least one selected from the group consisting of dimethylacetamide, N-methyl-pyrrolidone (NMP), gamma butyrolactone (GBL), and Diglyme, but is not limited thereto, and alone or as needed It can be used in combination of two or more.

In one example, the solvent may preferably be any one of N,N-dimethylformamide or N,N-dimethylacetamide.

Accordingly, in order to obtain the polyimide film of the present invention, a production method of preparing an aliphatic polyamic acid and aromatic polyamic acid solution obtained by going through the following steps, and imidizing the solution is preferable.

Thus, the present invention provides a method of manufacturing a polyimide film.

The manufacturing method,

Polymerizing an aliphatic diamine monomer and an aliphatic dianhydride monomer in an organic polar solvent to prepare an aliphatic polyamic acid solution;

Polymerizing an aromatic diamine monomer and an aromatic dianhydride monomer in an organic polar solvent to prepare an aromatic polyamic acid solution;

Preparing an aliphatic polyamic acid microsphere dispersion by adding microspheres to the aliphatic polyamic acid solution;

Preparing a precursor composition by mixing an aromatic polyamic acid solution with the aliphatic polyamic acid microsphere dispersion; And

The precursor composition may be formed on a support and dried to prepare a gel film, followed by heat treatment at a temperature of 200° C. to 450° C. to prepare a polyimide film in which the polyamic acid precursor is imidated.

As an example, the microspheres may be added to the aliphatic polyamic acid solution by blending 3 to 5 times for 5 to 10 minutes at 2,000 to 5,000 RPM at 0 to 10°C.

In the case of the present invention, preparing an aliphatic polyamic acid solution by polymerizing an aliphatic diamine monomer and an aliphatic dianhydride monomer in a solvent, and preparing an aromatic polyamic acid solution by polymerizing an aromatic diamine monomer and an aliphatic dianhydride monomer in a solvent And by mixing the aliphatic polyamic acid solution and the microspheres in advance in the step before the precursor composition production step, the polyimide resin and the microspheres are induced to exist in at least one state selected from the following in the polyimide film to be produced. I can.

(A) a first state in which microspheres are coated on the surface;

(B) a second state in which the microspheres are physically bound to the polymer chain of the polyimide resin;

(C) The third state in which microspheres are chemically bound to the polymer chain of the polyimide resin.

That is, by first mixing the microspheres in a relatively low hygroscopic aliphatic polyamic acid solution, and then mixing the aliphatic polyamic acid microsphere dispersion and the aromatic polyamic acid solution, the microspheres are easily mixed and/or dispersed. Therefore, the microspheres can be uniformly dispersed in the polyimide resin on the basis of excellent input stability, so that the electrical properties of air can be maximized, so that a low dielectric constant of the polyimide film can be achieved even at high frequencies.

In addition, storage stability problems such as layer separation of the aliphatic polyamic acid microsphere dispersion can be solved.

The polyamic acid precursor composition prepared according to the above steps has a molecular structure in which partial chains having different physical properties are connected. By controlling the position and length of the partial chain, and the type and content of the monomers constituting the same, the physical properties of the polyimide film obtained by imidizing the polyamic acid precursor, for example, permittivity, moisture absorption, etc., can be more precisely controlled. have.

Meanwhile, a filler may be added to the "precursor composition manufacturing process" for the purpose of improving various properties of the film such as sliding property, thermal conductivity, conductivity, corona resistance, and loop hardness. The filler to be added is not particularly limited, but preferred examples include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica, and the like.

The particle diameter of the filler is not particularly limited, and can be determined according to the film properties to be modified and the type of filler to be added. In general, the average particle diameter is 0.05 to 20 µm, preferably 0.1 to 10 µm, more preferably 0.1 to 5 µm, and particularly preferably 0.1 to 3 µm.

If the particle diameter is less than this range, the modification effect is difficult to appear, and if it exceeds this range, the surface properties may be greatly impaired or the mechanical properties may be greatly reduced.

Further, the amount of the filler to be added is not particularly limited, and may be determined by the film properties to be modified, the filler particle size, or the like. In general, the amount of the filler added is 0.01 to 10 parts by weight, preferably 0.01 to 5 parts by weight, and more preferably 0.02 to 1 part by weight based on 100 parts by weight of the polyimide resin.

If the amount of the filler added is less than this range, the effect of modifying by the filler is difficult to appear, and if it exceeds this range, the mechanical properties of the film may be greatly impaired. The method of adding the filler is not particularly limited, and any known method may be used.

For a method of imidizing the precursor composition prepared as described above to prepare a polyimide film, a conventionally known method can be used.

Specific methods of such imidization include thermal imidation, chemical imidation, or a complex imidization method in which the thermal imidation and chemical imidation are used in combination, and the following non-limiting examples are given. It will be described in more detail through.

<Thermal imidization method>

The thermal imidation method is a method of inducing an imidation reaction with a heat source such as hot air or an infrared dryer, excluding a chemical catalyst,

Drying the precursor composition to form a gel film; And

Heat treatment of the gel film may include a process of obtaining a polyimide film.

Here, the gel film can be understood as a film intermediate having self-supporting properties in an intermediate step for conversion from polyamic acid to polyimide.

In the process of forming the gel film, the precursor composition is cast in a film form on a support such as a glass plate, an aluminum foil, an endless stainless belt, or a stainless drum, and then the precursor composition on the support is 50°C to 200°C, Specifically, it may be drying at a variable temperature in the range of 80 ℃ to 150 ℃.

Accordingly, a gel film may be formed by partial curing and/or drying of the precursor composition, and a gel film may be obtained by peeling the formed gel film from the support.

In some cases, a process of stretching the gel film may be performed in order to adjust the thickness and size of the polyimide film obtained in the subsequent heat treatment process and improve orientation, and the stretching may be performed in the machine transfer direction (MD) and the machine transfer direction. It may be performed in at least one of the transverse directions TD.

The gel film thus obtained is fixed to a tenter and then heat-treated at a variable temperature ranging from 50° C. to 500° C., specifically 150° C. to 500° C. to remove water, residual solvent, etc. remaining in the gel film, and Almost all of the amic acid groups can be imidized to obtain the polyimide film of the present invention.

In some cases, the polyimide film obtained as described above may be heated and finished at a temperature of 300° C. to 600° C. for 5 seconds to 400 seconds to further cure the polyimide film, and may remain in the obtained polyimide film. It is also possible to do this under a predetermined tension in order to relieve the internal stress.

<Chemical imidization method>

The chemical imidization method is a method of promoting imidization of an amic acid group by adding a dehydrating agent and/or an imidizing agent to the precursor composition.

Here, the "dehydrating agent" means a substance that promotes a ring closure reaction through a dehydration action on polyamic acid, and non-limiting examples thereof include an aliphatic acid anhydride, an aromatic acid anhydride, N,N' -Dialkylcarbodiimide, halogenated lower aliphatic, halogenated lower patty acid anhydride, aryl phosphonic dihalides, and thionyl halides. Among these, aliphatic acid anhydride may be preferable from the viewpoint of availability and cost, and non-limiting examples thereof include acetic anhydride (AA), propion acid anhydride, and lactic acid anhydride. And the like, and these may be used alone or in combination of two or more.

In addition, the term "imidating agent" refers to a substance having an effect of promoting a ring closure reaction with respect to polyamic acid, and is an imine component such as an aliphatic tertiary amine, an aromatic tertiary amine, and a heterocyclic tertiary amine. I can. Among these, a heterocyclic tertiary amine may be preferable from the viewpoint of reactivity as a catalyst. Non-limiting examples of the heterocyclic tertiary amine include quinoline, isoquinoline, β-picoline (BP), pyridine, and the like, and these may be used alone or in combination of two or more.

The amount of the dehydrating agent added is preferably in the range of 0.5 to 5 moles, and particularly preferably in the range of 1.0 to 4 moles per 1 mole of the amic acid group in the polyamic acid. In addition, the amount of the imidizing agent added is preferably within the range of 0.05 to 2 moles, and particularly preferably within the range of 0.2 to 1 mole, per 1 mole of the amic acid group in the polyamic acid.

If the dehydrating agent and the imidizing agent are less than the above ranges, chemical imidization is insufficient, cracks may be formed in the polyimide film to be produced, and the mechanical strength of the film may be reduced. In addition, if the amount of these additions exceeds the above range, imidization may proceed excessively quickly, and in this case, it is difficult to cast into a film or the manufactured polyimide film may exhibit brittle characteristics, which is not preferable. not.

<Complex imidization method>

In connection with the above chemical imidization method, a composite imidization method in which a thermal imidization method is additionally performed can be used for the production of a polyimide film.

Specifically, the composite imidization method includes a chemical imidization process of adding a dehydrating agent and/or an imidizing agent to a precursor composition at a low temperature; And a thermal imidization process of drying the precursor composition to form a gel film and heat-treating the gel film.

When performing the chemical imidization process, the types and amounts of the dehydrating agent and the imidizing agent may be appropriately selected as described in the above chemical imidization method.

In the process of forming the gel film, a precursor composition containing a dehydrating agent and/or an imidizing agent is cast in a film form on a support such as a glass plate, an aluminum foil, an endless stainless belt, or a stainless drum, and then on the support. The precursor composition is dried at a variable temperature ranging from 50°C to 180°C, specifically 80°C to 180°C. In this process, a chemical converting agent and/or an imidizing agent may act as a catalyst to rapidly convert an amic acid group into an imide group.

In some cases, a process of stretching the gel film may be performed in order to adjust the thickness and size of the polyimide film obtained in the subsequent heat treatment process and improve orientation, and the stretching may be performed in the machine transfer direction (MD) and the machine transfer direction. It may be performed in at least one of the transverse directions TD.

The gel film thus obtained is fixed to a tenter and then heat-treated at a variable temperature in the range of 50°C to 700°C, specifically 150°C to 600°C to remove water, catalyst, residual solvent, etc. remaining in the gel film, By imidizing most of the remaining amic acid groups, the polyimide film of the present invention can be obtained. Even in such a heat treatment process, a dehydrating agent and/or an imidizing agent may act as a catalyst to rapidly convert an amic acid group into an imide group, thereby enabling a high imidation rate.

In some cases, the polyimide film may be further cured by heating and finishing the polyimide film obtained as described above at a temperature of 400° C. to 500° C. for 5 seconds to 400 seconds, and the interior may remain in the obtained polyimide film. It is also possible to do this under a certain tension to relieve the stress.

The present invention also provides an electronic device for high-speed transmission comprising the polyimide film.

The electronic device for high-speed transmission may be an electronic device that transmits a signal at a high frequency of at least 2 GHz, specifically, a high frequency of at least 5 GHz, and more particularly, a high frequency of at least 10 GHz.

The electronic device may be, for example, a communication circuit for a portable terminal, a communication circuit for a computer, or a communication circuit for aerospace, but is not limited thereto.

The aliphatic polyamic acid contained in the polyimide film of the present invention can be useful in suppressing the dielectric constant and hygroscopicity, and the microspheres having pores can further reduce the dielectric constant by implementing the electrical properties of air through this. By forming a network with the aliphatic polyamic acid, the microspheres not only improve stability, but also prevent layer separation between the microspheres and the polyimide precursor solution even if the precursor composition solution is stored for a long time.

Therefore, the electronic device for high-speed transmission including the polyimide film according to the present invention can implement high-speed communication at a high frequency of 10 GHz.

The manufacturing method according to the present invention has a substantial advantage in enabling the implementation of the polyimide film described above.

Hereinafter, the functions and effects of the invention will be described in more detail through specific embodiments of the invention. However, these embodiments are only presented as examples of the invention, and the scope of the invention is not determined thereby.

<Experimental Example 1> Evaluation of moisture absorption, dielectric constant, and film forming property of polyimide film

<Example 1-1>

Preparation Example 1-1: Preparation of aliphatic polyamic acid solution

450 g of N,N-dimethylacetylamide (DMAc) as a polar solvent was added to a 1 L reactor under a nitrogen atmosphere.

Then, after setting the temperature in the reactor to 25° C., 16.87 g of 1,3-cyclohexanediamine (CHDA) as an aliphatic diamine monomer was added and stirred for about 30 minutes to confirm that the diamine monomer was dissolved in the solvent. As an aliphatic dianhydride monomer, 1, 2,4,5-cyclohexanetetracarboxylicdianhydride (HPMDA) 33.13 g was dividedly added, and the amount was finally adjusted so that the viscosity became 5,000 cP to 10,000 cP.

After the addition was completed, an aliphatic polyamic acid solution polymerized to a final viscosity of 8,000 CP was prepared by stirring for 1 hour while maintaining the temperature.

Preparation Example 1-2: Preparation of aliphatic polyamic acid microsphere dispersion

60 g of the aliphatic polyamic acid solution prepared in Preparation Example 1-1 and borosilicate glass (manufactured by 3M, brand name Scotchlite) having an average particle diameter of 16 μm as microspheres having pores 42 g of 10% crude solution and N for concentration control , 0.2 g of N-dimethylformamide (DMF) was added to a 1 L reactor, followed by high-speed stirring at 10° C. for 5 minutes at 2500 RPM for 5 minutes to prepare an aliphatic polyamic acid microsphere dispersion.

Preparation Example 1-3: Preparation of aromatic polyamic acid solution

425 g of N,N-dimethylformamide (DMF) as a polar solvent was added to a 1 L reactor under a nitrogen atmosphere.

Subsequently, after setting the temperature in the reactor to 25° C., 12.41 g of 4,4'-oxydianiline (ODA) and 11.92 g of 1,4-phenylenediamine (PPD) were added as aromatic diamine monomers, and about 30 After confirming that the diamine monomer is dissolved in the solvent by stirring for a minute, 50.67 g of biphenyltetracarboxylic dianhydride (BPDA) as an aromatic dianhydride monomer is dividedly added and the viscosity is finally added so that the viscosity becomes 150,000 cP to 200,000 cP. Was adjusted.

After the addition was completed, the mixture was stirred for 1 hour while maintaining the temperature to prepare an aliphatic polyamic acid solution polymerized with a final viscosity of 180,000 CP.

Preparation Example 1-4: Preparation of polyamic acid precursor composition

30 g of the aliphatic polyamic acid microsphere dispersion prepared in Preparation Example 1-2 was mixed with 100 g of the aromatic polyamic acid solution prepared in Preparation Example 1-3 and a catalyst mixture (isoquinoline 5.67 g, acetic anhydride 17.92 g, N,N). -Dimethylformamide 6.41 g) was mixed at 0° C. for 1 to 2 minutes using a high shear mixer to prepare a polyamic acid precursor composition.

<Example 1-2>

A polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the amount of microspheres was changed to contain 5% by weight as shown in Table 1 below.

<Example 1-3>

As shown in Table 1 below, a polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the amount of aliphatic polyamic acid was changed to contain 20% by weight and 5% by weight of microspheres.

<Example 1-4>

As shown in Table 1 below, a polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the amount of aliphatic polyamic acid was changed to contain 30% by weight and 10% by weight of microspheres.

<Example 1-5>

As shown in Table 1 below, a polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the amount of aliphatic polyamic acid was adjusted to contain 5% by weight and 3% by weight of microspheres.

<Example 1-6>

A polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that a borosilicate glass having an average particle diameter of 20 μm was used as shown in Table 1 below.

<Example 1-7>

As an aliphatic diamine monomer, 22.06 g of 2,2-bis[(4-aminophenoxy)phenyl]propane (BAPP) was used in place of 1,3-cyclohexanediamine, and 1,2,4 as an aliphatic dianhydride monomer Examples, except that 27.94 g of 2,2-bis[4-(3,4 dicarboxyphenoxy)phenyl]propanedianhydride (BPADA) was used in place of,5-cyclohexanetetracarboxylicdianhydride. A polyamic acid precursor composition was prepared in the same manner as in 1-1.

<Example 1-8>

Instead of 1,3-cyclohexanediamine as an aliphatic diamine monomer, 25.88 g of 4,4'-methylenebiscyclohexylamine (MCA) was used, and as an aliphatic dianhydride monomer, 1,2,4,5-cyclohexanetetra A polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that 24.12 g of cyclobutane-1,2,3,4-tetracarboxylicdianhydride (CBDA) was used in place of the carboxylic dianhydride. Was prepared.

<Comparative Example 1>

As shown in Table 1 below, a polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the amount of aliphatic polyamic acid was changed to include 3% by weight and 1% by weight of microspheres.

<Comparative Example 1-2>

As shown in Table 1 below, a polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the amount of aliphatic polyamic acid was changed to contain 40% by weight and 15% by weight of microspheres.

<Comparative Example 1-3>

A polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the amount of microspheres was changed to contain 1% by weight as shown in Table 1 below.

<Comparative Example 1-4>

A polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the amount of aliphatic polyamic acid was changed to contain 3% by weight as shown in Table 1 below.

<Comparative Example 1-5>

A polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the amount of microspheres was changed to contain 15% by weight as shown in Table 1 below.

<Comparative Example 1-6>

As shown in Table 1 below, a polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the amount of aliphatic polyamic acid was changed to contain 40% by weight and 10% by weight of microspheres.

<Comparative Example 1-7>

A polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that microspheres having an average particle diameter of 50 μm were added as shown in Table 1 below.

<Comparative Example 1-8>

A polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that spherical silica powder having no pores was used instead of borosilicate glass as microspheres having pores.

<Comparative Example 1-9>

A polyamic acid precursor composition in the same manner as in Example 1-1, except that the microspheres according to Preparation Example 1-3 were not included, and the amount of aliphatic polyamic acid was changed to contain 40% by weight as shown in Table 1 below. Was prepared.

<Comparative Example 1-10>

A polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the aliphatic polyamic acid and microspheres according to Preparation Example 1-1 and Preparation Example 1-3 were changed so as not to be included.

<Comparative Example 1-11>

Polyamic acid precursor composition in the same manner as in Example 1-1, except that the aliphatic polyamic acid according to Preparation Example 1-1 was not included, and the amount of microspheres was changed to contain 15% by weight as shown in Table 1 below. Was prepared.

<Comparative Example 1-12>

A polyamic acid precursor composition was prepared in the same manner as in Example 1-1, except that the aliphatic polyamic acid solution, microspheres, and aromatic polyamic acid solution of Preparation Example 1-3 were simultaneously mixed using a high shear mixer.

Microsphere content
(weight%) Microsphere particle size
(㎛) Aliphatic polyamic acid content
(weight%) Example 1-1 7 16 10 Example 1-2 5 16 10 Example 1-3 5 16 20 Example 1-4 10 16 30 Example 1-5 3 16 5 Example 1-6 7 20 10 Example 1-7 7 16 10 Example 1-8 7 16 10 Comparative Example 1-1 One 16 3 Comparative Example 1-2 15 16 40 Comparative Example 1-3 One 16 10 Comparative Example 1-4 7 16 3 Comparative Example 1-5 15 16 10 Comparative Example 1-6 10 16 40 Comparative Example 1-7 7 50 10 Comparative Example 1-8 7 16 10 Comparative Example 1-9 0 - 40 Comparative Example 1-10 0 - 0 Comparative Example 1-11 15 16 0 Comparative Example 1-12 7 16 10

Each of the polyamic acid precursor compositions prepared in Examples 1-1 to 1-8 and Comparative Examples 1-1 to 1-12 was cast on a glass plate to a thickness of 500 μm using a doctor blade, and then firstly cast at 120° C. for 5 A gel film was prepared by drying for a minute, which was heat-treated in an oven at 250° C. (high temperature tenter) for 2 minutes, and then heat-treated again in an oven at 450° C. for 4 minutes to prepare a 50 μm polyimide film.

For the polyimide film thus prepared, the moisture absorption and dielectric constant were measured in the following manner, and the film-forming properties were visually observed, and the results are shown in Table 3 below.

1) moisture absorption rate measurement

According to the ASTMD 570 method, a polyimide film was cut into a square having a size of 5 cm × 5 cm to prepare a specimen, and the cut specimen was dried in an oven at 50° C. for 24 hours or more, and then the weight was measured, and the weight was measured. After immersing in water at 23° C. for 24 hours, the weight was measured again, and the difference in weight obtained here was expressed in% to measure the moisture absorption.

2) dielectric constant measurement

The permittivity at 10 GHz was measured using Keysight's SPDR meter.

permittivity Moisture absorption rate (%) Film production Example 1-1 2.5 1.2 Good Example 1-2 2.9 1.2 Good Example 1-3 2.8 0.9 Good Example 1-4 2.2 0.8 Good Example 1-5 3.1 1.5 Good Example 1-6 2.7 1.2 Good Example 1-7 2.5 1.1 Good Example 1-8 2.5 1.0 Good Comparative Example 1-1 3.3 1.7 Good Comparative Example 1-2 2.0 0.7 Poor production Comparative Example 1-3 3.3 1.2 Good Comparative Example 1-4 2.8 1.7 Good Comparative Example 1-5 2.1 1.2 Poor surface Comparative Example 1-6 2.0 0.7 Poor production Comparative Example 1-7 2.1 1.2 Poor surface Comparative Example 1-8 3.7 1.2 Good Comparative Example 1-9 3.5 0.7 Fever wrinkles Comparative Example 1-10 3.5 1.8 Good Comparative Example 1-11 2.0 1.8 Good Comparative Example 1-12 3.5 1.3 Good

As is clear from Table 2, it can be seen that the polyimide film according to the embodiment of the present invention has not only remarkably low moisture absorption and dielectric constant, but also excellent film forming properties.

This result is achieved only by the combination of the aliphatic polyimide resin and the microspheres having pores, which can be seen that the aliphatic polyimide resin and the content of the microspheres play a decisive role.

Specifically, the polyimide film of the comparative example that is out of the content range of the aliphatic polyamic acid and microspheres of the present invention exhibits remarkably higher dielectric constant compared to the example, or even if the dielectric constant is lowered, film formation properties such as surface defects or thermal wrinkles occur. It can be seen that it falls significantly. Likewise, polyimide films using particles having no pores or mixing aliphatic and aromatic polyamic acids with microspheres at the same time also have poor dielectric constant and/or film-forming properties, so it is practically difficult to apply to electronic devices that transmit high-frequency signals. Can be seen.

<Experimental Example 2> Addition and storage stability evaluation of aliphatic polyamic acid microsphere dispersion

<Production Example 2-1>

As shown in Table 3 below, an aliphatic polyamic acid microsphere dispersion was prepared in the same manner as in Preparation Examples 1-1 and 1-2, except that the aliphatic polyamic acid solution polymerized to a final viscosity of 5,000 CP was used.

<Production Example 2-2>

As shown in Table 3 below, an aliphatic polyamic acid microsphere dispersion was prepared in the same manner as in Preparation Examples 1-1 and 1-2, except that the aliphatic polyamic acid solution polymerized to a final viscosity of 10,000 CP was used.

<Comparative Production Example 2-1>

As shown in Table 3 below, an aliphatic polyamic acid microsphere dispersion was prepared in the same manner as in Preparation Examples 1-1 and 1-2, except that an aliphatic polyamic acid solution polymerized to a final viscosity of 1,500 CP was used.

<Comparative Production Example 2-2>

As shown in Table 3 below, an aliphatic polyamic acid microsphere dispersion was prepared in the same manner as in Preparation Examples 1-1 and 1-2, except that an aliphatic polyamic acid solution polymerized to a final viscosity of 15,000 CP was used.

Viscosity of aliphatic polyamic acid (cP) Preparation Example 1-2 8,000 Manufacturing Example 2-1 5,000 Manufacturing Example 2-2 10,000 Comparative Production Example 2-1 1,500 Comparative Production Example 2-2 15,000

After the aliphatic polyamic acid microsphere dispersion prepared as above was allowed to stand at room temperature for 1 day, whether or not the layers of the aliphatic polyamic acid and borosilicate glass were separated was visually observed, and the results are shown in Table 4 below.

Whether the layers are separated Preparation Example 1-2 X Manufacturing Example 2-1 X Manufacturing Example 2-2 X Comparative Production Example 2-1 O Comparative Production Example 2-2 X

As is clear from Table 4, in the case of the preparation example in which the viscosity of the aliphatic polyamic acid satisfies the content range defined in the present invention, layer separation was not observed, whereas comparative preparation using an aliphatic polyamic acid having a low viscosity of 1,500 cP In the case of Example 2-1, it can be seen with the naked eye that layer separation between aliphatic polyamic acid and borosilicate glass was observed.From the above results, it can be seen that the aliphatic polyamic acid microsphere dispersion according to the present invention has particularly excellent storage stability. .

Although the above description has been made with reference to the embodiments of the present invention, a person of ordinary skill in the field to which the present invention belongs will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

Claims (17)

Aliphatic polyimide resin;
Aromatic polyimide resin; And
It includes microspheres having pores,
The aliphatic polyimide resin contains at least one of a chain aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group,
The aliphatic polyimide resin or the microspheres are present in at least one state selected from the following,
(A) a first state in which an aliphatic polyimide resin is coated on the surface of the microspheres;
(B) a second state in which the microspheres are physically bound to the polymer chain of the aliphatic polyimide resin; And
(C) a third state in which microspheres are chemically bound to a polymer chain of an aliphatic polyimide resin;
The aliphatic polyimide resin is derived from an aliphatic polyamic acid in which an aliphatic diamine monomer and an aliphatic dianhydride monomer are polymerized,
The aromatic polyimide resin is derived from an aromatic polyamic acid in which an aromatic diamine monomer and an aromatic dianhydride monomer are polymerized,
It is prepared by imidizing a precursor composition comprising the aliphatic polyamic acid, aromatic polyamic acid, and microspheres having pores,
The aliphatic polyamic acid is a polyimide film contained in an amount of 5 to 30% by weight based on the total solid content of the aliphatic polyamic acid and the aromatic polyamic acid,
The polyimide film is prepared by a manufacturing method comprising the following steps, a polyimide film:
Polymerizing an aliphatic diamine monomer and an aliphatic dianhydride monomer in an organic polar solvent to prepare an aliphatic polyamic acid solution;
Polymerizing an aromatic diamine monomer and an aromatic dianhydride monomer in an organic polar solvent to prepare an aromatic polyamic acid solution;
Preparing an aliphatic polyamic acid microsphere dispersion by adding microspheres to the aliphatic polyamic acid solution;
Preparing a precursor composition by mixing an aromatic polyamic acid solution with the aliphatic polyamic acid microsphere dispersion; And
The precursor composition is formed on a support and dried to prepare a gel film, followed by heat treatment at a temperature of 200° C. to 450° C. to prepare a polyimide film in which the polyamic acid precursor is imidized. delete delete The method of claim 1,
The chain aliphatic hydrocarbon group C ₁ to C ₃₀ alkyl group, C ₂ to C ₃₀ alkenyl group, C ₂ to C ₃₀ alkynyl group, C ₁ to C ₃₀ alkylene group, C ₂ to C ₃₀ alkenylene group, and C ₂ to It contains at least one aliphatic organic group selected from the group consisting of C ₃₀ alkynylene groups,
The cyclic aliphatic hydrocarbon group C ₃ to C ₃₀ cycloalkyl group, C ₃ to C ₃₀ cycloalkenyl group, C ₃ to C ₃₀ cycloalkynyl group, C ₃ to C ₃₀ cycloalkylene group, C ₆ to C ₃₀ cycloalkenylene group , And C ₃ to C _{30 A} polyimide film comprising at least one alicyclic organic group selected from the group consisting of cycloalkynylene groups. The method of claim 1,
The aliphatic diamine monomers include cyclohexanediamine (CHDA), 1,4-cyclohexanebis (methylamine), 2,2-bis[(4-aminophenoxy)phenyl]propane (BAPP), 2,2-bis[ 4-(4-aminophenoxyphenyl)]hexafluoropropane (HFBAPP), 4,4'-methylenebiscyclohexylamine (MCA), 4,4'-methylenebis(2-methylcyclohexylamine) (MMCA ), 1,3-diaminoadamantane (DAA), and at least any one selected from the group consisting of 3,3'-diamino-1,1'-diadamantane (DADA),
The aliphatic dianhydride monomer is 1,2,4,5-cyclohexanetetracarboxylicdianhydride (HPMDA), 2,2-bis[4-(3,4dicarboxyphenoxy)phenyl]propanedianhydride (BPADA) and at least any one selected from the group consisting of cyclobutane-1,2,3,4-tetracarboxylicdianhydride (CBDA), a polyimide film. The method of claim 1,
The aromatic diamine monomer is 1,4-phenylenediamine (PPD), 4,4'-oxydianiline (ODA), 3,4'-oxydianiline, 4,4'-methylenedianiline (MDA), and 1,3-bis (4-aminophenoxy) benzene (TPE-R) is at least any one selected from the group consisting of,
The aromatic dianhydride monomers include pyromellitic dianhydride (PMDA), biphenyltetracarboxylic dianhydride (BPDA), oxydiphthalic anhydride (ODPA), and benzophenone tetracarboxylic dianhydride. The polyimide film which is at least any one selected from the group consisting of (BTDA). delete delete The method of claim 1,
The microspheres are contained in an amount of 3 to 10% by weight based on the total solid content of the aliphatic polyamic acid and the aromatic polyamic acid. The method of claim 1,
The microspheres contain at least one selected from the group consisting of silica, alumina, titania, zeolite, boron oxide, and glass, a polyimide film. The method of claim 1,
The microspheres are borosilicate glass, polyimide film. The method of claim 1,
The microspheres have an average particle diameter of 1 to 20 μm, a polyimide film. The method of claim 1,
The aliphatic polyamic acid has a viscosity of 2,000 to 20,000 cP, a polyimide film. The method of claim 1,
The polyimide film is a polyimide film having a dielectric constant of 3.0 or less and a moisture absorption of 1.5% or less at 10 GHz. As a method for producing the polyimide film according to claim 1,
Polymerizing an aliphatic diamine monomer and an aliphatic dianhydride monomer in an organic polar solvent to prepare an aliphatic polyamic acid solution;
Polymerizing an aromatic diamine monomer and an aromatic dianhydride monomer in an organic polar solvent to prepare an aromatic polyamic acid solution;
Preparing an aliphatic polyamic acid microsphere dispersion by adding microspheres to the aliphatic polyamic acid solution;
Preparing a precursor composition by mixing an aromatic polyamic acid solution with the aliphatic polyamic acid microsphere dispersion; And
After the precursor composition is formed on a support and dried to prepare a gel film, heat treatment at a temperature of 200° C. to 450° C. to prepare a polyimide film in which the polyamic acid precursor is imidized. Manufacturing method. The method of claim 15,
The method for producing a polyimide film in which the microspheres are added by blending 3 to 5 times for 5 to 10 minutes each at 2,000 to 5,000 RPM at 0 to 10°C at 0 to 10°C. Electronic device for high-speed transmission comprising the polyimide film according to claim 1.