KR102606060B1 - Polyimide film comprising gpaphene platelets and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a dianhydride component including benzophenone tetracarboxylic dianhydride (BTDA), biphenyl tetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (PMDA), and m-tolidine ( A polyimide film obtained by imidizing a polyamic acid solution containing diamine components including m-tolidine) and paraphenylene diamine (PPD) and containing 0.5 to 2.5% by weight of graphene nanoplatelets. provides.

Description

Polyimide film containing graphene nanoplatelets and its manufacturing method {POLYIMIDE FILM COMPRISING GPAPHENE PLATELETS AND MANUFACTURING METHOD THEREOF}

The present invention relates to a polyimide film containing graphene nanoplatelets with excellent dielectric properties and a method of manufacturing the same.

Polyimide (PI) 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 a rigid aromatic main chain and excellent chemical stability. am.

In particular, it is attracting attention as a highly functional polymer material in the electrical, electronic, and optical fields due to its excellent electrical properties such as excellent insulating properties and low dielectric constant.

Recently, as electronic products become lighter and smaller, thin circuit boards with high integration and flexibility are being actively developed.

These thin circuit boards tend to have a structure in which a circuit including metal foil is formed on a polyimide film that has excellent heat resistance, low temperature resistance, and insulation characteristics and is easy to bend.

Flexible metal clad laminates are mainly used as such thin circuit boards, and an example includes Flexible Copper Clad Laminate (FCCL), which uses a thin copper plate as a metal foil. In addition, polyimide is also used as a protective film and insulating film for thin circuit boards.

Meanwhile, as various functions have recently become embedded in electronic devices, fast calculation and communication speeds are required for the electronic devices, and to meet these requirements, thin circuit boards capable of high-speed communication at high frequencies are being developed.

In order to realize high-frequency, high-speed communication, an insulator with high impedance that can maintain electrical insulation even at high frequencies is needed. Since impedance is inversely proportional to the frequency and dielectric constant (Dk) formed in the insulator, the dielectric constant must be as low as possible to maintain insulation even at high frequencies.

However, in the case of conventional polyimide, the dielectric properties are not excellent enough to maintain sufficient insulation in high-frequency communication.

In addition, it is known that the lower the dielectric properties of the insulator, the less likely it is to generate undesirable stray capacitance and noise in thin circuit boards, thereby eliminating many of the causes of communication delays.

Therefore, polyimide with low dielectric properties is recognized as an important factor in the performance of thin circuit boards.

In particular, in the case of high-frequency communication, dielectric loss inevitably occurs through polyimide. The dielectric dissipation factor (Df) refers to the degree of electrical energy wasted in a thin circuit board and is closely related to the signal transmission delay that determines the communication speed, so keeping the dielectric dissipation factor of polyimide as low as possible is also important for thin circuit boards. It is recognized as an important factor in the performance of the board.

Additionally, the more moisture contained in the polyimide film, the greater the dielectric constant and the higher the dielectric loss rate. In the case of polyimide film, while it is suitable as a material for thin circuit boards due to its excellent inherent properties, it may be relatively vulnerable to moisture due to the polar imide group, which may deteriorate its insulating properties.

Therefore, there is a need to develop a polyimide film with dielectric properties that maintains the mechanical properties unique to polyimide at a certain level.

In addition, as transmission speeds have recently become faster, a method of absorbing energy by attaching a terminator to the end of the circuit is being applied to solve the problem of reflected signals disrupting the rising time region and interfering with semiconductor operation. . To apply this absorption method, the impedance of the terminator and the impedance of the transmission circuit must be the same.

At this time, since the impedance value of the terminator resistor is fixed, it is necessary to adjust the impedance of the circuit of the printed circuit board (PCB).

In other words, while the impedance decreases as the insulation thickness becomes thinner due to the miniaturization trend of electronic devices, the dielectric constant must be higher than that of the conventional polyimide film (Dk: 3.5) in order to meet the specified impedance value of the terminator resistance.

Republic of Korea Patent Publication No. 10-2015-0069318

Accordingly, in order to solve the above problems, the purpose is to provide a polyimide film with excellent dielectric properties and a method for manufacturing the same.

Accordingly, the practical purpose of the present invention is to provide specific examples thereof.

One embodiment of the present invention for achieving the above object is benzophenone tetracarboxylic dianhydride (BTDA), biphenyl tetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (PMDA). It is obtained by imidizing a solution of a polyamic acid containing a dianhydride component containing a dianhydride component and a diamine component containing m-tolidine (m-tolidine) and paraphenylene diamine (PPD), and graphene nanoplatelets (graphene). A polyimide film containing 0.5 to 2.5% by weight of nanoplatelets is provided.

Based on a total content of 100 mol% of the diamine component, the content of m-tolidine may be 20 mol% to 40 mol%, and the content of paraphenylene diamine may be 60 mol% to 80 mol%.

In addition, based on the total content of the dianhydride component of 100 mol%, the content of benzophenone tetracarboxylic dianhydride is 20 mol % to 45 mol %, and the content of biphenyl tetracarboxylic dianhydride is 20 mol %. % or more and 45 mol% or less, and the content of pyromellitic dianhydride may be 20 mol% or more and 45 mol% or less.

The graphene nanoplatelets may have an average thickness of 6 to 8 nm, an average particle size of 5 to 25 μm, and a specific surface area of 120 to 150 m ² /g.

Meanwhile, the polyimide film may have a dielectric constant of 4.0 or more and 7.0 or less, and a dielectric loss factor of 0.01 or less.

Another embodiment of the present invention is (a) dianhydride acid including benzophenone tetracarboxylic dianhydride (BTDA), biphenyl tetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (PMDA). A step of preparing polyamic acid by polymerizing a diamine component consisting of m-tolidine and paraphenylene diamine (PPD) in an organic solvent, (b) adding graphene nanoplatelets to the polyamic acid. and mixing, and (c) imidizing the polyamic acid containing the graphene nanoplatelets.

Another embodiment of the present invention provides a multilayer film including the polyimide film, a flexible metal clad laminate including the polyimide film and an electrically conductive metal foil, and an electronic component including the flexible metal clad laminate.

As described above, the present invention provides a polyimide film with excellent dielectric properties through a polyimide film composed of specific ingredients and a specific composition ratio and a manufacturing method thereof, and thus can be used in various fields where such properties are required, especially flexible metal clad laminates, etc. It can be usefully applied to electronic components, etc.

Hereinafter, embodiments of the invention will be described in more detail in the order of “polyimide film” and “method for producing polyimide film” according to the present invention.

Prior to this, the terms or words used in this specification and claims should not be construed as limited to their usual or dictionary meanings, and the inventor should appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle of definability.

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

In this specification, singular expressions include plural expressions, unless the context clearly dictates otherwise. In this specification, terms such as “comprise,” “comprise,” or “have” are intended to designate the presence of implemented features, numbers, steps, components, or a combination thereof, and are intended to indicate the presence of one or more other features or It should be understood that this does not exclude in advance the possibility of the presence or addition of numbers, steps, components, or combinations thereof.

When amounts, concentrations, or other values or parameters are given herein as ranges, preferred ranges, or enumerations of upper preferred values and lower preferred values, any pair of upper range limits or It is to be understood that the preferred values and any lower range limits or all ranges formed from the preferred values are specifically disclosed.

When a range of numerical values is stated herein, unless otherwise stated, the range is intended to include the endpoints and all integers and fractions within the range. The scope of the invention is not intended to be limited to the specific values recited when defining the scope.

As used herein, “dianhydride acid” is intended to include precursors or derivatives thereof, which may not technically be dianhydride acids, but which will nonetheless react with diamines to form polyamic acids, which in turn will form polyamic acids. It can be converted to mead.

As used herein, “diamine” is intended to include precursors or derivatives thereof, which may not technically be diamines, but which will nonetheless react with dianhydride to form polyamic acids, which in turn will form polyamic acids. It can be converted to mead.

In this specification, “a to b” and “a to b” that indicate numerical ranges, “to” and “~” are defined as ≥ a and ≤ b.

The polyimide film according to the present invention includes a dianhydride component including benzophenone tetracarboxylic dianhydride (BTDA), biphenyl tetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (PMDA), It is obtained by imidizing a polyamic acid solution containing diamine components including m-tolidine and paraphenylene diamine (PPD), and 0.5 to 2.5% by weight of graphene nanoplatelets. It can be included.

Based on a total content of 100 mol% of the diamine component, the content of m-tolidine may be 20 mol% to 40 mol%, and the content of paraphenylene diamine may be 60 mol% to 80 mol%.

In particular, m-tolidine has a particularly hydrophobic methyl group, contributing to the low moisture absorption properties of polyimide film.

Based on the total content of the dianhydride component of 100 mol%, the content of benzophenone tetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less, and the content of biphenyltetracarboxylic dianhydride is 20 mol% or more. It is 45 mol% or less, and the content of pyromellitic dianhydride may be 20 mol% or more and 45 mol% or less.

The polyimide chain derived from biphenyltetracarboxylic dianhydride of the present invention has a structure named charge transfer complex (CTC), that is, an electron donor and an electron acceptor. It has a regular straight structure located close to each other, and intermolecular interaction is strengthened.

In addition, benzophenone tetracarboxylic dianhydride, which has a carbonyl group, contributes to the expression of CTC like biphenyl tetracarboxylic dianhydride.

Since this structure has the effect of preventing hydrogen bonding with moisture, it can have an effect in lowering the moisture absorption rate and maximize the effect of lowering the hygroscopicity of the polyimide film.

In one specific example, the dianhydride component may additionally include pyromellitic dianhydride. Pyromellitic dianhydride is a dianhydride component with a relatively rigid structure and is preferred because it can provide appropriate elasticity to the polyimide film.

In order for a polyimide film to simultaneously satisfy appropriate elasticity and moisture absorption, the content ratio of dianhydride is particularly important. For example, as the content ratio of biphenyltetracarboxylic dianhydride decreases, it becomes difficult to expect a low moisture absorption rate due to the CTC structure.

In addition, biphenyltetracarboxylicdianhydride and benzophenonetetracarboxylicdianhydride contain two benzene rings corresponding to the aromatic portion, while pyromellitic dianhydride contains a benzene ring corresponding to the aromatic portion. Includes 1.

The increase in the pyromellitic dianhydride content in the dianhydride component can be understood as an increase in the imide group within the molecule based on the same molecular weight, which means that the imide group derived from the pyromellitic dianhydride is added to the polyimide polymer chain. It can be understood that the ratio of groups increases relative to the imide group derived from biphenyl tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride.

In other words, an increase in the pyromellitic dianhydride content can be seen as a relative increase in imide groups in the entire polyimide film, making it difficult to expect a low moisture absorption rate.

Conversely, when the content ratio of pyromellitic dianhydride is reduced, the component with a relatively rigid structure is reduced, and the elasticity of the polyimide film may be lowered below a desired level.

For this reason, if the content of the biphenyl tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride is above the above range, or the content of pyromellitic dianhydride is below the above range, the polyimide film Mechanical properties deteriorate, and heat resistance at an appropriate level for manufacturing flexible metal clad laminates cannot be secured.

Conversely, when the content of biphenyl tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride is below the above range, or when the content of pyromellitic dianhydride is above the above range, an appropriate level of dielectric strength is achieved. It is undesirable because the constant, dielectric loss rate, and moisture absorption rate are difficult to achieve.

Meanwhile, the graphene nanoplatelets may have an average thickness of 6 to 8 nm, an average particle size of 5 to 25 μm, and a specific surface area of 120 to 150 m ² /g.

The graphene nanoplatelets have relatively excellent dispersibility compared to other carbon nanomaterials, and when added to a polyimide film, the decrease in dielectric loss rate of the polyimide film can be minimized.

In one embodiment, the polyimide film may have a dielectric constant of 4.0 or more and 7.0 or less, and a dielectric loss factor of 0.01 or less.

The dielectric constant may be preferably 4.5 or more, and more preferably 5.0 or more.

In this regard, polyimide film that satisfies both dielectric constant (Dk) and dielectric loss factor (Df) can be used as an insulating film for flexible metal clad laminates, and the manufactured flexible metal clad laminates can transmit signals at high frequencies of 10 GHz or more. Even when used as an electrical signal transmission circuit, its insulation stability can be ensured and signal transmission delay can be minimized.

In the present invention, the production of polyamic acid is, for example,

(1) A method of polymerizing the entire amount of the diamine component in a solvent and then adding the dianhydride component in substantially equimolar amounts to the diamine component;

(2) A method of polymerizing the entire amount of the dianhydride component in a solvent, and then adding the diamine component in substantially equimolar amounts to the dianhydride component;

(3) After adding some of the diamine components into the solvent, mixing some of the dianhydride components in a ratio of about 95 to 105 mol% with respect to the reaction components, adding the remaining diamine components, and then adding the remaining dianhydride components continuously. A method of polymerizing by adding components such that the diamine component and the dianhydride component are substantially equimolar;

(4) After adding the dianhydride component into the solvent, some components of the diamine compound are mixed in a ratio of 95 to 105 mol% with respect to the reaction components, then other dianhydride components are added, and then the remaining diamine component is added, A method of polymerizing the diamine component and the dianhydride component in substantially equimolar amounts;

(5) In a solvent, some diamine components and some dianhydride components are reacted so that either one is in excess to form a first composition, and in another solvent, some diamine components and some dianhydride components are reacted in such a way that either one is in excess to form a first composition. 2 After forming the composition, the first and second compositions are mixed and polymerization is completed. In this case, if the diamine component is excessive when forming the first composition, the dianhydride component is added in excess in the second composition. When the dianhydride component is excessive in the first composition, the diamine component is excessive in the second composition, and the first and second compositions are mixed so that the total diamine component and dianhydride component used in these reactions are substantially equal. A method of polymerizing the molar mass may be included.

However, the polymerization method is not limited to the above examples, and of course, any known method can be used to produce the polyamic acid.

In one specific example, the method for producing a polyimide film according to the present invention includes,

(a) dianhydride components including benzophenone tetracarboxylic dianhydride (BTDA), biphenyl tetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (PMDA), and m-tolidine ( Preparing polyamic acid by polymerizing a diamine component consisting of m-tolidine) and paraphenylene diamine (PPD) in an organic solvent;

(b) adding and mixing graphene nanoplatelets to the polyamic acid; and

(c) imidizing the polyamic acid containing the graphene nanoplatelets may be included.

Based on the total content of the diamine component of 100 mol%, the content of m-tolidine is 20 mol% to 40 mol%, the content of paraphenylene diamine is 60 mol% to 80 mol%, and the dianhydride component Based on the total content of 100 mol%, the content of benzophenone tetracarboxylic dianhydride is 20 mol % to 45 mol %, and the content of biphenyl tetracarboxylic dianhydride is 20 mol % to 45 mol %. and the content of pyromellitic dianhydride may be 20 mol% or more and 45 mol% or less.

In the present invention, the polymerization method of the polyamic acid as described above can be defined as a random polymerization method, and the polyimide film manufactured from the polyamic acid of the present invention manufactured through the above process has excellent dielectric properties. It can be preferably applied in terms of maximizing the effect of the invention.

However, since the above polymerization method produces a relatively short length of the repeating unit in the polymer chain described above, there may be limitations in demonstrating each of the excellent properties of the polyimide chain derived from the dianhydride component. Therefore, the polymerization method of polyamic acid that can be particularly preferably used in the present invention may be a block polymerization method.

On the other hand, the solvent for synthesizing polyamic acid is not particularly limited, and any solvent can be used as long as it dissolves polyamic acid, but it is preferable that it is an amide-based solvent.

Specifically, the solvent may be an organic polar solvent, and in particular, may be an aprotic polar solvent, for example, N,N-dimethylformamide (DMF), N,N- It may be one or more selected from the group consisting of dimethylacetamide, N-methyl-pyrrolidone (NMP), gamma butyrolactone (GBL), and Diglyme, but is not limited thereto, and may be used alone or as necessary. Two or more types can be used in combination.

In one example, N,N-dimethylformamide and N,N-dimethylacetamide may be particularly preferably used as the solvent.

Additionally, in the polyamic acid manufacturing process, fillers may be added to improve various properties of the film such as sliding properties, thermal conductivity, corona resistance, and loop hardness. The added filler is not particularly limited, but preferred examples include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, and mica.

The particle size of the filler is not particularly limited and may be determined depending on the film properties to be modified and the type of filler to be added. Generally, the average particle diameter is 0.05 to 100 μm, preferably 0.1 to 75 μm, more preferably 0.1 to 50 μm, and particularly preferably 0.1 to 25 μm.

If the particle size is below this range, it becomes difficult to achieve a reforming effect, and if the particle size is above this range, the surface properties may be greatly damaged or the mechanical properties may be greatly reduced.

Additionally, the amount of filler added is not particularly limited and may be determined based on the film properties to be modified, the particle size of the filler, etc. Generally, the amount of filler added is 0.01 to 100 parts by weight, preferably 0.01 to 90 parts by weight, and more preferably 0.02 to 80 parts by weight, based on 100 parts by weight of polyimide.

If the amount of filler added is less than this range, it is difficult to achieve a reforming effect due to the filler, and if it is more than this range, the mechanical properties of the film may be significantly damaged. The method of adding the filler is not particularly limited, and any known method may be used.

In the production method of the present invention, the polyimide film can be produced by thermal imidization and chemical imidization.

In addition, it may be manufactured by a complex imidization method in which thermal imidization and chemical imidization are combined.

The thermal imidization method is a method of inducing an imidization reaction using a heat source such as hot air or an infrared dryer, excluding chemical catalysts.

The thermal imidization method can imidize the amic acid group present in the gel film by heat treating the gel film at a variable temperature in the range of 100 to 600 ℃, specifically 200 to 500 ℃, more specifically, The amic acid group present in the gel film can be imidized by heat treatment at 300 to 500°C.

However, even in the process of forming a gel film, some of the amic acid (about 0.1 mol% to 10 mol%) may be imidized, and for this purpose, the polyamic acid composition is dried at a variable temperature in the range of 50 ℃ to 200 ℃. It can also be included in the scope of the thermal imidization method.

In the case of chemical imidization, a polyimide film can be produced using a dehydrating agent and an imidizing agent according to methods known in the art.

As an example of a complex imidization method, a dehydrating agent and an imidizing agent are added to a polyamic acid solution, then heated at 80 to 200°C, preferably 100 to 180°C, partially cured and dried, and then heated at 200 to 400°C for 5 to 400 seconds. A polyimide film can be produced by heating.

The polyimide film of the present invention manufactured according to the above manufacturing method may have a dielectric constant of 4.0 or more and 7.0 or less, and a dielectric loss factor of 0.01 or less.

The present invention provides a multilayer film containing the above-described polyimide film and a flexible metal-clad laminate containing the above-described polyimide film and an electrically conductive metal foil.

The multilayer film may include a thermoplastic resin layer, particularly a thermoplastic polyimide resin layer.

There is no particular limitation on the metal foil to be used, but when using the flexible metal clad laminate of the present invention for electronic or electrical equipment, for example, copper or copper alloy, stainless steel or its alloy, nickel or nickel alloy (42 alloy) Also included), may be a metal foil containing aluminum or aluminum alloy.

In general flexible metal clad laminates, copper foils such as rolled copper foil and electrolytic copper foil are widely used, and can also be preferably used in the present invention. Additionally, a rust-prevention layer, a heat-resistant layer, or an adhesive layer may be applied to the surface of these metal foils.

In the present invention, the thickness of the metal foil is not particularly limited, and may be sufficient to provide sufficient function depending on the intended use.

The flexible metal clad laminate according to the present invention has metal foil laminated on one side of the polyimide film, or an adhesive layer containing thermoplastic polyimide is added to one side of the polyimide film, and the metal foil is attached to the adhesive layer. It may be a laminated structure.

The present invention also provides an electronic component including the flexible metal clad laminate as an electrical signal transmission circuit. The electrical signal transmission circuit may be an electronic component that transmits a signal at a high frequency of at least 2 GHz, specifically at a high frequency of at least 5 GHz, and more specifically at a high frequency of at least 10 GHz.

The electronic component 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.

Hereinafter, the operation and effects of the invention will be described in more detail through specific examples of the invention. However, these examples are merely presented as examples of the invention, and the scope of the invention is not determined by them.

<Manufacturing example>

DMF was added while nitrogen was injected into a 500 ml reactor equipped with a stirrer and nitrogen injection/discharge pipe, and the temperature of the reactor was set to 30°C or lower. Then, m-tolidine and paraphenylene diamine as diamine components and dianhydride as dianhydride component were added. Add benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, and pyromellitic dianhydride and confirm that they are completely dissolved.

Based on 100 mol% of the total content of the diamine component, the content of m-tolidine is 34 mol%, the content of paraphenylene diamine is 66 mol%, and based on the total content of the dianhydride component of 100 mol%, benzoyl The content of phenonetetracarboxylicdianhydride was 33 mol%, the content of biphenyltetracarboxylicdianhydride was 32 mol%, and the content of pyromellitic dianhydride was 35 mol%.

Afterwards, the temperature of the reactor was raised to 40°C under a nitrogen atmosphere and stirring was continued for 120 minutes while heating to prepare polyamic acid.

Graphene nanoplatelets were added to the polyamic acid prepared in this way and stirred.

A catalyst and a dehydrating agent were added to the final polyamic acid prepared in this way, bubbles were removed through high-speed rotation of over 1,500 rpm, and then it was applied to a glass substrate using a spin coater.

Afterwards, a gel film was prepared by drying at a temperature of 120°C for 30 minutes under a nitrogen atmosphere, which was heated to 450°C at a rate of 2°C/min, heat treated at 450°C for 60 minutes, and then heated to 30°C for 2 minutes. By cooling again at a rate of ℃/min, the final polyimide film was obtained, and it was peeled from the glass substrate by dipping in distilled water.

The thickness of the prepared polyimide film was 15 ㎛. The thickness of the produced polyimide film was measured using an electric film thickness tester from Anritsu.

<Examples 1, 2 and Comparative Examples 1 to 5>

It was manufactured according to the manufacturing example described above, but the content of graphene nanoplatelets was adjusted as shown in Table 1.

graphene nanoplatelets
(weight%) permittivity
(Dk) dielectric loss rate
(Df) Example 1 1.0 5.36 0.00538 Example 2 2.0 6.77 0.00761 Comparative Example 1 0 3.46 0.00440 Comparative Example 2 0.1 3.78 0.00460 Comparative Example 3 3.0 10.51 0.00877 Comparative Example 4 4.0 16.19 0.01245 Comparative Example 5 5.0 22.01 0.01521

<Experimental example> Evaluation of dielectric constant and dielectric loss rate

As shown in Table 1, the dielectric constant and dielectric loss factor were measured for the polyimide films prepared in Examples 1 and 2 and Comparative Examples 1 to 5, respectively.

(1) Dielectric constant measurement

The dielectric constant (Dk) was measured at 10 GHz using an SPDR meter from Keysight.

(2) Dielectric loss rate measurement

Dielectric loss factor (Df) was measured by leaving the flexible metal clad laminate for 72 hours using an Agilent 4294A resistance meter.

As shown in Table 1, the polyimide film manufactured according to the examples of the present invention satisfied all the conditions of having a dielectric constant of 4.0 or more and 7.0 or less, and a dielectric loss factor of 0.01 or less.

The polyimide films of Comparative Examples 1 and 2 that did not contain graphene nanoplatelets or contained a small amount (0.1% by weight) had a dielectric constant of less than 4.0.

In addition, Comparative Examples 3 to 5 containing an excessive amount (3% by weight or more) of graphene nanoplatelets had a dielectric constant exceeding 7.0, and in particular, Comparative Examples 4 and 5 also had a dielectric loss factor exceeding 0.01.

Therefore, it can be confirmed that the dielectric constant and dielectric loss rate are at desired levels only within the content range of the graphene nanoplatelets according to the example.

These results are achieved by the components and composition ratio specified herein, and it can be seen that the content of each component plays a decisive role.

On the other hand, the polyimide films of Comparative Examples 1 and 2, which have different components from those of the Examples, have more than one aspect of dielectric constant and dielectric loss rate compared to the polyimide film of the Examples, and can be used in electronic components in which signal transmission is performed at a high frequency in the giga unit. Difficulties can be expected.

Although the present invention has been described with reference to embodiments of the present invention, those skilled in the art will be able to make various applications and modifications based on the above contents within the scope of the present invention.

Claims (11)

Dianhydride components including benzophenone tetracarboxylic dianhydride (BTDA), biphenyl tetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (PMDA), and m-tolidine (m-tolidine). ) and paraphenylene diamine (PPD). It is obtained by imidizing a polyamic acid solution containing a diamine component,
Contains 0.5 to 2.5% by weight of graphene nanoplatelets,
The dielectric constant measured at 10 GHz is 4.0 or more and 7.0 or less,
Polyimide film. According to paragraph 1,
Based on the total content of the diamine component of 100 mol%, the m-tolidine content is 20 mol% to 40 mol%, and the paraphenylene diamine content is 60 mol% to 80 mol%,
Polyimide film. According to paragraph 1,
Based on 100 mol% of the total content of the dianhydride component, the content of benzophenone tetracarboxylic dianhydride is 20 mol% to 45 mol%,
The content of biphenyltetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less,
The content of pyromellitic dianhydride is 20 mol% or more and 45 mol% or less,
Polyimide film. According to paragraph 1,
The average thickness of the graphene nanoplatelets is 6 to 8 nm,
The average particle size is 5 to 25 μm,
The specific surface area is 120~150 m ² /g,
Polyimide film. According to paragraph 1,
With a dielectric loss ratio of 0.01 or less,
Polyimide film. (a) dianhydride components including benzophenone tetracarboxylic dianhydride (BTDA), biphenyl tetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (PMDA), and m-tolidine ( Preparing polyamic acid by polymerizing a diamine component consisting of m-tolidine) and paraphenylene diamine (PPD) in an organic solvent;
(b) adding and mixing graphene nanoplatelets to the polyamic acid; and
(c) comprising the step of imidizing the polyamic acid containing the graphene nanoplatelets,
The dielectric constant measured at 10 GHz is 4.0 or more and 7.0 or less,
Method for producing polyimide film. According to clause 6,
Based on the total content of the diamine component of 100 mol%, the content of m-tolidine is 20 mol% to 40 mol%, and the content of paraphenylene diamine is 60 mol% to 80 mol%,
Based on 100 mol% of the total content of the dianhydride component, the content of benzophenone tetracarboxylic dianhydride is 20 mol% to 45 mol%,
The content of biphenyltetracarboxylic dianhydride is 20 mol% or more and 45 mol% or less,
The content of pyromellitic dianhydride is 20 mol% or more and 45 mol% or less,
Method for producing polyimide film. According to clause 6,
With a dielectric loss ratio of 0.01 or less,
Method for producing polyimide film. Comprising the polyimide film according to any one of claims 1 to 5,
Multilayer film. Comprising the polyimide film according to any one of claims 1 to 5 and an electrically conductive metal foil,
Flexible metal foil laminate. Containing a flexible metal clad laminate according to paragraph 10,
Electronic parts.