Polyesterimide resin composition, polyesterimide resin layer, flexible metal foil laminate, and method for producing the same

Abstract

To provide a polyesterimide resin composition, a polyesterimide resin layer, a flexible metal foil laminate, and methods of preparing the same.SOLUTION: The polyesterimide resin composition includes a compound having a structural unit represented by Chemical Formula (1). (In Chemical Formula (1), m and n are mole fractions, and "m+n=1", "0.2≤m≤0.8" and "0.2≤n≤0.8" are satisfied. Ar1 and Ar2 are the same as or different from each other and are each independently a tetravalent organic group having at least one aromatic ring. R1, R2, and R4 to R6 each independently include at least one selected from the group consisting of -H, -F, -CH3, -OCH3, -CF3, and -OCF3. R3 is an ester group and includes -COO- or -OOC-.)SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a polyesterimide resin composition, a polyesterimide resin layer, a flexible metal foil laminate, and a method for producing the same.

Background Art

[0002] In recent years, driven by the trend toward higher performance and more functions in portable wireless communication devices typified by smartphones, the amount of signal transmission has increased and the speed of signal transmission has accelerated. In particular, with the commercialization of 5th generation wireless communication devices (5G NR), the use of communication frequencies in the GHz band has become commonplace. As the communication frequency increases, the signal loss flowing through the circuit increases, and in order to improve this, it is necessary to lower the dielectric loss tangent of the insulating material. In addition, when the moisture absorption rate of an insulating material is high, there is a phenomenon that the dielectric loss tangent increases due to absorption of moisture in the atmosphere, so reducing the moisture absorption rate of the insulating material is also an important consideration.

[0003] Recently, as insulating resins for reducing signal loss in high frequency bands, interest in liquid crystalline polymer materials and fluorine-based polymer materials has been increasing. These have the advantage of reducing signal loss because they have a low dielectric loss tangent and low moisture absorption in the atmosphere. For example, Patent Document 1 discloses an insulator in which a liquid crystalline polymer material is formed on both sides of a polyimide film, and a flexible metal foil laminate using the same.

[0004] Generally, polyimide-based resins are used as the insulating layer of flexible metal foil laminates. Polyimide-based resins are excellent in heat resistance, chemical resistance, low thermal expansion property and the like, and particularly have the advantage of excellent processing characteristics during circuit manufacturing.

[0005] On the other hand, although liquid crystalline polymers and fluorine-based polymers have excellent electrical properties, they lack processing characteristics during circuit manufacturing, and thus are greatly restricted in actual industrial use.

Prior Art Literature

Patent Literature

[0006] [Patent Document 1] Korean Public Bulletin No. 10-2022-0015562 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The present invention aims to solve the above-mentioned problems, and the object of the present invention is to provide a polyesterimide resin composition, a polyesterimide resin layer, a flexible metal foil laminate, and a method for manufacturing the same, as an insulating material for circuit boards with low signal loss that improves dielectric loss tangent and moisture absorption rate while maintaining the excellent processing characteristics of polyimide resins.

[0008] However, the problems that this invention aims to solve are not limited to those mentioned above, and further problems not mentioned can be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0009] A polyesterimide resin composition according to one embodiment of the present invention contains a compound of the structural unit shown in the following chemical formula (1). [ka] (In the above chemical formula (1), m and n are mole fractions, where m+n=1, 0.2≦m≦0.8, and 0.2≦n≦0.8.) In the aforementioned chemical formula (1), Ar1 and Ar2 are independently either identical or distinct from each other, and are tetravalent organic groups having one or more aromatic rings. The R1, R2, R4 to R6 in the aforementioned chemical formula (1) each independently contains at least one selected from the group consisting of -H, -F, -CH3, -OCH3, -CF3, and -OCF3, and R3 is an ester group containing -COO- or -OOC-.

[0010] The structural unit represented by said chemical formula (1) according to one embodiment may exist as a block copolymer or a random copolymer.

[0011] The resin represented by said chemical formula (1) according to one embodiment can be produced, for example, by producing polyamic acid via a reaction between a dianhydride and a diamine, converting the polyamic acid into a polyesterimide resin via thermal or chemical conversion, or producing the polyesterimide resin via a direct reaction between a dianhydride and a diisocyanate.

[0012] Said chemical formula (1) according to one embodiment may be the following chemical formula (2).

Chemical Formula

[0013] Ar1 and Ar2 constituting said chemical formula (1) according to one embodiment may include a compound having a structural unit of the following chemical formula (3).

Chemical Formula

[0014] The compound having a structural unit of said chemical formula (3) according to one embodiment may account for 50 mol% or more of Ar1 and Ar2 constituting said chemical formula (1).

[0015] A polyesterimide resin layer according to another embodiment of the present invention comprises a polyesterimide resin composition.

[0016] Said polyesterimide resin layer according to one embodiment may have a moisture absorption rate of 0.5% or less when measured at 23°C and 50% relative humidity.

[0017] Said polyesterimide resin layer according to one embodiment may have a dielectric loss tangent at 10 GHz of 0.0035 or less when measured at 23°C and 50% relative humidity.

[0018] The polyesterimide resin layer according to one embodiment may have a coefficient of linear thermal expansion of 50 ppm / K or less as measured in a range of 100°C to 250°C.

[0019] A flexible metal foil laminate according to another embodiment of the present invention includes at least one insulating layer and a metal layer formed on one side or both sides of the insulating layer, wherein the insulating layer comprises the polyesterimide resin layer according to one embodiment of the present invention.

[0020] The insulating layer according to one embodiment further includes at least one thermoplastic polyimide-based resin layer, and the thermoplastic polyimide-based resin layer may be a compound containing an imide group represented by the following chemical formula (4).

Chemical Formula

[0021] In one embodiment, the storage elastic modulus of the thermoplastic polyimide-based resin layer measured at 350°C is 1.0×10 8 Pa or less, and the difference between the coefficients of thermal expansion of the polyesterimide resin layer and the thermoplastic polyimide resin layer measured at 100°C to 380°C may be 100 ppm / K or less.

[0022] The surface roughness of the metal layer in contact with the insulating layer according to one embodiment satisfies Rz≦1.5μm, and the bonding strength between the metal layer and the insulating layer may be 0.8kgf / cm or more.

[0023] A method for producing a polyesterimide resin composition according to a further embodiment of the present invention is a method for producing a polyesterimide resin composition, comprising the steps of: preparing a polyamic acid through a reaction of a dianhydride and a diamine; and thermally or chemically converting the polyamic acid, wherein the polyesterimide resin composition is a compound having a structural unit represented by the following chemical formula (1). [ka] (In the above chemical formula (1), m and n are mole fractions, where m+n=1, 0.2≦m≦0.8, and 0.2≦n≦0.8.) In the aforementioned chemical formula (1), Ar1 and Ar2 are independently either identical or distinct from each other, and are tetravalent organic groups having one or more aromatic rings. The R1, R2, R4 to R6 in the aforementioned chemical formula (1) each independently contains at least one selected from the group consisting of -H, -F, -CH3, -OCH3, -CF3, and -OCF3, and R3 is an ester group containing -COO- or -OOC-.

[0024] In one embodiment, the step of preparing the polyamic acid can be performed by dissolving or diffusing the diamine in an organic solvent in an inert atmosphere, adding the dianhydride in a dissolved or diffused state in an organic solvent, or adding it in a solid state.

[0025] The diamine according to one embodiment may include at least one selected from the group consisting of 4,4'-diamino-3,3'-dimethylbiphenyl (o-Tolidine, CAS No. 119-93-7), 4,4'-diamino-2,2'-dimethylbiphenyl (m-Tolidine, CAS No. 84-67-3), 2,2'-bis(trifluoromethyl)benzidine (22TFMB, CAS No. 341-58-2), 3,3'-bis(trifluoromethyl)benzidine (33TFMB, CAS No. 346-88-3), 1,4-phenylene-di-4-aminobenzoate ethyl (ABHQ, CAS No. 22095-98-3), and bis(4-aminophenyl) terephthalate (BPTP, CAS No. 16926-73-1).

[0026] A method for producing a polyesterimide resin composition according to another embodiment of the present invention comprises the step of directly reacting a dianhydride with a diisocyanate and comprising a compound of the structural unit shown in the following chemical formula (1). [ka] (In the above chemical formula (1), m and n are mole fractions, where m+n=1, 0.2≦m≦0.8, and 0.2≦n≦0.8.) In the aforementioned chemical formula (1), Ar1 and Ar2 are independently either identical or distinct from each other, and are tetravalent organic groups having one or more aromatic rings. The R1, R2, R4 to R6 in the aforementioned chemical formula (1) each independently contains at least one selected from the group consisting of -H, -F, -CH3, -OCH3, -CF3, and -OCF3, and R3 is an ester group containing -COO- or -OOC-.

[0027] The dianhydride according to one embodiment is 2,2'-hexafluoropropyride diphthalic acid dianhydride, 2,2-bis(4-hydroxyphenyl)propanedibenzoate 3,3'',4,4'-tetracarboxylic acid dianhydride, butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbornane-2 -Aliphatic or alicyclic tetracarboxylic dianhydride comprising at least one selected from the group consisting of -acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5-(2,5-dioxytetrahydrofural)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, and bicyclo[2,2,2]-octo-7-ene-2,3,5,6-tetracarboxylic dianhydride, and pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenylsulfonetetracarboxylic di Anhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 3,3',4,4'-biphenyl ethertetracarboxylic acid dianhydride, 3,3',4,4'-dimethyldiphenylsilanetetracarboxylic acid dianhydride, 3,3',4,4'-tetraphenylsilanetetracarboxylic acid dianhydride, 1,2,3,4-furantetracarboxylic acid dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl Lufon dianhydride, 4,4'-bisphenol A dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, and bis(triphenylphthalic acid)-4,It may include at least one aromatic tetracarboxylic dianhydride selected from the group consisting of 4'-diphenylmethane dianhydride, and at least one selected from the group consisting of

[0028] A further embodiment of the present invention provides a method for producing a polyesterimide film, comprising the steps of: applying a polyamic acid-based resin composition convertible to a polyesterimide resin onto a metal belt; imidizing the polyamic acid-based resin composition thermally or chemically to form a gel film; and separating the gel film from the metal belt.

[0029] A further embodiment of the present invention provides a method for manufacturing a flexible metal foil laminate, comprising the steps of sequentially coating a metal layer with a polyamic acid-based resin layer that can be converted into a thermoplastic polyimide-based resin layer, a non-thermoplastic polyimide-based resin layer, and a thermoplastic polyimide-based resin layer, respectively, and imidizing the polyamic acid-based resin by thermal or chemical conversion.

[0030] A method for manufacturing a flexible metal foil laminate according to a further embodiment of the present invention includes the steps of preparing a multilayer polyimide film having a multilayer structure of thermoplastic polyimide resin layer / non-thermoplastic polyimide resin layer / thermoplastic polyimide resin layer, and laminating a metal layer to one or both sides of the multilayer polyimide film. [Effects of the Invention]

[0031] A polyesterimide resin composition and polyesterimide resin layer according to one embodiment of the present invention may have low hygroscopicity, low thermal expansion, and low dielectric loss characteristics. This allows them to be used as insulating layers in flexible metal foil laminated films. [Brief explanation of the drawing]

[0032] [Figure 1] This is a cross-sectional view of a flexible metal foil laminate according to one embodiment of the present invention. [Figure 2]This is a cross-sectional view of a double-sided flexible metal foil laminate according to one embodiment of the present invention. [Figure 3] This is a cross-sectional view of a cross-sectional flexible metal foil laminate according to another embodiment of the present invention. [Figure 4] This is a cross-sectional view of a cross-sectional flexible metal foil laminate according to a further embodiment of the present invention. [Figure 5] This is a cross-sectional view of a double-sided flexible metal foil laminate according to another embodiment of the present invention. [Figure 6] This is a cross-sectional view of a double-sided flexible metal foil laminate according to a further embodiment of the present invention. [Figure 7] This figure illustrates a method for manufacturing a flexible metal foil laminate according to one embodiment of the present invention. [Figure 8] This figure illustrates a method for manufacturing a flexible metal foil laminate according to another embodiment of the present invention. [Figure 9] This figure illustrates a method for manufacturing a double-sided flexible metal foil laminate according to a further embodiment of the present invention. [Modes for carrying out the invention]

[0033] The embodiments will be described in detail below with reference to the attached drawings. However, various modifications may be made to the embodiments, and the scope of the patent application will not be limited or restricted by such embodiments. All modifications, equivalents, or substitutes to the embodiments should be understood to be included within the scope of the patent.

[0034] The terms used in the embodiments are for illustrative purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “includes” or “having” indicate the presence of features, figures, steps, actions, components, parts, or combinations thereof described in the specification, and should not be understood as preemptively excluding the possibility of the presence or addition of one or more other features, figures, steps, actions, components, parts, or combinations thereof.

[0035] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this embodiment belongs. Commonly used, predefined terms should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as ideal or overly formal unless expressly defined herein.

[0036] Furthermore, when explaining with reference to the attached drawings, the same components will be assigned the same reference numerals regardless of the reference numerals used in the drawings, and redundant explanations will be omitted. In the description of embodiments, if a specific explanation of related prior art is deemed to unnecessarily obscure the gist of the embodiment, such detailed explanation will be omitted.

[0037] Furthermore, in describing the components in the embodiments, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are used to distinguish a component from other components, and the terms do not limit the nature, order, or sequence of the component.

[0038] Components included in any embodiment and components with common functions will be described using the same names in other embodiments. Unless otherwise stated, the descriptions given in one embodiment can be applied to the other embodiments, and specific descriptions will be omitted to the extent that they overlap.

[0039] The polyesterimide resin composition, polyesterimide resin layer, flexible metal thin laminate, and method for producing the same of the present invention will be described in detail below with reference to embodiments, production examples, and drawings. However, the present invention is not limited to these embodiments, production examples, and drawings.

[0040] A polyesterimide resin composition according to one embodiment of the present invention contains a compound of the structural unit shown in the following chemical formula (1). [ka] In the chemical formula (1) above, m and n are mole fractions, m+n=1, 0.2≦m≦0.8, and 0.2≦n≦0.8. In the chemical formula (1) above, Ar1 and Ar2 are independently either identical or different from each other, and are tetravalent organic groups having one or more aromatic rings. R1, R2, R4 to R6 included in the chemical formula (1) above each independently contain at least one selected from the group consisting of -H, -F, -CH3, -OCH3, -CF3, and -OCF3, and R3 is an ester group containing -COO- or -OOC-.

[0041] In one embodiment, in the chemical formula (1), m and n are expressed as mole fractions of m+n=1, 0.2≦m≦0.8, and 0.2≦n≦0.8. The polyesterimide resin according to the present invention can always achieve the expected physical properties through copolymerization of m and n. If m and n are less than 0.2 or greater than 0.8, properties such as moisture absorption rate and dielectric loss tangent will decrease, or the film-forming properties required for a film will be insufficient. Specifically, in the chemical formula (1), if m is less than 0.2 or n is greater than 0.8, the film will not be flexible enough to easily collapse, resulting in insufficient film-forming properties. Furthermore, if m is greater than 0.8 or n is less than 0.2, there are problems such as the dielectric loss tangent exceeding 0.0035 or the moisture absorption rate exceeding 0.5%.

[0042] In one embodiment, the structural unit represented by the chemical formula (1) exists as a block copolymer or a random copolymer.

[0043] The polyesterimide resin of the present invention can achieve desired physical properties through copolymerization of structural units represented by chemical formula (1), where the copolymer may exist as a block copolymer or as a random copolymer.

[0044] In one embodiment, the chemical formula (1) may be present in an amount of 80 mol% or more of the polyesterimide resin layer.

[0045] In one embodiment, the chemical formula (1) may be present in an amount of 80 mol% or more of the polyesterimide resin layer. If the chemical formula (1) is present in an amount of less than 80 mol% of the polyesterimide resin layer, the dielectric loss tangent increases, and other properties such as the coefficient of thermal expansion and moisture absorption rate also deteriorate, so it is necessary to maintain a content within the above range.

[0046] In one embodiment, the chemical formula (1) is the following chemical formula (2). [ka] In the aforementioned chemical formula (2), R3 may be an ester group-containing diamine monomer, and may include bis(4-aminophenyl)terephthalate (BPTP).

[0047] In one embodiment, the chemical formula (1) may be the following chemical formula (2-1). [ka] In the aforementioned chemical formula (2-1), R3 may be an ester group-containing diamine monomer, and may include 1,4-bis(4-aminobenzo-yloxy)benzene (ABHQ).

[0048] In one embodiment, Ar1 and Ar2 constituting the chemical formula (1) may include compounds of the structural unit of the following chemical formula (3). [ka]

[0049] In one embodiment, the compound of the structural unit of chemical formula (3) may contain 50 mol% or more of Ar1 and Ar2 that constitute chemical formula (1).

[0050] In one embodiment, when p is the mole fraction of the structure of chemical formula (3) relative to the total mole fraction of Ar1 and Ar2 constituting the chemical formula (1), 0.5 ≤ p ≤ 1.0 is also possible.

[0051] In one embodiment, by introducing the structures of chemical formula (2) and chemical formula (2-1) among the components of chemical formula (1), the moisture absorption rate of the overall insulating layer, the dielectric loss tangent, and the signal loss of the circuit can be further improved.

[0052] Another embodiment of the present invention includes a polyesterimide resin layer comprising a polyesterimide resin composition according to one embodiment of the present invention.

[0053] A polyesterimide resin composition according to one embodiment of the present invention contains a compound of the structural unit shown in the following chemical formula (1). [ka] In the chemical formula (1) above, m and n are mole fractions, m+n=1, 0.2≦m≦0.8, and 0.2≦n≦0.8. In the chemical formula (1) above, Ar1 and Ar2 are independently either identical or different from each other, and are tetravalent organic groups having one or more aromatic rings. R1, R2, R4 to R6 included in the chemical formula (1) above each independently contain at least one selected from the group consisting of -H, -F, -CH3, -OCH3, -CF3, and -OCF3, and R3 is an ester group containing -COO- or -OOC-.

[0054] In one embodiment, the chemical formula (1) is the following chemical formula (2). [ka]

[0055] In one embodiment, Ar1 and Ar2 constituting the chemical formula (1) may include compounds of the structural unit of the following chemical formula (3). [ka]

[0056] In one embodiment, the compound of the structural unit of chemical formula (3) may contain 50 mol% or more of Ar1 and Ar2 that constitute chemical formula (1).

[0057] In one embodiment, the moisture absorption rate measured at 23°C / 50% relative humidity may be 0.5% or less.

[0058] In order to achieve the low dielectric loss tangent and low moisture absorption rate required by the present invention, the polyesterimide resin layer according to one embodiment of the present invention must incorporate the structure of chemical formula (3) from the structure of chemical formula (1). If the content of p, which is the mole fraction of the structure of chemical formula (3) relative to the total mole fraction of Ar1 and Ar2, is less than 0.5, the moisture absorption rate measured at 23°C / 50% relative humidity will exceed 0.5%, or the dielectric loss tangent at 10 GHz measured at 23°C / 50% relative humidity will exceed 0.0035. However, structures other than chemical formula (3) can be used in a range of 50 mol% or less, within the range necessary for adjusting physical properties such as the thermal expansion coefficient of the resin or film.

[0059] In one embodiment, the dielectric loss tangent at 10 GHz measured at 23°C / 50% relative humidity may be 0.0035 or less.

[0060] The dielectric loss tangent of the insulating layer constituting a flexible metal foil laminate is affected not only by the dielectric loss tangent of the material itself, but also by the moisture absorbed by the insulating layer. Since moisture has a high dielectric loss tangent, keeping the moisture absorption of the insulating layer below a certain level is an important consideration for reducing the signal transmission loss of the flexible metal foil laminate.

[0061] In order for the dielectric loss tangent of the polyesterimide resin or polyesterimide resin layer of the present invention to remain 0.0035 or less at 10 GHz measured at 23°C / 50% relative humidity, the moisture absorption rate measured at 23°C / 50% relative humidity must be 0.5% or less.

[0062] In one embodiment, the linear thermal expansion coefficient measured in the 100°C to 250°C range may be 50 ppm / K or less. If the linear thermal expansion coefficient of the polyesterimide resin with the structure of chemical formula (1) of the present invention exceeds 50 ppm / K, the linear thermal expansion coefficient of the insulating layer will be excessively large, which will adversely affect the dimensional change rate of the flexible metal foil laminate.

[0063] In one embodiment, the polyesterimide resin layer may be a mixture of different resins or inorganic particles.

[0064] The miscible dissimilar resins according to one embodiment may include imide resins, amide-imide resins, dissimilar ester-imide resins, siloxane-imide resins, polysiloxane resins, epoxy resins, acrylic resins, perfluoroalkoxy resins, and fluororesins such as tetrafluoroethylene resins.

[0065] The mixable inorganic particles according to one embodiment may include at least one selected from the group consisting of silica, talc, barium titanate, titanium dioxide, and calcium titanate.

[0066] A flexible metal foil laminate according to a further embodiment of the present invention includes at least one insulating layer and a metal layer formed on one or both sides of the insulating layer, wherein the insulating layer includes a polyesterimide resin layer according to one embodiment of the present invention. Figure 1 is a cross-sectional view of a flexible metal foil laminate according to one embodiment of the present invention, and Figure 2 is a cross-sectional view of a double-sided flexible metal foil laminate according to one embodiment of the present invention.

[0067] Referring to Figure 1, the cross-sectionally flexible metal foil laminate according to one embodiment of the present invention includes an insulating layer and a metal layer.

[0068] Referring to Figure 2, the double-sided flexible metal foil laminate according to one embodiment of the present invention includes a metal layer, an insulating layer, and another metal layer.

[0069] In one embodiment, the insulating layer may further include at least one thermoplastic polyimide resin layer.

[0070] In one embodiment, the thermoplastic polyimide resin layer is a compound containing an imide group represented by the following chemical formula (4). [ka] In the aforementioned chemical formula (4), Ar3 is a tetravalent organic group having one or more aromatic rings in its structure, and Ar4 is an organic group having one or more aromatic rings in its structure.

[0071] In one embodiment, when constructing an insulating layer of a flexible metal foil laminate by laminating with different types of films, an insulating layer can typically be used that is laminated in the form of a thermoplastic polyimide resin layer / polyesterimide resin layer / thermoplastic polyimide resin layer using a thermoplastic polyimide layer that has good flow properties at high temperatures.

[0072] Furthermore, while there are no major restrictions on the thickness of each resin layer, it may have a thickness of 1 μm to 200 μm.

[0073] Figure 3 is a cross-sectional view of a cross-sectional flexible metal foil laminate according to another embodiment of the present invention.

[0074] Referring to Figure 3, a metal layer is formed on the entire surface of the insulating layer, and the insulating layer is composed of a thermoplastic polyimide resin layer / polyesterimide resin layer / thermoplastic polyimide resin layer.

[0075] Figure 4 is a cross-sectional view of a cross-sectional flexible metal foil laminate according to a further embodiment of the present invention.

[0076] Referring to Figure 4, a metal layer is formed on the entire surface of the insulating layer, and the insulating layer is composed of a thermoplastic polyimide resin layer / non-thermoplastic polyimide resin layer / thermoplastic polyimide resin layer.

[0077] Figure 5 is a cross-sectional view of a double-sided flexible metal foil laminate according to another embodiment of the present invention.

[0078] Referring to Figure 5, metal layers are formed on both sides of the insulating layer, and the insulating layer is composed of a thermoplastic polyimide resin layer / polyesterimide resin layer / thermoplastic polyimide resin layer.

[0079] Figure 6 is a cross-sectional view of a double-sided flexible metal foil laminate according to a further embodiment of the present invention.

[0080] Referring to Figure 6, metal layers are formed on both sides of the insulating layer, and the insulating layer is composed of a thermoplastic polyimide resin layer / non-thermoplastic polyimide resin layer / thermoplastic polyimide resin layer.

[0081] In one embodiment, the metal layer may include at least one selected from the group consisting of copper, aluminum, and SUS.

[0082] In one embodiment, the metal layer may be in the form of a thin film. In one embodiment, the storage modulus of the thermoplastic polyimide resin layer measured at 350°C is 1.0 × 10⁻⁶ 8 The coefficient of thermal expansion is Pa or less, and the difference between the coefficients of thermal expansion of the polyesterimide resin layer and the thermoplastic polyimide resin layer measured at 100°C to 380°C may be 100 ppm / K or less.

[0083] The thermoplastic polyimide resin layer according to one embodiment of the present invention is a resin of chemical formula (4) containing imide groups in the repeating units, and its storage modulus, measured at 350°C using a dynamic mechanical analysis (DMA), is 1 × 10⁻⁶. 8 As long as the resin has a Pa rating of less than or equal to 1 Pa, there are no special restrictions on its composition.

[0084] The thermoplastic polyimide resin constituting the insulating layer of the flexible metal foil laminate according to one embodiment of the present invention is a polyimide-based resin that can bond the insulating layer and the metal foil by applying heat and pressure, and has a storage modulus of 1.0 × 10 as measured at 350°C. 8 There are no particular compositional restrictions as long as the Pa is below. However, the storage modulus of the thermoplastic polyimide resin measured at 350°C must be 1.0 × 10⁻⁶. 8 If Pa exceeds the limit, the fluid properties at high temperatures are insufficient, making bonding with metal foil impossible. Therefore, the storage modulus of thermoplastic polyimide measured at 350°C is 1.0 × 10⁻⁶. 8 It must be less than or equal to Pa.

[0085] A thermoplastic polyimide resin according to one embodiment of the present invention can be laminated with a polyesterimide resin layer to form an insulating layer of a flexible metal foil laminate. The polyesterimide resin having the structure of chemical formula (1) is characterized by high crystallinity and low expansion at high temperatures. Therefore, when laminated with a normal thermoplastic polyimide resin layer, delamination between the polyesterimide resin layer and the thermoplastic polyimide resin layer is likely to occur due to the difference in thermal expansion coefficients at high temperatures. This can easily lead to a decrease in copper foil adhesion strength and cosmetic defects during the manufacturing process of the flexible metal foil laminate.

[0086] Therefore, the difference in expansion amounts at high temperatures between the thermoplastic polyimide resin layer and the polyesterimide resin layer according to one embodiment of the present invention must be kept low. The difference in linear thermal expansion coefficients of the polyesterimide layer and the thermoplastic polyimide layer constituting the flexible metal foil laminate according to the present invention is 100 ppm / K or less, measured at 100°C to 350°C.

[0087] In one embodiment, the surface roughness of the metal layer in contact with the insulating layer is Rz ≤ 1.5 μm, and the bonding strength between the metal layer and the insulating layer may be 0.8 kgf / cm or more.

[0088] A flexible copper foil laminated film according to one embodiment of the present invention may be included in a flexible printed circuit board (FPCB). As an electronic component developed to reduce the size and weight of electronic products, a flexible printed circuit board including the flexible copper foil laminated film of the present invention has superior physical properties.

[0089] A flexible printed circuit board according to one embodiment of the present invention may be used as a core component of an electronic product, including at least one selected from the group consisting of mobile phones, cameras, notebook computers, wearable devices, computers and peripherals, mobile communication terminals, video and audio equipment, video cameras, printers, DVD players, TFT LCD display devices, satellite equipment, military equipment, and medical equipment. Preferably, it may be used in at least one of mobile phones, cameras, notebook computers, and wearable devices.

[0090] A further embodiment of the present invention provides a method for producing a polyesterimide resin composition, comprising the steps of preparing a polyamic acid via a reaction between a dianhydride and a diamine, and thermally or chemically converting the polyamic acid.

[0091] In one embodiment, the polyesterimide resin composition is a compound of the structural unit shown in the following chemical formula (1). [ka] In the chemical formula (1) above, m and n are mole fractions, m+n=1, 0.2≦m≦0.8, and 0.2≦n≦0.8. In the chemical formula (1) above, Ar1 and Ar2 are independently either identical or different from each other, and are tetravalent organic groups having one or more aromatic rings. R1, R2, R4 to R6 included in the chemical formula (1) above each independently contain at least one selected from the group consisting of -H, -F, -CH3, -OCH3, -CF3, and -OCF3, and R3 is an ester group containing -COO- or -OOC-.

[0092] In one embodiment, the step of preparing the polyamic acid may be carried out via the reaction of a dianhydride with a diamine.

[0093] In one embodiment, the step of preparing the polyamic acid may be performed by dissolving or diffusing the diamine in an organic solvent in an inert atmosphere, adding the dianhydride in a dissolved or diffused state in an organic solvent, or in a solid state.

[0094] In one embodiment, the organic solvent used when synthesizing the precursor solution of the polyesterimide resin is not particularly limited as long as it dissolves the precursor of the polyesterimide resin. Examples include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N,N-dimethylformamide and N,N-diethylformamide, acetamide solvents such as N,N-dimethylacetamide and N,N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenolic solvents such as phenol, o-, m-, or p-cresol, xylenol, halogenated phenol, and catechol, ether solvents such as diglyme, triglyceride, tetraglyceride, tetrahydrofuran, and dioxysane, alcoholic solvents such as methanol, ethanol, and butanol, cellosolve solvents such as butyl cellosolve, or hexamethylphosphoramide and γ-butyrolactone. It is preferable to use these individually or in mixtures, but aromatic hydrocarbons such as xylene and toluene can also be used.

[0095] In one embodiment, the diamine is not limited to a specific component, but includes p(para)-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminophenyl sulfide, 4,4'-diaminophenyl sulfone, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl, 3,5-diaminobenzoic acid, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindan, 6- Amino-1-(4'-aminophenyl)-1,3,3-trimethylindan, 4,4'-diaminobenzanilide, 3,5-diamino-3'-trifluoromethylbenzanilide, 3,5-diamino-4'-trifluoromethylbenzanilide, 3,4'-diaminodiphenyl ether, 2,7-diaminofluorene, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-methylene-bis(2-chloroaniline), 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-di Amino 5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminophenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(4-aminophenoxy)benzene, 4,4-bis(4-aminophenoxy)-biphenyl, 1,3-bis(4-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)fluorene, 4, Aromatic diamines such as 4'(p-phenyleneisopropylidene)bisaniline, 4,4'(m-phenyleneisopropylidene)bisaniline, 4,4'-oxydianiline, 2,2'-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane, and 4,4'-bis[4-(4-amino-2-trifluoromethyl)phenoxy]-octafluorophenyl; aromatic diamines such as diaminotetraphenylthiophene, which have two amino groups bonded to an aromatic ring and heteroatoms other than the nitrogen atom of the relevant amino group;It may contain at least one selected from the group consisting of aliphatic diamines and alicyclic diamines such as 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptanediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanidylenediethylenediamine, and 4,4'-methylenebis(cyclohexylamine).

[0096] In one embodiment, the diamine may preferably include at least one selected from the group consisting of 4,4'-diamino-3,3'-dimethylbiphenyl (o-Tolidine, CAS No. 119-93-7), 4,4'-diamino-2,2'-dimethylbiphenyl (m-Tolidine, CAS No. 84-67-3), 2,2'-bis(trifluoromethyl)benzidine (22TFMB, CAS No. 341-58-2), 3,3'-bis(trifluoromethyl)benzidine (33TFMB, CAS No. 346-88-3), 1,4-phenylene-di-4-aminobenzoate ethyl (ABHQ, CAS No. 22095-98-3), and bis(4-aminophenyl) terephthalate (BPTP, CAS No. 16926-73-1).

[0097] In one embodiment, the dianhydride is 2,2'-hexafluoropropyride diphthalic acid dianhydride, 2,2-bis(4-hydroxyphenyl)propanedibenzoate 3,3',4,4'-tetracarboxylic acid dianhydride, butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 2,3,5-tricarboxymethyl Aliphatic or alicyclic tetracarboxylic dianhydrides comprising at least one selected from the group consisting of cycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic acid dianhydride, 5-(2,5-dioxytetrahydrofural)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, and bicyclo[2,2,2]-octo-7-ene-2,3,5,6-tetracarboxylic acid dianhydride;and pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-biphenylethertetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3',4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfone dianhydride, It may contain at least one aromatic tetracarboxylic dianhydride selected from the group consisting of 4,4'-bisphenol A dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, and bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride;

[0098] In one embodiment, the inert atmosphere may include at least one inert gas selected from the group consisting of argon, nitrogen, and helium.

[0099] In one embodiment, the step of thermally converting the polyamic acid may be used to convert the polyamic acid to polyimide via high-temperature heat treatment.

[0100] In one embodiment, the step of chemically converting the polyamic acid may be converted to polyimide via a chemical treatment using an anhydride and a catalyst.

[0101] A further embodiment of the present invention provides a method for producing a polyesterimide resin composition, comprising the step of directly reacting a dianhydride with a diisocyanate, and comprising a compound of the structural unit shown in the following chemical formula (1). [ka] In the chemical formula (1) above, m and n are mole fractions, m+n=1, 0.2≦m≦0.8, and 0.2≦n≦0.8. In the chemical formula (1) above, Ar1 and Ar2 are independently either identical or different from each other, and are tetravalent organic groups having one or more aromatic rings. R1, R2, R4 to R6 included in the chemical formula (1) above each independently contain at least one selected from the group consisting of -H, -F, -CH3, -OCH3, -CF3, and -OCF3, and R3 is an ester group containing -COO- or -OOC-.

[0102] In one embodiment, the step of directly reacting the dianhydride with diisocyanate is a method for directly producing polyimide without going through polyamic acid.

[0103] In one embodiment, the dianhydride is 2,2'-hexafluoropropyride diphthalic acid dianhydride, 2,2-bis(4-hydroxyphenyl)propanedibenzoate 3,3',4,4'-tetracarboxylic acid dianhydride, butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 2,3,5-tricarboxymethyl Aliphatic or alicyclic tetracarboxylic dianhydrides comprising at least one selected from the group consisting of cycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic acid dianhydride, 5-(2,5-dioxytetrahydrofural)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, and bicyclo[2,2,2]-octo-7-ene-2,3,5,6-tetracarboxylic acid dianhydride;and pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-biphenylethertetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3',4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfone dianhydride It may also contain at least one aromatic tetracarboxylic dianhydride selected from the group consisting of 4,4'-bisphenol A dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, and bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride;

[0104] In one embodiment, the diisocyanate may include both a siloxane-containing type and a siloxane-free type.

[0105] A further embodiment of the present invention provides a method for producing a polyesterimide film, comprising the steps of: applying a polyamic acid-based resin composition convertible to a polyesterimide resin onto a metal belt; imidizing the polyamic acid-based resin composition thermally or chemically to form a gel film; and separating the gel film from the metal belt.

[0106] In one embodiment, the step of applying the polyamic acid-based resin composition is the step of applying a polyamic acid-based resin composition that can be converted to a polyesterimide resin onto a metal belt.

[0107] In one embodiment, the metal belt may include at least one selected from the group consisting of copper, aluminum, and SUS.

[0108] In one embodiment, a polyamic acid-based resin composition convertible to a polyesterimide resin comprises a polyamic acid depending on the reaction of a dianhydride with a diamine, as described in the method for producing the polyesterimide resin composition. In one embodiment, the step of thermally converting the polyamic acid-based resin composition may involve converting the polyamic acid to a polyesterimide resin via high-temperature heat treatment.

[0109] In one embodiment, the step of chemically converting the polyamic acid-based resin composition may be performed by converting it to a polyesterimide resin via a chemical treatment using an anhydride and a catalyst.

[0110] In one embodiment, separating the gel film from the metal belt and subjecting it to additional heat treatment results in a polyester imide film.

[0111] A further embodiment of the present invention provides a method for manufacturing a flexible metal thin laminate, comprising the steps of sequentially coating a metal layer with a polyamic acid-based resin layer that can be converted into a thermoplastic polyimide-based resin layer, a non-thermoplastic polyimide-based resin layer, and a thermoplastic polyimide-based resin layer, respectively, and imidizing the polyamic acid-based resin by thermal or chemical conversion.

[0112] Figure 7 is a diagram illustrating a method for manufacturing a flexible metal foil laminate according to one embodiment of the present invention.

[0113] Referring to Figure 7, if a polyamic acid resin layer that can be converted to a thermoplastic polyimide resin layer, a polyamic acid resin layer that can be converted to a non-thermoplastic polyimide resin layer, and a polyamic acid resin layer that can be converted to a thermoplastic polyimide resin layer are laminated and then imidized, they are converted into a thermoplastic polyimide resin layer / non-thermoplastic polyimide resin layer / thermoplastic polyimide resin layer.

[0114] In one embodiment, the polyamic acid resin layer convertible to the non-thermoplastic polyimide resin layer may be a polyamic acid resin layer convertible to a polyesterimide resin layer.

[0115] In one embodiment, the non-thermoplastic polyimide resin layer may be a polyesterimide resin layer.

[0116] In one embodiment, the metal layer may contain at least one conductive metal selected from the group consisting of copper, aluminum, silver, palladium, nickel, chromium, molybdenum, and tungsten. The metal layer may also contain an alloy or mixture of conductive metals.

[0117] Preferably, the metal layer may be made of copper.

[0118] In one embodiment, the surface of the metal layer can be subjected to a physical or chemical surface treatment to increase the bonding strength between the metal layer and the polyimide resin layer in contact with it. According to one embodiment of the present invention, the physical or chemical surface treatment may impart a certain surface roughness to the surface of the metal layer.

[0119] The metal layer constituting the flexible metal foil laminate of the present invention may have a surface roughness (Rz) of 1.5 μm or less on the surface in contact with the insulating layer.

[0120] In one embodiment of the present invention, it is necessary to reduce the difference in thermal expansion coefficients between the polyesterimide resin layer and the thermoplastic polyimide resin layer. However, the lower the thermal expansion coefficient of the thermoplastic polyimide resin, the less fluid it is at high temperatures, which usually prevents it from completely filling the surface roughness of the metal foil. Therefore, to compensate for the low high-temperature fluidity of the thermoplastic polyimide resin in one embodiment of the present invention, the surface roughness (Rz) of the metal foil constituting the flexible metal foil laminate must be 1.5 μm or less. As a result, a flexible metal foil laminate can be manufactured in which the bonding strength between the metal foil and the insulating layer is 0.8 kgf / cm or more. Furthermore, the lower the surface roughness of the metal foil, the lower the transmission loss of signals flowing along the circuit.

[0121] In one embodiment, the step of sequentially applying the polyamic acid resin layer, which can be converted to a thermoplastic polyimide resin layer, a non-thermoplastic polyimide resin layer, and a thermoplastic polyimide resin layer, may be performed using knife coating, roll coating, die coating, or curtain coating methods. As the coating solution, it is possible to use not only a polyimide precursor solution, but also a pre-cured, semi-cured, or fully cured polyimide solution.

[0122] In one embodiment, a polyesterimide resin composition according to one embodiment of the present invention can be applied to a thermoplastic polyimide resin layer and then dried to form a polyesterimide resin layer.

[0123] A further embodiment of the present invention provides a method for manufacturing a flexible metal foil laminate, comprising the steps of preparing a multilayer polyimide film having a multilayer structure of thermoplastic polyimide resin layer / non-thermoplastic polyimide resin layer / thermoplastic polyimide resin layer, and laminating a metal layer to one or both sides of the multilayer polyimide film.

[0124] In one embodiment, the non-thermoplastic polyimide resin layer may be a polyesterimide resin layer.

[0125] In one embodiment, a precursor resin that can be converted into a thermoplastic polyimide resin layer is applied to both sides of a non-thermoplastic polyimide film, and then heat-treated to form a multilayer polyimide film having a multilayer structure of thermoplastic polyimide resin layer / non-thermoplastic polyimide resin layer / thermoplastic polyimide resin layer.

[0126] In one embodiment, a polyesterimide resin composition according to one embodiment of the present invention can be applied to a thermoplastic polyimide resin layer and then dried to form a polyesterimide resin layer.

[0127] Figure 8 is a diagram illustrating a method for manufacturing a flexible metal foil laminate according to another embodiment of the present invention.

[0128] Referring to Figure 8, a method for manufacturing a double-sided flexible metal foil laminate according to one embodiment of the present invention allows for the production of a double-sided flexible metal foil laminate by laminating a metal layer to one side opposite to a multilayer polyimide film which includes a multilayer structure of thermoplastic polyimide resin layer / non-thermoplastic polyimide resin layer / thermoplastic polyimide resin layer formed on a metal layer.

[0129] Figure 9 is a drawing illustrating a method for manufacturing a double-sided flexible metal thin laminate according to a further embodiment of the present invention.

[0130] Referring to Figure 9, in another embodiment of the present invention, a method for manufacturing a double-sided flexible metal foil laminate involves separately preparing two layers: a multilayer polyimide film containing a multilayer structure of a thermoplastic polyimide resin layer / non-thermoplastic polyimide resin layer / thermoplastic polyimide resin layer and a metal layer, and then laminating the metal layer to both sides of the polyimide film to produce a double-sided flexible metal foil laminate.

[0131] The present invention will be described in detail below with reference to the following manufacturing examples and comparative manufacturing examples. However, the technical concept of the present invention will not be limited or restricted thereby.

[0132] The abbreviations used in the following examples, manufacturing examples, and comparative manufacturing examples are as follows: DMAc: N,N-dimethylacetamide PMDA: Pyromellitic dianhydride BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride m-TD: m-Tolidine BPTP: Bis(4-aminophenyl)terephthalate TPE-R: 1,3-Bis(4-aminophenoxy)benzene BAPP: 2,2-Bis[4-(4-aminophenoxy)phenyl]propane

[0133] The physical properties mentioned in this invention were measured by the following method. (1) Measurement of dielectric loss tangent The insulating layer was cut into 8cm x 8cm squares, pre-treated for 24 hours on a constant temperature and humidity surface at 23°C / 50% relative humidity to allow moisture absorption, and then measured at 10GHz using the SPDR (split post dielectric resonator) method.

[0134] (2) Measurement of moisture absorption rate The insulating layer was cut into 5cm x 5cm squares. The cut test pieces were dried in a 150°C convection oven for more than one hour, and their mass was measured, which was taken as the dry mass (W1). The test pieces with the measured dry weight were pre-treated for 24 hours on a constant temperature and humidity surface at 23°C / 50% relative humidity to allow them to absorb moisture, and their mass was measured after moisture absorption, which was taken as the mass (W2). The measured values ​​were substituted into equation (1) to calculate the result.

number

[0135] (3) Measurement of linear thermal expansion coefficient The measurement was performed using Hitachi's TMA7100 model, with a tension of 0.03 N, in a nitrogen atmosphere, and the temperature was increased from 30°C to 400°C at a rate of 10°C per minute. Of the measured values, the average linear thermal expansion coefficient measured in the interval between 100°C and 250°C was defined as the linear thermal expansion coefficient from 100°C to 250°C.

[0136] (4) Measurement of the storage modulus Using Hitachi's DMA7100 model, measurements were taken under conditions of tensile force of 0.1 N, frequency of 10 Hz, and displacement of 30 μm, while the temperature was increased from 30°C to 400°C at a rate of 5°C per minute in a nitrogen atmosphere.

[0137] (5) Evaluation of film formation characteristics When the insulating layer was folded three times at a 180° angle at the same position, the film was considered good if there were no visible tears or rips in the insulating layer, and poor if there were visible tears or rips.

[0138] (6) Measurement of the surface roughness of the matte side of the metal foil. The surface texture (matt) of the metal foil was measured in accordance with JIS 1994.

[0139] (7) Evaluation of adhesion strength with metal foil To measure the bonding strength (peel strength) between the insulating layer and the metal layer of a flexible metal foil laminate, the metal layer of the laminate was patterned in 1 mm width strips, and the 180° peel strength was measured using a universal testing machine (UTM). Other measurements were performed according to the JIS C6471 standard.

[0140] [Example 1] m-TD and BPTP were gradually dissolved in DMAc at room temperature in a ratio of 82:20 mol%, respectively. Then, a mixture was prepared by adding 50 mol% BPDA and 50 mol% PMDA to a total diamine content of 102 mol% in several steps. The mixture was reacted at room temperature for 24 hours to produce a precursor solution for polyesterimide resin. In this solution, the solid content of the monomer in the total solution containing the monomer and DMAc was 13% by weight.

[0141] Subsequently, the precursor solution produced by the above method was applied to a 12 μm thick electrolytic copper foil so that the thickness after the final heat treatment was 20 μm, and then dried in a hot air dryer at 140°C for 10 minutes to form a precursor layer. The precursor film applied to the copper foil was heat-treated together with the copper foil in a nitrogen atmosphere at a temperature of 130°C to 395°C for 8 minutes to imide the precursor layer on the copper foil. The copper foil was removed from the copper foil / polyesterimide resin laminate by chemical etching to obtain a polyesterimide resin layer, and the physical properties of the film were measured and are shown in Table 2.

[0142] [Examples 2-5 and Comparative Examples 1-3] Precursor solutions were obtained using the same method as in Example 1, according to the components and content listed in Table 1. Subsequently, a resin film was obtained using the same method as in Example 1, and its physical properties are listed in Table 2.

[0143] [Table 1] [Table 2]

[0144] Referring to Table 2, the polyesterimide resin layers according to Examples 1 to 5 of the present invention have a lower dielectric loss tangent of 0.0032 or less, a lower moisture absorption rate of generally 0.46% or less, and a lower coefficient of thermal expansion (CTE) of 50 ppm / K or less compared to Comparative Examples 1 to 3, confirming that they have good film-forming characteristics.

[0145] The polyesterimide resin layers in Comparative Examples 1 to 3 of the present invention generally exhibited high dielectric loss tangents of 0.0034 or higher, and comparative examples 1 and 2, with their low moisture absorption rates, could not have their coefficient of thermal expansion (CTE) measured, confirming poor film formation characteristics. Furthermore, comparative example 3 was found to have excessively high dielectric loss tangents and moisture absorption rates.

[0146] Manufacturing of thermoplastic polyimide resins [Example 6] TPE-R was gradually dissolved in DMAc at room temperature, and then 101 mol% BPDA per 100 mol% of the total diamine was added in several steps to prepare a mixture. The mixture was reacted at room temperature for 24 hours. Here, a precursor solution was prepared in which the solid content of the monomer in the total solution containing the monomer and DMAc was 10% by weight.

[0147] Subsequently, the precursor solution prepared according to the above method was applied to a 12 μm thick electrolytic copper foil so that the thickness after final heat treatment was 20 μm, and then dried in a hot air dryer at 140°C for 10 minutes to form a precursor layer. The precursor film applied to the copper foil was heat-treated together with the copper foil in a nitrogen atmosphere at a temperature of 130°C to 395°C for 8 minutes to imide the precursor layer on the copper foil. After removing the copper foil from the copper foil / thermoplastic polyimide resin laminate by chemical etching to obtain a thermoplastic polyimide resin layer, the physical properties of the film were measured.

[0148] [Example 7 and Comparative Examples 5-6] A precursor solution was obtained using the same method as in Example 6, with the components and content listed in Table 3 below. Subsequently, a resin film was obtained using the same method as in Example 6, and its physical properties were measured.

[0149] [Table 3]

[0150] Manufacturing of flexible metal foil laminates [Manufacturing Example 1] A thermoplastic polyimide resin, manufactured according to Example 6, was applied to a 12 μm thick electrolytic copper foil with a surface roughness (Rz) of 1.0 μm after final heat treatment to a thickness of 3.0 μm, and dried at 140°C to form a first thermoplastic polyimide layer. Next, the polyesterimide resin layer produced via Example 2 was subjected to a final heat treatment on the first thermoplastic polyimide layer, then coated to a thickness of 19 μm and dried at 140°C to form a polyesterimide layer. Subsequently, the thermoplastic polyimide resin produced via Example 6 was applied to the polyesterimide resin layer to a thickness of 3.0 μm after final heat treatment and dried at 140°C to form a second thermoplastic polyimide resin layer. The precursor film applied to the copper foil was heat-treated together with the copper foil at a temperature of 130°C to 395°C for 8 minutes under a nitrogen atmosphere to imidize the precursor layer on the copper foil. The properties of the flexible metal foil laminate produced in this manner are shown in Table 4 below.

[0151] [Manufacturing Example 2] A flexible metal foil laminate was manufactured using the same method as in Manufacturing Example 1, based on the layer configurations shown in Table 4.

[0152] [Comparative Manufacturing Example 1 and Comparative Manufacturing Example 2] A flexible metal foil laminate was manufactured using the same method as in Manufacturing Example 1, based on the layer configurations shown in Table 4.

[0153] [Table 4]

[0154] Referring to Table 4, it was confirmed that the difference in the thermal expansion coefficients of the flexible metal foil laminates produced by Manufacturing Example 1 and 2 of the present invention is 12 or less, while the difference in the thermal expansion coefficients of the flexible metal foil laminates produced by Comparative Manufacturing Example 1 and 2 is 190 or more, which is clearly different.

[0155] Furthermore, the copper foil adhesion strengths of the flexible metal foil laminates produced by Manufacturing Examples 1 and 2 of the present invention were 1.24 kgf / cm and 1.19 kgf / cm, respectively, which were found to be significantly different from the copper foil adhesion strengths of the flexible metal foil laminates produced by Comparative Manufacturing Examples 1 and 2, which were 0.57 kgf / cm and 0.86 kgf / cm, respectively.

[0156] The polyesterimide resin layer according to the present invention has been confirmed to maintain low moisture absorption, low thermal expansion, and low dielectric loss tangent properties, and can be used as an insulating layer in a flexible metal foil laminate.

[0157] Although embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is not limited to the embodiments described above, and a person with ordinary skill in the art can apply various technical modifications and variations based on the above. For example, the described techniques may be performed in a different order than described, and / or the described systems, structures, devices, circuits, and other components may be combined or assembled in a different manner than described, or substituted or replaced by other components or equivalents, and still achieve appropriate results.

[0158] Therefore, other embodiments, other examples, and those equivalent to the claims described below also fall within the scope of the claims.

Claims

1. At least one insulating layer, A metal layer formed on one or both sides of the insulating layer, Includes, The insulating layer comprises a polyesterimide resin layer and at least one thermoplastic polyimide resin layer. The polyesterimide resin layer comprises a polyesterimide resin composition containing a compound of the structural unit shown in the following chemical formula (1), The thermoplastic polyimide resin layer consists of a compound containing an imide group represented by the following chemical formula (4): The storage modulus of the thermoplastic polyimide resin layer, measured at 350°C, was 1.0 × 10⁻⁶. ８ It is less than or equal to Pa, The difference in the linear thermal expansion coefficients of the polyesterimide resin layer and the thermoplastic polyimide resin layer, measured at 100°C to 380°C, is 100 ppm / K or less. Flexible metal foil laminate. 【Chemistry 1】 (In the above chemical formula (1), m and n are mole fractions, where m + n = 1, 0.2 ≤ m ≤ 0.8, and 0.2 ≤ n ≤ 0.8.) In the aforementioned chemical formula (1), Ar1 and Ar2 are independently either identical or distinct from each other, and are tetravalent organic groups having one or more aromatic rings. R contained in the above chemical formula (1) １ , R ２ , R ４ to R ６ are each independently at least one selected from the group consisting of -H, -F, -CH ３ , -OCH ３ , -CF ３ and -OCF ３ ; R ３ is an ester group and comprises -COO- or -OOC-) 【Chemistry 2】 (Of the chemical formula (4) above, Ar3 is a tetravalent organic group having one or more aromatic rings in its structure, Ar4 is an organic group that has one or more aromatic rings in its structure.

2. The flexible metal foil laminate according to claim 1, wherein the structural unit represented by the chemical formula (1) exists as a block copolymer or a random copolymer.

3. The flexible metal foil laminate according to claim 1, wherein the polyesterimide resin constituting the polyesterimide resin layer contains 80 mol% or more of the structural unit represented by the chemical formula (1).

4. The flexible metal foil laminate according to claim 1, wherein the chemical formula (1) is the following chemical formula (2). 【Transformation 3】

5. The flexible metal foil laminate according to claim 1, wherein Ar1 and Ar2 constituting the chemical formula (1) include the structure of the following chemical formula (3). 【Chemistry 4】

6. The flexible metal foil laminate according to claim 5, wherein 50 mol% or more of the Ar1 and Ar2 constituting the chemical formula (1) include the structure of the chemical formula (3).

7. The flexible metal foil laminate according to claim 1, wherein the polyesterimide resin layer has a moisture absorption rate of 0.5% or less as measured at 23°C / 50% relative humidity.

8. The flexible metal foil laminate according to claim 1, wherein the polyesterimide resin layer has a dielectric loss tangent of 0.0035 or less at 10 GHz measured at 23°C / 50% relative humidity.

9. The flexible metal foil laminate according to claim 1, wherein the polyesterimide resin layer has a linear thermal expansion coefficient of 50 ppm / K or less, measured in the range of 100°C to 250°C.

10. The surface roughness of the metal layer in contact with the insulating layer is Rz ≤ 1.5 μm. The flexible metal foil laminate according to claim 1, wherein the bonding strength between the metal layer and the insulating layer is 0.8 kgf / cm or more.

11. The step includes a direct reaction between a dianhydride and a diisocyanate, A method for producing a polyesterimide resin composition containing a compound of the structural unit shown in the following chemical formula (1). 【Transformation 5】 (In the above chemical formula (1), m and n are mole fractions, where m + n = 1, 0.2 ≤ m ≤ 0.8, and 0.2 ≤ n ≤ 0.8.) In the aforementioned chemical formula (1), Ar1 and Ar2 are independently either identical or distinct from each other, and are tetravalent organic groups having one or more aromatic rings. R included in the above chemical formula (1) １ , R ２ , R ４ R ６ These are, independently, -H, -F, and -CH. ３ , -OCH ３ , -CF ３ and -OCF ３ It includes at least one selected from the group consisting of R ３ (This is an ester group, and includes -COO- or -OOC-)

12. The aforementioned two anhydrous substances are 2,2'-Hexafluoropropyride diphthalic acid dianhydride, 2,2-Bis(4-hydroxyphenyl)propanedibenzoate, 3,3',4,4'-Tetracarboxylic acid dianhydride, Butanetetracarboxylic acid dianhydride, 1,2,3,4-Cyclobutanetetracarboxylic acid dianhydride, 1,3-Dimethyl-1,2,3,4-Cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-Cyclopentanetetracarboxylic acid dianhydride, 2,3,5-Tricarboxycyclopentyl an aliphatic or alicyclic tetracarboxylic dianhydride comprising at least one selected from the group consisting of dianhydride acetate, 3,5,6-tricarboxynorbornane-2-dianhydride acetate, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5-(2,5-dioxytetrahydrofural)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, and bicyclo[2,2,2]-octo-7-ene-2,3,5,6-tetracarboxylic dianhydride, Pyromelitter dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 3,3',4,4'-biphenylsulfonetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 3,3',4,4'-biphenylethertetracarboxylic acid dianhydride, 3,3',4,4'-dimethyldiphenylsilanetetracarboxylic acid dianhydride, 3,3',4,4'-tetraphenylsilanetetracarboxylic acid dianhydride, 1,2,3,4-furantetracarboxylic acid dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy) At least one aromatic tetracarboxylic dianhydride selected from the group consisting of diphenylsulfone dianhydride, 4,4'-bisphenol A dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, and bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride, A method for producing a polyesterimide resin composition according to claim 11, comprising at least one selected from the group consisting of the following.

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