Fluororesin composition, fluororesin film, laminated film, and metal laminate plate

Abstract

To provide: a fluororesin composition which can be used for a metal laminate having excellent dielectric loss tangent, adhesiveness, linear expansion coefficient and UV laser processability; a fluororesin film; a laminated film; and a metal laminate.SOLUTION: There is provided a fluororesin composition which comprises a fluororesin, a liquid crystal polymer resin, a polyimide resin and an inorganic filler, wherein the polyimide resin has a water absorption of 1.0 mass% or less, the content of the fluororesin is 55 mass%or more based on the total amount of the fluororesin composition, the content of the polyimide resin is 0.5 to 5.0 mass% based on the total amount of the fluororesin composition and the content of the inorganic filler is 18 to 67 mass% based on the content of the fluororesin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a fluororesin composition, a fluororesin film, a laminated film, and a metal laminate plate. [Background technology]

[0002] Polyimide resin is widely used as an insulating material for flexible printed circuit boards (FPCs), but it is becoming difficult for polyimide resin alone to meet the demand for high-speed transmission (low transmission loss) that comes with the high-speed communication of electronic devices and the improved safety features of automobiles equipped with millimeter-wave radar, etc. It is known that the dielectric constant and dielectric loss tangent of the insulating material affect this high-speed transmission.

[0003] For this reason, fluororesins such as PTFE and liquid crystal polymers (LCPs) are attracting attention as insulating materials with excellent dielectric properties. However, they have poor adhesion to different materials such as metal foils, and because fluororesins are colorless and transparent when made into a film, they are difficult to process with UV lasers when forming circuits, meaning that they can only be processed with CO2 lasers.

[0004] In addition, fluororesin has a large coefficient of linear expansion (CTE) and dimensional stability issues, making it difficult to use it alone in the insulating layer of FPC materials, so rigid materials that have been given dimensional stability by impregnating glass cloth with fluororesin are widely used. However, using glass cloth increases the product thickness, and there is a problem in that the dielectric constant of the insulating material deteriorates due to the glass.

[0005] As a means of solving these problems, the use of a laminated film of polyimide resin and fluororesin for the insulating layer of FPC materials has been investigated, and it has been confirmed that this is possible to improve the CTE. Also, although UV laser processability can be improved by adding coloring components to the fluororesin film, it cannot be said that UV laser processability and dielectric properties have been achieved at the same time, as the coloring components deteriorate the dielectric properties of the insulating material.

[0006] For example, Patent Document 1 discloses a low dielectric polyimide substrate using a thermocompression-bondable laminated polyimide film and a fluororesin film.

[0007] Furthermore, Patent Document 2 discloses a fluororesin film containing tetrafluoroethylene polymer particles and a thermosetting polymer which is a precursor of a polyimide resin, a polyimide resin, a cyanate ester resin, or an epoxy resin.

[0008] Furthermore, Patent Document 3 discloses that the CTE can be reduced by adding a thermosetting polyimide to a tetrafluoroethylene-based polymer, and also discloses that the UV laser processability can be improved by adding a functional compound containing specific atoms consisting of titanium, silicon, magnesium, aluminum, cerium, and nitrogen. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 4029732 [Patent Document 2] Patent Publication No. 2020-37661 [Patent Document 3] Patent Publication No. 2020-37662 Summary of the Invention [Problem to be solved by the invention]

[0010] The low dielectric polyimide substrate of Patent Document 1 has a problem in that it uses a fluororesin film, which does not absorb light in the UV region, making UV laser processing difficult.

[0011] Furthermore, the polyimide resin precursors and polyimide resins used in the thermosetting polymers of Patent Document 2 have excellent heat resistance, but their high water absorption and high dielectric properties (particularly dielectric loss tangent) are thought to degrade high-speed transmission. On the other hand, cyanate ester resins and epoxy resins have low water absorption, but the resins themselves have the problem of low heat resistance.

[0012] Furthermore, the thermosetting polyimide resin in Patent Document 3 has a high water absorption rate, which deteriorates the dielectric properties (particularly the dielectric loss tangent). Also, although it is described that liquid crystalline polyester can be added within a range that does not impair the effects, no specific examples of addition are given.

[0013] In other words, in order to apply these films to high-speed communications and millimeter-wave radar applications and to further improve circuit reliability, these films and metal laminates using the films are required to have excellent dielectric dissipation factor (hereinafter also referred to simply as dielectric dissipation factor), adhesion to dissimilar materials such as metal foil (hereinafter also referred to simply as adhesion), and linear expansion coefficient, as well as excellent UV laser processability that enables the formation of fine through-holes.

[0014] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fluororesin composition from which a metal laminate plate excellent in dielectric tangent, adhesiveness, linear expansion coefficient, and UV laser processability can be obtained, and a fluororesin film, a laminate film, and a metal laminate plate using the same. [Means for solving the problem]

[0015] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result have found that the above-mentioned problems can be solved by using a fluororesin composition comprising a fluororesin, a liquid crystal polymer resin, a polyimide resin, and an inorganic filler, wherein the polyimide resin has a water absorption rate of 1.0 mass% or less, the content of the fluororesin is 55 mass% or more relative to the total amount of the fluororesin composition, the content of the polyimide resin is 0.5 to 5.0 mass% relative to the total amount of the fluororesin composition, and the content of the inorganic filler is 18 to 67 mass% relative to the content of the fluororesin, and have completed the present invention.

[0016] That is, the present invention is as follows. (1) Fluorine resin and a liquid crystal polymer resin; A polyimide resin, and an inorganic filler, The polyimide resin has a water absorption rate of 1.0% by mass or less, the content of the fluororesin is 55% by mass or more based on the total amount of the fluororesin composition, the content of the polyimide resin is 0.5 to 5.0 mass% based on the total amount of the fluororesin composition; The content of the inorganic filler is 18 to 67 mass% relative to the content of the fluororesin. Fluororesin composition. (2) The content of the liquid crystal polymer resin is 35% by mass or more based on the total amount of the liquid crystal polymer resin and the polyimide resin. The fluororesin composition according to (1). (3) the polyimide resin is a polyimide resin precursor resin obtained by reacting a diamine component with an acid dianhydride component, the diamine component includes at least one of p-phenylenediamine, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2-(4-aminophenyl)benzoxazole-5-amine, and 1,3-bis(4-aminophenoxy)benzene; the acid dianhydride component contains at least one of p-phenylene bis(trimellitic acid monoester acid anhydride) and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride; The fluororesin composition according to (1) or (2). (4) The inorganic filler includes a silica filler. The fluororesin composition according to any one of (1) to (3). (5) The inorganic filler further comprises one or more selected from the group consisting of boron nitride and titanium oxide. (4) The fluororesin composition according to (4). (6) The fluororesin is selected from at least one of perfluoroalkoxyalkane and polytetrafluoroethylene. The fluororesin composition according to any one of (1) to (5). (7) the fluororesin contains perfluoroalkoxyalkane and polytetrafluoroethylene, The content of the perfluoroalkoxyalkane is 90% by mass or more relative to the total amount of the fluororesin. (6) The fluororesin composition according to (6). (8) A fluororesin film obtained by using the fluororesin composition according to any one of (1) to (7). (9) a layer formed using the fluororesin composition according to any one of (1) to (7); a layer made of a non-thermoplastic resin, At least one of the outermost layers is a layer formed using the fluororesin composition. Laminated film. (10) the coefficient of linear expansion of the non-thermoplastic resin is smaller than the coefficient of linear expansion of the fluororesin composition; The laminated film according to (9). (11) The non-thermoplastic resin is a polyimide resin. The laminated film according to (9) or (10). (12) A fluororesin film or laminate film according to any one of (8) to (11), A metal foil is provided. Metal laminate. (13) The metal foil is any one selected from the group consisting of copper foil, copper alloy foil, stainless steel foil, and aluminum foil. (12) The metal laminate according to (12). (14) the surface roughness (Rz) of the metal foil on the surface in contact with the layer made of the fluororesin composition or the layer made of the non-thermoplastic resin is 1.5 μm or less; The metal laminate according to (12) or (13). [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a fluororesin composition from which a metal laminate plate excellent in dielectric tangent, adhesiveness, linear expansion coefficient, and UV laser processability can be obtained. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the gist of the present invention.

[0019] 1. Fluororesin composition The fluororesin composition according to the present invention comprises a fluororesin, a liquid crystal polymer resin, a polyimide resin, and an inorganic filler, wherein the polyimide resin has a water absorption of 1.0% by mass or less, the fluororesin content is 55% by mass or more relative to the total amount of the fluororesin composition, the polyimide resin content is 0.5 to 5.0% by mass relative to the total amount of the fluororesin composition, and the inorganic filler content is 18 to 67% by mass relative to the total amount of the fluororesin. The fluororesin composition may also contain other components as necessary.

[0020] By including a specific amount of fluororesin in the fluororesin composition, the dielectric loss tangent of the metal laminate sheet obtained using the composition can be reduced, and by including a specific amount of liquid crystal polymer, the dielectric loss tangent of the metal laminate sheet obtained using the composition can be reduced and the adhesiveness can be improved. Furthermore, by including a specific amount of polyimide resin, the UV laser processability of the metal laminate sheet obtained using the composition can be improved without compromising the adhesiveness of the metal laminate sheet obtained using the composition. By including a specific amount of inorganic filler, the linear expansion coefficient of the metal laminate sheet obtained using the composition can be reduced without compromising the adhesiveness of the metal laminate sheet obtained using the composition. However, the relationship between the content and effect of each component is not limited to the above. Each component will be described in detail below.

[0021] 1.1.Fluororesin The fluororesin of the present embodiment is not particularly limited as long as it is a resin containing fluorine, and examples thereof include polymers containing a monomer having a fluorine atom (hereinafter referred to as a "fluorine-containing monomer") as a polymerization component. The fluororesin may be a homopolymer composed of one type of polymerization component, or a copolymer composed of two or more types of polymerization components.

[0022] Examples of fluorine-containing monomers include unsaturated fluorinated hydrocarbons (e.g., fluoroolefins such as tetrafluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene) and ether group-containing unsaturated fluorinated hydrocarbons (e.g., fluorinated alkyl vinyl ethers). These fluorine-containing monomers may be used alone or in combination of two or more.

[0023] The fluororesin is not particularly limited, but examples thereof include perfluoroalkoxyalkane (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), and polyvinylidene fluoride (PVDF). These fluororesins may be used alone or in combination of two or more.

[0024] Among these, it is preferable to select from at least one of perfluoroalkoxyalkane (PFA) and polytetrafluoroethylene (PTFE) because they tend to have a better dielectric loss tangent.Moreover, it is more preferable that the fluororesin contains perfluoroalkoxyalkane (PFA) and polytetrafluoroethylene (PTFE), and the content of perfluoroalkoxyalkane (PFA) is 90 mass% or more, and even more preferably 95 mass% or more, based on the total amount of the fluororesin.

[0025] As the fluororesin, a product prepared by a known method or a commercially available product may be used.

[0026] The content of the fluororesin is 55% by mass or more, preferably 55% by mass or more and 80% by mass or less, more preferably 65% ​​by mass or more and 80% by mass or less, and even more preferably 70% by mass or more and 80% by mass or less, based on the total amount of the fluororesin composition. When the content of the fluororesin is 55% by mass or more based on the total amount of the fluororesin composition, the dielectric loss tangent tends to be reduced, and when the content of the fluororesin is 80% by mass or less based on the total amount of the fluororesin composition, the effects of the present invention tend to be achieved within a range that does not impair the effects of the present invention.

[0027] 1.2. Liquid crystal polymer resin The liquid crystal polymer (LCP) of this embodiment is a thermoplastic polymer that forms an anisotropic molten phase, and generally refers to what is called a thermotropic liquid crystal polymer. Examples of such liquid crystal polymer resins include, but are not limited to, thermoplastic liquid crystal polyesters (also called thermotropic liquid crystal polyesters) and thermoplastic liquid crystal polyester amides (also called thermotropic liquid crystal polyester amides). Among these, thermoplastic liquid crystal polyesters are preferred in terms of dielectric loss tangent and adhesiveness.

[0028] As such a liquid crystal polymer (LCP), a preparation prepared by a known method may be used, or a commercially available product may be used.

[0029] Specific examples of liquid crystal polymers that can be used in this embodiment include, but are not limited to, "LAPEROS" manufactured by Polyplastics Co., Ltd., "VECTRA" manufactured by Celanese Corporation, "UENO LCP" manufactured by Ueno Pharmaceutical Co., Ltd., "Sumikasuper LCP" manufactured by Sumitomo Chemical Co., Ltd., "XYDAR" manufactured by SOLVAY SPECIALTY POLYMERS, "XYDAR" manufactured by ENEOS Corporation, and "Civelas" manufactured by Toray Industries, Inc.

[0030] The content of the liquid crystal polymer resin is preferably 35% by mass or more, more preferably 35% by mass or more and 85% by mass or less, even more preferably 45% by mass or more and 75% by mass or less, and even more preferably 55% by mass or more and 65% by mass or less, based on the total amount of the liquid crystal polymer resin and the polyimide resin. When the content of the liquid crystal polymer resin is 35% by mass or more based on the total amount of the liquid crystal polymer resin and the polyimide resin, the dielectric loss tangent tends to be reduced and the adhesiveness tends to be improved. Furthermore, when the content of the liquid crystal polymer resin is 85% by mass or less based on the total amount of the liquid crystal polymer resin and the polyimide resin, the above effects tend to be achieved within a range that does not impair the effects of the present invention.

[0031] 1.3.Polyimide resin The polyimide resin of this embodiment is not particularly limited as long as it has a water absorption rate of 1.0 mass % or less, but examples thereof include thermoplastic polyimide resins and thermosetting polyimide resins. From the viewpoint of the linear expansion coefficient, thermosetting polyimide resins are particularly preferred. Such thermosetting polyimide resins are not particularly limited, but examples thereof include condensation polyimide resins obtained by copolymerizing acid dianhydrides and diamines, bismaleimide resins, and maleimide resins. Among these, condensation polyimide resins are preferred from the viewpoints of availability, heat resistance, and adhesiveness.

[0032] In this embodiment, the "water absorption rate" refers to the water absorption rate measured by the following procedure. A sample of a two-layer flexible metal laminate consisting of copper foil and polyimide resin, in which all of the copper foil had been removed by etching, was dried at 105°C for 0.5 hours, and then cooled to room temperature. The mass of the sample was defined as the initial value (m0). The sample was then immersed in pure water at 23°C for 24 hours, after which the mass (md) was measured. The water absorption rate under treatment condition D-24 / 23 (treated in pure water at 23°C for 24 hours) was calculated from the change in mass between the initial value and the mass after immersion using the following formula (1). Water absorption rate (%)=(md-m0)×100 / m0...(1)

[0033] The two-layer flexible metal laminate is not particularly limited, but may be produced, for example, by applying the polyimide resin precursor obtained in Synthesis Example 1 described below to the roughened surface of a low-roughness copper foil using a bar coater so that the thickness of the resin layer after imidization is 12.5 μm, drying at 130°C for 10 minutes, cooling the copper foil on which the polyimide resin precursor has been applied and dried to room temperature, and then heating it stepwise to 360°C (object temperature), holding it at 360°C for 2 hours, and then naturally cooling it to room temperature.

[0034] The method for producing a polyimide resin having a water absorption rate of 1.0 mass % or less is not particularly limited, but may be, for example, the method described in the examples below.

[0035] Furthermore, polyimide resins are resins obtained by curing and dehydrating polyimide resin precursor resins, and polyimide resin precursor resins are resins obtained by reacting an acid dianhydride component with a diamine component. The inclusion of polyimide resins improves the light absorption of fluororesin compositions in the UV region without impairing adhesion to dissimilar materials, enabling UV laser processing. Furthermore, the interaction between the polyimide resin and LCP resin in the fluororesin composition tends to improve the adhesion between the two components.

[0036] In the above, the drying and curing conditions for curing and dehydrating the polyimide resin precursor resin to obtain the polyimide resin are not particularly limited, but examples include a heating temperature of 80 to 360°C and a heating time of 1 to 30 minutes.

[0037] The acid dianhydride is not particularly limited, and examples thereof include pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)propane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)propane dianhydride, Examples of suitable dianhydrides include 2,2-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, p-phenylene bis(trimellitic acid monoester anhydride), ethylene bis(trimellitic acid monoester anhydride), bisphenol A bis(trimellitic acid monoester anhydride), 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, and 2,2-bis(4-(3,4-dicarboxyphenoxy)phenyl)hexafluoropropane dianhydride. Among these, the dianhydride component preferably includes at least one of p-phenylene bis(trimellitic acid monoester anhydride) and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride. This tends to lower the water absorption rate of the polyimide resin and further reduce the dielectric loss tangent of the fluororesin composition.

[0038] These acid dianhydrides may be used alone or in combination of two or more.

[0039] The diamine is not particularly limited, but examples thereof include p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,4-diaminoxylene, 2,4-diaminodurene, 4,4'-diaminodiphenylmethane, 4,4'-methylenebis(2-methylaniline), 4,4'-methylenebis(2-ethylaniline), 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-methylenebis(2,6-diethylaniline), 4,4'-diamino Diphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 2,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminobenzanilide, benzidine, 3,3'-dihydroxybenzidine, 3,3'-dimethoxybenzidine, o-tolidine, m-tolidine, 2,2'-bis(trifluoromethyl) bis(4-aminophenoxy)benzidine, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(3-aminophenoxy)phenyl)sulfone, bis(4-(4-aminophenoxy)phenyl)sulfone, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, p-terphenylenediamine, 4,4'-methylenebis(cyclohexylamine), isophoronediamine, trans-1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1,4-cyclohexanebis(methylamine), 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane, 3,8-bis(aminomethyl)tricyclo[5.2.1]heptane.Examples of suitable diamine components include decane, 1,3-diaminoadamantane, 2,2-bis(4-aminocyclohexyl)propane, 2,2-bis(4-aminocyclohexyl)hexafluoropropane, 1,3-propanediamine, 1,4-tetramethylenediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, and 2-(4-aminophenyl)benzoxazole-5-amine. Among these, the diamine component preferably includes at least one of p-phenylenediamine, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2-(4-aminophenyl)benzoxazole-5-amine, and 1,3-bis(4-aminophenoxy)benzene. This tends to reduce the water absorption rate of the polyimide resin and further reduce the dielectric loss tangent of the fluororesin composition.

[0040] These diamines may be used alone or in combination of two or more.

[0041] The content of the polyimide resin is 0.5 to 5.0 mass% relative to the total amount of the fluororesin composition, preferably 1.0 to 4.0 mass%, and more preferably 2.0 to 3.0 mass%. When the content of the polyimide resin is 0.5 mass% or more relative to the total amount of the fluororesin composition, UV laser processability tends to be improved, and when the content of the polyimide resin is 5.0 mass% or less relative to the total amount of the fluororesin composition, adhesion tends to be maintained at a particularly high level.

[0042] 1.4.Inorganic fillers The inorganic filler of this embodiment is not particularly limited, but examples thereof include silica, clay, talc, calcium carbonate, mica, diatomaceous earth, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, titanium oxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dawsonite, hydrotalcite, calcium sulfate, barium sulfate, calcium silicate, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica-based balloons, carbon black, carbon nanotubes, carbon nanohorns, graphite, carbon fiber, glass balloons, carbon balloons, wood flour, zinc borate, boron nitride, etc. Among these, the inorganic filler preferably contains one or more selected from the group consisting of silica, boron nitride, and titanium oxide, more preferably contains silica, and even more preferably contains silica and one or more selected from the group consisting of boron nitride and titanium oxide.

[0043] The inorganic filler may be used alone or in combination of two or more kinds. Also, hollow fillers may be used as the inorganic filler.

[0044] The content of the inorganic filler is 18 to 67% by mass, preferably 20 to 50% by mass, more preferably 20 to 40% by mass, and even more preferably 20 to 33% by mass, relative to the content of the fluororesin. When the content of the inorganic filler is 18% by mass or more relative to the content of the fluororesin, the coefficient of linear expansion tends to be reduced, and when the content of the inorganic filler is 67% by mass or less relative to the content of the fluororesin, high adhesiveness tends to be maintained.

[0045] 1.5.Surfactants The fluororesin composition of this embodiment is not particularly limited as other components, and may contain, for example, a surfactant to disperse well the liquid crystal polymer resin and inorganic filler contained in the fluororesin composition. The surfactant is not particularly limited, and examples thereof include anionic, cationic, nonionic, and fluororesin surfactants. From the viewpoints of dispersibility and compatibility, fluororesin surfactants are particularly preferred. These surfactants may be used alone or in combination of two or more. The surfactant content is preferably 3 to 10 mass % and more preferably 3 to 8 mass % relative to the fluororesin.

[0046] 2. Fluorine resin film The fluororesin film of this embodiment is a film made using the fluororesin composition of this embodiment. Although there are no particular limitations on this fluororesin film, for example, by laminating it on a circuit made of a metal foil such as copper foil, a metal laminate plate excellent in dielectric loss tangent can be obtained.

[0047] 3.Laminated film The laminated film of this embodiment comprises a layer made of a fluororesin composition (hereinafter also referred to as a fluororesin layer) and a layer made of a non-thermoplastic resin (hereinafter also referred to as a non-thermoplastic resin layer), and at least one of the outermost layers is the fluororesin layer. By having this configuration, the fluororesin layer, which has an excellent dielectric loss tangent, can be in contact with the circuit, and the film tends to have excellent high-speed transmission characteristics.

[0048] When circuits are formed on both sides of the laminated film, it is preferable that both of the outermost layers of the laminated film be fluororesin layers from the viewpoint of the dielectric loss tangent and high-speed transmission characteristics.

[0049] In the laminated film of the present embodiment, the number of types of each of the fluororesin layer and the non-thermoplastic resin layer may be one or two or more.

[0050] The resin used in the non-thermoplastic resin layer is not particularly limited, but examples thereof include polyimide resin, polyamide resin, phenolic resin, and epoxy resin. Among these, the non-thermoplastic resin preferably contains a polyimide resin, and more preferably consists of a polyimide resin. This tends to provide excellent laser processability when used as a circuit material, etc., and also excellent conductivity reliability in plating treatment after laser processing. The resin used in the non-thermoplastic resin layer may be used alone or in combination of two or more types.

[0051] The polyimide resin usable for the non-thermoplastic resin layer may be the polyimide resin that can be contained in the fluororesin composition described above, or may be a preparation prepared by a known method or a commercially available product, such as the "Kapton EN Series," "Kapton H Series," and "Kapton V Series" from DuPont-Toray Co., Ltd., the "Apical HP Series" and "Apical NPI Series" from Kaneka Corporation, the "FS Series" from SKC Kolon, and the "Upilex S" from Ube Industries, Ltd.

[0052] The linear expansion coefficient of the non-thermoplastic resin is preferably smaller than that of the fluororesin composition of this embodiment. This allows the linear expansion coefficient of the laminate to be kept low even when the ratio of the fluororesin is increased. Therefore, the dimensional stability of the laminate tends to be improved by the non-thermoplastic resin with a small linear expansion coefficient, and the transmission loss tends to be kept low by the fluororesin with excellent dielectric properties.

[0053] The non-thermoplastic resin preferably has a dielectric constant of 4.0 or less at 10 GHz, more preferably 3.8 or less, and even more preferably 3.6 or less. The dielectric loss tangent at 10 GHz is preferably 0.0050 or less, more preferably 0.0045 or less, and even more preferably 0.0040 or less. Transmission loss tends to be reduced by using a non-thermoplastic resin with a particularly small dielectric loss tangent.

[0054] 4. Metal laminate The metal laminate plate (metal laminate) of this embodiment includes the fluororesin film or laminate film of this embodiment and a metal foil. The metal laminate plate may have a configuration in which a metal foil is disposed on each side of the laminate film, or a configuration in which a metal foil is disposed on only one side of the laminate film.

[0055] The metal foil is not particularly limited, but is preferably one or more selected from the group consisting of copper foil, copper alloy foil, stainless steel foil, and aluminum foil, and more preferably copper foil.

[0056] The thickness of the metal foil is not particularly limited, but in the case of a metal laminate as a circuit material, it may be, for example, about 6 to 70 μm.

[0057] The surface of the metal foil may be treated, for example, by rust prevention treatment to prevent oxidation, or by roughening treatment or treatment with a silane coupling agent to improve the adhesiveness of the laminate.

[0058] The surface roughness (Rz) of the metal foil on the surface in contact with the layer made of the fluororesin composition or the layer made of the non-thermoplastic resin is preferably 1.5 μm or less, more preferably 1.3 μm or less. When the metal laminate is used as a circuit material, the skin effect of the conductor of the circuit material can be reduced, and as a result, transmission loss tends to be improved.

[0059] 5.Metal laminate manufacturing method The method for producing the metal laminate of this embodiment can be a known method, and is not particularly limited, but examples include a method in which a metal foil is superimposed on at least one of the two surfaces of the laminate film of this embodiment and press-laminate them (hereinafter also referred to as a press-lamination method). In the press-lamination method, the pressing temperature is not particularly limited and may be about 250 to 350°C, and the pressure is not particularly limited and may be, for example, about 3 to 5 MPa.

[0060] Unless otherwise specified in this specification, the methods for evaluating and measuring the above-mentioned physical properties can be evaluated and measured according to the methods described in the following examples. [Example]

[0061] EXAMPLES The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples alone.

[0062] 1.Material The materials used in each of the examples and comparative examples are as follows. (Fluorine resin) Perfluoroalkoxyalkanes (PFAs) (powder form): AGC Inc.'s "Fulon+ EA-2000" (powder form) Perfluoroalkoxyalkane (PFA) (film form): AGC Inc. "Fulon+ EA-2000" (film type) 25 μm thick Polytetrafluoroethylene (PTFE): Mitsubishi Pencil Co., Ltd. "PTFE Dispersion" (Polyimide resin) It was prepared by the method described below. (LCP) "Zaidar" manufactured by ENEOS Corporation (inorganic filler) Denka Co., Ltd. "FB-3SDC" (surfactant) "Ftergent 710FL" manufactured by Neos Co., Ltd. (metal foil) Copper foil (Fukuda Metal Foil & Powder Co., Ltd. product "CF-T49A-DS-HD2-12μm"; hereinafter also referred to as "low-roughness copper foil") (Non-thermoplastic resin layer [polyimide film]) SKC Kolon FS series, thickness 12.5 μm (Fluororesin film) AGC Inc. "Fulon+ EA-2000" (film type) 25 μm thick

[0063] 2. Preparation of Polyimide Resin [Synthesis Example 1] PI-1 (low water absorption type: water absorption rate of 1.0 mass% or less) A reaction vessel was charged with 68 g of N-methyl-2-pyrrolidone (NMP), 1.9563 g (0.01809 mol) of p-phenylenediamine (p-PDA), and 0.8609 g (0.00295 g) of 1,3-bis(4-aminophenoxy)benzene (TPE-R). The mixture was stirred at room temperature to dissolve p-PDA and TPE-R in the NMP. To the resulting solution, 8.5710 g (0.01870 mol) of p-phenylenebis(trimellitic acid monoester anhydride) (TAHQ) and 0.6114 g (0.00208 mol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) were slowly added. The mixture was then stirred at room temperature for 3 hours to obtain the polyimide resin precursor PI-1.

[0064] PI-1 was applied to the roughened surface of low-roughness copper foil using a bar coater so that the resin layer thickness after imidization would be 12.5 μm, and then dried at 130°C for 10 minutes. The copper foil coated and dried with PI-1 was cooled to room temperature and then heated in stages to 360°C (material temperature). After holding at 360°C for 2 hours, it was naturally cooled to room temperature, yielding a two-layer flexible metal laminate consisting of copper foil and a polyimide layer.

[0065] The entire copper foil of this two-layer flexible metal laminate was removed by etching, and the sample was dried at 105°C for 0.5 hours. The sample's mass after cooling to room temperature was taken as the initial value (m0). The sample was then immersed in pure water at 23°C for 24 hours, after which its mass (md) was measured. The water absorption rate under processing conditions D-24 / 23 was calculated from the change in mass between the initial value and the immersion rate using the following formula (1). The resulting water absorption rate was 0.76%. Water absorption rate (%)=(md-m0)×100 / m0...(1)

[0066] [Synthesis Example 2] PI-2 (normal type: water absorption rate greater than 1.0% by mass) 68 g of NMP, 2.7991 g (0.02588 mol) of p-PDA, and 0.8408 g (0.00288 mol) of TPE-R were added to a reaction vessel and stirred at room temperature to dissolve the p-PDA and TPE-R in the NMP. 8.3602 g (0.02841 mol) of BPDA was gradually added to the resulting solution. The mixture was then stirred at room temperature for 3 hours to obtain polyimide resin precursor PI-2.

[0067] PI-2 was applied to the roughened surface of low-roughness copper foil using a bar coater so that the resin layer thickness after imidization would be 12.5 μm, and then dried at 130°C for 10 minutes. The copper foil coated and dried with PI-2 was cooled to room temperature and then heated in stages to 360°C (material temperature). After holding at 360°C for 2 hours, it was naturally cooled to room temperature, yielding a two-layer flexible metal laminate consisting of copper foil and a polyimide layer.

[0068] The entire copper foil of this two-layer flexible metal laminate was removed by etching, and the sample was dried at 105°C for 0.5 hours. The mass of the sample after cooling to room temperature was defined as the initial value (m0). The sample was then immersed in pure water at 23°C for 24 hours, after which the mass (md) was measured. The water absorption rate under processing conditions D-24 / 23 was calculated from the change in mass between the initial value and the immersion rate using the above formula (1). The resulting water absorption rate was 1.39%.

[0069] 3. Preparation of Metal Laminates and Fluoropolymer Films [Example 1] 100 parts by mass of the PFA (powder form), 2.5 parts by mass of the LCP, 20 parts by mass of the polyimide resin precursor (PI-1) prepared in Synthesis Example 1, 33 parts by mass of the inorganic filler, and 5 parts by mass of the surfactant were charged into a mixing tank, and mixed and stirred at a temperature at which each component could melt, to obtain a fluororesin composition.

[0070] A fluororesin composition was then applied to both sides of the 12.5 μm-thick polyimide film so that the dry thickness was 25 μm, and the coating was dried at 130° C. for 10 minutes, followed by heating at 300° C. for 10 minutes to obtain a laminate film with a fluororesin layer on both sides. The two sides of the laminate film were then stacked with the treated side of a low-roughness copper foil facing each other, and press-laminated at 320° C. and a pressure of 4 MPa for 10 minutes to produce a metal laminate with a low-roughness copper foil on both sides of the laminate film.

[0071] Next, the fluororesin composition prepared above was applied to the low-roughness copper foil so that the thickness after drying was 25 μm, and after drying at 130° C. for 10 minutes, it was heated at 300° C. for 10 minutes to obtain a fluororesin-coated copper foil having a fluororesin layer on one side. After that, all of the copper foil was removed by etching to produce a fluororesin film.

[0072] [Examples 2 to 9 and Comparative Examples 1 to 7] Metal laminates and fluororesin films of Examples 2 to 9 and Comparative Examples 1 to 7 were obtained in the same manner as in Example 1, except that the parts by mass of each component were changed according to Tables 1 and 2.

[0073] [Example 10] The fluororesin composition obtained in Example 1 was applied to both sides of the above-mentioned polyimide film having a thickness of 12.5 μm, each to a thickness of 12.5 μm, dried at 130°C for 10 minutes, and then heated at 300°C for 10 minutes to obtain a laminate film having a fluororesin layer on both sides. Furthermore, the fluororesin composition obtained in Example 1 was applied to the treated surface of the low-roughness copper foil to a thickness of 12.5 μm after drying, dried at 130°C for 10 minutes, and then heated at 300°C for 10 minutes to obtain a low-roughness copper foil with a fluororesin layer. A total of two low-roughness copper foils with a fluororesin layer were produced using the same method. The two sides of this laminated film were stacked with the fluororesin layer of the low-roughness copper foil with a fluororesin layer facing each other, and press-laminated at a temperature of 320°C and a pressure of 4 MPa for 10 minutes to produce a metal laminate plate with low-roughness copper foils arranged on both sides of the laminated film.

[0074] [Comparative Example 8] A metal laminate with copper foil on both sides of the laminated film was produced by stacking low-roughness copper foil, a 25 μm thick fluororesin film (film form), a 12.5 μm thick polyimide film, a 25 μm thick fluororesin film (film form), and low-roughness copper foil in that order and press-laminated for 10 minutes at a temperature of 320°C and a pressure of 4 MPa.

[0075] 3. Evaluation Method The physical properties of the metal laminates obtained in Examples 2 to 10 and Comparative Examples 1 to 8 were measured and evaluated by the following methods.

[0076] <Dielectric loss tangent> All of the copper foil on the metal laminate was removed by etching, and the laminate was left to stand in an atmosphere of 23°C and 50% RH for at least 24 hours. Then, the dielectric loss tangent was measured at a frequency of 10 GHz in accordance with the JPCA-DG03 SPDR method using an Agilent Technologies Network Analyzer N5230A in an atmosphere of 23°C, and the results were evaluated according to the following criteria. [Evaluation criteria] ◎: The dielectric loss tangent is less than 0.002. ◯: The dielectric loss tangent is 0.002 or more and less than 0.003. ×: The dielectric loss tangent is 0.003 or more.

[0077] <Adhesiveness> A circuit pattern was formed on the copper foil of the metal laminate by etching to a width of 3 mm, and the sample was left to stand for 24 hours or more in an atmosphere of 23°C and 50% RH at a peeling angle of 90° and a tensile speed of 50 mm / min in accordance with Section 8.1 of JIS C6471. The peel strength of the sample was measured, and the adhesion was evaluated according to the following criteria. [Evaluation criteria] ◎: Adhesion is 10 N / cm or more. ◯: Adhesion is 7.0 N / cm or more and less than 10 N / cm. ×: Adhesion is less than 7.0 N / cm.

[0078] <Coefficient of linear expansion> Samples with all copper foils of the metal laminate removed by etching, the fluororesin films obtained in Examples 1 to 10 and Comparative Examples 1 to 7, respectively, and the fluororesin film (film form) used in Comparative Example 8 were left standing in an atmosphere of 23°C and 50% RH for 24 hours or longer, and then the sample size was set to a width of 5 mm and a length of 15 mm. Using a thermomechanical analyzer TMA-60 manufactured by Shimadzu Corporation, the coefficient of linear expansion (CTE) in the MD direction was calculated from the dimensional change from 100°C to 200°C when heated at a heating rate of 10°C / min under a load of 5 g, and judged according to the following evaluation criteria. [Evaluation criteria] ○: The CTE of the sample with all copper foils of the metal laminate removed by etching is less than 30 [ppm / K], and the CTE of the fluororesin film is less than 130 [ppm / K]. ×: The CTE of the sample with all copper foils of the metal laminate removed by etching is 30 [ppm / K] or more, or the CTE of the fluororesin film is 130 [ppm / K] or more.

[0079] <UV laser processing property> The copper foil of the metal laminate was removed by etching to a shape with a diameter of 100 μmφ, and using a laser processing machine LC-2K212 manufactured by Biamechanics Co., Ltd., drilling was carried out under the conditions of a frequency of 2000 Hz, an output of 11.5 W, and a pulse width of 18 μs. Then, using a scanning electron microscope (hereinafter also referred to as "SEM") S-4800 manufactured by Hitachi High-Technologies Corporation, the bottom of the hole was observed under the conditions of an acceleration voltage of 20 kV, a magnification of 700 times, and an observation tilt angle of 10°, and the UV laser processing property was judged visually according to the following evaluation criteria. [Evaluation criteria] ○: There is no resin residue at the bottom of the hole. ×: There is resin residue at the bottom of the hole.

[0080] The measurement and evaluation results of the physical properties of the laminated films obtained in each example and comparative example are shown in Tables 1 and 2.

Table 1

[0081] [Table 2]

[0082] As shown in Tables 1 and 2, a comparison between Examples 1 to 10 and Comparative Examples 1 to 8 reveals that the fluororesin composition according to the present embodiment is superior in dielectric tangent, adhesiveness, coefficient of linear expansion, and UV laser processability to the fluororesin compositions according to Comparative Examples 1 to 8, which do not satisfy the constituent requirements of the fluororesin composition.

Claims

1. Fluorine resin and a liquid crystal polymer resin; A polyimide resin, and an inorganic filler, the polyimide resin has a water absorption rate of 1.0% by mass or less, the content of the fluororesin is 55% by mass or more based on the total amount of the fluororesin composition, the content of the polyimide resin is 0.5 to 5.0 mass% based on the total amount of the fluororesin composition; the content of the inorganic filler is 18 to 67% by mass relative to the content of the fluororesin, The fluororesin is at least one selected from the group consisting of perfluoroalkoxyalkane (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), and polyvinylidene fluoride (PVDF); Fluororesin composition.

2. The content of the liquid crystal polymer resin is 35% by mass or more based on the total amount of the liquid crystal polymer resin and the polyimide resin. The fluororesin composition according to claim 1.

3. the polyimide resin is obtained from a polyimide resin precursor resin obtained by reacting a diamine component with an acid dianhydride component, the diamine component includes at least one of p-phenylenediamine, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2-(4-aminophenyl)benzoxazole-5-amine, and 1,3-bis(4-aminophenoxy)benzene; The acid dianhydride component contains at least one of p-phenylenebis(trimellitic acid monoester acid anhydride) and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, The fluororesin composition according to claim 1 or 2.

4. The inorganic filler includes silica. The fluororesin composition according to any one of claims 1 to 3.

5. The inorganic filler further comprises one or more selected from the group consisting of boron nitride and titanium oxide. The fluororesin composition according to claim 4.

6. The fluororesin is selected from at least one of perfluoroalkoxyalkane and polytetrafluoroethylene. The fluororesin composition according to any one of claims 1 to 5.

7. the fluororesin contains perfluoroalkoxyalkane and polytetrafluoroethylene, The content of the perfluoroalkoxyalkane is 90% by mass or more relative to the content of the fluororesin. The fluororesin composition according to claim 6.

8. A fluororesin film obtained by using the fluororesin composition according to any one of claims 1 to 7.

9. A layer formed using the fluororesin composition according to any one of claims 1 to 7; a layer made of a non-thermoplastic resin, At least one of the outermost layers is a layer formed using the fluororesin composition. Laminated film.

10. the coefficient of linear expansion of the non-thermoplastic resin is smaller than the coefficient of linear expansion of the fluororesin composition; The laminated film according to claim 9.

11. The non-thermoplastic resin is a polyimide resin. The laminated film according to claim 9 or 10.

12. The fluororesin film or laminate film according to any one of claims 8 to 11, A metal foil is provided. Metal laminate.

13. The metal foil is any one selected from the group consisting of copper foil, copper alloy foil, stainless steel foil, and aluminum foil. The metal laminate of claim 12.

14. the surface roughness (Rz) of the metal foil on the surface in contact with the layer made of the fluororesin composition is 1.5 μm or less; The metal laminate according to claim 12 or 13.

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