Dispersion, composite particle, and method for producing composite particle

Abstract

The present invention provides a dispersion liquid of composite particles containing a tetrafluoroethylene-based polymer, which is excellent in dispersion stability. Also provided is a composite particle having high polarity and other desired properties, which is excellent in dispersion stability in a dispersion medium, and contains a prescribed tetrafluoroethylene-based polymer and silica. The dispersion liquid contains composite particles containing a tetrafluoroethylene-based polymer having a melting temperature of 260 to 320°C and an inorganic substance, an aromatic polymer, and a liquid dispersion medium, and is a dispersion liquid in which the composite particles are dispersed in the liquid dispersion medium, and the viscosity at 25°C is 1000 to 100000 mPa·s.

Description

Technical Field

[0001] This invention relates to dispersions of composite particles containing tetrafluoroethylene-based polymers.

[0002] The present invention also relates to composite particles containing the aforementioned tetrafluoroethylene polymer and silicon dioxide, and a method for manufacturing the same. Background Technology

[0003] Polytetrafluoroethylene (PTFE) and other tetrafluoroethylene-based polymers have excellent electrical properties, water and oil repellency, chemical resistance, and heat resistance. In recent years, their particles have attracted much attention as printed circuit board materials corresponding to high-frequency bands.

[0004] Patent Document 1 discloses a composition containing silica-coated fluororesin particles and resin components, which improves the flow characteristics, electrical properties, microwire embedding, heat resistance and developability of printed circuit board materials.

[0005] As composite particles of silica and tetrafluoroethylene polymers, specific embodiments are known in Patent Documents 2 and 3.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: International Publication No. 2017 / 135168

[0009] Patent Document 2: Japanese Patent Application Publication No. 2016-124729

[0010] Patent Document 3: International Publication No. 2018 / 212279 Summary of the Invention

[0011] The technical problem that the invention aims to solve

[0012] However, after conducting research, the inventors discovered that the resin composition described in Patent Document 1 lacks sufficient uniformity and dispersion stability when dissolved or dispersed in a liquid, leading to problems during processing. Furthermore, the molded articles obtained from the dispersion are prone to a decrease in the uniformity of component distribution, easily resulting in surface roughness and other defects in the appearance of the molded articles. Moreover, the processability and heat resistance of the resulting molded articles, as well as the compositions of epoxy resins, maleimide compounds, cyanate ester compounds, benzoxazine compounds, etc., specifically disclosed in Patent Document 1 as usable resin components, with tetrafluoroethylene-based polymers, have room for improvement.

[0013] On the other hand, tetrafluoroethylene polymers have extremely low polarity and low affinity for other components, making it difficult for them to interact strongly with silica. Therefore, it is difficult to incorporate a sufficient amount of silica into the composite particles of Patent Documents 2 and 3.

[0014] Furthermore, the composite particles described in the above literature exhibit insufficient stability due to the low interaction between silica and tetrafluoroethylene-based polymers, making it prone to detachment of silica. Therefore, ensuring the interaction between silica and tetrafluoroethylene-based polymers is crucial, which limits the range of silica selection (such as the amount of hydroxyl groups in silica).

[0015] Furthermore, this limitation restricts the application of the composite particles described in the above literature. For example, it is difficult to improve the affinity of the composite particles for liquid media, and severe foaming occurs when preparing liquid compositions containing the composite particles, making it difficult to ensure dispersion stability.

[0016] After careful research, the inventors discovered that a dispersion containing composite particles of a specified tetrafluoroethylene polymer and inorganic matter, an aromatic polymer, and a liquid dispersion medium, with the composite particles dispersed in the liquid dispersion medium, exhibits excellent dispersion stability. Furthermore, it was found that the molded articles obtained from this dispersion possess particularly superior characteristics such as density and a low coefficient of linear expansion.

[0017] The inventors have also discovered that a dispersion containing composite particles and a liquid dispersion medium comprising a specified tetrafluoroethylene polymer and inorganic matter, wherein the liquid dispersion medium contains two liquid dispersion media with different boiling points and the two liquid dispersion media have a relationship of forming an azeotropic mixture, exhibits excellent dispersion stability, and the molded product obtained from the dispersion has excellent properties such as density and a low coefficient of linear expansion, as represented by its appearance.

[0018] Furthermore, the inventors have discovered that the above-mentioned technical problems can be solved by using a specified tetrafluoroethylene polymer and controlling the atomic ratio of fluorine to silicon on the surface of the resulting composite particles.

[0019] The object of this invention is to provide a dispersion with excellent dispersion stability. Furthermore, the object of this invention is to provide a dispersion that yields a dense, well-formed product with excellent properties such as a low coefficient of linear expansion, as represented by its appearance. Additionally, the object of this invention is to provide composite particles with desirable physical properties such as excellent dispersion stability in a dispersion medium and high polarity, and a method for manufacturing the same.

[0020] Technical solutions adopted to solve technical problems

[0021] The present invention has the following forms.

[0022] <1> The dispersion comprises composite particles containing a tetrafluoroethylene-based polymer and inorganic matter with a melting temperature of 260–320°C, an aromatic polymer, and a liquid dispersion medium, wherein the composite particles are dispersed in the liquid dispersion medium, and the viscosity of the dispersion at 25°C is 1000–100000 mPa·s.

[0023] <2> like <1> The dispersion wherein the tetrafluoroethylene polymer is a tetrafluoroethylene polymer containing perfluorinated (alkyl vinyl ether)-based units and having polar functional groups, or a tetrafluoroethylene polymer containing 2.0 to 5.0 mol% of perfluorinated (alkyl vinyl ether)-based units relative to all units and not having polar functional groups.

[0024] <3> like <1> or <2> The dispersion, wherein the inorganic substance is silicon dioxide.

[0025] <4> like <1> ~ <3> A dispersion of any one of the following, wherein the content of the aromatic polymer is less than the content of the composite particles.

[0026] <5> like <1> ~ <4> The dispersion of any one of the following, wherein the aromatic polymer is selected from at least one of aromatic polyimide, aromatic polyamide, aromatic polyamide-imide, polyphenylene ether, liquid crystal polyester, and aromatic maleimide.

[0027] <6> A dispersion is a dispersion comprising composite particles containing a tetrafluoroethylene-based polymer with a melting temperature of 260–320°C and inorganic matter, and a liquid dispersion medium in which the composite particles are dispersed, wherein the liquid dispersion medium contains two liquid dispersion media with different boiling points and the two liquid dispersion media have a relationship of forming an azeotropic mixture.

[0028] <7> like <6> The dispersion wherein the tetrafluoroethylene polymer is a tetrafluoroethylene polymer containing perfluorinated (alkyl vinyl ether)-based units and having polar functional groups, or a tetrafluoroethylene polymer containing 2.0 to 5.0 mol% of perfluorinated (alkyl vinyl ether)-based units relative to all units and not having polar functional groups.

[0029] <8> like <6> or <7> The dispersion is wherein the mixing ratio of the high-boiling-point dispersion medium in the two liquid dispersion media with different boiling points is greater than the composition ratio (mass ratio) of the high-boiling-point dispersion medium in the azeotropic mixture of the two liquid dispersion media.

[0030] <9> like <6> ~ <8> The dispersion of any one of the following, wherein at least one of the two liquid dispersion media with different boiling points constituting the liquid dispersion medium is water, alcohol or amide.

[0031] <10> Composite particles, comprising a tetrafluoroethylene polymer with a melting temperature of 260–320°C and containing 1–5 mol% of perfluorinated (alkyl vinyl ether)-based units relative to all units, and silicon dioxide, wherein the ratio of silicon atomic mass to fluorine atomic mass on the surface of the composite particles, as determined by X-ray photoelectron spectroscopy, is greater than 1.

[0032] <11> like <10> The composite particles have an average particle size of more than 2 μm and less than 10 μm.

[0033] <12> like <10> or <11> The composite particles, wherein the silica comprises 15 to 85 parts by mass relative to 100 parts by mass of the tetrafluoroethylene polymer.

[0034] <13> like <10> ~ <12> The composite particle of any one of the following, wherein the tetrafluoroethylene polymer is used as the core and the silicon dioxide is present on the surface of the core.

[0035] <14> like <10> ~ <13> The composite particles of any one of the following, wherein the tetrafluoroethylene polymer is a tetrafluoroethylene polymer having polar functional groups.

[0036] <15> <10> ~ <14> A method for manufacturing composite particles according to any one of the following, wherein the composite particles are obtained by colliding the particles of the tetrafluoroethylene polymer and the silica in a floating state at a temperature above the melting temperature of the tetrafluoroethylene polymer.

[0037] The effects of the invention

[0038] According to the present invention, dispersions of tetrafluoroethylene polymers with excellent dispersion stability can be obtained.

[0039] The molded articles formed from the dispersion of the present invention are dense, have excellent physical properties such as appearance, heat resistance, electrical properties, and low linear expansion, and can be used as a constituent material of printed circuit boards, for example.

[0040] According to the present invention, composite particles with desired physical properties such as excellent dispersion stability and high polarity in a dispersion medium are provided, as well as a method for manufacturing the same. The coating film obtained when the dispersion containing the composite particles is coated onto a substrate exhibits excellent appearance. Furthermore, laminates and films possessing excellent properties (electrical properties, low linear expansion, etc.) based on tetrafluoroethylene polymers and inorganic materials, particularly silica, can be obtained from this dispersion. Detailed Implementation

[0041] The following terms have the following meanings.

[0042] "Average particle size (D50)" refers to the cumulative 50% diameter of the volume of an object (particle) obtained by laser diffraction scattering. That is, the particle size distribution of the object is determined by laser diffraction scattering, and a cumulative curve is obtained with the total volume of the particle group as 100%. The particle size at the point on the cumulative curve where the cumulative volume reaches 50% is the particle size.

[0043] "D90" is the cumulative 90% diameter of the volume reference of an object measured in the same way.

[0044] The D50 and D90 of the target object (particles) are obtained by dispersing the particles in water and analyzing them using a laser diffraction scattering method with a laser diffraction scattering particle size distribution measuring device (manufactured by Horiba Manufacturing Co., Ltd., LA-920 measuring instrument).

[0045] "Melting temperature (melting point)" refers to the temperature corresponding to the maximum value of the melting peak of a polymer as determined by differential scanning calorimetry (DSC).

[0046] "Glass transition temperature (Tg)" refers to the value determined by analyzing polymers using the dynamic viscoelasticity assay (DMA).

[0047] "Viscosity" refers to the value obtained by measuring the substance (dispersion or liquid composition) using a Type B viscometer at 25°C and 30 rpm. The measurement is repeated 3 times, and the average of the 3 measurements is taken.

[0048] "Thixotropic ratio" refers to the value (η1 / η2) obtained by dividing the viscosity η1 of the object (dispersion or liquid composition) measured at 30 rpm by the viscosity η2 measured at 60 rpm. Each viscosity measurement was repeated 3 times, and the average of the 3 measurements was taken.

[0049] "Specific surface area" is a value calculated by measuring particles using the BET multi-point method of gas adsorption (constant volume method), obtained using a NOVA4200e (manufactured by Quantachrome Instruments, USA).

[0050] In a polymer, a "unit" can be a group of atoms formed directly from a monomer, or it can be a group of atoms obtained by processing the polymer using a prescribed method to transform part of its structure. The unit in a polymer based on monomer A is also simply referred to as "monomer A unit".

[0051] The first dispersion of the present invention (hereinafter also referred to as "the dispersion A") comprises a composite particle containing a tetrafluoroethylene polymer (hereinafter also referred to as "F polymer") with a melting temperature of 260 to 320°C and an inorganic material (hereinafter also referred to as "the particle"), an aromatic polymer, and a liquid dispersion medium.

[0052] This dispersion A is a dispersion in which the particles are dispersed in a liquid dispersion medium, and the viscosity at 25°C is 1000~100000mPa·s.

[0053] The dispersion A exhibits excellent dispersion stability. The reasons for the improved dispersion stability of dispersion A, the correlation between the composition of the particles contained in dispersion A and dispersion stability, and the underlying mechanism are not necessarily clear, but the following can be speculated, for example.

[0054] The wettability of particles containing inorganic substances is greatly improved. If these particles with improved wettability are added to a liquid dispersion medium, the resulting liquid is less a dispersion and more a clear suspension in which the particles tend to settle easily.

[0055] On the other hand, this particle contains F polymer and inorganic matter. Compared with non-thermally fusible tetrafluoroethylene polymers, F polymers not only have excellent shape stability such as anti-fibrous properties, but also possess a high degree of freedom conformation with less restriction on molecular motion at the single-molecule level. Because such F polymers readily form microspheres at the molecular aggregate level, their surfaces easily develop minute uneven structures, thus increasing surface area. Therefore, it is assumed that the shape of the F polymer molecular aggregate remains stable without being damaged, and it physically and tightly adheres to the inorganic matter, thereby forming this particle. Furthermore, while F polymers have low surface energy and low dispersion stability, this particle formed by combining F polymers and inorganic matter interacts more readily with other particles and liquid dispersion media compared to F polymers themselves, thus exhibiting better dispersion stability.

[0056] Furthermore, it is believed that by coexisting an aromatic polymer, which is hydrophobic and has a high affinity for polymer F, in a liquid dispersion medium, it is possible to obtain dispersion A with improved dispersion stability, excellent dispersion properties such as viscosity, thixotropic ratio, and sedimentation rate, and superior operability. As a result, it is believed that dispersion A can yield molded articles that highly possess the properties of polymer F, inorganic materials, and aromatic polymers, exhibiting high compositional uniformity, density (low porosity), and excellent electrical properties.

[0057] In this invention, the polymer F constituting the particle is a thermomeltable polymer containing tetrafluoroethylene (TFE)-based units (TFE units). The melting temperature of the polymer F is 260–320°C, preferably 280–320°C, and more preferably 285–320°C. Under these conditions, the heat resistance of the molded article formed from this dispersion A tends to be better.

[0058] Here, a thermomeltable polymer refers to a polymer that, under a load of 49 N, reaches a melt flow rate of 1–1000 g / 10 minutes.

[0059] The glass transition temperature of polymer F is preferably 75–125°C, more preferably 80–100°C.

[0060] Examples of F polymers include polymers containing TFE units and perfluoro(alkyl vinyl ether)-based units (PAVE units) (PFA), and polymers containing TFE units and hexafluoropropylene (HFP)-based units (HFP units) (FEP), with PFA being preferred. As for PAVE, CF2=CFOCF3, CF2=CFOCF2CF3, and CF2=CFOCF2CF2CF3 (PPVE) are preferred, with PPVE being more preferred.

[0061] The melt viscosity of polymer F at 380°C is preferably 1×10⁻⁶. 2 ~1×10 6 Pa·s, more preferably 1×10⁻⁶ Pa·s 3 ~1×10 6 Pa·s.

[0062] If the melting temperature, glass transition temperature, and melt viscosity of polymer F are within this range, the above-mentioned mechanism of action is easily enhanced.

[0063] As a preferred form of F polymer, a polymer (1) containing TFE units and PAVE units and having polar functional groups is preferred, or a polymer (2) containing TFE units and PAVE units, having 2.0 to 5.0 mol% of PAVE units relative to all units and not having polar functional groups is preferred, and polymer (1) is more preferred.

[0064] These F polymers not only enhance the dispersion stability of the particles but also facilitate a denser and more uniform distribution of the particles in molded articles such as polymer layers obtained from dispersion A. Furthermore, when a dispersion containing these F polymers is coated onto a substrate to form a polymer layer, microspheres readily form within the polymer layer, improving adhesion to other components. As a result, it is easier to obtain molded articles with excellent electrical properties and other physical properties.

[0065] The polar functional groups of polymer (1) may be contained in the units contained in the polymer or in the terminal groups of the polymer backbone, preferably in the units contained in the polymer. Examples of the latter type of polymer include polymers having polar functional groups as terminal groups derived from polymerization initiators, chain transfer agents, etc., or polymers having polar functional groups obtained by plasma treatment or ionizing radiation treatment.

[0066] The number of polar functional groups in polymer (1) relative to 1×10 6 The number of carbon atoms in the main chain is preferably 10 to 5000, more preferably 100 to 3000. The number of oxygen-containing polar functional groups in polymer (1) can be quantified according to the composition of the polymer or the method described in International Publication No. 2020 / 145133.

[0067] As polar functional groups, groups containing hydroxyl groups, carbonyl groups, and phosphonoyl groups are preferred. From the viewpoint of easily improving the dispersibility and other physical properties of the particles, groups containing hydroxyl groups and carbonyl groups are preferred, and groups containing carbonyl groups are more preferred.

[0068] As a hydroxyl-containing group, it is preferred to include an alcohol hydroxyl group, and more preferably -CF2CH2OH, -C(CF3)2OH and 1,2-ethylene glycol group (-CH(OH)CH2OH).

[0069] As carbonyl groups, carboxyl groups, alkoxycarbonyl groups, amide groups, isocyanate groups, urethane groups (-OC(O)NH2), acid anhydride residues (-C(O)OC(O)-), imide residues (-C(O)NHC(O)-, etc.) and carbonate groups (-OC(O)O-) are preferred, and acid anhydride residues are more preferred.

[0070] The polymer (1) is preferably a polymer containing TFE units, PAVE units, and units based on monomers having polar functional groups. More preferably, it is a polymer containing, relative to all units, 90 to 99 mol% of TFE units, 0.5 to 9.97 mol% of PAVE units, and 0.01 to 3 mol% of units based on monomers having polar functional groups. The presence of polar functional groups further enhances the affinity and binding properties with inorganic materials, and is therefore preferred.

[0071] Monomers with polar functional groups are preferably itaconic anhydride, citraconic anhydride, or 5-norbornene-2,3-dicarboxylic anhydride (also known as nadic anhydride, hereinafter referred to as "NAH").

[0072] As a specific example of polymer (1), the polymer described in International Publication No. 2018 / 16644 can be cited.

[0073] The polymer (2) is preferably composed of only TFE units and PAVE units and contains 95.0 to 98.0 mol% of TFE units and 2.0 to 5.0 mol% of PAVE units relative to all units.

[0074] The content of PAVE units in polymer (2) is preferably 2.1 mol% or more, more preferably 2.2 mol% or more, relative to all units.

[0075] The polymer has a higher degree of freedom in molecular conformation, which makes it easier to enhance the above-mentioned mechanisms of action.

[0076] Furthermore, the fact that polymer (2) does not have polar functional groups means that, relative to 1×10 6 The number of carbon atoms constituting the polymer backbone and the number of polar functional groups in the polymer are less than 500. Preferably, the number of polar functional groups is less than 100, more preferably less than 50. The lower limit for the number of polar functional groups is typically 0.

[0077] The polymer (2) can be manufactured using a polymerization initiator or chain transfer agent that does not produce polar functional groups as terminal groups of the polymer chain, or it can be manufactured by fluorinating a polymer having polar functional groups (such as a polymer having polar functional groups from the polymerization initiator in the terminal groups of the polymer chain).

[0078] As a method of fluorination treatment, the use of fluorine gas can be cited as an example (see Japanese Patent Application Publication No. 2019-194314, etc.).

[0079] In this invention, the inorganic material constituting the particle is preferably in the shape of a particle. Examples of inorganic materials include particles composed of oxides, nitrides, elemental metals, alloys, and carbon. Preferably, particles are silicates (silicon dioxide, wollastonite, talc, mica), metal oxides (beryllium oxide, cerium oxide, aluminum oxide, basic alumina, magnesium oxide, zinc oxide, titanium oxide, etc.), boron nitride, and magnesium metasilicate (block talc). More preferably, particles contain inorganic oxides of at least one element selected from aluminum, magnesium, silicon, titanium, and zinc. Further preferably, particles are composed of silicon dioxide, titanium oxide, zinc oxide, block talc, and boron nitride, and most preferably, silicon dioxide particles. Additionally, the inorganic material can also be ceramic. One type of inorganic material can be used, or two or more types can be mixed. When mixing two or more inorganic materials, two types of silicon dioxide particles can be mixed before use, or silicon dioxide particles and metal oxide particles can be mixed before use.

[0080] The average particle size (D50) of the inorganic particles is preferably 20 μm or less, more preferably 5 μm or less. The average particle size is preferably 0.001 μm or more, more preferably 0.01 μm or more.

[0081] The specific surface area (BET method) of inorganic particles is preferably 1-20 m². 2 / g, more preferably 5-8mg 2 / g. In this case, the interaction between the inorganic material and the F polymer is easily enhanced. In addition, the inorganic material and the F polymer are more evenly distributed in the molded article (polymer layer, etc.), and the physical properties of both are more easily manifested.

[0082] The inorganic material readily enhances the interaction with polymer F, thereby further improving the dispersion stability of dispersion A. Furthermore, the inorganic-based properties are readily and significantly exhibited in the formed articles (e.g., polymer layers and films described later) derived from dispersion A.

[0083] In this dispersion A, the inorganic material preferably includes silica. The silica content in the inorganic material is preferably 80% by mass or more, more preferably 90% by mass or more, and the upper limit of the silica content is 100% by mass.

[0084] Preferably, at least a portion of the surface of the inorganic material is surface treated.

[0085] Examples of surface treatment agents used for this surface treatment include polyols (trimethylolethane, pentaerythritol, propylene glycol, etc.), saturated fatty acids (stearic acid, lauric acid, etc.), their esters, alkanolamines, amines (trimethylamine, triethylamine, etc.), paraffin wax, silane coupling agents, organosilicones, polysiloxanes, oxides, hydroxides, water and oxides of aluminum, silicon, zirconium, tin, titanium, antimony, etc., and their phosphates.

[0086] As a silane coupling agent, 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriethoxysilane or 3-isocyanatepropyltriethoxysilane are preferred.

[0087] Specific examples of inorganic materials include silica (Admafin series manufactured by Admatex Corporation, etc.), zinc oxide surface-treated with esters such as propylene glycol didecanoate (FINEX series manufactured by Sakai Chemical Industry Co., Ltd., etc.), spherical fused silica (SFP series manufactured by Denka Co., Ltd., etc.), rutile titanium dioxide coated with polyols and inorganic materials (TIPAQUE series manufactured by Ishihara Sangyo Co., Ltd., etc.), and rutile titanium dioxide surface-treated with alkylsilanes (JMT series manufactured by Teika Co., Ltd., etc.). Series, etc.), hollow silica (Pacific Cement Corporation's "E-SPHERES" series, Nippon Steel Mining Corporation's "SiliNax" series, Emerson Cummins' "Eccospheres" series, AEROSIL Corporation's "RX200" series, etc.), talc (Japan Talc Corporation's "SG" series, etc.), block talc (Japan Talc Corporation's "BST" series, etc.), boron nitride (Showa Denko Corporation's "UHP" series, Denka Corporation's "Electrochemical Boron Nitride (Denka)" series, etc.), etc.), hollow silica (Pacific Cement Corporation's "Eccospheres" series, Nippon Steel Mining Corporation's "SiliNax" series, Nippon Steel Mining Corporation's "Eccospheres" series, etc.), etc.), hollow silica (Japan Talc Corporation's "SG" series, etc.), hollow silica (Japan Talc Corporation's "BST" series, etc.), hollow silica (Japan Talc Corporation's "BST" series, etc.), hollow silica (Pacific Cement Corporation's "Eccospheres ... Boron Nitride series (GP, HGP, etc.).

[0088] The shapes of inorganic particles can be granular, needle-like (fibrous), and plate-like, and more specifically, spherical, scaly, layered, leaf-like, almond-like, columnar, cockscomb-like, equiaxed, leaf-like, mica-like, blocky, flat, wedge-shaped, rosette-like, mesh-like, and square columnar. Among these, spherical and scaly shapes are preferred, and spherical shapes are more preferred.

[0089] The spherical inorganic particles are preferably approximately spherical. Approximately spherical means that, when observed with a scanning electron microscope (SEM), the proportion of spherical particles with a minor axis to major axis ratio of 0.5 or higher reaches 95%. The minor axis to major axis ratio of the approximately spherical inorganic particles is preferably 0.6 or higher, more preferably 0.8 or higher. Such ratios are preferably less than 1. Using highly approximately spherical inorganic particles results in a more uniform distribution of inorganic matter and polymer F in the molded product (polymer layer, etc.), and their physical properties are more readily and effectively presented.

[0090] The aspect ratio of the flaky inorganic particles is preferably 5 or more, more preferably 10 or more. The aspect ratio is preferably 1000 or less.

[0091] Examples of the forms of particles present in this dispersion A include those with polymer F as the core and inorganic matter attached to the surface of the core (hereinafter also referred to as "Form I"), and those with inorganic matter as the core and polymer F attached to the surface of the core (hereinafter also referred to as "Form II"). Here, "core" refers to the core (central part) necessary for the particle shape of the composite particle, and not to the main component in the composition of the composite particle.

[0092] The adhering material (inorganic or F polymer) to the nucleus surface can adhere to only a portion of the nucleus surface, or it can adhere to most or even the entire surface. The former can be described as the adhering material adhering to the nucleus surface in a dust-like manner; in other words, it forms a state where most of the nucleus surface is exposed. The latter can be described as the adhering material covering the entire nucleus surface, or the adhering material covering the nucleus surface. This composite particle can also be described as possessing a core-shell structure formed by a nucleus and a shell covering the nucleus.

[0093] The preferred form of this particle is morphology I, where both the polymer F and the inorganic material are in particulate form. In this case, the inorganic material, which has a higher hardness and dispersion stability than the polymer F, is exposed on the surface. As a result, the polymer F is less prone to denaturation, and the flowability and workability of the particle are easily improved. Furthermore, the dispersion stability of the particle is easily improved.

[0094] Hereinafter, the particulate F polymer will also be referred to as "F particle," and the particle of form I will be described. The core of the F polymer may be composed of a single F particle or an aggregate of F particles. In the particle of form I, it is preferable to set the D50 of the F polymer core to be larger than the D50 of the inorganic particles, and to set the amount of F polymer in the particle to be greater than the amount of inorganic matter.

[0095] In the particles of Form I, based on the D50 of the F polymer core, the D50 of the inorganic particles is preferably 0.001 to 0.5, more preferably 0.01 to 0.3. Specifically, it is preferable that the D50 of the F polymer core exceeds 1 μm and the D50 of the inorganic particles is less than 0.1 μm. Furthermore, the amount of inorganic particles relative to 100 parts by mass of F polymer is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more. The upper limit is preferably 50 parts by mass, more preferably 25 parts by mass, and even more preferably 5 parts by mass.

[0096] In the resulting Form I particle, the aforementioned relationship is maintained, and the D50 of the F polymer core is greater than the D50 of the inorganic particles, while the mass of the F polymer in the particle is greater than the mass of the inorganic particles. In this case, the surface of the F polymer core can be coated with a larger amount of inorganic particles, and the particle is formed with a core-shell structure. Moreover, in this case, the aggregation between F particles is suppressed, and it is easy to obtain a particle with inorganic particles attached to the core formed by individual F particles.

[0097] The inorganic particles are preferably spherical, and more preferably approximately spherical. In this case, the dispersion stability of the resulting particles is easily improved. The ratio of the minor axis to the major axis of the approximately spherical inorganic particles is preferably 0.5 or more, and more preferably 0.8 or more. The above ratio is preferably less than 1. Here, "spherical" refers not only to spherical shapes, but also to slightly deformed spheres.

[0098] If inorganic particles that are approximately spherical are used, the inorganic and F polymers are more evenly distributed in the shaped material (polymer layer, etc.), and the physical properties of both are more easily and highly manifested.

[0099] Inorganic particles can be embedded in the core of the F polymer.

[0100] In the particles of morphology I, the D50 of the inorganic particles is preferably in the range of 0.001 to 0.3 μm, more preferably in the range of 0.005 to 0.2 μm, and even more preferably in the range of 0.01 to 0.1 μm. When the D50 is in the above range, the operability and flowability of the particles are easily improved, and the dispersion stability of the dispersion A is also easily improved.

[0101] Furthermore, the particle size distribution of the inorganic material, indicated by a D90 / D10 value, is preferably 3 or less, more preferably 2.9 or less. Here, "D10" is measured in the same manner as D50 and D90, and is the cumulative 10% diameter based on the volume of the object. In this case, the flowability control of the resulting particles becomes easier.

[0102] Preferably, at least a portion of the surface of the inorganic particles is surface-treated, more preferably with a silazane compound such as hexamethyldisilazane or a silane coupling agent. Examples of such compounds can be cited as silane coupling agents.

[0103] One type of inorganic particle can be used, or two or more types can be used in combination. When two types of inorganic particles are used in combination, the average particle size of each inorganic particle can be different, and the content ratio (mass ratio) of each inorganic particle can be appropriately set according to the required function.

[0104] In the particles of morphology I, the D50 of the F polymer core is preferably 0.1 μm or more, more preferably more than 1 μm. Its upper limit is preferably 100 μm, more preferably 50 μm, and even more preferably 10 μm.

[0105] Furthermore, the proportion of F polymer in the particles of form I is preferably 50–99% by mass, more preferably 75–99% by mass. The proportion of inorganic matter is preferably 1–50% by mass, more preferably 1–25% by mass.

[0106] The particles of form I can be further surface-treated according to the properties of the inorganic matter attached to their surface. As a specific example of such surface treatment, a method of surface-treating the particles of form I with siloxanes such as polydimethylsiloxane or silane coupling agents can be given.

[0107] This surface treatment can be performed by mixing a dispersion containing the particles with a siloxane or silane coupling agent, reacting the siloxane or silane coupling agent, and then recovering the particles. As the silane coupling agent, the aforementioned silane coupling agent with functional groups is preferred. This method allows for better adjustment of the surface properties of the particles.

[0108] The following is an explanation of the particle in form II.

[0109] In the morphology II particle, polymer F can be particulate or non-particulate. Preferably, at least a portion of polymer F is fused to the core of the inorganic material.

[0110] In the morphology II particle, the D50 of the inorganic core is preferably 1 μm or more, more preferably 3 μm or more. Its upper limit is preferably 40 μm, more preferably 30 μm.

[0111] In the form II particles, when polymer F is in particulate form, the D50 of the F particles is preferably in the range of 0.1 to 10 μm, more preferably 1 to 5 μm. If the D50 is within this range, the operability and flowability of the particles are easily improved, and the dispersion stability is easily enhanced.

[0112] Furthermore, the proportion of inorganic matter in the particles of form II is preferably 50–99% by mass, more preferably 60–90% by mass. The proportion of polymer F is preferably 1–50% by mass, more preferably 10–40% by mass.

[0113] The D50 of this particle is preferably below 30 μm, more preferably below 20 μm. The D50 of this particle is preferably above 0.1 μm, more preferably above 1 μm, and even more preferably above 3 μm.

[0114] The D90 of this particle is preferably below 30 μm, and more preferably below 20 μm.

[0115] If the D50 and D90 of this particle are within this range, the dispersion stability of this particle in this dispersion A and the physical properties of the shaped articles (polymer layers, etc.) obtained from this dispersion A are more easily improved.

[0116] The particles are preferably manufactured by the following methods: a method of colliding F particles and inorganic particles in a floating state at a temperature above the melting temperature of the F polymer (hereinafter also referred to as "dry method A"), and a method of colliding F particles and inorganic particles in a pressing or shearing state (hereinafter also referred to as "dry method B").

[0117] Alternatively, it can be manufactured by shearing a liquid composition containing F particles and inorganic particles to solidify the F particles (hereinafter also referred to as the "wet method").

[0118] In dry process A, for example, F particles and inorganic particles are supplied in a high-temperature turbulent atmosphere, and the collisions between the F particles and inorganic particles introduce stress between them, thus recombinating them. This dry process A is sometimes also referred to as hybridization treatment.

[0119] The atmosphere is formed by gases. Examples of usable gases include air, oxygen, nitrogen, argon, or mixtures thereof.

[0120] F particles and inorganic particles can be supplied all at once in an atmosphere as a premixed mixture, or they can be supplied separately in an atmosphere.

[0121] When supplying F particles and inorganic particles in a high-temperature atmosphere, it is preferable to form a state in which the particles do not aggregate. This method can be achieved by suspending the particles in a medium (gas or liquid). A mixture of gas and liquid can also be used as the medium.

[0122] In addition, in dry method A, F particles and inorganic particles can be supplied to the atmosphere after a high-temperature turbulent atmosphere has been prepared, or the F particles and inorganic particles can be allowed to float in the medium and then the medium can be heated to form a high-temperature turbulent atmosphere.

[0123] As an example of a device that can be used in the former case, one could cite a device that uses a stirring body, such as a stirring blade, to stir the particles while simultaneously clamping the particles between the inner wall of the container and the stirring body to apply stress. For example, one could cite the "Mixing System" (registered trademark) manufactured by Nara Machinery Works.

[0124] The temperature of the atmosphere is preferably above 80°C, more preferably above 110°C. The temperature of the atmosphere is preferably below 400°C, more preferably below 200°C, and even more preferably below 120°C.

[0125] In the dry process A, particles with a D50 within the aforementioned range, including both F particles and silica particles, can be used to collide in a floating state at a temperature above the melting temperature of the F polymer. Preferably, 15 to 85 parts by mass of silica and 100 parts by mass of F polymer are collided in a floating state at a temperature above the melting temperature of the F polymer.

[0126] Furthermore, when inorganic particles contain a large number of aggregates formed by the mutual aggregation of their primary particles, these aggregates can be broken up before being supplied to a high-temperature atmosphere. Examples of methods for breaking up these aggregates include using jet mills, pin mills, and hammer mills.

[0127] In dry method B, for example, centrifugal force is used to press F particles and inorganic particles onto the inner circumferential surface (bearing surface) of a cylindrical rotating body rotating around a central axis. The particles are then compounded by the synergistic effect of an inner stator positioned at a small distance from the inner circumferential surface, which applies pressure or shear force. This dry method B is sometimes also referred to as mechanical fusion processing.

[0128] The atmosphere inside the cylindrical rotating body can be an inert gas atmosphere or a reducing gas atmosphere. The temperature of the atmosphere is preferably below the melting temperature of the F polymer, and more preferably below 100°C.

[0129] The distance between the inner circumferential surface of the cylindrical rotating body and the inner stator can be appropriately set according to the average particle size of the F particles and inorganic particles. This distance is usually preferably 1 to 10 mm.

[0130] The rotational speed of the cylindrical rotating body is preferably 500 to 10000 rpm. Under this condition, the manufacturing efficiency of the particle can be easily improved.

[0131] When inorganic particles contain a large number of aggregates formed by the mutual aggregation of their primary particles, the aggregates can be broken up in the same manner as described in Dry Method A before being supplied to the cylindrical rotating body.

[0132] Dry method B can also be carried out using a pulverizing and mixing device equipped with a rotating trough and pulverizing mixing blades (for example, "Nobilta" manufactured by Hosokawa Micron Co., Ltd. (registered trademark)). The rotating trough has a pulverizing and mixing chamber with an elliptical (irregular) cross-section arranged with the rotation axis arranged in the horizontal direction. The pulverizing and mixing blades have an elliptical (irregular) cross-section and are rotatably inserted into the pulverizing and mixing chamber of the rotating trough, with their rotation axis arranged concentrically with the rotation axis of the rotating trough.

[0133] In this pulverizing and mixing apparatus, F particles and inorganic particles are pressed between the short-diameter portion of the pulverizing and mixing chamber and the long-diameter portion of the pulverizing and mixing blades, and these particles are subjected to pressing or shearing forces to combine them. Furthermore, in the pulverizing and mixing apparatus, it is preferable that the rotation direction of the rotating trough and the rotation direction of the pulverizing and mixing blades are opposite, and it is preferable that the rotation speed of the rotating trough is set slower than the rotation speed of the pulverizing and mixing blades.

[0134] In this pulverizing and mixing device, the pulverizing and mixing chamber and the pulverizing and mixing blades have irregular cross-sections. Inside the pulverizing and mixing chamber, instantaneous pressing or shearing forces can be repeatedly applied to the flowing F particles and inorganic particles that fall due to their own weight. In this way, the aforementioned particles can be pulverized and mixed in a short time while reducing the adverse effects of heat, thus easily obtaining particles with the desired characteristics.

[0135] The wet process is a method of obtaining the particles by, for example, stirring, applying shearing to destabilize a liquid composition containing phosphorus particles and inorganic particles, causing them to solidify, and thus combining the phosphorus particles and inorganic particles. When the inorganic particles are silica, colloidal silica is preferred.

[0136] Furthermore, the mass ratio of F particles to inorganic particles in the liquid composition is preferably such that the mass of F particles is 1, and the mass of inorganic particles is 0.001 to 2.0. More specifically, when obtaining particles in form I, the liquid composition preferably contains 20 to 50% by mass of F particles and 0.1 to 40% by mass of inorganic particles.

[0137] Liquid compositions are prepared by mixing F particles, inorganic particles, and a dispersion medium. Examples of mixing methods include: adding F particles and inorganic particles into the dispersion medium all at once; mixing while sequentially adding F particles and inorganic particles into the dispersion medium; pre-mixing F particles and inorganic particles and then mixing the resulting mixture with the dispersion medium; and pre-mixing F particles and the dispersion medium, and inorganic particles and the dispersion medium separately, and then further mixing the two resulting mixtures.

[0138] Specifically, after dispersing silica particles in a dispersion medium, they are added and mixed into a dispersion containing sulfur particles. This method facilitates the mixing of silica particles and sulfur particles.

[0139] If the mixture containing F particles and silica particles is destabilized and causes solidification, then the F particles and silica particles are composited.

[0140] As a dispersion medium, compounds of the same type as those used in the liquid dispersion medium described later can be used.

[0141] The liquid composition containing F particles can be stirred during or after the addition of inorganic particles. Examples of stirring devices include those with propeller blades, turbine blades, paddle blades, or shell-shaped blades as stirring blades. The stirring speed only needs to be sufficient to efficiently disperse the inorganic particles into the liquid composition containing F particles; high shear force on the F particles is not required.

[0142] When stirring the liquid composition, for example, the stirring device described above can be used, or the following can be employed: Henschel mixer, pressure kneader, Banbury mixer or planetary mixer; mixing using media such as ball mill, pulverizer, basket mill, sand mill, sand mill, DINO mill (bead mill using pulverizing media such as glass beads or zirconia beads), dispersion pad, SC mill, nail crusher or stirred mill; mixing without media such as high-pressure homogenizer, ultrasonic homogenizer, longitudinal disperser, disperser, high-pressure impact disperser, rotating / revolutionary mixer.

[0143] The shear treatment is preferably performed under high shear conditions. "High shear" means stirring at a speed of at least 300 rpm while stirring.

[0144] The shearing process can begin during the addition of inorganic particles to a liquid composition containing F powder, or it can be performed after the addition is complete.

[0145] Methods for separating the particles by removing the dispersion medium after shearing treatment include heating, depressurization, or filtration, and these methods can also be used in appropriate combinations.

[0146] Specific examples of methods for separating the particles include: (1) distilling away the dispersion medium under atmospheric pressure or reduced pressure to concentrate the mixture, and then filtering and drying it as needed; (2) condensing the particles while adjusting the temperature of the liquid composition, or condensing and crystallizing by adding electrolytes, coagulants, coagulation aids, etc., and then separating and drying it by filtration, etc.; (3) spraying the liquid composition into a dry gas at a temperature at which the dispersion medium can be volatile for drying and recovery; (4) centrifuging the liquid composition and then drying it, etc.

[0147] Here, vacuum drying, high-frequency drying, and hot air drying are examples of drying methods.

[0148] In the above methods (1) to (4), the liquid composition can be diluted with a dispersion medium as needed, and the total content of F polymer and inorganic matter in the liquid composition can be adjusted in advance.

[0149] When manufacturing these particles using the aforementioned dry method A, dry method B, and wet method, from the perspective of further improving the adhesion (bonding) with inorganic particles, it is preferable to perform surface treatment on the F particles before or during mixing with the inorganic particles. Examples of surface treatments include plasma treatment, corona discharge treatment, etching treatment, electron beam irradiation treatment, ultraviolet irradiation treatment, and ozone exposure treatment; plasma treatment is preferred, and low-temperature plasma treatment is particularly preferred.

[0150] Furthermore, when F particles collide with inorganic particles using dry methods A and B, heat is easily and uniformly transferred to these particles, facilitating the densification and sphericity of the particles. In this case, the sphericity of the particles is preferably 0.5 or higher, more preferably 0.93 to 0.99.

[0151] In the manufacture of these particles, the D50 of the F particles is preferably below 20 μm, more preferably below 10 μm. The D50 of the F particles is preferably above 0.01 μm, more preferably above 0.1 μm. Furthermore, the D90 of the F particles is preferably below 10 μm. F particles with D50 and D90 within this range exhibit good flowability and dispersibility, and the size of these particles in the dispersion medium is easily controlled in wet processes to prevent sedimentation.

[0152] The preferred bulk density of F particles is 0.15 g / m³. 2 More preferably, it is 0.20 g / m 2 The above. The preferred bulk density of F particles is 0.50 g / m³. 2 Below, more preferably at 0.35 g / m 2 the following.

[0153] Even when added in large quantities to a liquid dispersion medium, these particles can be stably dispersed. In the formed products (polymer layers, films, etc.) formed from this dispersion A, the polymer F and inorganic matter are more uniformly distributed, easily exhibiting properties based on the polymer F (electrical properties, adhesiveness, etc.) and properties based on the inorganic matter (low linear expansion, etc.). In addition, they also easily exhibit properties based on aromatic polymers (UV absorption, etc.).

[0154] In this dispersion A, the liquid dispersion medium is preferably a compound that is liquid at 25°C under atmospheric pressure. The liquid dispersion medium can be polar or non-polar, but is preferably polar. More preferably, the liquid dispersion medium is selected from at least one of water, amide, ketone, and ester. The boiling point of the liquid dispersion medium is preferably in the range of 50–240°C. One type of liquid dispersion medium can be used alone, or two or more can be used in combination. Using this liquid dispersion medium makes it easier for the particles in this dispersion A to maintain a more stable dispersion state.

[0155] Examples of liquid dispersion media include water, N,N-dimethylformamide, N,N-dimethylacetamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, N-methyl-2-pyrrolidone, γ-butyrolactone, cyclohexanone, cyclopentanone, butyl acetate, methyl isopropyl ketone, methyl ethyl ketone, and toluene. Water, N-methyl-2-pyrrolidone, γ-butyrolactone, methyl ethyl ketone, cyclohexanone, and cyclopentanone are preferred, and N-methyl-2-pyrrolidone and methyl ethyl ketone are more preferred.

[0156] The content of liquid dispersion medium in this dispersion A is preferably 30-90% by mass, more preferably 50-80% by mass.

[0157] This dispersion A also contains an aromatic polymer. The content of the aromatic polymer in this dispersion A is preferably 0.1% by mass or more, more preferably 1% by mass or more. The content of the aromatic polymer is preferably 40% by mass or less, more preferably 20% by mass or less.

[0158] Furthermore, the content of aromatic polymers in this dispersion A is preferably less than the content of the aforementioned particles. Specifically, the mass ratio (by mass) of the content of aromatic polymers in this dispersion A to the content of the aforementioned particles is preferably 0.01 or more, more preferably 0.1 or more. On the other hand, the aforementioned ratio is preferably 0.5 or less, more preferably 0.3 or less. When aromatic polymers are present at this ratio, this dispersion A exhibits excellent state stability based on the above-described mechanism of action.

[0159] The aromatic polymer can be thermosetting or thermoplastic, with thermoplastic being preferred. In this case, the dispersion stability of dispersion A tends to be better.

[0160] Examples of aromatic polymers include those with units containing imide bonds, units containing amide bonds, or those with N-substituted maleimide, succinimide, or phthalimide structures (specifically, aromatic polyimides, aromatic polyamide-imides, precursors of aromatic polyamide-imides, aromatic maleimides, aromatic polyamic acids as precursors of aromatic polyimides, and aromatic polyamides), polyphenylene ethers, liquid crystal polyesters, or aromatic elastomers (such as styrene elastomers).

[0161] As an aromatic polyimide, it is more preferable that one of the tetracarboxylic dianhydride and the diamine is a semi-aromatic polyimide having an aromatic ring, or that both are fully aromatic polyimides having an aromatic ring. Specific examples of aromatic polyimides include: the "UPIA-AT" series (manufactured by Ube Industries, Ltd.), the "Neopulim" series (manufactured by Mitsubishi Gas Chemical Co., Ltd.), the "SPIXAREA" series (manufactured by Somaron Co., Ltd.), the "Q-PILON" series (manufactured by PI Technology Research Institute), the "WINGO" series (manufactured by WINGO Technology Co., Ltd.), the "Tohmide" series (manufactured by T&KTOKA Co., Ltd.), and the "KPI-MX" series (manufactured by Kawamura Sangyo Co., Ltd.).

[0162] Specific examples of aramid polyimide or its precursors include "HPC-1000" and "HPC-2100D" (both manufactured by Showa Denko Materials Co., Ltd.).

[0163] As aromatic maleimides, maleimide resins having an N-substituted maleimide structure are preferred. Examples include reactants of diamines such as diamines and diamines with alicyclic structures with tetracarboxylic acid dianhydrides having aromatic rings, and bismaleimide resins obtained by reacting amino-terminated polyimides with maleic anhydrides. Bismaleimide resins may have an N-substituted maleimide structure only on the terminal group, or they may have an N-substituted maleimide structure on both the terminal group and the side chain.

[0164] These maleimide compounds are commercially available as part of the BMI series manufactured by DESIGNER MOLECULES Inc.

[0165] Examples of liquid crystal polyesters include aromatic polyesters or aromatic polyesteramides in which amide bonds are introduced. Further isocyanate bonds, such as imide bonds, carbonate bonds, carbodiimide bonds, or isocyanurate bonds, can be introduced into the aromatic polyester or aromatic polyesteramide.

[0166] The liquid crystal polyester is preferably thermoplastic, more preferably a liquid crystal polyester with a melting temperature in the range of 260 to 360°C, and even more preferably in the range of 270 to 350°C.

[0167] In liquid crystal polyesters, polyesters containing at least a unit based on p-hydroxybenzoic acid (HBA) or a unit based on 6-hydroxy-2-naphthoic acid (HNA) are preferred. Polyesters containing HBA units and HNA units are preferred. Polyesters containing at least one aromatic hydroxycarboxylic acid unit that is HBA or HNA are preferred. Polyesters containing at least one aromatic diol unit that is 4,4'-dihydroxybiphenyl or hydroquinone are preferred. Polyesters containing at least one aromatic dicarboxylic acid unit that is terephthalic acid, isophthalic acid or 2,6-naphthoic acid are preferred. Polyesters containing HBA units and 2,6-dihydroxynaphthoic acid units are preferred. Polyesters containing 2,6-dihydroxynaphthoic acid units, terephthalic acid units and acetaminophen units are preferred. Polyesters containing HBA units, terephthalic acid units and 4,4'-biphenyl units are preferred. These liquid crystal polyesters can be obtained through industrial manufacturing. Examples include the "Vectra" series manufactured by Celanese Japan, the "XYDAR" series manufactured by JX Energy, the "Laperos" series manufactured by Polyplastics, and the "UENOLCP" series manufactured by Ueno Pharmaceuticals.

[0168] As a styrene elastomer, a styrene elastomer that possesses properties of both rubber and plastic and exhibits flexibility upon heating and plasticizing is preferred. Examples include copolymers of styrene with conjugated dienes or (meth)acrylates (styrene-butadiene rubber; styrene-based core-shell copolymers; styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-butadiene-styrene block copolymers, styrene-based block copolymers such as styrene-isoprene-styrene block copolymers, and styrene-based block copolymers such as styrene-isoprene-styrene block copolymers). Styrene elastomers that possess properties of both rubber and plastic and exhibit flexibility upon heating and plasticizing are preferred.

[0169] In this invention, the aromatic polymer is preferably selected from at least one of aromatic polyimide, aromatic polyamide, aromatic polyamide-imide, polyphenylene ether, liquid crystal polyester, and aromatic maleimide.

[0170] Furthermore, considering the high dispersion stabilization effect of this dispersion A, the aforementioned aromatic polymer is preferably thermoplastic, more preferably thermoplastic aromatic polyimide or aromatic polyamide-imide, and even more preferably thermoplastic aromatic polyimide. In this case, it is considered that the thermoplastic aromatic polyimide or aromatic polyamide-imide functions as a surfactant or viscosity modifier in this dispersion A, or simultaneously as a surfactant and viscosity modifier. Therefore, the liquid properties (viscosity, thixotropic ratio, etc.) of this dispersion A are balanced, and its operability is easily improved. The adhesion and low linear expansion of the molded articles formed by this dispersion A are further improved.

[0171] Furthermore, at least a portion of the aforementioned aromatic polymer can be dispersed in particulate form in this dispersion A. In this case, particulate liquid crystal polyester can be used.

[0172] When using particulate liquid crystal polyester, its average particle size (D50) is preferably in the range of 1 to 40 μm, more preferably 5 to 20 μm. If the average particle size (D50) is within this range, the dispersion stability of this dispersion A is more easily improved.

[0173] This dispersion A may or may not contain a surfactant. If dispersion A contains a surfactant, its content is preferably 1 to 15% by mass; furthermore, the surfactant is preferably nonionic.

[0174] As surfactants, glycol-based surfactants, acetylene-based surfactants, silicone-based surfactants, and fluorinated surfactants are preferred. Furthermore, fluorinated surfactants are compounds having a hydrophilic site and a hydrophobic site containing a fluorinated organic group. One type of surfactant may be used, or two types may be used. When using two surfactants, silicone-based surfactants and glycol-based surfactants are preferred.

[0175] Specific examples of surfactants include the "Ftergent" series (manufactured by Neos Corporation), the "Surflon" series (manufactured by AGC Seimei Chemical Co., Ltd.), the "MEGA FACE" series (manufactured by DIC Corporation), the "Unidyne" series (manufactured by Daikin Industries, Ltd.), "BYK-347", and "B..." YK-349", "BYK-378", "BYK-3450", "BYK-3451", "BYK-3455", "BYK-3456" (BYK Japan Corporation) (manufactured by Shin-Etsu Chemical Industry Co., Ltd.), "KF-6011", "KF-6043" (manufactured by Shin-Etsu Chemical Industry Co., Ltd.), "Tergitol series (manufactured by Dow Chemical Company (Dow Chemical Company), Tergitol TMN-100X, etc.).

[0176] Based on the aforementioned mechanism of action, dispersion A exhibits excellent dispersion stability and workability even without the presence of surfactants, especially fluorinated surfactants. Dispersion A is preferably free of fluorinated surfactants. The low dielectric loss tangent and other properties of the molded articles formed from dispersion A, which is free of fluorinated surfactants, can be further enhanced.

[0177] From the perspective of improving the adhesion and low linear expansion of the molded articles formed by this dispersion A, this dispersion A may also contain polymer F and resin materials other than the aforementioned aromatic polymers. This resin material may be thermosetting or thermoplastic, may be modified, and may be soluble in this dispersion A or insoluble in this dispersion A but dispersed therein.

[0178] Examples of resin materials other than polymer F include tetrafluoroethylene polymers, acrylic resins, phenolic resins, polyolefin resins, modified polyphenylene ethers, vinyl ester resins, urea-formaldehyde resins, diallyl phthalate resins, melamine resins, guanidine resins, melamine-urea cocondensation resins, polycarbonates, and epoxy resins.

[0179] From the perspective of improving the electrical properties of the molded article formed from this dispersion A, the resin material is preferably a tetrafluoroethylene polymer other than polymer F. Examples of tetrafluoroethylene polymers other than polymer F include polytetrafluoroethylene (PTFE), high molecular weight PTFE, low molecular weight PTFE, and modified PTFE, which have anti-fibrous properties. Low molecular weight PTFE or modified PTFE also includes copolymers of TFE and trace amounts of comonomers (HFP, PAVE, FAE, etc.).

[0180] When this dispersion A contains resin material, its content is preferably 40% by mass or less relative to the total amount of this dispersion A.

[0181] This dispersion A may also contain a tetrafluoroethylene polymer, which is different from the polymer F contained in this particle. In this case, the dispersion stability of this dispersion A tends to be better.

[0182] The tetrafluoroethylene polymer can be the same type of polymer as the F polymer constituting this particle, or it can be a different type of polymer. Among them, PTFE or F polymer is preferred, PFA or FEP is more preferred, and polymer (1) or polymer (2) described above is even more preferred.

[0183] The tetrafluoroethylene polymer is preferably in particulate form and is preferably dispersed in dispersion A. Furthermore, the particles of the tetrafluoroethylene polymer may consist solely of the tetrafluoroethylene polymer, or may contain the tetrafluoroethylene polymer and other components (such as the aforementioned resin materials).

[0184] This dispersion A may also contain inorganic particles that are different from the inorganic particles contained in this particle. Examples of inorganic particles include particles identical to the inorganic particles described above that can constitute this particle. One type of inorganic particle may be used, or two or more types may be used in combination. When this dispersion A also contains inorganic particles, their content relative to the total content of this dispersion A is preferably in the range of 1 to 50% by mass, more preferably 5 to 30% by mass. Furthermore, the mass ratio (mass ratio) of the content of inorganic particles in this dispersion A to the content of this particle is preferably 0.01 to 2, more preferably 0.1 to 1.

[0185] In addition to the above-mentioned components, this dispersion A may also contain thixotropic agents, viscosity modifiers, defoamers, silane coupling agents, dehydrating agents, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, whitening agents, colorants, conductive agents, release agents, surface treatment agents, flame retardants, various fillers, and other components, without impairing the effects of the present invention.

[0186] This dispersion A is prepared by mixing and stirring the particles, aromatic polymers, liquid dispersion media, and other components such as the surfactants mentioned above, as needed. Stirring can be performed using the stirring apparatus exemplified in the wet method described above, or by means similar to those used for shearing.

[0187] The content of the particles in this dispersion A is preferably 20% by mass or more, more preferably 40 to 80% by mass, relative to the total mass of this dispersion A. In addition, the mass of polymer F is preferably 10% by mass or more relative to the total mass of this dispersion A.

[0188] Furthermore, the mass ratio of F particles to inorganic matter in this product is preferably such that the mass of F particles is 1, and the mass of inorganic matter is 0.01 to 2.0. From the perspective of suitability for forming a layered or other shaped article composed of this dispersion A, it is preferable that this dispersion A contains 20 to 40% by mass of F particles, 5 to 40% by mass of inorganic matter, and 0.1 to 30% by mass of aromatic polymer.

[0189] The viscosity of dispersion A at 25°C is 1000–100000 mPa·s. Preferably, the viscosity of dispersion A at 25°C is 5000 mPa·s or higher, more preferably 10000 mPa·s or higher. Preferably, the viscosity of dispersion A at 25°C is 100000 mPa·s or lower, more preferably 50000 mPa·s or lower, and even more preferably 20000 mPa·s or lower. In this case, dispersion A exhibits excellent coatability and can easily form molded articles (polymer layers, etc.) of arbitrary thickness.

[0190] Furthermore, within this viscosity range, especially in the high viscosity range, the inorganic matter in the shaped article formed by this dispersion A is less likely to agglomerate and is more likely to form a uniform distribution. Therefore, the physical properties of the polymer F and the inorganic matter are more easily and highly manifested.

[0191] The thixotropic ratio of this dispersion A is preferably 1.0 or higher. The thixotropic ratio of this dispersion A is preferably 3.0 or lower, more preferably 2.0 or lower. In this case, the coating properties and homogeneity of this dispersion A are excellent, and it is easy to form denser molded products (polymer layers, etc.).

[0192] This dispersion A is easily adjusted to the above range in terms of viscosity or thixotropy, and has excellent operability.

[0193] The sedimentation rate of the components in this dispersion A is preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more. Here, the sedimentation rate refers to the value calculated by the following formula, after dispensing 18 mL of this dispersion A into a spiral tube (internal volume: 30 mL) and allowing it to stand at 25°C for 14 days, based on the overall height of the dispersion in the spiral tube and the height of the sedimentation layer (dispersion layer). If no sedimentation layer is observed after standing and the state remains unchanged, it is determined that the overall height of the dispersion has not changed, and the sedimentation rate is 100%.

[0194] Component sedimentation rate (%) = (height of sedimentation layer) / (total height of dispersion) × 100

[0195] By contacting the dispersion A with the surface of the substrate layer and heating it, a polymer layer is formed, resulting in a laminate having a substrate layer and a polymer layer. More specifically, by contacting the dispersion A with the surface of the substrate layer to form a liquid film, heating the liquid film to remove the dispersion medium to form a dry film, and then heating the dry film to calcine polymer F, a laminate having a polymer layer (hereinafter also referred to as "F layer") containing polymer F and inorganic matter, preferably containing polymer F and silica, on the surface of the substrate layer can be obtained.

[0196] The heating temperature for the liquid coating is preferably 120°C to 200°C. On the other hand, the heating temperature for the dried coating is preferably 250°C to 400°C, and more preferably 300°C to 380°C.

[0197] Examples of heating methods include using an oven, using a ventilated drying furnace, and irradiating with infrared rays or other heat rays.

[0198] Examples of substrate layers include metal substrates such as copper, nickel, aluminum, titanium, and their alloys; films of heat-resistant resins such as polyimide, polyarylate, polysulfone, polyarylsulfone, polyamide, polyetheramide, polyphenylene sulfide, polyarylether ketone, polyamide-imide, liquid crystal polyester, and liquid crystal polyesteramide; prepregs (precursors to fiber-reinforced resin substrates); ceramic substrates such as silicon carbide, aluminum nitride, and silicon nitride; and glass substrates.

[0199] The ten-point average roughness of the substrate layer surface is preferably 0.01 to 0.05 μm.

[0200] The contact of this dispersion A is preferably carried out by coating, liquid ejection, or impregnation, and more preferably by coating.

[0201] Examples of coating methods include spray coating, roller coating, spin coating, gravure coating, micro-gravure coating, gravure offset coating, doctor blade coating, touch coating, bar coating, mold coating, spray Mayer wire-wound bar coating, and slot die coating.

[0202] During the drying of the liquid film, the liquid film is heated at a temperature at which the dispersion medium evaporates, forming a dried film on the surface of the sheet substrate. This heating temperature is preferably below +50°C of the boiling point of the dispersion medium, more preferably below the boiling point of the dispersion medium, and even more preferably below -50°C of the boiling point of the dispersion medium. The drying temperature is preferably between 120°C and 200°C. Alternatively, air may be blown during the process of removing the dispersion medium.

[0203] During drying, the dispersion medium does not necessarily need to be completely evaporated; it is sufficient to evaporate to the extent that the resulting layer shape is stable and can maintain the self-supporting film.

[0204] During the firing of polymer F, the drying film is preferably dried at a temperature above the melting temperature of polymer F. This heating temperature is preferably below 380°C, and more preferably below 350°C.

[0205] Examples of heating methods include using an oven, using a ventilated drying furnace, and irradiation with infrared rays or other heat rays. Heating can be carried out under either atmospheric or reduced pressure. Furthermore, the heating atmosphere can be any of the following: an oxidizing gas atmosphere (oxygen, etc.), a reducing gas atmosphere (hydrogen, etc.), or an inert gas atmosphere (helium, neon, argon, nitrogen, etc.).

[0206] The heating time is preferably 0.1 to 30 minutes, more preferably 0.5 to 20 minutes.

[0207] If heating is performed under the above conditions, the F layer can be formed appropriately while maintaining high productivity.

[0208] The thickness of layer F is preferably 0.1 to 150 μm. Specifically, when the substrate layer is a metal foil, the thickness of layer F is preferably 1 to 30 μm. When the substrate layer is a heat-resistant resin film, the thickness of layer F is preferably 1 to 150 μm, more preferably 10 to 50 μm.

[0209] The peel strength between layer F and the substrate layer is preferably 10 N / cm or more, more preferably 15 N / cm or more. The peel strength is preferably 100 N / cm or less. Using this dispersion A, this laminate can be easily formed without impairing the physical properties of the polymer F in layer F.

[0210] The dispersion A can contact only one surface of the substrate layer or both surfaces of the substrate layer. The former yields a laminate having a substrate layer and an F layer on one surface of the substrate layer, while the latter yields a laminate having a substrate layer and an F layer on both surfaces of the substrate layer. The latter type of laminate is less prone to warping, thus exhibiting superior operability during processing.

[0211] Specific examples of such laminates include metal-clad laminates having a metal foil and an F layer on at least one surface of the metal foil, and multilayer films having a polyimide film and F layers on two surfaces of the polyimide film.

[0212] Furthermore, a carrier-supported metal foil comprising two or more layers of metal foil can also be used. Examples of carrier-supported metal foils include a copper foil consisting of a carrier copper foil with a thickness of 10–35 μm and an extremely thin copper foil with a thickness of 2–5 μm laminated on top of the carrier copper foil via a release layer. Using this carrier-supported copper foil, fine patterns can be formed using the MSAP (modified semi-additive process). The release layer is preferably a nickel- or chromium-containing metal layer, or a multilayer metal layer incorporating such a metal layer.

[0213] As a specific example of a carrier-bearing metal foil, one can cite the product name "FUTF-5DAF-2" produced by Fukuda Metal Foil Powder Industry Co., Ltd.

[0214] Here, to further improve the low linear expansion and adhesion of the outermost surface of the laminate, it can be further surface-treated. The outermost surface of the laminate refers to the surface of layer F on the opposite side of the substrate.

[0215] Examples of surface treatment methods include corona treatment, plasma treatment, ozone treatment, excimer laser treatment, and silane coupling treatment.

[0216] Examples of gases used in plasma processing include oxygen, nitrogen, rare gases such as argon, hydrogen, ammonia, and vinyl acetate. One or more of these gases may be used.

[0217] To further improve the low linear expansion property of the laminate, it can be annealed. The annealing conditions are: temperature 120–180℃, pressure 0.005–0.015 MPa, and time 30–120 minutes.

[0218] Other substrates can be further stacked on the outermost surface of this laminate.

[0219] Other substrates may include heat-resistant resin films, prepregs used as precursors for fiber-reinforced resin boards, laminates having heat-resistant resin film layers, and laminates having prepreg layers.

[0220] Prepreg is a thin sheet substrate made by impregnating short hemp fibers or woven fabrics with thermosetting or thermoplastic resins.

[0221] A heat-resistant resin film is a film containing one or more heat-resistant resins. Examples of heat-resistant resins include the resins mentioned above, with aromatic polyimide being particularly preferred.

[0222] As a method of lamination, one example is the hot pressing of the laminate and other substrates.

[0223] When other substrates are prepregs, the preferred hot-pressing conditions are a temperature of 120–400°C, an atmosphere pressure of less than 20 kPa (vacuum), and a pressurization pressure of 0.2–10 MPa. This laminate has an F layer with excellent electrical properties, making it suitable as a printed circuit board material. Specifically, this laminate can be used as a flexible or rigid metal-clad laminate in the manufacture of printed circuit boards, and is particularly suitable as a flexible metal-clad laminate for the manufacture of flexible printed circuit boards.

[0224] A printed circuit board can be obtained by etching a metal foil, such as a metal foil with an F-layer, as the substrate layer, to form a transmission circuit. Specifically, a printed circuit board can be manufactured by etching the metal foil to form a specified transmission circuit, or by using electroplating methods such as the semi-additive plating (SAP) method or the MSAP method to form a specified transmission circuit.

[0225] A printed circuit board made of metal foil with an F layer has a transmission circuit formed by the metal foil and an F layer in sequence. Specific examples of the structure of the printed circuit board include transmission circuit / F layer / prepreg layer and transmission circuit / F layer / prepreg layer / F layer / transmission circuit.

[0226] In the manufacture of this printed circuit board, an interlayer insulating film can be formed on the transmission circuit, a solder resist can be laminated on the transmission circuit, and a coating film can be laminated on the transmission circuit. These interlayer insulating films, solder resists, and coating films can also be formed from this dispersion A.

[0227] The F-layer laminate with other substrates can be used as antenna components, printed circuit boards, aircraft components, automotive components, sporting goods, food industry products, coatings, cosmetics, etc. Specifically, it can be used as wire coating materials (aircraft wires, etc.), electrical insulating tapes, oil drilling insulation tapes, printed circuit board materials, separation membranes (precision filtration membranes, ultrafiltration membranes, reverse osmosis membranes, ion exchange membranes, dialysis membranes, gas separation membranes, etc.), electrode adhesives (for lithium secondary batteries, fuel cells, etc.), copier rollers, covers for furniture, automotive dashboards, and household appliances, sliding components (load bearings, sliding shafts, valves, bearings, gears, cams, conveyor belts, food conveyor belts, etc.), tools (shovels, files, awls, saws, etc.), boilers, hoppers, pipes, ovens, barbecue molds, chutes, plastic molds, toilets, and container coating materials.

[0228] The second type of dispersion of the present invention is a dispersion containing the particles and a liquid dispersion medium, wherein the particles are dispersed in the liquid dispersion medium, and the liquid dispersion medium contains two liquid dispersion media with different boiling points and the two liquid dispersion media have a relationship of forming an azeotropic mixture (hereinafter also referred to as "this dispersion B").

[0229] This dispersion B exhibits excellent dispersion stability. Furthermore, the molded articles obtained from this dispersion B are dense and possess good surface properties such as appearance (surface flatness or feel). The reasons for the improved dispersion stability and appearance of the resulting molded articles, the correlation between the composition of this dispersion B and its mechanism of action, are not necessarily clear, but the following can be speculated.

[0230] Composite particles containing tetrafluoroethylene-based polymers and inorganic materials typically readily adsorb or support the dispersion medium. Therefore, after a dispersion containing composite particles is applied to the surface of a substrate to form a liquid film, the volatilization or evaporation of the dispersion medium requires time when removed by means such as heating, leading to a decrease in the production efficiency and precision of the molded article. On the other hand, when manufacturing molded articles from a dispersion, if the dispersion medium is too volatile or easily evaporated, the composite particles cannot be sufficiently deposited, resulting in a decrease in the surface smoothness of the resulting molded article.

[0231] Since this dispersion B contains two liquid dispersion media with different boiling points and a relationship to form an azeotropic mixture, it is believed that the dispersion media can be evaporated at an appropriate evaporation rate. In addition, since the high-boiling-point liquid dispersion media evaporates or evaporates slowly, the particles are densely packed, and surface roughness caused by rapid bubble generation can be suppressed, thereby improving the appearance of the resulting molded product.

[0232] In addition, this particle contains F polymer and inorganic particles. F polymer has low surface energy and poor dispersion stability, but the particle formed by the aggregation of F polymer and inorganic matter interacts more easily with other particles and liquid dispersion media than F polymer, and its dispersion stability is excellent.

[0233] As a result, it is believed that dispersion B can form molded articles with high physical properties of polymer F and inorganic materials, high compositional uniformity, density, and excellent electrical properties and appearance.

[0234] The details of polymer F and the particles in dispersion B are the same as those in the description of dispersion A.

[0235] Furthermore, in this dispersion B, the F particles constituting the particles may include resins other than F polymers such as aromatic polyesters, polyamide-imide, thermoplastic polyimide, polyphenylene ether, and polyphenylene ether, but preferably are mainly composed of F polymers. The content of F polymers in the F particles is preferably 80% by mass or more, more preferably 100% by mass.

[0236] Even when a large amount of these particles are added to a liquid dispersion medium, they can be stably dispersed. In the shaped articles (polymer layers, films, etc.) formed by this dispersion B, the F polymer and inorganic matter are more evenly distributed, and they easily exhibit the physical properties based on the F polymer (electrical properties, adhesion, etc.) and the physical properties based on the inorganic matter (low linear expansion, etc.).

[0237] This dispersion B contains two liquid dispersion media with different boiling points. These two liquid dispersion media are related to form an azeotropic mixture. Here, an "azeotropic mixture" refers to a mixture in which the gas and liquid phases have the same composition.

[0238] Azeotropic mixtures can be obtained in either a homogeneous or heterogeneous form depending on the choice of the two liquid dispersion media. From the perspective of good productivity and process implementation in obtaining the shaped article from this dispersion B, a homogeneous azeotropic mixture is preferred.

[0239] In this dispersion B, it is preferable that the mixing ratio of the high-boiling-point dispersion medium in the two liquid dispersion media with different boiling points is greater than the composition ratio (mass ratio) of the high-boiling-point dispersion medium in the azeotropic mixture of the two liquid dispersion media.

[0240] The composition ratio of the azeotropic mixture can vary considerably depending on the selection of the two liquid dispersion media. Specifically, when a low-boiling-point liquid dispersion medium is used as dispersion medium S1 and a high-boiling-point liquid dispersion medium is used as dispersion medium S2, it is preferable that the composition ratio (mass ratio) of S1 to S2 in this dispersion B is greater than the composition ratio (mass ratio) of S1 to S2 in the azeotropic mixture of S1 and S2.

[0241] Furthermore, the azeotropic mixture preferably has a lower azeotropic point than the boiling point of the high-boiling-point dispersion medium among the two liquid dispersion media mentioned above, and more preferably, the azeotropic point is lower than the boiling point of either of the two liquid dispersion media mentioned above.

[0242] If the mixing ratio and azeotropic point are as described above, even high-boiling-point dispersion media can be easily removed as an azeotropic mixture at a lower temperature during the drying process of molding articles made from this dispersion B, which facilitates both increased productivity and improved appearance of the molded articles. Furthermore, the residual high-boiling-point liquid dispersion media also acts as a lubricant during the removal of the liquid dispersion media, promoting the accumulation of these particles and contributing to the formation of uniform molded articles with low surface roughness.

[0243] The two liquid dispersion media mentioned above are preferably compounds that are liquid at atmospheric pressure and 25°C, and can be either polar or non-polar.

[0244] The boiling points of the two liquid dispersion media are preferably in the range of 50 to 240°C, and at least one of the two liquid dispersion media is more preferably water, alcohol or amide.

[0245] If this liquid dispersion medium is used, it is believed that the dispersion state of the particles in this dispersion B can be maintained more stably.

[0246] Examples of liquid dispersion media include water [boiling point: 100℃ (boiling point at atmospheric pressure, unless otherwise specified)], ethylene glycol (boiling point: 197℃), N,N-dimethylformamide (boiling point: 153℃), N,N-dimethylacetamide (boiling point: 165℃), 3-methoxy-N,N-dimethylpropionamide (boiling point: 215℃), 3-butoxy-N,N-dimethylpropionamide (boiling point: 252℃), N-methyl-2-pyrrolidone (boiling point: 204℃), γ-butyrolactone (boiling point: 204℃), cyclohexanone (boiling point: 156℃), cyclopentanone (boiling point: 131℃), butyl acetate (boiling point: 126℃), methyl isopropyl ketone (boiling point: 118℃), methyl ethyl ketone (boiling point: 79.6℃), and toluene (boiling point: 111℃).

[0247] Examples of suitable combinations of two liquid dispersion media with different boiling points that have a relationship of forming an azeotropic compound in dispersion B include water and methyl ethyl ketone, water and cyclohexanone, ethylene glycol and toluene, and toluene and N,N-dimethylformamide. In this specification, the combination of toluene and N,N-dimethylformamide is considered an azeotropic mixture with an azeotropic point of 59.9–109.9 °C.

[0248] This dispersion B may also contain other liquid dispersion media that are different from the two liquid dispersion media mentioned above, without affecting the effect of the present invention.

[0249] Here, the other liquid dispersion medium may be related to at least one of the above two liquid dispersion media to form an azeotropic mixture, or it may be related to both of the above two liquid dispersion media to form an azeotropic mixture of three components, but preferably it is related to not forming any azeotropic mixture.

[0250] In this dispersion B, the total content of the liquid dispersion medium is preferably 30-90% by mass, more preferably 50-80% by mass.

[0251] This dispersion B may or may not contain a surfactant. Examples of surfactants include those described in the description of dispersion A. Dispersion B preferably contains a fluorinated surfactant.

[0252] From the perspective of improving the adhesion and low linear expansion of the molded articles formed by this dispersion B, other resin materials besides the particles may also be included. In this case, the dispersion stability of this dispersion B tends to be better. When this dispersion B includes other resin materials, their content is preferably 40% by mass or less relative to the total amount of this dispersion B.

[0253] Other resin materials include tetrafluoroethylene polymers other than F polymers, F polymers, and aromatic polymers. Other resin materials may be the same as the F polymer in this particle.

[0254] Examples of tetrafluoroethylene polymers other than F polymers include polytetrafluoroethylene (PTFE), polymers containing TFE units and ethylene-based units, polymers containing TFE units and propylene-based units, polymers containing TFE units and fluoroalkyl vinyl units, and polymers containing TFE units and trifluorochloroethylene-based units.

[0255] Polymer F can be the same type of polymer as the polymer F constituting this particle described above, or it can be a different type of polymer. Among them, PTFE or polymer F is preferred, PFA or FEP is more preferred, and polymer (1) or polymer (2) described above is even more preferred.

[0256] The F polymer is preferably in particulate form and is preferably dispersed in this dispersion B. Furthermore, the F polymer particles may consist solely of the F polymer, or may contain the F polymer and other components (such as the aforementioned resin materials).

[0257] As an aromatic polymer, the same polymers that can be included in dispersion A can be cited, and their preferred range is also the same.

[0258] This dispersion B may also contain inorganic particles that are different from the inorganic particles contained in this particle. Examples of inorganic particles are the same as those that may be further contained in this dispersion A, and the preferred examples are also the same.

[0259] In addition to the above-mentioned components, this dispersion B may also contain other components that are the same as those described in the description of this dispersion A, without impairing the effects of the present invention.

[0260] This dispersion B is prepared in the same manner as this dispersion A.

[0261] The suitable ranges for the content of this particle, the content of F polymer, and the mass ratio of F particles to inorganic matter in this dispersion B are the same as those preferred ranges in this dispersion A.

[0262] The content of polymer F in this dispersion B is preferably 40% by mass or more, and more preferably 50% by mass or more.

[0263] When dispersion B contains F polymers that are other resins different from the F polymers contained in this particle, the content of F polymers in dispersion B refers to the sum of the content of F polymers contained in this particle and the content of F polymers contained in other resins.

[0264] The suitable ranges for viscosity, thixotropic ratio, and component sedimentation rate of dispersion B are the same as those for viscosity and thixotropic ratio of dispersion A.

[0265] By contacting the dispersion B with the surface of the substrate layer and heating it, a polymer layer containing polymer F and inorganic matter is formed, thereby obtaining a laminate having a substrate layer and a polymer layer.

[0266] The specific manufacturing method of the laminate, the substrate layer, the morphology of the printed circuit board using the laminate, and the morphology of the multilayer printed circuit board, including the preferred morphology, are the same as those described in the description of dispersion A.

[0267] When drying the liquid film, the liquid film is heated at the temperature at which the dispersion medium evaporates, forming a dried film on the surface of the sheet substrate. This heating temperature is preferably below +50°C of the boiling point of the azeotropic mixture of the two dispersion media contained in dispersion B, and more preferably below that boiling point. The drying temperature is preferably between 120°C and 200°C.

[0268] The composite particle of the present invention is a composite particle containing an F polymer with a melting temperature of 260 to 320°C, containing 1 to 5 mol% of PAVE units relative to all units and silica, and whose surface silicon atomic weight to fluorine atomic weight ratio is 1 or more as determined by X-ray photoelectron spectroscopy (hereinafter also referred to as "this particle α").

[0269] This particle α is a complex of F polymer and silica, characterized by adjustable polarity and other properties and high stability. Its mechanism of action is not necessarily clear, but it can be hypothesized as follows.

[0270] Polymer F not only exhibits excellent shape stability, such as antigenic fibrillability, but also possesses a high degree of conformation, allowing for reduced restriction of molecular motion at the single-molecule level. Because such polymers readily form microspheres at the molecular aggregate level, minute uneven structures easily form on their surfaces. Therefore, it is believed that the shape of the polymer aggregate remains stable without being damaged, and it physically adheres tightly to silica. Furthermore, the interactions between the tightly adhered silica particles further promote silica adhesion, thus stabilizing the composite particles.

[0271] As a result, this particle α has high stability while containing a relatively large amount of silicon dioxide, and possesses the physical properties of F polymer and silicon dioxide.

[0272] The F polymer in particle α is a TFE-type polymer containing a melting temperature of 260–320°C and 1–5 mol% PAVE units relative to all units. More preferably, the F polymer is the aforementioned polymer (1) containing both TFE and PAVE units and having polar functional groups. If the F polymer is polymer (1), then in particle α, polymer (1) and silica adhere not only easily physically but also chemically, thus enhancing the aforementioned mechanism of action.

[0273] This particle α may contain polymers other than polymer F. However, the proportion of polymer F in the polymer contained in this particle α is preferably 80% by mass or more, more preferably 100% by mass.

[0274] Other polymers besides F polymers include heat-resistant resins such as aromatic polyesters, polyamide-imide, thermoplastic polyimide, polyphenylene ether, and polyphenylene ether.

[0275] This particle α contains silicon dioxide. Silicon dioxide can be a single type or a mixture of two or more types. In addition, it may contain inorganic substances other than silicon dioxide.

[0276] When the product contains inorganic substances other than silicon dioxide, with the total mass of silicon dioxide and other inorganic substances as 100% by mass, the silicon dioxide content is preferably 50% by mass or more, more preferably 75% by mass. The silicon dioxide content is preferably 100% by mass or less, more preferably 90% by mass or less.

[0277] Preferably, at least a portion of the surface of the silica is surface-treated. Examples of surface-treatment agents used for this surface treatment include the same compounds used for surface treatment of inorganic materials, such as silane coupling agents.

[0278] The preferred specific surface area (BET method) of silicon dioxide is 1–20 m². 2 / g, more preferably 5-8mg 2 / g. In this case, the interaction between silica and F polymer is easily enhanced. In addition, when a dispersion containing α particles is coated onto a substrate to form a polymer layer, silica and F polymer are more evenly distributed, and it is easier to achieve a balance of their physical properties.

[0279] Examples of silica fillers include the "admafin" series manufactured by Admatex Corporation, spherical molten silica (the "SFP" series manufactured by Denka Corporation), hollow silica fillers (the "E-SPHERES" series manufactured by Pacific Cement Corporation, the "SiliNax" series manufactured by Nippon Steel Mining Corporation, the "Eccospheres" series manufactured by Emerson Corning Corporation, and the hydrophobic AEROSIL series "RX200" manufactured by AEROSIL Corporation).

[0280] In addition, other inorganic substances besides silicon dioxide can be cited as examples of inorganic substances that can constitute the particles.

[0281] The preferred shape of silica is granular, including granular, needle-like (fibrous), or plate-like (columnar) shapes. Specific shapes of silica include spherical, flake-like, layered, leaf-like, almond-like, columnar, cockscomb-like, equiaxed, leaf-like, mica-like, blocky, flat, wedge-shaped, rosette-like, mesh-like, and square columnar, with spherical being the most preferred. If spherical silica is used, when a dispersion containing α-particles is coated onto a substrate to form a polymer layer, the silica and F polymer are more evenly distributed, and their performance is easily improved.

[0282] The spherical silica is preferably approximately spherical. The definition of approximately spherical is as described above.

[0283] When the α particle was measured by X-ray photoelectron spectroscopy (hereinafter also referred to as ESCA), the ratio of silicon atoms to fluorine atoms on the surface was greater than 1. ESCA is a method for quantifying the amount of elements present on the surface of particles, and can quantify elements such as carbon (C), oxygen (O), fluorine (F), and silicon (Si). In this invention, the surface refers to a depth of 2-8 nm from the particle surface. During the measurement, the particle was fixed with a carbon ribbon, and the particle sampling was carried out in a manner that ensured that the carbon ribbon was not exposed and that the surface was as flat as possible. The information on the apparatus and the analysis are as follows.

[0284] Analytical apparatus: ULVAC-Phi ESCA 5500

[0285] X-ray source: Al Kα 14kV

[0286] Beam diameter: 800μmφ

[0287] Measurement method: Broad spectrum measurement

[0288] Binding energy measurement range: 0~1100eV

[0289] Energy passing through: 93.8 eV

[0290] Energy level: 0.8 eV

[0291] Total number of cycles: 16

[0292] Neutralization gun: Use

[0293] Angle between detector and sample surface: 45 degrees

[0294] In this invention, the elements present at that depth of the particle α are determined by ESCA, and the atomic weights of silicon and fluorine are quantified. The particle α has a value greater than or equal to 1 obtained by dividing the quantified silicon amount by the fluorine amount.

[0295] The particle α with such a value, in other words, is a particle whose surface is highly coated with silica. Not only is it excellent in terms of particle properties such as the liquid dispersibility of silica, but also the molded articles formed from liquid compositions containing particle α tend to have high properties of silica and F polymer.

[0296] The ratio of silicon atoms to fluorine atoms on the α surface of this particle, as determined by ESCA, is preferably 1.0 or more, more preferably 1.1 or more, and even more preferably 1.2 or more. The ratio of silicon atoms to fluorine atoms is preferably 100 or less.

[0297] The elements measured in ESCA are carbon, oxygen, fluorine, and silicon. The proportion of fluorine and silicon in the total amount (in atomic percent) is used as the amount of each atom.

[0298] To ensure that the amounts of fluorine and silicon atoms on the surface of particle α are within the aforementioned range, particle α is preferably prepared using the aforementioned dry method A, dry method B, wet method, etc., with dry method A being more preferred. That is, particle α is preferably prepared by colliding F particles with silica in a floating state at a temperature above the melting temperature of the F polymer.

[0299] The D50 of this particle α is preferably 40 μm or less, more preferably 10 μm or less, and even more preferably 4 μm or less. The D50 of this particle α is preferably 0.1 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more.

[0300] Furthermore, the D90 of this particle α is preferably 40 μm or less, and more preferably 4 μm or less.

[0301] If the D50 and D90 of the particle α are within the above range, the dispersion stability of the particle α and the dispersion uniformity of the polymer layer (F layer) of the laminate obtained by coating the liquid composition containing the particle α onto the substrate to form a polymer layer (F layer) are further improved, and it is easy to obtain a laminate that has high physical properties of F polymer and silica.

[0302] The higher the amount of silica in particle α, the lower the bulk density of particle α, which is therefore preferable. On the other hand, the lower the amount of silica in particle α, the lower the viscosity of the liquid composition containing particle α, which is also preferable. From the above viewpoint, the amount of silica in particle α is preferably 15 to 85 parts by mass relative to 100 parts by mass of polymer F. Within this range, the amounts of fluorine and silicon elements on the surface of particle α are more likely to be within the above range. The amount of silica in particle α is more preferably 20 parts by mass or more relative to 100 parts by mass of polymer F, and even more preferably 30 parts by mass or more. The amount of silica in particle α is more preferably 70 parts by mass or less relative to 100 parts by mass of polymer F, and even more preferably 50 parts by mass or less.

[0303] Furthermore, based on the above range, it is easy to set the amount of fluorine atoms and silicon atoms on the surface of this particle α within the above range.

[0304] As a suitable form for this particle α, the preferred form is one with F polymer as the core and silicon dioxide attached to the surface of the core, namely the form I described above.

[0305] In morphology I, both the core of polymer F and the silica are preferably in particle form. In this case, since silica, which has a higher hardness than polymer F, is exposed on the surface, the fluidity of the particles α is improved, thus enhancing their workability.

[0306] In addition, in morphology I, the core of the F polymer can be composed of individual F particles or an aggregate of F particles.

[0307] In the morphology I boson α, the F particles and silica particles are preferably manufactured by the aforementioned dry method A or dry method B, more preferably by dry method A. In this case, it is preferable to set the D50 of the F particles to be greater than the D50 of the silica particles, and to set the amount of F particles to be greater than the amount of silica particles. If boson α is manufactured by dry method A or dry method B with such a relationship set, boson α of morphology I can be easily obtained.

[0308] Based on the D50 of the F particles, the D50 of the silica particles is preferably 0.001 to 0.5, more preferably 0.01 to 0.05. Specifically, it is preferred that the D50 of the F particles is greater than 1 μm, and the D50 of the silica particles is less than 0.8 μm.

[0309] In the resulting morphology I particle α, the aforementioned relationship is maintained: the D50 of the F polymer core is greater than the D50 of the silica particles, and the mass of the F polymer in particle α is greater than the mass of the silica. In this case, the surface of the F polymer core can be coated with a larger amount of silica particles, and the morphology I particle α is formed with a core-shell structure. Furthermore, in this case, aggregation between F particles is suppressed, and it is easy to obtain particle α composed of individual F particles with silica particles attached to their cores.

[0310] In Form I, the silica particles are preferably spherical, and more preferably approximately spherical. The definition of approximately spherical is as described above.

[0311] If silica particles with a highly approximately spherical shape are used, when a liquid composition containing these particles α is coated onto a substrate to form a polymer layer, the silica and F polymer are more evenly distributed, and a balance of their physical properties is easily achieved.

[0312] In Form I, the D50 of the silica particles is preferably in the range of 0.001 to 0.8 μm, more preferably 0.01 to 0.3 μm, and even more preferably 0.03 to 0.1 μm. Silica with a D50 in this range is sometimes referred to as nano-silica. The workability and flowability of these particles α are easily improved, and their dispersion stability is also easily enhanced. If silica in this range is used, the viscosity, thixotropic ratio, and other liquid properties of the liquid composition containing these particles α are easily adjusted, and its workability and defoaming properties tend to improve.

[0313] Furthermore, the particle size distribution of the silica particles, indicated by a D90 / D10 value, is preferably 3 or less, more preferably 2.9 or less. A narrow particle size distribution makes it easier to control the flowability of the resulting particles α, and is therefore preferred.

[0314] In Form I, it is preferable that at least a portion of the surface of the silica particles is surface-treated, more preferably with a silazane compound such as hexamethyldisilazane or a silane coupling agent. Examples of such compounds can be cited as silane coupling agents.

[0315] In Form I, one type of silica particles can be used, or two or more types can be used in combination. When two types of silica particles are used in combination, the average particle size of each silica particle can be different, and the mass ratio of the content of each silica particle can be appropriately set according to the required function.

[0316] Furthermore, in Form I, preferably a portion of the silica particles is embedded in the core of the F polymer. This further enhances the adhesion between the silica particles and the F polymer core, making it less likely for silica particles to detach from the α particle. In other words, the stability of the α particle is further improved.

[0317] In the morphology I particle α, the D50 of the F polymer core is preferably 0.1 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more. The D50 is preferably 30 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less.

[0318] Furthermore, the proportion of polymer F in the α-particle of form I is preferably 50% by mass or more, more preferably 60% by mass or more. The proportion of polymer F is preferably 99% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less. The proportion of silica is preferably 1% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more. The proportion of silica is preferably 50% by mass or less, more preferably 40% by mass or less. If silica within this range is used, not only is it easy to obtain α-particles with excellent operability and dispersion stability, but the adjustment of liquid properties such as viscosity and thixotropic ratio of the liquid composition containing α-particles becomes easier, and its operability and defoaming properties tend to improve.

[0319] The surface treatment of the α-particle in morphology I can also be performed. Specific examples of this surface treatment, as described above, not only adjust the amount of silica on the surface of the α-particle, but also further adjust its surface properties.

[0320] In this invention, if the above-mentioned particle α and the dispersion medium are mixed, a liquid composition containing the above-mentioned particle α and the dispersion medium, wherein the particle α is dispersed in the dispersion medium (hereinafter also referred to as this composition) can be obtained.

[0321] The α-particles exhibit sufficiently high polarity and can be stably dispersed even when added in large quantities in the dispersion medium. Furthermore, in polymer layers, laminates, and films formed from this composition, the F polymer and silica are more uniformly distributed, and the physical properties based on the F polymer, such as electrical properties and adhesion, and the physical properties based on silica, such as low linear expansion, are readily and highly exhibited.

[0322] The liquid dispersion medium in this composition is an inert liquid compound at 25°C, which serves as the dispersion medium for the particles α. The dispersion medium can be water or a non-aqueous dispersion medium. There can be one or more dispersion media. In this case, it is preferable that different types of liquid compounds are miscible with each other.

[0323] Examples of dispersion media include those that are the same as the liquid dispersion media in compositions A and B.

[0324] When the dispersion medium contains an aprotic polar solvent such as N-methyl-2-pyrrolidone, it is preferable that at least a portion of the surface of the silica contained in the particle α is surface-treated with a silane coupling agent having at least one group selected from amino, vinyl and (meth)acryloyloxy, more preferably with phenylaminosilane.

[0325] When the dispersion medium contains a non-polar solvent such as toluene, it is preferable to perform a hydrophobic treatment on at least a portion of the surface of the silica contained in the particle α, and preferably to perform surface treatment with a silane coupling agent having at least one group selected from alkyl and phenyl groups.

[0326] When the dispersion medium contains protic polar solvents such as water, the silica contained in the α particles is preferably not surface-treated.

[0327] When such a dispersion medium and silica surface treatment are combined, the dispersion stability of this composition tends to improve.

[0328] With this composition as 100% by mass, the content of the α-particle in this composition is preferably 1 to 50% by mass, more preferably 10 to 40% by mass.

[0329] The content of the dispersion medium in this composition is preferably 50 to 99% by mass relative to 100% by mass of the composition, and more preferably 60 to 90% by mass.

[0330] From the viewpoint of further improving the dispersion stability of particle α, and enhancing the sedimentation and workability of the particles, this composition may further contain a surfactant. However, due to the excellent dispersion stability of particle α, it is practically possible to contain no surfactant. Examples of surfactants mentioned above can be cited.

[0331] "Substantially free of surfactants" means that the concentration of surfactants in the composition does not exceed 1% by mass, the content of surfactants in the composition is less than 1% by mass, preferably less than 0.5% by mass, and more preferably 0% by mass.

[0332] The viscosity of this composition is preferably 50 mPa·s or higher, more preferably 100 mPa·s or higher. The viscosity of this composition is preferably 50,000 mPa·s or lower, more preferably 1,000 mPa·s or lower, and even more preferably 800 mPa·s or lower. In this case, the composition exhibits excellent coatability and readily forms polymer layers and other molded articles of arbitrary thickness.

[0333] The thixotropic ratio of this composition is preferably 1.0 or higher. The thixotropic ratio of this composition is preferably 3.0 or lower, more preferably 2.0 or lower. In this case, the composition not only has excellent coatability but also excellent homogeneity, thus easily forming denser polymer layers and other molded products.

[0334] This composition may also contain an F polymer, a polymer other than an F polymer, or a precursor thereof. Examples of such polymers or precursors include polytetrafluoroethylene (PTFE), polymers containing TFE units and PAVE units (PFA), polymers containing TFE units and hexafluoropropylene-based units (FEP), polymers containing TFE units and ethylene-based units (ETFE), polyvinylidene fluoride (PVDF), polyimide, polyarylate, polysulfone, polyarylsulfone, polyamide, polyetheramide, polyphenylene ether, polyphenylene sulfide, polyarylether ketone, polyamide-imide, liquid crystal polyester, liquid crystal polyesteramide, epoxy resin, maleimide resin, etc. The PFA may be an F polymer or a PFA other than an F polymer.

[0335] These polymers or their precursors may be dispersed in or soluble in this composition. Furthermore, these polymers or their precursors may be thermoplastic or thermosetting. This composition preferably contains the aforementioned aromatic polymers.

[0336] In addition to the above-mentioned components, this composition may also contain other components as described in the description of this dispersion A, without affecting the effects of the present invention.

[0337] The composition is brought into contact with the surface of a substrate layer and heated to form a polymer layer comprising polymer F and silica, thereby obtaining a laminate having a substrate layer and a polymer layer. The specific manufacturing method of the laminate, the substrate layer, the morphology of the printed circuit board using the laminate, and the morphology of the multilayer printed circuit board, including the preferred morphology, are the same as those described in the description of dispersion A.

[0338] In addition, a membrane can be prepared by melt-blending the α-particle with a fluorinated olefin polymer and then extruding it.

[0339] This particle α contains F polymer and silicon dioxide, which have high interaction (compatibility) with fluorinated olefin polymers. In addition, the surface of this particle α has silicon atoms in a specified proportion, thus it has a specified hardness. When this particle α is melt-blended with fluorinated olefin polymers, the composite particles and fluorinated olefin polymers collide and are easily crushed and micronized.

[0340] As a result, in the film obtained by uniformly melting and mixing the two, the F polymer, the fluorinated olefin polymer and silica are uniformly distributed, and it is easy to highly exhibit the physical properties, especially the electrical properties, based on the F polymer and the fluorinated olefin polymer, and the low linear expansion properties based on silica.

[0341] The fluoroolefin polymers melt-blended with this particle α can be F polymers or polymers other than F polymers that contain fluoroolefin-based units.

[0342] Examples of fluoroolefin polymers include PTFE, PFA, FEP, ETFE, and PVDF. PFA can be an fluoropolymer or a PFA other than an fluoropolymer. Fluoroolefin polymers can be the same fluoropolymer as the fluoropolymer contained in the composite particles.

[0343] The preferred melting temperature (melting point) of fluoroolefin polymers is 160–330 °C.

[0344] The glass transition temperature of fluoroolefin polymers is preferably 45–150 °C.

[0345] Fluorinated olefin polymers preferably have polar functional groups. The types and methods of introducing polar functional groups are the same as those described for polymer F above.

[0346] The melt blending of α-polymers and fluoroolefin polymers is carried out, for example, using a single-screw mixer. A single-screw mixer has a cylinder and a screw rotatably mounted within the cylinder. Using a single-screw mixer makes it easier to prevent the deterioration of the α-polymer and fluoroolefin polymers during melt blending.

[0347] In this case, when the total length of the screw is set as L (mm) and the diameter as D (mm), the effective length (L / D), expressed as the ratio of the total length L to the diameter D, is preferably 30 to 45. If the effective length is within this range, sufficient shear stress can be imparted to F polymers and TFE polymers while preventing their deterioration, making it easier to reduce temperature unevenness in the melt mixture.

[0348] The screw rotation speed is preferably 10 to 50 ppm.

[0349] The molten compound is ejected from a T-die located at the front of the cylinder. The molten compound ejected from the T-die then comes into contact with multiple cooling rollers and solidifies into a film. The resulting elongated film is wound onto a take-up roller.

[0350] The thickness of the membrane is preferably 5 to 150 μm, more preferably 10 to 100 μm.

[0351] The membrane can be elongated or leaf-shaped. For elongated membranes, the length of the long side is preferably 100 m or more. The upper limit of the long side length is typically 2000 m. Furthermore, for elongated membranes, the length of the short side is preferably 1000 mm or more, and the upper limit of the short side length is typically 3000 mm.

[0352] The resulting film is overlapped with a substrate layer and then hot-pressed to obtain a laminate containing a polymer layer formed by the film and a substrate layer.

[0353] The preferred hot pressing conditions are a temperature of 120–300°C, an atmosphere pressure of less than 20 kPa in a vacuum, and a pressurization pressure of 0.2–10 MPa.

[0354] Furthermore, the morphology of the substrate layer, the printed circuit board using the laminate, and the multilayer printed circuit board, including their preferred morphology, are the same as those described in Method 1 above.

[0355] In addition, a round mold can be used instead of a T-mold to manufacture blown films.

[0356] The dispersion, composite particles, and manufacturing method of the composite particles of the present invention have been described above, but the present invention is not limited to the configuration of the embodiments described above.

[0357] For example, for the dispersion and composite particles of the present invention, other arbitrary components can be added to the above embodiments, or they can be replaced with any component that performs the same function.

[0358] Furthermore, the method for manufacturing the composite particles of the present invention can be modified by adding any other steps to the above embodiments, or by replacing them with any steps that produce the same effect.

[0359] Example

[0360] The present invention will be described in detail below with reference to specific embodiments, but the present invention is not limited thereto.

[0361] The details of each component are shown below.

[0362] [F particle]

[0363] F particle 1: Particles composed of F polymer 1 with anhydride groups containing 97.9 mol% TFE units, 0.1 mol% NAH units, and 2.0 mol% PPVE units (melting temperature: 300℃) (D50: 2 μm, bulk density: 0.18 g / m³). 2 )

[0364] F particles 2: Particles composed of non-functionalized polymer F 2 (melting temperature: 305℃) containing 97.5 mol% TFE units and 2.5 mol% PPVE units (D50: 2 μm, bulk density: 0.19 g / m³). 2 )

[0365] F-particle 3: Particles composed solely of F polymer 3 (melting temperature: 305℃) consisting of TFE and PPVE units only (D50: 2μm, bulk density: 0.19g / m³). 2 )

[0366] F particles 4: Particles composed of F polymer 4 (melting temperature: 300℃) containing 97.5 mol% TFE units and 2.5 mol% PPVE units, which are non-polar functional groups (D50: 2.6 μm).

[0367] [PTFE particles]

[0368] PTFE1: Particles composed of non-thermally fusible PTFE (D50: 0.3 μm, bulk density: 0.2 g / m³). 2 )

[0369] PTFE2: Particles composed of antigen-fiber PTFE (D50: 2.4 μm)

[0370] [Inorganic substances]

[0371] Inorganic material 1: Silica filler (approximately spherical, average particle size 0.03 μm), surface-treated with silane coupling agent.

[0372] [Silica particles]

[0373] Silica particles 1: Approximately spherical particles composed of silica (D50: 0.05 μm)

[0374] Silica particles 2: Approximately spherical particles composed of silica (D50: 0.25μm).

[0375] [Dispersion medium]

[0376] NMP: N-methyl-2-pyrrolidone

[0377] Dispersion medium S1: Toluene (boiling point: 111℃)

[0378] Dispersion medium S2: N,N-dimethylformamide (DMF) (boiling point: 153℃)

[0379] [Aromatic polymers]

[0380] Polymer 1: Thermoplastic aromatic polyimide (PI1) soluble in NMP varnish

[0381] Polymer 2: A powder obtained by pulverizing a thermoplastic polymer obtained by reacting 2-hydroxy-6-naphthoic acid, 4,4'-dihydroxybiphenyl, terephthalic acid, and 2,6-naphthoic acid in the following proportions: 60 mol%, 20 mol%, 15.5 mol%, and 4.5 mol%. (D50: 16 μm)

[0382] Polymer 3: Thermosetting aromatic bismaleimide powder (D50: 20 μm)

[0383] [Example 1-1]

[0384] 1. Manufacturing of composite particles

[0385] Prepare a mixture of 99 parts by mass of F particles 1 and 1 part by mass of inorganic substance 1.

[0386] Then, the mixture is fed into a powder processing device (hybridization system) that uses a high-speed rotating agitator within a cylindrical container to agitate the particles while simultaneously applying stress by trapping the particles between the container's inner wall and the agitator. Next, F particles 1 and inorganic matter 1 are allowed to float and collide in a high-temperature turbulent atmosphere, thus instilling stress between them and performing a composite treatment. The temperature inside the device is maintained below 100°C under a nitrogen atmosphere for 15 minutes during the treatment.

[0387] The resulting processed material was in the form of a fine powder. Analysis of the fine powder using an optical microscope confirmed that it was a composite particle 1 with an F particle 1 as the core and inorganic matter 1 attached to the surface of the core to form a shell.

[0388] Composite particle 1 is spherical in shape and has a D50 of 4 μm.

[0389] 2. Preparation and evaluation of dispersions

[0390] NMP and polymer 1 were added to a tank equipped with a stirring blade and the tank was thoroughly stirred. Next, the resulting composite particles 1 were added to the tank and stirred at 800 rpm for 15 minutes to create an upflow for shear treatment, yielding a dispersion 1 containing composite particles 1 (100 parts by mass), polymer 1 (30 parts by mass), and NMP (120 parts by mass). The viscosity of the resulting dispersion 1 at 25°C was 18000 mPa·s. The dispersion stability and sedimentation rate of dispersion 1 were evaluated according to the following criteria.

[0391] <Evaluation Criteria for Dispersion Stability>

[0392] 〇: Minimal foaming and no agglomerates were observed immediately after preparation and storage; the mixture was evenly dispersed.

[0393] △: Some agglomerates were observed both immediately after preparation and after storage.

[0394] ×: Too much aggregate, not evenly dispersed.

[0395] <Evaluation Criteria for Component Sedimentation Rate>

[0396] 〇: The sedimentation rate of the components is above 60%.

[0397] △: Component sedimentation rate exceeds 40% but is below 60%

[0398] ×: Component sedimentation rate is below 40%

[0399] 3. Fabrication and Evaluation of Layered Bodies

[0400] The dispersion 1 was coated onto the surface of a strip of copper foil (18 μm thick) using a bar coater to form a wet film. Next, the copper foil with the wet film was passed through a drying oven at 110°C for 5 minutes to dry it and obtain a dry film. Then, the dry film was heated in a nitrogen furnace at 380°C for 3 minutes. This yielded a laminate 1 comprising a copper foil and a polymer layer (20 μm thick) on its surface, which is a molten sintered product containing F particles 1, inorganic material 1, and polymer 1.

[0401] Cut a 180 mm square test piece from laminate 1. Determine the coefficient of linear expansion of the test piece in the range of 25°C to 260°C according to the test method specified in JIS C 6471:1995. Evaluate the test piece according to the following criteria.

[0402] <Evaluation Criteria for Linear Expansion Coefficient>

[0403] 〇: The coefficient of linear expansion is below 50 ppm / ℃

[0404] △: Linear expansion coefficient exceeding 50 ppm / ℃ but below 75 ppm / ℃

[0405] ×: Linear expansion coefficient exceeds 75 ppm / ℃

[0406] [Example 1-2]

[0407] Prepare a mixture of 99 parts by mass of F particles 1 and 1 part by mass of inorganic matter 1.

[0408] Then, the mixture is introduced into a powder processing apparatus (mechanical fusion apparatus) having a cylindrical rotating body with a bearing surface on its inner circumference and an inner stator positioned at a small distance from the bearing surface. The cylindrical rotating body is then rotated at high speed around its central axis. Using the centrifugal force generated at this time, the particles are pressed against the bearing surface, and the mixture is guided into the narrow space (pressing space) between the bearing surface and the inner stator, where the particles are processed through shear-like collisions. The temperature of the cylindrical rotating body during processing is maintained below 100°C, and the processing time is 15 minutes.

[0409] The resulting processed material is in the form of a fine powder. Furthermore, analysis of the fine powder using an optical microscope confirmed that it is a composite particle with a core-shell structure, consisting of an F particle 1 as the core and an inorganic substance 1 attached to the surface of the core to form a shell.

[0410] The composite particle 2 is spherical in shape and has a D50 of 18 μm.

[0411] Using the obtained composite particles 2, dispersion 2 was prepared in the same manner as in Example 1-1, and laminate 2 was formed and evaluated. The evaluation results are shown in Table 1.

[0412] [Example 1-3~Example 1-8]

[0413] Except that the types and amounts of each component are varied as shown in Table 1 below, the same procedure as in Example 1-1 was followed to obtain composite particles 3 and 4 and dispersions 3-8, and to manufacture laminates 3-8. The evaluation results of the obtained dispersions and laminates are shown in Table 1.

[0414] [Table 1]

[0415]

[0416] [Example 2-1]

[0417] 1. Manufacturing of composite particles

[0418] A mixture of 99 parts by mass of F particles 1 and 1 part by mass of inorganic matter 1 was prepared, and the same procedure as in Example 1-1 was followed to obtain composite particles 1. The composite particles 1 were spherical in shape and had a D50 of 450.

[0419] 2. Preparation and evaluation of dispersions

[0420] Dispersion medium S1 (toluene), dispersion medium S2 (DMF), and the composite particles 1 obtained above were added to a tank equipped with stirring blades. The mixture was stirred at 800 rpm for 15 minutes to obtain a dispersion 9 containing composite particles 1 (100 parts by mass), toluene (30 parts by mass), and DMF (70 parts by mass). The viscosity of the obtained dispersion 9 at 25°C was 13000 mPa·s.

[0421] The dispersion stability of dispersion 9 was evaluated in the same way as that of Example 1-1.

[0422] 3. Preparation and evaluation of dry films and laminates

[0423] Dispersion 9 was applied to the surface of a long copper foil (18 μm thick) using a rod coating method to form a wet film. Then, the metal foil with the wet film was passed through a drying oven at 100°C for 5 minutes to dry it by heating, resulting in a dry film 1.

[0424] The smoothness of dry film 1 was evaluated visually according to the following criteria.

[0425] <Smoothness of dry film>

[0426] 〇: Overall smooth surface

[0427] △: Unevenness caused by aggregates or missing powder at the surface edges.

[0428] ×: Unevenness or dents caused by aggregates or powder loss are visible on the entire surface.

[0429] The metal foil with dry film 1 was reheated in a nitrogen furnace at 380°C for 3 minutes to obtain a laminate 1 having a metal foil and a polymer layer (20 μm thick) containing F particles 1, inorganic matter 1, and polymer 1 on its surface. No agglomerates or unevenness caused by foaming were found on the polymer layer, and the surface smoothness was excellent.

[0430] [Example 2-2~Example 2-5]

[0431] Except that the types and amounts of each component are varied as shown in Table 2 below, the same procedure as in Example 2-1 was followed to obtain composite particles 5 and dispersions 10-13, and dry films 2-5 were manufactured. The evaluation results of the obtained dispersions and dry films are shown in Table 2.

[0432] [Table 2]

[0433]

[0434] [Example 3-1]

[0435] 1. Manufacturing of composite particles

[0436] Prepare a mixture of 70 parts by mass of F particles 1 and 30 parts by mass of silica particles 1.

[0437] Then, the mixture is fed into a powder processing apparatus (mixing system (registered trademark) that applies stress by simultaneously agitating the particles within a cylindrical container using a high-speed rotating stirring blade and clamping the particles between the container's inner wall and the stirring blade. Next, F particles 1 and silica 1 are floated and collided in a high-temperature turbulent atmosphere, thus applying stress to them and performing a composite treatment. The temperature inside the apparatus is maintained below 120°C under a nitrogen atmosphere, and the composite treatment time is 15 minutes.

[0438] Analysis of the obtained microparticles using an optical microscope confirmed that they were spherical composite particles 6 (D50: 3 μm) with a core-shell structure, consisting of a particle-shaped polymer F 1 as the core and silica particles 1 attached to the surface of the core to form a shell.

[0439] 2. Surface determination of composite particles performed via ESCA

[0440] Surface measurements were performed using an ESCA5500 manufactured by ULVAC-Phi. A 14 kV monochromatic AlKα X-ray source was used, and a neutralization gun with an ion gun and barium oxide emitter was employed. To prevent surface charging, the photoelectron detection area was set to 800 μmφ, the photoelectron detection angle to 45 degrees, the pass energy to 93.8 eV, the energy level to 0.8 eV / step, and the number of cycles to 16. The fluorine atom content was calculated from the measured peak intensities (C1s, O1s, F1s, Si2s orbitals). The depth from the surface was determined based on the sputtering rate of the SiO2 sputtered film using C60 ions as sputtering ions. Table 3 shows the ratio of silicon atoms to fluorine atoms on the surface of each composite particle (hereinafter also referred to as "Si / F ratio").

[0441] 3. Evaluation

[0442] 3-1. Evaluation of Dispersion Stability

[0443] Composite particles 6 and NMP were added to a container without adding a surfactant. The container was stirred to prepare a liquid composition 1 in which composite particles 6 were dispersed. The liquid composition 1 was left to stand for a specified time, and its dispersion stability was evaluated according to the following criteria.

[0444] [Evaluation Criteria]

[0445] 〇: Foaming was suppressed during preparation, and no sediment was produced after standing at 25°C for 3 days following preparation.

[0446] △: Foaming occurred during preparation, but no sediment was formed after standing at 25℃ for 3 days following preparation.

[0447] ×: Sediment was produced after standing at 25℃ for 3 days.

[0448] 3-2. Evaluation of powder fallout and warping

[0449] Liquid composition 1 was applied to the surface of a strip of copper foil (18 μm thick) using a bar coater to form a liquid film. Next, the copper foil with the liquid film was passed through a drying oven at 120°C for 5 minutes to dry it, obtaining a dried film. Then, the dried film was heated in a nitrogen furnace at 380°C for 3 minutes. This yielded a laminate containing a copper foil and a polymer layer containing a polymer melt-sintered material and silica on its surface.

[0450] The powder shedding of the dried film and the warping of the laminate were evaluated.

[0451] The edges of the dried film were visually inspected, and the powder shedding from the dried film was evaluated according to the following criteria.

[0452] [Evaluation criteria for powder fallout]

[0453] 〇: No peeling was observed at the edges of the dried film.

[0454] △: Detachment was confirmed at a portion of the edge of the dried film.

[0455] ×: Delamination was confirmed over a wide area at the edge of the dry film.

[0456] In addition, a separate polymer layer was prepared by etching away the copper foil of the laminate using an aqueous ferric chloride solution. Square test pieces measuring 180 mm were cut from the polymer layer, and the test pieces were measured according to the determination method specified in JIS C 6471:1995. The evaluation was based on the following criteria.

[0457] [Evaluation Criteria for Warpage]

[0458] 〇: The coefficient of linear expansion is less than ±20ppm / ℃

[0459] △: Linear expansion coefficient is above ±20ppm / ℃ but below 30ppm / ℃

[0460] ×: Linear expansion coefficient is above ±30ppm / ℃

[0461] The following evaluation results are shown in Table 4.

[0462] [Example 3-2~Example 3-5]

[0463] Except for the variation of particle type and amount as shown in Table 1, composite particles 7 to 10 were obtained in the same manner as in Example 3-1, and liquid compositions 2 to 5 were prepared using composite particles 7 to 10. Furthermore, laminates were manufactured using liquid compositions 2 to 5 respectively. The surface measurement results of the composite particles, the dispersion stability of each liquid composition, the powder shedding of the dried film, and the evaluation results of the warpage of the laminates are shown in Tables 3 and 4.

[0464] [Table 3]

[0465]

[0466] *The values ​​in parentheses represent the content of each composite particle (unit: parts by mass).

[0467] [Table 4]

[0468]

[0469] Industrial availability

[0470] The dispersion of this invention exhibits excellent dispersion stability and can be easily processed into films, fiber-reinforced films, prepregs, and metal laminates (with resin-coated metal foil). The resulting processed products can be used as materials for antenna components, printed circuit boards, aircraft components, automotive components, sporting goods, food industry products, sliding bearings, etc.

[0471] Furthermore, the composite particles of the present invention exhibit excellent operability and dispersion stability in dispersion media. Liquid compositions containing the composite particles of the present invention can be used to manufacture molded articles (laminates, membranes, etc.) possessing F-based polymer-based properties and silica-based characteristics. Molded articles formed from the composite particles of the present invention can be used as antenna components, printed circuit boards, aircraft components, automotive components, sporting goods, food industry products, coatings, cosmetics, etc. Specifically, they can be used as wire coating materials (aircraft wires, etc.), electrically insulating tapes, oil drilling insulation tapes, printed circuit board materials, separation membranes (precision filtration membranes, ultrafiltration membranes, reverse osmosis membranes, ion exchange membranes, dialysis membranes, gas separation membranes, etc.), electrode adhesives (for lithium secondary batteries, fuel cells, etc.), photocopier rollers, covers for furniture, automotive dashboards, and household appliances, sliding components (load bearings, sliding shafts, valves, bearings, gears, cams, conveyor belts, food conveyor belts, etc.), tools (shovels, files, awls, saws, etc.), boilers, hoppers, pipes, ovens, barbecue molds, chutes, molds, toilets, and container coating materials.

Claims

1. A dispersion comprising a composite particle containing a tetrafluoroethylene-based polymer having a melting temperature of 260 to 320°C and an inorganic substance, the composite particle being in a form in which the tetrafluoroethylene-based polymer is a core and the inorganic substance is attached to the surface of the core, an aromatic polymer selected from at least one of aromatic polyimide, aromatic polyamide, aromatic polyamide-imide, polyphenylene ether, liquid crystal polyester, and aromatic maleimide, and a liquid dispersion medium selected from water, alcohol, or amide, the composite particle being dispersed in the liquid dispersion medium, the content of the aromatic polymer being less than the content of the composite particle, and the viscosity of the dispersion at 25°C being 1000 to 100000 mPa-s.

2. The dispersion of claim 1, wherein, The tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer containing a perfluoro(alkyl vinyl ether)-based unit and having a polar functional group, or a tetrafluoroethylene-based polymer containing 2.0 to 5.0 mol% of a perfluoro(alkyl vinyl ether)-based unit and not having a polar functional group with respect to the total units.

3. The dispersion of claim 1 or 2, wherein, The inorganic substance is silicon dioxide.

4. A dispersion which is a dispersion comprising composite particles containing a tetrafluoroethylene-based polymer having a melting temperature of 260 to 320°C and an inorganic substance, an aromatic polymer, and a liquid dispersion medium, and the composite particles are dispersed in the liquid dispersion medium, wherein, The composite particle is in a form in which the tetrafluoroethylene-based polymer is a core and the inorganic substance is attached to the surface of the core, the aromatic polymer is selected from at least one of aromatic polyimide, aromatic polyamide, aromatic polyamide-imide, polyphenylene ether, liquid crystal polyester, and aromatic maleimide, the content of the aromatic polymer is less than the content of the composite particle, and the liquid dispersion medium contains two liquid dispersion media having different boiling points and the two liquid dispersion media have a relationship in which an azeotrope is formed, at least one of the two liquid dispersion media having different boiling points that constitute the liquid dispersion medium is water, alcohol, or amide.

5. The dispersion of claim 4, wherein, The tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer containing a perfluoro(alkyl vinyl ether)-based unit and having a polar functional group, or a tetrafluoroethylene-based polymer containing 2.0 to 5.0 mol% of a perfluoro(alkyl vinyl ether)-based unit and not having a polar functional group with respect to the total units.

6. The dispersion of claim 4 or 5, wherein, The mixing amount ratio of the high-boiling-point dispersion medium in the two liquid dispersion media having different boiling points is greater than the composition ratio in mass of the high-boiling-point dispersion medium in the azeotrope of the two liquid dispersion media.

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