Surface-treated inorganic fluoride particles

Abstract

The surface-treated inorganic fluoride particles are characterized by being inorganic fluoride particles the surface of which is coated by an organic compound. The surface-treated inorganic fluoride particles of the present invention can be suitably used for various high-frequency devices and the like.

Description

Surface-treated inorganic fluoride particles

[0001] The present invention relates to surface-treated inorganic fluoride particles, a low dielectric loss resin composition containing the particles, and a high-frequency device.

[0002] BACKGROUND ART In recent years, in electronic components such as printed wiring boards, flexible circuit boards and high frequency boards, as well as in information and communication devices, the frequency of electrical signals used has been increasing in order to achieve high speed and large capacity data communication.

[0003] In particular, in electronic components for high-frequency applications, the attenuation of electrical signals increases due to transmission loss in the transmission path as the frequency increases, which can lead to a decrease in transmission reliability. Therefore, materials with a small loss factor are required for high-frequency devices and their components. Here, the loss factor is calculated by dividing the dielectric constant (ε ｒ ) and the dielectric loss tangent (tan δ).

[0004] On the other hand, inorganic fluoride particles are sometimes used as inorganic fillers in low dielectric loss resin compositions, but oxygen contaminated on the surfaces of the inorganic fluoride particles may affect their dielectric properties. Specifically, when inorganic fluoride particles are produced in an aqueous solution, residual moisture inevitably remains. During the drying process for removing the residual moisture or during powder processing processes such as pulverization in the atmosphere, trace amounts of oxygen may be contaminated on the surface of the inorganic fluoride particles. Because the amount is so small, it usually does not affect the properties of the fluoride. However, it may affect the properties of the fluoride when used, for example, as a raw material for optical lens materials or as a material for electronic components. For this reason, methods have been adopted to produce inorganic fluoride particles in anhydrous hydrofluoric acid, or to produce inorganic fluoride particles while avoiding contact with moisture.

[0005] For example, Patent Document 1 discloses a fluoride microparticle dispersion liquid characterized in that fluoride microparticles are dispersed in carboxylic acid, which is obtained by generating fluoride in water or a mixed solution of water and an organic solvent such as alcohol, and reacting the water remaining in the sol or gel with carboxylic acid anhydride. It states that by reacting the water present in the fluoride synthesis process with carboxylic acid anhydride, the water content in the dispersion liquid is reduced to 0.1% or less, and by preventing water from being adsorbed on the surface of the generated fluoride, a dispersion liquid exhibiting good dispersibility can be obtained.

[0006] Japanese Patent Application Laid-Open No. 2007-161509

[0007] However, although Patent Document 1 makes it possible to obtain a dispersion of inorganic fluoride particles in which oxygen contamination is suppressed, in order to recover the inorganic fluoride particles from the dispersion, care and ingenuity are required, such as the need to distill off a large amount of carboxylic acid without contacting the inorganic fluoride particles with the air, and a method that can more easily reduce the influence of oxygen is desired.

[0008] An object of the present invention is to provide novel surface-treated inorganic fluoride particles that reduce the dielectric loss tangent in the high frequency band and are excellent in reducing dielectric loss, a low dielectric loss resin composition containing the particles, and high-frequency devices.

[0009] The present invention relates to the following items [1] to [3]. [1] Surface-treated inorganic fluoride particles, characterized in that the particles are inorganic fluoride particles whose surfaces are coated with an organic compound. [2] A low dielectric loss resin composition containing a polymer resin and the surface-treated inorganic fluoride particles described in [1]. [3] A high-frequency device comprising a molded article of the low dielectric loss resin composition described in [2].

[0010] According to the present invention, it is possible to provide novel surface-treated inorganic fluoride particles that reduce the dielectric loss tangent in the high frequency band and are excellent in reducing dielectric loss, a low dielectric loss resin composition containing the particles, and a high-frequency device.

[0011] 1 shows IR spectra of inorganic fluoride fillers of Example A1 and Comparative Example A3, and TGA charts of Example A1 and Comparative Example A3.

[0012] As a result of intensive research by the present inventors to solve the above problems, they have newly discovered that the problems can be solved by coating the particle surfaces of inorganic fluoride particles with an organic compound. Although the mechanism behind this is unclear, it is thought that by coating oxygen inside or on the particle surfaces of inorganic fluoride particles, which promotes dielectric loss, with an organic compound, the adverse effects of this are shielded and the inherent low dielectric loss is maintained.

[0013] That is, the surface-treated inorganic fluoride particles of the present invention are characterized in that the particle surfaces are coated with an organic compound.

[0014] (Surface-Treated Inorganic Fluoride Particles) The surface-treated inorganic fluoride particles of the present invention are coated with an organic compound on the particle surface. Here, "coated with an organic compound" refers to a state in which the organic compound is not evaporated due to chemical bonds or chemical interactions, even under conditions in which the organic compound would essentially be evaporated. For example, when surface-treated inorganic fluoride particles are washed with an organic solvent that dissolves the organic compound, the organic compound present on the particle surface is washed away by the organic solvent. However, if the organic compound has chemical bonds or interactions, it cannot be evaporated even after repeated washing. Another example is a state in which the organic compound remains present without volatilizing even when heated under temperature conditions in which the organic compound essentially volatilizes. Whether the organic compound is surface-coated can be determined by observing the appearance of the powder, such as a change in color, or by indirectly confirming the presence of the organic compound on the powder surface based on thermal properties using optical techniques such as infrared spectroscopy (IR) or thermogravimetric analysis (TGA).

[0015] Thermogravimetric analysis (TGA) can be used as an index for determining the amount of organic compound coated on the surface-treated inorganic fluoride particles of the present invention. The thermal weight loss rate is preferably 0.3 to 20% by mass, more preferably 0.5 to 15% by mass, and even more preferably 1.5 to 10% by mass. The thermal weight loss rate is measured by the method described in the Examples below.

[0016] In the surface-treated inorganic fluoride particles of the present invention, the organic compound is preferably at least one selected from the group consisting of carboxylic acid anhydrides, amine compounds, and organosilane compounds, which are reacted with the inorganic fluoride particles by heating to form a coated form.

[0017] The degree of coating of the surface-treated inorganic fluoride particles of the present invention is not particularly limited, but coating at least a portion of the particle surface with an organic compound is expected to improve the mixability when used as a filler added to a resin, for example, or to shield the adverse effects of oxygen present on the particle surface as an active site in applications where such oxygen has a negative effect. As one embodiment of the use of the surface-treated inorganic fluoride particles of the present invention, a filler for a low dielectric loss resin composition will be described below, but the present invention is not limited thereto. In addition to low dielectric loss resin compositions, the particles can also be used as a filler for other applications, such as optical materials or resin compositions for optical materials, dental materials or resin compositions for dental materials, electricity storage materials or resin compositions for electricity storage, electronic materials or resin compositions for electronic materials, and pigments or resin compositions for pigments.

[0018] (Surface-treated inorganic filler for low dielectric loss resin composition) First, a surface-treated inorganic filler for a low dielectric loss resin composition according to an embodiment of the present invention (hereinafter referred to as "surface-treated inorganic filler") will be described below.

[0019] As described above, the surface-treated inorganic filler of the present embodiment is preferably a surface-treated inorganic filler that has been surface-treated by heating and reacting inorganic fluoride particles with at least one compound selected from the group consisting of a carboxylic acid anhydride, an amine compound, and an organosilane compound. Also, an embodiment in which a carboxylic acid anhydride and an amine compound are used in combination is preferred.

[0020] The carboxylic acid anhydride is not particularly limited as long as it is an anhydride of a carboxylic acid having at least two carboxyl groups in one molecule, and known anhydrides can be used. Specific examples include alicyclic carboxylic anhydrides such as methylbutenyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, methylcyclohexene dicarboxylic anhydride, dodecenylsuccinic anhydride, succinic anhydride, and maleic terpene; aromatic carboxylic anhydrides such as phthalic anhydride, trimellitic anhydride, and pyrrolimellitic anhydride; and aliphatic carboxylic anhydrides such as maleic anhydride and glutaric anhydride. These can be used alone or in combination of two or more. Among these acid anhydrides, it is preferable to use methylbutenyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, and maleic terpene. In particular, maleic terpenes can be preferably used. Among carboxylic acid anhydrides, phthalic anhydride compounds can be preferably used from the viewpoints of availability and ease of handling. Examples of phthalic anhydride compounds include phthalic anhydride, methylbutenyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and maleic terpenes.

[0021] When the carboxylic acid anhydride is not liquid, it is preferably used together with an organic solvent, if necessary. When the carboxylic acid anhydride is solid, examples of organic solvents that can be used as the reaction medium include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, sulfolane, hexane, benzene, toluene, xylene, cumene, methyl ethyl ketone, acetone, diethyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxymethane, diethylene glycol dimethyl ether, methanol, ethanol, propyl alcohol, isopropyl alcohol, methyl acetate, ethyl acetate, acetonitrile, methylene chloride, and chloroform. While the organic solvent is not particularly limited as long as it does not adversely affect the reactivity or intended use, N,N-dimethylacetamide is preferred from the viewpoints of availability and ease of handling.

[0022] In general, the presence of polar groups such as hydroxyl groups, ether groups, and carbonyl groups on the outermost surface of an inorganic compound tends to increase the relative dielectric constant and dielectric loss tangent. Therefore, by covering at least a portion of these active functional groups on the particle surface with an organic compound, it is expected that the influence of these groups will be shielded, and when used as a low-dielectric material, it is also expected that the relative dielectric constant and dielectric loss tangent will be reduced.

[0023] Examples of the amine compounds include aliphatic amines such as methylamine, ethylamine, propylamine, dimethylamine, methylethylamine, and dipropylamine; alicyclic amines such as cyclohexylamine and dicyclohexylamine; aliphatic amines containing an aromatic ring such as benzylamine and diphenylamine; and aromatic amines such as aniline and toluidine. Other examples include polyvalent amines such as ethylenediamine, hexamethylenediamine, and N,N'-dimethylethylenediamine. Examples of saturated cyclic amines include pyrrolidine derivatives, piperidine derivatives, and morpholine derivatives. Examples of unsaturated cyclic amines include pyrroline derivatives, pyrrole derivatives, indole derivatives, carbazole derivatives, imidazole derivatives, pyrazole derivatives, and purine derivatives. Examples of polyimide precursor compounds include polyamic acids. The polyamic acid is not particularly limited, and examples thereof include those produced by the reaction of an aromatic and / or aliphatic diamine compound with an aromatic and / or aliphatic tetracarboxylic acid dianhydride, preferably those produced by the reaction of an aromatic diamine with an aromatic carboxylic acid dianhydride. Known aromatic diamines can be used, such as 4,4'-diaminodiphenyl ether, 1,4-diaminonaphthalene, 4,4'-diaminodiphenylmethane, and 4,4'-diaminodiphenyl sulfone. Known compounds can be used as the aromatic carboxylic acid dianhydride, and examples thereof include pyromellitic dianhydride, mellophanic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, etc. Commercially available polyamic acids include, for example, Pyre-ML (registered trademark) manufactured by I.S.T. Co., Ltd.

[0024] Of these amines, imidazole derivatives are preferred from the viewpoints of reactivity and availability. The imidazole derivative is not particularly limited, and known derivatives can be used. Specific examples include 2-ethyl-4-methylimidazole, 4-ethyl-2-methylimidazole, 2,4-dimethylimidazole, and 2,4-diethylimidazole. These can be used alone or in combination of two or more. Of these imidazole derivatives, 2-ethyl-4-methylimidazole and 2,4-dimethylimidazole are preferred from the viewpoints of reactivity and ease of cleaning and removal after the reaction. 2-ethyl-4-methylimidazole is particularly preferred.

[0025] Examples of the organosilane compound include alkoxysilane compounds, siloxane compounds, silazane compounds, etc. Examples of the alkoxysilane compound include methyltrimethoxysilane, tetraethoxysilane, methyltrichlorosilane, dimethyldimethoxysilane, trimethylmethoxysilane, n-octadecyldimethylmethoxysilane, (N,N-dimethylamino)methylethoxysilane, etc., as well as silane coupling agents. Examples of silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, n-propyltrimethoxysilane, n-butyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, p-styryltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, etc. Examples of organosilane compounds include siloxane compounds such as modified silicones. Examples of modified silicones include methoxy-modified silicone, carboxy-modified silicone, alcohol-modified silicone, polyether-modified silicone, epoxy-modified silicone, mercapto-modified silicone, amino-modified silicone, methacrylate-modified silicone, and methylhydrogen silicone. Examples of organosilane compounds include silazane compounds such as hexamethyldisilane and nonamethyltrisilazane. Among these organosilane compounds, alkoxysilane compounds are preferred from the viewpoints of reactivity and availability.

[0026] The inorganic fluoride particles before being coated with the organic compound are of great technical significance when they contain oxygen at least partially inside or on the particle surface. During the manufacturing process of inorganic fluoride particles or during processing steps such as atmospheric grinding, trace amounts of oxygen may be introduced into the surface layer of inorganic fluoride particles. Because such trace amounts do not generally affect the properties of the fluoride, they may affect the properties of surface-treated inorganic fillers for low dielectric loss resin compositions. Therefore, the use of the surface-treated inorganic filler of this embodiment is expected to provide an improvement. The presence and content of oxygen can be measured by techniques such as X-ray diffraction (XRD), X-ray fluorescence analysis (XRF), and X-ray photoelectron spectroscopy (XPS). While XRD and XRF can obtain average information over a region approximately tens of micrometers deep due to the penetration depth of X-rays, detecting only trace amounts is difficult from the standpoint of analytical sensitivity. XPS can detect information from the surface region approximately several nanometers deep with relatively high sensitivity. Generally, inorganic fluoride particles contain a small amount of oxygen, and when the oxygen contained in them is influential due to the nature of the application, the inorganic fluoride particles of the present invention, which are coated with organic compound on at least a part of the particle surface, can easily obtain significant effects.From this point of view, when the inorganic fluoride particles of the present invention are coated with organic compound by XPS analysis, the oxygen content is preferably 2.0 atomic % or more, more preferably 3.0 atomic % or more, and particularly preferably 4.0 atomic % or more.In addition, the inorganic fluoride particles before being coated with organic compound can be the ideal inorganic fluoride particles that do not contain any oxygen.

[0027] The inorganic fluoride in the inorganic fluoride particles includes a fluoride containing at least one element selected from the group consisting of Li, Na, K, Mg, Al, Ca, Sc, Ti, Mn, Fe, Ga, Rb, Sr, Y, Zr, Sn, Ba, La, Ce, Yb, Hf, and Bi. More specifically, MF ｎ(wherein M is at least one selected from the group consisting of Li, Na, K, Mg, Al, Ca, Sc, Ti, Mn, Fe, Ga, Rb, Sr, Y, Zr, Sn, Ba, La, Ce, Yb, Hf, and Bi, and n is an integer of 1 to 4.) More specifically, for example, LiF (lithium fluoride), NaF (sodium fluoride), KF (potassium fluoride), MgF ２ (magnesium fluoride), AlF ３ (aluminum fluoride), CaF ２ (Calcium fluoride), ScF ３ (Scandium Fluoride), TiF ４ (Titanium fluoride), MnF ２ (manganese fluoride), FeF ３ (iron fluoride), GaF ３ (gallium fluoride), RbF (rubidium fluoride), SrF ２ (strontium fluoride), YF ３ (yttrium fluoride), ZrF ４ (zirconium fluoride), SnF ２ (Tin Fluoride), BaF ２ (barium fluoride), LaF ３ (lanthanum fluoride), CeF ３ (cerium fluoride), YbF ２ (ytterbium difluoride), YbF ３ (ytterbium trifluoride), HfF ４ (hafnium fluoride) and BiF ３ (bismuth fluoride), etc. Examples of inorganic fluorides include M １ ６－ｍ M ２ F ６ (In the formula, the M １ represents at least one alkali metal element selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium, and M ２ represents at least one trivalent or tetravalent element selected from the group consisting of silicon, germanium, tin, titanium, zirconium, hafnium, and aluminum, and m represents M ２ These inorganic fluorides may be, for example, those represented by Li２ SiF ６ 、Na ２ SiF ６ 、K ２ SiF ６ ,Rb ２ SiF ６ ,Cs ２ SiF ６ ,Li ２ GeF ６ 、Na ２ GeF ６ 、K ２ GeF ６ ,Rb ２ GeF ６ ,Cs ２ GeF ６ ,Li ２ SnF ６ 、Na ２ SnF ６ 、K ２ SnF ６ ,Rb ２ SnF ６ ,Cs ２ SnF ６ 、Li ２ TiF ６ 、Na ２ TiF ６ 、K ２ TiF ６ ,Rb ２ TiF ６ ,Cs ２ TiF ６ 、Li ２ ZrF ６ 、Na ２ ZrF ６ 、K ２ ZrF ６ ,Rb ２ ZrF ６ ,Cs ２ ZrF ６ 、Li ２ HfF ６ 、Na ２ HfF ６ 、K ２ HfF ６ ,Rb ２ HfF ６ ,Cs ２ HfF ６ 、Li ３ AlF ６ 、Na ３ AlF６ , K. ３ AlF ６ , Rb ３ AlF ６ , Cs ３ AlF ６ The cation site or the anion site may form a double salt.

[0028] Among the exemplified inorganic fluorides, from the viewpoint of reducing the dielectric loss of the surface-treated inorganic filler, aluminum fluoride, bismuth fluoride, cerium fluoride, ytterbium fluoride, zirconium fluoride, and hafnium fluoride are preferred, with aluminum fluoride and zirconium fluoride being more preferred. Furthermore, aluminum fluoride preferably contains crystalline aluminum fluoride having an α-phase as a main component. Crystalline aluminum fluoride having an α-phase exhibits excellent low dielectric loss characteristics in the high-frequency band of 1 GHz or higher. Therefore, using aluminum fluoride as a main component in a low dielectric loss resin composition provides a significant effect of reducing the dielectric loss of the low dielectric loss resin composition.

[0029] The half-width of the peak at the (012) plane of the α phase in the X-ray diffraction pattern of aluminum fluoride is 0.3° or less, preferably 0.25° or less, and more preferably 0.2° or less. Generally, as the average particle size of inorganic compound particles decreases, the proportion of the surface layer in the entire particle increases. Because the energy state of the particle surface is higher than that of the interior, structural order is easily disrupted, resulting in reduced crystallinity. As a result, the physical and chemical properties derived from the bulk change, and the dielectric loss tangent at the particle surface tends to increase. Therefore, regardless of the average particle size of the inorganic compound, high crystallinity is desirable. Here, in this embodiment, the degree of crystallinity can be evaluated by the half-width of the X-ray diffraction peak at the (012) plane derived from aluminum fluoride. Generally, the smaller the half-width, the higher the crystallinity and the smaller the fluctuation of the crystal structure, resulting in a smaller dielectric loss tangent. Therefore, in the case of aluminum fluoride, its crystallinity can be improved by reducing the half-width of the peak at the (012) plane in the X-ray diffraction pattern. From this perspective, in this embodiment, by setting the upper limit of the half-width to 0.3° or less, the crystallinity of aluminum fluoride is prevented from becoming too high while the increase in the dielectric dissipation factor is suppressed, thereby enabling a reduction in the loss factor and dielectric loss. Furthermore, the lower limit of the half-width is preferably 0.12° or more, more preferably 0.15° or more. By setting the lower limit of the half-width to 0.12° or more, excessive grain growth during crystallization or crystal growth of amorphous aluminum fluoride can be prevented, resulting in an excessive increase in the grain size of the crystal grains. This prevents the average particle diameter D50 of aluminum fluoride from becoming too large, and prevents the crystallinity of aluminum fluoride from becoming too high. As a result, when the surface-treated inorganic filler of this embodiment is applied to a low dielectric loss resin composition and formed into a film- or sheet-shaped molded article, even when used in electronic components such as thin-layered printed wiring boards, flexible circuit boards, and high-frequency boards, surface irregularities can be reduced or suppressed, preventing a deterioration in electrical properties. Furthermore, it is possible to produce a film- or sheet-shaped molded article with a sufficiently controlled film thickness. In this specification, the term "half width" means the full width at half maximum.Furthermore, "X-ray diffraction pattern" refers to the plot line of diffraction intensity measured at each incident angle in a two-dimensional graph in which the horizontal axis represents the incident angle and the vertical axis represents the diffraction intensity when a sample is measured by (powder) X-ray diffraction. "The (012) plane of the α-phase in the X-ray diffraction pattern of aluminum fluoride" refers to the oriented plane of the aluminum fluoride crystal, that is, the (012) plane of the α-phase in the X-ray diffraction pattern. The peak of the diffraction intensity due to the (012) plane of the α-phase of aluminum fluoride is located at a 2θ of approximately 25.3°.

[0030] Relative permittivity ε of inorganic fluoride particles ｒ１ The upper limit of [-] is preferably 6 or less, more preferably 4 or less, and even more preferably 3.5 or less at a frequency of 1 GHz or more and a temperature of 25°C. ｒ１ When the loss factor is 6 or less, the loss factor can be reduced, and the dielectric loss can be reduced.

[0031] In addition, the dielectric loss tangent tanδ of the inorganic fluoride particles １ The upper limit of [-] is preferably 0.008 or less, more preferably 0.005 or less, even more preferably 0.002 or less, and particularly preferably 0.001 or less, at a frequency of 1 GHz or more and a temperature of 25°C. １ When the loss factor is 0.008 or less, the loss factor can be reduced, and the dielectric loss can be reduced.

[0032] The upper limit of the loss factor of the inorganic fluoride particles is preferably less than 6, more preferably not more than 4, and even more preferably not more than 3. When the loss factor is less than 6, the loss factor of the low dielectric loss resin composition can be reduced, and the dielectric loss can be reduced.

[0033] The relative permittivity ε used to quantify the dielectric properties and dielectric loss ｒ１ and dielectric tangent tanδ １The numerical values ​​of the above are based on values ​​obtained by measuring inorganic fluoride particles made of powder and converting the measured values. The measurement method can be selected appropriately. Specifically, for example, each of the values ​​can be measured by the method described in the examples below.

[0034] The loss factor is the relative permittivity ε of the inorganic fluoride particles made of powder. ｒ１ and dielectric tangent tanδ １ The loss coefficient can be calculated using the measured values ​​based on the following formula: (loss coefficient) = (ε ｒ１ ) １／２ ×tan δ １ x10 ３ (In the formula, ε ｒ１ [-] represents the relative dielectric constant of the inorganic fluoride particles made of powder obtained by measurement, and tan δ １ [-] represents the dielectric tangent.)

[0035] Relative permittivity ε ｒ１ is a parameter that indicates the degree of polarization of inorganic fluoride particles obtained by measurement, and the higher the relative dielectric constant, the greater the delay in the propagation of electrical signals. Therefore, in order to increase the signal propagation speed, a lower relative dielectric constant is preferable. １ is a parameter obtained by measurement that indicates the amount of signal transmitted through the inorganic fluoride particle that is lost due to conversion to heat. Therefore, the lower the dielectric loss tangent, the less signal loss there is, and the better the signal transmission rate.

[0036] The average particle diameter D50 of the inorganic fluoride particles (particle diameter at 50% of the cumulative particle size in the volume-based cumulative particle size distribution) is not particularly limited and can be appropriately set depending on, for example, the shape (size, thickness, etc.) of the molded body containing the low dielectric loss resin composition, and the adjustment of the flowability of the material containing the inorganic fluoride particles in the preparation of the low dielectric loss resin composition. Generally, the upper limit of the average particle diameter D50 of the inorganic fluoride particles is preferably 75 μm or less, more preferably 50 μm or less, even more preferably 10 μm or less, and particularly preferably 1 μm or less. On the other hand, the lower limit of the average particle diameter D50 of the inorganic fluoride particles is preferably 0.05 μm or more, more preferably 0.075 μm or more, and even more preferably 0.1 μm or more. If the average particle diameter D50 of the inorganic fluoride particles is too large, it becomes difficult to obtain a flat surface when the molded body is applied to a film- or sheet-shaped molded body. As a result, for example, when forming a laminate, the electrical properties of the laminate may be impaired due to the unevenness of the surface of the molded product. On the other hand, if the average particle diameter D50 of the inorganic fluoride particles is too small, it may be difficult to uniformly mix the surface-treated inorganic filler with the polymer resin, and the viscosity of the mixture may increase to such an extent that molding of the low dielectric loss resin composition becomes difficult.

[0037] Furthermore, when the low dielectric loss resin composition of this embodiment is formed into a film- or sheet-like molded article, the average particle diameter D50 of the inorganic fluoride particles is preferably set to ½ or less, more preferably ⅕ or less, even more preferably ⅙ or less, and even more preferably ⅛ or less, of the thickness of the molded article within the above-mentioned numerical range. For example, when the molded article of the low dielectric loss resin composition is in the form of a film or sheet with a thickness of about 20 μm, the average particle diameter D50 of the inorganic fluoride particles is preferably 10 μm or less, more preferably 4 μm or less, even more preferably 2 μm or less, and even more preferably 1 μm or less. This allows the surface-treated inorganic filler containing the inorganic fluoride particles to be aligned in a single layer to be molded into a film- or sheet-like molded article. As a result, a molded article with reduced or prevented surface irregularities can be obtained. Furthermore, in a pre-curing slurry composition in which a surface-treated inorganic filler containing inorganic fluoride particles is dispersed in a solvent, sedimentation of the surface-treated inorganic filler can be suppressed, and a film- or sheet-shaped molded body in which the surface-treated inorganic filler is uniformly filled can be obtained.

[0038] The average particle diameter D50 of the inorganic fluoride particles is a value obtained by measurement by a laser diffraction / scattering method using, for example, Microtrac MT3300EXII (trade name: manufactured by Nikkiso Co., Ltd.).

[0039] Furthermore, in the inorganic fluoride particles of this embodiment, for example, the mass loss after heat treatment at 400°C or higher is preferably 2% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less, relative to the mass of the inorganic fluoride particles before heat treatment. By using inorganic fluoride particles with a mass loss of 2% by mass or less after heat treatment, it is possible to prevent a decrease in the low dielectric loss characteristics and mechanical strength of the low dielectric loss resin composition due to heat generation during polymerization of the monomers that form the polymer resin, degassing of impurities during heat treatment, and thermal decomposition of the main component of the polymer resin. There are no particular limitations on the method for reducing the mass loss of inorganic fluoride particles after heat treatment to 2% by mass or less. For example, materials with high thermal decomposition temperatures, materials that do not undergo phase change upon heating, and impurities that cause mass loss during the synthesis of the inorganic fluoride particles may be removed or reduced by prior heat treatment or chemical treatment.

[0040] Relative dielectric constant ε of surface-treated inorganic filler ｒ０ The upper limit of [-] is preferably 6 or less, more preferably 4 or less, and particularly preferably 3.5 or less, at a frequency of 1 GHz or more and a temperature of 25°C. ｒ０ When the loss factor is 6 or less, the loss factor can be reduced, and the dielectric loss can be reduced.

[0041] Dielectric loss tangent tanδ of the surface-treated inorganic filler according to this embodiment ０ [-] is the dielectric loss tangent tanδ of the surface-untreated inorganic filler ０ The dielectric loss tangent tanδ of the surface-untreated inorganic filler is reduced compared to [-]. ０ Dielectric tangent tanδ of surface-treated inorganic filler relative to [-] ０ The ratio [-] is preferably 0.90 or less, more preferably 0.80 or less, even more preferably 0.70 or less, even more preferably 0.60 or less, and even more preferably 0.55 or less. ０ The upper limit of [-] is not particularly limited, but as in the examples described later, ３In the embodiment using the above, the coefficient of repulsion is preferably 0.002 or less, and more preferably 0.001 or less, at a frequency of 1 GHz or more and a temperature of 25°C.

[0042] The loss factor of the surface-treated inorganic filler according to this embodiment is reduced compared to the loss factor of a surface-untreated inorganic filler. The ratio of the loss factor of the surface-treated inorganic filler to the loss factor of the surface-untreated inorganic filler is preferably 0.90 or less, more preferably 0.80 or less, even more preferably 0.70 or less, even more preferably 0.60 or less, and even more preferably 0.55 or less. The upper limit of the loss factor of the surface-treated inorganic filler is not particularly limited, but as in the examples described later, α-AlF ３ In the embodiment using the formula (I), the value is preferably 3.5 or less, more preferably 3 or less, and particularly preferably 2 or less.

[0043] The relative permittivity ε used to quantify the dielectric properties and dielectric loss ｒ０ and dielectric tangent tanδ ０ The numerical values ​​are based on values ​​obtained by measuring the surface-treated inorganic filler and converting the values ​​from the measurements. The measurement method can be selected appropriately. Specifically, for example, each can be measured by the method described in the Examples below.

[0044] The loss factor is the relative permittivity ε of the surface-treated inorganic filler. ｒ０ and dielectric tangent tanδ ０ The loss coefficient can be calculated using the measured values ​​based on the following formula: (loss coefficient) = (ε ｒ０ ) １／２ ×tan δ ０ x10 ３ (In the formula, ε ｒ０ [-] represents the relative dielectric constant of the surface-treated inorganic filler obtained by measurement, and tan δ ０ [-] represents the dielectric tangent.)

[0045] Relative permittivity ε ｒ０is a parameter that indicates the degree of polarization of the surface-treated inorganic filler obtained by measurement, and the higher the relative dielectric constant, the greater the delay in the propagation of electrical signals. Therefore, in order to increase the signal propagation speed, a lower relative dielectric constant is preferable. ０ is a parameter obtained by measurement that indicates the amount of signal transmitted through the surface-treated inorganic filler that is lost due to conversion to heat. Therefore, the lower the dielectric tangent, the less signal loss there is, and the better the signal transmission rate.

[0046] The shape of the surface-treated inorganic filler is not particularly limited and is appropriately selected in consideration of, for example, the fluidity of a slurry composition in which the surface-treated inorganic filler is dispersed in a solvent, or the fluidity of a mixture in which the surface-treated inorganic filler is mixed with a polymer resin. Furthermore, the shape can also be appropriately selected depending on the purpose, such as controlling the mechanical strength, thermal conductivity, gas diffusibility, etc. of a molded article containing the low dielectric loss resin composition.

[0047] The shape of the surface-treated inorganic filler can be, for example, any shape such as spherical, approximately spherical, elliptical, rod-like, needle-like, spindle-like, or plate-like. The surface-treated inorganic filler may have any of these shapes and may be hollow with an internal space. Furthermore, the surface-treated inorganic filler of this embodiment may contain surface-treated inorganic fillers of the same shape, or may contain surface-treated inorganic fillers of two or more different shapes.

[0048] <Method for Producing Surface-Treated Inorganic Filler> Next, a method for producing the surface-treated inorganic filler will be described below. The method for producing the surface-treated inorganic filler of this embodiment is not particularly limited, and known methods can be used. For example, an organic solvent is used as the solvent, and at least one compound selected from the group consisting of a carboxylic acid anhydride, an amine compound, and an organosilane compound, and inorganic fluoride particles are added. The mixture is heated to a temperature of preferably 30 to 180°C, more preferably 35 to 170°C, even more preferably 40 to 160°C, even more preferably 50 to 150°C, even more preferably 60 to 140°C, even more preferably 70 to 130°C, and even more preferably 80 to 120°C for preferably 1 to 24 hours, more preferably 2 to 10 hours, and even more preferably 3 to 9 hours for reaction. The solvent is then removed by evaporation using a spray dryer, a slurry dryer, or by heating, and the mixture is dried. Examples of organic solvents include aprotic polar solvents and protic polar solvents.

[0049] The blending amount (total amount) of at least one compound selected from the group consisting of carboxylic acid anhydrides, amine compounds, and organosilane compounds is preferably 5 to 400 parts by mass, more preferably 10 to 200 parts by mass, per 100 parts by mass of the inorganic fluoride.

[0050] In an embodiment in which a carboxylic acid anhydride and an amine compound are used in combination, the mass ratio of carboxylic acid anhydride to amine compound is preferably 400:1 to 10:1, more preferably 200:1 to 10:1.

[0051] The non-proton polar solvent is not particularly limited, and examples thereof include hexane, benzene, toluene, chloroform, dichloromethane, acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, tetrahydrofuran, diisopropyl ether, dibutyl ether, 1,4-dioxane, 1,3-dioxolane, dimethoxyethane, ethylene glycol dimethyl ether, γ-butyrolactone, γ-valerolactone, acetonitrile, propionitrile, dimethyl sulfoxide, dimethyl sulfone, sulfolane, 1,3-propane sultone, dimethyl sulfate, trimethyl phosphate, triethyl phosphate, N,N-dimethylformamide, N-methyl-2-pyrrolidone, methyl acetate, ethyl acetate, butyl acetate, propylene carbonate, ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, etc. These may be used alone or in combination of two or more.

[0052] The protic solvent is not particularly limited, and examples thereof include acetic anhydride, formic acid, methanol, ethanol, isopropyl alcohol, butanol, nitromethane, and nitroethane. These may be used alone or in combination. From the viewpoints of availability and ease of handling, alcohols such as methyl alcohol, ethanol, and isopropyl alcohol, toluene, xylene, cumene, hexane, and cyclohexane are preferred.

[0053] The stirring time is preferably 15 minutes to 10 hours, and the stirring temperature is preferably 30 to 150°C. The drying temperature for the solvent can be appropriately selected from 25°C to 200°C, and either batch drying or spray drying using a spray dryer can be selected. After drying, washing with the organic solvent described above, filtering and extracting, and drying again can remove excess components. If necessary, the surface-treated inorganic filler may be crushed again using a grinder or the like. In this method, a method can also be used in which the solvent is not completely evaporated after stirring, and the surface-treated inorganic filler containing the solvent is introduced into a resin varnish or the like.

[0054] <Slurry Composition for Low Dielectric Loss Resin Composition> The surface-treated inorganic filler of the present embodiment can be made into a slurry composition. The slurry composition for the low dielectric loss resin composition of the present embodiment (hereinafter referred to as "slurry composition") will be described below.

[0055] The slurry composition of this embodiment contains at least the above-described surface-treated inorganic filler and a solvent. The slurry composition is a dispersion in which the surface-treated inorganic filler is dispersed (including floating and suspended) in a solvent. In this specification, the term "dispersion" refers to a state in which the surface-treated inorganic filler is dispersed as a dispersoid in a solvent that is a dispersion medium. However, the term "dispersion" does not include a solid colloid (organogel) in which a dispersoid is dispersed in a solid dispersion medium and fluidity is lost.

[0056] The lower limit of the content of the surface-treated inorganic filler in the slurry composition of this embodiment is preferably 1% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, relative to the total mass of the slurry composition. On the other hand, the upper limit of the content of the surface-treated inorganic filler is preferably 85% by mass or less, more preferably 82% by mass or less, and even more preferably 79% by mass or less, relative to the total mass of the slurry composition. When the lower limit of the content of the surface-treated inorganic filler is 1% by mass or more, the loss factor of the slurry composition is reduced, and the dielectric loss is reduced.

[0057] As the solvent, a linear alkane is preferred, and a linear alkane having 10 or more carbon atoms and 16 or less carbon atoms is more preferred. More specifically, linear alkanes include n-decane, n-tetradecane, and n-hexadecane. These solvents can be used alone or in combination. Among these linear alkanes, n-hexadecane is particularly preferred because it can exist as a liquid at room temperature (e.g., 5°C to 35°C), has low polarity among linear alkanes, and is suitable for dielectric property evaluation. Linear alkanes having 10 or more carbon atoms have low relative permittivity and dielectric loss tangent due to their low polarity, and are poorly soluble in water. Furthermore, because they have a high boiling point, they can suppress concentration changes due to volatilization, unlike hexane, which has a low boiling point. On the other hand, linear alkanes having 16 or less carbon atoms can suppress the melting point to 20°C or less, thereby preventing the deterioration in handleability caused by their existence as a solid at room temperature. Herein, when a range of carbon numbers is expressed, the range means that all integer carbon numbers within that range are included. Therefore, for example, a linear alkane having "10 to 16 carbon atoms" means all linear alkanes having 10, 11, 12, 13, 14, 15, and 16 carbon atoms.

[0058] The lower limit of the solvent content in the slurry composition of this embodiment is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 15% by mass or more, relative to the total mass of the slurry composition, while the upper limit of the solvent content is preferably 99% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less, relative to the total mass of the slurry composition.

[0059] Relative dielectric constant ε of the slurry composition ｒ３ The upper limit of [-] is preferably 6 or less, more preferably 4 or less, and even more preferably 3 or less, at a frequency of 1 GHz or more and a temperature of 25°C. ｒ３ When the loss factor is 6 or less, the loss factor can be reduced, and the dielectric loss can be reduced.

[0060] The dielectric loss tangent tanδ of the slurry composition ３ The upper limit of [-] is preferably 0.005 or less, more preferably 0.002 or less, and particularly preferably 0.001 or less, at a frequency of 1 GHz or more and a temperature of 25°C. ３ When the loss factor is 0.005 or less, the loss factor can be reduced, and the dielectric loss can be reduced.

[0061] The upper limit of the loss factor of the slurry composition is preferably less than 6, more preferably not more than 4, and even more preferably not more than 3. When the loss factor is less than 6, the loss factor of the slurry composition can be reduced, and the dielectric loss can be reduced.

[0062] The relative permittivity ε used to quantify the dielectric properties and dielectric loss ｒ３ and dielectric tangent tanδ ３ The numerical values ​​are based on values ​​obtained by measuring the slurry composition and converting the values. The measurement method can be selected appropriately. Specifically, for example, each can be measured by the method described in the Examples below.

[0063] The loss factor is calculated by multiplying the relative dielectric constant ε of the slurry composition by ｒ３ and dielectric tangent tanδ ３ The loss coefficient can be calculated using the measured values ​​based on the following formula: (loss coefficient) = (ε ｒ３ ) １／２ ×tan δ ３ x10 ３ (In the formula, ε ｒ３ [-] represents the relative dielectric constant of the slurry composition obtained by measurement, and tan δ ３ [-] represents the dielectric tangent.)

[0064] Relative permittivity ε ｒ３ is a parameter that indicates the degree of polarization of the slurry composition obtained by measurement, and the higher the relative dielectric constant, the greater the delay in the propagation of electrical signals. Therefore, in order to increase the signal propagation speed, a lower relative dielectric constant is preferable. ３is a parameter obtained by measurement that indicates the amount of signal transmitted through the slurry composition that is lost due to conversion to heat. Therefore, the lower the dielectric loss tangent, the less signal loss there is, and the better the signal transmission rate.

[0065] The slurry composition of the present embodiment may contain other additives as long as they do not interfere with the object of the present invention. The other additives are not particularly limited, and examples thereof include ultraviolet inhibitors, colorants, flame retardants, stabilizers, and dispersants. The content of the other additives is not particularly limited, and can be appropriately determined depending on the application, purpose, etc.

[0066] The method for producing the slurry composition of the present embodiment is not particularly limited, and the slurry composition of the present embodiment can be produced by adding a predetermined amount of surface-treated inorganic filler to a solvent and stirring for a predetermined period of time.

[0067] <Low Dielectric Loss Resin Composition> Next, the low dielectric loss resin composition of this embodiment will be described below. The low dielectric loss resin composition of this embodiment contains at least the above-described surface-treated inorganic filler and a polymer resin.

[0068] Regarding the content of the surface-treated inorganic filler in the low dielectric loss resin composition of this embodiment, the lower limit is preferably 1% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, relative to the total mass of the low dielectric loss resin composition. Meanwhile, the upper limit of the content of the surface-treated inorganic filler is preferably 85% by mass or less, more preferably 82% by mass or less, and even more preferably 79% by mass or less, relative to the total mass of the low dielectric loss resin composition. When the lower limit of the content of the surface-treated inorganic filler is 1% by mass or more, the loss factor of the low dielectric loss resin composition is reduced, thereby achieving a reduction in dielectric loss. Meanwhile, when the upper limit of the content of the surface-treated inorganic filler is 85% by mass or less, deterioration of physical strength such as brittleness can be prevented, and improvements in hardness, a reduction in the thermal expansion coefficient, and weather resistance can be achieved.

[0069] The polymeric resin preferably comprises at least one thermoplastic resin and / or at least one thermosetting resin.

[0070] More specifically, the polymer resin may be at least one selected from the group consisting of olefin resins, styrene resins, polyvinyl resins, methacrylic resins, thermoplastic elastomer resins, thermoplastic polyurethane resins, polyacrylonitrile resins, polylactic acid resins, polyamide polyacetal resins, polycarbonate resins, polyphenylene ether resins, polyethylene terephthalate resins, polysulfone resins, polyether sulfone resins, polyphenylene sulfide resins, polyether ether ketone resins, liquid crystal polymer resins, polyimide resins, fluororesins, phenolic resins, amine resins, furan resins, unsaturated polyester resins, epoxy resins, diallyl phthalate resins, guanamine resins, ketone resins, silicone resins, thermosetting elastomer resins, natural rubber, synthetic rubber, and modified versions thereof. These polymer resins may be used alone or in combination depending on the processability and intended use of the low dielectric loss resin composition. The degree of polymerization of the polymer resin is not particularly limited and can be selected appropriately depending on the intended use of the low dielectric loss resin composition. For example, when a polymer resin obtained by mixing a polyphenylene ether resin with an epoxy resin is used, the processability can be improved by increasing the fluidity. The degree of polymerization of the polymer resin is not particularly limited and can be appropriately selected depending on the application of the low dielectric loss resin composition.

[0071] The content of the polymer resin in the low dielectric loss resin composition of this embodiment is preferably 15% by mass or more and 99% by mass or less, more preferably 18% by mass or more and 90% by mass or less, and even more preferably 21% by mass or more and 80% by mass or less, based on the total mass of the low dielectric loss resin composition. By setting the content of the polymer resin to 15% by mass or more, the properties of the polymer resin, such as adhesion and water resistance, can be fully exhibited. On the other hand, by setting the content of the polymer resin to 99% by mass or less, the dielectric loss of the resin composition can be reduced by adding a surface-treated inorganic filler while maintaining the properties of the polymer resin.

[0072] Relative dielectric constant ε of low dielectric loss resin composition ｒ４The upper limit of [-] is preferably 6 or less, more preferably 4 or less, and particularly preferably 3 or less, at a frequency of 1 GHz or more and a temperature of 25°C. ｒ４ When the loss factor is 6 or less, the loss factor can be reduced, and the dielectric loss can be reduced.

[0073] Dielectric loss tangent tanδ of the low dielectric loss resin composition according to this embodiment ４ [-] is the dielectric loss tangent tanδ of the composition using the surface-untreated inorganic filler ４ The dielectric loss tangent tanδ of the composition using the surface-untreated inorganic filler is reduced compared to [-]. ４ Dielectric tangent tanδ of low dielectric loss resin composition relative to [-] ４ The ratio [-] is preferably 0.97 or less, more preferably 0.95 or less, even more preferably 0.90 or less, even more preferably 0.85 or less, and even more preferably 0.80 or less. ４ The upper limit of [-] is not particularly limited, but in an embodiment in which an epoxy resin is used as in the Examples described later, at a frequency of 1 GHz or more and a temperature of 25°C, it is preferably 0.010 or less, more preferably 0.009 or less, and even more preferably 0.008 or less.

[0074] The loss factor of the low dielectric loss resin composition according to this embodiment is reduced compared to the loss factor of a composition using a surface-untreated inorganic filler. The ratio of the loss factor of the low dielectric loss resin composition to the loss factor of a composition using a surface-untreated inorganic filler is preferably 0.95 or less, more preferably 0.90 or less, even more preferably 0.85 or less, even more preferably 0.80 or less, even more preferably 0.75 or less, and even more preferably 0.70 or less. Furthermore, the upper limit of the loss factor of the low dielectric loss resin composition is not particularly limited, but in an embodiment using an epoxy resin as in the examples described below, it is preferably 13 or less, more preferably 12 or less, and particularly preferably 11 or less.

[0075] The relative permittivity ε used to quantify the dielectric properties and dielectric loss ｒ４and dielectric tangent tanδ ４ The numerical values ​​are based on values ​​obtained by measuring the low dielectric loss resin composition and converting the measured values. The measurement method can be selected appropriately. Specifically, for example, each can be measured by the method described in the Examples below.

[0076] The loss factor is the relative dielectric constant ε of the low dielectric loss resin composition ｒ４ and dielectric tangent tanδ ４ The loss coefficient can be calculated using the measured values ​​based on the following formula: (loss coefficient) = (ε ｒ４ ) １／２ ×tan δ ４ x10 ３ (In the formula, ε ｒ４ [-] represents the relative dielectric constant of the low dielectric loss resin composition obtained by measurement, and tan δ ４ [-] represents the dielectric tangent.)

[0077] Relative permittivity ε ｒ４ is a parameter that indicates the degree of polarization of a low dielectric loss resin composition obtained by measurement, and the higher the relative dielectric constant, the greater the delay in the propagation of an electric signal. Therefore, in order to increase the signal propagation speed, a lower relative dielectric constant is preferable. Dielectric loss tangent tanδ ４ is a parameter obtained by measurement that indicates the amount of signal transmitted through the low dielectric loss resin composition that is lost due to conversion to heat. Therefore, the lower the dielectric loss tangent, the less signal loss there is, and the better the signal transmission rate.

[0078] Next, a method for producing the low dielectric loss resin composition according to this embodiment will be described below. The low dielectric loss resin composition according to this embodiment can be produced by adding a surface-treated inorganic filler and any other additives to a polymer resin and uniformly mixing or kneading them. Alternatively, the low dielectric loss resin composition can be produced by adding and dispersing the surface-treated inorganic filler and any other additives to a solution (e.g., a varnish or dispersion) in which the polymer resin or a monomer that forms the polymer resin is dissolved or dispersed in an organic solvent.

[0079] The low dielectric loss resin composition of this embodiment may contain impurities to the extent that it does not contradict the object of the present invention. Examples of such impurities include metal impurities containing elements other than those constituting the inorganic fluoride, and metal oxides. The content of impurities is preferably 100 ppm or less, more preferably 10 ppm or less, based on the total mass of the low dielectric loss resin composition.

[0080] The low dielectric loss resin composition of the present embodiment may contain other additives as long as they do not interfere with the object of the present invention. The other additives are not particularly limited, and examples thereof include curing agents, lubricants, crystal nucleating agents, ultraviolet protection agents, colorants, flame retardants, stabilizers, plasticizers, reinforcing agents, and dispersants. The content of the other additives is not particularly limited, and can be appropriately determined depending on the application, purpose, etc.

[0081] The low dielectric loss resin composition of the present embodiment can be used as a resin composition for insulating films (solder resist), a resin composition for semiconductor encapsulation, an adhesive, a paint, a covering material for wiring for power supplies, communications, etc.

[0082] <Molded Article for High-Frequency Device and Manufacturing Method Thereof> The molded article for high-frequency device (hereinafter referred to as "molded article") of this embodiment is made of a molded article containing a low dielectric loss resin composition.

[0083] The molded body can be produced, for example, by using a known kneader and extruder. Examples of kneaders that can be used include an internal pressure kneader and an open roll. A sheet-shaped low dielectric loss resin composition material can be produced using these kneaders, and then a molded body can be produced using the low dielectric loss resin composition material. Alternatively, a pellet-shaped low dielectric loss resin composition material can be produced using an extruder, and then a molded body can be produced using an injection molding machine. When a polymer resin is mixed with a surface-treated inorganic filler and other additives using a molding machine such as an extruder, the number of steps can be reduced, and production efficiency can be improved. Furthermore, the surface-treated inorganic filler may be appropriately subjected to a drying treatment or the like before being mixed with the polymer resin.

[0084] Furthermore, a sheet-like molded product can be produced by a known method. For example, a surface-treated inorganic filler and any other additives are added to a varnish tank filled with a solution (resin varnish) containing a polymer resin, and the resulting mixture is uniformly dispersed. The dispersion is then heated at a predetermined temperature. The cured product produced by heating is stretched into a sheet, thereby producing a sheet-like molded product.

[0085] Alternatively, a sheet-like substrate such as glass cloth or a bonding sheet may be immersed in a bath of a dispersion containing a polymer resin, a surface-treated inorganic filler, and any other additives, and passed through the bath to impregnate the sheet-like substrate with the dispersion. The sheet impregnated with the dispersion is then dried to produce an impregnated sheet impregnated with the low dielectric loss resin composition. By passing the sheet-like substrate through the bath of the dispersion multiple times, it is also possible to produce a laminate in which multiple low dielectric loss resin composition layers are stacked.

[0086] <High-Frequency Device> The high-frequency device according to the present embodiment includes a molded article made of a low dielectric loss resin composition.

[0087] The high-frequency device of this embodiment is used for information processing and information communication performed by electronically exchanging signals. In particular, the high-frequency device of this embodiment is used in a high-frequency band in which the frequency band of radio waves and signals used during communication is 1 GHz or higher, more preferably 10 GHz or higher. The high-frequency device of this embodiment also includes high-frequency electronic components used in such high-frequency bands.

[0088] Examples of high-frequency devices or devices equipped with high-frequency devices include mobile phones, smartphones, tablets, antennas and mobile phone antenna base stations, notebook PCs, digital cameras, automobiles, car navigation systems, Wi-Fi-related devices, wearable devices, electronic circuit devices, medical devices, and communication devices. The molded article for high-frequency devices of the present embodiment can be used, for example, in housings for these information processing and information communication devices, circuit boards, printed wiring boards, transmission lines, capacitors, inductors, and other high-frequency electronic components. High-frequency devices of the present embodiment also include insulating films and semiconductor encapsulation resins formed from low-dielectric-loss resin compositions, and wiring coated with low-dielectric-loss resin compositions as a coating material. Low-dielectric-loss resin compositions can also be used for ceiling and wall materials in rooms where high-frequency devices are installed.

[0089] Preferred examples of the present invention are described in detail below. However, unless otherwise specified, the materials and blending amounts described in the examples are not intended to limit the scope of the present invention.

[0090] [Surface-treated inorganic fluoride particles] (Example A1) 40 g of maleic terpene (manufactured by Mitsubishi Chemical Corporation, jER Cure YH306: 1,2,3,6-tetrahydro-6-isobutenyl-3,4-dimethylphthalic anhydride) and 0.2 g of 2-ethyl-4-methylimidazole were placed in a 200 mL reaction vessel, and α-AlF ３ 20 g of the above was added to obtain a suspension. This suspension was stirred at room temperature for 15 minutes, and then stirred under heat at 80°C for 3 hours and at 120°C for 3 hours. Subsequently, after cooling to room temperature, 50 g of hexane was added to the suspension, and the mixture was stirred for 15 minutes and then filtered. The filtered solid was recovered, and 50 g of hexane was added again to the recovered solid, and the mixture was stirred for 15 minutes and then filtered. Next, the filtered solid was dried at 100°C under a reduced pressure of -0.1 MPa for 12 hours to obtain surface-treated inorganic fluoride particles. The surface-treated inorganic fluoride particles had a pale yellow appearance.

[0091] (Example A2) In this example, the amount of maleic terpene used in Example A1 was changed to 40 g and 0.2 g of 2-ethyl-4-methylimidazole, and the amount of maleic terpene used was changed to only 40 g. Otherwise, surface-treated inorganic fluoride particles according to this example were obtained in the same manner as in Example A1. The appearance of the surface-treated inorganic fluoride particles was pale yellow.

[0092] (Example A3) In this example, instead of 40 g of maleic terpene and 0.2 g of 2-ethyl-4-methylimidazole in Example A1, only 40 g of 2-ethyl-4-methylimidazole was used. Otherwise, surface-treated inorganic fluoride particles according to this example were obtained in the same manner as in Example A1. The appearance of the surface-treated inorganic fluoride particles was whitish gray.

[0093] (Example A4) In this example, 40 g of maleic terpene in Example A1 was changed to 40 g of dodecenyl succinic anhydride. Otherwise, surface-treated inorganic fluoride particles according to this example were obtained in the same manner as in Example A1. The appearance of the surface-treated inorganic fluoride particles was pale yellow.

[0094] (Example A5) In this example, the α-AlF of Example A1 was ３ ZrF ４ The surface-treated inorganic fluoride particles according to this example were obtained in the same manner as in Example A1 except for the above. The appearance of the surface-treated inorganic fluoride particles was pale yellow.

[0095] Example A6 In this example, 5 g of the surface-treated inorganic fluoride particles obtained in Example A1 and 50 g of hexane were placed in a 200 mL reaction vessel, stirred at room temperature for 15 minutes, and then filtered. The filtered solid was recovered, and 50 g of hexane was added again, stirred for 15 minutes, and then filtered. This operation was repeated four times, and the filtered solid was dried at 100°C under a reduced pressure of -0.1 MPa for 12 hours to obtain surface-treated inorganic fluoride particles. The surface-treated inorganic fluoride particles had a pale yellow appearance.

[0096] (Example A7) In this example, a 15% polyamic acid / N-methyl-2-pyrrolidone (NMP) solution (Pyre-ML (registered trademark) manufactured by I.S.T. Co., Ltd.) was diluted with NMP to obtain a 5% polyamic acid / NMP solution. α-AlF ３ The mixture was stirred at 30° C. for 1 hour. The NMP was completely removed by heating at 130° C. for 2 hours and then at 200° C. for 30 minutes, thereby obtaining surface-treated inorganic fluoride particles. The surface-treated inorganic fluoride particles had a brown appearance.

[0097] (Comparative Example A1) In this comparative example, 40 g of maleated terpene was placed in a 200 mL reaction vessel and dried for 12 hours at 100° C. under a reduced pressure of −0.1 MPa. After drying, the weight was measured, and it was found that all of the 40 g of maleated terpene placed in the 200 mL reaction vessel had evaporated.

[0098] In this comparative example, 0.2 g of 2-ethyl-4-methylimidazole was placed in a 200 mL reaction vessel and dried at 100° C. under a reduced pressure of −0.1 MPa for 12 hours. After drying, the weight was measured, and it was found that all of the 0.2 g of 2-ethyl-4-methylimidazole placed in the 200 mL reaction vessel had evaporated.

[0099] Comparative Example A3 In this comparative example, α-AlF ３ The mixture was dried at 100° C. under a reduced pressure of −0.1 MPa for 12 hours to obtain inorganic fluoride particles according to this comparative example. The obtained inorganic fluoride particles had a white appearance.

[0100] Comparative Example A4 In this comparative example, 50 g of hexane was placed in a 200 mL reaction vessel, and α-AlF ３ 20 g of α-AlF was added and mixed for 15 minutes. After filtering this suspension, the filtered solid was dried at 100°C under a reduced pressure of -0.1 MPa for 12 hours to obtain inorganic fluoride particles according to this comparative example. The obtained inorganic fluoride particles had a white appearance. (Comparative Example A5) In this comparative example, α-AlF ３20 g of hexane, 40 g of maleated terpene, and 0.2 g of 2-ethyl-4-methylimidazole were mixed and stirred at room temperature for 15 minutes in a 200 mL reaction vessel, and 50 g of hexane was added and stirred for 15 minutes, followed by filtration. The filtered solid was recovered, and 50 g of hexane was added again to this and stirred for 15 minutes, followed by filtration. Next, the filtered solid was dried at 100°C under a reduced pressure of -0.1 MPa for 12 hours, thereby obtaining inorganic fluoride particles according to this comparative example. The obtained inorganic fluoride particles had a white appearance.

[0101] (Comparative Example A6) In this comparative example, α-AlF ３ 20 g of hexane and 40 g of maleated terpene were mixed at room temperature in a 200 mL reaction vessel while stirring for 15 minutes. 50 g of hexane was added to the suspension, stirred for 15 minutes, and then filtered. The filtered solid was recovered, and 50 g of hexane was added again to the recovered solid, stirred for 15 minutes, and then filtered. The filtered solid was then dried at 100°C under a reduced pressure of -0.1 MPa for 12 hours to obtain inorganic fluoride particles according to this comparative example. The obtained inorganic fluoride particles had a white appearance.

[0102] (Infrared Spectroscopy (IR) Measurement) The inorganic fillers obtained in the Examples and Comparative Examples were measured using a Fourier transform infrared spectrometer (IR) (Model: FT / TR-4100, manufactured by JASCO Corporation). As an example, as shown in Figure 1 , which illustrates the IR spectra of the inorganic fluoride fillers of Example A1 and Comparative Example A3, a signal suggesting the presence of an organic substance thought to be derived from maleic terpene or 2-ethyl-4-methylimidazole was confirmed in the inorganic fluoride filler of Example A1, while no functional group signal suggesting the presence of an organic substance was confirmed in the inorganic fluoride filler of Comparative Example A3.

[0103] As can be seen from Figure 1, it was suggested that the inorganic fluoride filler obtained in Example A1 was coated with an organic compound. In Table 1, the results of the IR measurement indicate that a signal suggesting the presence of an organic substance was detected as "detected," and that no signal was detected as "undetected." IR measurements were also performed on the inorganic fillers of Examples A2 to A7 and Comparative Examples A3 to A6 in the same manner, and whether or not a signal suggesting the presence of an organic substance was detected is indicated in Table 1.

[0104] (Thermogravimetric analysis (TGA)) The inorganic fillers obtained in the examples and comparative examples were subjected to TGA measurement using a thermogravimetric analyzer (TGA) (model: TG-DTA8122, manufactured by Rigaku Corporation). As an example, as shown in the TGA charts of Example A1 and Comparative Example A3 in FIG. 2, α-AlF ３ In the present invention, there is an organic substance that is thought to be derived from maleic terpene or 2-ethyl-4-methylimidazole, equivalent to a mass concentration of 8.7%, and α-AlF ３ It was suggested that the surface was covered with

[0105] The IR measurement results in Figure 1 and the results in Figure 2 suggest that the inorganic fluoride filler obtained in Example A1 is coated with an organic compound. TGA measurements were also performed in the same manner on each of the inorganic fillers of Examples A2 to A7 and Comparative Examples A3 to A6, and the results of the thermal weight loss rates are shown in Table 1.

[0106] Comparison of Examples A1 to A7 with Comparative Examples A1 and A2 reveals that, even under heating conditions under which the carboxylic acid anhydride and amine compound would naturally be evaporated off by themselves, they are present in the presence of inorganic fluoride particles without being evaporated off. Furthermore, comparison of the Examples and Comparative Examples shown in Table 1 suggests that the carboxylic acid anhydride and amine compound are coated on the inorganic fluoride particles by a reaction caused by heating.

[0107]

[0108] (Examples 1, 2, 101, Comparative Example 1 (Measurement of Relative Dielectric Constant and Dielectric Loss Tangent)) As shown in Table 2, the relative dielectric constant and dielectric loss tangent of each sample of the surface-treated inorganic fillers according to Examples A1, A2, and A4 and the untreated inorganic filler according to Comparative Example A3 were measured. That is, each sample was filled into a quartz tube, and the relative dielectric constant and dielectric loss tangent were measured by a cavity resonator method in the 10 GHz frequency range under an ambient atmosphere at a temperature of 25°C and a relative humidity of 40%. A vector network analyzer (manufactured by Anritsu Corporation, product name: MS46122B) was used for the measurements. Furthermore, the measured values ​​of the relative dielectric constant and dielectric loss tangent of the quartz tube filled with each sample were corrected for voids using the bulk density and true density of each sample and the amount of each sample filled relative to the filling volume, and the relative dielectric constant ε ｒ０ [-] and dielectric tangent tanδ ０ The results are shown in Table 2.

[0109] As can be seen from Table 2, the surface-treated inorganic fillers according to Examples A1, A2, and A4 had lower dielectric loss tangent values ​​than the untreated inorganic filler according to Comparative Example A3, confirming that the dielectric loss was reduced. This is thought to be because the active sites and hydroxyl groups on the surface were reacted with the acid anhydride to convert them into functional groups that do not affect the dielectric properties, thereby preventing an increase in the dielectric constant and dielectric loss tangent.

[0110]

[0111] Example 3 (Preparation of Test Piece Using Epoxy Resin) 10 g of epoxy resin (trade name: jER (registered trademark) 828, manufactured by Mitsubishi Chemical Corporation), 5 g of epoxy resin curing agent (trade name: YH-306 (registered trademark), manufactured by Mitsubishi Chemical Corporation), and 15 g of the surface-treated inorganic filler obtained in Example A1 as an inorganic filler were placed in a container cup and kneaded with a defoaming mixer to prepare a paste.

[0112] The prepared paste was placed in a mold and heat-cured at 80° C. for 3 hours and then at 120° C. for 6 hours. After that, it was removed from the mold to prepare a molded body (inorganic-organic composite test piece) of the low dielectric loss resin composition according to Example 3.

[0113] Subsequently, the dielectric constant and dielectric loss tangent of the obtained molded body were measured in an environmental atmosphere of a temperature of 19°C and a relative humidity of 50% by a cavity resonator method in a frequency range of 10 GHz. For the measurement, a network analyzer (product name: E8361A, manufactured by Keysight Technologies, Inc.) was used. The results are shown in Table 3.

[0114] (Examples 4 to 7, 102 (Preparation of test pieces using epoxy resin)) In Examples 4 to 7, and 102, the surface-treated inorganic filler was changed to the example shown in Table 3. Otherwise, molded articles of the low dielectric loss resin composition according to each of Examples 4 to 7, and 102 were prepared in the same manner as in Example 3. Furthermore, the relative dielectric constant and dielectric loss tangent of each of the molded articles according to Examples 4 to 7, and 102 were measured in the same manner as in Example 3, and the results are shown in Table 3.

[0115] (Comparative Examples 2 to 4 (Preparation of Test Pieces Using Epoxy Resin)) In Comparative Example 2, only the epoxy resin was used, without adding any inorganic filler. In Comparative Examples 3 and 4, the inorganic filler was changed to that shown in Table 3. Otherwise, molded articles of the low dielectric loss resin compositions according to each of Comparative Examples 2 to 4 were prepared in the same manner as in Example 3. Furthermore, the relative dielectric constant and dielectric loss tangent of each of the molded articles according to Comparative Examples 2 to 4 were measured in the same manner as in Example 3, and the results are shown in Table 3.

[0116]

[0117] As can be seen from Table 3, the surface-treated inorganic fillers according to Examples 3 to 7 and 102 were similar to the epoxy resins or α-AlF according to Comparative Examples 2 to 4. ３ and ZrF ４ It was confirmed that the dielectric constant or dielectric loss tangent was lower than that of inorganic fillers consisting of , and that the dielectric loss was reduced. This is thought to be because, even when filled into epoxy resin, the active sites and hydroxyl groups on the surface react with the acid anhydride and are converted into functional groups that do not affect the dielectric properties, so that the dielectric constant and dielectric loss tangent do not increase.

[0118] The surface-treated inorganic fluoride particles of the present invention can be suitably used in various high-frequency devices and the like.

Claims

1. Surface-treated inorganic fluoride particles, characterized in that the particle surface is coated with an organic compound.

2. The surface-treated inorganic fluoride particles according to claim 1, characterized in that the organic compound is at least one selected from the group consisting of carboxylic acid anhydrides, amine compounds and organosilane compounds, which are reacted with the inorganic fluoride particles by heating to coat them.

3. The surface-treated inorganic fluoride particles according to claim 2, wherein the reaction by heating is a heat treatment at 30 to 150° C. for 1 to 12 hours.

4. The surface treated inorganic fluoride particles of claim 2, wherein the carboxylic acid anhydride comprises a phthalic anhydride compound.

5. The surface-treated inorganic fluoride particles according to claim 2, wherein the amine compound comprises one or more compounds selected from the group consisting of imidazole derivatives and polyimide precursor compounds.

6. The surface treated inorganic fluoride particles of claim 2, wherein the organosilane compound comprises an alkoxysilane compound.

7. The surface-treated inorganic fluoride particles according to claim 2, wherein the inorganic fluoride particles before being coated with the organic compound contain oxygen inside the particles or at least on a part of the particle surface.

8. The surface-treated inorganic fluoride particles according to claim 7, characterized in that the inorganic fluoride is a fluoride containing at least one element selected from the group consisting of Li, Na, K, Mg, Al, Ca, Sc, Ti, Mn, Fe, Ga, Rb, Sr, Y, Zr, Sn, Ba, La, Ce, Yb, Hf and Bi.

9. The inorganic fluoride is α-AlF ３ The surface-treated inorganic fluoride particles according to claim 7, characterized in that 10. The surface-treated inorganic fluoride particles according to claim 7, wherein the inorganic fluoride has an average particle diameter D50 of 0.05 μm or more and 75 μm or less.

11. The surface-treated inorganic fluoride particles according to claim 1, characterized in that they are a filler.

12. The surface-treated inorganic fluoride particles according to claim 1, which are a filler for a low dielectric loss resin composition.

13. A low dielectric loss resin composition comprising a polymer resin and the surface-treated inorganic fluoride particles according to any one of claims 1 to 12.

14. The low dielectric loss resin composition according to claim 13, wherein the content of the surface-treated inorganic fluoride particles is 1 mass % or more and 85 mass % or less based on the total mass of the low dielectric loss resin composition.

15. The low dielectric loss resin composition according to claim 13, wherein the polymeric resin comprises at least one thermoplastic resin and / or at least one thermosetting resin.

16. The low dielectric loss resin composition according to claim 13, wherein the polymer resin is at least one selected from the group consisting of olefin resins, styrene resins, polyvinyl resins, methacrylic resins, thermoplastic elastomer resins, thermoplastic polyurethane resins, polyacrylonitrile resins, polylactic acid resins, polyamide polyacetal resins, polycarbonate resins, polyphenylene ether resins, polyethylene terephthalate resins, polysulfone resins, polyether sulfone resins, polyphenylene sulfide resins, polyether ether ketone resins, liquid crystal polymer resins, polyimide resins, fluororesins, phenolic resins, amine resins, furan resins, unsaturated polyester resins, epoxy resins, diallyl phthalate resins, guanamine resins, ketone resins, silicone resins, thermosetting elastomer resins, natural rubber, synthetic rubber, and modified products thereof.

17. A high-frequency device comprising a molded article made of the low dielectric loss resin composition according to claim 13.

18. The high-frequency device according to claim 17, which is a mobile phone, a smartphone, a tablet, an antenna and a mobile phone antenna base station, a notebook PC, a digital camera, an automobile, a car navigation system, a Wi-Fi-related device, a wearable device, an electronic circuit device, a medical device, or a communication device.

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