JP5595629B2 - Dielectric resin composition and molded product obtained therefrom - Google Patents

Description

  The present invention relates to a dielectric resin composition that improves the degree of freedom in design of molded products and productivity, suppresses defects in molded products due to distortion during processing, and is excellent in dielectric constant, mechanical strength, and heat resistance.

  Fine ceramic products are used and attracted attention in all industrial fields because they have unique and excellent characteristics or functions that are not found in metal materials and polymer materials as one of the new materials. In particular, dielectric ceramics have grown greatly in the electrical and electronic industries.

  In addition, with the remarkable spread and development of wireless information communication networks such as satellite communication devices, mobile communication devices such as mobile phones and PHS, wireless LAN systems, and in-vehicle communication devices such as highway ETC systems and GPS, communication signals Therefore, there is a demand for higher frequency and a more compact and inexpensive communication device. Conventionally, since dielectric ceramics are sintered and each part is cut, it is difficult to reduce the size and precision. Therefore, resin is eagerly desired to improve the degree of freedom in product design for further miniaturization and to reduce the cost by improving productivity. For example, a dielectric resin composition (Patent Document 1) in which a synthetic resin, a dielectric ceramic material composed mainly of barium titanate and a heat-resistant oil are mixed, and a poly (phenylene sulfide) resin have a high dielectric constant and a low loss tangent. A polymeric composition (Patent Document 2) with the addition of ceramic, and a dielectric resin composition in which a material mainly composed of barium titanate and a specific ester compound, carboxylate, amide compound, etc. are mixed in a thermoplastic resin ( Patent Document 3), Tablet for antenna parts in which ceramic powder is mixed with thermoplastic resin such as liquid crystalline resin and polyarylene sulfide (Patent Document 4), and dielectric resin composition in which strontium titanate powder is mixed with aromatic liquid crystalline polyester In a dielectric resin film (Patent Document 5) and a synthetic resin matrix, granular inorganic particles having a median diameter of 10 μm or more are used. Like dielectric resin composition comprising a mixture of wood (Patent Document 6) have been proposed.

However, in the techniques disclosed in Patent Document 1 and Patent Document 3, an additive such as heat-resistant oil is added in order to add barium titanate to a thermoplastic resin and further impart dielectric properties and melt moldability. However, since the filler density cannot be increased only by adding an additive, it cannot be said that the characteristics such as dielectric constant are sufficient. If only is added, the fluidity is low and the development is limited. In addition, although the method described in Patent Document 4 can certainly obtain a highly filled composition by making it into a tablet, since the filling density of the filler cannot be increased, the characteristics that would originally be obtained are sufficiently exhibited. Absent. In addition, although the method described in Patent Document 5 is desired to improve the characteristics by high filling by controlling the filler particle size, since the particle size to be used is small, the fluidity at the time of melt molding is low, thereby reducing the molded product. Distortion occurs and usage is limited. In addition, the method described in Patent Document 6 has high fluidity because the filler used has a large particle size, but the filling density is low, and voids are generated in the molded product, so that characteristics such as dielectric constant are sufficiently satisfied. It was not a thing.
Japanese Patent Laid-Open No. 5-98069 (Page 2, Example) JP 2000-501549 A (pages 2-7, Examples) Japanese Patent Laid-Open No. 2003-73555 (Page 2, Example) JP 2004-161953 A (2nd page, Example) Japanese Patent Laying-Open No. 2005-78806 (Page 2, Example) Japanese Patent Laying-Open No. 2005-146209 (page 2, example)

  In view of the above-described problems, the present invention eliminates the problem, that is, melt molding is possible, and by suppressing distortion during molding, the number of defects in processing is excellent, and the dielectric ceramic particles used are By providing excellent particle filling properties due to agglomeration and void reduction, the obtained molded product provides a dielectric resin composition having a high dielectric constant, mechanical strength and heat resistance, and a molded product obtained therefrom. Let it be an issue.

  As a result of intensive studies to achieve the above object, the present inventors have reached the present invention.

That is, the present invention
(1) (a) a thermoplastic port Leary sulfide resins 1 0-35 volume% and the resin (b) barium titanate, strontium titanate selected, neodymium titanate, barium, and strontium titanate, barium / magnesium zirconate The dielectric ceramic comprises 90 to 65 % by volume of at least one kind or two or more kinds of dielectric ceramics, and the (b) dielectric ceramic has an average particle diameter of 0.2 to 5.0 μm and a BET specific surface area (m ² / g). The value divided by the average particle size (μm) is in the range of 2.5 to 40, and (c) at least selected from a fatty acid metal salt, an ester compound, an amide group-containing compound, an epoxy compound, and a phosphate ester One or more types are contained in an amount of 1 to 3 parts by weight with respect to 100 parts by weight of the total amount of (a) thermoplastic resin and (b) dielectric ceramic. A dielectric resin composition, comprising:
(2) A molded product obtained by injection molding the dielectric resin composition described in (1), and (3) the molded product described in (2), wherein the molded product is an automobile part or an electric / electronic part. It is a product.

  The dielectric resin composition of the present invention and a molded product obtained from the dielectric resin composition are excellent in heat resistance, mechanical properties and dielectric constant by controlling the average particle diameter and BET specific surface area of dielectric ceramics, and at the time of melt processing Since it is possible to suppress defects due to distortion of molded products, it is suitable for applications related to automobile parts and electrical / electronic parts that require a degree of product design freedom such as miniaturization and precision. In addition, it is very useful because it can be injection-molded as compared with ceramics, and therefore has high productivity and excellent shape selectivity.

  Embodiments of the present invention will be described below. In the present invention, “weight” means “mass”.

  One or more thermoplastic resins selected from (a) liquid crystalline resins and polyarylene sulfide resins used in the present invention will be described.

  First, the liquid crystalline resin is a resin that can form an anisotropic molten phase, and preferably has an ester bond. For example, a liquid crystal polyester comprising a structural unit selected from an aromatic oxycarbonyl unit, an aromatic dioxy unit, an aromatic and / or aliphatic dicarbonyl unit, an alkylenedioxy unit, etc., and forming an anisotropic melt phase, or A liquid crystal polyester amide comprising a structural unit selected from the structural unit and an aromatic iminocarbonyl unit, an aromatic diimino unit, an aromatic iminooxy unit, and the like, and forming an anisotropic melt phase, specifically, Is a liquid crystalline polyester comprising structural units produced from p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, a structural unit produced from p-hydroxybenzoic acid, and a structure produced from 6-hydroxy-2-naphthoic acid From units, aromatic dihydroxy compounds and / or aliphatic dicarboxylic acids A liquid crystalline polyester comprising the above structural units, a structural unit produced from p-hydroxybenzoic acid, a structural unit produced from 4,4′-dihydroxybiphenyl, an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid and / or adipic acid, Liquid crystalline polyester comprising a structural unit produced from an aliphatic dicarboxylic acid such as sebacic acid, structural unit produced from p-hydroxybenzoic acid, structural unit produced from ethylene glycol, liquid crystalline polyester comprising a structural unit produced from terephthalic acid , A structural unit generated from p-hydroxybenzoic acid, a structural unit generated from ethylene glycol, a liquid crystalline polyester composed of a structural unit generated from terephthalic acid and isophthalic acid, a structural unit generated from p-hydroxybenzoic acid, and ethylene glycol A structural unit formed from 4,4′-dihydroxybiphenyl, a liquid crystalline polyester comprising a structural unit formed from an aliphatic dicarboxylic such as terephthalic acid and / or adipic acid, sebacic acid, and p-hydroxybenzoic acid. Liquid crystal composed of structural units generated, structural units generated from ethylene glycol, structural units generated from aromatic dihydroxy compounds, and structural units generated from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid In addition to structural units selected from aromatic oxycarbonyl units, aromatic dioxy units, aromatic and / or aliphatic dicarbonyl units, alkylenedioxy units, and the like as liquid crystalline polyester amides and liquid crystalline polyester amides, p- Generated from aminophenol It is a polyesteramide that forms an anisotropic molten phase containing p-iminophenoxy units. Among the above-mentioned liquid crystalline resins, liquid crystalline polyesters are preferable, and in particular, liquid crystalline polyesters composed of structural units generated from p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, structures formed from p-hydroxybenzoic acid Units, structural units generated from ethylene glycol, structural units generated from aromatic dihydroxy compounds, liquid crystalline polyesters of structural units generated from aromatic dicarboxylic acids such as terephthalic acid, structural units generated from p-hydroxybenzoic acid, ethylene A liquid crystalline polyester having a structural unit generated from glycol and a structural unit generated from an aromatic dicarboxylic acid such as terephthalic acid can be particularly preferably used.

  The liquid crystalline polyester used in the present invention preferably has a melt viscosity of 0.5 to 80 Pa · s, more preferably 1 to 50 Pa · s in order to suppress a decrease in fluidity when the filler is highly filled. Moreover, when trying to obtain a composition with more excellent fluidity, the melt viscosity is preferably 40 Pa · s or less.

  The melt viscosity is a value measured by a Koka flow tester under the condition of melting point (Tm) + 10 ° C. and shear rate of 1,000 (1 / second).

  Here, the melting point (Tm) is the Tm1 +20 after the observation of the endothermic peak temperature (Tm1) observed when the polymer having been polymerized is measured from room temperature under the temperature rising condition at 20 ° C./min in the differential calorimetry. This is the endothermic peak temperature (Tm2) observed when the temperature is kept at a temperature of 5 ° C. for 5 minutes, then cooled to room temperature under a temperature drop condition of 20 ° C./minute, and then measured again under a temperature rise condition of 20 ° C./minute. .

  Typical examples of polyarylene sulfide resins include polyphenylene sulfide (hereinafter sometimes abbreviated as PPS), polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers thereof, block copolymers, and mixtures thereof. Can be mentioned.

  Of these, polyphenylene sulfide is particularly preferably used. Such polyphenylene sulfide is a polymer preferably containing 70 mol% or more, more preferably 90 mol% or more of the repeating unit represented by the following structural formula (I). When the repeating unit is 70 mol% or more, It is preferable at the point which is excellent in heat resistance.

  Further, such polyphenylene sulfide can be composed of 30 mol% or less of the repeating unit with a repeating unit having the following structural formula, and may be a random copolymer or a block copolymer. A mixture thereof may also be used.

  Such polyarylene sulfide resins are generally known in the art, that is, a method for obtaining a polymer having a relatively small molecular weight described in JP-B-45-3368, or JP-B-52-12240 and JP-A-61-7332. It can be produced by a method for obtaining a polymer having a relatively large molecular weight described in the publication.

  In the present invention, the polyarylene sulfide resin obtained as described above is subjected to crosslinking / polymerization by heating in air, heat treatment under an inert gas atmosphere such as nitrogen or under reduced pressure, an organic solvent, hot water, Of course, it is possible to use it after various treatments such as washing with an acid aqueous solution, activation with a functional group-containing compound such as an acid anhydride, amine, isocyanate, or a functional group-containing disulfide compound.

  Specific methods for crosslinking / high molecular weight polyarylene sulfide resin by heating include an atmosphere of an oxidizing gas such as air or oxygen, or a mixed gas atmosphere of the oxidizing gas and an inert gas such as nitrogen or argon. Below, a method of heating until a desired melt viscosity is obtained at a predetermined temperature in a heating container can be exemplified. In this case, the heat treatment temperature is preferably 150 to 280 ° C., more preferably 200 to 270 ° C., and the treatment time is preferably 0.5 to 100 hours, more preferably 2 A range of ˜50 hours is selected, but by controlling both, a target viscosity level can be obtained.

As a specific method for heat-treating the polyarylene sulfide resin under an inert gas atmosphere such as nitrogen or under reduced pressure, an inert gas atmosphere such as nitrogen or under reduced pressure (preferably 7,000 Nm ^-2 or less), Examples of the heat treatment method include a heat treatment temperature of 150 to 280 ° C, preferably 200 to 270 ° C, and a heating time of 0.5 to 100 hours, preferably 2 to 50 hours. Such a heat treatment apparatus may be a normal hot air dryer or a heating apparatus with a rotary or stirring blade. However, in the case of efficient and more uniform treatment, a heating apparatus with a rotary or stirring blade is used. Is more preferable.

  When the polyarylene sulfide resin is washed with an organic solvent, the organic solvent used for washing is not particularly limited as long as it does not have an action of decomposing the polyarylene sulfide resin. For example, nitrogen-containing polar solvents such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, sulfoxide sulfone solvents such as dimethyl sulfoxide, dimethylsulfone, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone, dimethyl ether, dipropyl ether , Ether solvents such as tetrahydrofuran, halogen solvents such as chloroform, methylene chloride, trichloroethylene, ethylene chloride, dichloroethane, tetrachloroethane, chlorobenzene, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, phenol, Alcohol / phenolic solvents such as cresol and polyethylene glycol, benzene and toluene Ene, and aromatic hydrocarbon solvents such as xylene may be used. Of these organic solvents, N-methylpyrrolidone, acetone, dimethylformamide, chloroform and the like are particularly preferably used. These organic solvents are used alone or in combination of two or more.

  As a specific method of washing with such an organic solvent, there is a method of immersing a polyarylene sulfide resin in an organic solvent, and it is possible to appropriately stir or heat as necessary. There is no restriction | limiting in particular about the washing | cleaning temperature at the time of wash | cleaning polyarylene sulfide resin with an organic solvent, Arbitrary temperature of about normal temperature-about 300 degreeC can be selected. Although the cleaning efficiency tends to increase as the cleaning temperature increases, a sufficient effect is usually obtained at a cleaning temperature of room temperature to 150 ° C. The polyarylene sulfide resin subjected to organic solvent washing is preferably washed several times with water in order to remove the remaining organic solvent. The water washing temperature is preferably 50 to 90 ° C, more preferably 60 to 80 ° C.

  The following method can be illustrated as a specific method when the polyarylene sulfide resin is treated with hot water (preferably 100 to 220 ° C.). That is, the water used is preferably distilled water or deionized water in order to exhibit a preferable chemical modification effect of the polyarylene sulfide resin by hot water washing. The operation of the hot water treatment is usually performed by adding a predetermined amount of polyarylene sulfide resin to a predetermined amount of water, and heating and stirring at normal pressure or in a pressure vessel. The ratio of the polyarylene sulfide resin and water is preferably as much as possible, and is preferably used at a bath ratio of 200 g or less of polyarylene sulfide resin with respect to 1 liter of water.

  The following method can be illustrated as a specific method in the case of acid-treating a polyarylene sulfide resin. That is, there is a method of immersing a polyarylene sulfide resin in an acid or an aqueous solution of an acid, and it is possible to appropriately stir or heat as necessary. The acid used is not particularly limited as long as it does not have the action of decomposing the polyarylene sulfide resin, such as aliphatic saturated monocarboxylic acids such as formic acid, acetic acid, propionic acid and butyric acid, chloroacetic acid and dichloroacetic acid. Halo-substituted aliphatic saturated carboxylic acids, aliphatic unsaturated monocarboxylic acids such as acrylic acid and crotonic acid, aromatic carboxylic acids such as benzoic acid and salicylic acid, oxalic acid, malonic acid, succinic acid, phthalic acid, fumaric acid, etc. Dicarboxylic acid and inorganic acidic compounds such as sulfuric acid, phosphoric acid, hydrochloric acid, carbonic acid and silicic acid are used. Of these acids, acetic acid and hydrochloric acid are particularly preferably used. The polyarylene sulfide resin subjected to the acid treatment is preferably washed several times with water in order to remove the remaining acid or salt. The water washing temperature is preferably 50 to 90 ° C, particularly preferably 60 to 80 ° C. The water used for washing is preferably distilled water or deionized water in the sense that the effect of the preferred chemical modification of the polyarylene sulfide resin by acid treatment is not impaired.

  The weight average molecular weight of the polyarylene sulfide resin used in the present invention is preferably 50000 or less, more preferably 40000 or less, and more preferably 25000 or less in terms of polystyrene in order to allow a large amount of filler to be filled. It is particularly preferred that Although there is no restriction | limiting in particular about the minimum of a weight average molecular weight, When considering residence stability etc., it is preferable that it is 1500 or more. Here, the weight average molecular weight is a value measured by GPC and calculated in terms of styrene. Two or more polyarylene sulfide resins having different weight average molecular weights may be used in combination.

(B) Dielectric ceramics used in the present invention refers to an electrical insulator that generates polarization when an electric field is applied to the ceramics, whereby positive charges are pulled in the negative direction and negative charges are pulled in the positive direction . ( B) Dielectric the dielectric constant of the ceramic from the viewpoint of efficiently exerted, for example, barium titanate, using strontium titanate, neodymium titanate, barium, and strontium titanate / magnesium zirconate, etc., high barium titanate dielectric constant are particularly preferred. These (b) dielectric ceramics may be used alone or in combination of two or more.

  In addition, said (b) dielectric ceramic used for this invention has the surface of a well-known coupling agent (For example, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, etc.) and other surfaces. It can also be used after being treated with a treating agent. These may be surface-treated with a surface treatment agent such as titanate, aluminum, or silane.

  In (b) dielectric ceramics, (a) the productivity at the time of mixing with at least one thermoplastic resin selected from a liquid crystalline resin and a polyarylene sulfide resin and the molding processability of the dielectric resin composition are improved. Therefore, it is essential that the average particle size of the dielectric ceramic used (b) is in the range of 0.2 μm to 5.0 μm, and the average particle size is preferably 0.2 μm to 4.0 μm, More preferably, it is 0.2 μm or more and 3.0 μm or less. When dielectric ceramics having an average particle size of less than 0.2 μm are used, characteristics are not obtained because the fluidity is lowered and mixing cannot be performed sufficiently when mixed with a resin, while the average particle size is 5. If it exceeds 0 μm, the filling property of the obtained molded product is insufficient, which adversely affects dielectric properties and mechanical strength.

Here, the average particle diameter is a volume-based average particle diameter measured by a laser diffraction scattering method after sufficiently dispersing dielectric ceramics in an aqueous slurry and sufficiently dispersing with a dispersing agent and ultrasonic treatment.
In addition, (b) the dielectric ceramic to be used reduces the porosity between the dielectric ceramics, and more densely fills up to exhibit high dielectric properties and suppresses distortion of the molded product during melt molding, that is, defects due to distortion In order to reduce and improve heat resistance, it is necessary to control the relationship between the particle size of the dielectric ceramic used, the BET specific surface area, and the average particle size, and the BET specific surface area (m ² / g) is set to the average particle size (μm ) Is a range of 2.5 to 40 . Preferably it is 2.5 or more and 30 or less. Dividing the BET specific surface area by the average particle size means an index of the particle size distribution of the dielectric ceramic used, and the value obtained by dividing the BET specific surface area (m ² / g) by the average particle size (μm) is 1. When a dielectric ceramic of less than 5 is used, there are particles having a small BET specific surface area with respect to the average particle size, that is, particles having a particle size larger than the average particle size. Alternatively, there are many particles having a particle size distribution close to a single particle, that is, particles having the same particle size. When such a dielectric ceramic is used, the contact area between the thermoplastic resin and the dielectric ceramic is reduced, so that distortion is easily generated in the molded product at the time of molding, which adversely affects the mechanical strength. On the other hand, when a dielectric ceramic having a value obtained by dividing the BET specific surface area (m ² / g) by the average particle size (μm) exceeds 40 , particles having a large BET specific surface area with respect to the average particle size, that is, average particles There are particles having a particle size smaller than the diameter. Alternatively, the particle size distribution is different from the average particle size, that is, particles having a very wide particle size distribution. When such dielectric ceramics are used, when filling thermoplastic resin and dielectric ceramics, the particles with small particle diameters become aggregates, resulting in insufficient filling properties and adversely affecting the strength and heat resistance of the molded product. Not only does this affect the dielectric constant, but also decreases the dielectric constant. In addition, in the case of particles with a very wide particle size distribution, particles with small particles become aggregates, and particles with large particle sizes cause distortion in the molded product during molding because the contact area of the dielectric ceramic is reduced. This will adversely affect the mechanical strength.

Here, the BET specific surface area (m ² / g) is a unit mass of dielectric ceramics obtained by adsorbing nitrogen gas to dielectric ceramics that have been sufficiently dried and vacuum degassed, and obtained from the amount of adsorbed gas and the mass of the dielectric ceramics. Per surface area.

  In the present invention, the ratio of (a) at least one thermoplastic resin selected from liquid crystalline resins and polyarylene sulfide resins to (b) dielectric ceramics exhibits the characteristics of the dielectric ceramics used, and melt processability. In view of the balance of (a) liquid crystal, the total amount of (a) at least one thermoplastic resin selected from liquid crystal resin and polyarylene sulfide resin and (b) dielectric ceramics is 100% by volume. 10 to 90% by volume of at least one thermoplastic resin selected from a conductive resin and a polyarylene sulfide resin, (b) 90 to 10% by volume of dielectric ceramics, and (a) selected from a liquid crystalline resin and a polyarylene sulfide resin 10 to 70% by volume of at least one thermoplastic resin, (b) dielectric ceramic 90 to 3 Preferably volume percent, (a) 10 to 50 volume% of at least one thermoplastic resin selected from liquid crystalline resins and polyarylene sulfide resins, and more preferably 90 to 50 volume% (b) dielectric ceramics.

  Further, the composition of the present invention includes (b) an aliphatic metal salt, an ester compound, an amide group-containing compound, an epoxy compound, and phosphorus from the viewpoint of imparting bondability at the dielectric ceramic interface and fluidity during processing. It is preferable to add at least one compound selected from acid esters. Such additives include sodium stearate, calcium stearate, magnesium stearate, potassium stearate, lithium stearate, zinc stearate, barium stearate, aluminum stearate, sodium montanate, calcium montanate, magnesium montanate , Aliphatic metal salts such as potassium montanate, lithium montanate, zinc montanate, barium montanate, aluminum montanate, and derivatives thereof, stearates such as methyl stearate and stearate stearates, and myristic such as myristyl myristate Methacrylic acid ester such as acid ester, montanic acid ester, behenyl methacrylate, pentaerythritol monostearate, cetyl 2-ethylhexanoate Palm fatty acid methyl, methyl laurate, isopropyl myristate, octyldodecyl myristate, 2-ethylhexyl stearate, isotridecyl stearate, methyl caprate, methyl myristate, methyl oleate, octyl oleate, lauryl oleate, olein Monohydric alcohol esters of fatty acids such as oleyl acid, 2-ethylhexyl oleate, decyl oleate, octidodecyl oleate, isobutyl oleate and their derivatives, distearyl phthalate, distearyl trimellitic acid, dimethyl adipate, adipic acid Dioleyl, adipic acid ester, ditridecyl phthalate, diisobutyl adipate, diisodecyl adipate, dibutyl glycol adipate, 2-ethylhexyl phthalate, phthalic acid Fatty acid esters of polybasic acids, such as isononyl, didecyl phthalate, tri-2-ethylhexyl trimellitic acid, triisodecyl trimellitic acid, stearic acid monoglyceride, palmitic acid, stearic acid monoglyceride, stearic acid mono-diglyceride, stearic acid, oleic acid, Fatty acid esters of glycerin such as mono-diglyceride and behenic acid monoglyceride and their derivatives, sorbitan tristearate, sorbitan monostearate, sorbitan distearate, sorbitan monopalmitate, polyethylene glycol monostearate, polyethylene glycol distearate, Polypropylene glycol monostearate, pentaerythritol monostearate, sorbitan monolaurate, sorbita Triolate, sorbitan monooleate, sorbitan sesquioleate, sorbitan monolaurate, polyoxymethylene sorbitan monolaurate, polyoxymethylene sorbitan monopalmitate, polyoxymethylene sorbitan monostearate, polyoxymethylene sorbitan monooleate, polyoxy Fatty acid esters of polyhydric alcohols such as methylene sorbitan tetraoleate, polyethylene glycol, polyethylene glycol monolaurate, polyethylene glycol monooleate, polyoxyethylene bisphenol A laurate, pentaerythritol, pentaerythritol monooleate, and their derivatives, Such as ethylene bisstearylamide, ethylenebisoleylamide, stearyl erucamide, etc. Bromide-containing compounds, novolak phenol type, bisphenol type monofunctional and polyfunctional epoxy compounds, aromatic phosphoric acid esters such as triphenyl phosphate, and phosphate esters such as aromatic condensed phosphate.

  In particular, the phosphoric acid ester is selected from monoesters, diesters, triesters, and tetraesters of phosphoric acid, and preferred examples include those represented by the following formula (1).

  First, the structure of the phosphate ester represented by the formula (1) will be described. In the formula of the formula (1), n is an integer of 0 or more, preferably 0 to 10, particularly preferably 0 to 5. The upper limit is preferably 40 or less from the viewpoint of dispersibility.

  K and m are each an integer of 0 or more and 2 or less, and k + m is an integer of 0 or more and 2 or less, preferably k or m is an integer of 0 or more and 1 or less, particularly preferably k or m. Is 1 respectively.

In the formula (1), R ^{3 to} R ¹⁰ represent the same or different hydrogen or an alkyl group having 1 to 5 carbon atoms. Specific examples of the alkyl group having 1 to 5 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, and tert-pentyl group. However, hydrogen, a methyl group, and an ethyl group are preferable, and hydrogen is particularly preferable.

Ar 1, Ar 2, Ar 3 and Ar 4 represent the same or different aromatic groups or aromatic groups substituted with an organic residue containing no halogen. Examples of the aromatic group include aromatic groups having a benzene skeleton, a naphthalene skeleton, an indene skeleton, and an anthracene skeleton, and among them, those having a benzene skeleton or a naphthalene skeleton are preferable. These may be substituted with a halogen-free organic residue (preferably an organic residue having 1 to 8 carbon atoms), and the number of substituents is not particularly limited, but may be 1 to 3. preferable. Specific examples include aromatic groups such as a phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, naphthyl group, indenyl group and anthryl group, and particularly preferred are phenyl group, tolyl group and xylyl group.

Y represents a direct bond, O, S, SO ₂ , C (CH ₃ ) 2, and CHPh, and Ph represents a phenyl group.

  Specific examples of such phosphate esters are selected from Daihachi Chemical Co., Ltd. PX-200, PX-201, PX-130, CR-733S, TPP, CR-741, CR-747, TCP, TXP, CDP. One or more selected from the group consisting of PX-200, TPP, CR-733S, CR-741, and CR-747, particularly preferably PX-200. , CR-733S and CR-741 can be used, but PX-200 is most preferable.

In the present invention, the compound selected from (c) fatty acid metal salt, ester compound, amide group-containing compound, epoxy compound and phosphate ester may be any one kind or a mixture of two or more kinds. The additive amount of such an additive is 1 to 1 part or more of (a) one or more thermoplastic resins selected from a liquid crystalline resin and a polyarylene sulfide resin, and (b) 100 parts by weight of a high dielectric ceramic . A range of 3 parts by weight is selected.

  (C) Bleed out to the surface of the obtained molded article by setting the addition amount of a compound selected from an aliphatic metal salt, an ester compound, an amide group-containing compound, an epoxy compound and a phosphate ester to the above amount. Therefore, it is preferable that (a) one or more thermoplastic resins selected from liquid crystalline resins and polyarylene sulfide resins and (b) dielectric ceramics interface are peeled off and mechanical properties are not deteriorated. .

  In the dielectric resin composition of the present invention, it is possible to add a fibrous or non-fibrous filler such as a plate, a scale, a granule, an indeterminate shape, and a crushed product as long as the effects of the present invention are not impaired. It is. Specifically, for example, glass fibers, PAN and pitch carbon fibers, stainless fibers, metal fibers such as aluminum fibers and brass fibers, organic fibers such as aromatic polyamide fibers, gypsum fibers, ceramic fibers, asbestos fibers, zirconia Fiber, alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, rock wool, aluminum borate whisker, silicon nitride whisker, mica, talc, kaolin, silica, calcium carbonate, glass beads, glass flakes, glass microballoons, clay, Molybdenum disulfide, wollastonite, titanium oxide, zinc oxide, calcium polyphosphate, graphite, metal powder, metal flake, metal ribbon, metal oxide, carbon powder, graphite, carbon flake, scaly carbon, carbon nanotube, etc. It is below. Specific examples of metal species of metal powder, metal flakes, and metal ribbons include silver, nickel, copper, zinc, aluminum, stainless steel, iron, brass, chromium, and tin. The type of glass fiber or carbon fiber is not particularly limited as long as it is generally used for reinforcing a resin, and can be selected from long fiber type, short fiber type chopped strand, milled fiber, and the like. In the present invention, among the above fillers, fibrous, plate-like, scale-like shapes and crushed products are preferably used from the viewpoint of the strength of the molded product in the dielectric resin composition.

  The dielectric resin composition according to the present invention includes a number of components within the range not impairing the effects of the present invention, such as antioxidants and heat stabilizers (hindered phenols, hydroquinones, phosphites, substitutes thereof, etc. ), Weathering agents (resorcinol, salicylate, benzotriazole, benzophenone, hindered amine, etc.), mold release agents and lubricants (montanic acid and its metal salts, esters, half esters, stearyl alcohol, stearamide, various bisamides) , Bisurea and polyethylene wax, etc.), pigments (cadmium sulfide, phthalocyanine, carbon black for coloring, etc.), dyes (such as nigrosine), crystal nucleating agents (talc, silica, kaolin, clay, etc.), plasticizers (p-oxybenzoate) Octyl acid, N-butylbenzenesulfonami Etc.), antistatic agents (alkyl sulfate type anionic antistatic agents, quaternary ammonium salt type cationic antistatic agents, nonionic antistatic agents such as polyoxyethylene sorbitan monostearate, betaine amphoteric antistatic agents Etc.), flame retardant (eg, red phosphorus, phosphate ester, melamine dinurate, magnesium hydroxide, aluminum hydroxide, hydroxide, ammonium polyphosphate, brominated polystyrene, brominated polyphenylene ether, brominated polycarbonate, brominated Epoxy resins or combinations of these brominated flame retardants and antimony trioxide, etc.) and other polymers can be added.

  The method for preparing the dielectric resin composition of the present invention is not particularly limited, but the raw material mixture is supplied to a generally known melt mixer such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, and a mixing roll. As a representative example, a method of kneading at a temperature of 280 to 380 ° C. can be given. There are no particular restrictions on the mixing order of the raw materials, a method in which all raw materials are blended and melt kneaded by the above method, a part of the raw materials are melted and kneaded by the above method, and the remaining raw materials are further blended and melt kneaded. Or a method of mixing the remaining raw materials using a side feeder during melt-kneading with a single-screw or twin-screw extruder after mixing some raw materials. As for the small amount additive component, other components may be kneaded and pelletized by the above-described method and then added before molding and used for molding.

  A molding method for molding the dielectric resin composition of the present invention is a three-dimensional molded product by a normal molding method (injection molding, press molding, injection press molding, etc.), gas injection molding, or “mucell” molding method, Although it can be processed into a sheet, a case (housing), etc., in consideration of productivity, injection molding or injection press molding is preferably employed. Moreover, when it has a welding part, it is possible to use general welding methods, such as a hot plate, a vibration, an ultrasonic wave, and a laser.

  The molded product thus obtained has few defects due to distortion of the molded product at the time of molding and can be melt-molded. For example, it is particularly useful for capacitor applications, multichip module applications, antenna applications, and microwave circuit element applications. Other suitable, such as sensors, LED lamps, connectors, sockets, resistors, relay cases, switches, coil bobbins, variable capacitor cases, optical pickups, oscillators, various terminal boards, transformers, plugs, printed circuit boards, tuners, speakers, Electric and electronic parts represented by microphones, headphones, small motors, magnetic head bases, power modules, parabolic antennas, computer-related parts; VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, acoustics Parts, audio・ Laser discs (registered trademark) ・ Computer discs such as audio equipment parts, lighting parts, refrigerator parts, air conditioner parts, household electrical appliance parts; office computer related parts, telephone related parts, facsimile related parts, Copier related parts, facsimile related parts; exhaust gas sensor, cooling water sensor, oil temperature sensor, throttle position sensor, crankshaft position sensor, brake pad wear sensor, air conditioner panel switch board, fuse connector, vehicle speed sensor, etc. Vehicle-related parts, personal computer housing, mobile phone housing, mobile phone base station antenna case, chip antenna, wireless LAN antenna, ETC (Electronic Toll Collection System) System), antennas for satellite communications, and other various applications. Especially, product design freedom by miniaturization and suppression of cracks due to distortion of molded parts, and dielectric properties, mechanical strength, It is useful for information communication applications, automotive parts applications, and electrical / electronic parts applications where heat resistance is required and ceramic substitutes are eagerly desired.

  Hereinafter, although an example is given and the present invention is explained in detail, the gist of the present invention is not limited only to the following examples.

  Hereinafter, although an example is given and the present invention is explained in detail, the gist of the present invention is not limited only to the following examples.

Reference Example 1 Thermoplastic Resin (1) Liquid Crystalline Resin LCP (Liquid Crystalline Polyester): 995 parts by weight of p-hydroxybenzoic acid, 126 parts by weight of 4,4′-dihydroxybiphenyl, 112 parts by weight of terephthalic acid, and an intrinsic viscosity of about 0. 216 parts by weight of 6 dl / g polyethylene terephthalate and 960 parts by weight of acetic anhydride were charged into a reaction vessel equipped with a stirring blade and a distillation tube, and reacted for 3 hours while raising the temperature from room temperature to 150 ° C., from 150 ° C. to 250 ° C. The temperature was raised in 2 hours, and the temperature was raised from 250 ° C. to 320 ° C. in 1.5 hours, then the pressure was reduced to 0.5 mmHg (67 Pa) in 320 ° C. and 1.5 hours, and the reaction was further continued for about 0.25 hours. As a result of polycondensation, aromatic oxycarbonyl unit 80 molar equivalent, aromatic dioxy unit 7.5 molar equivalent, ethylenedioxy unit 12.5 molar equivalent, aromatic The pellet which consists of 20 mol equivalent of a group dicarboxylic acid unit was obtained.

(2) Preparation of polyarylene sulfide resin PPS-1 To a 20 liter autoclave equipped with a stirrer and a valve at the bottom, 2383 g (20.0 mol) of 47% sodium hydrosulfide (Sankyo Kasei), 831 g of 96% sodium hydroxide ( 19.9 mol), 3960 g (40.0 mol) of N-methyl-2-pyrrolidone (NMP), and 3000 g of ion-exchanged water, and gradually heated to 225 ° C. over about 3 hours while passing nitrogen at normal pressure. After distilling 4200 g of water and 80 g of NMP, the reaction vessel was cooled to 160 ° C. The residual water content in the system per mole of the alkali metal sulfide charged was 0.17 mole. The amount of hydrogen sulfide scattered per mole of the alkali metal sulfide charged was 0.021 mol.

  Next, 2942 g (20.0 mol) of p-dichlorobenzene (Sigma Aldrich) and 1515 g (15.3 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. Then, while stirring at 400 rpm, the temperature was raised from 200 ° C. to 227 ° C. at a rate of 0.8 ° C./min, then the temperature was raised to 274 ° C. at a rate of 0.6 ° C./min and held at 274 ° C. for 50 minutes. Then, the temperature was raised to 282 ° C. Open the extraction valve at the bottom of the autoclave, pressurize with nitrogen, flush the contents to a vessel with a stirrer over 15 minutes, stir at 250 ° C for a while to remove most of the NMP, and polyarylene sulfide (PPS) Solids containing salts were collected.

  The obtained solid and 15120 g of ion-exchanged water were placed in an autoclave equipped with a stirrer and washed at 70 ° C. for 30 minutes, and then suction filtered through a glass filter. Next, 17280 g of ion-exchanged water heated to 70 ° C. was poured into a glass filter, and suction filtered to obtain a cake.

  The obtained cake and 11880 g of ion-exchanged water were charged into an autoclave equipped with a stirrer, and the inside of the autoclave was replaced with nitrogen, and then the temperature was raised to 192 ° C. and held for 30 minutes. Thereafter, the autoclave was cooled and the contents were taken out.

  The contents were subjected to suction filtration with a glass filter, and then 17280 g of ion-exchanged water at 70 ° C. was poured into the contents, followed by suction filtration to obtain a cake. The obtained cake was dried with hot air at 80 ° C., and further dried under vacuum at 120 ° C. for 24 hours to obtain dry PPS. The obtained PPS-1 had a polystyrene equivalent weight average molecular weight of 20000.

Preparation of PPS-2 In a 20 liter autoclave equipped with a stirrer, 2383 g (20.0 mol) of 47% sodium hydrosulfide (Sankyo Kasei), 848 g (20.4 mol) of 96% sodium hydroxide, N-methyl-2- Pyrrolidone (NMP) 3267 g (33 mol), sodium acetate 531 g (6.5 mol), and ion-exchanged water 3000 g were charged and gradually heated to 225 ° C. over about 3 hours while flowing nitrogen at normal pressure. After distilling 80 g of NMP, the reaction vessel was cooled to 160 ° C. The amount of hydrogen sulfide scattered was 0.018 mol per mol of the charged alkali metal sulfide. Next, 2974 g (20.2 mol) of p-dichlorobenzene (Sigma Aldrich) and 2594 g (26.2 mol) of NMP were added, the reaction vessel was sealed under nitrogen gas, and the mixture was stirred at 400 rpm to reach 227 ° C. The temperature was raised at a rate of 8 ° C./min, then raised to 270 ° C. at a rate of 0.6 ° C./min and held at 270 ° C. for 140 minutes. Thereafter, 684 g (38 mol) of ion-exchanged water was injected into the autoclave while cooling to 250 ° C. at a rate of 1.3 ° C./min. Then, after cooling to 200 ° C. at a rate of 0.4 ° C./min, it was rapidly cooled to near room temperature.

  The contents were taken out, diluted with 10 liters of NMP, the solvent and solids were filtered off with a sieve (80 mesh), and the resulting particles were washed several times with 20 liters of warm water and filtered off. Next, the obtained particles were washed with 20 liters of warm water containing 9.8 g of acetic acid and filtered, then washed with 20 liters of warm water and filtered to obtain polyarylene sulfide polymer particles. This was dried with hot air at 80 ° C. and dried under reduced pressure at 120 ° C. The obtained PPS-2 had a polystyrene equivalent weight average molecular weight of 52,000.

The weight average molecular weight was measured by the following method.
Polymer 5 mg, 1-chloronaphthalene 5 g was weighed into a sample bottle, placed in a high-temperature filter set at 210 ° C. (SSC-9300 manufactured by Senshu Kagaku), heated for 5 minutes (1 minute preheating, 4 minutes stirring), The sample was prepared by taking it out from the high-temperature filter and leaving it to room temperature. Subsequently, the weight average molecular weight was measured under the following measurement conditions.

GPC measurement condition device: Senshu Science SSC-7100
Column name: Senshu Science GPC3506 × 1
Eluent: 1-chloronaphthalene (1-CN)
Detector: Differential refractive index detector Detector sensitivity: Range 8
Detector polarity: +
Column temperature: 210 ° C
Pre-temperature bath temperature: 250 ° C
Pump bath temperature: 50 ° C
Detector temperature: 210 ° C
Sample-side flow rate: 1.0 mL / min
Reference side flow rate: 1.0 mL / min
Sample injection amount: 300 μL
Calibration curve preparation sample: polystyrene.

Reference Example 2 Dielectric ceramics Barium titanate (TB1): BT-01 (average particle size 0.1 μm, BET specific surface area 13.0 m ² / g, 130 value obtained by dividing BET specific surface area by average particle size, Sakai Chemical Industry (Made by company)
Barium titanate (TB2): BT-05 (average particle size 0.5 μm, BET specific surface area 2.3 m ² / g , value obtained by dividing BET specific surface area by average particle size 5, manufactured by Sakai Chemical Industry Co., Ltd.)
Barium titanate ceramics (TB3): MBRT-95 (average particle size 1.15 μm, BET specific surface area 1.0 m ² / g , BET specific surface area divided by average particle size 0.9, Fuji Titanium Industry Co., Ltd. Made)
Strontium titanate (TS1): ST-03 (average particle size 0.3 μm, BET specific surface area 4.3 m ² / g , value obtained by dividing BET specific surface area by average particle size 14, manufactured by Sakai Chemical Industry Co., Ltd.)
Strontium titanate (TS2): strontium carbonate (SW-K, manufactured by Sakai Chemical Industry Co., Ltd., BET specific surface area 7.7 m ² / g ), titanium dioxide (PT-401M, manufactured by Ishihara Techno, BET specific surface area 20.7 m) ² / g , rutile conversion rate of 50.7%) (measured weight loss when water and volatile components are removed by heating to 700 ° C) to correct weight deviation due to moisture and other volatile components A total of about 1.1 kg of powder was weighed so that the molar ratio of strontium carbonate to titanium dioxide was 1: 1. Using a 10 L polyethylene pot and a 15 mmφ iron core plastic ball, the mixed powder weighed by a dry ball mill was mixed for 20 hours. The BET specific surface area after mixing was 22.8 m ² / g . As a result of analyzing the mixture by TG-DTA, the production temperature of strontium titanate was 880 ° C. The mixture was fired using a tubular furnace (furnace core tube volume 20 L) having a quartz glass furnace core tube. The temperature inside the furnace was raised to a nitrogen atmosphere, and the temperature was raised. At 600 ° C., an atmosphere of 3% by volume of hydrogen chloride-97% by volume of nitrogen was introduced. The first firing was performed while maintaining the time. The pressure in the firing atmosphere is all atmospheric pressure (about 0.1 MPa). After firing, the obtained strontium titanate powder was dispersed in an aqueous 0.8% by weight ammonium hydrogen carbonate solution, filtered and washed. The powder after washing was dried at 130 ° C., and was fired for the second time at 900 ° C. for 3 hours in an air atmosphere. Further, the powder was pulverized for 20 hours by a ball mill using a 10 L polyethylene pot and a plastic ball with a core of 15 mmφ, and the average particle diameter of the particles was 0.154 μm, the BET specific surface area was 8.15 m ² / g , and the BET specific surface area was averaged. The value divided by the particle size was 53, and a strontium titanate powder having a specific gravity of 5.12 was obtained.

Strontium barium titanate (TSB1): Three types of powders (Ba / Sr / Ti = 0.5 / 0.5 / 1 molar ratio): 56.83 g of barium carbonate, 42.51 g of strontium carbonate, and 46.02 g of titanium oxide The solvent was mixed with ethanol using a ball mill for 24 hours. The powder dispersion after mixing was separated from the powder, balls and ethanol, and the powder was dried at 110 ° C. for 12 hours and used as a raw material. The dried powder was put into an alumina crucible and baked at 1300 ° C. for 24 hours using an electric furnace. The calcined powder was passed through a sieve while being pulverized in an alumina mortar, and the average particle diameter of the particles was 4.0 μm, the BET specific surface area was 10.0 m ² / g , and the BET specific surface area was divided by the average particle diameter. A strontium barium titanate powder having a specific gravity of 5.6 was obtained.

Strontium barium titanate (TSB2): Three types of powders (Ba / Sr / Ti = 0.5 / 0.5 / 1 molar ratio): 56.83 g of barium carbonate, 42.51 g of strontium carbonate, and 46.02 g of titanium oxide The solvent was mixed with ethanol using a ball mill for 24 hours. The powder dispersion after mixing was separated from the powder, balls and ethanol, and the powder was dried at 110 ° C. for 12 hours and used as a raw material. The dried powder was put into an alumina crucible and baked at 1300 ° C. for 24 hours using an electric furnace. The baked powder was passed through a sieve while being pulverized in an alumina mortar, the average particle diameter of the particles was 15 μm, the BET specific surface area was 0.6 m ² / g , the value obtained by dividing the BET specific surface area by the average particle diameter was 0.04, A strontium barium titanate powder having a specific gravity of 5.6 was obtained.

  In the above description, the average particle size is defined as follows: 1 g of dielectric ceramics is made into a slurry of 200 ml of water: ethanol = 1: 1 solution, and after dispersion for 10 minutes by ultrasonic wave, a laser diffraction particle size distribution analyzer SALD-2200 manufactured by Shimadzu Corporation. And measured.

  The BET specific surface area of the powder is as follows: 1 g of dielectric ceramics is filled in a sample cell, dried in a nitrogen atmosphere at 300 ° C. for 30 minutes, and a mixed gas of helium: nitrogen = 70/30% by volume is used. It measured with the specific surface area measuring apparatus (Shimadzu Corporation make, Flowsorb III2305 model).

Reference Example 3 Additive HWE: Montanate ester wax “Licowax E” (manufactured by Clariant Japan)
PX: PX-200 (powdered aromatic condensed phosphate ester, manufactured by Daihachi Chemical Industry Co., Ltd., CAS No.139
189-30-3)
PPE-OIL: OS-124 (manufactured by Monsanto, USA)
Examples 2-4, Comparative Example 1～5,7～ 11
PCM30 (biaxial extruder; manufactured by Ikekai Steel Co., Ltd.) in which the thermoplastic resin of Reference Example 1, the dielectric ceramics shown in Reference Example 2, and the additive of Reference Example 3 were blended in the amounts shown in Table 1 and the head part was removed. The mixture was melted and mixed at the resin temperatures shown in Table 1 to obtain an amorphous composition. Next, the large particles were removed, and after drying for 3 hours in a hot air dryer at 140 ° C., the following evaluation was performed.

Comparative Example 6
A rotary tableting machine manufactured by Tsukishima Machine, blended with the thermoplastic resin of Reference Example 1, the dielectric ceramics shown in Reference Example 2, and the additive of Reference Example 3 in an amount shown in Table 1 using a Henschel mixer and equipped with an automatic feed feeder Was tableted at room temperature to obtain a cylindrical tablet of 6.5 mm diameter × 3.5 mm length. Subsequently, after drying with a hot air dryer at 140 ° C. for 3 hours, the following evaluation was performed.

(1) Dielectric Constant Measurement Using a UH1000 (80t) injection molding machine (manufactured by Nissei Plastic Industry Co., Ltd.), a molded product having a thickness of 80 mm × 30 mm × 1.6 mm was obtained under the temperature conditions of the resin temperature and mold temperature shown in Table 1. Injection molding was performed at a minimum pressure of +5 MPa, and a dielectric constant of 1 GHz was measured by a loss separation method.

(2) Bending strength Using a UH1000 (80t) injection molding machine (manufactured by Nissei Plastic Industry Co., Ltd.), a corner forming shape of 100 × 100 × 3 mm thickness (film gate) under the temperature conditions of resin temperature and mold temperature shown in Table 1 The product was molded at a minimum pressure of +5 MPa, cut into two pieces with a width of 12.7 mm along the flow direction from the center, the bending strength was measured in accordance with ASTM D790, and the average value was calculated.

(3) Low distortion property of molded product Using a UH1000 (80t) injection molding machine (manufactured by Nissei Plastic Industry Co., Ltd.), a rectangular shape having a side and a height of 50 mm under the temperature conditions of the resin temperature and mold temperature shown in Table 1. Using a mold that can wrap a steel prism of 1.5 mm in a sample with a thickness of 1.5 mm, 50 pieces were injection-molded at a minimum pressure of +10 MPa, and the number of cracks caused by strain on the surface of the 50 molded products was evaluated visually. (The smaller the number of cracks due to strain, the better the low distortion property of the molded product).

(4) Heat resistance After 50 pieces of the molded product obtained in the above (3) were heat-treated at 250 ° C. for 3 hours using a perfect oven (PVH-331 manufactured by Espec Corp.), the molded product was taken out from the oven. It was left under an atmosphere of 20 ° C. Thereafter, the number of cracks generated on the surface was visually evaluated for 50 molded products (the smaller the number of cracks generated, the better the heat resistance).

  In Comparative Example 5, the heat resistance was not cracked, but all 50 molded products were deformed.

  As is apparent from the results in Table 1, the dielectric resin composition of the present invention controls the relationship between the particle size of the dielectric ceramic used and the BET specific surface area, By reducing the air gap, it is possible to reduce defects due to distortion of the molded product during molding, and the obtained molded product has a dielectric constant and achieves high mechanical strength and heat resistance. I understand that. In addition, because injection molding is possible, it is possible to expand into the fields of information communication, electrical / electronic parts, automobile parts, etc. that are eagerly desired to replace ceramics for the purpose of miniaturization and productivity improvement. Become.

Claims (3)

(A) at least selected thermoplastic Po Leary sulfide resins 1 0-35 volume% and the resin (b) barium titanate, strontium titanate, neodymium titanate, barium, and strontium titanate, barium / magnesium zirconate 1 type or 2 types or more of dielectric ceramics 90 to 65 % by volume, and (b) the dielectric ceramic has an average particle size of 0.2 to 5.0 μm and a BET specific surface area (m ² / g) of an average particle size The value divided by (μm) is in the range of 2.5 to 40, and (c) at least one selected from fatty acid metal salts, ester compounds, amide group-containing compounds, epoxy compounds, and phosphate esters 1 to 3 parts by weight per 100 parts by weight of the total amount of (a) thermoplastic resin and (b) dielectric ceramic Dielectric resin composition characterized Rukoto. A molded article obtained by injection molding the dielectric resin composition according to claim 1. The molded article according to claim 2, wherein the molded article is an automobile part or an electric / electronic part.