Resin member for electronic devices, resin composition, and electronic device

Abstract

Disclosed is a resin member for electronic devices, the resin member including a matrix resin 1 and dielectric particles that are dispersed in the matrix resin 1. The dielectric particles are aggregate particles 3 which are each aggregate of ferroelectric particles 2. The ferroelectric particles 2 have a particle diameter of 10 nm to 1,000 nm inclusive, and the aggregate particles 3 have a particle diameter of 1 μm to 100 μm inclusive.

Description

Resin member for electronic device, resin composition and electronic device

[0001] The present invention relates to a resin member for electronic devices, a resin composition, and an electronic device.

[0002] Resin compositions used in resin members for electronic devices are required to have high dielectric constants and moldability. Patent Document 1 discloses a resin composition containing barium titanate, a ferroelectric material with a particle size of about several μm and high sphericity, in a polycarbonate resin.

[0003] Japanese Patent Application Laid-Open No. 2021-66831

[0004] When a matrix resin is dispersed with a dielectric having a high dielectric constant, such as a ferroelectric or a paraelectric with a relative dielectric constant of 10 or more, the dielectric particles near the surface are polarized by friction or the like, causing the surface of a resin member for electronic devices to become charged, which poses a problem of making the surface more susceptible to dust adhesion. In particular, when relatively large particles with a particle diameter of 1 μm or more are used, the amount of surface charge tends to increase, and when used in a resin member for electronic devices, there is a problem of making the surface more susceptible to dust adhesion.

[0005] An object of the present invention is to provide a resin member for electronic devices having excellent electrical properties.

[0006] The resin member of the present invention is a resin member for an electronic device, and includes a matrix resin and dielectric particles dispersed in the matrix resin, wherein the dielectric particles are aggregate particles that are aggregates of ferroelectric particles, the particle diameter of the ferroelectric particles is 10 nm or more and 1,000 nm or less, and the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less.

[0007] Another resin member of the present invention is a resin member for an electronic device, comprising: a matrix resin; and dielectric particles dispersed in the matrix resin; the dielectric particles are aggregate particles that are aggregates of paraelectric particles having a relative dielectric constant of 10 or more; the particle diameter of the paraelectric particles is 10 nm or more and 1,000 nm or less; and the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less.

[0008] The resin composition of the present invention is a resin composition comprising a matrix resin and dielectric particles dispersed in the matrix resin, wherein the dielectric particles are aggregate particles that are aggregates of ferroelectric particles, the particle diameter of the ferroelectric particles is 10 nm or more and 1,000 nm or less, and the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less, and the matrix resin contains polyester and carbodiimide.

[0009] Another resin composition of the present invention is a resin composition comprising a matrix resin and dielectric particles dispersed in the matrix resin, wherein the dielectric particles are aggregate particles that are aggregates of paraelectric particles having a relative dielectric constant of 10 or more, the particle diameter of the paraelectric particles is 10 nm or more and 1,000 nm or less, and the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less, and the matrix resin contains polyester and carbodiimide.

[0010] According to the present invention, it is possible to provide a resin member for electronic devices having excellent electrical properties.

[0011] FIG. 1 is a conceptual diagram showing a state in which dielectric particles are dispersed in a matrix resin. FIG. 2 is a conceptual diagram showing a state in which dielectric particles are dispersed in a matrix resin. FIG. 3 is a conceptual diagram showing a state in which primary particles of the dielectric of FIGS. 1A and 1B are polarized. FIG. 4 is a conceptual diagram showing a state in which primary particles of the dielectric of FIGS. 1A and 1B are polarized. FIG. 5 is a schematic diagram for explaining an electronic device of the present embodiment.

[0012] The following describes in detail the embodiments of the present invention. The embodiments of the present invention are merely examples for explaining the present invention, and the present invention is not limited to the following details.

[0013] <<Resin Member for Electronic Device>> A first resin member for electronic device according to this embodiment is a resin member including a matrix resin and dielectric particles dispersed in the matrix resin. The dielectric particles are aggregate particles that are aggregates of ferroelectric particles. The particle diameter of the ferroelectric particles is 10 nm or more and 1,000 nm or less. The particle diameter of the aggregate particles is 1 μm or more and 100 μm or less.

[0014] A second resin member for an electronic device according to this embodiment is a resin member including a matrix resin and dielectric particles dispersed in the matrix resin. The dielectric particles are aggregate particles that are aggregates of paraelectric particles having a relative dielectric constant of 10 or more. The particle diameter of the paraelectric particles is 10 nm or more and 1,000 nm or less. The particle diameter of the aggregate particles is 1 μm or more and 100 μm or less.

[0015] When friction occurs between a resin component for electronic devices and another component, electrons are exchanged between them, and the component that transferred the electrons acquires a positive charge, while the component that received the electrons acquires a negative charge, resulting in a so-called electrified state. Ferroelectrics and paraelectrics with a relative dielectric constant of 10 or more (hereinafter, both may be collectively referred to as "dielectrics"), especially ferroelectrics, have a strong tendency to polarize and retain electric charges internally. Therefore, when a dielectric is included in the material of a resin component for electronic devices, the amount of electrification increases, making it easier for dust to adhere to them.

[0016] 1A and 1B are conceptual diagrams showing a state in which dielectric particles are dispersed in a matrix resin. Fig. 1A shows a state in which dielectric primary particles having a relatively large particle size are dispersed, and Fig. 1B shows a state in which dielectric primary particles having a relatively small particle size are aggregated and dispersed as aggregate particles (secondary particles) having approximately the same particle size as the particles in Fig. 1A. In Fig. 1A and 1B, 1 is the matrix resin, 2 is the dielectric primary particles, and 3 is the aggregate particles.

[0017] 2A and 2B are conceptual diagrams showing a polarized state of the dielectric primary particles 2 in Fig. 1A and Fig. 1B. Fig. 2A shows a polarized state of the dielectric primary particles 2 in Fig. 1A, and Fig. 2B shows a polarized state of the dielectric primary particles 2 in Fig. 1B. In Fig. 2A and Fig. 2B, the charged state of the dielectric primary particles 2 is shown by shading.

[0018] 1A, when the particle diameter of the dielectric primary particles 2 is relatively large, the amount of charge per particle increases in proportion to the volume of the particle. When these dielectric primary particles 2 are dispersed in a matrix resin 1 and are present in the vicinity of the surface of a resin member for an electronic device, the amount of charge on the surface of the resin member for an electronic device increases, and the amount of dust that adheres to the surface also increases.

[0019] In contrast to this, in this embodiment, the dielectric particles in the resin member for electronic devices are formed by aggregating dielectric primary particles 2 having a relatively small particle diameter as shown in Fig. 1B to form aggregate particles 3. In this case, the amount of charge on the surface of the resin member for electronic devices is smaller than that of dielectric primary particles 2 having approximately the same particle diameter as that of aggregate particles 3, and the amount of dust adhesion is suppressed.

[0020] This is thought to be due to the following. That is, in the case of primary particles with a relatively large particle size as shown in FIG. 1A, polarization occurs throughout the particle as shown in FIG. 2A, resulting in a large amount of charge. On the other hand, when primary particles with a relatively small particle size aggregate to form large aggregate particles as shown in FIG. 1B, the result is an aggregate of polarized individual primary particles as shown in FIG. 2B. Therefore, only the primary particles exposed on the surface of a resin member for electronic devices affect the amount of charge on the surface. As a result, in this embodiment, it is thought that the amount of dust adhesion is suppressed. Charging property is one of the electrical properties of a resin member and can be controlled by the shape of the dielectric particles.

[0021] Furthermore, since the dielectric particles are in an aggregated state and the aggregate particles have a particle size of a certain level or more, the interface area between the matrix resin and the dielectric particles does not become excessively large, and the increase in viscosity is kept low, thereby maintaining good moldability.

[0022] Furthermore, aggregate particles are more advantageous in terms of electromagnetic shielding properties. A parameter known as the dielectric loss tangent is an index related to electromagnetic shielding properties. Compared to the case of FIG. 1A, the dielectric loss tangent is higher in the case of FIG. 1B. The dielectric loss tangent is a parameter that represents the amount of energy that is converted into heat and lost when radio waves resonate with a dielectric, and the larger this value is, the better the electromagnetic shielding properties are. Electromagnetic shielding properties are one of the electrical properties of resin components, and can be controlled by the shape of the dielectric particles.

[0023] <<Method for manufacturing a resin member for an electronic device>> <Resin composition> First, a resin composition that can be used to manufacture a resin member for an electronic device of this embodiment will be described. The resin composition of this embodiment contains a matrix resin and dielectric particles. The resin composition of this embodiment may further contain an elastomer, and may also contain filler particles other than the dielectric particles that are primarily composed of an inorganic material.

[0024] [Matrix Resin] The matrix resin may be any polymer having a repeating structure, and includes thermoplastic resins and thermosetting resins. Thermoplastic resins are preferred.

[0025] Examples of thermoplastic resins include polyethylene, polystyrene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethersulfone, acrylonitrile-styrene resin, acrylonitrile-butadiene-styrene resin, acrylic resin, polycarbonate, polyetherimide, polyetheretherketone, polyacetal, polyphenylene oxide, and polyphenylene sulfide.

[0026] Examples of thermosetting resins include epoxy resins, unsaturated polyester resins, and vinyl ester resins.

[0027] The matrix resin is preferably a polar polymer, which is a resin with intramolecular polarization and can be oriented in the opposite direction to the polarization of the dielectric particles, thereby reducing charging.

[0028] Polar polymers are polymers containing polar groups, such as amide groups, imide groups, carbonyl groups (ketone groups), and ester bonds, in their main chains. Polar polymers are generally referred to as general-purpose engineering plastics or super engineering plastics, and are used in applications requiring higher physical properties, such as heat resistance and strength, than general-purpose resins such as polyethylene and polypropylene. Furthermore, if the mechanical properties can be improved, molded products can be made thinner and lighter, so further improvements in the physical properties of polar polymers are expected.

[0029] Specific examples of polar polymers include polymers having an amide group, such as polyamide and polyamideimide. Polymers having an imide group, such as polyimide, polyamideimide, and polyetherimide. Polymers having a carbonyl group (ketone group), such as polyetherketone and polyetheretherketone. Polymers having an ester bond, such as polyarylate, polycarbonate, and polyester. Polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate.

[0030] Among thermoplastic resins, it is preferable to use a crystalline polymer as the matrix resin. Since the molecules of a crystalline polymer are oriented in a specific direction, the polarization within the molecules is greater than in an amorphous state, which can alleviate the polarization of the dielectric particles. Furthermore, crystalline polymers are advantageous over amorphous polymers in that they have superior hardness, elasticity, and rigidity. Among the polar polymers mentioned above, examples of crystalline polymers include polyamide, polyether ketone, polyether ether ketone, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate. Among polyesters, polyarylate and polycarbonate are amorphous polymers. As the polar polymer, polyester is preferable, and polyethylene terephthalate is more preferable. Polyethylene terephthalate is a polar polymer as well as a crystalline polymer, and because molecular orientation is likely to occur, it can more effectively alleviate the polarization of the dielectric particles. Furthermore, CO during the production of polyethylene terephthalate is used. ２ CO emissions during polycarbonate production ２ The use of polyethylene terephthalate reduces CO emissions ２ The degree of crystallinity of the crystalline polymer is, for example, 1 to 50%, preferably 1 to 40%. The degree of crystallinity can be controlled by the molding conditions (temperature and pressure).

[0031] The matrix resin may also be a polar polymer crosslinked using a crosslinking agent. Examples of crosslinking agents include compounds that undergo a crosslinking reaction when heated, such as carbodiimide crosslinking agents, oxazoline crosslinking agents, epoxy crosslinking agents, and isocyanate crosslinking agents. The polar polymer may also be a recycled polymer, for example, obtained by recovering used polymers with reduced molecular weight and re-crosslinking the used polymers with a crosslinking agent to increase their molecular weight. Polyethylene terephthalate, which is widely produced and used, is a suitable used polymer and recycled polymer.

[0032] The carbodiimide crosslinking agent in this embodiment is a compound having at least one carbodiimide group in the molecule, and can be produced, for example, by heating an organic isocyanate in the presence of a suitable catalyst and subjecting it to a decarboxylation reaction. The carbodiimide group is represented by (-N=C=N-). In a matrix resin using a carbodiimide crosslinking agent, the carbodiimide group derived from the carbodiimide crosslinking agent is present as part of the polymer.

[0033] Examples of the carbodiimide crosslinking agent include diphenylcarbodiimide, dicyclohexylcarbodiimide, di-2,6-dimethylphenylcarbodiimide, diisopropylcarbodiimide, dioctyldecylcarbodiimide, di-o-toluylcarbodiimide, di-p-toluylcarbodiimide, di-p-nitrophenylcarbodiimide, di-p-aminophenylcarbodiimide, di-p-hydroxyphenylcarbodiimide, di-p-chlorophenylcarbodiimide, di-o-chlorophenylcarbodiimide, di-3,4-dichlorophenylcarbodiimide, Nylcarbodiimide, di-2,5-dichlorophenylcarbodiimide, p-phenylene-bis-o-toluylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, p-phenylene-bis-di-p-chlorophenylcarbodiimide, 2,6,2',6'-tetraisopropyldiphenylcarbodiimide, hexamethylene-bis-cyclohexylcarbodiimide, ethylene-bis-diphenylcarbodiimide, ethylene-bis-di-cyclohexylcarbodiimide, N,N'-di-o-tolylcarbodiimide, N,N'-di phenylcarbodiimide, N,N'-dioctyldecylcarbodiimide, N,N'-di-2,6-dimethylphenylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N,N'-di-2,6-diisopropylphenylcarbodiimide, N,N'-di-2,6-di-tert-butylphenylcarbodiimide, N-toluyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di-p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, N,N'-di-p-toluylcarbodiimide, N,N'-benzylcarbodiimide, N-octadecyl-N'-phenylcarbodiimide, N-benzyl-N'-phenylcarbodiimide, N-octadecyl-N'-tolylcarbodiimide, N-cyclohexyl-N'-tolylcarbodiimide, N-phenyl-N'-tolylcarbodiimide, N-benzyl-N'-tolylcarbodiimide, N,N'-di-o-ethylphenylcarbodiimide, N,N'-di-p-ethylphenylcarbodiimide, N,Mono- or dicarbodiimide compounds such as N'-di-o-isopropylphenylcarbodiimide, N,N'-di-p-isopropylphenylcarbodiimide, N,N'-di-o-isobutylphenylcarbodiimide, N,N'-di-p-isobutylphenylcarbodiimide, N,N'-di-2,6-diethylphenylcarbodiimide, N,N'-di-2-ethyl-6-isopropylphenylcarbodiimide, N,N'-di-2-isobutyl-6-isopropylphenylcarbodiimide, N,N'-di-2,4,6-trimethylphenylcarbodiimide, N,N'-di-2,4,6-triisopropylphenylcarbodiimide, and N,N'-di-2,4,6-triisobutylphenylcarbodiimide; Examples of polycarbodiimides include poly(4,4'-methylenebiscyclohexylcarbodiimide), poly(1,3-cyclohexylenecarbodiimide), poly(1,4-cyclohexylenecarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(3,3'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(tolylcarbodiimide), poly(diisopropylcarbodiimide), poly(methyl-diisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide).

[0034] The oxazoline crosslinking agent in this embodiment is a compound having an oxazoline group in the molecule. In particular, a polymer synthesized using a monomer containing an oxazoline compound as at least one of the raw material monomers is preferred. Examples of oxazoline compounds include 2-oxazoline, 3-oxazoline, and 4-oxazoline compounds. Any of these may be used, but 2-oxazoline compounds are particularly highly reactive and have been industrially put into practical use. Examples of oxazoline compounds include 2-vinyl-2-oxazoline, 5-methyl-2-vinyl-2-oxazoline, 4,4-oxazoline, 4,4-dimethyl-2-vinyl-5,6-dihydro-4H-1,-oxazine, 4,4,6-trimethyl-2-vinyl-5,6-dihydro-4H-1,3-oxazine, 2-isopropenyl-2-oxazoline, 4,4-dimethyl-2-isopropenyl-2-oxazoline, and 4-acryloyl-oxymethyl-2,4-dimethyl. 4-(4-vinylphenyl)-2-oxazoline, 4-methacryloyl-oxymethyl-2,4-dimethyl-2-oxazoline, 4-methacryloyl-oxymethyl-2-phenyl-4-methyl-2-oxazoline, 2-(4-vinylphenyl)-4,4-dimethyl-2-oxazoline, 4-ethyl-4-hydroxymethyl-2-isopropenyl-2-oxazoline, 4-ethyl-4-carbethoxymethyl-2-isopropenyl-2-oxazoline, and the like, but are not limited thereto.

[0035] As the epoxy-based crosslinking agent in this embodiment, for example, a glycidyl ether compound, a glycidyl ester compound, a glycidyl amine compound, a glycidyl imide compound, an alicyclic epoxy compound, or the like can be preferably used.

[0036] Examples of the glycidyl ether compound include butyl glycidyl ether, stearyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, o-phenylphenyl glycidyl ether, ethylene oxide lauric alcohol glycidyl ether, ethylene oxide phenol glycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether. Examples of suitable epoxy resins include bisphenol A diglycidyl ether epoxy resins, bisphenol F diglycidyl ether epoxy resins, and bisphenol S diglycidyl ether epoxy resins obtained by condensation reaction of epichlorohydrin with bisphenols such as cyclohexanedimethanol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol polyglycidyl ether, 2,2-bis-(4-hydroxyphenyl)propane, 2,2-bis-(4-hydroxyphenyl)methane, and bis(4-hydroxyphenyl)sulfone. Among these, bisphenol A diglycidyl ether epoxy resins are preferred.

[0037] Examples of the glycidyl ester compound include benzoic acid glycidyl ester, p-toluic acid glycidyl ester, cyclohexanecarboxylic acid glycidyl ester, stearic acid glycidyl ester, lauric acid glycidyl ester, palmitic acid glycidyl ester, versatic acid glycidyl ester, oleic acid glycidyl ester, linoleic acid glycidyl ester, linolenic acid glycidyl ester, terephthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, phthalic acid diglycidyl ester, naphthalenedicarboxylic acid diglycidyl ester, and the like. Examples of suitable glycidyl esters include glycidyl esters of benzoic acid, diglycidyl esters of methyl terephthalic acid, diglycidyl esters of hexahydrophthalic acid, diglycidyl esters of tetrahydrophthalic acid, diglycidyl esters of cyclohexanedicarboxylic acid, diglycidyl esters of adipic acid, diglycidyl esters of succinic acid, diglycidyl esters of sebacic acid, diglycidyl esters of dodecanedioic acid, diglycidyl esters of octadecanedicarboxylic acid, triglycidyl esters of trimellitic acid, and tetraglycidyl esters of pyromellitic acid. Of these, glycidyl esters of benzoic acid and glycidyl esters of versatic acid are preferred.

[0038] Examples of the glycidyl amine compound include tetraglycidylaminodiphenylmethane, triglycidyl-paraaminophenol, triglycidyl-metaaminophenol, diglycidyl aniline, diglycidyl toluidine, tetraglycidyl meta-xylenediamine, diglycidyl tribromoaniline, tetraglycidyl bisaminomethylcyclohexane, triglycidyl cyanurate, and triglycidyl isocyanurate. Examples of the glycidyl imide compound include N-glycidyl phthalimide, N-glycidyl-4-methylphthalimide, N-glycidyl-4,5-dimethylphthalimide, N-glycidyl-3-methylphthalimide, N-glycidyl-3,6-dimethylphthalimide, N-glycidyl-4-ethoxyphthalimide, N-glycidyl-4-chlorophthalimide, N-glycidyl-4,5-dichlorophthalimide, N-glycidyl-3,4,5,6-tetrabromophthalimide, and N-glycidyl-4-n-butyl-5- Examples of such an alkyl ester include bromophthalimide, N-glycidyl succinimide, N-glycidyl hexahydrophthalimide, N-glycidyl-1,2,3,6-tetrahydrophthalimide, N-glycidyl maleinimide, N-glycidyl-α,β-dimethylsuccinimide, N-glycidyl-α-ethylsuccinimide, N-glycidyl-α-propylsuccinimide, N-glycidyl benzamide, N-glycidyl-p-methylbenzamide, N-glycidyl naphthamide, and N-glycidyl steramide. Of these, N-glycidyl phthalimide is preferred.

[0039] Examples of the alicyclic epoxy compound include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, vinylcyclohexene diepoxide, N-methyl-4,5-epoxycyclohexane-1,2-dicarboxylic acid imide, N-ethyl-4,5-epoxycyclohexane-1,2-dicarboxylic acid imide, N-phenyl-4,5-epoxycyclohexane-1,2-dicarboxylic acid imide, N-naphthyl-4,5-epoxycyclohexane-1,2-dicarboxylic acid imide, and N-tolyl-3-methyl-4,5-epoxycyclohexane-1,2-dicarboxylic acid imide.

[0040] Other epoxy compounds that can be used include epoxy-modified fatty acid glycerides such as epoxidized soybean oil, epoxidized linseed oil, and epoxidized whale oil, phenol novolac epoxy resins, and cresol nosolac epoxy resins.

[0041] The isocyanate crosslinking agent used in this embodiment is not particularly limited as long as it has an isocyanate group as a functional group in the compound, and known polyisocyanate crosslinking agents can be used. Specifically, commonly used water-dispersible polyisocyanate crosslinking agents can be used. Water-dispersible polyisocyanate crosslinking agents are polyisocyanate polymers with hydrophilic groups introduced therein, and when added to water and stirred, they can be dispersed in water as fine particles.

[0042] Examples of polyisocyanates constituting the water-dispersible polyisocyanate include aliphatic isocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, lysine diisocyanate, and dimer acid diisocyanate; tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether isocyanate, and (m- or p-)phenylene diisocyanate. Examples of the isocyanate include aromatic polyisocyanates such as 4,4'-biphenylene diisocyanate, 3,3'-biphenylene diisocyanate, bis(4-isocyanatophenyl)sulfone, and isopropylidenebis(4-phenylisocyanate); and alicyclic diisocyanate compounds such as hydrogenated xylylene diisocyanate, isophorone diisocyanate, 4,4'-methylenebis(cyclohexylisocyanate), methylcyclohexane-2,4-(or -2,6-)diisocyanate, 1,3-(or 1,4-)di(isocyanatomethyl)cyclohexane, 1,4-cyclohexane diisocyanate, 1,3-cyclopentane diisocyanate, and 1,2-cyclohexane diisocyanate. As such a polyisocyanate compound, a polyisocyanate compound having an isocyanurate structure, a urethane structure, a biuret structure, an allophanate structure, a uretdione structure, a trimer structure, etc. A so-called blocked isocyanate in which an isocyanate group is blocked with an active hydrogen group may also be used.

[0043] The matrix resin is preferably formed from one of these polar polymers or a mixture of these.

[0044] [Dielectrics (Ferroelectrics and Paraelectrics with a Relative Dielectric Constant of 10 or More)] The ferroelectric is not particularly limited as long as it exhibits ferroelectricity. Ferroelectrics typically have a perovskite structure, but may also be tetragonal or rhombohedral crystals (rhombohedral). Examples of ferroelectrics include titanate compounds such as barium titanate, bismuth titanate, lead titanate, lead zirconate titanate, and lead lanthanum zirconate titanate, as well as bismuth ferrate (bismuth ferrite), strontium bismuth tantalate, and strontium bismuth niobate. Titanate compounds in which titanium is substituted with homologous elements such as Hf or Zr, and barium titanate in which Ba is substituted with homologous elements such as Ca or Sr, may also be used. It is also known that orthorhombic hafnium oxide exhibits ferroelectricity. Among these, titanate compounds are preferred due to their high relative dielectric constant, and barium titanate is more preferred. Ferroelectrics may be used alone or in combination of two or more.

[0045] Alternatively, the ferroelectric particles may have a core-shell structure having two phases: a core made of a crystal with a high dielectric constant and a shell surrounding the core and having a relatively low dielectric constant. For example, the ferroelectric particles may have a core-shell structure having a core made of a crystal of barium titanate and a shell containing a rare earth element such as dysprosium (Dy) or holmium (Ho).

[0046] Examples of paraelectrics having a relative dielectric constant of 10 or more include titanium oxide (titania), zirconium oxide (zirconia), hafnium oxide (hafnia), yttrium oxide (yttria), lanthanum oxide, cerium oxide (ceria), tantalum oxide, niobium oxide, zinc titanate, magnesium titanate, strontium titanate, calcium titanate, calcium zirconate, etc. The relative dielectric constant of the paraelectrics is preferably 50 or more, more preferably 100 or more, even more preferably 500 or more, and still more preferably 1,000 or more.

[0047] The particle diameter (primary particle diameter) of the ferroelectric particles (primary particles) and the paraelectric particles (primary particles) having a relative dielectric constant of 10 or more is preferably 10 nm or more and 1,000 nm or less. If the particle diameter of the dielectric primary particles is greater than 1,000 nm, the amount of charge within the particles increases, resulting in a large amount of charge on the surface of the resin component for electronic devices. Therefore, the particle diameter of the dielectric primary particles is preferably 1,000 nm or less. A particle diameter of the dielectric primary particles of 300 nm or less reduces the amount of charge, further suppressing dust adhesion, which is more preferable. Furthermore, if the particle diameter of the dielectric primary particles is smaller than 10 nm, the cohesive force between the particles increases, and when aggregate particles are formed, charge exchange occurs between the particles, resulting in a large amount of charge across the aggregate particles and a large amount of charge on the surface of the resin component for electronic devices. Therefore, the particle diameter of the dielectric primary particles is preferably 10 nm or more. It is more preferable that the particle diameter of the primary particles of the dielectric material is 50 nm or more, since the cohesive force between the particles is reduced and the particle diameter is more easily controllable.

[0048] The dielectric is preferably in an aggregated state. Furthermore, the particle diameter (secondary particle diameter) of the aggregate particles (secondary particles) is preferably 1 μm or more and 100 μm or less. If the particle diameter of the aggregate particles is less than 1 μm, the surface area of ​​the aggregate particles increases, the area of ​​the interface with the matrix resin increases, and the melt viscosity increases, making it difficult to obtain good moldability. Therefore, the particle diameter of the aggregate particles is preferably 1 μm or more. If the particle diameter of the aggregate particles is 5 μm or more, better fluidity is obtained, which is more preferable. Furthermore, if the particle diameter of the aggregate particles is 5 μm or more, complex charge interference occurs between the dielectric particles within the aggregate particles, resulting in a high dielectric loss tangent and improved electromagnetic shielding properties, which is more preferable. On the other hand, if the particle diameter of the aggregate particles is greater than 100 μm, the surface properties deteriorate due to the influence of the aggregate particles, making it difficult to obtain good moldability. Therefore, the particle diameter of the aggregate particles is preferably 100 μm or less. If the particle size of the aggregate particles is 50 μm or less, the surface properties become even better, which is more preferable.

[0049] The shape of the aggregate particles is not particularly limited, but is preferably scaly. When the aggregate particles are scaly, they function as a crystal nucleating agent or crystallization promoter, promoting crystallization of the matrix resin around the aggregate particles. As a result, within a resin component for an electronic device, there are portions where crystallization is promoted and portions where crystallization is not promoted. Because the portions where crystallization is promoted and the portions where crystallization is not promoted have different elastic moduli, if a small amount of aggregate particles are present unevenly, when vibration occurs, uneven deformation occurs, resulting in energy loss due to shear friction and improving vibration damping.

[0050] The aspect ratio of the aggregate particles is preferably 3 or more and 20 or less. If the aspect ratio of the aggregate particles is less than 3, the aggregate particles may be more likely to be exposed to the surface during molding, which may increase the amount of surface charge. Furthermore, since the amount of surface charge decreases, the aspect ratio of the aggregate particles is preferably 5 or more. On the other hand, if the aspect ratio of the aggregate particles exceeds 20, the surface properties may be deteriorated due to the influence of the aggregate particles, which may make it difficult to obtain good moldability. Furthermore, since the surface properties are improved, the aspect ratio of the aggregate particles is preferably 10 or less.

[0051] The number of aggregate particles per unit area is 1 particle / mm ２ More than 100 pieces / mm ２ The number of aggregate particles per unit area is preferably 1 / mm or less. ２ On the other hand, if the number of aggregate particles per unit area is less than 100 particles / mm ２ Above this value, there may be an increase in the number of dielectric particles near the surface, which may increase the surface charge, and therefore dust adsorption may increase.

[0052] The particle size of the primary particles of the dielectric, the particle size of the aggregate particles, the aspect ratio of the aggregate particles, and the number of aggregate particles may be measured by, for example, the following methods.

[0053] That is, a transverse cross-sectional sample is prepared from the resin member for electronic devices of this embodiment by pre-processing such as cross-sectional polishing, microtome, or ion milling. Ion milling is preferable because it provides a high level of cross-sectional smoothness and prevents particles from falling off. If the sample temperature rises due to processing, cooling such as cryo-processing may be performed.

[0054] Thereafter, observation is performed using a scanning electron microscope (SEM) under the conditions shown below to obtain a cross-sectional SEM image. It is preferable to use different observation magnifications depending on the particle diameter. For example, when the particle diameter is 100 nm or less, observation is performed at a magnification of 50,000 times, when the particle diameter is greater than 100 nm, observation is performed at a magnification of 10,000 times, and when the particle diameter is greater than 10 μm, observation is performed at a magnification of 1,000 times.

[0055] The obtained SEM image is binarized and image analyzed under the conditions shown below to determine the median diameter of the dielectric particles in an arbitrary region of the cross section of a resin member for electronic devices. The arbitrary region of the cross section of a resin member for electronic devices can be, for example, a quadrilateral region with adjacent sides of lengths L and M. The lengths L and M are, for example, 5 μm or more, preferably 10 μm or more, and are, for example, 500 μm or less, for example, 100 μm or less. The lengths L and M may be the same or different, and the ratio of the length L to the length M may be 0.5 or more and 2 or less. The binarization and image analysis of the SEM image are performed using the image processing software ImageJ (available from https: / / imagej.nih.gov / ij / ) of the National Institutes of Health.

[0056] [Conditions] {Device name} Schottky field emission scanning electron microscope JSM-F100 (manufactured by JEOL Ltd.)

[0057] {Accelerating voltage} 3 kV

[0058] {Magnification} 10,000x or 1,000x

[0059] {Measurement range} 12.8 μm x 9.6 μm (10,000 times magnification) or 128 μm x 96 μm (1,000 times magnification)

[0060] {Number of evaluations} 10 areas / sample

[0061] {Binarization and Image Analysis} ImageJ

[0062] {Binarization method} MaxEntropy (the threshold value is appropriately adjusted so that the dielectric particles can be separated by binarization. If binarization cannot be performed using image processing software, an image is prepared in which only the dielectric particles are visually filled in using paint software or the like.)

[0063] {Method of calculating particle diameter} The length at the position where the particle diameter of the aggregate particle is maximum was defined as the major axis, and the length at the position where the length in the direction perpendicular to the major axis is maximum was defined as the minor axis, and the particle diameter of each particle was calculated as (major axis + minor axis) / 2.

[0064] The median (median diameter; 50% particle diameter) was used as the representative value (statistical value) of the particle diameter. Alternatively, the average (average particle diameter) or the mode (mode diameter) can also be used as the representative value of the particle diameter.

[0065] {How to calculate aspect ratio} Major axis / minor axis (mass average value)

[0066] {Method for calculating the number of aggregate particles per unit area} From the binarized image, a group of primary particles of the contacting dielectric was determined to be one aggregate particle, and the number of aggregate particles was counted from the observed image. The value obtained by dividing the count by the observed area was taken as the number of aggregate particles per unit area.

[0067] The content of the dielectric particles is preferably 0.1% by mass or more and 30% by mass or less. If the content of the dielectric particles is less than 0.1% by mass, the dielectric loss tangent is low and it may be difficult to exhibit electromagnetic shielding properties. If the content of the dielectric particles is 1% by mass or more, the dielectric loss tangent increases and even better electromagnetic shielding properties are exhibited, which is more preferable. On the other hand, if the content of the dielectric particles is more than 30% by mass, the number of dielectric particles near the surface may increase, which may increase the surface charge and increase dust adsorption. If the content of the dielectric particles is 10% by mass or less, the amount of dust adsorption is reduced, which is more preferable.

[0068] [Elastomer Material] It is known that adding an elastomer material to a resin improves impact strength. Therefore, in this embodiment, an elastomer material may be contained to further improve impact strength. The content of the elastomer material is preferably 30% by mass or less. The elastomer material is a copolymer consisting of a combination of hard segments that act as crosslinking points and soft segments that exhibit rubber elasticity, and is preferably a thermoplastic elastomer that combines the properties of both plastic and rubber.

[0069] Examples of the elastomer material include urethane elastomers, ester elastomers, amide elastomers, acrylic elastomers, olefin elastomers, styrene elastomers, etc. The elastomer material is preferably an acrylic elastomer or an ester elastomer.

[0070] Examples of urethane elastomers include elastomers in which the hard segment is polyurethane containing urethane groups and the soft segment is polyester containing ester bonds or polyether containing ether bonds. Note that the urethane groups and ester bonds have polarity.

[0071] Examples of ester-based elastomers include elastomers in which the hard segment is a polyester containing an ester bond and the soft segment is a polyester containing an ester bond or a polyether containing an ether bond. Note that the ester bond has polarity.

[0072] Examples of amide elastomers include elastomers in which the hard segment is a polyamide containing an amide group and the soft segment is a polyester containing an ester bond or a polyether containing an ether bond. Note that the amide group and the ester bond have polarity.

[0073] Examples of acrylic elastomers include elastomers in which the hard segment is polymethyl methacrylate, a polymer of methyl methacrylate having an ester bond, and the soft segment is a copolymer of butyl acrylate, 2-ethylhexyl acrylate, or the like, having an ester bond. Also included are elastomers in which the hard segment is a polyolefin such as polyethylene, and the soft segment is polymethyl methacrylate, a polymer of methyl methacrylate having an ester bond. The ester bond has polarity.

[0074] Examples of olefin-based elastomers include elastomers in which the hard segment is a polyolefin such as polypropylene or polyethylene, and the soft segment is an ethylene propylene rubber or ethylene propylene diene rubber.

[0075] Examples of styrene-based elastomers include elastomers in which the hard segment is polystyrene and the soft segment is butadiene, isoprene, ethylene, or the like.

[0076] When the matrix resin is a polar polymer, the elastomer material preferably has a polar group from the viewpoint of affinity with the matrix resin. Examples of the polar group that the elastomer material has include a urethane group, an amide group, and an ester bond. In particular, the elastomer material preferably has an ester bond in either or both of the hard segment and the soft segment.

[0077] The polar groups such as ester bonds in elastomer materials provide heat resistance, making them suitable for melt-mixing with polar polymers, especially those with high heat resistance. Furthermore, elastomer materials with ester bonds have relatively high mechanical properties, contributing to improved physical properties.

[0078] The elastomer material has a glass transition temperature lower than room temperature, so that it functions as an elastomer at room temperature. The glass transition temperature of the elastomer material is preferably lower than 0°C, and more preferably -20°C or lower.

[0079] Impact strength is improved by melt-kneading an elastomer material with a thermoplastic matrix resin in a molten state and finely dispersing the elastomer particles in the matrix resin. Therefore, to enable melt-kneading with the matrix resin, the melting point of the elastomer material is preferably lower than the heating temperature (molding temperature) of the resin composition. The heating temperature of the resin composition is the temperature at which the thermoplastic matrix resin melts, and is higher than the glass transition point of the matrix resin. If the matrix resin is a crystalline polymer, it is preferably higher than the melting point of the matrix resin. Therefore, the melting point of the elastomer material is preferably lower than the melting point of the matrix resin. While the melting point of the elastomer material may be higher than the melting point of the matrix resin, this may cause thermal degradation, such as a decrease in the molecular weight of the matrix resin due to heating the matrix resin to melt the elastomer material. When the matrix resin is a crystalline polymer, the melting point of the elastomer material may be higher than the glass transition point of the matrix resin. When the matrix resin is an amorphous polymer, the melting point of the matrix resin is not defined, so the melting point of the elastomer material is preferably lower than the glass transition point of the matrix resin.

[0080] The glass transition point of the matrix resin is preferably 50°C or higher to ensure strength during use, and also preferably 200°C or lower in consideration of processability. The melting point of the matrix resin is preferably 100°C or higher, and preferably 200°C or higher in consideration of heat resistance, and preferably 300°C or lower in consideration of processability. The melting point of the elastomer material is preferably 50°C or higher to ensure strength during use, and preferably 300°C or lower, and preferably 200°C or lower in consideration of processability.

[0081] Elastomer materials, possessing rubber elasticity, i.e., flexibility, contribute to improving the impact strength of matrix resins. When impact is applied to a molded article obtained by molding a resin composition containing an elastomer, the matrix resin orients around the elastomer particles, forming crazes, thereby more efficiently absorbing the impact. Therefore, it is preferable that a large number of elastomer particles are finely dispersed. For this reason, the particle diameter of the elastomer particles is preferably 10 μm or less, more preferably 5 μm or less. To ensure efficient mechanical function of the elastomer particles, the particle diameter of the elastomer particles is preferably 0.1 μm or more, more preferably 0.5 μm or more. Elastomer particles are typically formed by dispersing and mixing by melt-kneading, and the particle diameter of such elastomer particles can be referred to as the dispersed particle diameter or dispersed particle size. The particle diameter can be measured, for example, by a method similar to that used to measure the particle diameter of dielectric particles.

[0082] [Filler Particles] Addition of filler particles to a resin is known to improve mechanical properties such as flexural modulus. Therefore, in this embodiment, filler particles composed primarily of an inorganic material other than dielectric particles may be contained to further improve flexural modulus and impact strength. The relative dielectric constant of the inorganic material is preferably less than 10. The content of the filler particles is preferably 40% by mass or less. The shape of the filler particles may be spherical (e.g., spherical or oblate spheroidal), polyhedral, irregular, plate-like, scaly, needle-like, or fibrous. The length of the needle-like or fibrous filler particles is, for example, 100 μm or less, preferably 30 μm or less, and more preferably 10 μm or less.

[0083] Filler particles primarily composed of an inorganic material are not particularly limited, and examples thereof include particles such as mica, glass fiber, glass spheres, zinc oxide, calcium carbonate, clays, talc, silicon oxide (silica), wollastonite, forsterite, zeolite, diatomaceous earth, silica sand, fly ash, pumice powder, slate powder, aluminum oxide (alumina), alumina white, aluminum sulfate, carbon fiber, carbon nanotubes, metal fiber, barium sulfate, calcium sulfate, molybdenum disulfide, shirasu balloons, and fly ash balloons.

[0084] The filler particles may have a base made of an inorganic material that is the main component of the filler particles, and a surface layer made of an organic or inorganic material that covers the base. The thickness of the surface layer is, for example, 100 nm or less, preferably 10 nm or less. In filler particles whose main component is an inorganic material, the volume occupied by the inorganic material is larger than the volume occupied by the organic material, preferably 90 volume % or more.

[0085] When an impact is applied to a molded article containing elastomer particles, the matrix resin orients around the elastomer particles, forming crazes, thereby more efficiently absorbing the impact. In this case, the filler particles preferably have a small particle size to avoid a decrease in impact strength due to material defects in the filler particles. If the filler particles are large and coarse, they may act as stress concentration points, reducing impact strength and causing cracks to propagate. On the other hand, in the resin composition production process, it is preferable to avoid poor dispersion due to particle aggregation caused by small particle sizes in order to thoroughly disintegrate and disperse the particles. If the filler particles are fine particles with a small particle size, particle aggregation may make it difficult to disperse the filler particles in the resin composition production process. As a result, material defects due to particle aggregation may occur, leading to a decrease in impact strength and the propagation of cracks.

[0086] For this reason, the particle diameter of the independently dispersed filler particles is, for example, 10 μm or less, preferably 5 μm or less, and more preferably 2 μm or less. When the particle diameter of the filler particles is 10 μm or less, the decrease in impact strength due to the addition of the filler particles can be effectively suppressed. Furthermore, when the particle diameter is 0.2 μm or more, the filler particles can be effectively finely dispersed in the matrix resin, thereby suppressing the decrease in impact strength. For this reason, the particle diameter of the filler particles is preferably 0.2 μm or more and 10 μm or less, more preferably 0.2 μm or more and 5 μm or less, and even more preferably 0.2 μm or more and 2 μm or less. The resin composition may contain filler particles having a particle diameter exceeding 10 μm. The particle diameter of filler particles having a particle diameter exceeding 10 μm is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. The particle diameter can be measured, for example, by the same method as that for the particle diameter of the dielectric particles.

[0087] The filler particles preferably have a substrate surface-treated with a surface treatment agent such as a coupling agent or a fatty acid. Surface-treated filler particles may be commercially available products that have already been surface-treated, or a separate surface treatment step may be included during the production of the resin composition. The amount of surface treatment agent used can be calculated from the specific surface area of ​​the filler particles to be treated and the minimum coverage area of ​​the surface treatment agent. When using filler particles with a small particle size, the specific surface area of ​​the filler particles increases, inevitably resulting in a larger amount of surface treatment agent used. For this reason, the amount of surface treatment agent used varies, and it is generally added in the range of 0.5% to 5% by mass relative to the filler particles. Treatment methods can be known, such as dry treatment methods such as integral blending or wet treatment methods using an aqueous solution of the surface treatment agent. The surface layer formed by the surface treatment constitutes part of the filler particles.

[0088] Examples of surface treatment agents include silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, and 3-trimethoxysilylpropylsuccinic anhydride. Titanate-based and aluminate-based coupling agents may also be used. Fatty acids include lauric acid, stearic acid, and oleic acid. Among these, silane coupling agents are preferred. These surface treatment agents may be used alone or in combination.

[0089] [Other Components] The resin composition of this embodiment may contain various other additives as needed. The type of additive is not particularly limited as long as it is one commonly used in compounding thermoplastic resins and thermoplastic elastomer materials. Examples of additives that improve functionality include flame retardants, waxes, lubricants and release agents such as various fatty acids, fatty acid amides, fatty acid esters, and metal salts of fatty acids, various antistatic agents, fatty acid esters, sliding property improvers such as polyolefins, olefin copolymer elastomers, and polysiloxanes, decomposition inhibitors such as polyamide resins and acrylamide polymers, amide compounds, amino-substituted triazine compounds and their derivatives, urea and its derivatives, hydrazine derivatives, imidazole compounds, imide compounds, and epoxy compounds, formic acid scavengers such as melamine, alkali metal hydroxides, and carbonates, and flame retardants such as organophosphorus compounds. Examples of additives that improve long-term stability include ultraviolet absorbers such as benzotriazole compounds, benzophenone compounds, and phenyl salicylate compounds, hindered amine light stabilizers, and hindered phenol antioxidants. The above additives may be used in combination of one or more.

[0090] The resin composition of the present embodiment may contain at least one of a metal material containing a transition metal element, a compound material containing a transition metal element, a metal material containing a typical metal element, and a compound material containing a typical metal element, other than the dielectric particles.

[0091] Examples of transition metal elements include titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr), niobium (Nb), molybdenum (Mo), hafnium (Hf), tantalum (Ta), tungsten (W), palladium (Pd), platinum (Pt), silver (Ag), and gold (Au). Examples of typical metal elements include sodium (Na), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), zinc (Zn), aluminum (Al), gallium (Ga), germanium (Ge), indium (In), tin (Sn), and antimony (Sb). Silicon (Si) and arsenic (As) can be classified as semimetals along with germanium (Ge) and antimony (Sb), but here, silicon (Si) and arsenic (As) are treated as nonmetallic elements. Metallic materials are simple metals or alloys, and metal compounds, which are compounds containing metal elements, are, for example, oxides, nitrides, carbides, inorganic acid salts, and organic acid salts of metal elements. Metallic compounds may be composite compounds containing multiple transition metal elements, multiple typical metal elements, or transition metal elements and typical metal elements. Compounds are classified into inorganic compounds and organic compounds, but organic compounds, which are metal compounds, i.e., organometallic compounds, are compounds having a bond between carbon and a metal element.

[0092] The materials containing transition metal elements or typical metal elements listed here may be filler particles having a particle diameter of 0.1 μm or more dispersed in a matrix resin, or may be particles having a particle diameter of less than 0.1 μm. Furthermore, when elastomer particles are included, the materials containing transition metal elements or typical metal elements listed here may be particles smaller than the elastomer particles, or may be particles dispersed in the elastomer particles. Alternatively, the materials containing transition metal elements or typical metal elements listed here may be dissolved in the matrix resin or elastomer particles.

[0093] The content of the material containing the transition metal element or typical metal element listed here is preferably 0.01% by mass or more and 5% by mass or less, which is lower than the content of the matrix resin and the dielectric particles. Within this range, ferroelectric interaction may occur, which may increase the dielectric loss tangent.

[0094] When the content of a specific metal element differs between the matrix resin and the elastomer material, obtaining a distribution image (mapping image) of the metal element can facilitate distinguishing between the matrix resin and the elastomer material in the observation image. For example, aluminum (Al), germanium (Ge), antimony (Sb), or titanium (Ti) can be contained in a compound that serves as a polymerization catalyst when polymerizing a polar polymer and can be dissolved or dispersed in the matrix resin. Alternatively, a material containing a transition metal element or a typical metal element can be contained in a compound that serves as a pigment for coloring a resin composition and can be dispersed in the matrix resin. Alternatively, the multiple filler particles can include, for example, filler particles primarily composed of calcium carbonate and filler particles primarily composed of titanium oxide, with both particles being independently dispersed.

[0095] <Method for Producing Resin Composition> The method for producing the resin composition is not particularly limited, but it is preferable to first aggregate the primary particles of the dielectric to form aggregate particles. Specifically, for example, polyvinyl butyral, dioctyl phthalate, toluene, ethanol, etc. are added to the primary particles of the dielectric, and the mixture is mixed and dispersed in a ball mill to prepare a dielectric slurry. The dielectric slurry is then applied to a polyethylene terephthalate film or the like using an applicator or the like, and dried to form a dielectric layer. The dielectric layer is peeled off using a squeegee or the like, and the peeled dielectric layer is pulverized using a ball mill or the like to obtain aggregate particles of the dielectric. In this case, the particle size and aspect ratio of the aggregate particles can be adjusted, for example, by adjusting the pulverization time.

[0096] Examples of methods for mixing the matrix resin and the dielectric particles include a method of melting and shearing the resin composition using screws or blades, such as in a twin-screw extruder or kneader. Another example is a method of melting and shearing the resin composition by passing it over multiple rolls in close proximity, such as in a roll mill. The sheared resin composition can be pelletized by continuously extruding the resin composition as a strand and finely cutting it, or by extracting the resin mass and subjecting it to a grinder for pulverization. The method for producing the resin composition of this embodiment may include a step of melt-kneading the matrix resin and the dielectric particles. Examples of kneading devices include a twin-screw extruder and a twin-roll mill. Specific examples include a TEM extruder (manufactured by Toshiba Machine Co., Ltd.), a TEX twin-screw kneader (manufactured by The Japan Steel Works, Ltd.), a PCM kneader (manufactured by Ikegai Iron Works), and a Kneadex (manufactured by Nippon Coke Company).

[0097] <Molding Method> The molding method is not particularly limited. Examples include injection molding, extrusion molding, press molding, and transfer molding. Injection molding may be performed using pellets produced by extrusion molding from a mold. Among these, injection molding, in which a resin composition is melted and injected into a mold, is preferred. This is because injection molding has a short molding cycle time and allows for efficient production. A resin composition molded by injection molding can be called an injection-molded article. Furthermore, a molded article formed by injection molding may be further processed by blow molding or the like.

[0098] <Electronic Device> As shown in Fig. 3, the electronic device 100 of this embodiment has resin members 10a and 10b for the electronic device of this embodiment. Examples of the electronic device 100 include office equipment such as printers and copiers, medical equipment such as CT scanners, and video equipment such as projectors and displays. These various electronic devices have at least one of an electric component 13, an optical component 12, and a metal component 11 in addition to the resin members 10a and 10b for the electronic device of this embodiment. These electric components 13, optical components 12, and metal components 11 realize the functions of the electronic device 100. The metal component 11 can also be used as a housing for ensuring the mechanical strength of the electronic device 100. The volumes of the resin members 10a and 10b are 10３ mm ３ The volume of the resin members 10a and 10b is preferably 10 ４ mm ３ That's it, 10 ８ mm ３ It may be 10 or less, ６ mm ３ The larger the volume, the more preferably the thickness of the resin member is 0.5 mm or more, and may be 1 mm or more or 5 mm or less.

[0099] The resin members 10a, 10b for electronic devices can be used as members that ensure the mechanical strength of the electronic device 100 and mechanically protect the electronic device 100. The resin member 10a for electronic devices may be an exterior body of the electronic device 100, for example, an exterior cover. This exterior body may be fixed to a metal housing (metal component 11). The resin member 10b for electronic devices of this embodiment may be an interior body of the device 100, for example, a mechanical component. This interior body may be fixed to a metal housing (metal component 11). It is preferable that the resin members 10a, 10b for electronic devices have radio wave shielding properties in terms of stable operation of the electronic device 100 and suppression of radio wave radiation from the electronic device 100.

[0100] The present invention will be further described below with reference to examples. The materials used in these examples (including comparative examples) are as follows.

[0101] (A) Matrix resin

[0102] (B) Ferroelectric particles

[0103] (C) Other ingredients

[0104] Example 1 (1) Production of Aggregate Particles To 50 parts by mass of the ferroelectric particles B-1, 5 parts by mass of polyvinyl butyral (S-LEC B KBM-2, manufactured by Sekisui Chemical Co., Ltd.), and 2 parts by mass of dioctyl phthalate (Dioctyl Phthalate, Special Grade, manufactured by Kanto Chemical Co., Ltd.), 69 parts by mass of toluene and 46 parts by mass of ethanol were added, and the mixture was mixed and dispersed in a ball mill to prepare a ferroelectric slurry.

[0105] The ferroelectric slurry was uniformly applied to a polyethylene terephthalate film using an applicator. The film was then dried at 80°C for 10 minutes to obtain a ferroelectric layer. The ferroelectric layer was peeled off using a squeegee. The peeled ferroelectric layer was pulverized using a ball mill to obtain aggregate particles of the ferroelectric.

[0106] (2) Production of Pellets 95 parts by mass of matrix resin A-1 and 5 parts by mass of the obtained aggregate particles were kneaded using a twin-screw extruder to obtain pellets. The melt viscosity of the pellets was measured and evaluated by the following method. The results are shown in Table 4.

[0107] <Melt viscosity> Melt viscosity: In accordance with JIS-K-7199:1999, specifically, the melt viscosity was measured at a shear rate of 1,000 / sec using an Intesco fully automatic capillary rheometer (Intesco Corporation) with a capillary of d=1 mm and L / D=30. Evaluation was based on the following criteria, with A to D being high evaluations and E being low evaluations. A: 150 Pa·s or less. B: More than 150 Pa·s and 250 Pa·s or less. C: More than 250 Pa·s and 400 Pa·s or less. D: More than 400 Pa·s and 1,000 Pa·s or less. E: More than 1,000 Pa·s.

[0108] (3) Production of Molded Articles (Resin Members for Electronic Devices and Test Pieces) (3-1) Production of Resin Members for Electronic Devices The obtained pellets were injected into a mold simulating a resin member for electronic devices, measuring 120 mm in length, 120 mm in width, 5 mm in thickness, and having a surface roughness Ra of 1.0 μm, to injection-molde a resin member for electronic devices. The ferroelectric material contained in this resin member for electronic devices was observed under an electron microscope to determine the particle size, aspect ratio, and number of aggregate particles. The results are shown in Table 4.

[0109] The resin member for electronic devices was also measured and evaluated for surface charge amount, dust adhesion amount, and surface roughness by the following methods. The results are shown in Table 4.

[0110] <Surface charge amount> A molded resin member for electronic devices was rubbed 100 times with a low-dust-generating wiper (Asahi Kasei Corporation, "Bemcot S-2") and left for 10 minutes. Thereafter, the upper part of the resin member for electronic devices was measured using a digital electrostatic potential meter (Kasuga Electric Co., Ltd., "KSD-0103"). Three measurements were taken, and the average was used as the measured value.

[0111] <Amount of Dust Adhesion> Cellulose powder (FUJIFILM Wako Pure Chemical Industries, Ltd., "Cellulose Powder 38 μm Passage") was adhered to the surface of a molded resin part for electronic devices, and then air was forcefully blown onto the surface to remove the cellulose powder. The dust was evaluated according to the following criteria, with ratings A to D being high ratings and E being low ratings. A: No cellulose powder adhered without removal. B: No cellulose powder adhered after removal. C: A small amount of cellulose powder adhered after removal. D: A large amount of cellulose powder adhered after removal. E: Cellulose powder adhered over the entire surface after removal.

[0112] <Surface roughness (evaluation of moldability)> The surface roughness of molded resin members for electronic devices was measured to evaluate moldability. Specifically, the arithmetic mean roughness (Ra) of the molded resin members for electronic devices was determined using a surface roughness measuring device in accordance with JIS-B0601, and the moldability was evaluated according to the following criteria, with ratings A to D being high ratings and E being low ratings. A: 0.3 μm or less. B: More than 0.3 μm and 0.5 μm or less. C: More than 0.5 μm and 0.7 μm or less. D: More than 0.7 μm and 1.0 μm or less. E: More than 1.0 μm.

[0113] (3-2) Production of Test Pieces The obtained pellets were injected into a cylindrical test piece mold having a height of 30 mm and a diameter of 8 mm to injection-molde test pieces. The dielectric loss tangent of the test pieces was measured and evaluated by the following method. The results are shown in Table 4.

[0114] <Dielectric loss tangent (evaluation of electromagnetic shielding property)> The dielectric loss tangent of the test piece was measured to evaluate the electromagnetic shielding property. Specifically, the dielectric constant and dielectric loss tangent of the test piece at 3 GHz were measured using a perturbation method cavity resonator type DPS18 manufactured by Keycom Corporation, and the electromagnetic shielding property was evaluated according to the following criteria: A: 0.01 or more. B: Less than 0.01, 0.001 or more. C: Less than 0.001, 0.0005 or more. D: Less than 0.0005, 0.0002 or more. E: Less than 0.0002.

[0115] Comparative Example 1 Pellets and a compact were produced and evaluated in the same manner as in Example 1, except that ferroelectric powder B-5 was used as is without producing aggregate particles. The results are shown in Table 4. The surface charge amount was −4.1 kV, and the dust adhesion amount was rated E, confirming a deterioration in dust adhesion. It is believed that the large particle diameter of the ferroelectric particles increased the surface charge amount, resulting in a deterioration in dust adhesion.

[0116] Comparative Example 2 Pellets and a molded product were produced and evaluated in the same manner as in Example 1, except that aggregate particles were not produced and ferroelectric powder B-2 was used as is. The results are shown in Table 4. The melt viscosity was 2,356 Pa s, and the evaluation was E, confirming a deterioration in fluidity. It is believed that the viscosity increased because the ferroelectric particles with a small particle size were dispersed in the matrix resin without agglomeration.

[0117] Comparative Example 3 Aggregate particles, pellets, and a molded body were produced and evaluated in the same manner as in Example 1, except that ferroelectric particles B-3 were used. The results are shown in Table 4. The surface roughness was Ra 1.61 μm, and the evaluation was E, confirming a deterioration in surface properties. It is believed that the deterioration in surface properties was due to the large particle diameter of the aggregate particles.

[0118] Example 2 Except for using ferroelectric particles B-2, aggregate particles, pellets, and compacts were produced and evaluated in the same manner as in Example 1. The results are shown in Table 4.

[0119] Example 3 Aggregate particles, pellets, and compacts were produced and evaluated in the same manner as in Example 2, except that the particle size and aspect ratio of the aggregate particles were adjusted by changing the grinding time using a ball mill in the production of the aggregate particles. The results are shown in Table 4.

[0120] Examples 4 to 7 Aggregate particles, pellets, and compacts were produced and evaluated in the same manner as in Example 1, except that the particle size and aspect ratio of the aggregate particles were adjusted by changing the grinding time using a ball mill in the production of the aggregate particles. The results are shown in Table 4.

[0121] Example 8 Except for using ferroelectric particles B-4, aggregate particles, pellets, and compacts were produced and evaluated in the same manner as in Example 1. The results are shown in Table 4.

[0122] Examples 9 and 10 Except for using matrix resins A-2 and A-3, respectively, aggregate particles, pellets, and molded bodies were produced and evaluated in the same manner as in Example 2. The results are shown in Table 5.

[0123] Examples 11 to 14 Aggregate particles, pellets, and compacts were produced and evaluated in the same manner as in Example 1, except that the blending amount of ferroelectric particles was changed as shown in Table 5. The results are shown in Table 5.

[0124] Examples 15 to 21 Aggregate particles, pellets, and molded articles were produced and evaluated in the same manner as in Example 1, except that in producing the pellets, other components C-1 to C-7 were kneaded together with the matrix resin and aggregate particles in the amounts shown in Table 5. The results are shown in Table 5.

[0125]

[0126]

[0127] The present invention is not limited to the above-described embodiments and examples, and many modifications are possible within the technical concept of the present invention. Furthermore, the effects described in the embodiments and examples of the present invention are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments and examples.

[0128] Furthermore, new matters may be added to at least one embodiment. The disclosure of this specification includes not only what is explicitly described in this specification, but also all matters that can be understood from this specification and the drawings attached hereto.

[0129] In addition, with regard to the specific numerical ranges exemplified in this specification, the notation "e to f" (e and f are numbers) means e or more and / or f or less. Furthermore, when a range of i to j and a range of m to n are both listed for the specific numerical ranges exemplified (i, j, m, and n are numbers), the set of lower and upper limits is not limited to the set of i and j or the set of m and n. For example, it is also possible to consider a combination of multiple sets of lower and upper limits. In other words, when a range of i to j and a range of m to n are both listed, it is also possible to consider the range of i to n or the range of m to j, as long as there is no contradiction. Furthermore, "e or more" means either e or greater than e (exceeding e), and it is also possible to adopt a value greater than e without adopting e. Furthermore, "f or less" means either f or smaller than f (less than f), and it is also possible to adopt a value smaller than f without adopting f.

[0130] Furthermore, the disclosure of this specification includes the complement of each individual concept described in this specification. In other words, if this specification contains a statement that "A is B," it can be said that this specification discloses "A is not B," even if it omits a statement that "A is not B." This is because a statement that "A is B" presupposes that the case in which "A is not B" is taken into consideration.

[0131] <<Configurations Included>> The disclosure of this embodiment includes the following configurations.

[0132] (Configuration 1) A resin member for an electronic device, comprising: a matrix resin; and dielectric particles dispersed in the matrix resin; the dielectric particles are aggregate particles that are aggregates of ferroelectric particles; the particle diameter of the ferroelectric particles is 10 nm or more and 1,000 nm or less; and the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less.

[0133] (Configuration 2) A resin member for an electronic device, comprising: a matrix resin; and dielectric particles dispersed in the matrix resin; wherein the dielectric particles are aggregate particles that are aggregates of paraelectric particles having a relative dielectric constant of 10 or more; the particle diameter of the paraelectric particles is 10 nm or more and 1,000 nm or less; and the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less.

[0134] (Configuration 3) The resin member according to configuration 1 or 2, wherein the aggregate particles are scaly.

[0135] (Configuration 4) The resin member according to any one of Configurations 1 to 3, wherein the aggregate particles have an aspect ratio of 3 or more and 20 or less.

[0136] (Configuration 5) The number of the aggregate particles per unit area is 1 particle / mm ２ More than 100 pieces / mm ２ 5. The resin member according to any one of configurations 1 to 4, wherein:

[0137] (Configuration 6) The resin member according to any one of Configurations 1 to 5, wherein the particle diameter of the aggregate particles is 5 μm or more.

[0138] (Configuration 7) The resin member according to any one of configurations 1 to 6, wherein the dielectric particles contain a titanic acid compound.

[0139] (Configuration 8) The resin member according to any one of configurations 1 to 7, wherein the dielectric particles contain barium titanate.

[0140] (Configuration 9) The resin member according to any one of configurations 1 to 8, wherein the content of the dielectric particles is 0.1% by mass or more and 10% by mass or less.

[0141] (Configuration 10) The resin member according to any one of configurations 1 to 9, wherein the matrix resin is a thermoplastic resin.

[0142] (Configuration 11) The resin member according to any one of configurations 1 to 10, wherein the matrix resin contains a polar polymer.

[0143] (Configuration 12) The resin member according to any one of Configurations 1 to 11, wherein the matrix resin contains a crystalline polymer.

[0144] (Configuration 13) The resin member according to any one of Configurations 1 to 12, wherein the matrix resin contains polyester.

[0145] (Configuration 14) The resin member according to any one of Configurations 1 to 13, wherein the matrix resin contains polyethylene terephthalate.

[0146] (Configuration 15) The resin member according to any one of Configurations 1 to 14, wherein the matrix resin contains polyester and carbodiimide.

[0147] (Configuration 16) The resin member according to any one of configurations 1 to 15, further comprising an elastomer.

[0148] (Configuration 17) The resin member according to any one of configurations 1 to 16, further comprising filler particles containing an inorganic material as a main component other than the dielectric particles.

[0149] (Configuration 18) The resin member according to Configuration 17, wherein the inorganic material has a relative dielectric constant of less than 10.

[0150] (Configuration 19) A resin member according to any one of Configurations 1 to 18, further comprising at least one of a metal material containing a transition metal element, a compound material containing a transition metal element, a metal material containing a typical metal element, and a compound material containing a typical metal element, other than the dielectric particles.

[0151] (Configuration 20) The volume of the resin member is 1,000 mm ３ 20. The resin member according to any one of configurations 1 to 19, characterized in that:

[0152] (Configuration 21) A resin composition comprising: a matrix resin; and dielectric particles dispersed in the matrix resin; wherein the dielectric particles are aggregate particles that are aggregates of ferroelectric particles; the particle diameter of the ferroelectric particles is 10 nm or more and 1,000 nm or less; and the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less; and the matrix resin contains polyester and carbodiimide.

[0153] (Configuration 22) A resin composition comprising: a matrix resin; and dielectric particles dispersed in the matrix resin; wherein the dielectric particles are aggregate particles that are aggregates of paraelectric particles having a relative dielectric constant of 10 or more; the particle diameter of the paraelectric particles is 10 nm or more and 1,000 nm or less; and the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less; and the matrix resin contains polyester and carbodiimide.

[0154] (Configuration 23) A method for producing a resin member, comprising melting the resin composition according to Configuration 21 or 22 and injecting the melted resin composition into a mold.

[0155] (Configuration 24) An electronic device comprising: the resin member according to any one of Configurations 1 to 20; and at least one of an electrical component, a metal component, and an optical component.

[0156] (Configuration 25) The electronic device according to configuration 24, wherein the resin member is an exterior body.

[0157] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to apprise the public of the scope of the present invention.

[0158] This application claims priority based on Japanese Patent Application No. 2023-223239, filed on December 28, 2023, the entire contents of which are incorporated herein by reference.

[0159] 1 matrix resin 2 primary particles of dielectric material 3 aggregate particles

Claims

1. A resin member for an electronic device, comprising a matrix resin and dielectric particles dispersed in the matrix resin, wherein the dielectric particles are aggregate particles that are aggregates of ferroelectric particles, the particle diameter of the ferroelectric particles is 10 nm or more and 1,000 nm or less, and the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less.

2. A resin member for an electronic device, comprising a matrix resin and dielectric particles dispersed in the matrix resin, wherein the dielectric particles are aggregate particles that are aggregates of paraelectric particles having a relative permittivity of 10 or more, the particle diameter of the paraelectric particles is 10 nm or more and 1,000 nm or less, and the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less.

3. The resin member according to claim 1 or 2, wherein the shape of the aggregate particles is scaly.

4. The resin member according to claim 1 or 2, wherein the aspect ratio of the aggregate particles is 3 or more and 20 or less.

5. The number of the aggregate particles per unit area is 1 piece / mm ２ or more and 100 pieces / mm ２ or less. The resin member according to claim 1 or 2, characterized in that.

6. The resin member according to claim 1 or 2, wherein the particle diameter of the aggregate particles is 5 μm or more.

7. The resin member according to claim 1 or 2, wherein the dielectric particles contain a titanium compound.

8. The resin member according to claim 1 or 2, wherein the dielectric particles contain barium titanate.

9. The resin member according to claim 1 or 2, wherein the content of the dielectric particles is 0.1% by mass or more and 10% by mass.

10. The resin member according to claim 1 or 2, wherein the matrix resin is a thermoplastic resin.

11. The resin member according to claim 1 or 2, wherein the matrix resin contains a polar polymer.

12. The resin member according to claim 1 or 2, wherein the matrix resin contains a crystalline polymer.

13. The resin member according to claim 1 or 2, wherein the matrix resin contains a polyester.

14. The resin member according to claim 1 or 2, wherein the matrix resin contains polyethylene terephthalate.

15. The resin member according to claim 1 or 2, wherein the matrix resin contains a polyester and carbodiimide.

16. The resin member according to claim 1 or 2, further comprising an elastomer.

17. The resin member according to claim 1 or 2, further comprising filler particles mainly composed of an inorganic material other than the dielectric particles.

18. The resin member according to claim 17, wherein the relative permittivity of the inorganic material is less than 10.

19. The resin member according to claim 1 or 2, further containing at least one of a metal material containing a transition metal element, a compound material containing a transition metal element, a metal material containing a typical metal element, and a compound material containing a typical metal element, other than the dielectric particles.

20. The volume of the resin member is 1,000 mm ３ or more. The resin member according to claim 1 or 2, characterized in that.

21. A resin composition comprising a matrix resin and dielectric particles dispersed in the matrix resin, wherein the dielectric particles are aggregate particles which are aggregates of ferroelectric particles, the particle diameter of the ferroelectric particles is 10 nm or more and 1,000 nm or less, the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less, and the matrix resin contains polyester and carbodiimide.

22. A resin composition comprising a matrix resin and dielectric particles dispersed in the matrix resin, wherein the dielectric particles are aggregate particles which are aggregates of paraelectric particles having a relative permittivity of 10 or more, the particle diameter of the paraelectric particles is 10 nm or more and 1,000 nm or less, the particle diameter of the aggregate particles is 1 μm or more and 100 μm or less, and the matrix resin contains polyester and carbodiimide.

23. A method for manufacturing a resin member, characterized by melting the resin composition according to claim 21 or 22 and injecting it into a mold.

24. An electronic device, characterized by having the resin member according to claim 1 or 2 and at least one of an electrical component, a metal component, and an optical component.

25. The electronic device according to claim 24, wherein the resin member is an exterior body.

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