31 results about "Dielectric breakdown strength" patented technology

A resin film (100) comprising a core layer (2) and adhesive resin layers (1) which are respectively provided to both sides of the core layer (2), wherein: the adhesive resin layers (1) each comprise an adhesive resin composition that contains an epoxy resin; the dielectric breakdown strength of a cured product of the adhesive resin composition is not less than 300 kV / mm; the core layer (2) comprises a polyimide film; and the dielectric breakdown strength of the polyimide film is not less than 300 kV / mm.

Provided is: an organopolysiloxane cured film that is superior as a thin film and, in terms of flatness, has significantly superior smoothness and flatness at the film surface, in addition to generally having high dielectric breakdown strength against a load voltage; along with a usage and manufacturing method therefor. The organopolysiloxane cured film, in which an arithmetic average height (Sa) of the film surface is less than 0.50 μm, while an average thickness at the center of the film is within a range of 1 to 20 μm. It is possible to obtain such a film by a manufacturing method including a die coating step in which a slot die is used to coat a curable organopolysiloxane composition on a continuously traveling substrate supported between a pair of support rolls by means of a tension support system.

The present invention belongs to the technical field of dielectric analysis. Disclosed is a method for determining the minimum number of samples required for acquiring dielectric breakdown strength. The method comprises: using the set current number of experimental samples, and a reliability measure value and a reliability estimate value of a Weibull sub-distribution corresponding to each breakdown cause to characterize the current key quantity of each sub-distribution, in order to select a target sub-distribution; and taking into account the relationship between the current key quantity of the target sub-distribution and a reference value, and if the current key quantity is greater than the reference value, increasing the current number of experimental samples until a corresponding current key quantity is lower than the reference value, and using the current number of experimental samples as the minimum number of samples. In the method for determining the minimum number of samples provided in the present invention, variation patterns of a plurality of breakdown causes are taken into account to design the current key quantity related to the current number of experimental samples, and on the basis of the relationship between the current key quantity and a reference value, the current number of experimental samples is dynamically adjusted, thereby ultimately quickly and accurately determining the minimum number of samples.

Provided is a stretched film having high dielectric breakdown strength even under a high temperature environment of 120°C or higher, and further capable of imparting excellent withstand voltage performance to a capacitor element even under a room temperature (for example, 25°C) and a high temperature environment of 120°C or higher.　The present invention is a stretched film that contains a polypropylene-based resin, and the number of regions R1 measured by a prescribed method is 10 or more. Alternatively, the present invention is a stretched film that contains a polypropylene-based resin, and the average value of the maximum lengths of regions 2 in the thickness direction, which are measured by a prescribed method, is 10-300 nm. Alternatively, the present invention is a stretched film that contains a polypropylene-based resin, and the average value of the maximum lengths of regions 3 in a direction orthogonal to the thickness direction, which are measured by a prescribed method, is 30 nm or more.

[Problem] To provide a heat-curable resin composition that achieves both high heat conductivity and dielectric breakdown resistance, that can form a cured product which has a highly smooth surface, and that has excellent storage stability at normal temperatures. [Solution] An epoxy resin, a thermally conductive filler, a phosphate ester-based wetting dispersant, and a urea-based rheology modifier are added to a thermosetting resin, the content of the phosphate ester-based wetting dispersant and the content of urea-based rheology modifier are adjusted to be in respective specific ranges, and a thixotropic index at 25°C is adjusted to be not less than 1.0 but less than 1.4.

Performance requirements of electroactive polymer materials used for transducer devices include dielectric breakdown strength, Young's modulus, dielectric constant, thickness, and electromechanical instability. There are correlation relationships therebetween but definitions of the correlation relationships have not been achieved. Therefore, it is necessary to search for an excellent material by trial and error, which requires a great deal of work. Disclosed herein is a curable elastomer composition that includes a compound having a high dielectric functional group. A cured product of the composition satisfies the following formula:E=α⁡(Yε0⁢εr)0.5where E is the dielectric breakdown strength in the range of 50 V / μm to 200 V / μm, α is a constant in the range of 0.4 to 0.9, Y is Young's modulus and is in the range of 0.001 MPa to 10 MPa, εγ is a specific dielectric constant and is 100 or less, and ε0 represents the dielectric constant of vacuum.

To provide a silicone rubber composition which gives a silicone rubber cured product exhibiting a high dielectric breakdown strength.SOLUTION: The silicone rubber composition contains: (A) 100 pts.mass of an organopolysiloxane having a degree of polymerization of 100 or more and having two or more alkenyl groups bonded to silicon atoms in one molecule; (B) 25-70 pts.mass of reinforcing silica having a specific surface area measured by a BET method of 50 m2 / g or more; (C) 5-50 pts.mass of flat boron nitride having an average particle diameter of 3-50 μm and an aspect ratio of 5 or more; and (D) an effective amount of a curing agent to cure the component (A).SELECTED DRAWING: None

The present invention provides a stretched film having a high dielectric breakdown strength even under a high temperature environment of 120°C or higher, and having little change in the dielectric breakdown strength under the high temperature environment with respect to the dielectric breakdown strength at room temperature (for example, 25°C).　The present invention is a stretched film containing a polypropylene resin, wherein the loss tangent tan δ at 100°C is 0.15 or less in temperature dispersion data in the TD direction at a frequency of 1 Hz obtained from dynamic viscoelasticity measurement, or the loss tangent tan δ has a peak in a region of 140°C or higher in temperature dispersion data in the TD direction at a frequency of 1 Hz obtained from dynamic viscoelasticity measurement.

The application discloses a kind of high dielectric breakdown strength nanostructure alumina insulation coating, the preparation steps of the nanostructure alumina insulation coating are as follows: one, in ball mill, deionized water, grinding ball, dispersing agent, submicron alumina powder, nano alumina powder, binder and defoaming agent are ball milled, to obtain slurry;Two, the slurry is carried out spray granulation, to obtain alumina agglomerated powder;Three, alumina agglomerated powder is carried out solid phase sintering, by screening to the powder after solid phase sintering, to obtain nanostructure alumina feed powder;Four, the nanostructure alumina feed powder is carried out atmospheric plasma spraying, to prepare the nanostructure alumina insulation coating with high dielectric breakdown strength.The method utilizes the high sintering activity of nanoscale size alumina, so that more nanoscale powder is retained in the powder as much as possible, thereby effectively improving the dielectric breakdown strength of the prepared coating.

The present disclosure discloses a method for determining the minimum number of samples required for obtaining dielectric breakdown strength, belonging to the field of dielectric analysis technology. The method includes: characterizing a current key quantity of each sub-distribution by using a set current experiment sample size, a reliability measure and a reliability estimate of Weibull sub-distributions corresponding to respective breakdown causes to select target sub-distributions; considering a relationship between the current key quantity of the target sub-distributions and a reference value, if the current key quantity is greater than the reference value, then increasing the current experiment sample size until the corresponding current key quantity is less than the reference value, and taking the current experiment sample size as the minimum number of samples.

The high-voltage and / or high-frequency pulse dielectric breakdown strength (DBS) of an implantable medical device is increased by strategically positioning insulation materials on or adjacent to the external surfaces of a filter capacitor. Dielectric breakdown strength is further increased by adding polymeric or ceramic nanoscale metal oxide insulative powders to the insulation materials.

To provide a resin composition, pellets, and molded articles that are excellent in flame retardancy and heat resistance, and that have a high dielectric breakdown strength retention rate. The resin composition according to this disclosure comprises 100 parts by mass of a resin component consisting of (a) 80 to 100 parts by mass of a polyphenylene ether resin and (b) 0 to 20 parts by mass of a styrene resin, (c) a phosphate compound having an aromatic ring substituted with a hydrocarbon group, and (d) a condensed phosphate ester flame retardant, wherein the total content of (c) the phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) the condensed phosphate ester flame retardant is 10 to 25 parts by mass per 100 parts by mass of the resin component, and the mass ratio (c) / (d) of the content of (c) the phosphate compound having an aromatic ring substituted with a hydrocarbon group and (d) the condensed phosphate ester flame retardant is 18 / 82 to 90 / 10.

This invention provides a lead-free piezoelectric element that exhibits excellent piezoelectric properties and superior dielectric breakdown strength. [Solution] A piezoelectric element comprising a piezoelectric ceramic layer mainly composed of an alkali niobate perovskite oxide and an internal electrode mainly composed of Ni, which are alternately stacked, wherein the alkali niobate perovskite oxide contains a first metal element which is at least one of Ni, Cu, and Ag, and the piezoelectric ceramic layer has an inert layer located at the end face in the stacking direction and an active layer located in the interior in the stacking direction, wherein the concentration [mol%] of the first metal element contained in the alkali niobate perovskite oxide in the active layer is higher than the concentration [mol%] of the first metal element contained in the alkali niobate perovskite oxide in the inert layer.

To provide a copolymer capable of obtaining a molded article excellent in dielectric breakdown strength and transparency even after drawing.SOLUTION: There is provided a 4-methyl-1-pentene copolymer having a content of a constitutional unit derived from 4-methyl-1-pentene of 90 to 99 mol% and a content of a constitutional unit derived from ethylene or an α-olefin having 3 to 20 carbon atoms other than 4-methyl-1-pentene of 1 to 10 mol%, and satisfying the following requirements (A) and (B). Requirement (A) is that (σ) determined by formula (1) and formula (2) in a temperature range of -20 to 150°C in an elution curve obtained by crystallization elution fractionation chromatography is 5 to 40. Requirement (B) is that the crystallization temperature (Tc) is 150°C or higher and lower than 200°C. In the formulas, Ci represents a concentration of polymer in solution at an ith data point, Ti represents a temperature (°C) at the ith data point, and Tw represents a weight average crystallization temperature.SELECTED DRAWING: None

The invention discloses a multi-element isovalent ion co-doped AgNbO3 lead-free anti-ferroelectric energy storage ceramic material as well as a preparation method and application thereof, and the chemical formula of the energy storage ceramic material is Ag (0.7-3x) Bi (0.1) Tm (x) Nb (0.9) Ta (0.1) O3, 0lt, tm < 3 + > is introduced to the A site again on the basis of the Ag0. 7Bi0. 1Nb0. 9Ta0. 1O3 anti-ferroelectric energy storage ceramic material, so that the AgNbO3 lead-free anti-ferroelectric energy storage ceramic material co-doped with Bi < 3 + > and Tm < 3 + > at the A site and Ta < 5 + > at the B site is formed. According to the invention, under the synergistic effect of improving the stability of an antiferroelectric phase and improving the dielectric breakdown strength and relaxation, the prepared Ag0. 655Bi0. 1Tm0. 015Nb0. 9Ta0. 1O3 energy storage ceramic material obtains the energy storage density as high as 11.04 J / cm < 3 > and the conversion efficiency as high as 79.62% under the action of 428kV / cm, which are about four times of that of an AgNbO3 ceramic material.

Provided is a polypropylene film having a high dielectric breakdown strength at high temperatures. Provided is a polypropylene film in which a polypropylene resin constituting the polypropylene film has a molecular-weight distribution (Mw / Mn) of the weight-average molecular weight Mw to the number-average molecular weight Mn of has a Z-average molecular weight Mz of 950,000-1,500,000, and has a weight proportion w of 2.6-4.2% in an integral molecular-weight distribution curve when the logarithmic molecular weight Log(M) is 4.0.

The application belongs to the technical field of dielectric materials, and provides a bismuth-based perovskite ceramic with a self-absorption doping strategy and a preparation method.The chemical formula of the bismuth-based perovskite ceramic is (1-x)(0.7BiFeO3-0.3SrTiO3)-xBi2Ti2O7, wherein 0x≤0.08.In the embodiment of the application, Bi2Ti2O7 (BTO) secondary phase which is prone to appear in bismuth-based perovskite is used as a doping component to improve the dielectric breakdown strength of BiFeO3-SrTiO3 (BFST) solid solution ceramic.After twice solid-phase sintering, the BFST-BTO solid solution ceramic is formed by mixing and sintering again, and the incorporation of BTO improves the dielectric breakdown strength and energy storage density of the BFST-based ceramic, thereby providing a new strategy for improving the dielectric breakdown strength without introducing new elements, and having potential application value for improving the energy storage performance of other bismuth-based ceramics.

This invention discloses a system and method for predicting the insulation breakdown strength of converter transformer oil paper, relating to the field of power system transformer technology. The method includes: measuring the breakdown strength values ​​of converter transformer oil paper at different aging levels; obtaining grayscale image features of converter transformer oil paper at different aging levels; establishing a database for analyzing the aging of converter transformer oil paper; placing converter transformer oil paper samples in a programmable temperature-controlled chamber; recording the changes in their grayscale values ​​at different temperatures; and calculating the grayscale correction slope. k； A dual-path imaging module is installed inside the manhole observation window of the converter transformer body. It collects images every hour and sends them back to the control center. The thermal images collected by the infrared focal plane thermal imager are processed to calculate the real-time operating temperature and obtain the predicted value of the oil-paper breakdown strength of the converter transformer.

To provide a powder coating composition that can form a coating film that exhibits high dielectric breakdown strength even in thin films, while also possessing high edge coverage and excellent smoothness. [Solution] A powder coating composition comprising a polyester resin (A) containing acidic groups at its terminals and having an acid value of 10 to 100 mg KOH / g, an epoxy resin (B), and a metal oxyhydroxide (C) containing at least one metal selected from the group consisting of aluminum, manganese, iron, nickel, cobalt, and vanadium.

Provided is a stretched film that has high dielectric breakdown strength even under a high-temperature environment of 120°C or higher, has a small change in the dielectric breakdown strength under the high-temperature environment with respect to dielectric breakdown strength at room temperature (for example, 25°C), and can improve the long-term durability of a capacitor element.　The present invention relates to a stretched film that contains a polypropylene-based resin, and the value of orientation coefficient ΔP represented by the following formula (1A), which is determined from birefringence values, is 0.007-0.0125. (1A): ΔP=(ΔNxz+ΔNyz) / 2 (In said formula (1A), ΔNxz represents a birefringence value in the x-axis direction with respect to the thickness direction (z-axis direction), and ΔNyz represents a birefringence value in the y-axis direction with respect to the thickness direction (z-axis direction).) Alternatively, the present invention is a stretched film that contains a polypropylene-based resin, and the value of an in-plane birefringence value ΔNyx is 0.009-0.016.

Provided is a silicon nitride substrate that has greatly improved strength and still maintains various characteristics such as thermal conductivity and dielectric breakdown strength, even when a large amount of iron or another inevitable substance is included, and a production method for the silicon nitride substrate. This silicon nitride substrate 1 includes iron (Fe). The silicon nitride substrate 1 is characterized in that the average major axis diameter, the average minor axis diameter, and the average aspect ratio (average major axis diameter / average minor axis diameter) of silicon nitride particles 11 at a 64 μm×48 μm mirror-polished surface as measured by observation with a scanning electron microscope are 5.5–9.0 μm, 2.2–3.1 μm, and 2.4–3.8, respectively.

An object of the present invention is to provide a polyester film having a high dielectric breakdown strength even in a case of being thinned.SOLUTION: A polyester film for a film capacitor contains a polyester resin (X) and a polypropylene resin (Y), and has a particle content of 0.001% by mass or less.SELECTED DRAWING: None

The purpose of the present invention is to provide a stretched film which has high dielectric breakdown strength even under a high temperature environment of 120°C or higher, can impart excellent withstand voltage performance to a capacitor element even under a room temperature (for example, 25° C) and a high temperature environment of 120°C or higher, and can impart excellent safety performance to the capacitor element even under a high temperature environment.　The present invention is a stretched film containing a polypropylene-based resin, wherein the stretched film has recesses and protrusions on at least one surface thereof, the average value of the major axes of the recesses and protrusions, the contours of which are observed in an elliptical shape by microscopic observation, is 150 um or less, or the density of the recesses and protrusions, the contours of which are observed in an elliptical shape by microscopic observation, is 30 items / mm2 or more.

To provide a film capable of maintaining dielectric breakdown strength at high temperatures, achieving high dielectric breakdown strength at high temperatures, and exhibiting high volume resistivity in high-temperature environments.SOLUTION: A stretched film has at least an A layer, wherein (1) the A layer contains 55 mass% or more and 99 mass% or less of a polypropylene resin based on 100 mass%, (2) in temperature dispersion data at a frequency of 1 Hz in a dynamic viscoelasticity measurement in a film machine direction (MD), the film has a dispersion peak of a loss tangent (tanδ) in a temperature range of 145°C or higher, and (3) the film is stretched in at least one direction.SELECTED DRAWING: None

The invention relates to the field of rail locomotive maintenance, in particular to a method for repairing aging cracks of an insulating top cover of a high-prototype locomotive, and the insulating top cover comprises a metal top cover, an insulating composite material layer, a frame shaped like a Chinese character'tian 'and a pantograph mounting seat. Repairing glue B which is low in viscosity, high in permeability, high in bonding strength, high in volume resistivity and high in dielectric breakdown strength is selected, and in a constant-temperature and constant-humidity environment, surface cracking fine lines and an internal cracking structure of the insulating composite material cover are repaired in a gravity permeation mode after gluing; at the position, where edge creepage and breakdown are prone to occurring, of the insulating top cover, an aging material is removed firstly, then repairing glue A with low bonding strength, high stretch rate, high volume resistivity and high dielectric breakdown strength is selected, and the insulating performance is repaired and enhanced through gluing.

The present invention provides a stretched film that has high dielectric breakdown strength even in high-temperature environments of 120°C or higher, and that can impart excellent voltage resistance performance to capacitor elements at room temperature (e.g., 25°C) and in high-temperature environments of 120°C or higher. [Solution] The present invention relates to a stretched film containing a polypropylene resin, wherein the number of regions R1 measured by a predetermined method is 10 or more. Alternatively, the present invention relates to a stretched film containing a polypropylene resin, wherein the average value of the maximum length in the thickness direction of region 2 measured by a predetermined method is 10 nm or more and 300 nm or less. Alternatively, the present invention relates to a stretched film containing a polypropylene resin, wherein the average value of the maximum length in the direction perpendicular to the thickness direction of region 3 measured by a predetermined method is 30 nm or more.

To provide a polypropylene film having excellent dielectric breakdown strength and heat shrinkage resistance at high temperature, and to provide a film capacitor using the polypropylene film and having excellent life performance and excellent thermal shock resistance at high temperature.SOLUTION: The polypropylene film is composed of a polypropylene resin, in the polypropylene resin: a molecular weight distribution (Mw / Mn) of a weight average molecular weight Mw and a number average molecular weight Mn is 5.0 or more and 6.7 or less; a Z-average molecular weight Mz is 650000 or more and 945000 or less; and a weight fraction w at a logarithmic molecular weight Log (M)=4.0 in an integral molecular weight distribution curve is 2.6% or more and 4.2% or less.SELECTED DRAWING: None

To provide a resin film with a low dielectric constant. [Solution] A resin film 100 comprising a core layer 2 and adhesive resin layers 1 provided on both sides of the core layer 2, wherein the adhesive resin layer 1 is made of a first adhesive resin composition containing polyamic acid which is a polyaddition reaction product of (A) an acid dianhydride and (B) a diamine, or a second adhesive resin composition containing an epoxy resin, wherein the polyamic acid in the first adhesive resin composition contains (B1) dimeramine in a molar ratio of 0.2 or more relative to the total diamine components, the dielectric breakdown strength of the cured product of the second adhesive resin composition is 300 kV / mm or more, and the core layer 2 is made of a polyimide film containing polyimide obtained by imidizing the polyamic acid in the first adhesive resin composition.

The application belongs to the technical field of capacitor film preparation, and particularly relates to a preparation method of a multilayer composite structure capacitor film. The film has a three-layer composite structure of a surface layer / a core layer / a surface layer, the surface layer material comprises high isotactic polypropylene, the core layer material comprises an electrical grade polypropylene, a bimodal polypropylene and an amino-terminated hyperbranched polyamide-amine with a specific structure. By adopting a multilayer co-extrusion casting, longitudinal stretching and segmented transverse stretching process, and performing high-temperature stress relaxation and segmented cooling solidification after transverse stretching, the film has a low high-temperature thermal shrinkage rate and a high high-temperature dielectric breakdown strength.

A resin film (100) comprises a core layer (2) and adhesive resin layers (1) provided respectively to both surfaces of the core layer (2), wherein the adhesive resin layers (1) are made of a first adhesive resin composition, which includes a poly(amic acid) that is a product of polyaddition reaction between an acid dianhydride (A) and a diamine (B), or a second adhesive resin composition, which includes an epoxy resin. In the first adhesive resin composition, the poly(amic acid) includes a dimer diamine (B1) at a molar ratio of 0.2 or higher with respect to the whole diamine component. A cured object formed from the second adhesive resin composition has a dielectric breakdown strength of 300 kV / mm or greater. The core layer (2) is a polyimide film comprising a polyimide obtained by imidizing the poly(amic acid) contained in the first adhesive resin composition.