Electret
US-2021184100-A1 · Jun 17, 2021 · US
Electret
US11915883B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-11915883-B2 |
| Application number | US-202017116204-A |
| Country | US |
| Kind code | B2 |
| Filing date | Dec 9, 2020 |
| Priority date | Dec 13, 2019 |
| Publication date | Feb 27, 2024 |
| Grant date | Feb 27, 2024 |
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Abstract
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An electret includes an electret layer. The electret layer is formed by subjecting a composite film in which inorganic dielectric particles are dispersed and held in a base film to a polarization treatment. The inorganic dielectric particles are mainly composed of an inorganic dielectric material having a bandgap energy of 4 eV or more.
First claim
Opening claim text (preview).
What is claimed is: 1. An electret comprising an electret layer, wherein the electret layer is formed by subjecting a composite film in which inorganic dielectric particles are dispersed and held in a base film to a polarization treatment, and the inorganic dielectric particles are mainly composed of an inorganic dielectric material having a bandgap energy of 4 eV or more. 2. The electret according to claim 1 , further comprising a substrate, wherein the electret layer is formed above a surface of the substrate. 3. The electret according to claim 1 , wherein the inorganic dielectric material is a composite oxide having an ABO 3 type perovskite structure containing two different metal elements A and B. 4. The electret according to claim 3 , wherein in the composite oxide, an A site of the perovskite structure is occupied by a rare earth element R selected from the group consisting of La, Y, Pr, Sm and Nd, and a B site of the perovskite structure is occupied by Al. 5. The electret according to claim 4 , wherein in the composite oxide, at least one of the metal elements A and B is partially substituted with a dopant element composed of a different metal element, the dopant element that substitutes for the metal element A is an alkaline earth metal element, and the dopant element that substitutes for the metal element B is one or more element selected from the group consisting of alkaline earth metal elements and Zn. 6. The electret according to claim 5 , wherein a substitution ratio of the dopant element that substitutes for the metal element A is 0.5 atomic % to 20 atomic %, and a substitution ratio of the dopant element that substitutes for the metal element B is 0.5 atomic % to 20 atomic %. 7. The electret according to claim 1 , wherein the inorganic dielectric material is an inorganic compound having an apatite structure containing phosphate ions and hydroxide ions. 8. The electret according to claim 1 , wherein the base film has a dielectric breakdown electric field strength higher than an electric field strength during the polarization treatment and is made of a material that is stable at a temperature during the polarization treatment. 9. The electret according to claim 1 , wherein a content of the inorganic dielectric particles in the composite film is 30% by volume or more and 75% by volume or less.
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- What does patent US11915883B2 cover?
- An electret includes an electret layer. The electret layer is formed by subjecting a composite film in which inorganic dielectric particles are dispersed and held in a base film to a polarization treatment. The inorganic dielectric particles are mainly composed of an inorganic dielectric material having a bandgap energy of 4 eV or more.
- Who is the assignee on this patent?
- Denso Corp, Univ Tokyo Science Found
- What technology area does this patent fall under?
- Primary CPC classification H01G7/025. Mapped technology areas include Electricity.
- When was this patent published?
- Publication date Tue Feb 27 2024 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 2 related publications on this page (citations in our corpus or others sharing the same primary CPC).