GB1135413A - An electret and method of making the same - Google Patents
An electret and method of making the sameInfo
- Publication number
- GB1135413A GB1135413A GB4676766A GB4676766A GB1135413A GB 1135413 A GB1135413 A GB 1135413A GB 4676766 A GB4676766 A GB 4676766A GB 4676766 A GB4676766 A GB 4676766A GB 1135413 A GB1135413 A GB 1135413A
- Authority
- GB
- United Kingdom
- Prior art keywords
- electret
- temperature
- field
- zone
- polyethylene terephthalate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000004519 manufacturing process Methods 0.000 title 1
- 239000000463 material Substances 0.000 abstract 9
- -1 polyethylene terephthalate Polymers 0.000 abstract 3
- 229920000139 polyethylene terephthalate Polymers 0.000 abstract 3
- 239000005020 polyethylene terephthalate Substances 0.000 abstract 3
- 229920001328 Polyvinylidene chloride Polymers 0.000 abstract 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 abstract 1
- 150000001342 alkaline earth metals Chemical class 0.000 abstract 1
- 229910052788 barium Inorganic materials 0.000 abstract 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 abstract 1
- AOWKSNWVBZGMTJ-UHFFFAOYSA-N calcium titanate Chemical compound [Ca+2].[O-][Ti]([O-])=O AOWKSNWVBZGMTJ-UHFFFAOYSA-N 0.000 abstract 1
- 229920002301 cellulose acetate Polymers 0.000 abstract 1
- 239000000919 ceramic Substances 0.000 abstract 1
- 238000001816 cooling Methods 0.000 abstract 1
- 230000005684 electric field Effects 0.000 abstract 1
- 239000002305 electric material Substances 0.000 abstract 1
- 239000011521 glass Substances 0.000 abstract 1
- 238000010438 heat treatment Methods 0.000 abstract 1
- 239000004033 plastic Substances 0.000 abstract 1
- 229920003023 plastic Polymers 0.000 abstract 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 abstract 1
- 239000004926 polymethyl methacrylate Substances 0.000 abstract 1
- 229920001296 polysiloxane Polymers 0.000 abstract 1
- 239000005033 polyvinylidene chloride Substances 0.000 abstract 1
- 239000005871 repellent Substances 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G7/00—Capacitors in which the capacitance is varied by non-mechanical means; Processes of their manufacture
- H01G7/02—Electrets, i.e. having a permanently-polarised dielectric
- H01G7/021—Electrets, i.e. having a permanently-polarised dielectric having an organic dielectric
- H01G7/023—Electrets, i.e. having a permanently-polarised dielectric having an organic dielectric of macromolecular compounds
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Treatments Of Macromolecular Shaped Articles (AREA)
- Filtering Materials (AREA)
- Artificial Filaments (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
Abstract
1,135,413. Electrets. PHILIP MORRIS Inc. 19 Oct., 1966 [23 Oct., 1965], No. 46767/66. Addition to 1,046,142. Heading H1M. An electret is made by heating an electretforming material at an elevated temperature until a substantially uniform temperature is obtained throughout the material, subjecting the material to an electric field of 0À001 to 1000 kilovolts while maintaining the temperature for a period of from one microsecond to twelve hours or more, and cooling the electret-forming material to a temperature below 30‹ C. while maintaining it in the field, and then removing the material from the field. The preferred electret-forming material is polyethylene terephthalate which forms an electret having a stable hetero-charge, but it may also be cellulose acetate, polyvinylidene chloride, P.C.T.F.E., P.T.F.E., P.V.C., or polymethylmethacrylate, or ceramics such as alkaline earth metal titanates or zirconates. In the case of plastics electret-forming materials, the forming temperature is above the glass temperature but below the softening point. The polyethylene terephthalate may contain semiconducting or ferro-electric materials such as barium or calcium titanate or zirconate or it may be coated with water-repellent materials, e.g. silicones or P.T.F.E. The material should have two flat surfaces on opposite sides and may be disc-shaped, doughnut-shaped or a flat sheet or plate. Preferably, for continuous operation it is in the form of a film. As shown, a film 20 of e.g. polyethylene terephthalate is passed, in zone 25, between charged rollers 21 and 22, the zone being mantained at 180- 190‹ C. by means of hot gas passed through ports 25a, 25b. In zone 26, maintained at about 30‹ C. by means of air passing through ports 26a, 26b the film 20 is cooled while remaining in the field of charged rollers 23, 24.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US50398365A | 1965-10-23 | 1965-10-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1135413A true GB1135413A (en) | 1968-12-04 |
Family
ID=24004358
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB4676766A Expired GB1135413A (en) | 1965-10-23 | 1966-10-19 | An electret and method of making the same |
Country Status (7)
| Country | Link |
|---|---|
| AT (1) | AT291404B (en) |
| BE (1) | BE688615A (en) |
| CH (1) | CH498479A (en) |
| ES (1) | ES332637A2 (en) |
| GB (1) | GB1135413A (en) |
| LU (1) | LU52224A1 (en) |
| NL (1) | NL6614505A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2467474A1 (en) * | 1979-10-11 | 1981-04-17 | Tno | METHOD OF MANUFACTURING ELECTRETS |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5946112B2 (en) * | 1975-12-29 | 1984-11-10 | 三菱油化株式会社 | Atsudenzairiyo |
-
1966
- 1966-10-14 NL NL6614505A patent/NL6614505A/xx unknown
- 1966-10-19 GB GB4676766A patent/GB1135413A/en not_active Expired
- 1966-10-20 BE BE688615D patent/BE688615A/xx unknown
- 1966-10-21 CH CH1528866A patent/CH498479A/en not_active IP Right Cessation
- 1966-10-21 LU LU52224D patent/LU52224A1/xx unknown
- 1966-10-22 ES ES0332637A patent/ES332637A2/en not_active Expired
- 1966-11-20 AT AT979066A patent/AT291404B/en not_active IP Right Cessation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2467474A1 (en) * | 1979-10-11 | 1981-04-17 | Tno | METHOD OF MANUFACTURING ELECTRETS |
Also Published As
| Publication number | Publication date |
|---|---|
| NL6614505A (en) | 1967-04-24 |
| ES332637A2 (en) | 1967-12-01 |
| CH498479A (en) | 1970-10-31 |
| LU52224A1 (en) | 1966-12-21 |
| AT291404B (en) | 1971-06-15 |
| BE688615A (en) | 1967-03-31 |
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