EP0512764A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for producing electret filter
Assignee: Mitsui Chemicals Inc
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Filing: 1992-05-01
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Granted: —
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Expires: 2012-05-01
Abstract
Abstract A method for producing an electret filter, which methods comprises forming a film comprising a high molecular weight compound, optionally stretching the film, splitting the optionally stretched film to form split yarns, subjecting the split yarns to homo charging to obtain charged split yarns, and forming the charged split yarns into the electret filter.
Inventors
- 👤 Satoshi C/O Mitsui Petrochem. Ind. Ltd. Matsuura
- 👤 Akira c/o Mitsui Petrochem. Ind. Ltd. Yokoyama
- 👤 Yoshio C/O Mitsui Petrochem. Ind. Ltd. Shinagawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 10:14
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/02; B01D39/04; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B01D39/08; B01D39/083; B03; B03C; B03C3/00; B03C3/28; B29; B29C; B29C55/00; B29C55/02; B29C55/04; B29C55/06; B29C71/00; B29C71/04; C; C07; C07C; C07C51/00; C07C51/42; H; H01; H01G; H01G7/00; H01G7/02; H01G7/021; H01G7/023; B01D2239/00; B01D2239/04; B01D2239/0407; B01D2239/0435; B01D2239/0457; B01D2239/06; B01D2239/0604; B01D2239/064; B01D2239/12; B01D2239/1291; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/085; B29C35/0866; B29C2035/0877; B29K; B29K2055/00; B29K2086/00; B29K2096/00; B29K2096/02; Y; Y10; Y10S; Y10S264/00; Y10S264/47
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
54 words
A method for producing an electret filter, which methods comprises forming a film comprising a high molecular weight compound, optionally stretching the film, splitting the optionally stretched film to form split yarns, subjecting the split yarns to homo charging to obtain charged split yarns, and forming the charged split yarns into the electret filter.
Claim 2
Dependent Claim
27 words
A method according to claim 1, wherein said film comprises at least one high molecular weight compound selected from non-polar compounds, polar compounds and modified non-polar compounds.
Claim 3
Dependent Claim
31 words
A method according to claim 2, wherein the modified non-polar high molecular weight compound is a graft copolymer with at least one compound selected from unsaturated carboxylic acids and derivatives thereof.
Claim 4
Dependent Claim
35 words
A method according to claim 3, wherein the modified non-polar high molecular weight compound contains from 0.05 to 15% by weight of the at least one compound selected from unsaturated carboxylic acids and derivatives thereof.
Claim 5
Dependent Claim
23 words
A method according to claim 3 or 4, wherein said unsaturated carboxylic acids and derivatives thereof are unsaturated dicarboxylic acids and anhydrides thereof.
Claim 6
Dependent Claim
28 words
A method according to claim 5, wherein said unsaturated dicarboxylic acids and anhydrides thereof are at least one compound selected from maleic acid, nadic acid, and anhydrides thereof.
Claim 7
Independent Claim
39 words
A method according to any one of the preceding claims, wherein said film comprises a mixture of a non-polar and a polar high molecular weight compound in a weight ratio of from 60 : 39.5 to 99 : 0.5.
Claim 8
Independent Claim
42 words
A method according to any one of claims 2 to 6 wherein said film comprises a polar high molecular weight compound and 0.5 to 20% by weight, based on the weight of the film, of a modified non-polar high molecular weight compound.
Claim 9
Independent Claim
20 words
A method according to any one of the preceding claims, wherein said film is from 10 to 100 µm thick.
Claim 10
Independent Claim
27 words
A method according to any one of the preceding claims, wherein said film is stretched by from 5 to 10 fold in length before the splitting step.
References Cited (Backward Citations)
No citation records indexed.
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