Method of making an electret article by transferring fluorine to the article from a gaseous phase
Assignee3M Innovative Properties Company
InventorsMarvin E. Jones, Christopher S. Lyons, David B. Redmond, Jeffrey L. Solomon, Seyed Abolhassan Angadjivand
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Abstract
An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.
Claims58
A method of making an electret comprising:
- fluorinating a polymeric nonwoven web to produce an article having surface fluorination;
- and
- charging the fluorinated web in a manner sufficient to produce an electret,
- the electret comprising at least about 45 atomic % fluorine as detected by ESCA.
A method of making an electret comprising:
- a) fluorinating a nonwoven polymeric fibrous web
- i) in an atmosphere comprising fluorine containing species and an inert gas, and
- ii) in the presence of an electrical discharge to produce a web having surface fluorination;
- and
- b) charging the fluorinated web in a manner sufficient to produce an electret,
- the electret comprising at least about 45 atomic % fluorine as detected by ESCA.
A method of making an electret article, which method comprises the steps of:
- (a) providing a nonwoven fibrous web, wherein the fibers comprise a polymeric nonconductive thermoplastic resin;
- (b) placing fluorine atoms on the surface of the polymeric fibers by transferring a fluorine-containing species from a gaseous phase to the fibers;
- and
- (c) charging the fluorinated nonwoven fibrous web,
- the charged nonwoven web comprising at least about 45 atomic % fluorine as detected by ESCA.
A method of making an electret comprising:
- fluorinating a polymeric article to produce an article having surface fluorination;
- annealing the fluorinated article;
- and
- charging the fluorinated article in a manner sufficient to produce an electret.
A method of making an electret comprising:
- fluorinating a polymeric article in the presence of an alternating current corona discharge at atmospheric pressure to produce an article having surface fluorination;
- and
- charging the fluorinated article in a manner sufficient to produce an electret.
A method of making an electret comprising:
- fluorinating a polymeric article at atmospheric pressure to produce an article having surface fluorination;
- and
- charging the fluorinated article in a manner sufficient to produce an electret.
A method of making an electret comprising:
- fluorinating a polymeric article to produce an article having surface fluorination;
- and
- charging the fluorinated article in a manner sufficient to produce an electret,
- the electret having a quality factor of at least 1.0/mmH2O.
A method of making an electret article, which method comprises the steps of:
- (a) providing a nonwoven fibrous web, wherein the fibers comprise a polymeric nonconductive thermoplastic resin;
- (b) placing fluorine atoms on the surface of the polymeric fibers by transferring a fluorine-containing species from a gaseous phase to the fibers;
- and
- (c) charging the fluorinated nonwoven fibrous web,
- the charged nonwoven web having a surface fluorination that comprises CF3 and CF2 at a CF3:CF2 ratio of at least 0.45 as determined according to the method for determining CF3:CF2.
A method of making an electret article, which method comprises the steps of:
- (a) providing a nonwoven fibrous web, wherein the fibers comprise a polymeric nonconductive thermoplastic resin;
- (b) placing fluorine atoms on the surface of the polymeric fibers by transferring a fluorine-containing species from a gaseous phase to the fibers;
- and
- (c) charging the fluorinated nonwoven fibrous web,
- the charged nonwoven web exhibiting a Quality Factor of at least about 1.0/mmH2O.
A method of making an electret article, which method comprises the steps of:
- (a) providing a nonwoven fibrous web, wherein the fibers comprise a polymeric nonconductive thermoplastic resin;
- (b) bubbling elemental fluorine gas through a liquid;
- (c) placing fluorine atoms on the surface of the polymeric fibers by transferring a fluorine-containing species from a gaseous phase to the fibers;
- and
- (d) charging the fluorinated nonwoven fibrous web.
Dependencies are inferred from the claim text.