US4595706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anti-static packing material
Assignee: Dow Chemical Co
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Filing: 1985-09-09
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Granted: 1986-06-17
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Expires: 2005-09-09
Abstract
Abstract A process and the product made thereby are disclosed in the preferred form of this process wherein a polymeric packing material is first fluorinated at ambient temperature for an interval of contact with elemental fluorine. Then, contact with a strong base converts the polymer into conjugated double bonds, reducing electrical resistance. The double bonds yield a surface layer able to controllably conduct electrical current.
Inventors
- 👤 Dennis J. Milligan
- 👤 Phil Rolland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:24
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/12; C08J7/126; H; H01; H01B; H01B1/00; H01B1/06; H01B1/12; H01B1/124; H01B1/125; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249954; Y10T428/249955; Y10T428/249959; Y10T428/249961
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
57 words
A method of imparting surface conductivity to polymeric packing material, the method comprising a step of at least partially fluorinating to an effective depth of up to about 50 microns of the surface a foamed packing material of polyethylene, polystyrene, polyolefin, polyurethane and co-polymers thereof and a subsequent step of dehydrofluorinating by contact with a strong base.
Claim 2
Independent Claim
57 words
A method of imparting surface conductivity to polymeric packing material, the method comprising a step of at least partially fluorinating to an effective depth of up to about 50 microns of the surface a foamed packing material of polyethylene, polystyrene, polyolefin, polyurethane and co-polymers thereof and a subsequent step of dehydrofluorinating by contact with a strong base.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein the fluorinating step occurs by contacting the foamed packing material with fluorine gas.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein the fluorinating gas is diluted by an inert gas.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein the dehydrofluorinating step occurs by contacting the packing material with a strongly basic solution including ethylenediamine, sodium hydroxide, or sodium methoxide.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein the treated packing material is washed and dried.
Claim 7
Dependent Claim
16 words
The method of claim 1 wherein the polymer is treated by contact with a Lewis acid.
Claim 8
Dependent Claim
23 words
The method of claim 1 including the steps of fabricating to a desired final shape of randomly sized particles before the dehydrohalogenating step.
Claim 9
Dependent Claim
46 words
The method of claim 1 including the step of placing the polymeric packing material in a closed reactor, initially purging the reactor to remove any oxygen therein, and thereafter conducting a flow of fluorine gas mixed with an inert gas into the reactor at ambient temperature.
Claim 10
Dependent Claim
43 words
The method of claim 8 including the subsequent step of contacting the treated polymeric packing material with a strong base solution to the degree necessary to obtain surface conversion of color in the polymeric packing material to form a brown surface layer thereon.
Claim 11
Dependent Claim
37 words
The method of claim 9 wherein the polymeric packing material at the surface is converted to provide conjugated double bonds in the polymeric chain yielding a surface layer having conductivity of 10 -9 /ohm cm or greater.
Claim 12
Dependent Claim
23 words
The method of claim 10 wherein the conductivity of the completed product is between about 10 -9 to about 10 -2 /ohm cm.
Claim 13
Dependent Claim
26 words
The method of claim 8 wherein conductivity is through a surface layer of brown coloration of at least about 40 microns thick having an oriented structure.
References Cited (Backward Citations)
US4490487A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |