US4824718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous film
Assignee: 3M Co
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Filing: 1987-12-04
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Granted: 1989-04-25
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Expires: 2007-12-04
Abstract
Abstract A disposable article such as a diaper or feminine hygiene product having a rattle-free, liquid impermeable, vapor permeable, microporous, polymeric film having pores defining passages extending therethrough, the passages being partially filled with a rattle-reducing additive material and a method for making same is disclosed.
Inventors
- 👤 Kirk K. Hwang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:24
CPC Classifications
A; A61; A61F; A61F13/00; A61F13/15; A61F13/51; A61F13/514; A61F13/51456; A61F13/51458; A61F13/51462; A61F13/15577; A61F13/15707; A61F13/15731; A61F13/51401; A61F13/51474; A61F13/51476; A61F13/51498; B; B29; B29C; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C59/00; B29C59/02; B29C59/022; A61F2013/00089; A61F2013/00182; A61F2013/51409; A61F2013/51411; A61F2013/51472; A61F2013/51486; A61F2013/5149; B29C55/00; B29K; B29K2105/00; B29K2105/04; B29K2105/041; B29K2995/00; B29K2995/0018; B29K2995/0025; B29K2995/0026; B29L; B29L2031/00; B29L2031/48; B29L2031/4871; B29L2031/4878; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/24998; Y10T442/00; Y10T442/60; Y10T442/674; Y10T442/678
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
67 words
A disposable article comprising a top sheet, an intermediate liquid absorbent core and an outer backsheet, said backsheet being a rattle-free, liquid impermeable, vapor permeable, microporous film with a rattle-reducing additive material partially filling said micropores uniformly distributed through said film, said film having a moisture vapor transmission rate of at least 2000 grams per square meter per 24 hours at 23° C. and 50% relative humidity.
Claim 2
Dependent Claim
67 words
A disposable article comprising a top sheet, an intermediate liquid absorbent core and an outer backsheet, said backsheet being a rattle-free, liquid impermeable, vapor permeable, microporous film with a rattle-reducing additive material partially filling said micropores uniformly distributed through said film, said film having a moisture vapor transmission rate of at least 2000 grams per square meter per 24 hours at 23° C. and 50% relative humidity.
Claim 3
Dependent Claim
22 words
The disposable article of claim 1 wherein said film has an air permeability Gurley number less than 500 seconds per 50 cc.
Claim 4
Dependent Claim
18 words
The disposable article of claim 2 wherein the film has a thickness ranging from 5 to 250 micrometers.
Claim 5
Dependent Claim
68 words
A method of making the microporous film of the disposable article of claim 1, comprising the steps of: (a) forming a blend of a crystallizable thermoplastic polymer, rattle-reducing additive material and nucleating agent system; (b) extruding the blend into a film; and (c) orienting said film by stretching at a temperature in the range of 10° C. to 10° C. below the melting temperature of said thermoplastic polymer.
Claim 6
Dependent Claim
34 words
A method according to claim 4 wherein the rattle-reducing additive material is selected from mineral oil, glycerin, petroleum jelly, soft carbowax, low molecular weight polyethylene, polyethylene oxide, polypropylene oxide, polytetramethylene oxide or mixtures thereof.
Claim 7
Dependent Claim
18 words
A method according to claim 4 wherein the crystallizable thermoplastic polymer is selected from polypropylene, polyethylene and polyethylene-polypropylene.
Claim 8
Dependent Claim
21 words
A method according to claim 4 wherein the rattle-reducing additive material comprises 5 to 50% by weight of the microporous film.
Claim 9
Dependent Claim
20 words
A method according to claim 4 wherein the nucleating agent system comprises a solid organic acid and an inorganic compound.
Claim 10
Dependent Claim
20 words
A method according to claim 8 wherein the solid organic acid is adipic acid and the inorganic compound is talc.
Claim 11
Dependent Claim
21 words
The disposable article of claim 1 wherein up to 50% of the surface area of said microporous film has been embossed.
Claim 12
Dependent Claim
11 words
A microporous film made according to the process of claim 4.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |