US4181637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sheet-like structure of polyurethane, which is capable of absorbing water vapor and transmitting water vapor
Assignee: Hoechst AG
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Filing: 1977-12-22
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Granted: 1980-01-01
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Expires: 1997-12-22
Abstract
Abstract This invention relates to a sheet-like structure of polyurethane, which is capable of absorbing water vapor and transmitting water vapor, with a uniformly incorporated additive composed of solid particles of at least one swellable, modified polymer. The invention also relates to a process for manufacturing the sheet-like structure.
Inventors
- 👤 Walter Busch
- 👤 Arno Holst
- 👤 Wilhelm Fischer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:31
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; D; D06; D06N; D06N3/00; D06N3/0043; D06N3/005; C08J2375/00; C08J2375/04; Y; Y10; Y10S; Y10S428/00; Y10S428/904; Y10S428/913; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31558; Y10T428/31971
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
82 words
In a sheet-like structure of polyurethane, which is capable of absorbing water vapor and transmitting water vapor, with a uniformly incorporated additive, the improvement comprising that said additive is composed of solid particles of at least one modified starch ether or cellulose ether, which has been modified by cross-linking, effected by means of heat energy, radiation or an additional chemical compound, which is insoluble in water to the extent of at least 50% by weight, and which is swellable in aqueous liquids.
Claim 2
Dependent Claim
82 words
In a sheet-like structure of polyurethane, which is capable of absorbing water vapor and transmitting water vapor, with a uniformly incorporated additive, the improvement comprising that said additive is composed of solid particles of at least one modified starch ether or cellulose ether, which has been modified by cross-linking, effected by means of heat energy, radiation or an additional chemical compound, which is insoluble in water to the extent of at least 50% by weight, and which is swellable in aqueous liquids.
Claim 3
Dependent Claim
69 words
A sheet-like structure as claimed in claim 1, wherein said additional chemical compound is selected from the group consisting of phosphorus oxychloride, dichloroacetic acid and a compound which carries the following group which is reactive towards hydroxy groups: ______________________________________
##STR8## the acrylamido group, R.sub.1 being H or CH.sub.3, or
##STR9## an α-halogenoepoxy group, Hal being Cl or Br, or
##STR10## the chloro-azomethine group, or
##STR11## the alloxy-azomethine group.
______________________________________
Claim 4
Dependent Claim
18 words
A sheet-like structure as claimed in claim 1 which comprises about 10 to 30% by weight of additive.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-31 | 1983-07-02 | 1984-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-31 | 1987-07-02 | 1988-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-31 | 1991-07-02 | 1992-01-01 | $7700.00 | Window Closed / Lapsed |