US4171987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Micro-porous sheet
Assignee: Fujifilm Holdings Corp
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Filing: 1975-03-13
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Granted: 1979-10-23
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Expires: 1995-03-13
Abstract
Abstract A micro-porous sheet having excellent thermostability which contains a cellulose ester as a basic component and 0.1 to 20 wt% of a cellulose ether based on the cellulose ester.
Inventors
- 👤 Masaru Horiguchi
- 👤 Nobuo Hiratsuka
- 👤 Sumio Otani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:39
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/14; B01D71/16; B01D69/00; B01D69/02; B01D71/18; B01D71/20; B01D71/22; C; C08; C08L; C08L1/00; C08L1/08; C08L1/10; G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/447; G01N27/44704; G01N27/44747
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
181 words
A micro-porous sheet comprising a cellulose ester as a basic component and about 0.1 to 20 wt% of a cellulose ether based on the cellulose ester wherein said cellulose ester is cellulose diacetate, cellulose triacetate, nitrocellulose, cellulose acetate butyrate, cellulose propionate or a mixture thereof and said cellulose ether has the formula ##STR4## wherein n is the degree of polymerization, and R is --H, --CH 3 , or --CH 2 CH 3 , with the average degree of substitution where R is --CH 3 or --CH 2 CH 3 ranging from about 1.0 to 1.9 and where a portion of the --CH 3 and --CH 2 CH 3 groups can be replaced by a member selected from the group consisting of --CH 2 CH 2 OH, --CH 2 CH 2 CH 2 OH, --CH 2 CH 2 OOCCH 3 , --CH 2 CH 2 CH 2 OOCCH 3 , ##STR5## such that the average degree of substitution by said member ranges from 0 to about 0.3 and wherein the average pore size of the microporous sheet is less than 10 microns.
Claim 2
Dependent Claim
181 words
A micro-porous sheet comprising a cellulose ester as a basic component and about 0.1 to 20 wt% of a cellulose ether based on the cellulose ester wherein said cellulose ester is cellulose diacetate, cellulose triacetate, nitrocellulose, cellulose acetate butyrate, cellulose propionate or a mixture thereof and said cellulose ether has the formula ##STR4## wherein n is the degree of polymerization, and R is --H, --CH 3 , or --CH 2 CH 3 , with the average degree of substitution where R is --CH 3 or --CH 2 CH 3 ranging from about 1.0 to 1.9 and where a portion of the --CH 3 and --CH 2 CH 3 groups can be replaced by a member selected from the group consisting of --CH 2 CH 2 OH, --CH 2 CH 2 CH 2 OH, --CH 2 CH 2 OOCCH 3 , --CH 2 CH 2 CH 2 OOCCH 3 , ##STR5## such that the average degree of substitution by said member ranges from 0 to about 0.3 and wherein the average pore size of the microporous sheet is less than 10 microns.
Claim 3
Dependent Claim
24 words
The micro-porous sheet of claim 1 wherein the average pore size of the pores of said micro-porous sheet is from 0.05 to 5 microns.
Claim 4
Dependent Claim
22 words
The micro-porous sheet of claim 1, wherein said cellulose ester contains about 30 wt% or more of a cellulose organic acid ester.
Claim 5
Dependent Claim
37 words
The micro-porous sheet of claim 1, wherein said cellulose ether is methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl ethyl cellulose, acetylpropyl methyl cellulose, carboxy-benzoyloxypropyl methyl cellulose, or carboxy-benzoyloxypropyl ethyl cellulose or a mixture thereof.
Claim 6
Dependent Claim
21 words
The micro-porous sheet of claim 1, wherein said cellulose ether has an average molecular weight of about 20,000 to about 200,000.
Claim 7
Dependent Claim
20 words
The micro-porous sheet of claim 4, wherein said cellulose ether is methylcellulose, ethylcellulose, hydroxypropyl methyl cellulose, or carboxybenzoyloxypropyl methyl cellulose.
References Cited (Backward Citations)
US3428584A
Cited
US3892665A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-22 | 1983-04-23 | 1983-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-22 | 1987-04-23 | 1987-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-22 | 1991-04-23 | 1991-10-23 | $7700.00 | Window Closed / Lapsed |