Patent US3894985A successfully refreshed from Google Patents.
US3894985A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-coloring diatomite-filled polyolefins
Assignee: CELITE Corp
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Filing: 1974-02-14
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Granted: 1975-07-15
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Expires: 1994-02-14
Abstract
Abstract Transparent polyolefin films containing diatomite as an antiblocking agent have in the past had a tendency to become discolored after an interval of time. That tendency is completely overcome by incorporation into the polyolefin of white diatomite having a pH not above 7.5, and preferably in the range of 5.5 to 7.5. Such diatomite can be obtained by chemical calcining of gray, tan or white diatomite with strong inorganic acids.
Inventors
- 👤 Garth Coombs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:33
CPC Classifications
D; D01; D01F; D01F1/00; D01F1/02; D01F1/10; C; C08; C08K; C08K9/00; C08K9/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
85 words
NON-COLORING TRANSPARENT POLYOLEFIN FILM HAVING INCORPORATED AS AN ANTI-BLOCKING AGENT THEREIN WHITE DIATOMITE HAVING A PH OF NOT GREATER THEN 7.5, SAID DIATOMITE BEING IN THE FORM OF PARTICLES OF FROM 0.5 TO 7 MICRONS IN SIZE AND BEING PRESENT IN A CONCENTRATION IN SAID FILM IN THE RANGE OF 2 TO 4 PARTS BY WEIGHT PER 1,000 PARTS BY WEIGHT OF POLYOLEFIN, SAID DIATOMITE BEING PRODUCED BY CHEMICALLY CALCINING WHITE DIATOMITE OF HIGH PH OR TAN OR GRAY DIATOMITE WITH A STRONG INORGANIC ACID.
Claim 2
Dependent Claim
85 words
NON-COLORING TRANSPARENT POLYOLEFIN FILM HAVING INCORPORATED AS AN ANTI-BLOCKING AGENT THEREIN WHITE DIATOMITE HAVING A PH OF NOT GREATER THEN 7.5, SAID DIATOMITE BEING IN THE FORM OF PARTICLES OF FROM 0.5 TO 7 MICRONS IN SIZE AND BEING PRESENT IN A CONCENTRATION IN SAID FILM IN THE RANGE OF 2 TO 4 PARTS BY WEIGHT PER 1,000 PARTS BY WEIGHT OF POLYOLEFIN, SAID DIATOMITE BEING PRODUCED BY CHEMICALLY CALCINING WHITE DIATOMITE OF HIGH PH OR TAN OR GRAY DIATOMITE WITH A STRONG INORGANIC ACID.
Claim 3
Dependent Claim
19 words
The film of claim 1 wherein said white diatomite has a pH in the range of 5.5 to 7.5.
Claim 4
Dependent Claim
19 words
The film of claim 2 wherein said white diatomite has a pH in the range of 6.0 to 7.5.
Claim 5
Dependent Claim
15 words
The film of claim 1 wherein said particles are 2 to 6 microns in size.
Claim 6
Dependent Claim
12 words
The film of claim 1 wherein said inorganic acid is phosphoric acid.
Claim 7
Dependent Claim
10 words
The film of claim 1 wherein said polyolefin is polyethylene.
Claim 8
Dependent Claim
10 words
The film of claim 1 wherein said polyolefin is polypropylene.
Claim 9
Dependent Claim
13 words
The film of claim 1 wherein said polyolefin is an ethylene propylene copolymer.
Claim 10
Dependent Claim
21 words
The film of claim 8 wherein said copolymer contains a relatively larger amount of ethylene monomer and possesses a polyethylenic character.
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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |