Patent US4374702A successfully refreshed from Google Patents.
US4374702A
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Microfibrillated cellulose
Assignee: Rayonier Inc
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Filing: 1981-10-22
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Granted: 1983-02-22
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Expires: 2001-10-22
Abstract
Abstract Microfibrillated celluloses having properties distinguishable from all previously known celluloses, are produced by passing a liquid suspension of cellulose through a small diameter orifice in which the suspension is subjected to a pressure drop of at least 3000 psig and a high velocity shearing action followed by a high velocity decelerating impact, and repeating the passage of said suspension through the orifice until the cellulose suspension becomes a substantially stable suspension. The process converts the cellulose into microfibrillated cellulose without substantial chemical change of the cellulose starting material.
Inventors
- 👤 Albin F. Turbak
- 👤 Fred W. Snyder
- 👤 Karen R. Sandberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:14
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/11; D21; D21B; D21B1/00; D21B1/04; D21B1/12; D21B1/30; D21B1/36; D21H; D21H11/00; D21H11/16; D21H11/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
91 words
A process for preparing microfibrillated cellulose comprising passing a liquid suspension of fibrous cellulose through a high pressure homogenizer having a small diameter orifice in which the suspension is subjected to a pressure drop of at least 3000 psi and a high velocity shearing action followed by a high velocity decelerating impact against a solid surface, repeating the passage of said suspension through the orifice until said cellulose suspension becomes a substantially stable suspension, said process converting said cellulose into microfibrillated cellulose without substantial chemical change of the cellulose starting material.
Claim 2
Dependent Claim
91 words
A process for preparing microfibrillated cellulose comprising passing a liquid suspension of fibrous cellulose through a high pressure homogenizer having a small diameter orifice in which the suspension is subjected to a pressure drop of at least 3000 psi and a high velocity shearing action followed by a high velocity decelerating impact against a solid surface, repeating the passage of said suspension through the orifice until said cellulose suspension becomes a substantially stable suspension, said process converting said cellulose into microfibrillated cellulose without substantial chemical change of the cellulose starting material.
Claim 3
Dependent Claim
23 words
The process of claim 1 in which the liquid suspension is heated to at least 50° C. prior to passage through the orifice.
Claim 4
Dependent Claim
17 words
The process of claim 3 in which the liquid suspension is heated to at least 80° C.
Claim 5
Dependent Claim
20 words
The process of claim 1 in which the suspension is subjected to a pressure drop of at least 5000 psi.
Claim 6
Dependent Claim
18 words
The process of claim 1 in which the suspension contains no more than 10% by weight of cellulose.
Claim 7
Dependent Claim
17 words
The process of claim 5 in which the suspension contains 4 to 7% by weight of cellulose.
Claim 8
Dependent Claim
13 words
The process of claim 1 in which the suspension is an aqueous suspension.
Claim 9
Dependent Claim
13 words
The process of claim 1 in which the suspension is an organic suspension.
Claim 10
Dependent Claim
16 words
The process of claim 1 in which the shearing action is a right angle shearing action.
Claim 11
Dependent Claim
19 words
The process of claim 1 in which the suspension is subjected to the pressure drop at an elevated temperature.
Claim 12
Dependent Claim
15 words
The process of claim 10 in which the elevated temperature is at least 50° C.
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) | 1986-02-21 | 1986-08-23 | 1987-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-21 | 1990-08-23 | 1991-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-21 | 1994-08-23 | 1995-02-22 | $7700.00 | Window Closed / Lapsed |