US4303641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrous silica gel containing dentifrice
Assignee: WR Grace and Co Conn
•
Filing: 1978-05-24
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Granted: 1981-12-01
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Expires: 1998-05-24
Abstract
Abstract Dentifrice compositions containing a hydrous silica gel having a water content of from about 20 to about 60 weight percent are disclosed. The abrasiveness of the gel is increased by contacting the gel with an alkaline medium to provide a gel pH of about 6 to about 10 and/or preparing the gel by drying and grinding a silica hydrogel that has been washed with an aqueous acidic solution having a temperature of from about 80° to about 100° F.
Inventors
- 👤 II Robert B. DeWolf
- 👤 Rimantas Glemza
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:27
CPC Classifications
A; A61; A61K; A61K8/00; A61K8/02; A61K8/04; A61K8/042; A61K8/18; A61K8/19; A61K8/25; A61Q; A61Q11/00; B; B65; B65D; B65D5/00; B65D5/42; B65D5/44; B65D5/46; B65D5/46008; B65D5/46016; B65D5/62; B65D5/64; A61K2800/00; A61K2800/40; A61K2800/41; A61K2800/412
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
63 words
A dentifrice composition comprising from about 5 to about 75 weight percent of a humectant and from about 5 to about 50 weight percent of a hydrous silica gel having a water content from about 20 to about 60 weight percent, an average particle size of from about 1 to about 40 microns, and a pH of from about 6 to about 10.
Claim 2
Dependent Claim
63 words
A dentifrice composition comprising from about 5 to about 75 weight percent of a humectant and from about 5 to about 50 weight percent of a hydrous silica gel having a water content from about 20 to about 60 weight percent, an average particle size of from about 1 to about 40 microns, and a pH of from about 6 to about 10.
Claim 3
Dependent Claim
36 words
The dentifrice composition of claim 1 in which a hydrous silica gel is contacted with an alkaline medium in an amount sufficient to provide the gel having the pH of from about 6 to about 10.
Claim 4
Dependent Claim
16 words
The dentifrice composition of claim 2 in which the gel is contacted with an ammoniacal medium.
Claim 5
Dependent Claim
15 words
The dentifrice composition of claim 2 in which the gel is contacted with gaseous ammonia.
Claim 6
Dependent Claim
20 words
The dentifrice composition of claim 1 in which the gel has a pH of from about 8 to about 9.5.
Claim 7
Dependent Claim
36 words
The dentifrice composition of claim 5 in which a hydrous silica gel is contacted with an ammoniacal medium in an amount sufficient to provide the gel having the pH of from about 8 to about 9.5.
Claim 8
Dependent Claim
15 words
The dentifrice composition of claim 6 in which the gel is contacted with gaseous ammonia.
Claim 9
Dependent Claim
40 words
The dentifrice composition of claim 2 in which the gel is prepared by washing a silica hydrogel with an aqueous acidic solution having a temperature of from about 80 to about 200° F. and drying and grinding the washed hydrogel.
Claim 10
Dependent Claim
19 words
The dentifrice composition of claim 8 in which the hydrogel is washed for about 6 to about 15 hours.
Claim 11
Dependent Claim
29 words
The dentifrice composition of claim 8 in which the drying and grinding are done simultaneously in an impact mill into which a moving stream of heated air is introduced.
Claim 12
Dependent Claim
34 words
The dentifrice composition of claim 8 in which the gel is contacted with an alkaline medium in an amount sufficient to provide the gel having the pH of from about 8 to about 9.5.
Claim 13
Dependent Claim
23 words
The dentifrice composition of claim 1 in which the gel has a water content of from about 35 to about 60 weight percent.
Claim 14
Dependent Claim
21 words
The dentifrice composition of claim 1 in which the gel has a radioactive dentin abrasion value of at least about 400.
Claim 15
Dependent Claim
21 words
The dentifrice composition of claim 1 in which the gel has a radioactive dentin abrasion value of at least about 600.
Claim 16
Dependent Claim
28 words
The dentifrice composition of claim 8 in which the hydrogel is washed with an aqueous acidic solution having a temperature of from about 80° to about 100° F.
Claim 17
Dependent Claim
34 words
The dentifrice composition of claim 8 in which the hydrogel is washed for a period of time sufficient to reduce the total salts content of the hydrogel to less than about 5 weight percent.
Claim 18
Dependent Claim
19 words
The dentifrice composition of claim 8 in which the hydrogel is washed for about 6 to about 12 hours.
Claim 19
Dependent Claim
14 words
The dentifrice composition of claim 8 in which the hydrogel is an acid-set hydrogel.
Claim 20
Dependent Claim
21 words
The dentifrice composition of claim 8 in which the washed hydrogel has a pH of from about 2.5 to about 5.
Claim 21
Dependent Claim
25 words
The dentifrice composition of claim 8 in which the hydrogel is dried to a water content of from about 35 to about 60 weight percent.
Claim 22
Dependent Claim
32 words
The dentifrice composition of claim 8 in which the washed hydrogel is dried by oven drying, rotary drying, or cascade drying and ground in a mill in the presence of heated air.
Claim 23
Dependent Claim
21 words
The dentifrice composition of claim 8 in which the gel is contacted with an alkaline medium comprising an alkali metal hyroxide.
Claim 24
Dependent Claim
21 words
The dentifrice composition of claim 10 in which the gel is contacted with gaseous anhydrous ammonia upon exit from the mill.
Claim 25
Dependent Claim
23 words
The dentifrice composition of claim 23 in which the gel is contacted with the ammonia not more than about 1 minute after milling.
Claim 26
Dependent Claim
44 words
The dentifrice composition of claim 10 in which the mill is an air-classifying hammer mill in which the heated air has an inlet temperature of from about 200° to about 500° F. and an outlet temperature of from about 80° to about 150° F.
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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) | 1984-11-30 | 1985-06-01 | 1985-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-30 | 1989-06-01 | 1989-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-30 | 1993-06-01 | 1993-12-01 | $7700.00 | Window Closed / Lapsed |