Patent EP0139754A1 successfully refreshed from Google Patents.
EP0139754A1
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Silica base for dentrifrice and process for its preparation
Assignee: Taki Chemical Co Ltd
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Filing: 1984-02-28
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Granted: —
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Expires: 2004-02-28
Abstract
Abstract Silica base for dentifrice having transparency and prolonged stability, desired abrasive ability, specific surface area of 5 to 60 m l /g as measured according to the BET or CTAB method, with the difference therebetween being 40 m 2 /g or less, and having a refractive index of 1.42 to 1.45, which can be prepared by reacting an alkali metal silicate solution with hydrochloric or sulfuric add in the presence of an electrolyte, controlling the ratio of the rate of adding chloride or sulfate ion in a silicaprecipitating step in which the pH of the reaction system is up to 10.0 to that in a neutralizing step of rendering the pH of the reaction system to 8.0 to 6.5 to at least 5:3, completing the neutralizing step within 30 minutes, and ripening for at least ten minutes.
Inventors
- 👤 Shozo Shinpo
- 👤 Tetsuo Fushino
- 👤 Akihiro Hachijo
- 👤 Shozo Ohtsu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 13:36
CPC Classifications
A; A61; A61Q; A61Q11/00; A61K; A61K8/00; A61K8/18; A61K8/19; A61K8/25; C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/18; C01B33/187; C01B33/193; C01P; C01P2006/00; C01P2006/12; C01P2006/60
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
66 words
A silica base material for dentifrice formulation, characterized by having a specific surface area by the B ET method of 5-60 m 2 /g-anhydride, and also, one by the CTA B method of 5-60 m 2 /g-anhydride; having the difference in specific surface area of less than 40 m 2 /g-anhydride between the BET method and the CTAB method; and having a refractive index of 1.42-1.45.
Claim 2
Dependent Claim
66 words
A silica base material for dentifrice formulation, characterized by having a specific surface area by the B ET method of 5-60 m 2 /g-anhydride, and also, one by the CTA B method of 5-60 m 2 /g-anhydride; having the difference in specific surface area of less than 40 m 2 /g-anhydride between the BET method and the CTAB method; and having a refractive index of 1.42-1.45.
Claim 3
Independent Claim
111 words
The method for the production of a silica base material for dentifrice formulation, characterized by the fact that the reaction between alkali metal silicate solution and hydrochloric or sulfuric acid under the presence of electrolyte is conducted in two stages; the silica crystallization stage for which the pH of reaction mixture is brought to 10.0, and the neutralization stage for which the pH is finally brought down to 8.0-6.5; the ratio of the rate of addition of chloride or sulfate ion between said two stages is at least 5:3; and the neutralization is carried out within 30 minutes; and the ageing should be performed for at least more than 10 minutes.
Claim 4
Independent Claim
111 words
The method for the production of a silica base material for dentifrice formulation, characterized by the fact that the reaction between alkali metal silicate solution and hydrochloric or sulfuric acid under the presence of electrolyte is conducted in two stages; the silica crystallization stage for which the pH of reaction mixture is brought to 10.0, and the neutralization stage for which the pH is finally brought down to 8.0-6.5; the ratio of the rate of addition of chloride or sulfate ion between said two stages is at least 5:3; and the neutralization is carried out within 30 minutes; and the ageing should be performed for at least more than 10 minutes.
Claim 5
Dependent Claim
18 words
The method described in claim 2, where the electrolyte is previously added to the alkali metal silicate solution.
Claim 6
Dependent Claim
25 words
The method described in claim 2, where the alkali metal silicate solution has a molar ratio, Si02/X 2 0 (X denotes alkali metal), of 2-4.
Claim 7
Dependent Claim
26 words
The method described in claim 2, where the Si02 concentration of the alkalimetal silicate solution before the addition of hydrochloric or sulfuric acid 5-15% by weight.
Claim 8
Dependent Claim
16 words
The method described in claim 2, where the electrolyte is alkali metal salt of mineral acid.
Claim 9
Dependent Claim
20 words
The method described in claim 2, where the amount of the electrolyte is 10-60% by weight of Sio 2 .
Claim 10
Dependent Claim
18 words
The method described in claim 2, where the concentration of hydrochloric or sulfuric acid is 5-15% by weight.
Claim 11
Dependent Claim
17 words
The method described in claim 2, where the reaction temperature during the silica crystallization stage is 60-100°C.
Claim 12
Dependent Claim
28 words
The method described in claim 2, where the addition of hydrochloric or sulfuric acid during the silica crystalization stage is conducted to take 40 minutes to 4 hours.
References Cited (Backward Citations)
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