US5093099A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flaky powder of zinc oxide and its composition for external use
Assignee: Kao Corp
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Filing: 1988-11-14
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Granted: 1992-03-03
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Expires: 2008-11-14
Abstract
Abstract Flaky fine particles of zinc oxide have an average particle diameter of 0.1 to 1 micron, an average particle thickness of 0.01 to 0.2 micron and a mean platy ratio (aspect ratio) of at least 3. They are useful as an ingredient for an external composition containing a medicine or cosmetic.
Inventors
- 👤 Tomoyuki Haishi
- 👤 Emi Sakamoto
- 👤 Hiroshi Itoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:45
CPC Classifications
A; A61; A61Q; A61Q1/00; A61Q1/02; A61K; A61K47/00; A61K47/02; A61K8/00; A61K8/02; A61K8/0241; A61K8/0254; A61K8/18; A61K8/19; A61K8/27; A61K9/00; A61K9/0012; A61K9/0014; B; B82; B82Y; B82Y5/00; C; C01; C01G; C01G9/00; C01G9/02; A61K2800/00; A61K2800/40; A61K2800/41; A61K2800/412; A61K2800/42; A61K2800/43
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
31 words
Zinc oxide particles having an average particle diameter of 0.1 to 1 micron, an average particle thickness of 0.01 to 0.2 micron and a mean platy ratio of at least 3.
Claim 2
Dependent Claim
31 words
Zinc oxide particles having an average particle diameter of 0.1 to 1 micron, an average particle thickness of 0.01 to 0.2 micron and a mean platy ratio of at least 3.
Claim 3
Dependent Claim
98 words
A process for preparing zinc oxide particles having an average particle diameter of 0.1 to 1 micron, an average particle thickness of 0.01 to 0.2 micron and a mean platy ratio of at least 3, comprising the steps of forming precipitates of zinc oxide , at a reaction temperature of 60° C. or lower, in a solution which (a) contains zinc ions, (b) contains one or more acid radicals in a total amount exceeding the equivalent with respect to the zinc ions and (c) has a pH of 11 or higher, and separating the precipitates from the solution.
Claim 4
Dependent Claim
98 words
A process for preparing zinc oxide particles having an average particle diameter of 0.1 to 1 micron, an average particle thickness of 0.01 to 0.2 micron and a mean platy ratio of at least 3, comprising the steps of forming precipitates of zinc oxide , at a reaction temperature of 60° C. or lower, in a solution which (a) contains zinc ions, (b) contains one or more acid radicals in a total amount exceeding the equivalent with respect to the zinc ions and (c) has a pH of 11 or higher, and separating the precipitates from the solution.
Claim 5
Dependent Claim
23 words
A process as claimed in claim 2, in which the formation of precipitates is conducted in the presence of a watersoluble organic substance.
Claim 6
Dependent Claim
101 words
A process for preparing zinc oxide particles having an average particle diameter of 0.1 to 1 micron, an average particle thickness of 0.01 to 0.2 micron and a mean platy ratio of at least 3, comprising the steps of mixing an aqueous solution of a zinc salt with a solution of a precipitating agent, agitating the mixed solutions and forming precipitates of zinc oxide, at a reaction temperature of 60° C. or lower, in a solution of the mixed solutions having (a) a zinc salt content of from 0.1 to 15 wt. % and (b) a pH of 11 or larger.
Claim 7
Dependent Claim
101 words
A process for preparing zinc oxide particles having an average particle diameter of 0.1 to 1 micron, an average particle thickness of 0.01 to 0.2 micron and a mean platy ratio of at least 3, comprising the steps of mixing an aqueous solution of a zinc salt with a solution of a precipitating agent, agitating the mixed solutions and forming precipitates of zinc oxide, at a reaction temperature of 60° C. or lower, in a solution of the mixed solutions having (a) a zinc salt content of from 0.1 to 15 wt. % and (b) a pH of 11 or larger.
Claim 8
Dependent Claim
22 words
A process as claimed in claim 4, in which the formation of precipitates is in the presence of a watersoluble organic substance.
Claim 9
Dependent Claim
43 words
A zinc oxide composition for external application to the human body comprising zinc oxide particles having an average particle diameter of 0.1 to 1 micron, an average particle thickness of 0.01 to 0.2 micron and a mean platy ratio of at least 3.
Claim 10
Dependent Claim
43 words
A zinc oxide composition for external application to the human body comprising zinc oxide particles having an average particle diameter of 0.1 to 1 micron, an average particle thickness of 0.01 to 0.2 micron and a mean platy ratio of at least 3.
Claim 11
Dependent Claim
20 words
A composition as claimed in claim 6, which comprises 0.1 to 50 wt. % of the particles of zinc oxide.
References Cited (Backward Citations)
CA572977A
Cited
DE1443462A1
Cited
US3453072A
Cited
FR2375904A1
Cited
JPS53116296A
Cited
JPS5419237A
Cited
JPS54115698A
Cited
JPS5542282A
Cited
US4255418A
Cited
US4261965A
Cited
US4512978A
Cited
US4544761A
Cited
JPS57149827A
Cited
JPS57205319A
Cited
JPS57209824A
Cited
US4603047A
Cited
EP0273089A1
Cited
US4842848A
Cited
US4772331A
Cited
US4713242A
Cited
JPS62270409A
Cited
JPH02260716A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-03 | 1995-09-02 | 1996-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-03 | 1999-09-02 | 2000-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-03 | 2003-09-02 | 2004-03-03 | $7700.00 | Window Closed / Lapsed |