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EP0243166A2
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Silica platelets
Assignee: Unilever PLC
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Filing: 1987-04-22
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Granted: —
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Expires: 2007-04-22
Abstract
Abstract This invention relates to positively-charged silica platelets and a process for their preparation from modified silica sols by formation of a silica film at an interface.
Inventors
- 👤 Michael Joseph Garvey
- 👤 Ian Charles Griffiths
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 10:47
CPC Classifications
B; B82; B82Y; B82Y30/00; C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/126; C01B33/14; C01B33/146; C01B33/149; C09; C09C; C09C1/00; C09C1/28; C09C1/30; C09C1/3045; C09C1/3054; C01P; C01P2004/00; C01P2004/01; C01P2004/04; C01P2004/20; C01P2004/60; C01P2004/61; C01P2004/62; C01P2004/64; C01P2004/80; C01P2004/82; C01P2004/84
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
48 words
Silica platelets characterised in that the platelets comprise positively-charged particles consisting of a dense silica core coated with a polyvalent metal-oxygen compound, the platelets consisting of at least a monolayer of the particles and having a dimension in the planar direction of at least l0 times their thickness.
Claim 2
Dependent Claim
48 words
Silica platelets characterised in that the platelets comprise positively-charged particles consisting of a dense silica core coated with a polyvalent metal-oxygen compound, the platelets consisting of at least a monolayer of the particles and having a dimension in the planar direction of at least l0 times their thickness.
Claim 3
Dependent Claim
39 words
Silica platelets according to claim 1 wherein the poly-valent metal-oxygen compound is selected from the group comprising metal oxides, metal hydroxides, hydrated metal oxides and mixtures thereof, the metal in each case having a valance of 3 to 4.
Claim 4
Dependent Claim
24 words
Silica platelets according to claim 2 wherein the poly-valent metal-oxygen compound is selected from the group comprising alumina, titania, zirconia, thoria and mixtures thereof.
Claim 5
Dependent Claim
24 words
Silica platelets according to any one of the preceding claims wherein the silica particles have a dimension in the range of 5 to 150nm.
Claim 6
Dependent Claim
21 words
Silica platelets according to any one of the preceding claims having planar dimensions in the range of from 0.05 to 20µm.
Claim 7
Dependent Claim
47 words
A process for the preparation of silica-containing platelets, characterised by forming a dispersion of charged silica-containing particles and adding a surfactant of opposite charge to cause the particles to aggregate at an interface to form the platelets, wherein the particles are coated with a polyvalent metal-oxygen compound.
Claim 8
Dependent Claim
47 words
A process for the preparation of silica-containing platelets, characterised by forming a dispersion of charged silica-containing particles and adding a surfactant of opposite charge to cause the particles to aggregate at an interface to form the platelets, wherein the particles are coated with a polyvalent metal-oxygen compound.
Claim 9
Dependent Claim
43 words
A process according to claim 6 comprising forming a dispersion of positively-charged particles consisting of a dense silica core coated with a polyvalent metal-oxygen compound and adding an anionic surfactant to cause the particles to aggregate at an interface to form the platelets.
Claim 10
Dependent Claim
35 words
A process according to claim 6 comprising adding a cationic surfactant to a negatively-charged silica sol to cause the particles to aggregate at an interface to form platelets and coating the platelets with a metal-oxide.
Claim 11
Dependent Claim
22 words
A process according to any one of claims 6 to 8 wherein the dispersion is agitated so as to rupture the interface.
Claim 12
Dependent Claim
29 words
A process according to any one of claims 6 to 9 wherein the polyvalent metal-oxygen compound is selected from the group comprising alumina, titania, zirconia, thoria and mixtures thereof.
Claim 13
Dependent Claim
44 words
A process according to any one claims 6 to 10 wherein the dispersion has a concentration of silica-containing particles in the range of from 0.001 to 30% w/w and a concentration of surfactant in the range 0.1 to 100g per gram of silica-containing particles.
References Cited (Backward Citations)
No citation records indexed.
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