EP0094801A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Compositions comprising inorganic particles
Assignee: Johnson Matthey PLC
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Filing: 1983-05-12
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Granted: —
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Expires: 2003-05-12
Abstract
Abstract loccular compositions comprising ultrafine inorganic particles having maximum particle dimensions of from 0.5 to 3000 (preferably 2 to 1500) nm combined with a size-stabiliser which is a lyophobic substance with lyophilic activity on its surface and also comprising a polyelectrolyte flocculating agent attached to the combination. The size-stabiliser protects the ultrafine particles against agglomeration during formation of the flocculates and the mixing of flocculates into various materials such as plastics, inks, paint or refractory materials. Also a method for making the flocculates from colloidal dispersions of particles, size-stabilisers and flocculating agents. The flocculates are particularly useful with particles of metals of the coinage and transition groups for making transparent colouring agents. Also materials containing the ultrafine particles.
Inventors
- 👤 Martyn Charles Barker
- 👤 Edward Gordon Rowlands
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 21:43
CPC Classifications
C; C09; C09K; C09K3/00; B; B82; B82Y; B82Y30/00; C03; C03C; C03C1/00; C03C1/04; C09C; C09C1/00; C09C1/02; C09C1/027; C09D; C09D11/00; C09D11/02; C09D11/03; C09D7/00; C09D7/40; C09D7/60; C09D7/61; C09D7/62; C09D7/66; C09D7/67; C01; C01P; C01P2002/00; C01P2002/80; C01P2002/84; C01P2004/00; C01P2004/50; C01P2004/51; C01P2004/52; C01P2004/60; C01P2004/61; C01P2004/64; C01P2006/00; C01P2006/10; C01P2006/22; C01P2006/32; C01P2006/33; C01P2006/34; C01P2006/60; C01P2006/80; C01P2006/90
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
129 words
A floccular composition comprising (a) ultrafine inorganic particles in which the maximum dimension of a major proportion of the particles is from 0.5 to 3000 nm, (b) a size-stabiliser in combination with the particles, the size-stabiliser being a lyophobic substance provided with means which impart lyophilic activity to the surface of the substance wherein the substance is lyophobic to at least one liquid dispersant to which the means is lyophilic and wherein the lyophobic substance is sufficiently impermeable to said liquid dispersant to prevent a reduction of more than 5X in the volume of the substance on removal of the substance from a dispersion of the substance in said liquid dispersant and (c) a flocculation modifier which comprises a polyelectrolyte attached to the combination of size-stabiliser and ultrafine particles.
Claim 2
Dependent Claim
129 words
A floccular composition comprising (a) ultrafine inorganic particles in which the maximum dimension of a major proportion of the particles is from 0.5 to 3000 nm, (b) a size-stabiliser in combination with the particles, the size-stabiliser being a lyophobic substance provided with means which impart lyophilic activity to the surface of the substance wherein the substance is lyophobic to at least one liquid dispersant to which the means is lyophilic and wherein the lyophobic substance is sufficiently impermeable to said liquid dispersant to prevent a reduction of more than 5X in the volume of the substance on removal of the substance from a dispersion of the substance in said liquid dispersant and (c) a flocculation modifier which comprises a polyelectrolyte attached to the combination of size-stabiliser and ultrafine particles.
Claim 3
Dependent Claim
23 words
A floccular composition according to claim 1 wherein the size-stabiliser comprises a hydrophobic organic substance having a molecular weight of at least 5000.
Claim 4
Dependent Claim
14 words
A floccular composition according to claim 1 wherein the size-stabiliser comprises an inorganic compound.
Claim 5
Dependent Claim
18 words
A floccular composition according to claim 8 wherein the size-stabiliser has a density above 3.5 g/cm 3 .
Claim 6
Dependent Claim
20 words
A floccular composition according to claim 1 wherein the molecular weight of the polectrolyte flocculation modifier is at least 3000.
Claim 7
Dependent Claim
37 words
A free-flowing composition comprising ultrafine particles, a size-stabiliser in combination with the ultrafine particles and a flocculation modifier attached to the combination of size-stabiliser and particles, the particles, size-stabiliser and modifier being as defined in claim 1.
Claim 8
Independent Claim
240 words
A method for making a floccular composition comprising ultrafine inorganic particles in which the maximum dimension of a major proportion of the particles is from 0.5 to 3000 nm wherein the method comprises steps of (a) adding a colloidal dispersion of ultrafine particles to a dispersion of a size-stabiliser in liquid dispersant whereupon the ultrafine particles and the size-stabiliser spontaneously enter into a combination, the size-stabiliser being a lyophobic substance having surface means which import lyophilic. activity to the surface of ' the substance, the substance and the means being respectively lyophobic and lyophilic. towards the liquid dispersant and wherein the lyophobic substance is sufficiently impermeable to the liquid dispersant to prevent a reduction of more than 5% in the volume of the substance on removal of the substance from the liquid dispersant, (b) either, before the addition of the colloidal dispersion of ultrafine particles to the dispersion of size-stabiliser, treating the size-stabiliser with a dispersion of a polyelectrolyte flocculation modifier which on the addition of the colloidal dispersion flocculates with the size-stabiliser and ultrafine particles producing a floccular composition comprising flocculation modifier and size-stabiliser in combination with ultrafine particles or, after the addition of the colloidal dispersion of ultrafine particles to the dispersion of size-stabiliser, treating the size-stabiliser with a dispersion of a polyelectrolyte flocculation modifier which flocculates with the size-stabiliser and the ultrafine particles producing a floccular composition comprising flocculation modifier and size-stabiliser in combination with ultrafine particles.
Claim 9
Independent Claim
240 words
A method for making a floccular composition comprising ultrafine inorganic particles in which the maximum dimension of a major proportion of the particles is from 0.5 to 3000 nm wherein the method comprises steps of (a) adding a colloidal dispersion of ultrafine particles to a dispersion of a size-stabiliser in liquid dispersant whereupon the ultrafine particles and the size-stabiliser spontaneously enter into a combination, the size-stabiliser being a lyophobic substance having surface means which import lyophilic. activity to the surface of ' the substance, the substance and the means being respectively lyophobic and lyophilic. towards the liquid dispersant and wherein the lyophobic substance is sufficiently impermeable to the liquid dispersant to prevent a reduction of more than 5% in the volume of the substance on removal of the substance from the liquid dispersant, (b) either, before the addition of the colloidal dispersion of ultrafine particles to the dispersion of size-stabiliser, treating the size-stabiliser with a dispersion of a polyelectrolyte flocculation modifier which on the addition of the colloidal dispersion flocculates with the size-stabiliser and ultrafine particles producing a floccular composition comprising flocculation modifier and size-stabiliser in combination with ultrafine particles or, after the addition of the colloidal dispersion of ultrafine particles to the dispersion of size-stabiliser, treating the size-stabiliser with a dispersion of a polyelectrolyte flocculation modifier which flocculates with the size-stabiliser and the ultrafine particles producing a floccular composition comprising flocculation modifier and size-stabiliser in combination with ultrafine particles.
Claim 10
Dependent Claim
40 words
A method according to claim 12 which additionally comprises the step of separating off dispersant from the floccular composition whereby there is obtained a dry floccular composition which flocculation modifier is attached to size stabiliser in combination with ultrafine particles.
Claim 11
Dependent Claim
22 words
A method according to claim 12 wherein the. colloidal dispersion of ultrafine particles is made by liberating metal from dissolved metal compound.
Claim 12
Dependent Claim
14 words
A floccular composition according to claim 1 wherein the composition also comprises adsorbed dye.
Claim 13
Dependent Claim
29 words
A method according to of claim 1 wherein the colloidal dispersion of ultrafine particles is treated with a sterically hindering protective colloid before treatment with the dispersion of size-stabiliser.
Claim 14
Dependent Claim
20 words
A plastics ink, paint or refractory material containing ultrafine inorganic particles as claimed any one of claims 1 to 10.
Claim 15
Dependent Claim
28 words
A material according to claim 16 in which the particles are particles of metal a majority of which have a maximum dimension of from 2 to 50 nm.
Claim 16
Dependent Claim
30 words
A material according to claim 16 in which the particles are particles of metal compound, a majority of which particles have a maximum dimension of from 2 to 50 nm.
References Cited (Backward Citations)
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