EP0063699A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for the production of high solids concentration pigmentary titanium dioxide slurries and titanium dioxide dispersions
Assignee: Tronox Pigment UK Ltd
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Filing: 1982-03-29
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Granted: —
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Expires: 2002-03-29
Abstract
Abstract Stable high concentration aqueous slurries of pigmentary metal oxide particles having a hydrous oxide surface-treatment comprising alumina, for example alumina surface-treated pigmentary titanium dioxide, may be formed by the use of a specified combination of anionic and amine dispersants and a milling in the presence of grinding elements, for example in a sand mill, to develop suitable viscosity and gloss characteristics. The slurries may show thixotropic properties and are suitable for incorporation in vinyl silk aqueous emulsion paints.
Inventors
- 👤 Brian Tear
- 👤 David George Othen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 11:53
CPC Classifications
C; C09; C09D; C09D17/00; C09D17/004; C09D17/007; C09D7/00; C09D7/40; C09D7/45; Y; Y10; Y10S; Y10S516/00; Y10S516/01; Y10S516/06
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
115 words
A process for the production of an aqueous slurry of pigmentary metal oxide particles characterised by forming an aqueous dispersion of washed pigmentary metal oxide particles which have been surface treated with one or more hydrous oxides comprising alumina, raising the solids concentration of the particles in the dispersion to above 60 % by weight, introducing into the dispersion, before or after the solids concentration thereof has been raised a combination of dispersants comprising an amine dispersant and an anionic dispersant and milling the raised solids concentration dispersion, containing the combination of dispersants, in the presence of grinding elements to improve the gloss and viscosity characteristics, in use, of the pigmentary metal oxide particles therein.
Claim 2
Dependent Claim
115 words
A process for the production of an aqueous slurry of pigmentary metal oxide particles characterised by forming an aqueous dispersion of washed pigmentary metal oxide particles which have been surface treated with one or more hydrous oxides comprising alumina, raising the solids concentration of the particles in the dispersion to above 60 % by weight, introducing into the dispersion, before or after the solids concentration thereof has been raised a combination of dispersants comprising an amine dispersant and an anionic dispersant and milling the raised solids concentration dispersion, containing the combination of dispersants, in the presence of grinding elements to improve the gloss and viscosity characteristics, in use, of the pigmentary metal oxide particles therein.
Claim 3
Dependent Claim
18 words
A process as claimed in claim 1 wherein the pigmentary metal oxide particles are pigmentary titanium dioxide particles.
Claim 4
Dependent Claim
29 words
A process as claimed in claim 1 or 2 wherein the pigmentary metal oxide bears a surface treatment of from 0.5 % to 4.0 % by weight of alumina.
Claim 5
Dependent Claim
27 words
A process as claimed in claim 3 wherein the pigmentary metal oxides bears a surface treatment of from 1.0 % to below 3.0 % by weight alumina.
Claim 6
Dependent Claim
21 words
A process as claimed in any preceding claim wherein the anionic dispersant is a polyacrylate, polyphosphate pyrophosphate, citrate, silicate or tartrate.
Claim 7
Dependent Claim
22 words
A process as claimed in claim 5 wherein the anionic dispersant is in the form of a sodium, potassium or ammonium salt.
Claim 8
Dependent Claim
40 words
A process as claimed in any preceding claim wherein the anionic dispersant is introduced into the pigment dispersion in less than 0.75 % but in at least 0.04 % by weight of the hydrous oxide surface-treated pigmentary metal oxide particles.
Claim 9
Dependent Claim
18 words
A process as claimed in any preceding claim wherein the amine dispersant is a secondary or tertiary amine.
Claim 10
Dependent Claim
14 words
A process as claimed in claim 8 wherein the amine dispersant is an alkanolamine.
Claim 11
Dependent Claim
35 words
A process as claimed in any preceding claim wherein the amine dispersant is introduced into the pigment dispersion in at least 0.3 % by weight of the hydrous oxide surface treated pigmentary metal oxide particles.
Claim 12
Dependent Claim
34 words
A process as claimed in any preceding claim wherein the total quantity of the anionic and amine dispersants is not more than 3 % by weight of the hydrous oxide surface-treated metal oxide particles.
Claim 13
Dependent Claim
32 words
A process as claimed in claim 10 or 11 wherein the quantity of the amine dispersant is not more than 2 % by weight of the hydrous oxide surface-treated metal oxide particles.
Claim 14
Dependent Claim
51 words
A process as claimed in any preceding claim wherein the raised solids concentration dispersion containing the ' combination of dispersants is milled to raise the gloss value to at least 50 and the Brookfield viscosity value to at least 400 but not more than 3000 both values being as herein defined.
Claim 15
Dependent Claim
41 words
A process as claimed in any preceding claim wherein the raised solids concentration dispersion containing the combination of dispersants is milled until less than 20 % by weight of the pigmentary metal oxide particles are greater than 0.5 microns in diameter.
Claim 16
Dependent Claim
106 words
An aqueous dispersion of pigmentary metal oxide particles surface treated with from 0.5 to 4.0 % of alumina by weight of the pigmentary metal oxide particles the dispersion having a solids concentration of above 60 % by weight and containing a combination of dispersants comprising an amine dispersant in at least 0.3 % and not more than 2 % and an anionic dispersant in at least 0.04 % less than 0.6 % by weight of the hydrous oxide surface-treated metal oxide particles less than 20 % of the said hydrous oxide surface treated metal oxide particles having a particle size greater than 0.5 microns in diameter.
Claim 17
Dependent Claim
106 words
An aqueous dispersion of pigmentary metal oxide particles surface treated with from 0.5 to 4.0 % of alumina by weight of the pigmentary metal oxide particles the dispersion having a solids concentration of above 60 % by weight and containing a combination of dispersants comprising an amine dispersant in at least 0.3 % and not more than 2 % and an anionic dispersant in at least 0.04 % less than 0.6 % by weight of the hydrous oxide surface-treated metal oxide particles less than 20 % of the said hydrous oxide surface treated metal oxide particles having a particle size greater than 0.5 microns in diameter.
Claim 18
Dependent Claim
23 words
An aqueous dispersion of pigmentary metal oxide particles the product of a process as claimed in any one of claims 1 to 14.
Claim 19
Dependent Claim
22 words
A process as claimed in claim 1 and substantially as described herein with reference to any one of Examples 1 to 5.
References Cited (Backward Citations)
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