Colored luster pigments
AssigneeCiba Specialty Chemicals Corporation
InventorsPatrice Bujard, Natacha Bonnard
Life of this patent
Estimating the term…
Abstract
The invention relates to colored luster pigments consisting of a transparent or metallic reflecting core, of a coating consisting of at least one silicon oxide of the composition SiO.sub.0.25 to SiO.sub.0.95 and of further optional coatings, to coating processes by coating metallic silicon in the presence of oxygen, if required with changing its partial pressure, as well as to the use of these luster pigments for pigmenting plastic materials, paints and printing inks, and to pigmented compositions comprising these luster pigments.
Claims36
A coloured pigment, comprising
- (a) a core consisting of a substantially transparent or metallic reflecting material, and
- (b) at least one coating consisting essentially of one or more than one silicon oxide, wherein the average molar ratio of oxygen to silicon of coating (b) is from 0.25 to 0.95.
A coated transparent or metallic reflecting substrate having a substantially smooth surface and having at least one dimension which is greater than 200 .mu.m, which comprises a layer of one or more than one silicon oxide, wherein the average molar ratio of oxygen to silicon of this silicon oxide layer is from 0.25 to 0.95.
A process for coating a substrate with a coating consisting essentially of one or more than one silicon oxide, the average molar ratio of oxygen to silicon being from 0.25 to 0.95, by vacuum evaporation, sputtering or chemical vapor deposition of metallic silicon in the presence of gaseous oxygen at an oxygen partial pressure of 3.0.multidot.10.sup.-4 Pa to 1.8.multidot.10.sup.-3 Pa.
A process for coating a substrate with two coatings (b") and (c"), each consisting essentially of one or more than one silicon oxide, by vacuum evaporation, sputtering or chemical vapor deposition of metallic silicon in the presence of gaseous oxygen, wherein
- the average molar ratio of oxygen to silicon of coating (b") is from 0.25 to 0.95,
- the average molar ratio of oxygen to silicon of coating (c") is from 1.0 to 2.0, and
- the oxygen partial pressure is changed in the course of the coating process.
Dependencies are inferred from the claim text.