Hematite Pigments

Simple SummaryContent extracted from patent full text and abstract with AI.

This patent describes a new type of hematite (iron oxide) pigment with improved color properties, specifically high color saturation and reduced unwanted orange tones. The pigment particles have a controlled, nearly spherical shape (low aspect ratio) and specific color metrics (CIELAB values) that result in more vibrant and pure red coloration. The pigments are made through a specific process involving goethite precursor particles, alkali metal phosphate treatment, and controlled thermal processing.

Use CasesContent extracted from patent full text and abstract with AI.

• Coloring paints, inks, and surface coatings for improved color vibrancy and stability.
• Use in building materials, plastics, and paper to achieve enhanced red hues.
• Coloring ceramics, enamels, sand granules, and glazed products where high color purity is desired.
• Application in food products, baking varnishes, and coil coatings that require safe and stable coloring agents.
• Use in pharmaceutical products, particularly for colored tablets.

BenefitsContent extracted from patent full text and abstract with AI.

• Delivers more saturated, pure, and stable red coloration compared to standard hematite pigments, minimizing undesired orange tint.
• Particles with low aspect ratio improve dispersibility and uniformity in various matrices (paints, plastics, coatings).
• Improved optical and color properties allow for broader and higher-value application use.
• Low levels of contaminants (phosphorous, silicon, chromium) enhance safety and reduce regulatory concerns in sensitive uses (e.g. food, pharma).
• Enhanced milling stability and color consistency over time and during processing.

Technical Classifications (CPCs)

Inventors & Applicants

Patent Abstract

A hematite pigment havingi) an aspect ratio AR of lower than 1.5, preferably lower than 1.3, most preferably lower than 1.2,ii) a CIELAB a* value of ≥ 28.5, in particular from 29 to 33,iii) a CIELAB b*-value of ≤ 71 % of the CIELAB a* value, preferably ≤ 70% of the CIELAB a* valueiv) a CIELAB L* value of ≥ 39, in particular from 40 to 43, preferably 40 to 41.