Pigment settling in storage
Heavy pigments and extenders settle into hard sediment in cans and tanks. Paint that cannot be stirred back to uniformity causes colour variation, complaints and wasted batches.
Industry · Paints & Coatings
Fillers, Extenders and Rheology Additives for Paints and Coatings
Calcium carbonate, dolomite and magnesium carbonate extenders, with attapulgite and organoclay rheology modifiers, for architectural and industrial coatings.
ISO 9001 certified processes
NABL-accredited lab testing
CoA, TDS & MSDS with every shipment
Export packaging worldwide
Overview
Minerals engineered for paints & coatings
Fillers and rheology additives for paints and coatings shape almost every property a formulator measures: opacity and sheen, scrub resistance, film build, storage stability and how the paint behaves on the brush, roller or spray gun. Obsidian Minerals supplies both the mineral extenders and the rheology modifiers used in architectural, industrial and protective coating formulations.
Extender pigments such as ground and precipitated calcium carbonate, dolomite and magnesium carbonate reduce the volume of costly prime pigment, adjust gloss and contribute to film hardness and durability. Particle size and brightness determine how far they can be used before colour or sheen suffers. Rheology modifiers solve a separate problem. Attapulgite and organoclay build a structured network that prevents pigment settling and sagging, then shears down for smooth application. Waterborne systems typically use attapulgite-type thickeners, while solvent-borne paints rely on organophilic clays that gel in hydrocarbon and polar solvents.
Our coatings range includes GCC, PCC and coated calcium carbonate, dolomite powder, industrial grade magnesium carbonate, solvent-borne, waterborne and high-polarity rheology modifier grades, and solvent-borne organoclay. Every lot is checked in our NABL-accredited laboratory, and a TDS and batch CoA accompany each delivery. Samples are available for ladder studies, and particle sizes can be developed with your laboratory.
Problems we help solve
Sag and levelling balance
Coatings must build film on vertical surfaces without sagging, yet level out brush and roller marks. Achieving both requires a thixotropic structure that recovers at a controlled rate after application.
Opacity and raw material cost
Titanium dioxide is often the most expensive component in a paint. Formulators need extenders that space prime pigment efficiently and maintain opacity, brightness and scrub resistance while managing cost.
Gloss and sheen control
Matt, eggshell and satin finishes depend on extender particle size and shape. Inconsistent fillers shift sheen from batch to batch and make colour matching harder for the plant.
Recommended products for Paints & Coatings
Calcium Carbonate
GCC Fine Grade Calcium Carbonate (D50 < 5 µm)
Fine ground calcium carbonate with a D50 below 5 µm for interior and exterior emulsion paints, extending titanium dioxide while supporting brightness, sheen control and scrub resistance.
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Calcium Carbonate
Precipitated Calcium Carbonate (PCC)
Precipitated calcium carbonate with fine, uniform particles for premium coatings, contributing to dry hide and a smooth film appearance in matt and low-sheen architectural and decorative finishes.
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Dolomite
Dolomite Powder (200 / 325 Mesh)
Dolomite powder in 200 and 325 mesh as a hard, durable extender in exterior paints, primers, texture coatings and road-marking paint, adding film hardness and resistance to wear.
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Rheology Modifier
Waterborne Attapulgite Rheology Modifier
Attapulgite rheology modifier for architectural waterborne paints, providing anti-settling and anti-sag structure that tolerates electrolytes, holds across a wide pH range and shear-thins for smooth brush, roller or spray application.
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Organoclay
Solvent-borne Organoclay
Organoclay gellant for alkyd, epoxy and other solvent-borne coatings, building viscosity and suspension in aliphatic and aromatic solvents to prevent pigment settling in storage and sagging on vertical surfaces.
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Magnesium Carbonate
Industrial Grade Magnesium Carbonate
Soft, white magnesium carbonate used as a flatting agent and extender in matt paints and printing inks, adjusting sheen and viscosity with low abrasion on dispersion equipment.
View grade specsPaints & Coatings — common questions
Which calcium carbonate grade suits emulsion paint?
For most interior and exterior emulsion paints, a fine ground calcium carbonate with a D50 below 5 µm offers a good balance of brightness, sheen control and scrub resistance. Precipitated calcium carbonate is used where finer, more uniform particles are needed for premium matt finishes. Coarser GCC grades suit textured coatings, primers and putties.
What is the difference between attapulgite and organoclay rheology modifiers?
Attapulgite is a natural needle-shaped clay that builds structure by particle entanglement, mainly in waterborne paints, and tolerates salts and a wide pH range. Organoclay is bentonite modified with quaternary ammonium compounds so that it disperses and gels in organic solvents, which makes it the usual choice for solvent-borne alkyd, epoxy and industrial coatings.
How much rheology modifier is used in paint?
Typical additions lie roughly between 0.2 % and 1.5 % of total formulation weight, depending on the modifier type, the paint system, pigment loading and the viscosity profile required. Organoclays usually also need correct activation, by shear and in some systems a polar activator. Confirm the level through viscosity, sag and storage stability tests on your own formulation.
Can you supply paint filler samples for formulation trials?
Yes. Samples of calcium carbonate, dolomite, magnesium carbonate, rheology modifier and organoclay grades are available for ladder studies and pilot batches. Tell us the paint type, binder system, current extender or thickener and the property you want to improve, and we will recommend grades and send samples with Technical Data Sheets.
Request a quote
Talk to a paints & coatings specialist
Describe your process and current material. We will recommend a grade, share the datasheet and arrange samples for trial.