Formulation — Process Challenge

Functional Fillers & Extenders for Coatings

Extenders/functional fillers reduce formula cost and tune opacity, sheen, and reinforcement while holding performance — managing PVC vs CPVC
Updated Jun 2026
Solution Approach

RawSource supplies the base chemicals that go into these programs. We can help with product selection, grade matching, and sourcing from multiple origins for supply security.

Typical Formulation Workflow
1
System & Substrate Assessment
Define the binder system (waterborne, solventborne, UV, powder), substrate, cure, and the VOC, durability, and appearance targets.
2
Additive & Resin Selection
Match resins, pigments and fillers, dispersants, rheology modifiers, defoamers, or biocides to the formulation and compatibility window.
3
Lab Let-Down & Optimization
Dial in loading and addition order through lab let-downs, checking dispersion, rheology, film properties, and storage stability.
4
Application & Performance Testing
Validate on the real application method and substrate, tracking gloss, adhesion, sag, cure, and weathering before scale-up.
Recommended Chemistries (6)
Calcium Carbonate
CAS 471-34-1
Mineral Fillers & Pigments
Primary extender pigment
Low-cost extender that builds volume solids and controls sheen, spacing TiO2 to improve hiding efficiency per dollar
Melting Point: 825–1339 °C (Decomposes)   Boiling Point: Decomposes   Density: 2.7 to 2.95
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Kaolin (china clay)
CAS 1332-58-7
Mineral Fillers & Pigments
Thickening / Rheology
Platy aluminosilicate extender that boosts dry hiding and holdout while partially replacing prime pigment
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Nepheline syenite
CAS 37244-96-5
Mineral Fillers & Pigments
Thickening / Rheology
Hard, low-oil-absorption mineral extender that raises solids and abrasion resistance with minimal viscosity penalty
Physical Description: Liquid
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Talc
CAS 14807-96-6
Mineral Fillers & Pigments
Conditioning
Lamellar magnesium silicate that improves sag control, sanding, and film reinforcement as a functional extender
Melting Point: 927–982 °C   Density: 2.7 to 2.8   Solubility: < 1 mg/mL at 21 °C
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Titanium Dioxide
CAS 13463-67-7
Mineral Fillers & Pigments
Primary white pigment for opacity
High-refractive-index prime pigment providing the hiding power that extenders are spaced around to optimize cost
Melting Point: 1860 °C (decomposes)   Boiling Point: 2500–3000 °C at 760 mmHg   Density: 3.9 to 4.2
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Mica
CAS 12001-26-2
Mineral Fillers & Pigments
Thickening / Rheology
Genuine low-cost lamellar extender pigment used precisely for filler-loading cost optimization: spaces/extends TiO2, reinforces film, reduces cracking and moisture permeability, and controls sheen at a fraction of TiO2/binder cost. Directly serves this exact use-case.
Melting Point: 1500 °C   Density: 2.6 to 3.2   Solubility: Insoluble
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