Lithopone pigment: composition, grades and buyer’s guide
Understand lithopone composition, grade selection and practical purchasing checks for paint, rubber, plastics and paper applications.
What is pigment lithopone?
Lithopone is a white inorganic pigment made from co-precipitated zinc sulfide (ZnS) and barium sulfate (BaSO4). Its Colour Index designation is Pigment White 5. The zinc sulfide component contributes light scattering, while the barium sulfate component contributes body to the composite pigment. It is used in selected paint, rubber, plastics and paper formulations.
Lithopone occupies a different position from both titanium dioxide and conventional mineral extenders. It can contribute whiteness and opacity, but it does not provide the same hiding power or durability as every TiO2 grade. Purchasing decisions should therefore start with the requirements of the finished product rather than a comparison of powder prices alone.
How production influences pigment performance
The general production route reacts zinc sulfate solution with barium sulfide solution to form a precipitate. Filtration, washing, controlled thermal treatment, milling and classification influence the finished particle characteristics. Residual soluble matter, particle distribution and dispersion behaviour can affect how the powder performs in a binder or polymer.
A supplier’s grade specification and a controlled application trial provide more useful evidence than appearance alone. A bright powder sample can still behave differently during milling, storage or film formation.
Compare commercial grades using the specification
Grade names such as B-301 and B-311 identify commercial products, but names from different suppliers are not sufficient proof of identical performance. Review the current specification, test methods and batch documentation. Longtai’s catalog provides separate pages for B-301 and B-311.
| Check | Why it matters |
|---|---|
| Specified ZnS content | Helps define the pigment composition being purchased. |
| Whiteness and tinting performance | Relates to finished colour and opacity under a stated test method. |
| Oil absorption and dispersion | Can influence binder demand, viscosity and processing. |
| Moisture and sieve residue | Helps assess handling consistency and coarse material. |
Match the pigment to the application
For interior paints, compare opacity, colour, scrub resistance and storage stability at the intended pigment volume concentration. For rubber, check dispersion, cure behaviour and the required mechanical properties. For plastics, assess colour, processing compatibility and surface appearance. Paper applications require evaluation in the actual wet-end or coating system.
Where lithopone is combined with titanium dioxide, run a sequence of controlled trials rather than assuming a fixed replacement ratio. Outdoor exposure and demanding durability requirements require particular attention.
A practical procurement checklist
- Define the finished product, substrate and service conditions.
- Request the current TDS, SDS and available batch inspection information.
- Approve a representative sample using the intended formulation and process.
- Agree on specification limits, packaging, shipment terms and batch traceability.
- Compare delivered cost at an equivalent finished-product performance.
Keep the material dry and protected from contamination during receiving and storage. Use the handling measures stated in the supplied SDS.
For component identity, consult the separate NIST Chemistry WebBook: zinc sulfide and NIST Chemistry WebBook: barium sulfate records. These are general chemistry references, rather than evidence of a Longtai grade’s composition limits, certification or application performance.
Frequently asked questions
Can lithopone replace all titanium dioxide?
There is no universal complete substitution. Opacity, durability, dispersion and end-use requirements determine whether partial substitution is practical.
Does a grade name establish a guaranteed ZnS percentage?
Use the supplier’s agreed specification and batch documents. Similar commercial labels do not replace those records.
How can I request a Longtai recommendation?
Discuss your application with Longtai Chemical. Include the target grade, required quantity, packaging and destination port so the team can prepare a relevant product recommendation and quotation.
