Silica Matting Agent
Vistamatt VS651
Vistamatt VS651 is a synthetic amorphous silica matting agent produced by Longyan Vista Chemical Co., Ltd. for water-based clear wood coatings. Vistamatt VS651 has a typical D50 of 4.9-5.2 µm, a BET specific surface area of 140 m²/g, an oil absorption of 180 g/100 g and an SiO2 content of 96.8 %. Particle size, pore structure and surface treatment are selected to reduce gloss while keeping transparency and dispersion behaviour in the target system.
Typical properties
| Property | Typical value | Method / note |
|---|---|---|
| Particle size D50 | 4.9-5.2 µm | Laser diffraction, ISO 13320 |
| Particle size D10 | 3.6 µm | Laser diffraction, ISO 13320 |
| Particle size D90 | 6.6 µm | Laser diffraction, ISO 13320 |
| SiO2 content | 96.8 % | Dry basis |
| Specific surface area | 140 m²/g | BET |
| Oil absorption | 180 g/100 g | DIN ISO 787-5 |
| pH (5 % suspension) | 6.4 | DIN ISO 787-9 |
| Loss on drying | 5.3 % | 2 h at 105 °C |
| Tamped bulk density | 0.35 g/cm³ | DIN ISO 787-11 |
| Whiteness | 93.8 | Ry value |
| Chemical basis | Synthetic amorphous silica, CAS 7631-86-9 | — |
| Appearance | White fine powder | Visual |
Typical values from standard production batches, not guaranteed specifications. Actual batch values may vary within tolerance; a certificate of analysis is supplied per batch on request, tested to HG/T 3061-2020.
Where Vistamatt VS651 fits
Vistamatt VS651 is positioned for water-based clear wood coatings. Selecting a matting agent for this application starts from three inputs: the binder system, the target gloss at 60°, and the film build at which that gloss must hold.
Particle size sets the average height at which silica protrudes through the dried film, which sets baseline gloss. The D10 to D90 spread — 3.6 to 6.6 µm for Vistamatt VS651 — governs how uniform those protrusions are, and therefore how stable gloss stays between batches. Oil absorption at 180 g/100 g determines how much binder the silica immobilises, which shifts the effective binder-to-pigment ratio at constant loading.
A grade matched only on mean particle size will often pass a bench drawdown and then drift at pilot scale, where dispersion energy and film build differ from laboratory conditions. Screening at matched gloss rather than matched loading is the reliable way to compare.
Frequently asked questions
What is Vistamatt VS651?
Vistamatt VS651 is a synthetic amorphous silica matting agent (CAS 7631-86-9) produced by Longyan Vista Chemical Co., Ltd. for water-based clear wood coatings. Its typical D50 is 4.9-5.2 µm, with a BET specific surface area of 140 m²/g and an oil absorption of 180 g/100 g.
What is the recommended dosage of Vistamatt VS651?
Vistamatt VS651 has no single fixed dosage published, because the required loading depends on binder, target gloss and film build. Dosage should always be adjusted to match the gloss of the incumbent grade rather than copied from its loading, because matting efficiency differs between grades at equal particle size.
What gloss level can Vistamatt VS651 reach?
The gloss reachable with Vistamatt VS651 depends on binder chemistry, loading and film build, and should be established by screening at matched gloss. Gloss is measured to ASTM D523 or ISO 2813; readings taken at 20° and 60° on the same panel are not comparable.
What is the particle size distribution of Vistamatt VS651?
Vistamatt VS651 has a D10 of 3.6 µm, a D50 of 4.9-5.2 µm and a D90 of 6.6 µm, measured by laser diffraction to ISO 13320. Distribution width matters more than mean size for gloss uniformity across batches.
How should Vistamatt VS651 be dispersed?
Vistamatt VS651 is added under moderate shear during the let-down stage and dispersed until no agglomerates remain. With a tamped bulk density of 0.35 g/cm³, wetting-in time should be checked on a fineness gauge before extending grind time, since over-grinding can reduce matting efficiency.
Is Vistamatt VS651 suitable for waterborne systems?
Vistamatt VS651 carries a pH of 6.4 in 5 % suspension and a loss on drying of 5.3 %. Suitability for a specific waterborne, solventborne or UV system depends on binder chemistry and catalyst package, and should be confirmed by screening in the actual formulation.
What documentation is available for Vistamatt VS651?
A TDS covering Vistamatt VS651, a 16-section GHS SDS and a TSCA compliance statement are available from the downloads page. A batch-specific certificate of analysis is supplied on request, tested to HG/T 3061-2020.
Is synthetic amorphous silica REACH registered?
Synthetic amorphous silica carries CAS 7631-86-9. REACH status depends on the importer of record and the destination market, and is confirmed on enquiry per shipment rather than stated as a blanket claim.
What packaging and shelf life apply to Vistamatt VS651?
Vistamatt VS651 carries a 24-month shelf life when stored sealed in a dry place away from direct sunlight. Packaging and minimum order quantity are confirmed at enquiry.
How can I get a sample of Vistamatt VS651?
Vistamatt supplies free 200-500 g evaluation samples of VS651 with freight prepaid, shipped with a screening plan matched to the customer's system. Send resin system, target gloss, application method and film build to receive a starting dosage recommendation.
Request a sample of Vistamatt VS651
Send your resin system, target gloss, application method and film build. Vistamatt ships a free 200-500 g sample with freight prepaid, together with a screening plan matched to your system.