A matting powder dispersant should be selected by silica type, resin and measured grind/storage behavior. DP-D2641R is the most direct published matting-powder route. DP-D241R is the documented solvent-primer route when matting powder sits inside a larger pigment/filler package. DP-D200R is removed from the first shortlist because its page does not identify matting powder or publish a dosage.
All three are grind-stage products, not universal letdown fixes. A lower initial viscosity does not prove target gloss, clarity, sag control or storage stability.
Matting-powder dispersant decision map
| Formulation evidence | First route | Approval gate |
|---|---|---|
| Matting powder is the main high-load dispersion problem | DP-D2641R | Confirm dose basis; measure fineness, rheology, gloss and storage |
| Solvent primer contains matting powder plus carbon black, bentonite, TiO2 or fillers | DP-D241R | Keep primer performance and multi-pigment stability visible |
| Organic-bentonite slurry is the actual problem | DP-D200R may fit that separate job | Obtain dosage; do not call it a matting-powder recommendation |
| Gloss changes only because film thickness or cure changed | Correct application first | No dispersant ranking until the blank is controlled |
| 제품 | Published data | Documented fit | Boundary |
|---|---|---|---|
| DP-D2641R | Block copolymer; DBE; 45% active | Solvent systems; high-pigment black, organic pigment and matting powder | Dose table basis is not labeled; epoxy-floor fineness example is application-specific |
| DP-D241R | Block copolymer; DBE/solvent oil; 48% active | Solvent primers with matting powder, bentonite, black, TiO2 and named fillers | Pigment-class dose basis requires confirmation |
| DP-D200R | Polyamide-polyester solution; DPM; 50% active | Organic-bentonite slurry and broad industrial/anticorrosion coatings | No public matting-powder fit or recommended dosage |
Characterize the matting powder first
Record precipitated, gel or fumed silica type, surface treatment, median/agglomerate size, pore volume, oil absorption, moisture and lot. Hold resin, solvent blend, solids, pigment/binder ratio and target dry-film thickness. Different silica grades can reverse the dispersant ranking.
Measure the blank at controlled temperature and rest time. Matting powders create structure and thixotropy; one low-shear cup result cannot show high-shear application viscosity or recovery after application.
Use DP-D2641R for the direct matting route
DP-D2641R explicitly supports matting powder with viscosity reduction, no stable foam and storage stability. Its public ranges are 1–10% for inorganic pigment, 15–35% for organic pigment and 25–100% for carbon black, but the reference basis is not stated. Confirm the current TDS before calculating a silica dose.
Report supplied product and active polymer. Compare gloss at equal dry-film thickness; a thinner or more sagged film can appear glossier or flatter without representing better dispersion.
Use DP-D241R for a primer package
DP-D241R directly lists solvent primers containing matting powder together with carbon black, bentonite, zinc phosphate, barium sulfate, mica, TiO2, talc and calcium carbonate. It is therefore the stronger comparator when the whole primer package—not silica alone—creates viscosity and floating-color pressure.
Its page also publishes pigment-class ranges without a clearly labeled basis. Confirm calculation and test hiding, corrosion-package behavior, sanding and topcoat recoat in addition to gloss.
Why DP-D200R is not a first screen
DP-D200R supports organic-bentonite slurry, viscosity reduction and industrial/anticorrosion coatings but does not name matting powder. It also provides no dosage. Use it only when bentonite or a supplier-confirmed broader application is the real hypothesis.
Run a controlled grind and letdown
- Prepare a blank and short supplier-supported dose ladder.
- Add dispersant to the grind vehicle before the matting powder.
- Hold vessel, media, fill, speed, energy, temperature and solvent loss.
- Let every mill base down into the same final resin at equal solids.
- Apply at equal wet and dry film and condition before gloss measurement.
Measure dispersion, rheology and gloss separately
ASTM D1210 provides a Hegman-type fineness assessment. ASTM D2196 covers rotational apparent viscosity, shear thinning and thixotropy. A good fineness reading does not prove stable matting efficiency.
Track fineness versus energy, viscosity at several shear conditions, yield/recovery, foam/density, target-angle gloss, haze, transparency, sag and surface texture. Age mill base and final coating, then repeat sediment, redispersibility, viscosity and gloss.
Interpret storage results by failure mode
Aged viscosity alone can hide separation. Record clear-layer volume, soft or hard sediment, redispersibility energy and whether the recovered material returns to its original gloss and texture. Compare sealed storage at room temperature with the customer-approved accelerated condition; heat can change resin solvation as well as silica structure, so an accelerated result is not automatically equivalent to a shelf-life claim.
Check the mill base and the fully let-down coating separately. A grind can remain pourable while the final formulation develops seeding, floating, loss of matting efficiency or an application-viscosity shift after other resins and additives are introduced.
Common matting errors
Judging gloss at unequal film build
Use controlled applicators and measure dry thickness beside gloss.
Borrowing a carbon-black dosage
Silica demand and the public table basis require separate confirmation.
Approving fresh viscosity only
Hard settling, gloss drift and loss of thixotropic control can appear after storage.
Request a silica-specific trial
Send silica grade/treatment/oil absorption, resin and solvent, solids, pigment/filler package, current dose basis, equipment, grind curve, rheology, film thickness, gloss/haze and storage failure. Ask Longchang Chemical to compare DP-D2641R and DP-D241R for the exact matting system.