D241R vs D2641R vs D265R is a mill-base selection based on pigment package and resin system. DP-D241R is the documented multi-pigment solvent-primer route. DP-D2641R directly names high-pigment carbon black, organic pigment and matting powder. DP-D265R is the thermoplastic-acrylic solvent coating/ink route for organic pigments and carbon black; its page does not name matting powder.
All three publish pigment-class dose tables without identifying the calculation basis. Confirm whether each percentage is on pigment, total solids or total formulation before a trial.
D241R/D2641R/D265R decision map
| Mill-base evidence | First route | Approval gate |
|---|---|---|
| Solvent primer contains carbon black, bentonite, matting powder and multiple mineral pigments | DP-D241R | Primer viscosity, floating/flooding, corrosion package and storage |
| High-pigment black, organic pigment or matting powder is the direct dispersion problem | DP-D2641R | Dose basis, grind curve, color/gloss and aged stability |
| Thermoplastic acrylic coating or ink needs organic-pigment color or carbon-black blackness | DP-D265R | Resin compatibility, tone, rub and storage |
| System is waterborne | Choose a waterborne dispersant family | None of these three is the documented route |
| Prodotto | Published data | Documented strength | Boundary |
|---|---|---|---|
| DP-D241R | Block copolymer; DBE/solvent oil; 48% active; solvent systems | Multi-pigment primers with black, bentonite, matting powder, zinc phosphate and fillers | Public dose-table basis is not labeled |
| DP-D2641R | Block copolymer; DBE; 45% active; solvent systems | High-pigment black, organic pigment and matting powder; storage/foam claims | Epoxy-floor fineness example is application-specific; dose basis unlabeled |
| DP-D265R | Block copolymer; DBE; 45% active; solvent coatings/inks | Thermoplastic acrylic, organic-pigment color development and carbon-black blackness | No public matting-powder fit; dose basis unlabeled |
Define pigment and resin demand
Record pigment identity, surface treatment, BET area or oil absorption where available, resin, solvent blend, pigment/binder ratio and target solids. A carbon-black grade change can reverse the ranking because surface area and chemistry control adsorption demand.
For matting silica, record type, treatment, pore volume and moisture. For a primer, retain the full zinc phosphate/filler/bentonite package rather than testing one pigment in isolation.
Use DP-D241R for a multi-pigment primer
DP-D241R explicitly lists carbon black, bentonite, matting powder, calcium carbonate, zinc phosphate, barium sulfate, mica, titanium dioxide and talc in solvent primers. It is therefore the strongest first route when viscosity, floating/flooding and dispersion arise from the complete primer package.
Measure hiding, color, settling, corrosion-package behavior, sanding and topcoat recoat in addition to grind and viscosity. Lower thinner demand alone does not prove primer performance.
Use DP-D2641R for direct black, organic or matting demand
DP-D2641R directly claims efficiency and viscosity reduction for high-pigment carbon black, organic pigment and matting powder, together with no stable foam and storage stability. Its solvent-free epoxy-floor example can guide a hypothesis but cannot be generalized to every binder.
Compare gloss or color at equal dry film. Track fineness versus energy, viscosity at multiple shear conditions and aged redispersibility.
Use DP-D265R for thermoplastic acrylic systems
DP-D265R is the only route here that explicitly identifies thermoplastic acrylic resin systems. Its page emphasizes organic-pigment color development and carbon-black blackness in solvent coatings and inks.
Do not extend it to matting powder without supplier evidence. In inks, add print density, shade, rub, adhesion and blocking to the mill-base checks.
Normalize the dosage comparison
D241R is 48% active; D2641R and D265R are 45% active. Report both supplied product and active polymer. More importantly, obtain the dose basis for every pigment-class range before calculating the ladder.
Use a short logarithmic or supplier-supported ladder. Keep any carrier solvent equal in the blank so viscosity changes are not credited to extra DBE or solvent oil.
When comparing the three products, calculate the active-polymer amount but do not assume equal active dose is automatically fair. Different adsorption and resin-compatibility behavior may place each optimum at a different point; the valid comparison is the lowest dose that passes the defined grind, color, rheology and storage gates.
Run a controlled grind and letdown
- Add dispersant to the grind vehicle before pigment.
- Hold vessel, media, fill, speed, energy and temperature.
- Sample fineness and viscosity against energy, not time alone.
- Let every mill base down into the same resin at equal solids.
- Apply, cure and age before final color, gloss and storage approval.
Measure fineness and rheology separately
ASTM D1210 provides a Hegman-type fineness assessment. ASTM D2196 covers rotational apparent viscosity, shear thinning and thixotropy. A clean fineness reading does not prove color development or storage stability.
Track color strength/tone or blackness, gloss/haze, transparency, density/foam, flooding/floating, sediment, redispersibility and viscosity drift. Repeat after mill-base and finished-product aging.
Common dispersant errors
Using the published percentages without a basis
Confirm the denominator with the current TDS.
Testing D265R as a matting specialist
Its public evidence concerns organic pigments, carbon black and thermoplastic acrylic.
Approving fresh viscosity only
Color drift, hard settling and gloss change can appear after storage.
Request a pigment-specific shortlist
Send pigment grades and oil absorption, resin/solvent, pigment/binder ratio, solids, current dose basis, equipment, grind curve, color/gloss, rheology, foam and storage failures. Ask Longchang Chemical to choose D241R, D2641R or D265R from the exact pigment-resin package.