D2645R vs D2791 vs D2792 is not a three-way waterborne comparison. DP-D2645R is a DBE-carried, 30%-active solvent-system dispersant. DP-D2791 is a 40±3%-solids, water-carried route for inorganic and organic pigments with pigment-based dose data. DP-D2792 is a 58±3%-solids water/DPM route that additionally names carbon black but publishes no dosage.
The old DP-D2791 link is incomplete; the current product page uses agesin-dp-d2791-dispersant. Preserve the article URL but correct the product path.
D2645R/D2791/D2792 decision map
The decision starts with carrier and pigment: CHLUMICRYL® DP-D2645R for solvent systems, CHLUMICRYL® DP-D2791 waterborne dispersant ve CHLUMICRYL® DP-D2792 for broader waterborne pigment coverage are not interchangeable without resin- and pigment-specific evidence.
| System and pigment | First route | Approval gate |
|---|---|---|
| Solvent or solvent-free epoxy route uses black, organic pigment or matting powder | DP-D2645R | Not waterborne; confirm dose basis and carrier impact |
| Waterborne TiO2, iron oxide or named organic pigment needs documented pigment-based dose | DP-D2791 | Check resin/pigment matrix; no public carbon-black route |
| Waterborne formulation needs broad inorganic/organic plus carbon-black coverage | DP-D2792 | Obtain current dosage before a ladder |
| System or pigment grade is unknown | Characterize first | No dispersant ranking |
| Ürün | Published data | Documented fit | Boundary |
|---|---|---|---|
| DP-D2645R | Block copolymer in DBE; 30% active; solvent systems | High-pigment carbon black, organic pigment and matting powder; solvent-free epoxy example | Not waterborne; pigment-class dose basis is not labeled |
| DP-D2791 | Polar-group copolymer in water; 40±3% solids; VOC/APEO-free | Waterborne inorganic and organic pigments across acrylic/PUD/PUA matrix | No supported carbon-black entry; dose is explicitly on pigment amount |
| DP-D2792 | Polar-group copolymer in water/DPM; 58±3% solids; APEO-free | Waterborne inorganic pigments, organic pigments and carbon black | No public recommended dosage |
Eliminate the wrong carrier system
DP-D2645R uses dibasic ester and its page says solvent-based systems. It should not be ranked inside a waterborne color-paste ladder. If the formulation is waterborne, begin with D2791 or D2792 and keep the DPM contribution from D2792 visible.
Record resin dispersion, pH, water/co-solvent, pigment grade, surface treatment, oil absorption or surface area, pigment/binder ratio and target solids.
Use DP-D2791 for documented pigment-based guidance
D2791 publishes its denominator: addition on pigment amount. Its table gives 10–15% for TiO2, 20–40% for iron oxides and 30–80% for listed organic pigments, with compatibility checks across acrylic, PUD and PUA systems.
The carbon-black MA-100 row has no supported resin check or dosage. Do not infer a carbon-black recommendation from the broad product description. Test only combinations actually supported or confirmed by current technical data.
Use DP-D2792 when carbon black is required
D2792 explicitly names carbon black together with inorganic and organic pigments and has the highest published solids in this group. However, it supplies no recommended dosage. Request a pigment-grade and resin-specific starting range before grinding.
Equal supplied percentages are not equal active polymer: D2791 is 40±3% solids and D2792 is 58±3%. Report both supplied and solids-based addition and equalize DPM in the blank when relevant.
Keep DP-D2645R in the solvent branch
D2645R is 30% active in DBE and directly supports high-pigment black, organic pigment and matting powder. Its 1–10%, 20–40% and 30–100% class ranges do not state the basis; obtain that denominator before calculation.
The solvent-free epoxy-floor example is application-specific. Validate resin compatibility, cure and VOC/carrier effects in the actual solvent or solvent-free system.
Run a pigment-specific grind
- Use the exact pigment/resin combination and additive-free blank.
- Add dispersant to the grind vehicle before pigment.
- Hold equipment, media, fill, speed, energy and temperature.
- Sample fineness, viscosity and color against energy.
- Let down at equal solids, apply, cure and repeat after aging.
Measure grind and rheology separately
ASTM D1210 provides a Hegman-type fineness assessment. ASTM D2196 covers rotational apparent viscosity, shear thinning and thixotropy.
Neither alone proves color strength, blackness, gloss, floating/flooding or storage. Measure those endpoints plus sediment, redispersibility, foam/density and viscosity drift in mill base and finished product.
Interpret color and storage together
Measure color strength and undertone at equal pigment concentration, film thickness and letdown resin. For carbon black, include jetness and undertone; for TiO2, include hiding and tint strength; for organic pigments, include transparency and shade. A lower mill-base viscosity can still produce poorer color development.
Age the mill base and finished coating separately. Record clear-layer volume, soft or hard sediment, redispersibility energy, viscosity and color/gloss drift. D2792’s broader pigment statement does not prove stability with a specific carbon-black surface or waterborne resin, and D2791’s matrix does not replace a real lot test.
Check co-solvent and pH compatibility
D2791 is water-carried, while D2792 includes dipropylene glycol methyl ether. Equalize this co-solvent contribution in the blank and monitor pH, resin-particle stability and drying. Recheck after adding the complete binder, coalescent, thickener and other formulation components; a stable color paste can destabilize during letdown.
Common comparison errors
Calling D2645R waterborne
Its current product page explicitly identifies solvent systems.
Using D2791 for carbon black
The published carbon-black matrix contains no supported entry.
Inventing a D2792 dose
The page gives no recommended addition level.
Request a pigment-resin shortlist
Send system, resin, pigment grade and surface data, pH, water/co-solvent, solids, pigment/binder ratio, equipment, grind curve, color/gloss, rheology, foam and storage failure. Ask Longchang Chemical to confirm the D2791 matrix or provide a D2792 pigment-specific dosage.