English
Español
tiếng việt
русский
Highly reactive melamine-formaldehyde resin offering rapid cure at low to medium baking temperatures.
Excellent compatibility with acrylic, polyester, and alkyd resins in solvent-based coating systems.
Delivers superior hardness, gloss retention, and chemical resistance in thermoset coatings.
Low formaldehyde emission profile, supporting compliance with stringent VOC and emissions regulations.
Good storage stability in acidic catalyzed formulations when properly inhibited.
Automotive OEM and refinish topcoats requiring high-gloss, durable finishes.
Industrial coil coatings for pre-painted metal substrates.
Air-dry and forced-dry can coatings for food and beverage containers.
General-purpose appliance and furniture coatings.
High-performance metal decorating inks and overprint varnishes.
| Chemical Type | Melamine-formaldehyde resin |
| Product Form | Liquid (solution in methanol and/or isobutanol) |
| Appearance | Clear, colorless to pale yellow liquid |
| Solids Content (wt%) | 80–84% |
| Viscosity (mPa·s, 25°C) | 800–1,500 |
| Density (g/cm³, 25°C) | 1.18–1.22 |
| pH (10% solution in water) | 7.5–9.0 |
| Primary Applications | Thermosetting decorative and protective coatings |
Q1: What is the primary function of CYMEL 251 in coating formulations?
A: CYMEL 251 acts as a highly reactive crosslinker for hydroxyl- and amide-functional resins—such as acrylics, polyesters, and alkyds—enabling durable, thermoset film formation upon curing. It contributes to improved hardness, chemical resistance, and gloss retention in baked coatings.
Q2: Is CYMEL 251 suitable for low-bake or ambient-cure systems?
A: CYMEL 251 is designed for thermal cure applications, typically requiring baking temperatures between 120–160 °C. While it can be formulated with strong acid catalysts to lower onset temperature, it is not intended for true ambient-cure systems without external activation.
Q3: How does CYMEL 251 compare to other melamine-formaldehyde resins in terms of reactivity and storage stability?
A: CYMEL 251 offers balanced reactivity—higher than fully alkylated melamines but more stable than partially methylated or butylated variants. Its formulation provides good shelf life under recommended storage conditions (cool, dry, sealed), though prolonged exposure to humidity or elevated temperature may affect viscosity and reactivity over time.
Q4: What types of acid catalysts are commonly used with CYMEL 251?
A: Conventional strong acid catalysts—including p-toluenesulfonic acid (p-TSA), dodecylbenzenesulfonic acid (DBSA), and blocked sulfonic acids—are frequently employed to accelerate cure kinetics. Catalyst selection and dosage depend on desired pot life, flow behavior, and final cure profile.
Q5: Can CYMEL 251 be used in waterborne coating systems?
A: Yes—CYMEL 251 is compatible with many waterborne resin systems when properly dispersed or emulsified. Formulators often use co-solvents and pH control to ensure colloidal stability and minimize premature reaction during storage.
Contact With Us:
E-mail: wangxingqiang@ericwchem.com
Have a Questions? Call Us:
Add:
Building A1, Jiete Industrial Park, Huangpu District, Guangzhou City, Guangdong Province, China
