Quick Search
CHEMICAL IDENTIFICATION & NOMENCLATURE
IUPAC Name: Sodium 2-methylnaphthalene-1-sulfonate (major isomer)
Common Name: Sodium methylnaphthalenesulfonate (commercial mixture)
Trade Names: Morwet D-425, Dispersant SS, Setamol WS, Lomar PW
CAS Registry Number: 26264-58-4 (for the commercial mixture/isomeric mixture)
EC Number: 247-556-3
Synonyms:
Sodium 2-methyl-1-naphthalenesulfonate,Methyl naphthalene sodium sulfonate,Sodium monomethylnaphthalenesulfonate,SMS (abbreviation),Akyporcel MNS
Molecular Formula: C₁₁H₉NaO₃S
Molecular Weight: 244.24 g/mol (for C₁₁H₉NaO₃S)
Chemical Structure: Commercial product consists of a mixture of isomers, primarily sodium 2-methylnaphthalene-1-sulfonate and sodium 1-methylnaphthalene-4-sulfonate (and their 6-sulfo analogs). Contains varying degrees of di- and trisulfonated species and unsulfonated oil.
MANUFACTURING PROCESS & INDUSTRIAL SYNTHESIS
This is the primary commercial product derived from methylnaphthalene sulfonation.
Sulfonation: Technical-grade methylnaphthalene (a mixture of 1- and 2-methyl isomers) is reacted with oleum (20-30% SO₃) or chlorosulfonic acid at 40-70°C. The reaction is exothermic and requires careful temperature control to minimize disulfonation and oxidation.
Neutralization: The crude sulfonic acid mixture is diluted with water and neutralized with sodium hydroxide (NaOH) or sodium carbonate (Na₂CO₃) to pH 7-9.
Reaction: R-SO₃H + NaOH → R-SO₃Na + H₂O
Purification: The neutralized mixture may be treated with lime (Ca(OH)₂) to precipitate calcium salts of undesirable byproducts, filtered, and then re-acidified and re-neutralized with sodium salts ("lime-soda process"). Alternatively, it is purified by extraction or directly dried.
Drying: The aqueous solution is spray-dried or drum-dried to yield a free-flowing tan to brown powder.
TECHNICAL FUNCTIONS & MECHANISM OF ACTION
Primary Functions: Dispersant, Wetting Agent, Emulsifier.
Mechanism: An anionic surfactant. The hydrophobic methylnaphthalene group provides affinity for organic surfaces and pigments. The hydrophilic sulfonate head group ionizes in water (R-SO₃⁻ Na⁺), imparting a strong negative charge. This facilitates:
Electrostatic Stabilization: Charged particles repel each other.
Steric Hindrance: The aromatic ring structure provides some steric bulk.
Wetting: Reduces interfacial tension, allowing liquids to penetrate agglomerates.
Key Feature: Excellent dispersing power for hydrophobic solids in aqueous systems, even in the presence of electrolytes (salt tolerance).
INDUSTRIAL & COMMERCIAL APPLICATIONS
Primary Applications:
Construction & Concrete: As a plasticizer/water reducer in concrete admixtures. Disperses cement particles, improving workability without adding water.
Agrochemicals: Key dispersant and tackifier in wettable powder (WP) and suspension concentrate (SC) pesticide formulations. Ensures stable suspensions and good spray coverage.
Dye & Pigment Industry: Dispersant for organic pigments (e.g., azo pigments) during synthesis ("primary dispersion") and in final formulations.
Textile Auxiliaries: Used in dye baths as a leveling and dispersing agent for disperse dyes.
Gypsum & Plasterboards: Dispersant for stucco slurry, improving fluidity and board strength.
Formulation Guidelines:
Typical use level: 0.1% - 2.0% based on total weight of solid material to be dispersed.
Best added to the aqueous phase before incorporating solids.
Compatible with most anionic and non-ionic surfactants; incompatible with cationic surfactants.
REGULATORY STATUS & CERTIFICATIONS
REACH: Registered for ≥ 1000 tpa as "Sulfonated methylnaphthalene, sodium salt" (EC 247-556-3).
FDA: 21 CFR 178.3400 - Listed as a component of coatings and plastics for food contact.
EPA: Exempt from tolerance when used as an inert ingredient in pesticide formulations (40 CFR 180.960).
Not classified as hazardous per GHS/CLP in its supplied form.
8. HANDLING, STORAGE & TRANSPORTATION
Storage: Store in a cool, dry, well-ventilated place in original, tightly closed containers. Protect from moisture to prevent caking.
Shelf Life: 24 months from date of manufacture.
PPE: Safety glasses, dust mask, and gloves are recommended during handling to avoid dust inhalation and eye contact.
Transport: Not regulated as dangerous goods.
GLOBAL SUPPLIERS
Arkema (CECA S.A.) - Brand: Setamol WS
Norman, Fox & Co. - Brand: Norfox SNS
Huntsman Corporation (Textile Effects)
Kao Corporation
Shanghai Longyang Chemical Plant
SAFETY INFORMATION ABOUT SODIUM METHYL NAPHTHALENE SULFONATE
First aid measures:
Description of first aid measures:
General advice:
Consult a physician.
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
If inhaled:
If breathed in, move person into fresh air.
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately.
Wash off with soap and plenty of water.
Consult a physician.
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
If swallowed:
Do NOT induce vomiting.
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
Consult a physician.
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment.
Avoid breathing vapours, mist or gas.
Evacuate personnel to safe areas.
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste.
Keep in suitable, closed containers for disposal.
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place.
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles.
Faceshield (8-inch minimum).
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Skin protection:
Handle with gloves.
Gloves must be inspected prior to use.
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product.
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices.
Wash and dry hands.
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls.
If the respirator is the sole means of protection, use a full-face supplied air respirator.
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions.
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company.
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product
