China-Xingzhenghe Chemical Co., Ltd. specializes in the production of special water reducing agent for concrete such as naphthalene series superplasticizer, sodium polynaphthalene sulfonate and polycarboxylate water reducer. Welcome your inquiry and negotiation. Tel: 86-138-9816- 8062 Email

The appearance of sodium polynaphthalene sulfonate is brown or dark brown powder. It’s widely used in diffusing dyes, reactive dyes, pesticides, diffusing agents, fillers, leather tanning agents, construction cement concrete water reducers, oil well cement water reducers and so on.

Chinese name:  sodium polynaphthalene sulfonate

Chinese alias: dispersant MF/diffusion agent MF; formaldehyde condensate of sodium methylnaphthalene sulfonate; dispersant PD; sodium polynaphthalene sulfonate; naphthalenesulfonic acid formaldehyde polycondensate sodium salt; methylnaphthalenesulfonic acid-formaldehyde polycondensate ; obtained by condensation of methylna phthalenesul fonic acid with formaldehyde; polymer sodium salt of naphthalenesulfonic acid, formaldehyde sodium-naphthalenesulfonic acid-formaldehyde.

Chemical Features

The appearance of sodium polynaphthalene sulfonate is brown or dark brown powder. It’s soluble in water, bearing acid, alkali and hard water. It has good diffusibility and is more resistant to high temperatures than the diffusing agent NNO. Prevent moisture absorption during storage.

Safety data

Dangerous goods mark: Xi; N

Hazard Category Code: 36/38

Category: Toxic

Toxicity classification: poisoning

Acute toxicity: Oral-rat LD50: 3800 mg/kg; Oral-mouse LD50: 3400 mg/kg

Flammability Hazardous Characteristics: Thermal decomposition of toxic sulfur oxides and nitrogen oxide gases

Storage and transportation characteristics: warehouse ventilation and low temperature drying

Extinguishing media: water, dry powder, dry sand, carbon dioxide, foam, 1211 fire extinguishing agent

production method

Method 1: The preparation process of the product is three steps of sulfonation of naphthalene, condensation of sulfonated product with formaldehyde, and neutralization.

550 kg of refined naphthalene was placed in the reaction vessel, and the temperature was raised to 50 ° C for 4 h. Then, the water vapor is cooled and the by-product is hydrolyzed to obtain 1-naphthalenesulfonic acid. After the completion of the hydrolysis, the material was driven into a polycondensation kettle, and a 37% aqueous formaldehyde solution was added thereto, and the reaction was carried out under a pressure of 196 kPa. Finally, the base is neutralized to a pH of 8-10. The reaction is over. The crystals were cooled, and the crude product was filtered and dried to give a finished product.

Method 2: The preparation process comprises methylnaphthalene sulfonation, condensation and neutralization of the sulfonated product with formaldehyde.

500 kg of methyl naphthalene was placed in a sulfonation kettle, heated and melted, stirred, and heated to a reaction 2 at 130 to 140 °C. Then, 210 L of water was added under rapid stirring, and after stirring for another half an hour, the acidity was sampled, and if the total acidity was 25% to 27%, it was qualified. Cool to 90-100 °C. 300 kg of a 37% aqueous solution of formaldehyde was added at a time. The temperature is raised naturally, and the reaction temperature is controlled at 130 to 140 ° C and the pressure is 0.15 to 0.20 MPa. The reaction was allowed to fully condense for 2 h. After the condensation is completed, 30% of the alkali solution is added for neutralization until the PH value reaching to 7 or so. Finally, the crystals becoming cooled, filtered, and the dried crystals are the finished product.


  1. This product is used as dispersant, leveling agent for disperse dyes, reactive dyes, vat dyes.
  2. It is used as a diffusing agent and filler for pesticides, a tanning agent for leather, a cement concrete water reducing agent for construction, and a water reducing agent for oil well cement.
  3. This product is a thinner used in the paper industry to control the pulp, reduce the two-sidedness, improve the retention of filler or fine fiber, improve the sizing, and reduce the viscosity of the coating. Used as a highly effective dispersant for waterborne coatings and pigment pastes. Used as a colorant dispersant in acrylic paints, aldehyde-acrylic series, and chlorine-based series of latex paints. It can also be used as an adhesive, as a filler in polymers and in improved water resistance in sealing layers.