Dibromoneopentyl Glycol

RX-975 Dibromoneopentyl Glycol

Chemical Name:2,2-Bis(bromomethyl)propane-1,3-diol

Brand Name: RX-975

CAS NO.: 3296-90-0

Chemical formula:C₅H₁₀Br₂O₂

Synonym: FR-522,DBNPG

Chemical Structure:

Application:

RX-975 is a reactive flame retardant. Its high purity is of benefit to the formulator.

Thermosetting polyester resins can be formulated over a wide range of compositions to provide a broader selection of resin properties than those available with anhydride flame retardants. Resins formulated with RX-975 have high flame retardancy, minimal thermal discoloration and excellent light stability.

The high bromine content of RX-975 and its ready reaction into polyurethanes（PU）make it suitable for use in rigid polyurethane foams. It is increasingly used in CFC-free foam systems designed to meet more stringent standards of flame retardancy.

Technical Data Sheet

Packing:

packed in 25kg paper bag,40 bags on pallet.

Total 20Mt per 20'FCL.

Production Process 1:

Synthesis method of Dibromoneopentyl Glycol, which involves esterification of pentaerythritol with acetic acid at a concentration above 98%. The weight of acetic acid added is 1.1 times that of pentaerythritol, and the reflux esterification reaction takes 5 hours; After the esterification reaction, the esterification products were separated by dehydration and acid evaporation. The dehydration and acid evaporation time was 3.5 hours and the temperature was 115 ℃; Dissolve the separated esterification product in acetic acid with a concentration of over 98%. The amount of acetic acid added is 0.9 times the weight of pentaerythritol, and hydrogen bromide gas is introduced for substitution reaction at 85 ℃. The amount of hydrogen bromide introduced is 1.2 times the weight of pentaerythritol, and the ventilation time is 4 hours. Then, keep it at 95 ℃ and atmospheric pressure for 3.5 hours; After insulation, the diethyl ester of Dibromoneopentyl Glycol was separated and subjected to constant pressure ester decomposition using methanol and sulfuric acid at a pressure of 0.6MPa. The amount of methanol was 1.7 times the weight of pentaerythritol, and the amount of sulfuric acid was 3% of the weight of pentaerythritol. The temperature for constant pressure ester decomposition was 70 ℃, and the time for ester decomposition was 4.5 hours; The product of ester decomposition is decolorized with activated carbon at 60 ℃. The amount of activated carbon added is 2% of the weight of pentaerythritol, and the time is 1.0 hours. After filtration, the filtrate is concentrated to obtain the crude product of Dibromoneopentyl Glycol.

Production Process 2:

The synthesis method of Dibromoneopentyl Glycol involves esterification of pentaerythritol with acetic acid at a concentration above 98%. The weight of acetic acid added is 1.2 times that of pentaerythritol, and the reflux esterification reaction takes 4 hours; After the esterification reaction, the esterification product is separated by dehydration and acid evaporation. The dehydration and acid evaporation time is controlled at 2.5 hours and the temperature is 125 ℃; Dissolve the separated esterification product in acetic acid with a concentration of over 98%. The amount of acetic acid added is 1.1 times the weight of pentaerythritol, and hydrogen bromide gas is introduced for substitution reaction at 105 ℃. The amount of hydrogen bromide introduced is 1.1 times the weight of pentaerythritol, and the ventilation time is 4.5 hours. Then, keep it at 100 ℃ and atmospheric pressure for 4.5 hours; After insulation, the diethyl ester of Dibromoneopentyl Glycol was separated and subjected to constant pressure ester decomposition using methanol and hydrochloric acid at a pressure of 0.5 MPa. The amount of methanol used was 1.8 times the weight of pentaerythritol, and the amount of hydrochloric acid used was 4% of the weight of pentaerythritol. The temperature for constant pressure ester decomposition was 65 ℃, and the time for ester decomposition was 4 hours; The product of ester decomposition is decolorized with activated carbon at 65 ℃. The amount of activated carbon added is 1.5% of the weight of pentaerythritol, and the time is 1.5 hours. After filtration, the filtrate is concentrated to obtain a crude product of Dibromoneopentyl Glycoll.

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