CAS No. 2809-21-4
Molecular
Formula: C2H8O7P2 Molecular
weight: 206.02
Structural Formula:

Properties:
HEDP is an organophosphoric acid corrosion inhibitor. It can
chelate with Fe, Cu, and Zn ions to form stable chelating
compounds.It can dissolve the oxidized materials on these
metals’ surfaces. HEDP shows excellent scale and corrosion
inhibition effects under temperature 250℃.
HEDP has good
chemical stability under high pH value, hard to be
hydrolyzed, and hard to be decomposed under ordinary light
and heat conditions. Its acid/alkali and chlorine oxidation
tolerance are better than that of other organophosphoric
acids (salt). HEDP can react with metal ions in water system
to form hexa-element chelating complex, with calcium ion in
particular. Therefore,
HEDP has good antiscale and visible
threshold effects. When built together with other water
treatment chemicals, it shows good synergistic effects.
The solid state of HEDP is crystal powder, suitable for
usage in winter and freezing districts. Because of its high
purity, it can be used as cleaning agent in electronic
fields and as additives in daily chemicals.
Specification:
Items |
Index |
Appearance |
Clear, Colorless to pale yellow aqueous solution |
White
crystal powder |
Active content
(HEDP)%
|
58.0-62.0 |
90.0 min |
Active content (HEDP·H2O)% |
- |
98.0 min |
Phosphorous acid (as
PO33-)% |
2.0
max |
0.8
max |
Phosphoric acid
(as PO43-
)% |
0.8
max |
0.5
max |
Chloride (as Cl-)% |
0.02
max |
0.01 max |
pH (1% water solution) |
2.0 max |
2.0 max |
Density
(20?)g/cm3 |
1.40
min |
- |
Fe, mg/L |
20.0
max |
10.0 max |
Ca sequestration (mg CaCO3/g) |
500.0 min |
|
Usage:
HEDP is used as scale and corrosion
inhibition in circulating cool water system, oil field and
low-pressure boilers in fields such as electric power,
chemical industry, metallurgy, fertilizer, etc.. In light
woven industry, HEDP is used as detergent for metal and
nonmetal. In dyeing industry,
HEDP is used as peroxide
stabilizer and dye-fixing agent; In non-cyanide
electroplating, HEDP is used as chelating agent. The dosage
of 1-10mg/L is preferred as scale inhibitor, 10-50mg/L as
corrosion inhibitor, and 1000-2000mg/L as detergent.
Usually,
HEDP is used together with polycarboxylic acid.
Package and Storage:
HEDP liquid: 200L plastic drum,IBC(1000L),customers’ requirement.
HEDP solid: 25kg/bag,customers’ requirement.
Storage for twelve months in room shady and dry
place.
Safety Protection:
Acidity, Avoid contact with eye and skin,
once contacted, flush with water.
Synonyms:
HEDP;HEDP(A);HEDPA;ETIDRONIC ACID;1-Hydroxy Ethylidene-1,1-Diphosphonic Acid; Hydroxyethylidene-1,1-diphosphonicacid(HEDP); 1-HYDROXYETHYLIDENEDIPHOSPHONIC
ACID;Hydroxyethylidene Diphosphonic acid(HEDP);1-hydroxy-1,1-Ethanediyl ester