| 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP)
CAS No.: 2809-21-4
Molecular Formula: C2H8O7P2
Molecular weight: 206.02
Dequest: 2010
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 |
Colorless or light yellow transparent liquid |
White crystal powder |
Active content (HEDP) % |
58.0-62.0 |
90.0min |
Phosphorous acid (asPO33-)% |
2.0max |
0.5max |
Phosphoric acid (asPO43- )% |
0.8max |
0.5max |
Chloride (as Cl-)% |
0.1max |
0.1max |
pH (1%solution) |
2max |
2max |
Density (20℃)g/cm3 |
1.40 |
- |
Fe (as Fe3+) (ppm) |
10max |
20max |
Colour APHA(Hazen) |
40max |
- |
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: Normally In 250kg net Plastic Drum, IBC drum can also be used as required.
HEDP solid: 25kg inner liner polyethylene (PE) bag, outer plastic woven bag,, or confirmed by clients.
Storage for ten months in room shady and dry place.
Safety Protection:
Acidity, Avoid contact with eye and skin, once contacted, flush with water.
Monosodium of 1-Hydroxy Ethylidene-l,1-Diphosphonic Acid
(HEDP·Na)
CAS No.: 29329-71-3
Molecular Formula: C2H7O7P2Na
Dequest: 2016A
Molecular weight: 228
Items |
Index |
Appearance |
Colorless or light yellow transparent liquid |
Active component(HEDP) % |
19.0-21.0 |
Fe (as Fe3+) (ppm) |
20max |
pH value (1% water solution) |
2.3-2.9 |
Density (20℃)g/cm3 |
1.11-1.21 |
Disodium of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid
(HEDP·Na2)
CAS No.: 7417-83-7
Molecular Formula: C2H6O7P2Na2
CubleK: 2012
Molecular weight: 250
Dequest: 2016BD
Items |
Index |
Appearance |
Colorless to light yellow transparent liquid |
White powder |
Active component (HEDP) % |
16.5min |
74.0-79.0 |
Active component (HEDP·Na2) % |
20.0min |
89.8min |
Density (20℃)g/cm3 |
1.12-1.22 |
- |
Fe (as Fe3+) (ppm) |
- |
35max |
Phosphorous acid (PO33-计)% |
- |
3max |
Dry weight loss, % |
- |
3-6 |
PH(1% water solution) |
4.0-6.0 |
4.0-6.0 |
Tetra sodium of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid
(HEDP·Na4)
CAS No.: 29329-71-3 (x-Na), 3794-83-0 (4-Na)
Molecular Formula: C2H4O7P2Na4
Dequest: 2016/2016DG
Molecular weight: 294
Items |
Index |
Appearance |
White powder |
Colorless to light yellow transparent liquid |
Active component (HEDP) % |
56.0min |
20.3-21.7 |
Active component (HEDP·Na4) % |
79.9min |
29.0-31.0 |
Total phosphoric acid (PO43-) % |
52.0-54.0 |
18.4-20.4 |
Fe (as Fe3+) (ppm) |
35.0max |
20max |
Dry weight loss, % |
15max |
- |
density (20℃) g/cm3 |
- |
1.26-1.36 |
PH |
11.0-12.0(1% water solution) |
10.0-12.0(as it) |
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