1-hydroxyethylidene-1(HEDP)

1-hydroxyethylidene-1(HEDP) with the cas 2809-21-4, also known as, 1-diphosphonic acid, Hydroxyethylidene diphosphonic acid, is a kind of organic phosphoric acid scale and corrosive inhibitor used in various industrial fields. In the presence of chlorine, it also shows good stability and has same corrosion inhibition performance as zinc and other phosphates. Solid HEDP chemical is crystalline powder in appearance, which is a high-purity product, suitable for winter in severe cold areas, especially suitable for cleaning agents and daily chemical additives in the electronics industry.

• It is a scale and corrosion inhibitor for boilers and heat exchangers, a complexing agent for non-cyanide electroplating, a chelating agent for soap, and a cleaning agent for metals and non-metals.
• It is often used as a scale and corrosion inhibitor in boiler water, circulating water, and oilfield water injection treatment.
• It is often compounded with polyhydroxy acid scale inhibitor and dispersant. Can also be used as complexing agent for non-cyanide electroplating, fixing agent for bleaching and dyeing industry, and hydrogen peroxide stabilizer.
• In the textile industry, 1-diphosphonic acid is used as a cleaning agent for metals and non-metals.
• In the printing and dyeing industry, HEDP chemical is used as a peroxide stabilizer and fixing agent.
• In non-cyanide electroplating, HEDPphosphonate is used as a chelating agent. Generally, it is used with polycarboxylic acids.
• As the main material of non-cyanide electroplating, it is formulated into a cyanide-free copper electroplating solution, and the bonding force of the copper electroplating layer directly on steel is good. The coating is smooth and the color is good.
• As a water treatment chemical, HEDP has a stable structure and is not easily hydrolyzed. The corrosion and scale inhibition effect is good. 1-hydroxyethylidene-1 is a cathode type corrosion inhibitor. Compared with inorganic polyphosphate, the corrosion inhibition rate is about 4 times higher. Iron ions in the water have a significant impact on the corrosion inhibition effect of HEDP chemical. When the iron ion concentration is greater than 3mg/L, the corrosion inhibition effect of hydroxyethylidene diphosphonic acid(HEDP) decreases exponentially with the increase of iron ion concentration. HEDP chemical is used in conjunction with other corrosion inhibitors and scale inhibitors, such as chromate, polyphosphate, molybdate, silicate, nitrite, zinc salt, polycarboxylate and its derivatives, etc. So that the efficacy of medicine can be improved.

• It can form stable complexes with iron, copper, zinc and other metal ions, and can dissolve oxide on the metal surface.
• Even at a high temperature of 250℃, HEDP can still play a good role in corrosion and scale inhibition.
• It is still very stable at high pH, not easily hydrolyzed, and not easily decomposed under general light and heat conditions.
• It has better acid and alkali resistance and chlorine oxidation resistance than other organic phosphoric acid.
• HEDP chemical can form a six-ring chelate with metal ions in water, especially calcium ions, so HEDP water treatment has a good scale inhibition effect and obvious solubility limit effect. When used in combination with other water treatment agents, it shows ideal synergistic effect.
• It can form a stable adduct with compounds containing active oxygen to keep active oxygen stable.