Hydroxyethylidene Diphosphonic Acid - Product Characteristics and Usuage of HEDP

HEDP(Hydroxyethylidene Diphosphonic Acid) is an organic phosphoric acid and corrosion inhibitor, which can form stable complexing agent with iron, copper, zinc and other metal ions, and can dissolve oxides on the metal surface. HEDP can still play a good role in corrosion and scale inhibition at 250°C, is still very stable at high pH values, not easy to be hydrolyzed, and not easy to decompose under general light and heat conditions. It has better acid and alkali resistance and chlorine oxidation resistance than other organic phosphoric acid (salt). HEDP can form a six-ring chelate with metal ions in water, especially calcium ions, so HEDP acid 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.

HEDP solid 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.

1. Hydroxyethylidene diphosphonic acid is a scale and corrosion inhibitor for boilers and heat exchangers, a complexing agent for non-cyanide electroplating, chelating agent for soap, and cleaning agent for metals and non-metals.

2. Hydroxyethylidene diphosphonic acid is often used as a scale and corrosion inhibitor in the treatment of boiler water, circulating water, and oilfield water injection. It is often compounded with polyhydroxy acid scale inhibitor and dispersant. It can also be used as complexing agent for non-cyanide electroplating, fixing agent for bleaching and dyeing industry, hydrogen peroxide stabilize.

3. Hydroxyethylidene diphosphonic acid is the main material of non-cyanide electroplating. It is formulated into a non-cyanide copper electroplating solution, and the bonding force of the copper electroplating layer directly on the steel is good. The coating is smooth and the color is good. The general dosage is 60%, and the content is 100～120 ml/L. The amount of copper sulfate is 15-20 g/L. In addition, before electroplating, immerse the plated parts in the 1% to 2% solution of this product to turn the plated parts into an activated state, and then electroplating can improve the effect.

4. Hydroxyethylidene diphosphonic acid used as a new type of chlorine-free electroplating complexing agent, used as the main agent for stable water quality in the circulating cooling water system, and has the effect of corrosion and scale inhibition. This product is one of the organic and non-phosphonic acid-free water sheeting agents. There are some other varieties of this kind of products produced in China, such as amino trimethylene phosphonic acid (ATMP): [CH2PO(OH)2]3N and ethyl Diamine tetramethylene phosphoric acid (EDTMP) and so on. Organic polyphosphonic acid is a type of water treatment agent developed in the late 1960s and confirmed around the 1970s. The emergence of this type of treatment agent has made water sheeting technology a big step forward. Compared with organic polyphosphate, organic polyphosphonic acid has good chemical stability, is not easy to be hydrolyzed, can withstand higher temperature and small dosage, and has the characteristics of anti-fouling performance. It is a kind of cathode type corrosion inhibitor and a kind of non-chemical equivalent scale inhibitor.

5. As a scale inhibitor, the general use concentration is 1~10mg/L, as a corrosion inhibitor, the general use concentration is 10~50mg/L; as a cleaning agent, the general use concentration is 1000~2000mg/L; it is usually used in conjunction with polycarboxylic acid type scale inhibitor and dispersant.