Biodegradable Chelating Agent: HIDS™ Tetrasodium 3-Hydroxy-2,2'-Iminodisuccinate

Main Applications
Household detergents, Industrial detergents, Fiber surface conditioner, Bleaching aids, Water treatment agents, Chemical agents for photography, Paper and pulp processing additives, Plated sheet steel detergents, Semiconductor detergents, Anti-deposition for aluminum cases (aluminum etching), Plating pretreatment agents (degreasing agents, derusting agents), Soil improving agents, Raw materials for cosmetics, etc.
Applications
Functions
- Dispersion / Aggregation
- Wash / Decomposition / Dissolution

Basic Information
Features and Properties
Examples of Applications
Details of Functions
Environmental Impact
Safety
Laws and Regulations

Basic Information

* The specifications may be changed without notice.

Chemical Structure
Chemical Formula	C₈H₇NO₉・4Na
CAS No.	190195-65-4
Molecular Weight	353.1
Appearance	Pale yellow~yellow, liquid
Product Form	50wt% aqueous solution
pH	10±1(*)
Density	1.40~1.60 (20 C)

Features and Properties

High biodegradable chelating capability: HIDS™ effectively traps and inactivates heavy metal ions such as Fe3+ and Cu2+, as well as Ca2+ and Mg2+ over wide range of pH; it prevents troubles caused by metal ions contained in water.
High performance under various conditions: HIDS™ shows superior performance as a chelating agent added to industrial and household detergents, etc. It has high thermal stability, high solubility in concentrated alkaline aqueous solutions, and low corrosion to glass.
Environmentally-friendly chelating agent: HIDS™ is a top-class biodegradable and safe chelating agent.

Examples of Applications

HIDS™ has a wide-range of applications including in: Household detergents, Industrial detergents, Fiber surface conditioner, Bleaching aids, Water treatment agents, Chemical agents for photography, Paper and pulp processing additives, Plated sheet steel detergents, Semiconductor detergents, Anti-deposition for aluminum cases (aluminum etching), Plating pretreatment agents (degreasing agents, derusting agents), Soil improving agents, Raw materials for cosmetics, etc.
Please use this product after investigating by yourself matters concerning the compliance of legal regulations, independent industry standards and other rules and the proper usage methods for your intended applications.

Details of Functions

Acid Dissociation Constants and Stability Constants of Chelate Complexes

Acid Dissociation Constants	pKa1:2.83 pKa2:3.56 pKa3:5.15 pKa4:9.11
Stability Constants of Chelate Complexes	pKaCa^2＋:4.8 pKaFe^3＋:12.5
C.V. Values	300mg CaCO₃/g

Fe3+ Chelating Capability

The biodegradable chelating agent HIDS™ forms stable water-soluble complexes with various metal ions over a wide range of pH values.
It is particularly excellent in chelating Fe3+ in alkaline solutions.

Test Solution	Chelating agent 0.01M Fe³⁺　　0.01M
Temperature	Room temperature
Test Method	The test solution was left to stand for seven days at room temperature. Then the solution was filtered to remove the sediments (hydrate Fe compounds), and the Fe3+ concentration in the filtrate was measured.

graph — (*) Residual Fe3+: Ratio of the Fe3+ dispersing evenly in the solution after the test to the initial Fe3+.

Thermal Stability and pH Stability

The biodegradable chelating agent HIDS™ has a wide range of applications including in harsh conditions; it is stable at high temperatures and at a range of pH 4-13.

Test Solution	Biodegradable chelating agent HIDS™: 10%
Temperature	80℃
Test Method	The test solution was incubated at 80°C, and aliquots were sampled at the indicated hours. The residual amount of the biodegradable chelating agent HIDS™ was measured using high-performance liquid chromatography (HPLC).

Solubility in Alkaline Aqueous Solutions

The biodegradable chelating agent HIDS™ is highly soluble in alkaline aqueous solutions.
In particular, HIDS™ can be added into highly-concentrated alkaline aqueous solutions without the addition of solubilizing agents.

Temperature	0℃

Solubilization of Water-insoluble Calcium Salt

The biodegradable chelating agent HIDS™ is able to solubilize water-insoluble calcium salt, which is the main component of scales.
HIDS™ can effectively remove scales in tanks and tubes, and prevent scale generation.

Test Solution	Water-insoluble calcium salt: 0.6%, Chelating agent: 0.2%, NaOH: 3%
Temperature	80℃
Test Method	The test solution was stirred at 80°C for one hour, and then the concentration of dissolved Ca2+ was measured.

Glass Corrosion

The biodegradable chelating agent HIDS™ is less corrosive to glass compared to other chelating agents.

Test Solution	NaOH 10%, Chelating agent 3%
Test Piece	Slide glass
Temperature	100℃
Test Method	The test pieces were placed in the test solution for three days at 100°C, and then removed from the solution and washed. The corrosion degree was calculated from the weight change per unit of area.

Environmental Impact

Biodegradability	Biodegradable (*1)
Fish Toxicity	LC₅₀ *≥ 2,000 ppm (Himedaka (Oryzias latipes) 96 hr) (1)**

(*1) These values were measured by an external test laboratory commissioned from Nippon Shokubai.

Safety

Acute Toxicity	Oral Toxicity LD50 > 2,000 mg/kg (*1)
Local Effect	No primary skin irritation (P.I.I. = 0.4 (45 wt%), P.I.I. = 0 (35 wt%), P.I.I. = 0 (10 wt%) P.I.I. = 0 (89 wt%, powder)) (1) No primary eye irritation (1)
Sensitization	No skin sensitization (*1)
Ames Test	Negative (*1)