Aminosulfonic acid is an inorganic solid acid formed by the substitution of hydroxyl groups in sulfuric acid with amino groups. Its chemical formula is NH2SO3H, molecular weight is 97.09, and it is generally a white, odorless oblique square shaped crystal with a relative density of 2.126 and a melting point of 205 ℃. It is soluble in water and liquid ammonia, and at room temperature, as long as it is kept dry and not in contact with water, the solid aminosulfonic acid is not hygroscopic and relatively stable. Aminosulfonic acid aqueous solution has the same strong acidity as hydrochloric acid, sulfuric acid, etc., so it is also known as solid sulfuric acid. It has the characteristics of non volatility, no odor, and low toxicity to the human body. Dust or solution can be irritating to the eyes and skin, causing burns, with a maximum allowable concentration of 10 mg/m3. Aminosulfonic acid can be used to synthesize herbicides, fire retardants, sweeteners, preservatives, metal cleaning agents, etc. It is a common chemical raw material.
Chinese name: Aminosulfonic acid
Foreign name: Sulfamic acid
Nicknames: sulfonic acid, sulfonamide, sulfamic acid
Chemical formula: NH2SO3H
Molecular weight: 97.094
CAS login number: 5329-14-6
EINECS login number: 226-218-8
Melting point: 205 ℃
Boiling point: 209 ℃ (decomposition)
Water solubility: easily soluble in water
Density: 2.126 g/cm ³
Appearance: White oblique square flake crystal
Application: Industrial raw materials, solid strong acids
Water solubility: 146.8 g/L (20 ° C)
Appearance: White rhombic crystals or white crystals. Odorless, non volatile, and non hygroscopic.
Density: 2.126 g/cm3
Melting point: 205 ℃ (decomposition begins at 209 ℃ and releases SO2, SO3, N2, water, and other trace products at 260 ℃)
Refractive index: α Type 1.553, β Type 1.563, γ Type 1.568
Dissociation constant: 1.10 × 10-2
Heat generation: 685.9kJ/mol
Solubility: Easily soluble in water and liquid ammonia, aqueous solutions are highly ionized substances and strong acids. Slightly soluble in methanol, insoluble in ethanol and ether.
Aminosulfonic acid is a dipole, and the infrared spectrum shows that the chemical environment of the three H's is completely the same, and the chemical environment of the three O's is also completely the same. Therefore, its structural formula is not H2NSO2OH, but H3NSO3, indicating that an intramolecular acid-base reaction has occurred.
Aminosulfonic acid cleaning agents have a wide range of applications and can be used to clean boilers, condensers, heat exchangers, jackets, and chemical pipelines. Use it to remove scale from glass lined storage tanks, pots, open beer coolers, and beer barrels in breweries; Clean the evaporator of the enamel factory and the equipment of the paper mill; In terms of air conditioning, it can remove rust and scale from the cooling system and evaporative condenser; It can be used to remove seaweed and scale from seawater evaporators (distillation equipment), heat exchangers, and brine heaters on sea vessels; Can clean scale from copper pots, radiators, tableware washing mechanisms, silverware, flush toilets, ceramic tiles, food and dairy processing equipment; It can remove protein deposits on the steamer and deposits on disinfectant used in fresh meat, vegetables, and cheese processing plants. The US Department of Agriculture allows the use of sulfamic acid as an acidic cleaning agent in fresh meat, poultry, rabbit, and egg processing enterprises.
Aminosulfonic acid can be used as an elimination agent for excess nitrite in the diazotization reaction in the dye industry, a color fixative for textile dyeing, and to form a fireproof layer on textiles. It can also be used as a cleaning agent and other additives in the textile industry.
Aminosulfonic acid can be used as a bleaching agent to reduce or eliminate the catalytic effect of heavy metal ions in the bleaching solution, ensuring the quality of the bleaching solution and reducing the oxidative degradation of fibers by metal ions. It can also prevent the peeling reaction of fibers and improve the strength and whiteness of pulp.
Aminosulfonic acid can be used to remove blockages in oil reservoirs and improve their permeability. Injecting amino sulfonic acid solution into carbonate reservoirs can avoid salt deposition due to its easy reaction with reservoir rocks. The treatment cost is slightly higher than using hydrochloric acid, but the oil production is doubled. The United States uses 48.5% potassium hydroxyacetate and 3.4% amino sulfonic acid. A 0.1-3% aqueous solution of wetting agent is used to clean the gypsum scale layer in the oil well casing, and the treatment time is about 30 hours.
Aminosulfonic acid and ammonium aminosulfonic acid were initially developed as herbicides. It is said that when they are directly applied to plants, they have the effect of coming into contact with toxic agents; And when applied to the soil, it has a male killing effect.
In the experiment conducted in Guangdong Province, China in 1978, the effect of sulfamic acid on male sterility in rice was found to be better than other salts. Spraying at a concentration of 0.05% to 0.5% resulted in a male sterility rate of 95% to 100%, but the effect was not stable enough and was harmful. The herbicide concentration of sulfamic acid is usually 75 g/L of the active ingredient.
Aminosulfonic acid is commonly used for gold or alloy plating. The plating solution for gold, silver, and gold silver alloys contains 60-170 g of aminosulfonic acid per liter of water. The typical electroplating solution for silver plated women's clothing needles is 125 g of amino sulfonic acid per liter of water, which can obtain a very shiny silver plating surface. Alkali metal sulfates, ammonium sulfates, or sulfates can be used as conductive and buffering compounds in new aqueous gold plating solutions.
When recovering from nickel plating waste liquid, cation exchange resin is used for adsorption treatment, and then amino sulfonic acid is used to clean the resin, so that the adsorbed substance is desorbed and the resin is regenerated. For example, when processing 400 ppmNi electroplating wastewater, 50 ml of 150 g/L amino sulfonic acid is used to recover 2112 g/L of (NH2SO3) and 4148 g/L of NiSO4. When repairing nickel plated parts, nickel plating is required on the nickel surface, and 100 g/L amino sulfonic acid can be used for anodizing treatment. Before nickel plating, the nickel plating surface should be cleaned with 0.003-0.1 grams of amino sulfonic acid solution.
The content of amino sulfonic acid in copper plating solution is 3-20 L. The role of amino sulfonic acid is to make the coating fine and ductile, with high viscosity.
When iridium plating, NH2SO3H/Ir ≥ 7, the obtained iridium coating has no cracks, a thickness of 15 microns, and strong adhesion. This product exhibits good activity in automatic anti pollution equipment.
When plating rhodium rhenium alloy on silverware and electrical components, the electrolyte contains 100 g/L of amino sulfonic acid. When the coating thickness is ≤ 5 microns, it has high hardness and strong corrosion resistance, and the electroplating coating is very bright and beautiful.
The smooth and beautiful rhodium rhenium electroplated layer on brass has high hardness and corrosion resistance. The plating solution contains 100 g/L amino sulfonic acid, 50 g/L concentrated sulfuric acid, 2 g/L rhodium (such as sulfate), and 0.05 g/L rhenium [such as K3N (RuCl4H2O2) 2]. The deposition rate is 3-4 milligrams per ampere minute at 65 ℃ and 1-2 ampere per minute.
Italy has used lead aminosulfonic acid baths instead of fluorosilicic acid baths to reduce pollution. There are various uses in the anti-corrosion aluminum industry. The product has good luster and excellent processing performance.
Chemical synthesis analysis
Aminosulfonic acid is an inexpensive and stable solid acid in organic synthesis, which has good catalytic effect on esterification reactions with acid and does not corrode equipment. At the same time, it is also a raw material for manufacturing synthetic sweeteners, herbicides, flame retardants, preservatives, and so on. Products with a purity of over 99.9% can also be used as standard solutions for acids during alkaline titration. Hazard Overview
Toxicity protection: This product is low in toxicity. Has a certain irritant effect on the skin and eyes. Production equipment should be sealed, and operators should wear protective equipment. Safety: Dust or solution can be irritating to the eyes and skin, and can cause burns. The maximum allowable concentration is 10 mg/m3. When the eyes are stimulated, they should be rinsed with water. In severe cases, medical treatment should be sought. When in contact with the skin, rinse with water and thoroughly wash with soap. At the entrance, rinse your mouth immediately and promptly seek medical attention. Pack in wooden boxes lined with polyethylene plastic bags, with a net weight of 25 kg per box. Store in a cool, ventilated, and dry place. The packaging should be sealed and moisture-proof. During transportation, it is necessary to prevent rain and sunlight exposure. When disposing of escaping materials, it is necessary to wear a gas mask and gloves, sweep with a mixture of sand and soil, or rinse with water. When a fire occurs, water, sand, and fire extinguishers can be used to extinguish it.
1. Acute toxicity: LD50: 3160mg/kg (orally administered to rats); 1312mg/kg (orally administered to mice).
2. Subacute toxicity: Rats were orally administered for 105 days, and the result was that when the concentration of amino sulfonic acid in food was 2%, it stimulated growth, but there was no significant toxic effect at a concentration of 1%.
Rabbit transdermal: 500 mg (24 hours), severe irritation.
Rabbit eye: 250 μ G (24 hours), severe stimulation.
Experiments were conducted with mice and dogs. When swallowing a solution with a concentration of 10%, it can damage the stomach. When the concentration reaches more than 20%, it can damage the sticky legs and stimulate the stomach due to its strong acidity.
4. Ecotoxicity LC50: 70 mg/L (96 h) (black headed fish).
Storage and transportation
Seal and dry for storage. Sealed packaging and stored in a dry and ventilated place. Separate storage and transportation with oxidants, alkalis, etc. Pay attention to personal protection and prohibit direct physical contact. Accidentally ingested, rinse mouth with water, drink milk or egg white.
During railway transportation, it is necessary to strictly follow the dangerous goods loading table in the Ministry of Railways' Dangerous Goods Transport Rules for loading. The packaging should be complete during transportation and the loading should be secure. During transportation, it is necessary to ensure that the container does not leak, collapse, fall, or be damaged. It is strictly prohibited to mix and transport with oxidants, alkalis, edible chemicals, etc. Transport vehicles should be equipped with leak emergency response equipment during transportation. During transportation, it is necessary to prevent exposure to sunlight, rain, and high temperatures