Quick Search
CAS no: 95-14-7
EC / List no: 202-394-1
Chemical formula: C6H5N3
Synonyms: 1,2,3-1H-Benzotriazole, Azimidobenzene, 1,2,3-triazaindene, 1,2,3-Benzotriazole, 1,2,3-Benzotriazole-1H-Benzotriazole, 1,2,3-benzotriazole, 1,2,3-triaza-1H-indene, 1H-1,2,3-benzotriazole, 1H-Benzotriazole, 1H-Benzo[d][1,2,3]triazole, 1H-Benzotraizole, 1H-Benzotriazol, 1H-Benzotriazole (vapor and aerosol), 1H-Benzotriazole, >10 - 24% in a non hazardous diluent, 1H-Benzotriazole; 1H-benzotriazole; azimidobenzene, 1H-Benzotriazole; Azimidobenzene; BTA Inhibitor, AZIMIDOBENZOL, Benzotriazole, Benzotriazole., benzotriazole, Benzotriazol, BENZOTRIAZOLE, 2H-Benzotriazole, 2H-benzotriazole, 1,2-AMINOAZOPHENYLENE, 1,2-benzothiazoli-3(2H)-one, 1-hexadecene, Hydrocarbons, C10-14 (even numbered), n-alkanes, isoalkanes, <2% aromatics, БТА corrosion inhibitor, COBRATEC 99, Cobratec 1,2,3 BZ-G
Benzotriazole (BTA), also known as 1H-benzotriazole or 1,2,3-benzotriazole , is a heterocyclic aromatic compound with the molecular formula C₆H₅N₃. It consists of a fused benzene ring and triazole ring, forming a highly stable structure with strong metal-binding and UV-absorbing properties.
It is widely recognized as one of the most effective corrosion inhibitors for copper and copper alloys, and is extensively used in industrial water systems, lubricants, coatings, electronics, and cleaning formulations.
Key Properties of 1,2,3-Benzotriazole
Molecular Weight: 119.12 g/mol
Appearance: White to off-white crystalline powder or solid
Odor: Odorless or very mild characteristic odor
Melting Point: ~98–100 °C
Boiling Point: Decomposes before boiling (~204–210 °C)
Density: ~1.36 g/cm³ (at 20 °C, typical value)
Solubility: Moderately soluble in water
Highly soluble in alcohols, acetone, and other polar organic solvents
Vapor Pressure: Very low (low volatility)
Acidity (pKa): ~8.2 (weak acidic behavior)
Stability: Stable under normal conditions; may decompose at high temperatures
Hydrolysis: Stable in neutral conditions; slow degradation in extreme pH
Structure and Chemical Behavior
Benzotriazole is a heterocyclic aromatic compound composed of three nitrogen atoms within a triazole ring fused to a benzene ring. This structure allows:
Strong coordination with metal ions (especially Cu⁺ and Cu²⁺)
High adsorption on metal surfaces
Formation of stable protective complexes
Resistance to degradation in industrial environments
These properties make benzotriazole highly effective in metal protection systems and corrosion control technologies.
Mechanism of Corrosion Inhibition
The corrosion inhibition mechanism of benzotriazole is based on the formation of a protective chemisorbed film on metal surfaces, particularly copper and its alloys.
Key steps in protection:
Adsorption of BTA molecules on the metal surface
Formation of copper–benzotriazole complex
Development of a thin, insoluble, and highly stable barrier layer
Blocking of anodic and cathodic corrosion reactions
Prevention of oxygen reduction and metal oxidation
This molecular film is extremely thin (nanometer scale) but highly durable, providing long-term protection even in aggressive environments.
Industrial Applications of Benzotriazole
Benzotriazole is a multi-industry functional chemical used across a wide range of applications:
Corrosion Inhibitor for Copper and Alloys
The most important application of BTA is corrosion protection of copper, brass, bronze, and silver.
It is widely used in:
Cooling water systems
Heat exchangers
Metalworking fluids
Industrial piping systems
Hydraulic systems
Automotive cooling circuits
It prevents:
Oxidation
Tarnishing
Pitting corrosion
Metal discoloration
Industrial Fluids and Lubricants
Benzotriazole is an essential additive in:
Engine oils
Hydraulic fluids
Brake fluids
Gear oils
Antifreeze formulations
Heat transfer fluids
It improves:
Metal compatibility
Oxidation resistance
System lifetime
Fluid stability
Water Treatment Applications
BTA is widely used in industrial water systems:
Cooling towers
Closed-loop water systems
Boiler systems
Heat exchange systems
It protects metal surfaces from corrosion caused by water circulation and dissolved oxygen.
Cleaning Products and Detergents
Benzotriazole is commonly found in:
Dishwasher detergents (silver protection)
Industrial cleaning agents
Metal cleaners
Degreasing formulations
It prevents tarnishing of silverware and corrosion of metallic components during washing processes.
Paints, Coatings, and Surface Protection
BTA is used in protective coating systems such as:
Anti-corrosion paints
Industrial varnishes and lacquers
Metal surface coatings
UV-protective coatings
It helps prevent:
Discoloration
Oxidation
Environmental degradation
Electronics and Semiconductor Industry
Benzotriazole is highly important in high-tech applications:
Copper interconnect protection in semiconductors
Electronic circuit surface treatment
Polishing and etching solutions
Conductive ink stabilization
Its ability to form stable metal complexes makes it essential in microelectronics manufacturing.
UV Stabilizers and Polymer Industry
Benzotriazole derivatives are widely used as:
UV absorbers in plastics
Light stabilizers in polymers
Anti-aging additives in coatings
Weather-resistant material additives
Photographic and Imaging Industry
BTA has historical and specialized use in:
Photographic emulsions
Antifogging agents
Film processing stabilizers
Silver protection in imaging systems
Chemical Intermediate
Benzotriazole is also used as a building block in organic synthesis:
Pharmaceutical intermediates
Dye and pigment production
UV absorber synthesis
Specialty chemicals
Physical Forms of Benzotriazole
Benzotriazole is commercially available in different forms:
Fine crystalline powder
Flakes
Granules
Liquid formulations (in glycol or alcohol solutions)
Liquid forms are often preferred in industrial systems for easier dosing and handling.
Advantages of Benzotriazole
Extremely effective at low concentration (ppm level)
Strong and long-lasting metal protection
Works in aqueous and non-aqueous systems
Compatible with copper, brass, aluminum, and silver
High stability in industrial environments
Cost-effective corrosion inhibitor
Manufacturing Process
Benzotriazole is typically synthesized via the diazotization of o-phenylenediamine, using sodium nitrite under acidic conditions, producing high-purity industrial-grade material.
Environmental and Safety Considerations
Moderately soluble in water
Persistent in aquatic environments
Requires controlled industrial handling
Regulated in wastewater discharge in some regions
Proper usage ensures safe and efficient industrial performance.
Benzotriazole (BTA) is a highly versatile industrial chemical widely used for corrosion inhibition, UV stabilization, and metal protection applications. Its unique ability to form stable protective films on copper and other metals makes it indispensable in industrial systems, electronics, coatings, and chemical formulations.
Due to its efficiency at low concentrations and broad compatibility, benzotriazole remains a key material in modern industrial chemistry and metal protection technologies.
