Sodium Mercaptobenzothiazole MBT·Na (2-benzothiazolylthio)-sodium CAS 2492-26-4

Tree Chem manufactures Sodium Mercaptobenzothiazole (MBT·Na) to support customers who need to purchase a high-performance thiolate corrosion inhibitor with reliable solubility and excellent copper-passivation behavior. MBT·Na is commonly incorporated into multi-component water-treatment programs and metal-surface formulations. For detailed specifications or quotations, please reach us at info@cntreechem.com.

As a widely used derivative of MBT, the product provides strong complexing ability with metal ions and demonstrates stability across typical industrial pH and temperature ranges. Its broad compatibility with phosphonates and polycarboxylates makes it suitable for performance-driven water-treatment blends.

Specification

Basic Information

Technical Specification

Applications

Water Treatment Industry

• Sodium 2-mercaptobenzothiazole (MBT·Na) is first and foremost a specialized copper and copper-alloy corrosion inhibitor in industrial water-treatment systems. In circulating cooling-water of power plants, chemical complexes, steel and fertilizer units, it adsorbs on copper surfaces through the mercapto and benzothiazole groups and then chelates surface copper atoms to build a compact, adherent protective film. This film effectively blocks oxygen, dissolved salts and other corrosive species from contacting the metal, sharply lowering corrosion rate on condensers, heat exchangers and other copper-based components.
• In practical cooling-water operation, MBT·Na is usually applied with an initial “film-forming” dosage of about 50–100 mg/L for 24–48 hours to establish a stable protective layer, followed by a continuous maintenance dosage of roughly 2–10 mg/L. It performs best in slightly alkaline conditions (pH about 8.0–9.0) and remains effective up to around 80 °C, so it fits modern alkaline-running, high-cycle systems. Typical composite formulations combine MBT·Na with zinc salts as synergistic corrosion inhibitors for mixed copper–steel systems, with polyphosphates or organophosphonates for scale control, and with dispersants to manage fouling. In such formulations, corrosion rates of copper alloys can be reduced from around tenths of a millimeter per year to only a few thousandths, well within industry standards.
• In boiler water and condensate systems, MBT·Na is used to protect copper-containing equipment such as condensers and economizers exposed to high-temperature, high-velocity aqueous streams. Dosed at only 2–5 mg/L in steam-condensate circuits with controlled pH and low dissolved oxygen, it forms a tenacious chemisorbed film that resists stripping under high shear. When used together with oxygen scavengers and phosphate alkalization, MBT·Na helps maintain very low copper corrosion rates over long operation cycles, cutting tube replacement and unscheduled downtime.
• Oilfield injection-water systems represent another important water-treatment outlet. Injection and produced waters often carry oxygen, sulfide and microorganisms that promote corrosion and under-deposit attack on tubing, valves and surface equipment, including copper-containing parts. MBT·Na functions here as a copper corrosion inhibitor and auxiliary biocidal component within composite packages that also contain glutaraldehyde, organophosphonate scale inhibitors and steel corrosion inhibitors. In such blends it contributes to film formation on copper alloys, complements the broader corrosion-protection strategy and helps extend service life of tubing, pumps and heat exchangers by several years.
• In reverse-osmosis (RO) and membrane systems, MBT·Na is used more selectively because of the sensitivity of membranes. At very low dosages, typically 0.5–2 mg/L in the pretreatment stage, it protects copper components in the feed side without significantly impacting membrane performance. It is normally added upstream of cartridge filtration and used together with non-oxidizing biocides, reducing agents and antiscalants. Careful control of dose and injection point allows MBT·Na to deliver copper protection while maintaining permeate quality and stable salt rejection.

Metalworking and Metal-Processing Industry

• In the metalworking sector, MBT·Na plays a central role in water-soluble cutting and grinding fluids formulated for machining nonferrous and multi-metal systems. In such emulsions and semi-synthetic fluids, alkaline components and surfactants can accentuate copper corrosion and staining on workpieces and machine parts. The mercapto and benzothiazole moieties in MBT·Na chemisorb on copper surfaces and coordinate copper ions released during machining, creating a thin, strongly adherent complex film that resists further attack and discoloration.
• Typical universal cutting-fluid formulations contain base oil or synthetic esters, emulsifiers or solubilizers, organic amines, borates, nitrite alternatives and 0.1–0.4 % MBT·Na. In conventional formulations, MBT·Na is used at about 0.1–0.3 %, while in “environmentally oriented” synthetic fluids it may be increased to 0.2–0.4 % to strengthen copper protection. Performance testing shows that fluids containing MBT·Na can keep copper corrosion at the “no-corrosion” level in standard copper-strip tests, extend rust protection times and improve pH stability during service compared with similar formulations without MBT·Na.
• MBT·Na is also incorporated in rust preventives and rolling oils designed for copper and copper-alloy strip, tube and profiles. In water-based rust preventives, it is combined with triethanolamine, sodium benzoate and carbonate to create alkaline, film-forming systems that protect stored or transported copper parts from atmospheric humidity and pollutants. In oil-based rust preventives and rolling oils, small amounts of MBT·Na interact with copper surfaces and with sulfur-containing extreme-pressure and antiwear agents, enhancing film continuity and preventing tarnishing or bright-finish loss, especially in humid or marine air. This is particularly important for electrical copper strips, brass parts and decorative components that must maintain surface appearance as well as mechanical integrity.
• In alkaline and neutral metal cleaners used prior to plating, painting or assembly, MBT·Na is used to prevent over-etching or staining of copper and brass while strong alkaline builders and surfactants remove oils, oxides and soils. Typical formulas include sodium hydroxide or carbonates, silicates or citrates, surfactant blends and 0.1–0.4 % MBT·Na to ensure that cleaned copper surfaces remain bright and active without pitting.

Coatings, Paints and Surface-Protection Systems

• In the coatings industry, MBT·Na is widely used as a copper corrosion inhibitor and auxiliary biocidal component in marine, industrial and ship coatings. Marine antifouling coatings, for example, typically contain high levels of cuprous oxide as the main biocidal pigment. Copper on the coating surface can undergo oxidation and leaching, and underlying bronze propellers, sea-water pumps and heat exchangers also need protection. MBT·Na added at about 0.5–1.0 % in traditional or acrylic-based antifouling paints contributes a passivating film on copper alloy surfaces and reduces underfilm corrosion, thereby supporting long-term antifouling and structural integrity of underwater metal components.
• In industrial anticorrosive coatings for power plants, petrochemical units and chemical equipment, MBT·Na is used in epoxy and polyurethane systems as a targeted inhibitor for copper-containing components. Formulations generally include film-forming resins, pigments and fillers, driers and 0.2–0.5 % MBT·Na. Within such systems it co-adsorbs with other inhibitors on copper surfaces, improves resistance to underfilm corrosion and enhances adhesion between coating and metal by stabilizing the interfacial layer, which is crucial for mixed-metal equipment where steel, copper and other alloys coexist.
• Ship coatings represent a large application category in which copper alloys are widely used for seawater pumps, condensers, propellers and piping. In primers and topcoats applied to these components, MBT·Na is added at about 0.2–0.5 % to protect copper and brass from seawater attack and atmospheric exposure. It helps maintain gloss and color stability, reduces pitting at coating defects and extends maintenance intervals for shipboard cooling and seawater-handling systems.
• In special functional coatings, MBT·Na plays a more targeted role. In conductive coatings loaded with copper powder or other metallic fillers, it helps prevent filler oxidation so that conductivity remains stable over time. In thermally conductive coatings containing copper and aluminum fillers, MBT·Na inhibits oxidation of copper-based particles during curing and service, preserving thermal conductivity. In high-temperature coatings for copper components, its relatively good thermal stability allows it to continue providing corrosion inhibition at elevated temperature, improving the reliability of components exposed to hot gases or heated fluids.

Daily Chemical, Personal-Care and Consumer Products

• In household detergents, MBT·Na is used in low dosage as a metal-ion chelating and anticorrosive component for copper-containing equipment and metal parts exposed to detergents. In laundry liquids, dishwashing liquids and other cleaning agents, it complements conventional chelators such as EDTA and sodium citrate by specifically protecting copper and copper-alloy parts in washing machines, dishwashers and plumbing. At levels on the order of a few hundredths of a percent, it helps reduce tarnishing and metal staining while also contributing to microbiological stability of the formulation.
• Personal-care products such as shampoos, body washes and oral-care items sometimes include MBT·Na at very low levels as a preservative-like, metal-related stabilizer. In such systems it can bind trace metal ions, inhibit corrosion of metallic components inside packaging or equipment and contribute to controlling microbial growth alongside standard cosmetic preservatives. In cosmetics that contain metallic pigments or substrates, including some eye shadows and nail polishes, MBT·Na helps prevent oxidation and color drift of metal-containing pigments, supporting long-term appearance and storage stability.
• In oral-care formulations like toothpaste and mouthwash, MBT·Na can act both as a mild antibacterial agent and as a chelator that prevents trace metal-catalyzed discoloration or degradation of sensitive ingredients. Its dosage is kept extremely low to match regulatory and safety requirements, while still providing measurable protective effects on metallic components and formulation stability.

Rubber, Plastics and Elastomer Industry

• In the rubber industry, MBT·Na is closely related to traditional mercaptobenzothiazole accelerators and is used as a vulcanization accelerator and anti-aging aid in certain formulations. In tire and general rubber goods, it speeds crosslinking between rubber chains and sulfur, improving curing efficiency and production throughput. The resulting vulcanizates show good mechanical properties and improved fatigue resistance. In seals and elastomer parts exposed to corrosive environments, MBT·Na and related derivatives can be used in formulations to stabilize interfaces with copper-containing inserts or hardware.
• Electronics, Electroplating and Precision Engineering
• In electronics and PCB manufacturing, MBT·Na is applied as a copper-surface protectant in etching, cleaning and storage steps. It forms a thin chemisorbed layer on copper foil and traces, protecting them from oxidation and tarnishing before and after pattern formation. This preserves solderability and ensures stable electrical performance in printed circuit boards and connectors.
• In electroplating, MBT·Na serves as a component of acid copper brighteners and leveling additives. At extremely low concentrations (often in the range of a few thousandths of a gram per liter), it participates in organic additive systems that refine grain structure, enhance brightness and improve throwing power of copper deposits. In combination with other brighteners, it helps produce dense, smooth and glossy plated copper layers for decorative and functional applications.

Petrochemical, Oilfield and Other Industrial Uses

• In the wider petrochemical field, MBT·Na is used in drilling fluids, completion fluids, fracturing fluids and refinery water systems to protect copper-based instrumentation, heat exchangers and equipment from corrosion by sulfide, chloride and other aggressive species. In drilling and completion fluids it may also be part of microbiological control packages and under-deposit corrosion-control strategies.
• In agriculture and related areas, MBT·Na can be formulated into seed-treatment emulsions and certain pesticide formulations where it acts as a stabilizer or protective agent for metallic components and as a contributor to antimicrobial performance. In agricultural machinery, rust preventives and maintenance fluids containing MBT·Na protect copper and brass components in humid storage or service environments.
• Across all these fields, the key technical features of MBT·Na are its strong and selective chemisorption on copper and copper alloys, the formation of durable coordination films, its high water solubility that enables straightforward use in aqueous systems and its ability to function in many composite packages where it cooperates with phosphonates, zinc salts, biocides and other functional additives to deliver integrated corrosion control, scale inhibition and microbiological stability.

Storage & Handling

• Store in tightly sealed containers away from sunlight and heat sources.
• Prevent contact with oxidizing agents and strong acids.
• Keep equipment clean and dry during handling.
• Ensure proper grounding to avoid static discharge.
• Avoid prolonged exposure to air to minimize oxidation.

Usage Notice

• Wear protective gloves, goggles, and appropriate work clothing.
• Avoid inhalation and direct skin contact.
• Dilute by adding MBT·Na into water, not the reverse.
• Verify compatibility when formulating with cationic products.
• Dispose of residues according to local regulatory requirements.
• Cooling-water copper-corrosion inhibitor program: MBT·Na is dosed initially at 50–100 mg/L for 24–48 hours to form a protective film on copper surfaces and then maintained at 2–10 mg/L together with zinc salts and polyphosphates so that copper corrosion rates in industrial circulating cooling-water fall to well below typical industry limits.
• Cooling-water composite with zinc: a formulation containing 3–5 mg/L MBT·Na and 2–3 mg/L zinc salt in alkaline cooling water builds a mixed organic–inorganic film on copper and steel that achieves copper corrosion inhibition efficiencies above about 95 % in multi-metal systems.
• Cooling-water composite with benzotriazole: a blend of 2–3 mg/L MBT·Na and 1–2 mg/L benzotriazole in moderately hard cooling water forms a synergistic adsorption film on copper and brass surfaces, giving outstanding protection to copper and copper alloys under relatively corrosive water qualities.
• Cooling-water composite with organophosphonates: a multi-functional treatment using 4–6 mg/L MBT·Na together with 5–8 mg/L HEDP and 3–5 mg/L ATMP in alkaline, moderately hard water combines copper corrosion inhibition with calcium scale control, making it suitable for high-hardness industrial cooling systems.
• Boiler condensate protection formula: MBT·Na applied at 3 mg/L in a boiler condensate system alongside hydrazine or other oxygen scavengers and 5–10 mg/L trisodium phosphate maintains condensate pH in the alkaline range and reduces copper-condensate corrosion rates to very low levels over extended operation.
• Oilfield injection-water corrosion-control package: an oilfield water-treatment formulation with 5–10 mg/L MBT·Na, 50–100 mg/L glutaraldehyde, 10–15 mg/L organophosphonate scale inhibitor and 15–20 mg/L steel corrosion inhibitor protects both copper and ferrous materials in injection pipelines and equipment while suppressing microbial corrosion.
• Reverse-osmosis pretreatment formula: an RO pretreatment blend containing 1 mg/L MBT·Na, 2–3 mg/L antiscalant and 1–2 mg/L reducing agent is dosed ahead of the membrane to protect copper components in the feed system without harming membrane flux or salt-rejection performance.
• Universal water-soluble cutting-fluid formula: a general-purpose water-soluble cutting fluid composed of 30–40 % base oil, 8–12 % emulsifier, 5–8 % triethanolamine, 3–5 % borate, 0.5–1.0 % nitrite-free rust inhibitor and 0.1–0.3 % MBT·Na provides copper and brass corrosion protection, good lubricity and acceptable foaming and pH stability.
• Environmentally oriented semi-synthetic cutting-fluid formula: a semi-synthetic fluid with 25–35 % synthetic ester, 10–15 % polyethylene glycol, 8–12 % organic amines, 0.2–0.4 % MBT·Na, 0.5–1.0 % non-formaldehyde biocide and 0.1–0.3 % defoamer offers strong copper protection, good microbial resistance and improved operator friendliness.
• Water-based rust-preventive concentrate: a water-based rust inhibitor containing 15–20 % triethanolamine, 8–12 % sodium benzoate, 3–5 % sodium carbonate and 0.3–0.5 % MBT·Na is diluted with water for use on copper and mixed-metal parts, forming a temporary protective film that resists humidity-induced tarnish and corrosion.
• Oil-based rust preventive and rolling-oil additive: a protective oil consisting of 70–80 % mineral oil, 8–12 % barium sulfonate, 3–5 % lanolin magnesium soap, 0.2–0.4 % MBT·Na and 0.5–1.0 % antioxidant protects copper strips and profiles from atmospheric corrosion during rolling, storage and transport.
• Alkaline metal-cleaner formulation: an alkaline cleaner made from 5–8 % sodium hydroxide, 10–15 % sodium carbonate, 8–12 % sodium metasilicate, 3–5 % surfactants and 0.2–0.4 % MBT·Na removes oils and oxides while preventing over-etching and staining of copper and brass components during cleaning.
• Neutral metal-cleaner formulation: a neutral cleaner built on 10–15 % sodium citrate, 5–8 % sodium carbonate, 5–8 % nonionic surfactants and 0.1–0.3 % MBT·Na cleans mixed-metal assemblies and protects copper parts from tarnishing throughout the cleaning cycle.
• Acidic electrolytic-processing bath: an acid electrolytic formulation containing 15–20 % sulfuric acid, 3–5 % sodium chloride and 0.05–0.1 % MBT·Na is used for specific electrochemical treatments, where MBT·Na helps protect copper-containing components from aggressive acid attack while processing proceeds.
• Alkaline electrolytic-processing bath: an alkaline electrolyte composed of 20–30 % sodium hydroxide, 5–8 % sodium nitrite and 0.1–0.2 % MBT·Na enables electrolytic machining or cleaning while MBT·Na reduces copper dissolution and pitting on exposed copper surfaces.
• Marine antifouling coating formula: a traditional antifouling paint using 25–30 % chlorinated rubber, 30–40 % cuprous oxide, 10–15 % rosin, 0.5–1.0 % MBT·Na, fillers and solvent produces an underwater coating that controls biological fouling and simultaneously protects copper alloys in contact with seawater.
• Acrylic-based antifouling coating: an acrylic antifouling system with 40–50 % acrylic resin, 25–35 % cuprous oxide, 2–3 % MBT·Na within a combined antifouling package and 20–25 % solvent delivers durable fouling resistance and copper protection for ship hulls and submerged equipment.
• Epoxy industrial anticorrosive coating: an epoxy coating consisting of 50–60 % epoxy resin, 20–25 % curing agent, 15–20 % pigments and fillers and 0.3–0.5 % MBT·Na is applied to equipment containing copper components and provides long-term barrier and copper-corrosion protection in industrial atmospheres and process environments.
• Ship primer formula: a shipyard primer built on 35–45 % alkyd or similar resin, 20–30 % red iron oxide, 15–20 % micaceous iron oxide and 0.3–0.5 % MBT·Na forms a protective basecoat on copper alloys and steel surfaces exposed to marine conditions.
• Conductive coating formulation: a conductive coating containing 30–40 % acrylic resin, 50–60 % copper powder, 2–3 % dispersant and 0.5–1.0 % MBT·Na maintains low electrical resistance by protecting copper filler from oxidation and ensuring stable conductive-network structure.
• Thermally conductive coating formulation: a thermal-management coating with 35–45 % silicone resin, 40–50 % copper powder, 10–15 % alumina and 0.3–0.5 % MBT·Na yields high thermal conductivity while MBT·Na limits oxidation of copper filler and preserves performance in service.
• High-temperature resistant coating formulation: a heat-resistant coating containing 40–50 % silicone resin, 20–30 % aluminum powder, 15–20 % glass powder and 0.2–0.4 % MBT·Na protects copper-based components at elevated temperatures and reduces oxidation and scale formation.
• Laundry-liquid formula with copper protection: a laundry liquid with 15–20 % AES, 8–12 % LAS, 1–2 % CMC, 0.5–1.0 % EDTA, 0.05–0.1 % MBT·Na, 0.2–0.5 % fragrance and water to balance washes fabrics effectively while slightly protecting copper-containing parts of washing equipment from detergent-induced corrosion.
• Dishwashing-liquid formula with copper protection: a dishwashing liquid comprising 10–15 % alkyl polyglucoside, 8–12 % fatty-acid methyl ester sulfonate, 3–5 % sodium citrate, 0.03–0.08 % MBT·Na, 0.1–0.3 % preservative and water uses MBT·Na as a targeted component to protect copper elements in dishwashers and piping while maintaining product stability.
• Shampoo formulation: a shampoo containing 12–18 % sodium lauryl sulfate, 3–5 % cocamidopropyl betaine, 1–2 % conditioning polymer, 0.02–0.05 % MBT·Na, 1–2 % pearlizing agent, 0.3–0.5 % fragrance and water uses very low levels of MBT·Na to help stabilize metal-sensitive ingredients and packaging components.
• Toothpaste formulation: a toothpaste with 40–50 % calcium carbonate, 15–20 % glycerin, 1–2 % sodium carboxymethyl cellulose, 1–2 % sodium lauryl sulfate, 0.02–0.05 % MBT·Na, 1–2 % flavor and water provides cleaning performance while MBT·Na contributes metal-ion chelation and formulation stability.
• Mouthwash formulation: a mouthwash containing 15–20 % ethanol, 5–8 % glycerin, flavor components, 0.01–0.03 % MBT·Na, 0.1–0.2 % sweetener and water uses MBT·Na in very low dosage as an antibacterial and metal-stabilizing additive within the overall preservative system.
• Rubber compound for tires: a tire tread compound made from 60–70 % natural rubber, 20–30 % styrene–butadiene rubber, 40–50 parts carbon black, 3–5 parts zinc oxide, 1–2 parts stearic acid, 0.5–1.0 parts MBT·Na and 2–3 parts sulfur uses MBT·Na-related chemistry as an accelerator to improve vulcanization speed and mechanical performance.
• Rubber sealing-compound formulation: an elastomeric sealing compound containing 80–90 % EPDM, 30–40 parts carbon black, 1–2 parts peroxide, 0.3–0.5 parts MBT·Na and other auxiliaries produces seals with good curing behavior and improved long-term resistance where contact with copper-containing components occurs.
• Acid copper electroplating bath: an acid copper bath with 180–220 g/L copper sulfate, 50–70 g/L sulfuric acid, 0.001–0.005 g/L MBT·Na, small amounts of chloride ions and proprietary brighteners generates bright, fine-grained copper deposits for decorative and functional electroplating applications.
• Seed-treatment emulsion: a seed-treatment formulation prepared as a 1 % MBT·Na emulsion and applied at appropriate seed-coating rates helps control certain seed-borne diseases while also improving protection of copper-containing equipment in seed-treatment systems.

Packaging

• 25 kg plastic drum
• Other packaging sizes available upon customer request