Benzotriazole and tolyltriazole, the azole corrosion inhibitors for copper, brass and bronze. Solid 99% granular and sodium-salt liquid grades for cooling water, coolants, metalworking fluids, VCI packaging, and metal finishing.
Benzotriazole and tolyltriazole are azole corrosion inhibitors that protect copper, brass, bronze, and other yellow metals. They are the standard chemistry for yellow-metal passivation in water-treatment and fluid-formulation work.
Both molecules bond to a copper surface and build a thin protective film. The film blocks the corrosive species, mainly chloride and sulfate, from reaching the metal, and it holds at very low dose rates. The surface ends up passivated, which means it resists pitting, tarnish, and the copper dissolution that feeds galvanic attack elsewhere in a system.
P.A.T. Products supplies benzotriazole and tolyltriazole corrosion inhibitors to North American industry, in both solid granular and liquid sodium-salt forms. The two products cover the same job. The choice between them, and between solid and liquid, comes down to the system they go into.
The names vary by trade. The class word is azoles, or triazoles, which is the term ASTM uses in its coolant analysis method. Water treaters say copper corrosion inhibitor or yellow-metal inhibitor; metal finishers say copper passivator or brass anti-tarnish. Benzotriazole is written BTA, BZT or BTZ, 1H-benzotriazole or 1,2,3-benzotriazole. Tolyltriazole is written TTA, tolutriazole, methylbenzotriazole or 4(5)-methyl-1H-benzotriazole, and is sometimes spelled tolytriazole. The sodium salts are written TT50, TT 50S, NaTTA or tolyltriazole sodium salt, and BTA-Na or sodium benzotriazolate. All of them land on the four grades below.
Yes. TT50, TT-50, TT 50S, NaTTA and tolyltriazole sodium salt all describe the same product: the sodium salt of tolyltriazole in water at about 50 percent, which we release at 49.5 to 51.0 percent as the salt. Sodium benzotriazole 40 percent is the benzotriazole equivalent, released at 39.5 to 41.0 percent.
They are all shorthand for benzotriazole, 1H-benzotriazole, CAS 95-14-7. TTA, tolutriazole, methylbenzotriazole and 4(5)-methyl-1H-benzotriazole all mean tolyltriazole, CAS 29385-43-1; it is sometimes spelled tolytriazole. The class word, used by ASTM in its coolant analysis method, is azoles.
No. The range is the two 99 percent granular azoles and the two sodium-salt liquids. Halogen-stable and otherwise modified triazoles, and tolyltriazole pre-dissolved in glycol or alcohol, are not in it; a formulator who needs a glycol cut can make it from the granular grade. Cross-references to other suppliers' grades are available on request.
Yes. Sodium tolyltriazole is the form commercial inhibited propylene-glycol coolants for direct-to-chip cooling list on their safety data sheets, at about 0.1 to 0.25 percent, and the same chemistry protects copper and brass in hydronic heating, chilled-water and solar-thermal loops. Tolyltriazole granular or the sodium salt both fit; the choice is a handling question.
They are one component of a cooling-water treatment program, dosed at a few parts per million alongside scale inhibitors, dispersants and biocides. The formulators and service companies that blend those programs buy the azole from us; the finished program is theirs. In that sense they are water treatment chemicals, and the same molecules go into coolants, metalworking fluids, packaging and metal finishing where water treatment is not the frame at all.
Benzotriazole, BTA, CAS 95-14-7, molecular formula C6H5N3, is the base yellow-metal inhibitor. It protects copper and copper alloys by forming an insoluble copper-azole film on the metal surface.
We supply benzotriazole in two forms: solid 99% granular (the fine-granular grades), a high-purity dry product for formulators who dose a powder or dissolve their own concentrate; and sodium benzotriazole liquid (CAS 15217-42-2), the water-soluble sodium salt supplied as a liquid for systems that meter a ready-to-use solution. Benzotriazole dissolves cleanly and is a common choice for water-based coatings and inks, mild closed-loop cooling systems, and silver and copper protection.
Pack codes such as "25" and "55" are pack sizes, a 25 kg fiber drum and a 55 lb fiber drum (about 25 kg), of the same 99% granular product. They are not different grades.
Tolyltriazole, TTA, CAS 29385-43-1, is a methyl-substituted benzotriazole.
Tolyltriazole is often chosen over benzotriazole when the system runs hot or carries an oxidizing biocide. It holds up better against chlorine and other halogen disinfectants and stays effective at higher operating temperatures, so it is common in cooling water with active chlorination, in engine coolant and antifreeze, and in long-life, high-temperature fluids.
We supply tolyltriazole as solid 99% and as sodium tolyltriazole liquid (CAS 64665-57-2), the sodium salt that is more soluble and easier to meter in many water-based systems. As with benzotriazole, the "25" and "55" pack codes are pack sizes of the same product, not separate specifications.
Benzotriazole and tolyltriazole both come two ways: a solid 99% granular, and a sodium-salt liquid. The active chemistry is the same. The form decides how you handle and dose it.
Solid granular is the high-purity dry product. It ships and stores compactly, and it suits formulators who dissolve their own concentrate or add a powder to a dry blend. The sodium-salt liquids, sodium benzotriazole and sodium tolyltriazole, are the water-soluble salts supplied ready to meter. They go straight into water-based formulations and into systems built around liquid feed, with no dissolving step. Tell us how you dose, and we will recommend the form that fits your process.
Four grades, supplied across the United States, Canada and Mexico. Each page carries the specification the material is released against, the packaging and storage facts, and the documents available on request.
| Grade | Form | CAS | What it is specified for |
|---|---|---|---|
| Benzotriazole Fine Granular 99% | Solid, 99.8% min | 95-14-7 | The base yellow-metal inhibitor. Cooling water, VCI packaging, metalworking fluids, plating and anti-tarnish |
| Tolyltriazole Granular 99% | Solid, 99.8% min | 29385-43-1 | Hot systems and oxidizing biocides. Chlorinated cooling water, engine coolant, long-life fluids |
| Sodium Benzotriazole 40% | Aqueous liquid, 39.5 to 41.0% | 15217-42-2 | Liquid feed. Water-treatment programs, water-based concentrates and cleaners |
| Sodium Tolyltriazole 50% | Aqueous liquid, 49.5 to 51.0% | 64665-57-2 | Liquid feed where the system runs hot or chlorinated. Coolants, deicing fluids, cleaners |
Browse the full P.A.T. Products corrosion inhibitor catalog for the specification, handling and documentation on each grade, or tell us the system and we will name the one that fits.
Benzotriazole has been used as a copper corrosion inhibitor since the 1950s. The accepted mechanism is a thin, insoluble copper(I)-azole film bonded to the copper surface through the triazole nitrogens; the surface shows both a chemisorbed and a physisorbed phase, and at defect sites the azole engages copper(I) species to form a polymeric complex over the cuprous oxide. The film blocks the anodic dissolution of copper and the cathodic reduction of oxygen at the same time, which is why it holds at parts-per-million doses. In deionized water more than 6 to 8 ppm is needed for better than 80 percent inhibition; in a treated cooling system the residual runs at 3 to 5 ppm because the film, once formed, needs only maintenance. Inhibition is effective at near-neutral pH and at pH 3, and ineffective at pH 1.
Because the film stops copper dissolving, it also protects the steel in the same system: copper ions that plate onto mild steel set up galvanic cells, and an azole keeps them out of the water.
The methyl group on tolyltriazole makes its film more hydrophobic, and the peer-reviewed comparisons attribute its advantage to that: in deionized water tolyltriazole shows more efficiency and persistence than benzotriazole above 6 ppm, the two methylbenzotriazole isomers form stable layers of 30 and 70 angstroms with higher efficiency than benzotriazole itself, and in sulfide-polluted salt water tolyltriazole's film is destroyed more slowly and gives about 40 percent higher efficiency. In unpolluted salt water the two perform about the same, and a combination of the two improves on either in acidic solutions.
Free chlorine consumes azole films: copper catalyzes the oxidation of tolyltriazole by free chlorine, and an excessively chlorinated system deactivates the triazole and copper corrosion rises. Monochloramine is gentler on the film. Tolyltriazole is the standard choice where an oxidizing biocide is in use, and halogen-stable triazole derivatives exist for heavy chlorination; those derivatives are not in our range. Benzotriazole is the base inhibitor, the one most formulations mean when they specify an azole without qualifying it, and the choice for closed loops, silver protection, packaging and finishing where no oxidizer is present.
The ranges below come from producer application guidance and published patent examples. The dose for a given system is settled by a ladder in that system.
| Application | Typical azole level | Usual form |
|---|---|---|
| Open recirculating cooling water (towers) | 3 to 5 ppm residual; about 30 ppm at start-up to form the film | Sodium tolyltriazole liquid; tolyltriazole granular in solid programs |
| Closed cooling and heating loops | 2 to 20 ppm azole alongside nitrite or molybdate | Sodium benzotriazole or sodium tolyltriazole liquid |
| Boiler condensate and reclaimed water with ammonia | 0.5 to 10 ppm | Sodium-salt liquid fed to the steam header |
| Engine coolant and inhibited glycol heat-transfer fluids | 0.05 to 0.3 percent of the concentrate; commercial data-center coolants list sodium tolyltriazole at 0.1 to 0.25 percent | Tolyltriazole granular or sodium tolyltriazole liquid |
| Water-based metalworking fluids | 0.5 to 5 percent of the concentrate, 10 to 100 ppm at use dilution | Sodium tolyltriazole liquid in the concentrate; granular where the formulator dissolves |
| VCI packaging | 0.5 to 1 percent benzotriazole in a commercial emitter; 0.5 to 10 grams per square meter in vapor-phase treatment | Benzotriazole granular |
| Anti-tarnish dips for copper and brass parts | About 0.1 to 0.5 percent in the dip bath | Benzotriazole or tolyltriazole granular, dissolved on site |
| Aqueous inks and fountain solutions | Up to about 0.5 percent | Sodium benzotriazole liquid |
Free chlorine and other oxidizing halogens consume the film, and re-forming it in a heavily chlorinated system takes high azole doses. Sulfide destroys it, benzotriazole faster than tolyltriazole. Strong acid defeats it: inhibition is ineffective at pH 1. Heat matters where sulfur species are present, since benzotriazole leaves copper above about 150 degrees C in a sulfur-bearing atmosphere against about 200 degrees C in nitrogen. Ammonia does not defeat the film: dissolved ammonia and oxygen are what corrode copper in condensate and reclaimed water, and the azole is dosed against them.
One related metal-passivation chemistry sits alongside the triazoles for specific jobs. A 1,3,4-thiadiazole (DMTD-type) is a dithiol heterocycle used as a copper and yellow-metal deactivator, mainly in lubricants, greases, and severe-duty metalworking fluids where extreme-pressure performance and metal protection are both needed.
This is a specialty addition, not the volume of the line. If your formulation calls for a thiadiazole deactivator, ask and we will tell you what we can supply.
Yellow-metal passivation in open recirculating towers and closed chilled-water and heating loops, with tolyltriazole where an oxidizing biocide is in use. How the azole is chosen and dosed is in azole inhibitors for copper and brass in cooling water.
Cooling-water corrosion control →The copper, brass and solder inhibitor in coolant and antifreeze packages, and in the inhibited glycols that run hydronic heating, chilled-water and snow-melt loops, solar-thermal systems and direct-to-chip data-center cooling. Sodium tolyltriazole is the form commercial data-center coolants list at 0.1 to 0.25 percent.
Copper and brass protection in soluble-oil, semi-synthetic and synthetic fluids, in the sump and on the part, and in the water-based lubricants that draw copper and brass wire.
Metalworking fluids & VCI →Benzotriazole is the copper and brass component in VCI papers, films and emitters, keeping bright metal bright through shipping and storage.
A dilute azole dip after plating, pickling or polishing films copper alloy strip, stampings, drawn parts and coin blanks against tarnish; the same chemistry works as a bath additive and for silver anti-tarnish.
Sodium benzotriazole in lithographic fountain concentrates and water-based inks, protecting the copper and brass a recirculating solution or an inkjet head touches.
Pressroom chemistry →Yellow-metal protection in hydraulic fluids, gear oils and other industrial fluids where copper attack degrades both the fluid and the equipment.
Benzotriazole protects silver and silver plate from oxygen-bleach tarnish in automatic dishwasher and institutional warewash formulations.
The same chemistry also goes into gas-dehydration and amine units in gas processing, where sodium tolyltriazole protects admiralty exchangers, and into brake and glycol-ether hydraulic fluids, where tolyltriazole granular is the usual form. Outside the grades we supply, azoles are used at electronic grade in copper CMP slurries, historically in printed-circuit surface finishes, in aircraft deicing fluids, as a monolayer on coin blanks at the mints, and by conservators on bronze; we do not supply electronic-grade material or those specialty forms.
Run a ladder across the range for the application and measure the copper in the system it protects: coupons or electrochemical corrosion rate in cooling water and closed loops, ASTM D1384 glassware and D2570 simulated service for a coolant, the fluid's own copper strip or chip test for a metalworking concentrate, and a tarnish exposure for a dip or a packaging film. Read the azole residual the way the program will, by the spectrophotometric or HPLC method your lab runs. Check the formulation for compatibility with the sodium salts, which arrive at pH 11 to 12 and raise the pH of a concentrate. And ask for the assay basis: a sodium-salt liquid is released as the salt, and the free-azole content is lower than the salt content by the weight of the sodium; the certificate of analysis states which basis the number is on.
Match on four numbers: assay and its basis, form, the concentration of a liquid, and pack. Benzotriazole and tolyltriazole from any producer are the same molecules, so a 99 percent granular grade released against a stated assay, water, melt point, ash, pH and chloride specification substitutes for another on the panel, and a 50 percent sodium tolyltriazole substitutes for another 50 percent sodium tolyltriazole once the assay basis is confirmed. Cross-references to other suppliers' grades and trade names are available on request. What is not in the range: halogenated and otherwise modified triazoles, and tolyltriazole pre-dissolved in glycol or alcohol.
P.A.T. Products supplies benzotriazole and tolyltriazole across the United States, Canada and Mexico. The granular grades ship in 25 kg fiber drums and the sodium-salt liquids in 500 lb drums. Samples typically go out the same business day. Every grade has a Technical Data Sheet and a Safety Data Sheet, a certificate of analysis ships with each lot, and REACH statements are available on request. Tell us the system, the metal, the feed method and the residual you have to hold, and we will name the grade and the form and send a sample.
| Benzotriazole | 1H-benzotriazole, 1,2,3-benzotriazole, BTA, BZT, BTZ. CAS 95-14-7. C6H5N3. |
|---|---|
| Tolyltriazole | Methylbenzotriazole, tolutriazole, 4(5)-methyl-1H-benzotriazole (a 4- and 5-methyl isomer mixture), TTA. CAS 29385-43-1. C7H7N3. |
| Sodium benzotriazole | Sodium benzotriazolate, benzotriazole sodium salt, BTA-Na, 40 percent solution. CAS 15217-42-2. |
| Sodium tolyltriazole | Tolyltriazole sodium salt, sodium methylbenzotriazole, NaTTA, TT50, TT 50S, 50 percent solution. CAS 64665-57-2. |
| Class | Azoles, triazoles; copper corrosion inhibitors; yellow-metal inhibitors; copper passivators; brass anti-tarnish agents |
Both are azole corrosion inhibitors that protect copper, brass, and other yellow metals by forming a protective film on the surface. Tolyltriazole (TTA) is benzotriazole (BTA) with a methyl group added to the ring, supplied as a 4-/5-methylbenzotriazole mixture. That methyl group gives tolyltriazole better thermal stability and better resistance to chlorine and other halogen biocides, so it is often chosen for hot systems and for cooling water under active chlorination. Benzotriazole dissolves cleanly and is common in mild closed-loop systems, water-based coatings and inks, and silver and copper protection.
They protect yellow metals: copper, brass, bronze, and copper alloys. Both also give anti-tarnish protection to silver. The inhibitor film suppresses copper dissolution, which also helps protect mild steel elsewhere in a system by reducing the copper plating that drives galvanic corrosion.
The active chemistry is the same. Solid 99% granular is the high-purity dry product, suited to formulators who dissolve their own concentrate or add a powder to a dry blend. The liquid grades are the sodium salts, sodium benzotriazole and sodium tolyltriazole, supplied water-soluble and ready to meter into water-based formulations and liquid-feed systems.
No. Those are pack sizes. A "25" is a 25 kg fiber drum and a "55" is a 55 lb fiber drum, which is about 25 kg, of the same 99% granular product. They are not different specifications.
Yes. We also supply a 1,3,4-thiadiazole (DMTD-type) deactivator used mainly in lubricants, greases, and severe-duty metalworking fluids where extreme-pressure performance and metal protection are both needed. Tell us your formulation and we will tell you what we can supply.
Yes. Samples of benzotriazole and tolyltriazole, in solid or liquid form, typically go out the same business day. Technical Data Sheets and Safety Data Sheets are available for every grade, a Certificate of Analysis ships with each lot, and we can provide additional documentation, including REACH statements, on request.
