Technical Specifications
| Property | Unit | Typical Value | Test Method |
|---|---|---|---|
| Appearance | Brownish-yellow transparent liquid | ||
| Density at 20 °C | kg/m³ | 975 | ASTM D4052 |
| Flash Point | °C | 190 | ASTM D93 |
| Nitrogen | % | 2.42 | ASTM D5762 |
| Boron | % | 1.05 | ASTM D4951 |
| Moisture Content | % | 0.15 | ASTM D95 |
| Mechanical Impurities | % | 0.05 | ASTM D473 |
| Solubility in mineral Group I, II and III | % | greater than 10 |
* Typical values from batch production. Batch-specific COA available on request.
Technical content reviewed by the CheMost additives team · Specifications last reviewed
Molecular Structure
Molecular structure · ashless borate ester
Nitrogen-containing borate ester · B–O ester backbone with amine-coordinated boron · B 1.05 % / N 2.42 % · no sulfur, phosphorus or halogen
A boron–oxygen ester carrying an amine function. The data sheet does not disclose the molecular structure, so no single formula is published for this grade; the boron builds the protective film at the rubbing surface and the nitrogen is what keeps a borate ester from hydrolysing.
What Is a Nitrogen-Containing Borate Ester Lubricant Additive (NB211)?
CheMost-NB211 is an ashless, nitrogen-containing borate ester — a borate ester lubricant additive supplied as an oil-soluble antiwear and extreme-pressure (EP) additive that also reduces friction and contributes antioxidant performance. It is a brownish-yellow transparent liquid with very little odour, containing 1.05 % boron and 2.42 % nitrogen, and it carries no sulfur, no phosphorus, no chlorine and no other halogen.
The data sheet states its performance plainly: the borate ester structure adsorbs and protects at the friction surface, and a boron nitride (BN) protective film forms during friction, which “effectively reduces friction and improves tribological performance”. That combination — wear protection, load carrying and friction reduction from one ashless molecule — is why it is classed with the friction modifiers rather than with the metal-bearing antiwear additives.
Chemically it belongs to the family that U.S. Borax describes as additives “containing nitrogen and boron … prepared by reacting polyamines, carboxylate esters, or amine/ester mixtures with boric acid or boric oxide at elevated temperatures.” The two elements do different jobs: boron builds the protective film at the rubbing surface, while nitrogen solves the one weakness that has historically limited this whole chemistry.
That weakness is hydrolysis. Most borate esters are readily attacked by water, and hydrolysis liberates oil-insoluble — and abrasive — boric acid. The established fix is to put an amine into the molecule: the nitrogen lone pair coordinates to the electron-deficient boron atom, and the accepted explanation in the literature is that the resulting stable ring structure inhibits water from reaching the boron–oxygen bonds. NB211’s data sheet lists exactly that property — “not easily hydrolyzed, hydrolytic stability” — so the nitrogen in this molecule is best read as functional rather than incidental. That is what makes an ashless borate ester practical in a real lubricant rather than a laboratory curiosity.
Two points of transparency. The data sheet does not disclose a CAS number or a molecular structure for NB211 — it is a proprietary borate ester composition, and regulatory documentation is available on request rather than being published here. It also does not state viscosity, pour point or a hydrolytic-stability test result; those are available from our technical team on request rather than being estimated on this page.
Because it introduces no metal and no sulfated-ash-forming element, NB211 belongs to the ashless, low-SAPS toolbox that formulators reach for as sulfur and phosphorus limits tighten — a category in which boron derivatives are recognised as one of the leading non-sulfur, non-phosphorus antiwear technologies.
How NB211 Works — Boron Film, BN Layer and Hydrolytic Stability
NB211 acts at the contact through two linked surface mechanisms, with its molecular architecture protecting it on the way there.
Adsorption of the borate ester film
The borate ester structure adsorbs onto the friction surface and forms a protective layer. Borate species interact with metal surfaces to build a resistant film that carries load and separates asperities — the load-carrying mechanism that gives boron chemistry its antiwear and EP character.
Boron nitride film under rubbing
Under friction, the nitrogen and boron in the molecule form a boron nitride (BN) protective film on the rubbing surface, which the data sheet credits with effectively reducing friction and improving tribological performance. Independent literature reaches the same conclusion more cautiously, attributing the improved antiwear behaviour of nitrogen-bearing borate esters probably to this additional BN film — a mechanism associated with the N + B combination rather than with boron alone.
N→B coordination resists hydrolysis
The nitrogen lone pair coordinates to the electron-deficient boron; the literature hypothesis is that the resulting stable ring structure substantially inhibits hydrolytic attack by water. It is the mechanism normally invoked to explain why a nitrogen-bearing grade can claim hydrolytic stability where a plain borate ester would degrade and drop abrasive boric acid into the oil.
Antioxidant contribution, no ash
Borate esters with nitrogen are recognised for antioxidant activity alongside their antiwear function, and NB211 introduces no metal — so the oxidation and wear benefits arrive without adding sulfated ash, sulfur or phosphorus to the finished oil.
Borate Ester vs the Other Antiwear & EP Routes
NB211 is best understood by what it does not bring into the formulation. The table compares the antiwear/EP routes CheMost supplies by their active elements — a qualitative positioning comparison, not a performance ranking.
| Route | Active elements | Ash-forming? | Positioning |
|---|---|---|---|
| Nitrogen-containing borate ester (this page) | B 1.05 % · N 2.42 % no S, P, Cl | No — ashless, metal-free | The route to take when sulfur, phosphorus, halogen and metal all have to stay out |
| Zinc dialkyldithiophosphate (ZDDP) | Zinc, phosphorus, sulfur | Yes — zinc forms sulfated ash | The benchmark antiwear additive; constrained by SAPS and phosphorus limits |
| Sulfurized olefin | Sulfur | No, but sulfur-bearing | Strong EP performance where active sulfur is acceptable |
| Triphenyl phosphorothioate (TPPT) | Phosphorus, sulfur | No, but S/P-bearing | Ashless antiwear/EP where phosphorus is still permitted |
| Organomolybdenum complex (S/P-free) | Molybdenum, nitrogen | Molybdenum-bearing | S/P-free, but a friction modifier first — and it is a metal |
The practical distinction against our nearest neighbour is worth stating plainly: the organomolybdenum complex is also sulfur- and phosphorus-free, but it is a molybdenum compound whose primary job is friction reduction. NB211 is metal-free and halogen-free, and its primary job is antiwear and EP protection.
Equally worth stating: boron chemistry on its own is not a like-for-like replacement for ZDDP’s antiwear performance. Its recognised strength is in combination — used alongside other antiwear/EP additives, it reduces wear and lets the formulator carry less of the sulfur- and phosphorus-bearing chemistry.
NB211 Applications in Lubricant Formulations
CheMost-NB211 is used in formulations targeting the duties below. Its oil solubility in mineral Group I, II and III base stocks (greater than 10 %) makes it straightforward to build into conventional and hydroprocessed blends.
Low-SAPS and ashless engine oils
Formulations where sulfated ash, phosphorus and sulfur are all constrained, and part of the antiwear duty has to be carried by chemistry that contributes none of the three.
Industrial gear and circulating oils
Gear and circulating systems needing load-carrying and antiwear support without introducing active sulfur or additional metal into the oil.
Greases
Grease formulations where an ashless, non-staining antiwear/EP booster is preferred and sulfur odour is undesirable.
Neat-oil metalworking and compressor oils
Oil-based metalworking fluids and compressor oils where a halogen-free, chlorinated-paraffin-free antiwear route is required.
NB211 is a single additive component. OEM and industry approvals — API, ACEA, ILSAC or equipment-builder specifications — belong to the fully formulated finished lubricant and its supplier, never to an individual additive. The data sheet makes no specification claim for NB211 itself, and neither do we.
NB211 Treat Rate and Boron Contribution
The CheMost-NB211 data sheet does not state a treat rate, and we are not going to borrow one. Dose windows published for other boron additives describe other molecules — a boron-sulfur compound, a potassium borate dispersion, a borated succinimide — and none of them is this product. Quoting one of those figures here would look like guidance and behave like a guess. What follows instead is the arithmetic you need to evaluate any trial level on your own bench, taken entirely from this product’s own analysis.
Boron and nitrogen contribution — exact, from this grade’s assay. NB211 assays at B 1.05 % and N 2.42 %, so at a trial treat rate of T wt % the finished oil gains:
ppm boron = T × 105 · ppm nitrogen = T × 242
Worked examples: 0.25 wt % → 26 ppm B, 61 ppm N · 0.50 wt % → 53 ppm B, 121 ppm N · 1.00 wt % → 105 ppm B, 242 ppm N. This matters because boron is what shows up in used-oil analysis, and some finished-oil specifications carry element ceilings — so in practice the treat rate you can afford is often set by the boron budget rather than by the wear result.
What actually decides the level. Four things, in roughly this order: how much of the antiwear duty you are shifting off sulfur- and phosphorus-bearing chemistry; the boron ceiling your target specification allows; the wear and oxidation results on your own base oil and package; and non-ferrous compatibility — boron and copper/lead bearing alloys interact, so that testing belongs alongside the wear work rather than after it. Note also that boron chemistry earns its keep in combination: raising NB211 on its own is not a substitute for a balanced antiwear package.
No treat rate is published for this grade because the data sheet does not establish one, and we would rather say so than repeat a number borrowed from a different molecule. The conversion above is arithmetic from the data-sheet assay, not a dosing recommendation. Send us your base oil, additive package and target specification and our technical team will work the starting level through with you — talk to our formulators or request a sample for bench trials.
Formulating With NB211 — Complementary Additives
Borate esters are documented as synergistic partners rather than standalone solutions. The pairings below are the ones with published rationale.
Diphenylamine antioxidants
Strong synergistic antioxidant action has been reported between borate esters and a dioctyl diphenylamine at a 1:1 weight ratio, measured by pressurised DSC at 180 °C in a PAO. Our closest grade is an octylated/butylated diphenylamine rather than the dioctyl isomer used in that study, so treat the synergy as an aminic-antioxidant family effect to be confirmed on your blend — but pairing NB211 with an aminic antioxidant is the best-documented way to exploit its antioxidant contribution.
ZDDP — the phosphorus-reduction play
The same synergistic effect is reported for mixtures of borate esters and ZDDP. Its practical value is specific: the combination allows a reduced phosphorus level in the finished lubricant without sacrificing oxidative stability — which is exactly the constraint driving low-SAPS formulation.
Sulfur-bearing EP additives
Where severe EP duty remains, NB211 works alongside sulfurised EP chemistry rather than replacing it, letting the formulator carry less active sulfur for the same protection. Boron’s tribological behaviour is known to depend on its interaction with sulfur, phosphorus and nitrogen already present in the oil.
Other friction modifiers
NB211 already reduces friction in its own right through the BN film, which is why it sits in this category. Where a demanding friction-coefficient target has to be met on top of that — a fuel-economy claim, for instance — it is normally stacked with a dedicated friction modifier such as an organomolybdenum grade rather than replaced by one. Evaluate the pair together: the interaction between boron and other active elements is formulation-specific.
Documentation, Qualification & Regulatory Support
Standard documentation — Certificate of Analysis (COA, per shipment), Technical Data Sheet (TDS), Safety Data Sheet (SDS) and Certificate of Origin — is provided. The full TDS and SDS are available on request rather than as a public download. Additional support is available on request:
Regulatory documentation
REACH, TSCA and country-specific market-registration documentation support available on request.
Third-party inspection
SGS / Intertek / BV pre-shipment inspection can be arranged on request.
Custom grades & packaging
Custom grades and drum / IBC packaging arrangements on request.
Formulation support
Treat-rate and compatibility guidance for your base oil and additive package from our technical team.
Packaging, Supply and Lead Time
CheMost-NB211 is stocked and shipped worldwide, with a typical lead time of 1–15 days and a 36-month shelf life at ambient temperature. Store in a dry, clean, well-ventilated warehouse; maximum storage temperature is 50 °C and maximum blending temperature is 70 °C. Samples and quotations are answered within 12 hours.
Packaging
200 kg metal drum · 1000 kg IBC tank.
Minimum order
By drum or IBC — contact us for your quantity.
Incoterms
FOB · CIF · EXW, to suit your freight arrangement.
Loading ports
All major Chinese ports.
Frequently Asked Questions
Is a borate ester lubricant additive the same thing as a boronic or boronate ester?
No — they are different chemistries that share a similar name, and the confusion is common enough to be worth stating. A borate ester is a boron–oxygen compound, B(OR)₃-type, formed by esterifying boric acid or boric oxide with an alcohol or an amino alcohol; that is what NB211 is, and its job is surface protection in a lubricant. A boronic ester (or boronate ester) has a direct boron–carbon bond and belongs to synthetic organic chemistry, where it is used as a coupling reagent — Suzuki–Miyaura chemistry — and is bought from a reagent catalogue in gram quantities. If you are formulating a lubricant, the borate ester is the one you want; if you are running a cross-coupling reaction, this page is not the product you are looking for.
Is a borate ester hydrolytically stable enough for real service?
Plain borate esters are not — susceptibility to hydrolysis is the recognised drawback of the chemistry, and hydrolysis releases oil-insoluble, abrasive boric acid. NB211 is a nitrogen-containing borate ester, and nitrogen is the remedy reported in the literature: the amine lone pair coordinates to the electron-deficient boron, and the resulting ring structure is thought to inhibit water attack on the boron–oxygen bonds. The data sheet lists “not easily hydrolyzed, hydrolytic stability” as a product characteristic. It does not report a hydrolytic-stability bench result, and the 0.15 % moisture figure in the table is a purity spec rather than evidence of hydrolytic resistance — if your qualification needs a measured result, ask our technical team what testing can be arranged.
Does CheMost-NB211 contain sulfur, phosphorus or chlorine?
No. The data sheet states the product contains no sulfur, phosphorus, chlorine or other halogen elements. It is also metal-free, so it contributes no sulfated ash. Its active elements are boron (1.05 %) and nitrogen (2.42 %). This is the reason to specify it: it delivers antiwear, EP and antioxidant contribution without adding any of the elements that SAPS and halogen limits restrict.
Can NB211 replace ZDDP in a formulation?
Not as a like-for-like substitute. Boron chemistry used on its own is unlikely to match ZDDP’s antiwear performance; its documented strength is in combination with other antiwear and EP additives. The more realistic use is partial: borate esters and ZDDP show synergistic antioxidant behaviour, and that synergy is reported to allow a reduced phosphorus level in the finished lubricant without sacrificing oxidative stability.
Which base oils is NB211 soluble in?
The data sheet specifies solubility greater than 10 % in mineral Group I, Group II and Group III base stocks, so it is suitable for conventional and hydroprocessed mineral formulations. Its density at 20 °C is 975 kg/m³ and its flash point is 190 °C (ASTM D93). For solubility in synthetic base stocks outside that list, ask our technical team to confirm against your specific fluid.
What treat rate should I use for NB211?
The data sheet does not state one, and we do not publish a borrowed figure — dose windows quoted for other boron additives (boron-sulfur compounds, potassium borate dispersions, borated succinimides) describe different molecules, not this one. What we can give you exactly is the element arithmetic: at a trial level of T wt %, NB211 contributes T × 105 ppm boron and T × 242 ppm nitrogen to the finished oil, so 0.5 wt % adds 53 ppm B and 121 ppm N. Since some specifications cap boron, that ceiling often decides the level before the wear result does. Send us your base oil, package and target specification and our technical team will establish the starting point with you.
Can I get the TDS, SDS and a sample?
Yes. The full Technical Data Sheet and Safety Data Sheet, a Certificate of Analysis per shipment, a Certificate of Origin and product samples are all available on request rather than as public downloads. Regulatory documentation support — REACH, TSCA and country-specific market registration — and SGS / Intertek / BV pre-shipment inspection can be arranged on request. Samples and quotations are answered within 12 hours.