Technical Specifications
| Property | Unit | Typical Value | Test Method |
|---|---|---|---|
| Appearance | Brown viscous liquid | Visual | |
| Density @ 20 °C | kg/m³ | 1035 | ASTM D4052 |
| Viscosity @ 100 °C | mm²/s | 30 | ASTM D445 |
| Barium | % | 11.0 | ASTM D4951 |
| Total Base Number | mg KOH/g | 45 | ASTM D2896 |
| Flash Point | °C | 175 | ASTM D93 |
| Moisture Content | % | 0.03 | ASTM D95 |
| Mechanical Impurities | % | 0.03 | ASTM D473 |
| Humidity Cabinet Rust Protection | A | ASTM D1748 | |
| Base-Oil Solubility | Mineral Group I, II, III >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
Supramolecular structure · overbased
Ba(dinonylnaphthalenesulfonate)₂ · colloidal BaCO₃
Overbased barium dinonylnaphthalenesulfonate: a sulfonate shell dispersing a colloidal barium-carbonate core that supplies the alkaline reserve (TBN 45).
What Is Overbased Barium Dinonylnaphthalenesulfonate?
CheMost-B1S is an oil-soluble, overbased synthetic barium dinonylnaphthalenesulfonate (barium DNNS) — a high-performance rust inhibitor and corrosion inhibitor. It is supplied as a brown viscous liquid containing 11.0% barium with a total base number of 45 mg KOH/g, and protects ferrous and non-ferrous metals by forming a tightly adsorbed film while its alkaline reserve neutralises acidic corrosion by-products.
Dinonylnaphthalene sulfonates are dialkylated, short-chain (C9–C10) alkylnaphthalene sulfonates — a chemistry long valued because barium DNNS is effective as a rust preventive at low treat rates compared with the calcium and sodium derivatives. Among the sulfonate cations, rust-prevention effectiveness rises with ionic radius (Na < Mg < Ca < Ba), so the barium salt is the strongest.
“Overbased” means the neutral sulfonate carries an excess of base — here a colloidal barium-carbonate core dispersed by the sulfonate shell. That gives B1S a dual role: the sulfonate forms the protective rust film, and the barium-carbonate reserve (TBN 45) absorbs acids. The trade-off is that in some extreme-pressure systems the excess base can interfere with EP additives — for those, the neutral grade CheMost-B1SA is recommended.
How Overbased Barium DNNS Works
Low-treat rust film
The barium dinonylnaphthalenesulfonate adsorbs onto steel, copper and aluminium and packs into a water-impervious film — and as a DNNS it is effective at low concentrations, so a little goes a long way.
Alkaline reserve
The colloidal barium-carbonate core (TBN 45) neutralises acidic corrosion by-products and oxidation acids, extending protection in storage and service — the function a neutral grade does not provide.
Demulsibility & detergency
The additive resists emulsification (so water separates from the oil) and carries detergency, keeping protected surfaces clean — suited to rust-preventive and slushing oils.
Overbased supramolecular structure
A sulfonate shell dispersing a barium-carbonate nanocore is the same overbased architecture used in detergent chemistry — combining film formation and acid neutralisation in one additive.
Choosing Between B1S (Overbased) and B1SA (Neutral)
Both are the same barium dinonylnaphthalenesulfonate rust film (full numbers in the Technical Specifications above); they differ in base number. B1S is overbased (TBN 45, Ba 11.0%) — choose it where an alkaline reserve to neutralise acids is wanted, in rust-preventive, mill and slushing oils. B1SA is neutral (TBN 0.8, Ba 6.7%) — choose it where the additive must stay inert and compatible with other additives, especially in extreme-pressure gear oils where B1S’s excess base could interfere with the EP system. The two are often used together: the neutral grade for film, the overbased grade for reserve alkalinity.
Applications
CheMost-B1S is used as the rust-inhibitor component in formulations targeting the duties below, where its alkaline reserve adds value:
Rust-preventive & slushing oils
The core application — long-term anti-rust and mill/slushing oils where the barium film plus acid-neutralising reserve protect parts through extended storage; neutral and overbased grades are often combined.
Industrial & circulating oils
Rust and corrosion protection with reserve alkalinity in industrial and circulating oils exposed to acidic oxidation products.
Greases
Adds rust protection and an alkaline reserve to greases for bearings and components in corrosive environments.
Finished-oil performance approvals belong to the fully formulated lubricant, not to an individual additive. Barium additives face tightening regional controls; CheMost can provide regulatory documentation support on request.
Treat Rate
The data sheet specifies the product but not a per-application dosage, so the figure below is indicative, derived from the chemistry and our formulating experience — confirm the final level.
First-order estimate. As a DNNS, B1S is effective at low treat — typically a fraction of a percent up to a few percent in rust-preventive and industrial oils, trimmed to the humidity-cabinet and acid-neutralisation target. The TBN 45 reserve means a little additive supplies meaningful alkalinity.
Barium DNNS is usually the low-dose rust/alkalinity component of a blend; in mill and slushing oils it is commonly paired with the neutral B1SA and a petroleum sulfonate. The exact level depends on the required protection period and the acid load of the system.
Treat rates are indicative, not fixed dosages. CheMost can provide formulation and treat-rate support on request.
Formulating With B1S — Complementary Additives
Neutral barium DNNS (B1SA)
The neutral partner: B1SA carries the inert, EP-safe rust film while B1S supplies the alkaline reserve — the classic neutral-plus-overbased rust-preventive pair.
Petroleum sulfonates
Sodium and barium petroleum sulfonates add emulsification or extra film strength; combining sulfonate types broadens the rust-preventive performance envelope.
Benzotriazole (metal deactivator)
While the barium sulfonate protects ferrous metals, BTA passivates copper and yellow metals — together they give multi-metal protection.
Antioxidants
For long-storage preventive oils, antioxidants slow oil oxidation so the protective film and carrier oil survive extended exposure.
The CheMost Barium DNNS & Sulfonate Rust-Inhibitor Family
CheMost manufactures the barium DNNS pair plus the petroleum sulfonates. B1S (this page) is the overbased, alkaline-reserve grade:
| Product | Type | Base number | Best for |
|---|---|---|---|
| Overbased barium DNNS (B1S) | Overbased, Ba 11.0% | TBN 45 (alkaline reserve) | Rust-preventive, mill & slushing oils |
| Neutral barium DNNS (B1SA) | Neutral, Ba 6.7% | TBN 0.8 (inert) | EP gear, hydraulic, turbine oils, greases |
| Calcium DNNS (C1A) | Neutral, barium-free | Low | Modern RP oils avoiding barium |
| Barium petroleum sulfonate (B50) | Petroleum sulfonate | — | Rust-preventive & sealing oils |
Documentation, Qualification & Regulatory Support
Standard documentation — Certificate of Analysis (COA, per shipment), Technical Data Sheet (TDS) and Safety Data Sheet (SDS, GHS/CLP) — is provided. The full TDS is 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 — relevant given tightening controls on barium additives.
Third-party inspection
SGS / Intertek / BV pre-shipment inspection can be arranged on request.
Custom grades & packaging
Custom grades and packaging — metal drum, IBC, ISO tank.
Formulation support
Rust-preventive formulation and treat-rate guidance from our technical team.
Packaging & Supply
CheMost-B1S is stocked and shipped worldwide, with a typical lead time of 1–15 days and a 36-month shelf life at ambient temperature. Samples and quotations are answered within 12 hours.
Packaging
200 kg metal drum · 1000 kg IBC tank.
Minimum order
1 drum or 1 IBC — no minimum order value.
Incoterms
FOB · CIF · EXW, to suit your freight arrangement.
Loading ports
All major Chinese ports.
Frequently Asked Questions
What is overbased barium dinonylnaphthalenesulfonate?
It is the overbased barium salt of dinonylnaphthalenesulfonic acid (CAS 25619-56-1), an oil-soluble rust and corrosion inhibitor. “Overbased” means it carries a colloidal barium-carbonate reserve (TBN 45) dispersed by the sulfonate, so it both forms a protective rust film and neutralises acidic corrosion by-products. CheMost-B1S contains 11.0% barium.
What is the difference between B1S and B1SA?
Both are barium DNNS rust inhibitors. B1S is overbased (TBN 45, Ba 11.0%) and adds an alkaline reserve to neutralise acids — best for rust-preventive, mill and slushing oils. B1SA is neutral (TBN 0.8, Ba 6.7%) and stays inert and additive-compatible — best for extreme-pressure gear, hydraulic and turbine oils where excess base would interfere.
Why is barium DNNS used at low treat rates?
Dinonylnaphthalene sulfonates are unusually effective rust preventives at low concentration compared with the calcium and sodium derivatives, so a small dose provides strong protection. This efficiency is the main reason DNNS chemistry is used in premium rust-preventive and industrial oils.
Is barium DNNS being phased out?
Barium-containing additives face tightening regional controls, and many formulators evaluate barium-free options such as calcium DNNS for new work. CheMost supplies both, and can provide REACH/TSCA and market-registration documentation support on request.
How is it supplied, and how fast can I get a sample?
It is supplied in 200 kg metal drums and 1000 kg IBC tanks with a 36-month shelf life, and shipped worldwide. As a manufacturer and sourcing partner (Est. 2013), CheMost answers sample and quotation requests within 12 hours.