Technical Specifications
| Property | Unit | Typical Value | Test Method |
|---|---|---|---|
| Appearance | — | Brown red thick liquid | Visual |
| TBN | mgKOH/g | 21 | ASTM D2896 |
| Nitrogen | % | 1.12 | ASTM D5762 |
| Viscosity at 100°C | mm²/s | 330 | ASTM D445 |
| Flash Point | °C | 205 | ASTM D93 |
| Color | — | 2.5 | ASTM D1500 |
| Density at 20°C | kg/m³ | 930 | ASTM D4052 |
| Moisture content | % | 0.03 | ASTM D95 |
| Mechanical impurities | % | 0.03 | ASTM D473 |
| Solubility, 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
Molecular structure · HMW ashless dispersant
(HMW PIB–succinimidyl)₂ · polyamine
A bis-succinimide built on a high-molecular-weight polyisobutylene tail — the larger oil-soluble tail boosts soot-suspending capacity and high-temperature dispersancy.
What Is HMW Polyisobutylene Bissuccinimide (T1620)?
CheMost T1620 is a high-molecular-weight (HMW) polyisobutylene bis-succinimide ashless dispersant, produced by a thermal, chlorine-free process from highly reactive, high-molecular-weight polyisobutylene. It has the two-armed bis-succinimide head of the standard grade but a substantially larger PIB tail.
That larger oil-soluble tail is the point: it increases the dispersant’s soot-carrying capacity and high-temperature dispersancy compared with a standard-molecular-weight grade. With a TBN of 21 and 1.12% nitrogen, T1620 is built for the high-soot, high-temperature duty of modern diesel engines — controlling deposits and soot-induced viscosity growth without contributing metal or ash.
How T1620 Works
High soot-carrying capacity
The high-molecular-weight PIB tail provides more oil-solubilising bulk per molecule, letting T1620 suspend higher soot loads — the defining requirement of high-EGR, high-soot diesel engines.
High-temperature dispersancy & detergency
HMW dispersants give superior detergency and high-temperature stability versus low-molecular-weight grades, keeping the ring-belt and hot surfaces clean through extended service.
Viscosity-growth control
By keeping soot finely dispersed, T1620 limits the soot-induced viscosity rise that otherwise impairs oil flow and pumpability in high-soot diesel oils.
Ashless deposit control
Delivers this dispersancy with no metal or sulphated ash, suiting it to low-SAPS heavy-duty formulations.
The CheMost Ashless Dispersant Family — Mono / Bis / Borated / HMW
T1620 is the high-molecular-weight grade in the CheMost succinimide dispersant family. The four recognised types differ in nitrogen, molecular weight and boron modification:
| Type | CheMost grade(s) | Distinctive feature | Best for |
|---|---|---|---|
| Monosuccinimide | T1351 | Single succinimide group, high nitrogen (2.1%) | Low-temperature sludge & varnish, gasoline/PCMO |
| Bissuccinimide | T1428 · T1428S | Two succinimide groups; standard & high-N grades | Balanced soot & sludge control, PCMO & HDDEO |
| Boron-modified | T1428B · T1620B | Borated head → antioxidancy, antiwear, seal compatibility | Low-SAPS, GDI/turbo PCMO, seal-sensitive oils |
| High molecular weight | T1620 | Large PIB tail → superior soot dispersancy (visc 330 mm²/s) | High-soot heavy-duty diesel |
Need the standard-molecular-weight grade? See PIB bissuccinimide (T1428). Want boron on the HMW backbone? The high-MW borated grade T1620B is on the boron-modified PIB succinimide page.
Applications
T1620 is used as the high-molecular-weight ashless dispersant component in formulations targeting the categories below.
Heavy-duty diesel engine oils
Disperses the high soot loads generated by EGR and modern combustion, supporting formulations targeting API CK-4/FA-4 and ACEA E6/E9 against soot-driven wear and viscosity growth.
High-grade internal-combustion engine oils
Provides high-temperature detergency and cleanliness in premium gasoline and mixed-fleet oils where deposit control is critical.
Industrial lubricants
Controls sludge and deposits where oxidation by-products accumulate at elevated temperatures.
Finished-oil OEM approvals (e.g. API, ACEA and OEM engine-test sequences) are held by the fully formulated oil, not by an individual additive component.
Treat Rate
Typical treat rates from the T1620 technical data sheet, by application:
| Application | Treat rate |
|---|---|
| Engine oils | 1.0–4.0 wt% |
| Industrial lubricants | 0.1–2.0 wt% |
In a finished engine oil the dispersant is normally the highest-treat additive — total dispersant content typically runs 3–7 wt%, around half the additive package. Because high-molecular-weight dispersants also contribute some thickening, T1620 can partly offset the viscosity-modifier requirement of a formulation, which is factored into the treat rate.
Treat rates are typical ranges from the TDS. The exact level depends on the soot load, the rest of the additive package and the target specification. CheMost can provide formulation and treat-rate support on request.
Formulating With T1620 — Complementary Additives
A high-MW dispersant covers high-soot suspension; a balanced heavy-duty package pairs T1620 with:
Detergents & TBN boosters
Overbased detergents neutralise combustion acids and clean hot surfaces; T1620 suspends the high soot loads. The detergent–dispersant balance is the backbone of every diesel package.
ZDDP antiwear additives
ZDDP provides antiwear protection; dispersant and ZDDP levels are balanced together, as high dispersant levels can interact with the antiwear film.
Antioxidants
Phenolic and aminic antioxidants slow oxidation and sludge formation, extending drain intervals alongside the dispersant’s deposit control.
Borated dispersants
Where added antioxidancy, antiwear or seal compatibility is wanted on the HMW backbone, the borated grade T1620B (on the boron-modified PIB succinimide page) can complement or partly replace T1620.
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 available on request.
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
Treat-rate calculation and formulation guidance from our technical team.
Packaging & Supply
T1620 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
170 kg metal drum · 900 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 HMW polyisobutylene bissuccinimide (T1620)?
It is an ashless bis-succinimide dispersant built on a high-molecular-weight polyisobutylene tail. The larger tail increases soot-carrying capacity and high-temperature dispersancy, making it well suited to high-soot diesel engine oils. TBN is 21 and nitrogen 1.12%.
Why choose a high-molecular-weight dispersant?
High-molecular-weight dispersants give superior detergency and high-temperature stability versus low-molecular-weight grades, and suspend higher soot loads. That is why HMW grades like T1620 are favoured in heavy-duty diesel oils running high EGR and extended drains.
How does T1620 differ from T1428?
Both are bis-succinimides; T1620 uses a higher-molecular-weight PIB tail (viscosity at 100°C 330 vs 180 mm²/s). The larger tail boosts soot dispersancy and high-temperature performance, while T1428 is a balanced general-purpose grade.
What treat rate should I use for T1620?
Typical ranges from the TDS are 1.0–4.0 wt% in engine oils and 0.1–2.0 wt% in industrial lubricants. The exact level depends on the soot load, the co-additive package and the target specification; our technical team can assist.
How is T1620 supplied, and how fast can I get a sample?
T1620 is supplied in 170 kg metal drums and 900 kg IBC tanks and shipped worldwide, with a 36-month shelf life. As a manufacturer and sourcing partner (Est. 2013), CheMost responds to sample and quotation requests within 12 hours.