Accelerator Masterbatch
Chemipat manufactures accelerator masterbatches for rubber compounding at our Salford, UK site. Each accelerator is pre-dispersed in a polymer binder at a fixed active content, giving dust-free handling, accurate weighing and consistent cure from batch to batch.
What is an accelerator masterbatch?
Rubber accelerators speed up sulphur vulcanization, lowering cure time and temperature and improving the physical properties of the finished part. An accelerator masterbatch is the same accelerator chemical supplied pre-dispersed in a polymer carrier, rather than as a loose powder. It is one type of polymer-bound masterbatch.
Many accelerators are fine, dusty powders and some carry handling hazards. Binding them in polymer reduces airborne dust, prevents cross-contamination between compounds and helps the accelerator distribute evenly – important because small amounts have a large effect on cure.
Our accelerator masterbatch range
| Class | Grades | Typical role |
|---|---|---|
| Sulfenamides | CBS 80E, CBS 80NR, TBBS 80E, TBBS 80NR | Primary accelerators with delayed action and good scorch safety – widely used in tyres and technical goods. |
| Thiazoles | MBT 80E, MBTS 80E, MBTS 75E, MBTS 75NBR | Primary accelerators, often used with a secondary accelerator. |
| Thiurams | TMTD 80E, TMTD 75E, TMTM 80E, TBzTD 70E, DPTT 70E/75E, DPTH 70E/75E | Fast secondary accelerators; several also act as sulphur donors for low-sulphur and efficient cure systems. |
| Dithiocarbamates | ZDEC 75E, ZDBC 80E, ZDMC 80E, ZBEC 80E, TDEC 75E | Ultra-fast accelerators, common in EPDM, latex-type and low-temperature cures. |
| Guanidines | DPG 75E | Secondary accelerator, often used to activate thiazoles. |
TBzTD is frequently chosen as an alternative to TMTD where nitrosamine formation is a concern. Full chemical names and CAS numbers are listed on our predispersed chemicals page.
Choosing the right binder
The letters at the end of each code show the binder: E = EPDM, NR = natural rubber, SBR = styrene butadiene, NBR = nitrile, CPE = chlorinated polyethylene. The number is the active content, so CBS 80E is 80% CBS in EPDM. Pick a binder compatible with your base polymer.
Switching from powder accelerators
To keep the same active level, divide the powder dosage by the active fraction. For example, 0.5 phr of powder TMTD becomes 0.625 phr of TMTD 80E. We are happy to help you convert a formulation – just get in touch.
Bespoke accelerator blends
We can produce bespoke single or blended accelerator masterbatches designed around your mixing equipment, binder and cure requirements, or manufacture your own formulation under a confidential toll agreement. Products are packed in 25 kg boxes, 500 kg net per heat-treated pallet.
Frequently asked questions
What is the difference between primary and secondary accelerators?
Primary accelerators (such as sulfenamides and thiazoles) control the main cure; secondary accelerators (thiurams, dithiocarbamates, guanidines) are added in smaller amounts to boost cure speed and state of cure.
Which accelerator masterbatch gives the best scorch safety?
Sulfenamides such as CBS and TBBS offer delayed action. For extra processing safety, pair them with our CTPI retarder masterbatch.
Related: Rubber additives · Sulfur masterbatch · What is vulcanization?
