# Rubber chemicals: Production route

How aniline becomes the chemicals that cure rubber

Source page: https://www.materialinsights.org/chemicals/rubber_chemicals/routes/

What this tab covers How it is made: the main production routes or, for product families, the main product types and technologies, compared on share of supply, inputs per tonne, plant scale, yield, co-products and unit cost.

The family has two main product groups made by multi-step synthesis. Accelerators are built on 2-mercaptobenzothiazole (MBT) made from aniline, carbon disulphide and sulphur, then converted to MBTS or to sulphenamides (CBS, TBBS, MBS) with amines; thiurams and dithiocarbamates come from secondary amines and CS2. Antidegradants are built on aniline: PPDs via 4-aminodiphenylamine and reductive alkylation with ketones, TMQ/TDQ by acid-catalysed condensation of aniline and acetone. Vulcanising agents (insoluble sulphur) and processing aids complete the range. Integration into aniline and 4-ADPA sets cost.

#### Routes compared

| Route | Share of supply | Inputs per tonne | Typical scale | Yield | Co-products | Unit cost |
|---|---|---|---|---|---|---|
| **Thiazole and sulphenamide accelerators (MBT, MBTS, CBS, TBBS)** | largest accelerator class (indicative) | MBT: 0.56 t aniline, 0.46 t CS2, 0.19 t S; TBBS: 0.70 t MBT + 0.31 t tert-butylamine (stoichiometry) | plants of 10-60 kt/yr (indicative) | not published | hydrogen sulphide (to sulphur recovery); salt-laden effluent | not published |
| **PPD antiozonants (6PPD, IPPD)** | largest antidegradant class (indicative) | 6PPD: 0.69 t 4-ADPA + 0.37 t MIBK + hydrogen (stoichiometry) | Chinese plants of 50-150 kt/yr (indicative) | not published | water | not published |
| **Quinoline antioxidants (TMQ/TDQ)** | large (indicative) | aniline and acetone | NOCIL's new TDQ unit at Dahej (Rs 250 crore capex), trial production started 2026 | not published | acidic effluent | not published |
| **Thiurams, dithiocarbamates, guanidines and insoluble sulphur** | smaller (indicative) | amines, CS2, sulphur | not published | not published | not published | not published |

#### How each route works
**Thiazole and sulphenamide accelerators (MBT, MBTS, CBS, TBBS)**

Aniline, CS2 and sulphur react at high temperature and pressure to MBT; MBT is oxidatively coupled with cyclohexylamine (CBS) or tert-butylamine (TBBS). Sulphenamides give delayed-action cure, ideal for tyres.

Workhorse for tyres; effluent-intensive.
 stoichiometry; CARE Ratings (NOCIL) **PPD antiozonants (6PPD, IPPD)**

Aniline and nitrobenzene give 4-ADPA, which is reductively alkylated with MIBK (6PPD) or acetone (IPPD) over a catalyst with hydrogen. PPDs migrate to the rubber surface and react with ozone before the rubber does.

No equal substitute yet; 6PPD-quinone toxic to coho salmon.
 stoichiometry; Tian et al., Science (2021) **Quinoline antioxidants (TMQ/TDQ)**

Aniline condenses with acetone under acid catalysis to polymerised 2,2,4-trimethyl-1,2-dihydroquinoline, a cheap heat-ageing antioxidant used in most tyres.

Low cost; commoditised.
 CARE Ratings (Oct 2025); PL Capital (May 2026) **Thiurams, dithiocarbamates, guanidines and insoluble sulphur**

Secondary amines with CS2 give dithiocarbamates and thiurams (TMTD) for fast cures and latex; DPG from aniline and cyanogen chloride is a secondary accelerator; polymeric insoluble sulphur prevents bloom in tyre compounds.

Some secondary-amine accelerators form carcinogenic nitrosamines.
 indicative Unit economics are indicative ranges from the sources named; costs move with feedstock and energy prices, plant size and region.

## Other sections

- [Summary](https://www.materialinsights.org/chemicals/rubber_chemicals/index.md)
- [Overview](https://www.materialinsights.org/chemicals/rubber_chemicals/overview/index.md)
- [Correlation](https://www.materialinsights.org/chemicals/rubber_chemicals/correlation/index.md)
- [Production](https://www.materialinsights.org/chemicals/rubber_chemicals/production/index.md)
- [Feedstocks](https://www.materialinsights.org/chemicals/rubber_chemicals/feedstocks/index.md)
- [Cycles](https://www.materialinsights.org/chemicals/rubber_chemicals/cycles/index.md)
- [Trading](https://www.materialinsights.org/chemicals/rubber_chemicals/trading/index.md)
- [Movement](https://www.materialinsights.org/chemicals/rubber_chemicals/movement/index.md)
- [Regulation](https://www.materialinsights.org/chemicals/rubber_chemicals/regulation/index.md)
- [Characteristics](https://www.materialinsights.org/chemicals/rubber_chemicals/characteristics/index.md)
- [Emissions](https://www.materialinsights.org/chemicals/rubber_chemicals/emissions/index.md)
- [Relationships](https://www.materialinsights.org/chemicals/rubber_chemicals/links/index.md)