Rubber chemicals: Production route
How aniline becomes the chemicals that cure rubber
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 sulphurSecondary 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.