Zinc oxide and rubber activators
Supplier & distributor · Chennai · Madurai · South India
Zinc oxide and stearic acid activate sulphur vulcanisation in nearly every rubber compound. We stock conventional and active zinc oxide grades, stearic acid, zinc and calcium stearates, magnesium oxide and litharge.
Types of zinc oxide & activators we supply
Zinc oxide (conventional and active)
The main activator for sulphur cures; active grades give the same activation at lower zinc levels. Grades include Active Zinc Oxide MLA 200, Active Zinc Oxide MLA 700, Active Zinc Oxide MLA 900, ZINC ACTIVE T150, ZINC OXIDE ACTIVE MLA T-80 JM, Zinc Oxide RG, Zinc Oxide.
Stearic acid and stearates
Stearic acid activates zinc; zinc and calcium stearates act as activators, lubricants and release agents. Grades include ZINC STEARATE, Zinc Stearate Mflow 20, Zinc Sterate ZS-LM, Calcium Stearate, STEARIC ACID DISTRIC, STEARIC ACID LUBSTRIC 995.
Magnesium oxide and litharge
Activators and acid acceptors for CR (neoprene), CSM and FKM compounds. Grades include Litharge, Starmag Magnesium Oxide.
Why buy zinc oxide & activators from Riddhi Polymers
- In stock in Chennai: held ready at our Chennai warehouse, with a branch in Madurai.
- Across South India: regular deliveries to Tamil Nadu, Kerala, Karnataka, Andhra Pradesh and Puducherry.
- Quality you can trace: ISO 9001:2015 certified, COA with every batch, MSDS and TDS on request.
- Trusted since 2009: 400+ regular buyers and 20+ global principals.
For prices and availability, request a quote, call +91 98418 19109 or email sales@riddhipolymers.com.
Buyer guide: Rubber accelerators: types and how to choose
Frequently asked questions
What is active zinc oxide?
Active zinc oxide has a much higher surface area than conventional grades, so lower dosages can give the same activation, reducing zinc content in the compound.
Why is stearic acid used with zinc oxide?
Stearic acid solubilises zinc in the compound, forming the zinc complexes that activate the accelerator system.
How much zinc oxide is used in a rubber compound?
Conventional zinc oxide is typically used at about 3 to 5 PHR with 1 to 2 PHR stearic acid; active zinc oxide allows lower dosages. Confirm with your own trials.
Grade list (16 grades)
| Grade | Type | Chemistry | Typical applications |
|---|---|---|---|
| Litharge | Activator | Litharge — Lead(II) oxide (PbO) CAS 1317-36-8 | Chemical-resistant lining compounds, polysulfide sealants, historical CR formulations |
| Active Zinc Oxide MLA 200 | Activator | Active Zinc Oxide MLA 200 — direct process, high surface area CAS 1314-13-2 | Low-zinc or zinc-free formulations, EPDM seals, environmental specification compounds |
| Active Zinc Oxide MLA 700 | Activator | Active Zinc Oxide MLA 700 — ultra-fine, direct process CAS 1314-13-2 | Demanding low-zinc formulations, medical rubber, environmental-grade products |
| Active Zinc Oxide MLA 900 | Activator | Active Zinc Oxide MLA 900 — surface-treated high surface area CAS 1314-13-2 | Premium low-zinc compounds, silica-filled systems, adhesive compounds |
| ZINC ACTIVE T150 | Activator | Zinc Oxide Active T150 — direct process, medium surface area CAS 1314-13-2 | General rubber goods, tyre compounds requiring reduced zinc loading |
| ZINC OXIDE ACTIVE MLA T-80 JM | Activator | Zinc Oxide Active MLA T-80 JM — coated grade CAS 1314-13-2 | General rubber goods, profiles, hoses requiring dust-free handling |
| Zinc Oxide RG | Activator | Zinc Oxide — rubber grade (RG specification, indirect process) CAS 1314-13-2 | General rubber goods, tyre compounds, belts, hoses |
| Zinc Oxide | Activator | Zinc Oxide (standard grade, indirect process) CAS 1314-13-2 | All sulphur-cured rubber compounds — tyres, hoses, belts, seals, mouldings |
| ZINC STEARATE | Activator | Zinc Stearate CAS 557-05-1 | Mould release in direct rubber moulding; lubrication in extrusion; anti-sticking for calendered sheets |
| Zinc Stearate Mflow 20 | Activator | Zinc Stearate Mflow 20 — free-flowing, low dust grade CAS 557-05-1 | Same as ZNST; preferred for automated dispensing lines and dustless operations |
| Zinc Sterate ZS-LM | Activator | Zinc Stearate ZS-LM — low-melt grade CAS 557-05-1 | Low-temperature mixing compounds, latex, foam rubber |
| Calcium Stearate | Activator | Calcium Stearate CAS 1592-23-0 | CR compounds (HCl scavenger), PVC blends, calendering lubricant, tablet rubber goods |
| STEARIC ACID DISTRIC | Activator | Stearic Acid — Distric grade (C18 fatty acid, >95% purity) CAS 57-11-4 | Every sulphur-cured rubber compound; also acts as internal lubricant and dispersing agent for fillers |
| STEARIC ACID LUBSTRIC 995 | Activator | Stearic Acid — Lubstric 995 grade (>99.5% C18 purity) CAS 57-11-4 | Premium rubber compounds where consistent cure and low bloom are critical — tyres, food-contact, medical |
| Starmag Magnesium Oxide | Activator | Magnesium Oxide — Starmag grade, rubber/chemical use CAS 1309-48-4 | CR/Neoprene seals, automotive weather seals, acid-resistant hoses, cable jacketing |
| ZINCOLET 222 | Additive | Zincolet 222 — zinc stearate complex / zinc soap activator CAS — | Light-coloured rubber, foam compounds, latex, where standard ZnO/SA combo causes surface blooming |
Need a grade that isn’t listed, or an equivalent? Ask us. The full catalogue is also available as a downloadable product list.
