Antioxidant 2246 in Rubber and Plastics

Antioxidant 2246 (2,2′-methylenebis(4-methyl-6-tert-butylphenol), CAS 119-47-1) is a non-staining hindered phenolic antioxidant used to protect rubber and plastics against heat and oxygen ageing. This page looks at how and where it is used – in which polymers, at what stage, and why the non-staining property matters.

Why 2246 in rubber and plastics?

Property	Benefit
Non-staining / non-discolouring	Suits white, pastel and bright compounds
Low volatility (MW about 340)	Stays in the compound through high-temperature processing
Hindered phenolic chemistry	Breaks the oxidation chain, extending heat-ageing life
Powder form	Disperses easily at typical loadings

In rubber

In rubber, 2246 protects the polymer backbone against heat and oxygen ageing during cure and service. It is used in NR, SBR, BR, NBR and blends, and is particularly valued in light-coloured and white goods where a staining amine antioxidant cannot be used.

Rubber application	Why 2246
White and light-coloured goods	Non-staining – the key requirement
Footwear and mechanical goods	Heat-ageing protection without discolouration
Latex compounds	Protection of latex film
General technical rubber	Anti-ageing during processing and service

In plastics and adhesives

Material	Role of 2246
Polyolefins (PE, PP)	Thermal-oxidative stabilisation
Styrenic polymers	Non-staining stabilisation
Adhesives and sealants	Prevents ageing-induced tack loss or hardening
Coatings and films	Protects the binder against ageing

How to use it

Level – a few phr in rubber, low percentages in plastics; set by the ageing test.
Stage – added during mixing/compounding so it disperses through the material.
Combination – often paired with a secondary (hydroperoxide-decomposing) antioxidant such as a phosphite or thioester.
Colour – because it is non-staining, it is the antioxidant of choice where appearance must be preserved.

When to choose a different antioxidant

Need	Better choice
Strong dynamic/fatigue protection in dark goods	Amine antioxidant (RD, 6PPD)
Fast, low-cost, oil-soluble protection	BHT (264)
Very high service temperature, plastics	High-MW phenolic such as 1010

Frequently Asked Questions

Does Antioxidant 2246 discolour rubber?

No – it is non-staining and non-discolouring, which is why it is used in white and light-coloured compounds.

What level is used?

A few phr in rubber, low percentages in plastics, set by the ageing test on the finished compound.

Can it replace an amine antioxidant?

Only partly. It gives heat/oxygen protection but not the strong fatigue protection of an amine; in tyres the two are often combined.

Is it used in latex?

Yes – it protects natural and synthetic latex compounds against ageing.

Does it need a secondary antioxidant?

For full protection it is often combined with a phosphite or thioester to handle hydroperoxides.