The Catalyst Review December 2020 - 11

SPECIAL FEATURE
and plasticizer loading, providing economical compounds. They can develop high tensile and tear properties, excellent abrasion
resistance, as well as improved oil swell resistance and flame retardance. EPDM is the most used elastomer in non-tire applications.
It is extensively used in automotive as weather-stripping and seals, glass-run channels, and radiators, in polymer impact modification,
in building and construction as roofing membrane, in industrial rubber goods and the rest in motor oil additive applications,
thermoplastic vulcanizates, garden and appliance hose, tubing, belts, electrical insulation, and so on. Polymers of ethylene, propylene
and a non-conjugated diene (EPDM) are usually produced in slurry, solution or gas phase processes. Specialized catalysts are used
to polymerize the monomers into controlled polymer structures. Since their introduction, EPR and EPDM rubbers are commercially
produced using homogeneous catalysts as vanadium-based ZN catalysts or, more recently, well-defined, highly active, homogeneous
catalysts, such as classical metallocenes and other advanced post-metallocene single-sites catalysts, targeted at production of new
types of EP elastomers with fast cure and high degrees of cure at very high yields.
A disadvantage of using conventional vanadium catalysts for EPDM results in the formation of very large branched molecules in
the polymerization reactor, leading to gel formation and ultimately to blockage and shutdown. Arlanxeo has further developed
and especially tailored for EPDM production a new class of SSC catalysts, which are extremely productive, named Keltan ACE
(Advanced Catalyst Elastomers). Lanxess has patented several enhancements related to ACE catalysts (van Doremaele et al. 2017)
- this invention relates to a new catalyst system for the polymerization of olefins comprising a metal complex of formula CyLMD
and an activating cocatalyst, wherein M is titanium, Cy is a
Figure 4: EPDM innovation for non-tire applications.
cyclopentadienyl-type ligand, L is an imine ligand, D is a diene.
The new catalyst system has a substantially improved heat
stability, allowing higher reactor temperatures and very
high catalyst productivity that enables the elimination of
the catalyst removal step. The ACE catalyst system allows
for the production of a complete EPDM grade portfolio with
products that perform identical to EPDM grades, produced
by ZN catalysts, but with a reduced environmental impact. In
addition, the ACE catalyst technology creates opportunities
to develop products that are not attainable with classical ZN
or state-of-the-art metallocene catalyst technologies, like
high molecular weight high VNB (vinyl norbornene) EPDMs.
Dow Elastomers commercializes successful EPDM products,
under the name Nordel, manufactured through a gas phase
technology using its Advanced Molecular Catalyst (SSC postmetallocene catalyst) that offers great efficiency and improved
performance across a broader range of applications. See
Source: Author
in Figure 4 the impressive EPDM innovation path involving
catalyst/process and elastomer products over the years.

Market Players and Moves
SR is a volume industry with over 15.3 million tons/year of production
in 2018 (Statista 2020, IRSG 2020), following only polyolefins, PVC,
and PET. In the same year, the global SR production capacity was 20.4
million tons (Meyer 2019). The breakup of the global SR capacity by
region and elastomer type is shown in Figure 5. Asia Pacific is the
largest producer and consumer of industrial rubber, with its tire sector
exhibiting promising growth rate. Global manufacturers have shifted
their SR production facilities to emerging economies, due to the low
labor and operating costs. Asia-Pacific controls 56% of overall SR capacity
worldwide, with China accounting for 27% and the rest of Asia 29%.
The rest of Asia overtook China at the end of 2016 because most new
projects and expansions came into this region. Relatively few companies
are accounting for the bulk of global SR production capacity; in 2014, 25
companies controlled 80 % of capacity. In 2018, 21 companies accounted
for that same 80 %. What has happened there is a combination of two
things: the big players are still growing and expanding their facilities
mainly through several new JVs, and the closure of some old plants.

Figure 5: Global synthetic rubber capacity by region and type.

Source: Meyer 2019

The Catalyst Review

December 2020 11

The Catalyst Review December 2020

Table of Contents for the Digital Edition of The Catalyst Review December 2020