Replacement of heavy metal catalysts in the plastics industry
Submitting Institution
University of BathUnit of Assessment
ChemistrySummary Impact Type
TechnologicalResearch Subject Area(s)
Chemical Sciences: Inorganic Chemistry, Organic Chemistry, Other Chemical Sciences
Summary of the impact
Catalysis is a major UK industry strength and wealth generator for the UK
economy. Research carried out in the group of Professor Matthew Davidson
in the Department of Chemistry at the University of Bath resulted in the
development of titanium and zirconium alkoxide catalysts for use in three
industrial polymerisation processes and patented by the UK companies ICI
Synetix and Johnson Matthey. Patents have recently also been acquired by
the Indian multinational Dorf Ketal and filed by the Dutch multinational
Corbion Purac. The research has resulted in the adoption of new catalysts
in industry leading to increased turnover, onward dissemination and
implementation of the Bath intellectual property. It has also generated
£4.6M from sale of intellectual property and an increase in generated
sales of new, sustainable titanium catalysts that replace heavy metals
such as tin, antimony and mercury in major industrial processes. The
intellectual property and process developments have been implemented
globally in the poly(ethylene terephthalate) (PET) and poly(urethane) (PU)
plastics markets, worth $23B and $33B, respectively, in 2010.
Underpinning research
The research group of Professor Matthew Davidson in the Department of
Chemistry at the University of Bath has been exploring the rich chemistry
of a range of ligands and their use in the stabilisation of highly
reactive Lewis acidic metal centres since 1999-2000. This work has focused
on the use of more environmentally friendly metals such as titanium as
replacements for heavy metals such as tin, antimony and mercury in areas
such as catalysis. The research is aligned to the Catalysis and
Sustainable Chemical Technologies research themes within Bath Chemistry.
The development of new and increasingly active homogeneous catalysts has
been one of the main driving forces behind recent advances in modern
organometallic chemistry. One such area has been the need to develop new
Lewis acid catalysts to mediate industrial polymerisation processes such
as PET and PU manufacture, as well as for the ring-opening polymerisation
(ROP) of cyclic esters. The chemistry is motivated by a drive for the use
of more sustainable metals in these high-volume manufacturing processes
and also by the introduction of a new generation of commercially viable,
sustainable degradable plastics available from renewable resources.
Chelating N- and O-containing ligands, which are capable of providing a
range of stable steric and electronic environments for catalytically
active metal centres, have been the subject of considerable research for
some time, not least for their ability to bind active metal centres in
well-defined environments [1, 2]. This has attracted huge industrial
interest, since the area of new catalyst development is highly competitive
and requires a continuous process of innovation and materials development,
to facilitate both new processes and new target products.
The important breakthrough resulting from this underpinning
metallo-organic coordination chemistry was the discovery in 2001-2002,
during Davidson's time as a Royal Society Industry Fellow with Johnson
Matthey (1999-2003), that well-defined molecular titanium-based complexes
being developed at Bath were highly effective in replacing the heavier and
more toxic metals that were used in PET and PU polymerisation processes,
notably tin, antimony and mercury. This initial discovery immediately led
to follow-on industrial funding, a detailed understanding of
structure-activity relationships for titanium complexes with commercially
viable ligands, and the protection of the chemistry though patents led by
the industrial partners as detailed below. Subsequent development in
Davidson's group and at Johnson Matthey refined the molecular chemistry
and processes, leading to functional catalysts that could be implemented
in relevant industrial contexts. For example, this work included the
synthesis and structural characterisation of a series of Group 4 metal
complexes and assessment of their potential as Lewis acid catalysts for
polyester synthesis. In this work, a series of ligands were prepared and
their Group 4 metal complexes studied, allowing isolation of well-defined
titanium and zirconium complexes which were shown to be active catalysts
for the ROP of cyclic esters such as 03b5-caprolactone and lactide with
excellent levels of conversion and control [3]. This work was subsequently
developed further with industrial collaborators and funding [4, 5],
exerting influence over the development of the entire Johnson Matthey
metal alkoxide catalyst portfolio.
Key Researchers
Professor Matthew Davidson (Whorrod Professor of Sustainable Chemical
Technologies, lead academic; at Bath since 1999)
Dr A L Johnson (PDRA, now Lecturer, at Bath 2000-), Dr M D Jones (PDRA,
now Senior Lecturer; at Bath 2004-), Dr C J Chuck (Industrial PhD and
PDRA, now Whorrod Fellow; at Bath 2004-)
Dr E Gullo (Industrial PDRA, 2004-2007); G F Eade (2001-2004), C L Doherty
(2004-2007), A L Chmura (2006-2009) (PhD students in Davidson group); M D
Lunn (2001-2005), L Paches (2004-2008) (Industrial PhD students in
Davidson group)
References to the research
[1] M.G. Davidson, C.L. Doherty, A.L. Johnson and M.F. Mahon, Chem.
Commun., 2003, 1832-1833. Isolation and characterisation
of transition and main group metal complexes supported by
hydrogen-bonded zwitterionic polyphenolic ligands. [DOI:
10.1039/b303618a]
[2] A.L. Johnson, M. G. Davidson, M. D. Lunn, M.F. Mahon, Eur. J.
Inorg. Chem., 2006, 3088-3098 (with industrial co-authors,
Johnson Matthey). Synthesis, Isolation and Structural Investigation of
Schiff-Base Alkoxytitanium Complexes: Steric Limitations of Ligand
Coordination. [DOI: 10.1002/ejic.200600113]
[3] A.J. Chmura, M.G. Davidson, M.D. Jones, M.D. Lunn, M.F. Mahon, Dalton
Trans., 2006, 7, 887-889 (with industrial
co-authors, Johnson Matthey). Group 4 complexes of amine
bis(phenolate)s and their application for the ring opening
polymerisation of cyclic esters. [DOI: 10.1039/b513345a]
[4] A.J. Chmura, M.G.Davidson, M.D. Jones, M.D. Lunn, M.F. Mahon, A.F.
Johnson, P. Khunkamchoo, S.L. Roberts and S.S.F. Wong, Macromolecules,
2006, 39, 7250-7257 (with Johnson Matthey co-authors). Group
4 complexes with aminebisphenolate ligands and their application for the
ring-opening polymerization of cyclic esters. [DOI:
10.1021/ma061028j]
[5] Direct industrial / translation funding
Total of £954k including: Royal Society Industry Fellowship (M G Davidson)
1999-2003 (£250k); Industrial PDRA (ICI Synetix, now Johnson Matthey)
2002-2004 (£134k);
EPSRC/TSB Link Project (with ICI Synetix, now Johnson Matthey) 2004-2007
(£200k);
Knowledge Transfer Account Award and Industrial co-funding (with Purac,
now Corbion Purac) 2010-2013 (£270k); Industrially-funded PhD (M Lunn, L
Paches), 2001-2008 (£100k).
Details of the impact
Impacts from this work: Adoption of new products and processes, wealth
generation from Intellectual Property transfer and environmental
benefits
- The performance of an existing business has been improved through the
introduction of new products, processes or services — Plastics
manufacturing
- A sector has adopted a new or significantly changed technology or
process, including through acquisition and/or joint venture — Intellectual
Property transferred (raising £4.6M) and implemented
- Highly skilled people having taken up specialist roles that draw on
their research — PhD Researchers from the programme of work
underpinning this Case Study joined IBM, Johnson Matthey, Cyton
Biosciences, EPSRC and Pfizer
- The environment has been improved through the introduction of new
product(s), process(es) — Elimination of heavy metals in industrial
catalysts and enhancement of processes for manufacture of degradable
materials from renewable resources
The Catalyst Industry
Catalysis is a major UK industry strength and wealth generator for the
economy, and a key component of cleaner, more sustainable manufacturing
processes for a wide range of products. The development of new catalysts
can lead to more efficient, sustainable, cost-effective processes; those
developed in Bath have been translated rapidly and effectively into
industrial processes. This direct reach into major players in the global
plastics industry underpins the impact of this work.
The Bath chemistry, the intellectual property pathway and product
development
Three classes of titanium and zirconium catalysts for plastics manufacture
have been developed at Bath and patented, covering manufacturing processes
for the important polymers poly(ethylene terephthalate) (PET),
poly(urethane) (PU) (with plastics markets worth $23B and $33B,
respectively, in 2010) and, more recently, towards use in improved
processes for poly(lactic acid) (PLA). Crucially, these catalysts are
based on titanium and zirconium rather than tin, antimony or mercury, thus
eliminating the environmentally unfriendly heavy metals from
the catalysts used in these large-scale industrial polymerisation
processes.
Demonstrating the impact of this work involves a detailed following of
the original Bath-invented intellectual property but also derivative
patents and processes advanced by the partner industries and their
successors (ICI Synetix, Johnson Matthey; [A]). The impact outlined here
focuses on PET and PU. Developing commercial applications of the third
strand of Bath Group 4 catalysts (for PLA manufacture) is more recent,
with patent applications in 2006 (Johnson Matthey; [A]) and a recent
collaboration with Corbion Purac leading to implementation of
Bath-developed benign tin-replacement catalysis for pilot scale PLA
manufacture and patent filing in 2013 [A].
A critical element of the Bath
research is not only the specific catalysts developed in the published
work but the fact that these innovations, and the sharing of the
intellectual property with Johnson Matthey, through extensive
collaboration and a Royal Society Industry Fellowship for Davidson,
resulted in the methodology from Bath heralding a new, more sophisticated
molecular approach to catalyst design in the PET and PU areas, thereby
influencing the development of the whole metal alkoxide Johnson
Matthey catalyst portfolio. The Bath-developed materials have
been described as "first in class", and have also resulted in the
establishment of rigorous molecular design process in the industrial
environment [B]:
"In addition to the specific catalysts and IP ..., the methodology
from Bath influenced the whole JM Ti- and Zr alkoxide catalyst
portfolio, including establishing the rigorous molecular design of these
families of materials, and the Bath Chemistry and materials are
acknowledged as being "first in class" in this area.... there is thus no
doubt that many of these developments including the whole VertecTM
and SnapcureTM portfolio can be linked directly
to the Bath research."
In March 2011 Dorf Ketal, an Indian Chemicals company
who are one of the largest in the world, purchased PET and PU catalyst
intellectual property from Johnson Matthey in a £4.6M
transaction [C]; this income can be directly
attributable to the Bath research [B]. Due to the high value
of the product portfolio, the sale of the order book was blocked by the UK
Office of Fair Trading [D]. The intellectual property covered titanium
citrate-based Vertec catalysts first characterised by Bath that are used
in PET manufacture and the titanium alkoxide 'Snapcure' catalysts
developed from Bath chemistry and used in PU manufacture. Dorf Ketal
rebranded these products as part of their Unilink range and they are now
manufactured at their new Mundra plant in India:
From Dorf Ketal release [E]: "the plant will produce up to
10,000 metric tons of the industry's broadest portfolio of titanates
annually, making it the largest facility of its kind in the world. The
Mundra plant joins the company's recently expanded Dadra plant in
shipping TYZOR®, and VERTEC™ organic titanates worldwide...In April
2011, the company acquired the patents, trademarks and related
intellectual property for VERTEC™ polyester catalysts and SNAPCURE™
polyurethane catalysts".
Implementation in Industrial Processes
The titanium citrate-based catalysts first characterised in Bath have
successfully replaced antimony in PET fibre and film applications, with
initial impact in bottle resin (PET is the main material used in drinks
bottles) with significant environmental and process benefits. In addition,
the price of antimony catalysts has recently escalated rapidly due to
mining restrictions in China such that there is now an additional
significant upsurge in take-up of titanium-based catalysts from a cost
basis. Large-scale manufacturers have made substantial process
improvements in PET manufacture that allow good quality titanium-based
PET; Dorf Ketal are supplying to this market. For example, a new
ThyssenKrupp Uhde (Germany) process makes PET through a route in which
Vertec titanium-based catalysts are the best on the market by far at
matching antimony catalyst performance. These PET catalysts are part of
the portfolio taken on by Dorf Ketal, to supply some of the largest PET
resin plants in the world (>600 tonnes per day currently with up to
1500 tpd planned) [B]; conversion in these plants results in substantial
reduction in antimony usage.
The Snapcure (now Unilink) solution has also been implemented widely for
PU [F], with significant trials run with a number of large mercury
catalyst users including full scale trials. This new process, based on the
molecular design principles introduced by Bath, is increasingly relevant
due to the onset of REACH regulations, which are, increasingly, severely
restricting the use of mercury.
These new Bath-developed catalysts have
thus had impact through their adoption in manufacturing processes, as a
replacement for undesirable heavy metal catalysts (notably antimony and
more recently mercury). In addition to their adoption in manufacturing
plants, aspects of these catalysts and associated processes have been sold
on internationally, providing evidence that this chemistry is of ongoing
value and impact.
Key Impacts Timeline
2008 — Snapcure range of products launched by Johnson Matthey
2008-2010 - Pilot scale developments of process for various polymerisation
products
2010 - Large scale implementation of Snapcure catalysis solution for
polyurethane
2011 - VERTEC portfolio of PET and PU catalyst IP acquired and used by
Dorf Ketal, generating £4.6M income from IP sale alone
2011 - Dorf Ketal implementing Ti catalysts in PET plant — branded
Unilink, and manufactured at new Mundra plant in India demonstrating
increasing global reach and uptake
2011-2013 - Molecular design principles applied to new Group 4 metal PLA
catalysts trialled with Corbion Purac and patent application filed
Sources to corroborate the impact
[A] Patents
- WO2005035622 (Johnson Matthey PLC, 2005). Catalyst for the
Manufacture of Esters, Partridge, McIntosh, Hanratty; Group 4
metal hydroxyacid complexes as PET catalysts. http://www.google.com/patents/WO2005035622A1
Led directly from the molecular characterization of the ammonium
titanium citrate complex described by Davidson & Partridge, Chem.
Br. 2002, 38(7), 26 (article can be accessed
through http://opus.bath.ac.uk/37761/).
- WO2003018662 (Johnson Matthey PLC, 2003). Catalysts and Curable
Compositions, Davidson, Lunn, Johnson, Stengel; Group 4 metal
alkoxide complexes as PU catalysts http://www.google.com/patents/WO2003018662A1
- WO2004052980 (Johnson Matthey PLC, 2006). Polymerisation Reaction
and Catalyst Therefor; Partridge, Davidson, Eade; covers a range
of Group 4 metal alkoxide complexes as ring-opening polymerization
catalysts for lactones and lactides.
http://www.google.com/patents/WO2004052980A1
All JM intellectual property in this area sold on to Dorf Ketal as part
of the IP acquisition [C]
- EP13166273.6 (Purac Biochem, 2013). Method to Manufacture PLA
Using a New Polymerization Catalyst, Chuck, Davidson, Gobius du
Sart; filed in May 2013.
[B] Letter of evidence of impact, R&D Director, Johnson
Matthey Process Technologies
[C] Purchase of Intellectual Property by Dorf Ketal,
18 April 2011
http://www.reuters.com/article/2011/04/18/idUS125100+18-Apr-2011+PRN20110418
"Dorf Ketal Purchases VERTEC™ Patents and Intellectual Property"
[D] UK Office of Fair Trading press release on the proposed
sale of business outright to Dorf Ketal, November/December
2010
http://www.oft.gov.uk/shared_oft/mergers_ea02/2010/Dorf-Ketal.pdf
[E] Dorf Ketal Announces Full Production at World's Largest
Organic Titanate Plant, 4 May 2011 http://www.prnewswire.com/news-releases/dorf-ketal-announces-full-production-at-worlds-largest-organic-titanate-plant-121228969.html
[F] Johnson Matthey Product Case Study
SNAPCURE — Replacing Mercury with Titanium in Catalysts for Polyurethane
Elastomers
http://www.matthey.com/Sustainability2009/case-studies/products_cs_24.html