2. 1
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Our global manufacturing and local sales offices mean we are able
to think globally, and act locally. We’re one step ahead in helping
you solve complex challenges to meet regulatory and legislative
challenges on the horizon.
From bespoke synthesis of new products, through to commercial
scale-up of new chemistry, we integrate strong regulatory expertise
to help develop the chemistry you need, when you need it.
Our sites are globally accredited so you know, consistency and
quality to your standard is guaranteed.
Croda create, make and sell speciality chemicals and additives. We overcome complex technical
challenges through applied sustainability, collaboration and deep scientific expertise, so that our
customers can efficiently power the world of tomorrow.
In emission control catalysts, we develop, manufacture and supply novel rheology and dispersant control
additives to help catalyst manufacturers optimise their washcoat and substrate manufacturing processes.
We couple our products with industry leading expertise – get in touch to start the conversation.
Introduction
Sanjuro Inoue
Business Development Manager | Asia | sanjuro.inoue@croda.com
Sanjuro has extensive experience in the advanced materials industry having worked in technical roles in the
chemical sector for over 15 years. He works globally and has an excellent understanding of catalyst processes
and is often the first liaison in helping customers optimise and develop their manufacturing processes.
Jérôme Gonthier
Technical Project Lead | Europe
Jerome is the project lead for catalyst product development and oversees technical support for our customers.
He has worked in the chemical industry for over 10 years in technical roles and has been integral in many new
product developments whilst at Croda.
Together for the future of emission control catalysts
Here to support you
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Hypermer™ KD
Our Hypermer KD brand is key to our success, which is a range of stand-out dispersants that have been developed directly
with customers to meet their evolving needs. Proven in industry, the range is able to meet the needs of most systems, although
where our existing products fail to resolve an unmet need, we have a range of collaborative development pathways to create
something new and bespoke for your system.
The Hypermer KD range of dispersants are suitable for a variety of washcoat slurries for emission control catalysts, helping
reduce the cost of the final catalyst unit and providing more accurate control of catalyst layers.
This is achieved through improved particle size distribution in washcoats through deagglomeration and reduced slurry viscosity.
In contrast to controlling viscosity through pH adjustment alone, increased solids loading can be achieved whilst maintaining
optimal particle dispersion and rheology
For over 20 years, we have been actively developing and manufacturing high performance dispersants. Our unique capabilities allow
us to work with R&D centres and individual manufacturing sites to optimise processes and systems through close collaboration.
Dispersants
Reduced
catalyst
cost
Increased
solids loading
Reduced
slurry viscosity
Features Benefits
Lower viscosity slurries Easier handling and optimised support penetration
Improved particle size dispersion Optimise metal use in achieving the same level of catalyst activity
Increased solids loading Reduce processing time and aid catalyst washcoat coverage
Fast, clean burn out Reduced contamination and rejects
Consistent quality of product Reproducible washcoat system, and reduced batch-to-batch variation that require process adjustments
A choice of polymeric, oligomeric and monomeric
dispersants
Products to suit a broad range of different particle types and sizes
Typical features and benefits of our Hypermer KD range
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*Thermogravimetric analysis carried out in air at 60ml/min. Heat up rate was 10°C/min, from 25°C
Product Name Form at 25°C Activity (%)
Burn Out
Temperature (°C)*
Molecular
Weight (g/mol) Recommended Slurries
Anionic
Hypermer KD7 Liquid 40 966 >10,000 Alumina, ceria, titania, zirconia
Hypermer KD73 Liquid 100 521 <1,000 Ceria, titania, zirconia
Hypermer KD77 Solid 100 545 <1,000 Ceria, titania, zirconia
Cationic
Hypermer KD2 Solid 100 419 1,000-10,000 Alumina, ceria, titania, zeolites
Hypermer KD28 Liquid 100 605 1,000-10,000 Alumina, zeolites
Nonionic
Hypermer KD6 Liquid 33 469 >10,000 Alumina,ceria,titania,zirconia,zeolites
The right dispersant for your system
Our dispersant range can be matched to the particles present in your washcoat formulation. The table below outlines the parameters that
should be considered when choosing the right dispersant candidates.
Dispersion Characteristic Dispersant Characteristic Result
Surface charge of particle Appropriate anchoring group Good adsorption of dispersant anchoring groups to particle surface
Solvent Solubility Good compatibility of dispersant in continuous phase
Particle size Molecular weight Optimal adsorption of dispersant anchoring groups to particle surface
Solids loading Molecular weight Optimal rheology of dispersion
Particle shape Dispersant architecture Optimal adsorption of dispersant to particle surface
5. 4
Figure 1 Liquid dispersion polymer mode of action
Rheoptima™
Croda’s range of rheology modifiers generally thicken formulations and are suitable for a variety of washcoat slurries for emission
control catalysts.
They can be used alongside, or without dispersant additives to control the viscosity of slurries in view of achieving optimal process
properties. Optimisation helps to reduce the cost of the final catalyst unit, whilst providing more accurate control of catalyst layers.
In contrast to controlling viscosity through pH adjustment alone, increased slurry stability can be achieved whilst maintaining optimal
particle dispersion and rheology.
We have consolidated our rheology modifier range under the Rheoptima brand for performance technology applications to demonstrate
our on-going commitment to these markets. For emission control catalysts, the range of Rheoptima rheology modifiers are based on a suite
of chemistries designed to give washcoat formulators the desired rheological characteristics required for these complex aqueous systems.
Rheology modifiers
Instant
thickening
Increased
dispersion
stability
Increased
viscosity
The different modes-of-action for our Rheoptima range are explored below:
Liquid Dispersion Polymers (LDPs)
Liquid dispersion polymers help stabilise formulation by forming a polymer matrix within the solution, offering the following benefits:
I
Provide formulations that are temperature stable and freeze-thaw stable
I
Very efficient (typical use rates of 0.5-2%)
I
Pseudoplastic (shear thinning) rheology
I
Able to suspend particulates
I
Offer both anionic and cationic functionality
On addition to water the inverter
emulsifies the carrier fluid
Product as supplied
Carrier Fluid
Polymer
in water
Inverter
The polymer particles can swell
by osmosis
Stirring
This gives a polymer matrix
entrapping the emulsified oil
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Figure 2 AEP mode of action
Figure 3 Speciality polymeric gellants mode of action
Speciality Polymeric Gellants
Our speciality polymeric gellants for catalysts are based on
renewable polyamide technology. These products form thermo
reversible gels with thixotropic rheology profiles, meaning viscosity
decreases over time when a constant shear force is applied.
The amine and acid functional groups of polyamide chemistry
provides stearic stabilisation to particle slurries allowing for slurries
with higher solids loading, whilst maintaining workable viscosities.
Aqueous Emulsion Polymers (AEPs)
Our aqueous emulsion polymers are a unique rheology modifier
technology, which are optimised to create pseudoplastic gels. The
gels formed are non-thixotropic, meaning that the recovery of the
viscosity once the applied shear is removed is time independent. As
such, the rheology of systems using AEPs instantly respond when
shear force is applied and removed.
Mode of Action
AEPs have acid and acrylate groups and pendant long chain
associative groups. The product is supplied as an acidic emulsion,
which needs to be neutralised with a suitable base, such as
sodium hydroxide solution or triethanolamine, to create a clear gel.
Thickening occurs as the acid groups in the polymer are neutralised
and the ionic groups repel each other within and between polymer
chains, creating a three-dimensional polymer containing micelles.
Ionic Acrylic Chain Cross-link Associative Group
C=O
O-
C=O
O-
Ionic Repulsion Cross-linking
Micellisation
C=O
O-
C=O
O-
C=O
O-
C=O
O-
C=O
O-
C=O
O-
C=O
O-
C=O
O- C
=
O
O
-
C
=
O
O
-
C
=
O
O
-
C
=
O
O
-
C
=
O
O
-
Gelled structure
Trapped liquid
The polymer forms a gelled structure,
trapping the liquid in the gel network.
Product Description
Viscosity (2% w/w cP,
25°C RVT/6/10 rpm) pH Tolerance
Relative
Electrolyte Tolerance
Liquid Dispersion Polymers
Rheoptima LA23 Cationic rheology modifier 63000 3-8 Low
Rheoptima LA25 Cationic rheology modifier 62000 2.5-9 Low
Rheoptima LA45 Cationic rheology modifier 68000 2.5-9 Low
Aqueous Emulsion Polymers
Rheoptima B32 Associative anionic rheology modifier 12000 6-12 High
Product Description Form at 25 °C Softening Point (°C)
Speciality Polymeric Gellants
Rheoptima X73 Polyether polyamide Solid 105
Rheoptima X84 Polyalkyleneoxy terminated polyamide Solid 93
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Figure 4 Hypermer KD selection tool
Figure 5 Rheoptima selection tool
You can use the selection tool below to help you find the right dispersant for your formulation, but please do get into contact with us to help
you find the right one. By speaking to us directly, we’re also able to suggest products in our development pipeline – we can also help where
multiple particle interactions might be an issue.
All dispersants in the table below are for water-based slurries. The material and size of the particles in your formulation will also dictate
which dispersant is suitable.
Application Carrier inorganic powder Catalyst pH of slurry Recommended dispersant
TWC Alumina/Ceria/Zirconia PGM 3.5 - 8 KD6, KD73, KD77
DOC Silica/Alumina/Zeolite PGM 3.5 - 6 KD6
SCR Titania V2
O3
-WO3
2 - 5 KD2, KD6
SCR Titania V2
O3
-WO3
6 - 9 KD6, KD7
SCR Zeolite Fe 3 - 6 KD2, KD6
SCR Zeolite Cu 3 - 6 KD2, KD6, KD28
Hypermer KD selection tool
Rheoptima selection tool
Increasing pH
Not pH dependant
Rheoptima X73 Rheoptima X84
7
6
5
4
3
2
1 8 10 12 14
Rheoptima B32
Rheoptima LA23
Rheoptima LA25
Rheoptima LA45
The Rheoptima selection tool is based on the pH range of your washcoat formulation. Obviously, when using rheology modifiers with disper-
sants, particle and chemical interactions are more complex. If you need help with your system, our experts can help.
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Smart science to improve lives™
Energy Technologies
Didn’t find what you were searching for?
Croda has an extensive product portfolio. If specific chemistries, temperature ranges or any other
parameters are required, Croda, a world leader in speciality chemicals, has the facilities and
expertise to help you find a tailored solution for your application.
Please contact your sales representative or nearest Croda office to discuss your requirements
and let us help you find the right solution.
Multiwet™
Multiwet is a range of fast-acting wetting additives that can help increase the speed and efficiency of catalyst monolith manufacturing.
Energy and time can be saved through the lowering of surface tension, reducing the torque and mixing time needed to achieve an
homogenous slurry before extrusion.
The increased flow-ability of the slurry also allows for easier extrusion, reducing the number of defects during production.
Multiwet is one of our heritage brands. These wetting agents exhibit low foam properties, excellent biodegradability and are silicone
and halogen free.
Wetting agents
Product Description
Static Surface
Tension (mN/m)
Dynamic Surface
Tension (mN/m)*
Critical Micelle
Concentration (%w/w)
Speciality Polymeric Wetting Agents
Multiwet BD Low foam wetting agent with excellent
biodegradability
26.9 43.7 0.010
Multiwet EF Low foam wetting agent with excellent
efficiency
27.3 52.5 0.001
Multiwet SU Low foam wetting agent, best used for
substrate wetting
26.7 43.4 0.100
Multiwet VE Versatile wetting agent with moderate foaming 27.2 48.2 0.008
*At a surface age of 305 milliseconds, 0.3 wt.%, 25°C