Anticorrosive concepts
for modern high-performance coating
Lars Kirmaier, Heubach GmbH
Agenda
„ Going chrome-free- Loss of performance?
„ Anticorrosive pigments
… Synergies
„ Solving corrosion problems with anticorrosive pigments
in assorted modern high-performance applications
… Chrome-free coil coating primer
… High-Solids chrome-free car refinish primer
… Waterbased DTM primer
… Solvent-free powder primer
… Solvent-free UV primer
„ Conclusions, future targets
Heubach GmbH, Lars Kirmaier
Why replacing chromates?
Replacement of hexavalent chrome is a challenge:
„ Excellent protection of nearly all metals, especially in galvanic couples
„ Broad compatibility to alloys, resin, universal applicability
„ Higher solubility allows migration to damaged areas, repair effect
„ Well-known protection mechanism
The driving force behind replacement trials:
„ Changes in regulations, REACH, End of Life Vehicles Directive ….
„ HSE issues, general awareness
„ Pressure by Department of Defense (USA)
Heubach GmbH, Lars Kirmaier
Chromate vs Phosphate in a waterborne alkyd on CRS
Control
Heubach GmbH, Lars Kirmaier
Zinc phosphate
Chromate
Modified Orthophosphates
Modified orthophosphates
Zinc phosphate
ZPA
ZPO
ZMP
Modification:
Zinc phosphate hydrate
Aluminium phosph.
Basic zinc phosphate hydrate
Organic component
Molybdenum oxide
Heubach GmbH, Lars Kirmaier
Benefits of modified orthophosphates
„ Compatibility with a wide range of resin types
Increased water soluble amount resulting in a better supply of inhibitive ions
over a long time
„ pH-stabilizing effect due to basic components (Zn(OH)2)
Improved pigment structure, particle size distribution and dispersibility
„ Improved long-term protection due to an increase of the phosphate content
Adhesion promoter function of the organic component between metal
substrate and organic coating or between inorganic anticorrosive pigment
and binder (ZPO)
Heubach GmbH, Lars Kirmaier
Chemistry of phosphates
Polyphosphates
Chemistry of phosphates
Orthophosphates
Condensed phosphates
Polyphosphates
3e.g.
Metaphosphates
5-
P
P
P
2P
P
P
P
52
P
2
Orthophosphate anion
Tripolyphosphate
anion
Trimetaphosphate
anion
Basic chemical reaction
Deacidification of
orthophosphoric acid
Condensation of acidic
phosphates at high temperatures
Heubach GmbH, Lars Kirmaier
Corrosion Protection with Polyphosphates
„ Aluminium triphosphate modified with zinc-, calcium-, strontium-compounds
for controlled solubility and reactivity
„ The mechanism that prevents the corrosion appears to be deposition of
polyphosphate films on the metal surface
„ Stabilizing metal cations by chelating effect
„ Dissociation back to orthophosphates, anodic passivation
Heubach GmbH, Lars Kirmaier
WSA – Wide Spectrum Anticorrosives
Car refinish
Solvent based Alkyd
Water based modified
Acrylic
Solvent based urethane alkyd
ZAM
Water based hybride
PLUS
&
ZCP
Water based amino acrylate
Solvent based
Water based
2-part-epoxy
2-part-epoxy
PLUS
Universal anticorrosive pigments
Water based alkyd
Polyester powder
Water based 2-part-polyurethane
Solvent based 2-part-polyurethane
Heubach GmbH, Lars Kirmaier
Modified silica pigments
„ Formation of a passive layer (barrier)
„ Adsorption of corrosion stimulators
Heubach GmbH, Lars Kirmaier
Solvent based 2-part- high-solid-epoxy
Synergies
Anticorrosive pigments
Organic corrosion inhibitors e.g.
Modified orthophosphates
Zinc salt of 5-isonitrophthalic acid
Modified polyphosphates
Zinc salt of cyanuric acid
Modified orthophosphate silicates
Zinc salt of phthalic acid
Modified polyphosphate silicates
Succinic acid derivates and their
amine salts
Zinc phosphate
Metal salts of dinonylnaphthalene
Sulfonates
Calcium modified silica
Dinonyl naphthalene sulfonates
Using synergies
Heubach GmbH, Lars Kirmaier
Using synergies- Let‘s work together
What are the key features?
„
Early substrate protection resulting in increased long term
substrate protection
„
Reducing the tendency of blistering
„
Enhancement of adhesion, especially wet adhesion
Heubach GmbH, Lars Kirmaier
Challenge
Goal:
„ Equal or improve performance of chromate based pigments
„ Find universal good performance over all the different
substrates which are used for protective coatings
„ Fulfil environmental requirements of today and tomorrow
The anticorrosion multi-tool
Heubach GmbH, Lars Kirmaier
Accelerated Weathering Tests
Blistering
Adhesion
Undercutting
Field Rusting
Heubach GmbH, Lars Kirmaier
Using synergies in Coil Coating primers
Binder:
High molecular polyester (primer)
Polyester (topcoat)
DFT:
Primer 6-8 microns / Topcoat 20-24 microns
Substrate:
Zincalume pre-treated Cr-free
HDG pre-treated Cr-free
-- Excellent
Excellent corrosion
corrosion resistance
resistance
-- Flexibility
Flexibility
-- Proven
Proven track
track record
record (1.3
(1.3 billion
billion sqm
sqm pre-coated
pre-coated metal
metal is
is used
used annually
annually in
in Europe)
Europe)
-- Sustainable
Sustainable production
production
-- Strontium
Strontium chromate
chromate still
still in
in use
use
Heubach GmbH, Lars Kirmaier
T-Bend AS/NZS 2728:2007
Heubach GmbH, Lars Kirmaier
Using synergies in Coil Coating primers
1120h salt spray test acc. to DIN EN ISO 9227/ ASTM B 117-09 on zincalume
Heubach GmbH, Lars Kirmaier
Using synergies in Coil Coating primers
1120h salt spray test acc. to DIN EN ISO 9227/ ASTM B 117-09 on zincalume
Strontium chromate
Heubach GmbH, Lars Kirmaier
SRPP/CAPP 1:1
T-Bend ECCA –T8 [1996]
Heubach GmbH, Lars Kirmaier
Using synergies in Coil Coating primers
2000h salt spray test acc. to DIN EN ISO 9227/ ASTM B 117-09 on HDG
Heubach GmbH, Lars Kirmaier
Using synergies in Coil Coating primers
2000h salt spray test acc. to DIN EN ISO 9227/ ASTM B 117-09 on HDG
Strontium chromate
SRPP/CAPP 4:1
Heubach GmbH, Lars Kirmaier
Using synergies in Coil Coating primers
2000h salt spray test acc. to DIN EN ISO 9227/ ASTM B 117-09 on HDG
Strontium chromate
Heubach GmbH, Lars Kirmaier
SRPP/CAPP 4:1
Cr-free High-Solids Automotive Re-Finish Primer
Primer:
High-Solids 2K Polyurethane
Topcoat:
2K Polyurethane metallic
DFT:
Primer 60 microns /
Topcoat 80 microns
Substrate:
CRS ST 1205 according to DIN 1623
Aluminium AlMgSi
-- Excellent
Excellent corrosion
corrosion resistance
resistance
-- Adhesion
Adhesion
-- Moisture
Moisture resistance
resistance
-- Flow,
Flow, dry
dry time
time
-- Ease
Ease of
of use
use
Heubach GmbH, Lars Kirmaier
Cr-free Automotive Re-Finish Primer, Application
Primer + metallic
Topcoat
Heubach GmbH, Lars Kirmaier
Primer
only
Cr-free Automotive Re-Finish Primer
456h Salt Spray ASTM B 117-03, steel
ZPA
Control
Zinc Phosphate
Chromated phosphate
Polyphosphate
Heubach GmbH, Lars Kirmaier
Cr-free Automotive Re-Finish Primer
456h Salt Spray ASTM B 117-03, steel
ZPA
Control
Heubach GmbH, Lars Kirmaier
Zinc Phosphate
Chromated phosphate
Polyphosphate
Cr-free Automotive Re-Finish Primer
720h Salt Spray (AASS), ASTM B 117-03, steel
Control
ZPA
Zinc Phosphate
Chromated phosphate
Polyphosphate
Heubach GmbH, Lars Kirmaier
Cr-free Automotive Re-Finish Primer
2000h Salt Spray ASTM B 117-03, aluminium
ZPA
Control
Heubach GmbH, Lars Kirmaier
Zinc Phosphate
Chromated phosphate
Polyphosphate
Cr-free Automotive Re-Finish Primer
2000h Salt Spray ASTM B 117-03, aluminium
ZPA
Control
Zinc Phosphate
Chromated phosphate
Polyphosphate
Heubach GmbH, Lars Kirmaier
Cr-free Automotive Re-Finish Primer
720h Salt Spray (AASS), ASTM B 117-03, aluminium
Control
Zinc Phosphate
Heubach GmbH, Lars Kirmaier
ZPA
Chromated phosphate
Polyphosphate
Using synergies in a waterborne DTM primer
Binder:
Water reducible alkyd
PVC:
29% (pigment/filler loading)
Loading:
9% total formula weight
DFT:
65 microns
Substrate:
CRS ST 1205 according to
DIN 1623
-- For
For waterbased
waterbased industrial
industrial maintenance
maintenance primers
primers
-- Low
Low odor,
odor, high-gloss
high-gloss
-- Elasticity,
Elasticity, Hardness
Hardness
Heubach GmbH, Lars Kirmaier
Using synergies in a waterborne DTM primer
672 h Salt Spray ASTM B 117-03, steel
Control
Heubach GmbH, Lars Kirmaier
ZCP-PLUS
ZCP-PLUS/RZ (9:1)
Anticorrosive pigments in a powder primer
Binder:
Carboxylated polyester powder
DFT:
100 microns
PVC:
25%
Substrate:
Q-Panels (DC 01B)
Baking:
20’ at 180 rC
Application :
Korona
-No
-No VOC’s
VOC’s
-Less
-Less waste.
waste.
-Processing
-Processing times
times for
for powder
powder are
are generally
generally shorter
shorter than
than for
for liquid
liquid coatings.
coatings.
-Reduced
-Reduced health
health risks
risks for
for operators.
operators.
-Thermosetting
-Thermosetting powder
powder coatings
coatings often
often have
have higher
higher chemical
chemical // physical
physical resistance
resistance
Heubach GmbH, Lars Kirmaier
Anticorrosive pigments in a powder primer
2520h salt spray test acc. to DIN EN ISO 9227/ ASTM B 117-09 on steel
Control
Heubach GmbH, Lars Kirmaier
Mod. zinc phosphate
CTF
Using anticorrosive pigments in a UV primer
Binder:
100% Epoxy-Acrylate
DFT:
30 microns
Substrate:
Q-Panels (DC 01B), Sandblasted steel
UV lamp :
Mercury lamp 120W/cm
Application:
Roller Coater
Loading:
7% Total formula weight
Milling:
Triple roll mill
-- Outstanding
Outstanding adhesion
adhesion on
on metal
metal substrates
substrates
-- Fast
Fast cure
cure response
response
-- High
High hardness
hardness
-- Good
Good chemical
chemical resistance
resistance
-- Excellent
Excellent corrosion
corrosion resistance
resistance
-- Improved
Improved storage
storage stability
stability with
with acidic
acidic adhesion
adhesion promoters
promoters
Heubach GmbH, Lars Kirmaier
Target applications
„ Pipes and Tubes
„ Automotive Underhood
„ 3D metal pieces
Heubach GmbH, Lars Kirmaier
Using anticorrosive pigments in a UV primer
480h salt spray test acc. to DIN EN ISO 9227/ ASTM B 117-09 on CRS
Control
Zinc phosphate
Mod. Zinc phosphate
CTF
Heubach GmbH, Lars Kirmaier
Using anticorrosive pigments in a UV primer
1200h salt spray test acc. to DIN EN ISO 9227/ ASTM B 117-09 on HDG
Control
Heubach GmbH, Lars Kirmaier
Zinc phosphate
Mod. Zinc phosphate
CTF
Conclusions so far
„ It is possible to equal chromate performance with
non-toxic inhibitors
„ Using synergies helps to improve the overall performance
of a protective coating system
„ The performance of pigment combinations is very specific
to the substrate
Heubach GmbH, Lars Kirmaier
Conclusions so far
Future targets:
„ Learn more about synergistic effects
„ Enhance universal applicability over different substrates
„ Find the multi-tool of corrosion protection
Heubach GmbH, Lars Kirmaier