Rust-free and long-lasting by functional coatings S. Goedicke, F. Groß, G. Frenzer, S. Sepeur NANO-X GmbH Automotive Coatings Protective Coatings September 13th Düsseldorf
Rust-free and long-lasting by functional coatings
S. Goedicke, F. Groß, G. Frenzer, S. Sepeur NANO-X GmbH
Automotive Coatings Berlin Nov. 25th 2011
Protective Coatings September 13th Düsseldorf
Overview Protective Coatings
Sol-Gel-Process or SiliXan®
Binder Use of transparent
binder solution
Coating formulation with functional pigments, particles, fillers etc.
The sol-gel process
Si
R
OR OR RO
Hydrolysis
+ H2O Si
R
HO
HO
Si
R
OH
OH
O - H2O
Condensation
Si
R
OH OH HO
nano condensates in solution
Further crosslinking after application to substrate
Evaporation of solvent and final crosslinking
- Si-O-Si = glass-like inorganic network
- R = OH or functional group
The sol-gel process
- Modification of nano particles, different function depending on type of particle, e.g. SiO2, TiO2, Al2O3, AlO(OH), CeO2, ZnO, ZrO2, Fe2O3
Example SiO2: Glass-like inorganic matrix and structuring by electrostatically stabilized nano particles
- Moiety R = Network modifier, e.g. methyl, propyl, phenyl, dimethyl... Flexibilisation of the inorganic network by targeted integration of „defects“.
- Moiety R = Network creator, organic moieties with functional groups such as epoxy, methacryl, isocyanato, amino... Creation of an additional organic network
Me
Me
Me
Me
O
O
O
Me
Me
O
Me
O
OH
HO HO
R Si
OH
OH
O
O
Stable Sol-Gel-Matrices Binders and their properties
Modification
Solubility Alcohols, glycol ether, esters, ketones
Alcohols, esters, ketones Water, alcohols
Stabilization Dilution Precipitation
Precipitation* Dilution, Additives (e.g. pigments)
Properties Glass-like, brittle, heat resistant
Scratch resistant, flexible Good adhesion on metals
Application Temperature-resistant coatings
Scratch resistant UV coatings
Corrosion protection
Sol-gel materials with shelf life between several months up to more than two years are obtained due to optimized production procedures *Worldwide patent WO 2002050191
CH3 O
O
O O
Binders and curing mechanism
• Lewis acids (AlOH, ZrOH …)
Activation temperature RT-80°C
• Acids / bases
Activation temperature: > 100°C
Innovation: Direct water-free curing of high-molecular silanes is possible
x
C
H
H
SiRO
RO
N C
O
O
y
C
H
H
x
C
H
H
NC
O
O ORSi
OR
OR
H HRO
x
C
H
H
SiRO
RO
N C
O
O
y
C
H
H
x
C
H
H
NC
O
O ORSi
OR
OR
H HRO
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
SiO2
Resins and catalysts available from:
x-protect® products
Product overview Corrosion protection for stainless steel,
aluminium, zinc galvanized steel
Coil coating for aluminium
- Anticorrosion coating for aluminium and highly polished aluminium - Coil coating application, PMT 200 - 250˚C, 1 min - Good adhesion without pretreatment - High transparency - Very good corrosion protection - Flexible, suitable for forming and punching
Aluminium after 1000 h salt spray test
coated uncoated
High transparent corrosion protection
Chemical resistant coatings
Protection for anodized aluminium
Anodized aluminium part coated with 5 µm transparent x-protect® coating after dipping in acidic (pH 1) and alkaline (pH 13.5) solution 15 min each at 40˚C, against uncoated reference
- Solvent and water based coatings based on sol-gel and SiliXan® binders - Spray or dip coating - Thermal curing at 130˚C - Good optical appearance - Abrasion resistant - Resistant against acidic (pH < 1) and alkaline cleaners (pH > 13)
Metallsubstrat
Unsichtbare Belegung vonMetalloberflächendurch Nanopartikel
Keine Anlaufspurendurch Fingerprints
No tarnish by fingerprints
Invisible layer of nanoparticles metal substrate
Antifingerprint coating For brushed stainless steel
• Strong reduction of the visibility of fingerprints
• Prevention of the blue tarnishing of the stainless surface (corrosion/oxidation by salts and organic acids from finger sweat)
• Easy and remainderless removal of the fingerprints with a dry cloth
• Suited for structured surfaces (e.g. brushed), unsuited for high polished surfaces
• Very thin transparent coating (0.5 – 4.0 µ)
• High abrasion resistance
• Good chemical resistance
• Conservation of the metal appearance
Reference Reference for spray coating
Spray cabinet with 4 spraying guns
Stainless steel dishwasher panels
InoxPlus®
Stainless steel outdoor lamps
Sanitary equipment
• Blanking, cutting, lasing
• Forming by bending, deep-drawing or rolling
• Joining technology: Welding, brazing, gluing
• Finishing by brushing, grinding or polishing
Requirements for Coil Coating Coilcoating
Household appliances
Exhaust hood
Washing machine
Oven Source: BSH
Forming and welding of stainless steel
Cross Cut Test
Crockmeter Test
Protection of stainless steel
Anti tarnish coatings
VP CA 1499 on stainless steel 1.4301 (AISI 304)
Stainless steel after 1h at 600˚C
• High temperature resistant coating for stainless steel
• Protection against tarnish (discoloration) at temperatures up to 600 °C
• Transparent → almost unaltered high-gloss appearance of stainless steel
• Application via dip-coating or spray-coating
Flexibility of Coating
After metal forming
Forming tool
Heat treatment 1h at 500°C after forming
Result: • Good layer adhesion after forming process • Very good tarnish protection also after forming
Tarnish Protection Properties
Protection of zinc and zinc-nickel galvanized steel and cast iron parts
Sealing for Zn and ZnNi
ZnNi galvanized steel sheet with 2 µm sol-gel coating after 720 h neutral salt spray test (DIN EN ISO 9227) against uncoated reference
- Water-based sealings for Zn and ZnNi galvanized parts - Spray or dip coating - Curing at 130˚C - Resistant against acidic (pH < 1) and alkaline cleaners (pH > 13)
Product overview x-tec® and x-tec® eco
Active corrosion protection for steel and cast iron
Titanid Active Corrosion Protection
Metal particles with Nano-TiOx passivation
SEM cross section of TiOx-modified Al-particles, TiOx layer thickness approx. 100 – 200 nm
Al
TiOx
5 µm
Titanid principle Passivation of discrete metal pigments without loss of electric conductivity Combination of aluminium, magnesium or zinc pigments possible Nano TiOx coating on the pigment Cathodic corrosion protection for steel and significant reduction of white rust formation
Titanid (Zn) on 22MnB5 steel compared to uncoated steel sheet and zinc-galvanized steel sheet with same coating thickness after salt spray test SST (ISO 9227)
Uncoated (22MnB5)
Electrogalvanized (7 µm Zn) on steel
NXACP-Zn coating (22MnB5) in 7 µm
1000 h salt spray 125 h SST > 1.000 h SST
Potential measurement of TITANID (Zn) on 22MnB5 in 3% NaCl solution
-0,9
-0,8
-0,7
-0,6
-0,5
-0,4
-0,3
-0,2
-0,1
0
0 20 40 60 80 100
t [h]
E [V
]
t [h]
E [V
]
Constant potential of -0.8 V
- No corrosion on steel sheet after > 1.000 h salt spray test - Considerably less „white rust“ as compared to electrogalvanized or HDG - Electrochemical potential of -0.8 V proves cathodic corrosion protection
Titanid Active Corrosion Protection
Titanid Active Corrosion Protection
• First Titanid serial product commercially available since September 2009 • MULTI ZINC from Würth (www.wuerth.com), new product name PROMAX • Room temperature curing zinc aerosol spray with cathodic corrosion protection • More than 500 h salt spray test with 15-20 µm coating thickness, worldwide unique performance • Bright silvery appearance
NXACP-Zn
Ideas for applications
Further applications
Corrosion protection for offshore wind power stations, industrial tubes, small parts like screws and bolts, cast iron parts, ...
Water-based formulation x-tec® eco Tailoring of sol-gel binders for anti corrosion coatings
Tailoring of binders with links to - inorganic or metallic substrates - fillers or functional particles, e.g. metals
Si
R
OR OR RO
Hydrolysis
+ H2O Si
R
OH OH HO
Si
R
HO Si
R
OH
OH
O - H2O
condensation
O surface modification
HO
Organic crosslinking
Inorganic condensation
Structuring by SiO2-particles
SiO2
-> Development of a water based sol-gel binder - With good anticorrosion properties - With low curing temperature - Suitable for bonding of metal pigments
Coating Formulation Basic optimization
Formulation of coating materials consisting of a water based binder, zinc and aluminium pigments and additives Optimization of - Appearance - Low curing temperature - Corrosion protection - Processability - Pot life -> Products x-tec® eco 4042 and x-tec® eco 4047
x-tec® eco on brake discs Coating of different types of brake discs
High-grade appearance and homogeneous coating thickness by automatic spray coating process
Cast iron brake disc coated with x-tec® eco 4042
Alternative brake disc types, lightweight construction disc partly coated
Corrosion test Neutral salt spray test (NSS) according to DIN EN ISO 9227
- No red rust after 120 h salt spray test - Up to > 400 h salt spray test possible on brake disc, more than 1000 h on steel sheet - “Absolute” resistance against rim cleaners by use of additional topcoat x-tec® eco top !
- After 120 h NSS test After 300 h NSS test
x-tec® eco black is a water based anticorrosion coating for brake discs with an attractive anthracite appearance. Properties: •Curing temperature: Roomtemp. -250˚C (RT-482˚F) • Temperature resistance: > 300˚C (482˚F) • Coating thickness: 5 – 30 µm • Salt spray test (DIN EN ISO 9227): up to 500 h (depending on geometry and coating thickness) • Application: Preferably spray coating. Dip and flow coating possible. • Free from chromium • Suitable for all functional surface areas including friction ring and flange
x-tec® eco black
Zinc flake, water based, black
x-tec® eco black
x-tec® eco black after 480 h salt spray test on cast iron part
480 h
Salt spray test DIN EN ISO 9227, 5% NaCl solution, 35°C
Linear taber with CS 17 friction pad, 550g load
x-tec® eco black on cast iron, after 200 double strokes
x-tec® eco black
Example of use – Cast iron tubes
State of the art anticorrosion coatings for pipelines: -2K polyurethane coating, 2-3 mm thickness -Epoxy coating 300..500 µm thickness -two or three layer systems - No black water based active corrosion protection available before x-tec® eco black
NANO-X GmbH Theodor-Heuss-Str. 11a 66130 Saarbrücken GERMANY Phone +49 (0)681-95940-0 Fax +49 (0)681-95940-15 E-Mail [email protected] Web www.nano-x.de Contact: Dr. Stefan Goedicke Phone +49 (0)681-95940-21 E-Mail [email protected]
NANO-X GmbH Saarbrücken
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