Transcript Marine and Protective Coatings

NEO Chemical Seminar 2007
Marine Coatings &
Protective Coatings.
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Marine & Protective Coatings
Main function of epoxy coatings is to
protect steel structures against
corrosion and against chemicals
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Marine and Offshore
Industrial Steel Structures
Industrial Maintenance
Tanks
Transportation
– Railcars
– Large vehicles
– Sea containers [China]
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Key Market Segments in Europe
Pulp and paper
3%
Food & beverage plants
8%
Others
7%
Marine
30%
Water and sew age
7%
Bridges & infrastructure
13%
Oil & gas production &
transmission
11%
Public Utilities
11%
Petrochemical plants
10%
Source: SRI Consulting
Worldwide consumption of anticorrosion coatings estimated at
ca. 1.1 Millions MT, with a value of ca. $ 5 Billions in 2001.
M&PC coatings represent 4% of the global coatings volume,
but 8-9% of the total value.
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Marine Coatings
Ballast tanks
The role of epoxy coatings is to protect against corrosion each part of
ships, which are continuously exposed to severe conditions, i.e. sea
water immersion, splashes of sea water, UV rays
– maintain the value of the assets
– ensure vessel safety
– protect cargoes, e.g. grain or liquids
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Marine sub-segments
– Water ballast tanks
– Under water hulls and sides
– Cargo tank linings
Key Performances
requirements
Resistance to corrosion
– Cargo holds
Chemical resistance
– Boot-topping and splash
zones
Mechanical resistance, e.g.
abrasion
– Topsides and external
superstructures
Weatherability
– Offshore oil drilling
platforms
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Typical Protective Coatings Markets
Oil & Gas
Chemical
Processing
Power
Generation
Pulp & Paper
Mining & Metals
Bridges & Infrastructure
Pictures downloaded from Akzo Nobel Coatings’ web-site
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Non-generic Competition
Consumption of High-Performance Anticorrosion
Coatings by Resin Type in Europe
2%
3%
10%
5%
2%
45%
Epoxy
Urethane
(aliphatic)
Urethane
(aromatic)
Inorganic Zinc
Vinyl
Acrylic
6%
7%
Chlorinated
Rubber
Alkyd
20%
Source: SRI report 2001
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Epoxy Resins are essential raw materials for Marine &
Protective Coatings.
Epoxy systems offer an outstanding balance between
performances [durable corrosion protection] and costs.
Toine Dinnissen / March 28th 2007
Other
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NEO Chemical Seminar 2007
Desired Properties of M&PC Coatings
Each end-use requires an optimum balance
between:
– Ambient application window
– Ease of applying [ spray, brush, roll ]
– Solids content, VOC content
– Film thickness
– Drying time
– Sufficient hardness / flexibility
– Edge covering
– Impact resistance
– Overcoating time window,
– Long term corrosion protection
– Long term adhesion, adhesion in wet
environment
e.g. in water immersion conditions
– Resistance against chemicals { acids,
solvents, caustic,… }
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Properties of ambient cured epoxy coatings
• Chemical cure
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2 pack systems
Limited pot life
Excellent adhesion on many substrates
Excellent corrosion protection
Superior resistance to water, chemicals, solvents & oil
Extremely resistant to mechanical stress
• Good surface preparation required
• Curing rate depends upon temperature.
• Chalking when exposed to sun light
• Over coat-ability limitations
Minimum & maximum intervals between layers to be respected
• Cathodic disbondment resistance required in some applications
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Main Dow resins employed in M&PC
• Bisphenol A epoxy resins & solutions
– D.E.R.™ 331™
– D.E.R. 337X80
– D.E.R. 660X80
– D.E.R. 671
– D.E.R. 671X75
– D.E.R. 671XB70
• Bisphenol F epoxy resin
– D.E.R. 354
• Epoxy novolac resins
– D.E.N.™ 425
Best chemical
– D.E.N. 431
resistance
– D.E.N. 438X80
}
Toine Dinnissen / March 28th 2007
Trend towards Liquid Epoxy Resins
and Semi-Solid Epoxy Resins
expected in Europe due to more
stringent VOC regulations
™ Trademark of the Dow Chemical Company
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NEO Chemical Seminar 2007
Schematic epoxy coatings formulation
2- Pack Solvent Borne Systems
Component A
Component B
Epoxy Resin(s)
Pigments & Extenders
Solvents
Additives
Curing Agent(s)
Pigments & Extenders
Solvents
Additives
Accurate Mix ratio.
Thorough mix prior to use.
Pot-life of 1 - 8 hours.
(Pot life depends on temperature, quantity, type of resin
and hardener)
Modifiers e.g. hydrocarbon resins or reactive diluents can
be used
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Typical curing agents used in M&PC
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Curing agents [mostly based on amine chemistry].
Polyamidoamines [VersamideTM type]
Amidoamines
Epoxy - Amine adducts
Mannich bases [Faster cure]
Phenalkamines [Low temperature cure]
Typical accelerators
Tertiary amines e.g. AncamineTM K54 type
Alkyl phenols
Remarks:
Induction time needed with some curing agents to overcome the
limited compatibility with epoxies and to minimize the “blushing
effect”.
Curing agents frequently used at under-stoichiometric levels to
minimize blushing [typical NH / epoxy stoichiometry = 80%]
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Example of Anticorrosion Coating System
• Top Coat:
• Mid Coat:
• Primer:
Appearance & Protection against UV-light
Barrier Protection effect. Intercoat
adhesion
Corrosion protection & Adhesion
ca 400 µm
Epoxy, PU, Alkyd, Acrylate
Topcoat; 150 µm
Epoxy
Mid coat; 150 µm
Epoxy
Primer; 70 µm
Metal Substrate
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Examples of commercial coatings systems (1)
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Epoxy zinc primer
Epoxy primer
Epoxy tie coat
Epoxy top coat
or weatherable PUR
• Epoxy zinc primer
• Epoxy aluminium primer
• Epoxy top coat
Toine Dinnissen / March 28th 2007
30 µ
50 µ
100 µ
50 µ
}
30 µ
300 µ
300 µ
Steel protection
}
Superior
steel protection,
e.g. off shore
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NEO Chemical Seminar 2007
Typical Epoxy Polyamide Primer Formulation.
(Red oxide & Zinc Phosphate)
Epoxy resin component
• D.E.R.™ 671X75 Epoxy Resin Solution
• Pigment grinding additive
• Zinc Phosphate
• Silica Powder
• Iron Oxide Red
• China Clay
• Fumed silica thickener
• Xylene
• n-Butanol
Curing agent component:
• Versamide ® 115/70X
Or similar polyamido-polyamine hardener
Toine Dinnissen / March 28th 2007
Parts by weight
18.7
0.5
10
5
20
5
1
17
7
10.6
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NEO Chemical Seminar 2007
Typical Properties of type 1 epoxy resin /
polyamide formulation.
• Pot-life:
• Coverage:
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min 8 hours
6 - 7 m2 per liter @ 100 µm
thickness
Surface hardness:
300 s Persoz Pendulum
Erichsen Flexibility:
min 7 mm
Salt Spray Test:
min 1000 hours
Low Temperature Cure:
10 °C
Adhesion to all kinds of substrates
Note:
Properties strongly depend on the surface
preparation
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Pot life @
20°C, hours
8 Hrs
Interdependency between Pot life, Drying Times and VOC
High VOC
[D.E.R. 671]
Low VOC,
<250 g / litre
1 Hr
Solvent
free
8 Hrs
16 Hrs
24 Hrs
48 Hrs
Low VOC or VOC free epoxy systems exhibit a poorer balance
between drying time and pot life than high VOC systems.
Toine Dinnissen / March 28th 2007
Drying times
(full dry)
hours at low
temperature
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NEO Chemical Seminar 2007
Drying times and pot life - Additional comments
• The coatings are often stored in a heated warehouse to prevent
addition of solvent to adjust the viscosity to spray viscosity.
• The epoxy – amine reaction is exothermic
Increase of the pot temperature after mixing of the 2
components
• Coatings drying time dominated by the temperature of the
substrate and by the degree of ventilation.
 Faster reaction kinetics in the pot than in applied paint film,
especially in winter time.
• Generally lower viscosity epoxies have a lower EEW (a higher
oxirane content)
 Higher levels of hardener needed or hardeners with higher
NH content needed.
 High solids / solvent free coatings have a higher
concentration of reactive groups in the mixed paint, which
goes against pot-life.
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Surface preparation
• The removal of
rust
salt
mill scale
weld spatter
grease & oil
dirt
old paint depending upon quality
and rounding of sharp edges
are critical to achieve optimum performances of epoxy
coatings
• Surface preparation is labour intensive and represents a
significant part of total costs of the coating process.
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Surface preparation techniques
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Blast cleaning
Hydro jetting
Mechanical wire brushing
Manual brushing
Ideal
Poor
• Note:
Hydro jetting is increasingly popular.
But it poses some specific problems
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Surface preparation rating
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SA 1
SA 2
SA 2 1/2
SA 3
• St 2
• St 3
Light blast cleaning
Thorough blast cleaning
Very thorough blast cleaning
Blast cleaning to visually clean
Thorough manual cleaning
Very thorough manual cleaning
Optimum coatings performances achieved with SA 2 1/2
cleaning.
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Typical cost structure of a Paint Job
[ Euros / m2 / 150 µm ]
( Brevoort Consultancy )
• Surface Cleaning
– Hand cleaning
– SA 2.5 blasting
– SA 3 Near White blasting
• Application
– Brush / Roller
– Spray
• Coating
– Alkyd
– Epoxy
4.6
8.0
9.2
2.1
2.6
1.6
1.9
Cost of coating is less than 20 % of total cost of painting job
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Estimated Service Lives of High-Performance
Anticorrosion Coatings (years)
Coating System
Water-Based Acrylic Primer/Topcoat
Epoxy Primer/High-Build Epoxy Topcoat
High-Build Epoxy Primer/High-Build Epoxy
Topcoat
Epoxy Waterborne
High-Build Epoxy Primer/Acrylic Urethane
Topcoat
Inorganic Zinc/Epoxy Mastic/Polyester
Urethane Topcoat
Inorganic Zinc/Epoxy Mastic/Acrylic
Urethane Topcoat
Inorganic Zinc Primer/Waterborne Acrylic
Topcoat
Salt Water
Immersion
na
6
Mildly
Corrosive
Environment
16.5
18
Moderately
Corrosive
Environment
12
12
Severely
Corrosive
Environment
9
9
7.5
19.5
13.5
10.5
na
18
12
9
na
16.5
10.5
7.5
na
31.5
22.5
16.5
na
30
21
15
na
24
16.5
12
Source: GH Brevoort et al
Epoxy based anticorrosive coatings provide long lasting service
life and corrosion protection
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Single feed Airless pump & spray gun
Typical pressure:
ca 250 Bars.
No pressurized airflow.
High fluid pressures force
the coating through a
small orifice
 Atomization
Minimum pot-life: 45 min
(time to spray 25 liters of
mixed paint)
Otherwise risk of gelation
in the pumps, hoses and
spray guns
Twin feed airless technology exists but is not
widely accepted, because of cost, less userfriendliness and lower robustness
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Technology Trends & Some unmet needs
• Higher solids coatings
• Solvent-free coatings
• Water borne coatings
}
VOC
reduction
• Faster cure
• Low temperature cure
to extend application window
• Surface tolerant coatings
to reduce surface preparation costs
• Improved overcoatability window
Productivity
gains
• Flexible Epoxy Resins
• Improved balance between drying time
and pot-life
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Epoxy Resins in Marine & Protective Coatings
Epoxy Resins are essential raw materials for these
high demanding coatings segments, thanks to the
outstanding benefits they provide :
– Corrosion protection
– Chemical resistance
– Mechanical properties, e.g. adhesion
– Low VOC levels achievable
Marine & Protective Coatings, a large and growing
market for epoxy resins
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
End of the Marine & Protective Coatings Part
Any questions I could possibly
answer on M&PC applications
?
Further Technical as well as Product Stewardship related information can be found
on www.Dowepoxy.com.
e.g.
Dow Epoxy Products Portfolio incl. Corresponding technical datasheets,
Dow Liquid Epoxy Resin Brochure
Dow Epoxy Novolac Brochure
Dow Epoxy Resin Product Stewardship Manual
Dow Epoxy Curing Agents Product Stewardship Manual
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Solvents
Role of solvents: Reduce the viscosity and aid the film formation
Types of solvents
• Aromatics, ketones, glycol-ethers, acetates … are suitable.
• Limitations with aliphatic alcohol's which must be used in
combination with better solvents.
• Aliphatic solvents are unsuitable with standard epoxy resins
Key parameters
• Solvency Power
• Hansen Solubility Parameters / Compatibility
• Evaporation profile
• Flash-point
• Solvent retention effect
• Influence on reactivity and pot-life
• Smell
• EH&S properties
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Pigments & Fillers
• Opacity and colour
– Titanium dioxide
– Iron oxides
– Organic pigments
• Anticorrosion
– Zinc dust
– Zinc phosphates
– Borates
– Whole range of new
environment friendly
anticorrosive pigments
Toine Dinnissen / March 28th 2007
• Extenders
– Barium sulphates
– Talc
– Silica
– Calcium carbonates
• Barrier
– Aluminium flakes
– Miox
– Mica
– Micaceous iron oxide
• Abrasion resistance
– Glass flakes
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NEO Chemical Seminar 2007
Additives
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Accelerators
Sagging control / Rheology modifiers
Wetting agents
Pigment and extender anti-settling additives
Film Flow additives
Craters, Orange Peel, Benard Cells
Foaming / Air release
Surface Tension
0.1 % of additive can significantly change the
performances
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Typical Wt Composition of D.E.R. 671X75 based coatings
Epoxy
Solvents
47%
7%
Additives
1%
Pigments
Extenders
21%
8%
Curing
agent
16%
Typical VOC content: 300 – 350 g / liter
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Typical Wt Composition of low VOC epoxy coatings
Epoxy
Solvents
50%
Additives
Pigments
Extenders
8%
1%
9%
15%
Curing
agent
17%
Typical VOC content: 200 – 250g / liter
Low VOC coatings are based on liquid epoxy resins or on
low viscous semi-solid epoxy resins
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Types of epoxy coatings
• Shop primers
– Zinc rich primers
• Epoxy primers
– Zinc phosphate primer
• Glass flakes reinforced
coatings.
• Tie coats
• Putty / Caulking
• Transparent varnishes
• Winter grades
• Etc…..
Toine Dinnissen / March 28th 2007
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Solvent borne
High solids
Solvent free
Water Borne
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NEO Chemical Seminar 2007
Examples of commercial coatings systems (2)
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Zinc silicate
Epoxy tie coat
High built epoxy coat
Weatherable PUR
• Epoxy primer
• Epoxy mineral flakes coat
Toine Dinnissen / March 28th 2007
70 µ
50 µ
200 µ
50 µ
}
30 µ
300 µ
}
Steel protection,
e.g. off shore,
above splash zone
Interior tank
lining
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NEO Chemical Seminar 2007
Typical Composition of High Solids Epoxy Primer
Epoxy Resin Component
• D.E.R.™331™ Epoxy Resin
• Pigment grinding additive
• Iron Oxide Red
• Barium sulphate filler
• Mica filler
• Fumed silica thickener
• Xylene
• Butanol
Curing Agent Component
• Ancamine® 2253 [Polyamide type]
Parts by weight
21
0.5
10
20
20
2
10
5
12
Note: Hydrocarbon resins [e.g. Necires grades] often employed as
co-binders to reduce the brittleness of “pure” high solids
epoxy coatings.
Toine Dinnissen / March 28th 2007
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NEO Chemical Seminar 2007
Drying time versus temperature of commercial coatings
40
Drying time Hours
35
100% solids
30
68 % Solids
25
82% Solids
20
15
10
60 % Solids
5
0
-10
-5
0
5
10
15
20
25
30
35
40
Temperature, °C
Drying time of epoxy coatings severely affected by temperature
Drying time strongly influenced by solids content
Note: More reactive curing agents generally employed in winter systems
Toine Dinnissen / March 28th 2007
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