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Marine Coatings & Protective Coatings.

Marine Coatings & Protective Coatings. Marine & Protective Coatings. Main function of epoxy coatings is to protect steel structures against corrosion and against chemicals Marine and Offshore Industrial Steel Structures Industrial Maintenance Tanks Transportation Railcars

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Marine Coatings & Protective Coatings.

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  1. Marine Coatings & Protective Coatings.

  2. Marine & Protective Coatings Main function of epoxy coatings is to protect steel structures against corrosion and against chemicals • Marine and Offshore • Industrial Steel Structures • Industrial Maintenance • Tanks • Transportation • Railcars • Large vehicles • Sea containers [China]

  3. Key Market Segments in Europe Source: SRI Consulting Worldwide consumption of anticorrosion coatings estimated atca. 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.

  4. 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

  5. Marine sub-segments Key Performances requirements Resistance to corrosion Chemical resistance Mechanical resistance, e.g. abrasion Weatherability • Water ballast tanks • Under water hulls and sides • Cargo tank linings • Cargo holds • Boot-topping and splash zones • Topsides and external superstructures • Offshore oil drilling platforms

  6. Oil & Gas Chemical Processing Power Generation Pulp & Paper Mining & Metals Bridges & Infrastructure Typical Protective Coatings Markets Pictures downloaded from Akzo Nobel Coatings’ web-site

  7. Non-generic Competition Source: SRI report 2001 • Epoxy Resins are essential raw materials for Marine & Protective Coatings. • Epoxy systems offer an outstanding balance between performances [durable corrosion protection] and costs.

  8. 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 environmente.g. in water immersion conditions • Resistance against chemicals { acids, solvents, caustic,… }

  9. Properties of ambient cured epoxy coatings • Chemical cure 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

  10. 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 • D.E.N. 431 • D.E.N. 438X80 } Trend towards Liquid Epoxy Resins and Semi-Solid Epoxy Resins expected in Europe due to more stringent VOC regulations Best chemicalresistance ™ Trademark of the Dow Chemical Company

  11. Schematic epoxy coatings formulation 2- Pack Solvent Borne Systems Component AComponent B Epoxy Resin(s) Curing Agent(s) Pigments & Extenders Pigments & Extenders Solvents Solvents Additives AdditivesAccurate 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

  12. Typical curing agents used in M&PC 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%]

  13. Example of Anticorrosion Coating System • Top Coat: Appearance & Protection against UV-light • Mid Coat: Barrier Protection effect. Intercoat adhesion • Primer: Corrosion protection & Adhesion ca 400 µm Epoxy, PU, Alkyd, Acrylate Topcoat; 150 µm Epoxy Mid coat; 150 µm Epoxy Primer; 70 µm Metal Substrate

  14. Examples of commercial coatings systems (1) } • Epoxy zinc primer 30 µ • Epoxy primer 50 µ • Epoxy tie coat 100 µ • Epoxy top coat 50 µor weatherable PUR • Epoxy zinc primer 30 µ • Epoxy aluminium primer 300 µ • Epoxy top coat 300 µ Steel protection } Superior steel protection, e.g. off shore

  15. Typical Epoxy Polyamide Primer Formulation. (Red oxide & Zinc Phosphate) Epoxy resin component Parts by weight • D.E.R.™ 671X75 Epoxy Resin Solution 18.7 • Pigment grinding additive 0.5 • Zinc Phosphate 10 • Silica Powder 5 • Iron Oxide Red 20 • China Clay 5 • Fumed silica thickener 1 • Xylene 17 • n-Butanol 7 Curing agent component: • Versamide ® 115/70X 10.6Or similar polyamido-polyamine hardener

  16. Typical Properties of type 1 epoxy resin / polyamide formulation. • Pot-life: min 8 hours • Coverage: 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

  17. Interdependency between Pot life, Drying Times and VOC Pot life @ 20°C, hours 8 Hrs High VOC [D.E.R. 671] Low VOC, <250 g / litre 1 Hr Solvent free Drying times (full dry) hours at low temperature 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.

  18. 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.

  19. Surface preparation • The removal of rustsaltmill scaleweld spattergrease & oildirtold 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.

  20. Surface preparation techniques • Blast cleaning Ideal • Hydro jetting • Mechanical wire brushing • Manual brushing Poor • Note: Hydro jetting is increasingly popular. But it poses some specific problems

  21. Surface preparation rating • SA 1 Light blast cleaning • SA 2 Thorough blast cleaning • SA 2 1/2 Very thorough blast cleaning • SA 3 Blast cleaning to visually clean • St 2 Thorough manual cleaning • St 3 Very thorough manual cleaning Optimum coatings performances achieved with SA 2 1/2 cleaning.

  22. Typical cost structure of a Paint Job[ Euros / m2 / 150 µm ]( Brevoort Consultancy ) • Surface Cleaning • Hand cleaning 4.6 • SA 2.5 blasting 8.0 • SA 3 Near White blasting 9.2 • Application • Brush / Roller 2.1 • Spray 2.6 • Coating • Alkyd 1.6 • Epoxy 1.9 Cost of coating is less than 20 % of total cost of painting job

  23. Estimated Service Lives of High-Performance Anticorrosion Coatings (years) Source: GH Brevoort et al Epoxy based anticorrosive coatings provide long lasting service life and corrosion protection

  24. 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 user-friendliness and lower robustness

  25. Technology Trends & Some unmet needs } • Higher solids coatings • Solvent-free coatings • Water borne coatings • Faster cure • Low temperature cureto extend application window • Surface tolerant coatingsto reduce surface preparation costs • Improved overcoatability window • Flexible Epoxy Resins • Improved balance between drying time and pot-life VOC reduction } Productivity gains

  26. 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

  27. 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

  28. 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

  29. Opacity and colour Titanium dioxide Iron oxides Organic pigments Anticorrosion Zinc dust Zinc phosphates Borates Whole range of new environment friendly anticorrosive pigments Extenders Barium sulphates Talc Silica Calcium carbonates Barrier Aluminium flakes Miox Mica Micaceous iron oxide Abrasion resistance Glass flakes Pigments & Fillers

  30. Additives • 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 Tension0.1 % of additive can significantly change the performances

  31. Typical Wt Composition of D.E.R. 671X75 based coatings Typical VOC content: 300 – 350 g / liter

  32. Typical Wt Composition of low VOC epoxy coatings Typical VOC content: 200 – 250g / literLow VOC coatings are based on liquid epoxy resins or on low viscous semi-solid epoxy resins

  33. 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….. • Solvent borne • High solids • Solvent free • Water Borne

  34. Examples of commercial coatings systems (2) } • Zinc silicate 70 µ • Epoxy tie coat 50 µ • High built epoxy coat 200 µ • Weatherable PUR 50 µ • Epoxy primer 30 µ • Epoxy mineral flakes coat 300 µ Steel protection, e.g. off shore, above splash zone } Interior tank lining

  35. Typical Composition of High Solids Epoxy Primer Epoxy Resin Component Parts by weight • D.E.R.™331™ Epoxy Resin 21 • Pigment grinding additive 0.5 • Iron Oxide Red 10 • Barium sulphate filler 20 • Mica filler 20 • Fumed silica thickener 2 • Xylene 10 • Butanol 5 Curing Agent Component • Ancamine® 2253 [Polyamide type] 12 Note: Hydrocarbon resins [e.g. Necires grades] often employed as co-binders to reduce the brittleness of “pure” high solids epoxy coatings.

  36. Drying time versus temperature of commercial coatings Drying time of epoxy coatings severely affected by temperatureDrying time strongly influenced by solids content Note: More reactive curing agents generally employed in winter systems

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