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Surface Coatings International

, Volume 81, Issue 2, pp 72–76 | Cite as

An epoxy novolac emulsion system for ambient cure protective coatings

  • DH Klein
  • KC. Jörg
Feature: Resins

Conclusions

Water-borne two-pack coatings based on a novel low particle size epoxy novolac emulsion, crosslinked with polycycloaliphatic polyamine provide a good balance of several properties. Because the films cured possess a high crosslink density of cross linkage, expectations such as rapid through film drying time, high hardness development at an early stage during cure, very good film formation at 10°C and 80% R.H., and chemical resistance can be met.

However, there are also adverse aspects to consider regarding the combination of a water-insoluble hydrophobic polyamine and a modified epoxy novolac emulsion. eg no visible end of pot life, relative short pot life and a brittleness of coatings associated with a tendency to peeling when exposed to salt spray and humid conditions.

The study also revealed that the quality of a cured two-component epoxy binder emulsion system depends to a great extent on the quality of the emulsion, particularly on the size and distribution of the droplets. A low particle size epoxy emulsion improves the film formation, drying time, water resistance, gloss, adhesion and hardness. For this purpose epoxy emulsions with a narrow particle size distribution and relatively low particle size (mean value ca. 0.4 µm) can be developed using a proprietary mechanical emulsion process.

The aqueous coating system described may be useful for applications where conventional epoxy novolacs are already used as low temperature heat cure coatings like drill pipe coatings, oil pipelines and fuel storage tanks and in fields where their chemical, water and solvent resistance can be utilised.

Further ambient cure applications may be protective coatings for indoor use, eg food factories, schools, hospitals and office buildings, industrial maintenance coatings for concrete, mortar, bricks, plaster and wood.

Keywords

Epoxy Benzyl Alcohol Salt Spray Narrow Particle Size Distribution High Crosslink Density 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Klein DH: ‘Cold curing epoxy systems for protection against heavy corrosion’,European Polymers, Paint, Colour Journal,181, 174, 1991.Google Scholar
  2. 2.
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  3. 3.
    Klein DH, Jörg K: ‘Two Component Aqueous Epoxy Binders Free of VOC’, 22nd International Conference in Organic Coatings, Athens, Greece, 203, July 1–5, 1996.Google Scholar
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    Technical Information: “Ancamine 2280 and Ancamine 2320 Curing Agents:, Air Products (UK) Ltd., Clayton, Manchester, UK.Google Scholar
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    Liu TY, The Valspar Corporation: ‘The Impact of VOC Regulations on Corrosion Protective Coatings in the 90s’, Corrosion 90 Soc. Meeting, Las Vegas, Paper No. 471, April 23–27, 1990.Google Scholar
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    Klein DH, ‘Formulating Water-Emulsifiable Epoxy Resins’, Congresso International de Tintas, Sao Paulo, Brasil, September 8–10, 1993, Volume 1.Google Scholar
  7. 7.
    Piechocki Ch: ‘Modified Polyoxyethylene Epoxy Resin Amphiphiles and stable Aqueous Dispersions thereof’, WO91/10695, 25th July 1991, Dow Chemical Co.Google Scholar

Copyright information

© OCCA 1998

Authors and Affiliations

  • DH Klein
    • 1
  • KC. Jörg
    • 1
  1. 1.Epoxy Products DepartmentDow Deutschland Inc, Werk RheinmünsterRheinmünsterGermany

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