Advertisement

Journal of Coatings Technology

, Volume 72, Issue 911, pp 51–60 | Cite as

UV curing of aqueous polyurethane acrylate dispersions. A comparative study by real-time FTIR spectroscopy and pilot scale curing

  • Armin Tauber
  • Tom Scherzer
  • Reiner Mehnert
Article

Abstract

Real-time FTIR spectroscopy was used to study the chemical and physical factors, e.g., photoinitiator and temperature, affecting the UV curing of dried films from aqueous polyurethane acrylate dispersions. Poor conversion of the acrylate double bonds (67%) observed at room temperature can be overcome by irradiation at elevated temperatures. At 353 K almost complete conversion is observed, even with reduced photoinitiator content. Single or multiple UV-light flash experiments were performed to simulate technical parameters, e.g., cure speed and number of required UV lamps, with the help of RTIR spectroscopy. The results obtained were confirmed by pilot-scale UV curing experiments: one or, at most, two UV lamps of high intensity are sufficient for the curing process with respect to the double-bond conversion. The coatings based on the polyurethane acrylate dispersion show low sensitivity towards oxygen from air. Moreover, in comparison to UV curing under inert nitrogen atmosphere, a small “positive” effect on the conversion in the presence of air has been observed, which might be due to the contribution of peroxyl radicals or their decomposition products to curing.

Keywords

Polymerization Rate Phosphine Oxide Urethane Acrylate Polyurethane Acrylate Double Bond Conversion 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. (1).
    Reich, W., Enenkel, P., Lokai, M., Menzel, K., and Schrof, W., “Recent Investigations into Aqueous Radiation Curable Systems,”Proc. RadTech Europe 97, Lyon, 144, 1997.Google Scholar
  2. (2).
    Reich, W., Enenkel, P., Keil, E., Lokai, M., Menzel, K., and Schrof, W., “Waterbased Radiation-Curable Systems—Newest Investigations,”Proc. RadTech North America 98, Chicago, 258, 1998.Google Scholar
  3. (3).
    Mehnert, R., “Radiation Curing: Definition and Basic Characteristics,” inUV & EB Curing Technology and Equipment, Mehnert, R., Pincus, A., and Janowsky, I. (Eds.), John Wiley and Sons/SITA Technology Ltd., London, 1999.Google Scholar
  4. (4).
    Wang, Z., Gao, D., Yang, J., and Chen, Y., “Synthesis and Characterization of UV-Curable Waterborne Polyurethane-Acrylate Ionomers for Coatings,”J. Appl. Polym. Sci., 2869 (1999).Google Scholar
  5. (5).
    Shimizu, T., Higashiura, S., Murase, H., and Akitomo, Y., “Waterborne Polyester for Inks and Coatings: Structural Elucidation of Acrylic Grafted Polyester and the Particle of its Aqueous Dispersion,”Polym. Adv. Technol., 10, 446 (1999).CrossRefGoogle Scholar
  6. (6).
    Noble, K.-L., “Waterborne Polyurethanes,”Prog. Org. Coat., 32, 131 (1997).CrossRefGoogle Scholar
  7. (7).
    Coogan, R.G., “Post-Crosslinking of Waterborne Urethanes,”Prog. Org. Coat., 32, 51 (1997).CrossRefADSGoogle Scholar
  8. (8).
    Peeters, S., Bleus, J.-P., Wang, Z.J., Arceneaux, J.A., and Hall, J., “UV Curable Aqueous Dispersions for Wood Coatings,”Proc. RadTech Europe 97, Lyon, 337, 1997.Google Scholar
  9. (9).
    Arceneaux, J.A., Bleus, J.-P., Corley, A., Lindekens, L., Moorehead, T., and Wang, Z.J., “Approaches to Radiation Curable, Tack-Free before Cure, Sprayable Wood Coatings,”Proc. RadTech North America 98, Chicago, 235, 1998.Google Scholar
  10. (10).
    Blank, W.J. and Tramontano, V.J., “Properties of Crosslinked Polyurethane Dispersions,”Prog. Org. Coat., 27, 1 (1996).CrossRefGoogle Scholar
  11. (11).
    Crivello, J.V. and Dietliker, K.,Photoinitiators for Free Radical Cationic & Anionic Photopolymerization, John Wiley and Sons/SITA Technology Ltd., London, 1998.Google Scholar
  12. (12).
    Decker, C. and Moussa, K., “A New Method Monitoring Ultra-Fast Photopolymerizations by Real-Time Infra-Red (RTIR) Spectroscopy,”Makromol. Chem., 189, 2381 (1988).CrossRefGoogle Scholar
  13. (13).
    Decker, C. and Moussa, K., “Real-Time Monitoring of Ultrafast Curing by UV-Radiation and Laser Beams,”Journal of Coatings Technology,62, No. 786, 55 (1990).Google Scholar
  14. (14).
    Decker, C., “Kinetic Analysis and Performance of UV-Curable Coatings,”Radiation Curing: Science and Technology, in Pappas, S.P. (Ed.), Plenum Press, New York, 1992.Google Scholar
  15. (15).
    Scherzer, T. and Decker, U., “Real-Time FTIR-ATR Spectroscopy to Study the Kinetics of Ultrafast Photopolymerization Reactions Induced by Monochromatic UV Light,”Vib. Spectr., 19, 385 (1999).CrossRefGoogle Scholar
  16. (16).
    Mehnert, R., Klenert, P., and Hartmann, E., “LEA Electron Accelerators for Radiation Processing,”Nucl. Instrum. Methods in Phys. Res. Sect. B, 68, 73 (1992).CrossRefADSGoogle Scholar
  17. (17).
    Mehnert, R., “Electron Beam (EB) Curing Equipment,” inUV & EB Curing Technology & Equipment, Mehnert, R., Pincus, A., and Janowsky, I. (Eds.), John Wiley and Sons/SITA Technology Ltd., London, 1999.Google Scholar
  18. (18).
    Mehnert, R., “UV Curing Equipment—Polychromatic UV Lamps,” inUV & EB Curing Technology & Equipment, Mehnert, R., Pincus, A., and Janowsky, I. (Ed.), John Wiley and Sons / SITA Technology Ltd., London, 1999.Google Scholar
  19. (19).
    Pietschmann, N., “Photoinitiator Efficiency in Waterborne UV-Curable Coatings,”Proc. RadTech Europe 99, Berlin, 785, 1999.Google Scholar
  20. (20).
    Moore, J.E., “Calorimetric Analysis of UV-Curable Systems,” inUV Curing: Science and Technology, Pappas, S.P. (Ed.), Technology Market Publishers, Stamford, 1978.Google Scholar
  21. (21).
    Broer, D.J., Mol, G.N., and Challa, G., “Temperature Effect on the Kinetics of Photoinitiated Polymerization Dimethacrylates,”Polymer, 32, 690 (1991).CrossRefGoogle Scholar
  22. (22).
    Anseth, K.S., Bowman, C.N., and Peppas, N.A., “Polymerization Kinetics and Volume Relaxation Behavior of Photopolymerized Multifunctional Monomers Producing Highly Crosslinked Networks,”J. Polym. Sci., Part A:Polym. Chem., 32, 139 (1994).CrossRefGoogle Scholar
  23. (23).
    Decker, C. and Moussa, K., “Photopolymerization of Multifunctional Monomers in Condensed Phase,”J. Appl. Polym. Sci., 34, 1603 (1987).CrossRefGoogle Scholar
  24. (24).
    Kloosterboer, J.G., Litjten, G.F.C.M., and Greidanus, F.J.A.M., “Structure and Stability of Polyacrylate Radicals Trapped in a Network,”Polym. Commun., 27, 268 (1986).Google Scholar
  25. (25).
    Mehnert, R., “Radiation Curing Technology-UV Curing,” inUV & EB Curing Technology & Equipment, Mehnert R., Pincus, A., and Janowsky, I. (Eds.), John Wiley and Sons/SITA Technology Ltd., London, 1999.Google Scholar

Copyright information

© Springer Science+Business Media 2000

Authors and Affiliations

  1. 1.Institut für Oberflächenmodifizierung (IOM)Germany

Personalised recommendations