Technical Developments in 1994: Organic Coatings, Processes, and Equipment by Michael Murphy
his review covers developments in the field since the completion of the author’s review for 1993, which appears in the February 1994 issue of Metal Finishing. In cases where an author has published more than one article, or where two authors have the same last name, references are further identified with a Roman numeral after the author’s name both in the text and in the following reference list. SURVEYSANDGENERAL REFERENCES The future of liquid coatings was addressed by Todd, who discussed the advantages and disadvantages of the alternatives and described the role of liquid paints. Challenges facing the aerospace industry regarding the development of more environmentally friendly coatings were outlined by Gerrits and by Neeson. Dickie reviewed the role of interfacial chemical reactions in suppressing the corrosion of paints. The effect of pigment size on the gloss of paint films was investigated by Braun and Fields. Pommersheim et al. provided a model for predicting the degradation and blistering of organic coatings on steel. References Braun, J.H. and D.P. Fields, Journal ofCourings Technology, 66(828):93; 1994 Dickie, R.A., Progress in Organic Coatings, 25(1):3; 1994 Genits, J.C.M., Asia Pacific lnterfinish ‘94, Vol. I, Melbourne, Austr., Oct. 1994 Neeson, A., Asia Pacific Interfllsh ‘94, Vol. II, Melbourne, Austr., Oct. 1994 Pommersheim, J.M. et al., Progress in Organic Coatings, 25(1):23; 1994
Todd, I.E., Asia PaciIic Interfiish Melbourne, Austr., Oct. 1994
‘94, Vol. II,
PRETREATMENT Lundquist and also Liebl (I and II) offered tips on how to find a substitute cleaner for ozone-depleting chemicals. Water- and energy-saving washer designs for the 90s were described by 10
Lissy. Haruch (I and II) obtained a pair of patents for spray nozzles with recessed deflectors. A rotating spray nozzle earned a patent for Bowen. Ellis discussed the replacement of aircraft solvent-based cleaning materials with water-based materials. The role of volatile corrosion inhibitors in the cleaning of cold-rolled steel was addressed by Sparrow. Steele and Strickland patented a metal cleaner. Procedures for minimizing pretreatment problems prior to powder coating were outlined by Gruss. Dolan obtained a patent for a dry-in-place conversion coating. A method for pretreatment combining inorganic and organic layers won a patent for Sabata and van Ooij. Ryntz reviewed the basics of adhesion to low surface free energy substrates, such as thermoplastic olefins and polypropylene, and discussed current ways to achieve adhesion including plasma, flame, chemical etching, solvents, and adhesion promotors. A cold plasma process for the pretreatment of polypropylene bumpers was described by Steinmann. A method for pretreatment of aluminum body panels for automobiles was patented by Koyama et al. Musing0 et al. were awarded a patent for a composition for a nonchromate dry-in-place conversion coating for aluminum and aluminum alloys. Patents for, aluminum conversion coatings were also awarded to Reichgott and Chen and to Das. Two patents for the passivation of galvanized steel were granted to Anderson (I and II). Miller et al. reviewed improvements in automotive phosphating technology from 1975 to 1995. A new military specification for phosphate coatings was discussed by Menke. Guidetti and Vercesi provided a program for pollution prevention in phosphate coating. The effect of four dithiocarbamates on the phase constituents, alkaline stability, and wet adhesion of phosphate coatings was investigated by Sankara Narayanan and Subbaiyan (I). Sienkowski and Cormier patented a
concentrate for use in zinc phosphating. Processes for zinc phosphating also garnered patents for Gehmecker et al., for Sobata et al., for Riesop et al., and for Jo. Kinkelaar obtained a patent for a heavy iron phosphate. A method for phosphating multimetal substrates, consisting of an aluminum alloy and steel or zinc-plated steel, won a patent for Nakatsukasa et al. Matsuda received a patent for a phosphating process incorporating a filter to prevent sludge formation. A method for recycling phosphating sludges earned a patent for Buchmeier and Roland. Lin and Wen devised an experimental strategy to improve zinc phosphate coating uniformity through application of Taguchi’s quality engineering method. Synchotron X-ray studies of potentiostatically formed phosphate layers on steel were reported by Doyle et al., who found the technique useful to follow the development of the coating over time. The use of electrochemical impedance spectroscopy to evaluate phosphate coatings was investigated by Sankara Narayanan and Subbaiyan (II), who used the technique to evaluate additives. Ludwig and Eliash patented a method for monitoring the quality of phosphate coatings. A comparison of chromium and chromium-free seal rinses for phosphate coatings on steel was reported by G6recki and Affinito. Joseph provided a commentary on the G6recki and Affinito paper. Chromium-free passivation rinses were the subject of patents granted to Gray et al., and to Hauffe et al. Flamme obtained a patent for a post-treatment dip coating containing a binder with titanium or zirconium compounds.
0 Copyright Elsevier Science Inc.
METAL FINISHING . FEBRUARY 1995
References Anderson, K.P. (I), U.S. Patent 5.252.363; Oct. 12.1993 Anderson, K.P. (II), U.S. Patent 5,321,061; June 14.1994 Bowen, SD., U.S. Patent 5,316,218; May 31, 1994 Buchmeier, W. and W.A. Roland, U.S. Patent