M A T E R I A L S OF C O N S T R U C T I O N
Protective Coatings
I s THE past year, the Building Research Institute held a 3-day conference on field applied paints and coatings. T h e report (4D) summarizes the current state of commercial developments of paints as engineering materials of construction so adequately that no reference to other summaries of the past year is included here. S e w developments continue: but, generally, they have not been tested long enough to be positive that they answer some of the long-standing problems of the industry. Reports of commercial trials of various coatings which \vere new and exciting a few years ago, and are now more or less standard, enable them to be properly evaluated. During the past year, the principal emphasis has been on the catalyzed coatings, and their close relativescoatings based on epoxy, urethane, or unsaturated polyester resins: usually used as two-component systems which are mixed just before application, a n d which have a tendency to have a short pot life. Despite efforts to produce the same effect in one-package systems: there is a long way to go. T h e interest in
FRANCIS SCOFIELD, director, scientific section of the National Paint, Varnish and Lacquer Association, has compiled our paint reviews since 1952. Following graduation from Lehigh (B.S. in chemistry) in 1931, he was on the staff of the National Bureau of Standards until 1936 when he became associated with the National Paint, Varnish and Lacquer Association. Scofield has been chairman of the Paint, Plastics, and Printing Ink Division of the ACS and president of the Baltimore Paint and Varnish Production Club. He i s a member of the ASTM, American Oil Chemists’ Society, and Optical Society of America.
water-thinned coatings continues with particular emphasis on the adaptation of these products, already widely used for architectural finishes, to the finishing of various industrial products. As always, there is a steady stream of information on many specialty materials and products that the paint industry makes.
Epoxy, Urethane, and Polyester Coatings Interest has grown to the point that a panel discussion on these coatings was held by the Federation of Paint a n d Varnish Production Clubs. Rhodes and others (7d.4) discuss the advantages and formulations of epoxy a n d urethane coatings. Howe (5A) has compared the properties of these catalyzed finishes. Leonard (6.41 and Dorman and Gruber (3A) discuss the future of epoxies generally and a review (70.4) emphasizes products that cure at room temperature. Maslow (8A) describes the use of epoxies on masonry, Dunn ($A) deals with their use for corrosion resistance, and Thomas (754) describes industrial primers based on epoxies Zonsveld ( 7 6 A ) and Zumstein (77A) describe epoxyamine combinations which can be used as solventfree coatings The technology of the urethane coatings is not as far advanced, but Bieneman (7.4) and Pfluger (72A) outline suggestions by which excellent coatings, of noteworthy abrasion and water resistance: may be obtained. T h e principal emphasis on polyester coatings, to date, has been in furniture finishing. Letsky (7.4) and Pfister (77A) discuss this phase. Chandler (24) summarizes research on these products, and Murray (SA) outlines their potentialities.
Water-Th inned Coatings Although water-thinned coatings have been widely adopted for architectural uses, their use in industrial finishes is still experimental. Hamilton and others (QB)in a panel discussion outlined the types of these products which have been
suggested and discussed their merits and defects. Brenner (5B) has summarized the utilization of the three principal latices offered for industrial finishes. Baatz (3B) and Fickenscher (8B) review the use of poly(viny1 acetates) in this field and Allyn (7B) covers the available acrylic latices. Other vehicles suggested a t this time include alkyd emulsions (4B), water-soluble alkyds (7B) a n d phenolics (72B). Some problems associated with the use of water-thinned coatings on metal are outlined by Broughton (6B) and Johnson (70B). T h e use of these materials in trade sales finishes continues to grow. Johnson ( 7 7B) has reviewed the types available, and Allyn (2B) discusses their use on masonry.
Corrosion and Plant Protection Wallgreen (20C) has reported on the organized research program of the Swedish paint industry on anticorrosive coatings, in which the climate, degree of rusting of the steel, pretreatment. and other factors are being studied. Results are not yet complete but the trends are interesting. Bradley (5C) discusses some factors which must be considered in choosing a coating system for structural steel. Gulyaev and Zhdanova (77C) recommend a polyisobutylene coating for corrosion resistance. Holden (73C) describes various phosphate pretreatments, and ,411en (7C) and Beck (4C) report on wash primers for the surface preparation of steel before painting. T h e coating of pipelines continues to develop much interest. T h e National Association of Corrosion Engineers ( 6 C ) has developed a tentative specification. Allen (2C) outlines a test program which utilizes both laboratory and field service tests to evaluate pipeline coatings. Rose (78C) describes the systems used in the Chicago area. Kulman (75C) has investigated the deterioration of pipeline coatings from microbiological attack. Another development is the coating of
VOL. 51, NO. 9, PART II
SEPTEMBER 1959
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Catalyzed coatings open up new fields, but there are serious bugs still to be removed the interior of pipes to reduce friction and the use of a proprietary compound
(770. Marine paints for underwater service are a specialized field. Kingcome (74C) describes raft tests for their evaluation. Gleser (70C) reports on tests of underwater coatings in fresh water, on the Mississippi. Schrieber (79C) and Gotoda and Sat0 (9C) discuss the relationship between paints and cathodic protection. Anders (3C) compares the properties of a number of thermoplastic and thermosetting coatings for the protection of chemical plants, and the National Association of Corrosion Engineers committee (7C) has reported on the use of coal-tar coatings. Cushing (8C) reports on the ability of coatings to resist chemical spillage. Larrabee and Mathay (76C) discuss the corrosion problems in coal-chemical plants, and suitable paints for paper mills have been summarized (27C). Higgins (72C) discusses the corrosion of magnesium alloys, and the place of paints in their protection.
Miscellaneous Several articles ( 7 0 , 20, 50, 760) emphasize the importance of a planned program of plant maintenance. T h e exact schedule depends upon local conditions and the standard to be maintained, but all the authors agree on the importance of establishing a regular schedule of maintenance painting. Paint films are often attacked by fungus growths. Krumperman (730) has reviewed the most common species and Teramoto, Yoshii, and Kawai ( 2 0 0 ) describe methods of coping Nith certain specific ones. Laster and Finlay ( 7 4 0 ) describe the general philosophy of dealing with fungus growth, and Eisenschiml ( 7 0 ) and Ross (770) recommend specific fungicides. Klens and Koda ( 7 2 0 ) discuss self-sanitizing paints which defeat bacteria as well as fungus. Among the other developments are reports on fire-retardant paints by Holderried ( 7 0 0 ) and Gross a n d Loftus (80). Hofstatter ( 9 0 ) discusses new finishes for high heat resistance a n d Shur (790) reports on industrial baking enamels. A future possibility is raised in the discussion of a synthetic resin with aluminum as a cross-linking element. with some analogy to the silicones ( 7 8 0 ) . These show some promise for the future, but their place in the coatings picture is not yet determined. Two reports (6D, 750) summarize the recent development in the field of
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paint and varnish removers which must move forward with the technology of the industry, because new and more resistant coatings demand new and more poiverful removers. Kazin ( 7 7 0 ) has reported on the coatings and application methods used in the Soviet Union. Finally, Birren (30) has outlined the use of properly selected colors to increase office efficiency.
Bibliography Epoxy, Urethane, and Polyester Coatings (Varnish Production Clubs 31, 23-35 (1959;. (21C) Wochbl. Papierfabrik. 84, 644 (1956).
Miscellaneous (ID) Bigos, Joseph, Am. Painter t3 Decorator 35, No. 2, 26-8, 43 (1958). (2D) Ibid., No. 3, 42-3, 46-7. (3D) Birren, Faber, Modern Sanitation 11, NO. 1, 17-19, 50 (1959). (4D) Bldg. Research Inst. Conf. on Field-
Applied Paints and Coatings, Washington, D. C., 1959.
(5D) Chem. Eng. 6 5 , No. 3, 125-8 (1958). (6D) Chem. W e e k 84, No. 4, 49-50, 52-54 (1959). . Fed(7D) Eisenschiml, Gerald, O ~ CDig. eration Paint @ Varnish Production Clubs 30, 398-407 (1958). (8D) Gross, Daniel, Loftus, J. J., Am. Sod. Testing Materials Bull. No. 230, 56-60 (1958). \ - - - - , .
(9D) Hofstatter, A . F., Prod. Finirhing (London) 11, No. 10, 52-8 (1958). (10D) Holderried, J. A., Paint Oil Chem. Reu. 121, No. 15, 8-9 (1958). (11D) Kazin, A., Can. Paint Varnish M a g . 32, No. 9, 27, 50 (1958). (12D) Klens, P. F., Koda, C. F., 086. Dig. Federation Paint & Varnish Production Clubs 30, 408-13 (1958). (13D) Krumperman, P. H., -4m. Paint J . 42, NO. 38, 72-84 (1958). (14D) Laster, G. R., Finlay, G., Paintindia Nn. 25-30 .7 ., . _ _ 9. ., -~ .. (19571. ~~.~ (15D) McLaughlin, P,’. H., Paint, 011 Chem. Rev. 122, No. 1, 8-9, 21 (1959). (I6D) M o d . Sanitation and Bldg., M a i n t . 10. NO. 4. 21-2. 49-51 11958). (l7D’, Ross: R. T., Spotlights 21, N o . 6, 12-16 11959). (18D) Sc‘hlenker, F., Farbe u. Lack 64, 174-83 (1958). (19D) Shur, E. G., Znd. Fcntshtng (Zndzanapolts) 34, No. 5, 26, 30, 32, 34, 36, 40 (1958). (20D) Teramoto, Shiro, Yoshii, Sohei, Kawai, Hanjo, K6g6y Kagaku Zassht 59, 650-2, 652-4 (1956).
Corrosion and Plant Protection
(1C) Allen, E. R., Corrosion 14, No. 10, 54 (1958).
INDUSTRIAL AND ENGINEERING CHEMISTRY
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( 2 C ) Zbid., No. 12, 18-24. (3C) Anders, Heinz, Kunrtstofe-Plastics 3, 281-8 (1956). (4C) Beck, E. S., Paint Ind. Ma,y. 73, No. 5, 23-30 (1958). (5C) Bradley, W. J., A m . Paint J . 43, No. 18, 70, 72-3, 76 (1959). (GC) Corrosion 14, S o . 7, 35-7 (1958). (7C) Ibid., KO,8, 37-8. (8C) Cushing, R., Cliem. Eng. 6 5 , N o . 4, 156, 158, 160 (1958). (9C) Gotoda, hfasao, Sato, Yasushi, Denki Kagaku 25, 208-13 (1957). (loci Gleser, S. AT., Corrosion 14, N o . 8, 41-50 (1958). (11Ci Gulyaev, B. N.,Zhdanova, A . V., Gidroliz. i. Lesokhim. Prom. 11, S o . 1, 8-9 (1958). (12C) Higgins, \V. F., Chem. t3 Ind. (London) 1958, No. 49, 1604-12. (13C) Holden, H. A,, Prod. Finishing (London) 12, No. 1, 76-9 (1959). (14C) Kingcome, J. C., Paint X a n u f . 28,375-8, 388 (1958); 29, 5-8 (1959). (l5C) Kulman, F. E., Corrosion 14, No. 5, 23 (1958). (16C) Larrabee, C. P., Mathay, W. L., Zbid.. No. 4. 37-40. (17C) ’Paint, ’ O i l Chem. Rev. 121, S o . 8, 18 (1958). (18C) Rose, W. T., Corrosion 14, No. 1 0 63-4 (1958). (1%) Schrieber, C. F., Ibid., No. 3, 26-30. (20C) M’allgreen, Per-.4ke, Ogic. D i g .
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