186 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1940 



physical characteristics — phisticizers, for example, to facilitate mold- 

 ing operations. Still other organic chemicals are used in the lubri- 

 cants and in motor fuel, but these will be covered in connection with 

 petroleum products. 



Mention was made of "Freon" in connection with air-conditioning. 

 Because these new fluorinated hydrocarbons are absolutely safe, they 

 are now widely used not only in air-conditioning, but also in domestic 

 refrigerators as well. Another important class of organic materials 

 used by manufacturers of mechanical refrigerators are the oil-modified 

 alkyd resin baking enamels. This new type of finish has to a consid- 

 erable degree displaced porcelain finishes. This shift from porcelain 

 to alkyd resin finishes has resulted in a marked decrease in cost of pro- 

 duction, which in turn is reflected in reduced prices to the ultimate 

 consumer. Alkyd resin finishes of the type used on refrigerators are 

 characterized by a high degree of toughness, resistance to grease and 

 stains, and by excellent color retention. Kelated alkyd resin finishes 

 are widely used for interior woodwork and for certain specialty out- 

 door applications — metal-protective paints in particular. Alkyd 

 resin finishes are also being used on several types of automobiles — 

 both passenger cars and motortrucks — on ships and railway cars. 



One of the principal intermediates used in making the alkyd resin 

 finishes is phthalic anhydride, made by the oxidation of naphthalene. 

 Whereas phthalic anhydride was more or less a laboratory curiosity 

 in 1917, selling for about $6 a pound,^^ some 43,000,000 pounds were 

 made in 1937, and the estimated production for 1939 was of the order 

 of 60,000,000 i^ounds. Currently the price of this important coal-tar 

 intermediate, the principal outlets for which are in the manufacture 

 of alkyd resins and certain types of dyes, is around 15 cents a pound. 

 Within recent years a new and greatly improved method has been 

 developed for the preparation of phthalic anhydride, involving oxida- 

 tion of naphthalene in the vapor phase, and it is largely due to this 

 improved method that alkyd resin finishes are available today at prices 

 which enable them to compete with the so-called orthodox finishes. 



I have taken a very personal interest in this new type of finish, since 

 much of the pioneering work on alkyd resin finishes was done under 

 my direction. Some 15 years ago when my attention was first called 

 by Dr. Whitney to resins made by the General Electric Co. through 

 the interaction of polyhydric alcohols such as glycerol, and polybasic 

 acids such as phthalic anhydride, it occurred to me that resins of this 

 type might find application in nitrocellulose lacquers to replace im- 

 ported natural resins such as damar. It likewise occurred to us about 

 the same time that resins of the same general type, suitable for use in 

 paints and varnishes, might be made through the simultaneous reac- 



« Oil, Paint, and Drug Reporter, 1918 Year Book, p. 127. 



