2598
INDUSTRIAL AND ENGINEERING CHEMISTRY
without supplemental preservation of the nonferrous metal parts, as very light attack on their surfaces by the vapor rust-inhibitor
,chemicals would not impair their subsequent, efficiency of operation. Here again it is necessary t o be careful of the type of inhibitor ueed because the various chemical compositions differ in their corrosive effect on nonferrous metals such as copper, nickel, silver, aluminum, and the bronzes. T h e suppleniental protection can be furnished by either a plastic or waxlike sprag, Tesulting in a film impervious to the vapor rust-inhibitor vapors. (These films should be removed before the equipment is placed in service.) Thus either complex assemblies such as radios, radar, other electronic equipment’, fire control equipment, typemiters, calculators, guns, rockets, machine tools, hydraulic pumps, aeronautical and automotive engines, watches, and chronometers, or Eimple equipment like tools, empty drums or cans, apare parts, and pipe, can easily be packaged and preserved for many years by utilizing vapor rust inhibitors. Optical equipment should not be packaged with such inhibitors unless some measure has been talrcn t o prevent the vapors from condensing on the optical surfaces. Halogenated solvents such as carbon tetrachloride, chloroform, trichloroet,hyIene, and perchloroethylene should not be used for cleaning items prior t o packaging with vapor rust inhibitors, as the acid usually produced by hydrolysis of the halogenated solvent interferes with t h e rust inhibition. Most of the commercial nonflammable solvents are of this general type. Nonhalogenated solvents of the Stoddard type can be used without danger of corrosive aftereffects. However, these solverits are flammable and should be handled with proper precautions. As the potential users of vapor rust inhibitors gain confidence in the merits of vapor rust inhibition and as storage data are accumulated t o prove these merits, such inhibitors will be adopted for use in many other packaging problems. If t h e indicated procedures are followed, instruments and equipment can be packaged and preserved safely for many years. Equipment and parts packaged with vapor rust inhibitors are ready for use immediately when unpacked. T h e saving in man-hours on reactivation of equipment is greater in many cases than the initial oost of packaging the equipment. Thus, for many applications i t is more economical than the old methods of preservation and packaging. ‘ICKNOWLEUGhIEZlT
The author acknowledges with pleasure many stimulating discussions on various aspects of rust inhibition with W.A. Zisman and C. R. Singleterry, whose suggestions have contributed largely both t o the practical testing and t o the theory of such inhibitors. LITERATURE CITED
Aviation A g e , 16, 32 (1951). Baker, H. It., “Properties, Saval Uses and Effect on Nonferrous Metals of Vapor Phase Inhibitors VPI 220 and 260,” AVRL R ~ p t P-3047 . (January 1947). Baker, H. R., Jones, D . T., and Zisman, W. A,, IND.EKG. C H E M . , 137 ~ ~ ,(1949). Baker, H. R., Shafrin, E. G., and Zismari, W. A , , J . Phys. Chem.,
56,406 (1952). Bakcr, H. R., Spcssard, D. R., W’olfe, J. K., and Zisman, W.A, U. S. Patent 2,602,780 (July 8, 1952). Baker, H. R.. and Zisman, W. d.,“Antirust Additives for Lubricating, Power Transmission, and Protective Oils,” iV‘RL Rept. P-2474 (February 1945). Baker, H. R., and Zkman, W. A,, IND.EHG.CHEM.,40, 2338 (1948). Baker, H. R., and Zisman, TV. A, Lubrication Eng., 7, 117 (1951). Bannister, €1. L., Research, 5 , 424 (1952). Black. A. R., and Wachter, A., Ordnance, 37, 1052 (1953). Brophy, J. E., and associates, 1x1). ENG.CHRM., 43,884 (1951). Cox, K. L., U. S. Patent 1,903,287 (1933).
Vol. 46, No. 12
Dreyfus, M. E., Heating and Ventilating, 39, 31 (1942). Fisher, E. ITr., InduStTy, 16, ?io. 1, 17-18, 50, 52, 54, 56 (October 1950). Foster, G., I r o n A g e , 167,99 (1951). Foster, G., Ordnance, 35,155 (1950). Gardner, F. T., Clothier, A. T., and Coryell, P., Corrosion, 6 , 58 (1950). Hackerman, If.,and Cook, E. L., J . Electrochem. Soc., 97, 1 (1950). Ilackerman, S . ,and Sudbury, J. D., I b i d . , 97, 109 (1950). Harkins, W. D., and Florence, R. T., J . Chem. Plays., 6, 847 (1935). Jacoby, A. L., U. S. Patents 2,580,923; 2,580,924 (Jan. 1, 1952). Kamlet, J., Ibid., 2,475,186 (July 5 , 1949). Kaufman, S., and Singleterry, C. R., J . Phys. Chem., 56, 604 (1952). Lane, R . W., and Thompson, IT. H., U.S. Patent 2,582,138 (Jan. 8, 1952). Lieber, Eugene, Ihid., 2,512,949 (June 27, 1950). XcOmie, W.A., and Anderson, H. H., Uniu. Calif. Pubs. Pharmacol., 2,231 (1949). Ilerker, R. L., and Zienian, W.A,, J . Phys. Chem., 56, 399 (1952). Llilyavskava, 1‘. O., U.S.S.R. Patent 69,947 (Dec. 31, 1937). Moore. R. AI., and Wachter, A., U. S.Patent 2,592,451 (April 8 , 1952). Ray, P. C., and Rakshit, J. K . , J . Ckern. Soc., 101, 612 (1812). Reiniger, S. W., Aviation W e e k , 55, 48 (1951). Schwoegler, E. J., and Hutter, C. -I.,U. S. Patent 2,521,311 (Sept. 5, 1950). Shafrin, E. G., and Zisman, W. il., J . Colloid Chem., 4, 571 (1949).
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1947) Ihid., 2,432,839 Ibid., 2,432,840 Ihid., 2,449,962 I b i d . , 2,484,395 Ibid., 2,563,764
(Dee. 16, 1947). (Doc. 16, 1947). (Sept. 21, 1948). (Oct. 11,1949). ( l u g . 7, 1951). Ibid.,2,577,219 (Dec.4, 1951). Stroud, E. G., and Vernon, W. H. .J., J . -4ppZ. C h e m . , 2, 166 (1952). Sussex. A. G., d ustralasian E n g r . , 1947, 68- 75 (Kovember), Temple, I
