TECHNOLOGY
Lighting N e w Horizons R O L A N D W A R D , University
of Connecticut, Storrs, Conn.
Both sides in World W a r II had devices for seeing in the dark, were slow to use them. Phosphors throw light on new paths for research; panel lighting is bright new vista
Q N E dark night in the spring of 1945 an assault boat moved out from the west bank of the Rhine. The boat was loaded with a raiding party moving into enemy territory. Anyone knowing how heavily the river was mined—by both sides—would have considered it sheer suicide for the boat to attempt crossing in pitch dark. Th«sre were holes in the mine fields, of course, but expecting a boat to twist through them without guiding landmarks was an impossible thing to ask. And it was very dark that night. AVhat the ordinary observer didn't know was that these men in the assault boat did have a way of seeing in the dark. From time to time, as the boat moved through the water, the helmsmen and platoon leader would raise an instrument to their eyes and look back toward the west bank of the Rhine—as if checking for landmarks. If one could have looked with their ey^s through those instruments, one could have se**" a series of lights shining on the west hank, like leading lights into a harbor. The lights were infrared lamps, normally invisible to the human eye. The device which enabled the soldiers to see these lights had been 4772
dubbed by the technicians as a "metascope." The metascope was developed independently by both German and American scientists in the course of World War II. The American metascope and its optical system was more elaborate ( Figure 1 ) than the German system, which was hardly more than a tin can fitted with a focusing lens at one end and a phosphor sheet at the other. For short distances, both metascopes were able to detect infrared signals from heavily filtered flashlights and the like. After the invasion of Normandy, it was evident to both sides that each could detect the other's signals; hence they shied away from this type of communication except in special instances as above. The snooperscope is a more refined version of the metascope—it can also detect reflected infrared light. It employs a phosphor screen and an image electron tube (Figures 2, 3, and 4 ) . However, this device developed more slowly than the metascope, although they were conceived together. The snooperscope was used only in the later stages of the war—once at Okinawa. Similar German snooperscopes were C H E M I C A L
discovered in France en route to submarine pens when the Allies entered the country. They were experimental types, however—not nearly so compact or versatile as the American version. Four men were needed to operate one machine. The American snooperscope, in some instances, is able to detect infrared signals at a distance of 17 miles. Used on a gun mount with an infrared spotlight, it outlines images for about 500 yards (Figure 3 ) . The same type, used with infrared headlights on an automobile, provides a device ( Figure 4 ) which enables driving in complete darkness. Signaling with infrared radiation was brought to practical usefulness by means of the infrared sensitive phosphors SrS:Ce-Sm and SrSe:Eu-Sm. The former could be excited efficiently with radium and the latter with blue light. Compact devices no bigger than binoculars were constructed using a disk of phosphor at the focal plane of the optical system. The phosphors were excited with the appropriate energy source and were found to retain their excitation for remarkably long periods of time. An infrared source, consisting A N D
E N G I N E E R I N G
NEWS
SPHERICAL MIRROR
VISIBLE LIGH
INFRARED _^ ENERGY
FLUORESCENT SCREEN
SCHMIDT CORRECTOR PLATE
ERECTING LENS PHOSPHOR BUTTON
OCULAR LENS
Figure 1 ( left ). American version of the metascope employing a phosphor button-type luminescent screen. This type was made to fit within a case much like a pocket telescope. Diagram courtesy Institute of Radio Engineers. Figure 2 (right). American
of a tungsten lamp covered with an infrared-transmitting filter giving good transmission at about 1μ, could b e viewed through this instrument. The small bulk of the equipment and its independence from heavy power units were attractive features for Army and Navy personnel. The development of these infrared stimulating phosphors came primarily from the investigations of Franz Urbach now with the Eastman Kodak. With some phosphors, electrons may be released from deep traps by absorp tion of radiation. This phenomenon, known as stimulation, has been shown to be due in many instances to the presence of two activators, one of which (the dominant activator) gives rise to the emission band and the other (the auxilliary activator) is responsible for the deep traps which appear after the phosphor has been excited. Outstanding examples of this type of phosphor are strontium sulfide acti vated either with europium and sa marium or with cerium and samarium. The former is excited with blue light and die latter with ultraviolet. Upon removal of the exciting source no ap preciable afterglow is observed. Sub sequent exposure to infrared radiation of 10,000 Α., however, causes the
3 1, N O .
europium phosphor to emit an orange light and the cerium phosphor to give a blue-green emission (Figure 5, curve I). When europium and bismuth are used as the activator pair, the stimula tion spectrum shown in curve II is ob tained but the emission is the charac teristic orange color of europium. These stimulation spectra are coinci dent with absorption bands observable in t h e excited phosphors. They repre sent the energy required to remove the electrons from deep traps introduced by the samarium or the bismuth; the latter giving the deeper trap. A slightly different but related phenomenon is shown with alkali halides activated with but one activa tor such as copper, silver, or thallium. W h e n these crystals are excited bv short wave length ultraviolet (less than 2 0 0 0 A.) a new absorption band is de veloped. With KChAg this band has a peak about 4200 A. The excited phosphor, when irradiated with blue light, gives an emission band in the ultraviolet with maximum intensity at 270O A. The KC1-TÎ crystal develops several absorption bands, the principal one lying in the near ultraviolet at 3 5 5 0 A. with others extending into the infrared. These are stimulation bands. Exposure of the excited phosphor to
46 . N O V E M B E R
16,
-CATHODE
version of the snooperscope optical system as developed by RCA. This small image tube (IP25) is essentially like a television tube but uses the infrared phosphor as the photosensitive element, Diagram courtesy of RCA Review
Figure 3. A snooperscope in action. Infrared spotlight, mounted on foreward end of gun stock, runs on power from a battery pack. Reflected infrared light is picked up by the image tube of the telescope-like sights. The image tube also is powered by the battery pack. Vision with this type of tube was good to over 500 yards and gave a well-defined picture
VOLUME
ELECTRON LENS
1953
radiation in the infrared causes emission in two bands, one with peak emission at 3000 A. and the other at 4700 A. Closely related to the stimulable phosphors are the quenching phos-
Figure 4. A modified version of the snooperscope tube to give binocular vision for night driving. It ran off the vehicle's power system. Courtesy RCA phors, the most notable examples of which are the zinc sulfide-cadmium sulfide phosphors containing copper or silver as dominant activators, and nickel, cobalt, or iron as auxilliary activators. The phosphorescence of these phosphors can be quenched by irradiation with infrared or by heating. The extraordinary sensitivity of their luminescence to temperature changes is a function of the composition of the base material, the concentration of the activators, and the degree of excitation. More recently Urbach's work with infrared quenching phosphors and superlinear phosphors has led to some intriguing possibilities. The brightness of most phosphors under excitation follows, within limits, the inverse square law. However, some of the zinc-cadmium sulfide phosphors activated with silver or copper and containing small amounts of a poison such as nickel 4773
TECHNOLOGY5. Stimulation Figure spectra of doubly acti( Urvated phosphors bach). I. SrS:Sm—Eu, SrS:Sm- —Μη, SrS:Sm— Ce. II. SrS:Bi—Ce
8 10 12 14 STIMULATING WAVE LENGTH (A.xlCT" 3 ) s h o w a w i d e departure from this rule, and in certain ranges o f excitation in tensity a m u c h more rapid increase in fluorescence is found. T h e fluorescence of these p h o p h o r s is also very sensitive to temperature c h a n g e s . B y s t u d y i n g t h e effect of phosphor composition u p o n the fluorescence-temperature relation ship it is p o s s i b l e to arrive at a c o m position w h i c h gives t h e maximum per c e n t a g e c h a n g e in efficiency of the phosphor per degree. A surface coated with a film of such a phosphor and ir radiated w i t h ultraviolet s h o w s slight irregularities in temperature over the entire surface by the contrast in bright ness of the phosphor. Application of this n o v e l m e t h o d of measuring surface temperatures might b e found in the study of heat distribu tion for large scale operating equip ment. Temperature changes in the range u p to 2 0 0 ° C. could c o n v e n i e n t l y b e observed in this w a y , b u t above this temperature the stability o f t h e phos phor film w o u l d b e c o m e a serious prob lem. T h i s limitation c a n b e overcome, h o w e v e r , b y placing a phosphor screen in the focal p l a n e of a n optical system and irradiating with ultraviolet. The radiation from t h e warm body brought t o focus on t h e screen produces a dark i m a g e w h i c h m a y be photographed or o b s e r v e d visually ( F i g u r e 6 ) . One feature of this d e v i c e is that there is n o limit to t h e w a v e length of t h e radia tion w h i c h it can detect p r o v i d e d the radiation c a n b e absorbed by t h e phos phor. Nuclear Radiation Detectors T h e e x t e n s i v e development a n d re search n o w g o i n g on i n nuclear energy, t h e w i d e s p r e a d use o f radioactive iso
4*774
t o p e s , a n d also t h e ever present threat o f t h e nuclear b o m b require t h e avail ability of simple d e v i c e s for the d e t e c t i o n and monitoring o f nuclear radia t i o n . T w o c l a s s e s of phosphors h a v e b e e n found useful for these purposes. T h e first of t h e s e , called scintillation c o u n t e r crystals, emit visible or ultra v i o l e t radiation w h e n exposed to nu c l e a r radiation. The emitted light is transmitted to a suitable photocell foiamplification. S o m e organic crystals s u c h as naphthalene, anthracene, stilb e n e , a n d terphenyl h a v e proved par ticularly effective. Some d i a m o n d s also exhibit this property to a marked de g r e e . T h e r e is n o activator in t h e s e materials, t h e l u m i n e s c e n c e b e i n g a property of the molecule. M a n y of t h e s e substances arc effec t i v e in solutions. T h e purest material g i v e s t h e best c o u n t e r . A m o n g t h e in organic materials suitable for this pur p o s e are sodium, potassium, and c e s i u m iodides, and cesium bromide activated w i t h thallium. T h e high density o f the s o d i u m iodide-thallium crystal m a k e s it a useful counter for β and γ radiation. L i t h i u m iodide activated with either thallium or tin is used for neutron counting. For t h e best practical re sults, these scintillating counter crystals must b e perfectly transparent to their o w n emission a n d should b e g r o w n as large single crystals. The art of g r o w i n g optically p e r f e c t single crystals from melts, w h i c h h a s b e e n so skill fully d e v e l o p e d b y Kramer of H a r s h a w Chemical, has m a d e these scintillation counter crystals readily available on a commercial scale. T h e emission from these crystals oc curs in less t h a n 1 0 8 seconds after their excitation for organic materials a n d within a b o u t 1 0 - β seconds for in
organic crystals. T h e h u n d r e d f o l d dif ference in s p e e d of response m a k e s the organic phosphors more desirable for certain application, but in general the inorganic phosphors s h o w a m u c h greater efficiency in their response t o nuclear radiation. T h e second t y p e of detector d e p e n d s on the p h e n o m e n o n of radiophotolumi n e s c e n c e first discovered b y K. Przibram at the institute for R a d i u m Re search, Vienna, in his investigations of the effects of ionizing radiation o n na tural crystals. An example of radiophotoluminescence has already been described in t h e action of short w a v e ultraviolet on KC1:T1 w h e r e i n t h e ab sorbed energy stored within t h e crystal can b e released b y stimulation. For usefulness as a dosimeter for h i g h en ergy radiation, however, J. H . Schulman and his collaborators at the N a v a l Research Laboratory have d e v e l o p e d a
Figure 6. Thermoradiograph of human hand taken against room background oi 27° C.
Figure 9. Radioactive objects, like this battery clip, can quickly be detected by allowing the radiation to impinge on a radiophotoluminescent phosphor stimu lated by ultraviolet light
CHEMICAL AND
ENGINEERING
NEWS
TECHNOLOGY Figure 7. Absorption spectra of phosphate glass activated with silver ( Schulman ) : a ) before irradiation with X-rays; b ) after irradiation with Xrays; c) dotted curve — new absorption band
Figure 8. Fluores cence of silver acti vated barium potas sium metaphosphate ( Schulman ) : a ) be fore exposure to Xrays; b ) same emis sion as A viewed through a red filter; c) after exposure to X-rays. Emission viewed through a red filter
240O 3200 4O0O 4 8 0 0
2400
WAVE LENGTH (A.) phosphor w h i c h b e c o m e s fluorescent after exposure to x-rays or -y-rays. W h i l e alkali h a l i d e s activated w i t h silver also h a v e this property, a b a r i u m potassium-aiuminum metaphosphate glass containing 8% silver m e t a p h o s p h a t e lias p r o v e d more generally satis factory. Measurement of t h e absorption spec t r u m of this phosphor before a n d after irradiation w i t h x-rays indicates that a n absorption b a n d has b e e n introduced ( Figure 7 ) . T h e difference b e t w e e n t h e fluorescence of t h e phosphor before a n d after exposure t o x-rays c a n also b e s h o w n graphically ( F i g u r e 8) in w h i c h the brightness of the fluorescence i s plotted against t h e w a v e length of t h e exciting light. C u r v e A represents t h e emission of the phosphor before exposure to x-rays, t h e emission being o b s e r v e d t h r o u g h a b l u e filter, w h i l e Β is the same emission s e e n through a r e d filter. After the e x p o s u r e to x-rays, t h e emission o b s e r v e d through a red filter is represented b y curve C . T h e excitation b a n d w h i c h p e a k s at 3 3 0 0 A. a n d the red e m i s s i o n h a v e b e e n in duced by irradiation with x-rays. O t h e r high e n e r g y radiations including γ-rays, are also effective, and t h e lumi n e s c e n t response to a constant excit i n g source is linear w i t h the t i m e of exposure. A d o s i m e t e r based on t h e behavior of this phosphor has b e e n d e v i s e d which c a n readily m e a s u r e doses a s small as 10 r o e n t g e n s from c o b a l t - 6 0 radiation. T h e r e is a sharp contrast b e t w e e n the fluorescence of the e x p o s e d a n d shielded p h o s p h o r ( F i g u r e 9 ) . Electroluminescence A b o u t 1 0 years a g o G. D e s t r i a u reported that certain p h o s p h o r s could b e excited by an a.c. field. Most of V O L U M E
3 1,
NO.
32Ο0
40Ο0
WAVE LENGTH (A.)
t h e s e investigations h a d b e e n carried o u t i n F r a n c e d u r i n g the war years. Considerable interest has b e e n dis p l a y e d in this p h e n o m e n o n recently since it offers the first e c o n o m i c a l pos sibility of a large area light source. T h e phenomenon is called electrolumi n e s c e n c e , but there is at present n o fun d a m e n t a l understanding of t h e m e c h a nism i n v o l v e d and c o n s e q u e n t l y it has not b e e n possible to evaluate its poten tialities as an effective m e t h o d of light ing. T h e electroluminescent l a m p is es sentially a condenser, o n e of the plates b e i n g a c o n d u c t i n g glass and the other a thin metal film, usually a l u m i n u m . A thin film consisting of a phosphor dispersed in an oil or plastic consti tutes t h e dielectric ( F i g u r e 1 0 ) . W h e n an a.c. field is applied across this con denser the phosphor is excited to lumi n e s c e n c e . T h e emission of light from the phosphor occurs w h e n the field is Figure 10. Electroluminescent sheet ( Sylvania ) is composed of laminates like the above. Installed as wall panels, they are expected to find wide use where low intensity light is desired SOLDERED WIRE T.EADS FOIL OR FLASHED METALLIC COATING 1/100" THICK PHOSPHOR -DIELECTRIC COATING
INVISIBLE CONDUCTING COAT ON GLASS
This is the last in a scries of articles on Luminescent Materials b y Roland Ward. Part I ( Putting the Mystic Glow to Work ), appeared Oct. 26, paces 4418 22.
ORDINARY WINDOW GLASS
46 - N O V E M B E R
16,
c h a n g i n g , a n d the brightness is a func tion of t h e applied v o l t a g e and the frequency. T h e development of light i n g systems of this type, promoted largely b y Sylvania Electric Products, h a s already progressed to s o m e appli cations requiring o n l y l o w intensity illumination. The p o w e r consumption i s l o w c o m p a r e d to other light sources for there is little heat loss. T h e useful life of a unit is estimated at o n e t o five years and t h e same range of colors can b e o b t a i n e d as with t h e fluorescent l a m p s . T h e s e , combined w i t h area lighting, are the v e r y attractive fea tures w h i c h account for t h e intensifica tion of research in electroluminescence. T h e most suitable phosphors appear t o b e of t h e zinc sulfide t y p e , b u t not m u c h d e t a i l e d information about the composition and m e t h o d s of prepara tion has b e e n released. A zinc sulfide activated w i t h copper and lead has b e e n described, but the h e a t treatment of the phosphor apparently h a s a great influence o n its efficiency. A systematic study of t h e chemical history and composition of t h e s e phos phors is obviously important not only for the practical d e v e l o p m e n t of a n e w light source b u t as a means of achieving a deeper understanding of l u m i n e s c e n t crystals. It s e e m s proper to e m p h a s i z e that m u c h remains t o b e a c c o m p l i s h e d in the scientific investi gation of phosphors. In this general field, w h i c h encompasses not only luminescent materials, but also photoconductors, semiconductors, transistors, ferroelectric and m a g n e t i c crystals, and contact catalysis, t h e c h e m i s t has very definite contributions t o make in furthering this work.
1953
4775
TECHNOLOGY^.
Super Greases for Supersonics Silicone greases, thickened with arylureas, offer high melting points and thermal stability . . . O x i d i z e d petroleum wax new source of saponîfîable grease bases CHICAGO.—Materials of construction have been looked upon as the main problem in engines for supersonic aircraft, but greases for high temperature operation also present a problem. Silicone greases offer a solution because they have much higher thermal stability than petroleum greases. Up to this time, lithium soaps and carbon black have been used as thickeners for silicone fluids, but the greases produced can only operate up to 400° F. since the lithium soaps melt above this temperature. Silicone greases, thickened with aryhirea compounds, function at temperatures from subzero to 45O°-50O° F., E. A. Swakon told the National Lubricating Grease Institute here. Arylureas, many of which melt above 600° F., are higher melting and more stable than alkylureas, he says, and thus show more promise. Substituted ureas can be made by reaction of an amine with an isocyanate; other methods start with an acid azide or carbamyl chloride. Some of the types of substituted compounds that can be made by varying groups attached to the urea linkage are arylmonoureas, aryldiureas, alkylarylmonoureas, and alkylaryldiureas. Laboratory and field tests have demonstrated the utility of aryhirea silicone greases, Swakon says. In most individual properties, such as mechanical stability or rust inhibition, they resemble common soap-petroleum greases. In two other respects—evaporation and thixotropy at high temperatures—arylurea silicone greases surpass other silicone greases; they are exceptional in performance tests for properties other than gear wear. Arylurea silicone greases are smooth opaque pastes, An NLGI No. 1 grade is obtained with 10 to 30% of thickener. Consistency depends upon the urea compound and its particle size; smaller particles give heavier greases. The electron microscope shows that particles in the grease are rod-shaped and about O.l micron wide and 1 micron long. Arylurea thickeners are not restricted to silicone greases. High melting greases have also been made from petroleum oils, diesters, fluorocarbons, and phosphate and silicate esters, although none of these has the wide temperature range of silicone greases because of the fluid's limitations. 4776
Several of these products, on the other hand, may be more satisfactory for applications involving sliding friction at high load. With arylurea thickeners available, says Swakon, more stable fluids again are needed for evolution of greases useful at still higher temperatures and in more diverse applications. Concurrent with Swakon's discussion of arylurea thickeners, Standard Oil announced that it is starting production of arylurea silicone greases for application in jet engines and guided missiles. No production figures have been released by the company. Oxidized Petroleum W a x . Despite current emphasis on specialized lubricants for extreme operating conditions, soap-thickened greases will supply a major portion of all requirements for years to come, and work on these materials has not been neglected. Paraffin wax obtained in normal refining of petroleum hydrocarbon oils has long been eyed as a practically limitless and non-fluctuating source of saponifiable base for soap-thickened greases, if only an economically and technically sound wax oxidation process could be developed. Manganese dioxide and zinc stéarate catalysis yields a product from which good greases can be produced, according to J. C. Kirk, Continental Oil. Sodium and lithium soaps, says Kirk, give best results with the oxidized wax base; mixed sodium-calcium base also shows some merit. Oxidized wax may be used as such, but much better results are secured through admixture with normal fats and fatty acids. All problems are not yet solved; for instance, yields are low in comparison with those for similar greases made from normal fats; a 50% increase in soap base is required for comparable consistency. Performance characteristics vary, said Kirk, but a sodium base grease made from oxidized wax has given excellent results in high temperature service. Lithium base greases from 75% oxidized wax and 25% hydrogenated tallow fatty acid have given excellent results as multi-purpose lubricants. Motor Greases. Progress in greases for electric motors has been so great in recent years that engineers are now approaching the problem of actually designing desired properties into imCHEMICAL
Free world outproduces communists 10 to one in petroleum industry, says Ole Berg, Jr., British American Oil, speaking before National Lubricating Grease Institute proved greases. Approximate values can be assigned, according to E. G. Jackson, of General Klectric, for such properties as bleeding rate, evaporation, and torque, which in turn depend on oil viscosity, soap type, and soap concentration. Variations in lubricant required by different types of bearings can be defined and specified, although further developments in rust inhibition, oxidization resistance, and other unique properties are still required for further improvement. Oil in Canada. In his general address in the meeting's opening session, Ole Berg, Jr., of British American Oil in Toronto, commented that decentralization of the petroleum industry is most noticeable trend in today's world oil picture. Symbolic of this changing pattern, said Berg, is development of Canadian petroleum industry. As late as 1947, Canada was eighteenth on list of world producers, importing 90% of requirements; today, after $1 billion worth of investment and development, she ranks eighth among producers and meets 45% of her daily requirements of 500,000 barrels through domestic production. Nearly a million dollars a day goes into exploration and production in Canada, bringing in a gas or oil discovery well at rate of one every third day. The free world as a whole produces 11.6 million barrels of oil per day as compared with an estimated 1.2 million for Russia and her satellites. This 10-fold lead in favor of fredeom, however, must be qualified by consideration that communist production is almost exclusively for the military, Berg warned. AND
ENGINEERING
NEWS
-* ιοα% ^ Polymerized Petroleujn . Resin
PICCOPAUE > a new petroleum ^available
BASIC KAW
in °}^| Λ / \ Jf% t ^ ρ ^ jzrs:
quantities
(^2§0ΐΐ5ί
6y //if» trainload
β $ low cost J per
MATERIAL
if yCH-CH=c'
Hfi
Ο Ο CHj-C-CH-C-O-CHaCHi HzC-CH=CHa Ο II HaC-CHjfO-C-CH^NHN
ETHYL-0/-ALLYLACETOACETATE
ETHYL DJAZOACETATE
OH,
Prepared by U. S. Industrial Chemicals Co.
ADVERTISEMENT—This entire page is a paid advertisement
U.S.I. CHEMICAL NEWS
November
CONTINUED
Allethrin Intermediates
double bond, the ketone group, and the termi nal methyl group. 2,5'Dimethylhexane-2,5'dioI — is a mildly aromatic crystalline glycol which undergoes such reactions as cyclization on treatment with dehydrating agents, ammonia, or amines. One or both of its hydroxy] groups can be reacted to produce esters, ethers, etc. 2,5'Dimethyl-2A-hexadiene — is a highly re active liquid hydrocarbon of symmetrical structure which contains two conjugated double bonds. It lends itself to a variety of condensation reactions, including the DielsAlder reaction with various dienophils. Ethyl-q-allylacetoacetate — is subject to the wide variety of reactions typical of a c e t o acetates. It can be reduced with sodium and alcohol to yield ^-ailyl ethanol. It reacts with hydrazine hydrate to form an allyl-substituted methyl pyrazolone, and with phenols to form allyl-substituted methyl unbelifferones. Ethyl diazoacetate derivatives—ethyl diazoacetate has been known for a long time and has been used widely in various laboratory syntheses. One of its many unique applica tions is its addition to aliphatic as well as aromatic double bonds to form cyclopropane derivatives. in spite of the many applications alreadyknown for this chemical on a laboratory scale, commercial use has been handicapped up to now by its relative instability and handling hazards. However, in the commercial produc tion of allethrin. U.S.I, now has extensive facilities designed to handle large quantities of ethyl diazoacetate safely. While it is im practical to supply ethyl diazoacetate as such even in sample quantities, U.S.I. is prepared to make these facilities available to other manufacturers for the synthesis of various derivatives. Research chemists and others in terested in its possible use are invited to contact l.S.I.'s Chemical Sales Department, 120 Broadway, New York 5, Ν. Υ.
ALCOHOLS Amy! Alcohol (Isoamyl Alcohol) Butanol (Normal-Butyl Alcohol) Fusel Oil — Refined Propanol (Normal-Propyl Alcohol)
CONTINUED
Milk Protein Deficiency
1953
TECHNICAL DEVELOPMENTS
Information about manufacturers of these items may be obtained by writing U. S. Î. A new flame proofing: chemical for cotton is claimed to make fabric impervious to combustion up to 4,500° F. and to resist repeated laundering and dry cleaning. (No. 980)
any method of drying, and that milk proteins are inherently low in cystine and methionine. F u r t h e r work is needed on the use of milk in human nutrition with regard to supplying adequate methionine. As a pioneer producer of Di.-methionine. U.S.T. carries strategically located stocks for supplying this amino acid to the animal feed and pharmaceutical industries.
«L-Ethionine, a methionine antagonist and inhibitor of some tumor growths, is now available as a research tool in methionine metabolism investigations a n d cancer studies. (No. 981)
Develop New Test Far Soil Phosphorus
A new aerosol valve for pressurized products is designed to operate at the slightest touch -when the valve head is moved in any direction. Device is said to allow faster pressure filling than any other on the market. (No. 982)
A rapid and reliable test has been developed for measuring; soil phosphorus in both acid and alkaline soils, according to a recent an nouncement. Information from the test is said to indicate, with greater accuracy than tests commonly used, where the addition of phos phate fertilizer will produce a response in increased crop yields. The new method is based o n relatively new knowledge of the reactions of calcium phosphates in the soil and the influence of these reactions on plant uptake of phosphorus. The test can be made in less than an hour and is readily adapted to routine procedures. During the past two years, the test has been used to measure phosphorus fertility in more than 20O soils from various sections of the country. Using t h e uptake of radioactive phosphorus a s a measuring stick, workers have found a close correlation between the amount of phosphorus taken up by the plant and the extent to which yields are increased. Field results with the new method indicate that most soils showing a level of less than 50 pounds of phosphoric oxide per acre will respond -with increased crop yields when phos phates a r e added. Above that figure, no re sponse would generally be expected from phosphate additions except in such crops as potatoes which have a small root-zone feeding area, it i s said.
ANSOLS Ansol* M Ansol* PR Ethanol (Ethyl Alcohol) ACETIC ESTERS Specially Denatured—all regular Amyl Acetate—Commercial and anhydrous formulas and High Test Completely Denatured—all regular Butyl Acetate and anhydrous formulas Ethyl Acetate—all grades Pure—190 proof U.S.P., Normal-Propyl Acetate Absolute—200 Proof OXALIC ESTERS Solox*—proprietary solventDibutyl Oxalate regular and anhydrous Diethyl Oxalate ANTI-FREEZE PHTHALIC ESTERS Super Pyro* Anti-Freeze Diamyl Phthalate U.S.I. Permanent Anti-Freeze Dibutyl Phthalate Diethyl Phthalate ETHERS OTHER ESTERS Ethyl Ether, U.S.P. Diatol* Ethyl Ether, Absolute—A.CS. Diethyl Carbonate ACETONE—A.C.S. Ethyl Chloroformate
RESINS (Synthetic and Natural) Arochem*—modified types Arodure*— urea-formaldehyde rosins Arofene*—pure phenolics Aro flat*—for special flat finishes Aroflint*—room temperature curing phenolic Aroplaz*—alkyds and allied materials Aropol*—copolymer modified alkyds Ester Gums—all types Natural Resins—all standard grades INSECTICIDE MATERIALS Allethrin CPR Concentrates: Liquid & Dust Piperonyl Butoxide Piperonyl Cyclonene Pyrenone* Concentrates: Liquid & Dust Pyrethrum Products: Liquid and Dust Rotenone Products: Liquid and Dust INSECTIFUGE MATERIALS
Indalone*
Triple-Mix Repellents
U.S. I nausTRim
Division of National
1 2 0 BROADWAY, NEW YORK 5 , Ν. Υ .
Electric socks, similar in principle to electric blankets, are now available for hunters, skiers, other cold-feet sufferers. Warming wires aro interwoven, connect by insulated -wires to a small battery worn on the belt. (No. 983) Paper thermometers, graded series of heat-sensitive coated papers, are calibrated to determine temperatures from 113° to 580° F. with accuracy of 1%, change permanently from white to black at stated temperatures. (No. 984) An effective rust-removing, corrosion-retarding, andl paint-conditioning technique for metal is reportedly available in a single treatment -with a new acid phosphate cleaner. Conditioner imparts superior impact-resistance to paint, the manufacturer states. (No. 985) A new brake-lining compound contains copper to dissiipatti heat una lead to act as lubricant. One application is claimed to give increased safety and to nearly double life of the lining. (No. 986) A new, stable organic active chlorine compound has been announced commercially. Compound contains at least 66% available chlorine, of which only 2% is lost after storage for 14 weeks at 140° F., according to the producer. (No. 987) Pipe leaks can b e sealed quickly, it is claimed, with, a new cast iron fitting -which encloses the leak within synthetic rubber gaskets, forms a gas-tight chamber that equalizes pressure inside and outside the pipe. (No. 988) New silicone resins can be foamed to form lightweight, nonflammable reinforcing or insulating structures of high compressive strength. Halfincti sections are claimed to show no significant decomposition on being brought to red heat in open flame. (No. 989) INTERMEDIATES Acetoacetanilide Acetoacet-ortho-chloroanilide Acetoacet-ortho-toiuidide Acetoacet-para-chloroanilide Ethyl Acetoacetate Ethyl Benzoylacetate Ethyl Sodium Oxalacetate FEED PRODUCTS Calcium Pantothenate (Feed Grade) Choline Chloride Curbay B-G* 80 DL-Methionine (Feed Grade) Niacin, U.S.P. Riboflavin Concentrates Special Liquid Curbay* U.S.I. Vitamin Βχ2 and Antibiotic Feed Supplements Vacatone* 40 OTHER PRODUCTS Acetaldehyde Metallic Sodium Caustic Soda Methionine (Pharm.) Ethylene N-Acetyl Du-Methîonîne IPC (Isopropyl-NNitrocellulose Soins. Phenyl Carbamate) Propionaldehyde C I PC Propionic Acid Liquid Chlorine Sulfuric Acid Urethan, U.S.P. *Reg. U.S. Pat. Off.
iHEmitnis Co Distillers Products Corporation BRANCHES IN ALL PRINCIPAL CITIES
TECHNOLOGY
cides with the upper surface of the sodium chloride. Choice of sodium chloride was dictated, in part, b y the atomic relationship of chlorine whose intimate contact serves to enhance sul fur excitation. A molybdenum x-ray target is em ployed. Collimation ratio is 400 to one, using a four-inch length of parallel plates at 0.010-inch spacing. Helium at atmospheric pressure is employed in the radiation path, and rock salt is used for an analyzing crystal. Intensities are measured at the sulfur K-alpha line and adjacent areas for background. Analysis of results obtained leads to the conclusion that the method has a probable sensitivity limit of 0.05% sul fur in oils.
PLANT
NEW
M O R E
Q O
F U R F U R Y L
A L C O H O L !
Natural Gas Substitute O n the W a y , Says IGT
An acceptable substitute for natural gas may b e available within a year, says E. S. Pettyjohn, director, institute of Gas Technology'. I C T has been working on this project since 1947. A substitute for natural gas has been produced at I G T by autohydrogenation of high B.t.u. oil gas. Last year was the first time a conversion to gas was accomplished without a solid or liquid residue resulting in the operation. Some of the work done at the institute w a s reported in a paper presented be fore the Division of Gas and Fuel Chemistry at the Chicago ACS meet ing bv H. R. Linden, C. E. Brooks, and L. N. Miller. New research projects planned by I G T for the coming year include a fundamental study of combustion char acteristics and radiant heat transfer in open flames, and a study of storage of hydrocarbons for peak loads.
N e w Furfuryl
V O L U M E
3 1,
NO.
Plant,
Memphis,
Tennessee
Quaker Oats is happy to announce the opening of its new plant a t Memphis, Tennessee for the production of furfuryl alcohol. The new plant is designed for the manufacture of a high quality product and is so sized that it further improves the good availability outlook on this chemical. This is good news to the growing number of industries which have found FA useful in the manufacture of a wide variety of products including resinous mortars, cements, binder resins, grinding wheels, textiles (furfuryl alcohol is used as a solvent for the dyes required in the printing operations), and in craze resistant gap filling urea adhesives* FA is derived from agricultural residues—the abundant supply of which is renewed annuaiiy. Now, with the new processing facilities, more and more industries can profit from the advantages of using furfuryl alcohol.
^ P h o t o g r a p h i c film molded almost into the shape of a bowl is one of the operating secrets of a highly efficient meteor camera being used by Harvard College observatory. The film, devel oped by Eastman Kodak, is molded after it is sensitized. The camera has a wide enough field to cover an area 10,000 times the size of the moon. ^ F e r r - O - N i e l pickling process devel oped by Nielco Labs provides a means for continuous pickling of steel with out involving a special and costly dis posal system, thus eliminating pollu tion of streams. Phosphoric acid is used as a base for the pickling solution. As iron phosphates accumulate in the bottom of the pickling tank, they are removed; fresh acid is added to bring the pickling solution u p to its original strength. Tank used can b e of stainless steel, wood, or acid-resistant tile.
Alcohol
How about your you investigated Furfuryl Alcohol
product—have FA? Send for Bulletin 205.
•Reg. U. S. PaL Off.
The Quaker Oafs (bm pany
46 - N O V E M B E R
J II LI 16,
1953
3 3 3 E The M e r c h a n d i s e M a r t , C h i c a g o 5 4 , Illinois R o o m 5 3 3 E . 1 2 0 W a l l St., N e w York 5, N . Y . R o o m 4 3 3 E , P . O . Box 4 3 7 6 , P o r t l a n d 8 , O r e g o n In Europe: Quaker Oats-Graanproducten N . V., Rotterdam, The Netherlands, Quaker Oats (France) S. Α., 3, Rue Pillef-Will, Paris IX, France In Austral!*»: Swift & Company. Ply., I f d . , Sydney In Japan: F. Kanematsu & Co., l t d . , Tokyo
4781
