NBS Issues Five Gamma-Ray Standards - C&EN Global Enterprise

Nov 6, 2010 - Five solid point-source standards of radioactivity are now available from the National Bureau of Standards, Washington, D.C. They are ...
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CHEMICALS

A new and complete line of vinyl stabilizers

PROTECT YOUR VINYL PRODUCTS AGAINST HEAT AND LIGHT T h e i m p r o v e d line of Metasap vinyl stabilizers is y o u r dependable and economical a n s w e r to the deteri­ oration found in vinyl products when they a r e e x p o s e d to heat a n d light. A n d , as always, Metasap chemists will welcome t h e opportunity to make r e c o m m e n d a t i o n s based on your spe­ cific n e e d s . W e invite your inquiry.

φ Indium Antimonide: 99.999999 + % Pure Indium antimonide specimen, to b e used in low temperature transistors a n d in IR detectors, is 99.999999' r /r pure, says developer Battelle Memorial Insti­ tute. Here, a Battelle scientist studies the pendant-shaped metal crystal, suspended in the glass column of t h e purification apparatus. Ttie special equipment was developed at the institute's Columbus, Ohio, research center. Without removing the crystal from the apparatus, it was first zone refined in the horizontal quartz tube, then poured into the furnace crucih>le, Next the indium antimonide was pulled into the vertical glass column. Battelle is studying the basic properties of crystals like ^his for t h e -Air Force Office of Scientific Research. It is also investigating uses of indium antiI monide in galvanomagnetic devices for the Wright Air Development Center.

NBS Issues Five Gamma-Ray Standards Write today for your copy of the new Metasap Vinyl Stabilizer file. It contains complete information about the types; properties and suggested, uses of all products in the line.

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ΠΗΡΜΙΠΔ! Γ.ίΊΜΡίΝΥ 6 0 Park P l a c e · Newark, N . J . A subsidiary o f Plants: Harrison, N.J. · Richmond, Calif. Cedartown, Ga. · London, Canada

56

C&EN

NOV.

16,

1959

Five solid point-source standards of radioactivity are now available from t h e National Bureau of Standards, W a s h ­ ington, D.C. They are sodiurn-22, zinc-65, niobium-95, strontium-85, a n d mercury-203. T h e standards are gamma ray emitters, can be used to a p ­ proximate ideal conditions i n calibrat­ ing scintillation counters and other beam-detecting devices, t h e b u r e a u says. Nb°"\ Sr s n , a n d Hg 2 0 3 have been available in a liquid form from NBS in sealed glass ampoules (C&EN, Oct. 12, page 8 8 ) . T h e emitters are issued under t h e bureau's program t o supply standards in

all areas of the physical sciences. Each standard consists of radioacrtive mate­ rial deposited between two layers of a thin polyester tape. I n this form, t h e nuclides have an activity of about 5 X 10 4 gamma rays per s e c o n d . Sodium2 2 has a half-life of 2.6 years and emits a gamma ray of 1280 k.e.v. energy. It also gives off an annihilation gamma r a y of 511 k.e.v. energy and x-radiation characteristic of neon. Zinc-65 emits a 1110-k.e.v. gamma ray, annihilation gamma ray of 511 lc.e.v-, and x-rays like copper. It has a 45 d a y halF-life. F u r t h e r information on these stand­ ards is contained in S t a n d a r d Materials, NBS Circular 552 (3rd edition, 3 5 cents). Write to the Superintendent of Documents, U.S. Government Printing Office, Washington 25, D.C. a

SILICONE

N E W S

from

D o wCor

ning

Knock-Out Drops For Foam!

Control Foam in Any Type of System with Low Cost Silicone Defoamers Does foam occur in your process operations? Chances a r e you c a n keep it under control a t all times with a Dow Corning silicone clefoamer. J o b p r o v e d in virtually every industry . . . petrochemical, textile, paper, paint, food and m a n y others . . . Dow Corninp: silicone defoamers knock down the most violent a n d persistent foam. Eliminate processing slow-downs and boil-overs. Reduce fire hazards. Cut waste and clean-up costs. And Dow Corning silicone defoamers a r e amazingly effective i n m i n u t e quantities. F o r example, just 1 ounce of a Dow Corni n g silicone clefoamer prevents foam in 31.250 pounds of clog shampoo, in 59.110 p o u n d s of wire d r a w i n g solution, and in 62.500 pounds o f paper coating solution . . . are similarly effective i n defoaming adhesives. latices. caustic liquor, soap, varnish, emulsion paints and coatings, cutting oils, petrochemicals, food p r o d u c t s . . . m a n y , many o t h e r s .

AVAILABLE IN HANDY SPRAY CAN

Dow C o m i n g ' s c o n t i n u i n g research study of foam and its control has b r o u g h t about the availability of silicone defoamers as c o m p o u n d s a n d emulsions for different

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types of production systems — a n d in handy spray cans for split-second defoaming of smaller b a t c h processes. Settle your foam problems once and for all time with a Dow Corning silicone defoamer. A gene r o u s trial sample is yours f o r the asking. Indicate your problem and system — oil, aqueous, nonaqueous, food product, o r any other. W r i t e Dept. 2823a for a rapid reply.

Your nearest Dow Corning office is t h e number one source for information and technical service on silicones.

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CORPORATBON MIDLAND

ATLANTA

BOSTON

CHICAGO

CLEVELAND

DALLAS

LOS ANGELES

N E W YORK

MICHIGAN W A S H I N G T O N , D. C.

buyASCOfor accurate^ ACCU-VAC ABSOLUTE VACUUM and

PRESSURE

GAUGES • Precalibrated · Not damaged by vacuum leaks or pressure fluctuation · A l l internal parts corrosive resistant · Light—weighs only 20 ounces · 4 " Diameïer dial set in black enamelled plastic case

The Accu-Vac gauges combine accuracy, sensitivity, ease of installation and ease of reading in popular ranges of O-20 mm., O-40 mm. and 0-760 mm. Hg. Accu-Vac gauges may be flush-mounted on instrument panels, or directly mounted into the line by use of the threaded coupling or rubber tubing coupling provided with the instrument. Both graduations and figures are large and accurately readable. Accuracy is 2 parts in 1O00 ana ail the gauge's internal parts are coated with chemically deposited nickel to resist corrosion. Model Pressure Range Each

A120

A140

A160

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0-40 mm. Hg. $94.00

0-760 mm. Hg. $94.00

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750 hour battery l i f e Lightweight Porta le Self-calibrating AVz" rectangular dial, angle set for easy reading • Rugged construction

« Low temperature thermocouple insures contamination-free readings and continued accuracy · Long tube life · No instrument drift · Instruction provided

Designed for accurate vacuum measurement in the range of 0.5 to 10O0 microns Hg. To operate, one simply connects the gauge tube to the vacuum system; no external power source is required. Finished in gray hammertone cabinet with carrying handle. Complete with gauge tube

$1Q4°° .^1500

Replacement tube, each

Dràcï/eà/ï WATER-COOLED O I U DIFFUSION P U M P • All steel construction · Ultimate vacuum : 5 χ ΙΟ- 6 m m . · Two-stage • Requires only 15 ml of pump fluid • Easy to clean · Light, portable • Speed: 15 liters per second at 10- 4 mm.

each * 7 6 0 0 —

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311 ALEXANDER S T . , ROCHESTER 4 , Η. Υ.

C&EN

NOV.

16,

Briefs . . .

19 59

• Rust solvent has good wetting power, penetrates into rust-frozen surfaces faster, according to its maker, Key­ stone Lubricating, Philadelphia, P a . Called K O P N o . 1, it is furnished in 1-, 5 - , 15-, 30-, a n d 55-gal. containers.

• High purity rare earth metals a n d alEoys are now available from Ronson Metals, Newark, X.J. T h e metals, in­ cluding Mischmetal, cerium, lan­ t h a n u m , a n d didymium, are furnished C7 as finely divided powers or a s ingots, rods, pellets, and turnings in purities • Plastic glazing material is unbreak­ of 9 9 . 5 to 99.9 r < , t h e company says. able, has good insulating characteris­ Uses: missile a n d rocket propellants, tics, says maker American Poly glas, pyrophoric alloys, solid state devices. Carlstadt, N . j . Designed for use in C1 chemical plants where window break­ age is a problem, Polyglaze resists cor­ • Ten research intermediates come rosion a n d temperature extremes, h a s from Sapon Laboratories, Valley good light transmission, a n d installs as Stream, Ν . Υ. T h e c o m p o u n d s are easily as glass, the c o m p a n y says. C 8 3-aminohexane, 3-chloropropylphthalimide, 4-diethylaminobutanol-l, di-2- k U.S. distributor of Procinyls (reac­ hexyl-5-ene amine, 5-dimethylamino- tive disperse dyes) is Arnold, Hoffman amyl alcohol, dimethyl ethylamine, & Co., Providence, R.I. Developed b y 2-ethylaminoethyl bromide hydrobro- Imperial Chemical Industries (C&EN, mide, hexamethylacetone, a n d 1- Oct. 5, page 5 3 ) , Procinyls color nylon methyl-3,4-dihydroisoquinoline. C 2 a n d other polyamide fibers. They a r e available in Canada from Canadian • Self-emulsifying additive for pulp Industries Ltd., Montreal, Q u e . a n d p a p e r mill operations is m a d e b y ( C & E N , Oct. 12, p a g e 9 0 ) . C9 H o d a g Chemical, Chicago, 111. A n antifoam agent, H o d a g W R - 3 2 1 forms a • ^-Aminolevulinic and its precursor, homogeneous emulsion which is stable δ-oximinolevulinic acid, are n o w sup­ on further dilution. It improves ash, plied b y Chemicals Procurement, N e w pick, a n d other properties of paper York City. Both compounds can b e stock, the company says. C 3 used in studies of t h e succinate-glycine cycle, t h e company says. CIO • Aisle marking protective finish, by

Hauger-Beegle Associates, Chicago, 111., is available in signal yellow a n d international orange. F o r application by brush or roller, the material is based upon a modified epoxy adhesive formu­ lation, resists abrasion, and shows good adhesion, t h e c o m p a n y says. C4 k N e w antiknock for a u t o m o t i v e gasoline h a s been developed b y Ethyl Corp., N e w York City. A mixture of tetraethyl lead ( T E L ) a n d methylcyclopentadienyl manganese tricarbonyl, it is t r a d e n a m e d Motor 3 3 Mix. Com­ pared to t h e u s e of T E L alone, 3 ml. of T E L as Motor 3 3 Mix can a d d u p t o 3 octane n u m b e r s to t h e most respon­ sive gasolines, the company says. C5 • Chromatograph nonpolar substrate

Fills the need for simple economical attainment, of high vacuum operating pressures at the rate of 15 liters per second. Built of carbon steel, the ASCO iflr 1" Diffusion Pump will operate against aforepressureof 0.5 mm, permitting operation with any standard single-stage mechanical pump.

58

CHEMICALS

has been a d d e d to its line by Fluorocarbon C o . , Fullerton, Calif. Devel­ oped from tetrafluoroethylene, Fluoropak 80 is inert to many chemicals, has a working range u p to 300° C , t h e com­ pany says. T h e substrate almost elimi­ nates tailing in analysis of polar com­ pounds such as water, amines, alcohols, and acids, Fluorocarbon adds. C6

• Organic halogen analytical reagent,

diphenyl sodium dimethoxyethane, is being m a d e by DistAnal, Baton Rouge, La. T h e reagent determines fluorides, chlorides, bromides, a n d iodides in in­ secticides, polymers, solvents, and other organic compounds, says DistAnal. C 11

• Plastic material of a resin-rubber blend h a s been developed b y Naugatuck Chemical Division, U. S. Rubber, N e w York City. A m e d i u m impact plastic, it is designed for molding prod­ ucts with high rigidity and resistance to cold flow, U. S. R u b b e r says. It has low moisture pick-up, high abrasion a n d corrosion resistance, and withstands h e a t s u p to 200° F . , the company adds. C 12 • Epoxy coating with 100% solids is

n o w possible by using two new curing agents, says maker Shell Chemical, N e w York City. T h e curing agents give controlled reactivity, need n o heat to effect curing, a r e n o t affected a d ­ versely by high humidity, a n d will not b u r n ( w h e n used with a liquid E p o n

We Have Taken the "Rare" out of "Rare Earths" You Now Have a Wide Choice of Readily Available

Materials

a r e p o r t by LINDSAY

W e w e r e thinking t h e other dav of t h e progress we have m a d e in taking t h e " r a r e " out of "rare earths." Even t h e " e a r t h " in rare earth is not completely descriptive, either. Actuallv, the name rare earths d o e s fît these elements into the periodic system, for they are e a r t h y when in t h e form of oxides. In this respect, they r e semble the "earth" elements, aluminum b e i n g a good example. T h e "rare" c a m e from t h e fact that t h o s e w o n d e r f u l chemists of t h e last centnrv t h o u g h t that thev w e r e indeed rare, since t h e only supplies available were derived from q u i t e r a r e a n d exotic m i n e r a l s found then in a very few pegmatitic deposits in Norway. Now, of course, y on can buy rare earths in almost any size, shape and form. You can order in grams, ounces, pounds, and in many cases in carloads! T h e s e elements have been described b y o t h e r n a m e s such as "lanthanides" a n d " l a n t h a n o n s . " Technically, t h e s e a r e t h e elements l a n t h a n u m , a t o m i c n u m b e r 57, and the next fourteen elem e n t s in the periodic system.Thus,rare earths include all t h e elements from atomic number 57 t o 71 (lanthanum t o lutetium). D u e to some remarkable similarities in properties, the rare earths tend t o occur together in n a t u r e . These s a m e properties m a k e it difficult to separate t h e m in some cases. From the s t a n d p o i n t of a v a i l a b i l i t y of c o m m e r c i a l materials, t h e r e are several choices. Rare Earth Materials. T h e ore mineral c o m m o n l y u s e d a s a s o u r c e of r a r e e a r t h s is m o n a z i t e . R a r e e a r t h s e x t r a c t e d without any appreciable separation are marketed commercially a s

High Purity M a t e r i a l s . TLindsaxj pioneered the first commercially installed ion exchange plant for t h e production of individually separated rare e a r t h s in purities up to 99.993?. These high puritv materials are now readily available at prices which were unheard of only a few vears ago.

THE RARE EARTHS ATOMIC NUMBER

ELEMENT

Yttrium Lanthanum Cerium

39 57 58 59 60 62 63 64 65 66 57 68 69 70 71 90

1

Neodymium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium

1 1 | 1 1

Thulium

1

Many applications. W e have m a d e remarkable progress . . . through the development of improved teohnicmes for the séparation of the rare earths, and expansion of production facilities . . .in taking t h e "rare" out of "rare earths." Needless to sav we were compelled by c o n s i d e r a b l e u r g e n c y to satisfy the rapid growth in demand by industry for many new uses.

1

Ytterbium Lutetium Thorium



·

·

W e have prepared a revised edition of our technical data describing our rare earth, vttrium and thorium materials. Your request for the "Lindsay Binder" will bring you this collection of data prompt! v. If you have a specific idea or use in m i n d , let us know and our technical people will try to supply pertin e n t data.

1 "rare earth" salts or materials. They contain these elements in about t h e same ratios as in the ore: roughly onehalf c e r i u m , o n e - q u a r t e r l a n t h a n u m , one-fifth n e o d v m i u m , a b o u t five p e r cent p r a s e o d y m i u m , a n d s m a l l e r amounts of the other rare earths. Being close to the starting material, "rare earth" salts are t h e most economical. Cerium. Cerium is the most important single rare earth, relatively easv to separate and available in a rather con V t e range from commercial to high purity grades. Didymium. Taking cerium out of t h e rare earth mixture leaves a collection of rare earths we call "didymium." Didymium materials, like cerium, a r e close to the starting; ore, so costs aren't excessive.

We shoia you this photo of bvilk handltJig of rare eartJi intermediates at our West Chicago plant to suggest that rare eartJi materials are produced in large tonnages. They are available? for prompt shipment, some of them in carload quantities. Prices, incidentally* are surprisingly low.

PLEASE ADDRESS INQUIRIES TO

LINDSAY C H E M I C A L D I V I S I O N

American Potash & Chemical Corporation

τΗΜΙΕ

266 A N N STREET · WEST CHICAGO, ILLINOIS

O F F I C E S : CHICAGO

·

LOS

ANGELES

·

S A N FRANCISCO

·

NEW

YORK

·

P O R T L A N D (ORE.)

·

ATLANTA

·

COLUMBUS

Co.)

·

SHREVEPORr

CHEMICALS

C&EN PROGRESS REPORT Commercial Chemicals C o m p a n i e s a d d e d these products to their lines during the past f o u r

2-Ethylhexyi acrylate Dimethylacetamide Organic titanium compounds (tetraisopropyl, totrabutyl. tetrakis (2-ethylhexyl), tetraoctylene glycol, and tetrastearyl titanates; triethanolamine titanate ester Thorium ehloranilate Hydrobromic acid, 48% Reactive unsaturated alcohol ( 2-hydrox\ methyl-5-norhorneiie ) Magnesium oxide, 99% pure Catalysts ( dibutyltin di-2-ethylhexoate, dibutyltin dilaurate, stannous octoate, and stannous oleate) Dihydropyran ( 2,3-dihydro—t-iZ-pyran ) Herbicide (Carbyne; 4-chioro-2-but\ nyl A T -(3-chlorophenyl )carbamate ) Scandium, 99% pure

Suggested Uses Include Protecting rubber against ozone attack, Hex cracking, and heat Controlling deep rooted weeds and hard-to-kill weed trees Making polymers for the paint, textile, paper coating, and adhesive fields Polymer solvent, chemical reaction cat­ alyst and medium, and crystalliza­ tion solvent Reaction intermediates, adhesion pro­ moters, and pigment dispersants

Company Arnold, Hoffman & Co. Providence, R. I. Allied Chemical Xew York City Celanese Chemical Xew York City Du Pont Wilmington, Del.

Material Antiozone chemical (p-isopropylaminodiphcm lamine ) Herbicide ( Urab )

weeks

Du Pont Wilmington, Del.

Fisher Scientific Pittsburgh, Pa. Food Machinery & Chemical New York City Interchemical New York City International Minerals & Chemical Chicago, 111. Metal & Thermit Rah way, X . J . Quaker Oats Memphis, Term. Spencer Chemical Kansas City, Mo. St. Eloi Corp. Cincinnati, Ohio

Determining fluoride colorirnetrically Reaction intermediate Improving properties of condensation and addition polymers Reagent chemical, stabilizing and vul­ canizing agent for rubber, acid neutralizer Making methane foams Making intermediates for synthesis of lysine; scmicommercially available Controlling wild oats; experimental quantities available Alloying with magnesium or tantalum; experimental quantities available

Available in commercial quantities unless otluiwist noted

resin b a s e ) . Shell claims. Because of these hardeners, the coating can be sprayed on a surface with conventional equipment, the company· adds. Shell foresees such uses as lining storage tanks, marine ballast, and cargo tanks. C 13 • Micro-fine

metal

oxides

are

now

available in development quantities from Monsanto Chemical, St. Louis, Mo. Trademarked Micria, the series consists of A D and AL ( aluminas), TIS (titania), and ZR (zirconia). Sug­ gested uses: catalyst carriers, polish­ ing agents, organic dye stabilizers, whiting agents, thermal insulators, flow agents, solvent thickeners, and rein­ forcing agents. C 14 60

C&EN

NOV.

16,

1959

• High

purity

potassium

silicate

is

now available from Sylvania Electric Products, New York City. Called PS-T, the silicate solution contains 3orf solids. Because of its high concentration, PS-7 will enable such users as cathode ray tube makers to save on shipping, han­ dling, and storage costs, the company says. C 15 • Paint and finish remover will not corrode magnesium, aluminum, brass, or any combinations of these metals, says developer Beck Equipment, Cleve­ land, Ohio, Epoxystrip NC-194 re­ moves finishes such as epoxies, polyurethanes, and acrylics as well as con­ ventional paints, lacquers, and enamels, the company says. C 16

• Ziegler catalysts—triethvl aluminum, diisobutylhydride aluminum, and tri— isobutyl aluminum—are now supplied commercially by Henley 6c Co., New York City. Samples are available on request, the company says. CIΎ • o-Anisaldehyde, a pharmaceutical and chemical intermediate, is made by Ansul Chemical, Marinette, Wis. The compound is furnished in quantities from 1-lb. bottles to 55-gal. drums. €18 I j j

Further useful information o n keyed Chemical items mentioned is readily available. - ·

ι

Use handy coupon on page 74 φ