* * * Present Status
of
E.R. BRIDGWATER E.I. du Pont de Nsmoun & Company, Inc., wilmin(lton, Dd.
Neoprene Conveyor Belt for Carrying Oily Brick
Blank -y.
T
Grst quastion a layman asks about any synthetic rubber is: Is it satisfadory for tires? There is no “yes” or “no” a w e r to mchaquestion. First youmustask: Sat&factory to whom or for what kind of tire? Few automobile owners realize bow greatly tire life is influenced by the d e sign of tbc car, its mecbanid condition, climatic and road conditions, and, above all, the speed and driving habits of the opemitor. Tires could be made from hundreds of synthetic rubbers that would look and feel like natural rubber tires and would give satisfactory service to an owner who keeps his paesen%er car in good mecbanical condition, drives only on gd roads and at moderate speeds, a s p e d l y around nwes, and accelerates and decaleratea slowly. For example, a fairly gd synthetic rubber can be d e by polymeri5ii isoprene or butdiene alone, either in a single-phase system or in an aqueous emulsion. Better products can be made hy inteqolynmiziq these hydrocarbons with other compounds containing active vinyl groups mcb as styrene (vinylbensene), acrylonitrile (vinyl cyanide), vinylidene chloride, methyl vinyl Iretone, methyl metbacrylate, or any one of a hundred other vinyl-subtituted hydrmhons, chlorinated bydm csibons, alcohols, e&, aldehydes, ketonas, acids, esters, nitrileu, etc. Another intereshg poup of synthetic rubbers wmprk the int8rpoIymers of a diene, mch as butadiene, with LUL OW, such as isobutylene. Then, too,we have the polymer8 of chloroprene and, like butadiene, chloroprene can i n t e r p l y m e with a wide range of vinyl compounds to e v e mmmercdy valuable products. Momver, dienes may be polymerbed with other dienea-e. g.. butadiene with c b l o r o p r e n ~there are many tbree-way interpolymers
d a P.nt
lhm-r
which poasesa unique and interesting properties. Them io almost no limit to the range of synthetic rubbers from wbicb tires can be made. Synthetics for Tires
However, the problem is not merely to produce synthetio rubbers from which tires can be made, but rather to produoe Bynthetics which will perform as well as natural rubber under n o d service conditions and wbicb can be produced emnomicslly from materials at band. Tbe list of synthetic rubbers that bave been found fully to meet theee requirementm io much aborter. Let UB 6rat consider what products are available that bave proved the equal of natural rubber for tire treada Streat and Ebert (3) stated that road teata on psenger ~ B Ttins bad &own the butadienestyrene interpolymers, neoprene, and butadi-crylonitrile interplymer8 to be equal to natural rubber in h a d wear. They pointed out that rubber manufacturers may bave to modify their equipment or prooessing techniques to uw thew synthetic rubbers in h a , but they believe that in o ~ s eof emergency we would not be Seriody handicapped fmm the standpoint of quality by the introduction of synthetic rubbers in pwenger car tire treade. Subsequent work hss demonstrated that truck tire treade made from certain of thme aynthetic rubbers may be delinitely superior to natural rubber compounds under unueually eevere conditione. The use of Syntheticrubbers in tire carcam stocks in lpas well developed than their use in tire treade. The industry hae not yet suflioient experience with synthetic rubbers in truck tire
Synthetic Rubber * * * carmesea to permit us to say tbat we could dispense with nab 0the.r Synthetics ural r u b h without sscri6ca of q w t y . On the other band, In addition to the butadiene interpolymers and the rn there is evidenoe tbat oertain typea of syntbetie rubber comprenes, another type of synthetio rubber-the polslulfids pounds may be actually superior to natural rubber for the rubbers--csn be used for m a y of these industrial produoto. o l l l c ~ ~ ~of e atruck tim operated at extremely high tempershues. Fwtherroad~enceisrequiredundervsryingserv- Although unsuitable for tiw and other prod& that must ioe conditions before definite mndueions em be drawn. withstand 8 ~ v mmechsniosl &wesw or high h p m a t u m , the polytrulfide rubbers have found important indudrid a p The development of 0 8 ~ 8 8 8compounds for car tires is a muoh essier problem. The hutadienwtymnemter- plicationsinhose,gsskets,anda wide variety of 0 t h me cbanioal goode. Their uea muld be greatly pa*mded if ow polymers and oolrtaintypeaof neemare &&my. Howsupply of crude rubber were shut ofi. BVPP, it mamu likely tbat if we should s&er a serious shortIn nuoh an emergenoy the prduot h o d as butyl rubber age of natural r u b h , mwmger car avoILBg stoclra would be would also play an important part. Although ths rubber made largely from reclsimed NWand the available qusnindustry has had little experhw with this produat# idtitiea of then synthetics would be used in treada. Despite the faot tbat about 76 per oent of our national con- cations are that it could be used as a substitute for natural rubberin many produota, especially insulated wire. sumption of natural rubber k used in k, other wen are just In addition to the eyntLwtio rubbers mentioned above, a as -tial to our 0ver-d ddenw e5ort. Ten yearn ago a number o f n o n v u l c s n i r a b l e p I a s t i c s k m 5 d e n t ~ c e complete cesation of s u p p h of natural rubber would have to rubber to d o w their uea as suhtitutea for it in c8rtein Stopped the wheel%of most,if not all, of our indwtrh; but applications. outatan* are the pkstioLed pQlyvinylohloduring the paet ten yema rubber manufaeturm have adapted e s and ‘‘VinfiW’. eynthetiorubhtothowmdsof usesforwhiohtheyhavebeem rides, sold under the trade ~ ~ m “Kmceed” TheybavefoundimportsntupplioationsininauktedBireand found to be superior to the natural pmduot. In eo doing they have acquired a bfv2kgound of experience that will em- - o e r t a i n t p e a o f o o a t e d f a b r i c s w ~ t h e y a r e a b ~ t o ~ a bigher price than natural rubber, and if cost mre no objeot, able them to use one or another of the available synthetics their u88 could be greatly expanded. P1 almhol haa fw praotidy every pmduot now made of natural rubber if also demonstrated its merit for the manufaohm of oertain the need &odd arise. types of tubing and gaskets. Polymerid isobutylene, sold under the trade name ‘Tihex’’, may be used as an eatender for natural rubber in wire insulation compounds and o h prcducte not subjeoted to e m mechanicat stresaas. However, in many of the important i n d d IWY)for rubber the requireme& are much the mum as for tire tresds, .&$ hen* the only available substitutes for the natural w a r e the hbdiemrubbers and the neoprenas. This
appscus tbst in tKe eveat of a stoppage of erude rubber imour painoipsl pmblepl would be to supply adequate ’ w t i t i e a of the butadiene rubban and of the neopntnes. The hU6wing table shows Ameriosn pmdiwtion of synthetic rubber in reoent yearn (in long tow):
i
m
NOM M
TOO
Mw
1W
Prior to the
clprrmt
m,
knns of our‘tdal crude rub-
beransumptiolqand eventhisyearthe
tdsl prodlletii of
d-m syn-
I
thetio rubber6 win be only about 1.6’ per oent of crude rubber mnaumption.
INDUSTRIAL A N D ENGINEERING CHEMISTRY
Future Conatmction of Plante
Vol. 23, No. 11
of the butadiene and stpene which these polymerization
plants will consume. It is understood that contracts am future looks much brighter. All manufacturere of aynnnder negotiation providing for the erection of three butsthetic rubbers havi under oonstruction additions to their diene and tbree styrene plank. In the absence of 05Cial plant facilities and by the end of next year we eorpect to have figures, I estimab that the cost of plants for produaing the in thia country capacity for producing about 1600 long tons butadiene and atyrene required for the production of 3300 a month of neoprene and 900 of butadiene rubbers, d protons a month of G h e d product willapproximate 85,000,000. vided by privately financed enterprises. In addition, there will be four plants for msking the butadiene-atyrene interOther Materiale Involved polymer, owned by and operated for the account of the GovAside from butadiene and styrene, the operation of the ernment, having a combined ospacity of 3300 tons a month. govermnent-owned plants will also require substantid Hence, by the end of next year we can produce a total of tonnages of other raw materiala Buoh 88 polymerisation osts8 b O U t 5800 long tons a month of them general-purpose synthetic rubbera, which is prubably considerably greater than lysts, mulejfying agents, stabilizers, etc. Materids of this oharaater are required in the production of d synthetic rubGermany’s syntheticrubber Capsoity. Moreover, this fieure does not include the pol-de rubbers. They would be of bers. lkiating facilities may be sdequate to supply a portion of them ingredients, but it has slready become apparent gregt value if an emergenw should ariea because plank for that private industry will have to make a ~ ~ b s h taddiid pmduoing them can be built more quiolrly and at lower cost than thw for the butadiene r u b h and neoprenes. Neither tional capital investment on this Bccoullt. Also, one should not overlook the problem of mpplying the basic raw matepials do the production 6gurea given above include the plasticised from which the idtermedistea for synthetic rubber are made. polYving.1 chloribes. Plants under construotion, which will The production of emulsifying agents will require animsl and be oompleted in the spring of 1942, will bring our capcity for vegetable oils, of which there may be a seriow shortage. them prcducta to 900long tolls a month of unphatickd Ammonia and alcohola are used in the manufacture of stabilequivalent to about 1My) tons of finished producta of average iaers. A sizable tonnsge of aluminum oomponnda will be plasticizer content. In addition, it is e~rpectedthat by the employed 88 ostalyata Even the common acids and alhalies end of next year there will be ospwity for prcducing about which are used in nearly d chemid operatiom are potential 400 tonn a month of butyl rubber. ALL in SU, it appears that bottlenecke. by the end of next year our position will be reaaonably well The government-owned polymerization plants and the d, although it is obvioun tbst we would have to dbpenae with rubber andsynthetiorubhfororallbutthemost~tial butadiene and styrene p h t a that will supply them will, in most caees,draw their electricityfrompublicutilitiesandtheir needs if importe of nut& r u b k should abruptly cease. mthetio rubber manufacturers are frequently asked how‘ s t a m , water, and other aervices from existing faoilities. Likewise, existing low it would take to maintenance shops, buil-d plants to pr* plant hospitals, cafeduce a quantity of terias, etc., will be utiSynthetic rubber e q d Pmlucrion of T h b l Synthetic Rubber Is Proceeding lized. However, if to half or some other 14 Hours a Day at the Dolo Chemiml Company’s Pbnt, circumstances should stated fraction of our M i d b n d , Mkh. require the building of ptesent m t d rubber much larger synthetic consumption and what rubber plsnts, and eait would co& How peoially if they wem long it would take d e built in isolated lowpenas upon the eortent tione, the constmction to Which we are willing cost invold in proand able to make S S ~ Vidingdtimwmices fiw in other direcwould barnme a very tions. Noonecantell subetantisl itam. in advance how rapidb Addinguptheooets, it would be poesible to we 888 that the b n b make available the diene, styrene, and necessary materisla of polymerisstion plank oonstruotion, the mafor msking 3300 tons chine took, the skilled a month of aynthetia labor, and the WY rubber will cost trained €ngillem that S36,000,000. Moatof would be required, this oapitalwillbesup w i t h o u t seriously DWbv the Governhandimpping other equallg. essential defenae industrie5. be able to &um a The total ooet ofthe portionof therislqthe four polymerization effeot on our t o t a l plants for which coneconomy would be no tracte bave beem let by merent. Inaddition, the Gowrnment is e8tithere will b e a f u r t h a mated at ,ll,ooo,000. indebminable inveetAt thia writing mment in f d t i e s for tracta have not been produoing MW malet for the pduction
c
1349
distribute the product on some equitable bssia to the rubber manufactm who will use it. No anuounoerment has been made as to the price at which distriiution will be made, but the general expotation io that the Rubber Reserve Corporation will prohably Sell the prcduct at the prevailing price for natural rubber, accepting whatever loea may be involved. Authoritative coat es6imates are not available, but one may be certainthat the wet dthe product to the Guvemment will be mbetantially hi&herthan the price (M.6 can& per pound)
I
Chmt-y, dm h o t
--
N s p n m e Cover. on Paint-Spray E- Res*ts the Detanoratins Wet. of the Paint
terialn and providing power and other necesssry services to
the extsnt not already available. If we should wish to build plant8 having a total capacity of 30,OOO tons a month, it seema probable that the i n w e n t in facilities for producing a c e wry raw materiala and services would be at le& half as p a t as the cost of the butadiene, styrene, and polymerization plank; this would result in a total investment of the order of half a billion dollars to construct facilities for making 30,OOO tons a month of this synthet6orubbm. To provide even such a huge sum would perhaps not be di5cult, but to provide the skilled lahor, &My spe&dised equipment, and oowtzuction matads that the money wmld buy would obviously require serious d c e m in o h
recantly k e d for crude rubber. How much h i g k de@ to a pat extent upon the risnumptiommade with resped to the productive life of the planta and DollsepuBntly the rate at whicbtheinitislplantin~~tshouldbeamortired.This involves much more gu-k in a new industry where the pace of developmat io mpid than in anold industrywhich 6as become relatidy stabfrom the teohndogioal p i n t of view. Although this operation will undoubtedly reault in a loas to the aovepPmen, to the 6rma that build and opemta the plank, and pmhably ala0 to the rubber manufacturea who uee the produot, it should not be i n f d that the venture io unwise. If naturalrubber is unavailable, we must provide a substitute. !The buMex&qmne inkpolymer io the leaat expensive syntheticrubher that io equal to natural rubher for tire treads. Although styrene rubber aa we now know it could not compete with natural ruhber in a free mar&, it io @ble that continued reseamh may result in impromenta that would placa t k s a plan& in a competitive pasition. But even if they should be uuable to stand on their own feet in patwar competition, thejr very &ce aa stand-by plantm would probably temd to stahilk the m d e rubber market.
Possible Postwar Expansion Aside from the government planta for making styrene rubber, after the war we will have privately owned planta ospable of produoing a total of at le& 2500 tone a month of neoprene and oil-reaisting butadiene inkpolymm. This monthly capacity happens to be just qual to the total production of them typa of synthetiw for the full year 1940. Hence it seema that our prewar exprience dm little baais for that the rubber industry willbeable to uee the capauty output of thes$ plank at prices that will cover the production costs,unlem the synthetic rubber industry should be given some protection against competition with the nab ural product produced by cheap labor in the Far East. However, the*picture is not 86 dark aa these statisti- aemn to indi-
directions.
Although contracts have becm let for the construction of the gommnmhmd h k to d e the butadime&vmwhhr&mer, contracts for the &tion of the plank have not yet been ooncludsd. It is Undewtood that the rubber who are building these plants d themfortheamuntof the&bb~aestp.ve Corporation; they will d e for their mviw a fee which will p h U y be ade quat43 to cover their direat lIuwgwmt coat, and may include a mode& rlloaancs for resaQMh and development, &ho& it ioquitelilelythat a c o n s i d m d d y ~ n u m willbespentonthiiaooount6hantbb tfeepmvids. €tism u b b e r Reserva Corporatmn will
A Neoprene Bond Is
Used to Eold &yon ThreodontheBobbin Becnouu, of I t . Re8i8canOs to oils and Chemfcob in the T h d du h
Chmt-y. t Cmm-7
ate. Cartaidy we may ex@ an even wider ose h how, g&ets, psnkingi Btc., which have be& imp0-t out%& for %Jnthetio~d&im in years gone by. Belts,both power trsn& -on rrnd eonpeyor,am Likelr to use p t h e t i c m b h to a much gneadsr extent tban in ohe past. S d quan$ities of aynthetica have been u t i h d in rainoostaand other gaements, and in w6eld great ~ o n i s r c r p e o t e d . shoe soles and huhIlade of Synthetio N b k h a w p t 0 d to be d d their cast on certain type of w6rkvlen2eah-, and the ~ ~ &trueofbdudtrislboob, althou& on a m d l a d e . Heme @n weantkiptea great in $ha use of -the&
m
e
e
M will help tot& up the slsolr. Not only in OUT industries bob in ow hames, &w, and haapitsas many mbber products am ysed under conditions fOr Which pbtturrl rubber is Wt mikd. 8yllthEtiE r u b h hape pmwdworththeadded oost inglovee, ho8pitsl eheeting, oxygen tents, heating pads, etc., and in the yearn to come they zaay 6ud camumroisl mketa in hob* bottlea, elabtip gam&, 8porting gooda, and many othsr m d w products. Their use for nome of them purposeahas been etaled by inferior elastidty 88 comprued with ~ 6 u r arubl im,but, mole m t l y , improved products and new oomr @miding teohnipups have beau developed for produfine:ey5 t h b ~ 0Nbber products that, UndgsOme conditions, are BvBn m(yB -0 thsn M t d N b h . It Likely that the emphasis now being laid on aynthetic N b k for defense purpaKs will genelute a expamion of cemnmrd ’ uses which would bsve developed much mom slowly without the impetw of this emergency. looking into the futureof aynthetio rubbers, one oan dieopan poaaibilitiee of still further M e n i n g their field of utility properties; or like neoprene, they are generic names for a olaas d products (in this 0888 polymers of ohloroprene) which through the development of improve3 typw. The we, msy and do mer widely among thermselveu. Rubber teobpraeent and zue.ntio& bbve are bgsed on the nologists who formmly had only to decide how natural rubber pmpertieu of six typw of neoprene and five of oit-reaisting should be formulated in order best to meet any preaoribed butadiene interpolymeaa now .in wmmemid ~~u condition of service now have the tsskofohoo%ing between nab But them are additional typw within eaah of those poup ural rubber and the many varieties of synthetica and the that have beau produced experimentally by the vsriouS b b numerous types w i t h each b d variety; they have to m b r h engaged in 8ynthetio rubber d; and typs bve properties that may 6t themfor new u 8 8 ~ for whiob seleot the one that mmt nearly meets their qequiremenb and then determine l U t d . .rubber the most advaninentirelyunsuie taaeous formulaable. It is mole Polybutene at One Step in the Manyfacturing Opemtion than I’bly that tion. Thechoice will never be an thebeet and most Cmutan. Sbndard OU Company of New Jeasy one for the useful producte Nbber teohnolothat e m bemade gist, and it will from butadiene be impoaaible for and from’ ohlothe mgirwr in roprene have another field yettobedirk who is not conCOVe&. stnntly working with natural and Pmpe!rties of Spth&O Nh various synW
a
-
ben.
thetics
,Noaort , hsa beeh.made.in .thie.. di&&$n
‘to gi@@+fi; the:W R
d i e s of the variow @Oup I of
LiteEatara
cited .,
. uwa. .
No, 1.
bers. A coneiderable volume of informationon this point baa Chadybeau con-
(5%) Street
. ..,
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and
E M . Rub
chum Troh.. 14. ~ll+(lOrl).
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