T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
V o l .
I. M A R C H , 1909. N o . 3
T
h eJ
o u r n a l o fI
n d u s t r i a l a n dE
n g i n e e r i n gC
h e m i s t r yPUBLISHED BY
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C o p y rig h t, 1908, for t h e A m e ric a n C h e m ic a l S o ciety b y W . D .‘R ic h a rd s o ri<;,£Vff/<>>'.
Vol. MARCH, 1909. No. 3
EDITO RIA LS.
e d u c a t i o n.
Therij have been a large num ber of papers
published w ithin the p ast y e a r w hich dealt w ith the preparation of engineers in general, or of chem ists and chemical engineers in particular. Most of them were w ritten b y practical engineers. I f the teachers of the land have read them all, th ey áre still justified in follow ing their own concepts to a considerable degree, because of the disp arity on the one side and im p racticab ility on the other.
If the teachers have read bu t part of them and have- been deeply impressed, th ey m ay be changing good plans for poorer ones. T h ey m ay be m aking the future graduate of their courses still more of a iand-book of ready d a ta and of evanescent pro
cesses, of quick conclusions and of decapitated
originality. T h e y m ay be turning out a m achine to fit the present requirem ents of a certain kind of mill, which m ill w ill p ay a ro y a lty of six ty dollars a m onth for the use of the m achine, b u t is this th best attain able? Should not such requiremen be considered m erely as a fortunate dem and fo' by-products? A re not the "s e c o n d s ” of the chem ist-plant good enough for the mill which w ants a cheap m achine? The broken saggers of a porcelain fa cto ry m ight be a useful by-product, but should we forget the m aking of the porcelain?
In chem ical industries and engineering, the one thing ' m ost needful is character; which m eans in tegrity, in d ivid uality, energy, push, etc. These m ust be greater than the average to w arran t greater than average success. T h e m em ory of the stored facts, the fam iliarity w ith the prices and nam es of com mon chem icals, the details of their m anu
facture, etc.* need be only an average-grade-acces- sory. If a m an cannot think independently, cannot talk or w rite decently, cannot listen inter
nally, and fin ally does n o t do so frequ en tly and better than the average, then the retention of;
stored know ledge will be a useless task to him.
I t m ay be m aintained th at such assets as char
acter, interest, judgm ent, etc., cannot be poured through a funnel, th at they cannot be driven in w ith a hamm er, th at th ey are hereditary in the m an or absent forever, b u t is it true? A re not these desiderata largely the result of intimate, co n tact w ith such personal qualities as distinct from physical co n tact w ith other things? T h ey are not openly dem anded of the teacher b y the student as he dem ands chem ical know ledge, nor are they lik ely to be dem anded a s 'lo n g as: every m an feels th at he does not need them. B u t m ay they be acquired? In practice it is the difference in these traits which is of greater influence than accum ulated knowledge, though the latter be ever so necessary. A w ell-trained engineer in any science w ill v e ry q u ick ly look and act and becom e like a well trained chem ist if he finds himself called upon to go deeply into chem istry. A poorly trained chem ist m ay have trouble keeping up with the office b o y on routine steel analysis if he lets him
self . latibulize. T h e deciding difference between
T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . M ar., 1909
the two is in the personality or character, and not in the stock of knowledge. I t seems as though the autom atic power of centering and m aintaining interest in things w as one of the m ost desired traits to im part to a ve ry youn g chemist.
W . R . Wh i t n e y.
THE NEXT STEP IN PUBLICATION FOR THE AMERICAN CHEMICAL SOCIETY.
Se v e r a l years ago Professor A. A . N oyes pro
posed a classification of the articles in the Journal of the American Chemical Society w ith a separate paging for cach class. A little more than two years ago the writer presented to the Council of the S o ciety a scheme for the publication of a set of separate journals representing the more im portant subdivisions of chem istry. The plan proposed was im perfect in some of its details and it involved a coordination of conflicting interests which is prob
a b ly too U top ian for com plete realization. The Am erican Chem ical S ociety has, however, accepted the most v ita l part of the proposal and has es
tablished a separate journal devoted to the in
terests of industrial and engineering chem istry.
E v e ry one will, I am sure, agree th at the develop
m ent of publication has been .so rapid recently th at w e should w ait till we can see more clearly the effect of present policies before taking another step forward. I t is, however, wise for us to begin to consider the direction which future developm ent should take.
The purposes which have led to the establishm ent of the Jo u r n a l o f In d u s t r i a l a n d En g i n e e r i n g
Ch e m i s t r y are: First, to care better for the in
terests of a class of chem ists and m anufacturers who form a ve ry large group of our membership.
Second, to furnish a more suitable medium for the publication of articles in this field in the hope th at we m ay bring a large portion of the best industrial articles together in a single journal where they will be easily accessible to the chem ists of the country.
Third, to gain new members w ith the support w hich they will give. A fourth reason which m ight ap p ly in other cases would be the desire to com bine the articles from some fields of chem istry which is represented in the Journal of the American Chemical Society with those published in some existing journal, w ith the hope of securing for this journal the publication of practically all Am erican w ork in the field.
A ll of the reasons given lead m any physical
chem ists in A m erica to desire the publication by the Am erican Chem ical S o ciety of a journal of physical chem istry. The difficulty of separating general and physical from inorganic articles, as indicated b y Germ an experience, m akes it seem desirable to com bine the three classes of articles in one journal. Such a journal, if established, w ould take about tw o-thirds of the articles which will p ro b ab ly !b e published in the Journal of the American Chemical Society during the present year.
E v id e n tly w h at would be left could no longer be called, appropriately, the Journal of the American Chemical Society, and the establishm ent or adoption b y the society of a journal of physical chem istry m eans also the establishm ent or adoption of a journal of organic and biological chem istry. This has not, perhaps, been sufficiently considered by the physical chemists.
If we assume that the publication of a journal of physical and inorganic chem istry is desirable, the n e xt questions are those of practical detail. In the first place it is to be hoped th at some arran gem en t can be made, satisfactory to the E d ito r of the Journal of Physical Chemistry, b y w hich the articles published In the Journal of the American Chemical Society can be united w ith those pub
lished in the former.
T h e financial side of the question is best con
sidered in connection w ith the different plans which m ay be proposed:
(1) T h e journal m ight be published on a sub
scription basis. It is extrem ely doubtful if suffi
cient financial support could be secured in this w ay, but, even if it could it w ould m ean th a t we should take awTa y from one class of m em bers of the A m erican Chem ical S o ciety those articles in which th ey are especially interested, com pelling them to do w ith ou t or p a y e x tra for them. I t would, in effect, raise the dues for those interested in physical chem istry. I am sure this is not desirable.
I f two journals were published in place of the Journal of the American Chemical Society, w ith an increase of 800 pages of m aterial, and both journals were to go to all our m em bers the additional cost of printing w ould be ab out $2500. If w e add $7° ° for the salary and expenses of the editor, w e have
$3200 a yea r as the sum needed for the estab lish m ent of this journal. T h is expenditure m igh t be m et b y one of the follow ing plans:
(2) On p aym en t of the present dues of $ i°
m em bers m ight be perm itted to select a n y three of the four journals w hich we w ould then publish-
E D I T O R I A L S . 149 Any one w ishing all four would p ay $3 additional.
If we assume th at 500 w ould do this (a liberal estimate) this w ould g ive $1500, while about $2800 would be saved b y the decrease of 3500 copies in the total circulation of the three journals. Such a plan would, in effect, add $3 to the dues of all who wished, as now, to h ave access to original papers in all fields and w ould deprive all the rest of the papers in some one field. T h e increase would be especially felt b y students and you n g men ju st beginning their professional career. T h e in ju ry which would result from givin g to the m ajority of our members a one-sided literature appears to me very serious. W e ough t not to think chiefly of the members of the council of the society and of chemists of sim ilar ch aracter and position but rather of m em bers w ith lim ited m eans and of the many who are isolated so th at the journals pub
lished b y the society are the only ones th ey can see.
The decreased circulation w ould also m ake the journals less a ttra c tiv e as a m eans of publication and m ight also interfere seriously w ith advertise
ments.
(3) A n increase of $ 1 in the dues w ould som ew hat more than m eet the increased expense. I t seems to be generally agreed th at such a plan is w h olly inadvisable and th a t the dues m ust n o t' be in
creased again for a n y purpose.
(4) A dd 640 new members. E ve n w ith the four journals it w ould cost only ab out $5 to print an extra copy of each, p a y the postage, and p a y the additional expenses for the secretary, local sections, etc. Hence each new m em ber adds $5 to the funds available for publication.
(5) Secure an endow m ent for publication. E v e ry one will adm it, I think, th at the m aintenance of our publications is of v e ry g reat im portance for the future of chem istry in A m erica and it does not seem too much to hope th at some of the leaders of in
dustries which h ave profited so largely b y our science m ay y e t contrib ute lib erally to their sup
port. W hat has been accom plished during the past two years is certain ly a sufficient basis for an earnest appeal.
It seems to be clear from w h a t has been said th at we ought to w ait for the publication of a journal of physical chem istry till it is possible, financially, to do this and send the jou rn al to all of our mem
bers. For the first tim e in the h istory of chem istry the Am erican Chem ical S o ciety has succeeded in uniting all classes of chem ists in a large organiza
tion which cares adeq uately for the interests of
both pure and applied science. Those of us who atten d the general m eetings of the society see ve ry clearly the advan tages which com e from the asso
ciation and acquaintance of chem ists w ith radically different habits of w ork and points of view . B u t w e m ust rem em ber that, after all, these m eetings reach only a small fraction of our mem bership, w hile the journals now go to all of our members.
W e have recen tly provided, b y the establishm ent of this Journal, a more suitable form of publication for articles in industrial and engineering chem istry.
I am sure th at industrial chem ists would be the last to say th at we ought not to continue to provide, as in the past, for the suitable publication of re
searches which have been undertaken w ithout reference to a n y industrial application.
W . A . No y e s.
SAMPLING.
Mr. Ba i l e y has done a sendee to an alytical
chem istry b y his careful physical and m athem atical investigation of sam pling, the results of which are published in this num ber. W hile the w ork con
cerns itself w ith the sam pling of coal, the results are of w ide application. In the past, and a t the present tim e, in thousands of cases the analysis has to bear the criticism w hich should fall upon im proper sam pling. T h e analyst, who is not his own sam pler, can an alyze only the sam ple which is delivered to him. A lm ost a n y an alyst can re
late how sam ples representing carload lots of coal were delivered to him in p in t m ilk bottles and lub ricatin g greases in can d y sacks. M embers of the engineering profession are not altogether blam eless in encouraging fa u lty sam pling, and occasionally the chem ist him self is deserving of censure in this regard. T h e simple truth th a t a correct analysis is dependent upon a correct sample, w ould appear to be sufficiently axiom atic to re
quire no dem onstration.
W . D. Ri c h a r d s o n.
O R IG IN A L P A P L R 5 .
T H E SY N T H E S IS, CO N STITU TIO N , AN D U SES OF B A K E L I T E .1
By L. H . Ba e k e l a n d, S c.D . R ec e iv e d F e b ru a ry 8, 1909.
Since m an y years it is know n th a t form aldehyde m ay react upon phenolic bodies. T h a t this re-
1 R e a d b e fo re th e N . Y . S ectio n of th e A m e ric a n C hem ical S o ciety o n F e b ru a ry 5, 1909
T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . Mar., 1909 action is not so ve ry simple is shown b y the fact,
th at according to conditions of operating or to modified quantities of reacting m aterials, ve ry different results m ay be obtained; so th at bodies v e ry unlike in chem ical and physical properties m ay be produced b y starting from the same raw m aterials. Some of these so-called condensation products are soluble in w ater, other ones are crystal
line, while some others are amorphous and resin
like. T h en again, am ong the latter resinous prod
u cts some are easily fusible and soluble in alcohol or sim ilar solvents while other ones are totally insoluble in all solvents and infusible. T h is paper w ill deal w ith a product of the latter class.
The co m plexity of m y su bject com pels m e to m ake a brief historical outline which will allow us to form a clearer idea of the scope of m y w ork arid differentiate it from prior or contem porary a t
tem pts in subjects som ew hat similar.
T h a t phenols and aldehydes react upon each other w-as shown as far b ack as 1872 b y A d. B ayer and others.1
T h e substances obtained b y these investigators were m erely of theoretical interests and no attem pt w as m ade to utilize them com m ercially; further
more their m ethod of preparation was too ex pensive and too uncertain and the properties of some of their resinous products were too undecided to suggest the possibility of utilizing them for technical purposes.
U n til 1891 attem p ts a t synthesis w ith form al
dehyde were generally lim ited to the use of its chem ical representatives, either m ethylal, m ethylen acetate, or m ethylen-haloid:compounds.
W ith the adven t of cheap com m ercial form al
dehyde, K leeb erg3 took up again this su b ject using form aldehyde solution in conjunction w ith phenol and in presence of strong H C1. U nder spontaneous heating he obtained a stick y paste w hich soon becomes a hard irregular mass. The latter is infusible and insoluble in all solvents and resists m ost chem ical agents; boiling w ith alkalies, acids or solvents will m erely ex tra ct sm all am ounts of apparent im purities.
A s K leeberg could "not crystallize this mass, nor p u rify it to constant com position, nor in fa ct do an yth in g w ith it after it w as once produced, he described his product in a few lines, dismissed the su bject and made him self happy w ith the stu d y of nicely crystalline substances as are obtained b y the
> B er.. S, 1095; 19, 3004 a n d 3009; 2 5 , 3477; 27 . 2411.
; A nnalcn, 2G3, 283 (1S91).
action of form aldehyde and polyphenols, gallic acid, etc.
T h e mass obtained after K le e b e rg ’s m ethod, is a hard and irregular porous substance containing free acid which can only be rem oved w ith difficulty after grinding and boiling w ith w ater or alkaline solutions. T h e porosity of the mass is due, as we shall see later, to the evolution of gaseous products during the process of heating.
In 1899 S m ith ,1 realizing p rob ably th a t K le e berg’s m ethod does n ot lend itself to m olding homogeneous articles, tried to m oderate the violent reaction b y using a solvent like m ethyl-alcohol or am yl-alcohol in which .he dissolves the reacting bodies, as wrell as the condensing agent, m uriatic acid. E ve n then the reaction is too vio len t if form aldehyde be used, so he does not use form al
dehyde, b u t instead he takes expen sive acetalde- hyde and paraldehyde, or expensive polym ers of form aldehyde. A fter the reaction, he slow ly ev ap orates the m ixtures and drives off the solven t at io o ° C. H e thus obtains, b y and b y, a hardened m ass in sheets or slabs wrhich can be sawed, cu t or polished.. In his Germ an p atent specification2 he insists on the fa c t th at in his process the m ethyl- or am yl-alcohol not on ly act as solvents b u t participate in the reaction and he states th a t this is clearly shown b y the color of the final product, which is dependent on the nature of the solven t he em ploys. H e m entions th at his d ryin g requires from 12-30 hours; m y own experience is th at it takes several d ays to expel enough of the solven t; and even after several m onths, there is still a very decided smell of slow ly liberated solvent. D uring the act of drying I observed in e very instance w arping and irregular shrinking of the m ass which thereby becom es deform ed and m akes this method unfit for accurate molding.
In 1902 L u ft,3 tried to overcom e these diffi
culties in a som ew hat sim ilar w ay. L ik e K le e berg he uses a m ixture of form aldehyde, phenol and an acid; b u t recognizing the im perfections of the product and desiring to m ake of it a plastic th at can be molded, he m ixes the m ass before hardening, w ith suitable solvents such as glycerine, alcohol or cam phor. H e v irtu a lly does the same thing as Sm ith w ith the difference, however, th at he adds his solvents after the m ain reaction is partially over and uses his acid condensing agen t in aqueous solution. H is aim, as clearly expressed in his
1 E n g l. P a t., A rth u r S m ith , 16247, A u g u st 9, 1899.
: D . R . P . A . S m ith , 112685. O c to b er 10, 1899.
3 D. R . P . A dolf L u ft, 140552, A p ril 29, 1902; U. S. P . 735278.
B A E K E L A N D Obi B A K E L I T E .
patent specifications,- is to obtain a m ass which re
mains “ transparent and more or less p lastic.” A fter pouring his m ixture in a suitable mold he dries at a tem perature of about ’50q C. He too- ihsists on the advan tages of using solvents and in his German patent (page 1, line 44) he states th a t from 2 to 10 per cent, glycérine m ust rem ain in the mass; m oreover he arranges m atters sô as to retain in his m ixture all the expensive cam phor. -The whole process of L u ft looks clearly like an âttem p t to make a plastic sim ilar to celluloid a n d 'to prepare it and to use it as the latter. T h e sim ilarity be
comes greater b y the use of cam phor-and the same solvents as in the celluloid process.
I have prepared L u ft’s product; it is relatively brittle, v e ry m uch less toùgh and flexible than celluloid; it does n o t m elt if heated although it softens d ecidedly; acetone swells" it and suitable solvents can e x tra c t free cam phor and glycerine from it.
And now w e com e to art a tte m p t of another kind, namely the form ation of soluble syn th etic resins, better know n as shellac substitutes.
Blunter1 bôils a m ixture of form aldehyde,’ pheribls and; a n 'b x ÿ acid , ' p referably tartaric acid and ob
tains à fusible, alcohol-soluble, resinous m aterial, which he proposes as a shellac substitute. T h is substance is soluble in 'b a u stic' soda lye ; it can be melted repeatedly, and behaves like a n y Soluble fusible natural resin. B lum er in his original English p aten t application puts great stress bn the 'u s e of an o xyâ cid and seems to think that the latter particip ates prom inently in the reaction ; he uses it in the proportion1 of one m ole
cule of acid for two m olecules-of phenol and two molecules of form aldehyde.
N athaniel Thurlow , Working iti m y lab oratory on the sam e subject, has conclu sively shown several years ago th at the identical m aterial can be ob
tained b y the use of m inute am ounts of inorganic acids; he has shown furtherm ore th at equim olecular proportions are n o t necessary ; in fa ct th ey are wrong and harm ful if the reaction be carried on in such a w a y th at no form aldehyde be lost ; he showed also th at in order to obtain a fusible sol
uble resin, an excess of phenol over equim olecular proportions m ust be used, unless some form alde
hyde be lost in the reaction.
So as to avoid confusion, I ought to mention here that B lum er and T h u rlow ’s resin is relatively very brittle, more so than shellac and th at no
1 Engl. P a t., E ouis B lu m er, J u n e 5, 1902. N o. 12880.
km ount of heating alone changes it into an in
soluble, infusible product.
A s to the real chem ical constitution of this interesting product which I have tried to establish b y indirect synthesis, I shall- read a paper on this su b je ct a t one of the n e x t m eetings of this society.
Abou't a yea r later, F a y o lle 1 tries to m ake g u tta percha substitutes b y m odifying L u ft’s m ethod:
he adds large am ounts of glycerine to the sul
phuric acid jused as condensing agent, and’ obtains a mass th at rem ains plastic and ta n be softened and k n e id e d whenever heat is applied. On trial, this i m ethod gdve m e a brittle u n satisfactory sub
stance of which it is difficult, if not im possible, to wash aw ay the free acid w ith o u t rem oving a t the sam e tim e much of th e glycerine. In this relation, L u ft’s w a y of adding the g ly ce rin e .: after elim i
nating, the; acid, seems more logical.*
L a te r,3 the same: inveintor modified his m ethod -b y adding a considerable am ount of pitch (“ b r a i” ) and oil thus tryin g to m ake another gutta-p erch a su bstitu te which also softens when heated and remains plastic,
In 1905 S t o r y 1 modifies , all above m ethods in the. follow ing w a y : H e discontinues the use of condensing agents and of added solvents; b u t he takes a decided excess of phenol, nam ely 3 parts of 40 per cent, form aldehyde, and 5 parts of 95 per cent, cresol or carbolic acid; b y this fa ct the latter is present in excess of equim olecular proportions.
H e boils this m ixture for 8 -10 hours, then con
cen trates in an open vessel which drives, off w ater and some form aldehyde, and which increases still more the excess of phenol; after the m ixture has b e c o m e . viscous he pours it into suitable molds, cools down and afterw ards hardens b y slow drying below 100° C., or as stated in his p atent, a t about 8o° C. H is product is infusible and insoluble.
B u t this m ethod has some v e ry serious draw backs which I shall describe sum m arily and which S to ry him self recognized later.5
H is process is necessarily slow. L eavin g out of consideration his long prelim inary boiling, the hardening process a t tem peratures below io o ° C.
is really a drying process where the excess of phenol th a t provisionally has acted as a solven t is slow ly expelled. T h is assertion I have been able to v e rify beyond d ou b t b y m y direct experim ents
1 F re n c h P a t., E . H . F ay o lle, 335584, S e p te m b e r 26. 1903.
2 See also a d d itio n p a te n ts to o rig in al F ren c h P a t. ad d . P a t. 2414.
F e b ru a ry 8, 1904 a n d 2485, F e b ru a ry 18, 1904. F ay o lle.
3 F re n c h P a t., E . H . F ay o lle. 341013, M arch 7, 1904.
4 E n g l. P a t., H e n ry S to ry , 8875, 1905.
5 See h is a d d itio n P a te n t, B elgium 210965, S e p te m b e r 30, 1908.
152 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . M ar., 1909 where hardening was conducted in closed vessels
at below 100° C. and where I succeeded in collect
ing phenol w ith the eliminated water. T he evap
oration or drying process m ay proceed acceptably fast for thin layers, or thin plates, but for masses of a som ewhat larger volum e, it requires weeks and m ouths; even then the m axim um possible hardness or strength is not reached a t such low temperatures.
A ll this not m erely involves much loss of time, but the long use of expensive molds, a very con
siderable item in m anufacturing methods; further
more, during the act of drying, the evaporation occurs quickest from the exposed surface, thus causing irregular contraction and intense stresses, the final result being misshapen molded objects, rents or cracks.
S tory states that if pure phenol be used the reaction proceeds very7 slow ly; I should add that in th at case the reaction does not take place, except ve ry im perfectly, even after several days of con
tinuous boiling. E ven then in some of m y own experim ents made w ith pure commercial crystal
lized phenol and w ith com mercial 40 per cent, form aldehyde, I obtained products not of the insoluble type, but sim ilar to the soluble fusible products of Blum er and Thurlow.
T aken in a broad sense, S to ry ’s process is very sim ilar to L u ft’s w ith this difference however, that he foregoes the use of an acid condensing agent and instead of using a solvent like alcohol, glycerine or camphor, he uses a better and cheaper one, nam ely an excess of phenol. In further sim ilarity w ith L u ft and S m ith ’s his method is, as he e x presses himself in his patent text, a drying process.
L ik e Sm ith and L u ft he is ve ry careful to specify tem peratures not exceeding io o ° C. for drying off his solvent.
Sh ortly after S to ry filed his patent, D eLaire1 obtained a French patent for m aking soluble and fusible resins either b y condensing phenols and form aldehyde in presence of acids, in about the same w ay as Blum er or Thurlow and then m elt
ing this product; or b y dissolving phenol in caustic alkalies used in molecular proportions, then pre
cipitating the aqueous solution with an acid and afterw ards resinifying the reprecipitated product b y heating it until it melts. I should remind you th at the French patent law s allow patents w ithout any exam ination w hatever as to novelty. A nd I should state also that D eLaire simply uses here
1 F ren c h P a t., D e L aire 361539, J u n e 8, 1905.
the old and well-known processes of L ederer1 and Manasse2 which consists in m aking a phenol- alcohol b y the action of form aldehyde on an aqueous solution of a phenolate and subsequent treatm ent with an acid.
I t is a well-known fa ct th at these phenol-alco- hols, for instance saligenin, if heated alone or w ith an acid, will give partial anhydrides such as saliretin and hom osaliretin,3 C X4H h03 or CUH 4 (O H )CH 2OC0H 4C H 2O H / fusible and soluble in alcohol, or caustic soda, and prccipitable from the latter b y the addition of chloride of sodium.
Trisaligenosaligenin, C2SI i 2fl05 or 4C7H 30 2— 3H 20 , r>
and heptasaligenosaligenin, C50H 50O9 or 8C 7H S02—
7H 20 ,° are both higher anhydrides of sim ilar resinous character, the first one obtained b y the action of sulphuric acid on saligenin, the la tte r b y the action of acetic anhydride.
T he direct homolog of saliretin, which is m ethyl- saliretin or homosaliretin, has properties sim ilar to saliretin, m elts a t 200° or 2 0 5 °C . and is less soluble.7
No wonder then if the E nglish8 and the Germ an patents0 of D eLaire v a ry considerably in te x t and claim s from the French p aten t; the claim s are reduced m erely to a m ethod consisting in resinify
ing phenol-alcohols b y heating them under reduced pressure or vacuum . T h e resins of D eLaire are fu sib le, soluble products, having all the general
properties of saliretin and homosaliretin.
In order to com plete m y enum eration of m ethods where alkalies are used, I ought to m ention two processes which aim at products v e ry different from those which we have in view . S p e y e r 10 pro
duces an antiseptic which easily gives off C H 20. F or this purpose he uses naphthol or polyphenols like resorcin or pyrogallol and adds an excess of am m onia and of form aldehyde. T his gives him an insoluble powder which easily liberates C H20 and N H 3. I t is a well-known fa ct th at am m onia reacts on form aldehyde and produces hexam ethylentetra-
1 J o u rn a l Praklische C hcm ii [2 ], vol. 50. p a g e 224.
2 B cr., 1894, 2409-2411; D . R . P . B ay e r, 85588; U. S. P ., M anasse, 5 2 6 7 8 6 ,1S94,
s B eilstein, Organ. Cliemie. Vol. 2, 1896, p a g e 1109.
* R . P iria, A n n . Cltem., 48, 75; 56, 3 7 ; 81, 245; 96, 357. M oitessier, J a h re s b e ric h t, 1886, page 676.
5 K ra u t, A n n . C han.. 156, 123; G e rh a rd t, A n n . C him . P h y s . [3], 7, p ag e 215.
« F . B eilstein a n d F . Seelheim , A n n . C hem ., 117, p a g e 83.
7 C. S c h o ttc n , Berichlc. 1S78, p a g e 784.
8 E n g l. P a t., D eL aire, 15517, 1905.
8 D . R . P ., D eL aire, 189262, J u ly 19, 1905.
10 D. R . P ., A rth u r Sp ey er, 99570, N o v e m b er 2, 1897.
B A E K E L A N D O N B A K E L I T E . 153 min, C J I^ N j,1 which easily acts upon acids and
forms again C H ,0, N H 3 and m eth ylam in .2
Tw o recent p atents relate d irectly to the m anu
facture of soluble fusible resins. O ne of Farben- fabriken Fried. B a ye r & C o .3 uses orthocresol so as to obtain an odorless shellac substitute.
1 The other issued to Grognot'1 also for a shellac substitute, adds glycerine first, then after the reaction is over distils the solvent off.
A fter I had filed m y own p aten t claim s in the U. S. which g ave me International Convention privileges, H elm 6 described, after me, am ines or ammonium salts as condensing agents for the m anufacture of syn th etic resins w ith phenols and form aldehyde. H e does not clearly indicate the chemical or p h ysical properties of his resins. H e furtherm ore m akes the rather am biguous sta te
ment th at am m onium nitrate can be used as well as aniline. I have shown (see below) th a t in the case of am m onium n itrate the end-product m ay be a fusible soluble resin, w hile in the case where aniline is used I obtain fin ally an insoluble in
fusible resin.
I t is true th at H elm uses large am ounts of aniline and nitrate of am m onium ; his indicated propor
tions are v e ry close to m olecular proportions and this undoubtedly has, as I w ill show later, a great influence on the nature of the resulting products.
K n o ll,0 who also applied for patents after the filing d ate of m y U. S. patents, uses sodium sulphite or neutral, or acid or alkaline salts as condensing agents; disregarding again the fa ct established b y me, th a t according to w hether an acid, a base, an acid salt, or an alkaline salt be used, the resinous products m ay be to ta lly different.
This will close m y review of the w ork done b y others and I shall begin the description of m y own work b y outlining certain facts, m ost of which seem to be unknow n to others, or if th ey were know n their im portance seems to have escaped attention.
Of these facts I have m ade the foundation of m y technical processes.
A s stated before, the condensation of phenols with form aldehyde can be m ade to give, according to conditions and proportions, two en tirely differ-
1 W o h l, B er., 19 , 1892; Tollens, B er., 17 , 653.
2 See also M o sch ato s a n d Tollens, A n n . der Chem ie., 272,280.
3 D . R . P ., F a rb e n fa b rik e n v o rm . F rie d r., B a y e r -& Co., 201,261, A pril 16, 1907.
4 L . G ro g n o t, U . S. P . 391436. 1908.
5 E ngl. P a t., L o u is H elm , 25216, N o v e m b er 13, 1907.
8 E n g . P a t., K n o ll & Co., 28009, D ecem b er 19, 1907; Sw iss P a t., D itto . 40994, D ecem b er 7, 1907.
en t classes of resinous products. The first class includes the products of the typ e of B lum er, De- Laire, Thurlow , etc. These products are soluble in alcohol acetone or sim ilar solvents, and in alkaline hydroxides. H eating, sim ply m elts them and th ey resolidify after cooling. M elting and cooling can be repeated indefinitely b u t further heating w ill not transform them into products of the sec
ond class. T h e y are generally called “ shellac s u b s t i t u t e s because th ey have some of the general physical properties of shellac.
T h e second class includes the products of K lee- berg, Sm ith, L u ft, S to ry , K n o ll as w ell as m y own product, in so far only as their general properties are concerned; bu t each one of them m ay be characterized b y v e ry d istin ct specific properties which have a considerable bearing on a n y technical applications. B ro a d ly speaking, this second class can be described as infusible resinous substances, derived from phenols w ith aldehydes; some of them are more or less attack ed b y acetone, b y caustic alkalies or undergo softening b y applica
tion of heat. A t least one of them is u nattacked b y acetone and does not soften even if heated at relatively high tem peratures. None of them can be re-transform ed into products of the first class even if heated w ith phenol.
These insoluble infusible substances can be produced d irectly in one operation b y the action of form aldehyde on phenols under suitable con
ditions, for instance the process of K leeb erg (see above). Or they m ay be produced in two phases (see L u ft and S to ry above), the first phase con
sisting of an incom plete reaction giving a viscous product th at is soluble in alcohols, glycerine, cam phor or phenol, and which on further heating or after drivin g off the solven t m ay grad ually change into an infusible product.
In order to be able to stop a t the first phase, the condensing agents m ay either be om itted (see S to ry above) or th ey m ay be used m oderately (see L u ft above) or th ey m ay be diluted w ith suitable solvents, for instance m ethyl- and am yl- alcohol (see Sm ith above) or w ith glycerine (see F a yo lle above).
In all these processes there is a fu rth er treatm ent b y which the solven t is driven off during a drying process. F or exam ple, in the process of Sm ith or L u ft, alcohol or glycerine is thus e x pelled p a rtia lly ; and in S to ry ’s process the excess of phenol is driven off in the same w a y b y slow
154 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . M ar., 1909 drying under io o ° G . In all these drying pro
cesses, some of the solvent is left, either purposely, so as to insure flexibility or plasticity, or it is left involuntarily, because at temperatures of io o ° C.
or below it is impossible to expel the totality of these solvents, p art of which are stubbornly re
tained b y the mass.
I f I except the processes of Blumer, Thurlow or D eLaire, and generally those which have in view fusible and soluble resins, in all above-mentioned patent specifications tem peratures of 100° C : or much belinir&xe insisted upon.
And y e t I have convinced m yself b y often re
peated experim ents that temperatures above 100° C. and considerably above 100° C. are best suited or indispensable for the complete arid rapid transform ation into a final insoluble, infusible product of exceptionally desirable qualities.. If this be so w h y have m y predecessors not used tem peratures above io o ° C.?
W h y do some of them recommend tem peratures.
as low. as 8o° C. ■ (Story) and even 50 f C, (Luf t) ? W hy do they prefer to m ake this..final hardening, a long and slow operation w h ich does not give.th e- best, the hardest, the m ost resisting product?
(See confirmation of m y statem ent b y S tory in Belgian addition patent 2x0965, Septem ber 30,
1908.) ■
F or the simple reason that if their initial mass be heated a t too high a tem perature it gives off gaseous products, m ainly composed of form al
dehyde; this produces bubbles in the mass, m akes it spongy, porous, and unfit for commercial use. .
More direct experim ents have proved to me that during the first stages of the process, we have to deal with a phenomenon that has all the char
acteristics of chemical dissociation w ith liberation of C H ,0.
If the initial mass be heated at tem peratures abbve 100 0 C. the tension of this gas becomes very pronounced. A t io o ° C . the tension m ay become as high as 1 kilogram per square centim eter (above atm ospheric pressure)', b u t th is tension subsides as soon as the final product is formed.
I shall explain later how I have utilized this knowledge to. good advantage, and how I counteract this dissociation sim ply b y exercising a com pensating external pressure.
In the historical part of m y paper, reference has repeatedly, been m ade to the use of condensing
agents. -We have seen how K leeberg, Sm ith, L uft, Fayolle, Blum er and Thurlow use acid condensing agents. Others like Speyer, H entsche, Lederer, Manasse, D eLaire, use alkalies, b u t e v e ry tim e in relatively la r g e , p roportions: p ractically one mole
cule or over; but the products thus obtained are of a nature very different from the substance I am about to describe.
S tory, on the other hand, adds no condensing agents w hatever. True, he is able, w ith com m ercial impure carbolic acid, to obtain a reaction after about 8-10 hours’ boiling,, and this heating process, has then to be supplemented b y much longer drying.
B u t if his process be carried out w ith pure or crystallized phenol, it takes m an y d ay s of con
tinuous boiling before a reaction sets in; even then the product obtained is of a dubious character hovering between a resin of class one (fusible and soluble) and a resin of ciass two (infusible and in
soluble). I t is more lik ely to be a fusible and soluble resin if for some reason or another the process has been carried out with an excess of phenol or if, some Way or another, too much C H 26 has escaped in the after concentration. F or in
stance b y following his'description and boiling for:
5 d ays in a retrirri condenser' a m ixtu re o f- 50 gK pure crystallin e phenol and 30 gr. 4 0 'p e i cent, com mercial form aldehyde, theri concentrating in’
an open dish, I obtained the fusible soluble resin of Blum er or Thurlow which on further h eatin g re- rriairis fusible and does not change into the in
soluble infusible product as described b y Stofy'.
I obtain the same result if the boiling be carried on in presence of a small am ount of a n y acid, any acid salt, or an y salt which on h ydrolyzin g m ay split, so as to give a preponderant acid reaction.
T his effect is : shown b y salts of; m ineral acids and h eavy m etals; it is shown even w ith amm onium chloride, and on acting upon form aldehyde liberates free hydrochloric acid.1
On the other hand, if I use an alkaline salt or a salt, w hich on hydrolyzin g splits into a w eak acid and a strong base, as for instance sodium acetate, I obtain under the same circum stances a resin of the insoluble, infusible v a rie ty even if to some extent, a slight excess of phenol has been used, showing conclusively th at w ithin certain lim its the am ount of phenol does not change the general character of the reaction. A ll w h a t m ay happen in that case is th at the final product is-rendered impure b y some excess of phenol which can be
1 See C am bier. B ro c h et, Com pt. rend., 1 2 0 , 557. *
B A E K E L A N D O N B A K E L I T E . 155 driven off afterw ards b y a d ryin g process sim ilar
to that of S tory.
I have obtained sim ilar results w ith m an y other alkaline salts as for instance am m onium carbonate, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbon ate, trisodium phosphate, borax, potassium cyanide, sodium silicate, soap, etc.
In the same w a y I have used sodium sulphite, which on actin g on C H20 liberates sodium h y droxide according to follow ing reaction:
CH20 + S03N a2 + H, 0 = C H ,(0H )S03N a + N aO H . I might say th at a sim ilar effect is obtained from all substances w hich can act d irectly or indirectly as bases.
In other term s: the quality as well as the quantity of condensing agen t has an enorm ous influence on the nature of the final products.
For the m an ufacture of insoluble, infusible, condensation products of form aldehyde and phenol, bases used in m oderate am ounts have v e ry decided advantages. T h e y accelerate the reaction w ith ou t degenerating sam e into a vio len t and irregular process. T h e relatively sm all am ount of base which m ay rem ain present in the finished product, either in com bined or uncom bined form, does not involve the sam e objectionable featu res for its technical uses as the presence of free acid.
Furthermore, for some reason or another acid condensing agents seem to fa v o r the form ation of soluble and fusible resins, w hile for some other reason, bases seem to fa vo r the form ation of in
soluble, infusible resins.
Moreover, b y the use of small am ounts of bases, I have succeeded in preparing a solid initial con
densation product, the properties of which sim plify enormously all m olding operations as w e shall see later.
I have tried all organic or inorganic bases which I could obtain readily. I have tried the hydroxides and carbonates of the alkali m etals, the hydrates of alkaline earths, am m onia and its alkaline salts, hydroxylam in, organic amines, pyridine, carbam ide and other am ides of w eak acids; and the effect, w ith slight variations, is alw ays ab out the same; it is quite natural, th at for reasons of econom y or expediency, I should prefer the com m ercially
more available bases. j i j
I wish it d istin ctly understood th at in order to obtain m y technical effect I use the bases in rel
atively small quantities, say less than one-fifth
of the am ount which would be required to trans
form the phenol into phenolate.
I f larger am ounts of base be used, the results are technically much inferior; in fa ct the process changes grad ually into such as g ive phenol-alco- hols or com pound condensation products of am m o
nia or amines w ith form aldehyde, all products ve ry different from those I desire to make.
I have good reason to believe th at in m y process the bases only act as catalyzers and intervene only tem porarily in the reaction. T h e y seem to be expelled in free condition during the last stage of the process. F or instance if I use amm onia, I find this am m onia b ack in the free state in the final hard condensation product.
A careful stu d y of the condensation process of phenols and form aldehyde, m ade me discover that this reaction instead of occurring in two stages can be carried out in three distinct phases. This fa ct is much more im portant than it appears at first sight. Indeed it has allowed me to prepare a so-called intermediate condensation product, the prop
erties of which sim plify still further m y m ethods of m olding and enlarge v e ry much the scope of use
ful applications of m y process.
T h e three phases of reaction can be described as follow s:
F irst phase. T h e form ation of a so-called in itial condensaticn product which I designate as A .
Second phase. T h e form at'on of a so-called intermediate condensation product, which I designate as B.
T h ird phase. T h e form ation of a final con- densation product, which I designate as C.
A s to the properties of each of these condensa
tion products I can define them in a few words:
A , a t ordinary tem peratures, m ay be liquid, or viscous, or p asty, or solid. Is soluble in alcohol, acetone, phenol, glycerine and sim ilar solvents; is soluble in N aO H . Solid A is ve ry b rittle and m elts if heated. A ll varieties of A heated long enough under suitable conditions w ill change first into B then fin ally into C.
B is solid a t all tem peratures. B rittle b u t sligh tly harder than solid A at ordinary tem pera
tures: insoluble in all solvents b u t m ay swell in acetone, phenol or terpineol w ith ou t entering into com plete solution. I f heated, does not m elt b u t softens decidedly and becom es elastic and some
w h a t rubber-like, bu t on cooling becom es again hard and brittle. F u rth er heating under suitable conditions changes it into C. A lth ough B is
T H E f O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . Mar., 1909 infusible it can be molded under pressure in a hot
mold to a homogeneous, coherent mass, and the latter can be further changed into C by the proper application of heat.
C is infusible, insoluble in all solvents; unat
tached by acetone, indifferent to ordinary acids, or alkaline solutions; is destroyed b y boiling con
centrated sulphuric acid, but stands boiling with diluted sulphuric acid; does not soften to any serious extent if heated, stands temperatures of 300° C .; at much higher tem peratures begins to be destroyed and chars w ithout entering into fusion.
It is a bad conductor of heat and electricity.
The preparation of these condensation products A and /' and their ultim ate transformation in C for technical purposes constitute the so-called B akelite process. This can be described easily:
1 take about equal amounts of phenol and form aldehyde and I add a sm all am ount of an alkaline condensing agent to it. If necessary I heat. The m ixture separates in two layers, a supernatant aqueous solution and a low er liquid which is the initial condensation product. 1 obtain thus a t will, either a thin liquid called Thin A or a more viscous mass, Visiow i .A or a Pasty .4, or even if the reaction be earned far enough, a Solid .4.
Either one o f these four substances are m y starting m aterials and I w ill show you now how they can be used for my purposes.
If T pour some of this .4 into a receptacle and sim ply heat it above too® C.. w ithout any pre- can ion. 1 obtain a porous spongy mass of C.
B u t bearing in mind w hat 1 said previously about dissociation, 1 learned to avoid this, a m p ly b y opposing an external pressure so as to counter
act the tension o f dissociation. W ith this purpose in view . I carry out m y heating under suitably sed pressure, and the result is totally different.
This m ay be accomplished in several w ays but is done ordinarily in an apparatus called a Bakelizer.
Snch an apparatus consists m ainly of an interior Chamber in which air can be pumped so as to bring its pressure to 50 or better too lbs. per square inch.
This cham ber can b e heated externally or inter-
«His to tem peratures vis high as '.60' C. or considerably higher, so that the heated object during the process of B akelizing m ay remain steadily under suitable pressure which will avoid porosity or blistering of the mass.
For instance it I pour liquid ,4 into a test rube and it I heat in a Bakelizer at sav 160
180° C., the liquid will change rap id ly into a solid mass of C th at will take e x a c tly the shape of its container; under special conditions it m ay affect the form of a transparent hard stick of B akelite.
I t is perfectly insoluble, infusible, and unaffected b y alm ost all chemicals, an excellent insulator for heat and electricity and has a specific g ra vity of about 1.25.
I t is ve ry hard, cannot be scratched w ith the finger nail; in this respect it is fa r superior to shellac and even to hard rubber. I t m isses one great q u ality of hard rubber and celluloid, it is not so elastic nor flexible. L a c k of flex ib ility is the most serious draw back of B akelite. A s an insu
lator, and for any purposes w here it has to resist heat, friction, dampness, steam or chem icals it is far superior to hard rubber, casein, celluloid, shellac and in fa ct all plastics. In price also it can splendidly com pete w ith all these.
Instead of pouring liquid .4 into a glass tube or mold I m ay sim ply dip an o bject into it or coat it b y means of a brush I f I take a piece of wood, and afterw ards p u t it into a B akelizer fo r an hour or so, I am able to provide it rapidly w ith a hard brilliant coat of B akelite, superior to a n y varnish and even better than the m ost expen sive Japanese lacquer. A piece of wood thus treated can be boiled in w ater for hours w ith o u t im pairing its gloss in the slightest w ay. I can dip it in alcohol or other solvents, or in chem ical solutions and y e t not m ar the beautiful brilliant finish of its surface.
B u t 1 can do better. I m ay prepare an A . much more liquid than this one, and w hich has great penetrating power, and I m ay soak cheap, porous soft wood in it, until the fibres h a ve absorbed as m uch liquid as possible, then transfer the im
pregnated wood to the B akelizer an d le t the syn
thesis take place in and around the fibres of the wood. T h e result is a v e ry hard w ood, as hard as m ahogany or ebony of w hich the tensile- and more specially the crushing strength, has been con
siderably increased and w hich can stand dilute acids or w ater or steam ; henceforth it is proof against dry rot. I m igh t go fu rth er and spend a full evening on this su b ject alone and tell y o u how w e are now bringing about som e unexpected possibilities in the m anufacture o f furniture and the wood-working industry in general. B u t I intend to devote a special evening to th is su b ject and s h o w
you then how w ith cheap soft w ood w e are able to accom plish results which never h a ve been obtained even w ith the most expensive hard w ood.
B A E K E L A N D O N B A K E L I T E .
157
In the same w a y I have succeeded in im pregnating cheap ordinary cardboard or pulp board and changing it into a hard resisting polished m aterial that can be carved, turned and brought into m any shapes. I m ight tak e up m uch more of you r time by simply enum erating to you the applications of this im pregnation m ethod, w ith wood, paper, pulp, asbestos, and other fibrous and cellular materials; how it can be applied for fastening the bristles of shaving brushes, p a in t brushes, tooth brushes, how it can be used to coat m etallic sur
faces w ith a hard resisting protecting m aterial;
how it m ay u ltim ately supplant tin in canning processes; b u t I have no d ou b t th at you r im agina
tion will easily supply you a list of possible technical uses even if I defer this su b ject for some other occasion.
As to Balcelite itself, you w ill readily under
stand that it m akes a substance far superior to amber for pipe stem s and sim ilar articles. It is not so flexible as celluloid, bu t it is m ore durable, stands heat, does not smell, does not catch fire and at the same time is less expensive.
It makes excellent billiard balls of which the elasticity is ve ry close to th a t of ivo ry, in short it can be used for sim ilar purposes like knobs, buttons, knife handles, for w hich plastics are generally used. B u t its use for such fa n c y articles has not much appealed to m y efforts as long as there are so m any m ore im portan t applications for engineering purposes.
Bakelite also acts as an excellen t binder for all inert filling m aterials. T h is m akes, th at it can be compounded w ith saw dust, wood pulp, asbestos, coloring m aterials, in fa c t w ith alm ost an yth in g the use of which is w arranted for special purposes.
I cannot better illu strate this than b y telling you that here y'ou h ave before y o u a grindstone m ade of Bakelite and on the other hand a self-lubricating bearing which has been run d ry for nine hours at 1800 rev. per m inute w ith ou t objectionable heating and w ith ou t injuring the q u ick ly rev o lv
ing shaft.
If I m ix B akelite w ith fine sand or slate dust I can make a paste of it w hich can be applied like a dough to the inside of m etallic pipes or containers, or pumps, and a fter B akelizin g, this gives an acid proof lining ve ry useful in chem ical engineering.
^ alve seats, w hich are unaffected b y steam, steam-packing th at resists steam and chem icals, have been produced in a sim ilar w ay.
Phonograph records have been m ade w ith it, and the fa c t th at B akelite is harder than rubber, shellac, or kindred substances indicates ad v an tageous possibilities in th at direction.
F or the electrical industry, B ak elite has already begun to do some useful work. T here too its possible applications are numerous. A rm atures or fields of dynam os and m otors, instead of being varnished w ith ordinary resinous varnishes, can sim ply be im pregnated w ith A , then pu t into a B akelizer and everyth in g transform ed into a solid infusible insulating m ass; u ltim ately this m ay enable us to increase the overload in m otors and dyn am os b y elim inating the possibility of the m elting or softening of such insulating varnishes as have been used until now7. B u t the su b ject of dynam os and m otor construction is only a t its v e ry m odest beginnings and I prefer to m ention to you w h at has been already achieved in the line of m olded insulators of which you will find here several ve ry interesting samples.
T h is brings me to the su bject of m olding B akelite.
F o r all plastics like rubber, celluloid, resins, etc., the m olding problem is a v e ry im portan t one.
S everal substances w hich otherw ise m ight be v e ry valu ab le are useless now because th ey cannot econom ically be molded. T h e great success of celluloid has m ainly been due to the fa c t th at it can easily be m olded. N itrated cellulose alone, is far superior in chem ical qualities to celluloid, b u t until H y a tts ’ discovery, it could only be given a shape b y an evaporation process and its applica
tions w ere v e ry lim ited. T h e addition of cam phor and a sm all am ount of solvent to cellulose n itrate w as a m aster-stroke, because it allowed q u ick and econom ic m olding.
In the same w ay w hite sand or silica w ould be an ideal substance for a good m any purposes, could it be easily compressed or m olded into shape and into a homogeneous mass. B u t it cannot; and therefore rem ains worthless. A nd th at is the m ain differ
ence betw een a plastic and a non-plastic. I t so happens th at B ak elite in C condition does not m old; it does not wreld together under pressure even if heated; on ly w ith m uch effort is it possible to shape some kind of an o b ject o ut of it, bu t some
w a y or another the particles do n ot stick w e lf to
gether; in other term s it is not a true plastic. T h ere
fore the m olding problem has to be solved in the anterior stages of the process. W e h ave seen how'
T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . Mar., 1909 Sm ith, L uft, and Story tried to solve a similar
problem b y the adm ixture of solvents and subse
quent evaporation, but we know now that these ve ry solvents im ply m ost serious drawbacks.
I have already shown you how I am able to mold and harden quickly b y pouring liquid A into a mold and heating it in a Bakelizer. B u t even that method is much too slow for most purposes.
Furthermore, molds cost m oney; any rubber or celluloid m anufacturer will tell you that the item of molds represents a big portion of the cost of his plant. If an order for 10,000 pieces has to be delivered and it takes an hour for molding, it will require between three and four years to fill this order w ith one mold and if the mold costs $100 it w ill require $5000 for molds alone if the order has to be finished within 20 days. For that very reason I have devised m y molding methods so as to use the molds only during the very minimum of time. I have succeeded in doing so in several ways. One of the sim plest w ays is the following:
A s stated before, the use of bases permits me to make a va riety of A that is solid although still fusible. The latter is as brittle as ordinary rosin and can be pulverized and m ixed with suitable filling m aterials. A m ixture of the kind is intro
duced in a mold and put in the hydraulic press, the mold being heated at tem peratures preferably about or above 160-200° C. T he A melts and m ixes with the filler, im pregnating everything; at the same time it is rapidly transformed into B. B u t I have told you th at B does not melt, so the molded object can be expelled out of the mold after a very short time and the mold can again be refilled.
All the molded articles are now in B condition;
relatively brittle bu t infusible. A t the end of the d a y ’s work or a t any other convenient time all the molded articles are put in the B akelizer and this of course w ithout the use of any molds; in this w ay they are finally transformed in “ C ” B akelite of m axim um strength and hardness and resisting power.
The process can still be further simplified. In stead of using A , we can use B and mold it in the hot press where it welds and shapes itself. A fter a ve ry short time, the B be
gins to transform into C and can now be expelled from the mold. If the transform ation in C is not com plete, a short after-treatm ent in the Bakelizer will finish everything. I have succeeded thus in reducing the m olding to less than tw o minutes for small objects.
The valuable properties of B m ay be used in m any other w ays; for instance A m ay be poured into a large container and be heated slow ly at 70° C. until it sets to a rubber-like m ass and shows that it is transformed into B . T h is block of B if warm has v e ry much the consistency of printers’
roller-composition, but is b rittle 'w h e n cold. The warm flexible mass can now be rem oved from its container or, divided, cut, or sawed to a n y desired shape and the so-shaped articles can be simply placed in a Bakelizer; 110 m elting nor deformation can occur, so we need no mold w hile maximum heat is applied to bring everyth in g in con
dition C.
I could m ultiply these exam ples b y numerous other m odifications of m y process bu t I believe that w hat I have said will be enough to convince you of its m any uses; w e are stu d yin g now applica
tions of B akelite in more than fo rty different industries on some of which I shall report on some future occasion.
The chem ical constitution of B ak elite and the nature of the reactions which occur in the Bakelite process are problems which I have endeavored to solve. This subject is not b y a n y m eans an easy one. Indeed, we have to deal here w ith a product th at cannot be purified b y crystallizatio n nor other ordinary methods, which is insoluble, does not m elt nor volatilize; in other terms, it is not a product which is amenable to our usual methods of m olecular w eight determ ination. Its chem ical inertness m akes it unfit for stu d yin g possible chem ical transform ations and unless m y friends, the physico-chemists, will come to m y aid, discover some w ay for establishing some op tical properties or other physical constants, we are v e ry m uch at a loss to establish the m olecular size of m y product.
B u t I have been so fortunate as to be able to obtain some insight into its chem ical constitution b y a rather round-about w a y : Indeed, I have suc
ceeded in m aking B akelite b y indirect synthesis.
A s stated previously, o xybenzylalcoh ol if heated at 150° C., or in presence of acids, gives various partial anhydrides, called saliretin , w hich m ay resinify further if heated a t higher tem peratures.
Saliretin products are more or less soluble in alco
hol and acetone and in N aO H solution, from which they m ay be reprecipitated b y m eans of NaCl.
W e have already seen th at D eB aire in heating phenol alcohols in vacuum obtains soluble resins.
B u t I have heated saligenin in sealed tubes under
