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forming tetramethyl ammonium iodide and an oil of particular but not unpleasant odor which was possibly an amine and may have contained the original radical. The quantity was insufficient for further investigation. The reaction of a sulfide with bromocyanogen1° is also a possible means of determining the radicals attached to sulfur: RBCN RIR2S BrCn+RIBr or
+
10
+
Von Braun, Ber., 43, 545 (1910); 66, 1573 (1923).
(CHi),S
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(CHz),SCN + BrCh’ +CH/\(CHd,Br
The sludge sulfides have been found to react with bromocyanogen, but the products of reaction have not been investigated. The high densities and refractive indices of these sulfides together with their reactions with bromine and methyl iodide make it probable that they have a cyclic structure.
Place of Synthetic Amyl Products among Lacquer Solvents’ M. M. Wilson and F. J. Worster SHARPLES SOLVENTS CORPORATION, PHILADELPHIA, PA.
Distillation and EvaporaRecent additions to the present group of lacquer LL who have worked tion Data solvents are synthetic amyl alcohol and synthetic amyl with lacquer are familacetate. This alcohol is made from pentane as a raw C om p a r a t i v e distillation iar with the acetate material. The synthetic amyl alcohol is practically curves of certain nitrocellumade from fusel oil which has a duplicate of the so-called high-test fusel oil offered lose solvents are given in been sold for years under the in the past. The synthetic amyl acetate is prepared Chart No. 1. All distillations name “amyl acetate.” Withfrom the alcohol and acetic acid. In lacquer formulawere m a d e a c c o r d i n g t o in the last two years a syntion this acetate ranks in the general class of high standard A. S. T. M. methods. thetic amyl acetate has been boilers, including butyl propionate, fusel oil acetate, C o m p a r a t i v e evaporation developed and used in lacCellosolve acetate, etc. rates are shown in Chart quer work under the name Laboratory data are given showing various relations Yo. 2. T h e s e t w o c h a r t s “Pent-acetate.” The correbetween these and other solvents. These comparisons should always be shown tosponding alcohol is also being are based on the usual methods of testing the suitagether, because most solvents used under the name “Pentbility of solvents, and consist of data on distillation, used today are not single asol.” This paper attempts tolerance of nitrocellulose solutions for hydrocarbons, chemic a 1 compounds and t o show the place Pentasol viscosities of nitrocellulose solutions, evaporation rates, consequently vary to some and Pent-acetate occupy in reextent with the source of and solubility of resins. lation to the other commonly s u p p l y . E v e n e t h y l and used solvents for lacquer. The specifications for Pentasol and Pent-acetate are giren butyl acetate vary quite a few degrees in boiling range from the boiling points of the pure materials. The method of in Table I. . determining rate of evaporation will be described later. It Table I-Specifications for Pentasol a n d Pent-acetate is seen from Chart No. 2 that butyl acetate and fusel ‘oil PENTASOL PENT-ACETATE acetate evaporate more rapidly than does Pent-acetate; Water white Water white Color 0.812-0.820 0.860-0.870 Specific gravity at 20’ C Pent-acetate and butyl propionate evaporate a t about the Less than 0.03 per cent Kone Acidity None None same average rate, while the other materials shown all Water content 0.02 per cent Less than Less than 0.02 per cent ;\‘on.volatile at 100’ C. evaporate more slowly than does Pent-acetate. None None Halogen content
A
Petroleum or coal-tar hydrocarbons Weight per gallon
0,0000 per cent 6 . 8Ibs.
Distillation PENTASOL cent above cent above cent above cent above End point not aboi
100 per 95 per 50 per 15 per
12O C. 18’ C. 25’ C. 30’ C. 140° C.
0,0000 per cent 7.2 Ibs.
PENT-ACETATE
100 per cent above 126’ C. 95 per cent above 130’ C. 75 per cent above 135’ C. 25 per cent above 140’ C. End point not above 155’ C
These specifications are based on the usual A. S. T. 11. methods. The Pentasol is a mixture of five of the amyl alcohols. The mixture contains about 75 per cent of primary alcohols and 25 per cent of secondary alcohols. About one-third of the primary alcohol content is normal primary amyl alcohol. The Pent-acetate is the acetate made from Pentasol and acetic acid. The source of Pentasol is the pentane fraction of natural gasoline. This pentane fraction is chlorinated to form amyl chloride and the amyl chloride is converted to amyl alcohol by treatment with caustic soda. 1 Presented by M. M. Wilson before the Division of Paint and Varnish Chemistry at the 76th Meeting of the American Chemical Society, SwampScott, Mass., September 10 to 14, 1928.
Dilution Ratios
The tolerance of various nitrocellulose solutions for toluene and petroleum naphtha is shown in Table 11. Table 11-Dilution Ratios-Hydrocarbon to Solvent LACTOL No. 1 TOLUENE SOLVENT 2.50 1.37 Butyl acetate 1.27 Pent-acetate 1.90 1.14 1.96 Butyl propionate 0.61 4.43 Ethyl lactate 4.00 1.14 Ethyl oxybutyrate 1.86 2.78 Butyl cellosolve 0.88 4.43 Cellosolve 2.42 0.76 Cellosolve acetate 1.27 2.25 Fusel oil acetate Pent-acetate, 60 parts 2.20 1.27 Butyl acetate, 40 parts
1
The toluene used was the usual commercial grade and the petroleum naphtha was the material sold as Lactol Spirits No. 1 having a boiling range from 80” to 130’ C. The method used in obtaining these dilution ratios was to dissolve 5 grams of dry half-second nitrocellulose in such an amount of the solvent under test that the final volume a t the precipitation or gel point was 40 cc. This gives constant final concentration of nitrocellulose for each solvent.
I S D C S T R I J L il.VD ESGISEERIZYGCHEMISTRY
June, 1929
An attempt was made to find the most economical ratio of ester-alcohol-hydrocarbon to use in lacquer. In Chart No. 3 is shown graphically the dilution ratios of various esteralcohol-hydrocarbon blends. These dilution ratios were determined by adding the indicated blends of alcohol and hydrocarbon to solutions of nitrocellulose in eithey butyl acetate or Pent-acetate. The usual precipitation of nitrocellulose was taken as the end point. Asin the previous dilution tests, these tests were all adjusted so that the concentration of nitrocellulose at the end point was the same in each case. The ratio as shown was determined by dividing the volume of alcohol-hvdrocarbon blend used by the amount of ester used. It is noted that in the blends high in hydrocarbon and low in alcohol the effect of the alcohol is more marked in the case of the petroleum compounds. I n the blends high in alcohol the effect of the alcohol is more marked in the case of the coal-tar compoundc. V. hl. P. naphtha shows about the same ratio as Lactol Spirits Xo. 1. Viscosities of Nitrocellulose Solutions Viscosities of solutions of half-second nitrocellulose determined by the usual falling-ball method are gi1,en in Table 111. T a b l e 111-Viscosities
of Nitrocellulose S o l u t i o n s .MZnUteS
Butyl acetate Pent-acetate Butyl propionate Fusel oil acetate Pent-acetate, 60 parts Butyl acetate, 40 parts Ethyl lactate Cellosolve Cellosolve acetate
0 0 0 0
1
09 1s 19 10
593
Comparison of Blends Containing High-Boiling Solvents
The majority of lacquers contain, in their solvent portion, a blend of hydrocarbon, ethyl acetate, and some higher boiling acetate or other nitrocellulose solvent. It mas thought that the best way of getting a more exact comparison of some of the higher boiling solvents was to incorporate them in such blends and compare the blends. It was believed that the closest comparison mould be between blends having about the same final time of complete evaporation. Such blends were prepared and tested for rate of evaporation and blush resistance. Since the methods used were not accepted as standard methods, the result of the blush tests cannot be shown. BLUSH REsIsTah-cE-The method used in determining blush resistance is one that mas developed in the laboratory of IC
I
I
I
I
0 11
0 05 0 05 0 09
The solutions were made of 72 grains of dry half-second nitrocellulose in 300 cc. of solvent which consisted of equal parts by volume of toluene and the respective solvent. These tests were made at 25' C. Solubility of Resins The solubility of various resins in Pent-acetate and Pentasol is shown in Table IT'. T a b l e IV-Solubility of Gums PENTASOL PENT-W E T ~ T E Ester gum Shellac Kauri Pontianac
Sanderac Congo East India Manila Dammar Cumar Amberol S-soluble; IS-insoluble.
S S S 5 S
Gels PS
S
PS PS IS PS-partly soluble.
S
IS
S
5
S Gels PS S PS 5
5
These solutions all consisted of 4 pounds (1.8 kg. 1 of gum to a gallon (3.78 liters) of solvent. Sone of these resins received any previous treatment to render them soluble. Any treatment of such resins as congo, kauri, or pontianac to increase their solubility aids as much in increasing their solubility in Pentasol and Pent-acetate a5 in other solvents.
the Sherwin-Williams Company a t Chicago. The apparatus used is illustrated in Figure 1. The cubical chamber is divided equally into an upper and a lower compartment by two horizontal aluminum baffle plates about 1inch (2.5 cm.) apart. These plates are perforated with 0.5-inch (1.3-cm.) holes. The lower compartment is the one in which the humidity and temperature are controlled. A battery of electric light bulbs,
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Fipure 1-Apparnius for Determining Rate of Evapt,rafion
half of wlriclr a.re controlled by a t,herrnostat, snpplies the heat. Humidity may be controlled by large evaporating dishes filled with a solution of a definite concentration of sulfuric acid. In practice snlfuric acid was found to be unnecessary. Tlre liumidity within the cabinet changed so slowly that when using water alone a test could be completed before any appreciable humidity change had taken place. The lower compartment also contains a motor-driven Esn to promote air circulation. The upper compartment contains a rotating drum, motor-driven from the outside. A circular shelf is built around the bottom of this drum to hold tlie test panels. Sufficient, panels for a given test are placed on this shelf around the drum, the elitire cabinet is brought t o the conditions desired, and the panels are then flow-cost,ed with the respective test lacquers through a sinal1 hole in the top of the cabinet. The drum is then rotated uritil t,he panc!s are dry and the relative degree of blush is noted. Humidity is ealculatcd froin readings of wet and dry bulb thermometers placed in the upper compnrtinent of the cabinet. This apparatus can be built in any shop a t a vrry small cost. In this apparatus consistent checks em he obtained on IL series of lacquers over a range of temperature and lwrnidity. Rrlative blush resistance of a series of lacquers as determined by this apparatus is tlie sanie at varying temperatures and humidities. Relative blusli re ance was judged in two mays. The relative degree of blush at a given temperature arid humidity was noted and the blush resistance of each member of a series of lacquers under test: was rioted as ternperature and humidity were gradually increased, and each member in turn blushed. The dew point, rather tlinn the
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humidity is the critical fact,or in determining whether g given lacquer will blush. RATEOF EvAPoRATIoN-The method of determining rate nf evaporation makes use of a small air tunnel as shown in Finire 2. At previous meet,ings the desirability of a standard method for determining rate of evaporation has been mentioned. It is \>clie-vedthat an air tunnel such as this could be dcveloped into :I defiiiite standard. Weiglred, ground-glasscovered dishes are part,ially filled with equal weighed volumes oS the solvents under test. These dislies are then placed in t,lre air tunnel, the covers removed, and the fan started. At intervals of time the air is turned off, the covers are placed on tlie dishes and the dishes weighed. The loss is recorded in per cent and refers t,o either weight or volume. Humidity has practically no effect on rate of evaporation. Temperature has a very decided effect. It,was found that when the temperature was kept within * 0.5" C. ehecks coiild be obtained on a given solvent within a rmge of 2 per cent.
Figure z-~pparstus for Determining Blush Resistance
In standardizing this test it, would be neressary to use a standard test liquid as a basis of comparison rather than to ,ittempt to build standard air tunncls. A standard test liquid could be such a thing as :t carefully purified fraction of butyl acet,ate. In running this test a eoustaiit voltage should be used on the fan inotor or a rheosbnt and vdtmeter should he in the line to control voltagc.
Effect of Various Driers on Linseed Oil Films during Aging' P. E. Marling Tne Lows B Y O T ~ E R COHPANY, S DAUTUS, om0
HIS paper shows the relationship, during aging, of acid value, iodine nuinber and solnbility of linseed oil films containing different conccirtrations of lead, manganese, and cobalt. It presents a cont,inuation of previously reported experiment^,^ in which it was concluded that, the acid value of linseed oil films containing cobalt acetate
as u drier is an increasing function of the drying time; and of other esperin~ents~ wiiirli attempted t o show that the iodine number of linseed oil films during drying bear a general inverse relationship to the acid value and the concentration of the cobalt bears a definite relationship to the decreasing iodine number.
1 Prfsoited under Lhr l i t l c " i h c EBect of Are on the Acid Valuc and Iodine Number 01 1.iilsr.r.d Oil Films Containing Various Conceiifiriions of kad, ~ * n and~ coba:i ~ ~ ~t i ~~before r ~ ~" the~nivisioir , of plillt rnci Varnish Chemistry ai the 76th Meetini: of the American Chernicd Socirts. Swamnrcolt, Mass., Seotcmbcr 10 to 14. 1828. * Eians, Mailinz, and Lower. IN". ENG.C ~ H N IS, . , 1220 (1028).
EnDerimental Procedure
T
The refined linseed oil that as used in tliese experiments had the follo&,g constaIits: Evans. Mailiiig, and Lower, INDENC.Casrs.. 19, 640 (1S27)
