exact method of cnrbouimtiou is not. known; a 11~1i111icr of other Stephenson patents are still pending. The plant started 011 Xovemher 12, 1935, bot was partly destroyed by fire on December 13, and a t the time of writing (February, 1936) the repairs have not yet been conipleted. According to statements made a t the anuual mn't.ing of Coal arid Allied Industries Ltd. (including reports in t h i s daily press), the process wiiuld mot operate with a 2: 1 coal-oil mixture, and the usual 50:50 proportion had to he uscd. Also it is now stated that present insta1latii.n~ at, the, Seaharn Harbour plant consist of fifty-one ovens, each of which can treat 2.75 tons of coal and 2.75 tiins of hcavy oil every 24 hours (equal to 140 tons of coal and much less thail the original estimate). Apparently also t.he ovens do not operate a t a pressure above atmospheric, and apparently shallow metal trays are used for the mixture. According to another statement in a progress report. issued hy Coal and Allied Industries LM., the estimated capacity of the plant of fifty-one ovens is 320 tons of coal-oil niixtnre
R day (50:50), producing &3,000 galloils 0 1 mirie oil which on treatment shorild give tlrp fdloiving yields in Imperial
gxllons:
l'iuducl
n'o infonuatioii is giveri as t u tlrc rjuaut,ity and quality of tlir heavy oil used as make-up that niust Be iricluded in the yields per ton of coal. The sinokeless fuel to tie placed on the market under the name of "Cauda" is estimated a t 130 tons a day, and the plant is stated to have cost ahout, 2205,000 ($1,025,000). Further infornmtinri ir au.sit,wl wit,h iiitrreat. Itrcvirb:s \Ieieh 91, 1U:W
Polymerized Acrylic Acid Derivatives
L. KLEIN AND W. T. PEARCE The Resinous Products & Chemical Company. Inc Philadelphia. Pa.
Properties of Interest to the Varnish and Lacquer Industry
OA
MOSC the more recent industrial de velopments in the field of synthetic resins has been the growing importance of thr, acrylic resins, supplied commercially in this country under the trade name of Acryloid.' This term has been applied generally to the polymerized derivatives of acrylic acid (CH? : CII-COOII) and a-inethyl acrylic acid (CHI : t.COOFI), CB,
hereafter daignated "methacrylic acid." 0 importance are the polymerized lower ester L Hegirteied trade name of the %ohm Br Haas Comp Pruduetr R. Chemical C o m p n n y of Philhdeiphis.
0
Eight: BILITY
DEMONRTRATI~N 011 TEE EXTENSIOF POLYMETHYL ACRYLATEF ~ m s
The unstretohed film ie oompared with one to which 8mdi damp ie added in one O B B ~and s 500gram weight in the other.
Below: DEMONSTRATION OF THE WATERWHITE COLORA N D TRANSPARENCY OF A 20 P E R CENT SOLUTION O F A N ACHYLO~D POLYXER
: u d &yl, d tlieae t , w acids and their co-polynlers. Higher aliplintir as wcll as aromatic and I~rancli-chained e s t e r s have I>eenprepartxl, h i t so far these types IIRV(~ had a rnore limited use-
INDUSTRIAL AND ENGINEERING CHEMISTRY
636
FIGURE-1. EXTENSIBILITY OF ACRYLOID POLYMERS AS FUNCTION OF TEMPERATURE AND COMPOSITION P M 4 (high) = pol methyl acrylate (high polymer) P: E. %, $ M.A. (00- o f A) = polyethyl methacrylate and methyl acrylate (co-polymer P. E.M. M. A. (copol. B) = polyethyl methacrylate and methyl acrylate (co-polymer B):
+
2)
A
VOL. 28, NO. 6
which are of outstanding importance: (a) water-white color, (b) nonyellowing on exterior or interior exposure, ( c ) resistance to petroleum hydrocarbons, (d) good adhesion to most surfaces, (e) good electrical properties, (f) good durability, (9) good extensibility and elasticity in the case of the acrylates. The properties of the resin depend on both the chemical composition and the conditions of polymerization. The methacrylates produce harder, tougher, but less elastic films than do the acrylates. To a smaller degree, the same is true for the methyl as compared to the ethyl ester of a given acid. Listed in order of hardness, methyl methacrylate is first and ethyl acrylate last, with ethyl methacrylate giving a distinctly harder film than methyl acrylate. The characteristics of a given polymer are also markedly affectedby variations in the conditions of polymerization, such as changes in temperature, time, solvent, and type and amount of catalyst. These variations control the polymeric size of the final product, and, as would be expected, the polymers of smaller size are characterized by lower viscosities, lower tensile strength, and generally poorer film-forming characteristics. I n general, the polymerization is effected either in the presence or absence of solvents, although the former is usually to be preferred, since the polymerization can be more easily controlled under these conditions.
lower esters possess the more generally useful properties. In addition, substituted derivatives, such as chlorides, nitriles, Properties of Acryloid Film amides, etc., are known but are so far of little practical imCOLOR,REFRACTIVE INDEX, GLOSS,OPTICALTRANSMISportance. In a recent paper Neher (5) traced the developSION, SPECIFICGRAVITY. All the Acryloids are absolutely ment of the acrylk compounds; he showed that, despite the fact water-white and transparent. The clear flms have a rethat acrylic acid has been known for almost a hundred years, the fractive index of approximately 1.49 and have excellent gloss. commercial importance of these compounds has only recently The light transmission is intermediate between that of ordibeen recognized. Both Neher (6) and Wurth (10) indicate nary window glass and quartz, so that the Acryloids transmit that the first complete investigations of the polymeric acrylic a fairly substantial portion of light in the ultraviolet portion compounds may be ascribed to Rohm (7, 8). These initial of the spectrum. The specific gravity of the films is apstudies were continued by R o b and his eo-workers, parproximately 1.15-slightly below cellulase acetate (1.26) and ticularly after the war, resulting in the first commercial use considerably below nitrocellulose (1.6). of acrylic resins as the intermediate layer in the manufacture FLEXIBILITY, EXTENSIBILITY, TENSILE STRENGTH, THERof laminated glass. Subsequently, these resins have taken MOPLASTICITY. The flexibility and extensibility of Acryloid their place among the important raw materials of industry. films are unique in the field of organic coatings. It is possible, The purpose of this paper is to consider the Acryloids solely for example, to stretch a dried film of polymethylacrylate with regard to their use as film-foming materials, either (0.008 mm. thick) in excess of 1000 per cent at room temperaalone or in combination with other materials. Some work ture. The extensibility is markedly influenced by the comon this subject has already appeared. Munziger (3, 4) deposition of the polymer and by temperature. Table I gives scribes the use of acrylates and methacrylates under the trade comparative figures for a series of polymers ranging in hardnames of Borronl and Plexigum3 in the manufacture of artiness from polyethyl acrylate to polyethyl methacrylate. ficial leather; Ohl (6) discusses the effect of retained solvent Films were prepared by flowing out the polymers on on the extensibility and tensile strength of polyethyl acrylate; amalgamated tin trays, air-drying for 24 hours, and then stripVan Heuckeroth (9)briefly describes two Acryloid polymers; ping from the trays. Films were aged 6 months before testing. Ellis (1) discusses the use of acrylic acid polymers generally and mentions a few applications i n the coatings industry; Wurth (IO)describes the use of acrylic TABLEI. EXTENSIBILITIES OF POLYMERIZED ACRYLIC ACIDDERIVATIVES resins in many fields, including coatings, under AT 30" C. the trade names of Plexigum3 and Acronal.4 (All derivatives contained 20 per cent solids.) The discussion in this paper has been limited -Per Cent Extensibilityto consideration of the polymers of methyl and 90 parts 75 parts 90 parts ethyl esters of acrylic and methacrylic acids, resin, 10 resin, 25 resin. Sward parts arts 10parts and to eo-polymers of these four esters. It is Viscosity Hardness Pure l(2-sec. lx-seo. celluin Poises of Dried resin nitronitro- lose possible to produce these resins with a wide range Polymer Solvent at 77O F. Film film ceIluIose cellulose acetate of physical properties. The characteristics of Polvethvl methacrvlate Toluene 1 . 0 54 2.1 0.4 Too .. the iilm, for example, may vary from a sticky, brittle Co-pol mer A (largely Ethylene, rubbery, almost liquid material to a hard, tough, ethyr methacrylate, dichloride 1 2 . 9 54 20.0 0.7 . .. .. almost brittle product. All polymers, however, some methyl acrylate) have the following p r o p e r t i e s i n c o m m o n , Co-polymer B (some Ethylene Registered trade-mark, Rohm & Haas, A.-G.. Darmstadt, Germany. 8 Regiatered trade-mark, R6hm & Haas, A.-G., Darmstadt, and Rdhm & H a a s Company, Philadelphia. 4 Registered trademark, I. G. Farbeninduatrie. 2
ethyl methacrylate, largely methyl acrylate) Pol methyl acrylate ffigh polymer) Po yethyl acrylate
diohloride
12.9
42
Ethyl acetate 148 Ethyl acetate 8 . 8
40 2
185
... ...
..
65
..
..
13 155
53
..
JUNE, 1936
INDUSTRIAL AND ENGINEERING CHEMISTRY
The percentage elongation on a film 10 cm. X 1em. X (0.0060.008 mm.) in size was determined at 30" C. by hanging a &-gram weight on the film and measuring the elongation after attaining equilibrium. Data are given not only for the resin alone, but also for combinations with varying amounts of 1/2.second nitrocellulose and cellulose acetate. In the case of polymethyl acrylate and softer polymers, the addition of nitrocellulose was necessary to remove tackiness and permit the determination. The figures are startling in indicating the enormous differences in extensibility of the various polymers. Polyethyl acrylate, the softest member of the series, shows an elongation of 155 per cent with 25 per cent l/rsecond nitrocellulose as compared to 0 per cent a t this concentration for the two upper members of the series. In Figure 1, stress-strain curves are given for three different polymers at several temperatures. These curves show that extensibility varies widely with both composition and temperature. I n obtaining stress-strain data in this work, films were carefully prepared as described and were tested in a modified Gardner-Parkes tester ( 2 ) . The instrument used here differs from the Gardner-Parkes tester in being supplied with a glass housing, thermostatically controlled, which ensures uniform temperature for the duration of the test. In addition, the load is applied by adding definite weights a t one-minute intervals. A rectangular section, 15 X 1 em., was used in the tests, and film thicknesses varied from 0.02 to 0.2 mm. All determinations were run in triplicate.
637
L O A D IN G R A M S
FIGURE2.
EXTENSIBILITY OF ACRYLOID POLYMERS AS FUNCTION O F COMPOSITION
A
It is interesting to note that the extensibility possible by use of a n Acryloid film exceeds greatly that obtained from the use of the most flexible nitrocellulose lacquer. For this reason the application of Acryloid films is recommended where high extensibility is required, such as coatings on rubber and cloth. ADHESION.Generally speaking, Acryloid films have excellent adhesion to most types of surfaces. It is always true that the softer polymers are superior in this respect. When used on metal, adhesion is improved- by baking. On cloth, rubber, and flexible surfaces, the softer OF POLYMERIZED ACRYLIC ACID DERIVATIVESO polymers are important base coatings because of TABLE11. PLASTICITY Elongatheir combination of softness, flexibility, and extion at Recovery cellent adhesion. End of or Time "ReLIUHT RESISTANCE,NONYELLOWING, DURAPolymer Thickness Temp. Time Interval bound" BILITY. In their water-white color and permaMm. a C. Min. PETcent Per cent nence Acryloid coatings are unexcelled. The exCo-polymer A (largely ethyl methacrylate, some methvl acrvlate) 0.08 42 10 100 65 posure of detached films of a eo-polymer of ethyl 21 65 methacrylate and methyl acrylate on a Philadel0.20 10 100 phia roof for 3 years has indicated no discolora33 137 0.20 6 28 21 130 0.20 10 35 tion, no loss of gloss, and no failure of any kind. 0.20 33 2 138 27 Methyl acrylate high) 14 30 10 151 Softer polymers have somewhat inferior water 0.20 Methyl acrylate [low, Films stretched 165 per cent and recovery or "rebound" noted. resistance and may possibly not show the extraordinary durability of this particular polymer. The films do not discolor on interior or exterior exFigure 2 illustrates the difference in extensibility resulting posure as far as it has been possible to observe. To date, discoloration appears to occur only after prolonged baking from variations in composition-eo-polymer A (chiefly ethyl a t temperatures sufficiently high to cause pyrolysis. methacrylate and some methyl acrylate), eo-polymer B (some Even accelerated exposure tests, such as the Atlas Fadeethyl methacrylate and chiefly methyl acrylate) , and methyl acrylate. It also illustrates the variation resulting from difometer, have shown complete absence of discoloration. The heat resistance is good, films withstanding temperatures as ferences in the molecular size-methyl acrylate (high polymer) high as 350" F. without apparent discoloration. and methyl acrylate (low polymer). FLAMMABILITY. Figure 3 illustrates the effect of additions of l/t-second All Acryloid coatings are relatively nonflammable showing approximately the fire resistance of cellunitrocellulose and cellulose acetate to polymethyl acrylate. The addition of both reduces extensibility considerably, and lose acetate and being much superior to nitrocellulose in this cellulose acetate appears to produce this effect to a higher respect. RESISTANCETO WATER AND CHEMICALS. Table I11 degree than does the nitrate. The Acryloid films are not truly elastic because on stretchsummarizes the results of tests on resistance of three Acryloid polymers to cold water, boiling water, 10 per cent sodium ing they exhibit some plasticity. They require an appreciable time interval to regain their original form. This "induction hydroxide, 40 per cent sulfuric acid, and 5 per cent acetic acid period" is reduced by increasing the temperature and appears a t room temperature and 212" F. Tests are included for much longer for low polymers than for high. Table I1 illusboth air-dried and baked b s . In the case of the two softer trates this feature. Air-dried films, after aging for 96 hours, polymers, 10 per cent l/Tsecond nitrocellulose was added to produce a nontacky film. The water tests were run on films were stretched until 165 per cent elongation was obtained, flowed out on tin panels, dried for 48 hours in the case of the and the speed of recovery was noted. air-dried films, and heated for 1 hour a t 250" F. in the case The tensile strength varies enormously with composition; polymers were investigated in the range of 10 to 1000 kg. per of the baked films. The acid and alkali tests were run on sq. em. a t room temperature. The films commonly used in films flowed on the outside of glass test tubes and air-dried for 72 hours. coatings generally fall in the range of 200-400 kg. per sq. em.
INDUSTRIAL A4NDENGINEERING CHEMISTRY
638
VOL. 28, NO. 6
TABLE111. RESISTANCE OF POLYMERIZED ACRYLIC ACID DERIVATIVES TO CHEMICAL REAGENTS Immersion Test 24 hr. in cold water
Co-polymer A (Largely Ethyl Methacrylate, Some Methyl Acrylate) -kir-Driedn Bakedb S o t affected Not affected
Polymethyl Acrylate (High Polymer) 90%, '/z-Sec. Nitrocelluose, 10% Air-dried" Bakedb Not affected Not affected
72 hr. in cold water
Kot affected
Not affected
15 min. in boiling Not affected water
Not affected
hr. a t room Not affected temp. in 5% NaOH 2 4 hr. a t room Not affected temp. in 10% NaOH 24 hr. a t room Not affected temp. in 40% HzSOi 2 4 hr. at room Not affected temp. in 5r0 acetic acid 15 min. a t 212' F. Loss in adhesion; ( 1 0 0 " C.) in 10% film unaffected NaOH
Not affected
Definite whitening and slight softening Very slight whitening; slight softening Not affected
Polymethyl Acrylate (Low Polymer) goy0,I/n-Sec. Nitrocellulose 10% Air-drieda Bakedb Appreciable whit- Appreciable whit ening and sofening and softening; recovered tening; recovon removal from ered on removal bath from bath Definitewhitening W h i t e n e d a n d W h i t e n e d a n d and slight sofsoftened badly softened badly tening N o w h i t e n i n g ; Whitened badly; Whitened badly; slight softendefinitely sofsoftened ing tened Not affected Not affected Nof affected
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
Not affected
24
15 min. a t 212O F.
in 40% HzSOn
15 min. a t 212' F. in 5 % acetic acid
0
b
-
Whitened badly in Whitened badly in Whitened badly in Whitened badly in 2 rnin.: film de5 min.; film de2 min.; film de5 m i n ; film destroyed in 15 stroyed in 15 stroyed in 15 stroyed in 15 min. min. min. min. unaffected Slightly cloudy; Slightly cloudy; Cloudy, severe Film very soft and Film unaffected Film film soft and film soft and pinholing; film easily removed except for few except for few soft and tacky cloudy spots cloudy spots tacky tacky with nail Film unaffected Film unaffected Whitened in 1 Whitened in 3 No whitening but No whitenir'g, but bad pinholing bad pinholing min.: slightly min.; slightly except for slight except for slight cloudy after 15 softening and loss in adhesion cloudy after 15 and loss of adand loss of admin. with loss min. with loss hesion hesion loss in adhesion of adhesion of adhesion Loss in adhesion: film unaffected
For water tests, films dried 48 hours: for acid and alkali tests, films dried 72 hours. Baked 1 hour at 250' F. for all tests. i
The resistance of the hardest polymer is outstanding. It is not affected by cold or boiling water, alkali, sulfuric acid, or acetic acid in the cold under the conditions of test. On heating a t 212' F., the 61ms showed only loss of adhesion and no attack of the film itself. The resistance of the polymethyl acrylates (both high and low polymers) is inferior particularly in their resistance to boiling water and hot acid and alkali solutions. The high polymer shows somewhat better resistance than the low one. The Acryloids are, as a rule, unaffected by exposure to petroleum oils, gasoline, greases, and petroleum hydrocarbons in general. They are attacked by aromatic hydrocarbons, chlorinated hydrocarbons, esters, etc. ELECTRICAL PROPERTIES. The following electrical constants of polymethyl acrylate were determined' and are of interest for electrical applications: Breakdown voltage, volts/cm. 280,000-340,000 Surface resistivity at 1000 volts, megohms (4-5) X lo6 4 x 1012 Specific electrical resistance, ohms Dielectric constant 5-6 In addition, the resistance of Acryloids in general to ozone, mineral oils, and aging is important. The compatibility of a wide range of COMPATIBILITY. materials with the more important Acryloid resins was investigated. Generally speaking, most materials investigated are incompatible, and, rather unexpectedly, it is generally true that the Acryloid polymers are not compatible with each other. This is not, however, the case with low and high polymers of Privata oommunication based on results obtained at Teohn. Reiohsanstalt, Berlin. 6
polymethyl acrylate, which are compatible with each other in all proportions. The results of the compatibility studies are summarized in Table IV. I n determining compatibility, solvents were carefully selected to prevent precipitation of the constituents of mixture. No effort was made to add a plasticizer or other substance to promote compatibility. It will be noted that '/Z-second nitrocellulose is compatible in all proportions and that cellulose acetate has limited compatibility. Of the other cellulose esters and ethers, the nitro-
P OL r M
E T tiY L ALRV LATE
WlTHvARYlNCq A M O U N T OF
NITROCELLULOSE AND CELLULOSE ACETATE
0
I
,
I20
z
LOP
FIGURE3. EFFECTON EXTENSIBILITY OF ADDITIONS OF CELLULOSE ACETATE AND NITROCELLVLOSE TO POLYMETHYL ACRYLATE (HIGH-VISCOSITY)
JURE, 1936
INDUSTRIAL AND ENGINEERING CHEMISTRY
639
-
__
acetate has limited compatibility and the ethyl and benzyl compounds are incompatible. Of TABLE Iv. RESULTS O F COMPATIBILITY STUDIESn Co-polymer -4 the customary esters used in nitrocellulose lac(Largely Polyethyl -Polvrr.ethyl---Polymethyl-Ntsi’l: Methacrylate, Some .&crylate Acrylate quers, dibutyl phthalate and tricresyl phosphate (the two investigated) were compatible Methyl Acrylate) (High) (LOW) in all proportions. In addition, chlorinated Ratio, -4cryloid to resin: 1 to 1 to 1 to 1 to 1 to 1 to 0 . 0 9 0 . 2 1 to 1 0 . 0 9 0 . 2 1 to 1 0 . 0 9 0 . 3 1 t o 1 .Iniberol 801 1 1 1 1 1 1 1 1 1 diphenyl (Aroclor 1254) appears compatible. 1 1 1 1 1 1 1 1 1 The Acryloids are not compatible with drying %$$L:f F-7 C c C c I I I I I c c c 1 1 1 1 1 1 oils, with oleoresinous varnishes, or with alkyd C 1 1 1 1 1 1 resins. Castor oil has a very limited comBenzyl cellulose 1 1 1 1 1 1 1 1 1 I 1 1 c c c c patibility with certain types. Some of the imI c c c c c c 1 1 1 1 1 1 1 1 1 portant synthetic resins used in varnishes and c . I I l l Castor oil C b 1 1 1 1 1 1 lacquer formulation are compatible. This in1 1 1 1 1 1 1 1 1 cludes resins of the so-called modified phenolnitrocellulose c c c c c c c c c c c 1 1 1 1 1 1 formaldehyde type, unmodified phenol-formalc c c c c c c c c Tricresyl phosphate c c c c c c c c c dehyde, and maleic acid resins. Ester gum and c c c c c c c c c rosin are compatible with the co-polymer of $ ~ ~ ~ $ ~ ~ & 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ethyl methacrylate and methyl acrylate and inE;:J;~:; 1 1 1 1 1 1 1 1 1 compatible with the others. Shellac, dammar, Linseed oil 1 1 1 1 1 1 1 1 1 a I = incompatible: C = compatible. and cumar have limited compatibility as do the b Oily (nondryinp). vinyl compounds. __~___ SOLUBILITY. The Acryloid resins are generally soluble in most types of organic solvents, ing comparative drying rates of an Acryloid and nitrocellulose with the exception of petroleum hydrocarbons, alcohols, and ethers. The more important solvents which may be used, lacquer: WATEREMULSIONS.The acrylates are produced in water either as thinners or to introduce other materials, are coalemulsions and sold under the trade name of Acrysol.‘j These tar hydrocarbons (toluene, xylene, etc.) ; chlorinated hydroproducts are completely miscible with latex and are useful ’ carbons (ethylene dichloride, dichlorobenzene, etc.) ; ketones as base coatings, chiefly on textiles and rubber. (acetone, hexone, butyrone, etc.); esters (ethyl acetate, butyl SUGGESTED APPLICATIONS.Acryloid coatings are recomacetate, dibutyl phthalate, etc.) ; ether alcohols (Cellosolve, mended for use where their outstanding properties of watermethyl Carbitol, etc.) ; ether esters (Cellosolve acetate, Carwhite color, nonyellowing, petroleum and oil resistance, good bitol acetate, etc.). electrical properties, adhesion, flexibility, ozone and chemical PIGMENTATION. The Acryloids are completely neutral, resistance, etc., are of importance. Specifically, their applicaand therefore reactivity is not to be feared, thus permitting tions in the field of clear metal lacquers, textiles and artificial the use of any type of pigment. Considerable work remains leather, electrical insulation, coatings on rubber, glass lampto be done in order to determine the best procedure to be shades, porous surfaces, containers, and chemically resistant used in preparing enamels. So far, all grinding tests have coatings would appear promising. been made in the pebble mill, and wetting characteristics apThe future importance of polymerized acrylic acid derivapear poor. In general, the smaller size polymers grind and tives as raw materials for the coatings industry cannot be wet most easily, producing coatings with the highest gloss. evaluated. In view of their having so many of the properties desired in the ideal coating material, it is felt that their Uses uses will multiply. Acryloid coatings can be applied by the customary methods employed with other coating materials-namely, brushing, spraying, dipping, and spreading. The most useful types, Acknowledgment however, give solutions of high viscosities, thus necessitating The authors are indebted to 0. B. Helfrich and H. Bloodsdilution to rather low solids concentration to permit applicaworth for assistance in securing the experimental data and tion. for aid in the preparation of the curves and tables. Acryloid films are similar to nitrocellulose in that they appear to dry by solvent evaporation. This would naturally Literature Cited suggest their use as air-drying coatings. However, wherever possible it is recommended that baking be employed, since (1) ~ l l i “Chemistry ~, of Synthetic ~ ~ ~vel.i 11,~ pp.~ 1077-9, , ” New York, Reinhold Publishing Corp., 1935. such coatings are generally superior to those produced by (2) Gardner, “Physical and Chemical Examination of Paints. %&drying in gloss, adhesion, and hardness. The Acryloid Varnishes, Lacquers, and Colors,” 5th ed., pp. 763-6 (1930). films show some solvent retention as indicated by the follow(3) Munaiger, Nitrocelpulose, (May, 1933).
cellulose
ate
g:;’,obk”z
yi$!e gr;;;l~$:;;$2 6::;
(4) Ibid., 5, 59-61 (1934). Acryloid Lacquer Nitrocellulose Lacquer Per Cent Solids 25 25 Per Cent Solvents 49.3 toluene 55.0 toluene 32.4 butyl acetate 14.3 ethyl acetate 2.0 ethyl alcohol 29.3 butyl acetate 7.6 butyl alcohol 1.4 ethyl alcohol 8.4 ethyl acetate Per Cent Composition of Solids 22 1 2 second nitrocellulose 60 methyl acrylate (low polymer) 22 dGberol 801 40 titanium dioxide 36 Paraplex 5-B 10 l/z-sec. nitrocellulose 20 titanium dioxide Tack-free, 30
Minutes of Drying Time Tack-free, 90; dust-free, 10
(5) Neher, IND.ENG.CHEM.,28, 267-71 (1936). (6) Ohl, Nitrocellulose, 5, 66 (1934). (7) Rohm, BeT:, 34, 573-4 (1901). (8) Rohm, “Uber Polymerisations produkte der bkrylsiiure,‘’ thesis, Tiibingen, 1901. (9) Van Heuckeroth, Natl. Paint, Varnish & Lacquer h s o c . , Circ. 472, 364 (1934). (10)Wurth, Chem.-Ztg., 99, 1001-12 (1935). RECEIVED Bpril 21, 1936. Presented before the Division of Paint and Varnish Chemistry a t the Qlst Meeting of the American Chemical Society, Kansas City, Ma., Bpril 13 t o 17, 1936. 6 Trade-mark registered in the U. S. Patent Office by the Resinous Products & Chemical Company, Inc.
