Document ZJYwopjMD1Mb4pkJVZk76aD60

DRUGS, OILS AND PAINTS , / f ('> ^ e / ? ? ) en temperature. The technologist has ride use of this characteristic in conwith his work on cellulose nitrate, and ubtless be able to apply much of that ition to similar products employing e acetate. However, a warning note e sounded in regard to this practice, it exhibits many of the properties of rate, cellulose acetate possesses a group inctive characteristics which are not jle to the treatment acorded cellulose or cellulose benzoate. For example, se nitrate is readily soluble in methyl , whereas the acetate is quite insoluble liquid. Any solvent formula, whether inning, coating, spraying, brushing or g, which contains methyl alcohol, may sidered in the case of cellulose nitrate g a formula containing a solvent; whereands. Representatives of this class are ie, 1, 4 dioxen and tetrahydro furfuryl en cellulose acetate is substituted the 1 alcohol becomes a diluent with respect cellulose ester. liquids which will dissolve cellulose aceetween 36% and 42% acetyl are not only as regards classes of compounds, but er properties as well. Among the very loiling liquids may be mentioned aniline, 84.5 C., and acetophenone, B. P. 198 C., irmer an amine and the later a ketone, g the esters which are solvents for cellucetate may be mentioned methyl formate, ri salicylate, methyl lactate and glycol ate. Some of the halogenated hydro- ns are also solvents, for example, tetrasthane, trichlorethane, and hot ethylene de. These are, however, all more or less ble and somewhat toxic, both of which them less desirable than other materials, lose acetate is also soluble in heterocyclic ol. Nitrobenzol is also a solvent, repreig another class of organic substances, itro-compounds. Heat is required to bring ose acetate into solution in the majority e nitro bodies. Of the alcohols, mention jeen made previously. However, cellulose te is readily soluble in diacetone alcohol, e ether-alcohols are also solvents, in the of the mono methyl or ethyl ether of >1, or trimenthylene glycol. The above rill suggest the wide variety of the solvents hich cellulose acetate is soluble. But this 5 only a part of the story, for as in the of cellulose nitrate, there are mixed sol- s for cellulose acetate in which neither ionent is a solvent. The action of these id solvents has offered a most perplexing lem to the scientific worker, not only in field of cellulose esters, but in other fields ganic chemistry where this same phenomehas been observed. Again, the technologist found such mixed solvents to be valuable, he case of cellulose nitrate the example immediately comes to mind is the use of U volumes of ether and alcohol, neither vhich will dissolve the ester when used e. A parallel to the above in the case of llose acetate is the use of mixtures of roform and alcohol. Other halogenated rocarbons with alcohols also may be used, the acetyl content of cellulose is reduced w the acetone soluble range, say to 30% yl, it becomes soluble in a still greater ety of solvents, such as hot 75% aqueous hoi. . However, the products so obtained e not been found useful by the technologist, rom the above it is seen that for technical poses the range of solvents for cellulose -ate is sufficiently broad to permit of great |tjf f i^ n c h o i c e s o th atth e optimum solvent LEAD is a lasting m e ta l.. LEAD in paints gives lasting satisfaction. Is there enough LEAD in your paints? EAGLE-PICHER 134 N o. La Salle St., Chicago W hite Lead, C arbonate Sublim ed Blue Lead R ed Lead Super Sublim ed W hite Lead Sublim ed W hite Lead Litharge O range M ineral Sublim ed Litharge Lithopone Zinc Oxide .. u.a. I' . t o e . the ratio of solvent to solute. This procedure is subject to grave limitations and usually is governed by the requirements imposed by the apparatus in which the solution is to be used or by the character of the coating which it is desired to obtain. The solutions of cellulose acetate for brush lacquers should, of course, be higher in viscosity than those to be used in spraying. It is obviously impractical to at tempt to use the spraying solution for brush ing both because of the difference in volatility of the solvent mixture and the viscosity of the solution which would produce brush marks. On the other hand, in a spraying lacquer it is not desirable to reduce the viscosity by ad dition of solvent because of the fact that a thin in the not very distant future, it will take l place among the new coating materials whic have become such important factors in th problem of the protection of all manner 0 surfaces against the forces of nature, or tha of the beautification of the home and its fui nishings. For some purposes it is believe that cellulose acetate lacquers will be muc more suitable than cellulose nitrate. Example will be given later. (To be concluded) NEWS AND COMMENTS Increased Production of Carbon Black