3,073,794 United States Patent Office Patiented Jan.5, 1963 2 evaporation of the solvent, to leave behind a thin, de 3,073,794 posited film of the polymer. Basically, a suitable poly SPRAYABLE, ANHYDROUS SOLUTION OF -V. mer is a “1-vinyl-2-pyrrolidone polymer" and this is the NYL-2-PYRERODONE POLYMER IN CHELOR principal component. However, the term is also defined FLUORO HYDRO CARBON PROPELLANT George G. Stoner, Easton, Pa., assignor to General herewith to include not only the homopolymers but also a Aniline & Film Corporation, New York, N.Y., a corpor wide range of heteropolymers, copolymers, interpolymers, ration of Delaware terpolymers (three-component polymers) and, in general, No Drawing. Fied May 22, 1959, Ser. No. 814,999 polymers in which vinylpyrrollidone is either the sole com 6 (Cais. (CE. 260-33.8) ponent, a major component or a substantial component. O In the latter two instances the vinylpyrrollidone is copolym This invention relates to film-forming compositions, erized with such substances as vinyl acetate, isopropenyl and relates more particularly to sprayable film-forming acetate, vinyl laurate, vinyl stearate, vinyl oleate, vinyl compositions which are non-flammable and non-alcoholic benzoate, and other vinyl and isopropenyl esters; vinyl and which are eminently suitable for therapeutic pur chloride, 2-chloropropene, and other vinyl and isopropenyl poses. 5 halides; methyl vinyl ether, ethyl vinyl ether, isopropyl This application is a continuation-in-part of my ap vinyl ether, isobutyl vinyl ether, 2-ethoxyethyl vinyl ether, plication Serial No. 580,443, filed April 25, 1956 and now phenyl vinyl ether and other vinyl ethers; acrylic acid and abandoned. methacrylic acid; maleic anhydride, chloromaleic an There are many instances in which a smooth, even hydride, citraconic anhydride, and itaconic anhydride; layer of solid polymer is desired, particularly for thera 20 methyl methacrylate, hexyl acrylate, methyl alpha-chloro peutic purposes, but to the present no satisfactory proce acrylate, etc.; acrylonitrile, methacrylonitrile, acrylamide, dure has been developed for applying such layers on the and methacrylamide; acrolein and alpha-methylacrolein; human system. Polyvinylpyrrollidone is a well known styrene, ethylene, isoprene, 1,3-butadiene, and isopropenyl water-soluble polymer which, if applied to human tissues, benzene; 9-vinylcarbazole; and allyl esters. would exert many very valuable effects. For instance, 25 The preferred solvents for the above vinylpyrrollidones a thin layer of polyvinylpyrrollidone on human skin ab are the chlorofluoro compounds identified broadly as the sorbs enough ultraviolet so that a relatively unclad bather, Freons. The following tables set out solvents for the coated with a thin layer of polyvinylpyrrolidone, can bask polyvinylpyrrolidone: TABLE 1. Hydrogen-Containing Chlorofluoroalkanes Formula, Trade name B.P., C. Chemical name Additional comments CHCF Freon 21---- 9 Dichlorofluoro-methale. -- M.P., -127C. d, 1,422 g/ml. CFCF- Freon.------- -41 Chlorodifluoro-methane. - M.P.-46° C. CHCl2-CHF2----------------------- 60 1,1-dichloro-2,2-difluoroethane- - d., 1.473 g.fm. CFICl2-C ClF3------------ 2 1,2,2-trichloro-1,1-difluoroethane.-------- d2, 1.54 g.fm. CHCl-CHClF--------------------- 102 1,1,2-trichloro-2-fluoroethane-...-------- d.17, 1.550g.fm. in the sun indefinitely without sunburning, but will obtain 40 It will be observed that all of these solvents contain the an excellent smooth tan. "methine” group; that is, -CH=. Other compounds Similarly, the very high-molecular-weight polyvinyl which are useful in the present invention are shown in pyrrolidones have a sufficiently low water solubility to be Table 2: highly desirable as coatings for injuries such as burns, bruises, cuts and the like. Heretofore, Collodion, which TABLE 2 is a solution of approximately 4 grams of pyroxylin 45 (chiefly nitrocellulose) in 100 milliliters of 1 volume of Formula B.P., C. M.P., C. Density, alcohol and 3 volumes of ether containing about 70 per g.fml. (C.) cent ether and 24 percent absolute alcohol by volume, CCl3-CEIClF-------------------- 17 --95. 1.625 (20) applied by a brush from an alcohol solution has been CCl2F-CHC------- a 17 -83 1.622 (20) 50 CHF-CCl3 73------------ 1.566 (20) used (under the name of "nu-skin'), but the resulting CECII--CCF 72 1.549 (25) layer is water-impervious and water-insoluble whereas a CHCF-CCF 28 1.496 88 9HCl2 CFs-------------------------------------------------------- similar layer of polyvinylpyrrollidone is not impervious 9FCCF-------------------------------------------------------- CHFCCF-------------------------------------------------------- to exudate, does not contract or shrink and can be re CHCFCF-------------------------------------------------------- moved by a gentle stream of water, which is not the case 55 CHCF-CHCIF---------------------------- with collodion. CFCF-CHF CHF-CHF Another advantageous use of polyvinylpyrrollidones is CHF's CC2- D D 37 -109 1.383 (20) in surgery. Thus, their characteristic water solubility, CHCl-CHF--------------------- O but slow solubility, make them desirable as coatings to separate tissues between which adhesions might tend to The solvents listed in these two tables show boiling occur after surgery. A film of polyvinylpyrrollidone de 60 points from -41° C. to 117°C. The lower boiling point posited upon internal organs during surgery will greatly Solvents are particularly useful for situations in which it is reduce the danger of adhesions, and the material does not desired to apply a dense, closely adherent layer of polymer need to be removed before the incision is closed since it free from solvents such as in cosmetic uses, for suntan is resorbed in normal course. Many other uses will be protectors, hair lacquers, wind protection and the like; obvious to those skilled in the art. 65 whereas the higher boiling solvents are particularly useful In accordance with the instant invention, a highly desir where a high boiling, high viscosity index, low flammabil able composition consists in a solution of a spirit-soluble ity fluid is desired for such uses as hydraulic fluids, brake polymer, such as polyvinylpyrrollidone, in a chlorofluoro fluids and the like. compound of relatively, or moderately, low boiling point It will be observed that the two tables above set out which may be below room temperature or somewhat 70 present only "Freons" which contain the methine group. above, but in any event is such as to permit of a rapid it is found that the methine group is essential to a high 3,073,794 a 3. 4. solubility of polyvinylpyrrollidone in Freon. However, polyvinylpyrrollidone, or copolymer thereof, is insoluble there are many other compounds such as those shown in in the Freons in the absence of alcohol, e.g., ethyl alco the subjoining Table 3 which, while they do not contain hol. Accordingly, in order to dissolve alcohol-free poly methine groups, are useful in this invention, particularly vinylpyrrollidone or copolymer thereof in Freons, it is as diluents, or boiling-point modifiers for the solution, 5 absolutely essential to make them substantially anhydrous. since their presence in moderate amounts does not signifi- This is a departure from prior art practices where aerosol cantly reduce the solvent properties of the methine- compositions of either polyvinylpyrrolidone or a copoly containing compounds for the polymer. mer of 60% vinylpyrrollidone and 40% vinyl acetate con TABLE 3 taining water were first dissolved in alcohol and then the 10 alcoholic solution was mixed with the Freons. As is Freons Which Do Not Contain Methine (-CH-) Well-known it is often highly desirable to have alcohol Groups free compositions, particularly in hair preparations. The following examples, which are offered as indicating Freon Formula B.P., M.P., Additional the best way of practicing the invention, not as limitations number o C. o C. comments 15 upon the claims. EXAPLE 1. ; : | d", 1494 g/ml. A glass vessel containing 10 parts of Plasdone (the 4. - Si: gill pharmaceutical grade of polyvinylpyrrollidone, Finkent CCF-CFs----- s-38 -166 '' gill. Scher K value of 32 which is 1000 times the k value de CHCClF------ 10 131 d-'', 1.194 g/ml. 20 termined by the method described by H. Fikentscher in Cellulosechemie, 13, 60 (1932), manufactured by Gen 'Genetron O' eral Aniline and Film Corp.) was kept at 0° C. while Still another group of usable compounds is presented Freon 21 (CHCl2F, dichlorofluoromethane) was con in the subjoined Table 4. These, however, are less satis- densed in the vessel. By the time that 90 parts of Freon factory since some of them are flammable and others diffi- 28 21 had condensed, a clear, light yellow fluid solution re cult to liquefy because of the low boiling point. Never- sulted. It was fluid at least within the range of -60° C. theless, all of these compounds are usable, at least as to 3 C. In a sealed vessel, such as an aerosol bomb, diluents, in the preparation of the composition of the the range could be extended considerably. In order to present invention. modify the Solution for cosmetic purposes, small amounts TABLE 4 30 of other ingredients may be added, such as the interpoly Freon-Like Compounds mer of methyl vinyl ether and monobutyl maleate to re duce tackiness, emollient oil, perfume, and a bactericide. Ethyl alcohol may be added in some cases at concentra Formula BE ME Objectionable property tions below which it would create a fire hazard (if used 85 in hair lacquers, for example). C-CF- -25 -17 Flammable, slighty toxic. EXAMPLE 2. CH3CIF2------------------------- Flammable. CE=CEF ? -160 Di?trict liduef An attempt was made to dissolve Plasdone in Freon CHE-CF3-3.E. 3: ar -82 -163- 103 Difficultcuit to liquefy,Ilguery. “Freon. 23.' 142 (Table 3, no methinead group present) but the result CF4---------- -28 -84 DES E. tiguely, “Freon 14' 40 was that only white, opaque, granular Plasdone floated on CCF-------- -8. -181. DifficultOO SOW3 to liquefy, “Freon 13,' the clear, liquid 1.chloro-1-diffuorpethane below w ts Poor Solwent, boiling point of -10° C.