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. Hence, K-32 polyvinylpyr rollidone is practically insoluble in CH-CCIF, quite a Still another group of compounds which are also contrast from the system illustrated in Example 1. usable, although less desirable, is shown in the subjoined 45 By adding ethyl alcohol in small increments, it was Table 5. found that the minimum amount was 27 parts for a mix TABLE 5 Halides of Borderline Desirability Flam- Tendency Formula B.P., O. M.P., C. Toxicity nable? to En- Connents 28

19 -5 Moderate No.-- Yes------28 'Kel-F'monomer, e-8 'Teflon' mononaer. Below -70 Low flash point. -25 Do. 6 No------dl, 1.389 g/ml. CHC-CCF- A No------d20, 1.416 g.fm, CHC -CCF.------88 -105 ------No------d20, 1.492 g.fml.

It will be observed from these tables, that a solution ture of 90 parts of Freon 142 (also called Genetron 101) of the desired polymer in almost any concentration may and 10 parts of polyvinylpyrrollidone at -15-5° C. be obtained in a solvent boiling at almost any desired The concentration of polyvinylpyrrollidone in this solu temperature by appropriate choice of mixed solvents 65 tion was approximately 8% and such a solution is not from these various substances. If it is desired that the nearly so safe from the standpoint of fire as that described solution would stand relatively high ambient temperatures, in Example 1. The flash point of ethyl alcohol is only the higher-boiling Freons should be chosen. 5.5 F. The important feature of the instant invention, how ever, is the obtaining of non-flammable, non-alcoholic, 70. - EXAMPLE 3 sprayable film-forming compositions wherein the Freons Freon 113 (Table 3) is a liquid up to 46° C. Never serve both as solvent and propellant. To this end, it is theless, it is practically not a solvent for polyvinylpyrroli essential that the polyvinylpyrrolidone be anhydrous as done. Plasdone merely floats on it at room temperature. well as the Freon or Freons used as the solvent propel- 1,1,2-trichloro-1,2,2-trifluoroethane contains no methine lant. It has been found that where water is present, the 75 (solubilizing) group, but it is non-flammable and virtu 8,073,794 5 6 ally non-toxic, so it makes a useful diluent where rela lose acetate, cellulose acetate propionate, methyl poly tively low volatility for a Freon is desired. methacrylate, and carboxymethylcellulose. Softeners EXAMPLE 4 may be added to plasticize the film of 1-vinyl-2-pyrroli Freon 114 was condensed at -155° C. in a glass done polymers, as for example, diethylene glycol, glycerol, vessel containing Piasdone, but no significant amount of 5 sorbitol, carbethoxymethyl ethyl phthalate (Santocizer polyvinylpyrrolidone was dissolved. Even a larger pro E-15), carbobutoxymethylbutyl phthalate (Santocizer B portion of ethyl alcohol was required than had been 16), benzyl butyl phthalate (Santocizer 160); and the needed with Freons 113 and 142 in the foregoing ex following resins act as plasticizers in addition to mini amples. At least 63 parts of ethyl alcohol was required mizing tack; carboxymethylcellulose, cellulose acetate, to solubilize a mixture of 10 parts of K-32 polyvinylpyr polyvinyl formal, and methyl polymethacrylate. rolidone and only 70 parts of CCFCCF at -15-5 EXAMPLE 8 C. Of course this was a colder temperature than had K-60 polyvinylpyrrollidone was plasticized by the foll been used with Freon 113 in Example 3, which might lowing procedure: Forty-five parts of polyvinylpyrroli account in part for the greater proportion of ethyl alco done, 24 parts of the interpolymer of methyl vinyl ether hol required. The same temperature of -155° C. was 15 and monobutyl maleate, made by treating polyvinyl methyl used in Example 2, which indicates that Freon 142 is ether/maleic anhydride with 1-butanol, and 31 parts of somewhat better as a cosolvent than is Freon 114. diethylene glycol were dissolved in ethyl alcohol. From Freon 114 is more volatile than Freon 113. They both this solution, two films were cast in glass weighing-dishes have virtually no toxic properties and are noncombustible, 20 and dried over calcium chloride at an absolute pressure and are useful as diluents for methine-containing chloro of approximately 50 mm. of mercury for one week. fluoroalkanes, such as those listed in Tables 1 and 2. During this period the relative humidity was 4 to 11%. EXAMPLE: 5 The resulting films were 4 to 8 mils thick. They were A solution was formed by mixing 90 parts of 1,1-di clear, colorless, well plasticized, and tack-free. chloro-2,2-difluoroethane and 10 parts of an interpolymer 25 The films were aged at 100% humidity for three days. of 1-vinyl-2-pyrrollidone and vinyl acetate. Inasmuch as The films remained clear, colorless, well plasticized with 10.7% of the solvent-free interpolymer was nitrogen (by good elasticity, and become only slightly tacky. analysis), the ratio of comonomers was 88/12. EXAMPLE 9 Evaporation of some of this solution on the skin left The above data indicated that polyvinylpyrrollidone a film which had an excellent protective effect in screening 30 (and other vinylpyrrollidone polymers) can be modified out infrared radiation. for several applications, e.g., aerosol-dispensed hair lac EXAMPLE 6 quers. Here the need for a plasticized, tack-free film of A 10% solution of an interpolymer of isobutyl vinyl polyvinylpyrrolidone would arise, even under extremes of ether and 1-vinyl-2-pyrrollidone was prepared in 1,2,2-tri 35 humidity. The following composition is recommended: chloro-1,1-difluoroethane. The solvent-free interpolymer 77 to 92 parts of K-32 polyvinylpyrrollidone, 2 to 11 parts had 10.1% nitrogen, indicating that the ratio of monomer of a half butyl ester of polyvinyl methyl ether/maleic units was 20/80. This solution was diluted with an equal anhydride, and 6 to 12 parts of diethylene glycol. The weight of dichlorodifluoromethane (as propellant), and resulting lacquer could be removed easily from the hair. 40 In addition to helping to plasticize the film, the interpoly applied to hair as an aerosol. It was effective as a hair mer derived from methyl vinyl ether, maleic anhydride, lacquer. The solution tolerance useful concentrations of and 1-butanol would reduce tackiness. Furthermore, 2,2' - methylenebis(3,4,6 - trichlorophenol) (also called the high hygroscopicity of these compositions conceiv hexachlorophene and G-11), perfume, and lanolin, and ably could enhance the effectiveness of the lacquer in was particularly easy to wash out. very damp weather without increasing tackiness. EXAMPLE Compositions of polyvinylpyrrolidone, polyvinyl methyl A 2% solution of K-90 polyvinylpyrrollidone was pre ether/maleic anhydride half butyl ester, and diethylene pared in 1,1,2-trichloro-2-fluoroethane, a dimethine liquid glycol may find application where the films must be solu listed in Table 1. This preparation is useful as a dense, ble in ethyl alcohol, but insoluble in water. Applications physiologically safe, non-flammable, hydraulic fluid. The 50 may include film for food packaging, films for incorpora K-90 polyvinylpyrrolidone has a high degree of polymeri tion of infrared, visible, or ultraviolet absorbers, optical zation and improves the viscosity characteristics of the brighteners, or fluorescers, or films for nail polishes. In solvent. such applications, the concentration of polyvinyl methyl A glass vessel containing 13 parts of K-32 polyvinyl ether/maleic anhydride half butyl ester should be ap pyrrollidone was kept at -4.5+5 C. while Freon 22 55 proximately 50% by weight of the polyvinylpyrrollidone (CHCIF, chlorodifluoromethane) was condensed in the in order to impart sufficient resistance to the dissolving vessel. By the time that 87 parts of Freon 22 had con action of water. densed, a clear, straw-colored, fairly fluid solution re Vinylpyrrollidone polymers are unusual in that they are sulted. both gums and resins, that is, they are quite soluble in The following comment applies to Examples 1, 2, 3, 4, 60 water and at the same time quite soluble in many organic and 7: When a very thin layer of the solution which was solvents. Furthermore they are either physiologically finally obtained was poured on a glass plate and allowed inert or beneficial, and have a thickening, detoxifying, to evaporate, then a colorless, clear film resulted. Below cleansing, or lacquering effect often desired in certain relative humidities of approximately 60% the film was cosmetic applications. Aerosol-dispensed cosmetics are tack-free. Agents which have been found for reducing 65 becoming very popular. Vinylpyrrolidone polymers have tackines of polyvinylpyrrollidone at 70% relative humidity made non-flammable, non-toxic hair lacquers possible be include derivatives of the interpolymers of alkyl vinyl cause these polymers are soluble in non-toxic, non-flam ethers and maleic anhydride (as partial butyl and isobutyl mable solvents such as those listed in Tables 1 and 2. esters of polyvinyl methyl ether/maleic anhydride, and Because of packaging limitations, water is not used in the ammonium salt of the complex of polyvinyl methyl 70 aerosol containers. Yet it is desirable to have cosmetics ether/maleic anhydride and polyvinylpyrrollidone) the which are water-soluble, that is, which can be washed off ammonium salt of the complex of polyvinylpyrrolidone the skin or hair when desired. Vinylpyrrolidone polymers and polyacrylic acid, interpolymers of 1-vinyl-2-pyr fill both of these requirements, whereas most other high rolidone and acrylonitrile (at least within the range of molecular-weight materials are poor compromises. 13 to 25% acrylonitrile), shellac, polyvinyl formal, cellu 75 Thus the composition of matter of the invention polym 3,073,794 7 8 erizes vinyl pyrrolidone with or without other unsaturates having 1 to 2 carbon atoms and 1 to 2 unreplaced hy and dissolves the resulting polymer in a "Freon' type drogens. of solvent to produce a fluid having a wide range of very 4. A non-flammable, sprayable film-forming composi valuable uses as above pointed out. tion consisting essentially of an anhydrous solution of an The term “1-vinyl-2-pyrrolidone,' as employed in the anhydrous copolymer of 1-vinyl-2-pyrrollidone having a claims, is to be construed as including within its scope K value between 30 and 90 and a copolymerizable mon not only the homopolymers, but also heteropolymers, omer selected from the group consisting of vinyl acetate, copolymers, interpolymers and terpolymers of 1-vinyl-2- isopropenyl acetate, vinyl laurate, vinyl stearate, vinyl pyrrollidone. oleate, vinyl benzoate, vinyl chloride, 2-chloropropene, While there are above disclosed but a limited num 10 methyl vinyl ether, ethyl vinyl ether, isopropyl vinyl ether, ber of embodiments of the process of the invention it is isobutyl vinyl ether, 2-ethoxyethyl vinyl ether, phenyl possible to provide still other embodiments without de vinyl ether, acrylic acid, methacrylic acid, maleic an parting from the inventive concept herein disclosed, and hydride, chloromaleic anhydride, citraconic anhydride, it is therefore desired that only such limitations be im itaconic anhydride, methyl methacrylate, hexyl acrylate, posed upon the appended claims as are stated therein or 5 methyl alpha-chloroacrylate, acrylonitrile, methacrylo required by the prior art. nitrile, acrylamide, methacrylamide, acrolein, alphameth What is claimed is: ylacrolein, styrene, ethylene, isoprene, 1,3-butadiene, iso 1. A non-fiammable, sprayable film-forming composi propenylbenzene and 9-vinylcarbazole wherein said 1 tion consisting essentially of an anhydrous solution of vinyl-2-pyrrollidone is a substantial component of said an anhydrous polymer of 1-vinyl-2-pyrrolidone and, both 20 copolymer and, both as solvent and propellant, at least as solvent and propellant, at least one liquid chlorofluoro one liquid chlorofluoroalkane hydrocarbon having 1 to alkane hydrocarbon having 1 to 2 carbon atoms and 1 2 carbon atoms and 1 to 2 unreplaced hydrogens. to 2 unreplaced hydrogens. 5. A non-flammable, sprayable film-forming composi 2. A non-flammable, sprayable film-forming composi tion consisting essentially of an anhydrous solution of an tion consisting essentially of an anhydrous solution of an anhydrous copolymer of 1-vinyl-2-pyrrollidone and vinyl anhydrous polymer of 1-vinyl-2-pyrrolidone having a K acetate wherein said 1-vinyl-2-pyrrollidone is a substantial value between 30 and 90 and, both as solvent and propel component of said copolymer and, both as solvent and lant, at least one liquid chlorofluoroalkane hydrocarbon propellant, at least one liquid chlorofluoroalkane hydro having 1 to 2 carbon atoms and 1 to 2 unreplaced hydro carbon having 1 to 2 carbon atoms and 1 to 2 unreplaced genS. 30 hydrogens. 3. A non-flammable, sprayable film-forming composi 6. A non-flammable, sprayable film-forming composi tion consisting essentially of an anhydrous solution of an tion consisting essentially of an anhydrous solution of an anhydrous copolymer of 1-vinyl-2-pyrrollidone and a co anhydrous copolymer of 1-vinyl-2-pyrrollidone having a polymerizable monomer selected from the group consist K value between 30 and 90 and vinyl acetate wherein ing of vinyl acetate, isopropenyl acetate, vinyl laurate, said I-vinyl-2-pyrrollidone is a Substantial component of vinyl stearate, vinyl oleate, vinyl benzoate, vinyl chloride, 2-chloropropene, methyl vinyl ether, ethyl vinyl ether, said copolymer and, both as solvent and propellent, at isopropyl vinyl ether, isobutyl vinyl ether, 2-ethoxyethyl least one liquid chlorofluoroalkane hydrocarbon having vinyl ether, phenyl vinyl ether, acrylic acid, methacrylic 1 to 2 carbon atoms and 1 to 2 unreplaced hydrogens. acid, maleic anhydride, chloromaleic anhydride, citraconic 40 anhydride, itaconic anhydride, methyl methacrylate, hexyl References Cited in the file of this patent acrylate, methyl alpha-chloroacrylate, acrylonitrile, meth UNITED STATES PATENTS acrylonitrile, acrylamide, methacrylamide, acrolein, 2,667,473 Morner et al. ------Jan, 26, 1954 alphamethylacrolein, styrene, ethylene, isoprene, 1,3- butadiene, isopropenylbenzene and 9 - Vinylcarbazole OTHER REFERENCES wherein said 1-vinyl-2-pyrrollidone is a substantial con Schimmel brief No. 233, August 1954. ponent of said copolymer and, both as solvent and propel GAF publication, “PVP in Pressurized Products,' 1954, lant, at least one liquid chlorofluoroalkane hydrocarbon 67-PVP.