Патент USA US2402872код для вставки
aEsme 25, 1946. F. M. CLARK 2,402,872 HALOGENÀTED NITRONAPHTHALENE COMPOSITIONS Filed NOV. 23,' 1943 n2. z. 0 3 0 /0 20 30 40 d'0 60 70 80 172.5. Inventor: 6 0 /00 Frank ÍV'LClar‘k , y His Attorney. 2,402,872 Patented June 25, 1946 , UNrrEosTATEs PATENT OFFICE 2,402,872 . HALOGEÑATED NITRONAPHTHALENE COMPOSITIONS Frank Clark, Pittsfield, Mass., assignor to Gen ' eral Electric Company, a corporation of New York Application November 23, 1943, Serial No. 511,440 8 Claims. ' 1 .( o1. 252-66) 2 . The present application relates to chlorinated stability and otherwise is Well suited for practical nitronaphthalene compositions and is a con use. Trichlor alpha nitro naphthalene, in partic- . tinuation-impart of my earlier application Se rial No. 466,021, ñled November 18, 1942„ which in ular, has been found to possess the best combina tion of properties whereby desirable characteris tics are imparted to capacitors and other electric turn is a continuation -oi' application Serial No. 355.588, ñled _September 6, 1940. devices, as, high efficiency, long life and desirable temperature-capacity characteristics. -It comprises new compositions suitable for di electric and insulating purposes in electric ca pacitors, capacitance bushings, or other electric In preferred compositions embodying my inven ‘ tion trichlor alpha nitronaphthalene constitutes devices, and in particular compositions consisting 10 at least about l0 per cent and up to about 40 per cent of the entire composition. However, for wholly or in part of trichlor alpha nitronaphtha Iene. My invention also includes compositions in which chlorinated nitronaphthalene is associated with halogenated polyphenyl products as, for ex some purposes the content of such chlorinated ` alpha nitronaphthalene may be as high as 60 per ` cent and in other cases may be as low as a fraction ample, pentachlor diphenyl. of one per cent. In the accompanying drawing Fig. 1 is a paper-spaced capacitor# shown partly unrolled, blends comprising about 80 to_90 per cent of chlo rinated diphenyl and about 20 to 10 per cent of as an example ci a device for the impregnation of which compositions embodying the present in trichlor alpha nitronaphthalene have the unique property of operating with substantially constant capacity -over the range of temperatures at which capacitors ordinarily operate, that is, from 25 to 100° C. or thereabouts, these limits being only vention are suitable; Fig. 2 is a graph showing the relation of capacity to a range of compositions containing trichlor alpha nitronaphthalene; Fig. 3 is a graph .showing the dielectric constants for a range of compositions made up of pentachlor approximate. diphenyl and trichlor alpha nitronaphthalene; Fig. 4 is a graph showing the relation of capacity to temperature for a range of compositions em - _ Compositions consisting mainly of mixtures of _ ‘ _ - - Alpha nitronaphthalene may be chlorinated by methods usually employed for the chlorination of - aromatic compounds. Preferably a suitable cat-v bodying my invention; and Fig. 5 is a graph show alysvt should be present, for example, iron, an v ing the relation to capacity to temperature for a timony, iodine or aluminum. Chlorination is con speciûc composition made-_ in accordance with my 30 tinued until the amount of combined chlorine as invention. .' determined by the speciñc gravity or the weight Capacitors ordinarily contain sheet material of a sample of the product has reached a value spacers or septa between metal armatures, as for .corresponding to a desired chlorination product. example capacitor linen or kraft paper. Capac For example, trichlor alpha nitronaphthalene itor spacers also may consist of derivatives of ce1 35 may be prepared by the following procedure: lulose, such as sheets or tapes of cellulose acetate, To 1780 parts byweight of alpha nitronaph Cellophane or cellulose ethers, as for.. example thalene is added a suitable catalyst, such for ex ethyl cellulose and its modifications. When ample as about 5 parts of comminuted iron. The coated or impregnated with my new compositions, mixture is heated to produce fusion which takes such spacers show surprisingly good dielectric 40 place at a temperature of about 60 to 70° C. chlo stability. ' rine gas is bubbled through the fused mass. The Chlorinated nitronaphthalenes like all nitro temperature should be raised as chlorination compounds, are not characterized by a high de proceeds. The following schedule’ is a general gree of chemical stability. When subjectedV to guide.> ` . heat in the range of from 75 to 100 C. or to light, When the increase in weight of the product even at room temperature, these compounds'de-A indicates that the chlorination has progressed to teriorate chemically. Theydarken yin color and about one to two atoms per molecule (abouty 22 increase in acidity and otherwise show a chem per cent chlorine), the chlorination is somewhat ical change which normally would be expected slowed. In order to accelerate the reaction the to result in a high degree of electrical instability 50 temperatureis raised to about 70 to 90° C. When in any dielectric assembly of _which they might be the total combined chlorine corresponds to about a part. Surprisingly, the contrary has been found 2.5 atoms per molecule (about 34 per cent chlo to be true. Electrical apparatus when impreg -rine), the reaction temperature should be raised nated with my improved dielectric compositions to about v9_0 to 110° C. It is maintained in this is characterized by a high degree of electrical range untilthe increase in weight indicates about 4 3 38 per cent chlorine in combination. This is the, theoretical amount of chlorine present in trichlor alpha nitronaphthalene. ' The chlorination then is discontinued. The reaction mass is cooled and dissolved in a suitable solvent as, for example, carbon tetrachloride. The iron particles are removed by ñltration. The solution is washed with an alkali, for example, a one per cent aqueous solution oi' sodium car bonato. The neutralized solution is concentrated by evaporation until crystals of trichlor alpha` nitronaphthalene separate therefrom. These crystals are removed by filtration, or other con» venient way, and dried in air or under vacuum or other known method. The crystalline product traces of the hydroxide. Purification by distil lation may be practised. Some decomposition may occur of the product being distilled. In that case. the distillate should be purined and neu tralized by washing with 3 to 5 per cent solution of sodium hydroxide and dried by heating under . reduced pressure. ` Trichlor alpha- nîtronaphthalene can be assc~ elated advantageously with chlorinated diphenyl or equivalent hologenated polyphenyl compound. - By the term “polyphenyl compound"> I mean to include various equivalents of dìphenyl, for eig, ample, diphenyi oxide, diphenyl methane, dì~ phenyl ketone, diphenyl benzene, and the like. While chlorine ordinarily is employed as the preferred halogen, other halogens, notably fluo at this stage has a melting point of about 132 to 135° C. It is-.suitable without further purifica rine, may be employed within the scope of my tion for many electrical uses. For some purposes invention.. . i A capacitor treated with a composition con a more highly purified product may be desirable. taining» 75 parts of pentachlor diphenyl and 25 This can be obtained by recrystallization. The parts of trichlor alpha nitronaphthalene oper melting point of the pure product is about 155° C. ates with a 7.5 per cent higher capacity at 100° Alternatively, the chlorination may proceed in ' than a. similar capacitor treated with. pentachlor the presence ofv an iron catalyzer until approxi diphenyl imassociated with a modifying ingre mately 38 per cent of chlorine has been intro ' dient. duced. At this stage most of the product will con Compositions containing up to about 60 per sist of trichlor alpha nitronaphthalene. Some cent of said trichlor nitro-naphthalenc product. tctrachlor and some dichlor alpha nitronaphn the remainder consisting of pentachlor diphenyl, thalene may be Present inthe chlorination prod. not only result in a markedly higher capacity uct. The mixture may be purified by distillation. It has a boiling point in the range of 230 to 280° C. 30 when used as impregnants for paper-spaced ca« pacitors than does such pentachlor diphenyl un~ at a pressure of 15 millimeters of mercury. The associated with the naphthalene compound, but yield'obtained is about 80 to 90 per cent. l':’re«r other advantages accrue. Capacitors when im sumably because of the presence of small amounts pregnated with approximately 90 parts pentachlor diphenyi associated with approximately l0 parts of dichlor andv tetrachlor products, the distillate cools to a non-crystalline, resinous solid at room of trichlor anitronaphthalene are characterizedA by a constant electrical capacity over a tempera ture rango from about 25 to 100“ C. Compositions consisting by weight of '75 to 90 parts of Denta Viscosity at 98.9° C---„_`-_-- 50 to 55 seconds 40 clilor diphenyl and 25 to 10 parts of trichlor alpha ~ Saybolt Universal nitrouaphthalene are liquid at room temperature, Bpeclilo gravity at 100° C._„_ 1.555 to i565 which is advantageous in the dielectric field. The most desirable proportion of the chlorinated The distillation product may be refined by coni tact with a .suitable absorbent, such as fullcr‘s , nitro-naphthalene in a dielectric composition de temperature having the following characteristics. . Color ................... -_ light yellow Flow point ._a'. ___________ ..„ ’l0 to 15° C. earth. preferably at 100° C. The product after nltration has the following average properties. ü ponds on the type of capacitor tissue, clampinr,1 pressure, etc., employed in the capacitor. In the results to bc given, the impregnated capacitors consisted of aluminum armatures separated by Color ...... __'___________ _u light yellow _Flow point ..-_-_ ..... __., ____ -„ '10 to 75° C. spacers of kraft capacitor paper. The latter has a thickness of .0004 inch. This thickness is not critical but has been chosen as representing a prevalent commercial thickness. Such a capaci tor is shown in Fig. 1, armatures being repre sented by the strips 2, 3. Two groups fl, 5 of paper spacers. are illustrated. The enclosing case is lnot shown. Electrical connection is made to the armatures by the tap straps E, l. The im~ proved characteristics are indicated by graphs Viscosity ________________ -_ 54 seconds Baybolt Universal at ‘ 08.0° C. Bpecißc gravity (100° C.)__- 1.2562` Reaction (neutralization number) ..---, ......... _.. 0 (neutral) Condition at 25° C ________ __ n o n -- crystalline, v resinous solid Dielectric constant at 25° C-- 8.0 Power factor at 80 cycles 25° C __________________ __ .i3 per cent Hesistivity at 25° C _______ _- 20x10x2 ohms/cm. 60 resent a range of percentages, of the trichlor Because of its non-crystalline condition, this composition is well adapted for the impregna tion of high voltage capacitors even without the l addition of modifying ingredients. l For the purification of some chlorinated prod which will be presently explained. In the graph shown in Fig. 2, the abscissa rep naphthalene compound, aNOnCiuHiCla, in admix ture of said compound with pentachlor diphcnyl and the ordinates indicate in per cent a relative 65 increase or decrease of capacity as compared with uots. a solution process is preferable. The -chlo rinated product is dissolved in a suitable solvent, a similar capacitor impregnated only with penta clllor dlphenyl. The graph l here shown repre " sents results taken at 100° C. capacitor tempera- ture. Itwill be observed that although an in auch,” carbon tetrachloride or trichlorbenzene. The solution is ?ltered free from the` suspended 70 crease of capacity occurs when even small addi catalyst if the catalyst is insoluble in the solvent which is employed. The solution is washed with water and, if somewhat acid, is washed with dilute sodium hydroxide (3 to 5 per cent solu tim) and is again washed with water to remove 75 tions of the naphthalene compound are present. the capacity rises to a. maximum when the per« centage of the naphthalene compound is between about 30 to 40 per cent. ¿ As shown in Fig. 3, the dielectric constant of 2,402,872 5 thc compositions of pentachlor diphenyl and tri 6 . l ever, from ‘é to> 5 per cent of the chlorinated chlor- anitronaphthalene reaches a. maximum at about 15 per cent of the latter ingredient and begins to decrease when the proportion of the nitronaphthalene exceeds about 25 per cent. The graph 9, which‘represents the dielectric' constant, rises at 25° C. to approximately 6„75 and at 100° ' ' ' C. rises to approximately 5.8 before decreasing. alpha nitro-naphthalene is present, this foil cor rosion is substantially eliminated with resulting dielectric stabilization of the capacity and a com mercially satisfactory lengthof life. ACapacitors impregnated with a composition in cluding about 99 parts of pentachlor diphenyl and 1 part of /trichlor alpha nitro naphthalene are characterized by a power factor at 25° C. in tions embodying my-iñvention are to be used 10 the range of„:30 to .35 per cent, and a direct cur When capacitors impregnated with `composi rent resistance value at least as high as 6000 under such. conditions/or-'in such circuits that the varìation’äif'capacit/y would produce an unde~- megohm-microfarads~ there is no 'change in capacity over a range >of advantageous electrical~characteristics. Capaci tors impregnated with either impregnant vfunc Capacitors impregnated sirable e‘i'î'ect, then the naphthalene compound . with a dielectric composition -consisting of 95 parts of pentachlor diphenyl and 5 parts of tri should be _restricted to a range of about 10 to 20 chlor alpha nitronaphthalene similarly possess 15 per cent. As shown in the graph Il of Fig. 4, temperature from about 25 to 100° C. when the> percentage of aC1cH4ClaN0z in the mixture is about 10 per cent. The graph Il crosses the zero line when 10 per cent of the latter nitrochlor 20 compound is present in the mixture. While I have illustrated my invention with 'par ticular reference to compositions of chlorinated tion satisfactorily on direct current voltage" un der stresses as high as 1000 volts per mil without dangerous loss in resistance or-'i increase in power factor. ' ^ What I claim as new and desire to secure’byLetters Patent of the United States is: 1. A non-crystalline, light yellow, resinous alpha nitro-naphthalene and pentachlor di phenyl, it is not restricted _to such examples. 25 material composed essentially of trichlor alpha nitronaphthalene, said material having a flow Other chlorinated polyphenyl compounds can be point of about 70 to '75° C., a dielectric constant similarly associated with the chlor alpha. nitro -of about 8, a power factor at‘ 60 cycles, 25° C. oi.' naph-thalene. For example, dielectric blends of about .13 per cent and a resistivity at said tem trichlorl alpha nitronaphthalene and tetrachlor diphenyl have advantageous dielectric properties. 30 perature of 29X 1012 ohms per centimeter cube. 2. A composition of matter consisting essen Fig. 5 of the drawing, the graph l2, illustrates the tially of chlorinated diphenyl and trichlor alpha very slight changes in capacity of a capacitor nitronaphthalene, the latter ingredient being containing such blend over the temperature range present in the range of about 10 to 40 per cent. 25 to 100° C. When impregnated with a dielec 3. A dielectric material consisting by weight of tric composition made up oi' about 15 per cent 35 about 75 to 90 per cent of pentachlor diphenyl of trichlor alpha nitronaphthalene and 85 per and about 25 to 10 per cent of trichlor alpha cent tetrachlor diphenyl, a substantially constant , nitronaphthalene. capacity results over this range. For many ap 4. A dielectric material which is suitable for plications, especially in radio circuits, such con capacltor'impregnation consisting by weight of stan-t capacity feature is of particular value. about one to 60 per cent by weight of trichlor The most advantageous compositions will vary alpha nitronaphthalene and about 99. to 40 per in the ratio oi components depending on the par cent of pentachlor diphenyl. ticular components chosen. For example, to se 5. A liquid dielectric material which is suitable cure constancy of capacity in a composition con taining pentachlor diphenyl, 10 per cent of the 45 for capacitor impregnation consisting by weight of‘about 90 to '75 parts of pentachlor diphenyl nitrochlor compound is required, whereas` in a and about 10 to 25 parts oi’ trichlor alpha nitro composition comprising tetrachlor diphenyl> 15 naphthalene. per cent of the nitrochlor compound is required. ~ I also have found very small amounts of the 6. A liquid dielectric material whichìis suitable -chlorinated alpha nitronaphthalene when asso 50 for capacitor impregnation consisting by weight ‘of 85 parts of pentachlordiphenyl and 15 parts ciated with other dielectric material to be useful of trichlor alpha nitronaphthalene. ,as a stabilizer, particularly for high temperature '1. A liquid dielectric material which is suitable -operation. When capacitors impregnated with for capacitor impregnation consisting mainly oi' chlor diphenyl, chlor diphenyl oxide or chlori nated diphenyl methane are placed on direct cur 55 a chlorinated polyphenyl compound which is ad mixed with at least about one-half of one per rent voltage at a stress in the range of 500 to cent of trichlor alpha nitronaphthalene. 1000 volts per mil (which is used in many com 8. A non-crystalline, resinous material having inercia). applications), the capacitor is charac a ilcw point-of about 70 to '15° C. composed es terized by an unsatisfactory short life at tem peratures of the order of 90° C. and higher. For 60 sentially of trichlor alpha nitronaphthalene and containing as impurities amounts o! dichlor and practical purposes, as for example in the case tetrachlor alpha nitronaphthalene which are in of many illter ~or blocking capacitors, operating suflicient to cause the boiling point of the com temperatures in the range of 90° C. and higher position to depart from a normal range of about even to 110° C., are encountered. The failure of ordinary chlorinated polyphenyl capacitors in 65 230 to 280° C. at a pressure lci' 15 mm. of mercury. this temperature range is accompanied by the , etching and corrosion of the toil. When. how FRANKMCIARK.