Patented Feb. 20, 1940 2,190,105 UNITED STATES. PATENT OFFICE 2,190,105 ‘ empress nnmva'nvn mansions Alfred Dreyling, South River, and William W. Lewers, Parlin, N. 1., assignors to E. I. du Pont de Nemours & Company, Wilmington, ml, a corporation of Delaware ‘No Drawing. Application August 15, 1935, Serial No. 86.388 8 Claim!- (CL 106-37) This invention relates to ‘emulsions and more A still further object is the provision of an im particularly cellulose derivative emulsions of the proved process for preparing aqueous cellulose de “high solids” type. It has been recognized that rivative emulsions by low-speed mixing. oil in water emulsions; i. e., those in which water Another object is the provision of a process for 5 is the continuous phase, are the more important preparing improved aqueous derivative emulsions 5 industrially. In the present invention, the col by means of kneading type equipment. _ loided cellulose derivative may be considered the A further object of the invention is the provi- . oil phase and the water the continuous phase of. sion of an aqueous nitrocellulose emulsion which the emulsion. According to the prior art, emul is high in ?lm forming solids and‘ which, if de o sions have been prepared by ?rst colloiding the sired, may contain nitrocellulose of high viscosity nitrocellulose with a high percentage of essen characteristic. tially water immiscible solvents and/or water im A still further object is the provision of aqueous miscible solvent or non-solvent softeners, after cellulose derivative emulsions which are charac which the nitrocellulose colloid is added with terized by good stability. 1 or rapid agitation to the aqueous phase which also It is ?nally an object of the present invention 15 contains a suitable emulsifying agent. The mix to provide aqueous cellulose derivative emulsions ture, may, if desired, be run through a colloid which areindustrlally useful for coating and im mill or homogenizing valve to improve the sta pregnating purposes. bility. These objects are accomplished by kneading a 20 . The nitrocelluloseemulsions of this type here relatively sti? cellulose derivative colloid together 20 tofore available are, however, subject to several with a viscous water colloided emulsifying agent de?ciencies, chief of which is the relatively low to form a paste type oil in water emulsion of high ?lm-forming solids content, thuslimiting their ?lm forming solids content and of good stability. more general industrial adaptation. Satisfactory In its simplest form low speed mixing procedure - 25 stability could not be assured, especially when at- ' consists merely in adding one liquid (the phase to 25 tempts were made to increase the solidscontent. be dispersed) to another liquid (the continuous Frequently, also, excessive amounts of expensive phase) accompanied by relatively gentle agita tion. This method has been suitable only in those solvents were required. I Emulsions have been prepared in several ways, instances where the two liquids emulsify readily 30 such as by homogenization, high speed mixing, or where very e?icient emulsifying agents‘ are 30 and low speed mixing. Because of speci?c limi used. The present invention affords a substantial tations imposed on low speed mixing processes as industrial advance in the art of manufacturing attempted ‘heretofore, high speed and/or homo cellulose derivative emulsions by providing an im'-%' genization methods only have been utilized. proved process for their preparation by .low speedy .: “ 35 High speed processes can only be used for liquids mixing. The new process is essentially a modia, a5 which are relatively mobile at temperatures of ?cation of and an improvement on lowv?speedk; 100° C. or less. Homogenization processes involve mixing methods hitherto available for preparing the use of a colloid mill or homogenization valve emulsions, whereby cellulose derivative emulsions through which the mixture of the constituent in in paste form and of high solids content maybe readily manufactured. , , 40 40 gredients or a preformed emulsion may be passed The following examples are given to illustrate to form an emulsion which is generally charac terized by a product of improved stability. the invention, but it will be understood that they This invention has as an object an improved are not limitative since modi?cations will readily aqueous cellulose derivative emulsion, and a proc occur to those skilled in the art. 45 ess for making the same. Exmrr: 1 . 45 ~ Another object of the invention is the provision Colloid #1 ‘ of a process for preparing aqueous nitrocellulose Per cent emulsions from water wet nitrocellulose. A further object of the invention is the provi Nitrocellulose (viscosity, 15" Hercules)--- 16.85 _ Isobutyl alcohol ______-_ 4.22 50 sion of a process for preparing aqueous nitrocellu " Castor 011 20.00 5° lose emulsions by the use of a viscous water col Tricresyl phosphate ______10.53, ‘ loided emulsifying agent. , Butyl acetate ______11.78 Another object is the provision of a process for Xylol 25.13 preparing aqueous nitrocellulose emulsions which 55 permits the use of a wide variety of emulsifying Colloid #2 _ , 55-, agents which may be utilized in combination with Casein - , ' 1.05 I an emulsifying agent of the water colloided vis-‘ Ammonium ricinoleate ______.. 0.84. . cous type; for example, “Glutoline,," which is a Water - ' 9.60 1, trade name for a commercial brand of methyl 100.00 60 . s: 17 00 cellulose. - 2 2, 1 90,705 The ammonium ricinoleate contains sufficient tion exists for those examples which follow where excess ammonia to permit the dispersion or the water wet nitrocellulose is used in preparing casein. \The same is true of the succeeding ex Colloid #1. amples in which soap-casein mixtures are used in Exmrr: 3 the formation of an aqueous colloid (emulsifying agent‘). Colloid #1 The butyl acetate ingredient shown in this Per cent example and in those which'follow is 88 to 92% Nitrocellulose (viscosity, 7.3" Hercules) ______13.7 ester calculated as normal butyl acetate, the re Water- ____ 6.8 10 mainder being principally normal butyl alcohol. Dlbutyl,‘ phthalate ______8.2 Colloid #1 is prepared by charging the in Isobutyl acetate _ ___ 13.7 10 gredients into a kneading machine such as 9. Tnlunl ______13_7 Werner and P?eiderer mixer, in the proportions Colloid #2 indicated and kneading for approximately 11/: Synthetic resin‘ ______10.9 15 Casein ______1.4 hours or until the nitrocellulose has been uni 15 formly colloided, after which the charge is re Ammonium rincinoleate ______0.9 moved from the mixer. Colloid #2 may be Water______30.7 conveniently prepared by means of a rapid agi tator mixer, whereby a homogeneous dispersion 100.00 20 is secured. This intermediate dispersion is then "The synthetic resin used in this example is a reaction 20 charged into a kneading machine and colloid . roduct of phthalic anhydride, castor oil, and lycerol pro ortions designed to yield a ?nished pro not of #1 is added gradually during kneading. This the to owing composition: kneading action is continued for approximately Per cent 2 hours or until a uniform emulsion of paste-like Glyceryl triplifhalnfe 63.0 25 Castor 0" 27.0 consistency has been obtained. Excess glycerol 10.0 25 In this example, the nitrocellulose has Been 100.0 dehydrated with isobutyl alcohol, but suitable and is prepared b heating the ingredients until a com emulsions may also be prepared from nitrocellu paratlvely low acd number (25 or below) is reached. Obviously, many other resins having a su?lciently low loses which have been dehydrated with other acid number so as to prevent the formation of water 30 suitable liquids, such as propyl alcohol, isopropyl colloidable alkaline salts may be substituted for the ex 30 alcohol, etc. Ethyl alcohol may be used, al ample given. though it is not preferred. The isobutyl acetate shown in this example and in those which follow is 88 to 92% ester calcu Exmrnn 2 lated as isobutyl acetate, the remainder being 85 Colloid #1 principally isobutyl alcohol. Per cent The product of this example may be used in Nitrocellulose (viscosity, 15" Hercules) _..___16.85 ?nishing wood surfaces. Water 7.22 The emulsion is prepared in the same manner Castor oil ' 20 00 as shown for Example 2. 40 Tricresyl phosphate ______._. ______10.53 Butyl acetate 11 78 Exsmrrr: 4 40 Xylol 25.13 Colloid ‘#1 Collm'd #2 ' - Per cent Casein 1.05 Nitrocellulose (viscosity, 7.8" Hercules) ____ ._14.45 45 Potassium rincinoleate ______0.84 Water _ 7.25 Water 6.60 Dibutyl phthalate______8.70 Butyl a’cetate ______14.45 100.00 'I'olunl _14.45 The ingredients of Colloid #1 are charged into Colloid #2 a kneading machine and kneaded until a smooth Synthetic resin‘ ______..11.55 paste is obtained. Colloid #2 which is pre Locust bean gum ______0.35 pared separately in a suitable rapid agitator mixer Water > a 28 75 is then added slowly to Colloid #1 in the knead Ammonia (28%) ______‘_-__; ______.05 ing machine and kneading continued for about 1%; hours or until a smooth uniform emulsion 100.00 paste is produced. ‘The synthetic resin and its preparation in this ex This example represents a modi?cation of Ex ample is the same as shown in Example 3. The com pos tion may be utilized in ?nishing wood surfaces or as ample 1 and differs therefrom essentially in the a thermoplastic adhesive. . use of water wet nitrocellulose in preparing 60 Colloid #1. This is of particular advantage Exmns 5 60 in that the customary step of dehydrating the Colloid #1 nitrocellulose is eliminated, thereby affording , . Per cent production economies. In addition the colloiding Nitrocellulose. (viscosity, 15.8" Hercules) _‘__15.50 65 of the nitrocellulose is greatly facilitated, since Water _ 6.60 the‘ di?icultly colloided lumps caused “by packing Castor oil _- ____ 19.50 of the nitrocellulose during the dehydration oper Tricresyl phosphate ______'______6.60 ation are eliminated. Butyl acetate ______' ______10.80 This example is also distinguished from Ex Xylnl - ______23.20 70 ample 1 in that when Colloid #1 is kneaded, Colloid #2 an emulsion is formed with the water as the in Turkey red oil ______1.03 70 side phase. When Colloid #2 is added, and "Glutoline" ‘ (water colloidable methyl kneading continued, the phase relationship is in cellulose) .52 verted and the water becomes the outside phase. the condition which has previously been pointed Water ______16.25 76 out as industrially desirable. The same situa 100.00 76. 9,190,705 3 This example which is prepared as in Exam Wu: 8 pie 1 illustrates the use of a combination 0! two COM #1 different types of emulsifying agents through Per cent which ‘certain advantages are secured. The Tur Cellulose acetate (medium viscosity) :.--..-.. 17.6 key red oil acts primarily in lowering the inter Dibutyl phthalate_....______..,-....-.... 4.1 fa'cial tension between the two phases; viz., water Ethylene dichloride ______.._..._-_.._..-_ 23.5 and the nitrocellulose colloid, while the water Acetylene tetrachloride______..-..-- 18.8 dispersable methyl cellulose iunctlons by en veloping the dispersed droplets by viscous or Colloid #2 more or less plastic ?lms. ‘.‘Glutohne” 0.3 10 . Water 33.3 Exmrn 6 Formamide 2.4 Colloid #1 ' ' 100.0 Total solids, 24.4%. 15 15 1 Per cent The above example illustrates the operative Nitrocellulose (viscosity 15.8" Hercules) -4 12.85 ness of our invention for formulations containing Water ' 5.85 cellulose acetate as the major ?lm-forming con Castor 011 16.10 stituent. Here methyl cellulose functions as de Tricresyl phosphate"; ______-_ 5.50 scribed previously, while iormamide operates as 20 20 IButyll acetate 8.90 XyloL- 19.12 an intro?er. ' - Colloid #2 Colloid #14 ’ Per cent .25 Ethyl cellulose‘ (high viscosity type) .... _- 18.21 25 Gardinol" 0.17 Glutoline (water colloldable methyl ‘cellu- ' Dibutyl phthalate ______.._ 8.47 Liquid petrolatum ______-, ...... _ 2.12 lose) . Ethylene glycol mono-ethyl ether ______.._ 3.40 in] ' ' 21.80 Normal bntyl alcohol ______.. 6.01 Water"--- ' 28.55 30 30 Colloid #2 100.00 Casein ' .24 Ammonium rincinoleate ______-1 ______.72 ‘The Gardinol used in this composition is sodium lorol Methyl cellulose ______-._ .13 sulphate. This example also illustrates the use of two 35 35 dissimilar types of emulsif ing agents used in comblnw Water _ 42.30 tion. The sodium lorol su phate functions by virtue of its ability to lower interfacial tension and, therefore; re’ duce the work required to cause emulsi?cat'lon to take 100.00 place while the methyl cellulose functions as in the pre ceding example by the formation of an envelopin or The above example illustrates the operative stabilizing ?lm around the individual globules const tut ness of our invention for the preparation of ing the dispersed phase. 40 emulsions containing an organosol of ethyl cel The ethylene glycol mono-ethyl ether assists lulose, with appropriate colloiding agents, as the the sodium lorol phthalate in lowering interfa dispersed phase. The compositions of Examples cial tension between the water phase and nitro 8 and 9 are prepared according to the directions given under Example 1. ' cellulose colloid by virtue of its solubility in both 45 45 phases. Compounds which function in this man 1 .1...» 1o ner are known as intro?ers. Colloid #1 Percent Nitrocellulose (viscosity. 15.8" Hercules)- 20.30 50 50 Colloid #1‘ Water 3.70 Titanox , 13.15 Per cent Raw castor oil 13.15 Nitrocellulose (viscosity 1/2" Hercules)..-“ 21.70 Butyl acetate 16.20 Water 9.10 Butyl alcohol 3.00 55 55 Raw castor oil ' 27.21 Tricresyl phosphate ______9.23 Colloid #2 , Isobutyl acetate ______12.45 Ammonium rincinoleate ______2.03 Xylnl > 8.80 Casein 2.03 “Lanette’” wax.- ______.._ .20 Colloid #2 69 60 Bayberry was .20 Water 15.44 “Glutoline" _____ - .110 Sodium oleate ______.._ .44 100.00 Water_____ > 10.67 The above example illustrates a pigmented ni 65 65 ' trocellulose emulsion. A pigment dispersion in 100.00‘ castor oil plus solvent was ?rst prepared. mul si?cation of this mill base was then carried out This composition is prepared according to the concurrently with the dispersion of the nitro method given under Example 2 and illustrates cellulose colloid. The mixed waxes, bayberry 70 the principle that higher solids may be obtained and “Lanette”, were employed in order that tex- ' by the use of low viscosity nitrocellulose. As in tiles coated with the resulting composition may the two preceding examples, the soap type agent, have water repellent properties. In addition the sodium oleate, functions in. lowering interfacial Lanette wax functions as a plasticizer for casein.‘ tension, while the methyl cellulose operates as This composition is prepared according to the 75 75 described in Examples 5 and 6.’ 4 8, 190,705 directions given under Example 2. “Lanette” Exempt: l2 wax is a trade name for a wax containing a mixture of monohydric alcohols containing 18 Colloid #1 and 18 carbon atoms respectively. Per cent Nitrocellulose (viscosity, 15 sec. Hercules)- 12.6 Exmeu: 11 Sec. amyl acetate______16.4 Colloid #1 Sec. hexyl acetate ______16.4 . - Per cent Castor oil 12.6 Nitrocellulose (viscosity, 15 sec.) ______-_ 17.9 Boiled linseed oil ______12.6 10 Water 7.7 Carnauba wax 1.5 Castor oil - 22.4 Para?in 1.0 10 Tricresyl phosphate ______.- _____ .._ 7.8 Water 8.0 Isobutyl acetate_____ ..______81.4 , Colloid #2 Colloid #2 15 ‘Potassium lorol phthalate______.8 Potassium loro phthalate ______0.3 Animal glue 1.7 15 Animal 21119 0.6 Water 16.4 Water 3.0 Water 8.9 100.0 20 In this example the cellulose nitrate is ?rst 20 100.0 colloided with the active solvents, secondary amyl This composition is prepared substantially in acetate and'secondary hexyl acetate. The re accordance with the procedure outlined for Ex maining ingredients of Colloid #1 are mixed at a ample 2. Colloid #2 is preferably heatedto fa temperature of about 85° C. to dissolve the waxes. 25 cilitate solution of the glue and it is desirable Colloid #1 is prepared by emulsifying the cel 25 also to add this colloid slowly at about 40° C. to lulose nitrate colloid and the wax-oil mixture ac ' Colloid #1. As indicated, the last portion of cording to the procedure outlined under Example water is added for thinning after inversion of 2.. The ?nal emulsion composition including the emulsion has taken place. Colloid #2 was prepared according to the pro 30 The term “lorol” is used to represent the mix cedure indicated for Example 2. This composi ture of alcohols obtained from the carboxylic tion is particularly suited for coating paper to hydrogenation of cocoanut oil or cocoanut oil provide a matte ?nish. acids. A similar‘ mixture of alcohols may be ob In preparing cellulose derivative type emul 35 tained from the carboxylic hydrogenation of sions, it is usually necessary to colloid the cellu palm-kernel oil or oil acids. lose derivative with solvents, plasticizers, etc., 35 Example 11 illustrates the use of potassium previous to emulsi?cation in order to place it in lorol phthalate as an emulsifying agent. This a ?uid condition so that it may be emulsi?ed. material has been found to be particularly suited A proportion of a suitable solvent must be in in preparing the emulsions of the type disclosed cluded in order to permit coalescence of emulsion . in the present invention. This agent possesses globules after deposition to form a continuous 40 the peculiar property of functioning with sat ?lm. An exception may be where there are suf isfactory results with the emulsion composition ?cient thermoplastic ingredients present to af at a pH of less than 7.0 as measured by a La ford the formation of a continuous ?lm by a Motte comparator, bromthymol blue as an in subsequent application of heat. dicator, while in general other emulsifying In preparing ?lm forming emulsions in solu 45 agents are not considered entirely satisfactory ' tion form the solvents should be substantially under these conditions. In the example the non-miscible and entirely non-reactive with wa agent is used in conjunction with animal glue, ter. They should also be stable in systems where 50 providing a combination of two distinct types of in the outside phase is either slightly acidic or emulsifying agents a?ording de?nite improve basic, the degree of stability necessary in any 50 ments in the preparation of the emulsions and particular case depending on the speci?c require in the properties of ?nished products. Other al ments which the emulsion is designed to ?ll; and, kaline lorol phthalates which are suitable include furthermore, in cases where the deposition of a 55 ammonium and sodium lorol phthalates. Water continuous ?lm is required, the solvent must colloidable emulsifying agents which may be have a su?iciently high vapor tension and latent 55 used in conjunction with the alkaline lorol heat of vaporization to be retained in the ?lm phthalates include gelatine, locust bean gum, gum until after the evaporation of the water phase is‘ tragacanth, gum arabic, Glutoline (water 001 complete. loidable methyl cellulose) gliadin, soaps, casein, Solvents for the cellulose derivatives (nitrocel etc. Such emulsifying agents are commonly lulose, cellulose acetate and the cellulose ethers) 60 known as water colloidable viscous type emulsify which are operable in the present invention are ing agents and this term is used in the claims to secondary hexyl acetate, secondary octyl acetate, designate such agents. butyl acetate, isobutyl acetate, amyl acetate, iso .65 While we have disclosed the use of alkali metal amyl acetate, ethylene dichloride, xylol, acety lorol phthalates and sulfates as emulsifying lene tetrachloride, etc. As illustrated in the ex 65 agents, in general we may use any of the alkali amples, suitable softeners, of the solvent and non metal salts of partial esters of polycarboxyllc ac solvent type, may also be employed. Such mate ids and alcohols of the lorol type or those ob rials as dibutyl phthalate, tricresyl phosphate, 70 tainable from the carboxylic hydrogenation of raw or blown castor oil, blown linseed oil and non-drying or semi-drying vegetable oils or the ‘other blown, drying, semi-drying and non-drying 70 corresponding oil acids. Such emulsifying agents oils may be incorporated in the compositions. are known as polar type emulsifying agents and Diluents either of the aromatic hydrocarbon or this term is used in the claims to designate such aliphatic hydrocarbon type such as toluol, xylol, 76 agents. .hlgh ?ash naphtha, as well as the cyclic aliphat 75 9,190,705 5 ics obtained from asphaltic crude oils, may be , wood pulp, nitrated regenerated‘ cellulose, smoke included as indicated in the examples, less powder, etc., may also be utilized. In conventional lacquer technology use is made While stable dilute emulsions have been made of certain monohydric alcohols such as ethyl al which are composed merely of two non-miscible cohol, butyl alcohol, isobutyl alcohol, secondary "liquid phases, the preparation of a stable con- 5 amyl alcohol, etc., which in themselves are not centrated emulsion requires the presence of a solvents for cellulose nitrate as fortifying solvents third substance which is termed an emulsifying for the same. It has been found that certain of agent. These agents cover a wide range of'dif these alcohols which may be either wholly or par ferent chemical types including sulfonated or 10 tially water miscible are distinct assets in emul ganic compounds, fats and their chemical deriva- 10 si?cation due to the fact that they lower the tives (not sulfonated), natural organic Products interfaclal tension between the phases. In ad other than fats and their derivatives. synthetic dition numerous other liquids soluble in both chemical agents and inorganic agents. In addi phases function in this manner decreasing the tion to functioning as an emulsion stabilizer, the work required to effect dispersion and adding to agent also exerts a governing in?uence on the 15 stability. Alcohols of this type are commonly phase relationship. In contradistinction to prior known in the art as intro?e's and a de?nition art processes, where speci?c emulsifying agents closely resembling the above will be found in the are generally required, the process of the present "Laboratory Manual of Colloid Chemistry” by invention permits the use of a wide variety of 20 H. N. Holmes, published by John Wiley and Sons, emulsifying agents, which may be used singly or 20 New York (1934), pages 115 and 167. in combinations depending upon the ?nal effect It is extremely important therefore in our desired. ' process dealing with the formation of high solids ' It has been determined that there are two dis nitrocellulose colloid oil in water type emulsions tinct types of emulsifying agent which have 25 that in order to insure ?nished products of max shown merit in the present process and which ap- 25 imum stability that a portion at least of the me parently function in di?erent ways. Both types dium effecting the dispersion of the nitrocellulose of agents belong to the more general group of (as an organophilic colloid) be capable of miscib so-called colloidally dissolving emulsifying agents ility with the aqueous phase to an extent su?'icient which includes soaps, resinates and caseinates of 30 to permit the reduction of interfacial tension be mono-valent alkaline metals, ammonia or or- 30 tween the phases to a point where emulsl?cation gano substituted ammonias, gelatine, glue, al will be facilitated. The signi?cance of the above bumin, hemoglobin, gliadin, protein hydrolysis is further emphasized by the fact that if the products (such as peptones, gelatoses), water soluble gums and mucllages (such as arabic, organic material selected as a solvent for the ni 35 tragacanth, Irish moss, locust bean and the like), 35 trocellulose (or more properly to effect the col colloidal carbohydrates (such as starches, dex ‘loidal dispersion of. the nitrocellulose) does not trine, etc.), carbohydrate ethers suchas water possess a certain degree of water miscibility as an colloidable methyl cellulose, methyl starch and inherent characteristic, then in the above de the like, alkaline salts of various types of sul scribed process at a point known as the ?rst fonated oils and sulphated higher alcohols such 40‘ 40 stage (the water in oil stage) instead of forming as Turkey red oil and “Gardinol”, respectively, a well dispersed water in oil emulsion suitable and the like, as well as the mono-valent alkaline for subsequent inversion, water separates from salts formed by the neutralization of. the acid the system either in whole or in part with the esters formed by reacting dibasic acids with one formation of a dilute imperfectly dispersed water molecular equivalent of higher alcohol. The 45 45 in oil emulsion which is dimcult or impossible to above agents may be divided into two distinct invert. While it is recognized that such a prod types with reference to which one of the follow uct may be utilized to perform certain useful ing two characteristics, viz. interfacial tension functions the conditions requisite to its forma lowering or bodying action, appears the more tion are to be avoided in the practice of our in prominent. The emulsifying agents which ex- 50 50 vention involving the formation of high solids hibit strong interfacial tension lowering tend oil in water emulsions of colloided cellulose deriv encies are called polar type emulsifying agents, atives. whereas those which dissolve colloidally in water The foregoing examples illustrate the use of ni and. increase the viscosity or body of the disper trocelluloses of a wide range of viscosity char sion to a large extent are called water colloidable 55 55 acteristics, depending upon the designed utility viscous type emulsifying agents. ,of the ultimate emulsion composition. Nitrocel The organic compounds containing polar lulosesofviscosity characteristics ranging between groups function in two ways. Primarily, they % sec. and 25 secs. as determined by A. S. T. M. lower the interfacial tension between the two liq speci?cations D-30l-33 may be successfully em uids, thus causing one liquid to disperse with re- 60 _ ployed. Likewise, the viscosity characteristic of spect to the other and in addition aiford the cellulor e acetate or cellulose ether is not crit some viscosity increase to the phase in which they ical, since suitable emulsions may be prepared are the more soluble, which is also desirable. from these materials whether of. high or low vis As illustrated in the examples, the emulsions may include more thanone emulsifying agent, 65. 65 cosity characteristic. The nitrogen content of the nitrocellulose which may also be of different types. In cer utilized in preparing the emulsions of the present tain instances, the inclusion of‘. three di?'erent invention is not critical, and may vary between emulsifying agents has been found advantageous. 10% and 12.5% depending upon the particular In any event, it is essential that at least one of use for which the ultimate emulsion composition the emulsifying agents be of the water colloided 70 70 viscous type in order to insure adequate body or is intended. _ The invention is not limited to the use of consistency to form the paste type emulsion. nitrocellulose in any speci?c form, since any, of In connection with the inclusion of more than the commercially available types in addition to one emulsifying agent in a single emulsion com the common nitrated linters, such as nitrated position, it has been demonstrated that changes 75 6 . 2,190,705 in the emulsifying agent only will substantially fulness of aqueous nitrocellulose emulsions and alter the properties of otherwise similar emul further simplifying production operations. sions to such an extent in one case the emulsion The emulsions of the present invention are also will penetrate into the surface (porous or semi particularly characterized by high film-forming porous) to which it is applied, whereas by using solids content and improved stability. 5 a different type of emulsifying agent, the coating A further advantage resides in the shipping and will remain substantially on the surface. It has storage considerations, since it is obviously de been determined that soap type emulsifying sirable to avoid the presence of excessive agents permit rapid and deep penetration into amounts of water from the economic standpoint. 10 porous or semi-porous surfaces, while materials The new products are quite stable during ship 10 of the methyl cellulose type yield emulsions that ping and extended storage periods and because act principally as surface coatings. of their paste-like condition greatly reduce set The products of the present invention are of tling and hard caking of pigments, when of the particular value in coating the backs of rugs and pigmented type. 16 carpeting. This is preferably carried out by re The process is adapted for the preparing of 15 verse roller coating in conjunction with a doctor cellulose derivative emulsions either by the knife, although other methods of application are method of’. direct preparation of oil-in-water also permissible such as spray coating or knifing emulsions or by the inversion method. operations. When one of the compositions here The process permits of the use of a wide va 20 in disclosed is used, the coating binds the fabric riety of emulsifying agents of various types which 20 pile of the carpeting, giving the semblance of a may be conveniently utilized in conjunction with closer weave. The use of such coatings permits the water'colloided viscous type such as “Gluto a less expensive weave if desired; and, in any line”, casein or glue. In addition, the fire and event, the strength of the weave is increased and explosion hazards commonly incident to the use 25 an improvement in general durability of the prod of nitrocellulose lacquers are considerably uct is secured. Ravelling tendencies, usually en lessened if not entirely eliminated. countered when uncoated carpeting is out, are It is apparent that many widely di?erent em entirely eliminated. ‘ bodiments of this invention may be made with Nitrocellulose solutions, as distinguished from out departing from the spirit and scope thereof; 30 nitrocellulose emulsions, have several defects and, therefore, it is not intended to be limited ex 30 which are eliminated in using the compositions cept as indicated in the appended claims. of the present invention. With the improved We claim: coatings, the appearance and “hand” of the coat 1. The process of preparing oil in water emul-' ed carpeting is substantially unaltered. The 36 sions having about a 25% to 60% non-volatile new compositions also present fewer industrial content and which is of. paste-like consistency as hazards, since the vehicle contains appreciable which comprises preparing a cellulose derivative quantities of water, and the loss of expensive solution in a water-immiscible and water-inert volatile solvents is thereby greatly reduced and organic solvent, preparing .a waterdispersion of the need for solvent recovery systems is avoided. . two colloidally dissolving emulsifying agents, one ' In addition, it has been determined that the high of which is of the polar type and the other of 40 solids compositions of the present invention will which is of the water colloidable viscous type, coat a greater area of carpet backing surface and combining the said cellulose derivative solu than a conventional nitrocellulose lacquer of tion and the said dispersion of emulsifying agents equal solids. by low speed mixing in a kneading machine. The improved compositions are also‘ of value 2. Process of claim 1 in which the cellulose 45 in coating and impregnating a great variety of derivative is water-wet cellulose nitrate. articles of manufacture: paper, textiles, fabrics, 3. Process of claim 1 in which the polar type cloth, wood and metal surfaces have likewise been of emulsifying agent is an alkali metal lorol phthalate and to which is added an alcoholic successfully coated and/or impregnated with intro?er. these cellulose derivative emulsions. In coating 4. Process of‘. claim 1 in which the cellulose wood surfaces, it is desirable to ?rst apply a wa derivative is cellulose nitrate and the polar type ter resistant primer coating. A further commer emulsifying agent is potassium lorol phthalate. cial usage is indicated in the application of emul 5. An oil in water emulsion of paste-like con sions to the surface of linoleum. The products sistency prepared in accordance with the process 55 may also be used as adhesives which function by of claim 1, said emulsion having a plurality of evaporation of the volatile constituents or they ingredients, the non-volatile content of which is may also be,prepared to function as heat ener the order of 25% to 60%, the predominating gizable cements. In this connection, they are solid ingredient of which is a cellulose deriva of particular merit in laminating cloth and other tive dissolved in a water-immiscible and water 60 fabrics, joining shoe parts in the manufacture inert' organic solvent, and as minor ingredients a of cemented shoes, laminating paper, regenerated plurality of colloidally dissolving emulsifying cellulose sheeting, manufacture of plywood, etc. agents one of which is of. the polar type and the The emulsions may be used to produce clear, other of which is of the water colloidable vis substantially colorless ?nishes or they may be cous typewhereby an emulsion is obtained which 65 colored with suitable pigments or other coloring is characterized by excellent stability. matter to afford decorative effects. 6. Product of claim 5 in which the emulsion The process of the present invention is of con contains a resin. siderable advantage in that low speed agitation 7. Product of claim 5 in which the cellulose 70 .may be used thus greatly simplifying industrial derivative is cellulose nitrate. 70 operation and permitting the use of less expen— 8. Product of claim 5 in which the polar type sive equipment. emulsifying agent is an alkali metal lorol phthal The use of nitrocellulose of high viscosity char ate and to which an alcoholic intro?er is added. acteristic is permitted as is nitrocellulose wet ALFRED DREYLING. with water, thus extending the industrial use-_ WILLIAM W. LEWERS. 75