[1]Patented June 1, 1954 296809101 UNITED STATES PATENT OFFICE 2,680,101 STABLE ARTIFICIAL RESIN EMULSIONS AND PROCESS OF MAKING SAME,UTALIZIING REACTION PRODUCT OF A PROTEIN Luzius Schibler, Riehen ' and Andreas Laely, Basel, Switzerland, assignors to Ciba Limited, BaseI, Switzerland, a Swiss firm No Drawing. Application August 27, 1951, St-rial No. 243,916 Claims priority, application SwitzerIand September 8, 1950 24 Claims. (Cl. 260-6) It is known that by additive combination with alkylene oxides, especially ethylene oxide, substances which are insoluble or have limited solubihty can be rendered soluble in water. It is also known that aciueous solutions of protein 5 substances, which are irreversibly gelatinisable by reaction with formaldehyde, after they have been reacted with ethylene oxide or propylene oxide are insensitive to formaldehyde even in high concentration. It has been shown that solu- 10 tions of protein substances reacted with alkylene oxides which have been mixed with formaldehyde have also lost their capability of being hardeiied, that is to say that after being dried, even at high temperatures, they no longer produce adhesive 15 effects of adeqltate resistance to water. Furthermore, such mixtures contain large amounts of free formaldehyde, which cannot enter into additive coinbination and therefore escape unconsumed upon drying. These preparations 20 therefore have only a relatively small field of application. The present invention is based on the observation that emulsions of the oil-in-water type can be made by emulsifying in an aqueous medium a 25 solution of a hardenable water-insoluble artificial resin in an orgariie solvent which is substantially iiiimiscible with water, if the aqueous mediura contains a reaction product of a protein with an alkylene oxide. 30 As hardenable water-insoluble artificial resins there come into consideration artificial resins soluble in organic solvents, such as phenoplasts and especially methylol compounds of substances of aniide character capable of forming a harden- 35 a@ole aminoplast with formaldehydej in which iriethylol compounds the oxygen atom of at least one methylol group is bound to an organic residue having more' than three carbon atoms. As substances of amide character capable of 40 forming a hardenable aminoplast with formaldehyde there may be mentioned urea, thiourea, guanidine, biuret, dicyandiamide, and also amino triazines which contain at least two prii-nary amino groups capable of reacting with formalde- 45 hyde, for example, melamine, benzoguanamine, acetoguanainin e and formoguanamine. These methylol compounds may be@ methylol ethers such as are obtained in known manner, for example, by subjecting condensation prod- 50 ucts of 'Lor.- Daldehyde and substances of amide character capable of forming a hardenable aminoplast with formaldehyde to etherification with an alcohol, which is substantially imnliscible Nvith water, for eiample, butyl alcohol, amyl alco- - 65 2 hol hexyl alcohol, cyclohexanol, octadecyl alcohol or benzyl alcohol ' In the present process there is generally used a solution of the methylol ether in an excess of the etherifying alcohol such as results from the process of etheril-leation. To these solutions may, if desired after being freed to a great extent from the excess of etherifying alcohol, be added the water-insoluble organic solvents mentioned below. Alternatively there may be used methylol esters wh.-Leh can be obtained in known manner, for exarnple, in the case of melamine by reacting the methylol ether, advantageously the methylol methyl ether, with a carboxylic acid containing inore than 8 carbon atoms such as pelargonic acid lauric acid, myristic acid, oleic acid, cerotic acid: stearic acid, fatty acid second runnings and colophony. As organic solvents which are substantially immiscible with water there may be used, on the one hand, the alcohols mentioned above or, on the other hand, water-insoluble organic solvents, for example, extraction benzine or lacquer benzine, xylene, toluene, chlorobenzene, tetrahydronaphthalene or "White spirit," or wax-like substances which ake solid at ordinary temperatures, for example, paraffin wax, with which the hardenable artificial resin to be used @'orms with the aid of heat more or less homogeneous solutions or melts. There may also be used mixtures of the above mentioned solvents. As the proteins of which the reaction products with an alkylene oxide are used as emulsifying agents, there may be mentioned for example, fish glue, soya casein, milk casein, lactalbumen-free aeid casein, gelatine or the like, and as alkylene oxides there are to be understood more especially alkylene oxides of low molecular weight having an oxirane ring and of at most 5 carbon atoms, and preferably not more than 3 carbon atoms, such as ethylene oxide, propylene oxide, epichlorhydrin and like compounds. For preparing the aqueous phase the protein is i,eacted in known manner with the alkylene oxide. Advantageously the protein is dissolved in water witli the aid of a basic substance, such as sodium hydroxide, potassium hydroxide, ammonia, triethanol@Lmine, morpholine, cyclohexylamine, borax, sodium carbonate, trisodium phosphate or the like, and the alkylene oxide is added to the resulting solution, if desired at a moderately raised temperature and preferably while stirring If the alkylene oxide is gaseous, as for example, in the case of ethylene oxide, it is of advantage to pass it directly into the protein solution. The
[2]2,680,10i 3 alkylene oxide may alternatively be added in the form of an aqi-ieous solut4@On thereof. In the case of epi.chlorhydrin i'Ll is of advantage to add it in the form of an alcoholic solution to the protein solution. The alkylene oxide is prefer- 5 n-bly added 'L-o the protein solution in such a proportion that after the reaction, that is to say, for example, after allowing the @eaction mixture to staiid for 24-43 hours, irreversible gelatinisatioii no longer occurs after the addition of formal- 10 dehyde. The resulting solut;@On of the reaction prod-act of the alkylene oxide and protein can be used as the aqveous phase directly or after being diluted with water to the desired visebsity. 15 The preparation of the arti.,icial resin emulsions is carried oulu in known manner by placing the aqueous phase in a sitita@ole emulsifying@appE,,ratus, and slowly addinp., the solution of th--, ar'Llificial resiii, advalitageously of an arninoplast, -,j to the aqueous phase wliile s'uirring. If desired the emulsification rnay be cari:ied out at a raised temperi:Lture, whei-eby tiie v-1scosity of the resin solution to be emulsified can be regulated ' Emuls@-Ecation at a raised temperature is espe- @5 cip-ily .,ecomirerded when a more or less homogeneous inol@u-en mixture of artii9-c-lal resin ar@d a wax-like substance such as paraffin wax 4is to be emi,ilsi,-aed. The artil@icial resn emulsions so obtained are 30 capable of dilution with water to any desired extent. Uv-on drying they leave beh-ind a film which, afte,@ being heated, is surpr-isingly resistant to water, notwitllstanding that the reaction prod,,ict of the protein and alkylene oxide 33 as already st@-ted, is no loiiger hardened by 'hforir@aldehyde liberated from the artificial resil'i. Especially water-resistant effects are obtained by us,n- an aminoplast emulsion to which has bee,.i 'aaded before use a hardening catalyst, fc)r 40 ex.-Lm@le, formic acid or ammonium thiocyanate. Since the catalyst 4's in the external a,,Iueous phase and tl.-Le resin in the internal o-ily phase, the catalyst has no marked effiect in the liq-,,ii-d e--,iiuls@@on so that the latter is remarkably stable. 45 When, however, the dr4.ed b,' nd,,T-ig agent is heated to a ternperature of 90-150' C., t' ie artificial res-in uiidergoes hardeiiing .ind a water-resistant filli'l is forried, in which the protein treated wit-l@l alkylene oxide has lost its emuls-ifying action. 50 The new ar@Llifici,@)l resin emulsions may be thickeiied by 'ul-le addition o'L a thickening agent, that is to say, a substance capable of forming highly viscous colloidal solutions, for example, gum tragacanth, starch, methyl-cellulose, poly- 5 vinyl al-,ohol or the like. An especially advantageous method of thickening emulsions suitable for certain purposes in -improving textiles consists in subsequeiitly emiilsifying ttierein an organic -tvater-imr@iiscible solvent, for example, extraction or heavy benzine, lacquer benz-ine, "White spiri'Ll," benzene, chlorobenzene, toluene, xylene, solvent naphtha, tetrahydronaphthalene, tripentene, turpentine, trichlorethylene or the 65 like vihereby 3-phase artif@cial resin emLilsion3 may, i@' desired, be obtained. The artificial resin emulsions may, if desired, be converted by a suitable evaporation process advantageously under reduced pressur.-, into 70 pulverulent preparations which can easily be redispersed in the presence of water. This is especially the case with those artificial resin emulsions in which the content of dry substance in 4 substance, that is to say the resin, in the internal phase. The new art@ficial resin emulsions can be used @@or a very wide variety of purposes, for example, a.3 adhesives in the paper, leatile@,, textile and wood indust,ries or as impregnating agents for fibrous materials, such for example, as textiles aiad paper, or for fx@,ng pigments on textile fabrics. The followiii@@ exariiples illustrate tf@e invention, the parts and percentages being by weight: Example 1 1000 parts of fish glue having a dry content of about 50 per ce-.nt. ore adjusted to a pH value of 9.5 by means of ammonia and 50 parts of eth@,lene oxide are introduced, while stirring. 80 parts of the reslilting thick condensation produi.,t are di-luted with 140 parts of water and 280 ri:@rts bf a solution in bi-i@tyl alcohol of about 60 per cent. s' ,rength of a condensation product of melamine and formaldehyde etherified with butyl alcohol, which solution contains 2.75 per cent. of free formaldehyde, are emulsified in the aqueous medium iii a suitable apparatus. The resulting mobile viscous emulsion is mixed with forriiic acid uii4uil it has an ac-ld reaction, and is used for glueing wood, paper and the like. After drying there is obtained a water-resistant bond. Example 2 200 parts o,-' gelatine are dissolved in 800 parts of warm water and the solution is rendered alkaline with amrnonia until a test portion diluted with an equal qua-ntity of wa-ter has a pH value of 8.7. 40 parts of ethylene oxide are then iiitroduced, while stirring, at a temperature of 30' C. A thinly liquid reaction mixture is obtained which does not gelatinise even after prolonged standj-iig. If formaldehyde is added to a test portion of the sOlutiO-," after 48 hours no further coagulation occurs. 100 parts of this reacti-On mixture, -,vhich is no longer sensitive to formaldehyde, are placed in avi emulsifying apparatus and 120 parts of a solution of 60 percent. strength in butyl alcohol of a urea-formaldehyde condensati-on product etherfied with butanol are introduced in s.-Luall portions. In this manner there is obtained a homogeneous mobile emulsion of the oil-inwater type. It can be used in the same manner as the emu-sion of Example 1. Example 3 200 par'us of acid casein are added to a solution of. 12 parts of borax in 788 parts of hot water. The solutioxi is stirred until cold. After the addition of 14 parts of an ammonia solution of 25 per cent. strength, 60 parts of ethylene oxide are introduced in the course of I hour. In 100 parts of the resulting viscous emulsifier solu'tion are emulsified 41 parts of the artifi--ial resin solution , described in Example 2, the latter forming the internal phase and the solution of casein reacted @vith ethylene oxide forming the external phase. A thick white salve is obtained, which may be dried in vacuo at 50' C. The diy product, after bein.- ground, is a stable powder whi-ch.is easily dispersable in water and after being pasted with water serv6s as a b'mding agent or anadhesive. Example 4 5 to 20 parts of a solution of 51 per cent. t-he external phase exceeds the content of dry 75_ strength in cyclohexylalcohol of a urea-formal-
[3]2i680il0l dehycle condensaiion product-etherfled with-eyclohexyl alcohol are slowly introduced into 10 parts of the viscous emulsifier solution described in Example 3. The resin solution may contain up to 2.5 per cent. of free formaldehyde. 5 Depending on the quantity of the resin solution emulsified in the aqueous phase there is obtained a thinly viscous to salve-like emulsion which, especially in the latter case, is of good stability and dries to form glass-clear films. It is 10 suitable for many,purposes, for example as a hardenable binding agent or adhesive. Instead of ethylene oxide -there may be used, for example, a corresponding quantity of propylene oxide. 15 Example 5 100 parts of acid casein are dissolved in 388 parts of water with the addition of 12 parts of ammonia solution of 25 per cent@ strength. 30 20 grams of ethylene oxide are passed into the resulting solution, ivhile stirring. The mixture is then diluted with 495 parts of water. In the resulting emulsifier solution there are slowly emulsified 1320 parts of the solution of the con- 25 densation product of melamine and formalde'hyde etherified with butyl alcohol, which is described in Example 1. A thick salve-like resin emulsion is obtained which is capable of dilution to any desired extent with Nvater, and which 3u may be freed from a part of the butanol content therein by evaporation in vacuo. This product, even after the addition of a hardening catalyst such as ammonium thiocyanate, is stable and may advantageously be used for fixing pigments 35 on textile fabrics in the following manner: 440 parts of a pigment-resin suspension are prepared by finely dispersing 30 parts of copper phthalocyani ne pigment in a mixture of 76 parts of the above described emulsifier solution prior 40 to dilution with water and 9 parts of a highly sulfonated castor oil. The resulting pigment suspension is diluted with 117 parts of water, then mixed with 200 parts of the resin emulsion described above and 8 parts of ammonium thio- 45 eyanate are added as a hardening catalyst. There is also produced as a thickening agent an emulsion (a so-called emulsion thickener) by diluting 60 parts of the above described undiluted emulsifier solution with 165 parts Of 50 water, and adding 25 parts of ethylene glycol, and then emulsifying in the resulting mixture 750 parts of benzine having a boiling range of 100-140, C. There is obtained a thick salve-like mass of which the external phase contains in 55 solution casein reacted with ethylene oxide, and of which the internal phase consists of benzine. To 560 parts of this so-called emulsion thickner the 440 parts of the pigment-resin suspension described above are added, and the mixture is 60 homogenised to form a viscous printing color. A cotton fabric, after being printed with this printing color, and then heated for 5 minutes at 1401 C., has a water-resistant print which does not stif.Len the fabric. The fixation may be cOm- (5 pleted by neutral or acid steaming. Exa?nple 6 Into an aqueous solution containing 20 per cent. of casein and 2.4 per cent. of borax and 7( rendered slightly alkaline with ammonia ethylene oxide is introduced until the mixture has taken up 30 parts of ethylene oxide for every 100 parts of casein. After 24 hours, 68 parts c)f the resulting reaction mixture are diluted with 75 32 iiarts of water, and in this diluted reaction' mixture there is emulsified a molten mixture of 83.5 parts of paraffin wax melting at 52, C. and 83.5 parts of a condensation product obtained by condensing about 2 mols of stearic acid (per mol of melamine) with a condensation product of 1 mol of melamine and 4-6 mols of formaldehyde highly etherified with methyl alcohol. After dilution with 33 parts of water there is obtained a finely dispersed salve-like stable emulsion, which can be used as an impregnating agent for textiles, paper and the like. Example 7 1000 parts of fish glue having a dry content of a;bout 50 per cent, are adjusted to a pH value of 8.6 with an-inionia, and then inixed, while stirring with a solution of 2.00 parts of ep3@chlorhydrin in 200 parts of ethyl alcohol. After 16 hours, 110 parts of this thick reaction mixture are diluted@ with 140 parts of water, and 230 parts of a solution of about 60 per cent strength in butyl alcohol of a ir -ela-mine-formaldehyde condensation product etherifi-ed with butyl alcohol, said solution cortaining 2.75 per cent of free formaldehyde,@ E?,re emulsified in the mixture in a suitable apparatus. The resulti-ng viscous emulsion is mixed v,7ith formic acid until ilu has an acid reaction, and is used for glueing wood, paper or the like. After d,-y,"ng, a water-resistant bond is obtained. Example 8 200 parts of gelatine are dissolved in 800 parts of warm v-.Tater and the solution -is rerdered alkaline with ammonia until a test portion diluted ivith an equal quantity of water has a pH value of 8.8. A solution ol4 160 parts of epichlorhydrin: in 160 parts of alcohol is stirred in, whereby a tl-iinly liquid solijtion is obtained which does not golatinise even after prolon.-ed standing. When formaldehyde is added to the solution after several days coagulation no lon.aer occurs. To 100 parts of this aqlieous phase, which is iio lon.@er sensitive to forn-.aldehyde, there are added in sm-all portions in an er.,iulsifying apparatus 120 parts of a solution of 60 per cent strength in butyl alcohol of a urea-formaldehyde condensation product etheri.)-Ied with butanol, whereby a homocyeneous visco,-is emulsion of the oil-,.n-water type is obtained. It ca,@i be used in. the same mann(-r as the emul@sion of Example l. What is
