US2087267A - Process of manufacturing soap - Google Patents

Description

Patented July 20, 1937 UNITED STATES PATENT OFFICE 2,087,267 PROCESS OF MANUFACTURING SOAP Julius Schaal, New York, N. Y.

No Drawing. Application May No. 22,557. In Germany December 21, 1935, Serial 1 Claim. (01. 87-16) In order to expedite the reaction, a small My invention relates to soap manufacture and has for its object to devise a new process whereby soap can be made with a minimum expenditure of time, labor and, expense.

and pressed require again from one to two days.

Moreover,- this method, besides being slow, requires the' installation of a heating plant or steam-boiler, large boiling kettles, cooling de- :vices, drying apparatus, pumps etc. necessitatstituents used,'i. e., the fats ing large buildings with sufiicient floor-space. Also large amounts of fuel, water and salts must be on hand, all of which requires large working capital. v

My new process of making soap does away with all these expensive installations, apparatus etc. and permits the manufacture of soap in a fraction of the time and with a fraction of the expense required by the ordinary soap-making process. According to the present method, the saponiflcation is efiected without the supply of any outside heat, either direct or indirect. The fats or oils, both of animal and vegetable origin, are

merely heated to a temperature somewhat higher than their melting point. previously dissolved in water have been added, there occurs after a brief period of time, 10 to 20 minutes, the reactiom'and the heat generated thereby is quite sufllci f t, to heat the entire mass to a temperature of to C. resulting in an Then, when the alkalis intense boiling of the In my process only enough water is used as is required for the saponifying operation to produce a homogeneous plastic soap body.

One of the conditions for the successful-practice of my new process is the maintenance of definite temperatures of the mixtures offats and the alkali solutions and the observation of certain procedures in the mixing together of the conand alkalis.

I have found that only with a quite definite percentage of the alkali solutions used in my process a complete saponification takes place. when saponifleation is effected with sodium oxid'e (NaOH) the percentage is 40%, while in the case of saponiflcation with caustic potash (KOH) the percentage is 49% (determined according to the specific weight at 15 C.)

any bleaching action.

about 30-60 minutes, elapse quality of the fats (neutral fats containing as and 50 kilograms of cocoanut amount (V of hydrogen peroxide (30%) is added to the mixture of fats and oils prior to the admixture of the alkalis. There is hardly From the time the constituents are mixed together until the finished complete saponification depending on the muchas 10% free fatty acid can be used) and the amount of the charge. At this time of the process, corrections can be made, that is to say, the alkalinity can be increased or decreased, the water content can be modified, and other ingredients, e. g. calcined soda, silicate, borax, tri-- sodiumphosphate, medicaments, perfumes, pigments, etc. can be added. With my saponlflcation method, also a good floating soap can be produced. The process can be carried out in any suitable mixing trough or good stirring apparatus. passed over cooling rolls and is then ready for any further treatment depending on the kind of soap desired, whether in the shape of bars, cakes, flakes, powder, etc. Since the glycerin remains in the soap, the soap can be advantageously used as a cosmetic soap. Instead of the soap being passed over cooling rolls, it can also be cast into molds or spread on a clean concrete floor. Any waste is returned to the kettle wherein the saponification is effected. a

- The following is an example of my new process for making a soap suitable for the manufacture of a toilet-soap.

1. 200 kilograms of beef-tallow (titre 40-41) oil are carefully weighed and are melted at a temperature of 50-52 C.

2. 38.65 kilograms of caustic soda (128-130), in the shape of scales or flakes, are dissolved in 40 kilograms of water. The dissolving operation generates a temperature of about 95 C.) The solution is left standing for about ten minutes. A light-layer of dirt collects on the surface, which layer is removed.

3. 8 kilograms of water, dium or potassium silicate and about 1 kilogram The finished soap is of the above alkali solution are mixed together enamelled vessel 5 kilograms of st.

kettle equipped with a I having a temperature of 50 to 52 C. is poured grams of water, and this small amount of soluthrough a fine cloth into the kettle, and the stirtion is stirred for about five minutes into the soap ring apparatus therein is started. Thereupon, mass. If upon another test the pink color does 1% kilograms of hydrogen peroxide and then the alkali solution having a temperature of to 92 C. are poured into the kettle. The stirring apparatus is permitted to operate, until the emulsion commences to thicken, which will occur after about 5 to 10 minutes, when the stirring apparatus is immediately stopped". After about 2 minutes, the mass in the kettle becomes stiff, and now commences the saponification. The temperature gradually rises inabout 8 to 10 minutes from about 60 to C., at which temperature the surface commences to rise. When it ruptures, there follows an intense boiling accompanied by a rising of the mass, the temperature increasing to from about to C. The

reaction is permitted to continue, until the entire kettle is completely stirring apparatus is set in operation for a short period to cause a breaking down of the boiling mass, whereupon the stirring apparatus is immediately stopped again, to prevent the reaction from being interrupted. The rising of the mass in the kettle will be repeatedabout 5 or 6 times, and each time, the stirring apparatus is set in operation for a brief period to prevent the mass from boiling over. Only after the reaction has come to a complete stop, the stirring apparatus is permitted to operate for about five minutes more to produce a thorough mixture of the constituents. It is very important not to prematurely interrupt the reaction by the operation of the stirring apparatus, because otherwise the genera-' tion of the heat in the mass and complete saponification would thereby be prevented.

After the mass has been stirred for about five minutes, it is uniformly homogeneous and rather thick. The stirring is then stopped for a while to permit all soap portions spattered on the walls of the container to be scraped ofl. Thereupon, the stirring apparatus is started again, and the above mentioned solution of silicate and water, which must have a temperature of at least 90 C. is then very slowly added to the mass. The latter again commences to rise, which is a second reaction produced by the generation of steam. This second reaction results" in a further saponification involving all mass of soap is in a very high globular state, that is to say, a state of which state each fat molecule must be positively saponified. During this stage, the stirring apparatus continuously operates and is stopped only after a uniformly homogeneous mass is obtained.

' correct, produces pink color.

This occupies about five to seven minutes.

The soap mass is now tested for its alkalinity, which will be absolutely correct when all the eonstituents have been carefully weighed. A small amount of the cooled soap is moistened with phenol-phthalein solution, which, if the alkalinity is In the absence of said color, some alkali is missing. In that case,

. fifty grams of flaky soda are dissolved in 100 filled. At this stage, the

the fat molecules, since the highest surface tension, in

not yet appear, further additions of the solution Just referred to are made, until the mass shows the proper alkalinity.

If,on the other hand, the alkalinity should be too great shown by dark-red color upon moistening with phenol-phthalein, the alkalinity must be reduced by the addition to the mass of cocoanut oil. By the slow admixture of 250 to 500 grams of cocoanut oil and stirring of the mass, the excess of alkalinity is. corrected, which requires stirring from ten to fifteen minutes depending on the amount of the soap mass.

Only after the saponification has been entirely completed, parafline is added, for a premature addition of parafline would lead to a serious disturbance. of the saponification process. The hot parafline is slowly added at various places while the mass is being continually stirred, resulting in a quick distribution of the paraffine in the mass. At the end of the entire process stirring of the mass is once more efiected for six to ten minutes. Because of the absorption of air during this last stirring operation, the volume of the mass increases somewhat, but the mass becomes thicker and more creamy. After the process has been finished, the temperature will be about 90 to 92 C. The soap is now taken out of the kettle and passed over a system of cooling rolls.

I claim:

In the manufacture of soaps having a controlled alkalinity by cold processing, said soap producing a pink color. when moistened with phenol-phthalein solution, the improvement which comprises mixing together 200 parts of beef tallow and 50 parts of cocoanut oil, heating the mixture to between 50 and 52 C., stirring the hot mixture and adding 1.2 parts of hydrogen peroxide solution, continuing the stirring and adding a preheated caustic soda solution, said solution being obtained by dissolving 38.65 parts of flake caustic soda in 40 parts of water and having a temperature of 90 to 92 C., discontinuing the stirring upon the thickening of the \emulsion and causing the spontaneous reaction to proceed with the simultaneous generation of heat until substantially complete, the generated heat bringing the soap mixture to about 120 C. and the hot mixture being intermittently stirred to control the reaction, again stirring the mixture after the exothermic reaction has subsided and adding to the hot soap mixture at preheated alkaline aqueous solution of silicate, said solution of silicate being obtained by mixing together 8 parts of water, 5 parts of silicate and 1 part of a caustic soda solution of the strength employed for saponification and heating the silicate mixture to 90 C., the said silicate solution being gradually added and the stirring being continued until the soap mixture has the desired alkalinity, and recovering the soap so produced.

. JULIUS SCHAAL.