US2274584A - Soap composition - Google Patents

Description

comes at. 24, 1942 SOAP COMPOSITION Hans Beller and John J. Owen, Baton Rouge, La, assignors to Jasco Incorporated, a corporation ot Louisiana No Drawing. Application September 10, 1937, Serial No. 163,248

2 Claims.

Our invention concerns preparations for the textile, laundry, detergent and related industries which are composed of or contain synthetic. fatty acids. Particularly, it i volves an improvement' in the sudsing power f such preparations.

It is known that synthetic fatty acids as such, or after a suitable purification, such as bleaching or distillation, may be converted into soaps. The acids are commonly manufactured by the oxidation of natural or synthetic hydrocarbons of high molecular weight, such as mineral oil, paraffln wax, crude scale wax, paramn oil or oils containing the same. They represent a mixture of individual acids, the average of which has more than carbon atoms in its molecule.

i'he preparations for the textile and related industries made from these synthetic fatty acids possess an excellent washing eficiency and a remarkable sudsing power. It has been quite generally noted, however, that the stability of the suds formed from these preparations from synthetic fatty acids is greatly inferior to that of the same preparations from natural fatty acids when used in the usual hard water containing calcium and magnesium salts. Instability of the suds occurs particularly if the preparations from synthetic fatty acids contain the usual inorganic builders, for instance, carbonates or trlbasic phosphates. In that case, one observes an entirely sumcient initial sudsing power of the preparations which is followed, nevertheless, by a surprisingly rapid breakdown of the suds. It is apparent that, for technical purposes, these compositions are at a great disadvantage when compared with the usual natural soap preparations of the trade.

It is, therefore, an object of our invention to improve the stability of. the suds from synthetic fatty acid preparations, such as soaps and soap mixtures, washing, cleansing, detergent and emulsifying agents. A further object are the improved preparations themselves. In particular, we are aiming to improve the stability of the suds from preparations of this type which have an admixture of builders. The preparations into which builders are incorporated and which possess an increased stability of the suds, are likewise an object'of our invention.

We have found that the surprisingly rapid breakdown of the suds from the aforementioned preparations for the textile and related industries, and especially of those containing builders, such as carbonates and tri-basic phosphates, may be prevented and preparations of strong sudsing stability be obtained, if a certain salt, such as we shall designate below, is added to these preparations, or to the solutions of such preparations. Salts which have. this beneficial effect are primarily pyrophosphates, (ll-basic phosphates,

borax, sesquicarbonates, metaphosphates and hexametaphosphates of the alkali metals and ammonium, either alone or in mixtures of those salts, or mixtures of one or more of the above salts with any of the common soap builders, such as silicates, tribasic phosphate, carbonates, etc. These salts are added to the preparations or to the solutions of such preparations in amounts of from about 1 to 50% or higher based on the soap content. In order to illustrate the distinction between compositions containing the added salt and those without it, we have ascertained, for example, that a synthetic fatty acid soap having incorporated with it 25% of a carbonate as a builder, requires 13 grams of built soap per gallon of washing liquid to achieve a stable sud; whereas only 5 grams of built soap are needed to gain a like sudsing effect and the same stability, if the builder comprises only 20% carbonate and 5% sodium pyrophosphate. The appended table presents further illustrations.

The synthetic fatty acids which are the components of any of the preparations contemplated by our present invention, may be prepared by any known method as, for example, by oxidation of crude scale wax, by blowing with air or any other oxidizing gases, or by treatment with other chemical oxidizing agents such as nitric acid, chromic acid, etc., at any desired oxidation temperature between and 180 C., but preferably at from 'to C. The oxidation reaction can take place at any suitable pressure, either atmospheric or below or above atmospheric pressure.

Instead of crude scale .wax, slack wax, etc., a

mixture of such wax with unsaponifiable material obtained from an oxidation product of hydrocarbons may be used as a charge to oxidation. This mixture may consist of any suitable proportion of each. But we have found a mixture of 40 parts by weight of crude scale wax with 60 parts by weight of unsaponifiable matter a convenient one.

' Instead of crude scale wax, any other natural or synthetic non-aromatic hydrocarbon or mixture of such hydrocarbon containing 10 or more carbon atoms per molecule may be used asfeed to the oxidation step. The synthetic hydrocarbons may be obtained, for example, by the hydrogenation of carbon monoxide in the presence of catalyst under suitable pressures.

The crude acids obtained by this process are converted into soap, or the acids may be purified mercury are used.

1 Example 1.Crude scale wax is blown for 14 hours with air at 110 C. and in the presence of 0.1% potassium permanganate. The oxidation product, which has an acid number of 60 and a saponification number of 112, is saponified at 200 C. with a 20% solution of sodium carbonate, and subsequently diluted with water and isopropyl alcohol until a soap solution containing about 20% soap is obtained. This soap solution is extracted with hydrocarbons with a boiling range of 80-120 C. in a countercurrent, packed, extraction tower where by maintaining a sumciently high volume ratio of gasoline to soap solution, the unsaponifiable material is essentially completely removed. After separation of the extracted soap solution from the gasoline extract, the isopropyl alcohol used in diluting the soap solution is recovered by distillation. The extracted soap solution, free from unsaponifiable matter and alcohol, is acidified with sulfuric acid and the liberated fatty acids are separated and washed with water; 7 i

. These crude acids are distilled in vacuum with steam and the acids distilling at temperatures from 150 to 215 C. or from 150 to 280 C. at 8 mm. mercury pressure separated for the production of soap. (a) These acids are saponified in a.

crutcher with the theoreticalamoimt of sodium hydroxide to give a soap which is light in color and possesses an agreeable odor, and whichis hereinafter referred to as a 100% synthetic fatty acid soap to distinguish it from a mixed soap prepared as follows: (b) Twenty-five parts of the above synthetic fatty acid cut aresaponified together with 75 parts by weight of tallow fatty acids in a crutcher with thetheoretical amount of sodium hydroxide. Such a soap will hereinafter be referred to as a mixed soap, and is to be understood to contain any suitable ratio of synthetic fatty acids to natural fatty acids useful as soap stock. Or a mixed soap may be prepared by any mechanical mixture of soaps from synthetic fatty acids and soaps from natural fatty acids.

Example 2.Synthetic fatty acids are prepared as in Example 1 except that a mixture of 40 parts by weight of crude scale wax and 60 parts by weight of, unsaponifiable material obtained from an oxidation product of crude scale wax is oxidized with air at 115 C. in the presence of 0.4%

manganese stearate and 0.2% sodium carbonate catalyst until an acid number of 68 in the product is obtained. The oxidation product is saponifled at" 120 C. for V hour with the theoretical. amount of sodium hydroxide in 40% aqueous solution, and the aqueous soap solution is heated to 320 C. under pressure for one hour. The unsaponiflable material is then removed from the soap by releasing the pressure and flashing off the volatile matter. The crude. fatty acids are then re- 2,274,584 with steam at an absolute pressure of 8 mm. of

The improvement in the soap preparations obtained by the addition of the various salts designated above is illustrated by the following examples: I

Example 4.--A laundry bar soap, containing 15% sodium silicate and 10% sodium carbonate builder, is prepared from a kettle boiled soap ob' tained by saponifying a mixture of 75% by weight of tallow and 25% by weight of, distilled fatty acids as described in Example 1. In washing soiled, oil-stained cloth, 12 grams of this soap per gallon of washing solution are required to give stable suds in the washing operation. After rinsing, the washed cloth shows that satisfactory detergent action was obtained.

By adding 10% of sodium pyrophosphate to the same built soap preparation only 8 grams of built soap per gallon of washing solution are necessary to obtain stable suds in washing a similar soiled, oil-stained cloth. In this case,'the washed cloth, after rinsing, also showed that satisfactory detergent action was obtained. When 10% additional sodium carbonate is used instead of the sodium pyrophosphate, no reduction of soap concentration'in the washing operation is obtained.

This laundry bar soap may quite generally be composedof a kettle boiled soap obtained by saponifying a mixture of at least 50% by weight of natural fats and at least5% by weight of fatty acids, manufactured by oxidizing solid paraffin hydrocarbons and having a boiling point range of from 150 to 280 C. at 8 mm. mercury pressure; a builder consisting of sodium silicate and sodium carbonate, and at least 1% sodium pyrophosphate.

Ezample 5.A soap is made in the kettle by saponifying synthetic fatty acids as described in Example 2 with caustic alkali, and run while hot into the crutcher where it is thoroughly mixed with a concentrated. solution of soda ash and then with a concentrated solution of sodium pyrophosphate.

.chilling rolls, scraped from the rolls and screened,

The mixture is then run over the coarse particles going to a grinder and the finer portion being packed. The finished product contains 30% synthetic fatty acid soap, 50% sodium carbonate and 20% sodium pyrophosphate. A solution containing 15 grams of this mixture per gallon gives satisfactory results in dishwashing as far as cleansing action and suds? covered and soaps prepared from them after dis-' 1 tillation as described in Example 1.

Similar batches of synthetic fatty acids may be prepared from any suitable mixture of crude scale wax and unsaponiflable material-obtained from an oxidation product ofcrude scale wax.

Example 3.Synthetic fatty acids are prepared as in Example 2 except that crude scale wax is oxidized at 140 C. in the presence of 03% manganese naphthenate and 0.2% sodium carbonate catalyst. Soaps are prepared as in Example 1 (a) or (b).

ing is concerned.

Other suitable proportions in the finished product of synthetic fatty acid soap, sodium carbonate and sodium pyrophosphate are, of course, within the purview of the present example and appended claims.

.When a-similar preparation containing 30% soap and 70% carbonateis. used, unsatisfactory results are obtained, especially with regard to the stability of the suds. I

Example 6.A soap powder such as is described in Example 5 ismixed with 60% powdered pumice and used as a scouring powder. The quality of this scouring powder is considerably improved when the builder present .in the soap powder used contains preponderant quantities of borax or pyrophosphate.

The soaps prepared by the above methods were tested by the following procedure: A solution of known concentration was prepared by dissolving the desired quantity of soap or soap plus-builder in water at 12926. in orderto give solution are used to obtain the desired soap concentration for the test. One gallon of water of '7 grains hardness per gallon is placed in a pan of approximately 3 gallon capacity and is heated to 115 F. for the test. A measured amount of the standard soap solution is added to give the soap or soap and builder concentration desired for the test. After mixing and allowing to stand for one minute, the test solution is agitated rapidly by a back and forth movement of the hand for one minute. The figures given represent. the concentration of real soap plus builder, in grams per gallon, necessary to give pan of suds after standing 3 minutes. For example, 6 grams of built soap represent 4.5 grams real soap and 1.5 grams of builder in the case where 25% of builder was used. The hard water used in the tests described was 7 grains per gallon, but the hardness consisted of Ca and Mg salts in a molar ratio of 2.9 to 1 which is considered representative of natural hard water in the United States. Data are given in Table I.

Mixed soap 25% parafiin fatty acid soap +75% tallow soap Unbuilt (paraflln fatty acids, 150-215 C. at

8 mm. Hg, with steam) 6 With 25% sodium pyrophosphate (NaePzOv) 5 With 25% sodium carbonate builder 13 With 10% sodium pyrophosphate+15% sodium carbonate 5 With 5% sodium pyrophosphate+20% sodium car 5 With 15% disodium phosphates-10% sodium carbonate 6 with 25% trisodium phosphate v) With 10%sodium pyrophosphate+15% trisodlum phosphate 5.5 With sodium pyrophosphate+20% trisodium phosphate 5.5 With b0rax+15% trisodium phosphate I 6 natural fats and at least 5% by weight or fatty acids distilling at ISO-280 C. at 8 mm. Hg with steam Unbuilt 5.5

With 25% sodium carbonate builder With 25% of mixture of sodium carbonate and bicarbonate in a molar ratio of 1:2 7

With 10% sodium pyrophosphate+15% sodium carbonate 5 With 25% 'trisodium phosphate Parajfin fatty With 10% trisodium phosphate-+15% sodium bicarbonate 7' 100% synthetic fatty acid soap Unbuilt -s .9 With 25% sodium silicate 3 With 15% sodium silicate+10% sodium pyrophosphate With 25% sodium carbonate With 15% sodium carbonate+10% sodium pyrophosphate;

"A pan of suds was not obtained at any concentration of soap.

We claim:

1. A laundry bar soap comprising a watersoluble, kettle-boiling soap-obtained by saponifying a mixture of at least by weight of acids, manufactured by oxidizing solid paraflin hydrocarbons and having a boiling point range of from 150-280 C. at 8 mm. mercury pressure, a builder consisting of sodium silicate and'sodium carbonate, and as a Ioamstabilizer at least 1% sodium pyrophosphate.

-2.- A laundry bar soap comprising a watersolub1e, kettle-boiled soap obtained by saponifying a mixture of by weight of tallow and 25% by weight of synthetic fatty acid manufactured by oxidizing crude scale wax to an acid number of 60 and a saponiflcation number of 112 and having a boiling point range of from -180 C. at 8 mm. mercury pressure, a builder consisting or 15% sodium silicate and 10% sodium carbonate. and as a foam stabilizer sodium pyrophosphate.

' a HANS BELLER.

JOHN J. OWEN.