US2813112A - Soap composition - Google Patents

Description

SOAP CGIWPOSITIQN Victor C. Fusco, Baltimore, Md, and Richard C. Harshman, Kenmore, N. Y., assignors to Olin Matlneson Chemical Corporation, a corporation of Virginia No Drawing. Application April 14, 1955, Serial No. 501,436

6 Claims. (Cl. 260398.5)

This invention relates to improved compositions containing fatty acid radicals including fats, oils, soaps and soap products. More particularly, it relates to soap compositions stabilized with respect to color and odor formation by the incorporation therein of azines.

' The tendency of soaps to discolor and become rancid in storage or use is well known. These effects have been attributed to a variety of causes including the manufacture of soaps from fats and oils which themselves tend to become rancid. It is also believed that minor metallic contaminants, particularly iron and copper in minute amounts, accelerate the formation of oxidation products resulting in undesirable odor or discoloration. These effects may appear in various forms of soap including bar soap, powdered soap, granulated soap and spray-dried soaps in the form of beads.

' The principal method of attack of this problem has been to add various anti-oxidants or other stabilizers to soap compositions in an effort to overcome these undesirable effects. Many of the suggested stabilizers afford a partial solution, for example, in inhibiting odor formation without atfecting or even in deleteriously affecting color stability.

It has now been discovered that soap compositions can be stabilized by the incorporation therein of minor amounts of azines. Effective amounts vary from about 0.05 percent to about one percent by weight of such azines.

Suitable azines for use in the present invention can be obtained by the reaction of hydrazine with aldehydes or ketones in known ways. The aldehydes and ketones can be aliphatic, aromatic, alicyclic or heterocyclic. The ketones can contain more than one of these types or groups. Suitable aldazines include acetalazine, benzalazine, tetrahydrofurfuralazine, salicylalazine and cinnamalazine. Azines from ketones include dimethylketazine from acetone and methylbenzylketazine from methylbenzyl ketone. Mixtures of two or more azines can be used or they may be used in conjunction with other known compatible stabilizers.

The stabilizers should not be added at a stage which will result in decomposition, leaching, or deterioration of the stabilizing agent. They are suitably incorporated in the soap compositions at any convenient step after the saponification. For example, they can be added to the neat soap as made in the kettle in the manufacture of frame soap. In the manufacture of milled soap, it is ordinarily preferable to add the stabilizer to the mixer preceding the milling together with perfume materials and coloring agents if desired. The stabilizer can also be incorporated during the crutching process. The stabilizers can be added conveniently in the form of aqueous suspensions or they can be incorporated as dry solids, preferably finely divided. Mixing subsequent to the addition of the stabilizer is suflicient to render the soap composition homogeneous.

The soap product can subsequently be dried and formed into cakes, plates, beads or other forms as desired. In

2,813,112 Patented Nov. 12, 1957 the manufacture of liquid soap compositions the stabilizers are suitably dissolved directly in the soap solutions.

The stabilizers are effective in soaps of various types, including laundry soaps, facial soaps and in soaps subsequently incorporated in cosmetic compositions including tooth paste, face creams and body creams.

The stabilizers of the present invention are also effective in delaying the oxidative deterioration of fatty materials generally as well as the soaps for which they are especially suited. Minor proportions of these stabilizers are effective in fats, fatty oils and other esters of unsaturated fatty acids as Well as inks, paints, varnishes, enamels and other materials containing them.

Example I A blend of dried pure soap stock (essentially the sodium soap of fatty acids derived from tallow) was prepared by thoroughly mixing 0.5 parts by weight of benzalazine with 99.5 parts by weight of the soap at about room temperature. The mixture was pressed into 20 gram bars under a pressure of 2000 p. s. i. g. Four test bars together with four similar bars prepared by the same procedure but omitting the benzalazine was stored in an oven at 110 C. for seven days. At the end of this period the light reflected from the surface of the blocks was measured with a Hunter reflectometer. Taking the reflectance of the soap immediately after preparation as percent, the test bars without any oxidant after the seven day heating period showed an average reflectance of 56.0 percent while the bars containing 0.5 percent of benzalazine showed an average light reflectance of 81.0 percent. These data show that color development was very materially inhibited by thev incorporation of the benzalazine in the soap.

Example II A blend of benzalazine and soap (essentially the sodium soap of fatty acids derived from tallow) was prepared as described in Example I using only 0.05 weight percent of benzalazine based on the soap. After the seven day heating at C., the average reflectance of four untreated soap bars was 30.5 percent of the soap bars before exposure. Four bars containing 0.05 percent of benzalazine showed an average reflectance of 52.3 percent.

Example III Three diiferent azines were blended with a purified and dried Bradford" white soap flakes (essentially the sodium soap of fatty acids derived from tallow) to form compositions containing 0.05 weight percent of the azine. Each blend was pressed into four ZO-gram blocks at 2000 p. s. i. g. The blocks were aged in an oven at 100-110 C. for seven days. After the aging treatment the reflectance of light from the surface of each block was measured with a Hunter refiectometer and compared to an untreated soap block without an additive. The results, each an average of four tests, are shown in the following table:

Example IV Two 50 gram samples of freshly churned, unsalted butter, one containing 0.5 weight percent of benzalazine dissolved therein, were placed in 240 milliliter glass stoppered Erlenmeyer flasks. To each flask was added a 7 centimeter circle of filter paper torn in small pieces and wetted with one milliliter of water. The flasks were stoppered and placed in an oven at 80 C. for several days. A rancid odor developed in the, untreated sample after 3, days but the stabilized sample was still sweet when the test was discontinued after 7 days.

Various modifications can be made in the procedures of the specific examples to provide other improved soaps and soap-containing compositions-falling within the scope of our invention. Our invention is generally applicable for the purpose of improving the properties of soaps and soap-containing compositions as .those terms are generally understood in the art. In the specific examples, the soaps employed were sodium soaps of tallow fatty acids. Other soaps can be substituted for those specifically used, and our invention comprehends the improvement of soaps and compositions containing them in which the cationic portion is, for example, ammonia, an amine, an alkali metal or an alkaline earth metal, such as sodium, potassium, lithium, calcium, barium, and so forth, as well as magnesium, aluminum, zinc and cadmium. The anionic portion of the soap is generally derived from one or more aliphatic monocarboxylic acids containing from 12 to 18 carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and so forth. The soaps suitable for use in our invention can also be derived in known manner from a wide varietyof naturally-occurring materials or derivatives thereof, including tallow, palm oil, hydrogenated marine oils such as whale oil, coconut oil, palm kernel oil, rosin, tall oil, lard, olive oil, cottonseed oil, peanut oil, soya bean oil, linseed oil and so forth.

A wide variety of azinescan suitably be employed for the purpose of preparing our improved soap and soapcontaining products. Thus, the azines can be those derived, for example, from aliphatic aldehydes, including aldehydes of the type 'RCHO- wherein R is an alkyl radical having from 2 to 12 carbon atoms, such as acetaldehyde, propionaldehyde, butyral'dehyde, isobutyraldehyde, valeraldehyde, isovaleraldehyde, caproaldehyde, enanthaldehyde, caprylaldehyde, pelargona-ldehyde, capraldehyde andlauraldehyde. As is apparent-from the specific examples, the azineswwhich can be used in preparing our improved soap and soap-containing compositions can be derived from. aromatic aldehydes, among which are benzaldehyde, p-tolualdehyde, Y p-isopropylbenzaldehyde, ochlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde, salicylaldehyde, anisaldehyde, vanillin, veratraldehyde, piperonal, phenylacetah. dehyde and cinnamaldehyde. Azines derived from furfural and tetrahydrofurfural can also be suitably employed.

The azines which can be used in accordance with our invention can also be derived from a wide variety of aliphatic ketones, particularly. dialkyl ketones, including acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl isopropyl ketone, diethyl ketone, methyl n-butyl ketone,. methyl isobutyl ketone, pinacolone, methyl namyl ketone, ethyl n-butyl ketone, di-n-propyl ketone, diisopropyl ketone, methyl n-hexyl ketone, 6-methyl-2-heptanone, diisobutyl' ketone, methyl n-nonyl' ketone and stearone. The azines can also'be derived from alicyclic or aromatic ketones, such as cyclopenta'none, cyclohexanone, acetophenone and benzophenone.

Azines may also be incorporated in greases. These are commonly soap-thickened petroleum oils containing lithium, sodium, calcium, aluminum or other metal soaps of various acids including those derived from tall oil, tallow, castor oil or waste fat acids, for example.

We claim:

1. A soap composition containing a soap of an aliphatic monocarboxylic acid containing from 12 to 18' carbon atoms and containing as a stabilizer an azine in amount from 0.05 to 1 percent by weight, based uponthe weight of the soap.

2. A composition according to claim 1 in which the soap is a sodium soap. 7

. 3. A composition according to claim 1 in which the azine is benzalazine.

4. A composition according to claim 1 in which the,

, azine is dimethylketazine.

5. A composition according to claim 1' in-which the azine is salicylalazine.

6. A composition according to claim 1 in which the azine is cinnamalazine.

Claims (1)

1. A SOAP COMPOSITION CONTAINING A SOAP OF AN ALIPHATIC MONOCARBOXYLIC ACID CONTAINING FROM 12 TO 18 CARBON ATOMS AND CONTAINING AS A STABILIZER AN AZINE IN AMOUNT FROM 0.05 TO 1 PERCENT BY WEIGHT, BASED UPON THE WEIGHT OF THE SOAP.