Soap, preparation

Lysol consists of a mixture of the three cresol isomers solubilized using a soap prepared from linseed oil and potassium hydroxide, to form a clear solution on dilution. Most vegetative pathogens, including mycobacteria, are killed in 15 minutes by 0.3—0.6% lysol. Lysol has a phenol coefficient of 2. Bacterial spores are very resistant. Lysol is also the name of a proprietary product, the formula of which has changed over the years other phenols have been substituted for the cresols. 

Clear soluble fluids. Cresol is a mixture of o-, m- and p-methyl phenol (Fig. 10.7A). Because of its poor solubility, it is solubilized with a soap prepared fiom linseed oil and potassium hydroxide. It forms a clear solution on dilution. This preparation, known as Lysol (Cresol and Soap Solution BP 1968) has been widely used as a general purpose disinfectant but has largely been superseded by less irritant phenolies. 

Soap prepared from fish oil is very similar to the last named. God-liver oil soap differs only in having a more unpleasant smell and less consistency. Suet or tallow soap is white and solid, and has a slight odor of the fat. Exposed to the air, it loses water, and becomes brittle. Soap prepared from lard is very white, solid, inodorous, and especially valuable for the production of toilet soaps. Rancid butter yields a soap whieh is white, and in properties similar to tallow soap, but retains a rancid smell. Castor oil and spermaceti soaps are emollient, and especially applicable to toilet pur-... 

Composition. Crystals deposited from ethanol solution as well-formed thin plates. The fatty acid content of the crystals is given in Table I. For all chain lengths the acid content approximates closely that required for 1 to 1 stoichiometry. This is also the case for most of the acid-soaps prepared by the petroleum ether route the low values of titratable acid in some instances are ascribable to the presence of free soap. 

Problem 22.28 What is the composition of the soap prepared by hydrolysis of this triacylglycerol ... 

Bodey GP, Arnett J, De Salva S. Comparative trial of bacteriostatic soap preparations Hexachlorophene versus triclosan and triclocarbon. Curr Ther Res 1978 24 542. 

White Castile soap—Sax>o (U. S.), Sapo durus (Br.)—is a Xa soap made from olive-oil strongly alkaline, hard, not greasy, very soluble contains 21 per cent. HjO. Sapo mollis (Br.) is a K soap made from olive-oil, and contains an excess of alkali and glycerol. TeUow soap is made from tallow or other animal fat, and contains about i its weight of rosin. Emplastrum plumbi (T7. S., Br.) is a lead soap, prepared by saponifying olive-oil with litharge. 

In the preparation of soap by the cold process the fat is treated with a strong aqueous solution of the exact amount of alkali required to saponify it. The mixture is well stirred, and heated a few minutes until reaction begins. The heat generated by saponification is sufficient to carry it on after it is once started. At the end of several days the reaction is complete. Soap prepared in this way contains all the glycerin formed and any excess of fat or alkali which may result from incomplete saponification or the incorrect mixing of the substances used. It is apt to turn yellow and become rancid. 

Early work, starting in 1930, used simple tanks filled with DR1 emulsion, a soap prepared with magnesium carbonate, animal fat, and kerosene,... 

The salts obtained from saponification depend on the base used. Sodium salts, known as hard salts, are found in most cake soap used in the home. Potassium salts, soft soaps, are used in some shaving creams and liquid soap preparations. 

In addition to sodium soaps, corresponding saponification and neutralization reactions of fatty acids can also be carried out to produce the softer potassium and ammonium soaps. Soaps prepared from coconut oil or oleic acid by the use of nitrilotriethanol are semi-solid or liquid in form. Salts of polyvalent ions such as calcium, zinc and aluminium, the so-called metal soaps , also form part of the market. 

Soap prepared from the above formula has a delicate rose colour, is very fragrant and emoUient, and is indeed one of the finest of toilet soaps. 

It is well known that tallow and similar soaps, when dried, are freely soluble in alcohol, and that the solution, when eyaporated to expel the spirit, leayes the soap as a trami lucent mass, which, on cooling, forms the weU-known transparent soap. The same result may, howeyer, be obtained in a greater or lesser degree with some soaps prepared by the cold process this is especially the case with castor-oil soda soap, either by the addition of a little spirit of wine or glycerine. The some result may also obtained by mixing sugar or petroleum with the mass. 

Castor Oil Soap.—This soap, prepared as below, is said, by Mr. Hammer to answer best for preparing soap liniment [Linimeatum Saponin Cb.) —... 

They are, moreover, noncorrosive and can be used on virtually all textiles without damage. Ethanolamine soaps prepared from oleic-, stearic-, lauric-, or caprylic acid are constituents of many toiletries and medicinal soaps. 

Hydrocarbon chain lengths of saturated fatty acids in oxidized paraffin soaps prepared in a certain Chinese factory are given by the following ... 

---