FR2780411A1 - Saponifiable composition for making hard toilet soap - Google Patents

Abstract

Saponifiable composition for making hard toilet soap comprises: (a) 25-55% of an oil with an iodine number above 80; and (b) 45-75% liquid saturated fatty acids.

Description

The subject of the present invention is a composition of a mixture of bodies

  fatty (oil and fatty acids) for the manufacture of a hard toilet soap by saponification, comprising 25 to 55% refined vegetable oil with an iodine index greater than 80 and 45 to 75% chain fatty acids saturated short. These fatty acids, such as lauric, myristic or palmitic acid are currently obtained by hydrolysis of palm, palm kernel or coconut (coconut) oils followed by separation by distillation of the fatty acids resulting from this hydrolysis. The new process consists in salifying fatty acids with short saturated chains by acid-base reaction and saponifying vegetable oil by hydrolysis with a defective soda solution; these two reactions taking place simultaneously but at speeds

different.

  Currently, hard soap is produced by saponification of palm, palm kernel, or copra (coconut) oil with or without tallow. Only these oils, which have an iodine index of less than 70, always have large proportions of saturated chain fatty acids. short such as lauric, myristic or palmitic acid. They allow the manufacture of a hard soap with satisfactory foaming power. These hard soaps can be produced by various methods. The so-called Marseille process is a discontinuous process in a tank, comprising several stages: saponification proper, which consists in introducing the sodium hydroxide into the oil and the various washes whose purpose is to eliminate the glycerine, the excess sodium hydroxide and unsaponifiable compounds. In the tank, glycerol lyes from different washes are recovered by decantation; each settling operation can last a whole day. The manufacture of hard soap can also be carried out according to continuous industrial processes. The various existing processes use either fatty acids alone without

  washing, either palm, palm kernel, or coconut (coconut) oils mixed or not with tallow.

  After the saponification of the oils or tallow, the soap paste obtained is washed several times with water against the current, then the glycerol lyes are removed by centrifugation, which saves time but also significant costs. All these processes are strongly conditioned by the particular physicochemical properties of solutions concentrated in soap and saponification requires the use of electrolytes such as NaCl to avoid certain undesirable phases which are difficult to implement. All these methods therefore consist in reacting excess sodium hydroxide with oil or tallow in order to carry out the saponification in its entirety, then in eliminating the sodium hydroxide which has not reacted by the various washes. These washes also make it possible to eliminate the unsaponifiable matter and possibly recover the glycerin. This produces a soap paste which can be enriched with glycerin or oil depending on the desired quality (Manufacture of soaps, other detergents and

  glycerin. Edgar WOOLLATT. Publisher: Ellis Horwood Limited).

  The present invention allows the use of vegetable oils with an iodine index greater than 80 such as rapeseed oil, sunflower oil, soybean, peanut, flaxseed or corn for the manufacture of a hard soap by saponification. It allows the manufacture of a toilet soap by saponification of a mixture of fatty substances containing 25 to 55% of rapeseed oil, 30% of lauric acid and 25 to 55% of myristic acid. The manufacture of this hard soap by saponification of refined vegetable oil in the presence of fatty acids with a short saturated chain is carried out according to a precise operating method: the method according to the invention consists in mixing i0 hot the liquid fatty acids with the liquid vegetable oil, perfectly miscible with each other, until a homogeneous and clear medium is obtained. Then this mixture is brought into contact, hot, with a faulty sodium hydroxide solution, with vigorous stirring in order to obtain a very fine emulsion. Indeed, the fatty acids are immediately salified with sodium hydroxide according to an acid-base reaction and the soap obtained makes it possible to emulsify the oil thus accelerating the saponification reaction. The soda must be faulty in order to salify the fatty acids and saponify the vegetable oil until the two reactions are completely finished. A liquid soap paste is obtained which must then be partially dehydrated until

  obtaining a hard soap in the form of powder, shavings, swabs or bread.

  This embodiment of the process according to the invention makes it possible to use oils with a high iodine index such as rapeseed, soybean, sunflower, peanut, corn or flaxseed oils which naturally cannot be used for the manufacture of hard soap. Indeed, these oils whose iodine index is greater than 80 (g 12 / 100g) essentially contain unsaturated C18 fatty acids such as oleic, linoleic and / or linolenic acid, which do not make it possible to obtain the hardness required for toilet soaps. On the other hand, the best foaming qualities are obtained from fatty acids with short saturated chains such as lauric, myristic or palmitic acid. This process also makes it possible to reduce the time of manufacture of the soap, to avoid washing and effluents and by

  therefore it limits production costs considerably.

  The present invention makes it possible to obtain, by molding, an excellent quality toilet soap according to a continuous industrial production mode. The hard soap according to the invention is composed of salts of fatty acids, of glycerin which has the property of promoting hydration of the epidermis and of lipids (triglycerides, diglycerides and monoglycerides) whose property

  protective skin is recognized in dermatology.

Claims (4)

Claims   1) Composition of a mixture of fatty substances, used for the manufacture by saponification of a hard toilet soap, containing 25 to 55% of iodine index oil   greater than 80 and 45 to 75% fatty acids with short saturated liquid chains.   2) Composition according to claim 1, characterized in that the vegetable oil   iodine index greater than 80 is rapeseed oil.   3) Composition according to one of claims I or 2, characterized in that the   mixture of fatty acids with short saturated chains contains 10 to 30% of lauric acid and 25 to% of myristic acid 4) Composition according to claim 1, characterized in that the mixture of fatty substances contains 25 to 55% of rapeseed oil, 10 to 30% lauric acid and 25 to 55% myristic acid.   ) Method for manufacturing a hard soap according to one of claims I to 4,   characterized in that: - the hot fatty acids with short saturated liquid chains are mixed hot with the refined liquid vegetable oil until a perfectly homogeneous and clear medium is obtained, - and then brought into contact, hot and under live conditions stirring, the mixture obtained previously with the faulty sodium hydroxide solution,   - then this paste is partially dehydrated in order to obtain hard soap.   6) Toilet soap characterized in that it is constituted by a mixture composed of salts of fatty acids, glycerin, triglycerides, diglycerides and monoglycerides   obtained by the method according to claim 5.