EP1276840B1 - Abrasive soap-type scouring composition - Google Patents

Abstract

The invention concerns an abrasive soap-type composition, designed in particular for washing the hands and a method for producing such a composition. The scouring composition is obtained by reacting a basic compound with the residue of oil filtering and/or decoloration, said residue containing fats, and mineral substances, so as to saponify at least part of said fats contained in said residue to obtain soaps.

Description

The present invention relates to a scouring composition, of the abrasive soap type, intended in particular for cleaning hands, and a method for producing such a composition.

It is known to wash one's hands with soap to which granular particles have been added in order to add a scouring effect to the detergent power of the soap, especially in the case where the hands are heavily soiled with grease or other grease.

Thus, scouring compositions in the form of paste are marketed with abrasive agents incorporated under the name "mechanic's soap". These compositions, in the form of homogeneous paste, abrasive to the touch, generally include sodium soaps, aluminum silicates, water, micro wood particles and possibly perfumes.

Thus, for example, the French patent FR 668 492 describes a soft soap obtained by mixing black soap and Meudon white to which water containing soda, clay and carbonate of lime is added.

Generally, the sodium soaps used are based on fats of animal origin whose characteristic fatty acids have been reacted with sodium hydroxide, and they represent less than 10% of the scouring composition. An abrasive agent and water are added to the soap mixture and they represent respectively between 30 and 40% and between 50 and 60% of the composition in weight values.

Although relatively inexpensive, these pasta require a first soap making operation and then mixing operations with water and abrasives, the latter having a certain market value.

A composition of this type is described in French patent FR 613 607 which describes a paste that can be used as a soap obtained by hot mixing of vegetaline, stearin, liquid potassium hydroxide, potassium carbonate, water and ground pumice.

Japanese Patent JP 11335692 describes the preparation of a composition containing clay and fatty acids from a fat filtration residue, by hydrolysis of fats in the presence of a lipase. One of the envisaged applications for the compositions thus prepared is the preparation of a soap by neutralization of the acids formed during the hydrolysis.

A first object of the present invention is to provide a scouring composition comprising soaps in proportions identical to or greater than those of the pasta described above and whose production costs are lower.

To achieve this object, according to the invention, the scouring composition, of the abrasive soap type, intended in particular for cleaning the hands, contains a mixture of soaps and mineral particles, said mixture being obtained by treatment of the filter residue and / or bleaching of oils, said residue containing fats and minerals, said treatment consisting in reacting a compound base with said residue, without any other intermediate reaction step, so as to saponify at least a portion of said fat that said residue contains to obtain the soaps.

Thus, the composition contains a mixture of soaps and abrasive mineral particles, which are derived from a filtration residue of the oils. This residue is generally eliminated in the composting or methanation processes, or even incineration. This elimination represents a relatively high cost for the oil producers and none of the specific characteristics of the residue makes it a raw material that can be used in the soap industry, given the impurities it contains.

An essential characteristic of the residue, more commonly referred to as a filter cake, which makes it an interesting basic constituent for making scouring compositions, is that it contains both fatty substances, necessary for the manufacture of soaps, and abrasive agents. . Quite unexpectedly, it turns out that the saponification reaction of the fatty substances that the residue contains can be carried out directly with the constituents of the residue without any further reaction step.

Advantageously, said scouring composition comprises soaps derived from the saponification of vegetable fats, waxes contained in said fats and mineral substances consisting of filtration aids and / or discolouration grounds.

Indeed, during the filtration of vegetable oils and more particularly during the so-called "winterization" or dewaxing step, the fatty substances, the waxes, and the mineral filtering aid particles are recovered in the residue. In some cases where it is necessary to discolour In the oil, discolouration grounds are added which are filtered and which also constitute another residue that can be mixed with the "winterisation" residue.

The residue obtained is capable of being converted to give a scouring composition.

Advantageously, the scouring composition comprises soaps derived from the saponification of fatty substances of animal origin and mineral substances consisting of filtration aids and / or discolouration grounds. In fact, in the case where the oils of animal origin are bleached, the resulting residue is also able to constitute a raw material for producing a scouring composition.

Advantageously, the inorganic particles constituting the abrasive in said composition and constituting a filtering aid for the oil, consist of siliceous products. These filter aids prevent clogging of the filters and are added to the oil before filtration at a rate of 0.05 to 0.5% by weight.

Preferably, the siliceous products come from siliceous shells of fossilized algae heat treated. These products called diatoms are heat-treated to partially convert them to crystalline silica.

Advantageously, the siliceous products consist of pearlites.

When the oil has been bleached, the inorganic particles constituting the abrasive in said composition and constituting soil for bleaching the oil, are preferably based on clay.

Indeed, the compounds of the clay type, with some treatments, have adsorbent properties vis-à-vis the dyes, especially vis-à-vis the carotenes or chlorophylls. These clays are also abrasive agents, quite interesting.

The types of soap come preferentially from the saponification of fatty substances contained in the corn oil when the residue is derived from its filtration at the stage of "winterization". However, advantageously, the soaps come from the saponification of fatty substances contained in sunflower oil when the residue comes from the filtration of this oil in the "winterization" stage.

In addition, the scouring composition preferably additionally contains additional water, in particular for practical reasons of spreading on the skin and rinsing with water. On the other hand, when the abrasive power of the composition is not sufficient, advantageously it also contains an additional abrasive agent.

• entre 5 et 25% de savons ;
• entre 15 et 65% d'eau ;
• entre 15 et 40% de particules minérales et/ou d'agent abrasif additionnel ;
• entre 1 et 8% de cires ; et,
• entre 1 et 5% de corps gras non saponifiés.

Thus, according to a preferred embodiment, the scouring composition comprises, in weight percent:

• between 5 and 25% of soaps;
• between 15 and 65% water;
• between 15 and 40% of mineral particles and / or additional abrasive agent;
• between 1 and 8% waxes; and,
• between 1 and 5% unsaponified fat.

The waxes present in the composition give it emollient and thickening properties which help to limit the irritating action of the soap on the skin.

A second object of the present invention is to provide a method for producing a scouring composition of the abrasive soap type, intended in particular for cleaning the hands, according to which a basic compound is reacted with the residue of the filtration and / or discoloration of oils, without any other intermediate reaction step, said residue containing fatty substances, and mineral substances, so as to saponify at least a portion of said fatty substances that said residue contains to obtain soaps. The only reaction step is the saponification reaction even if it is split into several phases.

A feature of the invention is the use of the filtration residues of the oils to produce cleaning abrasive compositions comprising soaps.

Advantageously, an additional fatty substance is added to said residue in order to saponify said additional fatty substance with the fatty substances of said residue. This additional fatty substance makes it possible in certain cases to modify certain properties of the soap resulting from the saponification reaction, in particular its foaming power. In other cases, especially when the scouring composition is used as a lubricant, this additional fatty substance makes it possible to increase the soap content.

Advantageously, the residue comprises fatty substances of vegetable origin, waxes contained in said fatty substances and mineral substances consisting of filtration aids and / or discoloration grounds.

Indeed, the filtration or dewaxing of vegetable oils is necessary in particular to remove the waxes they contain and which are in crystalline form. This crystallized form appears when the temperature of the oil is sufficiently low.

In order to facilitate this filtration, oil filter aids which are naturally collected in the filter cake, which constitutes the residue, are mixed with the waxes and a certain amount of fatty substance present in the oil.

In the case where the oil is discolored during refining, in the same way a filter cake is recovered containing the bleaching earths and fats, said cake being able to be converted to produce a scouring composition.

This is particularly the case for the bleaching of oils of animal origin, for which the residue comprises fatty substances of animal origin and mineral substances consisting of filtration aids and / or discolouration grounds.

The process for producing the scouring composition consists in directly reacting a strong base on this residue in order to directly transform the fatty substances that it contains into soaps so as to obtain the scouring composition.

• on mélange ledit résidu de filtration d'huiles avec une base forte et de l'eau, constituant un mélange, de façon à saponifier au moins une partie des corps gras ;
• on immobilise ensuite ledit mélange durant un temps déterminé ; et,
• on augmente la température dudit mélange de façon à augmenter le taux de corps gras saponifiés.

Preferably, the process for producing the scouring composition comprises the following steps:

• said oil filtration residue is mixed with a strong base and water, constituting a mixture, so as to saponify at least a portion of the fatty substances;
• said mixture is then immobilized for a predetermined time; and,
• the temperature of said mixture is increased so as to increase the level of saponified fatty substances.

The first step consists of mixing the filtration residue with water and a strong base in specific amounts so as to saponify most of the fatty substances in the mixture. Then the mixture is immobilized so as not to destabilize the emulsion for the reaction to continue. In a third step, the mixture is brought to the water bath to improve the yield of the saponification reaction, always being careful not to stir the mixture.

Advantageously, said mixture is diluted with water after the level of saponified fatty substances has been increased, that is to say after passage in the water bath. This operation is carried out with stirring and the water is added gradually.

The residue of the filtration of oils of plant origin preferably comprises between 20 and 60% fat in percent by weight. These amounts make it possible to obtain a final composition whose soap content is between 5 and 25%.

Furthermore, the residue of the oil filtration preferably comprises between 35 and 50% of mineral particles, in particular weight percentage, resulting in a final composition comprising between 15 and 40% of mineral particles.

These mineral particles are advantageously in the form of siliceous shells of thermally treated fossilized algae, more commonly known as diatoms. However, preferably, the residue of the oil filtration comprises inorganic particles in the form of perlites.

Furthermore, advantageously, the oil filter residue comprises clay-based mineral particles, in the case where the oil is bleached.

In addition, the residue preferably comprises between 1 and 15% of waxes in percentage by weight. These waxes are obviously the impurities that one wishes to remove from the oil and, surprisingly, they give the scouring composition the desired emollient properties. Moreover, the saponification conditions are not, here, drastic enough to saponify the waxes, which would make them lose their properties.

Advantageously, the residue of the oil filtration comprises between 5% and 20% of water, in percentage by weight, which must be taken into account when calculating the quantities of sodium hydroxide and additional water necessary for carrying out the saponification reaction. .

Other features and advantages of the invention will become apparent on reading the description given below of particular embodiments of the invention, given for information but not limiting.

First of all, a general method of producing a soap will be described before describing the specific method for producing a scouring composition according to the invention.

According to a general method, the oils and fats are capable of being transformed into soaps by a so-called "saponification" reaction. The saponification is carried out by successive additions of alkaline lye with oil and / or grease and by boiling the mixture. The mixture is stirred to emulsify.

The saponification reaction is the reaction of a triglyceride, or more generally an ester, and a strong base to obtain a soap and an alcohol. This reaction is carried out in two stages: the hydrolysis of triglycerides and the formation of fatty acids and the neutralization of fatty acids.

The basic compound used is generally soda, in view of its cost, but it goes without saying that any other base of the potassium hydroxide type, lithium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide or the like, alone or as a mixture , could be used.

In order to increase the saponification reaction rate, the contact surface of the two immiscible liquids, in particular water and oil, is increased by emulsifying the mixture with stirring. Furthermore, the soap being an excellent emulsifying agent, it promotes the stabilization of the emulsion, which is favorable to the reaction.

In fact, the saponification reaction is carried out from sodium hydroxide with which small droplets are dispersed in the oil.

We will now describe a specific process for producing a scouring composition based on oil filtration residues in accordance with the invention for a particular example of a residue containing 47% of fatty substances, of which 8.3% are waxes, 42.6%. of diatoms and 9% of water, in weight proportions.

The objective sought is to allow the most complete saponification possible of the fatty substances present in said residue while avoiding hydrolyzing and saponifying the waxes it contains. Indeed, these waxes give the scouring composition emollient and softening properties quite interesting.

To do this, the run times of the different phases must be controlled as well as the quantities of sodium hydroxide and water required for the reaction; the dilution ratio of the composition produced must also be determined.

Thus, it has been determined that for 35 kg of residue containing 47% of fatty substances, 2.2 kg of caustic soda and 6.4 kg of water were required to carry out the saponification reaction.

The 35 kg of residue corresponding to 16.45 kg of fat are first milled by means of a stirrer. The quantity of water required is then added and then the sodium hydroxide is slowly added in several stages with stirring in order to allow a more homogeneous diffusion of the alkaline solution within the fatty substances. This operation lasts about 10 minutes and allows the saponification of a large part of the triglycerides.

Then the mixture is left for 2 hours without contact with the ambient air so as to avoid any dehydration which would destabilize the emulsion. Moreover, this rest period makes it possible not to obtain a soap which is too alkaline and which does not have a defect of release.

The mixture is then heated to a temperature close to 100 ° C. without stirring for a period of 1 hour in order to guarantee good saponification. Thus, the soap obtained is slightly alkaline and soap release phenomena are avoided.

Then, the composition obtained is diluted. This ultimate phase of the protocol consists in adding a determined quantity of demineralized water in order to obtain the desired percentage of humidity.

The water content of the abrasive composition has an influence on the release ability of the product and on the abrasive power of the soap which directly conditions its ability to remove dirt from the skin.

Thus the optimum water content of the abrasive composition is set at 54%.
Analysis of the scouring composition previously described Elements of the composition Percentage in weight values Sodium soaps 19.5 Water 53.6 Abrasive agents 21.6 Vegetable waxes 2.3 Unsaponified glycerides 2.8

The scouring composition has about twice the soap content as commercial abrasive compositions. Moreover, the presence of waxes in the composition according to the invention that is not found in commercial abrasive compositions is very interesting because it helps to limit the irritating action of the soaps of the composition.

The manufacturing method according to the invention makes it possible to produce glycerine, which is the alcohol resulting from the production of the soap. This glycerine also provides the scouring composition with emollient properties.

In addition the scouring composition according to the invention is easy to spread on the skin given its water content. It also has a cleaning power equal to or greater than commercial scouring compositions and provides a feeling of softness on the skin after being used. In addition, the particle size of the abrasive particles is finer than that of the abrasive particles of the commercial abrasive compositions.

In order to improve the foaming properties of the composition, provision is made to incorporate an additional fatty substance of the coconut oil type in the said residue so that it is saponified with the fatty substances of the said residue. Coconut oil contains fatty acids of the lauric acid type, containing chains of 12 carbon atoms, which favors the foamability of the soap obtained. The amounts added to the residue are between 5 and 20%.

It is also planned to incorporate in the reaction mixture comprising residues from the filtration and / or bleaching of oils, additional fatty substances so as to increase the soap content of said scouring composition, especially for industrial soaps type applications where the lubricating properties are in particular sought. The levels of soap thus obtained are generally between 20% and 85%.

In addition, an additional abrasive agent is added to said composition when the abrasive properties provided by the mineral particles of the residue are not sufficient.

The scouring compositions are capable of being produced with the filtration residues of any vegetable oil which undergoes this dewaxing step. Examples include sunflower, corn, peanut, olive or rice bran oils.

Furthermore, it is expected to produce scouring compositions according to the invention from the residues from the filtration of fatty substances during the bleaching.

This process aims to bleach the fatty substances, removing the compounds that give them a certain color and especially carotenes and chlorophylls. For this purpose, bleaching earths of the activated clay or montmorillonite type having a large active surface area per gram of material are incorporated in the oil so that the dyes can be adsorbed.

When the oil is filtered, the discolouration grounds are recovered with the dyes and a certain amount of fat. This residue is capable of being converted into a scouring composition by a process according to the invention.

On the other hand, the discoloration can be carried out for fats of animal origin. Therefore, it is intended to use the residue of this filtration to produce scouring compositions.

Claims (18)

1. A method for producing a scouring composition of the abrasive soap type, notably intended for cleaning hands, characterized in that it comprises the following steps:

   - the residue of the filtration and/or of the decoloration of oils is recovered, said residue containing fats and mineral materials; and,

   - a basic compound is reacted on said residue, without any other intermediate reaction step so as to saponify at least one portion of said fats which said residue contains in order to obtain soaps.
2. The method for producing a scouring composition according to claim 1, characterized in that said basic compound consists of sodium, potassium, lithium, calcium, magnesium or barium hydroxide, alone or as a mixture.
3. The method for producing a scouring composition according to claim 1 or 2, characterized in that an additional fat is further added to said residue in order to saponify said additional fat with the fats of said residue.
4. The method for producing a scouring composition according to claim 3, characterized in that a determined amount of additional fats is added in order to obtain a scouring composition for which the soap content is between 20 and 85%, whereby a composition having lubricant properties is obtained.
5. The method for producing a scouring composition according to any of claims 1 to 4, characterized in that said residue comprises fats of vegetable origin, waxes which said fats contain, and mineral materials consisting of filtration adjuvants and/or decolorant earths.
6. The method for producing a scouring composition according to any of claims 1 to 4, characterized in that said residue comprises fats of animal origin and mineral materials consisting of filtration adjuvants and/or decolorant earths.
7. The method for producing a scouring composition according to any of claims 1 to 6, characterized in that it comprises the following steps:

   - said residue from filtration of oils is mixed with a strong base and water, forming a mixture so as to saponify at least one portion of the fats;

   - said mixture is then immobilized for a determined time; and,

   - the temperature of said mixture is increased so as to increase the content of saponified fats.
8. The method for producing a scouring composition according to claim 7, characterized in that said mixture is further diluted with water after having increased the content of saponified fats.
9. The method for producing a scouring composition according to any of claims 1 to 8, characterized in that said residue from filtration of oils comprises between 20 and 60% of fats, by weight percent.
10. The method for producing a scouring composition according to claim 5, characterized in that said filtration residue derives from the filtration of vegetable oil containing between 1 and 15% of waxes, by weight percent.
11. The method for producing a scouring composition according to any of claims 1 to 10, characterized in that said residue from filtration of oils comprises between 35 and 50% of mineral particles, by weight percent.
12. The method for producing a scouring composition according to any of claims 1 to 11, characterized in that said residue from filtration of oils comprises mineral particles as heat-treated siliceous shells of fossilized algae.
13. The method for producing a scouring composition according to any of claims 1 to 12, characterized in that said oil filtration residue comprises mineral particles as pearlites.
14. The method for producing a scouring composition according to any of claims 1 to 13, characterized in that said oil filtration residue comprises mineral particles based on clay.
15. The method for producing a scouring composition according to any of claims 1 to 14, characterized in that said oil filtration residue comprises between 5 and 20% water, by weight percent.
16. The method for producing a scouring composition according to any of claims 1 to 15, characterized in that an additional abrasive agent is further added.
17. A scouring composition of the abrasive soap type, characterized in that it is obtained by a method according to any of claims 1 to 16 and in that it comprises by weight percent:

    - between 5 and 25% of soaps;

    - between 15 and 65% of water;

    - between 15 and 40% of mineral particles from the treated filtration and/or decoloration residue and possibly from the further abrasive agent;

    - between 1 and 8% of waxes; and,

    - between 1 and 5% of non-saponified fats.
18. The composition according to claim 17, characterized in that said method is applied to a residue from the filtration and/or decoloration of sunflower, maize, groundnut, olive or rice bran oil.