A major problem in this context is the high impermeability of banknotes and securities, as a result of which defacement e. g. of a tight wad of notes with the aid of dyes as such has proved impossible hitherto.

Described hereinafter is a solvent composition having very high permeating and penetrating power. The solvent composition makes use of organic acids and salts having a strong tensioactive effect, in combination with surfactants. Optionally, solvents such as water, alcohols or ketones can be added. The composition allows an active devaluing agent to penetrate rapidly, deeply and irreversibly into banknotes or other objects.

The term devaluing agent refers to all substances or mixtures which are able to render, inter alia, banknotes definitively unusable, such as: permanent glues, permanent odourants, indelible dyes and more specifically indelible fluorescent substances.

More in particular, the present invention relates to a devaluing composition for money, securities and the like, said devaluing composition comprising a devaluing agent, at least one organic acid having a total number of carbon atoms less than or equal to five and having one carboxylic group, at least one organic salt having a total number of carbon atoms less than or equal to five, a surfactant and a solvent.

The invention also relates to the use, in conjunction with a devaluing agent, of a solvent composition comprising at least one organic acid having a total number of carbon atoms less than or equal to five and having one carboxylic group, at least one organic salt having a total number of carbon atoms less than or equal to five, a surfactant and a solvent.

The devaluing agent preferably is an indelible dye, a repulsive permanent odourant, an indelible fluorescent substance, a permanent glue or a combination of such substances.

The carboxylic acid chosen can be an acid selected from the group containing formic acid, acetic acid, butyric acid or a combination of these acids.

Typically, the devaluing composition comprises an organic salt selected from the group consisting of potassium, magnesium, sodium, calcium and ammonium salts of carboxylic acids.

The surfactants chosen can be mono-and/or diglycerides.

An advantageous solvent is water.

A typical example of the solvent composition can be compounded as follows: 1.49 parts by weight of propionic acid, ammonium and sodium propionates (pH = 5-6) This is prepared as follows (for 100 parts) : a mixture of 19 parts water and 67. 7 parts of propionic acid is slowly admixed with 6 parts ammonia (25t strength) and 7. 3 parts sodium hydroxide (50t in water).

2.1 part by weight of mono-and diglycerides

3.49 parts by weight of water.

The following comparative trial tested the permeation characteristics of different mixtures.

The mixtures tested are: A Water 99 Indelible red diazo dye 1 B Water 97 Indelible dye 1 Surfactant 2 C Water 50 Indelible red diazo dye 1 Surfactant 2 Propionic acid and its sodium and ammonium salts 47 D Water 67 Indelible red diazo dye 1 Surfactant 2 Citric acid and its sodium and ammonium salts 30 E Water 50 Indelible red diazo dye 1 Propionic acid and its sodium and ammonium salts 47 C is a devaluing composition according to the invention.

Taking a stack of four sheets of paper, a drop of the various mixtures A to E inclusive was applied, with the aid of a pipette, simultaneously and in equal amounts to the top side of the first (topmost) sheet of paper, five times in succession.

One minute after the mixtures had been applied to the stack of paper, a photograph was taken of the first sheet of paper. Mixture C, at that point, had already diffused in its entirety into the stack of paper, while at the same instant clearly visible drops of each of the compositions A, B, D and E were still present on top of the first sheet of paper.

Five minutes after the mixtures had been applied to the stack of paper, photographs were taken of the second to fourth (bottommost) sheet of paper inclusive, of the stack.

The penetrating power of mixtures A and D was found to be very poor (no visible staining of mixtures A or D on the third or fourth sheet). Mixtures B and E were found to have penetrated more deeply into the stack of paper, the penetration of mixture E into the stack proving somewhat better than that of mixture B. It was observed, however, that in the case of both mixture B and mixture E not all five drops applied to the first sheet had penetrated as far as the third or fourth sheet of paper.

The best mixture in terms of staining and penetrability was unambiguously the devaluing composition according to the invention, mixture C. Indeed, each of the five drops of mixture C applied to the first sheet was found, clearly visibly, to have penetrated as far as the fourth sheet of paper.

The above-described devaluing and solvent composition can be used, inter alia, for money security systems such as"exploding packs"or security systems for clothing.

The invention therefore also relates to the method of devaluing valuable objects, wherein such a devaluing composition is applied to the object.