WO2008096223A1

WO2008096223A1 - Method for manufacturing patterned paper and compounds implementing said method

Info

Publication number: WO2008096223A1
Application number: PCT/IB2008/000237
Authority: WO
Inventors: Clemente Nicolucci
Original assignee: Lecce Pen Company Spa
Priority date: 2007-02-05
Filing date: 2008-02-04
Publication date: 2008-08-14
Also published as: ITVI20070035A1

Abstract

The invention is a compound for manufacturing paper or cardboard including identification elements organised in patches. The compound comprises a mixture consisting of a cellulose pulp in water and also comprising a colloid solution and/or dispersion with the addition of a solution and/or dispersion of dyes or colour reagents, and/or tracer substances, comprising at least one colloid. The colloid solution and/or dispersion is able to be condensed using one or more coagulant substances and is able to be reduced to patches including coloured substances and/or tracer substances that can be dispersed in the compound through mechanical agitation means.

Description

"METHOD FOR MANUFACTURING PATTERNED PAPER AND

COMPOUNDS IMPLEMENTING SAID METHOD".

DESCRIPTION

The present invention concerns a special method for manufacturing industrial and/or handmade paper and cardboard with identification patterns.

The present invention also concerns the compounds suitable for manufacturing paper that include identification elements.

As is known, the paper usually manufactured both in paper machines and with handicraft techniques consists of fibrous, generally vegetable raw materials, felted together and then dried.

The material that is most commonly used for manufacturing paper is constituted by cellulose fibres obtained from trees or plants in general.

The surface of the raw paper is then covered using a range of additives that form a coat. However, the paper and the cardboard manufactured with the method described above pose some drawbacks, especially concerning the possibility of confirming with certainty the authenticity of paper documents.

A drawback is due to the fact that, when common paper is used, it is often impossible to distinguish the original from a non-authorised copy. This means that non-authorised copies are largely diffused, which causes considerable economic damage, in particular to the manufacturers of fine paper.

A further drawback is due to the counterfeiting of paper and in particular of important paper documents concerning official deeds and issued by public bodies or in any case by certified official bodies.

The object of the present invention is to carry out a compound for manufacturing paper and/or cardboard containing one or more univocal identification patterns, organized in patches, that ensure the traceability of a type of paper even if they are not visible to the naked eye. A further object of the present invention is to carry out a compound for the production of paper or cardboard that prevents counterfeiting of the paper or cardboard used.

The present invention also concerns a method for manufacturing paper that features univocal identification patterns and therefore is difficult to counterfeit. The objects mentioned above are achieved by the present invention concerning a compound for the manufacture of paper or cardboard, whose main characteristics are in accordance with the contents of the first claim. The objects mentioned above are also achieved by the present invention through a method for making compounds for the manufacture of paper whose main characteristics are in accordance with claim 32.

To advantage, the compound for manufacturing paper or cardboard according to the invention ensures the traceability of the paper produced as in said paper there are patches that make up one or more anti-counterfeiting systems. Still to advantage, the compound for manufacturing paper or cardboard according to the invention offers a univocal system for identifying the manufacturer of a given type of paper.

According to one feature of the present invention, the compound or mixture comprises a first solution consisting of a colloid with the addition of colouring and/or indicator substances, to which a second coagulant solution is added, wherein said second solution condenses the coloured patches into semisolid drops that can be added to the paper pulp.

The coloured patches can be produced in a random shape, whose size can in any case be controlled, or in a specific shape, and in this case they are also called pre-shaped patches. The shape of the patches that are not pre-shaped depends on several factors, such as:

- the concentration of colloids in the water solution;

- the turbulence (intended as mechanical agitation) exerted on the colloidal solution at the moment of addition of the coagulants; - the degree of coagulation reached by the patches.

The pre-shaped patches can be obtained by means of a continuous or discontinuous process, according to the following instructions.

Continuous process

As far as coloured patches are concerned, the following techniques are recommended.

The colloid is dissolved into a system for processing liquids, provided with a mechanical agitation device and preferably heatable.

For example, one thousand litres of water at ambient temperature are placed in the container and then the water is subjected to normal agitation. 20 kg of carboxymethylcellulose are added very slowly to the water, together with the desired quantity of auxiliary indicator substances, which can a colorant and/or pigment and/or mother-of-pearl powder and/or aluminium powder and/or a fluorescent substance and/or a reacting substance and/or a correcting agent and/or a magnetizable substance and/or a chromatic substance soluble in organic solvents and/or an opacifying filler.

The auxiliary indicator substances are preferably selected in the forms already existing in water-compatible dispersion or solution.

This is valid for all the non colloidal components of the coloured patches that can contribute to the formation of the same. The auxiliary indicator substances can be selected among an optical bleaching agent and/or a fluorescent substance and/or a dispersible colorant non-soluble in water, but soluble in organic solvents, and/or a substance that changes colour when in contact with specific reactive substances.

The reactive substances can be indicator dyes sensitive to pH (see bromocresol), sensitive to relative humidity (see cobalt chloride hexahydrate), sensitive to oxidants, to reducing agents, to gamma iron oxides, to fluorescent pigments.

The weight sum of the single constituent parts compared to the weight of the colloid/colloids should be included between 1 % and 100%, in order to avoid problems with printing or copying paper and cardboard that may make them less suitable for sale.

The colloidal system, after addition of the auxiliary substances that must be thoroughly mixed together, is kept under agitation for the necessary time.

This time is normally included between 10 and 120 minutes, in order to obtain a good dispersion of the auxiliary substances along with the dissolution of the colloid in water.

The solution/dispersion containing the indicator dyes is ready for the formation of the large coagulated elements.

The large coloured coagulated patches can be of the type carried out continuously or discontinuously.

For coloured patches intended to create chromatic patterns on papers having strongly coloured backgrounds, like for example black, blue, red, brown or dark green papers, before coagulation it is advisable to add to the colloidal suspension, along with the dyes and tracer substances already specified, a good opacifier like titanium dioxide, which provides a good contrast in the chromatic patterns, making them opaque and clear and eliminating any transparency effect.

In the continuous patch production process, the patch coagulation stage takes place directly in the line, but outside the paper manufacturing process, even if the patches coagulated in this way are introduced continuously at a certain point of the paper manufacturing process, that is, preferably in the so-called

"short" circulation circuit of the paper machine.

It can also be observed that coagulation in line is preferably achieved using a first pump to inject the chromatic solution/dispersion into a pipe that feeds a mechanical or hydraulic liquid mixer, while a second pump injects the very diluted water solution with the coagulant into the static or dynamic mixer.

The resulting suspension of coloured patches is conveyed to a continuous machine or to a storage tank that makes it possible to increase the contact time between the coloured patches and the coagulant solution, thus increasing its mechanical resistance.

The suspension of coloured patches is thus directly dispensed either into the headbox or, through a pump, preferably into the delivery pipe of the headbox of the continuous paper machine.

Discontinuous process Discontinuous coloured patches are obtained by adding to the solution

(colloid plus chromatic agents) the selected coagulant (for example, aluminium polychloride solution with 18% of dry material) as desired (for example,

10 litres in 1000 litres).

The introduction of the coagulant under agitation leads to the formation of coloured agglomerates that, according to the concentration of colloid, to the system agitation speed and to the speed at which the coagulant is added, generate the average size of the coagulated elements.

Advantageously, this discontinuous logic can be pre-tested in a laboratory.

To carry out the test, a sample of coloured patches is collected and then added to a sample of suspension of the fibre mixture, in the proportions that will be used for manufacturing the paper containing the coloured patches, and paper sheets are made with it in the lab.

These sheets are useful to evaluate the effect of the coloured patches in the paper. The chromatic pattern created by the coloured patches in the sheets made in the lab is usually and on average slightly larger than that obtained both in the manufacture of handmade paper and in the manufacture of industrial paper, since in the manufacture of industrial paper the paper pulp is subjected to strong mechanical actions that tend to divide some of the coloured patches contained in the paper pulp.

It has been observed that the pattern obtained in the lab becomes more and more similar to the pattern that can be obtained on a continuous industrial machine as the strong mechanical actions of the stirrers of the machine chests, pumps, deflackers and refiners diminish. Therefore, it is advisable to use a dosing pump to inject the water dispersion of coloured patches in a point where mixing is good, preferably downstream of the refiners, for example in the pipes delivering the paper pulp to the headbox. Dimensioning and shaping the patches In order to dimension the coloured patches, in addition to the liquid mixers it is also possible to use nozzles of the type used for producing microcapsules, that for this application must be obviously enlarged.

To produce coloured patches having a shape with predefined size, a concentrated solution of colloid is preferably used (for example, 5% of carboxymethylcellulose). Firstly, carboxymethylcellulose is dissolved in water under agitation, and then the identification substances, the anti-counterfeiting substances, the dyes, the pigments and the desired fillers, if any, are added to it.

When the system is homogeneous, a percentage portion of diluted coagulant is slowly added thereto (for example, 0.1% of aluminium polychloride diluted at 2%).

By slowly adding the aluminium polychloride or another coagulant, a mixture is obtained whose consistency can be compared to that of fresh dough. The whole is then shaped using systems like pasta and/or spaghetti extruders, having however the desired dimensions, which are normally smaller than those of small pasta shapes.

The coloured patches made in the lab have also been shaped with small injection extruders, starting from semi-condensed pre-agglomerates, and are then made discontinuous via a mechanical cutting operation at the exit of the extrusion die. The drawn product is then cut using systems suitable for making very short drawn elements, for example 0,1/10 mm in size, in such a way as to obtain the desired shape.

At the moment of cutting, or immediately afterwards, a water solution diluted with coagulant is added, in such a way as to obtain the individual shaped patches separate from one another and to ensure the preservation of their shape over time.

These shaped coloured patches are added to the paper fibre suspension as close as possible to the feeding point of the paper machine headbox. In the continuous processes for creating chromatic patterns on the paper manufactured in industrial plants and in case of production in a neutral pH system, it may be useful to neutralise the free acidity of the coagulant contained in the water dispersion of coloured patches or shaped coloured patches, in order to avoid the formation of air bubbles (small bubbles of carbon dioxide) in the sheet of paper. It is advisable to carry out the neutralisation process by simply adding calcium carbonate to the coagulant aqueous dispersion diluted in the coloured patches or in the shaped coloured patches, taking care to let the carbon dioxide bubbles that have formed degas before adding them to the paper fibre suspension, in such away as to prevent them from being released at the moment of formation of the cellulose panel on the paper wire.

This precaution makes it possible to prevent the excessive release of carbon dioxide bubbles in pulps reach in calcium carbonate at the moment of formation of the paper or cardboard panel. Distribution of the coloured patches In order to guarantee the distribution of the patches and reduce the risk of creating large agglomerates of coloured patches or shaped coloured patches in the paper, it is advisable to install a coarse fabric filter. A 3 mm mesh fabric has proven to be useful, positioned immediately before or immediately after the delivery pump of the coloured patches or shaped coloured patches, at the point where they are introduced in the fibre suspension.

In the case of production of handmade paper, it is sufficient to dilute the suspension of coloured patches or shaped coloured patches with water with a slight addition of coagulant (for example, 1 % of ltalclar 18® produced by ltalchemical lndustriale s.r.l.). In this case it is necessary to agitate and pour the whole on a wire sieve (for example with a 2/3 mm mesh) situated above the fibre suspension prepared for the production of paper, and then to mix the whole according to the methods usually employed for the production of good quality handmade sheets.

Condensation of the patches

As already explained, the condensation (coagulation or agglomeration) of the identification substances to be introduced in the compound for manufacturing paper takes place through a reaction between at least one colloid and one coagulant, like aluminium sulphate and/or aluminium polychloride and/or organic and/or inorganic coagulants like those used for blood coagulation.

For colloidal substances, natural colloids like polysaccharides or synthetic colloids are used.

The choice of the colloid, which is useful for the production of the coloured patches or of the shaped coloured patches, has been oriented towards those colloids that have less influence on some important characteristics of paper, like its suitability for printing, writing, copying, tracing and gluing.

In order to meet the needs of both paper manufacturers and users of paper and cardboard, the best colloids are those soluble in water, which are characterised by affinity with the cellulose compound also due to the high quantity of hydroxyls that remain outside the agglomerate.

Both carboxymethylcellulose, with different degrees of viscosity, and hydroxyethylcellulose have proven to be excellent colloids for the production of coloured patches and shaped coloured patches. For the same purposes, animal gelatines, polyvinyl alcohol and starches have proved to be good colloids.

The mixtures of colloids have proved to be suitable for the formation of coloured patches and/or shaped coloured patches.

Satisfying results were obtained using carboxymethylcellulose in percentage concentrations varying from 1 to 10%.

Both aluminium polychloride and aluminium sulphate, followed by iron chloride and zinc chloride, have proved to be excellent as coagulants in an aqueous system.

Colouring agents Inorganic and organic pigments, fluorescent substances, mica, mother-of-pearl powder, aluminium and bronze powder, acid, basic and direct dyes, natural dyes, food dyes and organic powders obtained from industrial and/or vegetable residues and excesses are recommended as colouring agents. Identification agents The following have proved to be excellent identification agents, perfect for papers and cardboards: fluorescent pigments and dyes, dyes that change colour and are sensitive to pH variations, oxidants, reducing agents, temperature or humidity variations, pigments and dyes that are not soluble in water but are soluble in organic solvents, metallic salts easily identifiable with colour reagents, like iron, nickel, cobalt salts, ecc, as well as substances having well-defined specific absorption peaks, and all those substances that when in contact with colour reagents generate typical colouring. Excellent results were obtained in laboratories using Prochima's line of powder pigments whose resistance to light varies from 6 to 8, for example the Pentasol lines of dye pastes, powder pigments,, fluorescent pigments, pearlescent pigments, metallic pigments like gold, bronze and silver. Further identification elements for paper are gamma iron oxides, which can be used allowing registration, with magnetic air gap, of magnetic patterns that are easy to identify and to register even if present in the coloured patches only. Some non-limiting examples of formulation of the compound produced according to the invention are illustrated here below.

The following examples have been carried out on a continuous paper-making machine suitable for manufacturing significant industrial samples and each example has been preceded by sampling of paper hand made in labs according to traditional handicraft techniques. EXAMPLE 1

This example concerns the manufacture of paper containing 0,65% of blue coloured dry patches. 150 litres of water at ambient temperature were introduced in a mechanical agitator. >

The water was subjected to agitation and the following was added thereto:

- half a kg of cobalt blue pigment 5002,

- 1 kg of mother-of-pearl powder (obtained from the micronization of mother- of-pearl waste generated by national button factories), - 5 kg of carboxymethylcellulose (CMC). The system was kept under agitation for 10 minutes, water was added until reaching a volume of 450 litres and then the system was left under agitation for other 50 minutes, that is, until the CMC dissolved completely.

Always keeping the system under agitation, 50 litres of coagulant aqueous solution containing 10 litres of 18% aluminium polychloride solution were added to this solution.

The addition of aluminium salt caused the coagulation of the coloured CMC, while the energy produced by the agitation fragmented the coagulated product into drops of coloured patches. The suspension of blue coagulated product was screened with a wire sieve having a 3 mm mesh (space between the wires) and poured into a machine chest containing 1000 kg of fibre suspension, called paper pulp and consisting of 54,65% of whitened cellulose obtained from eucalyptus, 10% of whitened cellulose obtained from fir, 10% of calcium carbonate, 20% of wastepaper and 0,65% of dry coloured patches.

40 litres of a water dispersion containing 4% of synthetic diketenic bonding agent (dimer of methylethylketene) were added to the cellulose pulp described above.

0.7% of cationic starch was added to the fibre suspension to increase retention of fine elements like fibrils, fillers and coloured patches.

The manufacturing speed of the paper strip was 45 m/min.

The composition of the pulp is illustrated in Table 1 , while the characteristics of the paper produced are illustrated in Table 2.

EXAMPLE 2 This example concerns the manufacture of paper containing 0.75% of metallic fuchsia, iridescent and anti-counterfeiting dry coloured patches.

150 litres of water at ambient temperature were introduced in a mechanical agitator and the water was subjected to agitation.

The following was added to the water: - half a kg of fluorescent fuchsia pigment (code PG 645),

- 2 kg of mother-of-pearl powder,

- 5 kg of carboxymethylcellulose (CMC).

The system was kept under agitation for 10 minutes, water was added until reaching a volume of 450 litres and then the system was left under agitation for other 50 minutes, that is, until the CMC dissolved completely. Always keeping the system under agitation, 50 litres of coagulant solution containing 10 litres of 18% aluminium polychloride solution were added to this solution/suspension.

The addition of aluminium salt caused the coagulation of the coloured CMC. The suspension of fuchsia coagulated product was screened with a wire sieve having a 3 mm mesh (space between the wires) and poured into a machine chest containing 1000 kg of fibre suspension, called paper pulp and consisting of 54.55% of whitened cellulose obtained from eucalyptus, 10% of whitened cellulose obtained from fir, 10% of calcium carbonate, 20% of wastepaper and 0.75% of dry coloured patches.

In order to improve the retention of fine elements, a water dispersion containing 4% of diketenic synthetic bonding agent and 0.7% of cationic starch was added to this pulp. The manufacturing speed of the paper strip was 45m/min. The composition of the pulp is illustrated in Table 1 , while the characteristics of the paper produced are illustrated in Table 2. EXAMPLE 3

This example concerns the manufacture of paper containing 1% of metallic, iridescent and anti-counterfeitinq opaque apple green patches. 150 litres of water at ambient temperature were introduced in a mechanical agitator and the water was subjected to agitation. The following was added:

- 2000 g of PG-642 PFA/ apple green,

- 2000 g of fluorescent yellow pigment, - 2500 g of mother-of-pearl powder,

- 500 g of titanium dioxide,

- 5 kg of carboxymethylcellulose (CMC).

The system was kept under agitation for 10 minutes, water was added until reaching a volume of 450 litres and then the system was kept under agitation for other 50 minutes, that is, until the CMC dissolved completely.

Always keeping the system under agitation, 50 litres of coagulant solution containing 10 litres of 18% aluminium polychloride solution were added to this solution/suspension.

The addition of aluminium salt caused the coagulation of the coloured CMC. The suspension of green coagulated product was screened with a wire sieve having a 3 mm mesh (space between the wires) and poured into a machine chest containing 1000 kg of fibre suspension, called paper pulp and consisting of 54.3% of whitened cellulose obtained from eucalyptus, 10% of calcium carbonate, 20% of wastepaper and 1% of dry coloured patches. In order to improve the retention of fine elements, a water dispersion containing 4% of diketenic synthetic bonding agent and 0.7% of cationic starch was added to the pulp described above.

The manufacturing speed of the paper strip was 45 m/min.

EXAMPLE 4

This example concerns the manufacture of paper containing 1.6% of metallic, iridescent and anti-counterfeiting opaque silver patches.

250 litres of water at ambient temperature were introduced in a mechanical agitator and the water was subjected to agitation.

The following was added:

- 3,800 g of micronized metallic aluminium (silver pigment),

- 3,800 g of mother-of-pearl powder,

- 400 g of fluorescent yellow pigment, - 8 kg of carboxymethylcellulose (CMC).

The system was kept under agitation for 10 minutes, water was added until reaching a volume of 750 litres and then the system was left under agitation for other 50 minutes, that is, until the CMC dissolved completely. Always keeping the system under agitation, 80 litres of coagulant solution containing 16 litres of 18% aluminium polychloride solution were added to this solution/suspension.

The addition of aluminium salt caused the coagulation of the coloured CMC. The suspension of silver coagulate was screened with a wire sieve having a 3 mm mesh (space between the wires) and poured into a machine chest containing 1000 kg of fibre suspension, called paper pulp and consisting of 53.7% of whitened cellulose obtained from eucalyptus, 10% of whitened cellulose obtained from fir, 10% of calcium carbonate, 20% of wastepaper and 1.6% of dry coloured patches. In order to improve the retention of fine elements, a water dispersion containing 4% of diketenic synthetic bonding agent and 0.7% of cationic starch was added to this pulp.

The manufacturing speed of the paper strip was 45 m/min. The composition of the pulp is illustrated in Table 1 , while the characteristics of the paper produced are illustrated in Table 2. EXAMPLE 5

This example concerns the manufacture of paper containing 2.12% of iridescent, anti-counterfeiting, flame-like white coloured patches with shot- effects, which, according to the relative humidity of the environment, change colour shifting from light blue to pink. 450 litres of water at ambient temperature were introduced in a mechanical agitator and the water was subjected to agitation. The following was added:

- 3 kg of titanium dioxide, rutile variety pigment,

- 3 kg of iridescent pigment obtained from the micronization of mica, - 15 kg of carboxymethylcellulose (CMC).

The system was kept under agitation for 10 minutes, water was added until reaching a volume of 1350 litres and then the system was left under agitation for other 50 minutes, that is, until the CMC dissolved completely. Always keeping the system under agitation, 1 kg of cobalt chloride (CoCI₂"6H₂O) diluted in 30 litres of water followed, after 5 minutes of agitation, by 150 litres of coagulant solution containing 50 litres of 18% aluminium polychloride solution were added to this solution/suspension. The addition of aluminium and cobalt salts caused the coagulation of the CMC containing the pigments. The suspension of shot-effect coagulate (pink/light blue) was screened with a wire sieve having a 3 mm mesh (space between the wires) and added into a machine chest containing 1000 kg of fibre suspension, called paper pulp. The fibre suspension consisted of 53.2% of whitened cellulose obtained from eucalyptus, 10% of whitened cellulose obtained from fir, 10% of calcium carbonate, 20% of wastepaper.

The pulp obtained in this way was coloured with black using 5% of direct black on the pulp, and after 10 minutes of agitation 2% of aluminium polychloride was added as fixing agent. It is important to remember that the same effect can be obtained by using carbon black as an alternative to direct black. The dye was kept in contact with the cellulose suspension under slight agitation for 20 minutes and then 2% of aluminium polychloride was added thereto.

After other 20 minutes, 5% of dry, shot-effect, silver patches was added. A water dispersion containing 4% of diketenic synthetic bonding agent and

0.7% of cationic starch was added to this pulp.

The manufacturing speed of the paper strip was 45 m/min.

The composition of the pulp is illustrated in Table 1 , while the characteristics of the paper produced are illustrated in Table 2. EXAMPLE 6

This example concerns the manufacture of paper containing 0.6% of transparent light blue-violet coloured patches.

150 litres of water at ambient temperature were introduced in a mechanical agitator, the water was then subjected to agitation and the following was added:

- 500 g of food dye patent blue V E 131 ,

- 500 g of Sudan red dye insoluble in aqueous systems but soluble in organic solvents,

- 500 g of Sudan blue dye insoluble in aqueous systems but soluble in organic solvents,

- 100 g of PG-643 PF/A orange fluorescent flame-like dye produced by Prochima,

- 400 g of optical bleaching agent Tinopal ABP produced by CIBA,

- 3 kg of hydroxyethylcellulose. The system was kept under agitation, water was added until reaching a volume of 450 litres and then the system was left under agitation for other 50 minutes, that is, until the colloid dissolved completely.

The suspension of light blue/blue coagulate was screened with a wire sieve having a 3 mm mesh (space between the wires) and added into a machine chest containing 1000 kg of fibre suspension, called paper pulp. The fibre suspension consisted of 54.7% of whitened cellulose obtained from eucalyptus, 10% of whitened cellulose obtained from fir, 10% of calcium carbonate, 20% of wastepaper.

After other 15 minutes 0.6% of dry light blue-violet coloured patches was added thereto.

A water dispersion containing 4% of diketenic synthetic bonding agent and

0.7% of cationic starch was added to this pulp.

The manufacturing speed of the paper strip was 45 m/min.

Table 1 below sums up all the elements that make up the compound described in the examples, suitable for manufacturing paper according to the invention.

The characteristics of the paper produced in this way are illustrated in Table 2.

TABLE 1 : Composition of the paper

TABLE 2: Characteristics of the paper obtained

The paper described in Example 6, patterned with light blue/violet patches, if tested in contact with organic solvents originates, near the patches, a typical red/violet/blue halo due to the solution and diffusion of the Sudan red and blue. The fluorescent yellow-orange is evidenced by Wood's light. In the various examples described, the temperature of the colloid solution, in which the coloured patches are usually generated, is usually included between 10° and 90⁰C.

Claims

1) Compound for manufacturing paper or cardboard including identification elements organised in patches, said compound comprising a mixture consisting of a cellulose pulp in water, characterised in that said mixture also comprises: a colloid solution and/or dispersion with the addition of a solution and/or dispersion of dyes or colour reagents, and/or tracer substances, comprising at least one colloid, said colloid solution and/or dispersion being able to be condensed using one or more coagulant substances, said condensable solution being able to be reduced to patches including coloured substances and/or tracer substances that can be dispersed in said compound through mechanical agitation means.

2) Compound according to claim 1), characterised in that said solution of said at least one colloidal substance comprises carboxymethylcellulose.

3) Compound according to claim 1), characterised in that said at least one colloidal substance is animal gelatine.

4) Compound according to claim 1), characterised in that said at least one colloidal substance is polyvinyl alcohol. 5) Compound according to claim 1), characterised in that said at least one colloidal substance is starch.

6) Compound according to claim 1), characterised in that said at least one colloidal substance is a synthetic colloid.

7) Compound according to claim 1), characterised in that said patches are shaped and include tracer substances.

8) Compound according to claim 2), characterised in that said carboxymethylcellulose is present in a percentage included between 1 and 10%.

9) Compound according to claim 1), characterised in that said dyes are coloured organic pigments.

10) Compound according to claim 9), characterised in that said organic pigments are fluorescent and/or phosphorescent pigments.

11) Compound according to claim 9), characterised in that said organic pigments are transparent and/or opaque. 12) Compound according to claim 9), characterised in that said organic pigments consist of cobalt blue pigment.

13) Compound according to claim 9), characterised in that said organic pigments consist of an apple green pigment.

14) Compound according to claim 9), characterised in that said organic pigments are soluble in organic solvents.

15) Compound according to claim 9), characterised in that said organic pigments consist of a fuchsia pigment.

16) Compound according to claim 9), characterised in that said organic pigments are not soluble in water, but are soluble in organic solvents. 17) Compound according to claim 9), characterised in that said organic pigments consist of carbon black.

18) Compound according to claim 1), characterised in that said dyes are inorganic pigments.

19) Compound according to claim 18), characterised in that said inorganic pigments consist of titanium dioxide.

20) Compound according to claim 18), characterised in that said inorganic pigments consist of metallic aluminium and/or bronze.

21) Compound according to claim 18), characterised in that said inorganic pigments consist of mica. 22) Compound according to claim 18), characterised in that said inorganic pigments are iron oxides.

23) Compound according to claim 1), characterised in that said at least one coagulant substance is aluminium sulphate.

24) Compound according to claim 1), characterised in that said at least one coagulant substance is aluminium polychloride.

25) Compound according to claim 1), characterised in that the temperature of the solution of said colloids is included between 10° C and 90⁰ C.

26) Compound for manufacturing paper or cardboard according to any of the preceding claims, characterised in that it comprises components according to the formulation of Example 1.

27) Compound for manufacturing paper or cardboard according to any of the preceding claims, characterised in that it comprises components according to the formulation of Example 2. 28) Compound for manufacturing paper or cardboard according to any of the preceding claims, characterised in that it comprises components according to the formulation of Example 3.

29) Compound for manufacturing paper or cardboard according to any of the preceding claims, characterised in that it comprises components according to the formulation of Example 4.

30) Compound for manufacturing paper or cardboard according to any of the preceding claims, characterised in that it comprises components according to the formulation of Example 5.

31) Compound for manufacturing paper or cardboard according to any of the preceding claims, characterised in that it comprises components according to the formulation of Example 6.

32) Method for manufacturing patterned paper or cardboard, characterised in that it comprises the following operations: a) adding water at ambient temperature into a container provided with a mechanical agitator; b) adding one or more organic or inorganic pigments to said water subjected to agitation; c) adding to said water an identification element selected among an optical bleaching agent and/or a fluorescent substance and/or a dispersible dye non soluble in water, but soluble in organic solvents, and/or a substance that changes colour when in contact with specific reactive substances like indicator dyes that are sensitive to pH, relative humidity, oxidants, reducing agents, gamma iron oxides, phosphorescent pigments; d) adding a c olloid to said water; e) keeping under agitation for a predefined time the system resulting from the operations from a) to e), at a temperature included between 10° and 90⁰C; f) adding other water until said colloid dissolves; g) adding a n aqueous solution containing a coagulant substance; h) screening the suspension of coagulated product obtained up to this moment with a wire sieve; i) introducing said suspension in a machine chest containing a cellulose- based or cellulose paste-based paper pulp for the production of paper;

I) adding a water dispersion of synthetic bonding agent; m) adding a diluted cationic starch solution to said suspension. 33) Method according to claim 32), characterised in that after step h) the pulp obtained in this way is introduced in an extrusion die and then cut at the exit of said extrusion die.

34) Method according to claim 33), characterised in that a diluted aqueous dispersion of coagulant for the preservation of the identification elements is added to the cut identification elements.

35) Method according to claim 32), characterised in that the screening operation of step h) is performed using a fabric positioned before the point where the coloured patches are fed into the paper pulp.