 PROCESS FOR PRODUCING PAPER IMPREGNATED BY A SUPERCRITICAL PRESSURE FLUID
专利摘要:
The invention relates to the field of papermaking and more particularly relates to a method of manufacturing a paper impregnated with a molecule of interest, in particular a colored paper and the associated product, that is to say a impregnated paper, said process using a supercritical pressure fluid. Such a paper, in particular colored paper, obtained from a paper pulp or paper formulation comprising latex, does not disgorge in contact with water. 公开号:FR3048982A1 申请号:FR1652246 申请日:2016-03-16 公开日:2017-09-22 发明作者:Celine Noel；Christophe Chartier；Gael Depres；Jean-Marie Vau；Olivier Poncelet；Aurelien Auger 申请人:Commissariat a lEnergie Atomique CEA；Commissariat a lEnergie Atomique et aux Energies Alternatives CEA；Arjo Wiggins Fine Papers Ltd； IPC主号:
专利说明:
The invention relates to the field of papermaking and more particularly to a method of manufacturing a paper impregnated with a molecule of interest, in particular a colored paper as well as the associated product, that is to say an impregnated paper and in particular a colored paper whose color does not disintegrate in contact with water, in other words a paper whose molecules d In particular, dyes are stable in the paper in contact with water. The means according to the invention and in particular the paper, in particular the colored paper produced can be implemented in many fields of application including packaging in general, papers intended for food contact (packaging paper, absorbent papers and especially napkins, tablecloths), papers used in the field of hygiene, wiping, papers intended for outdoor use such as advertising posters, envelopes, and also printing papers , including the fields of communication, advertising, publishing, arts and creative hobbies, secure papers such as banknotes, technical papers especially intended for scientific use such as membrane filters, papers intended for example medical tests, labels .... The colored papers currently produced present problems of disgorging dyes when they are wet. This is particularly troublesome for applications in the fields of packaging, particularly in the field of luxury, but also in the field of food packaging, the field of absorbent papers, papers for hygiene or technical papers. The principle of papermaking has evolved very little since its invention. From an aqueous suspension of cellulosic fibers, a sheet is formed on a fabric by dripping: this fibrous mat is then pressed and dried to remove excess water. The manufacture of the colored paper then consists in adding to the fibrous suspension dyes themselves soluble or dispersed in water and having sufficient affinity with the fibers so that a large part remains in the fibrous mat during the dewatering . Fixatives are used most of the time to improve the bond between the fibers and the dyes. Alternatively, the colored papers are obtained by coloring the surface of the paper for example using the size-press. In the same way white papers can be treated with brighteners. Adding dyes to the dough is the most common method used to obtain colored papers. In this case, the dyes are generally added to the dough, either in the pulper or in the mixing vat. Depending on the fibrous material to be colored and the intended use for the paper, different types of dyes are used such as basic dyes (anionic dyes), direct dyes, or acid dyes. In addition, fixing agents and other adjuvants are used to improve dye fixation and obtain better results. Despite this, a significant amount of dye is lost in the water circuits. Such a process generates aqueous pollutant discharges whose impact is harmful to the environment and requires the treatment of effluents. Moreover, despite the progress made in terms of fixation, these hydrophilic dyes tend to disgorge when the paper is wet. The colored paper manufacturing process further generates a portion of dyes simply trapped in the fibrous network. These dyes will disgorge more easily that they have not created chemical bonds with the fibers. When the surface of the paper is stained in the size press, the colorants are added to the "sauce" of the press. Surface coloration is therefore limited to certain special cases because it is difficult to obtain an even coloring of the paper. But this method has the advantage of eliminating the presence of dyes in the water circuits. The main impact of staining on the environment is the aqueous pollutant release in aquatic environments. Usually, paper mills work by "campaigns" and first produce the colored papers with the lightest colors and progressively move to the darker colored papers. However, after the production of the darker colored papers, the water circuit must be washed before a new production campaign. Colored sewage must be treated in a complex facility before it can reach streams. In addition, several times a month, the pipelines are chemically treated to remove deposits and dyestuff residues. Some plants use elemental chlorine and hypochlorite for this chemical treatment. In addition, such processes of paper coloring campaigns generate large stocks of paper necessary to make profitable production phases. Therefore, the paper mills must produce and store, for each color, and for each type of paper and each grammage, several coils or reams of each shade thus produced to meet the needs of customers between two production campaigns. In the 1980s, for example, dyes with improved water resistance were proposed [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] ] [11], Despite this, these dyes, hydrophilic or dispersed in water, keep a tendency to disgorge when the paper comes into contact with water. Unlike textile dyeing, especially cotton, which includes a washing step to remove unbound dye molecules, the process of making colored paper that does not involve a washing step generates a part of molecules simply trapped in the fibrous network. These molecules disgorge all the more easily in contact with water they have no real anchor on the fibers. Finally, more recently an article published in 2014 in the journal Fibers & Textiles in Eastern Europe [15] has proposed, in order to overcome the problem of disgorging, a method of coloring paper which relies on the use of reactive dyes, that is, capable of forming covalent bonds with cellulose. However, reactive dyes are not used to date in the paper industry because the reaction parameters are not compatible with the paper process. This article describes dyes usable at neutral pH, exhibiting almost total retention during a contact time compatible with the process and with a specially synthesized retention agent. The paper produced then has good properties of resistance to bleeding. This interesting alternative is currently not industrializable because neither the dyes nor the retention agent used are commercial products. Alternatives to conventional paper coloring processes have also been sought over time to improve the quality of paper coloring and facilitate industrial production. As such, some ways of evolution have been proposed for the methods of producing colored paper. Thus, a 1931 patent [12] describes calender staining with an acidic dye to which is added a compound of the group of guanidines in excess of the theoretical amount necessary for the precipitation of the dye and this in order to improve the character not disgorging paper. The document [13] also describes a post-coloring process: the paper roll is unwound in order to be dipped in a coloring bath; the surplus is removed and the paper is dried. The dye is then fixed by a size-press treatment. The paper is finally dried, calendered and rewound. Document [14] describes a dye composition containing both pigments (<200 nm) and a polymeric binder in the form of particles. This composition makes it possible to form a thin coloring layer on the surface of the support, having good properties in terms of color and strength. These techniques all have the advantage of being economic and ecological. On the other hand, they lead to obtaining a non-uniformly colored paper in the thickness of the sheet. The present invention proposes a solution to the problem of the observed bleeding of colored papers when they are brought into contact with water, which makes it possible to use commercially available dyes and uses an impregnation dyeing mode by means of dyeing. a fluid under supercritical pressure. The process according to the invention uses dyes which may be hydrophobic (so-called disperse dyes) which, insofar as they have no or low affinity with water, will not tend to migrate into the water at all. its contact if they are properly trapped within a hydrophobic polymeric network contained in the fibrous mat of the paper or on the surface of the paper. In the context of the invention, these hydrophobic coloring molecules are integrated and fixed within the network of hydrophilic fibers and homogeneously, to the heart of the paper and / or surface. The invention thus describes a multi-step manufacturing process which results in an impregnated cellulose product, in particular an intensely and uniformly colored product whose color does not fade on contact with water. Thus, a first step of the method consists in manufacturing on a traditional paper machine a white sheet containing a polymeric additive in bulk and / or surface added in the form of latex, and preferably added in bulk during the manufacture of paper. This white sheet is then impregnated, in particular stained with hydrophobic dyes, by impregnation with fluid (in particular CO 2) at supercritical pressure. The supercritical CO 2 impregnation could also be mentioned in the prior art for coloring papers, since the technique was known for the coloration of polymeric supports such as hydrophobic synthetic textiles. Staining of natural fibers such as cotton or paper cellulose poses problems of affinity between the various compounds in the presence (supercritical CO2, hydrophilic fiber and hydrophilic and hydrophobic dyes). Numerous studies have attempted to solve this technical problem for cotton textiles in particular, none of which has at the moment resulted in a satisfactory solution for industrialization. The coloring of a paper medium by means of a supercritical fluid has been the subject of rare studies. Thus, the document [16] describes, inter alia, the impregnation of a paper with hydrophobic dyes via the use of a supercritical fluid. The substrate described in this document is any paper whose constituent elements, essentially cellulose fibers, have no particular affinity for the hydrophobic dye. This results in a low intensity coloration where the dye is precipitated without any fixation within the fibrous network. The patent application [17] proposes a method for staining the cellulose fibers in supercritical CO 2 medium with a hydrophobic and uncharged dye comprising at least one step consisting in bringing said fibers into contact with an effective amount of at least one mono organo. primary urea under conditions conducive to the establishment of covalent bonds of carbamate type between the cellulose and the molecules of said organourea. This method has several disadvantages. Firstly, the reaction between the mono-organo-urea and the cellulose involves a gassing of NH3 which generates a risk of overpressure in the reactor. In addition, the proposed mechanism causes a modification of the cellulose, its morphology, as well as a destruction of a part of the hydrogen bonds of the fibrous network, bonds which ensure the initial mechanical properties of the sheet. The document [18] relates to the production of a colored paper by supercritical CO impregnation after the manufacture of a white sheet containing amphiphilic molecules. Thus, the product described in this document does not offer a totally satisfactory solution to the disgorging problem insofar as the amphiphilic molecules themselves having a hydrophilic character will tend to be entrained during contact with water and take the coloring molecules, although hydrophobic, with them. In addition, such a paper containing a substantial proportion of surfactant will have a degraded mechanical strength and poor resistance to penetration of water. Thus, no paper colored by supercritical CO2 impregnation with hydrophobic dyes described to date in the prior art does not fully meet the requirements for the prospect of industrial production. If the attempts made showed that the supercritical fluid impregnation technique offered attractive industrial prospects, the difficulties encountered in choosing the dyes and in the composition of the paper that could be treated by this technique did not occur. have not been resolved to consider this approach satisfactorily. Among the investigated lines of research relating to dyeing processes or the composition of dyes or paper, considering the advantages that the technique of impregnation with supercritical fluid in the industrial and ecological field, the inventors have been interested in alternative formulations of the fibrous pulp for papermaking that are likely to improve the quality of the coloring obtained from the paper by providing a stable color in contact with water and homogeneous to the core and / or the surface of the paper. In addition the inventors have considered that the conditions thus proposed could also be implemented for the impregnation of paper with other molecules of interest when they are soluble in a supercritical pressure fluid, in particular hydrophobic molecules. The original solution proposed according to the invention consists in impregnating, in particular in dyeing, a paper containing a polymeric additive introduced in latex form (hereinafter also referred to as "latex") introduced in bulk and / or applied on the surface. If it is known to use latex in the papermaking field, it is with the aim of modifying the properties specific to the paper produced and in particular its mechanical properties, on the one hand, and under conditions of contribution that stand out those proposed in the context of the invention, on the other hand. Latexes are thus most often used on the surface of the paper as binders of a pigmented layer, which is deposited by size-press or with the aid of a coater which makes it possible to improve various properties such as appearance ( brightness, whiteness, opacity), print rendering (contrast, definition of the image), reducing roughness and surface porosity or even providing the paper with specific properties such as barrier properties, insulating properties, etc. They can also be used to chemically consolidate nonwoven products. The latices are then introduced into the support by various techniques: impregnation (size-press or baths), spraying or coating according to the expected result. The consolidation action then develops in a dryer or a suitable oven. In contrast, the addition of latex to the wet portion of the paper machine so that it is evenly distributed in mass in the produced paper, i.e. throughout the thickness of the fibrous network although it has been the subject of several studies, has remained limited to the phase of the manufacture of the sheet of paper. By way of example, [19] and [20] both relate to a procedure for adding latex to the paper mass and its retention via cationic flocculation agents to improve the mechanical strength properties. of the product obtained. The document [21] relates to a fibrous substrate (containing at least 50% of cellulose) saturated with a latex in order to produce a paper that can be used in an environment that must remain free of contamination. The document [22] describes the addition of latex in the mass of a tracing paper to improve its mechanical properties of resistance to folding and traction, while the document [23] proposes the addition of a copolymer obtained by polymerizing one or more unsaturated monomers and a carbohydrate compound to improve the mechanical strength. Finally, the document [24] relates to a hydrophobic planar support, comprising at least the following elements: a fibrous mattress based on cellulose fibers and glass fibers, a fluorinated resin conferring hydrophobic properties on the fibrous mat, a polymer-type binder latex form for bonding glass fibers to cellulose fibers. None of these documents describing the use of latex addresses the interest that could have a composition used in the manufacture of a product by the paper route, in which the provision of a polymer in the form of latex would contribute actively to the effectiveness of the impregnation carried out in supercritical pressure fluid, in particular to carry out a coloration after having completed the production of the paper, and in particular to prevent the disgorging of the dyes / dyes in contact with the water and to allow its homogeneous distribution at heart and / or on the surface of the paper. These documents do not address more the problem of the resistance of the coloration or the impregnation by molecules of interest, in contact with water when said coloration or impregnation is obtained by implementing a method after the paper was made. Thus, unexpectedly, the colored paper or impregnated with a supercritical pressure fluid, after a process implemented after the manufacture of paper and using an impregnation step by means of a supercritical pressure fluid when said paper has been made from a pulp incorporating, in its core, a polymer-based composition in the form of a latex, or when the manufactured paper has, on the surface, a layer of such a polymer, has a very high intensity of coloration and also a homogeneity of the coloration in the thickness when said polymer is introduced in bulk, equivalent mechanical properties or even improved compared to a conventional impregnated or colored paper, as well as a resistance to disgorging at remarkable water. The subject of the invention is therefore, according to a first aspect, a process for impregnating paper by means of a supercritical pressure fluid, in particular such a process for coloring paper and a method of manufacturing impregnated paper, especially colored paper. , as well as, in a second aspect, an impregnated paper, in particular colored, uniformly throughout its thickness and / or its surface and whose color does not disintegrate in contact with water. The invention makes it possible to produce an impregnated paper, in particular colored paper, in a more ecological way (without releasing molecules, in particular dyes in the waters of the paper machine, wasting dye, incorporating an easy recycling of the CO2 used as dyeing vector) but also economic by eliminating color campaign operation in paper mills, thereby reducing the need for stockpiling and enabling on-demand production on minimum quantities well below what is possible propose to date. The subject of the invention is therefore a process for impregnating a paper, in particular a coloring process, by means of a supercritical pressure fluid, characterized in that it comprises a step of impregnation by placing in contact with one another. a paper with molecules of interest in the presence of a fluid in the supercritical or subcritical state, said paper comprising, (i) at heart, a polymeric additive introduced in latex form and / or, (ii) ) at the surface, a polymeric additive applied in latex form, identical to or different from the polymer of the latex possibly present in the core and / or a molecule, in particular a polymer, which can be impregnated with a molecule of interest, in particular a hydrophobic molecule by means of the supercritical pressure fluid. According to an advantageous embodiment of the invention, the paper intended to be brought into contact with the molecule of interest comprises, in the middle and / or on the surface, a polymeric additive introduced in latex form. According to a particular embodiment of the invention, the paper intended to be brought into contact with the molecule of interest comprises at heart a polymeric additive introduced in latex form. Advantageously, the coloring process is carried out on dry paper. Preferably, the paper is in the form of a sheet, said sheet being able to take the form of a continuous strip or a coil. In a particular embodiment of the invention, the additional surface treatments possibly applied to the sheet produced as well as the finishing operations (calendering, smoothing, coating, coating) were carried out prior to its impregnation, in particular prior to its coloring. In a particular embodiment, the supercritical pressure fluid used in the staining process is carbon dioxide. In a particular embodiment, said fluid is used in the supercritical state for the impregnation stage or alternatively in the subcritical state. In a particular embodiment, the carbon dioxide is mixed with an organic solvent, for example an alcohol, in particular ethanol. For example, the supercritical pressure fluid is CO 2 mixed with 1 to 20% by weight of ethanol. In another particular embodiment, the fluid is chosen from ethylene, propylene, ethane, propane, butane, nitrous oxide, fluorocarbons or is a mixture of one of these fluids with a fluid. suitable organic solvent such as an alcohol, for example ethanol. For the purposes of the invention, the term "supercritical pressure fluid" or "convenience" in the absence of reference to the specific conditions described below is used to describe a compound chosen for its ability to solubilize the molecules of the invention. interest, in particular hydrophobic molecules and preferably dyes, when it is brought to a supercritical state or alternatively to the sub-critical state. In the subcritical state, only the pressure is supercritical. In the supercritical state, temperature and pressure are supercritical. These states are therefore characterized by determined temperature and pressure conditions known to those skilled in the art for each type of fluid. By way of example, carbon dioxide in the supercritical state (CO 2 SC) is obtained at a temperature greater than or equal to 31 ° C. and at a pressure greater than or equal to 75 bars. Preferably, for carrying out the invention, the temperature is greater than or equal to 70 ° C. or 100 ° C. It is preferably less than 200 ° C, for example less than or equal to 150 ° C, especially in a range of 70 ° C to 130 ° C. Preferably, the pressure of the supercritical fluid is greater than or equal to 200 bars. This pressure is advantageously less than 1000 bar and in particular less than or equal to 400 bar. Advantageously, the supercritical CO 2 is obtained within the scope of the invention, at 100 ° C. and 300 bar. The carbon dioxide in the subcritical state is obtained at a temperature below 31 ° C and at a pressure above 74 bar. To do this, the temperature may in particular be less than 31 ° C. and the pressure may be greater than or equal to 200 bars. The pressure is advantageously less than 400 bar and advantageously of the order of 300 bar. The transition to the supercritical fluid state of CO 2 is described in the examples. According to a particular embodiment, the supercritical state is reached by gradually increasing the pressure in the reactor. In the same way, the C02 can be prepared in the subcritical state or any other supercritical pressure fluid among the examples given, by applying similar conditions for a temperature and a pressure determined according to the fluid. The temperature and pressure conditions of the fluid in the supercritical state can also be adjusted by those skilled in the art, depending on the solubility of the molecules used in particular for the coloration and, if appropriate, as a function of their sensitivity to the operating conditions, for example at a high temperature. The method thus used makes it possible to obtain impregnated papers, in particular colored papers which show a stable impregnation and in particular do not disgorge in contact with water. When the paper is treated with the supercritical pressure fluid to be colored, dye molecules or reactive disperse dyes are advantageously used. In the context of the invention, the coloring molecules are constituted by a dispersed hydrophobic dye or a mixture of dispersed hydrophobic dyes, the dye (s) being optionally pretreated to remove the dispersing agents, the dye (s) being brought (s) from 0.1% to 10%, for example from 1 to 10%, in particular from 1% to 5%, in particular from approximately 2.5% to 5% by dry weight of dye (s) relative to the weight of the paper or, if the dispersing agents are present, from 0.1 to 20%, in particular from 2 to 10% by dry weight of dye (s) relative to the weight of the paper. The dyes employed are advantageously commercially available dyes, such as those illustrated in the examples. These are hydrophobic dyes presented or prepared by the operator in the form of dispersible powder in water or liquid already dispersed in water and used as such or after treatment (for example by extraction with water). acetone) to remove dispersants. When the dye is used with the dispersant, the formulation usually comprises 50% dispersants relative to the total weight of said dye formulation (s). By way of illustration, the dyes of the disperse dye type can be used in the context of the dyeing process, these dyes being characterized by the absence of solubilization groups and a low molecular weight. These dyes may be simple azo compounds, anthraquinone compounds, methine-, nitro- and naphthoquinone-type dyes. The relative amount of dye supplied to the reactor for carrying out the dyeing process according to the invention varies according to the amount of paper to be treated and, if appropriate, the properties of the paper. In a particular embodiment of the invention, the dye or the mixture of dyes is provided at a level of from 0.1% to 10%, for example from 2% to 10% by dry weight of dye (s) relative to the weight. in particular 2.5 to 5% by dry weight of dye (s) relative to the weight of the paper or, if the dispersing agents are present, from 0.1 to 20%, in particular of 2 to 10% by dry weight of dye (s) relative to the weight of the paper. Other hydrophobic molecules may also be added or substituted for the dyes for impregnating the paper by means of the impregnation process, such as optical brighteners, fluorophores, antioxidants, ultraviolet absorbing molecules, surfactants, polymers, in particular polymers adapted to the transparency of paper, that is to say polymers soluble in CO 2 CS (having a low molecular weight) and whose refractive index is close to that of cellulose (1, 47) paraffin waxes and other molecules with particular functional characteristics such as conductive or insulating electrical products, conductive products or thermal insulators. In a particular embodiment of the invention, an intense coloration is obtained when it is measured by its K / S value (determined by the Kubelka-Munk equation), for example a coloration whose K / S is greater than or equal to 3, advantageously greater than or equal to 5. The impregnation process, in particular staining, according to the invention is advantageously a two-phase process or steps: the first step is that of impregnating the paper with the dye or the molecule of interest chosen and the second stage is a scan with clean supercritical pressure fluid (that is to say, not loaded with dye, respectively molecule of interest to impregnate) so as to remove the dye, respectively the molecule not impregnated paper. According to a particular embodiment of the invention, the process for impregnating a paper, in particular with a dye or a mixture of dyes by means of a supercritical pressure fluid, comprises the steps of: a) Loading in a reactor, dry paper to be impregnated and a determined amount of molecule of interest, in particular dye or dye mixture, followed by closure of the reactor; b) charging of the fluid, in particular CO 2, to the storage pressure of the fluid, c) Heating the reactor and / or pumping the fluid until the conditions of temperature and pressure for solubilization of the molecule of interest, including dye (s), in the fluid to the supercritical or sub-critical state and the impregnation of the molecule of interest, in particular of the dye (s), in the thickness of the paper, d) Circulation of the supercritical pressure fluid loaded into a molecule of interest, in particular in dye (s), through s, e) Sweeping with clean fluid and supercritical pressure, under conditions of supercritical temperature and pressure or where appropriate subcritical, identical or different from those of step c., to eliminate the molecule d non-fixed interest, in particular the non-fixed dye (s), f) Depressurization of the reactor to precipitate the dye (s) remaining and allow the passage of the fluid in the supercritical or sub-standard state Critical in the gaseous state, g) Recovery of dry paper, stained in the core and / or on the surface. The fluid is said to be "clean" insofar as it has not been used in the context of steps b) to d) above and is therefore not loaded with the molecule of interest to be impregnated. In a particular embodiment of the process thus defined, the supercritical pressure fluid is carbon dioxide and the temperature during the supercritical pressure impregnation phase is greater than or equal to the ambient temperature and in particular less than or equal to 200 ° C. C, for example less than or equal to 150 ° C, in particular between 70 ° C and 130 ° C and the pressure during the supercritical pressure impregnation phase is greater than or equal to 75 bar and less than 1000 bars, in particular in a range from 150 bar to 500 bar, preferably 300 bar. The stage of passage of the fluid in the supercritical state or in the subcritical state can be done by a progressive increase of the pressure in the reactor or, alternatively, by a rapid increase of the pressure to reach the supercritical pressure. The heating and / or pumping step can be arranged depending on the supercritical or sub-critical conditions to be reached. If heating and pumping are done, they can be done in any order. For example, it is possible to achieve temperature conditions of 100 ° C. and a pressure of 75 bars without a pumping step. The conditions of temperature lower than 31 ° C and pressure of 300 bars can be achieved without carrying out the heating step. The pumping of the fluid is also advantageously implemented when the paper is introduced into the reactor in the form of a coil: the pumping allows the circulation of the supercritical fluid (forced flow) in the reactor and thus promotes the coloration in the thickness of the reactor. the coil radially from the inside out to the heart of the paper. In order to produce the paper which is ready to be impregnated, in particular colored, by means of the process according to the invention, a paper pulp based on cellulose fibers suspended in the water is prepared according to the methods well known to those skilled in the art. water, and is incorporated in the mass in the suspension a polymeric additive in the form of latex composition. Alternatively, if the latex is only to be provided on the surface of the paper, it is for example applied by a size-press step during a processing step after the preparation of the paper sheet. Thus, according to a particular embodiment, the paper can be obtained from a pulp comprising: i) a fibrous suspension based on cellulose fibers in water at a cellulose fiber concentration of 2 to 50 g / l preferably from 15 to 25 g / l, the cellulose fibers being optionally composed of a mixture of cellulose fibers different in origin and / or size, said suspension being refined to at least 17 ° SR, preferably 20 ° SR to 45 ° SR, for example 30 to 35 ° SR. ii) a polymeric additive in latex form, said latex being added to the fibrous suspension in a proportion of 0.5 to 50% by weight of dry product, in particular from 0.5 to 20% by weight of dry product, so preferred from 1 to 15% by weight of dry product and even more preferably from 1 to 10% or from 5 to 10% by weight of dry product, based on the dry weight of the cellulose fibers. Refining measured in Shopper-Riegler degree is adjusted according to the mechanical or optical properties of the paper. Alternatively, the paper can be obtained: i) from a paper pulp comprising a fibrous suspension based on cellulose fibers in water at a concentration of cellulose fibers of 2 to 50 g / l preferably at 25 g / l, the cellulose fibers being optionally composed of a mixture of cellulose fibers different in origin and / or size, said suspension being refined to at least 17 ° SR, for example 20 SR at 45 ° SR, preferably 30 ° SR to 35 ° SR, and optionally a polymeric additive in latex form, said latex being added to the fibrous suspension in a proportion of 0.5 to 50% by weight of product dry, in particular from 0.5 to 20% by weight of dry product, preferably from 1 to 15% by weight of dry product and even more preferably from 1 to 10% or from 5 to 10% by weight of product dry weight, relative to the dry weight of the cellulose fibers and ii) according to a process for the manufacture of paper comprising a step of depositing on the surface of the paper a polymeric additive in latex form in a proportion by weight of 0.5 to 25% based on the weight of the paper. Whether it is introduced in bulk into the paper pulp or deposited on the surface of the prepared paper, the latex used in the context of the invention is an aqueous dispersion of polymer, in particular of copolymer, or an aqueous polymer emulsion, in particular particular copolymer. In a particular embodiment, the latex is an ionic dispersion of polymer, in particular of copolymer. In another particular embodiment of the invention, the latex is a nonionic dispersion of polymer, in particular of copolymer. A polymer or copolymer for the preparation of the latex may be hydrocarbon, fluorocarbon or be of organosiloxane type; the monomers constituting the polymer may or may not be organized in the form of a three-dimensional network, before or after the implementation of the process for preparing the paper. It is therefore an example of thermoplastic polymers. By way of example, a latex used in the context of the invention may be crosslinkable (for example thermally crosslinkable or self-crosslinking) and used in crosslinked form. In a particular embodiment of the polymeric additive for use in latex form, the polymer particles consist of monomers or prepolymers capable of thermally polymerizing or via a chemical polymerization initiator contained in the particle. The latex obtained can then be in the form of an emulsion, as is for example the fluororesin latex. In a particular embodiment of the invention, the latex is an aqueous ionic dispersion of polymer particles, in particular of copolymer, optionally crosslinked or crosslinkable, in particular thermally crosslinkable or thermoplastic or self-crosslinking, in particular of which the chains comprise basic groups in the Lewis sense, for example ether, carbonyl, carboxyl or phenyl groups, or mixtures thereof, said polymer or copolymer having a glass transition temperature of less than 100 ° C., preferably in the range of -20 ° C. ° C at 90 ° C, in particular from 0 ° C to 60 ° C for example from 30 to 35 ° C. According to one particular embodiment of the invention, the latex is obtained from a copolymer of which at least one of the monomers is chosen from ether monomers, vinyl, styrene and acrylic monomers, in particular methacrylic and urethane monomers. and dienic. Particularly advantageously, the latex is a polymer selected from the group of styrene-butadiene copolymers, in particular a carboxylated styrene-butadiene copolymer of styrene-acrylic copolymers, for example a styrene-acrylic ester copolymer, copolymers of styrene-butadiene copolymers, acrylonitrile acrylic ester, ethylene vinyl acetate copolymers, ether-urethane copolymers, vinyl chloride-vinyl acetate copolymers, and vinyl chloride-vinyl acetate-ethylene copolymers. The inventors have observed that the selected latices advantageously have the capacity to swell in the supercritical pressure fluid, in particular in the CO 2 CS and consequently, they are all the better impregnated in the paper with the chosen molecule and in particular with the dye. Swelling is also promoted when the polymers have a low molecular weight, and / or have a large free volume, and / or a low crystallinity, and / or a low degree of crosslinking. It is important for the realization of the invention that the polymer in the form of latex has a low glass transition temperature, and lower than the temperature of the supercritical conditions applied, especially less than 100 ° C and for example preferably comprised in the range from -20 ° C. to 90 °, especially from 0 ° C. to -60 ° C., for example from 30 ° to 35 ° C. The latex used is advantageously chosen so as not to negatively affect the mechanical properties, the aging and / or the printability of the paper sheet. It is also advantageously chosen so as not to hinder the manufacture of the paper sheet in the paper machine. To promote the attachment of the latex to the cellulosic fibers, the pulp or latex composition may further comprise a retention agent consisting of a cationic compound capable of binding the latex to the cellulosic fibers. Since the cellulose fibers are of a slightly anionic character, if the latex is also anionic, it creates ionic bonds with the cellulosic fibers via a cationic agent. Under these conditions, the latex is fixed (retained) in the mat or fibrous network during the dewatering step during the manufacture of the paper. When the latex is - more rarely - cationic it is able to attach itself spontaneously to the cellulose fibers. Such a retention agent is, for example, a cationic compound chosen from cationic flocculation agents, cationic resins capable of reacting with cellulosic fibers, in particular crosslinkable resins on cellulosic fibers, and cationic starch. Advantageously it is a cationic resin which is a polyamide-amine-epichlorohydrin resin (also called PAAE or PAE). In a particular embodiment of the invention, the cellulose fibers of the pulp are a mixture of fibers of different lengths selected from short fibers of length contained in the range of 0, there 0.49 mm, the medium fibers of length contained in the range of 0.5 to 1.5 mm and long fibers of length contained in the range of 1.6 to 3 mm. In another embodiment of the invention the proportion of cellulosic fibers of a first determined length is 40 to 50% and the proportion of cellulosic fibers of a second determined length is 60 to 50%, in particular the mixture consists of 40% long fibers and 60% short fibers or consists of 50% long fibers and 50% short fibers. In a particular embodiment of the invention, the ratio retention agent / latex expressed as a percentage of dry retention agent / dry mass of latex is chosen in a range of 0.1% to 20%, in particular of 0 , 1 to 15% and preferably from 0.1% to 13%. In particular, when the cationic retention agent is PAAE, said ratio can be in a range of 5% to 13% when the latex is anionic and in particular selected from the group of styrene-butadiene copolymers, in particular a styrene copolymer. carboxylated butadiene, styrene-acrylic copolymers, acrylic-acrylonitrile ester copolymers, vinyl ethylene acetate copolymers, ether-urethane copolymers and vinyl chloride-vinyl acetate copolymers ethylene, in particular is a latex as illustrated in the examples. Other compounds may be added to the pulp to adjust the composition depending on the paper to be prepared. These compounds are commonly used in the paper industry. It can be fillers (calcium carbonates, kaolin, talc, titanium dioxide), pigments, bonding agent, dry strength agent, wet strength agent, fluorescent agent, liquid or gas barrier product flame retardant. The subject of the invention is also a method of manufacturing paper impregnated with a molecule of interest, in particular colored paper, comprising the following steps: a. Preparation in a pulper of a paper pulp according to the modalities described above or in the examples which follow and preparation of the sheet of paper, b. Loading the paper, the molecule of interest, in particular the dye and the fluid into the reactor, said fluid being in particular CO2, at the fluid storage pressure, c. Heating the reactor and / or pumping the fluid until temperature and pressure conditions are obtained allowing the molecule of interest, in particular the dye (s), to dissolve in the fluid in the supercritical or subcritical state -critical and the impregnation of the molecule of interest, especially dye (s), in the thickness of the paper, d. Circulation of the supercritical pressure fluid loaded to the molecule of interest, in particular by dye (s), through the paper, e. Sweeping with clean fluid at supercritical pressure under conditions of supercritical or, where appropriate subcritical, temperature or pressure, identical or different from those of step c., To eliminate the molecule of unfixed interest, in particular the dye (s) not fixed, f. Depressurization of the reactor to precipitate the dye (s) remaining and allow the passage of fluid in the supercritical or subcritical state in the gaseous state, g. Recovery of dry paper, impregnated, especially colored, heart and / or surface. The invention also relates to the manufacture of a paper impregnated by means of a supercritical pressure fluid, in particular colored paper, comprising the following steps: a. Preparation in a pulper of a pulp as described herein, b. If necessary, adjustment of the prepared dough and / or dilution to the desired concentration, before being sent to the headbox for its homogeneous distribution especially on the canvas of a flat table, c. Draining of the pulp previously distributed on the fabric of the paper machine, the drainage being in particular carried out by gravity and by suction using suction boxes, to produce a sheet of paper, d. Spinning for example by means of a press composed of rolls and possibly of felts and drying for example by means of steam-heated cylinders of the sheet obtained in step c. to obtain a sheet whose moisture content is less than or equal to 7% e. If appropriate, applying a surface treatment to the dried sheet, for example a sizing with a sauce or a bath of determined composition, provided by a sizing press, f. If necessary drying in a post-drying area, g. If necessary, changing the surface state of the sheet by a calendering or smoothing, coating or coating operation, h. Impregnation, in particular staining, of the sheet obtained by carrying out the process according to the invention. The manufacture of the paper may comprise a step of physicochemical surface treatment of the paper sheet, in particular treatment by application, particularly by Prior to use, each latex was diluted to a solids content of about 10%, controlled and recalculated by a measure of solids. The pH of each latex was also adjusted to the pH of the fibrous suspension is about 7.1 and visual control is performed after a few hours or days to detect a possible destabilization of the solution. iii. Preparation of the retention agent The retention agent used is a cationic polyelectrolyte: a PAE type resin (cationic polyamide-epichlorohydrin), Kymene 617. In the same way as above, the PAE is diluted and its pH is adjusted. at 7.1. b) Study of the retention and optimization of the ratio [retention agent: latex] After performing the various preparations, the amount of PAE required for the total retention of each latex on the fibers is defined as follows: • Bottles suitable for centrifugation are filled with a known and identical amount of fibrous suspension. • In each of the bottles, a specified quantity of PAE is then added. Thus, a series of bottles respectively containing 0%, 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1.1%, 1.3% and 1.5% dry PAE / mass of the dry fibers is prepared and stirred for 4 min at using an orbital shaker. • The latex is then added to each flask at a level of 10% dry / mass of the dry fibers. An additional bottle, called control, containing water to which the same amount of latex will be added, is also prepared. The solutions are again stirred for 4 min using the orbital stirrer. • A centrifugation of all the bottles is carried out and the reading of the results is rendered. Thus, the control bottle is first examined to verify that no sedimentation of the latex is visible. Then the supernatants of each of the vials are examined, and the ratio [retention agent: latex] is determined by the presence of a perfectly transparent supernatant without Tyndall effect. Thus, the ratios [retention agent: latex] have been defined for each of the latices and are reported in the following Table 2: Table 1: Technical data of the various latexes tested. Table 2: Ratios [retention agent: latex] determined by each pair PAE + latex. c) Preparation of the forms For each of the latices, several forms were prepared containing 1%, 5% or 10% of latex (dry / fiber mass). To do this, in a vessel with mechanical stirring, the required amount of PAE, predetermined in the previous step, was added to the suspended fibers. This mixture was stirred for 4 min. The latex was then added. The mixture was homogenized again 4 min before proceeding to the production of the sheet. A sample can be made and centrifuged in order to check the good retention of the latex on the fibers. In order to manufacture the form, the amount of pulp required, a dilution in a form apparatus, a stirring, a filtration, a pressing and a drying were successively carried out. d) Characterization of the mechanical properties of the forms Various properties characteristic of the form were evaluated: the grammage and the specific hand or volume, the resistance to bursting and tearing, but also the breaking force, the elongation as well as the breaking length. All these characteristics were compared with those of a control formone containing only cellulose and collected in Table 3 below. Table 3: Evaluation of different mechanical properties of the forms in which were introduced 1, 5 or 10% latex (dry weight / dry weight of the fibers). Thus, it was verified that no degradation of the mechanical properties was observed following the addition of one or the other latex in the sheet. Forms containing a polymer in the form of latex even have better mechanical properties. e) Coloration of the forms The paper thus made was colored by a staining or impregnation process using a supercritical fluid which is supercritical CO 2. For this, the paper was placed inside a closed reactor in which was added a known amount of disperse dye (preferably previously treated Soxhlet extraction to remove the majority of dispersants). In the context of this example, the dye used was Foron Blue RD-E (Archroma Company) which was pretreated by Soxhlet extraction with acetone. It was then dried to remove all traces of solvent before being finely ground. Thus, 1 g of this pretreated dye was added to the bottom of the reactor. This reactor was provided with an accessory to guide the flow of CO 2 through the paper. Thus, discs of paper 3 cm in diameter have been cut to be perfectly adjusted to the internal diameter of the accessory. This accessory consists of a hollow and threaded rod, which is connected to the internal nozzle of the reactor corresponding to the flow inlet. This rod is then welded to a metal cylinder whose internal diameter is 3 cm and whose lower pierced portion can be detached from the assembly in order to introduce the samples to be impregnated. The closed reactor was then charged with liquid CO 2 to about 80-90 bar. To do this, the valves (1), (2), (3), and (4) are open, while the valves (5), (6) and (7) are closed. Then the whole was heated and conditions adjusted to 100 ° C-300bars. When the experimental conditions were reached (100 ° C-300bars), an overpressure is generated in the reactor core by starting the pump so that the supercritical CO 2, then dyed, passes through the paper. and this during 2h. The excess pressure thus generated is discharged continuously thanks to the weir set at 300 bar. At the end of the 2 hours, we scan the paper with clean CO2. For this, the valves (1), (3) and (4) are closed, the valve (2) remains open and the valves (5) and (6) are open. The sweep is maintained for 5 to 10 minutes and then the assembly depressurized (under a light flow of clean CO2) through the valve (7). Depressurization makes it possible, on the one hand, for the dye to precipitate at the bottom of the reactor and, on the other hand, for the fluid to pass from the supercritical state to the gaseous state and thus to obtain at the end of the dyeing process. impregnation, paper samples perfectly dry and colored on the surface as at heart. The Kubelka-Munk equation, K / S = (1-R) 2 / 2R, is used to determine the intensity of the coloration of the papers thus treated. In this equation, R is the minimum value of the reflectance curve, which is measured over the wavelength range between 400 and 700 nm using a spectrophotometer. The term (K / S), proportional to the dye concentration, makes it possible to evaluate the intensity of the coloration. Thus, in the context of this example and the examples presented below, the higher K / S, the more intense the coloration. Measurements have been made on these sheets. An intense level of coloration was obtained. Thus, depending on the added latex and its amount, the K / S values in Table 4 below were obtained. there Table 4: Value of K / S obtained on the forms in which were introduced 1, 5 or 10% of latex (dry weight / dry weight of the fibers) and stained by supercritical CO impregnation. f) Non-disgorging tests The colored paper samples were tested in contact with water according to EN NF 646. Thus, two sheets of uncolored glass fiber paper were immersed in the test liquid: distilled water. After saturation, the latter are freed of excess liquid by wiping them on the edge of the container. A sheet of uncolored fiberglass paper was deposited, smooth face upward, on a glass plate. The test specimen (paper sample tested) was immediately placed on this sheet. It was covered with a second sheet of saturated fiberglass paper so that the smooth side of the sheet was also in contact with the test piece. Another glass plate was placed on the second sheet of uncoloured fiberglass paper and then the assembly was wrapped in a polyethylene film to prevent drying of the edges. The assembly was placed under a load of 1kg and left standing for 24 hours away from direct penetration of light. After 24 hours, the assembly was undone. The unstained fiberglass paper sheets were placed on three adjacent glass rods, the face having respectively been in contact with the specimen facing upwards. The sheets of fiberglass paper were protected from light by being covered without contact, and then left to air-dry at room temperature. The coloring of the glass fiber papers was then evaluated against a control, a new uncolored fiberglass paper. In all cases, no staining was observed, which corresponds to a total absence of disgorging. Example 2: a) Preparation of the forms In the same way as described in Example 1, forms whose composition is detailed in Table 5 below were prepared. Table 5: Description of the completed forms. Retention of the latex was verified by taking a sample before making the truss by centrifugation according to power and time parameters which were further adjusted using different control samples. Thus, the parameters chosen are such that a solution of very dilute latex does not sediment whereas a solution containing a small amount of calcium carbonate in water has a perfectly clear supernatant. b) Characterization of the forms It has been verified that the mechanical properties of the sheets have not been altered by the presence of the polymer introduced in latex form. The results of the evaluation of the mechanical properties are given in Table 6 below. Table 6: Mechanical properties of the formed forms. The level of calcium carbonate retained in each of the forms was also estimated. The results are shown in Table 7 below. Table 7:% CaCO 3 / total weight of the dry paper according to the percentage of latex introduced. c) Coloring of the forms The paper thus produced was colored by the dyeing method described in Example 1, paragraph e. Spectrophotometric measurements were performed on these sheets. Thus, an intense level of coloration was obtained and the measured K / S values are contained in Table 8 I Table 8: Value of K / S obtained on fermettes in which were introduced 1, 5 or 10% of latex (dry weight / dry weight of the fibers) and stained by supercritical CO impregnation. d) Characterization of disgorging Disgorging tests were conducted according to the protocol described in Example 1, paragraph f. In all cases, no coloration was observed after 24 hours on non-colored glass fiber papers, which corresponds to a total absence of disgorging. Example 3: a) Paper Manufacturing A pulp was prepared in a pulper by mixing fibers in water. The composition of the cellulosic fiber mixture is 50% by dry weight of short cellulosic fibers of Cenibra type (eucalyptus-derived wood fibers) and 50% by dry weight of long cellulosic fibers, of the Pacifico type (wood fibers derived from Softwood). The dough thus prepared was refined to a Schopper degree of between 30 and 35. To this mixture were added, based on the dry weight of the cellulose fibers, 0.6% by dry weight of Acronal S728 type latex, 0.4% by weight. Asahi Guard E061 fluorinated resin dry and 0.1% by dry weight of Kymene 617 type cationic polyamide-epichlorohydrin resin (retention agent). Before being sent to the headbox, the composition of this paste was adjusted by the continuous addition of 2.5% wet weight (based on the weight of the paste before adjustment) of Asahi Guard type E061 fluorinated resin. and 0.7% by wet weight of AquapelJ215 type bonding agent. The dough thus prepared was sent to the headbox of the paper machine and then uniformly distributed over the moving web of the flat table, where it was driped through the mesh of the fabric by gravity and by suction using suction boxes, to achieve a sheet, as is known to those skilled in the art. Once formed, the paper sheet passed through the press section of the paper machine, and then a dryer made of a series of steam heated cylinders. When the moisture content of the sheet was greatly reduced, for example of the order of 5%, the sheet was subjected to surface sizing treatment by passing through a sizing press, composed for example of two rollers arranged side-by-side horizontally to form a bowl fed by a sauce of determined composition. The sheet is then passed between the rollers so as to coat its two opposite faces. As part of this example, the composition of the sauce was as follows: Between 8 and 12% by dry weight of a latex of Acronal S 728 type About 0.9% by dry weight of a styrene acrylic compound of Baysize BMP type About 1.8% by dry weight of a polyvinyl alcohol (P.V.A.) of type BF 17 The sheet is finally passed into a so-called post-drying section, into which it has come into contact again with one or more steam-heated rollers, up to a temperature of the order of 120 ° C. b) Characterization of paper properties The physical properties of the paper thus produced were evaluated. Thus, various characteristic measurements have been made, such as tensile strength, tear resistance or bursting resistance. An evaluation of the printability by measurement of the IGT tearing was also carried out. The different results are shown in Table 9 below. Weight (g / m2) 90 Main (cm3 / g) 1.32 Porosity Bendtsen (mL / min) 510 Both sides Bendtsen roughness (mL / min) ---- 234_ 294 _ Burst (kPa) 298 Machine direction Through Tear (mN) --------- 353 698 Cross machine direction Strength (N) 116 71 Traction --------------------------: Lengthening (%) 2.4 6.1 Break length (km) 8.8 5.4 Dry picking IGT (pressure _ Machine direction Crosswise 35kgf - increasing speed 0 to Wheel No lint No lint 7m / s - ink 3804) Strip No pull-out points] No pull-out points Table 9: Properties of the test roll c) Paper coloring and intensity measurements The paper thus made was colored by a staining or impregnation process using a supercritical fluid which is supercritical CO 2. For this purpose, a paper reel was placed inside a closed reactor in which a known quantity of disperse dye (preferably previously treated with Soxhlet extraction was added to remove the majority of the dispersants). In the context of this example, several dyes or mixture of dyes were used. These dyes are all commercial disperse dyes supplied by the Archroma Company and have all been pretreated by Soxhlet extraction with acetone. Thus, the following colorations were successively carried out: Yellow coloring with Foron Brilliant Yellow RD-E Green color using RD-E Foron Brilliant Yellow (75%) and Foron RD-E Blue (25%) Blue color with Foron Blue RD-E Black color with Black Foron RD-RM 400 The reactor used is designed so that the CO2 flow is guided through the thickness of a paper roll. After loading the paper, a quantity of dye equivalent to 2.5 to 5% of the weight of the paper to be impregnated was placed in the reactor. Once the reactor closed, the first step was to charge the reactor with CO 2 at the storage pressure (40-50 bar) and simultaneously the reactor was heated and CO 2 pumped to reach the working conditions: a temperature between 100 and 115 ° C and a pressure between 270 and 300 bar. Circulation was ensured by means of a pump. Thus, the supercritical CO 2 charged with dissolved dye was sent through the thickness of the coil, radially from the inside to the outside. After 2 h under the predefined supercritical conditions, a clean CO 2 scan was carried out at a temperature of 100-115 ° C and a pressure of 250 bar for 30 min to remove unbound dye prior to depressurization. which caused, on the one hand, the precipitation of the remaining dye and on the other hand, allowed the fluid to pass from the supercritical state to the gaseous state. At the end of the impregnation process, perfectly dry paper samples, colored on the surface as well as at the core, and whose color does not disintegrate on contact with water, were obtained. Spectrophotometric measurements were performed on these papers. Thus, intense staining levels were obtained and the K / S values measured at the maximum absorption wavelengths are contained in Table 10 below. Table 10: Value of K / S obtained on the test coils stained by supercritical CO 2 impregnation in different shades. d) Disgorging tests Disgorging tests were conducted according to the protocol described in Example 1, paragraph f. In all cases, regardless of the dye or the mixture of dyes used, no coloration was observed after 24 hours on non-colored glass fiber papers, which corresponds to a total absence of disgorging. REFERENCES 'Soluble anionic trisazo dyes of aromatic serial - for natural and synthetic fibers, esp. 1] leather ". Patent BE-834146,1976. "Halogen-GCon. isoindoline pigments - useful for coloring plastics, paint, etc. in 2] yellow shades ". Patent DE2805234,1978. "Anthraquinone pigments - and vat dyes, for cellulose fibers, paints, printing inks and 3] plastics". Patent DE2123963,1972. "Disazo disperson dyes pigment - for sunthetic fibers paints, printing inks, and 4] plastics". Patent DE2138014,1973. "Azo dyes having one or two triazinyl-gold pyrimidyl-acetic acid ester or amide coupling 5] component radicals". BE-820674,1973. "Blue cationic oxazine dye contg. tert. and prim. amino - for dyeing or printing paper 6] leather and polyacrylonitrile etc ". Patent IT7949811,1978. "Azo anthraquinone pigments". Patent CH-635218,1976. 7] "Monazo dyes free of sulphonic acid groups". Patent BE-740009,1968. 8] "Reactive polymeric monochlorotriazine dyes". Patent GB-923429,1958. 9] "Dyes substd. by imidazolyl-methyl gps. -esp. for coloring paper. Patent 10] DE3044563,1980. "Dyeing paper with 2, 1-benzoisothiazole sulphonic acid azo dyestuff - giving 11] brialing light-fast dyeing". Patent DE3041838, 1980. "Fixation of dyes on colored paper". US1926614,1931. 12] "Dip dyeing type paper dyeing method". Patent CN102877363, 2012. 13] "Coloring composition and method of coloring". Patent WO2006112452, 2006. 14] K. Blus, J. Czechowski and A. Kozirog, "New Eco-Friendly Method for Paper Dyeing," 15] Fibers & Textiles in Eastern Europe, pp. 121-125, 5 (107) 22, 2014. "Supercritical CO2". Patent EP 2 876 203, 2013. 161 "Method for coloring cellulose". Patent WO / 2015/140750, 2015. 17] "Impregnation of a paper with a supercritical fluid". Patent FR3015988, 18] 2015. "Latex containing papers". US Patent 4,510,019,1985. 19] "paper sheet having a very high proportion of latex, process for preparing same and 20] applications for a product substitution for impregnated glass webs". U.S. Patent 4,612,251,1986. "Latex-saturated paper". Patent CA 02211776,1997. 21] "Transparent or translucent paper sheet, its manufacturing process and 22] packaging containing it". Patent FR2916769, 2008. "Method of making paper". Patent WO 2011/146367 A1, 2011. 23] * "Hydrophobic planar support". Patent WO 2014/177586 A1, 2014. 24] coating, a polymer in the form of latex (identical to or different from the latex incorporated in the mass) or another polymer. This step can further improve the retention of the impregnated molecules in the paper, particularly that of the colorant in the paper when it has been colored. The invention also relates to a colored paper obtained by the implementation of a method according to any one of the aforementioned embodiments. A particular colored paper according to the invention is a colored paper using a supercritical pressure fluid whose color is stable in a water disgorging test and a composition of short fibers and long fibers in a ratio of 50. / 50, refined at 30-35 ° SR and comprising 1 to 5% of polymer introduced as a latex in the form of latex retained in the fibers by means of a cationic retention agent and having on the surface a layer of a polymeric additive comprising from 0 to 20%, preferably from 10 to 15% by dry weight of polymer relative to the dry weight of paper, said surface polymer additive being identical to or different from the polymeric additive introduced in bulk. The invention will be illustrated and described in more detail in the following examples and figure. FIG. 1 describes the diagram of the supercritical CO 2 impregnation assembly References numbered 1 to 7 designate valves whose operation is illustrated in the following examples. Example 1 Formula containing 1, 5 or 10% of a polymer introduced in bulk latex form, retained in the fibrous mat by using a polyamide-epichlorohydrin resin (PAE) a) Preparation of the fibrous suspension and the different elements used in the composition i. Preparation of the fibrous suspension The chosen composition is a mixture of long fibers (Sodra Black R®) and short fibers (Cenibra®). It should be noted that the Cenibra®-type fibers are cellulosic wood fibers derived from eucalyptus, with an average length in the range of 0.5 to 1.5 mm, and that the Sodra Black R® type fibers are long cellulosic wood fibers derived from softwood, with an average length in the range of 1.5 to 3 mm. Thus, at 500 g of pulp, formed of a mixture of 3/5 of Cenibra® type fibers and 2/5 of Sodra Black R® type fibers, 22L of water is added and then refining is carried out until a refining rate of the order of 45 ° SR (or Schopper-Riegler degree). ii. Preparation of latex Different commercial latexes were chosen and evaluated. The list and technical characteristics given by the suppliers are summarized in Table 1.
权利要求:
Claims (21) [1" id="c-fr-0001] 1. A process for impregnating a paper and in particular staining, using a supercritical pressure fluid characterized in that it comprises an impregnation step by contacting a paper with molecules of interest in the presence of a supercritical or subcrystalline fluid, said paper comprising, (i) at heart, a polymeric additive introduced in latex form and / or (ii) at the surface, a polymeric additive applied in the form of latex, identical or different from the polymeric additive optionally present in the core and / or a molecule, in particular a polymer that can be impregnated with a molecule of interest, in particular a hydrophobic molecule, by means of the supercritical pressure fluid. [2" id="c-fr-0002] 2. Method according to claim 1 characterized in that the impregnation step is performed on dry paper. [3" id="c-fr-0003] 3. Method according to claim 1 or claim 2, characterized in that the supercritical pressure fluid is carbon dioxide in the supercritical or subcritical state or a mixture of carbon dioxide with an organic solvent, for example a alcohol, especially ethanol. [4" id="c-fr-0004] 4. Method according to any one of claims 1 to 3 wherein the molecules of interest are chosen from dye molecules, reactive disperse dyes, optical brighteners, fluorophores, antioxidants, molecules absorbing ultraviolet radiation. purple, surfactants, paraffinic polymers and waxes. [5" id="c-fr-0005] 5. Method according to any one of claims 1 to 4 wherein the coloring molecules are constituted by a dispersed hydrophobic dye or a mixture of dispersed hydrophobic dyes, the dye (s) being optionally pretreated to remove dispersing agents, the (the) ) dye (s) being provided at a level of from 0.1 to 10%, in particular from 1 to 5% by dry weight of dye (s) relative to the weight of the paper. [6" id="c-fr-0006] 6. Process according to any one of claims 1 to 5 comprising the steps of: a) Loading into a reactor, dry paper to be impregnated with a molecule of interest, in particular with a dye or a mixture of dyes and dyes; a specific quantity of molecule of interest, in particular of dye or mixture of dyes, followed by the closure of the reactor, b) Loading of the fluid, in particular CO2, at the fluid storage pressure, c) Heating of the reactor and and / or pumping the fluid until the temperature and pressure conditions for the solubilization of the molecule of interest, in particular the dye (s), in the fluid in the supercritical or subcritical state and impregnation of the molecule of interest, in particular of the dye (s), in the thickness of the paper, d) Circulation of the supercritical pressure fluid loaded into the molecule of interest, in particular by dye (s), through paper, e) Scanning with clean fluid at supercritical pressure under conditions of supercritical or, if appropriate subcritical, temperature or pressure that are identical or different from those of step c., in order to eliminate the molecule of unfixed interest, in particular the ) unbonded dye (s), (f) Depressurization of the reactor to precipitate the remaining dye (s) and allow the passage of the fluid to the supercritical or subcritical state in the gaseous state, (g) Recovery of dry paper, stained at the heart and / or on the surface. [7" id="c-fr-0007] 7. Method according to any one of claims 1 to 6, wherein the supercritical pressure fluid is carbon dioxide and the temperature during the supercritical pressure impregnation phase is greater than or equal to ambient temperature and in particular lower or equal to 200 ° C., for example less than or equal to 15 ° C., in particular ranging from 70 ° C. to 130 ° C., and the pressure during the supercritical pressure impregnation phase is greater than or equal to 75 bars and less at 1000 bar, in particular in a range from 150 bar to 500 bar, preferably 300 bar. [8" id="c-fr-0008] A process according to any one of claims 1 to 7, wherein the paper is obtained from a paper pulp comprising: i) a fibrous suspension based on cellulose fibers in water at a concentration of cellulose fibers of 2 to 50 g / l, preferably 15 to 25 g / l, the cellulose fibers being optionally composed of a mixture of cellulose fibers different in origin and / or size, said suspension being refined at least 17 ° SR, preferably 20 ° SR to 45 ° SR, for example 30 to 35 ° SR. il) a polymeric additive in latex form, said latex being added to the fibrous suspension in a proportion of 0.5 to 50% by weight of dry product, in particular from 0.5 to 20% by weight of dry product, so preferred from 1 to 15% by weight of dry product and even more preferably from 1 to 10% or from 5 to 10% by weight of dry product, based on the dry weight of the cellulose fibers. [9" id="c-fr-0009] A method according to any one of claims 1 to 8, wherein the paper is obtained: i) from a pulp comprising a fibrous suspension based on cellulose fibers in water at a concentration of cellulose fibers of 2 to 50 g / l, preferably 15 to 25 g / l, the cellulose fibers being optionally composed of a mixture of cellulose fibers different in origin and / or size, said suspension being refined at least 17 ° SR, for example 20 ° SR to 45 ° SR, preferably 30 ° SR to 35 ° SR, and optionally a polymeric additive in latex form, said latex being added to the fibrous suspension in a proportion of 0.5 to 50% by weight of dry product, in particular from 0.5 to 20% by weight of dry product, preferably from 1 to 15% by weight of dry product and even more preferably from 1 to at 10% or 5 to 10% by weight of dry product, relative to the dry weight of the fibers of the cell and ii) according to a papermaking process comprising a paper surface deposition step, a polymeric additive in latex form in a proportion by weight of 0.5 to 25% based on the weight of the paper. [10" id="c-fr-0010] 10. Process according to any one of claims 1 to 9, wherein the latex is an aqueous ionic dispersion of polymer particles, especially copolymer, optionally crosslinked or crosslinkable, in particular thermally or self-crosslinking, or thermoplastic, in in which the chains contain basic groups in the Lewis sense, for example ether, carbonyl, carboxyl or phenyl groups, or mixtures thereof, said copolymer having a glass transition temperature of less than 100 ° C., preferably within the range of - 20 ° C to 90 ° C including 0 ° C to 60 "C. [11" id="c-fr-0011] 11. Process according to any one of claims 1 to 10, in which the latex is obtained from a copolymer of which at least one of the monomers is chosen from ether monomers, vinyl monomers, styrene monomers, and acrylic monomers. , especially methacrylic, Ufhananic and dienic. [12" id="c-fr-0012] 12. The method of claim 11, wherein the latex is obtained from a polymer selected from the group of styrene-butadiene copolymers including a carboxylated styrene-butadiene copolymer of styrene-acrylic copolymers, ester copolymers. acrylic-acrylonitrile, copolymers of vinyl ethylene acetate, copolymers of ether-urethane, and copolymers of vinyl chloride-vinyl acetate-ethylene. [13" id="c-fr-0013] 13. A method according to any one of claims 8 to 12 wherein the pulp comprises a retention agent consisting of a cationic compound capable of fixing the latex on the cellulosic fibers. [14" id="c-fr-0014] 14. Preparation process according to claim 13, wherein the cationic compound is chosen from cationic flocculating agents, cationic resins capable of reacting with cellulosic fibers, in particular crosslinkable resins on cellulosic fibers, and cationic starch. [15" id="c-fr-0015] The process of claim 14 wherein the cationic resin is a polyamide-amine-epichlorohydrin resin. [16" id="c-fr-0016] A process according to any one of claims 13 to 15, wherein the retention agent is added to the latex under conditions permitting the retention of the latex in the fibrous mat comprising the cellulose fibers, by forming ionic bonds with said fibers, said conditions comprising for example the addition of a retention agent according to a retention agent / latex ratio expressed as a percentage of dry retention agent / latex dry mass of 0.1% to 20%, in particular of 0.1 to 15%, preferably 0.1% to 13% ,. [17" id="c-fr-0017] 17. A method according to any one of claims 8 to 15 wherein the cellulose fibers are a mixture of fibers of different lengths selected from short fibers of length contained in the range of 0, there 0.49 mm, the fibers length averages in the range of 0.5 to 1.5 mm and long fibers in length in the range of 1.6 to 3 mm. [18" id="c-fr-0018] 18. Process according to any one of claims 8 to 17, wherein the cellulosic fiber proportion of a first determined length is 40 to 50% and the proportion of cellulosic fibers of a second determined length is 60 to 50%. , in particular the mixture consists of 40% of long fibers and 60% of short fibers or consists of 50% long fibers and 50% short fibers. [19" id="c-fr-0019] The method of any one of claims 8 to 18, wherein the formula of the dough is adjusted by the addition of fillers, pigments, tackifier, dry-strength agent, wet, fluorescent agent, flame retardant, liquid or gas barrier product [20" id="c-fr-0020] A method of making a paper impregnated with a supercritical pressure fluid, particularly colored paper, comprising the steps of: a. Preparation in a pulper of a pulp as defined in any one of claims 8 to 19, b. If necessary, adjustment of the prepared dough and / or dilution to the desired concentration, before being sent to the headbox for its homogeneous distribution especially on the canvas of a flat table, c. Draining of the pulp previously distributed on the fabric of the paper machine, the drainage being in particular carried out by gravity and by suction using suction boxes, to produce a sheet of paper, d. Spinning for example by means of a press composed of rolls and possibly of felts and drying for example by means of steam-heated cylinders of the sheet obtained in step c. to obtain a sheet whose moisture content is less than or equal to 7% e. If necessary, applying a surface treatment to the dried sheet, for example a sizing with a sauce or a bath of determined composition, provided by a sizing press, f. If necessary drying in a post-drying area, g. If necessary, change the surface state of the sheet by a calendering or smoothing, coating or coating operation h. Impregnation, in particular staining, of the sheet obtained by carrying out the process according to any one of Claims 1 to 6. [21" id="c-fr-0021] A colored paper obtained by carrying out a process according to any one of claims 1 to 20, wherein the paper is obtained from a fibrous suspension and the paper has a composition of short fibers and long fibers. in a ratio of 50/50, refined to 30-35 ° SR and comprising from 1 to 5% of polymeric additive in latex form introduced by mass and retained in the fibers by means of a cationic retention agent said paper comprising at the surface, a layer of polymeric additive, optionally applied in the form of a latex that is identical to or different from the polymeric additive introduced in bulk, and comprising from 0 to 20%, preferably from 10 to 15% by dry weight of polymer per relative to the weight of dry paper.
类似技术:
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同族专利:
公开号 | 公开日 US11091878B2|2021-08-17| WO2017158302A1|2017-09-21| US20190330801A1|2019-10-31| FR3048982B1|2020-09-25| EP3430199A1|2019-01-23|
引用文献:
公开号 | 申请日 | 公开日 | 申请人 | 专利标题 FR2795082A1|1999-06-01|2000-12-22|Essilor Int|Impregnating polymer latex with additive, e.g. dye, in presence of supercritical fluid, e.g. carbon dioxide, giving coagulate-free product useful for forming coatings, e.g. on optical components| FR3015988A1|2013-12-27|2015-07-03|Arjo Wiggins Fine Papers Ltd|IMPREGNATION OF A PAPER USING A SUPERCRITICAL FLUID| WO2015140750A1|2014-03-21|2015-09-24|Commissariat A L'energie Atomique Et Aux Energies Alternatives|Method for colouring cellulose| US1926614A|1931-07-24|1933-09-12|Du Pont|Fixation of dyes on colored paper| DE1155203B|1958-12-19|1963-10-03|Du Pont|Process for the preparation of polymeric dyes with a chain-like molecular structure| DE1802467A1|1968-10-11|1970-05-27|Bayer Ag|Pigment dyes| DE2123963A1|1971-05-14|1972-11-23|Farbenfabriken Bayer Ag, 5090 Leverkusen|Anthraquinone pigments - and vat dyes, for cellulose fibres, paints, printing inks and plastics| DE2138014A1|1971-07-29|1973-02-08|Bayer Ag|Disazo dispersion and pigment dyes - for synthetic fibres paints,printing inks, and plastics| CH585244A5|1973-10-05|1977-02-28|Sandoz Ag| CH585249A5|1974-10-04|1977-02-28|Sandoz Ag|Soluble anionic trisazo dyes of aromatic series - for natural and synthetic fibres, esp. leather | DE2659676C2|1976-12-30|1987-02-05|Bayer Ag, 5090 Leverkusen, De| DE2805234A1|1978-02-08|1979-08-09|Sandoz Ag|Halogen-contg. isoindoline pigments - useful for colouring plastics, paint, etc. in yellow shades| IT1162352B|1978-07-21|1987-03-25|Ciba Geigy Ag|BLue cationic oxazine dye contg. tert. and prim. amino - for dyeing or printing paper leather and polyacrylonitrile etc.| CH638548A5|1978-07-21|1983-09-30|Ciba Geigy Ag|CATIONIC OXAZINE DYES.| DE3041838A1|1980-11-06|1982-07-01|Basf Ag, 6700 Ludwigshafen|Dyeing paper with 2,1-benzoisothiazole sulphonic acid azo dyestuff - giving brilliant light-fast dyeing| DE3044563A1|1980-11-26|1982-07-08|Basf Ag, 6700 Ludwigshafen|Dyes substd. by imidazolyl-methyl gps. - esp. for colouring paper| US4510019A|1981-05-12|1985-04-09|Papeteries De Jeand'heurs|Latex containing papers| US4612251A|1982-07-30|1986-09-16|Arjomari-Prioux|Paper sheet having a very high proportion of latex, process for preparing same and applications thereof particularly as a substitution product for impregnated glass webs| US5895557A|1996-10-03|1999-04-20|Kimberly-Clark Worldwide, Inc.|Latex-saturated paper| JP3971770B2|2005-04-18|2007-09-05|三菱鉛筆株式会社|Colorant composition and coloring method| FR2916769B1|2007-05-31|2009-08-28|Arjowiggins Licensing Soc Par|TRANSPARENT OR TRANSLUCENT PAPER SHEET, METHOD OF MANUFACTURE AND PACKAGING CONTAINING SAME| WO2011146367A1|2010-05-17|2011-11-24|Basf Se|Method of making paper| CN102877363B|2012-10-12|2014-12-24|上海典旗材料科技有限公司|Dip dyeing type paper dyeing method| FR3005320B1|2013-05-02|2015-11-20|Arjo Wiggins Fine Papers Ltd|HYDROPHOBIC PLAN SUPPORT| EP2876203A1|2013-11-25|2015-05-27|CEPI aisbl|Supercritical CO2|WO2020102605A1|2018-11-15|2020-05-22|The Regents Of The University Of California|Vesicle-coated fibers and methods of making and using| FR3102478B1|2019-10-29|2021-09-24|Commissariat Energie Atomique|Process for preparing a compound comprising at least one imine function by a specific condensation reaction and particular application of this process to the field of coloring| CN111622018B|2020-05-14|2021-12-31|仙鹤股份有限公司|Production method of large ink level printing biblical paper|
法律状态:
2017-03-31| PLFP| Fee payment|Year of fee payment: 2 | 2017-09-22| PLSC| Search report ready|Effective date: 20170922 | 2018-03-30| PLFP| Fee payment|Year of fee payment: 3 | 2019-11-25| PLFP| Fee payment|Year of fee payment: 5 | 2019-11-29| ST| Notification of lapse|Effective date: 20191106 | 2020-01-24| TQ| Partial transmission of property|Owner name: COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERG, FR Effective date: 20191213 Owner name: AW BRANDING LIMITED, GB Effective date: 20191213 | 2020-01-24| CA| Change of address|Effective date: 20191213 | 2020-02-28| RN| Application for restoration|Effective date: 20200123 | 2020-03-20| FC| Favourable decision of inpi director general on an application for restauration.|Effective date: 20200213 | 2021-03-30| PLFP| Fee payment|Year of fee payment: 6 |
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申请号 | 申请日 | 专利标题 FR1652246A|FR3048982B1|2016-03-16|2016-03-16|METHOD OF MANUFACTURING PAPER IMPREGNATED BY A SUPERCRITICAL PRESSURE FLUID - IMPREGNATED PAPER, ESPECIALLY COLORED|FR1652246A| FR3048982B1|2016-03-16|2016-03-16|METHOD OF MANUFACTURING PAPER IMPREGNATED BY A SUPERCRITICAL PRESSURE FLUID - IMPREGNATED PAPER, ESPECIALLY COLORED| PCT/FR2017/050607| WO2017158302A1|2016-03-16|2017-03-16|Method for producing paper impregnated by a supercritical-pressure fluid, and impregnated, particularly coloured paper| US16/085,794| US11091878B2|2016-03-16|2017-03-16|Method for producing paper impregnated by a supercritical-pressure fluid, and impregnated, particularly coloured paper| EP17716947.1A| EP3430199A1|2016-03-16|2017-03-16|Method for producing paper impregnated by a supercritical-pressure fluid, and impregnated, particularly coloured paper| 相关专利
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