Method for acylating a hydroxylated solid material

Abstract

The present invention relates to a method for the chromatogenic acylation of solid materials (1, 2) having hydroxyl groups capable of reacting with gaseous fatty acid chlorides, wherein a reactive fatty acid chloride composition (20, 21, 22) is applied to the surface of the material (1, 2) by an applicator capable of releasing the composition (20, 21, 22) onto the surface of the solid hydroxyl material (1, 2). According to the invention, the composition (20, 21, 22) is applied to the surface of the material (1, 2) at an acylation temperature lower than the vaporization temperature of at least one fatty acid chloride of the composition (20, 21, 22) in order to enable the acylation of the material (1, 2) by reaction of at least one gaseous fatty acid chloride of the composition (20, 21, 22) with at least one of the hydroxyl groups of the solid hydroxyl material (1, 2), and the acylation temperature is between 160 °C and 250 °C.

Description

Technical Field

[0001] The present invention relates to a method for the chromatogenic acylation of a hydroxylated solid material that is utilizable with and capable of reacting with a gaseous fatty acid chloride, i.e., a solid material having reactive hydroxyl (-OH groups).

[0002] Throughout this text, the terms "chromatogenic" and the expression "by chromatogeny" that describe the acylation reaction indicate and evoke that this acylation reaction, or more simply "acylation", occurs between a hydroxylated solid material such as a paper support considered in the field of gas chromatography (GC) as a stationary phase and an eluate considered to be at least partially gaseous and incorporated into the liquid / vapor equilibrium by a mobile gas phase consisting of a high-temperature gas-phase stream, and a fatty acid chloride reagent.

Background Art

[0003] From International Publication No. WO 2012 / 066015, a semi-industrial method for the chromatogenic acylation of a web of a cellulose substrate such as paper moving between an upstream reel and a downstream take-up roll is known. According to this semi-industrial method, a liquid fatty acid chloride (R-CO-Cl) is deposited onto the paper of the moving paper web at an upstream fixed station by a cylinder known as an anilox roller, and then heated to a temperature at which acylation becomes possible downstream of the deposition. A part of the fatty acid chloride changes to a gaseous state due to the increase in the saturated vapor pressure of the fatty acid chloride associated with the increase in the heating temperature. The gaseous fatty acid chloride reacts with the reactive hydroxyls of the paper to form an ester bond between the paper and the hydrocarbon chain (R) of the fatty acid chloride according to the following equation (I): Paper-OH + R-CO-Cl ⇔ Paper-O-CO-R + HCl (I).

[0004] Chromogenic acylation is advantageously carried out without an organic solvent and a catalyst so that it is not necessary to remove the organic solvent and the catalyst at the end of the reaction. The acylation is facilitated by the removal of the gaseous hydrochloric acid (HCl) produced by the acylation, and this hydrochloric acid is taken up by applying a high-temperature air stream onto the cellulose substrate being acylated. By taking up the formed gaseous hydrochloric acid, it becomes possible to shift the equilibrium of the reaction in the direction of forming the acylated cellulose substrate.

[0005] However, the inventor has found that the method of International Publication No. 2012 / 066015 is not optimized. First, the acylated cellulose substrate according to International Publication No. 2012 / 066015 has a qualitatively lower hydrophobicity than the hydrophobicity of the acylated cellulose substrate obtained by impregnating the substrate with a pentane solution of fatty acid chloride and then heating the impregnated substrate by applying a high-temperature gas stream. In this method, it is not possible to impart hydrophobicity and, if appropriate, impermeability that is optimal and exhibits sufficient durability over time to the cellulose substrate. The contact angle of the pure water droplets deposited on the surface of the acylated cellulose substrate by the method of International Publication No. 2012 / 066015 is surely more than 90°, but it has still been found to be lower than the optimal value of 150° obtained by applying a pentane solution of fatty acid chloride. As a result, the hydrophobic properties are insufficient. Next, it is not possible to effectively acylate a paper web moving at a speed exceeding 50 meters per minute, specifically, a paper web of special paper with a high basis weight and / or porous paper having a high specific surface area and / or paper having a surface layer of polyvinyl alcohol. The method of International Publication No. 2012 / 066015 is actually not suitable for implementation on an industrial scale. In fact, the optimal acylation of such a paper web can only be obtained at the expense of excessive deposition of fatty acid chloride and / or excessive heating of the paper, which inevitably causes deterioration and / or browning of the paper.

[0006] An object of the present invention is to solve the above-mentioned drawbacks of the method of International Publication No. 2012 / 066015.

[0007] Furthermore, from International Publication No. WO 2022 / 033698, a method for solventless chromatographic acylation of paper pieces heated to a temperature of 160°C is known, in which stearic acid chloride in a liquid state is deposited on the paper pieces by means of a coating roller whose coating surface is formed by a pile. In this method, neither the pile nor the coating roller is heated, so that the stearic acid chloride filled in the pile is necessarily at a temperature lower than the acylation temperature during deposition, specifically a temperature between room temperature and the acylation temperature. Subsequently, the paper pieces are then subjected to a subsequent heat treatment for the completion of acylation. By the method of International Publication No. WO 2022 / 033698, it becomes possible to impart sufficient hydrophobic properties to the acylated pieces. However, the method of International Publication No. WO 2022 / 033698 is not fully configured to enable the acylation of paper of a paper web moving at a very high speed, specifically a running speed exceeding 100 meters per minute. Despite the improvement made by International Publication No. WO 2022 / 033698, the ungrafted liquid fatty acid chloride necessarily remains on the paper. On the one hand, such surplus is not economically acceptable. Such surplus is not functionally acceptable either. The remaining liquid fatty acid chloride is likely to be hydrolyzed by the release of hydrochloric acid during the long-term storage of the acylated paper. The released hydrochloric acid may damage the cellulose fibers and cellulose materials and have an adverse effect on their mechanical strength. Furthermore, the fatty acid released by this hydrolysis reduces the hydrophobicity and water impermeability of the acylated paper. Therefore, this surplus must be removed. The method of International Publication No. WO 2022 / 033698 must be optimized and its economic efficiency must be improved.

[0008] The present invention aims to solve this drawback.

Summary of the Invention

[0009] Therefore, the present invention aims to provide an improved method for chromatogenic acylation of a solid material having at least one gaseous fatty acid chloride available and capable of reacting with this (these) gaseous fatty acid chlorides and having a hydroxyl group.

[0010] Therefore, an object of the present invention is to provide such a chromatogenic acylation method, and its acylation efficiency is improved.

[0011] Another object of the present invention is to provide such an improved method that enables an increase in the rate of chromatogenic acylation.

[0012] Another object of the present invention is to provide such a chromatogenic acylation method that enables imparting sufficient hydrophobic properties to the hydroxylated solid material.

[0013] Specifically, an object of the present invention is to provide such a chromatogenic acylation method that enables imparting sufficient hydrophobic properties to the hydroxylated solid material with a small amount of fatty acid chloride.

[0014] However, another object of the present invention is to provide such a method for chromatogenic acylation of the hydroxylated solid material and converting this hydroxylated solid material into an acylated material having substantially the same porosity as the original hydroxylated solid material.

[0015] An object of the present invention is to provide such a method for chromatogenic acylation of the hydroxylated solid material that can be carried out by anyone skilled in the art by generally available means.

[0016] However, another object of the present invention is to provide an industrial method for acylating the paper of a certain width while moving it between an upstream reel for the paper of a certain width and a downstream winding roll device for the acylated paper of a certain width.

[0017] Therefore, specifically, an object of the present invention is to provide such an industrial chromatogenic acylation method that can conform to the technical constraints regarding the movement of the solid material and the high production rate of such acylated solid material.

[0018] Specifically, the object of the present invention is to provide such a method that enables a high-speed movement of a solid material while allowing a desired amount, specifically a large amount of fatty acid chloride, to be deposited in the case of a special solid material.

[0019] Furthermore, the object of the present invention is also to provide such a chromatogenic acylation method that does not require the use of environmentally toxic organic solvents, specifically non-polar organic solvents, for implementation.

[0020] However, the object of the present invention is also to provide such a chromatogenic acylation method that enables the limitation of the amount of fatty acid chloride remaining at the end of acylation.

[0021] The present invention also aims to provide such a chromatogenic acylation method that enables the deposition of a reactive fatty acid chloride that is an optimal amount with respect to the number and / or density of reactive hydroxyls, is available to and can react with gaseous fatty acid chloride.

[0022] For this reason, the object of the present invention is to provide such a chromatogenic acylation method that enables a substantially stoichiometric acylation of the reactive hydroxyls of a solid material.

[0023] The present invention also aims to provide such a chromatogenic acylation method that enables the acylation of various solid materials, specifically special solid materials such as cardboard and / or paper coated with polyvinyl alcohol.

[0024] The present invention also aims to provide such a chromatogenic acylation method that enables the reduction or complete elimination of the step of removing excess fatty acid chloride.

[0025] Therefore, the present invention specifically aims to provide such a simplified method, provided that it does not require a final step of removing the remaining non-grafted fatty acid chloride.

[0026] For this purpose, the present invention provides a method for chromatogenic acylation of a solid material having a hydroxyl group that is available for at least one gaseous fatty acid chloride and is capable of reacting with this (these) gaseous fatty acid chloride(s), wherein at least one composition, referred to as a reactive composition, of at least one fatty acid chloride is applied onto at least the surface of the hydroxylated solid material by means of at least one application device having a coating surface formed by filamentary elements, in particular a coating roller, the filamentary elements not reacting with the reactive composition and being capable of releasing and applying the reactive composition onto at least the surface of the hydroxylated solid material, i.e., over the surface and, where appropriate, to a depth of at least one thickness portion, by contact of the filamentary elements with the hydroxylated solid material, in particular by contact of the filamentary elements rotating by means of a roller, the reactive composition applied onto at least the surface of the hydroxylated solid material by means of an application device, in particular released in contact with the hydroxylated solid material, is, during its application, at a temperature referred to as an acylation temperature that is lower than the vaporization temperature of at least one of the reactive composition, in particular each fatty acid chloride, and is selected such that acylation of the solid material is enabled by reaction of at least one of the reactive composition, in particular at least one of each gaseous fatty acid chloride, with at least one of the hydroxyl groups of the solid material, and the acylation temperature is between 160 °C and 250 °C.

[0027] The inventor has, quite surprisingly and counterintuitively, found that by ensuring that the reactive composition to be applied is at an acylation temperature between 160°C and 250°C during application, i.e., a temperature high enough to enable acylation of the hydroxylated solid material by the gaseous acid chloride, it is actually advantageous to apply, i.e., deposit and distribute, the reactive composition onto the hydroxylated solid material by means of a coating device that is necessarily selected and intended to enable coating of the liquid composition without going through a prior step of depositing the liquid reactive composition. The inventor understands that the filamentous elements forming the coating surface of the coating device used in connection with the present invention, specifically a roller or a brush, when impregnated with the reactive composition at the acylation temperature between 160°C and 250°C, which is higher than the deposition temperature and the distribution temperature described in WO 2022 / 033698, and brought into short contact with the surface of the hydroxylated solid material, and when itself brought to the acylation temperature, enable more effective acylation of the hydroxylated solid material than when the liquid reactive composition is deposited essentially in liquid form at a low temperature and then heated to the acylation temperature after deposition. The inventor has observed that by bringing the hydroxylated solid material into contact with the reactive composition at the acylation temperature, it is possible to increase the rate of the acylation reaction, making it suitable for implementation on an industrial scale and enabling acylation of the moving hydroxylated solid material of the web of hydroxylated solid material, specifically the paper of a paper web. The high acylation temperature shifts the liquid / vapor equilibrium of the fatty acid chloride of the reactive composition in the direction of an increase in the gaseous fraction of the reactive composition, which is expected to diffuse freely away from the filamentous elements of the coating device and the hydroxylated solid material, thereby rendering it non-reactive towards the hydroxylated solid material, but in fact remaining trapped within the filamentous elements and being considered to react effectively and very rapidly with the hydroxylated solid material.Since the filamentary element forming the coating surface of the coating device is thought to function like a reservoir of gaseous fatty acid chloride, it is thought that the gaseous fatty acid chloride is retained by the filamentary element. Furthermore, when the reaction rate of the gaseous fatty acid chloride with respect to the hydroxyls of the hydroxylated solid material increases, it becomes possible to shift the liquid / vapor equilibrium of the fatty acid chloride in the vaporization direction with an equivalent time constant. As a result, the reaction is also improved and accelerated.

[0028] This increase in the acylation reaction rate enables multiple consecutive depositions of fatty acid chloride on the hydroxylated solid material at the acylation temperature, specifically on the moving paper of the paper web, and each deposition of the multiple depositions provides a stoichiometric amount of fatty acid chloride compared to the reactive hydroxyls of the hydroxylated solid material. In these embodiments, a stoichiometric amount of fatty acid chloride can be achieved due to the multiple consecutive depositions. Furthermore, each of the stoichiometric depositions of fatty acid chloride facilitates the dispersion of the fatty acid chloride deposited on the surface of the hydroxylated solid material at the acylation temperature during each deposition, thus making it possible to facilitate its reactivity.

[0029] However, even more surprisingly, this observation is not supported by known theory, but the retention of fatty acid chloride, specifically gaseous fatty acid chloride, in the region of the filamentary element is thought not to prevent the interaction between the gaseous fatty acid chloride and the hydroxylated solid material. The fact that the filamentary element capturing the gaseous fatty acid chloride comes into contact with the surface of the hydroxylated solid material is thought to disrupt the confinement of the reactive composition in the filamentary element, specifically its gaseous fraction, thus enabling a rapid reaction with the hydroxyls of the hydroxylated solid material facilitated by the high-temperature reactive composition. According to the expression used by the inventor, the gaseous fraction of the fatty acid chloride of the reactive composition is thought to be "sucked up" by the hydroxylated solid material.

[0030] Thus, the apparent phenomenon of sucking up the gaseous fatty acid chloride confined in the filamentous element actually overcomes the action of the gas layer called the gaseous boundary layer extending on the surface of the hydroxylated solid material, and it is considered possible to limit or even inhibit the approach of the gaseous fatty acid chloride to the reactive hydroxyls of the hydroxylated solid material by diffusion. The use of a coating device having a coating surface formed by the filamentous element, particularly a roller or a brush, makes it possible to deposit and distribute the gaseous fatty acid chloride in contact with the hydroxylated solid material while eliminating the action of the boundary layer. The coating device heated to the acylation temperature makes it possible to solve the hitherto unsolved problem of the presence of the boundary layer on the surface of the hydroxylated solid material.

[0031] The method according to the invention makes it possible to impart sufficient or even excellent hydrophobic properties to the solid material, which are evaluated, in particular, by measuring the Cobb value and / or by measuring the contact angle formed by the water droplets deposited on the surface of the acylated solid material and / or by testing the airtightness of the water pocket.

[0032] However, the method also enables a plurality of successive high-temperature depositions that enable a substantially stoichiometric acylation of hydroxylated solid materials having a large thickness and / or high porosity and / or large specific surface area, in relation to the chromatogenic acylation of hydroxylated solid materials such as high basis weight paper materials, cardboard, or solid materials coated with polyvinyl alcohol.

[0033] According to certain embodiments of the method according to the invention, at least one coating surface portion of the coating device is in contact with a surface portion of the hydroxylated solid material, and at least this surface portion of the hydroxylated solid material is at the acylation temperature during the application of the reactive composition to the hydroxylated solid material. According to these embodiments of the method according to the invention, the solid material is heated before the application of the reactive composition. In these embodiments, the solid material is heated in the absence of the reactive composition. Advantageously, heating the solid material before the application of the reactive composition enables at least partial dehydration of the solid material.

[0034] According to certain embodiments of the method according to the invention, the filamentous element forming the coating surface is at the acylation temperature during the application of the reactive composition to the hydroxylated solid material.

[0035] According to certain embodiments of the method according to the invention, the reactive composition is applied to at least the surface of the hydroxylated solid material in a thermal regulation chamber suitable for maintaining the reactive composition released by the coating device at the acylation temperature.

[0036] According to certain embodiments, the method according to the invention includes at least one step of redistributing fatty acid chlorides deposited on the hydroxylated solid material without newly supplying the reactive composition, and the redistribution step is performed by at least one dispensing device having a coating surface formed by a filamentous element, the filamentous element does not react with the fatty acid chloride of the reactive composition, and the contact between the filamentous element of the dispensing device and the hydroxylated solid material fills the fatty acid chlorides deposited on the hydroxylated solid material, and at least a part of the filled fatty acid can be released in contact with the hydroxylated solid material by the contact between the filamentous element and the hydroxylated solid material, and the dispensing device is at a temperature between 160 °C and 250 °C. Such a redistribution step at a high temperature prioritizes the previously supplied gaseous fatty acid chloride and its reactivity.

[0037] Advantageously, the filamentary elements of the coating device and / or the dispensing device are flexible, deformable upon contact with the hydroxylated solid material, and due to this flexibility, this deformation, and the displacement of the coating device and / or the dispensing device relative to the hydroxylated solid material, are suitable for the release of fatty acid chlorides at the surface and in the depth over at least a part of the thickness of the hydroxylated solid material, or for the removal of fatty acid chlorides from this surface.

[0038] According to certain embodiments of the method according to the invention, the coating surface of the coating device and / or the dispensing device is formed by a pile provided with filamentary elements. Also, the material forming the filamentary elements is selected to be resistant to the acylation temperature without loss of its adsorption properties and / or coating properties.

[0039] According to certain embodiments of the method according to the invention, the acylation temperature is between 160 °C and 250 °C, specifically between 165 °C and 240 °C, specifically between 170 °C and 230 °C, more specifically between 180 °C and 220 °C, preferably between 190 °C and 220 °C, more preferentially between 200 °C and 220 °C. The acylation temperature is adopted according to the solid material to be acylated. Specifically, the acylation temperature is selected to be below the browning temperature of the solid material. However, according to the invention, considering the rate of acylation by high-temperature deposition of the reactive composition and the shortening of the exposure time of the solid material to high temperatures, the risk of browning of the solid material due to high temperatures is reduced.

[0040] According to certain embodiments of the method according to the invention, at least one, and especially each, reactive composition is palmitic acid chloride (C 16 ), stearic acid chloride (C 18 ), arachidic acid chloride (C 20 ), and behenic acid chloride (C 22) contains at least one fatty acid chloride selected from the group formed thereby. There is nothing that prevents the reactive composition from containing acetyl chloride (CH3-CO-Cl) in a small proportion. The inventor has found that acetyl chloride, which is not a fatty acid chloride intended in the present invention, can react spontaneously and rapidly with free water molecules present in the solid material, while protecting the fatty acid chloride intended for acylation from possible hydrolysis. The inventor has also surprisingly observed that acetyl chloride does not react with the free hydroxyl groups of the solid material and the available hydroxyl groups, nor with the reactive hydroxyls of other hydroxylated polymers such as polyvinyl alcohol. More advantageously, acetic acid produced by the hydrolysis of acetyl chloride is volatile enough to be removed from the solid material. Advantageously, acetyl chloride is used as a protecting agent for the fatty acid chloride of the reactive composition. Advantageously, acetyl chloride is used as a transchlorination reagent for restoring fatty acid chloride from hydrolyzed free fatty acids.

[0041] In certain embodiments of the method according to the invention, the hydroxylated solid material is a paper material. This may be a solid material that is hydroxylated, i.e., a material that consists essentially of cellulose and has free hydroxyl groups that are available and reactive towards gaseous fatty acid chlorides, and is neither liquid nor gaseous. The hydroxylated solid material may also be a hydroxylated solid material having an outer layer formed of polyvinyl alcohol, particularly paper or cardboard, such as corrugated cardboard.

[0042] The reactive composition can be applied to the hydroxylated solid material in a total amount selected such that the hydroxylated solid material has a surface deposition amount of fatty acid chloride between 1 mg and 500 mg (mg / m 2 ) per square meter of the geometric surface area of the hydroxylated solid material. The amount of fatty acid chloride applied to the hydroxylated solid material is 1 mg / m 2 ~500 mg / m 2It is a hydroxylated solid material between. Advantageously, a plurality of successive depositions are carried out at said acylation temperature so as to achieve a substantially stoichiometric acylation of the hydroxylated solid material.

[0043] In certain embodiments, the coating device is a coating brush, and its filamentous elements are selected to be resistant to said acylation temperature. In these embodiments, the method according to the invention can be carried out manually by methods in the art.

[0044] According to certain industrial-scale embodiments of the method according to the invention, the hydroxylated solid material is a web of paper, which is formed between an upstream reel of said paper web and a downstream winding roll for the web of acylated paper, and moves in a running direction parallel to the maximum dimension of the web. When the reactivity of the acid chloride deposited at high temperature increases, the implementation of the method according to these embodiments becomes possible. In these embodiments, the paper of the paper web can move at a high running speed, in particular more than 50 m / min, preferably more than 100 m / min. In these embodiments, at least one, specifically each reactive composition, is applied at a fixed station on at least one major surface of the moving paper web. According to these industrial-scale embodiments of the method according to the invention, the reactive composition is applied while moving by a coating device that is fixed and immobile with respect to the moving paper. According to these industrial-scale embodiments of the method according to the invention, at least one, specifically each coating device, is a roll having a rotation axis parallel to the plane of the paper web but non-parallel, specifically orthogonal, to the running direction. According to some of these embodiments, when the paper web is a low basis weight paper web, said reactive composition is from 1 mg to 50 mg per square meter of the planar (geometric) surface area of the paper web (mg / m 2) is applied to the paper web in a total amount selected to have an average surface amount of fatty acid chloride between. That being said, according to certain other embodiments, when the paper web is a paperboard web, specifically a corrugated cardboard web, or a paper web coated with polyvinyl alcohol, the reactive composition is such that for every square meter of the planar surface area of the paper web, there is more than 50 mg (mg / m 2 ) and specifically up to 500 mg / m 2 is applied to the paper web in a total amount selected to have an average surface amount of fatty acid chloride that can reach, and is suitable for enabling substantially all (stoichiometric) acylation of the reactive hydroxyls.

[0045] In certain embodiments, the method according to the present invention includes at least two applications of the reactive composition at a fixed station on a moving paper web, and the reactive composition is at the acylation temperature during each application. According to this embodiment of the method according to the present invention, a small amount of fatty acid chloride is applied at the acylation temperature to enable rapid and substantially quantitative acylation, and this application is repeated several times to achieve substantially stoichiometric acylation of the paper in the paper web.

[0046] In certain embodiments, the solid material is a paper material coated with polyvinyl alcohol. These embodiments enable the method to be carried out when the polyvinyl alcohol on the surface is at a temperature higher than its melting temperature and in a sticky state, as the reactivity of the acid chloride deposited at a high temperature increases.

[0047] According to certain embodiments of the method according to the invention, the filamentary element is formed of at least one material selected from the group consisting of aramid fibers and microfibers, specifically Kevlar® (micro)fibers, and inorganic fibers and microfibers, specifically glass (micro)fibers and carbon (micro)microfibers. The filamentary element is formed of at least one fibrous or microfiber material that is heat-resistant, resistant to acidic media, and resistant to wear caused by the movement of the paper web. The filamentary element is formed of at least one fibrous or microfiber material that is inert to the fatty acid chlorides of the reactive composition.

[0048] According to certain embodiments of the method according to the invention, at least a portion of the gaseous hydrochloric acid formed by chromatogenic acylation is taken up at said acylation temperature by a stream of the gaseous composition circulating in contact with the solid material, in particular a countercurrent to the moving paper web. By removing the gaseous hydrochloric acid formed by the chromatogenic acylation reaction, it is possible to shift the equilibrium of the reaction in the direction of the acylation of the hydroxylated solid material and / or the paper material. By moving the formed hydrochloric acid, it is possible to prevent the degradation of the cellulose fibers of the paper material, more generally of the solid cellulose material, and the degradation of its mechanical strength properties, and the hydrochloric acid formed but not moved tends to facilitate the hydrolysis of the ester bond and the release of the acylated groups in free fatty acid form. By moving the formed hydrochloric acid, it is also possible to prevent the fatty acids released by this hydrolysis from adversely affecting the barrier properties of the acylated solid material.

[0049] According to certain other specific embodiments of the method according to the invention, the filamentary elements of at least one application roller are supplied by centrifugally diffusing the reactive composition from the axial inner cavity of the application roller that rotates by itself. In some of these embodiments, the reactive composition is introduced into the axial inner cavity of the application roller by a bar for distributing the reactive composition over substantially the entire length of the axial inner cavity, and the distribution bar extends over substantially the entire length of the axial inner cavity. According to certain specific embodiments, the distribution bar is pivotally mounted along the longitudinal axis of the distribution bar and along the axis of rotation of the application roller.

[0050] In these embodiments, the axial inner cavity of the application roller is suitable for accommodating a bar for supplying the reactive composition to the application roller and distributing the reactive composition over the entire length of the axial inner cavity. The distribution bar may be provided with orifices for dispersing the reactive composition, which are distributed along the distribution bar so that the reactive composition can be distributed over the entire length of the axial inner cavity of the application roller.

[0051] Any other form of supplying the filamentary elements is possible. According to certain other specific embodiments of the method according to the invention, the filamentary elements are suitable for filling the reactive composition by contact between the specifically rotated (external) application surface of the coating device and the device for dispensing the reactive composition. In some of these embodiments, the dispensing device is a cylinder known as an anilox roller, and is provided with a printing device having a plurality of concave cells formed on the outer surface of the anilox roller and having a predetermined dimension and volume suitable for controlling the amount of the reactive composition transferred onto the coating device.

[0052] In certain advantageous embodiments, at least one application roller is provided with means for heating the reactive composition to the acylation temperature. In these advantageous embodiments, the filamentary elements forming the application surface of the roller preferably act as a coating reservoir for fatty acid chlorides, specifically gaseous fatty acid chlorides.

[0053] According to certain embodiments of the method according to the present invention, at least one application roller rotates at a rotational angular velocity selected such that the peripheral end portion of the filamentary element rotates at a linear velocity having a value different from the value of the running speed of the paper web. In these other embodiments, the linear running speed of the free end of the filamentary element and the running speed of the paper web are not synchronized. The application of the reactive composition at the surface of the solid material and at a depth thereon is improved by a slight contact of the surface of the solid material and by discharging the reactive composition at a constant depth.

[0054] According to certain embodiments of the method according to the present invention, at least one application roller rotates in a rotational direction selected such that the peripheral end portion of the filamentary element moves in a countercurrent with respect to the movement of the paper web.

[0055] According to certain other embodiments of the method according to the present invention, at least one application roller rotates in a rotational direction selected such that the peripheral end portion of the filamentary element moves simultaneously with respect to the movement of the paper web.

[0056] According to certain embodiments of the method according to the present invention, the recovery of fatty acid chlorides on the paper web, specifically an excess of fatty acid chlorides, is carried out by a recovery device having a rotatable recovery surface provided with a filamentary element, the filamentary element not reacting with the reactive composition and · filling the fatty acid chloride by contact between the recovery surface and the paper web, and · releasing the fatty acid chloride by applying a flow of a gaseous composition heated to a temperature higher than the acylation temperature, specifically a temperature between the acylation temperature and the vaporization temperature of each fatty acid chloride of the reactive composition is possible.

[0057] According to certain embodiments, the flow of the gaseous composition is applied in contact with the recovery surface of the recovery device and / or in contact with the moving paper web.

[0058] An acylated solid material, specifically a paper web, substantially free of residual fatty acid chlorides and hydrochloric acid, is formed. The flow of the gaseous composition is applied in countercurrent to the running direction of the paper web in contact with the paper web so as to incorporate at least a part of the gaseous hydrochloric acid formed by acylation.

[0059] According to the invention, the reactive composition does not contain a solvent (except for possible trace amounts), specifically a non-polar solvent different from the fatty acid chloride.

[0060] The invention also relates to an acylated solid material obtainable by the method according to the invention. The invention also relates to an acylated solid material obtained by the method according to the invention.

[0061] The invention also relates to a method for the chromatogenic acylation of a solid material having hydroxyl groups which is available for at least one gaseous fatty acid chloride and is capable of reacting with this (these) gaseous fatty acid chloride(s), characterized in that it is in combination with all or some of the features described above or below. The various features described above or below should not be considered as being closely or tightly associated with each other in any form unless otherwise clearly specified. The invention can relate to only one of these structural or functional features, or only a part of these structural or functional features, or only a part of one of these structural or functional features, or actually to any population, combination, or juxtaposition of all or some of these structural or functional features.

[0062] Other objects, features, and advantages of the invention will become apparent by reading the following description, which refers to the accompanying drawings and to examples given only as non-limiting examples of the invention.

Brief Description of the Drawings

[0063]

Figure 1

[0064]

Figure 2

[0065]

Figure 3

[0066]

Figure 4

Embodiments for Carrying Out the Invention

[0067] A method for the chromatographic acylation of paper materials known from International Publication No. 2012 / 066015, which includes depositing a liquid fatty acid chloride on a paper material by means of a cylinder referred to as an anilox roll designed for printing, is not sufficient. The paper material obtained by such a known method contains a significant amount of free fatty acid chloride despite performing a final spraying (or "flashing") step. Since the remaining fatty acid chloride can be decomposed into free fatty acid and hydrochloric acid by hydrolysis, it can decompose solid materials. Furthermore, the formed free fatty acid changes the barrier properties of the solid material, and the remaining fatty acid chloride poses toxicity problems, especially for applications in the food packaging field and the biomedical field.

[0068] Methods for the chromatogenic acylation of tissues are also known from WO 2022 / 033698. According to this known method, stearic acid chloride is deposited on one side of the tissue brought to a temperature of 160° C. by a varnish roller impregnated with stearic acid chloride at room temperature. The amount of stearic acid chloride impregnated in the varnish roller and the amount deposited on the tissue are adjusted by continuous application without reloading the roller and by reducing the stearic acid chloride until the optimal amount of acid chloride impregnated in the roller is obtained. Subsequently, the tissue receiving the optimal amount of stearic acid chloride is placed in an oven at a temperature of 160° C. Such known methods cannot be applied as such on an industrial scale.

[0069] The above-known chromatogenic acylation method is illustrated in FIG. 1. Such known method includes a step 2' of heating the paper material 1' in an oven heated to a temperature referred to as the acylation temperature, which is sufficient to enable the acylation of the paper material 1' by the reaction of the gaseous fatty acid chloride 5', which is lower than the vaporization temperature of the fatty acid chloride, with the reactive hydroxyl of the paper material. In this known method, a high-temperature paper material 6' is formed at the acylation temperature. At the same time, 7', the varnish roller 3' with the coating surface formed by the pile 4' is impregnated by rolling in the liquid acid chloride 5' at atmospheric temperature under rolling conditions suitable for obtaining an optimal impregnation state enabling the deposition of an optimal amount of the liquid stearic acid chloride 5'. In this known method, the step 9' of applying the liquid stearic acid chloride 5' at atmospheric temperature to the high-temperature paper material 6' is carried out by rolling the impregnated varnish roller 8' on the high-temperature paper material 6', necessarily enabling the acylation of the high-temperature paper material 6' by the gaseous stearic acid chloride at a temperature lower than the acylation temperature and the formation of the acylated hydrophobic material 10'. According to this known method, the stearic acid chloride at room temperature and in an essentially liquid form is deposited on the paper material heated to a temperature sufficient to enable the chromatographic acylation of the paper material by the gaseous stearic acid chloride formed due to the temperature of the paper material.

[0070] A schematic diagram of the method according to the present invention for chromatogenic acylation of a solid material 1 having a hydroxyl group that is available for at least one gaseous fatty acid chloride and capable of reacting with this (these) fatty acid chlorides is shown in FIG. 2.

[0071] The hydroxylated solid material 1 may be a cellulosic material. The solid material 1 may also be formed of a fabric, specifically a fabric containing cotton fibers. The solid material 1 may be a paper material 1. That said, any kind of hydroxylated solid material can be used. The hydroxylated solid material 1 may have a non-uniform surface finish. This may be highly rough. However, the hydroxylated solid material 1 may also be a material with a uniform surface finish and low roughness, specifically calendared paper. The hydroxylated solid material 1 may be porous or non-porous. The hydroxylated solid material 1 may be a non-porous material having hydroxyl groups of a polymer that forms the free surface of the hydroxylated solid material, specifically PVA (polyvinyl alcohol). The hydroxylated solid material 1 may be a paper material that has been made non-porous and air-impermeable by surface coating with a PVA layer, as described in French Patent No. 2925910. The hydroxylated solid material 1 is less than 30 g / m 2 less, specifically less than 20 g / m 2 less, preferably less than 10 g / m 2 ~30 g / m 2 and, more preferably, between 10 g / m 2 ~20 g / m 2It may be a disposable paper tissue formed of a plurality of cellulose sheets having a basis weight therebetween. The paper material may be formed of crosslinked cellulose fibers with restricted rotational mobility, and the paper material is imparted with properties improved in terms of overall mechanical strength and particularly wet strength. Thereafter, the cellulose fibers are bonded to each other by hydrogen bonds and by covalent bonds formed with at least one group of crosslinking atoms such as 1-chloro-2,3-epoxypropane or epichlorohydrin derivatives. The hydroxylated solid material 1 may be a flexible material, i.e., deformable under the influence of its own weight. The hydroxylated solid material 1 may be a paper material in the form of a sheet of paper known as "paper towel", toilet paper, paper napkin, or filter paper. The hydroxylated solid material 1 may be cardboard. The cardboard may be rigid, i.e., not greatly deformed under the influence of its own weight. The hydroxylated solid material 1 is at least one corrugated paper sheet and 160 g / m 2 It may be a cardboard piece formed of at least one cardboard sheet having a basis weight exceeding

[0072] In the method according to the present invention shown in FIG. 2, a coating device 3 having a coating surface provided with a filamentous element 4 that does not react with the fatty acid chloride of a composition called a reactive composition 20 of at least one fatty acid chloride is selected. Such a coating device 3 is preferably selected that can be exposed to a temperature between 160° C. and 250° C. without impairing its adsorption function and coating function. This may be, for example, a filamentous element 4 of inorganic fibers or microfibers such as glass fibers or microfibers or carbon fibers or microfibers, or a filamentous element 4 of aramid fibers or microfibers such as aramid fibers known by the trademark Kevlar® or microfibers, and a coating surface is formed. The coating device 3 may be a coating roller, a coating pad, or a coating brush provided with the filamentous element 4. The coating device 3 may have a coating surface formed of a lipophilic filamentous element 4 (having an affinity for fatty substances). Any suitable type of lipophilic material can be used. However, the coating device 3 may have a coating surface formed of an oleophobic filamentous element 4. Specifically, the filamentous element may be a filamentous element 4 coated with a perfluorinated coating, specifically a Teflon® coating. The coating surface of the coating device 3 is formed of a chemically stable material that resists wear and temperature, particularly the acylation temperature. Preferably, the filamentous element has a free end suitable for cooperating with the surface of the hydroxylated solid material by brushing. The coating device 3 may be a roller suitable for showing resistance to the acylation temperature without impairing its adsorption characteristics and coating characteristics, specifically a roller of the “varnish roller” type. The filamentous element 4 is flexible and suitable for filling with fatty acid chloride and releasing at least a part of the filled fatty acid chloride, particularly by elastic deformation. The filamentous element 4 may have a length between 1 mm and 100 mm or more. The filamentous element may have a cross section between 1 μm and 1000 μm in diameter. The coating device may be a varnish roller, and its coating surface is 1 mm of the coating surface 2 per more than 10 filamentous elements, specifically 1 mm of the coating surface 2It is formed of a pile provided with filamentary elements having an injection density of filamentary elements between 50 and 500 per time. The filamentary elements are selected to exhibit the rigidity imparted by the rotation of the coating roller, especially during the rotation of the coating roller, and this rigidity is sufficient to enable the application of fatty acid chloride over at least a part of the thickness of the solid material without damaging the hydroxylated solid material. The filamentary elements have a flexibility selected so as not to damage the hydroxylated solid material by contact.

[0073] In the method according to the invention, a composition referred to as the reactive composition 20 of at least one fatty acid chloride is selected or prepared. The at least one fatty acid chloride is selected from the group consisting of fatty acid chlorides of the formula R-CO-Cl, wherein R is a hydrocarbon chain having from 13 (including the limit) to 29 (including the limit), specifically from 15 (including the limit) to 29 (including the limit) carbon atoms. The at least one fatty acid chloride is 16 ), stearic acid chloride (C 18 ), arachidic acid chloride (C 20 ), and behenic acid chloride (C 22 ) selected from the group consisting of. The at least one fatty acid chloride is behenic acid chloride (C 22 H 43 OCl), the vaporization temperature of which is about 385 ° C at atmospheric pressure. The at least one fatty acid chloride is palmitic acid chloride (C 16 H 31 OCl), the vaporization temperature of which is about 330 ° C at atmospheric pressure. The at least one fatty acid chloride is stearic acid chloride (C 18 H 35It is (OCl), and its vaporization temperature is about 350 ° C at atmospheric pressure. There is nothing that prevents the use of fatty acid chlorides that can be prepared by trans-chlorination of fatty acids using a trans-chlorinating agent such as acetyl chloride. The fatty acid chloride selected for the implementation of the method according to the present invention is liquid at room temperature. In the method according to the present invention, at least one liquid fatty acid chloride is impregnated into the filamentous element 4 of the coating device 3 5. This impregnation step 5 is carried out by bringing the filamentous element 4 into contact with the reactive composition 20 at room temperature, that is, at a temperature reached without using means for adjusting this temperature. However, there is nothing that prevents the filamentous element 4 from reaching a temperature higher than room temperature but necessarily lower than or at most equal to the acylation temperature during this impregnation 5. The temperature of the filamentous element 4 is suitable for essentially enabling the liquid reactive composition 20 to fill the filamentous element. There is nothing that prevents the reactive composition 20 from being brought to a temperature higher than room temperature but depending on the fatty acid chloride used so that the fatty acid chloride used is in an essentially liquid form and can be impregnated into the filamentous element 4 of the coating device 3 in a liquid state during this impregnation step 5. At the end of this impregnation step 5, a coating device 6 impregnated and filled with the liquid reactive composition 20 is formed.

[0074] In the method according to the present invention, a step 7 of heating the reactive composition 20 impregnated into the filamentous element 4 of the coating device 3 is carried out, and the reactive composition 20 is adapted to reach the acylation temperature. This heating 7 is carried out by any suitable means. These means may be radiant heating means (for example, by radiation in the infrared range), induction heating means, or convective heating means. These means may also be heating means specific to the coating device 3 and suitable for heating at least the filamentous element 4 and the reactive composition 20. At the end of this heating step 7, a coating device 3 provided with a filamentous element 8 filled with the reactive composition 20 brought to the acylation temperature is formed.

[0075] In the method according to the invention, before step 11 of applying the filamentary element 8 filled with and holding the reactive composition 20, step 9 of heating the solid material 1 is carried out so as to form a hydroxyl - modified solid material 10 at a high temperature, in particular at the acylation temperature. The application step 11 is carried out by rolling the coating device 3 on the hydroxyl - modified solid material 1. Advantageously, the hydroxyl - modified solid material 10 at a high temperature is at least partially dehydrated as a result of this heating 9. Furthermore, due to the fact that the hydroxyl - modified solid material 10 is at the acylation temperature, it is possible to maintain the reactive composition 20 at the acylation temperature, facilitate chromatogenic acylation, and assist in forming the acylated solid material 12.

[0076] Surprisingly, the inventor has observed that heating 7 of the reactive composition 20 adsorbed by impregnation of the filamentary element 4 of the coating device 3 enables the application of fatty acid chlorides to the hydroxyl - modified solid material 1 and the acylation of this hydroxyl - modified solid material 1 using gaseous acid chlorides. According to the invention, by applying the reactive composition 20 heated to the acylation temperature between 160 °C and 250 °C, no loss of gaseous fatty acid chloride due to diffusion into the atmosphere surrounding the filamentary elements 4, 8 occurs. In contrast, since the filamentary elements 4, 8 are considered to function, in particular, as reservoirs of gaseous fatty acid chlorides, they are capable of releasing / forming gaseous fatty acid chlorides in contact with the hydroxyl - modified solid material 1 and acylating it.

[0077] The present invention is contrary to the teachings provided by the prior art, which describes preferentially distributing liquid and necessarily low-temperature fatty acid chlorides by contacting them with low- or high-temperature solid materials, and then heating the low-temperature hydroxylated solid material to the acylation temperature or maintaining the high-temperature hydroxylated solid material at the acylation temperature. According to this teaching, the essentially liquid fatty acid chloride deposited in contact with the hydroxylated solid material constitutes a reservoir of essentially liquid fatty acid chloride disposed in contact with the hydroxylated solid material. According to this teaching, gaseous fatty acid chloride is formed in the vicinity of the available hydroxyls of the hydroxylated solid material due to heating the hydroxylated solid material to the acylation temperature. According to this teaching, the formation of gaseous fatty acid chloride in the vicinity of the available hydroxyls of the hydroxylated solid material makes it possible to overcome the drawbacks of the boundary layer. However, the teachings provided by the prior art cannot solve the problem of the remaining amount of liquid fatty acid chloride that has not been heated for a long enough time to vaporize and react with the gaseous hydroxylated solid material, especially due to the movement of the web of the hydroxylated solid material.

[0078] However, in a variant of the chromatogenic acylation method according to the present invention implemented on an industrial scale (not shown), there is nothing to prevent the hydroxylated solid material from taking the form of a web of paper wound in a roll, and this paper moves between an upstream reel and a downstream device for rewinding the web of acylated paper. In such a method implemented on an industrial scale, the paper has a running speed between 30 and 100 meters per minute. An example of an apparatus suitable for implementing such a method is shown in FIG. 4. In such a method, the reactive composition is applied at a fixed station to at least one major surface of the moving paper web. In such a method, the coating device comprises a coating roller provided with a filamentary element and having a coating surface arranged over the entire width of the paper web (i.e., the reel width). This roller has a rotational axis that is parallel to the plane in which the paper web travels but non-parallel, specifically orthogonal, to the running direction of this web. The roller is arranged vertically at a distance from the paper web so that the filamentary element lightly contacts the paper web without damaging the moving paper web. Advantageously, the roller may be of the type having an axial lumen for receiving the reactive composition and for distributing the reactive composition that is assisted by centrifugal force and conveyed along the filamentary element until it contacts the paper web.

[0079] In a certain advantageous embodiment, the roller is provided with means for heating the reactive composition to the acylation temperature. In these advantageous embodiments, the filamentary element forming the coating surface of the roller acts as a coating reservoir for the gaseous fatty acid chloride at the acylation temperature. In these advantageous embodiments, the volume in which the fatty acid chloride is at its saturated vapor pressure at the acylation temperature is limited to the free volume provided by the filamentary element of the roller heated to the acylation temperature. According to these advantageous embodiments, there is no need to provide a thermostat-controlled chamber at the acylation temperature in which the partial pressure of the fatty acid chloride is maintained at its saturated vapor pressure over its entire volume. That being said, there is nothing to prevent the provision of at least one fairing wall of the coating roller from preventing the gaseous fatty acid chloride from being confined in contact with the paper web.

[0080] In certain advantageous embodiments of the chromatogenic acylation method according to the invention carried out on an industrial scale, when the roller has an axial lumen for receiving the reactive composition and for centrifugally dispensing the reactive composition induced along the filamentous element until it contacts the paper web, the roller, specifically the heating roller, is supplied with fatty acid chloride by supplying the reactive composition into the axial lumen of the roller. In these embodiments, the impregnation of the filamentous element is effected at least in part by the centrifugal stress generated by the rotation of the roller, which the reactive composition undergoes within the coating roller.

[0081] In other embodiments, the coating apparatus may comprise, in addition to the roller, means for dispensing fatty acid chloride onto the roller. This may be a cylinder known as an anilox roller, which may be a cylinder for supplying the roller by lightly contacting the surface of the anilox roller with the filamentous element. Any type of anilox roller can be used. This can be used by adapting the dimensions of its cells and the surface density of the cells to the amount of fatty acid chloride deposited on the coating roller. The anilox roller may have a rotational angular velocity that is the same as or different from the rotational speed of the coating roll. The anilox roller may be supplied with liquid fatty acid chloride by the doctor blade chamber itself that specifically supplies the fatty acid chloride continuously.

[0082] The roller may rotate at a rotational angular velocity selected such that the free end of the filamentous element rotates at a linear velocity having a value different from the value of the running speed of the paper web. The linear velocity of the free end of the filamentous element and the running speed of the paper web are not necessarily the same and can be adjusted to provide the desired degree of contact. That said, the roller can rotate in a rotational direction selected such that the free ends of the filamentous elements of the pile move in a countercurrent or simultaneously with respect to the movement of the paper web.

[0083] In the chromatogenic acylation method according to the invention carried out on an industrial scale, there is nothing that prevents a roller and a dispensing device from being arranged in a thermally regulated housing maintained at the acylation temperature.

[0084] Although not shown, in an advantageous variant of the chromatogenic acylation method according to the invention carried out on an industrial scale, a flow of a gaseous composition capable of filling hydrochloric acid in contact with the paper web being acylated is formed so as to remove the hydrochloric acid formed as a result of this acylation from the paper web.

[0085] A schematic diagram of a variant of the method according to the invention for the chromatogenic acylation of solid materials 1, 2 which are available for at least one gaseous fatty acid chloride and which have hydroxyl groups capable of reacting with this (these) fatty acid chlorides is shown in FIG. 3. In this variant shown, a plurality of acylation steps 40, 50, 60 of the solid materials 1, 2 are carried out, each of the steps 40, 50, 60 comprising steps 11, 24, 34 of applying a reactive composition 20, 21, 22 to the solid materials 1, 2. The steps 40, 50, 60 of this plurality of steps can be carried out continuously in a manner known in the art on the same solid material 1, specifically on a piece of paper material. However, the steps 40, 50, 60 of this plurality of steps can be carried out during an industrial method for the chromatogenic acylation of a paper web 2 moving between an upstream reel of the paper web 2 and a downstream device 36 for rewinding the acylated paper webs 12, 25, 35. During this industrial scale implementation, each reactive composition 20, 21, 22 is applied by an application device 3, 15, 28 for applying the reactive composition 20, 21, 22 respectively. The application devices 3, 15, 28 are arranged at a distance from each other along the running zone of the paper webs 2, 12, 25, 35 extending in the thermally regulated chamber 39. Each reactive composition 20, 21, 22 may be formed of a single fatty acid chloride or may contain a plurality of fatty acid chlorides. Advantageously, each reactive composition does not contain an organic solvent either. The reactive compositions 20, 21, 22 may contain the same one or more fatty acid chlorides of different fatty acids and different fatty acid chain lengths.

[0086] The schematic diagram shown in Figure 3 also illustrates the method according to the invention carried out on an industrial scale for chromogenic acylation of the web 2 of paper material 1 moving between an upstream reel and a downstream device for rewinding the web of acylated paper. In this industrial method, the paper web 2 is moved by any means known to those skilled in the art, as a result of which the paper of the paper web 2 continuously passes through a plurality of successive treatment zones by this movement. The first stage 40 of acylation of the paper of the paper web 2 is carried out in the upstream zone of the plurality of successive treatment zones (with respect to the direction of travel of the paper web from upstream to downstream), then the second acylation stage 50 is carried out in the intermediate zone of this plurality of successive zones, and then the third acylation stage 60 is carried out in the downstream zone of this plurality of successive zones. For example, there is nothing to prevent the first acylation stage 40 from being carried out at an acylation temperature T1, the second acylation stage 50 from being carried out at an acylation temperature T2, and the third acylation stage 60 from being carried out at an acylation temperature T3, in which case T1 < T2 < T3.

[0087] During the first stage 40, the coating device 3 has a coating surface formed by a filamentary element 4 that does not react with the fatty acid chloride of the reactive composition 20. The coating device 3 and the filamentary element 4 are suitable for being arranged at a temperature of 160 °C to 250 °C without deterioration and without losing their coating function. In the method according to the invention carried out on an industrial scale, the coating device 3 may be a roller whose axis of rotation extends parallel to the plane of the moving paper web 2 but extends non-parallel, specifically orthogonally, to the running direction of this paper web 2. The coating device 3 is selected and arranged so as not to damage the paper of the moving paper web 2. During the first stage 40, the filamentary element 4 of the coating device 3 is impregnated with at least one liquid fatty acid chloride 5. This impregnation step 5 is carried out at a low temperature (i.e., a temperature lower than the assumed acylation temperature) by bringing the filamentary element 4 forming the coating surface of the coating device 3 into contact with the reactive composition 20 at the temperature reached at room temperature, i.e., without using means for adjusting this temperature. However, there is nothing to prevent the filamentary element 4 from being brought to a temperature higher than room temperature but necessarily lower than or at most equal to the acylation temperature during this impregnation 5. There is nothing to prevent the reactive composition 20 itself from being brought to a temperature higher than room temperature but depending on the fatty acid chloride used, during this impregnation step 5, so that the fatty acid chloride used is essentially in liquid form and can be filled in the filamentary element 4 of the coating device 3 in a liquid state. At the end of this impregnation step 5, a coating device 6 filled with the liquid reactive composition 20 is obtained.

[0088] In the method according to the invention, a step 7 of heating the reactive composition 20 adsorbed on the filamentary element 4 of the coating device 3 is carried out, and this heating step 7 is adapted so that the reactive composition 20 reaches the acylation temperature T1. This heating 7 is carried out by any suitable means. At the end of this heating step 7, a coating device 3 provided with a filamentary element 8 filled with the reactive composition 20 at the acylation temperature T1 is formed.

[0089] In the method according to the invention, the step 9 of heating the paper of the moving paper web 2 is carried out by rolling the coating device 3 on the hot paper 10 of the paper web 2 so as to form the hot paper 10 at the acylation temperature T1, before the step 11 of applying the hot filamentous element 8 holding the reactive composition 20. Further, due to the fact that the hot paper 10 is at the acylation temperature T1, it is possible to maintain the reactive composition 20 at the acylation temperature T1, facilitate chromatogenic acylation, and assist in forming the acylated solid material 12.

[0090] During the second chromatogenic acylation step 50, an application device 15 having an application surface formed by a filamentary element 16 that does not react with the fatty acid chloride of the second reactive composition 21 is used. The application device 15 and the filamentary element 16 are suitable for being arranged at a temperature of 160°C to 250°C without deterioration and without loss of the application function. In the method according to the invention carried out on an industrial scale, the application device 15 may be a roller having a rotation axis that extends parallel to the plane of the moving paper web 2 but extends non-parallel, specifically orthogonally, to the running direction of this paper. The application device 15 is selected and arranged so as not to damage the moving papers 1, 2, 14. During the second step 50, the filamentary element 16 of the application device 15 is impregnated with at least one liquid fatty acid chloride 17. This impregnation 17 is carried out at a temperature lower than the assumed acylation temperature T2 by bringing the filamentary element 16 into contact with the reactive composition 21 at the temperature reached without using means for adjusting this temperature, i.e., at room temperature. However, there is nothing to prevent the filamentary element 16 from reaching a temperature higher than room temperature during this impregnation 17. That being said, the filamentary element 16 is necessarily at a temperature lower than or at most equal to the acylation temperature T2. There is nothing to prevent the reactive composition 21 from being at a temperature higher than room temperature but at a temperature adopted according to the fatty acid chloride used during this impregnation step 17 so that the fatty acid chloride used is essentially in liquid form and the filamentary element 16 can be filled in a liquid state. At the end of this impregnation step 17, an application device 18 filled with the liquid reactive composition 21 is formed. Then, a step 19 of heating the reactive composition 21 adsorbed on the filamentary element 16 of the application device 15 is carried out, and the reactive composition 21 is adapted to reach the acylation temperature T2. This heating 19 is carried out by any suitable means. At the end of this heating step 19, an application device 3 is formed in which the filamentary element 23 is filled with the reactive composition 21 and brought to the acylation temperature T2.

[0091] The step 13 of heating the paper of the moving paper web 12 is performed by rolling the coating device 15 on the paper 14 and bringing the filamentous element 23 into contact with the hot paper 14 so as to form the hot paper 14 at the acylation temperature T2, before the step 24 of applying the reactive composition 21 to the hot paper 14. Further, due to the fact that the paper 14 is at the acylation temperature T2, it becomes possible to maintain the reactive composition 21 at the acylation temperature T2, facilitate chromatogenic acylation, and assist in forming the acylated paper 25 having acyl groups of the first reactive composition 20 and the second reactive composition 21.

[0092] In the embodiment shown, during the third stage 60, an application device 28 having an application surface formed of a filamentary element 29 that does not react with the fatty acid chloride of the reactive composition 22 is used. The application device 28 and the filamentary element 29 are suitable for being arranged at a temperature T3 between 160° C. and 250° C. without deterioration and without loss of the application function. In the method according to the invention carried out on an industrial scale, the application device 28 is preferably an application roller 28 having on itself a rotation axis that extends parallel to the plane of the paper of the moving paper webs 25, 2 but extends non-parallel, specifically orthogonally, to the running direction of this paper. The application device 28 is selected and arranged so as not to damage the paper of the moving webs 2, 25. During the second acylation stage 60, the filamentary element 29 is impregnated with at least one liquid fatty acid chloride 30. This impregnation 30 is carried out at a temperature lower than the assumed acylation temperature T3 by bringing the filamentary element 29 of the application device 28 into contact with the reactive composition 22 at the temperature reached at room temperature, i.e., without using means for adjusting this temperature. However, there is nothing to prevent the filamentary element 29 from reaching a temperature higher than room temperature but preferably lower than the acylation temperature T3 during this impregnation 30. There is nothing to prevent the reactive composition 22 from being brought to a temperature higher than room temperature but depending on the liquid fatty acid chloride used, such that the fatty acid chloride used is essentially in liquid form and can be filled in liquid state into the filamentary element 29 of the application device 28 by adsorption during this impregnation step 30. At the end of this impregnation step 30, an application device 31 filled with the liquid reactive composition 22 is formed. Then, a step 32 of heating the reactive composition 22 adsorbed / impregnated in the filamentary element 29 of the application device 28 is carried out, and the reactive composition 22 is adapted to reach the acylation temperature T3. This heating 32 is carried out by any suitable means. At the end of this heating step 32, a filamentary element 33 filled by impregnation with the reactive composition 22 brought to the acylation temperature T3 is formed.

[0093] The step 26 of heating the paper of the moving paper webs 2, 25 is performed to form the hot paper 27 at the acylation temperature T3 by rolling the coating device 28 on the paper 27, before the step 34 of applying the filamentous element 33 of the coating device 28 that holds the reactive composition 22. Further, due to the fact that the paper 27 is at the acylation temperature T3, it becomes possible to maintain the reactive composition 22 at the acylation temperature T3, facilitate chromatogenic acylation, and assist in forming the acylated solid material 35 having acyl groups of the first reactive composition 20, the second reactive composition 21, and the third reactive composition 22. Thereafter, another acylation step may be provided.

[0094] In one embodiment not shown, there is nothing that prevents the implementation of the final step of extracting the fatty acid chloride that may be present in excess on the running paper web. To do this, a recovery device equipped with an extraction roller, specifically a varnish roller having a recovery surface formed of a pile, can be applied to the paper web to remove the liquid fatty acid chloride from the paper.

[0095] An example of an acylating apparatus 100 that can be used to implement the method according to the present invention is shown in FIG. 4. The acylating apparatus 100 includes an upstream reel 66 of the web 2 of paper to be acylated and a downstream apparatus 36 for rewinding the web 35 of acylated paper. The acylating apparatus 100 is provided with means 37 for guiding the web 2 of paper moving between the upstream reel 66 and the downstream roll 36. The guiding means 37 includes a plurality of rollers for guiding the moving paper webs 2, 10, 12, 25, 35, and these are positioned to guide the paper webs 2, 10, 12, 25, 35 moving through the heat regulating chamber 39 of the acylating apparatus 100. The heat regulated and optionally compartmentalized chamber 39 has a first upstream zone 41 for the web of paper 1 to enter the first upstream zone 41 and the heat regulating chamber 39 (upstream as seen from the running direction 42 of the web 2 of paper 1). In this first upstream zone 41, there are provided at least one heated roller 38 and means for guiding the paper web 2 suitable for heating the paper web 2 to a temperature that enables at least partial dehydration while the paper web 2 is moving and before its acylation. The heat regulating chamber 39 extends downstream of the first upstream heating zone 41 and has a first acylation zone 43 suitable for the moving paper web 2 to pass through. The first acylation zone 43 may be provided with means (not shown) for heating and / or maintaining the atmosphere of this first acylation zone 43 at the chromatogenic acylation temperature T1. This zone also includes an apparatus 45 for dispensing at least one, specifically only one, reactive composition 20 of fatty acid chloride on the surface of the paper web 2. The dispensing apparatus 45 includes a support roller 44 and an application roller 3 having a coating surface formed by a filamentous element 4, specifically a filamentous element 4 forming a pile. The application roller 3 is suitable for rotating itself so that the filamentous element 4 sweeps the surface of the paper webs 2, 10 in light contact. The support roller 44 and the filamentous element 4 of the application roller 3 cooperate to guide the paper webs 2, 10 into contact with the filamentous element 4 of the application roller 3.

[0096] The heat regulation chamber 39 extends downstream of the first acylation zone 43 and has a second acylation zone 48 suitable for the web 2 of the moving paper 12 processed in the first acylation zone 43 to pass through. The second acylation zone 48 may be provided with means (not shown) for heating and / or maintaining the atmosphere of this second acylation zone 48 at the chromatogenic acylation temperature T2. This zone also comprises an apparatus 51 for dispensing at least one, specifically only one, reactive composition 21 of fatty acid chloride. The dispensing apparatus 51 comprises a support roller 49 and an application roller 15 having a coating surface formed by the filamentary elements 16, specifically the filamentary elements 16 forming a pile, and being suitable for rotating so as to sweep the surface of the web 2 of the moving paper 12 with a light contact by the filamentary elements 16. The support roller 49 and the application roller 15 cooperate to guide the web by bringing the web 2 of the paper 12 into contact with the filamentary elements 16 of the application roller 15.

[0097] The heat regulation chamber 39 extends downstream of the second acylation zone 48 and has a third acylation zone 54 suitable for the moving paper web 2 processed in the second acylation zone 48 to pass through. The third acylation zone 54 may be provided with means (not shown) for heating and / or maintaining the atmosphere of this third acylation zone 54 at the chromatogenic acylation temperature T3. This zone also comprises an apparatus 56 for dispensing at least one, specifically only one, reactive composition 22 of fatty acid chloride. The dispensing apparatus 56 comprises a support roller 55 and an application roller 28 having a coating surface formed by the filamentary elements 29, specifically the filamentary elements 29 forming a pile, and being suitable for rotating so as to sweep the surface of the web 2 of the moving paper with a light contact by the filamentary elements 29. The support roller 55 and the application roller 28 cooperate to guide the paper web 2 by bringing one side of the paper web 2 into contact with the application roller 28.

[0098] In certain advantageous embodiments, at least one, and in particular each of the coating rollers 3, 15, 28, is provided with means for heating the corresponding reactive compositions 20, 21, 22 to the acylation temperatures T1, T2, T3. In these embodiments, the first acylation zone 43, the second acylation zone 48, and the third acylation zone 54 of the thermally regulated and / or compartmentalized chamber 39 are not necessarily heated to the corresponding acylation temperatures T1, T2, T3 respectively. Further, at least one of the coating rollers 3, 15, 28, specifically each of them, advantageously has an axial lumen for specifically and continuously supplying the reactive compositions 20, 21, 22 to the filamentary elements 4, 16, 29 by means of centrifugation.

[0099] Nor is there anything preventing at least one, and in particular each, of the support rollers 44, 49, 55 from being a heating roller suitable for assisting in heating the paper web 2 to the acylation temperature.

[0100] In certain other embodiments not shown, at least one, and in particular each, of the dispensing devices 45, 51, 56 may comprise a cylinder known as an anilox roller for supplying the reactive compositions 20, 21, 22 to the coating rollers 3, 15, 28. The anilox roller is arranged to be slightly tangentially contactable by the corresponding coating rollers 3, 15, 28. In these embodiments, the temperature of the anilox roller and the temperature of the reactive compositions 20, 21, 22 presented by the corresponding anilox roller are substantially the same as the temperature of the coating rollers 3, 15, 28. The anilox roller may be supplied with liquid fatty acid chloride by the doctor blade chamber itself that specifically and continuously supplies fatty acid chloride. In these embodiments, the doctor blade chamber forms a wall covering the anilox roller facing its peripheral surface, except for an open strip that allows contact between the anilox roller and the coating rollers 3, 15, 28.

[0101] The heat regulation chamber 39 extends downstream of the third acylation zone 54 and has a zone 59 for extraction and reverse exchange of fatty acid chlorides that may be present in excess on the moving paper web. In the extraction zone 59, an extraction roller 62 having a recovery surface formed by filamentary elements 63 is provided, which cooperates with a support roller 61 arranged so as to be able to guide the running paper web 35. The recovery surface of the extraction roller 62 may be a pile provided with filamentary elements 63 capable of filling excess fatty acid chloride on the surface of the paper web 35. Advantageously, a gaseous composition stream 64, specifically an air stream, heated to a temperature higher than the acylation temperature, specifically between the acylation temperature and the vaporization temperature of at least one of the reactive compositions, specifically each fatty acid chloride, is applied in contact with the paper web 2 so as to capture the remaining fatty acid chloride vaporized under the influence of the gaseous composition stream 64. The stream 64 of the gaseous composition filled with fatty acid chloride is continuously taken in through the acylation zones 54, 48, 43, countercurrent to the running direction of the paper web 2 from downstream to upstream, and further enables the capture of gaseous hydrochloric acid formed by the acylation reaction in the heat regulation chamber 39.

[0102] In certain embodiments, the extraction roller 62 is heated to a temperature that facilitates the vaporization of fatty acid chloride, especially a temperature between 250 °C and 400 °C. In other embodiments, the stream of the gaseous composition heated to the vaporization temperature is applied onto the filamentary elements of the extraction roller.

[0103] In certain embodiments, the gaseous atmosphere of the heat-regulated and / or compartmentalized chamber 39, and / or the gaseous atmosphere extending into the inner cavity of at least one of the coating rollers 3, 15, 28, is depleted of gaseous oxygen. In these embodiments, a stream of at least one inert gas is introduced into the heat-regulated and / or compartmentalized chamber 39 and / or into the gaseous atmosphere extending into the inner cavity of at least one of the coating rollers 3, 15, 28.

[0104] Example 1 - Coating Conditions An application device is fabricated using glass microfibers joined together to form an application brush or pad. Glass microfibers that are resistant to temperatures between 160 °C and 250 °C are selected. These are preferably inert to the fatty acid chlorides to be used. The application brush is filled by briefly contacting a 100 mm × 100 mm sized microfiber fiber sheet impregnated with 4 ml of undiluted liquid fatty acid chloride. This qualitative approach has been shown to allow the deposition of a minimal amount of fatty acid chloride onto the solid material by maintaining contact between the brush and the solid material for only a few seconds to impart an acceptable hydrophobicity to the treated paper material after the acylation reaction has occurred.

[0105] Using the application brush filled with fatty acid chloride in this way, the fatty acid chloride is applied to the hydroxylated solid material. The application brush can be applied to the paper material with a contact time between the tip of the application brush and the hydroxylated solid material on the order of about one-tenth of a second, such that the tip of the microfiber brush deforms upon contact, creating a close physical contact between the microfibers of the brush and the surface of the paper material and facilitating the transfer of the fatty acid chloride.

[0106] However, by sliding the tip of the application brush over the surface of the paper material, it is possible to apply the fatty acid chloride like a paint. By applying the fatty acid chloride with the brush in this way, it becomes possible to mimic the application of the fatty acid chloride to the moving paper, which can be performed by, for example, a varnish roller provided with a filamentous element, by adopting an immediate application rather than a continuous application of the reagent.

[0107] Example 2 - Coating Conditions - Variable Temperature of the Application Brush - Paper Material at Room Temperature Example 2 describes the application of fatty acid chloride with an application brush, which applies a high-temperature acid chloride to a paper material at room temperature. Palmitic acid chloride (C 15 H 31 -CO-Cl) or stearic acid chloride (C 17 H 35-CO-Cl) was applied to blotting paper (Canson, 125 g / m 2 ) using the application brush described in Example 1. After filling with fatty acid chloride, it was maintained at the acylation temperature in a thermostat-controlled oven. After filling, the application brush was wrapped in aluminum foil to maintain its temperature and placed in a thermostat-controlled oven at the acylation temperature. After removing the aluminum foil, as described in Example 1, the fatty acid chloride at the acylation temperature was applied by bringing the hot application brush into point contact with the blotting paper at room temperature. At the end of this contact, when the blotting paper was placed in an oven at 180 °C for several minutes, the acylation reaction could occur, and then it was cooled to room temperature. The hydrophobicity of the treated blotting paper was evaluated by immersion in distilled water. The effectiveness of acylation can be evaluated by the hydrophobicity of the obtained blotting paper. The size of the formed hydrophobic spots was measured, and the hydrophobic properties of the blotting paper were evaluated by the strength reflecting its resistance to wetting.

[0108] It was observed that the application of the reagent with an application brush maintained at room temperature produced limited hydrophobic spots corresponding to the deposition zone of fatty acid chloride. As the temperature of the application brush increased, the size and hydrophobic strength of the observed spots increased up to a temperature limit value above which the hydrophobicity decreased. This limit value is about 200 °C for palmitic acid chloride (C 16 ) and about 220 °C for stearic acid chloride (C 18 ).

[0109] These results indicate that the effectiveness of acylation and the quality of the resulting grafting depend on the temperature of the application brush and its filamentous elements, as well as the temperature of the reactive composition containing the fatty acid chloride held by the filamentous elements. Unexpectedly, heating the fatty acid chloride held by the application brush necessarily involves shifting the liquid / vapor equilibrium of the fatty acid chloride to the vapor state, which actually does not cause loss of gaseous fatty acid chloride by diffusion into the atmosphere, but enables grafting of gaseous fatty acid chloride onto the paper material without substantially leaving liquid fatty acid chloride on the paper material.

[0110] Therefore, the present invention is contrary to the prior art concept that in order to enable the acylation of a moving paper web by heating the fatty acid chloride deposited on the paper web, it is necessary to deposit the fatty acid chloride in a substantially liquid state on this paper web by printing on the paper web.

[0111] Example 3 - Coating Conditions - High - Temperature Coating Brush - Paper Material at Variable Temperature Fatty acid (palmitic acid C 16 or stearic acid C 18 ) chloride is applied to the paper material heated to a temperature higher than room temperature by a high - temperature coating brush impregnated with the corresponding acid chloride. The coating brush impregnated with palmitic acid chloride (C 16 ) is maintained at a temperature of 200 °C, and the coating brush impregnated with stearic acid chloride (C 18 ) is maintained at a temperature of 220 °C as described in Example 1. The fatty (palmitic or stearic) acid chloride is placed in an oven at the acylation temperature and applied to blotting paper (Canson, 125 g / m 2 ). Immediately after applying the fatty acid chloride, a second blotting paper is placed on the blotting paper that was the subject of this application as a paper developing sheet. The superposition of the two "emitter / developer" sheets is maintained in the oven at the acylation temperature for several minutes. The hydrophobicity imparted to the developer sheet indicates that there is excess fatty acid chloride on the emitter sheet of the paper that did not react with this emitter sheet of the paper at the acylation temperature.

[0112] By combining the thermal deposition of palmitic acid chloride (C 16 ) on the emitter blotting paper at a temperature of 140 °C, 170 °C, or 200 °C by a coating brush heated to a temperature of 200 °C, it becomes possible to demonstrate that acylation is facilitated by the blotting paper at a higher temperature, especially at a temperature close to (or equal to) the temperature of the coating brush and the fatty acid chloride associated with the brush. The developer sheet superposed on the emitter sheet itself at 140 °C has high hydrophobicity. The hydrophobicity of the developer sheet decreases when the emitter sheet is at a temperature of 170 °C and becomes almost undetectable when the emitter sheet is at a temperature of 200 °C.

[0113] By combining the thermal deposition of stearyl chloride (C 18 ) onto an emitter absorbent paper piece at a temperature of 160 °C, 190 °C, or 220 °C using a coating brush heated to a temperature of 220 °C, it becomes possible to demonstrate that acylation is facilitated by the absorbent paper at a higher temperature, particularly at a temperature equal to the temperature of the coating brush and the fatty acid chloride associated with the brush. The developed piece overlaid on the emitter piece itself at 160 °C has high hydrophobicity. The hydrophobicity of the developed piece decreases when the emitter piece is at a temperature of 190 °C and becomes almost undetectable when the emitter piece is at a temperature of 220 °C.

[0114] The presence and amount of free acid chloride remaining on the emitter paper piece strongly depend on the temperature of the coating brush, the temperature of the fatty acid chloride associated with the brush, and the temperature of the paper piece on which the fatty acid chloride is deposited.

[0115] By combining the high-temperature deposition of fatty acid chloride onto a paper material piece itself at the acylation temperature using a coating brush heated to an acylation temperature between 160 °C and 220 °C, it becomes possible to obtain optimal acylation of the paper material that is completed almost instantaneously, particularly in 1 / 10 of a second, and is suitable for the treatment of a moving paper web while it is moving. Since the deposition of an amount of fatty acid chloride greater than the stoichiometric amount of available hydroxyls on the paper material makes it possible to leave residues of fatty acid chloride on the surface of the paper material, it goes without saying that such optimal acylation can only be achieved by controlling and adjusting the amount of fatty acid chloride deposited on the paper material.

[0116] Example 4 - Coating Conditions - High-Temperature Coating Brush - High-Temperature Paper Material - Continuous Deposition A series of high-temperature depositions of fatty acid chlorides is carried out on the same zone of a blotting paper piece referred to as the emitter piece, and each deposition of the series of depositions is carried out as described in Example 3 by a hot application brush filled with fatty acid chloride. After each high-temperature deposition of the series of depositions, a developing paper piece is overlaid on the emitter piece, and the overlay of the two "emitter / developer" pieces is maintained in an oven at the acylation temperature for several minutes. The hydrophobicity imparted to the developing piece indicates that there is an excess of fatty acid chloride on the emitter piece of the paper that did not react with this emitter piece of the paper at the acylation temperature. The hydrophobicity of the emitter piece increases with the number of depositions. The hydrophobicity of the developing piece corresponding to the first two depositions is still low, but increases with the third deposition. From this example, it is clear that acylation occurs during the first two depositions without a significant release of fatty acid chloride from the emitter piece, and only the third deposition is accompanied by a significant release of fatty acid chloride, resulting in the acylation of the third developing sheet. To enhance the efficiency of the chromatographic acylation reaction, it is desirable to carry out acylation at a high temperature compatible with the thermal resistance of the paper material and to carry out several consecutive depositions of a small amount of fatty acid chloride. This is emphasized by the fact that the grafting and immobilization of fatty acid chloride on the paper material has the effect of shifting the liquid / vapor equilibrium of fatty acid chloride towards the formation of fatty acid chloride and its grafting on the paper material by the mass effect. The paper material and surface hydroxyl groups tend to act like a specific "pump" for the vaporous fatty acid chloride, reducing the concentration of the vaporous fatty acid chloride on the substrate and facilitating the diffusion of the reagent from the application brush to the paper material.

[0117] The effectiveness of the chromatogenic acylation reaction is determined by evaluating the hydrophobicity of the acylated solid material by measuring the contact angle formed between the main plane of the acylated solid material and a droplet of pure water deposited on the surface of the acylated solid material. Typically, the value of the contact angle of the acylated solid material is between 90° and 150°, and a contact angle value of 150° corresponds particularly to hydrophobic and water-repellent materials. The quality of the acylation is also determined by measuring the period during which the contact angle value between 90° and 150° is maintained at room temperature and by means of the water pocket test. The water pocket test can only be carried out using a solid material in the form of a substantially square and flexible sheet that allows its corners to be brought together to form a water pocket. The impermeability of this water pocket is analyzed by monitoring the loss of water (taking evaporation into account).

[0118] Hydrophobicity can also be evaluated by observation of water repellency. 1 ml of distilled water is deposited on the surface of the solid material, and it is observed whether the formed water droplet adheres to the surface of the solid material and rolls on the surface or not. Good water repellency corresponds to a contact angle of about 150°C.

[0119] The present invention can be subject to numerous variations and applications other than those described above. In particular, unless otherwise specified, the various structural and functional features of the above embodiments should not be considered to be combined with each other and / or closely and / or tightly associated, but rather should be regarded as mere juxtapositions. Furthermore, the structural and / or functional features of the various embodiments described above can be the subject of any different juxtapositions or any different combinations, in whole or in part.

Claims

1. A method for chromatogenic acylation of solid materials (1, 2) having hydroxyl groups that are available for use with at least one gaseous fatty acid chloride and that can react with these gaseous fatty acid chlorides, At least one composition, referred to as a reactive composition (20, 21, 22), comprising at least one fatty acid chloride, is applied to at least the surface of the hydroxylated solid material (1, 2) by at least one coating device (3, 15, 28) having a coating surface formed of filamentous elements (4, 16, 29), wherein the filamentous elements do not react with the reactive composition (20, 21, 22), and the contact between the filamentous elements (4, 16, 29) and the hydroxylated solid material (1, 2) allows the reactive composition (20, 21, 22) to be released onto at least the surface of the hydroxylated solid material (1, 2). The reactive composition (20, 21, 22) applied by the coating device (3, 15, 28) onto at least the surface of the hydroxylated solid material (1, 2) is selected such that, during the application process, the acylation temperature is lower than the vaporization temperature of at least one fatty acid chloride of the reactive composition (20, 21, 22) and allows acylation of the solid material (1, 2) by a reaction between at least one gaseous fatty acid chloride of the reactive composition (20, 21, 22) and at least one of the hydroxyl groups of the solid material (1, 2), and the acylation temperature is between 160°C and 250°C. method.

2. The method according to claim 1, characterized in that at least one coating surface portion of the coating apparatus (3, 15, 28) is in contact with the surface portion of the hydroxylated solid material (1, 2), and at least this surface portion of the hydroxylated solid material (1, 2) is at the acylation temperature while the reactive composition (20, 21, 22) is being applied to the hydroxylated solid material (1, 2).

3. The method according to claim 1, characterized in that the filamentous elements (4, 16, 29) forming the coated surface are at the acylation temperature while the reactive composition (20, 21, 22) is applied to the hydroxylated solid material (1, 2).

4. The method according to claim 1, characterized in that the reactive composition (20, 21, 22) is applied to at least the surface of the hydroxylated solid material (1, 2) in a thermal control chamber (39) suitable for maintaining the reactive composition (20, 21, 22) released by the coating device (3, 15, 28) at the acylation temperature.

5. The method according to claim 1, comprising at least one step of redistributing fatty acid chlorides deposited on the hydroxylated solid material without supplying new reactive compositions (20, 21, 22), wherein the redistribution step is performed by at least one distributing device having a coating surface formed of filamentous elements, wherein the filamentous elements do not react with the fatty acid chlorides of the reactive compositions, and the filamentous elements of the distributing device fill the hydroxylated solid material (1, 2) with the fatty acid chlorides deposited on the hydroxylated solid material by contact between the filamentous elements of the distributing device and the hydroxylated solid material (1, 2), and at least a portion of the filled fatty acids can be released in contact with the hydroxylated solid material (1, 2) by contact between the filamentous elements and the hydroxylated solid material (1, 2), and the distributing device is at a temperature between 160°C and 250°C.

6. The method according to claim 1, characterized in that at least one reactive composition (20, 21, 22) comprises at least one fatty acid chloride selected from the group formed by palmitate chloride (C16), stearate chloride (C18), arachidin chloride (C20), and behenate chloride (C22).

7. The method according to claim 1, characterized in that the hydroxylated solid material (1, 2) is a paper material.

8. The method according to claim 1, characterized in that the hydroxylated solid material (1, 2) is a paper web (2, 10, 12, 25) and is formed by a paper web that moves in a running direction (42) parallel to the maximum dimension of the web (2, 10, 12, 25, 35) between an upstream reel (66) of the paper web (2, 10, 12, 25, 35) and a downstream take-up roll (36) for the acylated paper web (12, 25, 35).

9. The method according to claim 8, characterized in that at least one reactive composition (20, 21, 22) is applied at a fixed station on at least one main surface of the moving paper web (2, 10, 12, 25).

10. The method according to claim 8, characterized in that at least one coating device (3, 15, 28) is a roller having a rotation axis that is parallel to the plane of the paper web (2, 10, 12, 25) but not parallel to the running direction (42).

11. The method according to claim 8, comprising at least two applications of the reactive composition (20, 21, 22) at a fixed station on the moving paper web, wherein the reactive composition (20, 21, 22) is at the acylation temperature during the application.

12. The method according to claim 8, characterized in that the solid material (1, 2) is a paper material coated with polyvinyl alcohol.

13. The method according to claim 8, characterized in that the filamentous elements (4, 16, 29) of at least one coating roller (3, 15, 28) are supplied with the reactive composition (20, 21, 22) by centrifugal diffusion from the axial lumen of the coating roller (3, 15, 28) which rotates on its own.

14. The method according to claim 13, characterized in that the reactive composition (20, 21, 22) is introduced into the axial lumen of the coating roller (3, 15, 28) by a bar for distributing the reactive composition (20, 21, 22) over the length of the axial lumen, and the distribution bar extends over substantially the entire length of the axial lumen.

15. The method according to claim 8, characterized in that at least one coating roller (3, 15, 28) is provided with means for heating the reactive composition (20, 21, 22) to the acylation temperature.

16. The recovery of fatty acid chlorides on the paper web (12, 25, 35) is performed using a recovery device (62) having a rotatable recovery surface (63) equipped with filamentous elements, wherein the filamentous elements do not react with the reactive composition, and The fatty acid chloride is filled by contact between the recovery surface (63) and the paper web (12, 25, 35), A flow (64) of a gaseous composition heated to a temperature higher than the acylation temperature, wherein the flow (64) of the gaseous composition is applied in contact with the recovery surface (63) to release fatty acid chlorides. The method according to claim 8, which makes it possible.

17. The method according to claim 1, characterized in that the filamentous elements (4, 16, 29) are formed from at least one material selected from the group consisting of aramid fibers and microfibers, and inorganic fibers and microfibers.

18. The method according to claim 1, characterized in that at least a portion of the gaseous hydrochloric acid formed by the chromatogenic acylation is taken up by a flow of gaseous composition circulating in contact with the solid materials (1, 2) at the acylation temperature.

19. The method according to any one of claims 1 to 18, characterized in that the reactive composition (20, 21, 22) does not contain a solvent.

Images