FR3135980A1 - PROCESS FOR ACYLATION OF A HYDROXYLATED SOLID MATERIAL - Google Patents

Abstract

The invention relates to a process for the chromatogenic acylation of a solid material (1,2) carrying hydroxyl groups capable of reacting with fatty acid chlorides in the gaseous state, in which: a composition (20,21 ,22) reactive fatty acid chloride is applied to the surface of said solid hydroxylated material (1,2) by means of an applicator capable of releasing the composition (20,21,22) to the surface of said material (1,2). ), According to the invention, said composition (20,21,22) is applied to the surface of said hydroxylated solid material (1,2), at an acylation temperature lower than the vaporization temperature of at least one chloride of fatty acid of said composition (20,21,22) to allow acylation of said material (1,2) by reaction of at least one fatty acid chloride in the gaseous state of said composition (20,21,22) on at least one of the hydroxyl groups of said material (1,2), said acylation temperature being between 160°C and 250°C. Abstract Figure: Figure 4

Description

PROCESS FOR ACYLATION OF A HYDROXYLATED SOLID MATERIAL

The invention relates to a process for the chromatogenic acylation of a solid hydroxylated material, that is to say a solid material carrying reactogenic hydroxyl (–OH) groups, accessible and capable of reacting with a hydrochloride. fatty acid in gaseous state.

Throughout the text, the term "chromatogenic" and the expression "by chromatogeny" qualifying the acylation reaction, indicate and recall that this acylation reaction or more simply "acylation" occurs between a solid hydroxylated material such as a paper support considered in the field of separative gas chromatography (CPG), such as the stationary phase and a fatty acid chloride reagent at least partially in the gaseous state and considered as an eluate brought into liquid/vapor equilibrium by the mobile gas phase consisting of a flow of a hot gas phase.

We know from WO2012/066015 a semi-industrial process for chromatogenic acylation of a strip of a cellulosic substrate such as paper, driven in movement between an upstream winder and a downstream winder. According to this semi-industrial process, fatty acid chloride (R-CO-Cℓ) in the liquid state is deposited at a fixed upstream station by means of a cylinder, called anilox, on the paper of the driven paper strip moving then is heated downstream of the deposit to a temperature allowing acylation. A fraction of fatty acid chloride changes to the gaseous state due to the increase in the saturated vapor pressure of the fatty acid chloride, linked to the increase in the heating temperature. The gaseous fatty acid chloride reacts with reactogenic hydroxyls in the paper to form ester bonds 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).

Chromatogenic acylation is advantageously carried out without organic solvent or catalyst so that their elimination is not necessary at the end of the reaction. Acylation is promoted by the elimination of gaseous hydrochloric acid (HCℓ) produced due to acylation, which is driven by the application of a flow of hot air to the cellulose substrate being acylated. The entrainment of the gaseous hydrochloric acid formed makes it possible to shift the equilibrium of the reaction in the direction of the formation of the acylated cellulose substrate.

The inventor, however, noted that the process of WO2012/066015 is not optimized. On the one hand, the acylated cellulosic substrate according to WO2012/066015 has a hydrophobicity qualitatively lower than that of an acylated cellulosic substrate obtained by impregnation of the substrate with a solution of fatty acid chloride in pentane then heating the impregnated substrate by application of a hot gas flow. This process does not make it possible to give the cellulosic substrate hydrophobicity and, where applicable, optimal water impermeability and sufficient durability over time. He noted that the contact angle of a drop of pure water deposited on the surface of an acylated cellulosic substrate according to the process of WO2012/066015 is certainly greater than 90°, but remains lower than the optimal value of 150° obtained by application of the solution of fatty acid chloride in pentane. This results in unsatisfactory hydrophobic properties. On the other hand, it does not make it possible to effectively acylate the paper of a strip of paper - in particular a strip of special paper of heavy weight and/or of porous paper having a high specific surface area and/or of paper having a layer surface area of polyvinyl alcohol - driven in scrolling at a speed greater than 50 meters per minute. The method of WO2012/066015 is in reality incompatible with implementation on an industrial scale. Indeed, the optimal acylation of such a strip of paper could only be obtained at the cost of excessive deposition of fatty acid chloride and/or excessive heating of the paper which would necessarily lead to deterioration and/or browning of the latter.

The invention aims to overcome the aforementioned drawbacks of the method of WO2012/066015.

We also know from WO2022/033698, a solvent-free chromatogenic acylation process of a piece of paper heated to a temperature of 160°C and on which stearic acid chloride in the liquid state is deposited by means of an applicator roller whose applicator surface is formed of velvet. In this process, neither the velvet nor the applicator roller are heated, so that the stearic acid chloride loaded on the velvet is necessarily at a temperature lower than the acylation temperature during deposition, in particular at a temperature between room temperature and acylation temperature. The piece of paper is then subjected to a subsequent heat treatment to finalize the acylation. The process of WO2022/033698 makes it possible to confer satisfactory hydrophobic properties to the acylated part. On the other hand, the process of WO2022/033698 is not completely ready to allow the acylation of the paper of a strip of paper driven in scrolling at very high speed, in particular at a scrolling speed greater than 100 meters per minute. Despite the improvements made by WO2022/033698, there necessarily remains ungrafted liquid fatty acid chloride on the paper. On the one hand, such excess is not economically acceptable. Such excess is also not functionally acceptable. Residual liquid fatty acid chloride is likely to be hydrolyzed during prolonged storage of acylated paper, releasing hydrochloric acid. The released hydrochloric acid can deteriorate cellulose fibers and cellulose material, affecting its mechanical strength. In addition, the fatty acid released due to this hydrolysis reduces the hydrophobicity and water impermeability of the acylated paper. This excess must therefore be eliminated. The process of WO2022/033698 must be optimized and its economic efficiency must be improved.

The invention aims to overcome this drawback.

The invention therefore aims to propose an improved process for the chromatogenic acylation of a solid material carrying hydroxyl groups accessible to at least one fatty acid chloride in the gaseous state and capable of reacting with this chloride(s). s) fatty acid in the gaseous state.

The invention therefore aims to propose such a chromatogenic acylation process whose acylation yield is improved.

The invention also aims to propose such an improved process making it possible to increase the speed of chromatogenic acylation.

The invention also aims to propose such a chromatogenic acylation process making it possible to give a hydroxylated solid material satisfactory hydrophobic properties.

In particular, the invention aims to provide such a chromatogenic acylation process making it possible to give a hydroxylated solid material satisfactory hydrophobic properties with a reduced quantity of fatty acid chloride.

But the invention also aims to propose such a process for chromatogenic acylation of a solid hydroxylated material and transformation of this solid hydroxylated material into an acylated material substantially of the same porosity as the starting solid hydroxylated material.

The invention aims to propose such a process for the chromatogenic acylation of a solid hydroxylated material capable of being implemented in a traditional manner by any individual with commonly accessible means.

But the invention also aims to propose an industrial process for acylation of a width of paper during its movement between an upstream reel of said width of paper and a downstream winding device of a width of acylated paper.

In particular, the invention therefore aims to propose such an industrial chromatogenic acylation process which is compatible with the technical constraints relating to the movement of the solid material and a high rate of production of such an acylated solid material.

The invention aims in particular to propose such a process making it possible to deposit the desired quantity - in particular a significant quantity, in the case of special solid materials - of fatty acid chloride, while allowing high speed movement of the solid material.

Furthermore, the invention also aims to propose such a chromatogenic acylation process which does not require for its implementation to use an organic solvent toxic to the environment, in particular an apolar organic solvent.

But the invention also aims to propose such a chromatogenic acylation process making it possible to limit the quantity of residual fatty acid chloride at the end of the acylation.

The invention also aims to propose such a chromatogenic acylation process making it possible to deposit an optimal quantity of reactive fatty acid chloride, relative to the number and/or density of reactogenic hydroxyls, accessible and capable of reacting with fatty acid chloride in the gaseous state.

The invention thus aims to propose such a chromatogenic acylation process allowing substantially stoichiometric acylation of the reactogenic hydroxyls of the solid material.

The invention also aims to propose such a chromatogenic acylation process allowing acylation of different solid materials, in particular special solid materials such as corrugated cardboard and/or papers coated with polyvinyl alcohol.

The invention also aims to propose such a chromatogenic acylation process making it possible to reduce or even completely eliminate the step of eliminating excess fatty acid chloride.

The invention therefore aims in particular to propose such a simplified process since it does not require a final step of eliminating residual non-grafted fatty acid chloride.

To do this, the invention relates to a process for the chromatogenic acylation of a solid material carrying hydroxyl groups accessible to at least one fatty acid chloride in the gaseous state and capable of reacting with this chloride(s). s) fatty acid in the gaseous state, in which:

at least one composition, called reactive composition, of at least one fatty acid chloride is applied at least to the surface of said hydroxylated solid material by means of at least one device - in particular an applicator roller - having a shaped applicator surface filiform elements not reactive with said reactive composition and capable of being able to release - and apply - said reactive composition at least on the surface - that is to say on the surface and, where appropriate, in depth on at least a part thickness- of said solid hydroxylated material by contact of the filiform elements - in particular by contact of the filiform elements rotated by the roller - and of the solid hydroxylated material;

characterized in that said reactive composition applied - in particular released in contact with said solid hydroxylated material - by the applicator device at least on the surface of said solid hydroxylated material is, during its application, at a temperature, called acylation temperature, lower than the vaporization temperature of at least one - in particular of each - fatty acid chloride of said reactive composition and chosen to allow acylation of said solid material by reaction of at least one - in particular of each - fatty acid chloride with gaseous state of said reactive composition on at least one of the hydroxyl groups of said solid material, said acylation temperature being between 160°C and 250°C.

The inventor has discovered that, in a completely surprising and counter-intuitive manner, it is in reality advantageous to apply, that is to say to deposit and distribute, said reactive composition on the solid hydroxylated material by providing that said composition reagent applied either at said acylation temperature between 160°C and 250°C during application, that is to say at a temperature sufficiently high to allow the acylation of the solid material hydroxylated by acid chloride at the gaseous state, without going through a prior step of depositing said reactive composition in the liquid state, by means of an applicator device necessarily chosen and intended to allow the application of a liquid composition. He realized that the filiform elements forming the applicator surface of the device - in particular of a roller or brush - applicator used in the context of the present invention, when it is impregnated with said reactive composition brought to said acylation temperature between 160°C and 250°C - higher than the deposition and distribution temperature described in WO2022/033698 - and briefly brought into contact with the surface of the hydroxylated solid material, itself brought to said temperature d acylation, allows more efficient acylation of the solid hydroxylated material than when said liquid reactive composition is deposited at low temperature in essentially liquid form then subsequently heated upon deposition to said acylation temperature. The inventor has observed that bringing the hydroxylated solid material and said reactive composition into contact at said acylation temperature makes it possible to increase the speed of the acylation reaction, making it compatible with an implementation of the process at the industrial scale, by allowing the acylation of the solid hydroxylated material of a strip of solid hydroxylated material, in particular paper of a strip of paper, driven in scrolling. Although said high acylation temperature shifts the liquid/vapor equilibrium of the fatty acid chloride(s) of said reactive composition in the direction of an increase in the gas fraction of said reactive composition, this gaseous fraction, which could be expected to diffuse freely away from the filiform elements of the applicator device and the solid hydroxylated material, making it non-reactive with respect to this solid hydroxylated material, appears to remain in reality confined within the filiform elements and seems to react efficiently and very quickly with the hydroxylated solid material. The filiform elements forming the applicator surface of the applicator device seem to behave like a reservoir of fatty acid chloride(s) in the gaseous state, the fatty acid chloride(s) in the gaseous state appearing to be retained by the filiform elements. Furthermore, increasing the reaction rate of the fatty acid chloride in the gaseous state with the hydroxyls of the hydroxylated solid material makes it possible to shift, with an equivalent time constant, the liquid/vapor equilibrium of the fatty acid chloride. fatty acid in the direction of vaporization. The reaction is therefore also improved and accelerated.

This increase in the acylation reaction speed makes it possible to produce a plurality of successive deposits of fatty acid chloride(s) on the hydroxylated solid material and at said acylation temperature, in particular on the paper. of a strip of paper driven in motion, each deposit of the plurality of deposits providing a sub-stoichiometric quantity of fatty acid chloride(s) relative to the reactogenic hydroxyls of the hydroxylated solid material. In these embodiments, the stoichiometric quantity of fatty acid chloride(s) can be reached due to the multiplicity of successive deposits. In addition, each substoichiometric deposition of fatty acid chloride(s) makes it possible, during each deposition, to promote the dispersion of the fatty acid chloride(s) deposited at said temperature. acylation on the surface of the hydroxylated solid material, thus promoting its reactivity.

But even more surprisingly, without this observation being able to be supported by a known theory, the retention of the chloride(s) of fatty acid(s), in particular of the chloride(s) of fatty acid(s). s) fatty in the gaseous state, at the level of the filiform elements does not seem to prohibit the interaction of the fatty acid chloride(s) in the gaseous state and the hydroxylated solid material. The fact that the filiform elements trapping the fatty acid chloride(s) in the gaseous state come into contact with the surface of the hydroxylated solid material seems to break the confinement of said reactive composition, in particular of its gas fraction, in the filiform elements and allows a rapid reaction favored by the high temperature of said reactive composition, with the hydroxyls of the hydroxylated solid material. According to the expression of the inventor, the gaseous fraction of the fatty acid chloride(s) of said reactive composition seems to be “sucked up” by the hydroxylated solid material.

This apparent phenomenon of suction of the fatty acid chloride(s) in the gaseous state confined in the filiform elements actually seems to make it possible to overcome the effect of a layer, called a layer. limit, gaseous extending on the surface of the hydroxylated solid material and limiting, or even opposing, the approach by diffusion of the fatty acid chloride(s) in the gaseous state up to the hydroxyls reagents of the hydroxylated solid material. The use of an applicator device - in particular a roller or brush - having an applicator surface formed of filiform elements seems to make it possible to deposit and distribute acid chloride(s). fat in the gaseous state in contact with the hydroxylated solid material, bypassing the effect of said boundary layer. The applicator device heated to said acylation temperature makes it possible to resolve the hitherto unresolved problem of the existence of said boundary layer on the surface of the hydroxylated solid material.

The method according to the invention makes it possible to give the solid material satisfactory or even excellent hydrophobicity properties, in particular as evaluated by measuring the Cobb index and/or by measuring the contact angle formed by a drop of water deposited on the surface of the acylated solid material and/or by the tightness test of a water pocket.

But it also allows, in the context of the chromatogenic acylation of a solid hydroxylated material of great thickness and/or of great porosity and/or of large specific surface area, such as a high weight paper material, corrugated cardboard or a solid material coated with polyvinyl alcohol, to carry out a plurality of successive hot deposits allowing a substantially stoichiometric acylation of the hydroxylated solid material of great thickness and/or of great porosity and/or of large specific surface area.

According to certain embodiments of a method according to the invention, at least one part of the applicator surface of the applicator device being in contact with a part of the surface of the solid hydroxylated material, at least this part of the surface of the solid hydroxylated material is at said acylation temperature during the application of said reactive composition to the hydroxylated solid material. According to these embodiments of a process according to the invention, the solid material is heated prior to the application of said reactive composition. In these embodiments, the solid material is heated in the absence of said reactive composition. Advantageously, heating the solid material prior to the application of said reactive composition allows -at least partial- dehydration of the solid material.

According to certain embodiments of a process according to the invention, the filiform elements forming the applicator surface are at said acylation temperature during the application of said reactive composition to the hydroxylated solid material.

According to certain embodiments of a process according to the invention, said reactive composition is applied at least to the surface of said hydroxylated solid material, in a thermoregulated enclosure adapted to maintain said reactive composition released by the applicator device at said acylation temperature.

According to certain embodiments, the process according to the invention comprises at least one step of redistributing fatty acid chloride(s) deposited on the hydroxylated solid material, without new addition of said reactive composition, the redistribution step being carried out by means of at least one distributor device having an applicator surface formed of filiform elements not reactive with the fatty acid chlorides of said reactive composition and capable of being able to take charge of deposited fatty acid chloride on the solid hydroxylated material, by contact of the filiform elements of the distributor device and the solid hydroxylated material and to release at least part of the charged fatty acids, in contact with said solid hydroxylated material by contact of the filiform elements and the solid hydroxylated material, the device distributor being at a temperature between 160°C and 250°C. Such a redistribution step at high temperature promotes the gaseous state of the fatty acid chloride(s) previously supplied and their reactivity.

Advantageously, the filiform elements of the applicator device and/or the distributor device are flexible and deformable in contact with the solid hydroxylated material and adapted to be able, because of this flexibility, of this deformation and of the movement of the applicator device and/or of the distributor device with respect to the hydroxylated solid material, releasing fatty acid chloride on the surface and in depth over at least a portion of the thickness of the hydroxylated solid material or taking fatty acid chloride from this surface.

According to certain embodiments of a method according to the invention, the applicator surface of the applicator device and/or the distributor device is formed of a velvet provided with filiform elements. The material forming the filiform elements is also chosen to resist said acylation temperature, without loss of its adsorbent and/or applicator properties.

According to certain embodiments of a process according to the invention, said acylation temperature is between 160°C and 250°C. in particular between 165°C and 240°C, particularly between 170°C and 230C, more particularly between 180°C and 220°C, preferably between 190°C and 220°C, more preferably between 200°C C and 220°C. Said acylation temperature is adapted according to the solid material to be acylated. In particular, said acylation temperature is chosen to be lower than the browning temperature of the solid material. This being said, according to the invention, taking into account the speed of acylation due to the hot deposition of said reactive composition and the reduced duration of exposure of the solid material to high temperature, the risks of browning of the solid material due to high temperature are reduced.

According to certain embodiments of a process according to the invention, at least one - in particular each - reactive composition comprises at least one fatty acid chloride chosen from the group consisting of palmitic acid chloride (C ₁₆ ), stearic acid chloride (C ₁₈ ), arachidic acid chloride (C ₂₀ ) and behenic acid chloride (C ₂₂ ). There is nothing to prevent said reactive composition from comprising a small proportion of acetyl chloride (CH ₃ -CO-Cℓ). The inventor has discovered that acetyl chloride, which is not a fatty acid chloride within the meaning of the invention, is capable of reacting spontaneously and quickly with free water molecules present in the solid material in preserving fatty acid chlorides intended for acylation from possible hydrolysis. The inventor also observed that, surprisingly, acetyl chloride reacts neither with the free and accessible hydroxyl groups of the solid material, nor with said reactogenic hydroxyls of other hydroxylated polymers such as polyvinyl alcohol. Furthermore, advantageously, the acetic acid produced by hydrolysis of acetyl chloride is sufficiently volatile to be removed from the solid material. Advantageously, acetyl chloride is used as a protectant of the fatty acid chloride(s) of said reactive composition. Advantageously, acetyl chloride is used as a trans-chlorination reagent making it possible to restore fatty acid chlorides from hydrolyzed free fatty acids.

According to certain embodiments of a method according to the invention, the hydroxylated solid material is a paper material. It may be a solid material - that is to say a material which is neither liquid nor gaseous - hydroxylated, consisting essentially of cellulose and having free, accessible and reactive hydroxyl groups. vis fatty acid chlorides in the gaseous state. The hydroxylated solid material can also be a hydroxylated solid material - in particular a paper or a cardboard, for example a corrugated cardboard - having an exterior surface layer formed of polyvinyl alcohol.

Said reactive composition(s) can be applied to the solid hydroxylated material with a total quantity chosen so that the solid hydroxylated material presents a surface quantity of chloride ( s) fatty acid(s) deposited between 1 mg and 500 mg per square meter (mg/m ² ) of geometric surface area of said hydroxylated solid material. The quantity of fatty acid chloride(s) applied to the hydroxylated solid material is between 1 mg/m ² and 500 mg//m ² of hydroxylated solid material. Advantageously, a plurality of successive deposits is carried out at said acylation temperature so as to achieve a substantially stoichiometric acylation of the hydroxylated solid material.

In certain embodiments, the applicator device is an applicator brush whose filiform elements are chosen to withstand said acylation temperature. In these embodiments, the method according to the invention can be implemented manually in an artisanal manner.

According to certain modes of implementation on an industrial scale of a process according to the invention, the hydroxylated solid material is formed of a strip of paper driven in a running direction parallel to the largest dimension of the strip , between an upstream reel of said strip of paper and a downstream reel of a strip of acylated paper. The increased reactivity of the acid chloride(s) deposited at high temperature allows the implementation of the process according to these embodiments. In these modes of implementation, the paper of the paper strip can be driven at high speed, in particular greater than 50 m/min, preferably greater than 100 m/min. In these modes of implementation, at least one - in particular each - reactive composition is applied to fixed position(s) at least on one main face of the paper driven in scrolling. According to these modes of implementation on an industrial scale of a process according to the invention, the reactive composition(s) is(are) applied on the fly by means of a device applicator fixed and immobile in relation to the scrolling paper. According to these modes of implementation on an industrial scale of a process according to the invention, at least one - in particular each - applicator device is a roller with an axis of rotation parallel to the plane of the paper strip and not parallel - in particular orthogonal- to the direction of scrolling. According to some of these modes of implementation, the strip of paper being a strip of low weight paper, the said reactive composition(s) is(are) applied to the strip of paper with a total quantity chosen so that the strip of paper has an average surface quantity of fatty acid chloride(s) of between 1 mg and 50 mg per square meter (mg/m ² ) of flat surface (geometric) of the strip of paper. This being said, according to certain other modes of implementation, the strip of paper being a strip of cardboard - in particular corrugated cardboard - or a strip of paper coated with polyvinyl alcohol, the said composition(s) reagent(s) is(are) applied to the paper strip with a total quantity chosen so that the paper strip has an average surface quantity of fatty acid chloride(s) greater than 50 mg per square meter (mg/m ² ) of flat surface of the paper strip - in particular being able to reach 500 mg/m ² , and adapted to allow (stoichiometric) acylation of almost all of the reactogenic hydroxyls.

In certain embodiments, the method according to the invention comprises at least two applications of reactive composition(s) at fixed positions on the strip of paper driven in scrolling, each reactive composition(s) being at said acylation temperature during its application. According to this embodiment of a process according to the invention, a small quantity of fatty acid chloride(s) is applied at said acylation temperature so as to allow rapid and substantially quantitative acylation and we reproduce this application several times to achieve substantially stoichiometric acylation of the paper of the paper strip.

In some embodiments, the solid material is a paper material coated with polyvinyl alcohol. The increased reactivity of the acid chloride(s) deposited at high temperature allows the implementation of the process according to these embodiments, including when the surface polyvinyl alcohol is at a temperature higher than its melting temperature and is in a sticky state.

According to certain embodiments of a method according to the invention, the filiform elements are formed of at least one material chosen from the group consisting of aramid fibers and microfibers - in particular Kevlar® (micro) fibers - and fibers and inorganic microfibers - notably glass (micro)fibers and carbon (micro)fibers. The filiform elements are formed of at least one fibrous or micro-fibrous material resistant to temperature, resistant to acidic environments and resistant to abrasion provided by the running of the paper strip. The filiform elements are formed of at least one fibrous or micro-fibrous material inert with respect to the fatty acid chloride(s) of said reactive composition.

According to certain embodiments of a process according to the invention, at least a portion of gaseous hydrochloric acid formed due to chromatogenic acylation is driven by a flow rate of a gaseous composition circulating in contact with the solid material - in particular at countercurrent of the strip of paper driven in motion - at said acylation temperature. The remote entrainment of the gaseous hydrochloric acid formed due to the chromatogenic acylation reaction makes it possible to shift the equilibrium of the reaction in the direction of acylation of the hydroxylated solid material and/or the paper material. The displacement of the hydrochloric acid formed makes it possible to avoid deterioration of the cellulose fibers of the paper material and more generally of the solid cellulose material and a deterioration of its mechanical resistance qualities, the hydrochloric acid formed and not displaced being likely to promote hydrolysis of ester bonds and release of acylation groups in the form of free fatty acids. The displacement of the hydrochloric acid formed also prevents the fatty acids released due to this hydrolysis from affecting the barrier properties of the acylated solid material.

According to certain other embodiments of a method according to the invention, the filiform elements of at least one applicator roller are supplied by centrifugal diffusion of said reactive composition from an axial light of this applicator roller rotated on it -even. In some of these embodiments, said reactive composition is introduced into the axial lumen of the applicator roller by means of a distribution ramp for said reactive composition over substantially the entire length of the axial lumen, the distribution ramp extending over substantially the entire length of the axial lumen. According to certain embodiments, the distribution ramp is mounted oscillating along the longitudinal axis of the distribution ramp and along the axis of rotation of the applicator roller.

In these embodiments, the axial lumen of the applicator roller is adapted to accommodate a ramp for supplying the applicator roller with reactive composition and for distributing said reactive composition over the entire length of the axial lumen. The distribution ramp may be provided with orifices dispersing said reactive composition, distributed along the distribution ramp so as to be able to distribute said reactive composition over the entire length of the axial lumen of the applicator roller.

Any other method of feeding the filiform elements is possible. According to certain other embodiments of a method according to the invention, the filiform elements are adapted to be able to take on said reactive composition by contact between the (external) applicator surface - in particular driven in rotation - of the applicator device and a dispensing device of said reactive composition. In some of these embodiments, the dispensing device may comprise a printing device comprising a cylinder, called an anilox roller, having a plurality of recessed cells formed on the external surface of said anilox roller and of predetermined dimensions and volumes adapted to control the quantity of said reactive composition transferred to the applicator device.

In certain advantageous embodiments, at least one applicator roller is provided with means for heating said reactive composition to said acylation temperature. In these advantageous embodiments, the filiform elements forming the applicator surface of the roller advantageously act as an applicator reservoir for chloride(s) of fatty acid(s), in particular chloride(s) of fatty acid(s) with gaseous state.

According to certain embodiments of a method according to the invention, at least one applicator roller is rotated with an angular speed of rotation chosen so that the peripheral ends of the filiform elements are rotated with a linear speed of distinct value of the paper strip running speed value. In these other embodiments, the linear speed of travel of the free ends of the filiform elements and the speed of travel of the strip of paper are not synchronized. The application of said reactive composition to the surface and depth of the solid material by touching said surface and projection of said reactive composition into depth is improved.

According to certain embodiments of a method according to the invention, at least one applicator roller is rotated in a direction of rotation chosen so that the peripheral ends of the filiform elements are driven against the movement of the strip of paper.

According to certain other embodiments of a method according to the invention, at least one applicator roller is rotated in a direction of rotation chosen so that the peripheral ends of the filiform elements are driven in concurrent movement with respect to the movement of the strip of paper.

• se charger de chlorure(s) d’acide(s) gras par contact de la surface récupératrice et de la bande de papier, et
• libérer des chlorure(s) d’acide(s) gras par application d’un débit de composition gazeuse chauffée à une température supérieure à ladite température d’acylation -notamment à une température comprise entre ladite température d’acylation et la température de vaporisation de chaque chlorure d’acide gras de ladite composition réactive-.

According to certain embodiments of a method according to the invention, a sample of fatty acid chloride(s) - in particular excess fatty acid chloride(s) - on the strip of paper is produced by means of a recovery device having a rotating recovery surface and provided with filiform elements, non-reactive with said reactive composition and capable of:

• become charged with fatty acid chloride(s) by contact with the collecting surface and the paper strip, and
• release fatty acid chloride(s) by applying a flow of gaseous composition heated to a temperature higher than said acylation temperature - in particular at a temperature between said acylation temperature and the vaporization temperature of each fatty acid chloride of said reactive composition.

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

A solid material is formed - in particular a strip of acylated paper - substantially free of residual fatty acid chloride(s) and hydrochloric acid. The flow of gaseous composition is applied in contact with the strip of paper and countercurrent with respect to the direction of travel of the strip of paper so as to entrain at least a part of hydrochloric acid in the gaseous state formed due to the acylation.

According to the invention, said reactive composition is free of any solvent medium (with the exception of possible traces), in particular of any non-polar solvent medium distinct from the fatty acid(s) chlorides.

The invention also relates to an acylated solid material capable of being obtained by a process according to the invention. The invention also relates to an acylated solid material obtained by a process according to the invention.

The invention also relates to a process for the chromatogenic acylation of a solid material carrying hydroxyl groups accessible to at least one fatty acid chloride in the gaseous state and capable of reacting with this chloride(s). fatty acid in the gaseous state, characterized in combination by all or part of the characteristics mentioned above or below. Whatever the formal presentation given, unless explicitly indicated otherwise, the different characteristics mentioned above or below should not be considered as closely or inextricably linked together, the invention being able to relate to only one of these structural or functional characteristics, or only part of these structural or functional characteristics, or only part of one of these structural or functional characteristics, or any grouping, combination or juxtaposition of all or part of these structural or functional characteristics .

Other aims, characteristics and advantages of the invention will appear on reading the following description which refers to the appended figures and to the examples given for non-limiting purposes only of the invention, and in which:

there is a block diagram illustrating a chromatogenic acylation process known from the prior art (WO2022/033698) and presented solely for comparison with a process according to the invention,

there is a block diagram illustrating a first embodiment of a chromatogenic acylation process according to the invention,

there is a block diagram illustrating a second embodiment of a chromatogenic acylation process according to the invention, and

there is a schematic representation of a device for implementing an industrial process for chromatogenic acylation of a width of paper according to the invention.

The known method of WO2012/066015, for chromatogenic acylation of a paper material comprising a deposit on the paper material of liquid fatty acid chloride by means of a cylinder, called anilox roller, designed for printing is not not satisfying. The paper material obtained by such a known process contains a significant residual quantity of free fatty acid chloride, despite the implementation of a final blowing step (or “ flushing ”). Residual fatty acid chloride may decompose by hydrolysis into free fatty acid and hydrochloric acid which may degrade solid material. In addition, the free fatty acids formed alter the barrier properties of the solid material and the residual fatty acid chlorides pose a toxicity problem for applications particularly in the field of food packaging and in the biomedical field.

We also know from WO2022/033698 a process for the chromatogenic acylation of a paper tissue. According to this known process, stearic acid chloride is deposited using a lacquer roller impregnated with stearic acid chloride at room temperature, on one side of the handkerchief brought to a temperature of 160°C. The quantity of stearic acid chloride impregnated on the lacquer roller and the quantity deposited on the tissue are adjusted by successive applications, without reloading the roller, and exhaustion of the stearic acid chloride until the optimal quantity of chloride is obtained of acid impregnated on the roller. The tissue having received the optimal quantity of stearic acid chloride is then placed in an oven at a temperature of 160°C. Such a known process is not applicable as it stands on an industrial scale.

The known chromatogenic acylation process described above is illustrated in . Such a known process comprises a step 2' of heating a material 1' paper in an oven heated to a temperature, called acylation temperature, lower than the vaporization temperature of the fatty acid chloride, but sufficient to allow a acylation of the material 1' paper by reaction of a fatty acid chloride 5' in the gaseous state with reactogenic hydroxyls of the material 1' paper. In this known process, a hot paper material 6' is formed at said acylation temperature. In parallel, a lacquer roller 3' having an applicator surface formed of a velvet 4' is impregnated by rolling 7' in acid chloride 5' in the liquid state at atmospheric temperature under rolling conditions adapted to obtain a roller 8' lacquerer in an optimal state of impregnation allowing deposition of an optimal quantity of chloride 5' of stearic acid in the liquid state. In this known process, a step 9' of applying stearic acid chloride 5' in the liquid state and at atmospheric temperature is carried out on the hot paper material 6' by rolling the lacquer roller 8' impregnated on the hot paper material 6', allowing acylation of the hot paper material 6' with stearic acid chloride in the gaseous state, at a temperature necessarily lower than said acylation temperature and the formation of an acylated material 10' and hydrophobic. According to this known process, stearic acid chloride at room temperature and essentially in liquid form is deposited on a paper material heated to a temperature sufficient to allow chromatogenic acylation of the paper material by steric acid chloride in the gaseous state. formed due to the temperature of the paper material.

A synoptic diagram of a process according to the invention for chromatogenic acylation of a solid material 1 carrying hydroxyl groups accessible to at least one fatty acid chloride in the gaseous state and capable of reacting with this(s) fatty acid chloride(s) is represented in .

The hydroxylated solid material 1 may be a cellulosic material. The solid material 1 can also be formed from a fabric, in particular a fabric comprising cotton fibers. Material 1 solid can be material 1 paper. However, any type of hydroxylated solid material can be used. The hydroxylated solid material 1 may have an irregular surface condition. It may present significant roughness. The hydroxylated solid material 1 can, however, also be a material - in particular a calendered paper - having a regular surface condition and low roughness. 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 carried by a polymer - in particular PVA (polyvinyl alcohol) forming the free surface of the hydroxylated solid material. The hydroxylated solid material 1 can be a paper material made non-porous and impermeable to air by surface application of a layer of PVA, as described in FR2925910. The hydroxylated solid material 1 can be a disposable paper tissue and formed of a plurality of cellulosic sheets with a weight of less than 30 g/m ² - in particular less than 20 g/m ² preferably between 10 g/m ² and 30 g/m ² , more preferably between 10 g/m ² and 20 g/m ² -. The paper material can be formed from crosslinked cellulose fibers whose rotational mobility is restricted, giving the paper material improved properties of mechanical strength in general and mechanical strength in humid conditions (“ wet-strength ”) in particular. The cellulose fibers are then linked together by hydrogen bonds and by covalent bonds formed with at least one group of crosslinking atoms, such as for example a derivative of 1-chloro-2,3-epoxypropane or epichlorohydrin. The hydroxylated solid material 1 can be a flexible material, that is to say it is deformable under the effect of its own weight. The hydroxylated solid material 1 can be a paper material in the form of a sheet of paper called “paper towel”, toilet paper, a paper towel, or filter paper. The hydroxylated solid material 1 may be cardboard. It can be rigid, that is to say it does not noticeably deform under the effect of its own weight. The hydroxylated solid material 1 may be a piece of corrugated cardboard formed from at least one sheet of corrugated paper and at least one cardboard sheet with a weight greater than 160 g/m ² .

In the process according to the invention represented in , we choose an applicator device 3 having an applicator surface provided with filiform elements 4 non-reactive with the fatty acid chlorides of a composition, called reactive composition 20, of at least one fatty acid chloride. We choose such an applicator device 3 adapted to be able to be subjected to a temperature between 160°C and 250°C without loss of its adsorbent and applicator functionalities. It may, for example, be an applicator device 3 whose applicator face is formed of filiform elements 4 of inorganic fibers or microfibers, such as glass fibers or microfibers or carbon fibers or microfibers, or 4 filiform elements of aramid fibers or microfibers, such as aramid fibers or microfibers known under the brand kevlar®. The applicator device 3 can be an applicator roller, an applicator pad or an applicator brush provided with filiform elements 4. The applicator device 3 may have an applicator surface formed of oleophilic filiform elements 4 (having an affinity for fatty substances). Any type of suitable oleophilic material can be used. However, the applicator device 3 can have an applicator surface formed of oleophobic filiform elements 4. In particular it may be filiform elements 4 coated with a perfluorinated coating, in particular Teflon®. The applicator surface of the applicator device 3 is formed of a material that is chemically stable and resistant to abrasion and temperature, in particular at said acylation temperature. Preferably, the filiform elements have a free end adapted to be able to cooperate with the surface of the solid hydroxylated material by brushing. The applicator device 3 can be a roller, in particular a roller of the “lacquer roller” type and adapted to be able to withstand said acylation temperature, without loss of its adsorbent and applicator properties. The filiform elements 4 are flexible and adapted to be able to take on fatty acid chloride(s) and to be able to release at least part of the charged fatty acid chloride(s). ), in particular by elastic deformation. The filiform elements 4 may have a length of between 1 mm and 100 mm or more. The filiform elements may have a cross-section with a diameter of between 1 µm and 1000 µm. The applicator device can be a lacquer roller whose applicator surface is formed of a velvet provided with filiform elements having an implantation density greater than 10 filiform elements per mm ² of applicator surface, in particular between 50 and 500 filiform elements per mm ² of applicator surface. The filiform elements are chosen to present - in particular during the rotation of the applicator roller - a rigidity conferred by the rotation of the applicator roller, which is sufficient to allow application of acid chloride(s). fat on at least a portion of the thickness of the solid hydroxylated material, without damaging it. The filiform elements have a flexibility chosen so as not to damage the solid hydroxylated material by contact.

In a process according to the invention, a composition, called a reactive composition, of at least one fatty acid chloride is chosen or prepared. At least one fatty acid chloride is chosen from the group consisting of fatty acid chlorides of formula R-CO-Cℓ in which R is a hydrocarbon chain having a number of carbon atoms between 13 (limit inclusive) and 29 (terminal included), in particular between 15 (terminal included) and 29 (terminal included). At least one fatty acid chloride is chosen from the group consisting of palmitic acid chloride (C ₁₆ ), stearic acid chloride (C ₁₈ ), arachidic acid chloride (C ₂₀ ) and behenic acid chloride (C ₂₂ ). At least one fatty acid chloride is behenic acid chloride (C ₂₂ H ₄₃ OCℓ) whose vaporization temperature at atmospheric pressure is of the order of 385°C. At least one fatty acid chloride is palmitic acid chloride (C ₁₆ H ₃₁ OCℓ) whose vaporization temperature at atmospheric pressure is of the order of 330°C. At least one fatty acid chloride is stearic acid chloride (C ₁₈ H ₃₅ OCℓ) whose vaporization temperature at atmospheric pressure is of the order of 350°C. Nothing prevents us from planning to use a fatty acid chloride capable of being prepared by transchlorination of a fatty acid with a transchlorination agent such as, for example, acetyl chloride. The fatty acid chlorides chosen for carrying out a process according to the invention are liquid at room temperature. In a method according to the invention, an impregnation 5 of the filiform elements 4 of the applicator device 3 is carried out with at least one liquid fatty acid chloride. This impregnation step 5 is carried out by bringing the filiform elements 4 and said reactive composition 20 into contact at room temperature, that is to say at a temperature reached without using means for regulating this temperature. However, nothing prevents us from providing that the filiform elements 4 are during this impregnation 5 at a temperature higher than the ambient temperature but also necessarily lower than or at most equal to said acylation temperature. The temperature of the filiform elements 4 is adapted to allow their loading with said reactive composition 20 essentially in the liquid state. There is nothing to prevent said reactive composition 20 from being brought during this impregnation step 5 to a temperature higher than ambient temperature, but adapted, depending on the fatty acid chloride(s) used. , so that the fatty acid chloride(s) used are essentially in liquid form and capable of being impregnated in the liquid state on the filiform elements 4 of the applicator device 3. An applicator device 6 impregnated and loaded with said liquid reactive composition 20 is formed at the end of this impregnation step 5.

In a process according to the invention, a step 7 of heating said reactive composition 20 impregnated on the filiform elements 4 of the applicator device 3 is carried out and adapted so that said reactive composition 20 reaches said acylation temperature. This heating 7 is carried out by any appropriate means. These may be radiative heating means (for example by radiation in the infrared range), inductive heating means, or convective heating means. It may also be heating means specific to the applicator device 3 and adapted to heat at least the filiform elements 4 and said reactive composition 20. At the end of this heating step 7, an applicator device 3 is formed, provided with filiform elements 8 loaded with said reactive composition 20 brought to said acylation temperature.

In a process according to the invention, a step 9 of heating the solid material 1 is implemented so as to form a hot hydroxylated solid material 10 - in particular at said acylation temperature -, prior to a step 11 of applying the filiform elements 8 loaded with - and retaining - said reactive composition 20. Step 11 of application is carried out by rolling the applicator device 3 onto the hydroxylated solid material 1. Advantageously, the hot hydroxylated solid material 10 is at least partly dehydrated due to this heating 9. Furthermore, the fact that the hot hydroxylated solid material 10 is at said acylation temperature makes it possible to contribute to maintaining said reactive composition 20. at said acylation temperature, to promote chromatogenic acylation and to form the acylated solid material 12.

Surprisingly, the inventor found that heating 7 of said reactive composition 20 adsorbed by impregnation in the filiform elements 4 of the applicator device 3 allows an application of fatty acid chloride to the solid hydroxylated material 1 and an acylation of this material 1 solid hydroxylated by acid chloride in the gaseous state. According to the invention, the application of said reactive composition heated to said acylation temperature of between 160°C and 250°C does not lead to a loss of fatty acid chloride in the gaseous state by dissipation in the atmosphere surrounding the filiform elements 4.8. On the contrary, the filiform elements 4.8 seem to behave like a reservoir of fatty acid chloride - particularly in the gaseous state -, making it possible to release/form fatty acid chloride in the gaseous state on contact with the material 1 hydroxylated solid and acylate it.

The invention goes against the teaching provided by the state of the prior art, which describes distributing the fatty acid chloride(s) in a preferentially liquid state and necessarily at low temperature upon contact. cold or hot solid material, then heating the cold hydroxylated solid material to said acylation temperature or maintaining the hot hydroxylated solid material at said acylation temperature. According to this teaching, the fatty acid chloride(s) essentially in the liquid state deposited in contact with the solid hydroxylated material constitute(s) a reservoir of fatty acid chloride(s). essentially in the liquid state placed in contact with the hydroxylated solid material. According to this teaching, fatty acid chloride(s) in the gaseous state are formed near the accessible hydroxyls of the hydroxylated solid material, due to the heating of the hydroxylated solid material to said acylation temperature. According to this teaching, the formation of fatty acid chloride(s) in the gaseous state near accessible hydroxyls of the hydroxylated solid material makes it possible to overcome the disadvantages of said boundary layer. This being said, the teaching provided by the state of the prior art does not make it possible to resolve the problem of the persistence on the hydroxylated solid material of quantities of fatty acid chloride(s) in the liquid state n having not been heated for a sufficiently long time to be vaporized and to be able to react in the gaseous state with the hydroxylated solid material, in particular due to the movement of the strip of hydroxylated solid material.

Of course, nothing prevents us from providing, in a variant not shown of a chromatogenic acylation process according to the invention implemented on an industrial scale, that the hydroxylated solid material is in the form of a strip of paper wound into a reel on itself, the paper being driven between an upstream reel and a downstream device for rewinding a strip of acylated paper. In such a process implemented on an industrial scale, the paper has a running speed of between 30 and 100 meters per minute. An example of a device suitable for implementing such a method is shown in . In such a process, said reactive composition is applied at a fixed position to at least one main face of the strip of paper being moved. In such a method, the applicator device comprises an applicator roller having an applicator surface provided with filiform elements and arranged over the entire width (or width) of the strip of paper. The roller has an axis of rotation parallel to the plane of travel of the strip of paper and not parallel - in particular orthogonal - to the direction of travel of this strip. The roller is placed vertically at a distance from the strip of paper, so that the filiform elements touch the scrolling strip of paper, without damaging it. Advantageously, the roller can be of the type presenting an axial light for receiving said reactive composition and distributing - assisted by a centrifugal force - said reactive composition conveyed along the filiform elements until it is brought into contact with the strip of paper .

In certain advantageous embodiments, the roller is provided with means for heating said reactive composition to said acylation temperature. In these advantageous embodiments, the filiform elements forming the applicator surface of the roller act as an applicator reservoir for fatty acid chloride(s) in the gaseous state at said acylation temperature. In these advantageous embodiments, the volume in which the fatty acid chloride(s) are at the saturated vapor pressure at said acylation temperature is limited to the free volume provided by the filiform elements. of the roller heated to said acylation temperature. According to these advantageous embodiments, it is not necessary to provide a thermostatically controlled enclosure at said acylation temperature in which the partial pressure of the fatty acid chloride(s) is maintained at the pressure of saturating vapor in its entire volume. This being said, nothing prevents us from planning to have at least one fairing wall for the applicator roller(s) and for confining the fatty acid chloride(s) in the gaseous state in the contact of the paper strip.

In certain advantageous embodiments of a chromatogenic acylation process according to the invention implemented on an industrial scale, the roller having an axial light for receiving said reactive composition and centrifugal distribution of said reactive composition guided along of the filiform elements up to contact with the strip of paper, the roller - in particular the heating roller - is supplied with fatty acid chloride by supplying said reactive composition into the axial lumen of the roller. In these embodiments, the impregnation of the filiform elements is less partly ensured by the centrifugal stress produced due to the rotation of the roller, to which said reactive composition is subjected in the applicator roller.

In other embodiments, the applicator device may include, in addition to the roller, a fatty acid chloride dispensing device on the roller. It may be a cylinder, called an anilox roller, for feeding the roller by licking the surface of said anilox roller by the filiform elements. Any type of anilox roller can be used. It can be used by adapting the dimensions of its cells and their surface density to the quantity of fatty acid chloride to be deposited on the applicator roller. Said anilox roller may have an angular rotation speed identical to or distinct from the rotation speed of the applicator roller. Said anilox roll can be supplied with liquid fatty acid chloride by a doctor blade chamber which is itself supplied - in particular continuously - with fatty acid chloride.

The roller can be rotated with an angular speed of rotation chosen so that the free ends of the filiform elements are rotated with a linear speed of value distinct from the value of the speed of travel of the strip of paper. The linear speed of the free ends of the filiform elements and the running speed of the strip of paper are not necessarily identical and can be adjusted so as to produce the desired touch. This being said, the roller can be rotated in a chosen direction of rotation so that the free ends of the filiform elements of the velvet are driven countercurrently or concurrently with the movement of the strip of paper.

In a chromatogenic acylation process according to the invention implemented on an industrial scale, nothing prevents the roller and the dispensing device from being placed in a thermoregulated enclosure maintained at said acylation temperature.

In an advantageous variant not shown of a chromatogenic acylation process according to the invention implemented on an industrial scale, a flow rate of gaseous composition capable of taking on hydrochloric acid in contact with the strip of paper being processed. The acylation is formed so as to move the hydrochloric acid formed as a result of this acylation away from the paper strip.

A synoptic diagram of a variant of a process according to the invention, for chromatogenic acylation of a solid 1,2 material carrying hydroxyl groups accessible to at least one fatty acid chloride in the gaseous state and capable of being able to react with this fatty acid chloride(s) is represented in . In this variant shown, a plurality of phases 40,50,60 of acylation of a solid material 1,2 are carried out, each of the phases 40,50,60 comprising a step 11,24,34 of application of 'a composition 20,21,22 reactive on the solid material 1,2. Phases 40,50,60 of this plurality of phases can be implemented in a traditional manner successively on the same part of a solid material 1, in particular a paper material. But the phases 40,50,60 of this plurality of phases can be implemented during an industrial process of chromatogenic acylation of a strip 2 of paper driven in running between an upstream reel of the strip 2 of paper and a downstream device 36 for rewinding the strip 12,25,35 of acylated paper. During this implementation on an industrial scale, each reactive composition 20,21,22 is applied by means of a device 3,15,28 applicator of reactive composition(s) 20,21,22 respectively. The applicator devices 3,15,28 are arranged at a distance from each other, along a running zone of the strip 2,12,25,35 of paper, extending in the thermoregulated enclosure 39. Each reactive composition 20,21,22 may be formed from a single fatty acid chloride or comprise a plurality of fatty acid chlorides. Advantageously, each reactive composition is free of any organic solvent. The reactive compositions 20,21,22 may comprise the same fatty acid chloride or chlorides of different fatty acids and of different fatty chain lengths.

The synoptic diagram shown in also illustrates a process according to the invention implemented on an industrial scale, for chromatogenic acylation of a strip 2 of a paper material 1 driven in movement between an upstream reel and a downstream device for rewinding a strip of acylated paper. In this industrial process, the strip 2 of paper is caused to scroll by any means known to those skilled in the art, so that the paper of the strip 2 of paper passes successively, due to this scrolling, a plurality of successive zones treatment. A first phase 40 of acylation of the paper of the strip 2 of paper is carried out in an upstream zone (relative to the direction of travel from upstream to downstream of the strip of paper) of the plurality of successive zones of treatment, then a second acylation phase 50 is carried out in an intermediate zone of this plurality of successive zones, then a third acylation phase 60 is carried out in a downstream zone of this plurality of successive zones. For example, nothing prevents us from planning to carry out the first acylation phase 40 at an acylation temperature T1, the second acylation phase 50 at an acylation temperature T2 and the third acylation phase 60 at an acylation temperature T2. acylation temperature T3, T1 ≤ T2 ≤ T3.

During the first phase 40, the applicator device 3 has an applicator surface formed of filiform elements 4 which are non-reactive with the fatty acid chlorides of said reactive composition 20. The applicator device 3 and the filiform elements 4 are adapted to be able to be placed without deterioration at a temperature between 160°C and 250°C and without loss of their applicator functionalities. In a method according to the invention implemented on an industrial scale, the applicator device 3 can be a roller arranged so that its axis of rotation on itself extends in a plane parallel to the plane of the strip 2 of paper driven in scrolling and not parallel - in particular orthogonal - to the direction of scrolling of this strip 2 of paper. The applicator device 3 is chosen and arranged so as not to damage the paper of the scrolling paper strip 2. During the first phase 40, an impregnation 5 of the filiform elements 4 of the applicator device 3 with at least one liquid fatty acid chloride is carried out. This impregnation step 5 is carried out at low temperature (that is to say at a temperature lower than the envisaged acylation temperature) by bringing into contact the filiform elements 4 forming the applicator surface of the applicator device 3 and said composition 20. reactive at room temperature, that is to say at a temperature reached without using means of regulating this temperature. However, nothing prevents us from providing that the filiform elements 4 are during this impregnation 5 brought to a temperature higher than the ambient temperature but also necessarily lower than or at most equal to said acylation temperature. There is nothing to prevent said reactive composition 20 itself from being brought during this impregnation step 5 to a temperature higher than ambient temperature, but adapted, depending on the fatty acid chloride(s) used. (s), so that the fatty acid chloride(s) used are essentially in liquid form and loadable in the liquid state on the filiform elements 4 of the applicator device 3. An applicator device 6 loaded with said liquid reactive composition 20 is obtained at the end of this impregnation step 5.

In a method according to the invention, a step 7 of heating said reactive composition 20 adsorbed on the filiform elements 4 of the applicator device 3 is carried out, this heating step 7 being adapted so that said reactive composition 20 reaches a temperature T1 acylation. This heating 7 is carried out by any appropriate means. At the end of this heating step 7, an applicator device 3 is formed, provided with filiform elements 8 loaded with said composition 20 reactive at said acylation temperature T1.

In a process according to the invention, a step 9 of heating the paper of the strip 2 of paper driven in motion is implemented so as to form a hot paper 10 at said acylation temperature T1, prior to a step 11 d application of the hot filiform elements 8 retaining said reactive composition 20, by rolling the applicator device 3 on the hot paper 10 of the strip 2 of paper. Furthermore, the fact that the hot paper 10 is at said acylation temperature T1 makes it possible to contribute to maintaining said composition 20 reactive at said acylation temperature T1, to promote chromatogenic acylation and to form the acylated solid material 12. .

During a second phase 50 of chromatogenic acylation, an applicator device 15 is used having an applicator surface formed of filiform elements 16 which are non-reactive with the fatty acid chlorides of a second reactive composition 21. The applicator device 15 and the filiform elements 16 are adapted to be able to be placed, without deterioration, at a temperature between 160°C and 250°C and without loss of applicator functionalities. In a method according to the invention implemented on an industrial scale, the applicator device 15 can be a roller with an axis of rotation extending in a plane parallel to the plane of the strip 2 of paper driven in scrolling and not parallel -in particular orthogonal- to the direction of travel of the paper. The applicator device 15 is chosen and arranged so as not to damage the paper 1,2,14 as it moves. During the second phase 50, an impregnation 17 of the filiform elements 16 of the applicator device 15 with at least one liquid fatty acid chloride is carried out. This impregnation 17 is carried out at a temperature lower than the envisaged acylation temperature T2, by bringing the filiform elements 16 into contact with said reactive composition 21 at room temperature, that is to say at a temperature reached without using means of regulating this temperature. However, nothing prevents us from providing that the filiform elements 16 are during this impregnation 17 at a temperature higher than the ambient temperature. That being said, the filiform elements 16 are at a temperature necessarily lower than or at most equal to said acylation temperature T2. There is nothing to prevent said reactive composition 21 from being brought during this impregnation step 17 to a temperature higher than ambient temperature, but adapted, depending on the fatty acid chloride(s) used. , so that the fatty acid chloride(s) used are essentially in liquid form and loadable in the liquid state on the filiform elements 16. An applicator device 18 loaded with said liquid reactive composition 21 is formed at the end of this impregnation step 17. A step 19 is then carried out for heating said reactive composition 21 adsorbed on the filiform elements 16 of the applicator device 15 and adapted so that said reactive composition 21 reaches the acylation temperature T2. This heating 19 is carried out by any appropriate means. At the end of this heating step 19, an applicator device is formed, the filiform elements 23 of which loaded with said reactive composition 21 are brought to said acylation temperature T2.

A step 13 of heating the paper of the strip 12 of paper driven in motion is implemented so as to form a hot paper 14 at said acylation temperature T2, prior to a step 24 of applying said reactive composition 21 to the hot paper 14, by rolling the applicator device 15 on the paper 14 and bringing the filiform elements 23 into contact on the hot paper 14. Furthermore, the fact that the paper 14 is at said acylation temperature T2 makes it possible to contribute to maintaining said composition 21 reactive at said acylation temperature T2, to promote chromatogenic acylation and to form an acylated paper 25 carrying acyl groups of the first and second reactive 20,21 compositions.

In the embodiment shown, during a third phase 60, an applicator device 28 is used which has an applicator surface formed of filiform elements 29 which are non-reactive with the fatty acid chlorides of a reactive composition 22. The applicator device 28 and the filiform elements 29 are adapted to be able to be placed without deterioration at a temperature T3 of between 160°C and 250°C and without loss of applicator functionalities. In a method according to the invention implemented on an industrial scale, the applicator device 28 is preferably an applicator roller 28 with an axis of rotation on itself extending in a plane parallel to the plane of the paper of the strip 25.2 of paper driven in scrolling and not parallel - in particular orthogonal - to the direction of scrolling of the paper. The applicator device 28 is chosen and arranged so as not to damage the paper of the strip 2.25 as it moves. During the second acylation phase 60, an impregnation 30 of the filiform elements 29 with at least one liquid fatty acid chloride is carried out. This impregnation 30 is carried out at a temperature lower than an envisaged acylation temperature T3, by bringing the filiform elements 29 of the applicator device 28 into contact with said composition 22 which is reactive at room temperature, that is to say at a temperature achieved without using means of regulating this temperature. However, nothing prevents us from providing that the filiform elements 29 are during this impregnation 30 at a temperature higher than ambient temperature but also preferably lower than said acylation temperature T3. There is nothing to prevent said reactive composition 22 from being brought during this impregnation step 30 to a temperature higher than ambient temperature, but adapted, depending on the fatty acid chloride(s) used. , so that the fatty acid chloride(s) used are essentially in liquid form and chargeable by adsorption in the liquid state on the filiform elements 29 of the applicator device 28. An applicator device 31 loaded with said liquid reactive composition 22 is formed at the end of this impregnation step 30. A step 32 is then carried out for heating said reactive composition 22 adsorbed/impregnated in the filiform elements 29 of the applicator device 28 and adapted so that said reactive composition 22 reaches the acylation temperature T3. This heating 32 is carried out by any appropriate means. At the end of this heating step 32, filiform elements 33 charged by impregnation with said reactive composition 22 brought to said acylation temperature T3 are formed.

A step 26 of heating the paper of the strip 2.25 of paper driven in motion is implemented so as to form a hot paper 27 at said acylation temperature T3, prior to a step 34 of applying the filiform elements 33 of the applicator device 28 retaining said reactive composition 22, by rolling the applicator device 28 on the paper 27. Furthermore, the fact that the paper 27 is at said acylation temperature T3 makes it possible to contribute to maintaining said reactive composition 22 at said acylation temperature T3, to promote chromatogenic acylation and to form a solid acylated material carrying acyl groups of the first, second and third reactive compositions 20,21,22. Other subsequent phases of acylation can be planned.

In an embodiment not shown, nothing prevents us from carrying out a final phase of extraction of fatty acid chloride likely to be present in excess on the moving paper strip. To do this, a recovery device comprising an extractor roller, in particular a lacquer roller having a recovery surface formed of a velvet can be applied to the strip of paper to take back fatty acid chloride in the liquid state from paper.

An example of an acylation device 100 capable of being used for implementing a method according to the invention is shown in . The acylation device 100 comprises an upstream reel 66 of a strip 2 of paper to be acylated and a downstream device 36 for rewinding a strip 35 of acylated paper. The acylation device 100 is provided with means 37 for guiding the strip 2 of paper running between the upstream reel 66 and the downstream reel 36. The guide means 37 comprise a plurality of guide rollers of the strip 2,10,12,25,35 of paper driven in scrolling, positioned so as to guide the strip 2,10,12,25,35 of paper in scrolling in a thermoregulated enclosure 39 of the acylation device 100. The thermoregulated enclosure 39 and, where appropriate, compartmentalized, has a first upstream zone 41 (in the direction 42 of travel of the strip 2 of paper 1) for entry of the paper 1 of the strip into the first upstream zone 41 and into the thermoregulated enclosure 39. This first upstream zone 41 is provided with at least one heating roller 38 and means for guiding the strip 2 of paper, adapted to heat the strip 2 of paper to a temperature allowing its dehydration, at least partially during its running and beforehand. to its acylation. The thermoregulated enclosure 39 has, extending downstream of the first upstream heating zone 41, a first acylation zone 43 adapted to be able to be crossed by the strip 2 of moving paper. 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 a chromatogenic acylation temperature T1. It also includes a device 45 for dispensing a reactive composition 20 of at least one - in particular a single - fatty acid chloride on the surface of the strip 2 of paper. The dispensing device 45 comprises a support roller 44 and an applicator roller 3 having an applicator surface formed of filiform elements 4, in particular of filiform elements 4 forming a velvet. The applicator roller 3 is adapted to be able to rotate on itself so that the filiform elements 4 brush by touching the surface of the strip 2.10 of paper driven in scrolling. The support roller 44 and the filiform elements 4 of the applicator roller 3 cooperate to guide the strip 2.10 of paper into contact with the filiform elements 4 of the applicator roller 3.

The thermoregulated enclosure 39 has, extending downstream of the first acylation zone 43, a second acylation zone 48 adapted to be able to be crossed by the strip 2 of paper 12 driven in movement and processed in the first zone 43 acylation. 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 a chromatogenic acylation temperature T2. It also includes a device 51 for dispensing a reactive composition 21 of at least one - in particular a single - fatty acid chloride. The dispensing device 51 comprises a support roller 49, an applicator roller 15 having an applicator surface formed of filiform elements 16, in particular of filiform elements 16 forming a velvet, and adapted to be able to be rotated so that the filiform elements 16 scan by touching the surface of the strip 2 of paper 12 driven in scrolling. The support roller 49 and the applicator roller 15 cooperate to guide the strip 2 of paper 12 by applying it in contact with the filiform elements 16 of the applicator roller 15.

The thermoregulated enclosure 39 has, extending downstream of the second acylation zone 48, a third acylation zone 54 adapted to be able to be crossed by the strip 2 of moving paper processed in the second acylation zone 48 . 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 a chromatogenic acylation temperature T3. It also includes a device 56 for dispensing a reactive composition 22 of at least one - in particular a single - fatty acid chloride. The dispensing device 56 comprises a support roller 55 and an applicator roller 28 having an applicator surface formed of filiform elements 29, in particular of filiform elements 29 forming a velvet, and adapted to be able to be rotated so that the filiform elements 29 scan by touching the surface of the strip 2 of paper driven in scrolling. The support roller 55 and the applicator roller 28 cooperate to guide the strip 2 of paper by applying one of the faces of the strip 2 of paper into contact with the applicator roller 28.

In certain advantageous embodiments, at least one - in particular each - of the applicator rollers 3,15,28 is provided with means for heating said reactive composition 20,21,22 corresponding to the temperature T1,T2,T3 of acylation. In these embodiments, the first, second and third acylation zones 43,48,54 of the thermoregulated and/or compartmentalized enclosure 39 are not necessarily each heated to said corresponding acylation temperature T1,T2,T3. In addition, at least one - in particular each - of the applicator rollers 3,15,28 advantageously presents an axial centrifugal supply light - in particular continuously - of the filiform elements 4,16,29 in reactive compositions 20,21,22 .

Nothing prevents either from providing that at least one - in particular each - of the support rollers 44,49,55 is a heating roller adapted to contribute to the heating of the strip 2 of paper to said temperature d acylation.

In certain other embodiments not shown, at least one - in particular each - of the dispensing devices 45,51,56 may comprise a cylinder, called anilox roller, for supplying the applicator roller 3,15,28 with a composition 20 ,21,22 reactive. Said anilox roller is arranged so that it can be touched tangentially by the corresponding applicator roller 3,15,28. In these embodiments, the temperature of said anilox roller and of the reactive composition 20,21,22 presented by said corresponding anilox roller are substantially at the same temperature as the applicator roller 3,15,28. Said anilox roll can be supplied with liquid fatty acid chloride by means of a doctor blade chamber which is itself supplied - in particular continuously - with fatty acid chloride. In these embodiments, the doctor blade chamber forms a wall covering said anilox roller facing its peripheral surface, with the exception of an open strip allowing contact of said anilox roller and the applicator roller 3,15,28.

The thermoregulated enclosure 39 has, extending downstream of the third acylation zone 54, a zone 59 for extraction and return exchange of fatty acid chloride likely to be present in excess on the strip of scrolling paper. The extraction zone 59 is provided with a support roller 61 arranged to be able to cooperate with an extractor roller 62 having a recovery surface formed of filiform elements 63 and guide the strip 35 of paper as it moves. The recovery surface of the extractor roller 62 can be a velvet provided with filiform elements 63 capable of taking on excess fatty acid chloride(s) on the surface of the strip 35 of paper. Advantageously, a flow rate 64 of gaseous composition - in particular a flow rate of atmospheric air - heated to a temperature higher than said acylation temperature - in particular between said acylation temperature and the vaporization temperature of at least one - in particular of each fatty acid chloride of said reactive composition is applied in contact with the strip 2 of paper so as to entrain residual fatty acid chloride, vaporized under the effect of the flow 64 of gaseous composition. The flow 64 of gaseous composition loaded with fatty acid chloride is successively driven into acylation zones 54,48,43, countercurrent -from downstream to upstream- of the direction of travel of the strip 2 of paper and also allows a entrainment of the gaseous hydrochloric acid formed due to the acylation reaction in the thermoregulated enclosure 39.

In certain embodiments, the extractor roller 62 is heated to a temperature - in particular at a temperature between 250°C and 400°C - favoring the vaporization of fatty acid chloride(s). In other embodiments, the flow of gaseous composition heated to the vaporization temperature is applied to the filiform elements of the extractor roller.

In certain embodiments, the gaseous atmosphere of the thermoregulated and/or compartmentalized enclosure 39 and/or the gaseous atmosphere extending into the lumen of at least one applicator roller 3,15,28 is depleted in gaseous oxygen . In these embodiments, a flow rate of at least one applicator roller 3,15,28 is introduced into the thermoregulated and/or compartmentalized enclosure 39 and/or into the gaseous atmosphere extending into the lumen of at least one applicator roller 3,15,28. least an inert gas.

EXAMPLE 1 – Conditions of application

An applicator device is made using glass microfibers linked together to form an applicator pad or brush. Glass microfibers are chosen to be resistant to temperatures between 160°C and 250°C. They are advantageously neutral with respect to the fatty acid chlorides used. The applicator brush is loaded by briefly bringing the applicator brush into contact with a piece of microfiber measuring 100 mm x 100 mm impregnated with 4 mL of undiluted liquid fatty acid chloride. It has been shown that this qualitative approach makes it possible to deposit on a solid material by contact of the brush on the solid material maintained for a fraction of seconds, the minimum quantity of fatty acid chloride making it possible to confer a hydrophobicity on the treated paper material whatever. acceptable after development of the acylation reaction.

The applicator brush thus loaded with fatty acid chloride is used to apply fatty acid chloride to a solid hydroxylated material. The applicator brush can be applied to the paper material with a contact time of the tip of the applicator brush and the solid hydroxylated material of the order of magnitude of 1/ ^10th of a second and in such a way that the tip of the microfiber brush deforms on contact by generating intimate physical contact between the microfibers of the brush and the surface of the paper material promoting the transfer of fatty acid chloride.

However, it is possible to apply the fatty acid chloride by sliding the tip of the applicator brush over the surface of the paper material, like paint. The application of fatty acid chloride using a brush thus made makes it possible to mimic an application of fatty acid chloride on a scrolling paper such as it can be carried out using a lacquer roller provided with filiform elements, favoring an instantaneous application of reagent rather than a continuous application.

EXAMPLE 2 – Application conditions – Variable temperature of the applicator brush – Paper material at room temperature

Example 2 describes the application of a fatty acid chloride using a hot acid chloride applicator brush 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) is applied to a piece of blotting paper (Canson, 125 g/ m ² ) by means of an applicator brush as described in Example 1 and maintained after loading with fatty acid chloride at the acylation temperature in a thermostatically controlled oven. The applicator brush after loading is wrapped in a sheet of aluminum foil to maintain its temperature and placed in the thermostatically controlled oven at the acylation temperature. Fatty acid chloride at the acylation temperature is applied by point contact, as described in Example 1, of the hot applicator brush onto the blotting paper at room temperature after removal of the aluminum foil sheet. At the end of this contact, the blotting paper is placed for a few minutes in an oven at a temperature of 180°C to allow the acylation reaction to develop, then cooled to room temperature. The hydrophobicity of the treated blotting paper is evaluated by immersion in distilled water. The hydrophobic nature of the blotting paper obtained makes it possible to evaluate the efficiency of the acylation. The hydrophobic nature of the blotting paper is evaluated by measuring the dimensions of the hydrophobic spot formed as well as its intensity reflecting its resistance to humidification.

It is observed that the application of the reagent by the applicator brush maintained at room temperature produces a limited hydrophobic spot corresponding to the zone of deposition of the fatty acid chloride. When the temperature of the applicator brush increases, the spots observed increase in size and intensity of hydrophobicity up to a temperature limit value beyond which hydrophobicity decreases. This limit value is of the order of 200°C for palmitic acid chloride (C ₁₆ ) and of the order of 220°C for stearic acid chloride (C ₁₈ ).

These results indicate that the efficiency of the acylation and the quality of the grafting obtained depend on the temperature of the applicator brush and its filiform elements, and on the temperature of the reactive composition comprising the fatty acid chloride retained by the filiform elements. . Unexpectedly, heating the fatty acid chloride retained by the applicator brush, which necessarily promotes a shift in the liquid/vapor balance of the fatty acid chloride towards the vapor state, does not, in reality, lead to a loss of fatty acid chloride in the gaseous state by diffusion in the atmosphere, but allows grafting of the fatty acid chloride in the gaseous state onto the paper material without significantly leaving liquid fatty acid chloride on the paper material.

The invention therefore goes against a prejudice in the state of the art according to which fatty acid chloride must necessarily be deposited in an essentially liquid state by printing on a moving strip of paper to allow the acylation of this strip of paper by heating the fatty acid chloride deposited on the strip of paper.

EXAMPLE 3 – Application conditions – Hot applicator brush – Paper material at variable temperature

A fatty acid chloride (C ₁₆ palmitic acid or C ₁₈ stearic acid) is applied to a paper material heated to a temperature above room temperature using a hot applicator brush impregnated with the corresponding acid chloride. The applicator brush impregnated with palmitic acid chloride (C ₁₆ ) is maintained at a temperature of 200°C and the applicator brush impregnated with steric acid chloride (C ₁₈ ) is maintained at a temperature of 220°C as described in example 1. Fatty acid chloride (palmitic or stearic) is applied to a piece of blotting paper (Canson, 125 g/m ² ) placed in an oven at the acylation temperature. Immediately after the application of the fatty acid chloride, the piece of blotting paper which has been the subject of this application is covered with a second piece of blotting paper as a revealing piece of paper. The superposition of the two “emitting/revealing” pieces is maintained in the oven for a few minutes at the acylation temperature. The hydrophobicity imparted to the revealing piece is indicative of an excess of fatty acid chloride on the emitting piece of paper, having not reacted with this emitting piece of paper at the acylation temperature.

The combination of hot deposition of palmitic acid chloride (C ₁₆ ) using an applicator brush heated to a temperature of 200°C on a piece of emitting blotting paper brought to a temperature of 140°C, 170 °C or 200°C makes it possible to demonstrate that acylation is favored by blotting paper at a higher temperature, in particular at a temperature close to (or equal to) the temperature of the applicator brush and of the fatty acid chloride associated with the brush . The revealing part superimposed on the emitting part itself raised to 140°C presents significant hydrophobicity. The hydrophobicity of the revealing part decreases when the emitting part has been brought to a temperature of 170°C, to be almost undetectable when the emitting part has been brought to a temperature of 200°C.

The combination of hot deposition of stearic acid chloride (C ₁₈ ) using an applicator brush heated to a temperature of 220°C on a piece of emitting blotting paper itself brought to a temperature of 160° C, 190°C or 220°C makes it possible to demonstrate that acylation is favored by blotting paper at a higher temperature, in particular at a temperature equal to the temperature of the applicator brush and of the fatty acid chloride associated with the brush. The revealing part superimposed on the emitting part itself raised to 160°C presents significant hydrophobicity. The hydrophobicity of the revealing part decreases when the emitting part has been brought to a temperature of 190°C, to be almost undetectable when the emitting part has been brought to a temperature of 220°C.

The presence and amount of residual free acid chloride on the emitting piece of paper depends strongly on the temperature of the applicator brush and the temperature of the fatty acid chloride associated with the brush and the temperature of the piece of paper on which the fatty acid chloride is deposited.

The combination of hot deposition of fatty acid chloride using an applicator brush heated to the acylation temperature of between 160°C and 220°C on a piece of paper material itself brought to the temperature acylation makes it possible to obtain optimal acylation of the paper material for a reduced treatment time - in particular almost complete in 1/10 of a second - and compatible with on-the-fly treatment of a strip of paper driven in progress. Such optimal acylation can of course only be obtained by controlling and adjusting the quantity of fatty acid chloride deposited on the paper material, since a deposit of a quantity of fatty acid chloride greater than the stoichiometric quantity of hydroxyls accessible on the paper material will leave a remainder of fatty acid chloride on the surface of the paper material.

EXAMPLE 4 – Application conditions – Hot applicator brush – Hot paper material – Successive deposits

A succession of hot deposits of a fatty acid chloride is carried out on the same area of a piece of blotting paper, called the emitting piece, each deposit of the succession of deposits being carried out as described in Example 3 in using a hot applicator brush loaded with fatty acid chloride. After each hot deposition of the succession of deposits, a piece of revealing paper is superimposed on the emitting part, the superposition of the two “emitting/revealing” pieces being maintained in an oven for a few minutes at the acylation temperature. The hydrophobicity imparted to the revealing piece is indicative of an excess of fatty acid chloride on the emitting piece of paper, having not reacted with this emitting piece of paper at the acylation temperature. The hydrophobicity of the emitting part increases with the number of deposits. The hydrophobicity of the revealing part corresponding to the first two deposits remains low but increases with the third deposit. It appears from this example that the acylation takes place during the first two depositions without significant release of fatty acid chloride from the emitting part, only the third deposition being accompanied by a significant release of fatty acid chloride leading to acylation of the third revealing sheet. For greater efficiency of the chromatogenic 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 successive deposits of reduced quantities of fatty acid chloride . This is all the more so since the grafting of the fatty acid chloride onto the paper material and its immobilization has the effect of moving, by mass effect, the liquid/vapor balance of the fatty acid chloride towards the formation of vapor fatty acid chloride and its grafting onto the paper material. The paper material and the surface hydroxyl groups behave like a specific “pump” of the fatty acid chloride in the vapor state which will tend to lower the concentration of the fatty acid chloride in the vapor state at the level of the substrate and promote the diffusion of the reagent from the applicator brush towards the paper material.

The efficiency of the chromatogenic acylation reaction is defined 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 drop of pure water deposited on the surface of the acylated solid material. acylated solid material. Typically, a contact angle value of an acylated solid material is between 90° and 150°, the contact angle value of 150° corresponding to a particularly hydrophobic and water-repellent material. The quality of the acylation is also defined by measuring the duration during which the contact angle value between 90° and 150° is maintained at room temperature and by the water pocket test. The water pocket test can only be carried out with a solid material in the form of a flexible, approximately square sheet allowing the corners to be brought together to form a water pocket. We analyze the tightness of this water pocket by monitoring the loss of water (taking into account evaporation).

Hydrophobicity can also be assessed by observing water repellency. 1 mL of distilled water is placed on the surface of the solid material and we observe whether the drop of water formed rolls on the surface, clinging or not to the surface of the solid material. Satisfactory water repellency corresponds to a contact angle of approximately 150°.

The invention may be the subject of numerous variants and applications other than those described above. In particular, it goes without saying that unless otherwise indicated the different structural and functional characteristics of each of the embodiments described above should not be considered as combined and/or closely and/or inextricably linked to each other, but to the contrary as simple juxtapositions. In addition, the structural and/or functional characteristics of the different embodiments described above may be the subject in whole or in part of any different juxtaposition or of any different combination.

Claims (19)

Process for the chromatogenic acylation of a solid material (1,2) carrying hydroxyl groups accessible to at least one fatty acid chloride in the gaseous state and capable of reacting with this fatty acid chloride(s). fatty acid in the gaseous state, in which:
at least one composition, called reactive composition (20,21,22), of at least one fatty acid chloride is applied at least to the surface of said hydroxylated solid material (1,2) by means of at least one device ( 3,15,28) applicator having an applicator surface formed of filiform elements (4,16,29) non-reactive with said reactive composition (20,21,22) and capable of being able to release said composition (20,21,22) ) reactive at least on the surface of said solid hydroxylated material (1,2) by contact of the filiform elements (4,16,29) and the solid hydroxylated material (1,2),
characterized in that said reactive composition (20,21,22) applied by the applicator device (3,15,28) at least on the surface of said hydroxylated solid material (1,2) is, during its application, at a temperature, said acylation temperature, lower than the vaporization temperature of at least one fatty acid chloride of said reactive composition (20,21,22) and chosen to allow acylation of said solid material (1,2) by reaction 'at least one fatty acid chloride in the gaseous state of said composition (20,21,22) reactive on at least one of the hydroxyl groups of said solid material (1,2), said acylation temperature being between 160 °C and 250°C. Method according to claim 1, characterized in that at least one applicator surface portion of the applicator device (3,15,28) being in contact with a surface portion of the hydroxylated solid material (1,2), at least this portion surface of the hydroxylated solid material (1,2) is at said acylation temperature during the application of said reactive composition (20,21,22) to the hydroxylated solid material (1,2). Method according to one of claims 1 or 2, characterized in that the filiform elements (4,16,29) forming the applicator surface are at said acylation temperature during the application of said composition (20,21,22 ) reactive on the material (1,2) hydroxylated solid. Method according to one of claims 1 to 3, characterized in that said reactive composition (20,21,22) is applied at least to the surface of said solid hydroxylated material (1,2), in a thermoregulated enclosure (39) adapted for maintaining said reactive composition (20,21,22) released by the applicator device (3,15,28) at said acylation temperature. Method according to one of claims 1 to 4, characterized in that it comprises at least one step of redistribution of fatty acid chloride(s) deposited on the hydroxylated solid material, without new addition of said reactive composition (20,21,22), the redistribution step being carried out by means of at least one distributor device having an applicator surface formed of filiform elements not reactive with the fatty acid chlorides of said reactive composition and capable of being able to take charge of fatty acid chlorides deposited on the solid hydroxylated material, by contact of the filiform elements of the distributor device and of the solid hydroxylated material (1,2) and to release at least part of the charged fatty acids, on contact of said solid hydroxylated material (1,2) by contact of the filiform elements and the solid hydroxylated material (1,2), the distributor device being at a temperature between 160°C and 250°C. Method according to one of claims 1 to 5, characterized in that at least one reactive composition (20,21,22) comprises at least one fatty acid chloride chosen from the group consisting of palmitic acid chloride ( C16), stearic acid chloride (C18), arachidic acid chloride (C20) and behenic acid chloride (C22). Method according to one of claims 1 to 6, characterized in that the hydroxylated solid material (1,2) is a paper material. Method according to one of claims 1 to 7, characterized in that the solid hydroxylated material (1,2) is formed of a strip (2,10,12,25) of paper driven in a direction (42) running parallel to the largest dimension of the strip (2,10,12,25,35), between a reel (66) upstream of said strip (2,10,12,25,35) of paper and a winder ( 36) downstream of a strip (12,25,35) of acylated paper. Method according to claim 8, characterized in that at least one reactive composition (20,21,22) is applied to fixed position(s) at least on one main face of the strip (2,10,12,25 ) of paper driven in scrolling. Method according to one of claims 8 or 9, characterized in that at least one applicator device (3,15,28) is a roller with an axis of rotation parallel to the plane of the strip (2,10,12,25 ) of paper and not parallel to the direction (42) of scrolling. Method according to one of claims 8 to 10, characterized in that it comprises at least two applications of reactive composition(s) (20,21,22) at fixed positions on the strip of paper driven in motion, each reactive composition(s) (20,21,22) being at said acylation temperature during its application. Method according to one of claims 8 to 11, characterized in that the solid material (1,2) is a paper material coated with polyvinyl alcohol. Method according to one of claims 8 to 12, characterized in that the filiform elements (4,16,29) of at least one applicator roller (3,15,28) are supplied by centrifugal diffusion of said composition (20, 21,22) reactive from an axial light of this roller (3,15,28) applicator driven in rotation on itself. Method according to claim 13, characterized in that said reactive composition (20,21,22) is introduced into the axial lumen of the applicator roller (3,15,28) by means of a distribution ramp for said composition (20, 21,22) reactive over the length of the axial light, the distribution ramp extending over substantially the entire length of the axial light. Method according to one of claims 8 to 14, characterized in that at least one applicator roller (3,15,28) is provided with means for heating said composition (20,21,22) reactive to said temperature. acylation. Method according to one of claims 8 to 15, characterized in that a sample of fatty acid chloride(s) from the strip (12,25,35) of paper is carried out by means of a device (62) recuperator having a rotating recuperative surface (63) provided with filiform elements, non-reactive with said reactive composition and able to:

• take on fatty acid chloride(s) by contact with the recovering surface (63) and the strip (12,25,35) of paper, and
• releasing fatty acid chloride(s) by applying a flow of gaseous composition (64) heated to a temperature higher than said acylation temperature, the flow of gaseous composition (64) being applied in contact with the recovering surface (63).

Method according to one of claims 1 to 16, characterized in that the filiform elements (4,16,29) are formed of at least one material chosen from the group consisting of aramid fibers and microfibers and fibers and microfibers inorganic. Method according to one of Claims 1 to 17, characterized in that at least a portion of gaseous hydrochloric acid formed due to chromatogenic acylation is entrained by a flow rate of a gaseous composition circulating in contact with the material (1 ,2) solid, at said acylation temperature. Method according to one of claims 1 to 18, characterized in that said reactive composition (20,21,22) is free of any solvent medium.