EP0664357A1 - Water resistant and repulpable compact material from broken cellulose and process of preparation thereof - Google Patents

Abstract

A novel compact, water-resistant material (I), based on ground cellulosic material, is repulpable and contains: (A) an organic binder selected from starch (or derivs.), flour, proteins, starch mfr. by-products, cellulose (or derivs.), hemicellulose (or derivs.) and mixts.; and (B) an organosilicon or fluorinated acrylic copolymer hydrophobic agent to provide water resistance.

Description

The subject of the invention is a compact "repulpable" and water-resistant material, obtained from crushed cellulosic materials.

It also relates to a process for the preparation of this material.

By the term "compact material" is meant, within the meaning of the present invention, a material having sufficient cohesion and mechanical strength to be able to be used for example in the furniture industry, in the construction industry (for example for the production of panels or partitions), in the horticultural industry (for example for the production of trays for potted plants) or in the packaging industry (for example for the production of pallets, support elements, shims, spacers ...).

By the term "repulpable" is meant, still within the meaning of the present invention, the property that the material can be used directly, after any grinding, as a raw material in the manufacture of paper, without requiring any operation sorting or physical, mechanical, or physicochemical separation or separation, and without generating any waste other than the waste normally produced during the manufacture of paper. Such repulpable material can therefore be introduced directly at the pulp of the paper machine, without prior sorting operation.

We know that many activities consume wood or wood-based materials. This is particularly the case with the manufacture and use of wooden panels or wood particle boards, pallets, wooden presentation trays, boards, holds, etc ... A major problem, and one that is growing, lies in the difficulty of recovering the wood waste generated by these activities. Thus, if we take the example of wooden pallets, commonly used in industry and in distribution, it appears that it is increasingly difficult to recover and recover them after use. Their recovery is indeed difficult, in particular because of their high volume / weight ratio and because of the need to remove the nails used for their manufacture. In addition, the wood thus recovered can hardly be used for anything other than destruction by fire.

There is also a major problem of disposal, and a fortiori recovery, of paper and cardboard waste. In Germany, for example, the incineration of waste paper has been banned. It is indeed polluting and causes fouling of the boilers used for their combustion.

In order to try to reduce the consumption of this eminently ecological resource that constitutes wood, and in order to try to recover the large quantities of waste paper and cardboard generated by the various industrial or commercial activities mentioned above, it has already been proposed to make, from old paper or cardboard, insulating materials and building materials similar to wood.

However, the materials thus produced are not satisfactory.

On the one hand, in fact, they do not always have the water resistance which is necessary for certain uses.

And on the other hand and above all, they cannot be recycled directly in the manufacturing circuit of a paper machine. Even by carrying out pre-sorting operations, their recycling can thus cause serious difficulties in the manufacture of paper or in the subsequent use of paper (problems of printability, or problems of sticking of the groove in the case of the manufacture of corrugated cardboard, for example). Huge losses in paper production are thus incurred in the event of pollution of the circuit by said materials. Various treatments (skimming, heat treatments) minimize these risks, but they are very expensive and not necessarily entirely reliable.

The Applicant Company, after becoming aware of these difficulties, had the merit of completely redefining the technical problem and of establishing that a truly satisfactory solution could only be found on the condition of manufacturing, using materials cellulosics such as the waste of old paper and old cardboard, compact materials which, while being resistant to water, offered a particular property, namely a "repulpability" total and whole.

In addition to this complete redefinition of the technical problem, the invention consists in selecting, for the manufacture of the compact materials according to the invention, products which prove to be compatible with this property of total repulpability. In particular, in accordance with the invention, binding agents are selected on the one hand, and agents capable of imparting a certain resistance to water on the other hand, which are perfectly compatible with said repulpability property.

The presence of binding agents is necessary in order to allow obtaining compact materials having sufficient solidity and cohesion, in particular high compressive and flexural strengths.

The presence of agents capable of imparting a certain resistance to water is desirable, since the compact materials targeted by the invention can be used in very humid atmospheres, or be brought into contact with moist soils.

Various types of binders, possibly associated with agents capable of imparting a certain resistance to water have already been used or proposed in the prior art for the manufacture of compact materials of the type of those targeted by the present invention.

Thus, binders such as polyvinyl alcohols and their derivatives, celluloses and their derivatives, lignosulfonates, starches and their derivatives, alkali silicates, clays, tars, pitches and bitumens have already been proposed.

It has more particularly been proposed to use, as a binding agent, starch which, used alone or in admixture with other binders, as taught, for example, in patents EP 4 135 330, DE 4,141,864 and DE 3,627,255 have many advantages.

However, and this constitutes a major drawback, even prohibitive in most applications, the materials thus bonded with starch, just like those linked with bentonite, exhibit an extremely marked sensitivity to water, making impossible their storage in the open air and even their storage in a humid atmosphere.

It has therefore been proposed, in an attempt to remedy this essential drawback, to combine the starch with pitch, asphalt or bitumen, or even to insolubilize the starch with urea-formaldehyde resins, phenol-formaldehyde, melamine-formaldehyde, ketone-formaldehyde or mixtures thereof, or alternatively to combine plastics or hot-melt resins with starch.

None of these solutions turns out to be satisfactory, however, since none of them makes it possible to obtain, under economically and ecologically acceptable conditions, compact materials based on finely ground cellulosic material having simultaneously high mechanical characteristics, sufficient water resistance. , and above all a total repulpability.

Indeed, all the solutions proposed up to present have used binders and / or adjuvants which make the compact materials obtained non-repulpable and these cannot therefore be easily recycled, without prior sorting operation, and without creating any problem for manufacture or use subsequent paper and / or cardboard.

Due to the adequate reformulation of the technical problem and thanks to the selection of certain binding agents and certain water resistance agents, the Applicant Company therefore had the merit of remedying the drawbacks of the prior art and of offering a completely advantageous solution to the problems raised by the consumption of wood or wood derivatives and by the recovery and recovery of wood, paper or cardboard waste, by allowing the manufacture of compact materials, resistant to water and repulpable, based on cellulosic materials.

• d'une part une quantité efficace d'un liant organique choisi dans le groupe comprenant les amidons, les dérivés d'amidon, les farines, les protéines, les sous-produits d'amidonnerie et de féculerie, les celluloses et leurs dérivés, les hémicelluloses et leurs dérivés, ainsi que les mélanges de ces produits et,
• d'autre part une quantité efficace d'un agent de résistance à l'eau choisi parmi les agents hydrofugeants organosiliciques et les copolymères acryliques fluorés.

In accordance with the invention, the materials in question are characterized in that they comprise:

• on the one hand, an effective amount of an organic binder chosen from the group comprising starches, starch derivatives, flours, proteins, starch and starch by-products, celluloses and their derivatives, hemicelluloses and their derivatives, as well as mixtures of these products and,
• on the other hand, an effective amount of a water resistance agent chosen from organosilicon waterproofing agents and fluorinated acrylic copolymers.

The effective quantity denotes the quantity sufficient to obtain the desired effect.

According to an advantageous embodiment of the compact material according to the invention, the organic binder is chosen from starches, starch derivatives, and / or starch by-products.

• en ce qui concerne l'amidon, les amidons de toute origine, naturels ou hybrides, provenant par exemple de la pomme de terre, du manioc, du maïs, du maïs cireux, du maïs à haute teneur en amylose, du blé et des coupes qui peuvent en être faites, de l'orge et de sorgho,
• en ce qui concerne le dérivé d'amidon, les amidons modifiés par voie physique et/ou chimique.

When the organic binder forming part of the compact material according to the invention is a starch or a starch derivative, these terms:

• with regard to starch, starches of all origins, natural or hybrid, originating for example from potatoes, cassava, maize, waxy maize, maize with a high amylose content, wheat and cuts that can be made of it, barley and sorghum,
• as regards the starch derivative, the starches modified physically and / or chemically.

Advantageously, the organic binder is chosen from native starches, optionally made soluble in cold water using a physical cooking-extrusion and / or gelatinization treatment on a drum.

When the organic binder forming part of the compact material according to the invention is chosen from starch and starch by-products, deproteinized waste water from a starch protein factory, in particular starch starch, is preferably used. potato. The deproteinized waste waters in question can be obtained in various ways, and in particular result from the treatment of potato starch effluents known to those skilled in the art under the terms "vegetable water" or " red waters ", the general principle of which is obtained is described in French patent FR 2 256 727.

dans laquelle R et R₁, qui peuvent être identiques ou différents l'un de l'autre sont de l'hydrogène ou des radicaux organiques choisis dans le groupe comprenant les radicaux méthyle, alcoyle, fluoroalcoyle, phényle éventuellement substitué, vinyle ou leurs dérivés chlorés, alcoxy, alcoylamino, ledit composé étant avantageusement choisi dans le groupe comprenant les huiles silicones non réactives, les résines silicones, les huiles silicones réactives notamment hydroxylées, alcoylées, arylées, hydroalcoylées, hydroarylées ainsi que les mélanges de ces produits et les émulsions qui peuvent être préparées à partir de ces produits.According to another advantageous embodiment of the compact material according to the invention, the water-resistance agent is chosen from organosilicon water-repellants, the structural unit of which corresponds to the formula:

in which R and R₁, which may be the same or different from each other, are hydrogen or organic radicals chosen from the group comprising: methyl, alkyl, fluoroalkyl, optionally substituted phenyl radicals, vinyl or their chlorinated derivatives, alkoxy, alkylamino, said compound being advantageously chosen from the group comprising non-reactive silicone oils, silicone resins, reactive silicone oils, especially hydroxylated, alkylated, arylated , hydroalkylated, hydroarylated as well as the mixtures of these products and the emulsions which can be prepared from these products.

dans laquelle

• R₂ est un groupement alcoyle (C₁-C₁₀), alkényle (C₁-C₁₀) ou aryle (C₆-C₁₀)
• X est un atome de métal alcalin ou alcalino-terreux et
• 1 ≦ n ≦ 10
  le siliconate de potassium étant particulièrement préféré.

According to a particularly advantageous embodiment of the compact material according to the invention, the organosilicon water-repellent agent is chosen from the group of siliconates of general formula:

in which

• R₂ is an alkyl (C₁-C₁₀), alkenyl (C₁-C₁₀) or aryl (C₆-C₁₀) group
• X is an alkali or alkaline earth metal atom and
• 1 ≦ n ≦ 10
  potassium siliconate being particularly preferred.

• a) 35 à 98 %, de préférence 69 à 93 %, d'un ou plusieurs monomères polyfluorés de formule générale :
  
  dans laquelle Rf représente un radical perfluoro-alkyle à chaîne droite ou ramifiée, contenant 2 à 20 atomes de carbone, de préférence 4 à 16 atomes de carbone, Q représente un atome d'oxygène ou de soufre, B représente un enchaînement bivalent lié à Q par un carbone et pouvant comporter un ou plusieurs atomes d'oxygène, de soufre et/ou d'azote, l'un des symboles R représente un atome d'hydrogène et l'autre un atome d'hydrogène ou un radical alkyle contenant 1 à 4 atomes de carbone ;
• b) 1 à 15 %, de préférence 5 à 11 % et surtout 7 à 10 %, d'un ou plusieurs monomères de formule générale :
  
  dans laquelle B' représente un radical alkylène linéaire ou ramifié, contenant 1 à 4 atomes de carbone, R' représente un atome d'hydrogène ou un radical alkyle contenant 1 à 4 atomes de carbone, R₁ représente un radical alkyle contenant 1 à 18 atomes de carbone, hydroxyéthyle ou benzyle, R₂ représente un atome d'hydrogène ou un radical alkyle contenant 1 à 18 atomes de carbone, hydroxyéthyle ou benzyle ou R₁ et R₂ ensemble avec l'atome d'azote forment un radical morpholino, pipéridino ou pyrrolidinyle-1 ;
• c) 1 à 50 %, de préférence 2 à 20 %, d'un ou plusieurs monomères de formule générale
  
  dans laquelle R₃, R'₃, R₄ et R₅ sont identiques ou différents et représentent chacun un atome d'hydrogène ou un radical alkyle contenant 1 à 4 atomes de carbone ; et éventuellement
• d) jusqu'à 10%, de préférence moins de 5 %, d'un monomère quelconque autre que les monomères de formules (I), (II) et (III).

According to another embodiment of the compact material according to the invention, the water resistance agent is chosen from fluorinated copolymers as described in European patent 0 034 527. These copolymers, optionally salified or quaternized, comprise in weight :

• a) 35 to 98%, preferably 69 to 93%, of one or more polyfluorinated monomers of general formula:
  
  in which Rf represents a perfluoroalkyl radical with a straight or branched chain, containing 2 to 20 carbon atoms, preferably 4 to 16 carbon atoms, Q represents an oxygen or sulfur atom, B represents a divalent chain linked to Q by a carbon and possibly comprising one or more oxygen, sulfur and / or nitrogen atoms, one of the symbols R represents a hydrogen atom and the other a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms;
• b) 1 to 15%, preferably 5 to 11% and especially 7 to 10%, of one or more monomers of general formula:
  
  in which B 'represents a linear or branched alkylene radical containing 1 to 4 carbon atoms, R' represents a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms, R₁ represents an alkyl radical containing 1 to 18 atoms of carbon, hydroxyethyl or benzyl, R₂ represents a hydrogen atom or an alkyl radical containing 1 to 18 carbon atoms, hydroxyethyl or benzyl or R₁ and R₂ together with the nitrogen atom form a morpholino, piperidino or pyrrolidinyl radical- 1;
• c) 1 to 50%, preferably 2 to 20%, of one or more monomers of general formula
  
  wherein R₃, R'₃, R₄ and R₅ are the same or different and each represents a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms; and eventually
• d) up to 10%, preferably less than 5%, of any monomer other than the monomers of formulas (I), (II) and (III).

According to a particularly advantageous embodiment of the compact material according to the invention, the water-repellent agent is chosen from fluorinated copolymers such as those sold by the company ELF ATOCHEM under the name FORAPERLE, and very particularly under the name FORAPERLE 321.

• une proportion de 0,5 à 40 %, de préférence de 1 à 25 %, et plus préférentiellement encore de 2 à 20 % en poids de liant organique,
• une proportion de 0,05 à 10 %, de préférence de 0,025 à 6 %, et plus préférentiellement encore de 0,05 à 4 % en poids d'agent hydrofugeant.

Relative to the weight of milled cellulosic materials forming part of the compact material according to the invention, the latter advantageously comprises:

• a proportion of 0.5 to 40%, preferably from 1 to 25%, and more preferably still from 2 to 20% by weight of organic binder,
• a proportion of 0.05 to 10%, preferably from 0.025 to 6%, and more preferably still from 0.05 to 4% by weight of water-repellent agent.

The proportion of water-repellent agent is, ultimately, calculated so as to give the compact material a satisfactory water resistance, knowing that the main objective targeted by the invention is to ensure repulpability of the material obtained.

The compact material according to the invention can optionally comprise other constituents such as by example of hardening agents, present in a proportion of 0.5 to 25%, preferably from 1 to 5% by weight relative to the weight of crushed cellulosic materials.

The hardening agents in question can be chosen from the group of alkaline agents, more particularly from the group of hydroxides and oxides of alkali or alkaline earth metals, or from the group of salts of strong bases or weak bases, and in particular from carbonates of alkali or alkaline earth metals. The preferred hardening agent is hydrated lime.

The compact material according to the invention can also comprise other constituents such as, for example, bactericides, fungicides, rat poisons ...

• que l'on sélectionne un matériau cellulosique broyé, un liant organique du groupe précédemment défini, un agent hydrofugeant organosilicique ou un copolymère fluoré, et éventuellement un agent durcisseur,
• que l'on mélange l'agent hydrofugeant avec soit le matériau cellulosique, soit le liant organique, soit avec l'un et l'autre de ces produits ou leur mélange,
• et que l'on soumet le mélange ainsi obtenu à un traitement de mise en forme, par exemple par pression, compression, agglomération, compactage ou extrusion.

The process according to the invention for preparing the compact material according to the invention is characterized by the fact:

• that a ground cellulose material, an organic binder from the group defined above, an organosilicon water repellant or a fluorinated copolymer, and possibly a hardening agent, are selected,
• that the water-repellent agent is mixed with either the cellulosic material or the organic binder, or with both of these products or their mixture,
• and that the mixture thus obtained is subjected to a shaping treatment, for example by pressure, compression, agglomeration, compacting or extrusion.

According to this process, the water-repellent agent is therefore distributed throughout the compact material, which makes it possible to obtain excellent water resistance. Optionally, this water resistance can be further reinforced by applying an additional quantity of water-repellent agent to the surface of the compact material already formed, by any known technique, for example by coating, impregnation, immersion, spraying or brushing.

• que l'on sélectionne un matériau cellulosique finement broyé, un liant organique du groupe précédemment défini, et éventuellement un agent durcisseur,
• que l'on mélange le matériau cellulosique, le liant organique et éventuellement le durcisseur,
• que l'on soumet le mélange ainsi obtenu à une mise en forme, par exemple par pression, compression, agglomération, compactage, ou extrusion.
• que l'on applique une quantité choisie d'agent hydrofugeant en surface du matériau compact ainsi obtenu, par exemple par enduction, imprégnation, immersion, pulvérisation ou brossage.

However, for certain uses, we can content to apply only the water-repellent agent to the compact material already formed and the process according to the invention is then characterized by the fact:

• that a finely ground cellulosic material is selected, an organic binder from the group defined above, and optionally a hardening agent,
• that the cellulosic material, the organic binder and possibly the hardener are mixed,
• that the mixture thus obtained is subjected to shaping, for example by pressure, compression, agglomeration, compaction, or extrusion.
• that a selected quantity of water-repellent agent is applied to the surface of the compact material thus obtained, for example by coating, impregnation, immersion, spraying or brushing.

According to another embodiment, a composition of matter is prepared comprising the organic binder and at least part of the water-repellent agent. An intimate mixture of the finely ground cellulosic materials and this material composition is produced, and this mixture is subjected to a shaping treatment, the possible part of water-repellent agent not included in the material composition being for example applied to the product. resulting from the shaping treatment.

The nature and the proportions of the constituents are selected so that the compact material obtained has the characteristics of mechanical resistance, water resistance and repulpability indicated above.

According to an advantageous embodiment of the process according to the invention, the compact material obtained at the end of the shaping treatment is subjected to a steaming treatment under temperature conditions generally between approximately 80-100 ° C. and about 200-220 ° C. The duration of this parboiling treatment depends on the temperature, but it is generally between 15 minutes and 5 hours, preferably between 30 minutes and 3 hours.

When the water-repellent agent used is a siliconate and in particular a potassium siliconate, this steaming treatment is optional and does not constitute an essential step in the process which is the subject of the invention. Unlike the various techniques of the prior art, the compact materials in accordance with the present invention indeed have in this case, by simple treatment at room temperature, the required physical characteristics and in particular a high mechanical resistance; steaming only accelerates the drying of the compact materials obtained.

In the case of the use of another waterproofing agent and in particular in the case of the use of fluorinated copolymers, it is generally preferable to subject the compact material obtained at the end of the shaping treatment to the aforementioned treatment. steaming.

The compact material according to the invention has variable mechanical characteristics depending on the pressure which is exerted during the shaping treatment.

Thus, if a low pressure is exerted, one obtains a "mattress" made of cellulosic materials which is flexible and elastic. Such a material may be suitable, for example, in setting operations or as an anti-shock or anti-vibration product.

Conversely, if a high pressure is exerted, the compact material obtained has very high flexural, tensile and compressive strengths and can be advantageously used as a wedging material, or even as a coil core. It can also be used as a material for the production of biodegradable and repulpable pallets. This constitutes an essential advantage of the present invention.

Another essential advantage of the present invention lies in the fact that by selecting binding agents and water-repellent agents whose contact with foodstuffs is permitted, compact materials can be obtained which can be used, for example, as packing materials in packaging for food products or as packing materials for packaging of toys, for example.

The invention can be understood even better with the aid of the examples which follow and which relate to advantageous embodiments.

EXAMPLE 1

In a mixer of the Robot coupe type, 1000 g of crushed waste paper having a particle size of less than 1 cm is introduced on the one hand, and 100 g of AGGLOFROID ^R 009 (pregelatinized starch sold by the company ROQUETTE FRERES) on the other hand - (62-LESTREM) and 250 g of drinking water containing 30 g of potassium siliconate The mixture obtained is then kneaded for 5 minutes, then it is agglomerated by molding in the form of square panels 6 cm wide and 1 cm high, under a pressure of 3432 10⁴ pascals The test pieces thus obtained have sufficient green cohesion to undergo transport.

• en flexion :
  • à vert   : 500 N
  • après 48h de séchage à température ambiante   : 1000 N
  • après 2h de séchage à 100°C   : 1200 N
• compression sur champs :
     après 72h de séchage à température ambiante   : 4000 N

The resistance of these test pieces, determined using a PERRIER brand compression tester, has the following values:

• in flexion:
  • green: 500 N
  • after 48 hours of drying at room temperature: 1000 N
  • after 2 hours of drying at 100 ° C: 1200 N
• compression on fields:
  after 72 hours of drying at room temperature: 4000 N

These test pieces are then placed in a humid atmosphere, at 100% relative humidity and at 25 ° C. No disintegration was observed, even after several weeks. The mechanical strength of the test pieces remains unchanged after this stay in wet storage. The interior of the test specimens does shows no trace of moisture.

On the other hand, if one of these plates is placed in a beaker of cold water with gentle stirring for 4 to 5 hours, we see that it begins to swell slightly and then to disintegrate. After 6 to 7 hours, a coarse paper pulp is obtained, which can be directly worked in a stationery pulper.

• en flexion :
  • à vert   : 100 N
  • après 48h de séchage à température ambiante   : 150 N
  • après 1/2h de séchage à 80°C   : 150 N
• en compression sur champs :
     après 72h de séchage à température ambiante   : 800 N

If paper waste of the same composition is compacted under the same conditions but in the absence of any binder, samples are obtained having the following mechanical strengths, always determined using the PERRIER compression tester:

• in flexion:
  • green: 100 N
  • after 48 hours of drying at room temperature: 150 N
  • after 1/2 hour of drying at 80 ° C: 150 N
• in compression on fields:
  after 72 hours of drying at room temperature: 800 N

These test pieces then being placed in a humid atmosphere, at 100% relative humidity and at 25 ° C., the platelets swell after 24 hours. After 96 hours, the material no longer has any cohesion.

• en flexion :
  • à vert   : 500 N
  • après 48h de séchage à température ambiante   : 1000 N
  • après 2h de séchage à 100°C   : 1200 N
• en compression sur champs :
     après 72h de séchage à température ambiante   : 4000 N

If paper waste of the same composition is now compacted with the same amount of binder and water but without the addition of potassium siliconate, test tubes with the following resistances are obtained, determined using the PERRIER compression tester:

• in flexion:
  • green: 500 N
  • after 48 hours of drying at room temperature: 1000 N
  • after 2 hours of drying at 100 ° C: 1200 N
• in compression on fields:
  after 72 hours of drying at room temperature: 4000 N

These test pieces being placed in a humid atmosphere, at 100% relative humidity and at 25 ° C., the platelets swell after 24 hours. After 72 hours, the material no longer has any cohesion.

This example shows that the addition of 10% of AGGLOFROID ^R 009 and 3% of potassium siliconate by dry weight relative to the weight of paper waste makes it possible to obtain compact materials satisfying the requirements of the technique, namely having sufficient mechanical resistance and resistance to humidity while remaining plumpable in a stationery pulper.

EXAMPLE 2

In a mixer of the Robot coupe type, on the one hand, 1000 g of crushed corrugated cardboard having a particle size of less than 0.5 cm are introduced and, on the other hand, 150 g of waste water from potato starch protein production, consisting of vegetable water, or red water, partially deproteinized, with 55% dry matter, sold under the name FONDLYS ^R 55007 by the company ROQUETTE FRERES. The mixture obtained is kneaded for 3 minutes, then 50 g of hydrated lime is introduced into it and the kneading is continued for 2 minutes. The mixture is then agglomerated by molding in the form of pucks 5 cm in side and 1 cm thick under a pressure of 3432 10⁴ pascals.

The samples thus obtained have sufficient green cohesion to undergo transport.

• en flexion :
  • à vert   : 800 N
  • après 72h de séchage à température ambiante   : 1500 N
  • après 2h de séchage à 80°C   : 1500 N
• en compression sur champs :
     après 72h de séchage à température ambiante   : 1500 N

The resistance of these test pieces, determined using a PERRIER compression tester, has the following values:

• in flexion:
  • green: 800 N
  • after 72 hours of drying at room temperature: 1500 N
  • after 2 hours of drying at 80 ° C: 1500 N
• in compression on fields:
  after 72 hours of drying at room temperature: 1500 N

After drying for 72 hours at room temperature, the test pieces are immersed in a 10% potassium siliconate solution.

The test pieces absorb 5% of said solution. After drying at room temperature, they exhibit a "pearling" effect, that is to say a repellent effect with respect to water, very marked.

These test pieces are then placed in a humid atmosphere, at 100% relative humidity and at 25 ° C. No disintegration is observed, even after several weeks. The mechanical strengths of these test pieces remain unchanged after this stay in a humid atmosphere. Likewise, the "sparkling" effect is preserved.

On the other hand, if a whole test tube is placed in cold water with stirring, it begins to disintegrate after 4 to 5 hours. If this plate is broken into several pieces before being placed in water, we obtain, after only two hours, a coarse paper pulp, sufficiently dispersed to be subjected to the work of a stationary disintegrator.

This example shows that the addition of 15% of FONDLYS ^R 55007 and 5% of hydrated lime by dry weight relative to the weight of waste paper waste, as well as the immersion in a potassium siliconate solution, make it possible to obtain compact materials with satisfactory mechanical strength and sufficient water resistance so that the compact material can be stored in a humid place. On the other hand, the compact material in question has a property of total repulpability.

EXAMPLE 3

In a mixer of the Robot coupe type, 500 g of paper waste having a particle size less than 2 mm and 500 g of paper waste having a particle size between 1 cm and 2 cm are introduced on the one hand, and on the other hand share, 200 g of a modified corn starch glue sold by the company ROQUETTE FRERES under the name AMILYS ^R 100, the dry matter of this glue being 35% by weight. The mixture is kneaded for 5 minutes then 20g of water-repellent product sold under the name HYDROFUGE 68 by RHONE POULENC is added. After two minutes of mixing, the mixture is agglomerated by molding in the form of rectangles 30 cm long, 12 cm wide, and 2 cm thick, under a pressure of 3432 10⁴ pascals. The samples thus obtained have a very high green cohesion, allowing all useful manipulations.

• en flexion :
  • à vert   : 2000 N
  • après 72h à température ambiante   : 4000 N
  • après 2h de séchage à 120°C   : 5000 N
• en compression sur champs :
  • après 72h à température ambiante   : 80000 N
  • après séchage 2h à 120°C   : 100000 N

The resistance of these test pieces, determined using a PERRIER compression tester, has the following values:

• in flexion:
  • green: 2000 N
  • after 72 hours at room temperature: 4000 N
  • after 2 hours of drying at 120 ° C: 5000 N
• in compression on fields:
  • after 72 hours at room temperature: 80,000 N
  • after drying for 2 hours at 120 ° C: 100,000 N

These test pieces are then placed in a humid atmosphere, at 100% relative humidity and at 25 ° C. No disintegration is observed, even after several weeks. The mechanical resistance of the test pieces remains unchanged after this stay in a humid atmosphere. The interior of the test pieces does not show any trace of moisture upon observation.

On the other hand, if a test tube is placed in a beaker of cold water with gentle stirring for 4 to 5 hours, it is observed that the test tube begins to swell slightly and then disintegrates. After 6 to 7 hours, a coarse paper pulp is obtained, sufficient to be worked in a stationery refiner.

• en flexion :
  • à vert   : 500 N
  • après 72h à température ambiante   : 800 N
  • après 2h de séchage à 120°C   : 1000 N
• en compression sur champs :
  • après 72h à température ambiante : 2000 N
  • après 2h à 120°C : 5000 N

If paper waste of the same nature and of the same composition is compacted under the same conditions but in the absence of any binder, samples are obtained having the following resistances, determined using a PERRIER compression tester:

• in flexion:
  • green: 500 N
  • after 72 hours at room temperature: 800 N
  • after 2 hours of drying at 120 ° C: 1000 N
• in compression on fields:
  • after 72h at room temperature: 2000 N
  • after 2h at 120 ° C: 5000 N

These test pieces are then placed in a humid atmosphere at 100% relative humidity and at 25 ° C. There is swelling of these specimens after only 24 hours. After 96 hours, the compact material thus obtained no longer exhibits any cohesion.

This example shows that the addition of 7% of AMILYS ^R 100 (in the form of an adhesive obtained by steaming) and 2% of WATER-REPELLENT 68 by weight relative to the weight of paper waste makes it possible to '' obtain agglomerates satisfying in all respects the requirements of the technique.

EXAMPLE 4

In a mixer of the Robot coupe type, 1000 g of crushed old paper with a particle size of less than 5 mm is introduced on the one hand and 100 g of AGGLOFROID ^R 313E and 250 g of drinking water containing 30 g of liquid on the other hand a fluorinated acrylic copolymer, marketed by the company ELF ATOCHEM under the brand FORAPERLE 321. The mixture obtained is kneaded for 5 minutes, then it is agglomerated by molding in the form of square panels 6 cm wide and 1 cm thick, under a pressure of 3432 10⁴ pascals. The samples thus obtained have sufficient green cohesion to undergo transport.

• en flexion :
  • à vert   : 500 N
  • après 48h à température ambiante   : 900 N
  • après 2h de séchage à 100°C   : 1300 N
• en compression sur champs :
     après 72h à température ambiante   : 3500 N

The resistance of these test pieces is determined using a PERRIER compression tester and has the following values:

• in flexion:
  • green: 500 N
  • after 48 hours at room temperature: 900 N
  • after 2 hours of drying at 100 ° C: 1300 N
• in compression on fields:
  after 72h at room temperature: 3500 N

These test pieces are placed in a humid atmosphere at 100% relative humidity and at 25 ° C. There is swelling of these specimens after 96 hours. After 144 hours, these test pieces have only a weak cohesion.

EXAMPLE 5 :

Test pieces, prepared under the same conditions as in Example 4 above, are immersed in a FORAPERLE 321 solution at 50%. It is found that the test pieces absorb 10% of the solution. After drying at room temperature, they have a slight "pearling" effect. On the other hand, after drying for 2 hours at 120 ° C., it is found that the "beading" effect obtained is very marked.

EXAMPLE 6

Test pieces, prepared under the same conditions as in Example 4 above, are immersed in a solution of pregelatinized potato starch with 5% dry matter, mixed with 20% calcium carbonate and 10% of FORAPERLE ^R 321. The test pieces thus absorb 5% of the solution. After drying at room temperature, these test pieces show practically no "beading" effect. On the other hand, after drying at 120 ° C for 2 hours, the "beading" effect is very marked.

Claims (10)

Compact water-resistant material, based on crushed cellulosic materials, characterized in that it is plumpable and that it comprises: - an effective amount of an organic binder chosen from the group comprising starches and starch derivatives, flours, proteins, starch and starch by-products, celluloses and their derivatives, hemicelluloses and their derivatives as well that mixtures of these products, and - an effective amount of a water resistance agent chosen from organosilicon water repellents and fluorinated acrylic copolymers. Compact material according to claim 1, characterized in that the water-resistance agent is chosen from organosilicon water-repellants, the structural unit of which corresponds to the formula:

in which R and R₁, which may be the same or different from each other, are hydrogen or organic radicals chosen from the group comprising methyl, alkyl, fluoroalkyl, optionally substituted phenyl, vinyl or their derivatives chlorinated, alkoxy, alkyllamino, said compound being advantageously chosen from the group comprising non-reactive silicone oils, silicone resins, reactive silicone oils, especially hydroxylated, alkylated, arylated, hydroalkylated, hydroarylated as well as mixtures of these products and the emulsions which can be prepared from these products. Compact material according to claim 2, characterized in that the water-repellent agent organosilicon is chosen from the group of siliconates of general formula:

in which - R₂ is an alkyl (C₁-C₁₀), alkenyl (C₁-C₁₀) or aryl (C₆-C₁₀) group - X is an alkali or alkaline earth metal atom and - 1 ≦ n ≦ 10,
potassium siliconate being particularly preferred. Compact material according to claim 1, characterized in that the water-resistance agent is chosen from fluorinated copolymers, optionally salified or quaternized, comprising by weight: a) 35 to 98%, preferably 69 to 93%, of one or more polyfluorinated monomers of general formula:

in which Rf represents a perfluoroalkyl radical with a straight or branched chain, containing 2 to 20 carbon atoms, preferably 4 to 16 carbon atoms, Q represents an oxygen or sulfur atom, B represents a divalent chain linked to Q by a carbon and possibly comprising one or more oxygen, sulfur and / or nitrogen atoms, one of the symbols R represents a hydrogen atom and the other a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms; b) 1 to 15%, preferably 5 to 11% and especially 7 to 10%, of one or more monomers of general formula:

in which B 'represents a linear or branched alkylene radical containing 1 to 4 carbon atoms, R' represents a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms, R₁ represents an alkyl radical containing 1 to 18 atoms of carbon, hydroxyethyl or benzyl, R₂ represents a hydrogen atom or an alkyl radical containing 1 to 18 carbon atoms, hydroxyethyl or benzyl or R₁ and R₂ together with the nitrogen atom form a morpholino, piperidino or pyrrolidinyl radical- 1; c) 1 to 50%, preferably 2 to 20%, of one or more monomers of general formula:

wherein R₃, R'₃, R₄ and R₅ are the same or different and each represents a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms; and eventually d) up to 10%, preferably less than 5%, of any monomer other than the monomers of formulas (I), (II) and (III). Compact material according to any one of Claims 1 to 4, characterized in that the organic binder is chosen from starches, starch derivatives, and or by-products of starch manufacture. Compact material according to one of claims 1 to 5, characterized in that it comprises: a proportion of 0.5 to 40%, preferably from 1 to 25%, and more preferably still from 2 to 20% by weight of organic binder, a proportion of 0.005 to 10%, preferably from 0.025 to 6%, and more preferably still from 0.05 to 4% by weight of water-resistance agent, the percentages being expressed by weight relative to the weight crushed cellulosic materials. Compact material according to any one of Claims 1 to 6, characterized in that it comprises a proportion of 0.5 to 25% and preferably from 1 to 5% of a hardening agent, the percentages being expressed by weight relative to the weight of crushed cellulosic materials. Process for the preparation of a compact material according to one of Claims 1 to 7, characterized in that: - that a ground cellulosic material, an organic binder from the group defined above, an organosilicon water-repellent agent or a fluorinated copolymer, and possibly a hardening agent, are selected, - that the water-repellent agent is mixed with either the cellulosic material or the organic binder, or with both of these products or their mixture, - That the mixture thus obtained is subjected to a shaping treatment, for example by pressure, compression, agglomeration, compacting or extrusion. Process for the preparation of a compact material according to one of Claims 1 to 7, characterized in that: - a finely ground cellulosic material, an organic binder from the group defined above, and possibly a hardening agent, are selected, - that the cellulosic material, the organic binder and possibly the hardener are mixed, - That the mixture thus obtained is subjected to shaping, for example by pressure, compression, agglomeration, compaction, or extrusion. - That a selected amount of water repellant of the compact material thus obtained is applied, for example by coating, impregnation, immersion, spraying or brushing. Method according to one of claims 8 or 9, characterized in that the material obtained at the end of the shaping treatment is subjected to a steaming treatment under temperature conditions between about 80-100 ° C and about 200-220 ° C.