EP1349807A1

EP1349807A1 - Mineral compounds, method for preparing same and use thereof in thermoplastic materials

Info

Publication number: EP1349807A1
Application number: EP01965341A
Authority: EP
Inventors: Emmanuelle Bougelot; Dominique Dupuis; Gilles Robert; Jo[L Varlet
Original assignee: Rhodianyl SAS
Current assignee: Rhodianyl SAS
Priority date: 2000-08-23
Filing date: 2001-08-23
Publication date: 2003-10-08
Also published as: AU2001286002A1; US7241827B2; KR20030053505A; BR0113434A; FR2813300B1; WO2002016264A1; KR100639290B1; FR2813300A1; US20040033186A1; MXPA03001583A; CA2420323A1; JP2004506585A

Abstract

The invention concerns a mineral compound with lamellar structure, the method for its preparation, and its use for reinforcing macromolecular materials. More precisely, the invention concerns a compound based on zirconium and/or titanium phosphate. The method for preparing the compound comprises a treatment step with pH ranging between 3 and 9.

Description

Mineral compounds, their preparation process and their use in thermoplastic materials

The present invention relates to a mineral compound with a lamellar structure, its preparation process, and its use for the reinforcement of macromolecular materials. It relates more precisely to a compound based on zirconium phosphate and / or titanium.

In order to modify the thermomechanical properties of macromolecular materials, it is known to use mineral particles. It is thus possible to modify, for example, the modulus of the materials, the impact resistance, the ductility, the dimensional stability, the deformation temperature under load, the resistance to abrasion or the abrasive power. It is known to reinforce macromolecular materials, and in particular thermoplastic materials, with platelet particles of nanometric thickness. Such particles can for example be obtained by exfoliation from an inorganic compound with a lamellar structure. This is the case for example for the particles obtained from montmorillonite. For this, montmorillonite, which has a lamellar structure, is treated with an organic swelling agent, which is inserted between the lamellae and separates them from one another, in order to promote their exfoliation. The organic agent often comprises an ammonium group, and at least one relatively long chain. The preferred ammoniums are quaternary ammoniums.

The patent application in Japan JP05306370 describes the use of platelet particles obtained by exfoliation from a compound based on zirconium phosphate with a lamellar structure. The compound with a lamellar structure is treated with an organic swelling agent, before incorporation into polyamide, in order to ensure its exfoliation.

The exfoliation of these mineral compounds with a lamellar structure is important for improving the thermomechanical properties of the macromolecular materials in which they are introduced. This exfoliation is favored in particular by the prior treatment of the mineral compounds with often bulky organic swelling agents, as indicated in the state of the art described above.

The preliminary treatment of the mineral compound with these organic blowing agents can sometimes have drawbacks. On the one hand, this involves an additional step in the process of manufacturing the final material, between the synthesis or the extraction of the compound with a lamellar structure, and its use for example as reinforcement. On the other hand, the presence of the organic swelling agent can induce difficulties during the incorporation of the compound, or during the processes for shaping the materials. The organic swelling agent can be degraded during these operations and thus either deteriorate the quality of the macromolecular compound in which it is used, or lose its potential for assisting exfoliation. Finally, the compounds used are generally smelly, which makes their handling unpleasant, or requires high investment to overcome the odor. This is a particular case for agents comprising an ammonium group.

The object of the present invention is to provide new lamellar compounds based on zirconium phosphate and / or titanium having good exfoliation properties, and a process for preparing this compound comprising a treatment which does not have the drawbacks mentioned above. above. It also aims to propose new macromolecular materials comprising these lamellar compounds.

To this end, the invention firstly provides a compound based on zirconium phosphate and / or titanium comprising a compound according to the following formula (I): A-R-B (I) in which

A and B are functions, identical or different, capable of reacting with the acid functions of zirconium phosphate and / or titanium, R is an aliphatic, cycloaliphatic or aromatic hydrocarbon radical, substituted or not, comprising from 2 to 20 atoms of carbon, and which may include heteroatoms characterized in that the molar ratio α between the number of moles of functions A and B and the number of moles of zirconium phosphate and / or titanium being between 0.1 and 0.8.

Secondly, it proposes a process for preparing the above compound optionally dispersed in a liquid, comprising the following successive steps: a) Precipitation in an acid medium of a compound based on zirconium phosphate and / or titanium, starting from phosphoric acid and a zirconium compound and / or a titanium-based compound or mixed titanium-zirconium-based compounds, the titanium and / or zirconium being at oxidation state IV b) Crystallization of the compound c) Treatment of the crystallized compound, in a liquid medium, at a pH between 3 and 9. Thirdly, it offers compositions comprising a macromolecular material, preferably a thermoplastic polymer and, the lamellar compound, dispersed at least partially under form of sheets in the composition. Fourthly, it proposes a process for manufacturing compositions comprising a thermoplastic matrix and a lamellar compound, as well as the compositions obtained according to this process, the lamellar compound being dispersed at least partially in the form of sheets in the composition. Fifth, it offers articles shaped from the compositions, for example by molding, or by spinning.

Finally, it proposes the use of particles based on zirconium phosphate as a modifier of the abrasion resistance of threads, fibers or filaments.

The compound of formula (I), present in the compound based on zirconium phosphate and / or titanium of the first subject of the invention, comprises two functions A and B capable of reacting with the acid functions of zirconium phosphate and / or titanium.

The functions A and B can for example be basic functions capable of reacting with the protons of zirconium phosphate and / or of titanium. Functions A and

B are preferably in neutral or positively charged form. As examples of functions A and B which may be suitable for the invention, mention may be made of amines, ammoniums, phosphoniums.

According to a preferred embodiment of the first subject of the invention, the functions A and B are amino functions. Preferably the compound (I) is chosen from hexamethylene diamine, methyl-2-pentamethylene diamine, metaxylene diamine.

According to the first subject of the invention, the molar ratio α between the number of moles of functions A and B and the number of moles of zirconium and / or titanium phosphate is between 0.1 and 0.8. By number of moles of functions A and B is meant the sum of the number of moles of functions A and the number of moles of functions B. For example, one mole of compound of formula (I) corresponds to two moles of functions A and B .

By number of moles of zirconium and / or titanium phosphate is meant the number of moles of phosphorus element. For example, one mole of zirconium phosphate compound generally corresponds to two moles of phosphorus element.

Preferably the molar ratio α is between 0.4 and 0.6. Advantageously, the molar ratio α is substantially equal to 0.5.

According to a particular characteristic of the first subject of the invention, the compound based on zirconium phosphate and / or titanium has a interleaf distance less than or equal to 15 Å. In general, the radical R is not reactive with respect to the acid functions of zirconium phosphate and / or titanium, nor with respect to phosphate in general.

The second object of the invention relates to a process for the preparation of the above compound. The preparation process according to the invention comprises at least the three successive stages a), b), and c). It may include other steps or phases of the process before, after or between these steps. These are, for example, washing, purification, filtration, dilution, centrifugation, addition of compounds in order to regulate certain process parameters such as pH, ionic strength. The implementation of such process phases will appear in particular in the light of the examples which are presented below.

Step a) consists of a precipitation of a compound based on zirconium phosphate and / or titanium. The preparation of such precipitates is known to those skilled in the art. It is carried out from phosphoric acid and a zirconium compound and / or a titanium compound, the zirconium and / or titanium being at the oxidation state IV. Mention is made of zirconium and / or titanium tetra-halides, zirconium and / or titanium oxyhalides, in particular zirconium oxychloride and titanium oxychloride. Mixed compounds based on zirconium and titanium can also be used. A simplified assessment of the precipitation reaction is, for example, as follows: 2 H ₃ P0 ₄ + ZrOCI ₂ → Zr (H ⁺ , PO ₄ ^{3 "} ) ₂ + 2 HCI

The precipitation is preferably carried out in an aqueous medium. The use of phosphoric acid induces an acidity of the precipitation medium. The precipitation can advantageously be carried out at acid pH, preferably controlled, for example between

0.5 and 2. An acid can be used for this purpose, in addition to the precursors of the precipitate. Mention is made, for example, of hydrochloric acid.

The precipitate can crystallize in a lamellar structure, at room temperature, without it being necessary to carry out a crystallization operation distinct from the precipitation step.

It may however be advantageous to use a separate crystallization step. Such a step makes it possible to obtain for the precipitated compound a more marked and / or more regular lamellar structure. The crystallization can be carried out by hot treatment in water or in an aqueous solution, for example by immersion of the compound in water at a temperature between 100 ° C and 200 ° C. The crystallization is preferably carried out in an acidic aqueous solution, for example a phosphoric acid solution. The crystallization time can be several hours. The crystallization step is advantageously preceded by a phase for washing the precipitate, making it possible inter alia to eliminate the ionic species resulting from the precipitation reaction.

The crystallization step is advantageously followed by a washing and centrifugation phase. According to a preferred characteristic, the pH measured in the aqueous phase of a dispersion comprising the crystallized compound, at 20% by weight in dry extract, is between 0.5 and 2.

According to a preferred characteristic of the process, all the stages of the process are thus carried out at acid pH, between 0.5 and 2. According to another preferred characteristic, the lamellar compound is never dried, the only operations for removing water being filtration or centrifugation operations. The term “drying operation” is understood here to mean an operation during which the compound is introduced into a hot atmosphere and devoid of water, for a period greater than 15 minutes, for example in an oven. The compound crystallizes in the α phase of zirconium phosphate. The structure of this phase has for example been described in J. Inorg. Nucl. Chem vol 26, p 117-129. This phase has a lamellar structure, with protons interposed between the lamellae. Without wishing to be bound by any theory, it is believed that these protons can be exchanged by a positively charged chemical species. Treatment step c) consists in treating the compound, crystallized, in a liquid medium, at a pH of between 3 and 9.

The liquid medium is preferably an aqueous solution, in which the zirconium phosphate-based compound is dispersed. The aqueous solution comprises a mineral or organic compound of a nature and / or in an amount such that the pH is between 3 and 9. According to a preferred characteristic, the pH is between 4 and 7.

The mineral or organic compound is chosen from the compounds which, in aqueous solution, have a pH greater than 3, preferably greater than 7.

The compound is generally the compound of formula (I) described above, corresponding to the compound based on zirconium phosphate and / or titanium which it is desired to prepare. The use of these organic compounds can be very particularly indicated for the use of the compound with a lamellar structure for the reinforcement of polyamides.

According to a preferred embodiment of the second subject of the invention, the organic compound is hexamethylene diamine.

By way of example, the mineral compound for the treatment at a pH of between 2 and 7 can also be chosen from hydroxides of metals, alkalis, or alkaline earths, for example sodium hydroxide; the mineral compounds of the ammonium ion, such as ammonium hydroxide; lithium, sodium, potassium cations in the presence, optionally, of a basic agent. The organic compound can be for example caprolactam or ammonia. These compounds may be indicated for the use of the compound with a lamellar structure for the reinforcement of polyamides. After the treatment step, the compound can be washed and / or separated from the liquid medium, for example by filtration, evaporation of the liquid medium, preferably evaporation of water. It can also be dried.

A mineral compound with a lamellar structure is thus obtained which can easily exfoliate into platelet particles. The compound can be packaged in different forms. It can be packaged in powder form, after elimination of the liquid medium, and optionally drying. It can be packaged in the form of a dispersion in a liquid medium, for example water.

The form of packaging generally depends on the use for which it is intended. Thus, for the use for the reinforcement of synthetic polymers, the compound can be advantageously introduced in the form of a dispersion in the medium for synthesis of the polymer. Preferably the compound is introduced in the form of a dispersion into the medium containing the monomers at the origin of the synthetic polymer.

The third subject of the invention relates to compositions comprising a matrix consisting of a macromolecular material, and a lamellar compound based on zirconium phosphate and / or titanium, dispersed at least partly in the form of sheets in the matrix. The lamellar compound is the compound described above.

The macromolecular material can be of different natures: elastomeric, thermoplastic, thermoset. The macromolecular material is preferably a thermoplastic polymer. As examples of polymers which may be suitable, mention is made of: polylactones such as poly (pivalolactone), poly (caprolactone) and polymers of the same family; polyurethanes obtained by reaction between diisocyanates such as 1,5-naphthalene diisocyanate; p-phenylene diisocyanate, m-phenylene diisocyanate, 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3, 3-'dimethyl-4,4'-biphenyl diisocyanate, 4,4'- diphenylisopropylidene diisocyanate, 3,3'-dimethyl-4,4'-diphenyl diisocyanate, 3,3'- dimethyl-4,4 ' -diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, dianisidine diisocyanate, toluidine diisocyanate, hexamethylene diisocyanate, 4,4'-diisocyanatodiphenylmethane and compounds of the same family and long diols linear chains such as poly (tetramethylene adipate), poly (ethylene adipate), poly (1, 4 -butylene adipate), poly (ethylene succinate), poly (2,3-butylene succinate), polyether diols and compounds of the same family; polycarbonates such as poly [methane bis (4-phenyl) carbonate], poly [1,1-ether bis (4-phenyl) carbonate], polyfdiphenylmethane bis (4-phenyl) carbonate], poly [1,1 -cyclohexane bis (4-phenyl) carbonate] and polymers of the same family; polysulfones; polyethers; polyketones; polyamides such as poly (4-amino butyric acid), poly (hexamethylene adipamide), poly (6-aminohexanoic acid), poly (m-xylylene adipamide), poly (p-xylylene sebacamide), poly ( 2,2,2-trimethyl hexamethylene terephthalamide), poly (metaphenylene isophthalamide), poly (p-phenylene terephthalamide), and polymers of the same family; polyesters such as poly (ethylene azelate), poly (ethylene-1,5-naphthalate, poly (1,4-cyclohexane dimethylene terephthalate), poly (ethylene oxybenzoate), poly (para-hydroxy benzoate), poly (1, 4-cyclohexylidene dimethylene terephthalate), poly (1, 4-cyclohexylidene dimethylene terephthalate), polyethylene terephthalate, polybutylene terephthalate and polymers of the same family; poly (arylene oxides) such as poly (2, 6-dimethyl-1,4-phenylene oxide), poly (2,6-diphenyl-1,4-phenylene oxide) and polymers of the same family; poly (arylene sulfides) such as poly (phenylene sulfide) and polymers of the same family; polyetherimides; vinyl polymers and their copolymers such as polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride; polyvinyl butyral, polyvinylidene chloride, ethylene-vinyl acetate copolymers, and polymers of the same family; acrylic polymers, polyacrylates and their copolymers such as polyethyl acrylate, poly (n-butyl acrylate), polymethylmethacrylate, polyethyl methacrylate, poly (n-butyl methacrylate), poly (n-propyl methacrylate), polyacrylamide, polyacrylonitrile, poly (acrylic acid), ethylene-acrylic acid copolymers, ethylene-vinyl alcohol copolymers, acrylonitrile copolymers, methyl methacrylate-styrene copolymers, ethylene-ethyl acrylate copolymers , methacrylate-butadiene-styrene copolymers, ABS, and polymers of the same family; polyolefins such as low density poly (ethylene), poly (propylene), low density chlorinated poly (ethylene), poly (4-methyl-1-pentene), poly (ethylene), poly (styrene), and polymers of the same family; the ionomers; poly (epichlorohydrins); poly (urethane) such as diol polymerization products such as glycerin, trimethylol-propane, 1, 2,6-hexanetriol, sorbitol, pentaerythritol, polyether polyols, polyester polyols and compounds of the same family with polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1, 6-hexamethylene diisocyanate, 4,4'-dicycohexylmethane diisocyanate and the compounds of the same family; and polysulfones such as the reaction products between a sodium salt of 2,2-bis (4-hydroxyphenyl) propane and 4,4'-dichlorodiphenyl sulfone; the furan resins such as poly (furan); cellulose-ester plastics such as cellulose acetate, cellulose acetate butyrate, cellulose propionate and polymers of the same family; silicones such as poly (dimethyl siloxane), poly (dimethyl siloxane co-phenylmethyl siloxane), and polymers of the same family; mixtures of at least two of the above polymers.

Among these thermoplastic polymers, polyamides are particularly preferred, such as polyamide 6, polyamide 66, semi-aromatic polyamides, PVC, PET, PPO and mixtures and copolymers based on these polymers.

The compositions can also comprise other additives, such as for example stabilizers, plasticizers, flame retardants, dyes, lubricants, catalysts. This list is in no way limiting. They may also include other reinforcing additives such as impact resistance modifiers such as optionally grafted elastomers, mineral reinforcements such as clays, kaolin, fibrous reinforcements such as glass fibers, aramids, carbon fibers.

Any method making it possible to obtain a dispersion of compounds in a macromolecular material can be used to produce the composition. A first method consists in mixing the lamellar compound in a thermoplastic material in molten form and optionally subjecting the mixture to significant shearing, for example in a twin-screw extrusion device, in order to achieve good dispersion. Another method consists in mixing the compound to be dispersed with the monomers in the polymerization medium, then in carrying out the polymerization. Another method consists in mixing with a thermoplastic polymer in molten form, a concentrated mixture of a thermoplastic polymer and dispersed particles, prepared for example according to one of the methods described above.

There is no limitation to the form in which the lamellar compound is introduced into the synthesis medium of the macromolecular compound, or in a molten thermoplastic polymer. It can for example be introduced in the form of a solid powder or in the form of a dispersion in water or in an organic dispersant. In the context of compositions based on polyamide, an advantageous embodiment consists in introducing into the polymerization medium a dispersion in water of the lamellar compound based on zirconium phosphate. In particular, the dispersion can be introduced into the medium comprising the monomers of the polyamide to be manufactured. The polymerization processes used in the context of this embodiment are the usual processes.

The proportion by weight of the lamellar compound in the composition is preferably less than or equal to 5%. The fourth subject of the invention relates to a process for manufacturing a composition comprising a thermoplastic matrix and a compound based on zirconium phosphate and / or titanium according to which a compound based on zirconium phosphate and / or titanium having a interleaf distance of less than or equal to 15Å in the matrix or in the polymerization medium of the matrix.

All that has been described previously concerning the method of introducing compounds into a macromolecular material for the third object of the invention, is valid here identically for the fourth object of the invention.

The compound based on zirconium phosphate and / or titanium, introduced into the matrix according to the fourth object of the invention, preferably has a interleaf distance of less than or equal to 13 Å.

This compound based on zirconium phosphate and / or titanium comprises an inorganic or organic compound comprising at least one function capable of reacting with the acid functions of zirconium phosphate and / or titanium. For example, such an inorganic or organic compound can be in the form of a cation. As mineral compound in cationic form, there may be mentioned, by way of example, metal cations, alkaline cations such as Na ⁺ , K ⁺ , Li ⁺ , the ammonium ion NH ₄ ⁺ . Without wishing to be bound by any theory, it is believed that such cations can be exchanged with the protons of zirconium and / or titanium phosphate. A cation such as Na ⁺ , K ⁺ , Li ⁺ or NH ₄ ⁺ corresponds to a function capable of reacting with the acid functions of zirconium and / or titanium phosphate.

Preferably the mineral compound is the Na ⁺ ion.

According to a particular embodiment of the fourth object of the invention, the mineral or organic compound comprises a function capable of reacting with the acid functions of zirconium and / or titanium phosphate.

This function can be a basic function. As basic function, one can cite for example the amino function. The function can for example be in a neutral form or positively charged.

According to a preferred mode, the organic compound is a monoamine. It may for example be an aliphatic monoamine such as n-butylamine.

According to another advantageous mode, the organic compound is an amino acid or a lactam. Mention may be made, for example, of caprolactam.

According to another particular embodiment of the fourth object of the invention, the mineral or organic compound comprises two functions capable of reacting with the acid functions of zirconium and / or titanium phosphate.

In particular, the organic compound is a compound according to the following formula (II): ARB (II) in which

A and B are functions, identical or different, capable of reacting with the acid functions of zirconium phosphate and / or titanium, R is an aliphatic, cycloaliphatic or aromatic hydrocarbon radical, substituted or not, comprising from 2 to 20 atoms of carbon, and may include heteroatoms

All that has been described above concerning the compound of formula (I), in particular the nature of the functions A and B and of the radical R, for the first object of the invention, is valid here identically for the fourth subject of the invention.

According to a preferred embodiment of the fourth object of the invention, the molar ratio β between the number of moles of functional groups capable of reacting with the mineral or organic compound and the number of moles of zirconium and / or titanium phosphate is between 0, 1 and 0.8. By number of moles of functions capable of reacting means the sum of the number of moles of each function of the mineral or organic compound capable of reacting. For example, for a compound comprising a single function capable of reacting, the number of moles of functions capable of reacting corresponds to the number of moles of the compound. For a compound comprising two functions capable of reacting, the number of moles of functions capable of reacting corresponds to twice the number of moles of the compound.

By number of moles of zirconium and / or titanium phosphate is meant the number of moles of phosphorus element. For example, one mole of zirconium phosphate compound generally corresponds to two moles of phosphorus element. Preferably the β molar ratio is between 0.4 and 0.6. Advantageously, the molar ratio β is substantially equal to 0.5.

According to a particular variant of the fourth object of the invention, the compound based on zirconium phosphate and / or titanium having an interleaf distance less than or equal to 15 Å is obtained by the process for preparing the second object of the invention. The inorganic or organic compound of treatment step c) is suitably chosen as a function of the compound based on zirconium phosphate and / or titanium which it is desired to prepare.

The invention also relates to the compositions obtained by the process for manufacturing the fourth object of the invention, at least part of the compound based on zirconium phosphate and / or titanium being dispersed in the form of sheets in the composition. All that has been described above concerning the compositions of the third object of the invention is valid here identically for the compositions obtained by the method of the fourth object of the invention, in particular what relates to the nature of the matrix, to the proportion of the compound based on zirconium phosphate and / or titanium in the composition, and to the addition of other additives.

The invention also relates in a fifth object to the articles shaped from the compositions of the invention described above in the third and the fourth object of the invention. The articles can be shaped by molding or spinning.

The methods of manufacturing molded articles that can be used are, for example, injection, extrusion, extrusion blow-molding methods.

The invention also relates to yarns, fibers or filaments consisting of a composition of the invention.

The spun articles, threads, fibers or filaments are produced according to the usual spinning techniques from a material comprising a thermoplastic polymer and the compound based on zirconium phosphate and / or titanium. Spinning can be carried out immediately after the polymerization of the thermoplastic polymer, the latter being in molten form. It can be produced from a granulated composite comprising the compound and the polymer. The compound can be incorporated into the molten polymer before the spinning operation, as a concentrated mixture in a polymer. All modes of incorporating the compound into a spinning polymer can be used.

The yarns, fibers or filaments according to the invention can be subjected to all the treatments that can be carried out in steps subsequent to the spinning step. They can in particular be stretched, textured, crimped, heated, twisted, dyed, sized, cut, etc. These additional operations can be carried out continuously and can be integrated after the spinning device or be carried out discontinuously. The list of post-spinning operations has no limiting effect.

The yarns, fibers or filaments according to the invention can be used in woven, knitted or non-woven form. The fibers according to the invention are in particular suitable for the manufacture of felts for paper machines. They can also be used for the manufacture of carpet yarns.

The use of platelet particles based on zirconium phosphates makes it possible to improve the abrasion resistance of a material. This improvement is particularly advantageous in the context of the use of the material in the form of threads, fibers or filaments.

Other details or advantages of the invention will appear more clearly in the light of the examples below, given only for information. Examples 1-: Preparation of a compound based on crystallized zirconium phosphate.

The following reagents are used:

- hydrochloric acid (Prolabo 36% d = 1.19) - phosphoric acid (prolabo 85% d = 1.695)

- deionized water

- zirconium chloride (in powder form) with 32.8% ZrO ₂ .

Step a): precipitation An aqueous solution of zirconium oxychloride at 2.1 mol / L in ZrO ₂ is prepared beforehand.

In a stirred 1 liter reactor, the following solutions are added at ambient temperature:

- Hydrochloric acid 50 ml - Phosphoric acid 50 ml

- Deionized water 150 ml

After stirring the mixture is added continuously with a flow rate of 5.7 mL / min

140 mL of the 2.1 M aqueous zirconium oxychloride solution

Stirring is continued for 1 hour after the end of the addition of the zirconium oxychloride solution.

After elimination of the mother liquors, the precipitate is washed by centrifugation at 4500 rpm, with 1200 ml of H ₃ PO 20 g / L then with deionized water, until a conductivity of 6.5 mS (supernatant) is reached. A cake of the precipitate based on zirconium phosphate is obtained.

Step b): Crystallization

The cake is dispersed in 1 liter of 10 M aqueous phosphoric acid solution, the dispersion thus obtained is transferred to a 2 liter reactor and then heated to 115 ° C. This temperature is maintained for 5 hours. The dispersion obtained is washed by centrifugation with deionized water to a conductivity of less than 1 mS (supernatant). The cake from the last centrifugation is redispersed so as to obtain a dry extract close to 20%, the pH of the dispersion is between 1 and 2. A dispersion of a crystallized compound based on zirconium phosphate is obtained, of which the characteristics are as follows:

- Particle size and morphology: Analysis with a Transmission Electron Microscope (TEM) highlights the production of a lamellar structure, the lamellae have a hexagonal shape with a size between 200 and 500 nm. The particles consist of a stack of substantially parallel plates, the thickness of the stacks in the direction perpendicular to the plates being approximately 200 nm. - DRX analysis shows that the crystallized phase Zr (HPO ₄ ) ₂ , 1 H ₂ 0 has been obtained

- Dry extract: 18.9% (by weight) - pH 1.8

- Conductivity: 8 mS

Examples 2-3: Treatment of the compound with a mineral base (Step c) 805 g (in dry extract) of product from Example 1 are centrifuged. The centrifugation pellet is redispersed in an aqueous sodium hydroxide solution at 10 ^"3 mol / L (500 ml). Three washes are carried out under these same conditions. The cake resulting from the last centrifugation is redispersed in 500 ml of sodium hydroxide solution. 10 ^"3 mol / L. The pH is adjusted to 5 (example 2) or to 3 (example 3) by adding 8 mol / l sodium hydroxide. The dispersion is centrifuged and the pellet is redispersed in 300 ml of purified water (dry extract: 30% by weight). The final conductivity of the suspension is less than 1 mS.

EXAMPLE 4 Treatment of the Compound with an Organic Base (Step c))

The product from Example 1 is neutralized by adding hexamethylene diamine: To the dispersion is added an aqueous solution of HMD at 70% until a pH of 5 is obtained. The dispersion thus obtained is homogenized with using an Ultraturax. The final dry extract is adjusted by adding deionized water (dry extract: 15% by weight).

Example 5: Treatment of the compound with caprolactam (Step c)) Caprolactam is incorporated into the mineral sol obtained according to example 1 (33% by weight of caprolactam relative to the dry extract). The pH measured in the solution is 3.3. Then by distillation of the water, a powder is recovered containing the corresponding fraction of caprolactam.

Examples 6-10: Compositions comprising platelet particles based on zirconium phosphate.

A polyamide 6 is synthesized from caprolactam according to a conventional process, by introducing into the polymerization medium an aqueous dispersion obtained in examples 2 to 4, or the powder obtained in example 5. The proportion of compound based of zirconium phosphate introduced is 2% by weight. A polymer is also synthesized that does not contain the compound (Example 10, comparative). After polymerization, the polymer is formed into granules. These are washed to remove the residual caprolactam (the granules are immersed in an excess of water at 90 ° C for a few hours) and are then dried under primary vacuum (<0.5 mbar) for 16 hours at 110 ° C.

Tensile tests are carried out on extruded rods and conditioned for 30 days at 50% RH and 23 ° C. The diameter of the rods is between 0.5 and 1 mm. An INSTRON 1185 traction machine is used with a force sensor with a capacity of 100 N. The nominal stress is reported (ratio of the force measured over the section evaluated by diameter measurement with Palmer) as a function of the relative deformation applied. The results are reported in Table 1.

Table 1

A composition based on polyamide is obtained whose elongation at break is greater than that of a polyamide not comprising the mineral compound, and whose modulus is improved.

Observed at TEM, compositions obtained as above comprising PA 6 and 5% by weight of compound based on zirconium phosphate, on sections of average thickness 0.1 μm. We observe the presence of very numerous dispersed mineral lamellae, of nanometric thickness and of width 50 to 100 nm. FIG. 1 represents a photograph of a composition observed under the microscope comprising the zirconium phosphate compound corresponding to example 2.

FIG. 2 represents a photograph of a composition observed under the microscope comprising the zirconium phosphate compound corresponding to example 4.

We observe the presence of very numerous dispersed mineral lamellae, of nanometric thickness and of width 50 to 100 nm.

Example 11-14: Filaments Monofilaments with a diameter of approximately 250 μm are spun at low speed from a composition according to Example 9, or from a pure polyamide according to Example 10. The monofilaments are stretched. in recovery at different drawing rates. The mechanical properties and the abrasion resistance of the monofilaments are evaluated according to the following tests:

- Mechanical characterization (elongation at break, stress at break): carried out on an Erichsen traction machine placed in an air-conditioned room at 50% RH and

23 ° C after conditioning the wires for 72 hours under these conditions. The initial length of the wires is 50 mm and the crosshead speed is 50 mm / min.

- Abrasion resistance: A simultaneous friction is imposed on 15 stationary wires, the tension of which is kept constant at 15 wires by 3 brass rollers ensuring interlocking. The point of application of the lashing area is moved along the wires over an amplitude of 90 mm at a frequency of 220 cycles per minute. Abrasion resistance is defined by the number of cycles (back and forth) required to break 13 of the 15 wires. The measurements presented are the average of the values obtained on three tests with similar wires.

The characteristics of the yarns produced are presented in Table 2. The properties measured are presented in Table 3.

Table 2

Table 3

Examples 15-17: Compositions comprising platelet particles based on zirconium phosphate.

A polyamide 6 is synthesized from caprolactam according to a conventional process, by introducing into the polymerization medium an aqueous dispersion obtained in Example 4. The proportion of compound based on zirconium phosphate introduced is 1 (Example 16) or 2 (example 17)% by weight. A polymer is also synthesized that does not contain the compound (Example 15, comparative).

After polymerization, the polymer is formed into granules. These are washed to remove the residual caprolactam (the granules are immersed in an excess of water at

90 ° C for a few hours) then are dried under primary vacuum (<0.5 mbar) for 16 hours at 110 ° C.

Evaluations

Various tests have been carried out on the compositions:

-Tension at break according to ISO 527, measured after conditioning the test piece at 23 ° C and a relative humidity of 50%.

- Traction module according to ISO standard 527, measured after conditioning of the test piece at 23 ° C and at a relative humidity of 50%.

-Flexion module according to ISO 178, measured after conditioning the test piece at 23 ° C and at a relative humidity of 50%.

-Deformation temperature under load (HDT-Heat Deflection Temperature) according to ISO 75, under load of 1.81 N / mm ² .

The different compositions and the evaluations are presented in Table 4 below. Table 4

Polyamide-based compositions are obtained whose tensile strength, modulus and deformation temperature under load are higher than those of a polyamide not comprising the mineral compound.

Claims

1. Compound based on zirconium phosphate and / or titanium comprising a compound according to formula (I) below:

A-R-B (I) in which

2. Compound according to claim 1, characterized in that the molar ratio α is between 0.4 and 0.6.

3. Compound according to claim 2, characterized in that the molar ratio α is substantially equal to 0.5.

4. Compound according to one of claims 1 to 3, characterized in that the functions A and B are amino functions.

5. Compound according to Claim 4, characterized in that the compound (I) is chosen from hexamethylene diamine, methyl-2-pentamethylene diamine, metaxylene diamine

6. Compound according to one of the preceding claims, characterized in that the interleaf distance of the compound is less than or equal to 15Â.

7. Method for preparing a compound according to one of the preceding claims, optionally dispersed in a liquid, comprising the following successive steps: d) Precipitation in an acid medium of a compound based on zirconium phosphate and / or titanium, from phosphoric acid and a compound of zirconium and / or a compound based on titanium or mixed compounds based on titanium and zirconium, the titanium and / or zirconium being at the oxidation state IV e) Crystallization of the compound f) Treatment of the crystallized compound, in a liquid medium, at a pH between 3 and 9.

8. Method according to claim 7 characterized in that the treatment consists in immersing the crystallized compound in a liquid comprising an inorganic or organic compound which, in aqueous solution has a pH greater than 3.

9. Method according to claim 8 characterized in that the liquid is an aqueous solution.

10. Method according to one of claims 7 to 9 characterized in that the liquid comprises hexamethylene diamine.

11. Method according to one of claims 7 to 10, characterized in that it comprises a washing phase d) after step c)

12. Method according to one of claims 7 to 11 characterized in that it comprises a drying step e) after step d).

13. Method according to one of claims 7 to 12 characterized in that step a) is carried out in an aqueous medium, at a pH below 2, and in that the zirconium compound is zirconium oxychloride, the compound of titanium is titanium oxychloride.

14. Method according to one of claims 7 to 13 characterized in that the crystallization step is carried out in phosphoric acid.

15. Compound based on zirconium phosphate and / or titanium capable of being obtained by a process according to one of claims 7 to 14.

16. Dispersion in water of a compound according to one of claims 1 to 6 or of a compound obtained by the process according to one of claims 7 to 14.

17. Composition comprising a thermoplastic matrix and a compound according to one of claims 1 to 16, at least part of the compound being dispersed in the matrix in the form of sheets.

18. Composition according to Claim 17, characterized in that it is obtained by introduction of an aqueous solution according to Claim 16 into the polymerization medium of the matrix.

19. A method of manufacturing a composition comprising a thermoplastic matrix and a compound based on zirconium phosphate and / or titanium, characterized in that a compound based on zirconium phosphate and / or titanium having a interleaf distance less than or equal to 15A in the matrix or in the polymerization medium of the matrix.

20. The method of claim 19, characterized in that the interleaf distance of the compound based on zirconium phosphate and / or titanium is less than or equal to

13 Â

21. The method of claim 19 or 20, characterized in that the compound based on zirconium phosphate and / or titanium comprises an inorganic or organic compound comprising at least one function capable of reacting with the acid functions of zirconium phosphate and / or titanium.

22. Method according to claim 21, characterized in that the mineral or organic compound in cationic form.

23. The method of claim 22, characterized in that the mineral compound is the Na ⁺ ion.

24. Method according to one of claims 21 to 23, characterized in that the inorganic or organic compound comprises a function capable of reacting with the acid functions of zirconium phosphate and / or titanium.

25. The method of claim 24, characterized in that the function capable of reacting is an amino function.

26. The method of claim 25, characterized in that the organic compound is a monoamine.

27. The method of claim 25, characterized in that the organic compound is an amino acid or a lactam.

28. Method according to one of claims 21 to 23, characterized in that the organic compound is a compound according to the following formula (II):

A-R-B (II) in which

A and B are functions, identical or different, capable of reacting with the acid functions of zirconium phosphate and / or titanium,

R is an aliphatic, cycloaliphatic or aromatic hydrocarbon radical, substituted or unsubstituted, comprising from 2 to 20 carbon atoms, and which can comprise heteroatoms

29. Method according to claim 28, characterized in that the functions A and B are amines.

30. The method of claim 29, characterized in that the compound (II) is chosen from hexamethylene diamine, methyl-2-pentamethylene diamine, metaxylene diamine

31. Method according to one of claims 21 to 30, characterized in that the molar ratio β between the number of moles of functional groups capable of reacting with the mineral or organic compound and the number of moles with zirconium and / or titanium phosphate being between 0.1 and 0.8

32. Method according to claim 31, characterized in that the ratio β is between 0.4 and 0; 6

33. Method according to claim 32, characterized in that the ratio β is substantially equal to 0.5.

34. Method according to one of claims 19 to 33; characterized in that the compound based on zirconium phosphate and / or titanium is obtained by the process according to one of claims 7 to 14.

35. Method according to one of claims 19 to 34, characterized in that an aqueous solution of the compound based on zirconium phosphate and / or titanium is introduced into the polymerization medium of the matrix.

36. Composition capable of being obtained by the process according to one of claims 19 to 35, at least part of the compound being dispersed in the form of sheets.

37. Composition according to one of claims 17, 18 or 36, characterized in that the matrix is chosen from polyamide 6, polyamide 66, mixtures and copolymers based on these polyamides

38. Composition according to one of claims 17, 18 or 36, characterized in that the proportion by weight of the compound based on zirconium phosphate and / or titanium in the composition is less than or equal to 5%.

39. Articles obtained by molding or shaping a composition according to one of claims 17, 18 or 36.

40. Yarns, fibers and filaments consisting of a composition according to one of claims 17, 18 or 36:

41. Felts for paper machines comprising fibers according to claim 40

42. Use of compounds based on zirconium phosphate in composition in yarns, fibers or filaments made of thermoplastic material, as a modifier of the abrasion resistance of said yarns, fibers or filaments.