EP3642267A1

EP3642267A1 - Fibrous material impregnated with reactive thermoplastic prepolymer

Info

Publication number: EP3642267A1
Application number: EP18733251.5A
Authority: EP
Inventors: Gilles Hochstetter; Mathieu Capelot; Thibaut SAVART; Arthur Pierre BABEAU; Denis Huze; François TANGUY; Patrice Gaillard
Original assignee: Arkema France SA
Current assignee: Arkema France SA
Priority date: 2017-06-22
Filing date: 2018-06-21
Publication date: 2020-04-29
Also published as: CN110785455A; FR3067969B1; JP2020524616A; KR102330131B1; JP7041694B2; KR20200020847A; US20200216627A1; WO2018234441A1; FR3067969A1

Abstract

The present invention relates to an impregnated fibrous material comprising a fibrous material made of continuous fibres and at least one reactive thermoplastic prepolymer, and optionally a chain extender, characterised in that the at least one reactive thermoplastic prepolymer is partially polymerised, optionally with the chain extender, and has a number-average molecular weight (Mn) ranging from 500 to 10,000, preferably from 4000 to 8000, the proportion of fibres in the impregnated fibrous material being 45 to 65% by volume, preferably 50 to 60% by volume, and in particular 54 to 60%.

Description

FIBROUS MATERIAL IMPREGNATED WITH REACTIVE THERMOPLASTIC PREPOLYMER

[Field of the invention]

The present invention relates to a fibrous material impregnated with reactive thermoplastic prepolymer of low average molecular weight Mn number.

More particularly, the invention relates to a fibrous material impregnated with at least one reactive thermoplastic prepolymer and optionally a chain extender, characterized in that said at least one reactive thermoplastic prepolymer is partially polymerized, optionally with said chain extender. and has a number average molecular weight Mn of from 500 to 10,000, preferably from 4000 to 8000, and a fiber content in said impregnated fibrous material of from 45 to 65% by volume, preferably from 50 to 60% by weight. volume, especially 54 to 60%.

In the present description, the term "fibrous material" means an assembly of reinforcing fibers. Before it is shaped, it is in the form of wicks. After shaping, it comes in the form of strips (or tape), or tablecloths. When the reinforcing fibers are continuous, their assembly constitutes a unidirectional reinforcement or a fabric or a nonwoven (NCF). When the fibers are short, their assembly constitutes a felt or a mat of fibers.

Such impregnated fibrous materials are particularly intended for the production of lightweight composite materials for the manufacture of mechanical parts having a three-dimensional structure and having good mechanical and thermal properties. When the fibers are carbon or the resin is loaded with suitable additives, these fibrous materials are able to evacuate electrostatic charges. The use of flame retardant resins or flame retardant additives in non-flame resins allows impregnated fibrous materials to be fire resistant. They therefore have properties compatible with the manufacture of parts in particular in the fields of mechanics, aeronautics, nautical, automotive, oil and gas, particularly offshore, gas storage, energy, health and medical, sports and recreation, and electronics.

Such impregnated fiber materials are also referred to as composite materials. They comprise the fibrous material, constituted by the reinforcing fibers, and a matrix constituted by the polymer impregnating the fibers. The primary role of this matrix is to maintain the reinforcing fibers in a compact form and to give the desired shape to the final product. This matrix also ensures the charge transfer between the fibers and therefore conditions the mechanical strength of the composite. Such a matrix also serves to protect the reinforcing fibers against abrasion and an aggressive environment, to control the surface appearance and to disperse any fillers between the fibers. The role of this matrix is important for the long-term behavior of the composite material, especially with regard to fatigue and creep.

[Prior art!

A good quality of the three-dimensional composite parts made from impregnated fibrous materials passes in particular through control of the impregnating process of the reinforcing fibers by the thermoplastic polymer and thus the impregnated fibrous material obtained. In the present description, the term "band" is used to designate strips of fibrous material whose width is greater than or equal to 400 mm. The term "ribbon" is used to designate ribbons of calibrated width and less than or equal to 400 mm. The term "wick" is also used to refer to the fibrous material.

Until now, the manufacture of strips of fibrous materials reinforced by impregnation of thermoplastic polymer or thermosetting polymer was carried out according to several processes which depend in particular on the nature of the polymer, the type of final desired composite material and its field of application. applications, some of these processes consisting of an impregnation step followed by a heat calendering step of the impregnated fibrous material or a drying step optionally followed by a step of melting the thermoplastic polymer.

Thus wet impregnation technologies or by means of a liquid precursor or very low viscosity, polymerizing in situ, are often used to impregnate the reinforcing fibers with thermosetting polymers, such as epoxy resins for example, such as described in the patent WO2012 / 066241 A2. These technologies are generally not directly applicable to the impregnation with thermoplastic polymers, because they rarely have liquid precursors,

Steep extrusion impregnation processes of a molten polymer are suitable for the use of thermoplastic polymers of low viscosity only. Thermoplastic polymers, in particular those with a high glass transition temperature, have a melt viscosity that is too high to allow satisfactory impregnation of fibers and semi-finished or finished products of good quality.

The international application WO 2014/064375 describes a method of manufacturing a thermoplastic composite material, in particular a mechanical part or a structural part based on said material, comprising a step of implementing or molding a non-reactive polyamide composition after impregnation of a fibrous material to form the final composite part in a mold or with another processing system or a step of melt impregnation of a fibrous material with a composition of reactive prepolymer and implemented by molding or by another implementation system with simultaneously a step of polymerization of the reactive composition. Said implementation can be carried out according to a RTM, S-RIM, injection-compression, pultrusion or infusion process.

However, these processes require a large cycle time and expensive energy. On the other hand, when the reactive prepolymer has a Tg or Tf temperature close to the Tf or Tg of the final polymer, the prepolymer begins to polymerize before the injection is completed, causing defects in the part (lack of material, inhomogeneity of properties). thermomechanical constitutive polymer ...)

The object of the invention is therefore to remedy at least one of the drawbacks of the prior art, and in particular to obtain fibrous material impregnated with a reactive thermoplastic prepolymer which subsequently makes possible the preparation of a composite material impregnated with a polymer. non-reactive thermoplastic, in particular a mechanical part or a structural part based on said material, with a short cycle time, in particular of the order of one minute for thermo stamping, an energy cost less than prior art and the use of simpler hardware and therefore a reduced hardware investment. The invention aims in particular to provide a fibrous material impregnated with a reactive thermoplastic prepolymer, having a fiber content in said impregnated fibrous material being comprised of 45 to 65% by volume, preferably 50 to 60% by volume, in particular 54% by weight. at 60% and likely to react later during its implementation to obtain thereafter a fibrous material impregnated with a non-reactive thermoplastic polymer and having mechanical performance necessary for the final composite part.

[Brief description of the invention!

For this purpose, the subject of the invention is an impregnated fibrous material comprising a fibrous material made of continuous fibers and at least one reactive thermoplastic prepolymer, and optionally a chain extender, characterized in that the said at least one reactive thermoplastic prepolymer is partially polymerized. optionally with said chain extender, and has a number average molecular weight (Mn) of from 500 to 10,000, preferably from 4000 to 8000, the fiber content in said impregnated fibrous material being 45 to 65% by weight. volume, preferably 50 to 60% by volume, especially 54 to 60%.

The reactive thermoplastic prepolymer is a non-reactive thermoplastic polymer precursor.

The term "reactive thermoplastic prepolymer" means that the molecular weight of said reactive prepolymer will evolve during its subsequent use by reaction of reactive prepolymers with each other by condensation with evolution of water or by substitution or reaction of reactive prepolymers with a chain extender by polyaddition and without elimination of volatile by-products to drive subsequently after processing to the final thermoplastic non-reactive polymer of the thermoplastic matrix. The expression "non-reactive final thermoplastic polymer" means that the final thermoplastic polymer has a molecular weight that is no longer likely to change significantly, that is to say that its number-average molecular mass (Mn) changes from less than 50% during its implementation and therefore corresponding to the final polymer of the thermoplastic matrix.

The term "partially polymerized" means that the prepolymers have an initial molecular weight Mni and an initial melt viscosity ηι corresponding to the molecular weight and the viscosity obtained during their preparation.

During the impregnation of the fibrous material, this mass evolves by partial reaction of the thermoplastic prepolymers, with each other or with the chain extender, which means that the number-average molecular weight Mn2 and the melt viscosity n.2 prepolymer after impregnation are greater than or equal to the initial molecular weight Mni and an initial melt viscosity η-ι.

Said partially polymerized reactive prepolymers, optionally with the chain extender, have a number average molecular weight (Mn2) ranging from 500 to 10,000, preferably from 4000 to 8000.

This number average molecular weight is obviously in the solid state after cooling of the prepolymer.

Said final non-reactive thermoplastic polymer is derived from a reactive thermoplastic prepolymer comprising or not a chain extender or a polymerization of a mixture of reactive prepolymers, optionally a prepolymer with the chain extender. The number-average molecular mass Mn of said final non-reactive thermoplastic polymer is greater than 10,000, preferably in a range from 10,000 to 40,000, preferably from 12,000 to 30,000, determined in particular by calculation from the terminal function rate determined by potentiometric titration in solution and the functionality of said prepolymers or by NMR assay (Postma et al (Polymer, 47, 1899-191 1 (2006)).

Advantageously, said impregnated fibrous material is non-flexible.

The impregnation being carried out in the process of the invention, this renders the non-flexible impregnated fibrous material as opposed to fibrous materials impregnated in the art in which the impregnation is partial, which leads to the obtaining of a flexible fibrous material. Advantageously, said at least one reactive thermoplastic prepolymer that is partially polymerized, optionally with said chain extender, has a melt viscosity of from 0.1 to 100 Pa.s. The melt viscosity is measured by oscillatory rheology at a temperature Tf≤T <Tf + 50 ° C, at 10 rad / sec under a nitrogen sweep with 5% deformation on a Physica MCR301 apparatus between two parallel planes of 25 mm in diameter.

The partially polymerized prepolymer, optionally with said chain extender, has a low number average molecular weight Mn or a melt viscosity of 0.1 to 100 Pa.s, which means that this prepolymer and optionally The chain extender has a low viscosity and therefore a high fluidity, thus permitting good impregnation of said fibrous material on both sides and in the core of the fibrous material.

Nevertheless, the impregnation on both sides does not necessarily mean that the impregnation is similar on both sides of said fibrous material. Indeed, the impregnation can lead to an impregnated material having a zone rich in thermoplastic prepolymer and optionally a chain extender on one side of said material and a fiber-rich zone on the opposite face of said material, which means that the material impregnated with prepolymer is asymmetrical.

Advantageously, the volume ratio of the fibers is constant in at least 70% of the volume of the band or ribbon, especially in at least 80% of the volume of the band or ribbon, in particular in at least 90% of the volume of the band or ribbon, more particularly in at least 95% of the volume of the tape or ribbon.

Advantageously, the distribution of the fibers is homogeneous in at least 95% of the volume of the band or ribbon.

The term "homogeneous" means that the impregnation is uniform and that there is no dry fiber, i.e., not impregnated, in at least 95% of the volume of the strip or strip of material fibrous impregnated.

The measurement of the volume ratio of fibers is carried out locally on a representative elementary volume (VER).

The term "constant" means that the volume fiber ratio is constant at the nearest measurement uncertainty of plus or minus 1%.

Advantageously, the impregnation with the prepolymer is homogeneous and at heart.

Thermoplastic prepolymer

Thermoplastic, or thermoplastic prepolymer, is understood to mean a material that is generally solid at ambient temperature, that can be semi-crystalline or amorphous, and that softens upon an increase in temperature, in particular after passing its glass transition temperature (Tg). and flows at a higher temperature when it is amorphous, or can present a blunt fusion at the passage of its so-called melting temperature (Tf) when it is semi-crystalline, and which becomes solid again during a decrease in temperature below his crystallization temperature (for a semi-crystalline) and below its glass transition temperature (for an amorphous).

Tg and Tf are determined by Differential Scanning Calorimetry (DSC) according to standard 1 1357-2: 2013 and 1 1357-3: 2013 respectively.

Throughout the description the terms "prepolymer", "thermoplastic prepolymer" "reactive thermoplastic prepolymer" or "partially polymerized reactive thermoplastic prepolymer" are used and refer to the same compound.

With regard to the prepolymer constituting the impregnating matrix of the fibrous material, it is advantageously a thermoplastic prepolymer or a mixture of thermoplastic prepolymers. This prepolymer or mixture of thermoplastic prepolymers can be milled in powder form so that it can be used in a device such as a tank, in particular in a fluidized bed or in an aqueous dispersion.

The device in the form of a tank, in particular in a fluidized bed, can be open or closed.

The above-mentioned molecular weight ranges are thus equally valid for Mni or Mn2, which means that Mn2 is never greater than 10,000.

Mn are determined in particular by the calculation from the rate of terminal functions determined by potentiometric titration in solution and the functionality of said prepolymers. Mn masses can also be determined by size exclusion chromatography or by NMR.

According to a first possibility, said at least one partially polymerized reactive thermoplastic prepolymer comprises at least one reactive (polyamide) prepolymer carrying on the same chain (ie on the same prepolymer), two terminal functions X 'and Y' functions respectively coreactive between them by condensation, with X 'and Y' being amine and carboxy or carboxy and amine respectively.

Advantageously, said at least partially polymerized reactive thermoplastic prepolymer consists of at least one reactive (polyamide) prepolymer carrying on the same chain (ie on the same prepolymer), two terminal functions X 'and Y' functions respectively coreactive between them by condensation, with X 'and Y' being amine and carboxy or carboxy and amine respectively.

There is therefore no presence of chain extender in this first embodiment. According to a second possibility, said at least one partially polymerized reactive thermoplastic prepolymer comprises at least two polyamide prepolymers which are reactive with one another and each carrying two identical terminal functions X 'or Y' (same for the same prepolymer and different between the two prepolymers), said function X 'of a prepolymer that can react only with said function Y' of the other prepolymer, in particular by condensation, more particularly with X 'and Y' being amino and carboxy or carboxy and amine respectively. Advantageously, said at least one partially polymerized reactive thermoplastic prepolymer consists of at least two polyamide prepolymers which are reactive with each other and each carrying two identical terminal functions X 'or Y' (identical for the same prepolymer and different between the two prepolymers), said function X 'of a prepolymer that can react only with said function Y' of the other prepolymer, in particular by condensation, more particularly with X 'and Y' being amino and carboxy or carboxy and amine respectively.

The at least two prepolymers may be mixed together or not beforehand. This condensation reaction (or polycondensation) can cause the elimination of by-products. These can be removed by preferably working in a method using open mold technology. In the case of a closed mold process, a step of degassing, preferably under vacuum, by-products removed by the reaction is present, this to avoid the formation of microbubbles by-products in the final composite material , which (microbubbles) can affect the mechanical performance of said material if they are not removed as well.

There is therefore no presence of chain extender in this second embodiment. The reaction of the two prepolymers can be total or partial.

According to a third possibility, said at least one reactive thermoplastic prepolymer partially polymerized with the chain extender comprises:

a1) at least one reactive thermoplastic prepolymer as already defined above with this prepolymer carrying n identical terminal reactive functions X, chosen from: -NH2 (amine), -CO2H (carboxy) and -OH (hydroxyl), preferably- NH 2 (amine) and -CO 2 H (carboxy), with n being 1 to 3, preferably 1 to 2, more preferably 1 or 2, more particularly 2

a2) at least one Y-A'-Y chain extender, with A being a hydrocarbon biradical carrying 2 identical Y terminal reactive reactive functions by polyaddition (without elimination of reaction by-product), with at least one function X of said prepolymer a1), preferably of molecular weight less than 500 and more preferably less than 400.

Advantageously, said at least one reactive thermoplastic prepolymer partially polymerized with the chain extender is composed of a1) and a2) defined above.

Advantageously, Y is chosen from: oxazine, oxazoline, oxazolinone, oxazinone, imidazoline, epoxy, isocyanate, maleimide, cyclic anhydride, especially oxazine, oxazoline, oxazolinone, oxazinone, imidazoline, maleimide, cyclic anhydride and preferably X1 is CO2H and Y1 is chosen from an epoxy and an oxazoline.

NH2 (amine) means primary and secondary amine. As suitable examples of elongators a2) as a function of the X functions carried by said semicrystalline polyamide prepolymer a1), the following may be mentioned:

when X is NH2 or OH, preferably NH2:

the chain extender Y-A'-Y corresponds to

Y chosen from the groups: maleimide, optionally blocked isocyanate, oxazinone and oxazolinone, cyclic anhydride, preferably oxazinone and oxazolinone, in particular maleimide, oxazinone and oxazolinone, cyclic anhydride, preferably oxazinone and oxazolinone;

and

A 'is a spacer or a carbon radical carrying the functions or reactive groups Y, chosen from:

a covalent bond between two functions (groups) Y in the case where Y = oxazinone and oxazolinone or

an aliphatic hydrocarbon chain or an aromatic and / or cycloaliphatic hydrocarbon chain, the latter two comprising at least one optionally substituted 5- or 6-carbon ring, optionally with said aliphatic hydrocarbon chain optionally having a molecular weight of 14 to 200 g / mol -1

either the chain extender Y-A'-Y corresponds to Y being a caprolactam group and to A 'may be a carbonyl radical such as carbonyl biscaprolactam or A' may be a terephthaloyl or isophthaloyl,

either said chain extender Y-A'-Y carries a group Y of cyclic anhydride and preferably this extender is chosen from a cycloaliphatic and / or aromatic carboxylic dianhydride and more preferably it is chosen from ethylenetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, perylenetetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 1,2-dianhydride, , 3,4-Cyclobutanetetracarboxylic acid, hexafluoroisopropylidene bisphthalic dianhydride, 9,9-bis (trifluoromethyl) xanthenetetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylsulfonetetracarboxylic dianhydride, bicyclo [2.2.2] octanediolide ene-2, 3,5,6-tetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 3,3 ', 4,4'-diphenyl ether tetracarboxylic dianhydride or mixtures thereof

and

when X is COOH:

said Y-A'-Y chain extender corresponds to:

Y chosen from the groups: oxazoline, oxazine, imidazoline or aziridine, such as 1,1'-iso- or terephthaloylbis (2-methylaziridine) or epoxy, A 'being a spacer or a carbon radical as defined above.

More particularly, when in said Y-A'-Y extension, said Y function is chosen from oxazinone, oxazolinone, oxazine, oxazoline or imidazoline, in particular oxazoline, in this case, in the chain extender represented by Y-A ' -Y, A 'may represent an alkylene such that - (CH2) m- with m ranging from 1 to 14 and preferably from 2 to 10 or A may represent cycloalkylene and / or substituted arylene (alkyl) or unsubstituted, such as benzene arylenes, such as o-, m-, -p phenylenes or naphthalenic arylenes and preferably A 'is arylene and / or cycloalkylene.

In the case of carbonyl- or terephthaloyl- or isophthaloyl-biscaprolactam as Y-A'-Y chain extender, the preferred conditions avoid the elimination of by-product, such as caprolactam during said polymerization and implemented at the same time. melted state.

In the case where Y is an epoxy, the chain extender may be chosen from bisphenol A diglycidyl ether (DGEBA), and its hydrogenated derivative (cycloaliphatic) bisphenol F diglycidyl ether, tetrabromo bisphenol A diglycidyl ether, or hydroquinone diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, polyethylene glycol diglycidyl ether Mn <500 , polypropylene glycol diglycidyl ether of Mn <500, polytetramethylene glycol diglycidyl ether of Mn <500, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, bisphenol A polyethylene glycol diglycidyl ether of Mn <500, bisphenol A polypropylene glycol diglycidyl ether of Mn <500, diglycidyl esters dicarboxylic acid such as glycidyl ester of terephthalic acid or epoxidized diolefins (dienes) or epoxidized ethylenically unsaturated double fatty acids, diglycidyl 1, 2-cyclohexanedicarboxylate, and mixtures thereof.

In the eventual case cited above where Y represents a blocked isocyanate function, this blocking can be obtained by blocking agents of the isocyanate function, such as epsilon-caprolactam, methyl ethyl ketoxime, dimethyl pyrazole, diethyl malonate.

Similarly, in the case where the extender is a dianhydride reacting with a prepolymer P (X) n where X = NH 2, the preferred conditions avoid any formation of imide ring during the polymerization and during the implementation in the state molten.

For X = OH or NH2, the group Y is preferably chosen from: isocyanate (not blocked), oxazinone and oxazolinone, more preferably oxazinone and oxazolinone, with a spacer or hydrocarbon radical A 'being as defined above. As examples of chain extenders carrying oxazoline or oxazine reactive functions Y that are suitable for the implementation of the invention, reference may be made to those described under references "A", "B", "C" and "D". on page 7 of application EP 0 581 642, as well as to their preparation processes and the other reaction modes which are exposed to them. "A" in this document is bisoxazoline, "B" bisoxazine, "C" 1, 3 phenylene bisoxazoline and "D" 1,4-phenylene bisoxazoline.

By way of example, in the case where X = CO2H and the chain extender Y-A'-Y is 1,4-phenylenebisoxazoline, the reaction product obtained has at least one repeating unit of the following structure:

-O-C (O) -P-C (O) -O-R 1 -NH-C (O) -A'-C (O) -NH-R 1 - in which:

P is an acid-terminated polyamide HO-C (O) -P-C (O) -OH obtained from the amide units (A), (B) or (C),

R1 (CH2) 2, and

A 'is a phenyl.

As examples of Y-imidazoline reactive chain extenders suitable for the implementation of the invention, reference may be made to those described ("A" to "F") on pages 7 to 8 and Table 1 of the page 10 in the application EP 0 739 924 as well as their processes of preparation and their modes of reaction which are exposed to it.

As examples of Y = oxazinone or oxazolinone reactive functional chain extenders which are suitable for the implementation of the invention, reference may be made to those described under references "A" to "D" on pages 7 to 8 of EP 0 581 641, and to their preparation processes and their reaction modes which are exposed to them.

Examples of groups Y oxazinones (6-atom ring) and oxazolinones (5-atom ring) are suitable Y groups derived from: benzoxazinone oxazinone or oxazolinone, with spacer A as a simple covalent bond with corresponding respective lengtheners being: bis- (benzoxazinone), bisoxazinone and bisoxazolinone.

A may also be a C1 to C14 alkylene, preferably a C2 to C10 alkylene, but preferably A 'is an arylene and more particularly it may be a phenylene (substituted with Y at the 1, 2 or 1, 3 or 1, 4 positions). or a naphthalene radical (disubstituted by Y) or phthaloyl (iso- or terephthaloyl) or A 'may be a cycloalkylene.

For the Y functions such as oxazine (6-ring), oxazoline (5-ring) and imidazoline (5-ring), the radical A can be as described above with A possibly being a single covalent bond and with the respective corresponding extenders being: bisoxazine, bisoxazoline and bisimidazoline. A 'may also be a C1 to C14 alkylene, preferably a C2 to C10 alkylene. The radical A is preferably arylene and more particularly it may be phenylene (substituted with Y at the 1, 2 or 1, 3 or 1, 4 positions) or a naphthalene (disubstituted with Y) or phthaloyl (iso- or terephthaloyl) radical or A 'may be cycloalkylene.

In the case where Y = aziridine (nitrogenous heterocycle with 3 atoms equivalent to ethylene oxide by replacing the ether -O- with -NH-), the radical A 'may be a phthaloyl (1, 1' iso). or terephthaloyl) with, as an example of such an extender, isophthaloyl-bis (2-methyl aziridine).

The presence of a catalyst for the reaction between said P (X) n prepolymer and said Y-A'-Y extender at a level ranging from 0.001 to 2%, preferably from 0.01 to 0.5% relative to The total weight of two co-reactants mentioned can accelerate the (poly) addition reaction and thus shorten the production cycle. Such a catalyst may be chosen from: 4,4'-dimethylaminopyridine, p-toluenesulphonic acid, phosphoric acid, NaOH and optionally those described for polycondensation or transesterification as described in EP 0 425 341, page 9, lines 1 to 7.

According to a more particular case of the choice of said extender, A 'may represent an alkylene, such that - (CH2) m - with m ranging from 1 to 14 and preferably from 2 to 10 or represents a substituted arylene alkyl or unsubstituted, such as benzene arylenes (such as o-, m-, -p) or naphthalenic phenylenes (with arylenes: naphthalenylenes). Preferably, A represents an arylene which may be benzene or naphthenic substituted or not.

As already stated, said chain extender (a2) preferably has a molecular weight of less than 500, more preferably less than 400.

The denatured elongation rate used varies from 1 to 20%, in particular from 5 to 20%, especially from 10 to 20% by weight.

In the case of the reactive compositions of the invention according to definition a), said reactive prepolymers are prepared by conventional polycondensation reaction between the corresponding diamine and diacid components and optionally amino acids or lactams. Prepolymers carrying X 'and Y' amino and carboxy functions on the same chain can be obtained for example by adding a combination of monomers (amino acid, diamine, diacid) having in total an equal amount of amino and carboxy units. Another way of obtaining these prepolymers carrying a function X 'and a Y' is, for example, by combining a prepolymer bearing 2 identical functions X '= amine, with a diacid prepolymer carrier of Y': carboxy, with an overall molar rate in acid functions equal to that of the amine functions X 'starting.

In order to obtain prepolymers functionalized with identical functions (amines or carboxy) on the same chain, it suffices to have an excess of diamine (or of amine functional groups as a whole) to have terminal amino functions or excess of diacid (or of carboxy functions globally) to have carboxyl terminal functions. In the case of a prepolymer P (X1) n with n identical functions X1, the functionality 1 can be obtained in the presence of a monofunctional blocking component (monoacid or monoamine depending on the nature of X1 = amine or carboxy).

Functionality n = 2 can be obtained from difunctional components: diamines and diacids with an excess of one to fix X1 as a function of this excess.

For n = 3 for example, for a prepolymer P (X1) n, the presence of a trifunctional component is required, for example the presence of a triamine (one mole per prepolymer chain) with a diamine in the reaction with a diacid . The preferred functionality for P (X1) n is n = 2.

Optionally, the thermoplastic prepolymer or thermoplastic prepolymer mixture further comprises carbonaceous fillers, in particular carbon black or carbon nanofillers, preferably chosen from carbon nanofillers, in particular graphenes and / or carbon nanotubes, and or carbon nanofibrils or mixtures thereof. These charges make it possible to conduct electricity and heat, and therefore make it easier to melt the prepolymer matrix when it is heated.

Optionally, said thermoplastic prepolymer comprises at least one additive, especially chosen from a catalyst, an antioxidant, a thermal stabilizer, a UV stabilizer, a light stabilizer, a lubricant, a filler, a plasticizer, a flame retardant, a nucleating agent , a dye, an electrical conductive agent, a thermal conductive agent or a mixture thereof.

Advantageously, said additive is chosen from a flame retardant agent, an electrical conductive agent and a thermal conductive agent.

Said flame retardants may be halogen-free flame retardants, as described in US 2008/0274355 and in particular a metal salt selected from a metal salt of phosphinic acid, a metal salt of diphosphinic acid, a polymer containing at least one salt phosphinic acid, a polymer containing at least one metal salt of diphosphinic acid or red phosphorus, an antimony oxide, a zinc oxide, an iron oxide, a magnesium oxide or metal borates such as zinc borate or melamine pyrophosphates and melamine cyanurates. They may also be halogenated flame retardants such as brominated or polybrominated polystyrene, brominated polycarbonate or brominated phenol.

According to another variant, the thermoplastic prepolymer or thermoplastic prepolymer blend may further comprise liquid crystal polymers or cyclized poly (butylene terephthalate), or mixtures containing said liquid crystal polymers or said cyclized poly (butylene terephthalate) as that additives, like resin CBT100 marketed by CYCLICS CORPORATION. These compounds make it possible in particular to fluidize the prepolymer matrix in the molten state, for better penetration into the core of the fiber locks. Depending on the nature of the prepolymer, or mixture of thermoplastic prepolymers, used to make the impregnation matrix, in particular its melting point, one or other of these compounds will be chosen.

The thermoplastic prepolymers forming part of the impregnation matrix of the fibrous material are precursors of polymers and can be chosen from: the family of aliphatic, cycloaliphatic polyamides (PA) or semi-aromatic PAs (also called polyphthalamides (PPAs)) )

polyureas, in particular aromatic,

family of acrylics such as polyacrylates, and more particularly polymethyl methacrylate (PMMA) or its derivatives

the family of polyarylether ketones (PAEK) such as polyether ether ketone (PEEK), or polyaryletherketone ketones (PAEKK) such as polyetherketone ketone (PEKK) or their derivatives,

aromatic polyether-imides (PEI),

polyarylsulfides, in particular polyphenylene sulfides (PPS),

polyarylsulphones, in particular polyphenylene sulphones (PPSU),

polyolefins, in particular polypropylene (PP);

polylactic acid (PLA),

polyvinyl alcohol (PVA),

fluorinated prepolymers, in particular polyvinylidene fluoride (PVDF), or polytetrafluoroethylene (PTFE) or polychlorotrifluoroethylene (PCTFE), and mixtures thereof.

The prepolymer may be in the form of homopolyamide or copolyamide.

Advantageously, when said prepolymer is a mixture of two prepolymers P1 and P2, the proportion by weight of prepolymer P1 and P2 is from 1 -99% to 99-1%.

Advantageously, when said thermoplastic prepolymer is mixed and used in a tank, it is added to the tank in powder form previously obtained by "dry blend" or "compound" or directly into the tank in the form of "dry blend".

Advantageously, it is added in powder form previously obtained by "dry blend" or directly in the tank in the form of "dry blend" and the mixture of two prepolymers P1 and P2 is a mixture of PEKK and PEI.

Advantageously, the PEKK PEI mixture is from 90-10% to 60-40% by weight, in particular from 90-10% to 70-30% by weight.

The number-average molecular weight Mn of said final non-reactive thermoplastic polymer is greater than 10,000, preferably in a range from 10,000 to 40,000, preferably, in a range from 10,000 to 40,000, preferably from 12,000 to 30,000. These Mn values may correspond to inherent viscosities greater than or equal to 0.8 as determined in m-cresol according to ISO 307: 2007 but changing the solvent (use of m-cresol in place of sulfuric acid and the temperature being 20 ° C).

The Mn are determined in particular by the calculation from the terminal function rate determined by potentiometric titration in solution.

Mn masses can also be determined by size exclusion chromatography or by NMR.

The nomenclature used to define polyamides is described in ISO 1874-1: 201 1 "Plastics - Polyamide (PA) materials for molding and extrusion - Part 1: Designation", especially on page 3 (Tables 1 and 2) and is well known to those skilled in the art.

The polyamide may be a homopolyamide or a copolyamide or a mixture thereof. Advantageously, the prepolymers constituting the matrix are chosen from polyamides (PA), in particular chosen from aliphatic polyamides, cycloaliphatic polyamides, and semi-aromatic polyamides (polyphthalamides) optionally modified with urea units, and their copolymers, polymethyl methacrylate (PPMA) and its copolymers, polyetherimides (PEI), polyphenylene sulphide (PPS), polyphenylene sulphone (PPSU), polyetherketoneketone (PEKK), Poly (ether ether ketone) (PEEK), fluorinated polymers such as polyvinylidene fluoride (PVDF).

For the fluoropolymers, it is possible to use a homopolymer of vinylidene fluoride (VDF of formula CH2 = CF2) or a copolymer of VDF comprising by weight at least 50% by weight of VDF and at least one other monomer copolymerizable with VDF. The VDF content must be greater than 80% by weight, or even better 90% by weight, to ensure good mechanical strength to the structural part, especially when subjected to thermal and chemical stresses. The comonomer may be a fluorinated monomer such as, for example, vinyl fluoride.

For structural parts that must withstand high temperatures, in addition to the fluorinated polymers, PAEK (PolyArylEtherKetone) such as PEK polyether ketones, PEEK poly (etheretherketone) and PEKK poly (etherketoneketone) are advantageously used according to the invention. PEKEKK poly (etheretherketoneetherketone) or PAs with high glass transition temperature Tg).

Advantageously, said at least one thermoplastic prepolymer is selected from polyamides, PEKK, PEI and a mixture of PEKK and PEI. Advantageously, said polyamide is chosen from aliphatic polyamides, cycloaliphatic polyamides and semi-aromatic polyamides (polyphthalamides). Advantageously, said aliphatic polyamide prepolymer is chosen from:

polyamide 6 (PA-6), polyamide 11 (PA-11), polyamide 12 (PA-12), polyamide 66 (PA-66), polyamide 46 (PA-46), polyamide 610 (PA-610), polyamide 612 (PA-612), polyamide 1010 (PA-1010), polyamide 1012 (PA-1012), polyamide 1 1/1010 and polyamide 12/1010, or a mixture of them or a copolyamide thereof, and the block copolymers, in particular polyamide / polyether (PEBA), and said semi-aromatic polyamide is a semi-aromatic polyamide, optionally modified with urea units, in particular an MXD6 PA and an MXD10 PA or a semi-aromatic polyamide of formula X / YAr, as described in EP1505099, in particular a semi-aromatic polyamide of formula A / XT in which A is chosen from a unit obtained from an amino acid, a unit obtained from a lactam and a unit corresponding to the formula (diamine Ca). (diacid in Cb), with a representing the number of carbon atoms of the diamine and b representing the number of carbon atoms of the diacid, a and b being each between 4 and 36, advantageously between 9 and 18, the (Ca diamine) unit being chosen from linear or branched aliphatic diamines, cycloaliphatic diamines and alkylaromatic diamines and the (Cb diacid) unit being chosen from linear or branched aliphatic diacids, cycloaliphatic diacids and aromatic diacids .

XT denotes a unit obtained from the polycondensation of a diamine in Cx and terephthalic acid, with x representing the number of carbon atoms of the diamine in Cx, x being between 6 and 36, advantageously between 9 and 18, in particular a polyamide of formula A / 6T, A / 9T, A / 10T or A / 1 1T, A being as defined above, in particular a polyamide PA 6 / 6T, a PA 66 / 6T, a PA 6I / 6T, PA MPMDT / 6T, PA PA1 1 / 10T, PA 1 1 / 6T / 10T, PA PA MXDT / 10T, PA MPMDT / 10T, PA PA / 10T, PA PA / 6T , PA BACT / 10T / 6T.

T is terephthalic acid, MXD is m-xylylene diamine, MPMD is methylpentamethylene diamine, and BAC is bis (aminomethyl) cyclohexane.

Advantageously, the partially polymerized reactive prepolymer, optionally with a chain extender, has a glass transition temperature Tg greater than or equal to 80 ° C., preferably greater than or equal to 100 ° C., in particular greater than or equal to 120 ° C., in particular greater than or equal to 140 ° C, or is a semi-crystalline prepolymer whose melting temperature Tf is greater than or equal to 150 ° C.

Fibrous material: As regards the fibers of constitution of said fibrous material, they are in particular fibers of mineral, organic or vegetable origin in the form of locks.

Among the fibers of mineral origin, mention may be made of carbon fibers, glass fibers, basalt fibers, silica fibers, or silicon carbide fibers, for example.

Advantageously, these are carbon fibers whose fiber number per wick is greater than or equal to 30K, in particular is greater than or equal to 50K or glass fibers whose weight is greater than or equal to 1200 Tex, in particular greater or equal to 2400 Tex, in particular greater than or equal to 2400 Tex.

Among the fibers of organic origin, mention may be made of thermoplastic or thermosetting polymer-based fibers, such as semi-aromatic polyamide fibers, aramid fibers or polyolefin fibers, for example. Preferably, they are based on amorphous thermoplastic polymer and have a glass transition temperature Tg greater than the Tg of the prepolymer or thermoplastic prepolymer mixture of constitution of the impregnation matrix when the latter is amorphous, or greater than the Tf of the prepolymer or mixture of thermoplastic prepolymer of constitution of the impregnation matrix when the latter is semi-crystalline. Advantageously, they are based on semicrystalline thermoplastic polymer and have a melting temperature Tf greater than the Tg of the prepolymer or thermoplastic prepolymer mixture of constitution of the impregnation matrix when the latter is amorphous, or greater than the Tf of the prepolymer or mixture of thermoplastic prepolymer of constitution of the impregnation matrix when the latter is semicrystalline. Thus, there is no risk of fusion for the organic fibers constituting the fibrous material during impregnation with the thermoplastic matrix of the final composite. Among the fibers of vegetable origin, mention may be made of natural fibers based on flax, hemp, lignin, bamboo, silk, especially spider, sisal, and other cellulosic fibers, in particular viscose fibers. These plant-based fibers can be used pure, treated or coated with a coating layer, in order to facilitate the adhesion and impregnation of the thermoplastic prepolymer matrix.

The fibrous material may also be a fabric, braided or woven with fibers.

It can also correspond to fibers with holding threads.

These constituent fibers can be used alone or in mixtures. Thus, organic fibers may be mixed with the mineral fibers to be impregnated with thermoplastic prepolymer, optionally with a chain extender, and form the impregnated fibrous material.

The locks of organic fibers may have several grammages. They can also have several geometries. The fibers may be in the form of short fibers, which then compose the felts or nonwovens which may be in the form of webs, webs, or pieces, or in the form of continuous fibers, which make up 2D fabrics, unidirectional (UD) or non-woven fibers or tows. The fibers constituting the fibrous material may also be in the form of a mixture of these reinforcing fibers of different geometries. Preferably, the fibers are continuous. Preferably the fibrous material is constituted by continuous fibers of carbon, glass or silicon carbide or their mixture, in particular carbon fibers. It is used in the form of a lock or several locks.

The thermoplastic prepolymer of impregnation must be distributed as homogeneously as possible within the fibers in order to obtain a minimum of porosities, ie a minimum of voids between the fibers. Indeed, the presence of porosities in this type of material can act as points of concentration of stress, when placed under tensile stress, for example, and which then form fracture initiation points of the impregnated fibrous material. and mechanically weaken it. A homogeneous distribution of the prepolymer or mixture of prepolymers thus improves the mechanical strength and the homogeneity of the composite material formed from these impregnated fibrous materials. Thus, the level of fibers in said impregnated fibrous material is 45 to 65% by volume, preferably 50 to 60% by volume, especially 54 to 60% by volume.

The measurement of the impregnation rate can be carried out by image analysis (use of microscope or camera or digital camera, in particular), a cross section of the ribbon, by dividing the surface of the tape impregnated with the polymer. by the total surface of the product (surface impregnated plus surface of the porosities). In order to obtain an image of good quality, it is preferable to coat the ribbon cut in its transversal direction in a standard polishing resin and to polish with a standard protocol allowing observation of the sample under a microscope. . Advantageously, the porosity of said impregnated fibrous material is less than 10%, especially less than 5%, in particular less than 2%.

It should be noted that a zero porosity rate is difficult to access and therefore, advantageously the porosity rate is greater than 0% but lower than the rates mentioned above.

The porosity rate corresponds to the closed porosity rate and can be determined either by electron microscopy or as being the relative difference between the theoretical density and the experimental density of said impregnated fibrous material as described in the examples of the present invention. Process for preparing the fibrous material

The fibrous material impregnated with a partially polymerized thermoplastic prepolymer, optionally with a chain extender, may be prepared in two steps: A first step of pre-impregnating with a thermoplastic prepolymer and optionally a chain extender and a second heating step by means of at least one docking piece (E) and at least one heating system, said piece of being located at the level of the heating system

First step: pre-impregnation

The first pre-impregnation step for obtaining a material can be carried out according to the techniques well known to those skilled in the art and in particular chosen from those described above.

Thus, it can be carried out by powdered pre-impregnation technology, by melting, in particular by pultrusion, by extrusion at the head end of the molten prepolymer, by continuous passage of the fibers in an aqueous dispersion of prepolymer powder or aqueous dispersion of prepolymer particles or an aqueous prepolymer emulsion or suspension, by fluidized bed, equipped or not with at least one jetting (Ε '), by spray nozzle or spray gun in a tank, equipped or not with at least one docking (Ε ').

However, the pre-impregnation step depends on the nature of the reactive prepolymer used. Thus, in the case of a reactive prepolymer bearing, on the same chain, two terminal functions X 'and Y', functions respectively coreactive to one another by condensation, the use of the molten route imposes the use of an extruder and this cause polymerization of the prepolymer in this extruder, to lead to the final non-reactive thermoplastic polymer at the exit of the extruder, which would significantly impair the quality of impregnation of the fibers; this could even in some cases block the screw of the extruder.

Therefore, it is necessary to use an aqueous dispersion of prepolymer particles or an aqueous prepolymer emulsion or suspension, a fluidized bed or a spray nozzle or spray gun in a tank.

The squeeze may be a concave, convex or cylindrical compression roll, in particular it is cylindrical.

FIG. 1 shows an example of a vessel provided with a jig and FIG. 2 shows an example of a vessel comprising a fluidized bed in which the jig is a cylindrical compression roller.

The same tank can be used without the presence of a fluidized bed and equipped with a spray gun.

In the case of at least two polyamide prepolymers which are reactive with one another and each carrying two identical terminal functions X 'or Y' respectively, or at least one thermoplastic polyamide prepolymer bearing n terminal reactive functions X with a chain extender, the melt impregnation can be carried out only by the separate introduction of the different reactive species together, in a mixer, just before the impregnation of the fibers or directly in the impregnation chamber. Preferably, the pre-impregnation stage is carried out by means of an aqueous dispersion of prepolymer particles or of an aqueous emulsion or suspension of prepolymer, of a fluidized bed or of a projection by nozzle or spray gun by dry route. in a tank, in particular by means of a fluidized bed.

Advantageously, the pre-impregnation is carried out with a system as defined above and one or more jets (E ") is (are) present (s) upstream of said system. (E) and (E ") can be identical or different in terms of material or shape and its characteristics (diameter, length, width, height ... depending on the shape).

Melted path:

The pre-impregnation stage can be carried out by melting, in particular by pultrusion. The melt pre-impregnation techniques are well known to those skilled in the art and are described in the references above.

The pre-impregnation step is carried out in particular by passing said wick or said locks in a bath comprising the prepolymer matrix and then passing through a heated die, the bath being provided with fixed or rotating locks on which the wick scrolls thus causing a blooming of said wick for pre-impregnation of said wick.

The pre-impregnation may especially be carried out as described in US

2014/0005331 A1 with a feed as described in this application or a resin feed is performed on both sides of said wick and there is no contact surface removing a portion of the resin on one of the two surfaces.

Advantageously, the pre-impregnation step is carried out by a high speed melt, that is to say with a running speed of said wick or said wicks greater than or equal to 5 m / min, in particular greater than 9 m. / min.

Fluidized bed:

The pre-impregnation stage may be carried out in a fluidized bed.

An exemplary implementation unit of a manufacturing method without the heating step by means of at least one mating part is described in international application WO 2015/121583.

This system describes the use of a vessel comprising a fluidized bed to perform the pre-impregnation step and can be used in the context of the invention. Advantageously, the vessel comprising the fluidized bed is provided with at least one docking piece (Ε ') (FIG. 1) which may be a compression roller (FIG. 2)).

By docking part (Ε '), we mean any system on which the wick to the possibility of scrolling in the tank. The docking piece (Ε ') can have any shape from the moment the wick can scroll on contact.

An example of a docking piece (Ε '), without restricting the invention to it, is detailed in FIG.

It should be noted that the parts (E) and (Ε ') can be identical or different in terms of material or shape and its characteristics (diameter, length, width, height ... depending on the form).

However, the docking piece (Ε ') is neither heated nor heated.

The step of pre-impregnating the fibrous material is carried out by passing one or more wicks in a continuous pre-impregnation device, comprising a tank (10) provided with at least one docking piece (Ε ') and comprising a fluidized bed (12) of powder of said at least one prepolymer and optionally a chain extender.

The powder of said at least one prepolymer and optionally a chain extender is suspended in a gas G (air for example) introduced into the tank and circulating in the tank (10) through a hopper (1 1). The wick (s) are circulated in this fluidized bed (12).

The tank may have any shape, in particular cylindrical or parallelepipedal, in particular a rectangular parallelepiped or a cube, advantageously a rectangular parallelepiped. The tank (10) can be an open or closed tank.

In the case where the tank is closed, it is then equipped with a sealing system so that the powder of said at least one prepolymer and optionally a chain extender can not leave said tank.

This pre-impregnation stage is therefore carried out dry, that is to say that said at least one prepolymer and optionally a chain extender is in powder form, in particular in suspension in a gas, in particular air, but can not be dispersed in a solvent or in water.

Each wick prepreg is unwound from a reel device under the traction generated by cylinders (not shown).

Each reel is provided with a brake (not shown) so as to apply tension to each fiber strand. In this case, an alignment module allows to arrange the fiber locks parallel to each other. In this way the fiber locks can not be in contact with each other, which makes it possible to avoid mechanical degradation of the fibers by friction between them. The fiber wick or the parallel fiber locks then pass into a tank (10), in particular comprising a fluidized bed (12), provided with a docking piece (Ε ') which is a compression roll (24). in the case of Figure 2. The fiber lock or the parallel fiber locks then spring (ent) from the tank after pre-impregnation after possible control of the residence time in the powder.

The term "residence time in the powder" means the time during which the wick is in contact with said powder in the fluidized bed.

If the fibrous material, such as fiberglass, has a sizing, an optional de-sizing step can be performed before the fibrous material passes into the tank. The term "sizing" refers to the surface treatments applied to the reinforcing fibers at the end of the die (textile size) and on the fabrics (plastic sizing).

Advantageously, the vessel used in the process of the invention comprises a fluidized bed and said pre-impregnation stage is carried out with simultaneous expansion of said wick or said wicks between the inlet and the outlet of the vessel comprising said fluidized bed. The expression "inlet of the tank of said fluidized bed" corresponds to the vertical tangent of the edge of the vessel which comprises the fluidized bed.

The expression "outlet of the tank of said fluidized bed" corresponds to the vertical tangent of the other edge of the vessel which comprises the fluidized bed.

Depending on the geometry of the tank, the distance between the inlet and the outlet thereof is therefore the diameter in the case of a cylindrical tank, the side in the case of a cubic tank or the width or the length in the case of a rectangular parallelepipedic tank. The development consists in singling out as much as possible each fiber constituting said wick of the other fibers which surround it in its nearest space. It corresponds to the transverse spreading of the wick.

In other words, the transverse spreading or the width of the wick increases between the inlet of the fluidized bed (or of the vessel comprising the fluidized bed) and the outlet of the fluidized bed (or of the vessel comprising the fluidized bed) and thus allows improved pre-impregnation of the fibrous material.

The use of at least one docking (Ε '), in particular a cylindrical compression roller, in the pre-impregnation stage thus allows an improved pre-impregnation compared with the methods of the prior art.

The expression "compression roll" means that the wicking bit rests partially or completely on the surface of said compression roller, which induces the development of said wick.

Advantageously, said at least one compression roller is of cylindrical shape and the percentage of expansion of said wick or said wicks between the inlet and the output of the tank of said fluidized bed is from 1% to 1000%, preferably from 100% to 800%, preferably from 200% to 800%, preferably from 400% to 800%.

The percentage of bloom is equal to the ratio of the final width of the lock to the initial width of the lock multiplied by 100.

The diameter of said at least one compression roller is from 3 mm to 500 mm, preferably from 10 mm to 100 mm, in particular from 20 mm to 60 mm.

Below 3 mm, the deformation of the fiber induced by the compression roll is too great.

Advantageously, the compression roller is cylindrical and not grooved and in particular is metallic.

When the starting piece (Ε ') is at least one compression roll, according to a first variant, a single compression roll is present in the fluidized bed and said pre-impregnation is carried out at the angle α formed by said wick or wicks between the inlet of said compression roller and the vertical tangent to said compression roller.

The angle α formed by said wick or said wicks between the inlet of said compression roller and the vertical tangent to said compression roller allows the formation of an area in which the powder will concentrate thus leading to a "wedge effect" which with the simultaneous development of the wick by said compression roller allows a pre-impregnation over a larger width of the wick and therefore improved pre-impregnation compared to techniques of the improved prior art.

Advantageously, the angle α is from 0 to 89 °, preferably 5 ° to 85 °, preferably from 5 ° to 45 °, preferably from 5 ° to 30 °.

Nevertheless, an angle α of 0 to 5 ° is likely to generate risks of mechanical stress, which will lead to breakage of the fibers and an angle α of 85 ° to 89 ° does not create enough mechanical stress for create the "corner effect".

A value of the angle ai equal to 0 ° therefore corresponds to a vertical fiber. It is obvious that the height of the cylindrical compression roller is adjustable thus allowing to position the fiber vertically.

Advantageously, the inlet edge of the vessel (23a) is equipped with a roller, in particular a cylindrical and rotating roller, on which said wick or said wicks runs, thus leading to a prior development.

It is obvious that the "wedge effect" caused by the angle a1 favors the pre-impregnation on one face, but the development of said wick obtained thanks to the compression roll also makes it possible to have a pre-impregnation on the other face of said wick. In other words, said pre-impregnation is favored on one face of said wick or said wicks at the angle α formed by said wick or said wicks between the entrance. said at least one compression roller Ri and the vertical tangent to the compression roller Ri, but the expansion also makes it possible to pre-impregnate the other face.

The angle α1 is as defined above.

Advantageously, the inlet edge of the tank (23a) is equipped with a roller, in particular a cylindrical and rotary roller, on which said wick or said wicks runs, thus leading to a development prior to the pre-impregnation.

In one embodiment, the blooming is initiated at the entrance edge of the tank (23a) and continues at the said one or more of the aforementioned (Ε ') jams.

In another embodiment, one or more embellishments (E ") are present upstream of the vessel comprising the fluidized bed at which the blooming is initiated.The cracks (E") are as defined for (Ε). ').

Advantageously, the blooming is initiated at the level of the aforementioned jam (E ") above and possibly continues at the level of the inlet edge of the tank of the tank and then at the level of the said (Ε ') ci above defined.

The blooming is then maximum after passage at the compression roll (s) (Ε ').

Advantageously, the percentage of development of said wick or said wicks between the entry of the jams (E ") and the outlet of the tank of said fluidized bed is comprised from 1% to 1000%, preferably from 100% to 800%, preferably from 200% to 800%, preferably 400% to 800%.

In other embodiments, two, three or more rollers may be present in the fluidized bed.

Advantageously, the volume diameter D90 of the thermoplastic polymer powder particles is 30 to 500 μηι, advantageously 80 to 300 μηι.

Advantageously, the volume diameter D10 of the thermoplastic polymer powder particles is from 5 to 200 μηη, advantageously from 15 to 100 μηη.

Advantageously, the volume diameter of the thermoplastic polymer powder particles is included in the D90 / D10 ratio, ie between 1.5 and 50, advantageously between 2 and 10.

Advantageously, the average diameter D50 by volume of the thermoplastic polymer powder particles is between 10 and 300 μηι, in particular from 30 to 200 μηι, more particularly from 45 to 200μη "ΐ.

Spray spray:

The step of pre-impregnating the fibrous material may also be carried out by passing one or more wicks in a continuous projection pre-impregnation device, comprising a vessel, comprising one or more nozzles or one or more gun (s) projecting the reactive prepolymer powder, optionally with a chain extender, on the fibrous material at the roll inlet.

The reactive prepolymer powder, optionally with a chain extender, is thrown into the tank by means of nozzle (s) or gun (s) at the part of the binder including the compression roller (input) on said fibrous material. The wick or wicks are circulated in this tank.

An example without being limited to it with a gun is shown in Figure 3.

All the characteristics of the jams, and in particular the compression rolls, and the angle α causing the wedge effect and detailed for the fluidized bed are also valid for the spray gun.

According to other variants, two, three or more rollers may be present each provided with a pistol.

Second step: heating

The pre-impregnation step can therefore be carried out by any means provided or not with at least one docking (Ε ').

The presence of the docking allows the development of the wick and promotes pre-impregnation. However, the presence of this docking is not essential from the moment when a heating system provided with at least one docking piece (E) is present after the pre-impregnation stage.

The term "docking piece (E)" means any system on which the wick has the ability to scroll. The docking piece (E) can have any shape from the moment the wick can scroll on. It can be fixed or rotating.

The heating system is any system that emits heat or emits radiation that can heat the mating part (E) and the wick pre-impregnated with resin.

It can be an infra-red heating, a UV lamp, a convection heating.

The engaging piece (E) is therefore conductive or absorbs radiation emitted by heat.

The term "heat-conducting bartack (E)" means that the bartack (E) is made of a material capable of absorbing and conducting heat. It can also be a heating system by microwave or laser.

In this case, the docking piece is non-conductive of heat or does not absorb the radiation emitted by heat.

The expression "non-heat-conductive (E) -center" means that the bartack (E) is made of a material incapable of absorbing and conducting heat. Said at least one docking piece (E) is located or included in the environment of the heating system, that is to say, it is not outside the heating system. Advantageously, said heating system overcomes said at least one mating piece (E). The heating system is at a height sufficient for the deduction of at least one prepolymer and optionally the chain extender present on the wick to melt but without degrading said prepolymer and optionally the chain extender. Nevertheless, said heating system comprises either only said at least one mating piece (E) but may also comprise a portion of the wick, outside said mooring system (E), said wick portion being located before and / or after said docking system (E).

A representation of a heating system and three mishaps (E), corresponding to R'i, R'2 and R'3, is shown in Figure 4, without being limited in any way to it.

It is obvious that a second heating system can be present under the constraints thus allowing a uniform melting of said prepolymer on both surfaces of the wick.

The height between the heating system and the interferences is from 1 to 100 cm, preferably from 2 to 30 cm, in particular from 2 to 10 cm.

The heating system shown in Figure 4 is a horizontal system. However, the heating system (s) can be arranged vertically with also vertical scrolling of the wick through the jams.

It should be noted that the speed of travel of the wick at the level of the heating system is sufficient for said prepolymer and optionally the chain extender to melt and optionally to partially polymerize but without causing the complete polymerization of the prepolymers or the prepolymer with extender. chain.

Therefore, this heating step makes it possible to complete the impregnation of the wick carried out beforehand during the pre-impregnation stage and in particular to obtain a homogeneous and thorough impregnation without causing the complete polymerization which would lead to the final thermoplastic polymer . .

In fact, whatever the system used for the pre-impregnation step, a first blooming occurs during this step, in particular if the pre-impregnation step is carried out with the use of sparing pieces (Ε '). , such as in a fluidized bed with at least one docking as described above.

A first development of the wick occurs at the level of said compression rollers corresponding to the "wedge effect" (Ε ') with the "corner effect" due to the partial or total movement of said wick on said piece (s) of (Ε ') and a second expansion occurs during the heating step, at said compression rollers corresponding to the parts of the boot (E) due to the partial or total movement of said wick on said part ( s) (E). This second expansion is preceded during the passage of the wick in the heating system, before its partial or total scrolling on the said room (s) of docking (E), a retraction of the wick due to the merger polymer on said wick.

This second expansion combined with the melting of said polymer matrix by the heating system and the retraction of the wick make it possible to homogenise the pre-impregnation and thus finalize the impregnation and thus to have an impregnation at heart and to have a high level of fibers by volume, especially constant in at least 70% of the volume of the band or ribbon, in particular in at least 80% of the volume of the band or ribbon, in particular in at least 90% of the volume of the band or ribbon, more particularly in at least 95% of the volume of the tape or ribbon, as well as to decrease the porosity.

The development is a function of the fibrous material used. For example, the blooming of a carbon fiber material is much greater than that of a flax fiber. The development is also a function of the number of fibers in the wick, their average diameter and their cohesion by the size.

Advantageously, the percentage of expansion during the heating step between the inlet of the first compression roller R'i and the outlet of the third compression roller R'3 is approximately 20 to 150%, in particular 50 at 75%.

After passing the tape through the first heating system, the tape retracts.

The various bloomings during the heating step combined with the melting of the thermoplastic polymer and the shrinkage of the wick during said heating step make it possible to obtain a fiber content impregnated after the heating step of 45% to 45%. 64% by volume, preferably 50 to 60% by volume, in particular 54 to 60% by volume (rate of fibers which can not be attained by standard melting techniques), the fiber content by volume and the distribution of the fibers being substantially identical on average on both sides of the median plane of the fibrous material over the entire length of said fibrous material, thus leading in particular to the production of a fibrous material, in particular a monolayer material.

Below 45% of fibers, the reinforcement has no interest as regards the mechanical properties.

Above 65%, the process limits are reached and the mechanical properties are lost.

Advantageously, the porosity rate in said impregnated fibrous material is less than 10%, especially less than 5%, in particular less than 2%.

This makes it possible to work with high speeds of scrolling and thus reduce production costs.

Step of formatting Optionally, a step of shaping the wick or said parallel locks of said impregnated fibrous material is performed.

A calendering system as described in WO 2015/121583 may be used.

In the same way as above, the speed of travel of the wick at the level of the calender is sufficient for said prepolymer and optionally the chain extender to be shaped and possibly to partially polymerize but without causing the complete polymerization of the prepolymers or prepolymer with chain extender. According to another aspect, the present invention relates to the use of an impregnated fibrous material, as defined above, for the preparation of an impregnated fibrous material comprising a fibrous material made of continuous fibers and at least one non-reactive thermoplastic polymer of which the number-average molecular mass Mn is greater than 10,000, preferably in a range from 10,000 to 40,000, preferably from 12,000 to 30,000. Advantageously, and the melt viscosity is greater than 100 Pa.s, especially greater than 200 Pa.s, preferably> 400 Pa.s and more preferably> 600 Pa.s. Advantageously, the preparation of said impregnated fibrous material comprising a fibrous material made of continuous fibers and at least one non-reactive thermoplastic polymer is carried out by heating allowing the polymerization of said reactive thermoplastic prepolymer.

According to another aspect, the present invention relates to the use of an impregnated fibrous material, as defined above, for the preparation of calibrated ribbons suitable for the manufacture of three-dimensional composite parts, by automatic removal of said ribbons by means of of a robot.

According to yet another aspect, the present invention relates to a ribbon comprising at least one fibrous material as defined above.

Advantageously, said ribbon is a single unidirectional ribbon or a plurality of unidirectional parallel ribbons.

Advantageously, said ribbon has a width (I) and a thickness (ep) adapted for robot removal in the manufacture of parts in three dimensions, without the need for slitting, and preferably at a width (I) of at least 5 mm. and up to 400mm, preferably between 5 and 50mm and even more preferably between 5 and 20mm. Advantageously, the thermoplastic prepolymer of said tape is a polyamide chosen from, in particular, an aliphatic polyamide such as PA 6, PA 1 1, PA 12, PA 66, PA 46, PA 610, PA 612, PA 1010, PA 1012, PA 1 1 / 1010 or PA 12/1010 or a semi-aromatic polyamide such as PA MXD6 and PA MXD10 or selected from PA 6 / 6T, PA 6I / 6T, PA 66 / 6T, PA 1 1 / 10T, PA 1 1 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 6T, PA BACT / 10T and PA BACT / 10T / 6T, PEEK, PEKK and PEI or a mixture thereof.

Advantageously, it is chosen from, in particular, an aliphatic polyamide such as PA 6, PA 11, PA 12, PA 1 1/1010 or PA 12/1010 or a semi-aromatic polyamide such as PA MXD6. and PA MXD10 or selected from PA 6 / 6T, PA 6I / 6T, PA 66 / 6T, PA 1 1 / 10T, PA 1 1 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T and PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T.

According to another aspect, the present invention relates to the use of a ribbon as defined above, in the manufacture of composite parts in three dimensions.

Said fibrous material impregnated with a prepolymer as defined above may be used for thermo stamping, for example, by preforming by flat by robotic deposition of tape impregnated with a prepolymer and then preheating said impregnated tape to perform the recovery in viscosity at the molten state and therefore the increase in number average molecular weight and then transfer ribbon impregnated with non-reactive thermoplastic final polymer in a mold allowing a cycle time of about 1 min and a much lower energy cost.

Advantageously, said manufacture of said composite parts relates to the fields of transport, in particular automobile, oil and gas, in particular offshore, gas storage, aeronautical, nautical, railway; renewable energy, in particular wind turbine, tidal turbine, energy storage devices, solar panels; thermal protection panels; sports and recreation, health and medical and electronics.

According to another aspect, the present invention relates to a three-dimensional composite part characterized in that it results from the use of at least one unidirectional tape of fibrous material impregnated as defined above.

Advantageous embodiments of the method of the invention

Advantageously, the fibrous material is chosen from carbon fiber and glass fiber tows.

Advantageously, the thermoplastic prepolymer used for impregnating the carbon fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, a PA BACT / 10T / 6T, an MXD6 PA and an MXD10 PA, a PEKK and an PEI or a mixture thereof.

Advantageously, the thermoplastic prepolymer used for impregnating the glass fiber is chosen from a polyamide, in particular an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, a PA BACT / 10T / 6T, an MXD6 PA and an MXD10 PA, a PEKK and an PEI or a mixture thereof.

Advantageously, the fibrous material comprises strands of carbon fiber and the thermoplastic prepolymer used to impregnate the carbon fiber is chosen from a polyamide, in particular an aliphatic polyamide such as PA 1 1, PA 12, PA, PA 1 1/1010 and PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, a PA BACT / 10T / 6T, an PA MXD6 and an PA MXD10, a PEKK and a PEI or a mixture of these.

Advantageously, the fibrous material consists of carbon fiber locks and the thermoplastic prepolymer used for impregnating the carbon fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof.

Advantageously, the fibrous material comprises glass fiber strands and the thermoplastic prepolymer used for impregnating the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof.

Advantageously, the fibrous material consists of glass fiber strands and the thermoplastic prepolymer used for impregnating the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof.

Advantageously, the fibrous material comprises strands of carbon fiber and the thermoplastic prepolymer used for impregnating the carbon fiber is chosen from a polyamide, in particular an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 80 ° C or Tf is ≥ 150 ° C .

Advantageously, the fibrous material consists of carbon fiber locks and the thermoplastic prepolymer used to impregnate the carbon fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, or a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, one PA MXDT / 10T, one PA MPMDT / 10T, one PA BACT / 10T, one PA BACT / 6T, one PA BACT / 10T / 6T, one PA MXD6 and one PA MXD10, one PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 80 ° C or Tf is ≥ 150 ° C.

Advantageously, the fibrous material comprises strands of carbon fiber and the thermoplastic prepolymer used for impregnating the carbon fiber is chosen from a polyamide, in particular an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 100 ° C or Tf is ≥ 150 ° C .

Advantageously, the fibrous material consists of carbon fiber locks and the thermoplastic prepolymer used to impregnate the carbon fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 100 ° C or Tf is ≥ 150 ° C.

Advantageously, the fibrous material comprises strands of carbon fiber and the thermoplastic prepolymer used for impregnating the carbon fiber is chosen from a polyamide, in particular an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 120 ° C or Tf is ≥ 150 ° C .

Advantageously, the fibrous material consists of carbon fiber locks and the thermoplastic prepolymer used to impregnate the carbon fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 120 ° C or Tf is ≥ 150 ° C .

Advantageously, the fibrous material comprises strands of carbon fiber and the thermoplastic prepolymer used for impregnating the carbon fiber is chosen from a polyamide, in particular an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, a PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer ≥ 140 ° C or Tf is ≥ 150 ° C.

Advantageously, the fibrous material consists of carbon fiber locks and the thermoplastic prepolymer used for impregnating the carbon fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and Tg of said thermoplastic prepolymer≥ 140 ° C or Tf is ≥ 150 ° C .

Advantageously, the fibrous material comprises strands of fiberglass fiber and the thermoplastic prepolymer used for impregnating the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12 and a PA 1 1/1010 , a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 80 ° C or Tf is ≥ 150 ° C.

Advantageously, the fibrous material consists of fiberglass fiber tows and the thermoplastic prepolymer used to impregnate the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1 / 1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a BACT / 6T PA, a BACT / 10T / 6T PA, an MXD6 PA and an MXD10 PA, a PEKK and a PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 80 ° C or the Tf is ≥ 150 ° C.

Advantageously, the fibrous material comprises strands of fiberglass fiber and the thermoplastic prepolymer used for impregnating the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 100 ° C or Tf is≥ 150 ° C.

Advantageously, the fibrous material consists of fiberglass fiber tows and the thermoplastic prepolymer used to impregnate the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1 / 1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a BACT / 6T PA, a BACT / 10T / 6T PA, an MXD6 PA and an MXD10 PA, a PEKK and a PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 100 ° C or the Tf is ≥ 150 ° C. Advantageously, the fibrous material comprises strands of fiberglass fiber and the thermoplastic prepolymer used for impregnating the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 120 ° C or Tf is≥ 150 ° C.

Advantageously, the fibrous material consists of fiberglass fiber tows and the thermoplastic prepolymer used to impregnate the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1 / 1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a BACT / 6T PA, a BACT / 10T / 6T PA, an MXD6 PA and an MXD10 PA, a PEKK and a PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 120 ° C where the Tf is ≥ 150 ° C.

Advantageously, the fibrous material comprises strands of fiberglass fiber and the thermoplastic prepolymer used for impregnating the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, PA PA MXD6 and PA MXD10, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 140 ° C or Tf is ≥ 150 ° C.

Advantageously, the fibrous material consists of fiberglass fiber tows and the thermoplastic prepolymer used to impregnate the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, a PA 1 1 / 1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, or PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PEKK and PEI or a mixture thereof and the Tg of said thermoplastic prepolymer is ≥ 140 ° C or Tf is ≥ 150 ° C.

Advantageously, the fibrous material comprises strands of glass fibers or of carbon fibers as defined above and the thermoplastic prepolymer used for impregnating the fiber is chosen from an aliphatic polyamide such as PA 1 1, PA 12, PA 1 1/1010 and a PA 12/1010, a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, or PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T and the Tg and Tf of said thermoplastic prepolymer are as defined above.

Description of figures FIG. 1 details a tank (10) comprising a fluidized bed (12) with a height-adjustable bartack (22). The edge of the tank inlet is equipped with a rotating roller 23a on which the wick 21a runs and the edge of the tank outlet is equipped with a rotary roller 23b on which the wick 21b runs.

Fig. 2 shows a single-roll embodiment with a vessel (10) comprising a fluidized bed (12) in which a single cylindrical compression roll (24) is present and showing the angle CM.

The arrows at the fiber indicate the direction of travel of the fiber.

Fig. 3 shows a single-pressurized embodiment with a tub (30) including a powder spraying gun (31) in which a single cylindrical compression roll (33) is present and showing the angle α'Ί.

The arrows at the fiber indicate the direction of travel of the fiber.

Figure 4 shows a diagram of a three-roll heating system.

FIG. 5 shows a scanning electron microscope image of a sectional view of a 1/4 "Toray, 12K T700S 31 E carbon fiber wick impregnated with a D50 MPMDT / 10T PA non-reactive polymer powder. = 1 15μηι according to Example 1.

The diameter of a fiber is 7 μηη.

FIG. 6 shows a scanning electron microscope image of a sectional view of a 1/4 "Toray, 12K T700S 31 E carbon fiber wick impregnated with a two-function MPMDT / 10T reactive prepolymer powder. co-reactants NH2 and CO2H with a Tg 125 ° C of Mn 5100 and then polymerization with a heating system.

The diameter of a fiber is 7 μηη.

The following examples illustrate in a nonlimiting manner the scope of the invention.

Example 1: Procedure comprising a step of pre-impregnating a fibrous material (carbon fiber) with a non-reactive polyamide powder in a fluidized bed with a single roller preceded by jams upstream of the tank and a heating step by Infra Red (Comparative example)

The following procedure was performed:

Four cylindrical and fixed rollers 8 cm in diameter are present upstream of the vessel comprising the fluidized bed which scrolls the wick.

The rolls are 54 cm apart (distance between the first and the last roll)

Pre-impregnation step

A cylindrical compression roller Ri in the tank (L = 500 mm, l = 500mm, H = 600mm), diameter 25 mm.

Residence time of 0.3 sec in the powder

CM angle of 25 ° Bloom about 100% (2 times the width) for a 1/4 "Toray carbon fiber wick, 12K T700S 31 E

D50 = 1 μηι (D10 = 49μηΊ, D90 = 207μη-ι) for the MPMDT / 10T powder.

edge of the tank equipped with a fixed roller.

The fibrous material (¼ "carbon fiber wick) was pre-impregnated with a MPMDT / 10T polyamide of particle size defined above according to the following procedure:

Heating step

The heating system used is that described in Figure 1 but with eight cylindrical rollers R'i to R's fixed diameter 8 mm.

The speed of advancement of the wick is 10 m / min

The infrared used has a power of 25 kW, the height between the infrared and the upper roller is 4 cm and the height between the infrared and the lower rollers is 9 cm.

The angles αΊ to α are identical and 25 °.

The height h is 20 mm

The length I is 1000 mm

The eight rolls are each 43 mm apart. Calender using two series-mounted calender fitted with IR of 1 kW each after the heating step.

Figure 5 shows the impregnated fibrous material obtained with MPMDT / 10T. Example 2: Procedure comprising a step of pre-impregnating a fibrous material (carbon fiber) with a prepolymer powder MPMDT / 10T reactive fluidized bed with a single roller preceded by jams upstream of the tank and a step Infra Red heating system according to the invention

The same procedure as for Example 1 was carried out using an MPMDT / 10T prepolymer bearing two co-reactive functions NH2 and CO2H with Tg 125 ° C and Mn 5100.

Ο50 = 1 15 μηΊ, (Ο10 = 49μηΊ, D90 = 207μη-ι) for the MPMDT / 10T powder.

edge of the tank equipped with a fixed roller.

The Mn of the MPMDT / 10T after passing under the heating system is 16000.

Figure 6 shows the fibrous material impregnated with MPMDT / 10T prepolymer obtained. This demonstrates the effectiveness of the impregnation process with a reactive prepolymer powder carrying two co-reactive functions NH2 and CO2H and then polymerization with an infrared heating system.

Example 3: Determination of the porosity ratio the relative difference between theoretical density and experimental density (general method)

a) The required data are:

The density of the thermoplastic matrix

- The density of the fibers

The weight of the reinforcement:

• linear density (g / m) for example for a ¼ inch tape (from a single rowing)

• mass per unit area (g / m ² ) for example for a wider slab or fabric b) Measures to be carried out:

The number of samples must be at least 30 for the result to be representative of the studied material.

The measures to be carried out are:

The size of the samples taken:

o Length (if known linear density).

o Length and width (if known mass per unit area).

The experimental density of the samples taken:

o Mass measurements in air and water.

The measurement of the fiber content is determined according to ISO 1172: 1999 or by thermogravimetric analysis (TGA) as determined for example in B. Benzler, Applikationslabor, Mettler Toledo, Giesen, UserCom 1/2001.

The measurement of the carbon fiber content can be determined according to ISO 14127: 2008.

Determination of the theoretical mass fiber ratio:

a) Determination of the theoretical mass fiber ratio:

m ,. The

% Mf _th = -

^{1 1} air

With

mid linear mass of the tape,

L the length of the sample and

I _have the mass of the sample measured in the air. The variation of the mass ratio of fibers is supposed to be directly related to a variation of the matrix level without taking into account the variation of the quantity of the fibers in the reinforcement. b) Determination of the theoretical density:

With dm and df the respective densities of the matrix and fibers.

The theoretical density thus calculated is the accessible density if there is no porosity in the samples. c) Evaluation of the porosity:

The porosity is then the relative difference between theoretical density and experimental density.

Claims

An impregnated fibrous material comprising a continuous fiber fibrous material and at least one reactive thermoplastic prepolymer, and optionally a chain extender, characterized in that said at least one reactive thermoplastic prepolymer is partially polymerized, optionally with said chain extender, and present a number-average molecular weight (Mn) ranging from 500 to 10,000, preferably from 4000 to 8000, the level of fibers in said impregnated fibrous material being from 45 to 65% by volume, preferably from 50 to 60% by volume , especially from 54 to 60%.

Impregnated fibrous material according to Claim 1, characterized in that the said at least one partially polymerized reactive thermoplastic prepolymer comprises at least one reactive prepolymer carrying on the same chain two terminal functions X 'and Y', functions which are respectively coreactive to one another by condensation. with X 'and Y' being amino and carboxy or carboxy and amino respectively.

Impregnated fibrous material according to claim 1, characterized in that said at least one partially polymerized reactive thermoplastic prepolymer comprises at least two polyamide prepolymers reactive with each other and each bearing two identical terminal functions X 'or Y' respectively, said function X 'd a prepolymer which can react only with said function Y 'of the other prepolymer, in particular by condensation, more particularly with X' and Y 'being amine and carboxy or carboxy and amine respectively.

Impregnated fibrous material according to claim 1, characterized in that said at least one reactive thermoplastic prepolymer partially polymerized with said chain extender comprises:

a1) at least one reactive thermoplastic prepolymer bearing n terminal functional functions X, chosen from: -NH 2, -CO 2 H and -OH, preferably NH 2 and -CO 2 H with n being 1 to 3, preferably from 1 to 2, more preferably 1 or 2, more particularly 2,

a2) at least one Y-A'-Y chain extender, with A 'being a hydrocarbon biradical carrying 2 identical terminal reactive Y functions, reactive with polyaddition with at least one function X of said prepolymer a1), preferably of molecular weight less than 500, more preferably less than 400, in particular Y is chosen from: oxazine, oxazoline, oxazolinone, oxazinone, imidazoline, epoxy, isocyanate, maleimide cyclic anhydride, especially oxazine, oxazoline, oxazolinone, oxazinone, imidazoline, epoxy, maleimide, cyclic anhydride and preferably X is CO2H and Y is selected from epoxy and oxazoline.

Fibrous material according to one of claims 1 to 4, characterized in that said material is non-flexible.

Impregnated fibrous material according to one of claims 1 to 5, characterized in that said at least one thermoplastic prepolymer is selected from: poly (aryl ether ketones) (PAEK), in particular poly (ether ether ketone) (PEEK); poly (aryl ether ketone ketone) (PAEKK), in particular poly (etherketoneketone) (PEKK); aromatic polyetherimides (PEI); polyaryl sulfones, in particular polyphenylene sulfones (PPSU); polyarylsulfides, in particular polyphenylene sulfides (PPS); polyamides (PA), in particular semi-aromatic polyamides (polyphthalamides) optionally modified by urea units; PEBAs, polyacrylates, in particular polymethyl methacrylate (PMMA); polyolefins, in particular polypropylene, polylactic acid (PLA), polyvinyl alcohol (PVA), and fluorinated polymers, in particular polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE) or polychlorotrifluoroethylene (PCTFE); and mixtures thereof, in particular a mixture of PEKK and PEI, preferably from 90-10% by weight to 60-40% by weight, in particular from 90-10% by weight to 70-30% by weight.

Impregnated fibrous material according to one of claims 1 to 6, characterized in that said at least one thermoplastic prepolymer is selected from polyamides, PEKK, PEI and a PEKK and PEI mixture.

Impregnated fibrous material according to claim 7, characterized in that said polyamide is chosen from aliphatic polyamides, cycloaliphatic polyamides and semi-aromatic polyamides (polyphthalamides).

Impregnated fibrous material according to claim 8, characterized in that said aliphatic polyamide is chosen from polyamide 6 (PA-6), polyamide 11 (PA 1 1), polyamide 12 (PA-12), polyamide 66 (PA-66), polyamide 46 (PA-46), polyamide 610 (PA-610), polyamide 612 (PA-612), polyamide 1010 (PA-1010), polyamide 1012 (PA-1012), polyamide 1 1/1010 and polyamide 12/1010, or a mixture thereof or a copolyamide thereof, and block copolymers, in particular polyamide / polyether (PEBA), and said semi-aromatic polyamide is a semi-aromatic polyamide, optionally modified with urea units, in particular an MXD6 PA and an MXD10 PA or a semi-aromatic polyamide of formula X / YAr, in particular a semiaromatic polyamide of formula A / XT wherein A is selected from a unit obtained from an amino acid, a unit obtained from a lactam and a unit having the formula (diamine Ca). (diacid in

Cb), with a representing the number of carbon atoms of the diamine and b representing the number of carbon atoms of the diacid, a and b being each between 4 and 36, advantageously between 9 and 18, the unit (diamine in Ca) being chosen from linear or branched aliphatic diamines, cycloaliphatic diamines and alkylaromatic diamines and the (Cb diacid) unit being chosen from linear or branched aliphatic diacids, cycloaliphatic diacids and aromatic diacids;

XT denotes a unit obtained from the polycondensation of a diamine in Cx and terephthalic acid, with x representing the number of carbon atoms of the diamine in Cx, x being between 6 and 36, advantageously between 9 and

18, in particular a polyamide of formula A / 6T, A / 9T, A / 10T or A / 1 1T, A being as defined above, in particular a polyamide PA 6 / 6T, a PA 66 / 6T, a PA 6I / 6T, MPMDT / 6T PA, PA1 1 / 10T PA, PA 1 1 / 6T / 10T PA, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T.

10. Impregnated fibrous material according to one of claims 1 to 9, characterized in that said at least one reactive thermoplastic prepolymer has a glass transition temperature Tg≥80 ° C, preferably≥100 ° C, in particular≥120 ° C, especially≥ 140 ° C, or a melting temperature Tf≥150 ° C.

1 1. Impregnated fibrous material according to one of claims 1 to 10, characterized in that said fibrous material comprises continuous fibers selected from carbon fibers, glass, silicon carbide, basalt, silica, natural fibers in particular flax or hemp, lignin, bamboo, sisal, silk, or cellulosic, in particular viscose, or amorphous thermoplastic fibers with a glass transition temperature Tg greater than the Tg of said prepolymer or prepolymer mixture when the latter is amorphous or superior to Tf said prepolymer or said prepolymer mixture when the latter is semi-crystalline, or the semi-crystalline thermoplastic fibers having a melting temperature Tf greater than the Tg of said prepolymer or said prepolymer mixture when the latter is amorphous or higher than the Tf of said prepolymer or said mixture of prepolymers when the latter is semi-crystalline, or a mixture of two or more of said fibers, preferably a mixture of carbon fibers, glass or silicon carbide, in particular carbon fibers.

Impregnated fibrous material according to one of claims 1 to 1 1, characterized in that said thermoplastic prepolymer further comprises carbonaceous fillers, in particular carbon black or carbon nanofillers, preferably chosen from carbon nanofillers, in particular particularly graphene and / or carbon nanotubes and / or carbon nanofibrils or mixtures thereof. Impregnated fibrous material according to one of claims 1 to 12, characterized in that said thermoplastic prepolymer further comprises liquid crystal polymers or cyclized poly (butylene terephthalate), or mixtures containing said liquid crystal polymers or said poly (butylene terephthalate) cyclized as additives.

14. Use of an impregnated fibrous material, as defined in one of claims 1 to 13, for the preparation of an impregnated fibrous material comprising a fibrous material made of continuous fibers and at least one non-reactive thermoplastic polymer whose molecular weight number average Mn is greater than 10000, preferably in a range from 10000 to 40000, preferably from 12000 to 30000.

15. Use of a fibrous material as defined in one of claims 1 to 13, for the preparation of calibrated ribbons suitable for the manufacture of composite parts in three dimensions, by automatic removal of said ribbons by means of a robot.

16. Tape comprising at least one fibrous material as defined in one of claims 1 to 13. 17. Tape according to claim 16, characterized in that it is made of a single unidirectional tape or a plurality of parallel ribbons. unidirectional.

18. Tape according to one of claims 16 or 17, characterized in that it has a width (I) and a thickness (ep) adapted to robot removal in the manufacture of parts in three dimensions, without the need for slitting , and preferably has a width (I) of at least 5 mm and up to 400 mm, preferably between 5 and 50 mm and even more preferably between 5 and 20 mm.

19. Tape according to one of claims 16 to 18, characterized in that the thermoplastic prepolymer is a polyamide prepolymer chosen from in particular an aliphatic polyamide such as PA 6, PA 1 1, PA 12, PA 66, PA 46, PA 610 , PA 612, PA 1010, PA-1012, PA 1 1/1010 and PA12 / 1010, a semi-aromatic polyamide selected from PA

1 1 / 10T, PA 1 1 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T and PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA MXD6 and PA MXD10, PEKK and PEI or a mixture PEKK and PEI. 20. Use of a tape, as defined in one of claims 16 to 19, in the manufacture of composite parts in three dimensions.

21. Use according to claim 20, characterized in that said manufacture of said composite parts concerns the fields of transport, in particular automobile, oil and gas, in particular offshore, gas storage, aeronautical, nautical, rail; renewable energy, in particular wind turbine, tidal turbine, energy storage devices, solar panels; thermal protection panels; sports and recreation, health and medical and electronics.

22. Three-dimensional composite part, characterized in that it results from the use of at least one unidirectional tape of preimpregnated fibrous material as defined in one of claims 16 to 19.