Liquid composition comprising wax compound, its process of polymerization, use and material or composition obtained following polymerization of composition

Abstract

To provide a liquid composition comprising a (meth)acrylic monomer, which reduces evaporation of the (meth)acrylic monomer.SOLUTION: A liquid composition LC1 comprises, a) a (meth)acrylic polymer (P1), b) a (meth)acrylic monomer (M1), and c) a wax compound (W), the liquid composition having a dynamic viscosity of between 10 mPa s and 10,000 mPa s at 25°C.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a liquid composition comprising a monomer, a (meth)acrylic polymer, and a wax compound.

[0002] The present invention particularly relates to a liquid composition comprising a monomer, a (meth)acrylic polymer and a wax compound. This liquid composition can be used as a sizing agent, particularly as a sizing agent for impregnating fibers or fibrous materials. It also relates to the thermoplastic material obtained after polymerization of the liquid composition. The present invention also relates to a method for producing such a liquid composition. The present invention also relates to a method for impregnating a fibrous substrate of long fibers or continuous fibers with the liquid composition. The present invention also relates to a fibrous substrate impregnated with the liquid composition, which is useful for producing composite parts.

[0003] The present invention also relates to a method for producing a machine part or structural element made of a composite material, and a machine part or structural element made of a composite material obtained by a method of using such a liquid composition.

Background Art

[0004] Thermoplastic polymers are materials that are widely used today in several fields and applications, for example, as part of machine parts in the fields of construction, aviation, automotive, or railway.

[0005] These machine parts that must withstand high stresses during use are widely manufactured from composite materials. A composite material is a macroscopic combination of two or more immiscible materials. A composite material consists of at least one material that forms a matrix, i.e., a continuous phase that ensures the bonding of the structure and the reinforcing material.

[0006] The purpose of using composite materials is to obtain performance qualities that are not achievable from each of their components when used separately. Thus, composite materials are widely used in various industrial fields, such as buildings, automobiles, aerospace, transportation, leisure, electronics, and sports, because of their particularly superior mechanical properties (higher tensile strength, higher tensile modulus, higher fracture toughness) compared to homogeneous materials and their lower density.

[0007] In order to enable thermoforming and recycling, it is preferable to also use thermoplastic polymers in composite materials, which are incompatible with thermosetting polymers.

[0008] Thermoplastic polymers usually consist of linear or branched polymers that are not cross-linked. Thermoplastic polymers are heated to mix the components required for the production of composite materials and cooled to fix the final form. The problem with these molten thermoplastic polymers is, for example, that their viscosity in the molten state is very high for uniformly impregnating a fiber substrate. Wetting or proper impregnation of the fibers with a thermoplastic polymer can only be achieved when the thermoplastic resin is sufficiently fluid. It is necessary to reduce the chain length or molecular weight in order to lower the viscosity of the thermoplastic polymer or give it sufficient fluidity. However, if the molecular weight is too low, it will have an adverse effect on the performance of the composite material and the mechanical properties of mechanical or structural parts, particularly the coefficient of deformation.

[0009] To prepare polymer composite materials based on thermoplastic polymers, a thermoplastic polymer resin, generally known as a "syrup agent", is used to impregnate a reinforcing material, such as a fiber substrate. Once polymerized, the syrup agent of the thermoplastic polymer constitutes the matrix of the composite material.

[0010] Another way to reduce the viscosity of thermoplastic polymers, which is an important method, is to increase the temperature. As a result, the continuous working temperature is relatively high, exceeding 200 °C, and due to the influence of high energy costs, the economic costs of composite materials and mechanical or structural parts increase. Furthermore, thermoplastic polymers tend to deteriorate when the temperature is too high, which is particularly true for semi-crystalline thermoplastic polymers with high melting points such as polyamides like PA6.6, polyethersulfone (PES), polyetherimide (PEI), polyetheretherketone (PEEK) or polyphenylene sulfide (PPS). This heat-induced decomposition leads to a decrease in the molecular weight of the polymer matrix on the fiber substrate, which is important for the bonding of composite materials and mechanical or structural parts.

[0011] Another way to impregnate the fiber substrate is to dissolve the thermoplastic polymer in an organic solvent. However, this method requires a large amount of solvent that has to be evaporated. From the perspective of energy and pollution, there are environmental problems associated with using a large amount of solvent.

[0012] Yet another way to impregnate the fiber substrate is to use each monomer for impregnation and polymerize to form the thermoplastic polymer after impregnation. However, this method usually uses monomers that partially evaporate or may have an unpleasant odor. This is particularly problematic when impregnation is carried out in an open impregnation method in contact with the environment or air. Furthermore, there are also environmental problems when using specific monomers in an open environment.

[0013] When preparing a polymer composite material during impregnation, the viscosity of the impregnating syrup must be controlled and adapted so that each fiber of the fiber substrate is properly impregnated, without flowing too much or being too viscous. When wetting is partial, depending on whether the syrup flows too much or is too viscous, a "naked" zone, i.e., a non-impregnated zone, and a zone where polymer droplets that cause the generation of bubbles are formed on the fibers appear respectively. These "naked" zones and these bubbles cause the appearance of defects in the final composite material, which in particular cause a loss of the mechanical strength of the final composite material. Furthermore, the evaporation of the monomer affects the viscosity.

[0014] One object of the present invention is to propose a liquid composition containing a (meth)acrylic monomer, which is to reduce the evaporation of the (meth)acrylic monomer.

[0015] (Meth)acrylic monomer-containing liquid compositions or syrups containing (meth)acrylic polymers are described in WO2013 / 056845 and WO2014 / 013028. In neither of these documents is a wax compound used, and when the composition is used in an open mold or outdoors, part of the (meth)acrylic monomer evaporates, changing the weight ratio and further the viscosity in the composition.

[0016] Document WO2015 / 110534 discloses a liquid (meth)acrylic syrup. This syrup contains specific (meth)acrylic monomers with high boiling points and low vapor pressures to prevent their evaporation. The impregnation method requires these specific monomers, which may be more expensive and reduces the choice of monomers in this method.

[0017] None of these documents suggest that incorporating a wax compound into the liquid composition significantly reduces the evaporation of the monomer. SUMMARY OF THE INVENTION

[0018] Accordingly, an object of the present invention is to improve at least one of the drawbacks of the prior art.

[0019] One object of the present invention is to propose a liquid composition containing a (meth)acrylic monomer with reduced evaporation of the (meth)acrylic monomer. By reducing evaporation, it is understood that less than 20% by weight, preferably less than 10% by weight, more preferably less than 5% by weight, and advantageously less than 2% by weight of the (meth)acrylic monomer evaporates. Evaporation is observed at 23 °C for 20 minutes.

[0020] Another object of the present invention is also to obtain a liquid composition containing a (meth)acrylic monomer and a (meth)acrylic polymer with reduced evaporation of the (meth)acrylic monomer and capable of polymerizing with a high conversion rate quickly and well. A high conversion rate means that at least 95% of the monomer is polymerized.

[0021] Another object of the present invention is also to obtain a method for polymerizing a liquid composition containing a (meth)acrylic monomer and a (meth)acrylic polymer with a high conversion rate while reducing the evaporation of the (meth)acrylic monomer.

[0022] Yet another object of the present invention is to use a liquid composition containing a (meth)acrylic monomer and a (meth)acrylic polymer for impregnating a fibrous substrate, with reduced evaporation of the (meth)acrylic monomer.

[0023] Surprisingly, a) a (meth)acrylic polymer (P1), b) a (meth)acrylic monomer (M1), and c) a wax compound (W) A liquid composition LC1 containing the same, wherein the liquid composition LC1 having a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C results in a liquid composition with reduced evaporation of the (meth)acrylic monomer (M1) as compared to a composition not containing the wax compound (W).

[0024] Furthermore, a) a (meth)acrylic polymer (P1), b) a (meth)acrylic monomer (M1), and c) a wax compound (W) A liquid composition LC1 containing the same, wherein the liquid composition LC1 having a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C can be used to produce a thermoplastic composite polymer composition after polymerization of the (meth)acrylic monomer (M1), and it was also found that the conversion rate of the thermoplastic polymer composition is good.

[0025] Similarly, a liquid composition LC1 or a liquid (meth)acrylic composition LC1 for impregnating a fiber substrate, wherein the fiber substrate is made of long fibers or continuous fibers, and the composition a) a (meth)acrylic polymer (P1), b) a (meth)acrylic monomer (M1), and c) a wax compound (W) characterized by containing the same, and the liquid composition LC1 or the liquid (meth)acrylic syrup agent has a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C. The liquid composition LC1 or the liquid (meth)acrylic composition LC1 can be used as an impregnating liquid composition with reduced evaporation of the (meth)acrylic monomer (M1) as compared to a composition not containing the wax compound (W).

[0026] Also, surprisingly, a method for impregnating a fiber substrate, comprising the following steps: i) applying to the fiber substrate a) a (meth)acrylic polymer (P1), b) (Meth)acrylic monomer (M1), and c) wax compound (W) By a method including the step of impregnating such a liquid composition LC1 or a (meth)acrylic syrup agent containing the wax compound (W), it was found that an impregnated fiber substrate with reduced evaporation of the (meth)acrylic monomer (M1) compared to a composition not containing the wax compound (W) can be obtained.

[0027] Also, surprisingly, a method for manufacturing a composite part, comprising the following steps: i) On a fiber substrate a) (Meth)acrylic polymer (P1), b) (Meth)acrylic monomer (M1), and c) wax compound (W) impregnating such a liquid composition LC1 or a (meth)acrylic syrup agent containing the wax compound (W), and ii) a step of polymerizing By a method including the steps, it was found that an impregnated fiber substrate with reduced evaporation of the (meth)acrylic monomer (M1) compared to a composition not containing the wax compound (W) can be obtained.

DETAILED DESCRIPTION OF THE INVENTION

[0028] According to a first aspect, the present invention relates to a) (Meth)acrylic polymer (P1), b) (Meth)acrylic monomer (M1), and c) wax compound (W) A liquid composition LC1 having a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C.

[0029] According to a second aspect, the present invention relates to a liquid composition LC1 for impregnating a fiber substrate, wherein the fiber substrate is made of long fibers, and the liquid composition LC1 is a) (Meth)acrylic polymer (P1), b) (Meth)acrylic monomer (M1), and c) Wax compound (W) and the liquid composition LC1 or the liquid (meth)acrylic syrup agent has a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C, relating to the liquid composition LC1.

[0030] According to a third aspect, the present invention is a method for preparing a liquid composition LC1, wherein the liquid composition LC1 a) (meth)acrylic polymer (P1), b) (meth)acrylic monomer (M1), and c) Wax compound (W) and the liquid composition LC1 or the liquid (meth)acrylic syrup agent has a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C, and the liquid composition LC1 comprises the following steps: i) A step of preparing a liquid mixture of (meth)acrylic polymer (P1) and (meth)acrylic monomer (M1), ii) A step of adding the wax compound (W) to the mixture prepared in the previous step and is prepared by a method comprising the above steps, relating to the method.

[0031] According to a fourth aspect, the present invention is the use of the liquid composition LC1 for impregnating a fiber substrate, wherein the fiber substrate is made of long fibers, and the liquid composition LC1 a) (meth)acrylic polymer (P1), b) (meth)acrylic monomer (M1), and c) Wax compound (W) and the liquid composition LC1 or the liquid (meth)acrylic syrup agent has a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C, relating to the use.

[0032] According to a fifth aspect, the present invention is the use of the liquid composition LC1 for manufacturing a thermoplastic part or for manufacturing a composite part, wherein the liquid composition LC1 a) (Meth)acrylic polymer (P1), b) (Meth)acrylic monomer (M1), and c) wax compound (W) The liquid composition LC1 or the liquid (meth)acrylic syrup agent contains the above components, and is characterized in that it has a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C, which relates to use.

[0033] According to a sixth aspect, the present invention is a method for manufacturing a thermoplastic composite part, comprising the following steps: i) preparing a liquid mixture of (meth)acrylic polymer (P1) and (meth)acrylic monomer (M1); ii) adding wax compound (W) to the mixture prepared in the previous step; iii) putting the liquid (meth)acrylic composition or liquid composition LC1 prepared in i) and ii) into a polymerization means, wherein the composition contains: a) (meth)acrylic polymer (P1), b) (meth)acrylic monomer (M1), c) wax compound (W) and d) initiator (Ini) The liquid composition LC1 or the liquid (meth)acrylic syrup agent contains the above components, and is characterized in that it has a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C, which is a step; iv) a step of polymerizing relates to a method according to a method comprising the above steps.

[0034] According to a seventh aspect, the present invention is a method for manufacturing a composite part, comprising the following steps: i) preparing a mixture of (meth)acrylic polymer (P1), (meth)acrylic monomer (M1) and wax compound (W); ii) adding initiator (Ini) to the mixture prepared in the previous step; iii) impregnating a fiber or a fiber substrate with the liquid (meth)acrylic composition or liquid composition LC1 prepared in i) and ii), wherein the composition contains: a) (Meth)acrylic polymer (P1), b) (Meth)acrylic monomer (M1), c) wax compound (W) and d) initiator (Ini) comprising, wherein the liquid (meth)acrylic syrup agent or liquid composition LC1 has a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C, a process, iv) a step of polymerizing relates to a method by a method comprising.

[0035] The term "fiber substrate" used refers to several fibers, unidirectional rovings, continuous filament mats, fabrics, felts or non-woven fabrics, which may be in the form of strips, wraps, blades, locks, or pieces.

[0036] The term "(meth)acrylic" used refers to any type of acrylic monomer or methacrylic monomer.

[0037] The term "PMMA" used refers to homopolymers and copolymers of methyl methacrylate (MMA), and the weight ratio of MMA in PMMA is at least 70% by weight for MMA copolymers.

[0038] The term "monomer" used refers to a molecule that can undergo polymerization.

[0039] The term "polymerization" used refers to a method of converting a monomer or a mixture of monomers into a polymer.

[0040] The term "thermoplastic polymer" used refers to a polymer that changes to a liquid when heated, or becomes more fluid or has a lower viscosity and is softer, and can take on a new form by the application of heat and pressure. This also applies to slightly cross-linked thermoplastic polymers that can be thermoformed when heated above the softening temperature.

[0041] The term "polymer composite material" as used herein refers to a multi-component material that includes several different phase domains, wherein at least one type of phase domain is a continuous phase and at least one component is a polymer.

[0042] The term "initiator" as used herein refers to a compound that can initiate / induce the polymerization of one or more monomers.

[0043] The abbreviation "phr" means parts by weight per 100 parts of the composition. For example, 1 phr of a compound in a composition means that 1 kg of that compound is added to 100 kg of the composition.

[0044] The abbreviation "ppm" means parts by weight per million parts of the composition. For example, 1000 ppm of a compound in a composition means that 0.1 kg of the compound is present in 100 kg of the composition.

[0045] When referring to a range from x to y in the present invention, the upper and lower limits of this range are included and are at least x and at most synonymous with y.

[0046] When referring to a range between x and y in the present invention, it means that the upper and lower limits of this range are not included and are synonymous with greater than x and less than y.

[0047] The liquid composition LC1 or the liquid (meth)acrylic syrup agent according to the present invention comprises a (meth)acrylic monomer (M1) or a mixture of a (meth)acrylic monomer (M1) and (M1 + x), a (meth)acrylic polymer (P1), and a wax compound (W). The expressions "liquid composition LC1" or "liquid (meth)acrylic syrup agent" or "(meth)acrylic syrup agent" or "liquid (meth)acrylic composition" are used as synonyms throughout this text, and said composition or syrup agent comprises at least three essential compounds: a) a (meth)acrylic polymer (P1), b) a (meth)acrylic monomer (M1), and c) a wax compound (W).

[0048] The dynamic viscosity of the liquid composition LC1 or the (meth)acrylic syrup agent ranges from 10 mPa·s to 10000 mPa·s, preferably from 20 mPa·s to 7000 mPa·s, advantageously from 20 mPa·s to 5000 mPa·s, more advantageously from 20 mPa·s to 2000 mPa·s, even more advantageously between 20 mPa·s and 1000 mPa·s, still even more advantageously between 25 mPa·s and 1000 mPa·s, and most advantageously between 30 mPa·s and 1000 mPa·s. The viscosity of the syrup agent can be easily measured with a rheometer or viscometer. The dynamic viscosity is measured at 25°C. When the liquid (meth)acrylic syrup agent exhibits Newtonian behavior and has no shear thinning viscosity, the dynamic viscosity does not depend on the shear of the rheometer or the speed of the moving device of the viscometer. When the liquid composition exhibits non-Newtonian behavior, i.e., shear thinning viscosity, the dynamic viscosity is measured at a shear rate of 1 s -1 at 25°C.

[0049] The liquid composition LC1 or the (meth)acrylic syrup agent according to the present invention contains, in particular, a (meth)acrylic monomer (M1) or a mixture of a plurality of (meth)acrylic monomers, a (meth)acrylic polymer (P1), and a wax compound (W) for impregnating a fiber substrate.

[0050] The amount of the wax compound (W) in the liquid composition LC1 is at least 0.1 phr based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1). Preferably, the amount of the wax compound (W) in the composition is at least 0.15 phr, more preferably at least 0.2 phr, even more preferably at least 0.25 phr, advantageously at least 0.3 phr, more advantageously at least 0.4 phr, still more advantageously at least 0.5 phr, even still more advantageously at least 0.55 phr, and most advantageously at least 0.59 phr based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

[0051] The amount of the wax compound (W) in the composition is at most 2 phr based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1). Preferably, the amount of the wax compound (W) in the composition is at most 1.8 phr, more preferably at most 1.5 phr, even more preferably at most 1.3 phr, and advantageously at most 1.2 phr, based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

[0052] Preferably, the amount of the wax compound (W) in the liquid composition LC1 is between 0.1 phr and 2 phr based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

[0053] More preferably, the amount of the wax compound (W) in the liquid composition LC1 is between 0.15 phr and 1.9 phr, even more preferably between 0.2 phr and 1.8 phr, still more preferably between 0.25 phr and 1.7 phr, advantageously between 0.3 phr and 1.6 phr, more advantageously between 0.4 phr and 1.5 phr, even more advantageously between 0.45 phr and 1.4 phr, still more advantageously between 0.5 phr and 1.3 phr, yet still more advantageously between 0.55 phr and 1.3 phr, and most advantageously between 0.59 phr and 1.3 phr, based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

[0054] Regarding the liquid composition LC1 of the present invention, this composition contains a (meth)acrylic monomer (M1), a (meth)acrylic polymer (P1), and a wax compound (W). Once polymerized, the (meth)acrylic monomer (M1) is converted into a (meth)acrylic polymer (P2) containing the monomer units of the (meth)acrylic monomer (M1). In a modified example, a mixture of once-polymerized (meth)acrylic monomers is converted into a (meth)acrylic copolymer containing the monomer units of each (meth)acrylic monomer.

[0055] Regarding the (meth)acrylic monomer (M1), the monomer is selected from acrylic acid, methacrylic acid, alkyl acrylate monomers, alkyl methacrylate monomers, hydroxyalkyl acrylate monomers and hydroxyalkyl methacrylate monomers, and mixtures thereof.

[0056] Preferably, the (meth)acrylic monomer (M1) is selected from acrylic acid, methacrylic acid, hydroxyalkyl acrylate monomers, hydroxyalkyl methacrylate monomers, alkyl acrylate monomers, alkyl methacrylate monomers and mixtures thereof, the alkyl group contains 1 to 22 linear, branched or cyclic carbons, and the alkyl group preferably contains 1 to 12 linear, branched or cyclic carbons.

[0057] Advantageously, the (meth)acrylic monomer (M1) is selected from methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, methacrylic acid, acrylic acid, n-butyl acrylate, isobutyl acrylate, n-butyl methacrylate, isobutyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, hydroxyethyl acrylate and hydroxyethyl methacrylate, and mixtures thereof.

[0058] According to a preferred embodiment, at least 50% by weight, preferably at least 60% by weight of the (meth)acrylic monomer (M1) is methyl methacrylate.

[0059] According to a first more preferred embodiment, at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, advantageously at least 80% by weight, even more advantageously 90% by weight of the monomer (M1) is a mixture of methyl methacrylate and optionally at least one other monomer.

[0060] According to a second more preferred embodiment, the liquid composition or (meth)acrylic syrup agent contains a monomer (M2) between 0.01 and 10 phr by weight, based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1), and the (meth)acrylic monomer (M2) contains at least two (meth)acrylic functional groups, and preferably contains the (meth)acrylic monomer (M2) between 0.1 and 5 phr by weight.

[0061] The (meth)acrylic monomer (M2) can be selected from ethylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, or a mixture thereof.

[0062] Examples of the (meth)acrylic polymer (P1) include polyalkyl methacrylate or polyalkyl acrylate. According to a preferred embodiment, the (meth)acrylic polymer is polymethyl methacrylate (PMMA).

[0063] The term "PMMA" means a methyl methacrylate (MMA) homopolymer or copolymer, or a mixture thereof.

[0064] According to one embodiment, the methyl methacrylate (MMA) homopolymer or copolymer contains at least 70% by weight, preferably at least 80% by weight, advantageously at least 90% by weight, more advantageously at least 95% by weight of methyl methacrylate.

[0065] According to another embodiment, PMMA is a mixture of at least one homopolymer and at least one copolymer of MMA, or a mixture of at least two homopolymers or two copolymers of MMA having different average molecular weights, or a mixture of at least two copolymers of MMA having different monomer compositions.

[0066] The copolymer of methyl methacrylate (MMA) contains 70% to 99.9% by weight of methyl methacrylate and 0.1% to 30% by weight of at least one monomer containing at least one ethylenically unsaturated group copolymerizable with methyl methacrylate.

[0067] These monomers are well-known, and particularly include acrylic acid, methacrylic acid, and alkyl (meth) acrylates in which the alkyl group contains 1 to 12 carbon atoms. By way of example, methyl acrylate and ethyl (meth) acrylate, butyl (meth) acrylate or 2-ethylhexyl (meth) acrylate can be mentioned. Preferably, the comonomer is an alkyl acrylate in which the alkyl group contains 1 to 4 carbon atoms.

[0068] According to a first preferred embodiment, the copolymer of methyl methacrylate (MMA) contains from 80% to 99.9% by weight, advantageously from 90% to 99.9% by weight, more advantageously from 90% to 99.9% by weight of methyl methacrylate and from 0.1% to 20% by weight, advantageously from 0.1% to 10% by weight, more advantageously from 0.1% to 10% by weight of at least one monomer containing at least one ethylenically unsaturated group copolymerizable with methyl methacrylate. Preferably, the comonomer is selected from methyl acrylate and ethyl acrylate, and mixtures thereof.

[0069] It is desirable that the weight average molecular weight of the (meth) acrylic polymer (P1) is high, which means exceeding 50,000 g / mol, preferably exceeding 100,000 g / mol.

[0070] The weight average molecular weight can be measured by size exclusion chromatography (SEC).

[0071] (Meth)acrylic polymers are completely soluble in (meth)acrylic monomers or mixtures of (meth)acrylic monomers. This can increase the viscosity of the (meth)acrylic monomer or mixture of (meth)acrylic monomers. The resulting solution is generally called a "syrup agent" or a "prepolymer". The dynamic viscosity value of the liquid (meth)acrylic syrup agent is between 10 mPa·s and 10,000 mPa·s. The viscosity of the syrup agent can be easily measured with a rheometer or a viscometer. The dynamic viscosity is measured at 25°C.

[0072] Advantageously, the liquid (meth)acrylic syrup agent does not contain any optionally added extra solvent.

[0073] Regarding the liquid composition LC1 of the present invention, this composition contains a wax compound (W) which is a low melting point wax.

[0074] The wax compound (W) may be single or a mixture of wax compounds as long as the mixture has a melting point given below.

[0075] The melting point of the wax compound (W1) is expressed as the freezing point. The melting point is evaluated or measured as the freezing point according to ASTM D938. Preferably, the freezing point of the wax compound (W) is less than 85°C. More preferably, the melting point of the wax compound (W1) is less than 80°C, still more preferably less than 75°C, even still more preferably less than 70°C, advantageously less than 65°C, more advantageously less than 60°C.

[0076] More preferably, the freezing point of the wax compound (W) exceeds 15°C. Still more preferably, the freezing point of the wax compound (W) exceeds 20°C, even still more preferably exceeds 21°C, even still more preferably exceeds 22°C, advantageously exceeds 24°C, more advantageously exceeds 25°C.

[0077] More preferably, the freezing point of the wax compound (W) is between 15°C and 85°C. Still more preferably, the freezing point of the wax is between 20°C and 80°C, even still more preferably between 21°C and 75°C, even still more preferably between 22°C and 70°C, advantageously between 24°C and 65°C, and more advantageously between 25°C and 60°C.

[0078] The density of the wax compound (W) is lower than the combined density of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1). The combined density of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1) means a composition consisting of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1). One of the components itself may have a density lower than that of the wax compound (W) alone, but the composition of both components together has a density exceeding that of the wax compound (W).

[0079] More preferably, the wax compound (W) has a density of less than 1.1 g / cm 3 More preferably, the density of the wax compound (W) is less than 1.05 g / cm 3 and still more preferably less than 1.02 g / cm 3 and even still more preferably less than 1.0 g / cm 3 and advantageously less than 0.99 g / cm 3 and more advantageously less than 0.98 g / cm 3 and less than 0.98 g / cm.

[0080] More preferably, the wax compound (W) has a density exceeding 0.7 g / cm 3 Still more preferably, the density of the wax (W) exceeds 0.72 g / cm 3 and even still more preferably exceeds 0.75 g / cm 3 and even still more preferably exceeds 0.78 g / cm 3 and even still more preferably exceeds 0.8 g / cm 3exceeds, more preferably 0.85 g / cm 3 exceeds.

[0081] More preferably, the density of the wax compound (W) is 0.7 g / cm 3 and 1.1 g / cm 3 in between. Still more preferably, the density of the wax compound (W) is 0.72 g / cm 3 and 1.05 g / cm 3 in between, and even still more preferably 0.75 g / cm 3 and 1.02 g / cm 3 in between, and even still more preferably 0.78 g / cm 3 and 1.0 g / cm 3 in between, preferably 0.8 g / cm 3 and 0.99 g / cm 3 in between, more preferably 0.85 g / cm 3 and 0.98 g / cm 3 in between.

[0082] Regarding the wax compound (W), this compound can be made of natural wax or synthetic wax, or a blend mixture of both.

[0083] The wax compound (W1) can be made of natural wax or synthetic wax, or a blend mixture of both, as long as it has the required freezing point and density defined previously.

[0084] Useful natural waxes can include plant waxes, animal waxes, and mixtures thereof, and can also be mineral waxes such as petroleum wax or lignite wax, peat wax or montan wax.

[0085] Useful synthetic waxes can particularly include synthetic waxes such as fatty acid amides and mixtures thereof, and can also be fully synthetic waxes such as polyolefin wax or Fischer-Tropsch wax, or polar synthetic waxes.

[0086] Since the wax compound (W) can be a mixture, the melting point may be a range rather than a single peak or point. However, the melting range is below, above, or within the indicated temperature.

[0087] Optionally, the liquid composition additionally comprises d) an initiator (Ini).

[0088] The amount of the initiator (Ini) in the composition is at least 0.1 phr based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1). Preferably, the amount of the initiator (Ini) in the composition is at least 0.2 phr, more preferably at least 0.5 phr, even more preferably at least 0.75 phr, and advantageously at least 1 phr based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

[0089] The amount of the initiator (Ini) in the composition is at most 15 phr based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1). Preferably, the amount of the initiator (Ini) in the composition is at most 12 phr, more preferably at most 10 phr, even more preferably at most 8 phr, and advantageously at most 5 phr based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

[0090] The amount of the initiator (Ini) in the composition is between 0.1 phr and 15 phr based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1). Preferably, the amount of the initiator (Ini) in the composition is between 0.2 phr and 12 phr, more preferably between 0.5 phr and 10 phr, even more preferably between 0.75 phr and 8 phr, and advantageously between 1 phr and 5 phr based on the total of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

[0091] Regarding the initiator (Ini), the initiator generates radicals that induce one or more monomers to initiate radical polymerization of the monomers in order to form polymer chains through a growth reaction.

[0092] Preferably, the initiator (Ini) is activated by heat.

[0093] The heat-activated initiator (Ini) is preferably a radical initiator.

[0094] The radical initiator (Ini) can be selected from peroxy group-containing compounds or azo group-containing compounds, preferably from peroxy group-containing compounds or mixtures thereof.

[0095] Preferably, the peroxy group-containing compound contains 2 to 30 carbon atoms.

[0096] Preferably, the peroxy group-containing compound is selected from diacyl peroxides, peroxy esters, peroxydicarbonates, dialkyl peroxides, peroxyacetals, hydroperoxides or peroxyketals.

[0097] More preferably, the initiator (Ini) is diisobutyryl peroxide, cumyl peroxy neodecanoate, di(3-methoxybutyl) peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxy neodecanoate, cumyl peroxy neoheptanoate, di-n-propyl peroxydicarbonate, tert-amyl peroxy neodecanoate, di-sec-butyl peroxydicarbonate, diisopropyl peroxydicarbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate, di-(2-ethylhexyl)-peroxydicarbonate, tert-amyl peroxy neodecanoate, tert-butyl peroxy neodecanoate, di-n-butyl peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxy pivalate, tert-butyl peroxy neoheptanoate, tert-amyl peroxy pivalate, tert-butyl peroxy pivalate, di-(3,5,5-trimethylhexanoyl)-peroxide, dilauroyl peroxide, didecanoyl peroxide, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)-hexane, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, dibenzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy diethylacetate, tert-butyl peroxyisobutyrate, 1,1-di-(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(tert-amylperoxy)cyclohexane, 1,1-di-(tert-butylperoxy)-cyclohexane, tert-amyl peroxy-2-ethylhexyl carbonate, tert-amyl peroxyacetate, tert-butyl peroxy-3,5,5-trimethylhexanoate, 2,Selected from 2,2 - di-(tert - butylperoxy)-butane, tert - butylperoxyisopropyl carbonate, tert - butylperoxy - 2 - ethylhexyl carbonate, tert - amylperoxybenzoate, tert - butylperoxyacetate, butyl 4,4 - di(tert - butylperoxy)valerate, tert - butylperoxybenzoate, di - tert - amyl peroxide, dicumyl peroxide, di-(2 - tert - butyl - peroxyisopropyl)-benzene, 2,5 - dimethyl - 2,5 - di(tert - butylperoxy)-hexane, tert - butylcumyl peroxide, 2,5 - dimethyl - 2,5 - di(tert - butylperoxy)hexine - 3, di - tert - butyl peroxide, 3,6,9 - triethyl - 3,6,9 - trimethyl - 1,4,7 - triperoxonan, 2,2’ - azobisisobutyronitrile (AIBN), 2,2’ - azodi-(2 - methylbutyronitrile), azobisisobutyramide, 2,2’ - azobis(2,4 - dimethylvaleronitrile), 1,1’ - azodi(hexahydrobenzonitrile) or 4,4’ - azobis(4 - cyanopentanoic acid) and mixtures thereof.,

[0098] To maintain the dynamic viscosity of the liquid composition LC1 or the (meth)acrylic syrup agent, and further to enable good impregnation of the fibrous substrate if necessary, and to maintain the thermoplastic properties of the matrix obtained after polymerization of the fibrous substrate pre - impregnated with the syrup agent, the compounds of the syrup agent are incorporated in the following mass percentages.,

[0099] The (meth)acrylic monomer(s) (M1) in the liquid composition LC1 or the (meth)acrylic syrup agent is / are present in a proportion between 40% by weight and 90% by weight, preferably between 45% by weight and 85% by weight, more preferably between 50% by weight and 85% by weight, still more preferably between 60% by weight and 85% by weight, and advantageously between 65% by weight and 85% by weight, of the composition comprising the (meth)acrylic monomer(s) (M1) or one or more (meth)acrylic monomers (M1) and the (meth)acrylic polymer (P1).

[0100] The (meth)acrylic polymer(s) (P1) in the liquid composition LC1 or the (meth)acrylic syrup agent is / are present in a proportion of at least 1% by weight, preferably at least 5% by weight, and advantageously at least 10% by weight, of the composition comprising one or more (meth)acrylic monomers (M1) and the (meth)acrylic polymer (P1).

[0101] The (meth)acrylic polymer(s) (P1) in the liquid composition LC1 or the liquid (meth)acrylic syrup agent is / are present in a proportion of 50% by weight or less, preferably 40% by weight or less, still more preferably 35% by weight or less, and advantageously 30% by weight or less, of the composition comprising the (meth)acrylic monomer(s) (M1) or one or more (meth)acrylic monomers (M1) and the (meth)acrylic polymer (P1).

[0102] Preferably, the (meth)acrylic polymer (P1) or one or more (meth)acrylic polymers (P1) in the liquid composition LC1 or the liquid (meth)acrylic syrup agent are present in a proportion between 10% by weight and 60% by weight, preferably between 15% by weight and 55% by weight, more preferably between 15% by weight and 50% by weight, still more preferably between 15% by weight and 40% by weight, and advantageously between 15% by weight and 35% by weight, of the composition comprising the (meth)acrylic monomer (M1) or one or more (meth)acrylic monomers (M1) and the (meth)acrylic polymer (P1).

[0103] The composition comprising the (meth)acrylic monomer (M1) or one or more (meth)acrylic monomers (M1) and the (meth)acrylic polymer (P1) is a liquid mixture comprising the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1) prepared by each method of the present invention. In the composition comprising the (meth)acrylic monomer (M1) or one or more (meth)acrylic monomers (M1) and the (meth)acrylic polymer (P1), the two compounds together amount to 100% by weight, which can be regarded as 100 parts by weight, and the amounts of the wax compound (W) and other additives are calculated based thereon.

[0104] All optional additives and fillers are added to the liquid (meth)acrylic syrup agent before impregnation and / or polymerization.

[0105] Regarding the method for producing the liquid composition LC1 or the (meth)acrylic syrup agent, the first step consists of preparing a first syrup agent comprising a mixture of the (meth)acrylic monomer (M1) or a plurality of (meth)acrylic monomers and the (meth)acrylic polymer (P1).

[0106] The wax compound (W) is added to the composition prepared in the first step.

[0107] In order to maintain a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C, if necessary, an initiator (Ini) is added to the syrup agent at the above-mentioned ratio.

[0108] Preferably, the initiator (Ini) is added at a temperature T add below 50°C, more preferably below 40°C, advantageously below 30°C, and even more advantageously below 25°C.

[0109] The liquid composition according to the invention detailed in the previous paragraph can be used for impregnating a fiber or a fiber substrate, or for manufacturing a thermoplastic part, or for manufacturing a composite part.

[0110] Regarding a method for impregnating a fiber or a fiber substrate, the method includes a step of impregnating the fiber substrate with the liquid composition LC1 or the (meth)acrylic syrup agent.

[0111] This impregnation step can be carried out in a mold or a tank.

[0112] If the viscosity of the liquid (meth)acrylic syrup agent at a given temperature is slightly too high for the impregnation method, it is possible to heat the syrup agent to have a more liquid syrup agent for sufficient wetting of the fiber substrate and proper and complete impregnation.

[0113] Examples of the fiber substrate may include strips, wraps, blades, locks, or several fibers in the form of pieces, unidirectional rovings, or continuous filament mats, fabrics, felts, or non-woven fabrics. The fiber material may have various forms and dimensions in any of one-dimensional, two-dimensional, or three-dimensional. The fiber substrate includes an aggregate of one or more fibers. When the fibers are continuous, these aggregates form a fabric.

[0114] The one-dimensional form corresponds to linear long fibers. The fibers may be discontinuous or continuous. The fibers can be arranged randomly or parallel to each other in the form of continuous filaments. The fibers are defined by the aspect ratio, which is the ratio of the length to the diameter of the fiber. The fibers used in the present invention are long fibers or continuous fibers. The fibers have an aspect ratio of at least 1000, preferably at least 1500, more preferably at least 2000, advantageously at least 3000, more advantageously at least 5000, even more advantageously at least 6000, more advantageously still at least 7500, and most advantageously at least 10,000.

[0115] The two-dimensional form corresponds to a non-woven or woven fiber mat or reinforcement or bundle of fibers, which can also be knitted. If the two-dimensional form has a certain thickness, then, in principle, even if it is three-dimensional, according to the present invention, this is regarded as two-dimensional.

[0116] The three-dimensional form corresponds to, for example, a non-woven fiber mat or reinforcement, or a laminated or folded bundle of fibers, or a mixture thereof, an assembly of two-dimensional forms in three dimensions.

[0117] The source of the fiber material may be natural or synthetic. Examples of natural materials include plant fibers, wood fibers, animal fibers, or mineral fibers.

[0118] Natural fibers are, for example, sisal, jute, hemp, flax, cotton, coconut fibers, and banana fibers. Animal fibers are, for example, wool or hair.

[0119] Examples of synthetic materials include polymer fibers selected from fibers of thermosetting polymers, thermoplastic polymers, or mixtures thereof.

[0120] The polymer fibers may consist of polyamide (aliphatic or aromatic), polyester, polyvinyl alcohol, polyolefin, polyurethane, polyvinyl chloride, polyethylene, unsaturated polyester, epoxy resin, and vinyl ester.

[0121] The mineral fibers can also be selected in particular from E, R or S2 type glass fibers, carbon fibers, boron fibers or silica fibers.

[0122] The fiber substrate of the present invention is selected from plant fibers, wood fibers, animal fibers, mineral fibers, synthetic polymer fibers, glass fibers and carbon fibers, and mixtures thereof.

[0123] Preferably, the fiber substrate is selected from mineral fibers.

[0124] The diameter of the fibers of the fiber substrate is between 0.005 μm and 100 μm, preferably between 1 μm and 50 μm, more preferably between 5 μm and 30 μm, and advantageously between 10 μm and 25 μm.

[0125] Preferably, the fibers of the fiber substrate of the present invention are continuous fibers for one-dimensional forms (meaning that the aspect ratio is not necessarily applicable in the case of long fibers), or long fibers or continuous fibers for two-dimensional or three-dimensional forms of the fiber substrate.

[0126] According to another additional aspect, the present invention is a polymer composite material comprising a thermoplastic (meth)acrylic matrix and a fiber substrate used as a reinforcement, wherein the fiber substrate consists of long fibers, and the composite material is obtained after polymerization of the fiber substrate pre-impregnated with the liquid composition LC1 according to the present invention or the (meth)acrylic syrup agent by the thermoplastic (meth)acrylic matrix, and relates to a polymer composite material.

[0127] Another aspect of the present invention is a method for manufacturing a mechanical part or a structural part or a product, comprising the following steps: i) Impregnating the fibrous substrate with the liquid composition LC1 or the (meth)acrylic syrup agent according to the present invention; ii) Polymerizing the liquid composition LC1 or the (meth)acrylic syrup agent impregnated in the fibrous substrate; and the method comprises the above steps.

[0128] During the polymerization process in all embodiments or aspects of the present invention, or during the manufacturing method of mechanical parts, structural parts or products, the polymerization of the liquid composition LC1 or the (meth)acrylic syrup agent impregnated in the fibrous substrate occurs at a temperature between 40°C and 140°C.

[0129] According to another additional aspect, the present invention relates to the use of the liquid composition LC1 for the manufacture of thermoplastic parts or composite parts.

[0130] According to another additional aspect, the present invention relates to the use of the liquid composition LC1 prepared by the method of the present invention for manufacturing thermoplastic parts or composite parts.

[0131] According to another additional aspect, the present invention provides a method for manufacturing a thermoplastic part, comprising the following steps: i) Preparing a liquid mixture of a (meth)acrylic polymer (P1) and a (meth)acrylic monomer (M1); ii) Adding a wax compound (W) to the mixture prepared in the previous step; iii) Placing the liquid (meth)acrylic composition or the liquid composition LC1 prepared in i) and ii) into a polymerization means, wherein the composition additionally contains d) an initiator (Ini) as described in any one of claims 1 to 10, and the liquid (meth)acrylic syrup agent or the liquid composition LC1 has a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C; iv) Polymerizing; and the method relates to a method comprising the above steps.

[0132] According to another additional aspect, the present invention is a method for manufacturing a composite part, comprising the following steps: i) preparing a mixture of a (meth)acrylic polymer (P1), a (meth)acrylic monomer (M1), and a wax compound (W); ii) adding an initiator (Ini) to the mixture prepared in the previous step; iii) impregnating a fiber or a fiber substrate with the liquid composition or liquid composition LC1 prepared in i) and ii), wherein the composition comprises a) a (meth)acrylic polymer (P1), b) a (meth)acrylic monomer (M1), c) a wax compound (W), and d) two initiators (Ini1) and (Ini2) and the liquid (meth)acrylic sizing agent or liquid composition LC1 has a dynamic viscosity between 10 mPa·s and 10,000 mPa·s at 25°C; iv) a step of polymerization and relates to a method according to the method.

[0133] Regarding a method for manufacturing a thermoplastic composite part, according to six aspects, the method preferably includes a step of adding an initiator (Ini) to the liquid composition LC1 before putting the liquid composition LC1 into a polymerization means.

[0134] Regarding a method for manufacturing a thermoplastic composite part or not only a composite part but also a mechanical part or a structural part or a product, various methods can be used to prepare these parts. Open molding, drawing, hand lay-up, and filament winding can be mentioned.

[0135] A first preferred manufacturing method for manufacturing a composite part is a method of moving a liquid composition LC1 to a fiber substrate by impregnating the fiber substrate in an open mold.

[0136] A second preferred manufacturing method for producing composite parts is a method of using a liquid composition in a drawing forming method. Fibers are guided through a resin batch containing the composition according to the present invention. The fibers as the fiber substrate are, for example, in the form of unidirectional rovings or a mat of continuous filaments. After impregnation in a resin bath, the wet fibers are drawn out from a heated mold where polymerization occurs.

[0137] A third preferred manufacturing method is hand lay-up.

[0138] A fourth preferred manufacturing method is filament winding.

[0139] Methods for manufacturing not only composite parts but also mechanical parts or structural parts or products can further include a post-forming step. Post-forming includes bending when changing the form of the composite part. Preferably, post-forming occurs after the polymerization step.

[0140] Methods for manufacturing not only composite parts but also mechanical parts or structural parts or products can further include a welding or bonding or laminating step. Preferably, welding or bonding or laminating occurs after the polymerization step.

[0141] The thermoplastic composite parts obtained from the method according to the present invention can be post-formed after the polymerization of the liquid composition LC1 of the present invention. Forming includes bending when changing the form of the composite part.

[0142] After the polymerization of the liquid composition of the present invention and / or the thermoplastic parts obtained from the method according to the present invention or the composite parts to be manufactured can be welded, bonded, or laminated.

[0143] According to another additional aspect, the present invention relates to a polymer composite material comprising a thermoplastic (meth)acrylic matrix and a fibrous substrate used as a reinforcing material, wherein the fibrous substrate consists of long fibers, and the composite material is characterized in that the thermoplastic (meth)acrylic matrix is obtained after polymerization of a liquid composition LC1, and the fibrous substrate is pre-impregnated with the liquid composition LC1.

[0144] According to yet another additional aspect, the present invention relates to a mechanical part or a structural element made of the polymer composite material.

[0145] According to yet another additional aspect, the present invention relates to a mechanical part or a structural element made by any manufacturing method of the present invention.

[0146] Regarding the use of mechanical parts made of the composite material manufactured in this way, examples include automotive applications, transportation applications such as buses or large trucks, marine applications, railway applications, sports, aviation and aerospace applications, photovoltaic applications, computer-related applications, construction and architectural applications, telecommunication applications, and wind energy applications.

[0147] Mechanical parts made of the composite material are, in particular, automotive parts, boat parts, bus parts, train parts, sports goods, airplane or helicopter parts, spaceship or rocket parts, photovoltaic module parts, construction or building materials such as composite steel bars, dowels and stirrups for civil engineering and high-rise buildings, wind turbine parts such as spar caps of girders of wind turbine blades, furniture parts, construction or building parts, telephone or mobile phone parts, computer or TV parts, or printer or photocopier parts.

[0148] Method Density of the compound (unit g / cm 3) is measured by measuring the mass and volume of the estimated compound and simply calculated by dividing the mass by the volume. Preferably, the density is measured with a specific gravity bottle, and still more preferably, it is measured at 25 °C.

[0149] The freezing point is measured in accordance with ASTM D938.

Examples

[0150] The liquid composition is prepared by dissolving 25% by weight of PMMA (a copolymer of MMA containing ethyl acrylate as a comonomer, BS520) as (P1) in 75% by weight of methyl methacrylate as (M1), and this is stabilized with HQME (hydroquinone monomethyl ether). As the wax compound (W), Feruwax 13015 from PARAMELT BV is used. This wax has a freezing point in accordance with ASTM D938 of 52 °C to 54 °C. As shown in Table 1, in order to prepare several liquid compositions LC1 according to the present invention, this wax compound is dispersed in the liquid composition at different ratios from 0.3 phr to 1 phr. The dynamic viscosity of the composition is 500 mPa·s at 25 °C. TIFF2025084749000001.tif63170

[0151] Each composition is applied to the fabric before weight increase in a known amount and exposed to air at 23 °C. The combined weight of the two is measured every 2 minutes.

[0152] The weight loss of methyl methacrylate (MMA) is tracked by thermogravimetric analysis at 23 °C. TIFF2025084749000002.tif90170

[0153] Table 2 shows that for the examples in which the wax compound was present, the evaporated MMA decreased with time. Using 0.3 phr of the wax compound significantly reduced evaporation, using 0.5 phr or more of the wax compound made evaporation very low, and using 0.7 phr and 1 phr of the wax compound resulted in almost no evaporation.

Claims

1. 1. Liquid composition LC1, a) (meth)acrylic polymer (P1), b) a (meth)acrylic monomer (M1), and c) Wax Compound (W) and having a dynamic viscosity of between 10 mPa·s and 10,000 mPa·s at 25° C.

2. 2. Liquid composition LC1 according to claim 1, characterized in that the amount of wax compound (W) in the composition is between 0.1 and 2 phr relative to the sum of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

3. 2. Liquid composition LC1 according to claim 1, characterized in that the amount of wax compound (W) in the composition is between 0.55 and 1.3 phr relative to the sum of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

4. 4. Liquid composition LC1 according to claim 1, 2 or 3, characterized in that the density of the wax compound (W) is lower than the combined density of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

5. The density of the wax compound (W) is 1.1 g / cm ３ Liquid composition LC1 according to claim 1 or 2 or 3, characterized in that it is less than 10 ...

6. The density of the wax compound (W) is 0.7 g / cm ３ and 1.1 / cm ３ The liquid composition LC1 according to claim 1 , 2 or 3 , characterized in that:

7. The density of the wax compound (W) is 0.85 g / cm ３ and 0.98 g / cm ３ The liquid composition LC1 according to claim 1 , 2 or 3 , characterized in that:

8. Liquid composition LC1 according to any one of claims 1 to 7, characterized in that the liquid composition additionally comprises d) an initiator (Ini).

9. 8. Liquid composition LC1 according to claim 7, characterized in that the amount of initiator (Ini) in the composition is between 0.75 and 8 phr, preferably at most between 1 and 5 phr, relative to the sum of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

10. Initiators (Ini) include diisobutyryl peroxide, cumyl peroxyneodecanoate, di(3-methoxybutyl)peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, cumyl peroxyneoheptanoate, di-n-propyl peroxydicarbonate, tert-amyl peroxyneodecanoate, di-sec-butyl peroxydicarbonate, diisopropyl peroxydicarbonate, di(4-tert-butylcyclohexyl)peroxydicarbonate, di-(2-ethylhexyl)-peroxydicarbonate, peroxydicarbonate, tert-amyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, di-n-butyl peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxypivalate, tert-butyl peroxyneoheptanoate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, di-(3,5,5-trimethylhexanoyl)-peroxide, dilauroyl peroxide, didecanoyl peroxide peroxide, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)-hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, tert-amylperoxy-2-ethylhexanoate, dibenzoyl peroxide, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxydiethylacetate, tert-butylperoxyisobutyrate, 1,1-di-(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(tert-amylperoxy) tert-butylperoxy)cyclohexane, 1,1-di-(tert-butylperoxy)-cyclohexane, tert-amylperoxy-2-ethylhexyl carbonate, tert-amylperoxyacetate, tert-butylperoxy-3,5,5-trimethylhexanoate, 2,2-di-(tert-butylperoxy)-butane, tert-butylperoxyisopropyl carbonate, tert-butylperoxy-2-ethylhexyl carbonate, tert-amylperoxybenzoate, tert-butylperoxyacetate, butyl-4,4-di(tert-butylperoxy)valerate, tert-butylperoxybenzoate, di-tert-amyl peroxide, dicumyl peroxide, di-(2-tert-butyl-peroxyisopropyl)-benzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexane, tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, di-tert-butyl peroxide, 3,6,9- The liquid composition LC1 according to claim 8 or 9, characterized in that it is selected from triethyl-3,6,9-trimethyl-1,4,7-triperoxonane, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azodi-(2-methylbutyronitrile), azobisisobutyramide, 2,2'-azobis(2,4-dimethylvaleronitrile), 1,1'-azodi(hexahydrobenzonitrile) or 4,4'-azobis(4-cyanopentanoic acid) and mixtures thereof.

11. Liquid composition LC1 according to any one of claims 1 to 10, characterized in that the wax compound (W) has a freezing point between 15°C and 85°C.

12. Liquid composition LC1 according to any one of claims 1 to 10, characterized in that the wax compound (W) has a freezing point between 25°C and 60°C.

13. Liquid composition LC1 according to any one of claims 1 to 12, characterized in that the (meth)acrylic polymer (P1) comprises at least 50% by weight of methyl methacrylate (MMA).

14. Liquid composition LC1 according to any one of claims 1 to 13, characterized in that the (meth)acrylic monomers are selected from methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, methacrylic acid, acrylic acid, n-butyl acrylate, isobutyl acrylate, n-butyl methacrylate, isobutyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, and mixtures thereof.

15. 15. Liquid composition LC1 according to any one of claims 1 to 14, characterized in that at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, advantageously at least 80% by weight and even more advantageously at least 90% by weight of the monomer (M1) is a mixture of methyl methacrylate and optionally at least one other monomer.

16. 16. Liquid composition LC1 according to claim 1, characterized in that the liquid composition LC1 has a dynamic viscosity at 25°C of between 25 mPa·s and 1000 mPa·s.

17. Liquid composition LC1 according to any one of claims 1 to 15, characterized in that the liquid composition LC1 has a dynamic viscosity, measured with a rheometer, of between 30 mPa·s and 1000 mPa·s at 25°C.

18. 18. Liquid composition LC1 according to claim 1, characterized in that the liquid composition LC1 comprises between 0.01 phr by weight of a monomer (M2) relative to the sum of the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1), and the (meth)acrylic monomer (M2) comprises at least two (meth)acrylic functional groups.

19. 19. Liquid composition LC1 according to claim 18, characterized in that the (meth)acrylic monomer (M2) is selected from ethylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate or mixtures thereof.

20. Liquid composition LC1 according to any one of claims 1 to 19, characterized in that the (meth)acrylic polymer (P1) has a weight average molecular weight of more than 50,000 g / mol, preferably more than 100,000 g / mol.

21. 21. Liquid composition LC1 according to any one of claims 1 to 20, characterized in that the one or more (meth)acrylic monomers (M1) in the liquid composition LC1 or in the (meth)acrylic syrup are present in a proportion of between 40% and 90% by weight, preferably between 45% and 85% by weight, of the composition comprising the one or more (meth)acrylic monomers (M1) and the (meth)acrylic polymer (P1).

22. 21. Liquid composition LC1 according to any one of claims 1 to 20, characterized in that the (meth)acrylic monomer (M1) in the liquid composition LC1 or in the (meth)acrylic syrup is present in a proportion of between 60% and 85% by weight of the composition comprising the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

23. 21. Liquid composition LC1 according to any one of claims 1 to 20, characterized in that the (meth)acrylic monomer (M1) in the liquid composition LC1 or in the (meth)acrylic syrup is present in a proportion of between 65% and 85% by weight of the composition comprising the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

24. 21. Liquid composition LC1 according to any one of claims 1 to 20, characterized in that the (meth)acrylic polymer (P1) in the liquid composition LC1 or in the (meth)acrylic syrup is present in a proportion of between 10% and 60% by weight of the composition comprising the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

25. 21. Liquid composition LC1 according to any one of claims 1 to 20, characterized in that the (meth)acrylic polymer (P1) in the liquid composition LC1 or in the (meth)acrylic syrup is present in a proportion of between 15% and 40% by weight of the composition comprising the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

26. 21. Liquid composition LC1 according to any one of claims 1 to 20, characterized in that the (meth)acrylic polymer (P1) in the liquid composition LC1 or in the (meth)acrylic syrup is present in a proportion of between 15% and 35% by weight of the composition comprising the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

27. A method for preparing a liquid composition LC1 according to any one of claims 1 to 26, comprising the following steps: i) preparing a mixture of a (meth)acrylic polymer (P1) and a (meth)acrylic monomer (M1); ii) adding a wax compound (W) to the mixture prepared in the previous step; The method includes:

28. 28. The method according to claim 27, characterized in that the (meth)acrylic polymer (P1) in the liquid composition LC1 or in the (meth)acrylic syrup is present in a proportion of between 15% and 40% by weight of the composition comprising the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1), and that the (meth)acrylic monomer (M1) in the liquid composition LC1 or in the (meth)acrylic syrup is present in a proportion of between 60% and 85% by weight of the composition comprising the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

29. 28. The method according to claim 27, characterized in that the (meth)acrylic polymer (P1) in the liquid composition LC1 or in the (meth)acrylic syrup is present in a proportion of between 15% and 35% by weight of the composition comprising the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1), and that the (meth)acrylic monomer (M1) in the liquid composition LC1 or in the (meth)acrylic syrup is present in a proportion of between 65% and 85% by weight of the composition comprising the (meth)acrylic monomer (M1) and the (meth)acrylic polymer (P1).

30. 28. The method according to claim 27, characterized in that an initiator (Ini) is added to the liquid composition LC1.

31. The initiator (Ini) is heated at a temperature T ａｄｄ 31. The method of claim 30, wherein the compound is added at

32. 28. The method according to claim 27, characterized in that the wax compound (W) has a freezing point between 25°C and 60°C.

33. Use of a liquid composition LC1 according to any one of claims 1 to 26, or a liquid composition LC1 prepared by a method according to any one of claims 27 to 32, for producing a thermoplastic part or for producing a composite part.

34. 33. Use of a liquid composition LC1 according to any one of claims 1 to 26, or a liquid composition LC1 prepared by the method according to any one of claims 27 to 32, for impregnating a textile or textile substrate.

35. 27. Use of liquid composition LC1 according to any one of claims 1 to 26 for producing a thermoplastic part or for producing a composite part.

36. 1. A method for manufacturing a thermoplastic part, comprising the steps of: i) preparing a liquid mixture of a (meth)acrylic polymer (P1) and a (meth)acrylic monomer (M1); ii) adding a wax compound (W) to the mixture prepared in the previous step; iii) placing the liquid (meth)acrylic composition prepared in i) and ii) in a polymerization means, said composition additionally comprising d) an initiator (Ini) as described in any one of claims 1 to 10, said liquid (meth)acrylic syrup being characterized in that it has a dynamic viscosity at 25°C between 10 mPa·s and 10,000 mPa·s; iv) polymerizing; A method comprising the steps of:

37. 1. A method for manufacturing a thermoplastic composite part comprising the steps of: i) preparing a liquid mixture of a (meth)acrylic polymer (P1) and a (meth)acrylic monomer (M1); ii) adding a wax compound (W) to the mixture prepared in the previous step; iii) subjecting the liquid (meth)acrylic composition prepared in i) and ii) to a polymerization means, said composition comprising: a) (meth)acrylic polymer (P1), b) (meth)acrylic monomer (M1); c) a wax compound (W) and d) Initiator (Ini) wherein the liquid (meth)acrylic syrup has a dynamic viscosity of between 10 mPa·s and 10,000 mPa·s at 25° C.; iv) polymerizing; A method comprising the steps of:

38. 1. A method for manufacturing a thermoplastic composite part comprising the steps of: i) preparing a mixture of a (meth)acrylic polymer (P1) and a (meth)acrylic monomer (M1) and a wax compound (W); ii) adding an initiator (Ini) to the mixture prepared in the previous step; iii) impregnating a fiber or fiber substrate with the liquid (meth)acrylic composition prepared in i) and ii), said composition comprising: a) (meth)acrylic polymer (P1), b) (meth)acrylic monomer (M1); c) a wax compound (W) and d) Initiator (Ini) wherein the liquid (meth)acrylic syrup has a dynamic viscosity of between 10 mPa·s and 10,000 mPa·s at 25° C.; iv) polymerizing; A method comprising the steps of:

39. 1. A method for manufacturing a composite part, comprising the steps of: i) preparing a mixture of a (meth)acrylic polymer (P1), a (meth)acrylic monomer (M1) and a wax compound (W); ii) adding an initiator (Ini) to the mixture prepared in the previous step; iii) impregnating a fiber or fiber substrate with the liquid composition prepared in i) and ii), said composition comprising: a) (meth)acrylic polymer (P1), b) (meth)acrylic monomer (M1); c) a wax compound (W) and d) Two initiators (Ini1) and (Ini2) wherein the liquid (meth)acrylic syrup has a dynamic viscosity of between 10 mPa·s and 10,000 mPa·s at 25° C.; iv) polymerizing; A method comprising the steps of:

40. 40. The method of any one of claims 36 to 39, wherein the method is performed by open mold molding, pultrusion, hand layup, or filament winding.

41. 41. The process according to any one of claims 36 to 40, characterized in that the polymerization step is carried out at a temperature between 40°C and 140°C.

42. 42. The method according to any one of claims 36 to 41, further comprising a step of post-molding.

43. 42. The method according to any one of claims 36 to 41, further comprising a welding or gluing or laminating step.

44. A polymer composite comprising a thermoplastic (meth)acrylic matrix and a fibrous substrate used as reinforcement, the fibrous substrate consisting of long fibers having an aspect ratio of at least 1000, the composite being characterized in that the thermoplastic (meth)acrylic matrix is ​​obtained after polymerization of a liquid composition LC1, the fibrous substrate being pre-impregnated with a liquid composition LC according to any one of claims 1 to 10.

45. A machine part or structural element made of a composite material according to claim 44 or obtained by the method according to any one of claims 36 to 43.

46. 46. ​​The part of claim 45, wherein the part is an automobile part, a boat part, a train part, a sporting item, an airplane or helicopter part, a spacecraft or rocket part, a photovoltaic module part, a construction or building material such as composite rebar, dowels and stirrups for civil engineering and high rise construction, a wind turbine part such as spars caps for wind turbine blade girders, a furniture part, a construction or building part, a telephone or mobile phone part, a computer or television part, a printer or photocopier part.

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