阅读说明：本技术 丙烯酸类热塑性复合材料的前体组合物及其制备方法和用途 (Precursor composition of acrylic thermoplastic composite material and preparation method and application thereof ) 是由 P·热拉尔 于 2019-03-05 设计创作，主要内容包括：本发明涉及(甲基)丙烯酸类热塑性复合材料的前体组合物、其制备方法及其用途。具体而言,本发明涉及包含(甲基)丙烯酸类聚合物、单体、纤维材料和至少一种引发剂的半成品组合物。更具体地,本发明涉及包含(甲基)丙烯酸类聚合物、单体、纤维材料和至少两种引发剂的前体组合物。本发明还涉及制备包含(甲基)丙烯酸类聚合物、单体、纤维材料和至少两种引发剂的组合物的方法。(The present invention relates to a precursor composition of a (meth) acrylic thermoplastic composite material, a method for producing the same, and use thereof. In particular, the invention relates to a semi-finished composition comprising a (meth) acrylic polymer, monomers, a fibrous material and at least one initiator. More specifically, the present invention relates to precursor compositions comprising a (meth) acrylic polymer, a monomer, a fibrous material, and at least two initiators. The invention also relates to a process for preparing a composition comprising a (meth) acrylic polymer, a monomer, a fibrous material and at least two initiators.)

1. A liquid composition LC1 suitable for impregnating fibrous substrates, making prepregs and polymer composites, said liquid composition comprising:

a) a (meth) acrylic polymer (P1),

b) a (meth) acrylic monomer (M1), and

c) two initiators (Ini1) and (Ini2),

the liquid composition has a dynamic viscosity at 25 ℃ of between 10 and 10000mPa · s, characterized in that the initiator (Ini1) is activated by absorbing radiation and the initiator (Ini2) is activated by heating.

2. Liquid composition LC1 according to claim 1, characterized in that the total amount of the two initiators (Ini1) and (Ini2) in the composition is between 0.1phr and 15phr, relative to the sum of the (meth) acrylic monomer (M1) and the (meth) acrylic polymer (P1).

3. The liquid composition LC1 according to claim 1 or claim 2, characterized in that the radiation absorbed by the initiator (Ini1) is selected from ultraviolet, visible or infrared radiation.

4. The liquid composition LC1 according to claim 3, characterized in that the initiator (Ini1) is selected from acetophenone, alkoxyacetophenone, hydroxyacetophenone, alkylaminoacetophenone, benzoin ether or phosphine oxides; benzophenones, thioxanthones, quinones, benzoyl formate, dibenzylidene ketone or coumarins; dyes, for example triazines and derivatives thereof, fluorones and derivatives thereof, cyanines and derivatives thereof, safranins and derivatives thereof, 4,5,6, 7-tetrachloro-3 ',6' -dihydroxy-2 ',4',5',7' -tetraiodo-3H-spiro [ isobenzofuran-1, 9' -xanthene ] -3-one, pyrylium and thiopyrylium and derivatives thereof, thiazines and derivatives thereof, flavins and derivatives thereof, pyronins and derivatives thereof, oxazines and derivatives thereof, rhodamines and derivatives thereof.

5. Liquid composition LC1 according to any one of claims 1 to 4, characterized in that the amount of initiator (Ini1) in the composition is between 0.1phr and 5phr, relative to the sum of the (meth) acrylic monomer (M1) and the (meth) acrylic polymer (P1).

6. The liquid composition LC1 according to any one of claims 1-5, characterized in that the initiator (Ini2) has a half-life t of 1 hour at a temperature of at least 60 ℃, preferably at least 65 ℃, more preferably at least 70 ℃, still more preferably at least 75 ℃_1/2。

7. The liquid composition LC1 according to any one of claims 1-6, characterized in that the initiator (Ini2) is selected from the group consisting of diacyl peroxides, peroxyesters, peroxydicarbonates, dialkyl peroxides, peroxyacetals, hydroperoxides or peroxyketals.

8. The liquid composition LC1 according to any one of claims 1 to 7, characterized in that the initiator (Ini2) is selected from diisobutyryl peroxide, cumyl peroxyneodecanoate, bis (3-methoxybutyl) peroxydicarbonate, 1,3, 3-tetramethylbutyl peroxyneodecanoate, cumyl peroxyneoheptanoate, di-n-propyl peroxydicarbonate, tert-amyl peroxyneodecanoate, di-sec-butyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-tert-butylcyclohexyl) peroxydicarbonate, bis (2-ethylhexyl) peroxydicarbonate, tert-butyl peroxyneodecanoate, di-n-butyl peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, 1,3, 3-tetramethylbutyl peroxypivalate, dicetyl peroxydicarbonate, dicumyl peroxydicarbonate, and mixtures thereof, Tert-butyl peroxypivalate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, bis (3,5, 5-trimethylhexanoyl) peroxide, dilauroyl peroxide, didecanoyl peroxide, 2, 5-dimethyl-2, 5-bis (2-ethylhexanoylperoxide) -hexane, 1,3, 3-tetramethylbutyl peroxy-2-ethylhexanoate, tert-amyl peroxy2-ethylhexanoate, dibenzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxydiethylacetate, tert-butyl peroxyisobutyrate, 1-bis (tert-butylperoxy) -3,3, 5-trimethylcyclohexane, 1-bis (tert-amylperoxy) cyclohexane, 1-bis (tert-butylperoxy) -cyclohexane, tert-butylperoxy-hexane, T-amyl peroxy-2-ethylhexyl carbonate, t-amyl peroxyacetate, t-butyl peroxy-3, 5, 5-trimethylhexanoate, 2-di (t-butylperoxy) -butane, t-butyl peroxyisopropyl carbonate, t-butyl peroxy-2-ethylhexyl carbonate, t-amyl peroxybenzoate, t-butyl peroxyacetate, butyl 4, 4-di (t-butylperoxy) valerate, t-butyl peroxybenzoate, di-t-amyl peroxide, dicumyl peroxide, di (2-t-butylperoxyisopropyl) benzene, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, t-butylcumyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexyne-3, di-t-butyl peroxide, t-butyl peroxy-3, tert-butyl peroxy acetate, t-butyl peroxy-3, t-butyl peroxy-butane, tert-, 3,6, 9-triethyl-3, 6, 9-trimethyl-1, 4, 7-triperoxonane, 2' -Azobisisobutyronitrile (AIBN), 2' -azobis (2-methylbutyronitrile), azobisisobutyramide, 2' -azobis (2, 4-dimethylvaleronitrile), 1' -azobis (hexahydrobenzonitrile) or 4, 4' -azobis (4-cyanovaleric acid).

9. The liquid composition LC1 according to any one of claims 1-7, characterized in that the initiator (Ini2) is selected from the group consisting of tert-amyl peroxypivalate, tert-butyl peroxypivalate, bis (3,5, 5-trimethylhexanoyl) peroxide, dilauroyl peroxide, didecanoyl peroxide, 2, 5-dimethyl-2, 5-bis (2-ethylhexanoylperoxide) -hexane, 1,3, 3-tetramethylbutyl peroxy2-ethylhexanoate, tert-amyl peroxy2-ethylhexanoate, dibenzoyl peroxide, tert-butyl peroxy2-ethylhexanoate, tert-butyl peroxydiethylacetate, tert-butyl peroxyisobutyrate, 1-bis (tert-butylperoxy) -3,3, 5-trimethylcyclohexane, 1, 1-bis (t-butylperoxy) cyclohexane, 1-bis (t-butylperoxy) -cyclohexane, t-amyl peroxy-2-ethylhexyl carbonate, t-amyl peroxyacetate, t-butyl peroxy-3, 5, 5-trimethylhexanoate, 2-bis (t-butylperoxy) -butane, t-butyl peroxyisopropylcarbonate, t-butyl peroxy-2-ethylhexyl carbonate, t-amyl peroxybenzoate, t-butyl peroxyacetate, butyl 4, 4-bis (t-butylperoxy) valerate, t-butyl peroxybenzoate, di-t-amyl peroxide, dicumyl peroxide, bis (2-t-butylperoxyisopropyl) benzene, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, t-butylcumyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexyne-3, di-t-butyl peroxide or 3,6, 9-triethyl-3, 6, 9-trimethyl-1, 4, 7-triperoxonane.

10. The liquid composition LC1 according to any one of claims 1 to 9, characterized in that at least two different free radical initiators (Ini2) are present.

11. The liquid composition LC1 according to claim 10, characterized in that the temperature difference between the two different initiators (Ini2) is at least 5K for a given half-life.

12. Liquid composition LC1 according to any one of claims 1 to 11, characterized in that the (meth) acrylic polymer (P1) comprises 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.

13. Liquid composition LC1 according to any one of claims 1 to 12, characterized in that the composition LC1(meth) acrylic polymer (P1) having a weight-average molecular weight M of greater than 100000g/mol_w。

14. The liquid composition LC1 according to any one of claims 1-13, characterized in that the (meth) acrylic monomer (M1) is selected from acrylic acid, methacrylic acid, alkylacrylic monomers, alkylmethacrylic monomers, hydroxyalkylacrylic monomers and hydroxyalkylmethacrylic monomers, and mixtures thereof.

15. The liquid composition LC1 according to any one of claims 1-13, characterized in that the (meth) acrylic monomer (M1) is selected from the group consisting of 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.

16. The liquid composition LC1 according to any one of claims 1 to 13, characterized in that the (meth) acrylic polymer (P1) in the liquid (meth) acrylic resin syrup LC1 is present in a proportion of not more than 30% by weight of the composition comprising the (meth) acrylic monomer (M1) and the (meth) acrylic polymer (P1).

17. Liquid composition LC1 according to any one of claims 1 to 13, characterised in that the fibres of the fibrous substrate 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, still more advantageously at least 7500, most advantageously at least 10000.

18. Liquid composition LC1 according to any one of claims 1 to 13, characterised in that the fibres of the fibrous substrate have a diameter between 0.005 μ ι η and 100 μ ι η, preferably between 1 μ ι η and 50 μ ι η, more preferably between 5 μ ι η and 30 μ ι η, advantageously between 10 μ ι η and 25 μ ι η.

19. A process for preparing a liquid composition LC1 according to any one of claims 1-18, the process comprising the steps of:

i) preparing a mixture of a (meth) acrylic polymer (P1) and a (meth) acrylic monomer (M1);

ii) initiators (Ini1) and (Ini2) are added, jointly or in succession, to the mixture prepared in the preceding step.

20. Use of a liquid composition LC1 according to any one of claims 1 to 18 or a liquid composition LC1 prepared by a process according to claim 19 for the manufacture of a prepreg, a thermoplastic part or for the manufacture of a composite part.

21. Use of the liquid composition LC1 according to any one of claims 1 to 18 or the liquid composition LC1 prepared by the process according to claim 19 for impregnating fibers or fibrous substrates consisting of long fibers.

22. Impregnation process for impregnating a fibrous substrate, said fibrous substrate consisting of long fibers and said process comprising the step of impregnating said fibrous substrate with a liquid composition LC1 according to any one of claims 1 to 18.

23. A composition PRE1 suitable for making a prepreg PRE2 and a polymer composite, the composition comprising:

a liquid composition according to any one of claims 1 to 18, and

a fibrous material.

24. A process for preparing a prepreg composition PRE2 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), fibrous material and at least initiator (Ini2), the process comprising the steps of:

i) impregnating a fibrous material with a liquid composition LC1 according to any of claims 1 to 18, and

ii) partially polymerizing the product obtained in step i) by using an initiator (Ini1),

characterized in that the initiator (Ini1) is activated by absorption of radiation and the initiator (Ini2) is activated by heating.

25. A method of preparing a polymer composite from a composition comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), a fibrous material, and at least initiators (Ini1) and (Ini2), the method comprising the steps of:

i) impregnating a fibrous material with a liquid composition LC1 according to any one of claims 1-18;

ii) partially polymerizing the product obtained in step i) by using an initiator (Ini 1);

iii) storing the product prepared in step ii);

iv) continuing the polymerization by using the initiator (Ini2),

characterized in that the initiator (Ini1) is activated by absorption of radiation and the initiator (Ini2) is activated by heating.

26. The process according to claim 24 or claim 25, characterized in that the conversion of (meth) acrylic monomer (M1) in step ii) is between 30% and 90%, more preferably between 40% and 80%, even more preferably between 50% and 75%, most preferably between 55% and 75%, and advantageously between 58% and 70%.

27. The process according to claim 24 or claim 25, characterized in that the polymerization temperature in step ii) is between 0 ℃ and 40 ℃, more preferably between 5 ℃ and 35 ℃, still more preferably between 10 ℃ and 35 ℃, even more preferably between 15 ℃ and 30 ℃.

28. The process according to claim 24 or claim 25, characterized in that the radiation source used for the polymerization in step ii) emits radiation with a wavelength λ (nm) of 200nm to 800nm, more preferably 250nm to 500 nm.

29. The method according to claim 25, characterized in that the storage of step iii) is carried out at a temperature below 35 ℃, preferably said storage is at a half-life temperature T of 1 hour greater than the half-life temperature T of the initiator (Ini2)_1/2A half-life temperature T of at least 40K lower, even more preferably than 1 hour of the initiator (Ini2)_1/2At a temperature at least 50K lower, still more preferably at least 60K lower, advantageously at least 70K lower, more advantageously at least 80K lower.

30. The process according to claim 25, characterized in that the continuing polymerization step iv) is carried out by one of the following methods: hot compaction, hot compaction with injection of thermoplastic polymers, continuous process for hollow structures, compaction under vacuum with (meth) acrylic surface layers, resin transfer molding and filament winding on the composition of the invention.

31. The process according to claim 25, characterized in that the continuation of the polymerization step iv) is carried out by thermo-compression.

32. The process according to claim 25, characterized in that the continuation of the polymerization step iv) is carried out by compaction under vacuum.

33. The process according to claim 25, characterized in that the continuation of the polymerization step iv) is carried out by filament winding.

34. A polymer composite obtainable by a process according to claim 25, claim 29 or claims 30 to 33.

35. Use of the polymer composite according to claim 34 in automotive and motorcycle sports applications, such as pressure vessels, ballistic & defense applications, marine applications, railway and transportation applications, sports, leisure and recreation applications, art and recreation applications, aviation and aerospace applications, building and civil engineering applications, oil and gas applications, renewable applications, such as photovoltaic applications and wind energy applications.

36. Use of a mechanical part made of a composite material according to claim 34 in automotive applications, transportation applications such as buses or trucks, marine applications, railway applications, sports, aeronautic and aerospace applications, photovoltaic applications, computer-related applications, construction and construction applications, telecommunication applications and wind energy applications.

Technical Field

The present invention relates to a precursor composition of a (meth) acrylic thermoplastic composite material, a method for producing the same, and use thereof.

In particular, the invention relates to a semi-finished composition comprising a (meth) acrylic polymer, monomers, a fibrous material and at least one initiator.

More specifically, the present invention relates to precursor compositions comprising a (meth) acrylic polymer, a monomer, a fibrous material, and at least two initiators.

The invention also relates to a process for preparing a composition comprising a (meth) acrylic polymer, a monomer, a fibrous material and at least two initiators.

Technical problem

A composite material is a macroscopic combination of two or more immiscible materials. The composite material is composed of at least a matrix material forming a continuous phase for structural bonding and a reinforcement material having various structures for mechanical properties.

The purpose of using the composite is to obtain properties from the composite that cannot be obtained when the individual components thereof are used alone. Thus, composite materials are widely used in various industrial sectors, such as construction, automotive, aerospace, transportation, leisure, electronics and sports, in particular due to their better mechanical properties (higher tensile strength, higher tensile modulus, higher fracture toughness) and their low density than homogeneous materials.

On a commercial industrial scale, the most important class in terms of volume is composite materials with an organic matrix, where the matrix material is usually a polymer. The primary matrix or continuous phase of the polymer composite is a thermoplastic polymer or a thermoset polymer.

Thermosetting polymers consist of a crosslinked three-dimensional structure. Crosslinking is obtained by curing reactive groups in so-called prepolymers. For example, curing may be obtained by heating the polymer chains to permanently crosslink and harden the material. To prepare the polymer composite, the prepolymer is mixed with the other components (e.g., with glass beads for particulate composites or short fibers for fibrous composites) or the other components are wetted or impregnated (e.g., woven web) and then cured.

Examples of prepolymers or matrix materials for thermosetting polymers are unsaturated polyesters, vinyl esters, epoxy resins or phenolic resins (epoxy or phenolic ones). The production of such semifinished products results in so-called prepregs.

Another disadvantage of thermoset polymer matrices is their cross-linking. The matrix is not easily formed into other forms. Once the polymer is cured, the form is fixed. This also makes recycling of thermoset composites difficult.

The thermoplastic polymer consists of an uncrosslinked linear or branched polymer. The thermoplastic polymer is heated to mix the two components necessary to produce the composite material and cooled to solidify. The limitation of using thermoplastic polymers to make composites is their high viscosity in the molten state. If the thermoplastic resin has sufficient flowability, the fibers can be wetted or properly impregnated with the thermoplastic polymer alone. In order to provide the thermoplastic polymer with a low viscosity or sufficient flowability, the chain length (molecular weight) may be reduced. However, too low a molecular weight has a negative effect on the properties of the composite, in particular on the mechanical properties. On the other hand, the temperature of the thermoplastic polymer can be increased in order to reduce the viscosity in an important manner. Therefore, the continuous working temperature is relatively high, above 200 ℃, since this implies high energy costs, directly affecting the economics (cost) of the composite material. Furthermore, thermoplastic polymers tend to degrade if the temperature is high, especially for semi-crystalline thermoplastic polymers with high melting points, such as polyamides (e.g. PA6.6), Polyethersulfones (PES), Polyetherimides (PEI), Polyetheretherketones (PEEK) or polyphenylene sulfides (PPS). This heat-induced degradation reduces the molecular weight of the polymer matrix, which is important for the bonding of the composite.

Another method of impregnating a fibrous substrate is to dissolve the thermoplastic polymer in an organic solvent. However, this method requires evaporation of a large amount of solvent. The use of large amounts of solvents presents environmental problems in terms of energy and pollution.

To prepare polymer composites based on thermoplastic polymers, thermoplastic polymer resins, commonly referred to as "resin syrup" (syrup), are used to impregnate reinforcing materials, such as fibrous substrates. Once polymerized, the thermoplastic polymer resin syrup forms the matrix of the composite. In impregnation, when preparing the polymer composite, the viscosity of the impregnating resin slurry must be controlled and adjusted so that it is not too fluid or too viscous to properly impregnate each fiber of the fibrous base material. When partially wetted, depending on whether the resin syrup is too fluid or too viscous, there appear "bare" areas (i.e., unimpregnated areas) and areas where polymer droplets form on the fibers (which are responsible for bubble generation), respectively. These "bare" areas and these air bubbles lead to defects in the final composite material, which is responsible, among other things, for the loss of mechanical strength of the final composite material. However, the viscosity range available for impregnation is too low for storing such materials.

These are limitations or disadvantages of the preparation of thermoplastic composites, especially with fibre reinforcement.

To achieve thermoforming and recycling, it is preferred to also use thermoplastic polymers in the composite material.

There is a need for thermoplastic precursor compositions for the preparation of prepregs and thermoplastic composites that can be easily stored for reasonable periods of time. Further, there is a need for a method of making a thermoplastic precursor composition or prepreg for a thermoplastic composite.

It is an object of the present invention to provide a precursor composition for a prepreg used to prepare a thermoplastic composite.

It is another object of the present invention to provide a precursor composition that can be converted into a prepreg and further into a polymeric thermoplastic composite material having satisfactory mechanical properties that can be converted and shaped.

It is another object of the present invention to provide a precursor composition that can be converted into a prepreg and further into a polymeric thermoplastic composite in which the polymeric matrix can be easily recycled and repaired.

It is a further object of the present invention to provide a process for preparing a precursor composition which can be converted into a prepreg and further into a polymer thermoplastic composite in which the fibrous material is properly and completely wetted, wherein the precursors of the polymer composite can be stored.

It is another object to provide a prepreg composition that can be converted into a polymeric thermoplastic composite.

Background of the invention Prior Art

Document WO2013/056845 discloses composites prepared by in situ polymerization of thermoplastic (meth) acrylic resins, polymer composites obtained by in situ polymerization of thermoplastic (meth) acrylic resins and fiber materials comprising long fibers and uses thereof, a process for preparing such composites and manufactured mechanical or structured parts or articles comprising the polymer composites. The polymerization uses a radical initiator selected from diacyl peroxides, peroxyesters, dialkyl peroxides, peroxyacetals, or azo compounds. This document does not disclose a composition comprising a mixture of two initiators, one of which is activated by absorption of radiation. This document does not disclose the preparation of prepregs.

Document WO2014/013028 discloses a process for impregnation of a fibrous substrate, a liquid (meth) acrylic resin syrup for use in the impregnation process, a process for polymerization thereof and a structured article obtained thereby. The liquid (meth) acrylic resin syrup comprises a (meth) acrylic polymer, a (meth) acrylic monomer, and at least one initiator or initiation system for initiating polymerization of the (meth) acrylic monomer. The initiator or initiation system is activated by heating. This document does not disclose a composition comprising a mixture of two initiators, one of which is activated by absorption of radiation. This document does not disclose the preparation of prepregs.

Document WO2014/174098 discloses liquid (meth) acrylic resin syrup, polymerization process, use thereof and molded articles obtained therefrom. The liquid (meth) acrylic resin syrup comprises an initiation system for polymerization at low temperatures comprising at least one accelerator, at least one organic aldehyde, at least one peracid, and at least one liquid peroxy compound. This document does not disclose a composition comprising a mixture of two initiators, one of which is activated by absorption of radiation. This document does not disclose the preparation of prepregs.

Document EP2471849 discloses a process for manufacturing acrylic films. An acrylic film is prepared by using an acrylic resin syrup comprising an acrylic polymer, a reactive monomer, and a photoinitiator. The resin syrup may further contain a thermal initiator, if necessary.

All prior art documents do not disclose the preparation of prepregs nor compositions comprising a mixture of two initiators, one of which is activated by absorption of radiation.

Brief description of the invention

Surprisingly, a liquid composition LC1 suitable for impregnating fibrous substrates, making prepregs and polymer composites has been found, comprising:

a) a (meth) acrylic polymer (P1),

b) a (meth) acrylic monomer (M1), and

c) two initiators (Ini1) and (Ini2),

the liquid composition having a dynamic viscosity at 25 ℃ of between 10 and 10000mPa · s, characterized in that the initiator (Ini1) is activated by absorbing radiation, the initiator (Ini2) is activated by heating, the liquid composition LC1 allowing to provide an impregnation liquid for the preparation of thermoplastic prepregs.

Surprisingly, it has been found that a composition PRE1 suitable for the preparation of a prepreg PRE2 and a polymer composite, said composition PRE1 comprising:

a) a (meth) acrylic polymer (P1),

b) a (meth) acrylic monomer (M1),

c) two initiators (Ini1) and (Ini2), and

d) the material of the fibers is a mixture of fibers,

characterized in that the initiator (Ini1) is activated by absorption of radiation, the initiator (Ini2) is activated by heating, and the composition PRE1 allows the preparation of a thermoplastic prepreg.

Surprisingly, a process has also been found for preparing a composition PRE2 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), fibrous material and at least an initiator (Ini2), said process comprising the steps of:

i) impregnating a fibrous material with a liquid composition LC1, said liquid composition LC1 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), and at least two initiators (Ini1) and (Ini2),

ii) partially polymerizing the product obtained in step i) by using an initiator (Ini1),

characterized in that the initiator (Ini1) is activated by absorption of radiation and the initiator (Ini2) is activated by heating, the method allowing the preparation of thermoplastic prepregs.

Surprisingly, it has also been found that a liquid composition LC1 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1) and at least two initiators (Ini1) and (Ini2) can be used for preparing a composition PRE1, said composition PRE1 comprising:

a) a (meth) acrylic polymer (P1),

b) a (meth) acrylic monomer (M1),

c) two initiators (Ini1) and (Ini2), and

d) the material of the fibers is a mixture of fibers,

characterized in that the initiator (Ini1) is activated by absorption of radiation and the initiator (Ini2) is activated by heating.

Surprisingly, a process has also been found for preparing a polymer composite from a composition PRE2, the composition PRE2 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), a fibrous material and at least an initiator (Ini2), the process comprising the steps of:

i) impregnating a fibrous material with a liquid composition LC1, said liquid composition LC1 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), and at least two initiators (Ini1) and (Ini2),

ii) partially polymerizing the product obtained in step i) by using an initiator (Ini1),

iii) storing the product prepared in step ii),

iv) continuing the polymerization by using the initiator (Ini2),

characterized in that the initiator (Ini1) is activated by absorbing radiation and the initiator (Ini2) is activated by heating, the method allowing the preparation of thermoplastic composites.

Detailed Description

According to a first aspect, the present invention relates to a liquid composition LC1 suitable for impregnating fibrous materials, making prepregs and polymer composites, said liquid composition LC1 comprising:

a) a (meth) acrylic polymer (P1),

b) a (meth) acrylic monomer (M1), and

c) two initiators (Ini1) and (Ini2),

the liquid composition LC1 has a dynamic viscosity at 25 ℃ between 10 mPa-s and 10000 mPa-s, characterized in that the initiator (Ini1) is activated by absorbing radiation and the initiator (Ini2) is activated by heating.

According to a second aspect, the present invention relates to a composition PRE1 suitable for the preparation of a prepreg PRE2 and a polymer composite, said composition comprising:

a) a (meth) acrylic polymer (P1),

b) a (meth) acrylic monomer (M1),

c) two initiators (Ini1) and (Ini2), and

d) the material of the fibers is a mixture of fibers,

characterized in that the initiator (Ini1) is activated by absorption of radiation and the initiator (Ini2) is activated by heating.

According to a third aspect, the present invention relates to a process for preparing a composition PRE2, said composition PRE2 comprising a (meth) acrylic polymer (P1), a (meth) acrylic monomer (M1), a fibrous material and at least an initiator (Ini2), said process comprising the steps of:

i) the fibrous material was impregnated with a liquid composition LC1, said liquid composition LC1 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), and at least two initiators (Ini1) and (Ini 2).

ii) partially polymerizing the product obtained in step i) by using an initiator (Ini1),

characterized in that the initiator (Ini1) is activated by absorption of radiation and the initiator (Ini2) is activated by heating.

According to a fourth aspect, the present invention relates to the use of a liquid composition LC1 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1) and at least two initiators (Ini1) and (Ini2) for preparing a composition PRE1, said composition PRE1 comprising:

a) a (meth) acrylic polymer (P1),

b) a (meth) acrylic monomer (M1),

c) two initiators (Ini1) and (Ini2), and

d) the material of the fibers is a mixture of fibers,

characterized in that the initiator (Ini1) is activated by absorption of radiation and the initiator (Ini2) is activated by heating.

According to a fifth aspect, the present invention relates to a process for preparing a polymer composite from a composition PRE2, the composition PRE2 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), a fibrous material and at least an initiator (Ini2), the process comprising the steps of:

i) impregnating a fibrous material with a liquid composition LC1, said liquid composition LC1 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), and at least two initiators (Ini1) and (Ini2),

ii) partially polymerizing the product obtained in step i) by using an initiator (Ini1),

iii) storing the product prepared in step ii),

iv) continuing the polymerization by using the initiator (Ini2),

characterized in that the initiator (Ini1) is activated by absorption of radiation and the initiator (Ini2) is activated by heating.

The term "(meth) acrylic" is used to denote any of a variety of acrylic and methacrylic monomers.

The term "PMMA" is used to denote homopolymers and copolymers of Methyl Methacrylate (MMA), the weight ratio of MMA in PMMA being at least 70% by weight with respect to the copolymer of MMA.

The term "monomer" is used to indicate a molecule that can be polymerized.

The term "polymerization" is used to denote a process of converting a monomer or a mixture of monomers into a polymer.

The term "thermoplastic polymer" is used to denote a polymer that becomes liquid or more fluid or less viscous when heated, and can assume a new shape by the application of heat and pressure. This also applies to slightly crosslinked thermoplastic polymers which can be thermoformed when heated above the softening temperature.

The term "thermoset polymer" is used to denote a soft solid or viscous state prepolymer that upon curing irreversibly becomes an infusible, insoluble polymer network.

The term "prepreg" is used to denote a composition of fibrous substrates that has been impregnated with a curable prepolymer, or a liquid reactant or a thermoplastic polymer and that may be further polymerized.

The term "prepolymer" is used to denote a polymer or oligomer whose molecules are capable of further polymerization by reactive groups.

The term "oligomer" is used to denote polymer molecules of moderate relative molecular weight comprising between 5 and 500 monomer units.

The term "polymer composite" is used to denote a multicomponent material comprising a plurality of distinct phase domains, wherein at least one type of phase domain is a continuous phase and wherein at least one component is a polymer.

The term "initiator" is used to denote a chemical species that forms a compound or intermediate compound that initiates polymerization of a monomer, enabling it to be connected in sequence with a number of other monomers to form a polymeric compound.

The abbreviation "phr" refers to parts by weight per hundred parts of the composition. For example, 1phr of initiator in a composition means that 1kg of initiator is added to 100kg of composition.

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

In the present invention, a range of x-y is intended to include the upper and lower limits of that range, meaning at least x and at most y.

In the present invention, the range between x and y means that the upper and lower limits of the range are excluded, and is equivalent to more than x and less than y.

The liquid composition LC1 or (meth) acrylic resin syrup according to the present invention comprises a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1) or a mixture of (meth) acrylic monomers (M1) and (M1+ x) and at least two initiators (Ini1) and (Ini 2).

The liquid composition LC1 or the (meth) acrylic resin syrup has a dynamic viscosity of 10 mPas to 10000 mPas, preferably 20 mPas to 7000 mPas, advantageously 20 mPas to 5000 mPas, more advantageously 20 mPas to 2000 mPas, even more advantageously 20 mPas to 1000 mPas. The viscosity of the resin syrup can be easily measured using a rheometer or a viscometer. The dynamic viscosity was measured at 25 ℃. If the liquid (meth) acrylic resin syrup has Newtonian properties, i.e. no shear thinning, thenThe dynamic viscosity is independent of the shear in the rheometer or the speed of the moving device (mobile) in the viscometer. If the liquid composition LC1 has non-Newtonian properties, i.e. shear thinning, it is present in 1s at 25 ℃^-1The shear rate of (c) measures the dynamic viscosity.

The liquid composition LC1 or (meth) acrylic resin syrup for impregnating a fibrous substrate according to the invention comprises in particular a (meth) acrylic monomer (M1) or a mixture of (meth) acrylic monomers, (meth) acrylic polymer (P1) and at least two different initiators (Ini1) and (Ini 2).

As regards the liquid composition LC1 of the present invention, it comprises (meth) acrylic monomer (M1), (meth) acrylic polymer (P1) and at least two different initiators (Ini1) and (Ini 2). Once polymerized, the (meth) acrylic monomer (M1) is converted into a (meth) acrylic polymer (P2) comprising monomer units of the (meth) acrylic monomer (M1).

As the (meth) acrylic polymer (P1), mention may be made of polyalkyl methacrylates or polyalkyl acrylates. According to a preferred embodiment, the (meth) acrylic polymer (P1) is polymethyl methacrylate (PMMA).

The term "PMMA" denotes a homopolymer or copolymer of Methyl Methacrylate (MMA) or a mixture thereof.

According to one embodiment, the Methyl Methacrylate (MMA) homopolymer or copolymer comprises at least 70 wt.%, preferably at least 80 wt.%, advantageously at least 90 wt.%, and more advantageously at least 95 wt.% of methyl methacrylate.

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

Copolymers of Methyl Methacrylate (MMA) comprise from 70 wt% to 99.7 wt% methyl methacrylate and from 0.3 wt% to 30 wt% of at least one monomer containing at least one ethylenic unsaturation copolymerizable with the methyl methacrylate.

These monomers are well known and mention may in particular be made of acrylic acid and methacrylic acid and alkyl (meth) acrylates in which the alkyl group contains from 1 to 12 carbon atoms. Mention may be made, as examples, of methyl acrylate and ethyl (meth) acrylate, butyl (meth) acrylate or 2-ethylhexyl (meth) acrylate. Preferably, the comonomer is an alkyl acrylate wherein the alkyl group contains 1 to 4 carbon atoms.

According to a first preferred embodiment, the copolymer of Methyl Methacrylate (MMA) comprises 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 ethylenic unsaturation copolymerizable with the methyl methacrylate. Preferably, the comonomer is selected from methyl acrylate and ethyl acrylate and mixtures thereof.

The weight average molecular weight of the (meth) acrylic polymer (P1) should be high, which means more than 50000g/mol, preferably more than 100000 g/mol.

Weight average molecular weight can be measured by Size Exclusion Chromatography (SEC).

The (meth) acrylic polymer (P1) was completely dissolved in the (meth) acrylic monomer (M1) or the mixture of (meth) acrylic monomers. This can increase the viscosity of the (meth) acrylic monomer (M1) or the mixture of (meth) acrylic monomers. The resulting solution is a liquid composition commonly referred to as a "resin syrup" or "prepolymer". The liquid (meth) acrylic syrup has a dynamic viscosity value of between 10mpa.s and 10000 mpa.s. The viscosity of the resin syrup can be easily measured using a rheometer or a viscometer. The dynamic viscosity was measured at 25 ℃.

Advantageously, the liquid (meth) acrylic composition or resin syrup does not comprise additional actively added solvent.

With respect to the (meth) acrylic monomer (M1), the monomer is selected from acrylic acid, methacrylic acid, alkyl acrylic monomers, alkyl methacrylic monomers, hydroxyalkyl acrylic monomers and hydroxyalkyl methacrylic monomers and mixtures thereof.

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

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.

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.

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.

Since the liquid composition LC1 or (meth) acrylic resin syrup according to the present invention may contain a (meth) acrylic monomer (M1) or a mixture of (meth) acrylic monomers; the mixture of (meth) acrylic monomers (M1) and (M1+ x) is also referred to simply as one or more (meth) acrylic monomers (M1).

As fibrous substrates, mention may be made of several types of fibers, unidirectional rovings or continuous filament mats, fabrics, felts or nonwovens, which may be in the form of strips, rolls (laps), braids, mats (locks) or sheets. The fibrous material can have a wide variety of forms and dimensions, one, two, or three dimensions. The fibrous substrate comprises a combination of one or more fibers. When the fibers are continuous, their combination forms a fabric.

The one-dimensional form corresponds to linear long fibers. The fibers may be discontinuous or continuous. The fibers may be arranged randomly or parallel to each other in the form of continuous filaments. A fiber is defined by its aspect ratio, which is the ratio of the length and 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 at least 7500, most advantageously at least 10000.

The two-dimensional form corresponds to a non-woven or woven fibre mat or reinforcement or fibre bundle, which may also be braided. Even if the two-dimensional form has a certain thickness and therefore in principle this thickness is the third dimension, it is considered to be two-dimensional according to the invention.

The three-dimensional form corresponds to, for example, a non-woven fibrous mat or reinforcement or a stack or plied bundle of fibers or a mixture thereof, the combination of the two-dimensional form in the third dimension.

The source of the fibrous material may be natural or synthetic. As natural materials, mention may be made of vegetable fibers, wood fibers, animal fibers or mineral fibers.

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

As synthetic material, mention may be made of polymer fibers selected from fibers of thermosetting polymers, thermoplastic polymers or mixtures thereof.

The polymer fibers may include polyamides (aliphatic or aromatic), polyesters, polyvinyl alcohol, polyolefins, polyurethanes, polyvinyl chloride, polyethylene, unsaturated polyesters, epoxies, and vinyl esters.

The mineral fibres may also be selected from glass fibres, in particular glass fibres of the type E, R or S2, carbon fibres, boron fibres or silica fibres.

The fibrous substrate of the present invention is selected from the group consisting of plant fibers, wood fibers, animal fibers, mineral fibers, synthetic polymer fibers, glass fibers and carbon fibers and mixtures thereof.

Preferably, the fibrous substrate is selected from mineral fibers. More preferably, the fibrous substrate is selected from glass fibers or carbon fibers.

The diameter of the fibres of the fibrous base material is between 0.005 μm and 100. mu.m, preferably between 1 μm and 50 μm, more preferably between 5 μm and 30 μm, advantageously between 10 μm and 25 μm.

Preferably, for long fibers or continuous fibers in one-dimensional form or for two-dimensional or three-dimensional form of the fibrous base material, the fibers of the fibrous base material of the present invention are selected from continuous fibers (which means that the aspect ratio does not necessarily apply to long fibers).

With regard to initiators (Ini1) and (Ini2), initiator (Ini1) was activated by absorbing radiation and initiator (Ini2) was activated by heating.

The radiation activated initiator (Ini1) is preferably activated by absorption of radiation which may be ultraviolet, visible or infrared radiation. Preferably, it is Ultraviolet (UV) or visible radiation.

This is also referred to as photopolymerization, the corresponding initiator being referred to as photoinitiator.

The photoinitiator is selected from a type I free radical photoinitiator or a type II free radical photoinitiator or dyes.

The type I photoinitiator is selected from acetophenone, alkoxy acetophenone, hydroxyacetophenone, alkyl aminoacetophenone, benzoin ether or phosphine oxide.

The type II photoinitiator is selected from benzophenones, thioxanthones, quinones, benzoyl formate, dibenzylidene ketones or coumarins.

Photoinitiators of the dye class are, for example, triazines and derivatives thereof, fluorones and derivatives thereof, cyanines and derivatives thereof, safranins and derivatives thereof, 4,5,6, 7-tetrachloro-3 ',6' -dihydroxy-2 ',4',5',7' -tetraiodo-3H-spiro [ isobenzofuran-1, 9' -xanthen ] -3-one, pyrylium and thiopyrylium and derivatives thereof, thiazines and derivatives thereof, flavins and derivatives thereof, pyronines and derivatives thereof, oxazines and derivatives thereof, rhodamines and derivatives thereof.

The thermally activated initiator (Ini2) is preferably a free radical initiator.

The radical initiator (Ini2) may be chosen from compounds containing peroxy groups or compounds containing azo groups, preferably from compounds containing peroxy groups.

Preferably, the peroxy-group containing compound contains 2-30 carbon atoms.

Preferably, the peroxy group-containing compound is selected from the group consisting of diacyl peroxides, peroxyesters, peroxydicarbonates, dialkyl peroxides, peroxyacetals, hydroperoxides or peroxyketals.

More preferably, the second initiator (Ini2) has a half-life t of 1 hour at a temperature of at least 60 ℃, preferably at least 65 ℃, more preferably at least 70 ℃, more preferably at least 75 ℃_1/2。

More preferably, the second initiator (Ini2) has a half-life t of at least 1 hour at a temperature between 60 ℃ and 150 ℃, preferably between 65 ℃ and 150 ℃, more preferably between 70 ℃ and 145 ℃, more preferably between 75 ℃ and 140 ℃, even more preferably between 75 ℃ and 130 ℃_1/2。

The initiator (Ini2) is selected from diisobutyryl peroxide, cumyl peroxyneodecanoate, di (3-methoxybutyl) peroxydicarbonate, 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, tert-butyl peroxyneodecanoate, di-n-butyl peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, 1,3, 3-tetramethylbutyl peroxypivalate, tert-butyl peroxypivalate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, Bis (3,5, 5-trimethylhexanoyl) peroxide, dilauroyl peroxide, didecanoyl peroxide, 2, 5-dimethyl-2, 5-bis (2-ethylhexanoylperoxide) -hexane, 1,3, 3-tetramethylbutyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, dibenzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxydiethylacetate, tert-butyl peroxyisobutyrate, 1-bis (tert-butylperoxy) -3,3, 5-trimethylcyclohexane, 1-bis (tert-amylperoxy) cyclohexane, 1-bis (tert-butylperoxy) -cyclohexane, tert-amyl peroxy-2-ethylhexylcarbonate, tert-amyl peroxyacetate, Tert-butyl 3,5, 5-trimethylhexanoate peroxide, 2-di (tert-butylperoxy) -butane, tert-butyl peroxyisopropylcarbonate, tert-butyl peroxy2-ethylhexyl carbonate, tert-amyl peroxybenzoate, tert-butyl peroxyacetate, butyl 4, 4-di (tert-butylperoxy) valerate, tert-butyl peroxybenzoate, di-tert-amyl peroxide, dicumyl peroxide, di (2-tert-butylperoxyisopropyl) 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-triethyl-3, 6, 9-trimethyl-1, 4, 7-Triperoxononane, 2' -Azobisisobutyronitrile (AIBN), 2' -azobis (2-methylbutyronitrile), azobisisobutyramide, 2' -azobis (2, 4-dimethylvaleronitrile), 1' -azobis (hexahydrobenzonitrile) or 4, 4' -azobis (4-cyanovaleric acid).

Preferably, the initiator (Ini2) is selected from the group consisting of tert-amyl peroxypivalate, tert-butyl peroxypivalate, bis (3,5, 5-trimethylhexanoyl) peroxide, dilauroyl peroxide, didecanoyl peroxide, 2, 5-dimethyl-2, 5-bis (2-ethylhexanoylperoxy) -hexane, 1,3, 3-tetramethylbutyl peroxy 2-ethylhexanoate, tert-amyl peroxy2-ethylhexanoate, dibenzoyl peroxide, tert-butyl peroxy 2-ethylhexanoate, tert-butyl peroxydiethylacetate, tert-butyl peroxyisobutyrate, 1-bis (tert-butylperoxy) -3,3, 5-trimethylcyclohexane, 1-bis (tert-amylperoxy) cyclohexane, 1-bis (tert-butylperoxy) -cyclohexane, di (tert-butylperoxy) cyclohexane, di (tert-butyl peroxy) hexane, tert-amyl peroxy-2-ethylhexylcarbonate, tert-amyl peroxyacetate, tert-butyl peroxy-3, 5, 5-trimethylhexanoate, 2-di (tert-butylperoxy) -butane, tert-butyl peroxyisopropylcarbonate, tert-butyl peroxy-2-ethylhexylcarbonate, tert-amyl peroxybenzoate, tert-butyl peroxyacetate, butyl 4, 4-di (tert-butylperoxy) valerate, tert-butyl peroxybenzoate, di-tert-amyl peroxide, dicumyl peroxide, di (2-tert-butylperoxyisopropyl) 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 or 3,6, 9-triethyl-3, 6, 9-trimethyl-1, 4, 7-triperoxonane.

In one embodiment of the invention, at least two different free radical initiators (Ini2) are present. This may be two different free radical initiators that generate free radicals at different temperatures. The temperature difference between the two different initiators (Ini2) is at least 5K for a given half-life. This means that the half-life t for 1 hour is_1/2In other words, if the temperature of the first initiator (Ini1) is 75 ℃, then for a half-life t of 1 hour_1/2In general, the temperature of the second initiator (Ini2) is at least 80 ℃.

As regards the liquid resin LC1 impregnating the fibrous material according to the invention, it comprises a (meth) acrylic polymer (P1), a (meth) acrylic monomer (M1) or a mixture of (meth) acrylic monomers (M1) and (M1+ x) and at least two initiators (Ini1) and (Ini 2).

The total amount of the two initiators (Ini1) and (Ini2) in the liquid composition LC1 was at least 0.1phr relative to the sum of (meth) acrylic monomer (M1) and (meth) acrylic polymer (P1). Preferably, the total amount of the two initiators (Ini1) and (Ini2) in the composition is at least 0.2phr, more preferably at least 0.5phr, even more preferably at least 0.75phr, advantageously at least 1phr, with respect to the sum of the (meth) acrylic monomer (M1) and the (meth) acrylic polymer (P1).

The total amount of the two initiators (Ini1) and (Ini2) in the composition is at most 15phr relative to the sum of the (meth) acrylic monomer (M1) and the (meth) acrylic polymer (P1). Preferably, the total amount of the two initiators (Ini1) and (Ini2) in the composition is at most 12phr, more preferably at most 10phr, even more preferably at most 8phr, advantageously at most 5phr, with respect to the sum of the (meth) acrylic monomer (M1) and the (meth) acrylic polymer (P1).

The total amount of the two initiators (Ini1) and (Ini2) in the composition is between 0.1phr and 15phr, relative to the sum of the (meth) acrylic monomer (M1) and the (meth) acrylic polymer (P1). Preferably, the total amount of the two initiators (Ini1) and (Ini2) in the composition is between 0.2phr and 12phr, more preferably between 0.5phr and 10phr, even more preferably between 0.75phr and 8phr and advantageously between 1phr and 5phr, with respect to the sum of the (meth) acrylic monomer (M1) and the (meth) acrylic polymer (P1).

The amount of initiator (Ini1) in the composition is between 0.1phr and 5phr, with respect to the sum of (meth) acrylic monomer (M1) and (meth) acrylic polymer (P1). Preferably, the amount of initiator (Ini1) in the composition is between 0.2phr and 4phr, more preferably between 0.3phr and 3phr and advantageously between 0.5phr and 2phr, with respect to the sum of (meth) acrylic monomer (M1) and (meth) acrylic polymer (P1).

The one or more (meth) acrylic monomers (M1) present in the liquid composition LC1 is at least 40 wt%, preferably at least 50 wt%, advantageously at least 60 wt%, more advantageously at least 65 wt% of the total amount of liquid (meth) acrylic resin syrup.

The one or more (meth) acrylic monomers (M1) in the liquid composition LC1 or the (meth) acrylic resin syrup are present in a proportion of between 40 and 90 wt%, preferably between 45 and 85 wt% of the composition comprising the one or more (meth) acrylic monomers (M1) and the (meth) acrylic polymer (P1).

The one or more (meth) acrylic polymers (P1) in the liquid composition LC1 or (meth) acrylic resin syrup are present in a proportion of at least 1 wt%, preferably at least 5 wt%, more preferably at least 10 wt%, even more preferably at least 15 wt%, advantageously at least 18 wt%, more advantageously at least 20 wt% of the composition comprising the one or more (meth) acrylic monomers (M1) and the one or more (meth) acrylic polymers (P1).

The one or more (meth) acrylic polymers (P1) in the liquid (meth) acrylic resin syrup LC1 are present in a proportion of not more than 50% by weight, preferably not more than 40% by weight, advantageously not more than 30% by weight of the composition comprising the one or more (meth) acrylic monomers (M1) and the one or more (meth) acrylic polymers (P1).

After impregnation, a composition PRE1 was obtained comprising (meth) acrylic polymer (P1), (meth) acrylic monomer (M1) or a mixture of (meth) acrylic monomers (M1) and (M1+ x), at least two initiators (Ini1) and (Ini2), and a fiber material.

After impregnation and partial polymerization, a composition PRE2 was obtained, comprising (meth) acrylic polymer (P1), (meth) acrylic monomer (M1) or a mixture of (meth) acrylic monomers (M1) and (M1+ x), initiator (Ini2) and fibrous material.

Composition PRE2 can be stored. Composition PRE2 can be stored between two films.

As regards the film of the composition according to the invention, it is a polymer film. Preferably, the membrane is made of a thermoplastic polymer.

Composition PRE2 is a prepreg. Prepregs are increasingly used in high performance applications in the composite industry as well as other industries. Some important areas in which prepregs are currently used are listed below:

-aircraft interior, aerospace components, aircraft floors, cargo aircraft (cargo) linings,

automotive parts and assemblies, tools, ballistic panels,

-A/C pipeline, electronic transmission applications,

UV-resistant parts, sporting goods, high-temperature parts,

-honeycomb and foam sheets, flame-retardant laminates,

carbon-carbon composite, high-rise flooring (high-rise flooring), high impact surface,

UAV, seat back, multiplier.

Regarding the process for preparing liquid composition LC 1: all the components may be mixed in a container to obtain a liquid composition LC1 according to the invention.

The process for preparing liquid composition LC1 comprises the steps of:

i) preparing a mixture of a (meth) acrylic polymer (P1) and a (meth) acrylic monomer (M1);

ii) initiators (Ini1) and (Ini2) are added, jointly or in succession, to the mixture prepared in the preceding step.

One aspect of the present invention relates to a process for preparing a polymer composite from a composition comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), a fibrous material, and at least an initiator (Ini2), the process comprising the steps of:

i) impregnating a fibrous material with a liquid composition LC1, said liquid composition LC1 comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), and at least two initiators (Ini1) and (Ini2),

ii) partially polymerizing the product obtained in step i) by using an initiator (Ini1),

iii) storing the product prepared in step ii),

iv) continuing the polymerization by using the initiator (Ini2),

characterized in that the initiator (Ini1) is activated by absorption of radiation and the initiator (Ini2) is activated by heating.

After step i), a composition PRE1 was obtained comprising a (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), at least two initiators (Ini1) and (Ini2), and a fibrous base material.

As regards the partial polymerization step ii), it is done by polymerizing a portion of the (meth) acrylic monomer (M1) using an initiator (Ini1) activated by absorbing radiation.

Preferably, the conversion of (meth) acrylic monomer (M1) in step ii) is between 30% and 90%, more preferably between 40% and 80%, even more preferably between 50% and 75%, most preferably between 55% and 75%, advantageously between 58% and 70%.

Preferably, the polymerization temperature in step ii) is between 0 ℃ and 40 ℃, more preferably between 5 ℃ and 35 ℃, still more preferably between 10 ℃ and 35 ℃, even more preferably between 15 ℃ and 30 ℃.

After step ii), a composition PRE2 was obtained comprising (meth) acrylic polymer (P1), (meth) acrylic monomer (M1), initiator (Ini2) and fibrous base material. The initiator (Ini1) has been used to partially polymerize the (meth) acrylic monomer (M1).

Preferably, the radiation source used for the polymerization in step ii) emits radiation having a wavelength λ (nm) of from 200nm to 800nm, more preferably from 250nm to 500 nm.

As regards the storage step iii), it is done at a temperature lower than 35 ℃. Preferably, the half-life temperature T of the initiator (Ini2) is taken into account_1/2And (5) storing. More preferably at a half-life temperature T of 1 hour greater than that of the initiator (Ini2)_1/2A half-life temperature T of at least 40K lower, even more preferably than 1 hour of the initiator (Ini2)_1/2Storage at a temperature at least 50K lower, still more preferably at least 60K lower, advantageously at least 70K lower, more advantageously at least 80K lower.

With regard to the continued polymerization step iv), further polymerization can be carried out by: hot compaction, hot compaction with injection of thermoplastic polymers, continuous process for hollow structures, compaction under vacuum with (meth) acrylic surface layers, resin transfer molding and filament winding on the composition of the invention.

By continuing to polymerize composition PRE2 in step iv), a polymer composite or polymer composite material is obtained.

According to a first preferred embodiment of the process for continuing to polymerize composition PRE2 according to the present invention, it is a thermal compression.

According to a second preferred embodiment of the process for continuing to polymerize composition PRE2 according to the present invention, it is the compaction under vacuum.

According to a third preferred embodiment of the process for continuing to polymerize composition PRE2 according to the present invention, it is a filament winding.

The process for preparing the polymer composite according to steps i) to iv) given previously may also be filament winding.

The method of manufacturing a composite part and a mechanical or structured part or product may further comprise a post-forming step. Post-forming involves bending as the form of the composite part changes.

The method of manufacturing a composite part as well as a mechanical or structured part or product may further comprise the step of welding or gluing or laminating.

The thermoplastic composite part obtained by the process according to the invention may be post-formed after polymerization of the liquid composition of the invention. The shaping includes bending as the form of the composite material changes.

The thermoplastic parts or the manufactured composite parts obtained after polymerization of the composition of the invention and/or obtained by the method according to the invention may be welded, glued or laminated.

As regards the use of the polymer composite, mention may be made of automotive and motorcycle sports applications, such as pressure vessels, ballistic & defense applications, marine applications, railway and transportation applications, sports, leisure and recreation applications, art and recreation applications, aviation and aerospace applications, building and civil engineering applications, oil and gas applications, renewable applications, such as photovoltaic applications and wind energy applications.

As to the use of mechanical parts made of the composite material thus manufactured, mention may be made of automotive applications, transport applications such as buses or trucks, marine applications, railway applications, sports, aeronautical and aerospace applications, photovoltaic applications, computer-related applications, building and construction applications, telecommunication applications and wind energy applications.

Mechanical parts made of composite materials are in particular motor vehicle parts, ship parts, bus parts, train parts, sports goods, aircraft or helicopter parts, spacecraft or rocket parts, photovoltaic module parts, building or construction materials, wind turbine parts, for example spar caps of beams of wind turbine blades, furniture parts, building or construction parts.

Drawings

FIG. 1-Process for preparing a composition PRE2(1) in tablet form from a liquid composition LC1(3) of the invention: impregnating the fibrous material (2) from the roll (4) between two rolls (6) with a liquid composition LC1(3) from a feeder (5) to produce a composition PRE1(10), partially polymerizing the composition PRE1(10) with a UV source (15) to obtain a thermoplastic prepreg.

Examples

An example is shown in fig. 1, a roll (4) of carbon tows or glass filaments (2) as fibrous material is impregnated with a liquid composition LC1 (3). The liquid composition LC1(3) was added by means of feeder (5). The impregnation of the fibrous material is carried out between two rolls (6). Composition PRE1(10) was obtained. The partial polymerization is initiated by means of a UV lamp (15). Composition PRE2(1) was obtained. Thermoplastic films (20) were added to each side of the composition PRE2(1), and the product was cut into sheets (1b) by means of a cutter (25).

The composition (1b) in the form of a sheet was compression-molded and a thermoplastic material was obtained.