(METH)ACRYLIC COMPOSITION COMPRISING TWO MONOMERS, PROCESS FOR PREPARING SAID COMPOSITION AND USES THEREOF

Abstract

(Meth)acrylic composition COMPRISING TWO MONOMERS, process for preparing SAID COMPOSITION and uses thereof The present invention relates to a (meth)acrylic composition comprising two monomers, a process for preparing the (meth)acrylic composition and uses of such a (meth)acrylic composition. In particular, the present invention relates to a (meth)acrylic composition comprising two monomers, said two monomers being different and capable of being copolymerized, a process for preparing the (meth)acrylic composition and uses of such a (meth)acrylic composition, in particular for increasing the kinetics during polymerization.The invention also relates to a (meth)acrylic polymeric composition and a (meth)acrylic polymeric composite material, both comprising or being composed of a (meth)acrylic composition comprising the two monomers, a process for preparing such a (meth)acrylic polymeric composition or such a (meth)acrylic composite material comprising or composed of a (meth)acrylic composition comprising the two monomers and an object comprising such a (meth)acrylic polymeric composition or such a (meth)acrylic polymeric composite material comprising or composed of a (meth)acrylic composition comprising the two monomers.

Description

Title of the invention: (meth)acrylic composition COMPRISING TWO MONOMERS, process for preparing SAID COMPOSITION and uses thereof Technical field

[0001] The present invention relates to a (meth)acrylic composition comprising two monomers, a process for preparing the (meth)acrylic composition and uses of such a (meth)acrylic composition.

[0002] In particular, the present invention relates to a (meth)acrylic composition comprising two monomers, said two monomers being different and capable of being copolymerized, a process for preparing the (meth)acrylic composition and the uses of such a (meth)acrylic composition, in particular for increasing the kinetics during polymerization.

[0003] The invention also relates to a (meth)acrylic polymeric composition and a (meth)acrylic polymeric composite material, both comprising or being composed of a (meth)acrylic composition comprising the two monomers, a method for preparing such a (meth)acrylic polymeric composition or such a (meth)acrylic composite material comprising or composed of a (meth)acrylic composition comprising the two monomers and an object comprising such a (meth)acrylic polymeric composition or such a (meth)acrylic polymeric composite material comprising or composed of a (meth)acrylic composition comprising the two monomers. [Technical problem]

[0004] Thermoplastic polymers are materials that are widely used today in several fields and applications, for example in the construction, aeronautics, automotive or railway sectors, where they are part of mechanical parts.

[0005] These mechanical parts that must withstand high stresses during their use are widely manufactured from composite materials. A composite material is a macroscopic combination of two or more immiscible materials. The composite material consists of at least one material that forms the matrix, i.e. a continuous phase that ensures the cohesion of the structure, and a reinforcing material. The objective of using a composite material is to obtain performance qualities that cannot be obtained from each of its constituents when used separately. Therefore, composite materials are widely used in several industrial sectors, for example construction, automotive, aerospace, transportation, leisure, electronics, and sports, in particular due to their better mechanical performance (higher tensile strength, higher tensile modulus, higher fracture toughness) and their low density, compared to homogeneous materials.

[0006] In order to enable thermoforming and recycling, it is preferred to use thermoplastic polymers also in composite materials.

[0007] Thermoplastic polymers consist of linear or branched polymers, which are usually not crosslinked. Thermoplastic polymers are heated to mix the necessary constituents for the manufacture of the composite material and are cooled to take the final shape. The problem with these molten thermoplastic polymers is their very high viscosity. In order to prepare a polymer composite material based on thermoplastic polymer, a thermoplastic polymer resin, commonly called "syrup", is used to impregnate the reinforcing material, for example a fibrous substrate. Once polymerized, the thermoplastic polymer syrup constitutes the matrix of the composite material.

[0008] Furthermore, when used without impregnation, it is desirable to have a liquid composition that polymerizes quickly with good conversion in order to increase productivity. At the end of use of the object or article comprising the composite material, said object or article must be easily recyclable.

[0009] There is a need for (meth)acrylic compositions having improved reactivity to improve cycle times.

[0010] There is a need for (meth)acrylic compositions having improved kinetics, faster reaction time.

[0011] There is also a need to provide a method of manufacturing (meth)acrylic compositions useful for preparing a (meth)acrylic polymeric material with a reduced cycle time.

[0012] There is also a need for a process for preparing (meth)acrylic composite materials that have a reduced cycle time.

[0013] Another aim of the present invention is to propose a method for manufacturing a (meth)acrylic polymer composite material having a reduced cycle time, which is recyclable. [BACKGROUND OF THE INVENTION] Prior Art

[0014] Document WO2013 / 056845 describes a composite material obtained by in situ polymerization of thermoplastic (meth)acrylic resins. The polymeric composite material obtained by in situ polymerization of a thermoplastic (meth)acrylic resin and a fibrous material containing long fibers and its use, a method for manufacturing such a composite material and a manufactured mechanical or structured part or article comprising this polymeric composite material. The document does not disclose anything about the use of a mixture of two specific monomers.

[0015] Document WO2014 / 013028 describes an impregnation method for a substrate fibrous, a liquid (meth)acrylic syrup for the impregnation process, its polymerization method and a structured article thus obtained. The liquid (meth)acrylic syrup comprises a (meth)acrylic polymer, a (meth)acrylic monomer and at least one initiator or initiation system for starting the polymerization of the (meth)acrylic monomer. The document does not disclose anything about the use of a mixture of two specific monomers.

[0016] No prior art document cited discloses a liquid (meth)acrylic syrup having a reduced polymerization time or cycle time. [Brief description of the invention]

[0017] Surprisingly, we found that a (meth)acrylic (MCI) composition comprising:

[0018] (a) 100 parts by weight of a liquid (meth)acrylic syrup comprising:

[0019] (aO from 1% by weight to 50% by weight of one or more (meth)acrylic polymers (PI), and

[0020] (a2) from 50% by weight to 99% by weight of at least two (meth)acrylic monomers different (Ml) and (M2), each monomer Ml and M2 comprising only one (meth)acrylic function per monomer,

[0021] b) optionally from 0.01 part by weight to 5 parts by weight of a polymerization initiator (Ini);

[0022] characterized in that the monomer Ml is in excess in the component (a2);

[0023] makes it possible to provide a composition for the preparation of polymeric compositions (meth)acrylics and (meth)acrylic composite materials, while reducing polymerization time.

[0024] Surprisingly, we have discovered that a process for preparing a (meth)acrylic composition (MCI), said process comprising the following steps:

[0025] (i) providing a (meth)acrylic polymer (PI) and monomers (meth)acrylics (Ml) and (M2),

[0026] (ii) preparation of 100 parts by weight of (a) a liquid (meth)acrylic syrup comprising:

[0027] (aO from 1% by weight to 50% by weight of one or more (meth)acrylic polymers PI, and

[0028] (a2) from 50% by weight to 99% by weight of at least two (meth)acrylic monomers different (Ml) and (M2), each monomer Ml and M2 comprising only one (meth)acrylic function per monomer and the monomer (Ml) being in excess compared to the monomer (M2),

[0029] by mixing the components (aj and (a2),

[0030] (iii) optionally providing from 0.01 part by weight to 5 parts by weight of a polymerization initiator (Ini),

[0031] (iv) mixing the components,

[0032] provides a composition for the preparation of (meth)acrylic polymeric materials MPM1 and (meth)acrylic polymeric composite materials MPCM1 which, while having a reduced cycle time. Description of the embodiments

[0033] According to a first aspect, the present invention relates to a (meth)acrylic MCI composition, said composition comprising:

[0034] (a) 100 parts by weight of a liquid (meth)acrylic syrup comprising:

[0035] (aO from 1% by weight to 50% by weight of one or more (meth)acrylic polymers (PI), and

[0036] (a2) from 50% by weight to 99% by weight of at least two (meth)acrylic monomers different (Ml) and (M2), each monomer Ml and M2 comprising only one (meth)acrylic function per monomer,

[0037] b) optionally from 0.01 part by weight to 5 parts by weight of a polymerization initiator (Ini);

[0038] characterized in that the monomer Ml is in excess in component (a2).

[0039] According to a second aspect, the present invention relates to a (meth)acrylic (MCI) composition, said composition comprising:

[0040] (a) 100 parts by weight of a liquid (meth)acrylic syrup comprising:

[0041] (aO from 1% by weight to 50% by weight of one or more (meth)acrylic polymers (PI), and

[0042] (a2) from 50% by weight to 99% by weight of at least two (meth)acrylic monomers different (Ml) and (M2), each monomer Ml and M2 comprising only one (meth)acrylic function per monomer,

[0043] (b) from 0.01 part by weight to 5 parts by weight of a polymerization initiator (Ini);

[0044] characterized in that the monomer (Ml) is in excess in the component (a2).

[0045] According to a third aspect, the present invention relates to a process for preparing a (meth)acrylic composition (MCI) comprising the following steps:

[0046] (i) providing the (meth)acrylic polymer (PI) and the (meth)acrylic monomers (Ml) and (M2) of the first or second aspect,

[0047] (ii) preparation of 100 parts by weight of (a) a liquid (meth)acrylic syrup comprising:

[0048] (aO from 1% by weight to 50% by weight of one or more (meth)acrylic polymers PI, and

[0049] (a2) from 50% by weight to 99% by weight of at least two (meth)acrylic monomers different (Ml) and (M2), each monomer Ml and M2 comprising only one (meth)acrylic function per monomer and the monomer (Ml) being in excess compared to the monomer (M2),

[0050] by mixing the components (aj and (a2),

[0051] (iii) optionally providing from 0.01 part by weight to 5 parts by weight of a polymerization initiator (Ini),

[0052] (iv) mixing the components.

[0053] According to a fourth aspect, the present invention relates to a process for preparing a (meth)acrylic composition (MCI), the process comprising the following steps

[0054] (i) providing the (meth)acrylic polymer (PI) and the (meth)acrylic monomers (Ml) and (M2) of the first or second aspect,

[0055] (ii) preparation of 100 parts by weight of (a) a liquid (meth)acrylic syrup comprising:

[0056] (ai) from 1% by weight to 50% by weight of one or more (meth)acrylic polymers PI, and

[0057] (a2) from 50% by weight to 99% by weight of at least two (meth)acrylic monomers different (Ml) and (M2), each monomer Ml and M2 comprising only one (meth)acrylic function per monomer and the monomer (Ml) being in excess compared to the monomer (M2),

[0058] by mixing the components (aj and (a2),

[0059] (iii) providing from 0.01 part by weight to 5 parts by weight of a polymerization initiator (Ini),

[0060] (iv) mixing the components.

[0061] According to a fifth aspect, the present invention relates to the use of a (meth)acrylic composition (MCI) for preparing a (meth)acrylic polymeric material (MPM1) or a (meth)acrylic polymeric composite material (MPCM1), said (meth)acrylic composition (MCI) comprising:

[0062] (a) 100 parts by weight of a liquid (meth)acrylic syrup comprising:

[0063] (aO from 1% by weight to 50% by weight of one or more (meth)acrylic polymers (PI), and

[0064] (a2) from 50% by weight to 99% by weight of at least two (meth)acrylic monomers different (Ml) and (M2), each monomer (Ml) and (M2) comprising only one (meth)acrylic function per monomer,

[0065] b) optionally from 0.01 part by weight to 5 parts by weight of a polymerization initiator (Ini);

[0066] characterized in that the monomer (Ml) is in excess in the component (a2).

[0067] According to a sixth aspect, the present invention relates to a polymeric material (meth)acrylic (MPM1) or a (meth)acrylic polymer composite material (MPCM1) prepared by polymerization of the (meth)acrylic composition (MCI).

[0068] According to a seventh aspect, the present invention relates to a process for preparing a (meth)acrylic polymeric material (MPM1), said process comprising the following steps:

[0069] (i) providing a (meth)acrylic (MCI) composition according to the first or second aspect,

[0070] (ii) polymerization of the (meth)acrylic composition (MCI).

[0071] According to an eighth aspect, the present invention relates to a method for preparing a (meth)acrylic polymer composite material (MPCM1), said method comprising the following steps: i. provision of a (meth)acrylic composition (MCI) according to the first or second aspect, ii. bringing the (meth)acrylic composition (MCI) into contact with a reinforcing material, (iii) polymerization of the (meth)acrylic composition (MCI).

[0072] The term "(meth)acrylic monomer" covers both an acrylic monomer and a methacrylic monomer. Similarly, the term "(meth)acrylic polymer" covers not only an acrylic homopolymer but also a methacrylic homopolymer, an acrylic copolymer and a methacrylic copolymer.

[0073] The term "PMMA" denotes homo- and copolymers of methyl methacrylate (MMA), for the MMA copolymer the weight ratio of MM A within the PMMA is at least 50% by weight.

[0074] The term "initiator" denotes a chemical species which forms a compound or an intermediate compound which initiates the polymerization of a monomer, one which is capable of successively binding with a large number of other monomers into a polymeric compound.

[0075] The term "polymer composite" denotes a multi-component material comprising several different phase domains in which at least one type of phase domain is a continuous phase and in which at least one component is a polymer.

[0076] The term "thermoplastic" means a polymer that transforms into a liquid or becomes more liquid or less viscous when heated and can take new shapes by the application of heat and possibly pressure. This also applies to slightly crosslinked thermoplastic polymers that can be thermoformed when heated above the softening temperature. smoothing.

[0077] By specifying that a range is from x to y in the present invention, this means that the upper and lower limits of this range are included, which is equivalent to at least x and up to y.

[0078] By specifying that a range is between x and y in the present invention, this means that the upper and lower limits of this range are excluded, which is equivalent to more than x and less than y.

[0079] The liquid (meth)acrylic syrup (a) of the composition according to the invention comprises (a1) a (meth)acrylic polymer (PI) and (a2) at least two different (meth)acrylic monomers (M1) and (M2), each monomer (M1) and (M2) comprising only one (meth)acrylic function per monomer.

[0080] The liquid (meth)acrylic syrup (a) according to the (meth)acrylic composition (MCI) of the invention comprises between 1% by weight and 50% by weight of a (meth)acrylic polymer (PI) and between 50% by weight and 99% by weight of at least two different (meth)acrylic monomers (Ml) and (M2), each monomer (Ml) and (M2) comprising only one (meth)acrylic function per monomer. The range between 50% by weight and 99% by weight relates to the sum of at least two different (meth)acrylic monomers (Ml) and (M2).

[0081] Preferably, the liquid (meth)acrylic syrup (a) comprises between 2% by weight and 50% by weight of a (meth)acrylic polymer (PI) and between 50% by weight and 98% by weight of at least two different (meth)acrylic monomers (Ml) and (M2), more preferably between 2% by weight and 40% by weight of a (meth)acrylic polymer (PI) and between 60% by weight and 98% by weight of at least two different (meth)acrylic monomers (Ml) and (M2), even more preferably between 3% by weight and 40% by weight of a (meth)acrylic polymer (PI) and between 60% by weight and 97% by weight of at least two different (meth)acrylic monomers (Ml) and (M2),advantageously between 3% by weight and 35% by weight of a (meth)acrylic polymer (PI) and between 65% by weight and 97% by weight of at least two different (meth)acrylic monomers (Ml) and (M2) and more advantageously between 3% by weight and 30% by weight of a (meth)acrylic polymer (PI) and between 70% by weight and 97% by weight of at least two different (meth)acrylic monomers (Ml) and (M2).

[0082] The dynamic viscosity of the liquid (meth)acrylic syrup is in a range from 10 mPa*s to 10,000 mPa*s, preferably from 20 mPa*s to 7,000 mPa*s and advantageously from 20 mPa*s to 5,000 mPa*s and more advantageously from 20 mPa*s to 2,000 mPa*s and even more advantageously between 20 mPa*s and 1,000 mPa*s. The viscosity of the syrup can easily be measured with a rheometer or a viscometer. The dynamic viscosity is measured at 25°C. If the liquid (meth)acrylic syrup has Newtonian behavior, which means that it does not exhibit fluidization under protrusion, the dynamic viscosity is independent of the shear in a rheometer or the speed of the spindle in a viscometer. If the liquid composition has non-Newtonian behavior, meaning that it exhibits shear thinning, the dynamic viscosity is measured at a shear rate of 1 s 1 at 25 °C.

[0083] As for the liquid (meth)acrylic syrup (a), it comprises (a1) the (meth)acrylic polymer (PI) and (a2) the at least two different (meth)acrylic monomers (Ml) and (M2). Once the (meth)acrylic composition (MCI) has been polymerized, the at least two different (meth)acrylic monomers (Ml) and (M2) finally polymerize with other (meth)acrylic monomers and are transformed into a (meth)acrylic polymer (P2) comprising the monomeric units of the (meth)acrylic monomers (Ml) and (M2) and other possible comonomers.

[0084] The liquid (meth)acrylic syrup of the (meth)acrylic composition (MCI) according to the invention may comprise a single (meth)acrylic polymer (PI), but may also comprise a mixture of two, three or even more (meth)acrylic polymers (PI). If there is a mixture of different (meth)acrylic polymers (PI), the difference is the composition of the respective (meth)acrylic polymer (PI) or the molecular weight of the respective (meth)acrylic polymer (PI) or both.

[0085] The or each (meth)acrylic polymer (PI) included in the liquid (meth)acrylic syrup may in particular be chosen from:

[0086] . poly(alkyl acrylate)s which comprise homopolymers of alkyl acrylate and alkyl acrylate copolymers, and

[0087] . poly(alkyl methacrylate)s which comprise homopolymers of me alkyl acrylate and alkyl methacrylate copolymers.

[0088] According to a preferred embodiment, the or each (meth)acrylic polymer (PI) is a poly(methyl methacrylate) (PMMA), it being understood that, as indicated above, the poly(methyl methacrylate) (PMMA) can denote a homopolymer of methyl methacrylate (MMA) or a copolymer of MMA.

[0089] In particular, in the case where the liquid (meth)acrylic syrup comprises a mixture of two or more poly(methyl methacrylate) (PI), this mixture can be formed by mixing at least two MMA homopolymers of different molecular weight, by mixing at least two MMA copolymers having an identical monomer composition and a different molecular weight, by mixing at least two MMA copolymers having a different monomer composition or by mixing at least one MMA homopolymer and at least one MMA copolymer.

[0090] According to a first preferred embodiment, the (meth)acrylic polymer (PI) is chosen from a methyl methacrylate homopolymer or a methyl methacrylate copolymer or a mixture thereof, methyl methacrylate re advantageously having at least 50% by weight of the or each (meth)acrylic polymer (PI).

[0091] According to one embodiment of the invention, methyl methacrylate represents at least 55% by weight of the or each (meth)acrylic polymer (PI).

[0092] According to another particular embodiment, the or each (meth)acrylic polymer (PI) comprises at least 70%, advantageously at least 80%, preferably at least 90% and more preferably at least 95% by weight of methyl methacrylate.

[0093] When the or each (meth)acrylic polymer (PI) is a methyl methacrylate (MMA) copolymer, it may comprise at least one comonomer containing at least one ethylenic unsaturation and which is capable of copolymerizing with methyl methacrylate. Among these comonomers, mention may in particular be made of acrylic and methacrylic acids and alkyl (meth)acrylates in which the alkyl group contains from 1 to 12 carbon atoms. By alkyl (meth)acrylates is meant an alkyl ester of acrylic acid or methacrylic acid. As examples of comonomers, mention may be made of methyl acrylate and an ethyl, butyl or 2-ethylhexyl (meth)acrylate.

[0094] Advantageously, the or each (meth)acrylic polymer (PI) is a homopolymer of methyl methacrylate or a copolymer of methyl methacrylate and an alkyl acrylate or an alkyl methacrylate whose alkyl group contains from 1 to 12 carbon atoms, advantageously from 1 to 6 carbon atoms and preferentially from 1 to 4 carbon atoms.

[0095] According to a first preferred embodiment, when the or each (meth)acrylic polymer (PI) is a methyl methacrylate (MMA) copolymer, this methyl methacrylate (MMA) copolymer comprises from 70% to 99.9%, advantageously from 80% to 99.9%, preferably from 90% to 99.9% and more preferably from 95% to 99.9% by weight of methyl methacrylate and from 0.1% to 30%, advantageously from 0.1% to 20%, preferably from 0.1% to 10% and more preferably from 0.1% to 5% by weight of at least one comonomer containing at least one ethylenic unsaturation copolymerizable with methyl methacrylate. Preferably the or each comonomer is chosen from methyl acrylate and ethyl acrylate.

[0096] In an advantageous variant of the first preferred embodiment, when the or each (meth)acrylic polymer (PI) is a copolymer of methyl methacrylate (MMA), the (meth)acrylic polymer (PI) is a copolymer of methyl methacrylate and alkyl acrylate.

[0097] In a preferred variant of the first preferred embodiment, when the or each (meth)acrylic polymer (PI) is a methyl methacrylate copolymer (MMA), (meth)acrylic polymer (PI) is a copolymer of methyl methacrylate and methyl acrylate or ethyl acrylate.

[0098] According to a second preferred embodiment, when the or each (meth)acrylic polymer (PI) is a methyl methacrylate (MMA) copolymer, this methyl methacrylate (MMA) copolymer comprises from 50% to 99.9%, advantageously from 52% to 99.9%, preferentially from 53% to 99.9% and more preferentially from 55% to 99.9% by weight of methyl methacrylate and from 0.1% to 50%, advantageously from 0.1% to 48%, preferentially from 0.1% to 47% and more preferentially from 0.1% to 45% by weight of at least one comonomer containing at least one ethylenic unsaturation copolymerizable with methyl methacrylate. Preferably, the or each comonomer is selected from methyl acrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate and butyl methacrylate.

[0099] The weight average molecular weight, denoted Mw, of the or each (meth)acrylic polymer (PI) is generally high and may therefore be greater than 40,000 g / mol, advantageously greater than 45,000 g / mol and preferably greater than 50,000 g / mol. The weight average molecular weight can be measured by size exclusion chromatography (SEC).

[0100] The (meth)acrylic polymer PI, if not crosslinked, usually has a melt mass flow rate (MFR) according to ISO 1133-2:2011 (230 °C / 3.8 kg) of between 0.1 g / 10 min and 20 g / 10 min or a melt mass flow rate of between 0.2 g / 10 min and 18 g / 10 min, or between 0.3 g / 10 min and 16 g / 10 min or between 0.4 g / 10 min and 13 g / 10 min

[0101] As regards the (meth)acrylic monomers (M1) and (M2), the weight ratio of monomers (M1) / (M2) is between 95 / 5 and 51 / 49.

[0102] Preferably, the weight ratio of monomers (M1) / (M2) is between 95 / 5 and 65 / 35.

[0103] The glass transition temperature Tg of a respective homopolymer of (meth)acrylic monomers (Ml) and (M2) is at least 50°C, preferably at least 60°C and even more probably at least 70°C.

[0104] The glass transition temperature Tg of polymers is measured by dynamic differential scanning calorimetry (differential scanning calorimetry, DSC) according to ISO 11357-2 / 2013.

[0105] The reactivity ratios of the monomers ri and r2 between the two different (meth)acrylic monomers (Ml) and (M2) are at least 0.35.

[0106] In a preferred embodiment, r2>0.4, preferably r2>0.5.

[0107] In a first preferred embodiment, ri>0.35 and r2>0.8.

[0108] In a second preferred embodiment, ri>0.4 and r2>0.8.

[0109] In a third preferred embodiment, ri>0.6 and r2>0.9.

[0110] The monomer reactivity ratios r1 and r2 of the two monomers, also called radical copolymerization reactivity ratios, are a well-known parameter in polymer chemistry. The ratios are listed, for example, in the Polymer Handbook (ed. J. Brandrup et al., John Wiley & Sons Inc.) 4th ed., 1999.

[0111] With regard to the (meth)acrylic monomer (Ml), the monomer is chosen from alkyl methacrylic monomers. By alkyl methacrylic monomer is meant an alkyl ester of methacrylic acid.

[0112] More preferably, the (meth)acrylic monomer (Ml) is chosen from the me methyl acrylate.

[0113] Preferably, each monomer (M1) and (M2) is a methacrylic monomer.

[0114] With regard to the (meth)acrylic monomer (M2), the monomer is preferably chosen from 2-hydroxypropyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, glycidyl methacrylate or methacrylic acid.

[0115] More preferably, the (meth)acrylic monomer (M2) is chosen from the me 2-hydroxypropyl methacrylate or cyclohexyl methacrylate.

[0116] According to a first even more preferential embodiment, the (meth)acrylic monomer (M2) is chosen from 2-hydroxypropyl methacrylate.

[0117] According to a first even more preferential embodiment, the (meth)acrylic monomer (M2) is chosen from cyclohexyl methacrylate.

[0118] In a first variant of the invention, the liquid (meth)acrylic syrup comprises:

[0119] (aO from 3% by weight to 45% by weight and preferably from 3% by weight to 40% by weight of the (meth)acrylic polymer(s) (PI), and

[0120] (a2) from 55% by weight to 97% by weight and preferably from 60% by weight to 97% by weight of at least two different (meth)acrylic monomers (Ml) and (M2).

[0121] In a second variant of the invention, the liquid (meth)acrylic syrup comprises:

[0122] (aO from 10% by weight to 35% by weight and preferably from 12% by weight to 35% by weight and more preferably from 15% by weight to 30% by weight and even more preferably from 20% by weight to 30% by weight of the (meth)acrylic polymer (PI), and

[0123] (a2) from 65% by weight to 90% by weight and preferably from 65% by weight to 88% by weight and more preferably from 70% by weight to 85% by weight and even more preferably from 70% by weight to 80% by weight of the at least two different (meth)acrylic monomers (M1) and (M2).

[0124] In a third variant of the invention, the liquid (meth)acrylic syrup comprises

[0125] (ai) from 10% by weight to 30% by weight and preferably from 11% by weight to 28% by weight and more preferably from 12% by weight to 27% by weight and even more preferably from 15% by weight to 25% by weight of the (meth)acrylic polymer (PI), and

[0126] (a2) from 70% by weight to 90% by weight and preferably from 72% by weight to 89% by weight and more preferably from 73% by weight to 88% by weight and even more preferably from 75% by weight to 85% by weight of the at least two different (meth)acrylic monomers (M1) and (M2).

[0127] Stabilizers, or reaction inhibitors, may also be present in the liquid (meth)acrylic syrup to prevent spontaneous polymerization of the (meth)acrylic monomers (M1) and (M2).

[0128] These stabilizers may in particular be chosen from hydroquinone (HQ), hydroquinone monomethyl ether (HQME), 2,6-di-tert-butyl-4-methylphenol (BHT), 2,6-di-tert-butyl-4-methoxyphenol (Topanol O) and 2,4-dimethyl-6-tert-butylphenol (Topanol A).

[0129] These stabilizers may be present, in the liquid (meth)acrylic syrup, in a proportion of at most 5 parts by weight, advantageously at most 4 parts by weight and preferably in a proportion of between 0.3 and 3 parts by weight, per 100 parts by weight of the sum of the (meth)acrylic polymer(s) (PI) and the (meth)acrylic monomers (Ml) and (M2).

[0130] The respective preferred embodiments may be combined in any logical combination.

[0131] The (meth)acrylic composition (MCI) according to one aspect of the invention also comprises a polymerization initiator whose function is to ensure the start of the polymerization of the (meth)acrylic monomers (M1) and (M2).

[0132] The polymerization initiator (Ini) may be chosen from organic peroxides, peroxyesters, peroxyacetals and azo compounds.

[0133] The polymerization initiator (Ini) may in particular be chosen from diacyl peroxides, peroxyesters, peroxydicarbonates, dialkyl peroxides, peroxyacetals, hydroperoxides or peroxyketals.

[0134] In one embodiment, the polymerization initiator (Ini) is chosen from benzoyl peroxide.

[0135] In another embodiment, the polymerization initiator (Ini) is selected from 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, per- di(4-tert-butylcyclohexyl oxydicarbonate), di-(2-ethylhexyl) peroxydicarbonate, tert-amyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, di-n-butyl peroxydicarbonate, dicetyl peroxydicarbonate, di-myristyl peroxydicarbonate, 1,1,3,3-tetramethylbutylperoxypivalate, tert-butyl peroxyneoheptanoate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, di-(3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, didecanoyl peroxide, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, peroxy-2-ethylhexanoate 1,1,3,3-tetramethylbutyl, tert-amyl peroxy-2-ethylhexanoate, dibenzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxydiethylacetate, tert-butyl peroxyisobutyrate, l,l-di-(tert-butylperoxy)-3,3,5-trimethylcyclohexane, l,l-di(tert-amylperoxy)cyclohexane, l,l-di-(tert-butylperoxy)-cyclohexane, tert-amyl peroxy-2-ethylhexylcarbonate, tert-amyl peroxyacetate, peroxy-3,5,tert-butyl 5-trimethylhexanoate, 2,2-di-(tert-butylperoxy)-butane, tert-butyl peroxyiso-propylcarbonate, tert-butyl peroxy-2-ethylhexylcarbonate, tert-amyl peroxy-benzoate, tert-butyl peroxyacetate, butyl 4,4-di(tert-butylperoxy)valerate, tert-butyl peroxybenzoate, 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-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), l,l'-azodi(hexaliydrobenzonitrile) or 4,4'-azobis(4-cyanopentanoic acid).

[0136] Preferably, the polymerization initiator (Ini) is chosen from diacyl peroxides, peroxyesters, peroxydicarbonates, dialkyl peroxides, peroxyacetals, hydroperoxides or peroxyketals.

[0137] The (meth)acrylic composition (MCI) according to the invention may comprise from 0.01 part by weight to 5 parts by weight of polymerization initiator per 100 parts by weight of a liquid (meth)acrylic syrup.

[0138] According to a particular embodiment, the (meth)acrylic MCI composition according to the invention comprises from 0.02 parts by weight to 4 parts by weight or from 0.03 parts by weight to 3 parts by weight of polymerization initiator per 100 parts by weight of the liquid (meth)acrylic syrup.

[0139] What has just been described for a polymerization initiator is entirely transposable to an initiator system, such as a system consisting of a polymerization initiator and a polymerization activator or accelerator.

[0140] The (meth)acrylic MCI composition according to the invention may also effectively further comprise, in certain aspects, a polymer activator or accelerator. rization.

[0141] According to a particular embodiment, the (meth)acrylic composition according to the invention comprises between 100 ppm and 10,000 ppm, advantageously between 100 ppm and 7,000 ppm and preferably between 200 ppm and 5,000 ppm of polymerization activator or accelerator per 100 parts by weight of the (meth)acrylic syrup.

[0142] The present invention also relates to a process for preparing a (meth)acrylic composition (MCI).

[0143] According to the invention, this method comprises the following steps: providing the respective components and iv) mixing the components.

[0144] Step iv) of the preparation process according to the invention is carried out by mixing all the components included in the (meth)acrylic composition (MCI). In one embodiment, care is taken to first prepare the liquid (meth)acrylic syrup and then to introduce, into this (meth)acrylic syrup where appropriate, the polymerization activator or accelerator, the polymerization initiator being introduced last.

[0145] This mixing can be done manually or using a mixing means.

[0146] Optionally, the mixing is carried out by stirring, and for a period of time between between 1 minute and 36 hours, advantageously between 2 minutes and 24 hours, more advantageously between 3 minutes and 24 hours and preferably between 4 minutes and 24 hours.

[0147] The manufacturing process according to the invention is thus a process which is particularly simple to carry out and which can be easily carried out in current installations dedicated to the manufacture of a (meth)acrylic composition.

[0148] The (meth)acrylic composition (MCI) comprising compounds aj to a2) or the other components optionally added has a viscosity of between 10 mPa*s and 10,000 MPa*s at 25°C.

[0149] Preferably, the viscosity of the (meth)acrylic MCI composition comprising compounds a1) to a2) at 25°C is in a range from 50 mPa*s to 10,000 mPa*s, more preferably from 50 mPa*s to 9,000 mPa*s, even more preferably from 50 mPa*s to 8,000 mPa*s, even more preferably from 50 mPa*s to 7,500 Pa*s, even more preferably between 50 mPa*s and 7,000 mPa*s, advantageously between 50 mPa*s and 6,000 mPa*s and more advantageously between 50 mPa*s and 5,000 mPa*s.

[0150] As regards the (meth)acrylic polymer composite material (MPCM1), it comprises a reinforcing material.

[0151] In one embodiment, the reinforcing material is a fibrous substrate.

[0152] In another embodiment, the reinforcing material is a mineral filler.

[0153] The present invention relates, in a further aspect, to a molded part (MPI) comprising a (meth)acrylic polymer composite material (MPCM1).

[0154] The molded part may be prepared by resin transfer molding (RTM) or a variant such as C-RTM or the like.

[0155] In a first preferred embodiment, the (meth)acrylic polymer composite material (MPCM1) is a fiber-reinforced (meth)acrylic polymer composite material.

[0156] In a second preferred embodiment, the (meth)acrylic polymer composite material (MPCM1) is a particle-reinforced (meth)acrylic polymer composite material. [Processes]

[0157] The weight average molecular weight can be measured by size exclusion chromatography (SEC). The chromatography column is calibrated with PMMA references having a molecular weight between 402 g / mol and 1,900,000 g / mol. The average molecular weight is expressed in g / mol for the number and average molecular weight Mn and Mw respectively. For the measurement, the concentration is 1 g / L.

[0158] The viscosity of (meth)acrylic compositions comprising at least components a1) and a2) is measured using a Brookfield viscometer at 23°C, according to ISO 2555:2018 “Plastics — Resins in liquid form or in emulsions or dispersions — Determination of apparent viscosity by the single-cylinder rotational viscometer method”.

[0159] The glass transition temperature Tg of the polymers was measured using a TA Q2000 apparatus, according to ISO 11357-2 / 2013 at a heating rate of 20 K / min

[0160] The reactivity is measured with the following method. A 20x180 mm test tube is filled to a height of 7.5 cm with a liquid syrup and an added initiator. A thermocouple is placed in the syrup. The tube is immersed for at least 140 mm in an oil bath at 90°C. The temperature is measured continuously and the time at the peak temperature is taken. Examples

[0161] First step: preparation of a liquid composition or Imeth)acrylic syrup

[0162] A liquid composition is prepared by dissolving 20% ​​by weight of PMMA (BS520, an MMA copolymer comprising ethyl acrylate as a comonomer) as (PI) in 80-x wt% methyl methacrylate as (Ml), which is stabilized with HQME (hydroquinone monomethyl ether), and x wt% (meth)acrylic monomer (M2). In the examples, cyclohexyl methacrylate (CHMA) and 2-hydroxy propyl methacrylate (HPMA) are used.

[0163] Different quantities of initiator (Ini) are added to this liquid composition. As initiator (Ini) di(4-tert-butylcyclohexyl) peroxydicarbonate (P16 - Perkadox® 16 from Akzo Nobel) is used.

[0164] For comparative examples x = 0. For examples x = 10 or x = 30.

[0165] Second step: polymerization of a liquid composition or syrup (meth)acrylic

[0166] The polymerization of the respective compositions is carried out by adding to 100 parts by weight of the liquid composition (based on (Ml) or (Ml) + (M2) and (PI) only) the initiator in an amount as indicated in Table 1. The respective compositions are heated up to 90 °C in a metal press under a pressure of 10 bar. The kinetics are measured by following the temperature and the time to the peak is taken.

[0167] Table 1 - Compositions of the respective liquid (meth)acrylic syrup samples and results for time to peak [Tables 1] (M2) x [wt%] (Ini) [phr] time [s] Comparative example 1 - 0 1 354 Comparative example 2 - 0 2 240 Example 1 CHMA 10 1 294 Example 2 CHMA 30 1 270 Example 3 HPMA 10 1 300 Example 4 HPMA 30 1 192 Example 5 CHMA 10 2 186 Example 6 CHMA 30 2 174 Example 7 HPMA 10 2 180 Example 8 HPMA 30 2 138

[0168] The decrease in polymerization time in Table 1 for the examples means better kinetics, faster polymerization. The processing time can be reduced with the composition according to the invention.

Claims

Claims

1. (Meth)acrylic composition (MCI) comprising: (a) 100 parts by weight of a liquid (meth)acrylic syrup comprising: (ai) from 1% by weight to 50% by weight of one or more (meth)acrylic polymers (PI), and (a2) from 50% by weight to 99% by weight of at least two different (meth)acrylic monomers (Ml) and (M2), each monomer (Ml) and (M2) comprising only one (meth)acrylic function per monomer, b) optionally from 0.01 part by weight to 5 parts by weight of a polymerization initiator (Ini); characterized in that the monomer (Ml) is in excess in component (a2).

2. (Meth)acrylic composition (MCI) according to claim 1, characterized in that it comprises (b) from 0.01 part by weight to 5 parts by weight of a polymerization initiator (Ini).

3. (Meth)acrylic MCI composition according to any one of claims 1 to 2, characterized in that each monomer (M1) and (M2) is a methacrylic monomer.

4. (Meth)acrylic MCI composition according to any one of claims 1 to 3, characterized in that the weight ratio of monomers (M1) / (M2) is between 95 / 5 and 51 / 49.

5. (Meth)acrylic MCI composition according to any one of claims 1 to 3, characterized in that the weight ratio of monomers (M1) / (M2) is between 95 / 5 and 65 / 35.

6. (Meth)acrylic MCI composition according to any one of claims 1 to 5, characterized in that the glass transition temperature Tg of a homopolymer of the (meth)acrylic monomers (M1) and (M2) is at least 50°C, preferably at least 60°C and even more probably at least 70°C.

7. Composition according to any one of claims 1 to 6, characterized in that the reactivity ratios of the monomers r1 and r2 between the two different (meth)acrylic monomers (M1) and (M2) are at least 0.35 and preferably r2 > 0.5, preferably r2 > 0.

8.

8. Composition according to any one of claims 1 to 7, characterized in that the (meth)acrylic monomer (Ml) is methyl methacrylate.

9. Composition according to any one of claims 1 to 8, characterized in that the (meth)acrylic monomer (M2) is chosen from 2-hydroxypropyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, glycidyl methacrylate or methacrylic acid.

10. Composition according to any one of claims 1 to 8, characterized in that the (meth)acrylic monomer (M2) is chosen from 2-hydroxypropyl methacrylate or cyclohexyl methacrylate.

11. Composition according to any one of claims 1 to 10, characterized in that the or each (meth)acrylic polymer (PI) is chosen from a homopolymer of methyl methacrylate or a copolymer of methyl methacrylate or a mixture thereof, the methyl methacrylate advantageously representing at least 50% by weight of the or each (meth)acrylic polymer PI.

12. Composition according to any one of claims 1 to 11, characterized in that the liquid (meth)acrylic syrup has a viscosity of between 10 mPas and 10,000 mPas at 25°C.

13. A process for preparing the (meth)acrylic composition (MCI) according to any one of claims 1 to 12, comprising the following steps: (i) providing a (meth)acrylic polymer (PI) and the (meth)acrylic monomers (Ml) and (M2), (ii) preparing 100 parts by weight of (a) a liquid (meth)acrylic syrup comprising: (aO from 1% by weight to 50% by weight of one or more (meth)acrylic polymers PI, and (a2) from 50% by weight to 99% by weight of at least two different (meth)acrylic monomers (Ml) and (M2), each monomer (Ml) and (M2) comprising only one (meth)acrylic function per monomer and the monomer (Ml) being in excess relative to the monomer (M2), by mixing the components (aj and (a2), (iii) optionally providing from 0.01 part by weight to 5 parts by weight of a polymerization initiator (Ini), (iv) mixing the components.

14. Use of the (meth)acrylic composition (MCI) according to any one of claims 1 to 12 for preparing a (meth)acrylic polymeric material (MPM1) or a (meth)acrylic polymeric composite material (MPCM1).

15. A (meth)acrylic polymeric material (MPM1) prepared by polymerizing the (meth)acrylic composition (MCI) according to any one of claims 1 to 12.

16. A (meth)acrylic polymer composite material (MPCM1) prepared by polymerizing the (meth)acrylic composition (MCI) according to any one of claims 1 to 12.

17. A process for preparing a (meth)acrylic polymer material (MPM1) comprising the following steps: i) providing a (meth)acrylic composition (MCI) according to any one of claims 1 to 12, ii) polymerizing the (meth)acrylic composition (MCI).

18. A method for preparing a (meth)acrylic polymer composite material (MCPM1) comprising the following steps: i) providing a (meth)acrylic MCI composition according to any one of claims 1 to 12, ii) bringing the (meth)acrylic (MCI) composition into contact with the reinforcing material, iii) polymerizing the (meth)acrylic (MCI) composition.

19. A method according to claim 18, characterized in that the reinforcing material is a fibrous substrate.