EP3420006A1 - Low-viscosity polymerizable precursor composition for impact-reinforced materials - Google Patents

Abstract

The invention relates to a low-viscosity polymerizable precursor composition for impact-reinforced materials. A composition of said type is useful in fields such as adhesives, varnishes and coatings, resins for impregnating fabrics or woven materials, coatings for flexible substrates, or 3D printing processes.

Description

Polymerizable composition of low viscosity precursor of materials reinforced at impact

The present invention relates to a low viscosity precursor polymerizable composition of impact-reinforced materials.

 Such a composition is useful in areas such as adhesives, varnishes and coatings, fabric impregnating resins or woven materials, in flexible substrate coatings or in 3D printing processes.

 The composition may be polymerized using a photoinitiator under the influence of electromagnetic radiation (gamma, UV, visible, infrared) from a source such as a lamp capable of generating such radiation ( lasers, plasma arc lamps, xenon lamps, mercury lamps, halogen lamps or light-emitting diode lamps). In addition to 3D printing applications, a multi-photonic emitter source can be used.

According to an alternative to the invention, the composition may also be polymerized using a radical initiator.

In these technical fields, compositions which have good mechanical properties at the end of the polymerization and which, during application, ie before polymerization, have a low viscosity are sought.

It is known to strengthen such compositions by heart-bark particles. However, such polyerized compositions have a level of resistance to crack propagation and insufficient impact when seeking compositions which have low viscosity typically less than 10 Pa.S. Moreover, this approach requires preparing these particles separately which complicates the manufacture of these compositions.

Another improved approach is to strengthen such polymerized compositions using block copolymers. Such an approach is described for example in WO2008110564 or WO2007124911.

However, the incorporation of an impact modifier whether of the core-shell or block copolymer type, in addition to the requirement to prepare it separately, induces an increase in the viscosity of the composition, which may pose problems of use. in the various fields concerned by the invention, for example the impregnation of woven fibers or in the field of printing 3 D. Indeed in the latter case it has been noticed that it is preferable for a composition to exhibit a certain behavior. rheological Newtonian type rather than pseudo plastic, this to avoid turbulence phenomena and thus to keep laminar flow profiles.

The Applicant has found that the incorporation of flexible reactive polymeric sequences in "dormant" form and conferring on the polymerized composition mechanical strength properties is possible and advantageously allows to overcome the drawbacks found in the prior art. Summary of the invention

The invention relates to a polymerizable composition comprising a mixture of at least one monomer capable of radically polymerizing and having at least one polymerizable function, at least one dormant polymeric flexible sequence capable of generating at least one radical, and at least one generator. free radicals. Detailed description :

As regards the monomers capable of radical polymerization, they may be multifunctional monomers or not chosen from vinyl, vinylidene, diene, olefinic, allylic or (meth) acrylic monomers chosen more particularly from vinylaromatic monomers such as styrene or substituted styrenes in particular alpha-methylstyrene, silylated styrenes, acrylic monomers such as acrylic acid or its salts, alkyl acrylates, cycloalkyl acrylates or aryl acrylates, such as methyl acrylate or ethyl acrylate; , butyl, ethylhexyl or phenyl, isobornyl, hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate, alkyl ether acrylates such as 2-methoxyethyl acrylate, alkoxy acrylates, and the like. - or aryloxy-polyalkylene glycol such as methoxypolyethylene glycol acrylates, ethoxypolyethylene glycol acrylates, methoxypolypropylene glycol acrylates, acrylates methoxy-polyethylene glycol-polypropylene glycol or mixtures thereof, aminoalkyl acrylates such as 2- (dimethylamino) ethyl acrylate (ADAME), fluorinated acrylates, silyl acrylates, phosphorus acrylates such as alkylene glycol phosphate acrylates, glycidyl acrylates, dicyclopentenyloxyethyl acrylates, methacrylic monomers such as methacrylic acid or its salts, alkyl, cycloalkyl, alkenyl or aryl methacrylates such as methyl methacrylate ( MAM), lauryl, cyclohexyl, allyl, phenyl or naphthyl, isobornyl, hydroxyalkyl methacrylates such as 2-hydroxyethyl methacrylate or 2-hydroxypropyl methacrylate, methacrylates of ether alkyl such as 2-ethoxyethyl methacrylate, alkoxy- or aryloxy-polyalkylene glycol methacrylates such as methoxypolyethylene glycol methacrylates, ethoxypolyethylene glycol methacrylates, methoxypolypropylene glycol methacrylates, methoxypolyethylene glycol-polypropylene glycol methacrylates or mixtures thereof, methacrylates aminoalkyl such as 2- (dimethylamino) ethyl methacrylate (MADAME), fluorinated methacrylates such as 2, 2, 2-trifluoroethyl methacrylate, silylated methacrylates such as 3-methacryloylpropyltrimethylsilane, phosphorus methacrylates such as alkylene glycol phosphate methacrylates, hydroxyethylimidazolidone methacrylate, methacrylate, hydroxy-ethylimidazolidinone, 2- (2-oxo-1-imidazolidinyl) ethyl methacrylate, acrylonitrile, acrylamide or substituted acrylamides, 4-acryloylmorpholine, N-methylolacrylamide, methacrylamide or substituted methacrylamides, N-methylolmethacrylamide, methacrylamido-propyltrimethylammonium chloride (MAPTAC), glycidyl methacrylates, dicyclopentenyloxyethyl, itaconic acid, maleic acid or its salts, maleic anhydride, maleates or hemi-maleates of alkyl or alkoxy- or aryloxy-polyalkylene glycol, the polyol polyacrylates, alkylene glycol polyacrylates or allyl acrylate, ethylene glycol diacrylate,

1,3-butylene glycol, 1,4-butylene glycol, polyfunctional methacrylic monomers such as polyol polymethacrylates, alkylene glycol polymethacrylates or allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butylene glycol , from

1,4-butylene glycol, divinylbenzene or trivinylbenzene, vinylpyridine, vinylpyrrolidinone, (alkoxy) poly (alkylene glycol) vinyl ether or divinyl ether, such as methoxy poly (ethylene glycol) vinyl ether, poly (ethylene glycol) divinyl ether, olefinic monomers, among which mention may be made of ethylene, butene, hexene and 1-octene, 1,1-diphenyl ethylene, dienic monomers including butadiene, isoprene and the monomers fluorinated olefins, and vinylidene monomers, among which mention may be made of vinylidene fluoride, alone or as a mixture. As regards the monomers capable of radical polymerization, they may also be polymeric or oligomeric sequences capable of radically polymerizing in addition to one or more monomers listed above. Polymeric or oligomeric sequences capable of radical polymerization are understood to mean polymeric or oligomeric sequences having any Tg (glass transition temperature) as measured by DSC (differential thermal analysis), but preferably greater than 0 ° C. and even more preferably greater than 0 ° C. 50 ° C and having at least one double bond. It may be single or multifunctional epoxy acrylates or methacrylates derived from the reaction of acrylic or methacrylic acid with a mono- or polyepoxidized compound, urethane acrylates derived from the reaction of a hydroxylated acrylate or methacrylate (such as hydroxy alkyl acrylate or methacrylate with C 2 -C 4 alkyl, in particular hydroxyethyl acrylate or methacrylate, HEA or HEMA) on an isocyanate or polyisocyanate, preferably aliphatic or cycloaliphatic, mono or multifunctional acrylate aminoacrylates, derived from the addition of Michael of a secondary amine on a multifunctional acrylate and partial saturation by this addition of acrylate functions (with at least one or more residual acrylate functions per aminoacrylate molecule), (meth) acrylic oligomers selected from the following groups:

 acrylate or methacrylate polyethers resulting from the esterification with acrylic or methacrylic acid of a polyether polyol or monool, of Mn up to 2000 (oligoether based on C2-C4 alkoxy unit, in particular polyoxyethylenes or polyoxypropylenes) or polyoxybutylene or random or sequential copolyethers oxyethylene / oxypropylene / oxybutylene). Polyoxyethylene or polyoxypropylene is also called polyethylene glycol or polypropylene glycol;

acrylate or methacrylate polyesters derived from the esterification with acrylic or methacrylic acid of a polyester polyol or monool. The said polyesters are polycondensation products between a polyacid (diacid) and a polyol (diol) and may be of variable structure depending on the structures of these polyacid components and / or polyols.

-polyurethanes acrylates or methacrylates that may result from the esterification reaction of a polyurethane polyol or monool (of polyester type for example) with acrylic or methacrylic acid or reaction between a polyurethane prepolymer (oligomer)

polyisocyanate and a hydroxyalkyl acrylate or methacrylate. epoxy acrylate oligomers resulting from the acrylation or methacrylation of a mono or polyepoxidized oligomer (for example epoxidized oligodienes such as epoxidized polybutadiene or epoxidized polyunsaturated oils).

 Acrylic or methacrylated acrylic oligomers such as copolymers of glycidyl methacrylate (MAGLY) with another acrylic or methacrylic comonomer, by reaction with acrylic or methacrylic acid. These sequences have a weight-average molecular mass of between 200 and 10,000 g / mol and preferably between 300 and 2,000 g / mol, as measured by steric exclusion chromatography (polystyrene standards).

As regards the dormant polymeric flexible sequences capable of generating at least one radical, they exhibit a Tg (glass transition temperature) measured by DSC (differential thermal analysis) below 0 ° C. and preferably below -20 ° C.

 They consist of monomers as listed in the monomers capable of radical polymerization and have a weight-average molecular mass of between 5,000 and 1,000,000 g / mol, preferably between 50,000 and 400,000 g / mol, more preferably between 50,000 and 300,000 g. mole, and more particularly between 50000 and 200000 g / mole, measured by SEC (size exclusion chromatography, polystyrene standards). Preferably, the soft sequences comprise butyl acrylate.

The flexible sequences are present within the composition in mass proportions between 0.1 and 50%, preferably between 0.1 and 30%, more preferably between 0.1 and 15%, and more preferably between 0.1 and 7% and more particularly between 0.1 and 5%, ideally between 2 and 5%. At 3.5% it is highlighted a singular point where the resistance to the impact goes through a maximum.

These dormant polymeric soft sequences are prepared by controlled radical polymerization such as NMP ("Nitroxide Mediated Polymerization"), RAFT ("Reversible Addition and Fragmentation Transfer"), ATRP ("Atom Transfer Radical Polymerization"), INIFERTER ("Initiator-Transfer- Termination "), RITP (" Reverse Iodine Transfer

Polymerization "), ITP (" Iodine Transfer Polymerization). For example, the notion of "dormant" or dormant chain sequence in English is explained in the book "the chemistry of radical polymerization" by Graeme Moad and David H. Solomon, Elsevier 2006, page 456. In particular, they are capable of generating at least a radical which can then initiate a polymerization on said sequence.

According to a preferred form of the invention, the dormant polymeric flexible sequences are prepared by radical polymerization controlled by nitroxides, and more particularly nitroxides from alkoxyamines derived from the stable free radical (1). The dormant polymeric soft sequences in this case are therefore alkoxyamines: (1)

- C- N- O *

Wherein the radical R 1 has a molar mass greater than 15.034 g / mol. The radical R 1 can be a halogen atom such as chlorine, bromine or iodine, a linear, branched or cyclic, saturated or unsaturated hydrocarbon-based group such as an alkyl or phenyl radical, or an ester - COOR or an alkoxyl group -OR, or a phosphonate group -PO (OR) 2 _{> as long} as it has a molar mass greater than 15.0342. The monovalent radical R- ^ is said in position β with respect to the nitrogen atom of the nitroxide radical. The remaining valences of the carbon atom and the nitrogen atom in the formula (1) can be linked to various radicals such as a hydrogen atom, a hydrocarbon radical such as an alkyl, aryl or aryl radical. -alkyl, comprising from 1 to 10 carbon atoms. It is not excluded that the carbon atom and the nitrogen atom in the formula (1) are connected to each other via a divalent radical, so as to form a ring. Preferably, however, the remaining valencies of the carbon atom and the nitrogen atom of the formula (1) are attached to monovalent radicals. Preferably, the radical R 1 has a molar mass greater than 30 g / mol. The radical R 1 may, for example, have a molar mass of between 40 and 450 g / mol. By way of example, the radical R 1 may be a radical comprising a phosphoryl group, said radical R 1 may be represented by the formula: R ¹

P ²

 O

 (2)

Wherein R and R, which may be the same or different, may be selected from alkyl, cycloalkyl, alkoxyl, aryloxyl, aryl, aralkyloxy, perfluoroalkyl, aralkyl, and may include from 1 to 20 carbon atoms. R and / or R may also be a halogen atom such as a chlorine or bromine atom or a fluorine or iodine atom. The radical R 1 may also comprise at least one aromatic ring as for the phenyl radical or the naphthyl radical, the latter may be substituted, for example by an alkyl radical comprising from 1 to 4 carbon atoms.

More particularly alkoxyamines derived from the following stable radicals are preferred:

 N-tert-butyl-1-phenyl-2-methylpropyl nitroxide,

N-tert-butyl-1- (2-naphthyl) -2-methylpropyl nitroxide,

 N-tert-butyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide,

 N-tert-butyl-1-dibenzylphosphono-2,2-dimethylpropyl nitroxide,

 N-phenyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide,

 N-phenyl-1-diethyl phosphono-1-methyl ethyl nitroxide,

 N- (1-phenyl-2-methylpropyl) -1-diethylphosphono-1-methylethyl nitroxide,

 4-oxo-2,2,6,6-tetramethyl-1-piperidinyloxy nitroxide

2,4,6-tri-tert-butylphenoxy nitroxide. The alkoxyamines used in controlled radical polymerization must allow good control of the sequence of monomers. Thus they do not all allow good control of certain monomers. For example, the alkoxyamines derived from TEMPO make it possible to control only a limited number of monomers, the same goes for the alkoxyamines derived from 2,2,5-tri-methyl-4-phenyl-3-azahexane-3-nitroxide. (TIPNO). On the other hand, other alkoxyamines derived from nitroxides corresponding to formula (1), particularly those derived from nitroxides corresponding to formula (2) and even more particularly those derived from N-tert-butyl-1-diethylphosphono-2, 2-dimethylpropyl. nitroxide allow to expand to a large number of monomer controlled radical polymerization of these monomers.

The dormant polymeric flexible sequences are therefore polyalkoxyamines and can be represented by the formula Z (-T) _n in which Z denotes the flexible segment, T is a nitroxide and n is an integer greater than or equal to 1, and preferably between 2 and 4 terminals included. According to a still preferred form, n is equal to 3.

Such flexible polyalkoxyamine pendant sequences can be prepared by reacting the monomers of the flexible sequence with precursors, themselves polyalkoxyamines and described in EP1526138.

The polymerization reaction of the composition is initiated with the aid of a free radical resulting from the decomposition of an initiator or a photoinitiator. According to a first preference, it acts of a radical resulting from the decomposition of a radical initiator either by temperature, or by a redox reaction, or other redox system that can generate radicals, for example the methylene bis (diethyl) pair. malonate) - cerium IV, or the couple H ₂ 02 / Fe ²⁺ .

As regards the radical initiator, it may be chosen from diacyl peroxides, peroxyesters, dialkyl peroxides, peroxyacetals and azo compounds. Suitable radical initiators are, for example, isopropyl carbonate, benzoyl peroxide, lauroyl, caproyl, dicumyl, tert-butyl perbenzoate, tert-butyl 2-ethyl perhexanoate, cumyl hydroperoxide, l, 1-di (tert-butylperoxy) -3,3,5-trimethylcyclohexane, t-butyl peroxyisobutyrate, tert-butyl peracetate, tert-butyl perpivalate, amyl perpivalate, tert-butyl peroctoate. It would not depart from the scope of the invention using a mixture of radical initiators selected from the above list. The preferred radical initiator is a peroxide, and more particularly benzoyl peroxide. According to one variant, the radical is generated by the reaction between a peroxide and an amine.

With regard to the amine, any type of amine capable of reacting with a peroxide may be used.

Preferably, they are substituted amines, and more particularly tri-substituted amines, among which mention may be made of N, N-dimethyl aniline (DMA) and its para-substituted derivatives such as dimethyl-p-amine. toluidine (DMPT), p-hydroxymethyl-N, N-dimethyl aniline (HMDA), p-nitro-N, N-dimethyl aniline (NDMA) and p-dimethylamino benzaldehyde (DMAB). More particularly, it is dimethyl-p-toluidine.

According to a second preference, which is the preference of the invention, the radical is derived from the decomposition of a photoinitiator.

 Photoinitiators are compounds that can generate free radicals when these compounds are exposed to electromagnetic radiation. Preferably, the electromagnetic radiations have wavelengths in the ultraviolet or visible range, but it is not beyond the scope of the invention to use wavelengths in shorter wavelength ranges ( X-rays, or gamma) or longer (infra-red see beyond).

It may also be a photoinitiator capable of generating free radicals by absorption at least two photons.

This latter example is particularly useful when it is a matter of selectively polymerizing a zone in the mass of the reaction mixture, in particular in the fields of 3D printing involving polymerization in the presence of a photoinitiator, that is, that is to say the creation of three-dimensional objects and prototypes by polymerization of successive layers using a laser beam. The photoinitiators can be of any type. Preferably, they are chosen from those which generate the free radicals by a homolytic cleavage reaction in position a relative to the carbonyl group, such as the ether derivatives. benzoines, hydroxyalkylphenones, dialkoxyacetophenones, as well as derivatives of acylphosphine oxides, and in the β-position such as ketone sulphides and derivatives of sulfonyl ketones, those which form free radicals by the removal of hydrogen from a hydrogen donor. such as benzophenones or thioxanthones. The process involves a charge transfer complex with an amine, followed by electron and proton transfer to form an initiator alkyl radical and an inactive cetyl radical. Mention may be made of benzyl diacetals, hydroxy-alkyl phenones, alpha amino ketones, acyl phosphine oxides, benzophenones and thioxanthones. It would not depart from the scope of the invention by using a combination of several photoinitiators, or a combination of photoinitiators and radical initiator (s) whose radicals are generated thermally or by a reaction of oxido-reduction, for example methylene bis (diethyl malonate) - cerium IV or the pair ¾02 / Fe ²⁺ .

Among the initiators used in combination with photoinitiators are diacyl peroxides, peroxyesters, dialkyl peroxides, peroxyacetals and azo compounds. Suitable radical initiators are, for example, isopropyl carbonate, benzoyl peroxide, lauroyl, caproyl, dicumyl, tert-butyl perbenzoate, tert-butyl 2-ethyl perhexanoate, cumyl hydroperoxide and the like. 1-di (tert-butylperoxy) -3,3,5-trimethylcyclohexane, t-butyl peroxyisobutyrate, tert-butyl peracetate, tert-butyl perpivalate, amyl perpivalate, tert-butyl peroctoate. The compositions of the invention may also comprise various additives, such as plasticizers, thermal stabilizers or UV stabilizers, mercaptans, sulphites, bisulphites, thiosulfites, hydroxylamines, amines, hydrazine (N ₂ H ₄ ), phenylhydrazine (PhNHN¾), hydrazones, hydroquinone, flavonoids, beta carotene, vitamin A, tocopherols, vitamin E, propyl or octyl gallate, BHT, propionic acid, ascorbic acid , sorbates, reducing sugars, sugars comprising aldehydes, glucose, lactose, fructose, dextrose, potassium tartrate, nitrites, dextrin, aldehydes, glycine, antioxidants, dyes , fillers or short or long organic or mineral fibers depending on the end use of the object obtained by using the composition of the invention.

 The compositions of the invention are thus preferably used in 3D-lithographic printing (SLA) processes (digital light processing (DLP, "polyjet" technology and 2PP (using 2-photon polymerization).

The compositions of the invention can also be used in the field of adhesives, coextrusion binders, varnishes and coatings, impregnating resins for fabrics or woven materials, short or long fibers, whether or not they are mineral, printing on flexible media (paper, polymer, metal). The compositions are usable in a range of

temperature between -50 and +150 ° C, preferably between -20 and + 80 ° C, and more preferably between 5 and 50 ° C. They have a viscosity at room temperature

(typically 20 ° C) less than 10 Pa.S preferably less than 5 Pa.S, more preferably less than 2 Pa.S, and more preferably less than 1 Pa.S and a Newtonian rheological behavior.

The invention also relates to the polymerized compositions in object form as well as the objects thus obtained. Example 1 Synthesis of a Flexible Trifunctional Polyalkoxyamine Butyl Polyacrylate Suspension Block (PAbu)

1 liter glass reactor equipped with a propeller stirrer is introduced into a double jacket for heating by circulation of oil.

 26 g pentaerythrytol triacrylate (ie 0.0874 moles)

• 100g of blockbuilder ^® (0.2622mol) (from Arkema)

 • Ethanol 211 g

After introduction of the reagents, the reaction mixture is heated (temperature setpoint on the oil circulating in the jacket: 90 ° C.). The temperature of the reaction mixture reaches 80 ° C in about 30 minutes.

The temperature of the reactor is maintained at 80 ° C. for 240 min.

 At the end of this step, the resulting reaction mixture is introduced by suction into a jacketed stainless steel reactor, the ethanol solvent is then removed by evaporation at 55 ° C under reduced pressure for 2 hours.

126 g of a trialkoxylamine are thus recovered, the yield is quantitative. A 738.6 g of butyl acrylate and 9.626 g of trialkoxyamine are introduced into a 2-liter metal reactor equipped with a propeller stirrer, a double jacket of heating by circulation of oil and a vacuum / nitrogen plug.

After introducing the reagents, the reaction mixture is degassed three times under vacuum / nitrogen. The reactor is then closed and stirring (100 rpm) and heating (temperature setpoint on the oil flowing in the jacket 125 ° C) are started. The temperature of the reaction mixture reaches 113 ° C. in about 30 minutes. The pressure is around 1.5 bar. The reactor temperature is maintained at 115 ° C for 510 min. The excess butyl acrylate is then removed by evaporation at 80 ° C under reduced pressure for 2 hours.

The steric exclusion chromatographic analysis (polystyrene standards) of the polyfunctional polyoxyalkylated butyl polyacrylate flexible block sequence (PAbu) gives the following results: M _n : 91000 g / mol; M _w : 250000 g / mol; Polymolecularity: 2, 7

Example 2: Formulation and Evaluation:

Monomers that may polymerize:

isobornyl acrylate (SR506D, from Sartomer)

- Aliphatic poly ester urethane diacrylate (CN991 from Sartomer).

 -Tricyclodecanedimethanol diacrylate (SR833S, Sartomer origin)

 2 (2-ethoxyethoxy) ethyl acrylate (SR256 - Sartomer source).

Polyethylene Glycol (200) Diacrylate (SR259 - Sartomer sourced). Cyclic Trimethylopropane Formal Acrylate (SR531 from Sartomer).

 Lauryl Methacrylate (SR313A - Sartomer Origin). hydroxypropylmethacrylate (HPMA, from Dow)

- Methyl methacrylate (MAM - provenance Arkema)

 - 3,3,5 Trimethyl Cyclohexanol Acrylate (SR420 - Sartomer origin).

 - acrylate polyester (CN2505 - Sartomer origin).

 - urethane acrylate (CN9900 - Sartomer origin).

α-hydroxyacrylate resulting from the opening of epoxide functional groups by acrylic acid (CN 104-Sartomer source)

- Polyester Acrylate hyperbranché carrying 16 functions acrylate (CN2305 - Sartomer provenance). -Photo-initiator:

Ethyl (2, 4, 6-trimethylbenzoyl) phenyl phosphinate (TPO, photoinitiator, from Lambson) Reference block copolymers (comparative tests):

These block copolymers are prepared according to the protocol described in EP1526138 and are also available commercially (Nanostrength M52N ^® and D51N, from Arkema).

The first block copolymer (BCP 2, M52N) is a polymethyl methacrylate-butyl polyacrylate-polymethyl methacrylate (PMMA-PABu-PMMA) copolymer with a weight-average molecular weight of 140 Kg / mole, measured by SEC (polystyrene standards).

The second block copolymer (BCP 1, D51N) is a copolymer polymethyl methacrylate-butyl polyacrylate (PMMA-PABu) with a molecular weight of 62 Kg / mole measured by SEC (polystyrene standards). The monomers capable of polymerizing are mixed in darkness either with PABu or with the block copolymer together until dissolution, then the photoinitiator is added. The resulting mixture is then poured into a mold consisting of 2 glass panes separated by a PVC seal which is then irradiated in a UV oven (Delolux 03S mercury UV lamp) for 60 seconds. Specimens type 1 according to the standard NF EN ISO 179-1 (February 2001) are made by cutting after demolding of the polymerized composition:

Bar length: 80mm

Width: 10mm

Thickness: 4mm

 Distance between support when measuring: 62mm

Table 1 summarizes the different types of compositions used in the context of the invention and outside the invention (comparative tests), the values of the constituents are given in% by mass, as well as the measured values of their viscosity, rheological behavior and resistance to corrosion. impact after polymerization:

The impact resistance is measured according to standard NF EN ISO 179-1 (February 2001); Charpy shock not cut. The viscosity of the formulations is determined on an imposed stress rheometer type MCR301 from ANTON PAAR.

The measurement is performed by flow stress sweep at 20 ° C. The geometry used is of the duvet type for which the temperature regulation is ensured by the Peltier effect. The quilt geometry used is given in FIG.

The formulation without photoinitiator is introduced into the air gap of the comet geometry. using a disposable pipette. The range of shear gradient varies in logarithmic mode from 0.1 to 1000 s ^-1 with a measurement of 10 points per decade.

 The product flow curve. viscosity as a function of shear rate can then be obtained (Figure 2). From these measurements, it is found that the formulations of the invention all have a Newtonian behavior. In addition, the viscosity values obtained with the formulations of the invention are much lower than with the comparative formulations even with a molecular weight of the flexible sequence greater than those of the block copolymers used in the comparisons (FIG. 3).

Finally, the impact resistance is surprisingly much better for the compositions of the invention at low levels (3.5% in the example), FIG. 4.

By studying more precisely the influence of the rate of PABu in formulations similar to those of Table 1 we can highlight the existence of a singular point: Table 1a and Figure 5:

Example 3: Formulation and Evaluation

Tables 2 and 3 show the different types of compositions used in the context of the invention and outside the invention (comparative control tests), the values of the constituents are given mass shares, as well as the measured values of their viscosity, and resistance to impact after polymerisation: viscosity

CN9900 MAM SR506D SR833S SR256 SR259 SR531 SR313 HPMA SR420 Pabu Impact

Table 2 TPO @ 23 ° C

(g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (Kj / m ² )

 (MPa.s)

Trial 9 - Witness 18 7 75 7 1 13 9

Test 11 18 7 75 7 1 3 34 17

Test 12 18 7 75 7 0.5 3 33 19

Test 13 - Witness 18 7 65 7 10 1 12 8

Test 14 18 7 65 7 10 1 3 29 34

Test 15 - Witness 18 7 65 7 10 1 11 13

Test 16 18 7 65 7 10 1 3 31 27

Test 17 - Witness 18 7 65 7 10 1 15 9

Test 18 18 7 65 7 10 1 3 37 15

Test 19 - Witness 18 7 65 7 10 1 11 7

Test 20 18 7 65 7 10 1 3 25 16

Trial 21 - Witness 18 7 75 1 9 14

Test 22 18 7 75 1 3 26 40

viscosity

CN 104 CN2305 CN2505 MAM S 506D SR833S SR256 Pabu Impact

Table 3 TPO @ 23 ° C.

(g) (g) (g) (g) (g) (g) (g) (g) (Kj / m ² )

 (MPa.s)

Test 23 - Control 18 7 65 7 10 1 25 8 Test 24 18 7 65 7 10 1 3 55 13

Test 25 - Control 18 7 65 7 10 1 7 8 Test 26 18 7 65 7 10 1 3 19 17

Test 27 - Control 18 7 65 7 10 1 10 7 Test 28 18 7 65 7 10 1 3 26 25

From these measurements, it is found that the formulations of the invention all have a low viscosity but all exhibit an increase in impact resistance compared to the references and in the presence of a large variety of polar monomers (SR 256, SR259 or SR531 - Tests 13 to 18) or apolar (SR 313 - Tests 19 and 20) acrylates or methacrylates (SR 313 and HPMA - Tests 19 and 20) of high functionality (CN2305, hyperbranched acrylate - Tests 25 and 26) or low functionality (SR 420, monofunctional acrylates - Tests 25 to 28), as well as in the presence of various chemical functions such as hydroxyls (HPMA - Test 19 and 20 or CN104 - Tests 23 and 24), urethane functions (CN9900) or simple esters (CN2505 - Tests 27 and 28).

 The effect is also observed in the presence of a variable amount of photoinitiator (Test 9-12).

Claims

Claims polymerizable composition comprising a mixture of at least one monomer capable of radically polymerizing and having at least one polymerizable function, at least one dormant polymeric flexible sequence capable of generating at least one radical, and at least one free radical generator derived from decomposition of a photoinitiator. The composition of claim 1 wherein at least one dormant polymeric soft sequence is a polyalkoxyamine represented by the formula Z (- T) _n wherein Z is the soft segment, T is a nitroxide and n is an integer greater than or equal to 1. Composition according to claim 2 wherein the nitroxide is N- (1-phenyl-2-methylpropyl) -1-diethyl phosphono-1-methyl ethyl nitroxide.

Composition according to one of claims 1 to 3 wherein at least one monomer capable of radical polymerization is a multifunctional acrylate or methacrylate or not.

 Composition according to one of Claims 2 to 4, in which Z is a sequence whose Tg is less than 0 ° C.

The composition of claim 5 wherein Z is a sequence comprising butyl acrylate. Composition according to one of claims 1 to 4 comprising at least one functional polymer block capable of radically polymerizing the type of aliphatic polyester diacrylate or polyurethane diacrylate. The composition of claim 1 wherein the free radical generator is derived from the decomposition of an initiator.

 Composition according to one of claims 1 to 8 having a viscosity at room temperature of less than 10 Pa.s at 20 ° C.

 Use of a composition according to one of claims 1 to 9 in the fields of adhesives, coextrusion binders, varnishes and coatings, impregnating resins of fabrics or woven materials of short or long fibers, mineral or not, l printing on flexible media (paper, polymer, metal) or 3D printing.

 Object obtained with one of the uses according to claim 10.