Ethylenically unsaturated metal salts based on zirconium and on lanthanum

Abstract

The invention relates to an ethylenically unsaturated and (co)polymerizable metal salt which is soluble in an ethylenically unsaturated reactive diluent, said salt being based on zirconium or lanthanum and on an ethylenically unsaturated hemiester of a dicarboxylic diacid. The invention also relates to a method for preparing said salt, to a cross-linkable composition comprising same and to optical and dental uses, uses in composite materials, in molding compositions, in 3D printing compositions and for 3D articles as well as for coatings or adhesives, and to the resulting cross-linked finished product.

Description

[0001] Ethyleneically unsaturated metallic salts based on zirconium and lanthanum

[0002] The present invention relates to an ethylenically unsaturated and (co)polymerizable metal salt soluble in an ethylenically unsaturated reactive diluent, which is based on zirconium or lanthanum and an ethylenically unsaturated hemi-ester of a dicarboxylic acid; a process for preparing said salt; a crosslinkable composition comprising it; and its various uses in materials for optical and dental applications, in composite materials, in molding compositions, in 3D printing compositions and for 3D articles, as well as for coatings or adhesives; and also relates to the resulting crosslinked finished product. Ethylenically unsaturated metal salts are already known, and in particular zinc or calcium salts such as zinc di(meth)acrylates or calcium di(meth)acrylates used as crosslinking agents in elastomers as described in US 5,314,187 or US 5,506,308.The major drawback of these salts for wider use is that they are not soluble in reactive diluent media and more particularly in crosslinkable compositions either by peroxide or under radiation and this fact limits their use in homogeneous crosslinkable compositions (homogeneous and transparent crosslinkable composition with all reactive components being soluble in said composition) in the field of coatings (including varnishes, inks), adhesives, composite materials, dental compositions, 3D printing compositions, compositions for 3D articles and molding compositions or for compositions of transparent materials for optical applications.

[0003] WO 00 / 075241, and more specifically EP 1 980 565 and EP 1 189 994, describe the synthesis of soluble zinc salts from zinc oxide (ZnO) and a functionalized (meth)acrylate hemiester / acid. The first step is the synthesis of the hemiester / acid by reacting a cyclic anhydride with HE(M)A. The second step is a conventional esterification reaction between the hemiester / acid and zinc oxide. The water formed during the reaction is distilled to shift the equilibrium with an azeotropic solvent. Once this reaction is complete, a (meth)acrylate monomer is added to the mixture, and then the solvent is removed under reduced pressure. However, the described preparation method is not sufficient for obtaining other soluble metal salts, such as zirconium oxide, zirconium, or lanthanum salts.On the other hand, the described soluble ethylenically unsaturated zinc salts have limited functionality (2) and are insufficient for applications in even higher-performance materials, particularly those with a high refractive index, high mechanical strength, and high thermal stability. The new soluble and copolymerizable ethylenically unsaturated metal salts, whether in an ethylenically unsaturated reactive diluent or in a crosslinkable composition containing it, overcome the drawbacks and shortcomings of known prior art metal salts. They offer the additional advantages of a broad spectrum of use in homogeneous and varied crosslinkable compositions, with a wide range of targeted applications depending on the choice of components in said composition, due to the performance of the metal salt and its solubility in said compositions.

[0004] The first object of the invention relates to an ethylenically unsaturated (co)polymerizable metallic salt, soluble in an ethylenically unsaturated reactive diluent, which salt is based on zirconium or lanthanum and a specific ethylenically unsaturated hemi-ester of a dicarboxylic acid. This salt may be, or may be, presented as a homogeneous solution in at least one ethylenically unsaturated reactive diluent.

[0005] Another object of the invention relates to a first process for preparing said metallic salt with recovery of said salt as such in bulk form (100%). A process for preparing it as a solution in at least one ethylenically unsaturated reactive diluent is another object of the invention.

[0006] Another object of the invention relates to a crosslinkable composition comprising at least one metallic salt according to the invention.

[0007] Two final objects of the invention relate respectively to the use of said metallic salt according to the invention in crosslinkable compositions and also to the resulting finished crosslinked object.

[0008] Therefore, the first object of the present invention relates to an ethylenically unsaturated (co)polymerizable metallic salt soluble in an ethylenically unsaturated reactive diluent, which salt is a zirconium salt or zirconium oxide or a lanthanum salt with an ethylenically unsaturated hemi-ester of a dicarboxylic acid of formula (I): (X) n -Rl-C>2C-R- CO2H and optionally in addition to said hemi-ester (I), in the presence (or there is presence) of a saturated monocarboxylic acid of formula (II): R2CO2H and said salt is defined according to one of the following formulas (III), (IV) or (V):

[0009] [(X) n Rl-02C-R-C02-] 4-x Zr(-C>2CR2) x (III), with x = 0 or 1 or 2 or 3, in particular x = 0 or 1

[0010] [(X)nRl-02C-R-C02-]2-xZr(=0)(-02CR2)x (IV), with x = 0 or 1 and

[0011] [(X) n Rl-02C-R-C02-] 3-x The (-C>2CR2) x (V), with x = 0 or 1 or 2, in particular x = 0 or 1 and

[0012] R being the residue without the carboxy groups, of a dicarboxylic acid of aliphatic, cycloaliphatic, aromatic or mixed structure,

[0013] Rl-(X) n being the residue without OH of an ethylenically unsaturated monoalcohol and bearing n ethylenically unsaturated functional groups X, chosen from (meth)acrylate (-CO2- C(R3)=CH2 with R3: -H or -CH3), vinyl (-(¾=(¾) or allyl (-CH2-CH2=CH2), with n being an integer from 1 to 5 or from 1 to 3 or n being equal to 1, and

[0014] R2 being the residue without a carboxyl group of a saturated monocarboxylic acid (without ethylenic unsaturation) chosen from: - a monoacid other than a hemi-ester of a dicarboxylic acid, said monoacid being aliphatic, cycloaliphatic, heterocyclic, aromatic or mixed, or a hemi-ester of a dicarboxylic acid, of formula (VI): R'IC^C-R'-CChH, with in this case, R2 = R'IC^C-R'- and R'1 being the residue of a saturated monoalcohol of aliphatic, cycloaliphatic, aromatic or mixed structure and R' being the residue of a dicarboxylic acid without carboxy groups of saturated structure (without ethylenic unsaturation) of aliphatic, cycloaliphatic, aromatic or mixed structure, with R' being identical to R when R is of saturated structure or with R' being different from R, and optionally said metal salt being in solution in at least an ethylenically unsaturated reactive diluent copolymerizable with said salt.

[0015] According to a particular option of said metallic salt, said dicarboxylic acid R(-¥2H)2 is selected from: for aliphatic diacids: maleic, fumaric, succinic, itaconic, butanedioic, pentanedioic, hexanedioic, heptanedioic, octanedioic, nonanedioic, decanedioic, dodecanedioic, C36 fatty acid dimers, or mixtures thereof, preferably from: maleic acid, succinic acid, and itaconic acid; for cycloaliphatic diacids: cyclohexane 1,4-, 1,3-, or 1,2-dicarboxylic acid, tetrahydrophthalic acid, norbornane dicarboxylic acids, or mixtures thereof; for aromatic diacids: ortho-, iso-, or tere-phthalic acid, tetrabromophthalic acid, naphthalene dicarboxylic acids, biphenyl dicarboxylic acids, in particular 2,2'-biphenyl dicarboxylic acid (diphenic acid) or mixtures thereof. More particularly, in said metallic salt, said ethylenically unsaturated monoalcohol HO-Rl-(X) nis selected from:

[0016] for X being allyl: allylic alcohol, monoether of allylic alcohol with an aliphatic diol from C2 to C36 that can be alkoxylated or an oligoether diol or an oligoester diol, diether of allylic alcohol with an aliphatic triol that can be alkoxylated or a triol oligoether or triol oligoester, triether of allylic alcohol with an aliphatic tetrol that can be alkoxylated or with a tetrol oligoether or oligoester, mono-, di- or tri-allylic ester derivatives of a dicarboxylic acid / allylic alcohol hemi-ester with a polyol of respective OH functionalities of 2, 3 and 4, preferably among: allylic alcohol and monoether of allylic alcohol with an aliphatic diol from C2 to C36 that can be alkoxylated; for X being vinyl: vinyl alcohol, monoether of vinyl alcohol with an aliphatic diol in the C2 to C36 range, which can be alkoxylated, or an oligoether diol, or an oligoester diol.vinyl alcohol diether with an aliphatic triol that can be alkoxylated or an oligoether triol or oligoester triol; vinyl alcohol triether with an aliphatic tetrol that can be alkoxylated or with an oligoether tetrol or oligoester; mono-, di-, or tri-allylic ester derivatives of a dicarboxylic acid / vinyl alcohol hemiester with a polyol of respective OH functionalities of 2, 3, and 4, and preferably among: vinyl alcohol and vinyl alcohol monoether with an aliphatic diol from C2 to C36 that can be alkoxylated for X being (meth)acrylate; hydroxy alkyl mono(meth)acrylate with alkyl from C2 to C8; oligoether diol or oligoester diol mono(meth)acrylate; aliphatic triol di(meth)acrylate that can be alkoxylated; oligoether triol di(meth)acrylate or of triol oligoester, aliphatic tetrol tri(meth)acrylate which may be alkoxylated or of tetrol oligoether tri(meth)acrylate or of tetrol oligoester,aliphatic hexol penta(meth)acrylate, which may be alkoxylated, or hexol oligoether penta(meth)acrylate or hexol oligoester penta(meth)acrylate, preferably from: hydroxy alkyl mono(meth)acrylate with alkyl in C2-C8 and oligoether diol or oligoester diol mono(meth)acrylate.

[0017] According to one of the preferred options of said metallic salt, said group X is a (meth)acrylate group CH2=C(R3)-CC>2- with R3 being -H or -CH3 and with n ranging from 1 to 5 or from 1 to 3 or with n equal to 1, and with the following general formulas (III), (IV) and (V) for said salt:

[0018] [(CH2=C(R3)-C02-)nRl-02C-R-CC>2-] 4-x Zr(-C>2CR2) x (III) with x = 0 or 1 or 2 or 3, in particular x = 0 or 1

[0019] [(CH2=C(R3)-C02-)nRl-02C-R-C02-]2-x Zr(=0)(-02CR2) x (IV) with x = 0 or 1 and [(CH2=C(R3)-CO2-) n Rl-02C-R-CC>2-] 3-x La(-C>2CR2) x (V) with x = 0 or 1 or 2, in particular with x = 0 or 1.

[0020] According to a particular option of said metal salt, said dicarboxylic acid of residue R is selected from aromatic dicarboxylic acids. More specifically, said diacid is iso- and terephthalic acid and 2,2'-biphenyldicarboxylic acid.

[0021] More specifically, said group X is a (meth)acrylate group and said monoalcohol HO-Rl-(X) nis selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, hydroxyhexyl (meth)acrylate, diethylene glycol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, tripropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate of Mn < 1000, polypropylene glycol mono(meth)acrylate of Mn < 1000, polytetramethylene glycol mono(meth)acrylate, polycaprolactone hydroxylated mono(meth)acrylate of Mn < 1000, monoepoxide (meth)acrylic compound with a secondary hydroxyl group, mono(meth)acrylic alkoxylated diepoxide, trimethylol propane di(meth)acrylate optionally ethoxylated and / or propoxylated, glycerol di(meth)acrylate optionally ethoxylated and / or propoxylated, tris(2-hydroxyethyl) isocyanurate di(meth)acrylate, pentaerythritol tri(meth)acrylate, propane ditrimethylol tri(meth)acrylate,diglycerol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate and preferably said monoalcohol HO-Rl-(X), n is selected from: hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate.

[0022] According to a preferred option of said metallic salt, x = 0 for the salts of respective formulas (III), (IV) and (V) as defined above.

[0023] According to another particular option of said metal salt, x = 1 or 2 or 3 for said salt of formula (III), x = 1 for said salt of formula (IV) and x = 1 or 2 for said salt of formula (V), and said monocarboxylic acid R2CO2H is a monocarboxylic acid other than a dicarboxylic acid hemiester (is not a dicarboxylic acid hemiester) and is chosen from: an aliphatic monoacid with R2 being a linear C1-C alkyl 21 or C4-C branched alkyl 21cycloaliphatic monoacid with R2 being a C6 to Cis cycloalkyl aromatic monoacid with R2 being a C6 to Cis aryl monoacid with R2 being a radical (residue) with a heterocycle comprising a heteroatom from O, N and S and in particular said heterocycle being chosen from the thiophene, phthalimide or furan rings and more particularly said acid R2CO2H being chosen from: thiophene carboxylic acid, N-phthaloylglycine and furic acid (also called furan carboxylic acid).

[0024] According to another particular option of said metallic salt, x = 1 or 2 or 3 for said salt of formula (III), x = 1 for said salt of formula (IV) and x = 1 or 2 for said salt of formula (V) and said monocarboxylic acid R2CO2H is a dicarboxylic acid hemi-ester of formula (VI): R'1-ChC-R'-CChH, as defined above.

[0025] The presence (if x is not equal to 0) of R2CO2- and its selection in the formulas of the metal salts according to the invention, following respective formulas (III), (IV), and (V), can adjust the properties of said metal salt and its affinity with the components of the target crosslinkable composition to fine-tune a specific performance in the desired application. R2 is therefore an important, tunable structural parameter, like the parameter x, both of which can be adjusted according to the application requirements and the final performance targets for the crosslinkable composition.

[0026] The said metallic salt according to the invention is more particularly in solution in at least one ethylenically unsaturated reactive diluent, in particular chosen from (meth)acrylic, vinylic or allylic monomers and mixtures thereof, more particularly with a functionality in ethylenically unsaturated groups ranging from 1 to 6.

[0027] The second object of the invention relates to a process for preparing said metallic salt, which process comprises the following steps: i) Preparation of said ethylenically unsaturated hemi-ester of formula (I), and optionally of said saturated hemi-ester of formula (VI) by respective reactions:

[0028] - of the dicarboxylic anhydride of formula R(CO)2Ü with said ethylenically unsaturated monoalcohol HO-Rl-(X) n , with R, RI, X and n as defined above and optionally

[0029] - of the dicarboxylic anhydride R'(CO)2O with said saturated monoalcohol R'1-OH, with R' and R'1 being as defined above; ii) neutralization with a weak base in aqueous medium of said hemi-ester of formula (I), optionally in mixture with said saturated monoacid (without ethylenic unsaturation) of formula (II), which may be a monoacid other than a hemi-ester or a hemi-ester according to formula (VI), preferably said weak base being chosen from: sodium carbonate, sodium bicarbonate or tertiary amine, to obtain a soluble salt of said hemi-ester (I), optionally of said mixture with said monoacid (II) as defined above; iii) addition in aqueous solution under stirring, depending on the salt referred to, of respective formulas (II), (IV) or (V), of respectively zirconium tetrachloride (ZrCl4), zirconium oxydichloride (Zr(=0)O2) or of lanthanum trichloride (LaCU), with precipitation of said salt.(iv) filtration of said precipitated salt with washing with water, drying and recovery of said salt in solid mass form.

[0030] The invention also covers a process for preparing said metal salt in solution in at least one ethylenically unsaturated reactive diluent, which process comprises, in addition to steps i) and ii) as defined for the preceding process (above), the following additional steps iii) to vi): iii) addition to the aqueous solution of step ii) of an inert organic solvent (non-reactive without ethylenic unsaturation) which is a solvent of said metal salt and immiscible with water to create a biphasic medium; iv) addition, under stirring, to the biphasic medium according to the salt referred to, of respective formulas (II), (IV) or (V), of zirconium tetrachloride (ZrCl4), zirconium oxydichloride (Zr(=0)Ü2) or lanthanum trichloride (LaCls), with transfer of said metal salt formed in solution into the organic phase of the water-organic solvent biphasic medium.(v) decantation with removal of the aqueous phase and addition to the recovered organic phase of at least one ethylenically unsaturated reactive diluent; (vi) removal of said inert organic solvent by evaporation under reduced pressure and recovery of the solution of said metallic salt in said at least one reactive diluent.

[0031] Suitable inert solvents may be cited as follows: C1-C3 alkyl acetates, alkanes in particular hexane or heptane, cycloalkanes in particular cyclohexane, methylcyclohexane, methylcyclopropane, methylcyclobutane, aromatics in particular toluene, benzene, xylene, ethylbenzene, cumene, mesitylene and preferably from among: ethyl acetate, heptane, cyclohexane, methylcyclohexane and toluene.

[0032] Another object of the invention relates to a crosslinkable composition, which comprises at least one metallic salt as defined above or obtained by a process as defined above according to the invention.

[0033] According to a particular option, said composition is crosslinkable by peroxide and / or by radiation. More particularly, said composition comprises, in addition to said salt, at least one reactive diluent copolymerizable with said salt, selected from mono- or multifunctional (meth)acrylic, vinyl or allylic monomers, preferably mono- or multifunctional (meth)acrylic or vinyl monomers. In particular, said reactive diluent copolymerizable with said salt is at least one (meth)acrylic monomer selected from the following: Ci-Cis alkyl (meth)acrylates optionally alkoxylated, hydroxy alkyl (meth)acrylates with C2-C4 alkyl optionally alkoxylated, (meth)acrylate esters of alcohols of aromatic or cycloaliphatic structure, epoxy(meth)acrylates, urethane (meth)acrylates, multi-(meth)acrylic esters of aliphatic polyols, optionally alkoxylated polyols or oligoether polyols having 2 to 4 ether units, of functionality from 2 to 6."Of aromatic or cycloaliphatic structure" means "comprising aromatic or cycloaliphatic groups".

[0034] According to a more specific option, said composition further comprises at least one ethylenically unsaturated oligomer bearing at least one ethylenically unsaturated group. More particularly, said oligomer bears from 1 to 6 ethylenically unsaturated groups selected from: (meth)acrylate, vinyl, and allyl, preferably (meth)acrylate or vinyl. Even more particularly, said oligomer is selected from: vinyl esters, unsaturated polyesters, (meth)acrylate polyethers, (meth)acrylate polyesters, (meth)acrylic (meth)acrylic copolymers, (meth)acrylate epoxy, (meth)acrylate oligourethane, (meth)acrylate polycarbonate, and (meth)acrylate urethane polycarbonate.

[0035] According to a more specific option, the said composition is crosslinkable by UV radiation with the presence of a photoinitiator or by electron beam without a photoinitiator.

[0036] The said crosslinkable composition is chosen in particular from: coating composition, adhesive composition, molding composition, composition of composite material reinforced with glass or carbon fibers, 3D printing composition.

[0037] One object of the invention relates to the use of said metallic salt in crosslinkable compositions.

[0038] More specifically, this use relates to high refractive index materials for optical applications, particularly for ophthalmic corrective lenses, optical prisms, or fiberglass- or carbon-fiber-reinforced composite materials, materials for dental applications, 3D printing compositions, the fabrication of 3D objects, and the promotion of the adhesion of coatings or adhesives to polar substrates. Finally, the present invention also covers a crosslinked product resulting from the use of at least one metallic salt as defined above or obtained by a process as defined above, or from the crosslinking of a composition as defined above according to the invention.

[0039] More specifically, with regard to the said crosslinked product, it is: a coating, an adhesive, a composite material, in particular reinforced with glass or carbon fiber, a molded part, a corrective lens or a high refractive index optical prism, a dental part, a 3D print or a 3D article.

[0040] The following examples are provided to illustrate the invention and its performance and do not limit the scope of the invention, which is defined by the scope of the claims. EXAMPLES

[0041] 1) Raw materials used [Table 1]

[0042] 2) Preparation of ethylenically unsaturated metallic salts

[0043] Example 1 (invention): Zirconyl diphthalate of HEA diluted in biphenyl methanol acrylate (KPX H008)

[0044] Step 1: In a 1 L reactor, introduce, under stirring and bubbling with air (0.3 mL / h / kg), 29.71 g of hydroxyethyl acrylate (HEA, Mw 116.12 g / mol, Sigma Aldrich), 37.89 g of phthalic anhydride (Mw 148.12 g / mol, Sigma Aldrich), and 0.07 g of hydroquinone methyl ether (EMHQ, Aldrich). Heat and maintain at 100°C until the final stopping criterion determined by measuring the acid value (AI) expressed in mg KOH / g. The expected theoretical final AI value is 212.3 mg KOH / g.

[0045] Step 2: In the same reactor, at 60°C and with air bubbling, add over 30 minutes a solution of 21.29 g of sodium bicarbonate (NaH₃, Mw 84.0 g / mol, Aldrich) dissolved in 70 g of demineralized water. CO₂ is released. At the end of the sodium bicarbonate solution addition, the reaction mixture is milky but becomes homogeneous and slightly cloudy after 1 hour of stirring. The pH of the solution is measured at 7.

[0046] Step 3: At 60°C, with stirring and air bubbling, 500 g of ethyl acetate is added to the medium. Then, a solution of 48.19 g of zirconyl dichloride octahydrate (ZrO₂·2.8H₂O, Mw 322.25 g / mol, Alfa aesar) dissolved in 32.0 g of demineralized water is added over 15 minutes to the biphasic medium. As the solution is added, a white precipitate forms in the medium, which then dissolves into the organic phase. At the end of the addition, with the stirrer stopped, two phases are observed: a clear, colorless aqueous phase and an opaque white organic phase. Step 4: In a separatory funnel, the aqueous phase is removed, and the organic phase is washed once with 50 g of a 20% sodium chloride solution.

[0047] Step 5: After filtration through paper, 55 g of biphenyl methanol acrylate (H008, BPX) is added to the organic medium and then the ethyl acetate is evaporated under reduced pressure.

[0048] After evaporation of the solvent, the resulting product is a homogeneous liquid weighing 121.94 g, representing a final yield of 84% for the zirconyl diphthalate salt of HEA. The viscosity of the mixture at 25°C is 5400 mPa·s, and its refractive index is 1.591.

[0049] Example 2 (invention): HEMA zirconyl diphthalate diluted in cumyl phenol acrylate (Sartomer CD590) Step 1: In a 1 L reactor, introduce, under stirring and air bubbling (0.3 mL / h / kg), 31.62 g of hydroxyethyl methacrylate (HEMA, Mw 130.14 g / mol, Sigma Aldrich), 35.98 g of phthalic anhydride (Mw 148.12 g / mol, Sigma Aldrich), and 0.07 g of hydroquinone methyl ether (EMHQ, Aldrich). Heat and maintain at 100°C until the final stopping criterion determined by measuring the acid value (AV) expressed in mg KOH / g. The expected theoretical final AV value is 201.6 mg KOH / g.

[0050] Step 2: In the same reactor, at 60°C and with air bubbling, add over 30 minutes a solution of 21.75 g of sodium bicarbonate (NaH₃, Mw 84.0 g / mol, Aldrich) dissolved in 70 g of demineralized water. CO₂ is released. At the end of the sodium bicarbonate solution addition, the reaction mixture is milky but becomes homogeneous and slightly cloudy after 1 hour of stirring. The pH of the solution is measured at 7.

[0051] Step 3: At 60°C, with stirring and air bubbling, 500 g of ethyl acetate is added to the medium. Then, a solution of 49.22 g of zirconyl dichloride octahydrate (ZrO₂·8H₂O, Mw 322.25 g / mol, Alfa aesar) dissolved in 32.0 g of demineralized water is added over 15 minutes to the biphasic medium. As the solution is added, a white precipitate forms in the medium, which then dissolves into the organic phase. At the end of the addition, with the stirrer stopped, two phases are observed: a clear, colorless aqueous phase and an opaque white organic phase. Step 4: In a separatory funnel, the aqueous phase is removed, and the organic phase is washed once with 50 g of a 20% sodium chloride solution.

[0052] Step 5: After filtration through paper, 84.79 g of cumyl phenol acrylate (CD590, Sartomer) is added to the organic medium and then the ethyl acetate is evaporated under reduced pressure.

[0053] After evaporation of the solvent, the resulting product is a homogeneous liquid of 155.72 g, representing a final yield of approximately 88% of the zirconyl diphthalate salt of HEMA. The viscosity of the mixture at 25°C is 4590 mPa·s, and it has a refractive index of 1.561.

[0054] Example 3 (invention): Diphthalate of phenyl glycidyl ether acrylate zirconyl diluted in biphenyl methanol acrylate (KPX H008) Step 1: In a 1 L reactor, introduce, under stirring and bubbling with air (0.3 mL / h / kg), 44.32 g of phenyl glycidyl ether acrylate (CN131B, Mw 300 g / mol, Sartomer), 35.98 g of phthalic anhydride (Mw 148.12, Sigma Aldrich), and 0.07 g of hydroquinone methyl ether (EMHQ, Aldrich). Heat and maintain at 100°C until the final stopping criterion determined by measuring the acid value (AV) expressed in mg KOH / g. The expected theoretical final AV value is 123.5 mg KOH / g. Step 2: In the same reactor, at 60°C and under air bubbling, add over 30 minutes a solution of 15.38 g of sodium bicarbonate (NaH₃, Mw 84.0 g / mol, Aldrich) dissolved in 70 g of demineralized water. A release of CO₂ is observed.At the end of the sodium bicarbonate solution addition, the reaction mixture is milky but becomes homogeneous and slightly cloudy after 1 hour of stirring. The pH of the solution is measured at 7.

[0055] Step 3: At 60°C, under stirring and air bubbling, a solution of 29.45 g of zirconyl dichloride octahydrate (ZrO2.8H2O, Mw 322.25 g / mol, Alfa aesar) dissolved in 25.0 g of demineralized water is added to the medium over 15 minutes. A white precipitate forms very rapidly.

[0056] Step 4: The white precipitate is isolated by filtration and then dried overnight in an oven at 100°C. The recovered product is then dissolved in 100 g of toluene. The cloudy solution is filtered through paper to obtain a clear and homogeneous filtrate. Step 5: After filtration through paper, 80.0 g of biphenyl methanol acrylate (KPX H008) is added to the organic medium, and then the toluene is evaporated under reduced pressure.

[0057] After evaporation of the solvent, the resulting product is a slightly hazy, homogeneous liquid of 132.0 g, representing a final yield of approximately 66% of the zirconyl salt of phenyl glycidyl ether acrylate diphthalate. The viscosity of the mixture at 25°C is 35,000 mPa·s, and it has a refractive index of 1.594.

[0058] Example 4 (invention): HEMA triphthalate lanthanum diluted in biphenyl methanol acrylate (KPX H 008)

[0059] Step 1: In a 1 L reactor, introduce, under stirring and bubbling with air (0.3 mL / h / kg), 15.56 g of hydroxyethyl methacrylate (HEMA, Mw 130.14 g / mol, Sigma Aldrich), 17.70 g of phthalic anhydride (Mw 148.12 g / mol, Sigma Aldrich), and 0.035 g of hydroquinone methyl ether (EMHQ, Aldrich). Heat and maintain at 100°C until the final stopping criterion determined by measuring the acid value (AI) expressed in mg KOH / g. The expected theoretical final AI value is 201.6 mg KOH / g. Step 2: In the same reactor, at 60°C and with air bubbling, add over 30 minutes a solution of 10.69 g of sodium bicarbonate (NaHCC>3, Mw 84.0 g / mol, Aldrich) dissolved in 100 g of demineralized water. CO2 is released. At the end of the sodium bicarbonate solution addition, the reaction mixture is milky but becomes homogeneous and slightly cloudy after 1 hour of stirring. The pH of the solution is measured at 7.Step 3: At 60°C, with stirring and air bubbling, 350 g of ethyl acetate is added to the medium. Then, a solution of 49.22 g of lanthanum trichloride heptahydrate (La3.7H2O, Mw 371.37 g / mol, Aldrich) dissolved in 50.0 g of demineralized water is added to the biphasic medium over 15 minutes. As the solution is added, a white precipitate forms in the medium, which then dissolves into the organic phase. At the end of the addition, with the stirrer stopped, two phases are observed: a clear, colorless aqueous phase and a slightly cloudy organic phase.

[0060] Step 4: In a separatory funnel, the aqueous phase is removed and the organic phase is washed once with 50 g of a 10% sodium chloride solution.

[0061] Step 5: After filtration through paper, 30 g of biphenyl methanol acrylate (KPX H008) is added to the organic medium and then the ethyl acetate is evaporated under reduced pressure.

[0062] After evaporation of the solvent, the resulting product is a homogeneous liquid of 65.8 g, representing a final yield of approximately 91% of the lanthanum triphthalate salt of HEMA. The viscosity of the mixture at 25°C is 9200 mPa·s and its refractive index is 1.588.

[0063] 3) Characteristics of the prepared salts [Table 2]

[0064]

Claims

Demands 1. An ethylenically unsaturated metallic salt (co)polymerizable and soluble in an ethylenically unsaturated reactive diluent, characterized in that it is a zirconium salt or zirconium oxide salt or a lanthanum salt with an ethylenically unsaturated hemi-ester of a dicarboxylic acid of formula (I): (Xjn-Rl-C^CR-CChH and optionally in addition to said hemi-ester (I), in the presence of a saturated monocarboxylic acid of formula (II): R2CO2H and said salt is defined according to one of the following formulas (III), (IV) or (V): [(X) n Rl-02C-R-C02-] 4-x Zr(-C>2CR2) x (III) with x = 0 or 1 or 2 or 3, in particular x = 0 or 1 [(X)nRl-02C-R-C02-]2-xZr(=0)(-02CR2)x (IV) with x = 0 or 1 and [(X)nRl-02C-R-C02-]3-xLa (-02CR2) X (V) with x = 0 or 1 or 2, in particular x = 0 or 1 R being the residue without the carboxy groups, of a dicarboxylic acid of aliphatic, cycloaliphatic, aromatic or mixed structure, Rl-(X) n being the residue without OH, of an ethylenically unsaturated monoalcohol bearing n ethylenically unsaturated functional groups X, chosen from (meth)acrylate (-CO2-C(R3)=CH2 with R3: -H or -CH3), vinyl (-CH2=CH2) or allyl (-CH2-CH2=CH2), with n being an integer from 1 to 5 or from 1 to 3 or n being equal to 1 and R2 being the residue without a carboxyl group of a saturated monocarboxylic acid (without ethylenic unsaturation) chosen from: a monoacid other than a hemi-ester of a dicarboxylic acid, said monoacid being aliphatic, cycloaliphatic, heterocyclic, aromatic or mixed, or a hemi-ester of a dicarboxylic acid, of formula (VI): R'IC^C-R'-CChH, with in this case, R2 = R'IC^C-R'- and R'1 being the residue of a saturated mono-alcohol of aliphatic, cycloaliphatic, aromatic or mixed structure and R' being the residue of a dicarboxylic acid without carboxy groups, with a saturated structure (without ethylenic unsaturation), and an aliphatic or cycloaliphatic structure. aromatic or mixed, which may be identical to R when R is of saturated structure or which may be different from R, and optionally said metal salt being in solution in an ethylenically unsaturated reactive diluent copolymerizable with said salt.

2. Metallic salt according to claim 1, characterized in that said dicarboxylic acid R(- ¥2H)2 is selected from: - for aliphatic diacids: maleic acid, fumaric acid, succinic acid, itaconic acid, butane dioic acid, pentane dioic acid, hexane dioic acid, heptane dioic acid, octane dioic acid, nonane dioic acid, decane dioic acid, dodecane dioic acid dimers of C36 fatty acids or mixtures thereof - for cycloaliphatic diacids: cyclohexane 1,4-, 1,3- or -1,2- dicarboxylic acid, tetrahydrophthalic acid, norbornane dicarboxylic acids or mixtures thereof - for aromatic diacids: ortho-, iso- or tere- phthalic acid, tetrabromo phthalic acid, naphthalene dicarboxylic acids, biphenyl-dicarboxylic acids in particular biphenyl-2,2' dicarboxylic (diphenic acid) or their mixtures.

3. Metallic salt according to claim 1 or 2, characterized in that said ethylenically unsaturated monoalcohol HO-Rl-(X) n is selected from: - for X being allyl: allylic alcohol, monoether of allylic alcohol with an aliphatic diol at C2 to C36 that can be alkoxylated or an oligoether diol or an oligoester diol, diether of allylic alcohol with an aliphatic triol that can be alkoxylated or a triol oligoether or triol oligoester, triether of allylic alcohol with an aliphatic tetrol that can be alkoxylated or with a tetrol oligoether or oligoester, mono-, di- or tri-allylic ester derivatives of a dicarboxylic acid / allylic alcohol hemi-ester with a polyol of respective OH functionalities of 2, 3 and 4 - for X being vinyl: vinyl alcohol, vinyl alcohol monoether with an aliphatic diol in C2 to C36 that can be alkoxylated or an oligoether diol or an oligoester diol, vinyl alcohol diether with an aliphatic triol that can be alkoxylated or a triol oligoether or triol oligoester, vinyl alcohol triether with an aliphatic tetrol that can be alkoxylated or with a tetrol oligoether or oligoester, mono- ester derivatives, di- or tri-allylic compounds of a dicarboxylic acid / vinyl alcohol hemi-ester with a polyol of respective OH functionalities of 2, 3 and 4 - for X being (meth)acrylate: hydroxy alkyl mono(meth)acrylate with alkyl in C2-C8, mono(meth)acrylate of oligoether diol or oligoester diol, di(meth)acrylate of aliphatic triol which may be alkoxylated, di(meth)acrylate of oligoether triol or oligoester triol, tri(meth)acrylate of aliphatic tetrol which may be alkoxylated or tri(meth)acrylate of oligoether tetrol or oligoester tetrol, penta(meth)acrylate of aliphatic hexol which may be alkoxylated or penta(meth)acrylate of oligoether hexol or oligoester hexol.

4. Metallic salt according to any one of claims 1 to 3, characterized in that said grouping X is a (meth)acrylate group CH2=C(R3)-¥2- with R3 being -H or -CH3 and with n ranging from 1 to 5 or from 1 to 3 or with n being equal to 1, and with the following general formulas (III), (IV) and (V) for said salt: [(CH2=C(R3)-C02-)nRl-02C-R-C02-] Zr(-02CR2) X (III) with x = 0 or 1 or 2 or 3, in particular x = 0 or 1 [(CH2=C(R3)-C02-)nRl-02C-R-C02-]2-x Zr(=0)(-02CR2) x (IV) with x = 0 or 1 and [(CH2=C(R3)-C02-)nRl-02C-R-CC>2-]3-x La(-C>2CR2)x (V) with x = 0 or 1 or 2, in particular x = 0 or 1.

5. Metallic salt according to any one of claims 1 to 4, characterized in that said dicarboxylic acid of residue R is selected from aromatic dicarboxylic acids.

6. Metallic salt according to claim 5, characterized in that said diacid is iso- and tere-phthalic acid and biphenyl-2,2'dicarboxylic acid.

7. Metallic salt according to any one of claims 1 to 6, characterized in that said group X is a (meth)acrylate group and that said monoalcohol HO-Rl-(X) nis selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxy pentyl (meth)acrylate, hydroxy hexyl (meth)acrylate, diethylene glycol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, tripropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate of Mn < 1000, polypropylene glycol mono(meth)acrylate of Mn < 1000, polytetramethylene glycol mono(meth)acrylate, polycaprolactone hydroxylated mono(meth)acrylate of Mn < 1000, monoepoxide (meth)acrylated compound with a secondary hydroxy, mono(meth)acrylated alkoxylated diepoxide, trimethylol propane di(meth)acrylate optionally ethoxylated and / or propoxylated, glycerol di(meth)acrylate optionally ethoxylated and / or propoxylated, tris(2-hydroxyethyl) isocyanurate di(meth)acrylate, pentaerythritol tri(meth)acrylate, ditrimethylol propane tri(meth)acrylate, diglycerol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate.

8. Metallic salt according to any one of claims 1 to 7, characterized in that x = 0 for salts of respective formulas (III), (IV) and (V) as defined according to any one of claims 1 to 7.

9. Metallic salt according to any one of claims 1 to 7, characterized in that x = 1 or 2 or 3 for said salt of formula (III), that x = 1 for said salt of formula (IV) and that x = 1 or 2 for said salt of formula (V) and in that said monocarboxylic acid R2CO2H is a monocarboxylic acid other than a dicarboxylic acid hemi-ester and selected from: - aliphatic monoacid with R2 being a linear alkyl at C1-C21 OR a branched alkyl at C4- C21 - cycloaliphatic monoacid with R2 being a C6 to C18 cycloalkyl - aromatic monoacid with R2 being an aryl at C6 to C18 - monoacid with R2 comprising a heterocycle comprising a heteroatom from O, N and S and in particular from the thiophene, phthalimide or furan rings and more particularly from: thiophene carboxylic acid, N-phthaloylglycine and furic acid (also called furan carboxylic acid).

10. Metallic salt according to any one of claims 1 to 6, characterized in that x = 1 or 2 or 3 for said salt of formula (III), that x = 1 for said salt of formula (IV) and that x = 1 or 2 for said salt of formula (V) and in that said monocarboxylic acid R2CO2H is a hemi- dicarboxylic diacid ester, of formula (VI): R'I-ChC-R'-CChH, as defined according to claim 1.

11. Metallic salt according to any one of claims 1 to 10, characterized in that it is in solution in an ethylenically unsaturated reactive diluent, in particular selected from (meth)acrylic, vinylic or allylic monomers and mixtures thereof, more particularly with an ethylenically unsaturated group functionality from 1 to 6.

12. A process for preparing metallic salt as defined according to any one of claims 1 to 11, characterized in that it comprises the following steps: i) Preparation of said ethylenically unsaturated hemi-ester of formula (I), and optionally of said saturated hemi-ester of formula (VI) by respective reactions: - of the dicarboxylic anhydride of formula R(CO)2Ü with said ethylenically unsaturated monoalcohol HO-Rl-(X) n , with R, RI, X and n as defined in claim 1 - and optionally of the dicarboxylic anhydride R'(CO)2O with said saturated monoalcohol R'1-OH, with R' and R'1 being as defined in claim 1; ii) neutralization with a weak base in aqueous medium of said hemi-ester of formula (I), optionally in mixture with said saturated monoacid (without ethylenic unsaturation) of formula (II), which may be a monoacid other than a hemi-ester or a hemi-ester according to formula (VI), preferably said weak base being selected from: sodium carbonate, sodium bicarbonate or tertiary amine, to obtain a soluble salt of said hemi-ester (I), optionally of said mixture with said monoacid (II) as defined above; iii) addition in aqueous solution under stirring, depending on the salt referred to, of respective formulas (II), (IV) or (V), of respectively zirconium tetrachloride (ZrCl4), zirconium oxydichloride (Zr(=0)Ü2) or lanthanum trichloride (LaCU),with precipitation of said salt; iv) filtration of said precipitated salt with washing with water, drying and recovery of said salt in solid mass form.

13. A process for preparing a metal salt as defined according to any one of claims 1 to 11, in solution in an ethylenically unsaturated reactive diluent, characterized in that it comprises, in addition to steps i) and ii) as defined according to the process of claim 12, the following additional steps iii) to vi): iii) adding to the aqueous solution of step ii) an inert organic solvent (non-reactive without ethylenic unsaturation) which is a solvent of said metal salt and immiscible with water to create a biphasic medium; iv) adding, with stirring, to the biphasic medium, depending on the salt referred to, of respective formulas (II), (IV), or (V), zirconium tetrachloride, respectively. (ZrCl4), zirconium oxydichloride (Zr(=0)Ü2) or lanthanum trichloride (LaCU), with transfer of said metallic salt formed in solution into the organic phase of the two-phase water-organic solvent medium v) decantation with removal of the aqueous phase and addition in the recovered organic phase of at least one ethylenically unsaturated reactive diluent, vi) removal of said inert organic solvent by evaporation under reduced pressure and recovery of the solution of said metallic salt in said at least one reactive diluent.

14. Crosslinkable composition, characterized in that it comprises at least one metallic salt as defined according to any one of claims 1 to 11 or obtained by a process as defined according to any one of claims 12 or 13.

15. Composition according to claim 14, characterized in that it is crosslinkable by peroxide and / or by radiation.

16. Composition according to claim 14 or 15, characterized in that it comprises in addition to said salt, at least one reactive diluent copolymerizable with said salt, selected from mono- or multi-functional (meth)acrylic, vinyl or allylic monomers, preferably mono- or multi-functional (meth)acrylic or vinyl monomers.

17. Composition according to claim 16, characterized in that said reactive diluent copolymerizable with said salt is at least one (meth)acrylic monomer selected from the following: Ci-Cis alkyl (meth)acrylates optionally alkoxylated, hydroxy alkyl (meth)acrylates optionally alkoxylated, epoxy(meth)acrylates, urethane (meth)acrylates, multi-(meth)acrylic esters of aliphatic polyols, optionally alkoxylated polyols or oligoether polyols having 2 to 4 ether units, of functionality from 2 to 6.

18. Composition according to any one of claims 14 to 17, characterized in that it further comprises at least one ethylenically unsaturated oligomer, bearing at least one ethylenically unsaturated group.

19. Composition according to claim 18, characterized in that said oligomer bears from 1 to 6 ethylenically unsaturated groups selected from: (meth)acrylate, vinyl and allyl, preferably (meth)acrylate or vinyl.

20. Composition according to claim 18 or 19, characterized in that said oligomer is selected from: vinyl esters, unsaturated polyesters, polyethers (meth)acrylates, polyesters (meth)acrylates, (meth)acrylic (meth)acrylated copolymers, epoxy (meth)acrylates, oligourethane (meth)acrylates, polycarbonate (meth)acrylates, polycarbonate urethane (meth)acrylates.

21. Composition according to any one of claims 14 to 20, characterized in that it is crosslinkable by UV radiation with the presence of a photoinitiator or by electron beam without a photoinitiator.

22. Composition according to any one of claims 14 to 21, characterized in that it is a crosslinkable composition selected from: coating composition, adhesive composition, molding composition, composition of composite material reinforced with glass or carbon fibers, 3D printing composition.

23. Use of the metallic salt according to any one of claims 1 to 11 in crosslinkable compositions.

24. Use according to claim 23, characterized in that it relates to high refractive index materials for optical applications, in particular for ophthalmic corrective lenses, optical prisms or glass or carbon fiber reinforced composite materials, materials for dental applications, 3D printing compositions, the manufacture of 3D objects and the promotion of the adhesion of coatings or adhesives on polar substrates.

25. Crosslinked product, characterized in that it results from the use of at least one metallic salt as defined according to any one of claims 1 to 11 or obtained by a process as defined according to claim 12 or 13 or from the crosslinking of a composition as defined according to any one of claims 14 to 22.

26. Product according to claim 25, characterized in that it is: a coating, an adhesive, a composite material, in particular reinforced with glass or carbon fiber, a molded part, a corrective lens or a high refractive index optical prism, a dental part, a 3D print or a 3D article.