Hydrosilylation process photocatalytic by manganese complexes

Abstract

The present invention relates to the hydrosilylation reaction between monosubstituted alkene compounds and compounds comprising at least one hydrogen atom bonded to a silicon atom. More particularly, the invention relates to a process for the hydrosilylation of an unsaturated compound (A) comprising at least one monosubstituted alkene function with a compound (B) comprising at least one hydrosilyl function, the method comprises a step of irradiating the unsaturated compound (A) and the compound (B) in the presence of a photocatalyst (C) composed of manganese carbonyl. This hydrosilylation reaction between an alkene compound and a compound comprising at least one hydrogen atom bonded to a silicon atom makes it possible, in particular, to cure a silicone composition by cross-linking it.

Description

Technical Field

[0001] The present invention relates to a hydrosilylation reaction between a monosubstituted olefinic compound and a compound comprising at least one hydrogen atom bonded to a silicon atom. More particularly, the present invention relates to a hydrosilylation process photocatalyzed by a manganese complex. This hydrosilylation reaction between an olefinic compound and a compound comprising at least one hydrogen atom bonded to a silicon atom makes it possible, in particular, to cure an organosilicon composition by crosslinking it. Background Art

[0002] During the hydrosilylation (also called polyaddition) reaction of olefinic compounds, a compound comprising at least one double bond reacts with a compound comprising at least one hydrosilyl functional group (i.e. a hydrogen atom bonded to a silicon atom). This reaction can be described, for example, in the following manner:

[0003]

[0004] The hydrosilylation reaction may be accompanied by or even sometimes replaced by a dehydrosilylation reaction (also called déshydrosilylation). This reaction can be described as:

[0005]

[0006] The hydrosilylation reaction is used in particular for crosslinking silicone compositions comprising an organopolysiloxane carrying alkenyl units and an organopolysiloxane comprising hydrosilyl functional groups.

[0007] The hydrosilylation of olefinic compounds is typically carried out by catalysis with the aid of organometallic catalysts or metallic catalysts. At present, the catalysts suitable for this reaction are platinum catalysts. Thus, most industrial hydrosilylation processes, especially for olefins, are catalyzed by Speier hexachloroplatinic acid or by Karstedt Pt(0) complexes of the general formula Pt2(divinyltetramethyldisiloxane)3 (or abbreviated as Pt2(DVTMS)3).

[0008] At the beginning of the 2000s, the preparation of platinum-carbene complexes made it possible to obtain more stable catalysts (see, for example, patent application WO 01 / 42258).

[0009] However, the use of metal or organometallic platinum catalysts remains problematic. It is an expensive metal that is becoming scarce and its price fluctuates greatly. Its use on an industrial scale is therefore difficult. It is therefore desirable to reduce the amount of catalyst required for the reaction as much as possible without reducing the yield and rate of the reaction. Numerous studies have been conducted to find alternatives to the Karstedt catalyst.

[0010] For example, international patent application WO 2014 / 096719 A2 describes a process for the hydrosilylation of unsaturated compounds with hydrosilane compounds catalyzed by a photocatalyst selected from polyoxometalates (eg tetrabutylammonium decatungstate).

[0011] In 1966, the problem of replacing chloroplatinic acid as a hydrosilylation catalyst was mentioned in US Pat. No. 3,271,362. The inventors of this patent proposed the use of a catalyst selected from dicarbonylcyclopentadienylcobalt [C5H5Co(CO)2], decacarbonyldimanganese [Mn2(CO) 10 ] and dicobalt octacarbonyl [Co2(CO)8] carbonylation metal catalysts. In the only embodiment using dimanganese decacarbonyl, the reaction is carried out at 125°C and no precise information is given about the reaction yield and the nature of the polyaddition product.

[0012] In 2021, Dong et al. described a manganese-based catalyst for the dehydrogenative silylation and hydrosilylation of alkenes in a scientific publication ("Manganese-catalysed divergent silylation of alkenes", Nature Chemistry, Vol. 13, pp. 182-190 (2021)). Mn2(CO) 10 It is used as a metal precursor and must be combined with a ligand (preferably a JackiePhos ligand) to promote the hydrosilylation reaction. The reaction is carried out at 120°C.

[0013] Dimanganese decacarbonyl is also described as a catalyst in other reactions. For example, the scientific publication by Liang et al. (“Visible-Light-Initiated Manganese-Catalyzed E-Selective Hydrosilylation and Hydrogermylation of Alkyne”, Org. Lett., 2019, 21, 8, 2750-2754) describes the use of 10 mol % Mn2(CO) 10 As a photocatalyst for the hydrosilylation of alkynes. Unlike alkenes, alkynes cannot undergo dehydrogenative silylation.

[0014] Regarding dehydrogenative silylation, a scientific paper by Stefan Weber et al. ("Manganese-Catalyzed Dehydrogenative Silylation of Alkenes Following Two Parallel Inner-Sphere Pathways", J. Am. Chem. Soc., 2021, 143, 17825-17832) describes the use of Mn(I) catalysts for the dehydrogenative silylation of terminal olefins. Two catalysts were proposed: fac-[Mn(dippe)(CO)3(CH2CH2CH3)] and fac-[Mn(ddre)(CO)3(CH2CH2CH3)] (dippe = 1,2-bis(diisopropylphosphino) and drpe = 1,2-bis(di-n-propylphosphino)).

[0015] It is in this context that the inventors sought a more efficient hydrosilylation process for olefinic compounds. Advantageously, it is desirable that the reaction be rapid and at moderate temperatures, preferably at ambient temperature. In addition, it is desirable that the hydrosilylation reaction be selective, with reduced or even negligible dehydrogenative silylation and / or isomerization of olefinic compounds. Finally, it is desirable that the catalyst comprise abundant, inexpensive and non-toxic chemical elements. Summary of the invention

[0016] Summary of the Invention

[0017] Surprisingly, the present inventors have found that the hydrosilylation reaction of monosubstituted olefins can be photocatalyzed by manganese carbonyl complexes under mild conditions with excellent yields and excellent selectivity. In particular, this photocatalyzed reaction produces little or no dehydrogenative silylation and / or isomerization products of the monosubstituted olefin compound.

[0018] The object of the present invention is a process for the hydrosilylation of an unsaturated compound (A) comprising at least one monosubstituted olefinic function and a compound (B) comprising at least one hydrosilyl function, said process comprising a step of irradiating said unsaturated compound (A) and said compound (B) in the presence of a photocatalyst (C) consisting of manganese carbonyl.

[0019] The present invention also relates to the use of manganese carbonyl as a photocatalyst for the hydrosilylation reaction of an unsaturated compound (A) comprising at least one monosubstituted olefinic function with a compound (B) comprising at least one hydrosilyl function.

[0020] Detailed description of the invention

[0021] Unless otherwise stated, all viscosities of the silicone oils considered in this document correspond to the so-called “Newtonian” dynamic viscosity quantity at 25° C., i.e. the dynamic viscosity measured in a manner known per se using a Brookfield viscometer at a sufficiently low shear rate gradient that the measured viscosity is independent of the rate gradient.

[0022] Although not described, the possible tautomeric forms of the compounds described in this disclosure are included within the scope of the invention.

[0023] In the present invention, the alkyl group can be linear or branched. The alkyl group preferably contains 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and even more preferably 1 to 6 carbon atoms. The alkyl group can be selected from the following groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl and n-dodecyl.

[0024] In the present invention, cycloalkyl can be monocyclic or polycyclic, preferably monocyclic or bicyclic. Cycloalkyl preferably contains 3-30 carbon atoms, more preferably 3-8 carbon atoms. Cycloalkyl can be selected from the following groups: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl and norbornyl.

[0025] In the present invention, the aryl group may be monocyclic or polycyclic, preferably monocyclic, and preferably contains 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms. The aryl group may be unsubstituted or may be substituted one or more times by an alkyl group. The aryl group may be selected from phenyl, naphthyl, anthracenyl, phenanthrenyl, phenyl, tolyl, xylyl, diisopropylphenyl and triisopropylphenyl.

[0026] In the present invention, the aryl-alkyl group preferably contains 6 to 30 carbon atoms, more preferably 7 to 20 carbon atoms. The aryl-alkyl group may, for example, be selected from the group consisting of benzyl, phenylethyl, phenylpropyl, naphthylmethyl, naphthylethyl and naphthylpropyl.

[0027] In the present invention, the halogen atom may be, for example, selected from fluorine, bromine, chlorine and iodine, preferably fluorine. The alkyl group substituted by fluorine may be, for example, trifluoropropyl.

[0028] According to the definition given by IUPAC (Glossary of Terms Used in Photochemistry, 3rd edition; IUPAC Recommendations 2006), a photocatalyst is a catalyst that can produce a chemical transformation on its reaction partners through light absorption. The excited state of the photocatalyst interacts with the reaction partners to form reaction intermediates and regenerates itself after each interaction cycle.

[0029] The present invention employs a photocatalyst (C) consisting of a manganese carbonyl. Advantageously, manganese is an abundant natural element and is generally considered non-toxic in dosages that make it a trace element. In the present invention, the manganese carbonyl is a metal complex consisting of one or more manganese atoms and a carbonyl ligand bound to the manganese. No other type of ligand is bound to the manganese. Preferably, the manganese carbonyl is more specifically a compound of the formula [Mn2(CO) 10 Advantageously, it is an inexpensive and air-stable commercial product.

[0030] The photocatalyst (C) according to the invention is advantageously used without organic ligands, in particular:

[0031] - nitrogen-free ligands such as pyridine ligands, and / or

[0032] - phosphorus-free ligands such as phosphine ligands, and / or

[0033] - no acyl type ligands, and / or

[0034] - no diketo ligands such as β-diketo ligands, and / or

[0035] - unsubstituted or unsubstituted cyclopentadienyl ligands, and / or

[0036] - No organometallic ligands such as triphenylarsine.

[0037] The manganese in the metal complex is preferably in oxidation state 0. The metal complex is free of X-type ligands, in particular halogen ligands.

[0038] The molar concentration of the photocatalyst (C) can be 0.01 mol % to 15 mol %, more preferably 0.05 mol % to 10 mol %, more preferably 0.1 mol % to 5 mol %, still more preferably 0.5 mol % to 2 mol %, relative to the total moles of unsaturation carried by the unsaturated compound (A). According to a preferred variant, in the method of the present invention, no platinum-, palladium-, ruthenium- or rhodium-based compounds are used. The amount of platinum-, palladium-, ruthenium- or rhodium-based compounds in the reaction medium is, for example, less than 0.1 wt %, preferably less than 0.01 wt %, more preferably less than 0.001 wt % relative to the weight of the photocatalyst (C).

[0039] The present invention firstly lies in a method for the hydrosilylation of an unsaturated compound (A) containing at least one monosubstituted olefinic functional group and a compound (B) containing at least one hydrosilyl functional group, the method comprising a step of irradiating the unsaturated compound (A) and the compound (B) in the presence of a photocatalyst (C) as described above.

[0040] The unsaturated compound (A) used in the hydrosilylation process according to the invention is a compound containing at least one monosubstituted ethylenic unsaturation which does not form part of an aromatic ring. It can be chosen from those known to the person skilled in the art and it contains no reactive chemical functional groups which could interfere with or even prevent the hydrosilylation reaction.

[0041] In the present context, the term "monosubstituted alkene" or "monosubstituted alkenyl" is understood to mean a covalent double bond between two carbon atoms that do not form part of an aromatic ring, which are bonded to three hydrogen atoms and a monovalent group different from hydrogen atoms. The unsaturated compound (A) used in the hydrosilylation process according to the invention can be represented by the general formula (I):

[0042] RCH=CH2(I)

[0043] Wherein R represents a monovalent group.

[0044] According to one embodiment, the unsaturated compound (A) comprises one or more monosubstituted olefin functional groups and 2 to 40 carbon atoms. The unsaturated compound (A) can be represented by the general formula (I):

[0045] RCH=CH2(I)

[0046] Wherein R represents a monovalent group selected from the following:

[0047] - an alkyl group having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 6 carbon atoms, which is optionally substituted by one or more halogen atoms such as chlorine or fluorine, and optionally substituted by one or more groups selected from -OH and -OSiR'3, wherein each R' independently of one another represents H or an alkyl group;

[0048] - an aryl group having 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms, which is optionally substituted by one or more halogen atoms such as chlorine or fluorine, and optionally substituted by one or more groups selected from -OH and -OSiR'3, wherein each R' independently of one another represents H or an alkyl group;

[0049] - aryl-alkyl preferably containing 6 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, optionally substituted on its aryl part and / or its alkyl part by one or more halogen atoms such as chlorine or fluorine, and optionally substituted by one or more groups selected from -OH and -OSiR'3, wherein each R' independently of one another represents H or alkyl;

[0050] - an ether group of the formula -LOR", wherein L represents a bond or a divalent group, preferably an alkylene group having 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and R" represents a group selected from the following: an alkyl group having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 6 carbon atoms, which is optionally substituted with one or more halogen atoms such as chlorine or fluorine, and optionally substituted with one or more groups selected from -OH and -OSiR'3, wherein each R' independently represents H or an alkyl group; an alkyl group having 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms; an aryl group of 6 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, optionally substituted by one or more halogen atoms such as chlorine or fluorine, and optionally substituted by one or more groups selected from -OH and -OSiR'3, wherein each R' independently represents H or alkyl; and an aryl-alkyl group preferably containing 6 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, optionally substituted by one or more halogen atoms such as chlorine or fluorine on its aryl part and / or its alkyl part, and optionally substituted by one or more groups selected from -OH and -OSiR'3, wherein each R' independently represents H or alkyl;

[0051] - an ester group of the formula -LOC(O)-R" in which L and R" have the same meanings as given above.

[0052] The unsaturated compound (A) may preferably be an organic compound containing a monosubstituted alkene group, selected from:

[0053] - α-olefins, preferably 1-octene and 1-hexene,

[0054] - chlorinated α-olefins, preferably allyl chloride,

[0055] - a fluorinated α-olefin, preferably 4,4,5,5,6,6,7,7,7-nonafluoro-1-heptene,

[0056] - allyl alcohol,

[0057] - allyl ethers, such as allyl benzyl ether, allyl C1-C8 alkyl ethers, allyl glycidyl ether, allyl piperidinyl ethers, preferably sterically hindered allyl piperidinyl ethers, allyl silyl ethers, preferably allyl trimethylsilyl ether,

[0058] - Allyl esters, such as allyl acetate

[0059] - Styrenes,

[0060] -1,2-Epoxy-4-vinylcyclohexane,

[0061] - C1-C4 alkyl acrylates and acrylic acid.

[0062] The unsaturated compound (A) may be a disiloxane such as vinylpentamethyldisiloxane and divinyltetramethyldisiloxane.

[0063] The unsaturated compound (A) can be selected from compounds containing a plurality of monosubstituted olefinic functional groups, preferably two or three monosubstituted olefinic functional groups, and particularly preferably, the compound (A) is selected from the following compounds:

[0064]

[0065]

[0066] According to a particularly preferred embodiment, the unsaturated compound (A) may be an organopolysiloxane compound containing one or more monosubstituted alkene functional groups, preferably at least two monosubstituted alkene functional groups. The hydrosilylation reaction of alkene is one of the key reactions in organosilicon chemistry. It not only enables crosslinking between organopolysiloxanes with SiH functional groups and organopolysiloxanes with alkenyl functional groups to form a network and provide mechanical properties to the material, but also enables functionalization of organopolysiloxanes with SiH functional groups to change their physical and chemical properties.

[0067] The organopolysiloxane compound may be formed especially from the following units:

[0068] - at least two siloxy units of the formula: Y a R 1 b SiO (4-a-b) / 2

[0069] in:

[0070] Y is C2-C 12 A monosubstituted alkenyl group, preferably a vinyl group,

[0071] R 1 is a monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably selected from an alkyl group having 1 to 8 carbon atoms such as methyl, ethyl or propyl, a cycloalkyl group having 3 to 8 carbon atoms and an aryl group having 6 to 12 carbon atoms, and

[0072] a=1, 2 or 3, preferably a=1 or 2, more preferably a=1; b=0, 1 or 2; and the sum of a+b=1, 2 or 3; and

[0073] - Optionally, a unit of the formula: R 1 c SiO (4-c) / 2

[0074] Where R 1 has the same meaning as above, and c=0, 1, 2 or 3.

[0075] It should be understood that in the above formula, if there are multiple R 1 If there are multiple Y groups, they may be the same or different from each other. 1 R may represent a monovalent group selected from an alkyl group having 1 to 8 carbon atoms (optionally substituted by at least one halogen atom such as chlorine or fluorine), a cycloalkyl group having 3 to 8 carbon atoms and an aryl group having 6 to 12 carbon atoms. 1 It may advantageously be selected from the group consisting of methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl and phenyl.

[0076] These organopolysiloxane compounds containing one or more monosubstituted olefin functional groups may have a linear structure, a cyclic structure, or a branched structure.

[0077] In the present invention:

[0078] -Siloxy unit《M Vi 》Expression YR 1 2SiO 1 / 2 or Y2R 1 SiO 1 / 2 The siloxy units of

[0079] -Siloxy unit "M" represents the formula R 1 3SiO 1 / 2 The siloxy units of

[0080] -Siloxy unit《D Vi 》Expression YR 1 SiO 2 / 2 The siloxy units of

[0081] -Siloxy unit《D》expression R 1 2SiO 2 / 2 The siloxy units of

[0082] -Siloxy unit《T》expression R 1 SiO 3 / 2 The siloxy units of

[0083] -Siloxy unit "Q" represents SiO 4 / 2 The siloxy units of

[0084] Symbols Y and R 1 As mentioned above.

[0085] As the end of "M" and "M ViAs examples of the "" unit, there may be mentioned trimethylsiloxy, dimethylphenylsiloxy, dimethylvinylsiloxy or dimethylhexenylsiloxy.

[0086] As "D" and "D Vi As examples of "" units, there may be mentioned dimethylsiloxy, methylphenylsiloxy, methylvinylsiloxy, methylbutenylsiloxy, methylhexenylsiloxy, methyldecenylsiloxy or methyldecadienylsiloxy.

[0087] The linear organopolysiloxane compound containing one or more monosubstituted olefinic functional groups is essentially composed of siloxy units "D" and "D Vi 》 and siloxy units《M》 and《M Vi Examples of linear organopolysiloxanes that may be organopolysiloxane compounds containing one or more monosubstituted olefinic functional groups according to the present invention are:

[0088] - poly(dimethylsiloxane) having dimethylvinylsilyl terminal ends;

[0089] - poly(dimethylsiloxane-co-methylphenylsiloxane) having dimethylvinylsilyl terminal ends;

[0090] - poly(dimethylsiloxane-co-methylvinylsiloxane) having dimethylvinylsilyl terminal ends; and

[0091] - Poly(dimethylsiloxane-co-methylvinylsiloxane) having trimethylsilyl termini.

[0092] In the most preferred form, the organopolysiloxane compound comprising one or more monosubstituted olefinic functional groups comprises terminal dimethylvinylsilyl units. More preferably, the organopolysiloxane compound comprising one or more monosubstituted olefinic functional groups is a poly(dimethylsiloxane) having dimethylvinylsilyl terminal groups.

[0093] Silicone oils generally have a viscosity of 1 to 2 000 000 mPa.s. Preferably, the organopolysiloxane compound containing one or more olefinic functional groups is a silicone oil having a dynamic viscosity at 25°C of 20 to 100 000 mPa.s, preferably 20 to 80 000 mPa.s, more preferably 100 to 50 000 mPa.ss.

[0094] The cyclic organopolysiloxane compound containing one or more monosubstituted olefinic functional groups is essentially composed of siloxy units "D" and "D" as described above. ViAn example of a cyclic organopolysiloxane that can be an organopolysiloxane compound containing one or more monosubstituted olefinic functional groups according to the present invention is a cyclic poly(methylvinylsiloxane).

[0095] Optionally, the organopolysiloxane compound comprising one or more monosubstituted olefinic functional groups may additionally comprise siloxy units "T" and / or siloxy units "Q". The organopolysiloxane compound comprising one or more monosubstituted olefinic functional groups then has a branched structure. Examples of branched organopolysiloxanes (also referred to as resins) that may be organopolysiloxane compounds comprising one or more monosubstituted olefinic functional groups according to the invention are:

[0096] -MD Vi Q, wherein a vinyl group is contained in unit D,

[0097] -MD Vi TQ, wherein a vinyl group is contained in unit D,

[0098] -MM Vi Q, wherein vinyl groups are contained in a portion of the units M,

[0099] -MM Vi TQ, wherein vinyl groups are contained in a portion of the units M,

[0100] -MM Vi DD Vi Q, wherein vinyl groups are contained in a portion of the units M and D,

[0101] - and mixtures thereof.

[0102] Preferably, the organopolysiloxane compound comprising one or more monosubstituted olefin functional groups has a mass content of monosubstituted olefin units of 0.001% to 30%, preferably 0.01% to 10%, preferably 0.02% to 5%.

[0103] The unsaturated compound (A) is reacted according to the invention with a compound (B) which comprises at least one hydrosilyl function.

[0104] According to one embodiment, the compound (B) comprising at least one hydrosilyl functional group is a silane or polysilane compound comprising at least one hydrogen atom bonded to a silicon atom. In the present invention, a "silane" compound refers to a compound comprising a silicon atom bonded to four hydrogen atoms or to an organic substituent. In the present invention, a "polysilane" compound refers to a compound having at least one ≡Si-Si≡ unit. Among the silane compounds, the compound (B) comprising at least one hydrosilyl functional group may be a phenylsilane or a mono-, di- or tri-alkylsilane, such as triethylsilane.

[0105] According to another embodiment, the compound (B) comprising at least one hydrosilyl functional group is an organopolysiloxane compound comprising at least one hydrogen atom bonded to a silicon atom, also known as an organohydrogenpolysiloxane. The organohydrogenpolysiloxane may advantageously be an organopolysiloxane formed from the following units:

[0106] - at least two siloxy units of the formula: H d R 1 e SiO (4-d-e) / 2

[0107] in:

[0108] R 1 is a monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably selected from an alkyl group having 1 to 8 carbon atoms such as methyl, ethyl or propyl, a cycloalkyl group having 3 to 8 carbon atoms and an aryl group having 6 to 12 carbon atoms, and

[0109] d=1, 2 or 3, preferably d=1 or 2, more preferably d=1; e=0, 1 or 2; and d+e=1, 2 or 3; and,

[0110] -optionally, other units of the formula: R 1 f SiO (4-f) / 2

[0111] Where R 1 has the same meaning as described above, and f=0, 1, 2 or 3.

[0112] It is to be understood that in the above formula, if there are multiple groups R 1 , then they may be the same or different from each other. Preferably, R 1 R may represent a monovalent group selected from an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and an aryl group having 6 to 12 carbon atoms, which is optionally substituted by at least one halogen atom such as chlorine or fluorine. 1 It may advantageously be selected from the group consisting of methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl and phenyl.

[0113] The organohydrogenpolysiloxane may have a linear, branched or cyclic structure. The degree of polymerization is preferably greater than or equal to 2. Typically, it is less than 5,000.

[0114] In the following, the siloxy units "M", "D", "T" and "Q" are as defined above, and

[0115] -Siloxy unit《M'》expression HR 12SiO 1 / 2 The siloxy units of

[0116] -Siloxy unit《D'》expression HR 1 SiO 2 / 2 The siloxy units of

[0117] Symbol R 1 As mentioned above.

[0118] When linear polymers are concerned, they are essentially composed of siloxy units chosen from siloxy units "D" and "D'" and siloxy units "M" and "M'". Examples of organohydrogenpolysiloxanes that may be compounds (B) comprising at least one hydrosilyl functional group according to the invention are:

[0119] - poly(dimethylsiloxane) having hydrodimethylsilyl terminal ends;

[0120] - poly(dimethylsiloxane-co-methylhydrogensiloxane) having trimethylsilyl termini;

[0121] - poly(dimethylsiloxane-co-methylhydrogensiloxane) having hydrodimethylsilyl terminal ends; and

[0122] - poly(methylhydrogensiloxane) having trimethylsilyl termini.

[0123] When the organohydrogenpolysiloxane has a cyclic structure, it consists essentially of siloxy units selected from siloxy units "D" and "D'". An example of a cyclic organohydrogenpolysiloxane that can be the compound (B) comprising at least one hydrosilyl functional group according to the present invention is a cyclic poly(methylhydrogensiloxane).

[0124] When the organohydrogenpolysiloxane has a branched structure, it is preferably selected from the organosilicon resins of the following formula:

[0125] -M'Q, in which the hydrogen atom bonded to the silicon atom is carried by the M group,

[0126] -MM'Q, in which the hydrogen atom bonded to the silicon atom is carried by a part of the M unit,

[0127] -MD'Q, in which the hydrogen atom bonded to the silicon atom is carried by the D group,

[0128] -MDD'Q, in which the hydrogen atom bonded to the silicon atom is carried by a portion of the D group,

[0129] -MM'TQ, in which the hydrogen atoms bonded to the silicon atoms are carried by a portion of the M units,

[0130] -MM'DD'Q, in which the hydrogen atoms bonded to the silicon atoms are carried by a portion of the M and D units,

[0131] - and mixtures thereof.

[0132] Preferably, the organohydrogenpolysiloxane compound has a hydrosilyl Si—H functional group content of 0.2% to 91%, more preferably 3% to 80%, and more preferably 15% to 70%.

[0133] According to a particular embodiment of the invention, the unsaturated compound (A) and the compound (B) comprising at least one hydrosilyl function may be the same compound, which comprises, on the one hand, at least one monosubstituted alkene function and, on the other hand, at least one silicon atom and at least one hydrogen atom bonded to the silicon atom. Such a compound may then be referred to as "bifunctional" and it is capable of reacting with itself by a hydrosilylation reaction. The invention may therefore also relate to a process for the hydrosilylation of a bifunctional compound, which comprises, on the one hand, at least one monosubstituted alkene function and, on the other hand, at least one silicon atom and at least one hydrogen atom bonded to the silicon atom, with itself, said process being photocatalyzed by a photocatalyst (C) as described above.

[0134] Examples of organopolysiloxanes which may be difunctional compounds are:

[0135] - poly(dimethylsiloxane-co-hydrogenmethylsiloxane-co-vinylmethylsiloxane) having dimethylvinylsilyl terminal ends;

[0136] - poly(dimethylsiloxane-co-hydrogenmethylsiloxane-co-vinylmethylsiloxane) having dimethylhydrogensilyl terminal ends; and

[0137] - Poly(dimethylsiloxane-co-hydrogenmethylsiloxane-co-propyl glycidyl ether methylsiloxane) having trimethylsilyl terminal ends.

[0138] When it comes to the use of unsaturated compounds (A) and compounds (B) comprising at least one hydrosilyl function, the person skilled in the art understands that this also means the use of difunctional compounds.

[0139] The amounts of compound (A) and compound (B) can be controlled so that the molar ratio of the hydrosilyl functional group of compound (B) to the monosubstituted alkene functional group of compound (A) is preferably 1:10 to 10:1, more preferably 1:5 to 5:1, and more preferably 1:3 to 3:1, and still more preferably 1:2 to 2:1.

[0140] The method according to the present invention comprises the step of irradiating the unsaturated compound (A) and the compound (B) in the presence of a photocatalyst (C).

[0141] The irradiation is preferably exposure to UV and / or visible radiation. In this article, "UV" refers to ultraviolet light. Ultraviolet radiation is defined as electromagnetic radiation with a wavelength between about 100nm and about 400nm, i.e., below the spectrum of visible light. Within UV radiation, UV-A radiation with a wavelength between about 315nm and about 400nm, UV-B radiation with a wavelength between about 280nm and about 315nm, and UV-C radiation with a wavelength between about 100nm and about 280nm can be defined. Visible radiation is defined as electromagnetic radiation with a wavelength between about 400nm and about 800nm. Preferably, irradiation is carried out by exposure to radiation with a wavelength between 100nm and 450nm, or between 200nm and 420nm, or between 250nm and 405nm.

[0142] The radiation can be emitted by a doped or undoped mercury vapor lamp with an emission spectrum ranging from 100 nm to 450 nm. Light sources such as LEDs providing point-shaped UV or visible light can also be used. In addition, in this article, "LED" is an abbreviation for "light emitting diode" well known to those skilled in the art (also abbreviated as DEL in French).

[0143] According to one embodiment, the irradiation is carried out using UV radiation whose light source is a UV-LED lamp. The UV-LED lamp can emit radiation with a wavelength of 365nm, 385nm, 395nm or 405nm. Preferably, the UV-LED lamp is a lamp emitting at 395nm. The power of the UV-LED lamp is preferably 2W / m 2 and 200 000W / m 2 between.

[0144] According to a preferred embodiment, the irradiation step is carried out under an inert atmosphere, for example under nitrogen, argon or oxygen-depleted air.

[0145] The irradiation step is carried out at a temperature of 0-60°C, more preferably 15-60°C, more preferably 20-40°C and even more preferably at ambient temperature (ie typically about 25°C).

[0146] The hydrosilylation reaction can be carried out in a solvent or in the absence of a solvent. A suitable solvent is a solvent that is miscible with compound (B). For example, the solvent can be selected from aliphatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, decalin and liquid paraffin; aromatic hydrocarbons such as toluene and xylene; hydrocarbon mixtures of mineral or synthetic origin such as white-spirit; ethers such as tetrahydrofuran, dimethicone, cyclohexane, cyclopent ... Alkanes, diethyl ether and diphenyl ether; chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, perchloroethylene and chlorobenzene; esters such as ethyl acetate, butyl acetate and butyrolactone; acetonitrile; dimethylformamide; dimethyl sulfoxide; N-methylpyrrolidone; polyethylene glycol; and mixtures thereof. Preferably, the solvent can be selected from aliphatic hydrocarbons, aromatic hydrocarbons and chlorinated hydrocarbons, more preferably hexane, cyclohexane, decalin and toluene. As a variant, the solvent can be selected from volatile silicones, octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), polydimethylsiloxane oil (PDMS), polyphenylmethylsiloxane oil (PPMS) or mixtures thereof. As a variant, one of the reactants such as an unsaturated compound (A) can serve as a solvent. Preferably, organic solvents that are harmful to the environment and to the health of workers in the manufacturing workshop are avoided.

[0147] According to a preferred embodiment of the invention, the compounds (A) and (B) used are selected from organopolysiloxanes as defined above. In this case, a three-dimensional network is formed, which leads to the curing of the composition. The crosslinking involves a gradual physical change of the medium constituting the composition. Therefore, the method according to the invention can be used to obtain elastomers, gels, foams, etc. In this case, a crosslinked organosilicon material is obtained. The term "crosslinked organosilicon material" refers to any silicone-based product obtained by crosslinking and / or curing a composition comprising an organopolysiloxane with at least two unsaturated bonds and an organopolysiloxane with at least three hydrosilyl units. The crosslinked organosilicon material can be, for example, an elastomer, a gel or a foam.

[0148] Still according to this preferred embodiment of the process of the invention, in which compounds (A) and (B) are selected from organopolysiloxanes as defined above, it is possible to use functional additives commonly used in organosilicon compositions. As categories of commonly used functional additives, mention may be made of:

[0149] -filler,

[0150] - adhesion promoters,

[0151] - inhibitors or retarders of the hydrosilylation reaction,

[0152] - adhesion regulators,

[0153] - Silicone resin,

[0154] - Additives for improving consistency;

[0155] - pigments (organic or inorganic); and

[0156] - Additives for heat resistance, oil resistance or flame retardancy, such as metal oxides.

[0157] The fillers which are optionally provided are preferably mineral. The fillers may be very finely divided products, the average particle size of which is less than 0.1 μm. The fillers may in particular be siliceous. In the case of siliceous materials, they may function as reinforcing or semi-reinforcing fillers. Reinforcing siliceous fillers are selected from powders of colloidal silica, fumed silica and precipitated silica or mixtures thereof. These powders generally have an average particle size of less than 0.1 μm (micrometer) and a BET specific surface area of ​​greater than 30 m 2 / g, preferably 30-350m 2 / g. Semi-reinforced siliceous fillers can also be used, such as diatomaceous earth or ground quartz. These silicon dioxides can be added as is or added after being treated with the organic silicon-containing compound that is generally used for this purpose. Among these compounds, methylpolysiloxanes such as hexamethyldisiloxane, octamethylcyclotetrasiloxane, methylpolysilazane such as hexamethyldisilazane, hexamethylcyclotrisilazane, tetramethyldivinyldisilazane, chlorosilanes such as dimethyldichlorosilane, trimethylchlorosilane, methylvinyldichlorosilane, dimethylvinylchlorosilane, alkoxysilanes such as dimethyldimethoxysilane, dimethylvinylethoxysilane, trimethylmethoxysilane, and mixtures thereof can be mentioned. About non-siliceous mineral materials, they can be used as semi-reinforced or filled mineral fillers. Examples of these non-siliceous fillers, which can be used alone or in a mixture, are calcium carbonate, optionally surface-treated with an organic acid or an ester of an organic acid, calcined clay, rutile titanium dioxide, oxides of iron, zinc, chromium, zirconium or magnesium, various forms of aluminum oxide (hydrated or non-hydrated), boron nitride, lithopone, barium metaborate, barium sulfate and glass microspheres. These fillers are relatively coarse, usually having an average particle size of more than 0.1 μm and a specific surface area of ​​less than 30 m 2 / g. These fillers may have been surface-modified with various organic silicon-containing compounds commonly used for this purpose. Preferably, the filler is silicon dioxide, even more preferably fumed silicon dioxide. Advantageously, the silicon dioxide has a molecular weight of 75-410 m 2 The organic silicon composition may contain 5% to 20% by weight of filler relative to the total weight of the organic silicon composition. Advantageously, the organic silicon composition may contain 8% to 15% by weight of filler.

[0158] The discovery of this novel hydrosilylation process according to the invention, which is photocatalytic under mild conditions, makes it possible to envisage numerous applications.

[0159] According to a first embodiment, the hydrosilylation method according to the present invention can be used for the functionalization of organopolysiloxanes with SiH functional groups. The purpose of this functionalization is to change the physical and / or chemical properties of the organopolysiloxane and produce novel compounds with improved properties. According to this embodiment, the unsaturated compound (A) containing at least one monosubstituted alkene functional group is selected from unsaturated compounds containing one or more monosubstituted alkene functional groups and 2-40 carbon atoms, and the compound (B) containing at least one hydrosilyl functional group is an organopolysiloxane compound containing at least one hydrogen atom bonded to a silicon atom. The functionalization method of organopolysiloxanes with SiH functional groups can be described, characterized in that the addition reaction between the organopolysiloxane with SiH functional groups and the unsaturated compound (A) containing one or more monosubstituted alkene functional groups and 2-40 carbon atoms is obtained by the hydrosilylation method as described above.

[0160] According to another particularly preferred embodiment, the hydrosilylation method according to the invention can be used for crosslinking between organopolysiloxanes having SiH functional groups and organopolysiloxanes having alkenyl functional groups to form a network and impart mechanical properties to the material. According to this embodiment, the unsaturated compound (A) containing at least one monosubstituted alkene functional group is an organopolysiloxane compound containing at least two monosubstituted alkene functional groups, and the compound (B) containing at least one hydrosilyl functional group is an organopolysiloxane compound containing at least three hydrogen atoms bonded to silicon atoms. A method for preparing a crosslinked organosilicon material can be described, characterized in that a crosslinking reaction between an organopolysiloxane having SiH functional groups and an organopolysiloxane having alkenyl functional groups is obtained by a hydrosilylation method as described above. The crosslinked organosilicon material thus obtained can be used for different applications, in particular:

[0161] - "coating" type applications, where the support is covered with a silicone coating;

[0162] - Applications in the electronics sector, such as conformal coatings for printed circuits and potting of microcircuits and electronic components such as IGBTs;

[0163] - Additive manufacturing methods using photopolymerization (also known as 3D printing methods). DETAILED DESCRIPTION

[0164] Further details or advantages of the invention will become more apparent from the following examples given by way of pure indication.

[0165] Example

[0166] Example 1-3 and Comparative Example 1-3: Hydrogenation of 1-octene (1) and 1,1,1,3,5,5,5-heptamethyltrisiloxane (2) Silanization

[0167]

[0168] Under argon atmosphere, 1-octene (1) and 1,1,1,3,5,5,5-heptamethyltrisiloxane (2) were introduced into a 4 mL vial at ambient temperature. 10 The solution in toluene was injected into the vial and toluene was added. Mn2(CO) 10 The final concentration (relative to 1-octene) = 1 mol %.

[0169] In Examples 1, 2 and 3, the reaction mixture was placed under UV light for 4 hours (300 W, λ=250-420 nm). In Comparative Examples 1, 2 and 3, the reaction mixture was not irradiated but heated for 24 hours. Table 1 shows the concentrations of the reactants and the reaction conditions, as well as the yields of the hydrosilylation product (3) and the isomerization product of (1) (determined by gas chromatography, calculated relative to 1-octene).

[0170] [Table 1]

[0171] condition Concentration(1) Concentration (2) (3) Yield (1) Isomerization Embodiment 1 UV,4h 0.825M 1.650M 94％ No product Example 2 UV,4h 1.650M 1.650M 78％ 1％ Example 3 UV,4h 3.3M 1.650M 86％ 3％ Comparative Example 1 30℃,24h 0.825M 1.650M No product No product Comparative Example 2 60℃,24h 0.852M 1.650M No product No product Comparative Example 3 100℃,24h 0.825M 1.650M No product No product

[0172] Examples 1, 2 and 3 show that under mild reaction conditions (4 hours at ambient temperature) the 10 The photocatalytic hydrosilylation reaction between 1-octene (1) and 1,1,1,3,5,5,5-heptamethyltrisiloxane (2) enables the product (3) to be obtained with excellent yield and excellent selectivity. In contrast, the catalyst does not show activity by thermal activation (Comparative Examples 1, 2 and 3).

[0173] Example 4-12 and Comparative Example 4-6: Hydrosilylation of Different Olefins (1')

[0174]

[0175] The same procedure described in Example 1 was followed (UV, 4 h), while changing the structure of the olefin compound (1′), as shown in Table 2 below. The yield of the hydrosilylation product (3′) (determined by gas chromatography, calculated relative to the olefin) is shown in Table 2.

[0176] [Table 2]

[0177]

[0178]

[0179] In Examples 4-12, hydrosilylation products were obtained with excellent selectivity. No C=C isomerization was observed, nor were any products from the cleavage of the CO bond observed. On the other hand, hydrosilylation products could not be obtained from geminal disubstituted alkenes (Comparative Examples 4 and 5) or from internal alkenes (Comparative Example 6).

Claims

1. A method for the hydrosilylation of an unsaturated compound (A) containing at least one monosubstituted olefinic functional group with a compound (B) containing at least one hydrosilyl functional group, the method comprising the step of irradiating the unsaturated compound (A) and the compound (B) in the presence of a photocatalyst (C) consisting of carbonyl manganese.

2. The hydrosilylation method according to claim 1, characterized in that The manganese in the manganese carbonyl is in the oxidation state 0.

3. The hydrosilylation method according to claim 1 or 2, characterized in that: The manganese carbonyl has the chemical formula [Mn2(CO) 10 ] of dimanganese decacarbonyl.

4. The hydrosilylation method according to any one of claims 1 to 3, characterized in that: The unsaturated compound (A) is an organic compound containing a monosubstituted olefinic group, selected from: - α-olefins, preferably 1-octene and 1-hexene, - chlorinated alpha-olefins, preferably allyl chloride, - fluorinated alpha-olefins, preferably 4,4,5,5,6,6,7,7,7-nonafluoro-1-heptene, - Allyl alcohol, - allyl ethers, such as allyl benzyl ether, allyl C1-C8 alkyl ethers, allyl glycidyl ether, allyl piperidinyl ethers, preferably sterically hindered allyl piperidinyl ethers, allyl silyl ethers, preferably allyl trimethylsilyl ether, - Allyl esters, such as allyl acetate - Styrenes, - 1,2-Epoxy-4-vinylcyclohexane, - C1-C4 alkyl acrylates and acrylic acid.

5. The hydrosilylation method according to any one of claims 1 to 3, characterized in that: The unsaturated compound (A) is an organopolysiloxane compound comprising one or more monosubstituted olefinic functional groups, preferably at least two monosubstituted olefinic functional groups.

6. The hydrosilylation method according to any one of claims 1 to 5, characterized in that: The compound (B) comprising at least one hydrosilyl functional group is an organopolysiloxane compound comprising at least one hydrogen atom bonded to a silicon atom.

7. The hydrosilylation method according to any one of claims 1 to 6, characterized in that: Irradiation is performed by exposure to radiation having a wavelength of 100 nm to 450 nm, or 200 nm to 420 nm, or 250 nm to 405 nm.

8. The hydrosilylation method according to any one of claims 1 to 7, characterized in that: The irradiation is carried out using UV radiation whose light source is a UV-LED lamp.

9. The hydrosilylation method according to any one of claims 1 to 8, characterized in that: The irradiation is carried out at a temperature of 0°C to 60°C, more preferably 15°C to 60°C, more preferably 20°C to 40°C and even more preferably at ambient temperature.

10. The hydrosilylation method according to any one of claims 1, 2, 3, 7, 8 and 9 for functionalizing an organopolysiloxane having SiH functional groups, characterized in that: The unsaturated compound (A) comprising at least one monosubstituted olefinic functional group is selected from unsaturated compounds comprising one or more monosubstituted olefinic functional groups and 2 to 40 carbon atoms, and the compound (B) comprising at least one hydrosilyl functional group is an organopolysiloxane compound comprising at least one hydrogen atom bonded to a silicon atom.

11. The hydrosilylation method according to any one of claims 1, 2, 3, 7, 8 and 9, for preparing a cross-linked organosilicon material, characterized in that: The unsaturated compound (A) containing at least one monosubstituted olefin functional group is an organopolysiloxane compound containing at least two monosubstituted olefin functional groups, and the compound (B) containing at least one hydrosilyl functional group is an organopolysiloxane compound containing at least three hydrogen atoms bonded to silicon atoms.

12. Use of manganese carbonyl as a photocatalyst for the hydrosilylation reaction of an unsaturated compound (A) comprising at least one monosubstituted olefinic function with a compound (B) comprising at least one hydrosilyl function.

13. The use according to claim 12, characterized in that The manganese in the manganese carbonyl is in the oxidation state 0.

14. The use according to claim 12 or 13, characterized in that The manganese carbonyl has the chemical formula [Mn2(CO) 10 ] of dimanganese decacarbonyl.

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