Photocatalytic hydrosilylation method using manganese complexes

Abstract

The present invention relates to a hydrosilylation reaction between a monosubstituted alkene compound and a compound containing at least one hydrogen atom bonded to a silicon atom. More specifically, the present invention relates to a method for hydrosilylation of an unsaturated compound (A) containing at least one monosubstituted alkene functional group with 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) consisting of manganese carbonyl. The hydrosilylation reaction between an alkene compound and a compound containing at least one hydrogen atom bonded to a silicon atom makes it possible in particular to cure silicone compositions by crosslinking.

Description

Technical Field

[0001] The present invention relates to a hydrosilylation reaction between a monosubstituted alkene compound and a compound containing at least one hydrogen atom bonded to a silicon atom. More specifically, the present invention relates to a hydrosilylation method photocatalyzed by a manganese complex. The hydrosilylation reaction between an alkene compound and a compound containing at least one hydrogen atom bonded to a silicon atom enables curing particularly by crosslinking of silicone compositions.

Background Art

[0002] Level of conventional technology During the hydrosilylation reaction of an alkene compound (also known as polyaddition), a compound containing at least one double bond reacts with a compound containing at least one hydrosilyl functional group, i.e., a hydrogen atom bonded to a silicon atom. This reaction can be explained, for example, by the following formula.

Chemical formula

[0003] The hydrosilylation reaction may involve a dehydrogenative silylation reaction (also known as deshydrosilylation) and may be replaced by it. This reaction can be explained by the following formula:

Chemical formula

[0004] The hydrosilylation reaction is particularly used to crosslink silicone compositions containing an organopolysiloxane having an alkenyl unit and an organopolysiloxane having a hydrosilyl functional group.

[0005] The hydrosilylation reaction of alkene compounds is typically carried out by catalytic action using metal or organometallic catalysts. Currently, platinum catalysts are suitable for this reaction. Therefore, the majority of industrial hydrosilylation processes, particularly for the hydrosilylation of alkenes, are catalyzed by Karlstedt Pt(0) complexes of Speier hexachloroplatinic acid or Pt2(divinyltetramethyldisiloxane)3 (or abbreviated as Pt2(DVTMS)3).

[0006] In the 2000s, the production of platinum-carbene complexes made it possible to obtain more stable catalysts (see, for example, International Publication No. 01 / 42258).

[0007] However, the use of metallic or organometallic platinum catalysts still presents problems. Platinum is an expensive metal, its scarcity is increasing, and its cost is rising exponentially. Therefore, its use on an industrial scale is difficult. Consequently, there is a desire to reduce the amount of catalyst required for the reaction as much as possible without reducing yield or reaction rate. Numerous studies have been conducted to find alternatives to Karlstedt catalysts.

[0008] For example, International Publication No. 2014 / 096719 describes a method for hydrosilylation of an unsaturated compound and a hydrosilane compound catalyzed by a photocatalyst selected from polyoxometalates, such as tetrabutylammonium decathungstate.

[0009] The issue of replacing chloroplatinic acid as a hydrosilylation catalyst was already addressed in U.S. Patent No. 3,271,362 of 1966. The inventor of this patent proposed cyclopentadienylcobalt dicarbonyl [C5H5Co(CO)2] and dimanganesedecacarbonyl [Mn2(CO) 10The use of a carbonyl metal catalyst selected from the group consisting of ] and dicobalt octacarbonyl [Co2(CO)8] was proposed. In the only embodiment using dimanganese decacarbonyl, the reaction was carried out at 125°C, and precise information regarding the reaction yield and the properties of the polyaddition product is not provided.

[0010] In 2021, Dong et al. described manganese-based catalysts for the dehydrosilylation and hydrosilylation of alkenes in a scientific paper ("Manganese-catalysed divergent silylation of alkenes," Nature Chemistry, Vol. 13, pp. 182-190 (2021)). 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.

[0011] Dimanganese decacarbonyl is also used as a catalyst in other reactions. For example, 10 mol% Mn2(CO) is used as a photocatalyst for the hydrosilylation reaction of alkynes. 10 A scientific paper outside of Liang that mentions the use of this method is "Visible-Light-Initiated Manganese-Catalyzed E-Selective Hydrosilylation and Hydrogermylation of Alkyne", Org. Lett., 2019, 21, 8, 2750-2754. Unlike alkenes, alkynes cannot undergo dehydrosilylation. Regarding dehydrosilylation, a scientific paper by Stefan Weber ("Manganese-Catalyzed Dehydrogenative Silylation of Alkenes Following Two Parallel Inner-Sphere Pathways", J.Am.Chem.Soc., 2021, 143, 17825-17832) describes the use of a Mn(I) catalyst for the dehydrogenative silylation of terminal alkenes. Two catalysts have been proposed: fac-[Mn(dippe)(CO)3(CH2CH2CH3)] and fac-[Mn(ddre)(CO)3(CH2CH2CH3)] (where dippe = 1,2-bis(diisopropylphosphinone) and drpe = 1,2-bis(di-n-propylphosphinone)).

[0012] Against this backdrop, the inventors have sought a more effective process for the hydrosilylation of alkene compounds. Advantageously, the reaction is desirable to be rapid and carried out at a moderate temperature, preferably ambient temperature. Furthermore, it is desirable that the hydrosilylation reaction be selective, that the dehydrosilylation and / or isomerization reactions of the alkene compound be reduced, or even negligibly reduced. Finally, the catalyst is desirable to contain abundant, inexpensive, and non-toxic chemical elements. [Prior art documents] [Patent Documents]

[0013] [Patent Document 1] International Publication No. 01 / 42258 [Patent Document 2] International Publication No. 2014 / 096719 [Patent Document 3] U.S. Patent No. 3,271,362 [Non-patent literature]

[0014] [Non-Patent Document 1] Dong, et al., "Manganese-catalysed divergent silylation of alkenes," Nature Chemistry, Vol. 13, pp. 182-190 (2021) [Non-Patent Document 2] Liang et al., “Visible-Light-Initiated Manganese-Catalyzed E-Selective Hydrosilylation and Hydrogermylation of Alkyne”, Org. Lett., 2019, 21, 8, 2750-2754 [Non-Patent Document 3] Stefan Weber, “Manganese-Catalyzed Dehydrogenative Silylation of Alkenes Following Two Parallel Inner-Sphere Pathways”, J.Am.Chem.Soc.,2021,143,17825-17832 [Overview of the Initiative] [Problems that the invention aims to solve]

[0015] Summary of the Invention Unexpectedly, the inventors discovered that the hydrosilylation reaction of monosubstituted alkenes can be photocatalyzed by a manganese carbonyl complex under mild conditions with excellent yield and selectivity. In particular, this photocatalytic reaction produces little to no dehydrosilylation and / or isomerization products of the monosubstituted alkene compound. [Means for solving the problem]

[0016] The subject of the present invention is a method for hydrosilylation of an unsaturated compound (A) containing at least one monosubstituted alkene 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) comprising manganese carbonyl.

[0017] Another subject of the present invention is the use of manganese carbonyl as a photocatalyst for a hydrosilylation reaction between an unsaturated compound (A) containing at least one monosubstituted alkene functional group and a compound (B) containing at least one hydrosilyl functional group. [Modes for carrying out the invention]

[0018] Unless otherwise specified, all silicone oil viscosities relating to this description correspond to the "Newtonian" kinematic viscosity at 25°C, that is, the kinematic viscosity measured using a Brookfield viscometer in a method known in itself, at a shear rate gradient low enough that the measured viscosity is independent of the velocity gradient.

[0019] Although not described herein, possible tautomeral forms of the compounds described herein are within the scope of the present invention.

[0020] In the present invention, the alkyl group may 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, for example, the following groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl.

[0021] In the present invention, the cycloalkyl group can be monocyclic or polycyclic, preferably monocyclic or bicyclic. The cycloalkyl group preferably contains 3 to 30 carbon atoms, more preferably 3 to 8 carbon atoms. The cycloalkyl group can be selected from, for example, the following groups: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, and norbornyl.

[0022] In the present invention, the aryl group can 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 substituted with one or more alkyl groups. The aryl group can be selected from phenyl, naphthyl, anthracenyl, phenanthryl, mesityl, tolyl, xylyl, diisopropylphenyl, and triisopropylphenyl groups.

[0023] In the present invention, the arylalkyl group preferably comprises 6 to 30 carbon atoms, more preferably 7 to 20 carbon atoms. The arylalkyl group can be selected from, for example, the following groups: benzyl, phenylethyl, phenylpropyl, naphthylmethyl, naphthylethyl, and naphthylpropyl.

[0024] In the present invention, the halogen atom can be selected from the group consisting of, for example, fluorine, bromine, chlorine, and iodine, with fluorine being preferred. The fluorine-substituted alkyl group can be, for example, trifluoropropyl.

[0025] According to the definition provided by IUPAC (Glossary of Terms Used in Photochemistry, 3rd edition; IUPAC Recommendations 2006), a photocatalyst is a catalyst that can cause a chemical transformation in a reaction partner by absorbing light. The excited state of the photocatalyst interacts with the reaction partner to form a reaction intermediate, which is itself regenerated after each interaction cycle.

[0026] This invention uses a photocatalyst (C) composed of manganese carbonyl. Advantageously, manganese is an abundant natural element that is generally considered non-toxic within the range of trace element additions. In this invention, manganese carbonyl is a metal complex consisting of one or more manganese atoms and a carbonyl ligand bonded to manganese. Other types of ligands do not bond to manganese. Preferably, manganese carbonyl is, more specifically, a compound with the chemical formula [Mn2(CO) 10This is dimanganese decacarbonyl. Advantageously, it is an inexpensive, air-stable, commercially available product.

[0027] The photocatalyst (C) according to the present invention does not use an organic ligand, and in particular, • Without using nitrogen-based ligands such as pyridine ligands, and / or • Without using phosphorus ligands such as phosphine ligands, and / or • Without using acyl ligands, and / or • Without using diketone ligands such as β-diketone ligands, and / or Without using substituted or unsubstituted cyclopentadienyl ligands, and / or • Without using organometallic ligands such as triphenylarsine, It gives you an advantage in recruitment.

[0028] The manganese in the metal complex is preferably in the oxidized state of 0. The metal complex does not contain an X-type ligand, particularly a halogen ligand.

[0029] The molar concentration of the photocatalyst (C) can be 0.01 mol% to 15 mol%, more preferably 0.05 mol% to 10 mol%, even more preferably 0.1 mol% to 5 mol%, and even more preferably 0.5 mol% to 2 mol%, relative to the total number of moles of unsaturated compounds held by the unsaturated compound (A). In another preferred embodiment, the method according to the present invention does not use platinum, palladium, ruthenium, or rhodium-based compounds. The amount of platinum, palladium, ruthenium, or rhodium-based compounds in the reaction medium is, for example, less than 0.1% by weight, preferably less than 0.01% by weight, and more preferably less than 0.001% by weight, relative to the weight of the photocatalyst C.

[0030] The present invention first comprises a method for hydrosilylation of an unsaturated compound (A) containing at least one monosubstituted alkene 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) as described above.

[0031] The unsaturated compound (A) used in the hydrosilylation method according to the present invention is a compound containing at least one monosubstituted alkene unsaturated ring that does not form part of an aromatic ring. This compound can be selected from those known to those skilled in the art, and from those that do not contain reactive chemical functional groups that may interfere with or actually inhibit the hydrosilylation reaction.

[0032] In this specification, the terms "monosubstituted alkene" or "monosubstituted alkenyl" mean a covalent double bond between two carbon atoms that does not form part of an aromatic ring, wherein the two carbon atoms are bonded to three hydrogen atoms and a monovalent group other than hydrogen atoms. The unsaturated compound (A) used in the hydrosilylation method according to the present invention can be represented by the following general formula (I): RCH=CH2(I) In the formula, R represents a monovalent group.

[0033] According to one embodiment, the unsaturated compound (A) contains one or more monosubstituted alkene functional groups and 2 to 40 carbon atoms. The unsaturated compound (A) can be represented by the following general formula (I): RCH=CH2(I) In the formula, R represents a monovalent group selected from the following group: • Alkyl alkyl groups having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and even more preferably 1 to 6 carbon atoms, which may be substituted with one or more halogen atoms such as chlorine or fluorine, and may be substituted with one or more groups selected from -OH and -OSiR'3 (where each R' independently represents H or an alkyl group); • An aryl group having 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms, which may be substituted with one or more halogen atoms such as chlorine or fluorine, and may be substituted with one or more groups selected from -OH and -OSiR'3 (where each R' independently represents H or an alkyl group); Preferably, an arylalkyl group having 6 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, wherein the aryl portion and / or the alkyl portion may be substituted with one or more halogen atoms such as chlorine or fluorine, and may be substituted with one or more groups selected from -OH and -OSiR'3 (where each R' independently represents H or an alkyl group); · An ether group of the formula -LOR” where 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 groups: an alkyl group having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, even more preferably 1 to 6 carbon atoms, which may be substituted with one or more halogen atoms such as chlorine or fluorine, and may be substituted with one or more groups selected from -OH and -OSiR'3 (wherein R' independently represents H or an alkyl group); an alkyl group having 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms A reel group which may be substituted with one or more halogen atoms such as chlorine or fluorine, and may be substituted with one or more groups selected from -OH and -OSiR'3 (where each R' independently represents H or an alkyl group); and an arylalkyl group which preferably has 6 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, wherein the aryl portion and / or the alkyl portion may be substituted with one or more halogen atoms such as chlorine or fluorine, and may be substituted with one or more groups selected from -OH and -OSiR'3 (where each R' independently represents H or an alkyl group); • Ester group of formula -LOC(O)-R'' (wherein L and R'' are the same as defined above).

[0034] The unsaturated compound (A) can preferably be an organic compound having a monosubstituted alkene group selected from the following group: • α-olefins, preferably 1-octene and 1-hexene, • Chlorinated α-olefin, preferably allyl chloride, • Fluorinated α-olefin, 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 ether, allyl glycidyl ether, allyl piperidinyl ether, preferably sterically hindered allyl piperidinyl ether, or allyl silyl ether, preferably allyl trimethylsilyl ether. • Allyl esters such as allyl acetate, ·styrene, · 1,2-Epoxy-4-vinylcyclohexane, C1-C4 alkyl acrylates and acrylic acid.

[0035] The unsaturated compound (A) can be a disiloxane such as vinylpentamethyldisiloxane or divinyltetramethyldisiloxane.

[0036] The unsaturated compound (A) can be selected from compounds containing several monosubstituted alkene functional groups, preferably two or three monosubstituted alkene functional groups, and particularly preferably, compound (A) is selected from the following compounds. [ka]

[0037] According to a particularly preferred embodiment, the unsaturated compound (A) can be an organopolysiloxane compound containing one or more monosubstituted alkene functional groups, preferably at least two monosubstituted alkene functional groups. The hydrosilylation reaction of alkenes is one of the important reactions in silicone chemistry. This not only crosslinks an organopolysiloxane having a SiH functional group and an organopolysiloxane having an alkenyl functional group to form a network and impart mechanical properties to the material, but also enables the functionalization of an organopolysiloxane having a SiH functional group to modify its physical and chemical properties.

[0038] The organopolysiloxane compound is particularly · At least two siloxyl units of the following formula: Y a R 1 b SiO (4-a-b) / 2 (In the formula, Y is a monosubstituted C2-C 12 alkenyl group, preferably a vinyl group, R 1 is a monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms such as a methyl group, an ethyl group or a propyl group, a cycloalkyl group having 3 to 8 carbon atoms, and an aryl group having 6 to 12 carbon atoms, a = 1, 2 or 3, preferably a = 1 or 2, more preferably a = 1; b = 0, 1 or 2; and the sum a + b = 1, 2 or 3. ) and · Optionally, a unit of the following formula: R 1 c SiO (4-c) / 2 (In the formula, R 1 has the same meaning as above, and c = 0, 1, 2 or 3. ) and is composed of.

[0039] In the above formula, when a plurality of R 1 groups are present, or when a plurality of Y groups are present, it is understood that they may be the same or different from each other. Preferentially, R1 R can represent a monovalent group selected from the group consisting of alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 3 to 8 carbon atoms, and aryl groups having 6 to 12 carbon atoms, which may be substituted with at least one halogen atom such as chlorine or fluorine. 1 Advantageously, the compounds can be selected from the group consisting of methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl, and phenyl.

[0040] These organopolysiloxane compounds containing one or more monosubstituted alkene functional groups may have a linear, cyclic, or branched structure.

[0041] In the present invention • Siloxyl unit "M" Vi " is formula YR 1 2SiO 1 / 2 or Y2R 1 SiO 1 / 2 It represents the siloxyl unit, • The siloxyl unit "M" is in formula R 1 3SiO 1 / 2 It represents the siloxyl unit, • Siloxyl unit "D" Vi " is formula YR 1 SiO 2 / 2 It represents the siloxyl unit, • The siloxyl unit "D" is in formula R 1 2SiO 2 / 2 It represents the siloxyl unit, The siloxyl unit "T" is in formula R 1 SiO 3 / 2 It represents the siloxyl unit, The siloxy unit "Q" is represented by the formula SiO 4 / 2 It represents the siloxyl unit, Symbols Y and R 1 The above is true.

[0042] Terminal "M" and "M ViExamples of units include the trimethylsiloxy group, dimethylphenylsiloxy group, dimethylvinylsiloxy group, or dimethylhexenylsiloxy group.

[0043] "D" and "D Vi Examples of units include the dimethylsiloxy group, methylphenylsiloxy group, methylvinylsiloxy group, methylbutenylsiloxy group, methylhexenylsiloxy group, methyldecenylsiloxy group, or methyldecadienylsiloxy group.

[0044] Linear organopolysiloxane compounds containing one or more monosubstituted alkene functional groups are "D" and "D Vi "Siloxyl unit, and "M" and "M Vi Essentially consisting of a siloxyl unit. Examples of linear organopolysiloxanes that can be organopolysiloxane compounds containing one or more monosubstituted alkene functional groups according to the present invention are as follows: • Poly(dimethylsiloxane) having dimethylvinylsilyl terminators; • Poly(dimethylsiloxane-comethylphenylsiloxane) having dimethylvinylsilyl terminators; • Poly(dimethylsiloxane-co-methylvinylsiloxane) having a dimethylvinylsilyl terminus; and • Poly(dimethylsiloxane-co-methylvinylsiloxane) having a trimethylsilyl terminus.

[0045] In the most preferred embodiment, the organopolysiloxane compound containing one or more monosubstituted alkene functional groups contains terminal dimethylvinylsilyl units. More preferably, the organopolysiloxane compound containing one or more monosubstituted alkene functional groups is a poly(dimethylsiloxane) having dimethylvinylsilyl termini.

[0046] The viscosity of silicone oil is generally between 1 mPa.s and 2,000,000 mPa.s. Preferably, an organopolysiloxane compound containing one or more alkene functional groups is a silicone oil having a dynamic viscosity of 20 mPa.s to 100,000 mPa.s at 25°C, preferably between 20 mPa.s and 80,000 mPa.s, and more preferably between 100 mPa.s and 50,000 mPa.s at 25°C.

[0047] A cyclic organopolysiloxane compound containing one or more monosubstituted alkene functional groups is defined as "D" and "D" above. Vi Essentially consisting of siloxyl units. An example of a cyclic organopolysiloxane that can be an organopolysiloxane compound containing one or more monosubstituted alkene functional groups according to the present invention is a cyclic poly(methylvinylsiloxane).

[0048] Optionally, an organopolysiloxane compound containing one or more monosubstituted alkene functional groups may further contain a "T" siloxy unit and / or a "Q" siloxy unit. Furthermore, an organopolysiloxane compound containing one or more monosubstituted alkene functional groups has a branched structure.

[0049] Examples of branched organopolysiloxanes, also known as resins, which are organopolysiloxane compounds containing one or more monosubstituted alkene functional groups according to the present invention, are as follows: ·MD Vi Q: Here, the vinyl group is included in the D unit. ·MD Vi TQ, where the vinyl group is included in the D unit, ·MM Vi Q: Here, the vinyl group is included as part of the M unit. ·MM Vi TQ, where the vinyl group is part of the M unit, ·MM Vi DD Vi Q: Here, the vinyl group is included in part of the M unit and the D unit. • and mixtures thereof.

[0050] Preferably, the organopolysiloxane compound containing one or more monosubstituted alkene functional groups has a monosubstituted alkenyl unit content of 0.001% to 30% by weight, preferably 0.01% to 10% by weight, and more preferably 0.02% to 5% by weight.

[0051] An unsaturated compound (A) reacts with a compound (B) containing at least one hydrosilyl functional group, according to the present invention.

[0052] According to one embodiment, compound (B) containing at least one hydrosilyl functional group is a silane or polysilane compound containing at least one hydrogen atom bonded to a silicon atom. In the present invention, "silane" means a compound containing four hydrogen atoms or a silicon atom bonded to an organic substituent. In the present invention, "polysilane" means a compound having at least one ≡Si-Si≡ unit. Among the silane compounds, compound (B) containing at least one hydrosilyl functional group can be phenylsilane, or mono-, di-, or trialkylsilane, such as triethylsilane.

[0053] According to another embodiment, compound (B) comprising at least one hydrosilyl functional group is an organopolysiloxane compound comprising at least one hydrogen atom bonded to a silicon atom, and is also called an organohydropolysiloxane. The organohydropolysiloxane is advantageously, • At least two siloxy units in the following equation: H d R 1 e SiO (4-d-e) / 2 (In the formula, R 1 This is a monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably selected from alkyl groups having 1 to 8 carbon atoms such as methyl, ethyl, or propyl groups, cycloalkyl groups having 3 to 8 carbon atoms, and aryl groups having 6 to 12 carbon atoms. 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. • Units of choice: R 1 f SiO (4-f) / 2 (In the formula, R 1 This has the same meaning as above, and f = 0, 1, 2, or 3.) It can be an organopolysiloxane composed of the following:

[0054] In the above formula, some R 1 If bases exist, they may be identical or different from each other. Preferentially, R 1 R can represent a monovalent group selected from the group consisting of alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 3 to 8 carbon atoms, and aryl groups having 6 to 12 carbon atoms, which may be substituted with at least one halogen atom such as chlorine or fluorine. 1 Advantageously, the compounds can be selected from the group consisting of methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl, and phenyl.

[0055] Organohydropolysiloxanes can have linear, branched, or cyclic structures. The degree of polymerization is preferably 2 or higher, and generally 5000 or lower.

[0056] In the following, the siloxyl units "M", "D", "T", and "Q" are defined as above, and • The "M'" siloxyl unit is represented by formula HR 1 2SiO 1 / 2 It represents the siloxyl unit, • The "D'" siloxyl unit is represented by formula HR 1 SiO 2 / 2 It represents the siloxyl unit, Symbol R 1 The above is true.

[0057] In the case of linear polymers, these essentially consist of siloxy units selected from the following formulas "D" and "D'" siloxy units, and "M" and "M'" terminal siloxy units.

[0058] Examples of organohydropolysiloxanes that can be compound (B) containing at least one hydrosilyl functional group according to the present invention are as follows: • Poly(dimethylsiloxane) having a hydrodimethylsilyl terminus; • Poly(dimethylsiloxane-comethylhydrosiloxane) having a trimethylsilyl terminus; • Poly(dimethylsiloxane-comethylhydrosiloxane) having a hydrodimethylsilyl terminus; and • Poly(methylhydrosiloxane) having a trimethylsilyl terminus.

[0059] If the organohydropolysiloxane has a cyclic structure, it essentially consists of siloxy units selected from "D" and "D'" siloxy units. An example of a cyclic organohydropolysiloxane that can be compound (B) containing at least one hydrosilyl functional group according to the present invention is a cyclic poly(methylhydrosiloxane).

[0060] When the organohydropolysiloxane has a branched structure, it is preferably selected from the group consisting of the following silicone resins: ·M'Q, where the hydrogen atom bonded to the silicon atom is held by the M group, ·MM'Q, where the hydrogen atom bonded to the silicon atom is held by a portion of the M unit, • MD'Q, where the hydrogen atom bonded to the silicon atom is held by the D group, MDD'Q, where the hydrogen atom bonded to the silicon atom is held by part of the D group, ·MM'TQ, where the hydrogen atom bonded to the silicon atom is held by a portion of the M unit, ·MM'DD'Q, where the hydrogen atom bonded to the silicon atom is held by the M unit and part of the D unit. • and mixtures thereof.

[0061] Preferably, the organohydropolysiloxane compound has a hydrosilyl Si-H functional group content of 0.2% to 91% by weight, more preferably 3% to 80% by weight, and even more preferably 15% to 70% by weight.

[0062] According to certain embodiments of the present invention, the unsaturated compound (A) and the compound (B) comprising at least one hydrosilyl functional group can be the same compound comprising, on the one hand, at least one monosubstituted alkene functional group and on the other hand, at least one silicon atom and at least one hydrogen atom bonded to the silicon atom. This compound can be described as "bifunctional" and can react by hydrosilylation reactions. Thus, the present invention can also relate to a method for hydrosilylation of a bifunctional compound itself, wherein the bifunctional compound comprises, on the one hand, at least one monofunctional alkene functional group and on the other hand, at least one silicon atom and at least one hydrogen atom bonded to the silicon atom, and the method is catalyzed by a photocatalyst (C) as described above.

[0063] Examples of organopolysiloxanes that can be bifunctional compounds are as follows: • Poly(dimethylsiloxane-co-hydromethylsiloxane-co-vinylmethylsiloxane) having a dimethylvinylsilyl terminus, • Poly(dimethylsiloxane-co-hydromethylsiloxane-co-vinylmethylsiloxane) having a dimethylhydrosilyl terminus; and • Poly(dimethylsiloxane-co-hydromethylsiloxane-co-(propylglycidyl ether)methylsiloxane) having a trimethylsilyl terminus.

[0064] In the case of the use of an unsaturated compound (A) and a compound (B) containing at least one hydrosilyl functional group, it will be understood by those skilled in the art that this also implies the use of a bifunctional compound.

[0065] 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, even more preferably 1:3 to 3:1, and even more preferably 1:2 to 2:1.

[0066] 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).

[0067] Irradiation is preferably exposure to ultraviolet and / or visible light. In this specification, "UV" means ultraviolet light. Ultraviolet light is defined as electromagnetic radiation with wavelengths between about 100 nm and about 400 nm, i.e., below the visible light spectrum. Within ultraviolet light, UV-A radiation with wavelengths between about 315 nm and about 400 nm can be defined, UV-B radiation with wavelengths between about 280 nm and about 315 nm, and UV-C radiation with wavelengths between about 100 nm and about 280 nm. Visible light is defined as electromagnetic radiation with wavelengths between about 400 nm and about 800 nm. Preferably, irradiation is carried out by exposure to radiation having wavelengths between 100 nm and 450 nm, or between 200 nm and 420 nm, or between 250 nm and 405 nm.

[0068] The radiation is emitted from doped or undoped mercury lamps, with emission spectra ranging from 100 nm to 450 nm. Light sources such as LEDs emitting point UV or visible light can also be used. Furthermore, in this specification, "LED" is an abbreviation for "light-emitting diode," as is well known to those skilled in the art.

[0069] According to one embodiment, irradiation is performed by UV irradiation, and the irradiation source is a UV-LED lamp. This UV-LED lamp can emit radiation with wavelengths of 365 nm, 385 nm, 395 nm, or 405 nm. Preferably, the UV-LED lamp is a lamp that emits light at 395 nm. The power of the UV-LED lamp is preferably 2 W / m². 2 ~200,000W / m2 It is between these two points.

[0070] According to a preferred embodiment, the irradiation step is carried out under an inert atmosphere, for example, under nitrogen, argon, or oxygen-deficient air.

[0071] The irradiation stage 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 more preferably even more preferably at ambient temperature, typically around 25°C.

[0072] Hydrosilylation reactions can be carried out in or without a solvent. Suitable solvents are those miscible with compound (B). For example, solvents can be selected from the group consisting of aliphatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, decalin, and liquid paraffin; aromatic hydrocarbons such as toluene and xylene; mixtures of mineral or synthetic hydrocarbons such as white spirit; ethers such as tetrahydrofuran, dioxane, diethyl ether, and diphenyl ether; chlorinated hydrocarbons such as methylene chloride, 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 the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, and chlorinated hydrocarbons, and more preferably from the group consisting of hexane, cyclohexane, decalin, and toluene. In another embodiment, the solvent can be selected from volatile silicones, octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), polydimethylsiloxane oil (PDMS), polyphenylmethylsiloxane oil (PPMS), or mixtures thereof. In another embodiment, one of the reactants, for example, an unsaturated compound (A), can act as the solvent. Preferably, the use of organic solvents that are harmful to the environment and the health of workers in the manufacturing plant is avoided.

[0073] According to a preferred embodiment of the present invention, the compounds (A) and (B) employed are selected from the organopolysiloxanes defined above. In this case, a three-dimensional network is formed, and as a result, the composition hardens. Crosslinking involves a gradual physical change of the medium constituting the composition. As a result, elastomers, gels, foams, etc., can be obtained using the method according to the present invention. In this case, a crosslinked silicone material is obtained. The term "crosslinked silicone material" means any silicone-based product obtained by crosslinking and / or hardening a composition comprising an organopolysiloxane having at least two unsaturated bonds and an organopolysiloxane having at least three hydrosilyl units. The crosslinked silicone material may be, for example, an elastomer, a gel, or a foam.

[0074] According to this preferred embodiment of the method of the present invention, in which compounds (A) and (B) are selected from organopolysiloxanes as defined above, it is possible to use conventional functional additives in the silicone composition. Examples of conventional functional additives include: • Fillers, • Adhesion promoter, • Inhibitor or retarder of hydrosilylation reaction, • Adhesion modifier, • Silicone resin, • Consistency-improving additives, • Pigments (organic or inorganic) • Heat-resistant additives, oil-resistant additives, fire-resistant additives, such as metal oxides.

[0075] The optional filler is preferably inorganic. The filler can be a very finely divided product with an average particle size of less than 0.1 μm. The filler can be siliceous in particular. With respect to siliceous materials, they can act as reinforcing fillers or semi-reinforcing fillers. Reinforcing siliceous fillers are selected from colloidal silica, fumed silica powder, precipitated silica powder, or mixtures thereof. These powders generally have an average particle size of less than 0.1 μm (micrometers) and 30 m 2A value exceeding / g, preferably 30-350m 2 It has a BET specific surface area of ​​1 / g. Semi-reinforced siliceous fillers such as diatomaceous earth and crushed quartz can also be used. These silicas can be blended as is or after being treated with organosilicon compounds commonly used in this application. These compounds include methylpolysiloxanes such as hexamethyldisiloxane and octamethylcyclotetrasiloxane, methylpolysilazanes such as hexamethyldisilazane, hexamethylcyclotrisilazane or tetramethyldivinyldisilazane, chlorosilanes such as dimethyldichlorosilane, trimethylchlorosilane, methylvinyldichlorosilane or dimethylvinylchlorosilane, alkoxysilanes such as dimethyldimethoxysilane, dimethylvinylethoxysilane or trimethylmethoxysilane, and mixtures thereof. Non-siliceous inorganic materials can be used as semi-reinforced or bulking inorganic fillers. Examples of these non-siliceous fillers, which can be used alone or in mixtures, include calcium carbonate, calcined clay, rutile-type titanium oxide, oxides of iron, zinc, chromium, zirconium, or magnesium, various forms of alumina (hydrated or unhydrated), boron nitride, lithopone, barium metaborate, barium sulfate, and glass microbeads, which may be surface-treated with organic acids or esters of organic acids. These fillers generally have an average particle size greater than 0.1 μm and a specific surface area generally of 30 m². 2 The fillers are coarse, less than / g. These fillers may be surface-modified by treatment with various organosilicon compounds commonly used in this application. Preferably, the filler is silica, more preferably fumed silica. Advantageously, the silica is 75-410m 2 The silicone composition has a BET ratio surface of / g. The silicone composition may contain 5% to 20% by weight of filler relative to the total weight of the silicone composition. Advantageously, the silicone composition may contain 8% to 15% by weight of filler.

[0076] The discovery of a novel hydrosilylation method using photocatalysis under mild conditions according to the present invention opens up many potential applications.

[0077] According to the first embodiment, the hydrosilylation method according to the present invention can be used for the functionalization of organopolysiloxanes having SiH functional groups. The purpose of functionalization is to modify the physical and / or chemical properties of the organopolysiloxane and produce a novel compound having 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 to 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. A method for functionalizing an organopolysiloxane having SiH functional groups can be described, characterized in that the addition reaction between the organopolysiloxane having SiH functional groups and the unsaturated compound (A) containing one or more monosubstituted alkene functional groups and 2 to 40 carbon atoms is obtained by the hydrosilylation method described above.

[0078] According to another particularly preferred embodiment, the hydrosilylation method according to the present invention can be used to crosslink an organopolysiloxane having a SiH functional group with an organopolysiloxane having an alkenyl functional group 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 a silicon atom. A method for producing a crosslinked silicone material can be described, characterized in that the crosslinking reaction between an organopolysiloxane having a SiH functional group and an organopolysiloxane having an alkenyl functional group is obtained by the hydrosilylation method described above. The crosslinked silicone material thus obtained can be used in a variety of applications, particularly: • Coating applications where the support is covered with a silicone coating; • Applications in the electronics field, such as the manufacture of conformal coatings for printed circuits, and potting of electronic components such as microcircuits and IGBTs; • Additive manufacturing processes using photopolymerization (also known as 3D printing processes).

[0079] Other details or advantages of the present invention will become more apparent in light of the examples shown below, which are provided merely as illustrations. [Examples]

[0080] Examples 1-3 and Comparative Examples 1-3: Hydrosilylation of 1-octene (1) with 1,1,1,3,5,5,5-heptamethyltrisiloxane (2) [ka]

[0081] 1-Octene (1) and 1,1,1,3,5,5,5-Heptamethyltrisiloxane (2) were introduced into 4 ml vials at ambient temperature under an argon atmosphere. Dimanganese Decacarbonyl Mn2(CO) 10 A toluene solution was poured into a vial, and toluene was added. Mn2(CO) 10 The final concentration (relative to 1-octene) was 1 mol%.

[0082] In Examples 1, 2, and 3, the reaction mixture was exposed to ultraviolet light for 4 hours (300 W, λ = 250-420 nm). In Comparative Examples 1, 2, and 3, the reaction mixture was not irradiated and was heated for 24 hours. The concentrations of the reactants and the reaction conditions are shown in Table 1, as well as the yields of the hydrosilylated product (3) and the isomerized product of (1) (determined by gas chromatography and calculated relative to 1-octene).

[0083] [Table 1]

[0084] Examples 1, 2, and 3 are Mn2(CO) 10This shows that the hydrosilylation reaction of 1-octene (1) and 1,1,1,3,5,5,5-heptamethyltrisiloxane (2), catalyzed by photocatalysis, can yield product (3) with excellent yield and selectivity under mild reaction conditions (4 hours at ambient temperature). Conversely, this catalyst does not show activity upon thermal activation (Comparative Examples 1, 2, and 3).

[0085] Examples 4-12 and Comparative Examples 4-6: Hydrosilylation of various alkenes (1') [ka]

[0086] As shown in Table 2 below, the same procedure as described in Example 1 (UV, 4 hours) was followed while varying the structure of the alkene compound (1'). The yield of the hydrosilylation product (3') (determined by gas chromatography and calculated relative to the alkene) is shown in Table 2.

[0087] [Table 2]

[0088] In Examples 4-12, hydrosilylation products were obtained with excellent selectivity. Neither C=C isomerization nor products resulting from CO bond cleavage were observed. On the other hand, when starting with gem-disubstituted alkenes (Comparative Examples 4 and 5) or internal alkenes (Comparative Example 6), no hydrosilylation products were obtained.

Claims

1. A method for hydrosilylation of an unsaturated compound (A) containing at least one monosubstituted alkene 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) comprising manganese carbonyl.

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

3. The manganese carbonyl has the chemical formula [Mn 2 (CO) 10 The hydrosilylation method according to claim 1, characterized in that it is dimanganesedecacarbonyl.

4. The hydrosilylation method according to any one of claims 1 to 3, characterized in that the unsaturated compound (A) is an organic compound having a monosubstituted alkene group selected from the following group: α-olefin, Chlorinated α-olefin, Fluorinated α-olefins, Allyl alcohol, Allyl benzyl ether, Allyl C 1 ~C 8 Allyl ethers selected from alkyl ethers, allyl glycidyl ethers, allyl piperidinyl ethers, and allyl silyl ethers, • Allyl esters, ·styrene, 1,2-epoxy-4-vinylcyclohexane, Acrylate C 1 ~C 4 Alkyl and acrylic acids.

5. The hydrosilylation method according to any one of claims 1 to 3, characterized in that the unsaturated compound (A) is an organopolysiloxane compound containing one or more monosubstituted alkene functional groups.

6. The hydrosilylation method according to any one of claims 1 to 3, characterized in that 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.

7. The hydrosilylation method according to claim 1, characterized in that the irradiation is carried out by exposure to radiation with a wavelength between 100 nm and 450 nm.

8. The hydrosilylation method according to claim 1, characterized in that the irradiation is carried out by UV irradiation using a UV-LED lamp as the light source.

9. The hydrosilylation method according to claim 1, characterized in that the irradiation is carried out between 0°C and 60°C.

10. The hydrosilylation method according to claim 1, characterized in that the irradiation is carried out at ambient temperature.

11. A hydrosilylation method for functionalizing an organopolysiloxane having an SiH functional group, according to claim 1, 2, 3, 7, 8, 9, or 10, characterized in that 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 to 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.

12. A hydrosilylation method according to claim 1, 2, 3, 7, 8, 9, or 10 for producing a crosslinked silicone material, characterized in that 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 a silicon atom.

13. The use of manganese carbonyl as a photocatalyst for a hydrosilylation reaction between an unsaturated compound (A) containing at least one monosubstituted alkene functional group and a compound (B) containing at least one hydrosilyl functional group.

14. The use according to claim 13, characterized in that the manganese in the manganese carbonyl is in an oxidized state of 0.

15. The manganese carbonyl has the chemical formula [Mn 2 (CO) 10 The use according to claim 13 or 14, characterized in that it is dimanganesedecacarbonyl.

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