Hydrosilylation method catalyzed by iron complex

Abstract

The present invention relates to a process for the hydrosilylation of an unsaturated compound containing at least one alkene or at least one alkyne functional group with a compound containing at least one hydrosilyl functional group, said process being catalyzed by an iron complex C of formula (1): Fe[Si(SiR3)3]2L n (1) (wherein each R is independently a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with one or more halogen atoms, and each L is an ether ligand, and n=1, 2 or 3.) The present invention also relates to a method for producing the iron complex, and to the use of the iron complex as a catalyst for hydrosilylation of alkenes or alkynes.

Description

Technical Field

[0001] Technical Field The present invention relates to hydrosilylation reactions of alkene or alkyne compounds with compounds containing at least one hydrogen atom bonded to a silicon atom. In particular, the present invention relates to the use of a novel type of catalyst for these reactions. These catalysts enable curing, in particular by crosslinking of silicone compounds.

Background Art

[0002] State of the Art During the hydrosilylation reaction (also known as polyaddition), an unsaturated compound, i.e., a compound containing at least one double or triple bond type of unsaturation, reacts with a compound containing at least one hydrosilyl functional group, i.e., a compound containing a hydrogen atom bonded to a silicon atom. This reaction can be illustrated, for example, in the case of alkene type unsaturation by the following formula:

Chemical Formula

Chemical Formula

[0003] The hydrosilylation reaction may involve a dehydrogenative silylation reaction and may be replaced by it. This reaction can be illustrated by the following formula:

Chemical Formula

[0004] The hydrosilylation reaction is particularly used to crosslink silicone compositions comprising an organopolysiloxane having alkenyl or alkynyl units and an organopolysiloxane having hydrosilyl functional groups.

[0005] The hydrosilylation reaction of unsaturated compounds is typically carried out by catalysis using a metal catalyst or an organometallic catalyst. Currently, the catalyst suitable for this reaction is a platinum catalyst. Therefore, in particular, most of the industrial hydrosilylation processes for the hydrosilylation of alkenes are catalyzed by Speier's hexachloroplatinic acid or the Karstedt Pt(0) complex of the general formula Pt2(di vinyltetramethyldisiloxane)3 (which may be 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, WO 01 / 42258).

[0007] However, there are still problems with the use of metal or organometallic platinum catalysts. Platinum is an expensive metal, and its scarcity is increasing, and its cost is also rising enormously. Therefore, its use on an industrial scale is difficult. Thus, it is desired to reduce the amount of catalyst required for the reaction as much as possible without reducing the yield and reaction rate. Numerous studies have been carried out to find alternatives to the Karstedt catalyst.

[0008] Against this background, research has been carried out for many years to find a new catalyst for carrying out the hydrosilylation of alkenes.

[0009] For example, the use of iron - based catalysts is described in WO 2019 / 008279. In this document, the described catalyst is an iron compound of the general formula [Fe(N(SiR3)2) x y where the symbol R represents a hydrogen atom or a hydrocarbon group, x has a value of 1, 2 or 3, and y has a value of 1 or 2. The catalyst seems to be able to efficiently catalyze the hydrosilylation reaction or the dehydrogenative silylation reaction. In particular, these catalysts have the advantage of not requiring the use of a solvent because they show good solubility in silicone oil. However, in the cross - linking test of the silicone composition, it has been found that the stirring stop time is about several hours.​

[0010] U.S. Patent Application Publication No. 2016 / 0023196 describes a mononuclear iron complex that exhibits catalytic activity for the hydrosilylation, hydrogenation, and reduction of carbonyl compounds. This iron complex has the general formula [Fe(SiR3)2]CO n L m and, in particular, n has a value of 1 to 3. Thus, this complex necessarily contains one or more carbonyl ligands coordinated to the iron. According to this document, carbon monoxide CO is an essential ligand that enables the securing of catalytic activity.

[0011] International Publication No. 2010 / 016416 describes a catalyst for hydrosilylation reactions that includes an iron complex compound represented by the general formula X t -Fe-R 1 s (Y u ), wherein X represents a ligand selected from a cyclic structure having an unsaturated aliphatic C 4-10 group, tris(pyrazolyl)borate, tetrafluoroborate, hexafluorophosphate, porphine, and phthalocyanine, R 1 represents a ligand formed from H, an alkyl group, or a SiR3 group, and Y represents a ligand formed from an ammonia molecule, a carbonylated molecule, an oxygen atom, an oxygen molecule, an amine molecule, a phosphine molecule, or a phosphite molecule. The only iron complex exemplified is cyclopentadienylmethyldicarbonyliron.

[0012] Against such a background, the present inventors have sought a more effective catalyst to replace the above catalysts. It is desired to be able to utilize a catalyst that can catalyze the hydrosilylation reaction between a hydrosilyl functional group and an alkene or alkyne functional group. Advantageously, it is desired that the reaction be rapid and occur at a moderate temperature, preferably ambient temperature. Further, it is desired that the catalyst contain abundant, inexpensive, and non-toxic chemical elements.

[0013] In recent years, in the paper by S. Arata and Y. Sunada (An Isolable Iron(II) Bis(Supersilyl) Complex as an Effective Catalyst for Reduction Reactions, Dalton Trans., 2019, 48, 2891 - 2895), the iron bis(supersilyl) complex of the formula Fe[Si(SiMe3)3]2(THF)2 and its activity towards the hydrosilylation of carbonyl compounds and the reductive silylation of molecular nitrogen are described. However, this paper does not describe the use of these catalysts for the hydrosilylation of alkenes or alkynes. Furthermore, from the XRD analysis of the purple crystals obtained in the paper by S. Arata and Y. Sunada, the obtained compound (1) was shown to have the formula C 34 H 70 FeO4Si8 and a molecular weight of 823.46 g.mol -1 (see the Supporting Information of the same paper). The compound isolated in this paper does not correspond to the complex Fe[Si(SiMe3)3]2(THF)2.

Prior Art Documents

Patent Documents

[0014]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Non - Patent Documents

[0015]

Non - Patent Document 1

Summary of the Invention

Means for Solving the Problems

[0016] Summary of the Invention The subject of the present invention is a method for hydrosilylating an unsaturated compound (A) containing at least one functional group selected from an alkene functional group and an alkyne functional group with a compound (B) containing at least one hydrosilyl functional group, wherein the method is catalyzed by an iron complex (C) represented by the following formula (1): Fe[Si(SiR3)3]2L n (1) In the formula, · Each R independently represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with one or more halogen atoms, · Each L independently represents an ether ligand, · n = 1, 2 or 3.

[0017] Another subject of the present invention is a composition comprising at least one unsaturated compound (A) containing at least one functional group selected from an alkene functional group and an alkyne functional group, at least one compound (B) containing at least one hydrosilyl functional group, and an iron complex (C) represented by the following formula (1): Fe[Si(SiR3)3]2L n (1) In the formula, · Each R independently represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with one or more halogen atoms, · Each L independently represents an ether ligand, ·n = 1, 2 or 3.

[0018] Unexpectedly, the inventors have found that the iron complex (C) as described above can be advantageously recrystallized in order to efficiently catalyze the hydrosilylation reaction of an alkene or alkyne compound. Therefore, another subject of the present invention is a method for producing an iron complex (C) represented by the following formula (1): Fe[Si(SiR3)3]2L n (1) In the formula, · Each R independently represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with one or more halogen atoms, · Each L independently represents an ether ligand, · n = 1, 2 or 3, The method includes a step of producing a crude iron complex (C) and then a step of recrystallizing the crude iron complex (C).

[0019] The purified iron complex (C) obtained or obtainable by the method is also a subject of the present invention, as well as its use as a hydrosilylation catalyst for alkenes or alkynes.

Embodiments for Carrying Out the Invention

[0020] Detailed Description of the Invention The symbol → in the text represents a covalent coordination bond due to the presence of a lone pair of electrons in the ligand L.

[0021] Unless otherwise indicated, all viscosities of silicone oils related to this description are the "Newtonian" kinematic viscosity at 25 °C, that is, the kinematic viscosity measured using a Brookfield viscometer at a shear rate gradient low enough that the measured viscosity does not depend on the velocity gradient, by a method known per se.

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

[0023] 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.

[0024] 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.

[0025] 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 a phenyl group, a naphthyl group, an anthracenyl group, a phenanthryl group, a mesityl group, a tolyl group, a xylyl group, a diisopropylphenyl group, and a triisopropylphenyl group.

[0026] In the present invention, the arylalkyl group preferably contains 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.

[0027] In the present invention, the halogen atom can be selected from the group consisting of, for example, fluorine, bromine, chlorine and iodine, and fluorine is preferred. The alkyl group substituted with fluorine can be, for example, trifluoropropyl.

[0028] The subject of the present invention is a novel method for hydrosilylating an unsaturated compound (A) and a compound (B) containing at least one hydrosilyl functional group, which is catalyzed by an iron complex (C). The iron complex (C) is represented by the following formula: Fe[Si(SiR3)3]2L n (1) In the formula, · Each R independently represents a hydrocarbon group having 1 to 30 carbon atoms, which may be substituted with one or more halogen atoms, · Each L independently represents an ether ligand, · n = 1, 2 or 3.

[0029] Preferably, each R independently represents a group selected from an alkyl group, a cycloalkyl group, an aryl group and an arylalkyl group, and the group may be substituted with one or more halogen atoms. More preferably, each R independently represents a C1-C 12 alkyl group, a C3-C8 cycloalkyl group, a C6-C 12 aryl group or a C7-C 24 arylalkyl group. More preferably, each R independently represents a group selected from a methyl group, an ethyl group, a propyl group, a 3,3,3-trifluoropropyl group, a xylyl group, a tolyl group and a phenyl group. More preferably, the R group is methyl.

[0030] In formula (1) according to the present invention, each L represents an ether ligand, and iron is coordinated by the lone pair of electrons held by the oxygen atom. n represents the number of ligands L. n has a value of 1, 2, or 3. Preferably, n has a value of 2. When L has a value of 2 or 3, the ligands L may be the same or different. In this formula (1), iron is in the +II oxidation state.

[0031] The ether ligand L can be selected from compounds of the formula R 1 OR 2 wherein R 1 and R 2 each independently represent a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, which may contain one or more heteroatoms, or R 1 and R 2 together with the oxygen atom to which they are attached form a cyclic hydrocarbon group containing one or more heteroatoms. The heteroatom is preferably selected from O, N, S, and P.

[0032] According to the first embodiment, R 1 and R 2 each independently represent a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, which may contain one or more heteroatoms. The heteroatom is preferably selected from O, N, S, and P. Preferably, R 1 and R 2 each independently represent a group selected from an alkyl group, a cycloalkyl group, an aryl group, and an arylalkyl group, and the said group may be substituted by one or more halogen atoms and one or more carbon atoms may be substituted by an oxygen atom. More preferably, R 1 and R 2 each independently represent a C1 - C 12 alkyl group, a C3 - C8 cycloalkyl group, a C6 - C 12 aryl group, a C7 - C 24 arylalkyl group, a (C1 - C 12 alkyl)oxy(C1 - C 12 alkyl) group, a (C3 - C8 cycloalkyl)oxy(C1 - C 12(alkyl) group, (C6 - C 12 aryloxy(C1 - C 12 alkyl) group, or (C7 - C 24 arylalkyl)oxy(C1 - C 12 alkyl) group. More preferably, R 1 and R 2 each independently represent a group selected from a methyl group, an ethyl group, a propyl group, a xylyl group, a tolyl group, a phenyl group, a methoxymethyl group, a methoxyethyl group, a methoxypropyl group, an ethoxymethyl group, an ethoxyethyl group, an ethoxypropyl group, a propoxymethyl group, a propoxyethyl group, a propoxypropyl group, a phenyloxymethyl group, a phenyloxyethyl group, and a phenyloxypropyl group. The ligand L can be selected, for example, from the following group: methyl ether, ethyl ether, ethyl methyl ether, and dimethoxyethane.

[0033] According to a second embodiment, R 1 and R 2 together with the oxygen atom to which they are attached form a cyclic hydrocarbon group containing one or more heteroatoms. The heteroatom is preferably selected from O, N, S, and P. The ligand L can be selected from cyclic compounds, preferably monocyclic compounds, containing one or two oxygen atoms and 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms, and optionally substituted with one or more halogen atoms. The ligand L can be selected, for example, from the following group: tetrahydrofuran, ethylene oxide, 1,3 - propylene oxide, tetrahydropyran, oxepane, 1,2 - dioxane, 1,3 - dioxane, and 1,4 - dioxane. Preferably, the ligand L may be tetrahydrofuran.

[0034] According to a very preferred embodiment, the iron complex (C) according to the present invention can be the following compound.

Chemical formula

[0035] Unexpectedly, the present inventors have found that the iron complex (C) as described above can be advantageously recrystallized in order to efficiently catalyze the hydrosilylation reaction of alkene or alkyne compounds. Therefore, another main subject of the present invention is a method for producing the iron complex (C) as described above, the method including a step of producing a crude iron complex (C) and then a step of recrystallizing the crude iron complex (C).

[0036] The production of the crude iron complex (C) can be carried out according to methods known to those skilled in the art or methods described in the literature. For example, reference can be made to the production method described in S. Arata and Y. Sunada, An Isolable Iron(II) Bis(Supersilyl) Complex as an Effective Catalyst for Reduction Reactions, Dalton Trans., 2019, 48, 2891-2895.

[0037] According to one embodiment, the production of the iron complex (C) can be carried out by reacting iron(II) halide, such as FeCl2 or FeBr2, with an alkali salt of a persilylated anion, such as KSi(SiR3)3, in the presence of a ligand L. The amount of the alkali salt of the persilylated anion is at least 2 molar equivalents relative to the iron halide. The ligand L can be in an excess amount. Typically, the ligand L can be used as the reaction solvent. After completion of the reaction, the iron complex (C) can be separated from the reaction medium and optionally crystallized according to techniques known to those skilled in the art. In this way, the crude iron complex (C) is obtained.

[0038] According to the present invention, the crude iron complex (C) is subjected to a recrystallization step. The recrystallization solvent can be selected from pentane, toluene, hexane, heptane, cyclopentane, cyclohexane and methylcyclohexane. Preferably, the recrystallization solvent is pentane. The amount of the recrystallization solvent can preferably be 0.5 ml to 5.0 ml per 100 mg of the crude complex, more preferably 1.0 ml to 2.0 ml per 100 mg of the crude complex.

[0039] The iron complex (C) purified in this way is also the subject of the present invention, in the same way as its use as a hydrosilylation catalyst for alkenes or alkynes.

[0040] It has been found that the above iron complex (C) can be used as a catalyst for the hydrosilylation reaction of an unsaturated compound (A) having at least one functional group selected from an alkene functional group and an alkyne functional group and a compound (B) having at least one hydrosilyl functional group.

[0041] The hydrosilylation reaction can involve a dehydrogenative silylation reaction. The above iron complex (C) can advantageously also be used as a catalyst for the dehydrogenative silylation reaction of an unsaturated compound (A) containing at least one functional group selected from an alkene functional group and an alkyne functional group and a compound (B) containing at least one hydrosilyl functional group. In this specification, unless otherwise specified, the explanations and descriptions regarding the hydrosilylation reaction also apply to the dehydrogenative silylation reaction.

[0042] Another subject of the present invention is a composition comprising at least one unsaturated compound (A) containing at least one functional group selected from an alkene functional group and an alkyne functional group, at least one compound (B) containing at least one hydrosilyl functional group, and an iron complex (C) represented by the following formula (1): Fe[Si(SiR3)3]2L n (1) In the formula, · Each R independently represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with one or more halogen atoms, · Each L independently represents an ether ligand, · n = 1, 2 or 3.

[0043] In the hydrosilylation method according to the present invention, the unsaturated compound (A) used is a compound containing at least one alkene or alkyne unsaturation that does not form part of an aromatic ring. The unsaturated compound (A) contains at least one functional group selected from an alkene functional group and an alkyne functional group, preferably at least one functional group selected from an alkene functional group. This can be selected from those known to those skilled in the art and those that do not contain reactive chemical functional groups that may interfere with and actually inhibit the hydrosilylation reaction.

[0044] According to one embodiment, the unsaturated compound (A) contains one or more alkene functional groups and 2 to 40 carbon atoms. According to another embodiment, the unsaturated compound (A) contains one or more alkyne functional groups and 2 to 40 carbon atoms.

[0045] The unsaturated compound (A) can preferably be selected from the group consisting of acetylene, C1-C4 alkyl acrylates and methacrylates, acrylic acid or methacrylic acid, alkenes, preferably octene, more preferably 1-octene, allyl alcohol, allyl amine, allyl glycidyl ether, allyl piperidinyl ether, preferably allyl sterically hindered piperidinyl ether, styrene, preferably α-methylstyrene, 1,2-epoxy-4-vinylcyclohexane, chlorinated alkenes, preferably allyl chloride, fluorinated alkenes, preferably 4,4,5,5,6,6,7,7,7-nonafluoro-1-heptene.

[0046] The unsaturated compound (A) can be a disiloxane such as vinylpentamethyldisiloxane, divinyltetramethyldisiloxane.

[0047] The unsaturated compound (A) can be selected from compounds containing several alkene functional groups, preferably 2 or 3 alkene functional groups. Particularly preferably, the compound (A) is selected from the following compounds.

Chemical formula

[0048] According to a particularly preferred embodiment, the unsaturated compound (A) can be an organopolysiloxane compound containing one or more alkene functional groups, preferably at least two alkene functional groups. The hydrosilylation reaction of alkenes is one of the important reactions in silicone chemistry. This not only crosslinks an organopolysiloxane having an SiH functional group and an organopolysiloxane having an alkenyl functional group to form a network and imparts mechanical properties to the material, but also enables the functionalization of an organopolysiloxane having an SiH functional group to modify its physical and chemical properties. The organopolysiloxane compound particularly includes · At least two siloxyl units of the following formula: Vi a U b SiO (4-a-b) / 2 (In the formula, Vi is a C2-C6 alkenyl group, preferably a vinyl group, U 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, and is selected from a = 1, 2 or 3, preferably a = 1 or 2; b = 0, 1 or 2; and the total a + b = 1, 2 or 3.) and · Optionally, a unit of the following formula: U c SiO (4-c) / 2 (In the formula, U has the same meaning as above, and c = 0, 1, 2 or 3.) and is composed of.

[0049] In the above formula, when a plurality of U groups are present, they may be the same or different from each other.

[0050] These organopolysiloxane compounds containing one or more alkene functional groups include siloxyl units Vi2SiO 2 / 2 , ViUSiO 2 / 2 and U2SiO 2 / 2A siloxyl unit "D" and "D" selected from the group consisting of Vi ", and a terminal siloxyl unit "M" and "M" selected from the group consisting of ViU2SiO 1 / 2 , Vi2USiO 1 / 2 and U3SiO 1 / 2 ". It can have a linear structure essentially consisting of Vi ". The symbols Vi and U are as defined above.

[0051] Examples of the terminal "M" and "M" Vi units include a trimethylsiloxy group, a dimethylphenylsiloxy group, a dimethylvinylsiloxy group, or a dimethylhexenylsiloxy group.

[0052] Examples of the "D" and "D" Vi units include a dimethylsiloxy group, a methylphenylsiloxy group, a methylvinylsiloxy group, a methylbutenylsiloxy group, a methylhexenylsiloxy group, a methyldecenylsiloxy group, or a methyldecadienylsiloxy group.

[0053] Examples of the linear organopolysiloxane that can be an organopolysiloxane compound containing one or more alkene functional groups according to the present invention are as follows: · Poly(dimethylsiloxane) having dimethylvinylsilyl terminals; · Poly(dimethylsiloxane-co-methylphenylsiloxane) having dimethylvinylsilyl terminals; · Poly(dimethylsiloxane-co-methylvinylsiloxane) having dimethylvinylsilyl terminals; · Poly(dimethylsiloxane-co-methylvinylsiloxane) having trimethylsilyl terminals; and · Cyclic poly(methylvinylsiloxane).

[0054] In the most preferred embodiment, the organopolysiloxane compound containing one or more alkene functional groups contains terminal dimethylvinylsilyl units. More preferably, the organopolysiloxane compound containing one or more alkene functional groups is poly(dimethylsiloxane) having dimethylvinylsilyl terminals.

[0055] The viscosity of the silicone oil is generally from 1 mPa·s to 2,000,000 mPa·s. Preferably, the organopolysiloxane compound containing one or more alkene functional groups is a silicone oil having a dynamic viscosity of from 20 mPa·s to 100,000 mPa·s at 25°C, preferably from 20 mPa·s to 80,000 mPa·s at 25°C, more preferably from 100 mPa·s to 50,000 mPa·s.

[0056] Optionally, the organopolysiloxane compound containing one or more alkene functional groups may further contain siloxyl unit "T" (USiO 3 / 2 ) and / or siloxyl unit "Q" (SiO 4 / 2 ). The symbol U is as described above. And the organopolysiloxane compound containing one or more alkene functional groups has a branched structure.

[0057] Examples of the branched organopolysiloxane, also called a resin, which is the organopolysiloxane compound containing one or more alkene functional groups according to the present invention are as follows: · MD Vi Q, where the vinyl group is contained in the D unit, · MD Vi TQ, where the vinyl group is contained in the D unit, · MM Vi Q, where the vinyl group is contained in a part of the M unit, · MM Vi TQ, where the vinyl group is contained in a part of the M unit, · MM Vi DD Vi Q, where the vinyl group is contained in a part of the M unit and the D unit, · And mixtures thereof; where M Vi= Siloxyl unit of formula (U)2(Vinyl)SiO 1 / 2 , D Vi = Siloxyl unit of formula (U)(Vinyl)SiO 2 / 2 , T = Siloxyl unit of formula (U)SiO 3 / 2 , Q = Siloxyl unit of formula SiO 4 / 2 , M = Siloxyl unit of formula (U)3SiO 1 / 2 , and D = Siloxyl unit of formula (U)2SiO 2 / 2 , where U is as described above.

[0058] Preferably, the organopolysiloxane compound containing one or more alkene functional groups has an alkenyl unit content of 0.001 wt% to 30 wt%, preferably 0.01 wt% to 10 wt%, more preferably 0.02 wt% to 5 wt%.

[0059] The unsaturated compound (A) reacts with the compound (B) containing at least one hydrosilyl functional group according to the present invention.

[0060] According to one embodiment, the 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, the "silane" compound means a compound containing a silicon atom bonded to four hydrogen atoms or organic substituents. The "polysilane" compound means a compound having at least one ≡Si-Si≡ unit in the present invention.

[0061] Among the silane compounds, the compound (B) containing at least one hydrosilyl functional group can be phenylsilane, or mono-, di- or trialkylsilane, such as triethylsilane.

[0062] According to another embodiment, 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, and is also called an organohydrogenpolysiloxane. The organohydrogenpolysiloxane is preferably ·At least two siloxyl units of the following formula: H d U e SiO (4-d-e) / 2 (wherein, U 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, and is selected from d = 1, 2 or 3, preferably d = 1 or 2; e = 0, 1 or 2; and d + e = 1, 2 or 3.) and ·Optionally a unit of the following formula: U f SiO (4-f) / 2 (wherein U has the same meaning as above and f = 0, 1, 2 or 3.) and It can be an organopolysiloxane composed of

[0063] In the above formula, when several U groups are present, they may be the same or different from each other. Preferably, U can represent a monovalent group selected from the group consisting of 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 may be substituted with at least one halogen atom such as chlorine or fluorine. U can preferably be selected from the group consisting of methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl and phenyl.

[0064] In the above formula, the symbol d is preferably equal to 1.

[0065] The organohydrogenpolysiloxane can have a linear, branched or cyclic structure. The degree of polymerization is preferably 2 or more and generally 5000 or less.

[0066] In the case of linear polymers, these are of the following formula D: U2SiO 2 / 2 or D’: UHSiO 2 / 2A siloxyl unit selected from the units of, and the following formula M: U3SiO 1 / 2 Or M': U2HSiO 1 / 2 An end siloxyl unit selected from the units of, where U has the same meaning as above.

[0067] Examples of organohydrogenpolysiloxanes that can be the compound (B) containing at least one hydrosilyl functional group according to the present invention are as follows: · Poly(dimethylsiloxane) having a hydrogen dimethylsilyl end; · Poly(dimethylsiloxane-co-methylhydrogensiloxane) having a trimethylsilyl end; · Poly(dimethylsiloxane-co-methylhydrogensiloxane) having a hydrogen dimethylsilyl end; · Poly(methylhydrogensiloxane) having a trimethylsilyl end; and · Cyclic poly(methylhydrogensiloxane).

[0068] When the organohydrogenpolysiloxane has a branched structure, preferably, it is selected from the group consisting of silicone resins of the following formula: · 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 part 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 a part of the D group, · MM'TQ, where the hydrogen atom bonded to the silicon atom is held by a part of the M unit, · MM'DD'Q, where the hydrogen atom bonded to the silicon atom is held by a part of the M unit and the D unit, · And mixtures thereof Here, M, M', D and D' are as defined above, T: the siloxyl unit of the formula USiO 3 / 2 And Q: the siloxyl unit of the formula SiO 4 / 2is a siloxyl unit, where U has the same meaning as above.

[0069] Preferably, the organohydro polysiloxane compound has a content of hydrosilyl Si-H functional groups of 0.2% to 91% by weight, more preferably 3% to 80% by weight, and still more preferably 15% to 70% by weight.

[0070] According to a specific embodiment of the present invention, the unsaturated compound (A) and the component (B) containing at least one hydrosilyl functional group can, on the one hand, be the same compound containing at least one ketone functional group, one aldehyde functional group, one alkene functional group and / or one alkyne functional group, and on the other hand, contain 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 itself by a hydrosilylation reaction. Therefore, the present invention can also relate to a method for hydrosilylating the bifunctional compound itself, and the bifunctional compound contains, on the one hand, at least one functional group selected from the group consisting of a ketone functional group, an aldehyde functional group, an alkene functional group and an alkyne functional group (preferably at least one alkene functional group and / or at least one alkyne 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 the iron complex (C) as described above.

[0071] Examples of organopolysiloxanes that can be bifunctional compounds are as follows: · Poly(dimethylsiloxane-co-hydroxymethylsiloxane-co-vinylmethylsiloxane) having dimethylvinylsilyl terminals, · Poly(dimethylsiloxane-co-hydroxymethylsiloxane-co-vinylmethylsiloxane) having dimethylhydrosilyl terminals; and · Poly(dimethylsiloxane-co-hydroxymethylsiloxane-co-(propyl glycidyl ether)methylsiloxane) having trimethylsilyl terminals.

[0072] When it comes to the use of an unsaturated compound (A) and a compound (B) containing at least one hydrosilyl functional group, those skilled in the art will understand that this also means the use of a bifunctional compound.

[0073] The amounts of compound (A) and compound (B) can be controlled such that the molar ratio of the hydrosilyl functional group of compound (B) to the alkene functional group and alkyne functional group of compound (A) is preferably 1:10 to 10:1, more preferably 1:5 to 5:1, and even more preferably 1:3 to 3:1.

[0074] The hydrosilylation reaction can be carried out in a solvent or in the absence of a solvent. In another embodiment, one of the reactants, for example, the unsaturated compound (A), can act as a solvent. Suitable solvents are solvents miscible with compound (B). The hydrosilylation reaction can be carried out at a temperature of 15°C to 300°C, preferably 20°C to 240°C, more preferably 50°C to 200°C, more preferably 50°C to 140°C, and even more preferably 50°C to 100°C.

[0075] The molar concentration of the iron complex (C) can be 0.01 mol% to 15 mol%, more preferably 0.05 mol% to 10 mol%, and even more preferably 0.1 mol% to 8 mol% with respect to the total number of moles of unsaturation held by the unsaturated compound (A). According to another form, the amount of iron used in the method according to the present invention is 10 ppm to 3000 ppm, more preferably 20 ppm to 2000 ppm, and even more preferably 20 ppm to 1000 ppm with respect to the total weight of compounds (A), (B), and (C), without considering the possibility of the presence of a solvent. According to another preferred form, in the method according to the present invention, compounds based on platinum, palladium, ruthenium, or rhodium are not used. The amount of a compound based on platinum, palladium, ruthenium, or rhodium 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 with respect to the weight of the catalyst C.

[0076] 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 cures. The crosslinking is accompanied by a gentle physical change in 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" shall mean any silicone-based product obtained by crosslinking and / or curing a composition comprising an organopolysiloxane having at least two unsaturated bonds and an organopolysiloxane having at least three hydrosilyl units. The crosslinked silicone material can be, for example, an elastomer, a gel or a foam.

[0077] According to this preferred embodiment of the method according to the present invention, in which the 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 can include: · fillers, · adhesion promoters, · inhibitors or retarders of the hydrosilylation reaction, · adhesion regulators, · silicone resins, · consistency improvers, · pigments · heat resistance additives, oil resistance additives, fire resistance additives, such as metal oxides, etc.

[0078] Other details or advantages of the present invention will become more clearly apparent in light of the examples shown below for illustrative purposes only.

Examples

[0079] Example 1: Synthesis of Tris(trimethylsilyl)silyl Potassium 1 equivalent of ((CH3)3Si)4Si (5.00 g, 1.56×10 -2 mol) and 1 equivalent of t-BuOK (1.75 g, 1.56×10 -2(1.029 g, 4.77×10

[0080] Example 2: Iron Complex (THF) According to the Prior Art 2 Fe[Si(SiMe 3 ) 3 ] 2 Synthesis The synthetic protocol described by S. Arata and Y. Sunada (Dalton Trans., 2019, 48, 2891 - 2895) was reproduced.

Chemical formula

[0081] FeBr2 (1.029 g, 4.77×10 -3 mol) suspension was prepared with 20 ml of THF in a 100 ml Schlenk tube. 2 equivalents of K[Si(SiMe3)3]·1.4THF (3.700 g, 9.54×10 -3 mol) obtained according to Example 1 was dissolved in 15 ml of THF in a 25 ml Schlenk tube. The K[Si(SiMe3)3]·1.4THF solution was rapidly added dropwise to the FeBr2 suspension at ambient temperature. After reacting for 1 hour, the dark purple solution was centrifuged at 3 °C for 10 minutes in a sealed PTFE tube packaged under argon to remove insoluble substances. After recovering the solution, the solvent was evaporated under dynamic vacuum. Subsequently, the obtained purple solid was dissolved in 80 ml of pentane. Then, the green solution was centrifuged at 3 °C for 10 minutes in a sealed PTFE tube packaged under argon to remove insoluble substances. After adding 5 ml of THF, the solution was concentrated to about 15% of its initial volume and cooled to -30 °C. In this way, the complex (THF)2Fe[Si(SiMe3)3]2 was obtained in the form of purple crystals after crystallization and dried under vacuum (yield: 83.0%).

[0082] Example 3: Iron Complex (THF) According to the Present Invention 2 Fe[Si(SiMe 3) 3 ] 2 Synthesis The purple crystals obtained in Example 2 were recrystallized according to the prior art (1.5 ml of pentane per 100 mg portion of crystals).

[0083] In this way, after recrystallization according to the present invention, the complex (THF)2Fe[Si(SiMe3)3]2 was obtained in a recrystallization yield of 84%.

[0084] Analysis of the crystals obtained in Example 3 according to the present invention showed that the formula C 26 H 70 FeO2Si8 and a molecular weight of 695.39 g.mol -1 of the complex was obtained. For comparison, the purple crystals obtained in the paper by S. Arata and Y. Sunada corresponded to a compound of the formula C 34 H 70 FeO4Si8 and a molecular weight of 823.46 g.mol -1 (see Supporting Information, Dalton Trans., 2019, 48, 2891 - 2895).

[0085] Examples 4 to 16: Crosslinking Tests The required weight of the catalyst was weighed in a glove box under an inert argon atmosphere and introduced into a dry, sealed flask. Subsequently, the organopolysiloxane was also introduced into the flask under an inert atmosphere, and then the flask was placed in a small metal barrel preheated to the desired temperature (t = 0). The gel time of the cross - linking test was qualitatively measured by the stir - stop time (SST). This SST is associated with such a large increase in viscosity that the medium can no longer be stirred (corresponding to a viscosity of about 1000 mPa.s).

[0086] In Examples 4 to 9, the unsaturated compound is poly(dimethylsiloxane) having a dimethylvinylsilyl end containing 1.1 wt% to 1.25 wt% of vinyl functional groups. The compound having a hydrosilyl functional group is poly(methylhydrogensiloxane) having a trimethylsilyl end containing 56 wt% of SiH functional groups. SiH / SiVi molar ratio = 4, catalyst amount = 7 mol% (molar percentage of iron element contributed by the catalyst with respect to the number of moles of vinyl groups bonded to silicon contributed by the unsaturated compound), and T = 30 °C.

[0087]

Table 1

[0088] Under these experimental conditions, for the reactions catalyzed by the catalyst according to the present invention that have undergone the recrystallization step (Examples 7, 8, 9), the stirring stop time was 1 hour to 2 hours. In the case of the reactions carried out using the prior art catalysts that have not been recrystallized (Examples 4, 5, 6), the reproducibility of the test was poor, and it was found that the stirring stop time was 2 hours 40 minutes to 45 hours.

[0089] As is clear from these examples, the same technical results as those of the catalyst of the present invention cannot be obtained with the catalysts described in the prior art. Thus, the two are physically different.

[0090] In Examples 10 to 16, the unsaturated compound is poly(dimethylsiloxane) having a dimethylvinylsilyl end containing 1.1 wt% to 1.25 wt% of vinyl functional groups, the compound having a hydrosilyl functional group is poly(methylhydrogensiloxane) having a trimethylsilyl end containing 56 wt% of SiH functional groups, SiH / SiVi molar ratio = 4, the catalyst: the recrystallized (THF) 2Fe[Si(SiMe3)3]2 complex of Example 3, and the catalyst amount = 7 mol% (molar percentage of iron element contributed by the catalyst with respect to the number of moles of vinyl groups bonded to silicon contributed by the unsaturated compound).

[0091]

Table 2

[0092] Examples 17 to 22: Functionalization Tests In a glove box under an inert argon atmosphere, a catalyst of the required weight was weighed and introduced into a dry, sealed flask. First, dodecane (0.3 g) was introduced. The medium was stirred to dissolve the catalyst. First, a compound having a hydrosilyl functional group of the required weight was introduced, and then an alkene of the required weight was introduced into the flask. Thereafter, the flask was placed in a small metal barrel preheated to the desired temperature (t = 0).

[0093] The reaction medium was quantitatively analyzed by gas chromatography to determine the conversion rate and selectivity.

[0094] In Examples 17 to 22, the compound having a hydrosilyl functional group is 1,1,1,3,5,5,5-heptamethyl-3-hydrotrisiloxane (= MD’M), the SiH / SiVi molar ratio = 1, the catalyst is the recrystallized (THF) 2Fe[Si(SiMe3)3]2 complex of Example 3, and the catalyst amount = 0.5 mol% (molar percentage of iron element contributed by the catalyst relative to the number of moles of vinyl groups bonded to silicon contributed by the unsaturated compound). (Vpdms = vinylpentamethyldisiloxane; Dvtms = divinyltetramethyldisiloxane).

[0095] [Table 3]

Claims

1. A method for hydrosilylating an unsaturated compound A containing at least one functional group selected from an alkene functional group and an alkyne functional group with a compound B containing at least one hydrosilyl functional group, which is catalyzed by an iron complex C represented by the following formula (1): Fe[Si(SiR 3 ) 3 2 L n (1) In the formula, - Each R independently represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with one or more halogen atoms, - Each L independently represents an ether ligand, - n = 1, 2 or 3.

2. The method according to claim 1, wherein each R independently represents a group selected from an alkyl group, a cycloalkyl group, an aryl group and an arylalkyl group, and the group may be substituted with one or more halogen atoms.

3. The method according to claim 1 or 2, wherein the ether ligand L is a compound of the formula R 1 OR 2 (wherein R 1 and R 2 independently represent a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, which may contain one or more heteroatoms, or R 1 and R 2 together with the oxygen atom to which they are attached form a cyclic hydrocarbon group containing one or more heteroatoms).

4. The iron complex C is the following compound: 【Chemical Formula 1】 The method according to any one of claims 1 to 3.

5. The method according to any one of claims 1 to 4, wherein the unsaturated compound A is an organopolysiloxane compound containing one or more alkene functional groups.

6. The unsaturated compound A is - At least two siloxyl units of the following formula: ViaUbSiO(4-a-b) / 2 (In the formula, Vi is a C2-C6 alkenyl group, U is a monovalent hydrocarbon group having 1 to 12 carbon atoms, a = 1, 2 or 3, b = 0, 1 or 2; and the total a + b = 1, 2 or 3.) and - Optionally, a unit of the following formula: UcSiO(4-c) / 2 (In the formula, U has the same meaning as above, and c = 0, 1, 2 or 3.) and The method according to claim 5, which is an organopolysiloxane compound composed of

7. The method according to any one of claims 1 to 5, wherein 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.

8. The compound B containing at least one hydrosilyl functional group is - At least two siloxyl units of the following formula: HdUeSiO(4-d-e) / 2 (In the formula, U is a monovalent hydrocarbon group having 1 to 12 carbon atoms, d = 1, 2 or 3, e = 0, 1 or 2; and d + e = 1, 2 or 3.) and - Optionally, a unit of the following formula: UfSiO(4-f) / 2 (In the formula, U has the same meaning as above, and f = 0, 1, 2 or 3.) and The method according to claim 7, which is an organopolysiloxane composed of

9. A composition comprising at least one unsaturated compound A containing at least one functional group selected from an alkene functional group and an alkyne functional group, at least one compound B containing at least one hydrosilyl functional group, and an iron complex C represented by the following formula (1): Fe[Si(SiR 3 ) 3 2 L n (1) In the formula, ・ Each R independently represents a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a hydrogen atom or one or more halogen atoms, ・ Each L independently represents an ether ligand, ・ n = 1, 2 or 3.

10. The following formula (1): Fe[Si(SiR 3 ) 3 2 L n (1) (In the formula, ・ Each R independently represents a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with a hydrogen atom or one or more halogen atoms, ・ Each L independently represents an ether ligand, ・ n = 1, 2 or 3,) A method for producing an iron complex C represented by, The method includes a step of producing a crude iron complex C, and then recrystallizing the crude iron complex C using a recrystallization solvent selected from pentane, toluene, hexane, heptane, cyclopentane, cyclohexane and methylcyclohexane.

11. The iron complex C obtained by the method according to Claim 10.

12. Use of the iron complex C according to Claim 11 as a catalyst for hydrosilylation of an alkene or an alkyne.​​

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