JP6844384B2 - Liquid silicon compound and its manufacturing method - Google Patents

Description

One embodiment of the present invention relates to a liquid silicon compound and a method for producing the same.

Generally, an organosilicon compound having three hydrolyzable groups represented by an alkoxide group has already been widely used as a silane coupling agent. It is known that the silsesquioxane compound obtained by hydrolyzing and condensing this silane coupling agent has a random structure without a specific structure, a ladder structure capable of determining the structure, and a cage-type structure. .. In particular, silsesquioxane having a cage-shaped structure has excellent properties in heat resistance, electrical insulation, transparency, etc., and therefore has attracted attention as a semiconductor or electronic material, and many studies have been reported.

Of these, the cage-type silsesquioxane, which is composed of eight Sis and has high symmetry, is called T8. In this T8, all eight substituents on Si are converted to reactive substituents, that is, eight-substituted T8, or one is converted to another reactive substituent, that is, mono-substituted XT8. Has commercialized a number of derivatives with different substituents.

Further, among these T8s, the derivative in which two on Si are converted into other reactive substituents, that is, the disubstituted 2X-T8, is, for example, two types of trialkoxysilanes or trichlorosilanes as in Non-Patent Document 1. It is known that it can be synthesized from compounds. However, when the reactive substituent is a vinyl group, vinyltrichlorosilane and alkyltrichlorosilane, which are raw materials for synthesis, are highly reactive with water and even react with water vapor in the atmosphere. In addition, hydrochloric acid gas generated as a by-product of the reaction is highly corrosive and requires special manufacturing equipment with a glass coating or the like. In addition, silanol produced from chlorosilane tends to condense in the presence of an acid, and in addition to the thermodynamically stable product, a by-product is generated by a kinetic reaction mechanism, and the yield of the target compound decreases. Tend to do. Therefore, in order to obtain the desired disubstituted 2X-T8 in good yield, it is necessary to devise the reaction conditions and the charging ratio of the reaction raw materials.

Recently, as in Non-Patent Documents 2 and 3, a method of selectively synthesizing a di-substituted 2X-T8 at the p-position in two steps from a mono-substituted XT8 has been proposed. Further, in Non-Patent Document 3, a polymer in which the disubstituted 2X-T8 is linked with a siloxane and introduced into a polymer main chain is synthesized. Although this polymer has excellent heat resistance such as a 5% thermogravimetric reduction temperature exceeding 470 ° C, it forms a film when it is dissolved in a solvent and applied and dried on glass, and the film thickness can be measured. Solid. Therefore, it is difficult to apply it to oils such as electrically insulating oil, heat transfer oil, diffusion pump oil and lubricating oil.
Further, in the polymer of Non-Patent Document 3, two methylene chains are bonded to the p-position of the cage-type silsesquioxane structure, but the structure of the disubstituted 2X-T8 at the p-position is industrially selective. It is not limited to the method for producing a polymer having the above.

Journal of Organometallic Chemistry, (1994), 483, 33-38 Chemistry Letters, (2014), 43, 1532 to 1534 Polymer Chemistry, (2015), 6,7500-7504

One object of the present invention is to provide a liquid silicon compound having excellent heat resistance and having a cage-type silsesquioxane structure introduced into the main chain.

（一般式（Ｉ）中、Ｒ^１は炭素数１〜８の直鎖または分岐鎖を有するアルキル基、または炭素数６〜１４のアリール基を表し、６個のＲ^１は、全て同一であっても、一部または全て異なってもよく、Ｒ^２、Ｒ^３、Ｒ^４、及びＲ^５は、それぞれ独立的に、炭素数１〜８の直鎖または分岐鎖を有するアルキル基、または炭素数６〜１４のアリール基を表し、ｍは１〜３０の整数を表し、ｎ個の構造単位において、ｍは全て同一であっても、一部または全て異なってもよく、ｎは重量平均分子量２，０００〜１，０００，０００を満たす数字を表す。） An embodiment of the present invention has the following gist.
[1] A liquid silicon compound having a structural unit represented by the following general formula (I).

In (formula (I), R ¹ represents an alkyl group or an aryl group having 6 to 14 carbon atoms, having a straight-chain or branched-chain having 1 to 8 carbon atoms, six R ¹ are all a same even, it may be partially different, or ^{all, R 2, R 3, R} 4, and ^{R 5} are, each independently, an alkyl group having a linear or branched chain having 1 to 8 carbon atoms or carbon atoms, Represents an aryl group of 6 to 14, m represents an integer of 1 to 30, and in n structural units, m may be all the same, partially or all different, and n is a weight average molecular weight of 2. Represents a number that satisfies 000 to 1,000,000.)

（一般式（Ｉ）中、Ｒ^１は炭素数１〜８の直鎖または分岐鎖を有するアルキル基、または炭素数６〜１４のアリール基を表し、６個のＲ^１は、全て同一であっても、一部または全て異なってもよく、Ｒ^２、Ｒ^３、Ｒ^４、及びＲ^５は、それぞれ独立的に、炭素数１〜８の直鎖または分岐鎖を有するアルキル基、または炭素数６〜１４のアリール基を表し、ｍは１〜３０の整数を表し、ｎ個の構造単位において、ｍは全て同一であっても、一部または全て異なってもよく、ｎは重量平均分子量２，０００〜１，０００，０００を満たす数字を表す。）

（一般式（ＩＩ）中、Ｒ^１は炭素数１〜８の直鎖または分岐鎖を有するアルキル基、または炭素数６〜１４のアリール基を表し、６個のＲ^１は、全て同一であっても、一部または全て異なってもよい。）
［３］下記一般式（ＩＩＩ）で表される化合物を用いて製造される工程を含む、請求項２に記載の液状ケイ素化合物の製造方法。

（一般式（ＩＩＩ）中、Ｒ^２、Ｒ^３、Ｒ^４、及びＲ^５は、それぞれ独立的に、炭素数１〜８の直鎖または分岐鎖を有するアルキル基、または炭素数６〜１４のアリール基を表し、ｍは１〜３０の整数を表す。） [2] A method for producing a liquid silicon compound having a structural unit represented by the following general formula (I), which comprises a step of producing using the silicon compound represented by the following general formula (II). A method for producing a silicon compound.

In (formula (I), R ¹ represents an alkyl group or an aryl group having 6 to 14 carbon atoms, having a straight-chain or branched-chain having 1 to 8 carbon atoms, six R ¹ are all a same even, it may be partially different, or ^{all, R 2, R 3, R} 4, and ^{R 5} are, each independently, an alkyl group having a linear or branched chain having 1 to 8 carbon atoms or carbon atoms, Represents an aryl group of 6 to 14, m represents an integer of 1 to 30, and in n structural units, m may be all the same, partially or all different, and n is a weight average molecular weight of 2. Represents a number that satisfies 000 to 1,000,000.)

In (formula (II), ^{R 1} represents an alkyl group or an aryl group having 6 to 14 carbon atoms, having a straight-chain or branched-chain having 1 to 8 carbon atoms, six ^{R 1} are all a same However, some or all of them may be different.)
[3] The method for producing a liquid silicon compound according to claim 2, which comprises a step of producing using the compound represented by the following general formula (III).

(In the general formula ^{(III), R 2, R} 3, R 4, and ^{R 5} are, each independently, an alkyl group having a straight-chain or branched-chain having 1 to 8 carbon atoms or 6 to 14 carbon atoms, Represents an aryl group, and m represents an integer of 1 to 30.)

According to one embodiment of the present invention, it is possible to provide a liquid silicon compound having excellent heat resistance and having a cage-type silsesquioxane structure introduced into the main chain.

The figure which shows each fraction division. MALDI-TOF MS measurement results for each fraction. ^{1 1 1} H NMR spectrum of each fraction. ¹³ C NMR spectrum of each fraction. ²⁹ SI NMR spectra of each fraction. Positional isomer of bisvinyl POSS.

Hereinafter, an embodiment of the present invention will be described, but the present invention is not limited by the following examples.
"Liquid silicon compound"
The liquid silicon compound according to one embodiment is characterized by being represented by the following general formula (I).

In the general formula (I), R ¹ represents an alkyl group or an aryl group having 6 to 14 carbon atoms, having a straight-chain or branched-chain having 1 to 8 carbon atoms, six R ¹ is all the same also may be partially different, or ^{all, R 2, R 3, R} 4, and ^{R 5} are, each independently, an alkyl group having a straight-chain or branched-chain having 1 to 8 carbon atoms or carbon atoms, 6 Represents an aryl group of ~ 14, m represents an integer of 1 to 30, and in n structural units, m may be all the same, partly or all different, and n is a weight average molecular weight 2, Represents a number that satisfies 000 to 1,000,000.

Alkyl group represented by R ¹ is preferably an alkyl group having 1 to 8 carbon atoms, more preferably from 1 to 6 carbon atoms may have a straight or branched chain, acyclic Alternatively, it may be a ring type.
The ^{aryl group represented by R 1} is preferably an aryl group having 6 to 14 carbon atoms, more preferably 6 to 12 carbon atoms, and further preferably 6 to 8 carbon atoms. Within this range of carbon numbers, the aryl group may have an alkyl group having a straight chain or a branched chain bonded to at least one carbon atom forming a carbon ring.
Examples of R ¹ include a methyl group, an ethyl group, an isobutyl group, a cyclohexyl group, an isooctyl group, a phenyl group and the like.
R ¹ is preferably an alkyl group or a phenyl group having 1 to 8 carbon atoms.

In the general formula (I), the six R ^1s may be all the same, or partly or all different. It is preferable that all six R ^{1s are the same.}
Further, in the n structural units, six combinations of R ¹ between the structural units may all be of the same or may be different partially or all.

In the general formula ^{(I), R 2, R} 3, R 4, and ^{R 5} are, each independently, an alkyl group or an aryl having 6 to 14 carbon atoms, having a straight-chain or branched-chain having 1 to 8 carbon atoms Represents a group.
The ^{alkyl group represented by R 2} , R ³ , R ⁴ and R ⁵ is preferably an alkyl group having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and is a straight chain or a branched chain. It may have an acyclic type or a ring type.
^{R 2, R 3, R 4} , and aryl group represented by ^{R 5} is preferably an alkyl group having 6 to 14 carbon atoms, more preferably 6 to 8 carbon atoms. Within this range of carbon numbers, the aryl group may have an alkyl group having a straight chain or a branched chain bonded to at least one carbon atom forming a carbon ring.
^{R 2, R 3, R 4} , and as ^{R 5} are, each independently, for example, a methyl group, an ethyl group, n- propyl group, i- propyl, n- butyl group, i- butyl, sec- Butyl group, t-butyl group, hexyl group, octyl group, 2-ethylhexyl group, 3-ethylhexyl group, phenyl group and the like can be mentioned.
^{R 2, R 3, R 4} , and ^{R 5} are preferably, from the viewpoint of heat resistance, it is preferably an unsubstituted alkyl group or a phenyl group having 1 to 8 carbon atoms, non of 1 to 4 carbon atoms More preferably, it is a substituted alkyl group or phenyl group.

_{Regarding the positions of the two -CH 2-} CH 2- (methylene chains) bound to the cage-type silsesquioxane structure, if the same naming convention as the benzene ring is applied, the two are mediated by one oxygen. There are three positions: the o-position where Si has a methylene chain, the m-position where the second Si via oxygen-Si-oxygen has a methylene chain, and the p-position which is diagonally located.
The liquid silicon compound may have at least one cage-type silsesquioxane structure selected from three types of cage-type silsesquioxane structures in which the methylene chain is at the o-position, the m-position, and the p-position. preferable. More preferably, a silicon compound having one or more cage-type silsesquioxane structures selected from two types of cage-type silsesquioxane structures in which the methylene chain is at the o-position and the m-position is preferable. Further, a liquid silicon compound having at least two cage-type silsesquioxane structures selected from three types of cage-type silsesquioxane structures in which the methylene chain is at the o-position, the m-position, and the p-position is preferable.

Non-Patent Document 3 is an example of a polymer having only a cage-type silsesquioxane structure in which the bond position of the methylene chain is at the p-position. When this bond position is only at the p-position, it is considered that the attractive interaction based on the cohesive force of the cage-type silsesquioxane structure introduced into the polymer chain is strengthened, and as a result, the polymer chain becomes solid. In order to make it liquid, at least two kinds selected from three kinds of cage-type silsesquioxane structures whose bond positions are at the o-position, the m-position, and the p-position are not limited to the polymer whose bond position is only at the p-position. In particular, a polymer having three types of cage-type silsesquioxane structures is preferable.

In the general formula (I), m is preferably an integer of 1 to 30.
The siloxane structure that connects the cage-type silsesquioxane structures violently moves at high temperatures. Combined with the vibration based on the cohesive force of the cage-type silsesquioxane structure, it is considered that the polymer according to one embodiment has improved heat resistance by performing a peculiar molecular chain motion at a high temperature. Therefore, when m exceeds 30, the influence of the cage-type silsesquioxane structure on the siloxane structure becomes small, so that the effect of heat resistance is significantly reduced. The peculiar molecular chain motion for improving heat resistance is more preferably m 1 to 25, and even more preferably m 1 to 20.
m may be all the same in n structural units, or may be partially or completely different.

n is preferably a number satisfying the weight average molecular weight of 2,000 to 1,000,000.
When n is small and the weight average molecular weight is less than 2,000, it contains only two cage-type silsesquioxane structures in calculation, and is therefore shown by, for example, Macromolecules (2011), 44, 6039-6045. As described above, the 5% thermogravimetric reduction temperature is about 290 to 310 ° C., and it becomes difficult to obtain heat resistance exceeding 400 ° C.
Further, when the weight average molecular weight exceeds 1,000,000, the viscosity becomes too large and there is almost no application destination as an oil.
From the viewpoint of heat resistance and viscosity, n is more preferably a number having a weight average molecular weight of 3000 to 500,000, and further preferably a number having a weight average molecular weight of 4000 to 100,000.
Specifically, n is preferably 3 to 500, and preferably 4 to 100.

"Manufacturing method of liquid silicon compound"
Hereinafter, an example of a method for producing a liquid silicon compound represented by the general formula (I) will be described. The liquid silicon compound represented by the general formula (I) is not limited to the one produced by the following production method.

The method for producing the liquid silicon compound represented by the general formula (I) includes, for example, a step of producing the liquid silicon compound using the compound represented by the following general formula (II).

In the general formula (II), R ¹ represents an alkyl group or an aryl group having 6 to 14 carbon atoms, having a straight-chain or branched-chain having 1 to 8 carbon atoms, six R ¹ is all the same May be partially or wholly different.
Alkyl group represented by R ¹ is preferably an alkyl group having 1 to 8 carbon atoms, more preferably from 1 to 6 carbon atoms may have a straight or branched chain, acyclic Alternatively, it may be a ring type.
The ^{aryl group represented by R 1} is preferably an aryl group having 6 to 14 carbon atoms, more preferably 6 to 12 carbon atoms, and further preferably 6 to 8 carbon atoms. Within this range of carbon numbers, the aryl group may have an alkyl group having a straight chain or a branched chain bonded to at least one carbon atom forming a carbon ring.
Examples of R ¹ include a methyl group, an ethyl group, an isobutyl group, a cyclohexyl group, an isooctyl group, a phenyl group and the like.
R ¹ is preferably an alkyl group or a phenyl group having 1 to 8 carbon atoms.

_{Regarding the positions of the two} -CH = CH 2 (vinyl groups) bonded to the cage-type silsesquioxane structure, if the same naming convention as the benzene ring is applied, two Sis via one oxygen can be obtained. There are three positions: the o-position where the vinyl group is present, the m-position where the vinyl group is present in the second Si via oxygen-Si-oxygen, and the p-position which is the diagonal position.
In the reaction, it is preferable to use at least two or more, more preferably three kinds of compounds among the three kinds of compounds in which the two vinyl groups are at the o-position, the m-position and the p-position. Further, in the reaction, it is preferable to use a compound containing at least one of two kinds of compounds having two vinyl groups at the o-position and the m-position, or a mixture thereof.
As a result, the liquid silicon compound having the structural unit represented by the general formula (I) can be prevented from becoming a solid state.

An example of a method for producing a compound represented by the general formula (II) will be described.
The compound represented by the general formula (II) can be obtained, for example, by reacting an alkylalkoxysilane with a vinylalkoxysilane.
According to such a method, in the compound represented by the general formula (II), as shown in FIG. 6, a compound in which two vinyl groups are at the o-position, the m-position and the p-position can be produced.
In particular, a compound represented by the following general formula (IV) and a compound represented by the following general formula (V) are used to obtain a compound represented by the general formula (II), which is represented by the general formula (II). A liquid silicon compound can be obtained by producing a compound having a structural unit represented by the general formula (I) using the compound. Since this silicon compound is liquid, it is considered that in FIG. 6, not only the structural unit in which the two vinyl groups are in the p-position but also at least one of the two types of structural units in the o-position and the m-position is contained. Be done.

As a method for producing a compound represented by the general formula (II), for example, a compound represented by the following general formula (IV) can be used.

In the general formula (IV), R ¹ represents an alkyl group having a linear or branched chain having 1 to 8 carbon atoms or an aryl group having 6 to 14 carbon atoms.
Alkyl group represented by R ¹ is preferably an alkyl group having 1 to 8 carbon atoms, more preferably from 1 to 6 carbon atoms may have a straight or branched chain, acyclic Alternatively, it may be a ring type.
The ^{aryl group represented by R 1} is preferably an aryl group having 6 to 14 carbon atoms, more preferably 6 to 12 carbon atoms, and further preferably 6 to 8 carbon atoms. Within this range of carbon numbers, the aryl group may have an alkyl group having a straight chain or a branched chain bonded to at least one carbon atom forming a carbon ring.
Examples of R ¹ include a methyl group, an ethyl group, an isobutyl group, a cyclohexyl group, an isooctyl group, a phenyl group and the like.
R ¹ is preferably an alkyl group or a phenyl group having 1 to 8 carbon atoms.
^{R 1} in the general formula (IV) is introduced as ^{R 1} of the compound of formula (II), is introduced as ^{R 1} in addition compounds of the general formula (I).

In the general formula (IV), R ⁶ independently represents an alkyl group, preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms. The ^{alkyl groups represented by R 6} may independently have a linear or branched chain, and may be acyclic or cyclic.
Examples of R ⁶ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, hexyl group, octyl group, 2 -Ethylhexyl group, 3-ethylhexyl group and the like can be mentioned.
Among them, R ⁶ is preferably an unsubstituted alkyl group having 1 to 8 carbon atoms, and more preferably an unsubstituted alkyl group having 1 to 4 carbon atoms, from the viewpoint of controlling reactivity.

As the compound represented by the general formula (IV), for example, an alkylalkoxysilane such as isobutyltrimethoxysilane can be used.
These may be used alone or in combination of two or more.
By combining the alkylalkoxysilane compound represented by the general formula (II) with one of a silane, R ¹ in the general formula (II) can be obtained all the same compound.
By synthesizing the alkyl alkoxy represented by formula (II) compound with R ¹ is 2 or more different among silanes, R ¹ in the general formula (II) is to obtain some or all different compounds it can.

Further, as a method for producing a compound represented by the general formula (II), for example, a compound represented by the following general formula (V) can be used.
Preferably, the compound represented by the general formula (II) can be obtained by reacting the compound represented by the general formula (IV) with the compound represented by the general formula (V).

In the general formula (V), R ⁷ independently represents an alkyl group, preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms. The ^{alkyl groups represented by R 7} may independently have a linear or branched chain, and may be acyclic or cyclic.
Examples of R ⁷ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, hexyl group, octyl group, 2 -Ethylhexyl group, 3-ethylhexyl group and the like can be mentioned.
Among them, R ⁷ is preferably an unsubstituted alkyl group having 1 to 8 carbon atoms, and more preferably an unsubstituted alkyl group having 1 to 4 carbon atoms, from the viewpoint of controlling reactivity.

As the compound represented by the general formula (V), for example, vinylalkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane can be used.
These may be used alone or in combination of two or more.

For the reaction between the compound represented by the general formula (IV) and the compound represented by the general formula (V), a basic compound represented by M (OH) may be used. M is not particularly limited as long as it contains at least one metal element selected from the group consisting of Li, Na, and K. Li (OH) is preferable from the viewpoint of controlling reactivity and yield.

The reaction between the compound represented by the general formula (IV) and the compound represented by the general formula (V) is preferably carried out in a solvent.
The solvent is not particularly limited, but the compound represented by the general formula (IV) and the compound represented by the general formula (V) are highly compatible, and when mixed, a uniform solution is given, while the solvent is given. A solvent having low compatibility with M (OH) and in which M (OH) remains in the system without being dissolved when mixed is preferable. The uniformly dispersed silane raw material is advantageous in providing a thermodynamically stable product. Further, it is advantageous that the M (OH) concentration remains constant in the system during the reaction to provide a thermodynamically stable product.
Further, by adding water to the solvent, the reaction can proceed in the presence of water. Water may be added in an amount of 5 to 15 parts by mass with respect to a total of 100 parts by mass of the alkoxysilane represented by the general formula (IV) and the vinyl alkoxysilane represented by the general formula (V).

There is no particular limitation on the molar ratio of the compound represented by the general formula (IV), which is a silane raw material, to the compound represented by the general formula (V). Assuming that a compound can be obtained statistically thermodynamically according to the charging ratio, when compound (II) is the target compound, 75:25 is the molar ratio expected to have the highest yield. Therefore, the molar ratio is preferably 90: 10 to 40:60. Further, considering the fractionation by normal phase chromatography, 85: 15-45: 55 is preferable. Further, 80:20 to 50:50 is preferable.

As described above, the medium for carrying out the synthesis preferably has low solubility in LiOH and is compatible with the silane raw material and water. Specifically, a mixed solvent of methanol and acetone is preferable. At this time, there is no particular limitation on the mixing ratio.
In addition, there is no particular limitation on the temperature at which the synthesis is carried out. However, from the viewpoint of shortening the reaction time, 30 to 56 ° C. is preferable, and 40 to 55 ° C. is more preferable.

A chromatography method may be used as a method for separating and purifying compound (II) from the product after the reaction. As the chromatography method, normal phase liquid chromatography using a column containing silica particles as a filler is preferable. By using normal phase liquid chromatography, the polarization state of the molecule is slightly different, so that compound (II) can be separated. Further, since the polarization of these molecules is small, the developing solvent is preferably a solvent containing hexane or petroleum ether, which has low polarity and is inexpensive.

Further, the method for producing the liquid silicon compound represented by the general formula (I) preferably includes a step of producing using the compound represented by the following general formula (III).
Preferably, the step of reacting the compound represented by the general formula (II) with the compound represented by the general formula (III) to produce a liquid silicon compound is included.

In the general formula ^{(III), R 2, R} 3, R 4, and ^{R 5} are, each independently, an alkyl group or an aryl having 6 to 14 carbon atoms, having a straight-chain or branched-chain having 1 to 8 carbon atoms It represents a group, and m represents an integer of 1 to 30.

In the general formula ^{(III), R 2, R} 3, R 4, and ^{R 5} are, each independently, an alkyl group or an aryl having 6 to 14 carbon atoms, having a straight-chain or branched-chain having 1 to 8 carbon atoms Represents a group.
The ^{alkyl group represented by R 2} , R ³ , R ⁴ and R ⁵ is preferably an alkyl group having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and is a straight chain or a branched chain. It may have an acyclic type or a ring type.
^{R 2, R 3, R 4} , and aryl group represented by ^{R 5} is preferably an alkyl group having 6 to 14 carbon atoms, more preferably 6 to 8 carbon atoms. Within this range of carbon numbers, the aryl group may have an alkyl group having a straight chain or a branched chain bonded to at least one carbon atom forming a carbon ring.
^{R 2, R 3, R 4} , and as ^{R 5} are, each independently, for example, a methyl group, an ethyl group, n- propyl group, i- propyl, n- butyl group, i- butyl, sec- Butyl group, t-butyl group, hexyl group, octyl group, 2-ethylhexyl group, 3-ethylhexyl group, phenyl group and the like can be mentioned.
^{R 2, R 3, R 4} , and R ⁵ is preferably a heat-resistant aspect of the liquid silicon compound is synthesized, it is preferably an unsubstituted alkyl group or a phenyl group having 1 to 8 carbon atoms, More preferably, it is an unsubstituted alkyl group or phenyl group having 1 to 4 carbon atoms.

In the general formula (III), m is preferably an integer of 1 to 30, more preferably an integer of 1 to 25, and even more preferably an integer of 1 to 20. Within this range, the heat resistance of the synthesized liquid silicon compound can be improved.

In the method for producing a liquid silicon compound having a structural unit represented by the general formula (I), the compounds represented by the general formula (III) are of the above R ² , R ³ , R ⁴ , and R ⁵ , and m. At least one or a combination of two or more of a plurality of compounds having different combinations can be used.

In the reaction between the compound represented by the general formula (II) and the compound represented by the general formula (III), it is preferable to use a catalyst such as a platinum-based catalyst.
Examples of the platinum-based catalyst include a catalyst of platinum chloride, platinum chloride and alcohol, aldehyde, ketone, etc., a platinum-olefin complex, a platinum-carbonyl vinyl methyl complex (Oskko catalyst), and a platinum-divinyl tetramethyl siloxane complex (Platinum-divinyltetramethylsiloxane complex) Karstedt catalyst), platinum-cyclovinylmethylsiloxane complex, platinum-octylaldehyde complex, platinum-phosphine complex Pt [P (C ₆ H ₅ ) ₃ ] ₄ , PtCl [P (C ₆ H ₅ ) ₃ ] ₃ , Pt [P (C ₄ H ₉ ) ₃ ] ₄ , Platinum-phosphite complex Pt [P (OC ₆ H ₅ ) ₃ ] ₄ , Pt (OC ₄ H ₉ ) ₃ ] ₄ , dicarbonyldichloroplatinum, etc. Can be mentioned.

The reaction between the compound represented by the general formula (II) and the compound represented by the general formula (III) is preferably carried out in a solvent.
The solvent is not particularly limited, but can be arbitrarily selected depending on the compound represented by the general formula (II), the compound represented by the general formula (III), and the solubility of the catalyst.
Specific examples of the solvent include toluene, ethylbenzene, xylene, hexane, heptane, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, tetrahydrofuran (THF), propylene glycol monomethyl ether acetate and the like.

The reaction temperature varies depending on the catalyst and solvent used, but is preferably 40 to 150 ° C, more preferably 60 to 130 ° C.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "%" is based on mass.

<Example 1>
"Synthesis of compound represented by general formula (II)"
In the general formula (II), all the six ^{R 1} is isobutyl group Bisubiniru POSS; was synthesized (POSS cage oligo silsesquioxane (Polyhedral Oligomeric SilSesquioxanes)) by the following procedure.
Acetone (300 mL), methanol (40 mL), and purified water (5.60 mL) were added to a 500 mL three-necked flask, and a Dimroth condenser, a thermometer, and a dropping funnel were provided to create a nitrogen atmosphere.
To this three-necked flask, 7.00 g of LiOH monohydrate as a basic compound was added, and the mixture was heated in an oil bath with stirring so that the liquid temperature became 55 ° C.
Weigh 49.00 g of isobutyltrimethoxysilane as the alkoxysilane represented by the general formula (IV) and 13.56 g of vinyltrimethoxysilane as the vinyl alkoxysilane represented by the general formula (V) in the dropping funnel. It was taken and slowly added dropwise to a three-necked flask over 50 minutes. After the dropping, the liquid temperature was adjusted to 50 ° C., and the mixture was heated and stirred under a nitrogen atmosphere for 18 hours.
After heating, the oil bath was removed, the mixture was allowed to cool to room temperature (25 ° C.), and 150 mL of 1N HCl solution was added to make the mixture cloudy. The mixture was stirred as it was for 1 hour, and the supernatant was removed by inclining. The remaining white viscous substance was washed 3 times with 100 mL of acetonitrile, and then hexane was added to dissolve the white viscous substance. This solution was quantitatively transferred to a 500 mL flask, the solvent was distilled off with an evaporator, and the solution was dried under reduced pressure with an oil pump to obtain 34.64 g of a white viscous substance.

The obtained white viscous product was separated and purified.
"LC-forte / R" manufactured by YMC Co., Ltd. was used for preparative purification using a medium-pressure column, and "Universal Column Premium (2L)" manufactured by Yamazen Corporation was used as the column. The preparative condition was 10 mL / min, and the developing solvent was hexane. 2.64 g of white viscous material was dissolved in 1.47 g of hexane and charged directly onto the top of the column. While monitoring the outflow RI detection, the mixture was divided into each fraction at the outflow time shown in FIG. 1, the solvent was distilled off with an evaporator for each fraction, and the solvent was dried under reduced pressure with an oil pump to obtain white crystals from each fraction. The masses of white crystals obtained from each fraction are shown in Table 1.

MALDI-TOF MS analysis was performed on the white crystals obtained from fractions 2 to 4 using "AutoFlex" manufactured by Bruker Daltonics. The results are shown in FIG. From FIG. 2, peaks of H + and Na + adducts were observed.
Table 2 shows the observed values of white crystals obtained from each fraction and the calculated values of vinyl POSS, bisvinyl POSS, and trisvinyl POSS.
Fraction 2 was vinyl POSS, fraction 3 was the target bisvinyl POSS, and fraction 4 was trisvinyl POSS.

For bisvinyl POSS, in order to investigate the bonding position of the vinyl group, white crystals obtained from fractions 1 to 5 were each _{dissolved in CDCl 3} (deuterated chloroform), and Bruker's "Avance 300" was used for ¹ H. , ¹³ C and ²⁹ Si NMR were measured.
The measurement conditions are as follows.
( ^{1 1} H NMR)
Observation nucleus: 1H
Resonance frequency: 300MHz
Measurement temperature: 25 ° C
Reference substance: Tetramethylsilane ( ¹³ C NMR)
Observation nucleus: 13C
Resonance frequency: 75MHz
Measurement temperature: 25 ° C
Reference substance: Tetramethylsilane ( ²⁹ Si NMR)
Observation nucleus: 29Si
Resonance frequency: 60MHz
Measurement temperature: 25 ° C
Reference substance: Tetramethylsilane

^{1 H, 13} C and ²⁹ Si NMR measurement results are shown in FIGS. 3, 4 and 5 show.
Comparing with the result of the vinyl POSS of the fraction 2, it can be seen that the bisvinyl POSS of the fraction 3 has two vinyl groups.

"Synthesis of a silicon compound having a structural unit represented by the general formula (I), m = 1"
In the general formula (I), all the six R ¹ is isobutyl group, R ² to R ⁵ is a methyl group, to synthesize a compound having a structural unit is m = 1 in the following procedure. As the bisvinyl POSS, white crystals obtained from the above fraction 3 were used.
1.000 g of bisvinyl POSS was weighed in a 30 mL two-necked flask, and a Dimroth condenser was provided to create a nitrogen atmosphere. 6mL toluene by syringe, 1,1,3,3 (m = ¹ in the general formula ^{(III), R 2 ~R 5} = methyl group, Tokyo Chemical Industry Co., Ltd.) tetramethyldisiloxane 0.226 mL, platinum ( 0) 0.040 mL of -2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane complex solution was added. It was heated at 105-111 ° C. for 12 hours under reflux conditions. Then, the solvent was distilled off with an evaporator and dried under reduced pressure with an oil pump to obtain 1.09 g of a light brown transparent liquid. This light brown transparent liquid was separated by gel permeation chromatography (GPC) using "LC-forte / R" manufactured by YMC Co., Ltd. to obtain 0.19 g of a colorless transparent viscous liquid. The weight average molecular weight (Mw) was 96,900.

<Example 2>
"Synthesis of silicon compound represented by general formula (I), m = 2"
In the general formula (I), all the six R ¹ is isobutyl group, R ² to R ⁵ is a methyl group, to synthesize a compound having a structural unit is m = 2 in the following procedure. As the bisvinyl POSS, white crystals obtained from the above fraction 3 were used.
1.000 g of bisvinyl POSS was weighed in a 30 mL two-necked flask, and a Dimroth condenser was provided to create a nitrogen atmosphere. 6mL toluene by syringe, 1,1,3,3,5,5 (m = ² in the general formula ^{(III), R 2 ~R 5} = methyl group, Tokyo Chemical Industry Co., Ltd.) hexamethyl trisiloxane 0. 332 mL and 0.040 mL of platinum (0) -2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane complex solution were added. It was heated at 105-111 ° C. for 12 hours under reflux conditions. Then, the solvent was distilled off with an evaporator and dried under reduced pressure with an oil pump to obtain 1.15 g of a light brown transparent liquid. This light brown transparent liquid was separated by gel permeation chromatography (GPC) using "LC-forte / R" manufactured by YMC Co., Ltd. to obtain 0.76 g of a colorless and transparent viscous liquid. The weight average molecular weight (Mw) was 21,400.

<Comparative example 1>
As Comparative Example 1, methylphenylpolysiloxane (“KF-54” manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the heat-resistant silicone oil.
<Reference example>
As a reference example, bisvinyl POSS having 6 isobutyl groups (white crystals obtained from the above fraction 3) synthesized in Example 1 was used.

(Comparison of 5% weight loss temperature)
As a method for evaluating heat resistance, a 5% weight loss temperature during heating was compared. Using a differential thermal / thermogravimetric simultaneous measuring device "DHG-60H" manufactured by Shimadzu Corporation, measurement was performed under a nitrogen atmosphere at a heating rate of 10 L / min, and a 5% weight loss temperature was recorded. The results are shown in Table 3.
From Table 3, it can be seen that the silicon compounds of each example are superior in heat resistance as compared with Comparative Example 1 and Reference Example.

Claims (1)

A liquid silicon compound having a structural unit represented by the following general formula (I).

In (formula (I), R ¹ represents an alkyl group or an aryl group having 6 to 14 carbon atoms, having a straight-chain or branched-chain having 1 to 8 carbon atoms, six R ¹ are all a same even, it may be partially different, or ^{all, R 2, R 3, R} 4, and ^{R 5} are, each independently, an alkyl group having a linear or branched chain having 1 to 8 carbon atoms or carbon atoms, Represents an aryl group of 6 to 14, m represents an integer of 1 to 30, and in n structural units, m may be all the same, partially or all different, and n is a weight average molecular weight of 2. Represents a number that satisfies 000 to 1,000,000.)

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