JP2001048891A - Production method for tetraol of cyclic tetramer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method capable of efficiently synthesizing 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol or their substitution product by using an alkoxysilane or hydroxysilane having no corrosivity and easy to handle as raw materials. SOLUTION: In production of the 1,3,5,7-tetraphenylcyclotetra-siloxane-1,3,5,7- tetraol expressed by formula I (R1 is a (substituted) phenyl group) or their substitution product a silicone compound expressed by formula II: R1-Si(OR2)3 (R1 is a (substituted) phenyl; and R2 is H or a univalent 1-18C linear or branched hydrocarbon) is used as raw material and the reaction is carried out in an acidic aqueous solution and includes collection of the product precipitation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to 1,3,5,7-
Tetraphenylcyclotetrasiloxane-1,3,5
The present invention relates to a method for producing 7-tetraol or a substituted product thereof.

[0002]

2. Description of the Related Art Recent studies by the present inventor have shown that 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol or a substituted product thereof. It has been elucidated that a cyclic tetramer tetraol (hereinafter, referred to as a cyclic tetramer) is condensed in a solvent under mild conditions to form a so-called ladder polymer having a ladder-like structure (Japanese Patent Application No. 11-53475). The ladder polymer synthesized in this way has excellent heat resistance and electrical insulation properties, and exhibits properties particularly excellent in coating properties and crack resistance, so that it can be applied to semiconductor insulating materials and the like.

In addition, the present cyclic tetramer tetraol can be applied to various fields as a phenylsiloxane oligomer whose structure is completely controlled.

[0004] However, the synthesis of this cyclic tetramer tetraol has been reported by several researchers, but it hydrolyzes phenyltrichlorosilane in water and makes it hydrolyzed at low temperature for a long time. However, there is a problem in that chlorosilane having corrosiveness is used as a raw material and that the synthesis efficiency is low. That is, Brown et al. Am. Ch
em. Soc. 87, 4317 (1965), a solution prepared by dissolving phenyltrichlorosilane in acetone is added to a large amount of ice water with stirring, and the mixture is allowed to stand at 0 ° C. for 2 days to form crystals. By forming, filtering, washing with carbon disulfide and drying,
That is, tetraol was obtained with a yield of 52%. However, in this method, since phenyltrichlorosilane generates a violent heat when reacting with water, there is a problem that the reaction temperature needs to be controlled and a long time of 2 days is required. 140 mL of acetone and 3100 g of ice water are required to react phenyltrichlorosilane. Investigations by the present inventors have revealed that when the reaction is carried out at a high concentration by reducing the amount of ice water, the yield of tetraol is greatly reduced. Having.

Kimura et al. Have also studied hydrolysis of phenyltrichlorosilane, and the Pol
ymer Journal, vol. 30, 234 (1998)
According to 1988), 6.3 g of phenyltrichlorosilane was hydrolyzed at 0 ° C. using 163 mL of toluene and 815 mL of water, neutralized with sodium bicarbonate, and further kept at 0 ° C. overnight to obtain a weight average. A solid having a molecular weight of 540 is obtained. In this case, the structure of the product has not been clarified, it is unknown whether or not cyclic tetramer tetraol has been formed, and even if it has been formed, the pot yield is still low, and the productivity is low. However, the drawback of low is not eliminated.

In view of the above, instead of chlorosilane,
Development of a method for synthesizing cyclic tetramer tetraol from alkoxysilane or hydroxysilane which has no corrosive property by itself has been awaited. However, conventionally, such a method was not known.

[0007]

DISCLOSURE OF THE INVENTION In view of the above-mentioned circumstances, the present inventor has proposed a cyclic tetramer made from alkoxysilane or hydroxysilane which is non-corrosive and easy to handle. An efficient synthesis method with high productivity of oars was studied.

As a result, the following general formula (2) R ¹ —Si (OR ² ) ₃ (2) (wherein R ¹ represents a substituted or unsubstituted phenyl group, and R ² represents a hydrogen atom or a carbon atom When an organosilicon compound represented by 1 to 18 linear or branched monovalent hydrocarbon groups is hydrolyzed in an acidic aqueous solution, oligomers produced by hydrolytic condensation are separated as the condensation proceeds. When the solution is cooled and left to the extent that the solution does not freeze, the deposited liquid gradually solidifies, and colorless and slightly viscous crystals are formed in water. After standing under cooling, the resulting precipitate was separated and analyzed. This solid was found to be cyclic tetramer tetraol, that is, 1,3,5 represented by the following general formula (1). It was found that 7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol or a substituted product thereof was a main component. The precipitate is dispersed in a solvent in which the cyclic tetramer tetraol (1) such as benzene, toluene, and xylene is insoluble, and the soluble component in the precipitate is dissolved in the solvent to recover an insoluble solid. By doing
It has been found that a pure cyclic tetramer tetraol (1) can be efficiently obtained, and the present invention has been accomplished.

[0009]

Embedded image (In the formula, R ¹ represents a substituted or unsubstituted phenyl group.)

Therefore, the present invention relates to the production of 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol represented by the above formula (1) or a substituted product thereof. The following general formula (2): R ¹ —Si (OR ² ) ₃ (2) (wherein, R ¹ represents a substituted or unsubstituted phenyl group, and R ² represents a hydrogen atom or a straight-chain having 1 to 18 carbon atoms. Using an organosilicon compound represented by a chain or branched monovalent hydrocarbon group) as a raw material, reacting the same in an acidic aqueous solution, and collecting a formed precipitate. Provided is a method for producing 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol or a substituted product thereof. In this case, after drying the collected precipitate, it is dispersed in a solvent in which 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol or a substituted product thereof is insoluble, It is effective to recover the insoluble solid in the solvent.

Hereinafter, the present invention will be described in more detail.
The method for producing 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol of the above formula (1) or a substituted product thereof according to the present invention is represented by the following general formula (2): ^The organic silicon compound represented by ^1- Si (OR ² ) ₃ (2) is hydrolyzed and condensed in an acidic aqueous solution.

Here, in the formula (2), R ¹ is a substituted or unsubstituted phenyl group. In this case, the substituent of the substituted phenyl group includes a halogen atom, a nitro group, an amino group, a monovalent aliphatic group. Group, an aromatic hydrocarbon group, and an alkoxy group.

Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom.

Examples of the monovalent aliphatic hydrocarbon group include an alkyl group, an alkenyl group and an alkynyl group, which have 1 to 18 carbon atoms, particularly preferably 1 to 6 carbon atoms. Methyl group, ethyl group, 1-propyl group, 2-propyl group, 1-butyl group, 2-butyl group,
tert-butyl group, 1-heptyl group, 1-hexyl group, vinyl group, allyl group, 1-propen-2-yl group,
An ethynyl group and a 1-propen-3-yl group are exemplified.

As the aromatic hydrocarbon group, a phenyl group,
Naphthyl groups are mentioned by way of example, these being the methyl group,
It may be substituted with an ethyl group or a halogen atom.

The alkoxy group has 1 to 18 carbon atoms,
Particularly preferred is an alkoxy group having 1 to 4 carbon atoms. Examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and tert.
-Butoxy group.

R ² is a hydrogen atom or a carbon atom having 1 to 18 carbon atoms.
A linear or branched monovalent hydrocarbon group, preferably an alkyl group, particularly preferably an alkyl group having 1 to 6 carbon atoms, a methyl group, an ethyl group, an n-propyl group, an iso group.
-Propyl group, n-butyl group, tert-butyl group, n
-Hexyl group and the like.

Specifically, the organosilicon compound includes:
Phenylsilanetriol, 4-vinylphenylsilanetriol, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltri-iso-propoxysilane, phenyltri-n-butoxysilane, phenyltri-iso-
Examples include butoxysilane, phenyltri-n-hexyloxysilane, 4-vinylphenyltrimethoxysilane, 4-vinylphenyltriethoxysilane, and the like.

Next, the acid used in the acidic aqueous solution is not particularly limited as long as it is water-soluble, but acetic acid, formic acid, oxalic acid, malonic acid, maleic acid, fumaric acid, adipic acid, trifluoro acid and the like. Carboxylic acids such as acetic acid, methanesulfonic acid, benzenesulfonic acid, para
-Sulfonic acids such as toluenesulfonic acid, trifluoromethanesulfonic acid, hydrochloric acid, hydrobromic acid, hydroiodic acid,
Examples thereof include inorganic acids such as sulfuric acid and nitric acid. Among these, it is desirable to use an acid which is itself volatile such as hydrochloric acid or hydrobromic acid, because the acid can be easily removed by vacuum drying.

The concentration of the acid is not particularly limited as long as it is a concentration sufficient for hydrolysis and condensation to proceed, but is usually 0.001 to 2.0 mol / L, more preferably 0.2 to 2.0 mol / L. １．０1.0 mol / L.

The concentration of the organosilicon compound in the acidic aqueous solution can be in the range of 1 to 50% by weight, but it is particularly preferable to carry out the concentration in the range of 2 to 10% by weight.

For the purpose of controlling the formation of a precipitate, an organic solvent which is soluble in water can be added. Examples of such a solvent include methanol, ethanol and isomer.
Examples thereof include o-propyl alcohol, tert-butanol, acetone, methyl ethyl ketone, methyl-iso-butyl ketone, acetonitrile, tetrahydrofuran, and the like, and the amount thereof is in the range of 1 to 50% by weight in the acidic aqueous solution.

The reaction can be carried out at a temperature within a range where the aqueous solution does not freeze, and is carried out at room temperature to -5 ° C. Normally, at room temperature, the organosilicon compound reacts with the acidic aqueous solution, and the hydrolysis proceeds to form a uniform solution.
Cool and promote the formation of a precipitate. During this time, a reaction time of about 30 minutes is required. Subsequent aging is -5 to 10 ° C
In the range of 5 to 100 hours, usually 10 to 24 hours.

The resulting precipitate can be converted to an amorphous solid by removing the supernatant aqueous solution by decantation, washing with water, and vacuum drying.

This amorphous material is composed of GPC and ²⁹ Si-
NMR measurement and analysis revealed that the mixture was a mixture containing a cyclic tetramer tetraol. Usually, the purity is 10 to 50%, but the present invention is not particularly limited by the purity of the product.

The most efficient method for separating the cyclic tetramer tetraol from this mixture is to utilize the difference in solubility with impurities, and to obtain a solid obtained by drying the cyclic tetramer such as benzene, toluene or xylene. When a solvent in which the tetramer tetraol is insoluble is added and stirred, the cyclic tetramer tetraol is kept in a crystalline state because it is insoluble in these solvents, but other components are dissolved. Thus, pure material can be isolated by filtering it and drying the residue in vacuo.

The cyclic tetramer tetraol thus obtained is represented by the following general formula (1), which can be further purified by recrystallization. It has a purity of at least 90% or more, and can be said to be sufficiently pure for ordinary use.

[0028]

Embedded image (In the formula, R ¹ represents a substituted or unsubstituted phenyl group.)

The cyclic tetramer tetraol represented by the general formula (1) is a so-called highly structurally controlled, so-called, highly heat-resistant, electrically insulating, and particularly excellent in coating property and crack resistance. It is useful as a raw material for producing a silicone resin having a ladder-type structure, or as an additive to a heat- or room-temperature-curable resin.

[0030]

The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[Example 1] 7.7 L of pure water, 36 of acetone
252 mL of concentrated hydrochloric acid was added to the 3 mL of the mixture, and the mixture was stirred while being cooled with ice, and heated to 5 ° C. When 400 g of phenyltrimethoxysilane was added thereto and stirring was continued, the cloudy solution became a homogeneous solution after several minutes, and became cloudy again after about 10 minutes. When the mixture was further kept under these conditions for 15 hours, a viscous precipitate was formed on the vessel wall, and the aqueous layer became a slightly cloudy suspension. After removing the supernatant, the precipitate was washed with pure water and dried under vacuum to obtain 252.2 g of an amorphous solid. 1 L of benzene was added to this solid, and the mixture was stirred at room temperature for 3 hours. Thereafter, the insoluble solid was recovered by filtration and dried under vacuum to obtain 85.83 g of a colorless crystalline powder (35% yield).
was gotten. The melting point of this crystal was 181 ° C. Its GPC spectrum (FIG. 1) and IR spectrum (FIG. 2)
The analysis confirmed that the crystal was 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol.

Example 2 Using 125.5 g of phenyltriethoxysilane, a reaction was carried out in exactly the same manner as in Example 1. As a result, 55.3 g of an amorphous solid was obtained. This was dissolved in 400 mL of benzene, and
After stirring for an hour, the insoluble solid was collected by filtration and dried under vacuum to obtain 25.3 g of 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol (39.7% yield). )was gotten.

Example 3 A reaction was carried out in exactly the same manner as in Example 1 except that 134.9 g of phenyltri-iso-propoxysilane was used. As a result, the amorphous solid 4
9.8 g were obtained. This was dissolved in 400 mL of benzene, stirred at room temperature for 2 hours, and the insoluble solid was collected by filtration and dried in vacuo to give 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetrafluorosiloxane. All 1
8.0 g (30.8% yield) was obtained.

Example 4 Using 213.3 g of phenyltri-n-hexyloxysilane, the reaction was carried out in exactly the same manner as in Example 1. As a result, the amorphous solid 5
0.9 g was obtained. This was dissolved in 400 mL of benzene, stirred at room temperature for 2 hours, and the insoluble solid was collected by filtration and dried in vacuo to give 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetrafluorosiloxane. All 1
2.6 g (19.8% yield) was obtained.

Example 5 Using 117.1 g of 4-vinylphenyltrimethoxysilane, the reaction was carried out in exactly the same manner as in Example 1. As a result, the amorphous solid 6
2.1 g were obtained. This was dissolved in 400 mL of benzene, stirred at room temperature for 2 hours, and the insoluble solid was collected by filtration and dried in vacuo to give 1,3,5,7-tetra (4-vinylphenyl) cyclotetrasiloxane-1,3,3. 5,7-
31.0 g (19.8% yield) of tetraol was obtained.

[0036]

According to the present invention, 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7 is prepared from alkoxysilane or hydroxysilane which is non-corrosive and easy to handle. -A tetraol or a substituted product thereof can be efficiently synthesized.

[Brief description of the drawings]

FIG. 1 is a GPC spectrum of a cyclic siloxane of Example 1.

FIG. 2 is an IR spectrum of the cyclic siloxane of Example 1.

Claims (3)

[Claims] [Claim 1] The following general formula (1) (Wherein, R ¹ represents a substituted or unsubstituted phenyl group) represented by 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol or its substitution In producing the compound, the following general formula (2): R ¹ —Si (OR ² ) ₃ (2) (wherein, R ¹ represents a substituted or unsubstituted phenyl group, and R ² represents a hydrogen atom or carbon number. A linear or branched monovalent hydrocarbon group of 1 to 18) as a raw material, reacting it in an acidic aqueous solution, and collecting a formed precipitate. A method for producing 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol or a substituted product thereof, characterized by the following: 2. The recovered precipitate is dried and then dispersed in a solvent in which 1,3,5,7-tetraphenylcyclotetrasiloxane-1,3,5,7-tetraol or a substituted product thereof is insoluble. 2. The method according to claim 1, further comprising the step of recovering the insoluble solid in the solvent. 3. The method according to claim 2, wherein the solvent is benzene, toluene or xylene.