JPH0357111B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a silanol compound,
More specifically, the present invention relates to an improved method for producing a silanol compound by hydrolyzing a disilazane compound.

[Conventional technology]

Silanol compounds, especially triorganosilanols, can be used as raw materials for polymerization initiators and terminal terminators for organosiloxane polymers, as raw materials for industrially useful triorganosiloxy group-containing compounds, or as raw materials for useful substances in a wide range of fields, including medical materials. It is an important substance that can become

The simplest method for obtaining silanol compounds is to hydrolyze the corresponding chlorosilane compound, but this method does not produce by-product hydrogen chloride even when carried out in the presence of a scavenger for by-product hydrogen chloride, such as triethylamine. acts as a catalyst, and the obtained silanol compound cannot be prevented from being further dehydrated and condensed to become a disiloxane compound, and as a result, the silanol compound can only be obtained at a considerably low yield. Therefore, in order to prevent further dehydration condensation of silanol compounds, various methods for producing silanol compounds have been devised. For example, a mixture of triorganochlorosilane and hexaorganodisilazane is prepared under conditions of pH 6 to 9. Method of hydrolysis (Special Publication No. 46-8690),
A method of simply hydrolyzing a mixture of triorganochlorosilane and hexaorganodisilazane without using a pH regulator, etc. (Japanese Patent Application Laid-Open No. 60-23385)
and a method of hydrolyzing triorganosiloxysilane in the presence of an alkali metal or alkaline earth metal carbonate (Japanese Patent Publication No. 51598/1983) has been proposed.

[Problem that the invention seeks to solve]

However, since the method and method produces a large amount of ammonium chloride as a by-product, it is necessary to use a large amount of water to prevent precipitation of the ammonium chloride, which has the disadvantage that the volumetric efficiency of the reaction is low. Since three or two types of main raw materials are used, industrial equipment requires a number of stock tanks and adjustment tanks for mixing depending on the raw materials, and the piping becomes complicated accordingly, requiring a large amount of equipment cost and requiring a large amount of equipment. It is also disadvantageous in terms of operation, such as having to make precise adjustments.

This method is an attempt to improve the method using triorganosiloxysilane as a starting material, and when triorganosiloxysilane is simply hydrolyzed, triorganosiloxysilane is catalyzed by the catalytic action of the by-product organic acid. Since dehydration condensation of silanol occurs, resulting in a decrease in yield, attempts were made to capture the organic acids produced as by-products by carrying out the hydrolysis reaction in the presence of alkali metal or alkaline earth metal carbonates. This is the way to do it. Therefore, this method has exactly the same equipment and operational problems as the above method due to the use of two types of main raw materials and the need to dissolve a large amount of by-product salt. -ing

[Means for solving problems]

The inventors of the present invention have conducted extensive research to solve the problems of the prior art and develop a method for producing silanol compounds using simple equipment and operations. When the reaction is carried out in the presence of an equivalent or more water-soluble carboxyl group-containing compound to the disilazane compound to neutralize the by-produced ammonia, a side reaction occurs in which the produced silanol compound is further dehydrated and condensed to become a disiloxane compound. We have discovered a new fact that is extremely unlikely to occur. Here, the term "equivalent to the disilazane compound" means that the equivalent ratio of the carboxyl group to ammonia for neutralizing ammonia produced by hydrolysis of the disilazane compound is 1. What is more surprising is that the hydrolysis reaction proceeds when the ratio is less than 1, even when the catalytic amount is sufficiently small, and that the ammonium salt of a carboxyl group-containing compound is water-soluble. The present invention was achieved by discovering that the hydrolysis reaction proceeds in the same way when using silanol compounds, and the side reaction of the produced silanol compound further dehydrating and condensing to form a disiloxane compound is extremely unlikely to occur.

(Here, R ¹ , R ² , and R ³ are hydrogen atoms, with 1 to 1 carbon atoms.
18 alkyl groups, aliphatic double bond-containing groups having 2 to 7 carbon atoms, halogenated alkyl groups having 1 to 10 carbon atoms,
Represents a group selected from phenyl groups. ) is hydrolyzed to produce a silanol represented by the general formula [B] R ¹ R ² R ³ Si-OH (where R ¹ , R ² and R ³ have the same meanings as above). When producing a compound, a water-soluble carboxyl group-containing compound or a water-soluble ammonium salt of a carboxyl group-containing compound (hereinafter referred to as
"Water-soluble carboxyl group-containing compounds" and "water-soluble ammonium salts of carboxyl group-containing compounds" are referred to as "carboxyl group-containing compounds, etc." ) is a method for producing a silanol compound, characterized in that the hydrolysis reaction is carried out in the presence of a silanol compound.

According to the present invention, a disilazane compound and water are charged into a reactor, and a carboxyl group-containing compound diluted with water is added dropwise to the reactor while stirring at room temperature, or a disilazane compound is added to an aqueous solution of a carboxyl group-containing compound, etc. A silanol compound can be easily produced by adding the disilazane compound, water, a carboxyl group-containing compound, etc. all at once and stirring at room temperature. The formation of a disiloxane compound, which is a condensation product, can be very effectively prevented.

The present invention will be explained in more detail below.

The disilazane compound to which the present invention is applied is a compound represented by general formula [A]. This is the general formula [C] (Here, R ¹ , R ² and R ³ have the same meanings as above.) It can be obtained by reacting a chlorosilane represented by the following formula with ammonia. R ¹ , R ² and R ³ are groups selected only on the condition that they are not easily mutated by ammonia as long as they can exist stably as a chlorosilane of the general formula [C], and the disilazane Compounds essentially include a very wide range of compounds.
A few examples are 1,1,3,3-tetramethyldisilazane, hexamethyldisilazane, hexaethyldisilazane, 1,3-dioctyl-1,1,3,3-tetramethyldisilazane. ,
1,3-dioctadecyl-1,1,3,3-tetramethyldisilazane, 1,3-divinyl-1,
1,3,3-tetramethyldisilazane, 1,3-
Divinyl-1,3-diphenyl-1,3-dimethyldisilazane, 1,3-bis(γ-methacryloxypropyl)-1,1,3,3-tetramethyldisilazane, 1,3-bis(chloromethyl )-1,
1,3,3-tetramethyldisilazane, 1,3,
-bis(trifluoropropyl)-1,1,3,
3-tetramethyldisilazane, 1,3-bis(heptadecafluorodecyl)-1,1,3,3-tetramethyldisilazane, 1,1,3,3-tetraphenyl-1,3-dimethyldisilazane, etc. is exemplified.

Next, the carboxyl group-containing compound used in the present invention may be any compound as long as it is water-soluble or can react with ammonia to form a water-soluble salt. However, examples include aliphatic monobasic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and isovaleric acid, oxalic acid, malonic acid, methylmalonic acid, succinic acid, and glutaric acid. acids, aliphatic dibasic acids such as adipic acid, pimelic acid, aliphatic double bond-containing carboxylic acids such as crotonic acid, isocrotonic acid, itaconic acid, glutaconic acid, citraconic acid, fumaric acid, maleic acid, glycolic acid, tartaric acid General examples include hydroxy group-containing carboxylic acids such as glyceric acid, citric acid, lactic acid, malic acid, oxaloacetic acid, and citramalic acid, aromatic carboxylic acids such as benzoic acid and salicylic acid, and halides of the above carboxylic acids. be able to. Further, similar effects can be obtained by using ammonium salts of these carboxylic acids.

The amount of these carboxyl group-containing compounds used is based on the equivalent ratio to the disilazane compound.
The range is preferably 0.005 to 2, more preferably 0.01 to 0.2. Although there is a description in the prior art (Japanese Patent Publication No. 61-51598) that the presence of a by-product organic acid causes dehydration condensation of the triorganosilanol produced, in the present invention, the disilazane compound There is no problem even if the carboxyl group-containing compound is used in an amount equal to or more than the amount of the carboxyl group-containing compound to create a state in which free carboxyl groups exist. However, using a carboxyl group-containing compound in such an excessive amount that the reaction system becomes a uniform layer, for example,
This is not preferable because the advantage of the present invention, which is that the water layer is only separated after the hydrolysis reaction, does not require a water washing step and, in some cases, can even omit a distillation step. However, industrially, there are cases where it is necessary to carry out the reaction in a short time in order to give priority to production efficiency, and considering such cases, it is appropriate to set the upper limit of the equivalent ratio to the disilazane compound to be about 2. Note that when using a water-soluble ammonium salt of a carboxyl group-containing compound, the reaction system will not form a uniform layer even if it is used in a large amount, but there are restrictions in terms of solubility in water, and in this case as well. It is appropriate that the upper limit of the equivalent ratio to the disilazane compound is about 2. Further, even if the amount of the carboxyl group-containing compound used is a catalytic amount, it is a feature of the present invention that the hydrolysis reaction proceeds while producing ammonia as a by-product. In this case, the generated ammonia gas can be discharged outside the reactor and then neutralized using inexpensive hydrochloric acid or sulfuric acid without affecting the reaction, or it can be used as is for other purposes. A very good effect can be obtained. However, if the amount of the carboxyl group-containing compound used is too low, the reaction will take a long time and will be impractical, so the equivalent ratio to the disilazane compound
It is desirable to set the lower limit to about 0.005.

In addition, the amount of water used in the hydrolysis reaction is stoichiometrically 2 times the mole of the disilazane compound, but it is 2 to 50 times the theoretical amount, preferably 3 to 20 times the theoretical amount. It is desirable to double the amount. If you want to give priority to the volumetric efficiency of the reactor, you can choose a lower value within this range, and if you want to omit purification steps such as water washing or distillation after the reaction, you can choose a higher value. The advantage of the present invention is that it can also be used. In a range lower than twice the theoretical amount, it is necessary to select fairly severe stirring conditions, and a value exceeding 50 times the theoretical amount is not practical even if volumetric efficiency does not have to be given priority.

Note that the reaction temperature may be room temperature. There is no need for special heating, and depending on the conditions, a considerable temperature increase due to reaction heat may be observed, but in this case also there is no need for special cooling. Therefore, the temperature range during the reaction is approximately 10 to 80°C when the reaction is allowed to take its course without heating or cooling.

There is no particular need to use a solvent, but if necessary for a reaction process using a silanol compound as a raw material, a poorly water-soluble or water-insoluble inert solvent such as an aliphatic hydrocarbon, aromatic hydrocarbon, or ether compound may be used. There is no problem in using it as a solvent, and in this case, after separating the aqueous layer, it can be supplied to the next step as it is. In addition, when the hydrolysis reaction is carried out using a catalytic amount of a carboxyl group-containing compound, etc., the salting out effect is small, so the generated silanol compound easily dissolves into the water layer, resulting in a large amount of loss. Particularly effective is the use of solvents.

Next, the mode of the reaction in the present invention will be explained using a reaction formula. The reaction in the present invention proceeds in the form of the following formulas and formulas in combination or in the form of each alone depending on the type and amount of the carboxyl group-containing compound used.

(Here, R ¹ , R ² and R ³ have the same meanings as above, R is a carboxyl group of a carboxyl group-containing compound or the like or a residue excluding an ammonium carboxylate group, and a is usually 1, 2 or 3 (a) When the carboxyl group-containing compound is used in an equivalent ratio of 1 or more to the disilazane compound, the entire amount of by-produced ammonia is neutralized, (b) The carboxyl group-containing compound is used as the disilazane compound When using an amount in which the equivalent ratio to the compound is less than 1, a combination of a reaction formula in which an ammonium salt of a carboxyl group-containing compound is produced as a by-product and a formula in which the ammonium salt acts as a catalyst and the reaction proceeds while producing ammonia as a by-product, and (c) a reaction in which the ammonium salt of a carboxyl group-containing compound acts as a catalyst and the reaction proceeds while producing ammonia as a by-product.

〔Example〕

The present invention will be explained below with reference to Examples, but the present invention is not limited thereto.

Example 1 161 g (1 mole) of hexamethyldisilazane and 180 g of water were charged in one reactor equipped with a stirrer, and 25 g of water was charged.
60 g of a wt % acetic acid aqueous solution was added dropwise to react (equivalent ratio of acetic acid to hexamethyldisilazane: 0.25).
The temperature of the reaction solution was raised from 20°C to 60°C due to exothermic heat.
After 1 hour, stop stirring and separate the upper organic layer.
Got 180g. When this was analyzed by gas chromatography, it was found to be trimethylsilanol. Its purity was approximately 100% by weight, and no hexamethyldisiloxane was detected.

Example 2 Using the same reactor as in Example 1, 161 g (1 mol) of hexamethyldisilazane and 180 g of water were charged, and 360 g of a 25% by weight acetic acid aqueous solution was added dropwise to react (equivalent of acetic acid to hexamethyldisilazane). ratio
1.5). The temperature of the reaction solution was raised from 20°C to 60°C due to exothermic heat. Stirring was stopped after 1 hour, and 180 g of the upper organic layer was obtained by liquid separation. When this was analyzed by gas chromatography, it was found to be trimethylsilanol. Its purity is almost 100% by weight
No hexamethyldisiloxane was detected.

Example 3 161 g (1 mol) of hexamethyldisilazane and 250 g of water were charged into a reactor equipped with a stirrer and a reflux condenser connected to a gas discharge pipe, and 24 g of a 25% by weight acetic acid aqueous solution was dropped into the reactor (hexamethyldisilazane). Equivalent ratio of acetic acid to methyldisilazane 0.10). As the reaction progressed, ammonia was generated in the form of bubbles, and during this time the temperature of the reaction solution rose from 20°C to 33°C due to heat generation. 5
After a period of time, stop stirring and separate the upper organic layer.
Obtained 178g. Analysis of this by gas chromatography revealed that the main component was trimethylsilanol. Its purity was greater than 99% by weight and less than 1% by weight of hexamethyldisiloxane.

Example 4 Using the same reactor as in Example 3, 161 g (1 mol) of hexamethyldisilazane and 250 g of water were charged, and 25 g of a 25% by weight ammonium acetate aqueous solution was added dropwise to react (ammonium acetate relative to hexamethyldisilazane). equivalent ratio of 0.081). As the reaction progressed, ammonia was generated in the form of bubbles, and during this time the temperature of the reaction solution rose from 20°C to 30°C due to heat generation. After 5 hours, stirring was stopped and 178g of the upper organic layer was separated.
I got it. Analysis of this by gas chromatography revealed that the main component was trimethylsilanol. Its purity was greater than 99% by weight and less than 1% by weight of hexamethyldisiloxane.

Example 5 Using the same reactor as in Example 3, 161 g (1 mol) of hexamethyldisilazane, 100 g of toluene, and water were added.
To this was added 2.5 g of a 25% by weight acetic acid aqueous solution and stirred for 10 hours (equivalent ratio of acetic acid to hexamethyldisilazane: 0.010). As the reaction progressed, ammonia was generated in the form of bubbles, and during this time the temperature of the reaction solution rose from 20°C to 30°C due to heat generation. After the separation, the upper organic layer was analyzed by gas chromatography, and it was found that the components after the solvent was removed contained 98% by weight of trimethylsilanol and 2% by weight of hexamethyldisiloxane. The percentage was calculated to be 97.5 mol%.

Comparative Example 1 Using the same reactor as in Example 3, 161 g (1 mol) of hexamethyldisilazane and 250 g of water were charged, and 25 g of a 25% by weight aqueous sodium acetate solution was added thereto.
The mixture was stirred for 20 hours (equivalent ratio of sodium acetate to hexamethyldisilazane: 0.076). As the reaction progressed, ammonia was generated in the form of bubbles, but during this time the temperature of the reaction solution was 20°C, with almost no increase in temperature observed. 173g of upper organic layer by liquid separation
When analyzed by gas chromatography, it was found that 64% by weight of trimethylsilanol was present and a large amount of hexamethyldisiloxane was produced as a by-product.

Example 6 Using the same reactor as in Example 3, 161 g (1 mol) of hexamethyldisilazane and 250 g of water were charged, and 30 g of a 25% by weight citric acid aqueous solution was added thereto and stirred for 5 hours (hexamethyldisilazane). equivalent ratio of citric acid to 0.12). As the reaction progressed, ammonia was generated in the form of bubbles, and during this time the temperature of the reaction solution rose from 20°C to 26°C due to heat generation. 179g of the upper organic layer was obtained by liquid separation, and analysis of this by gas chromatography revealed that trimethylsilanol was detected.
It was found that 99% by weight or more of hexamethyldisiloxane was present and a trace amount of hexamethyldisiloxane was present.

Comparative Example 2 Using the same reactor as in Example 3, 161 g (1 mol) of hexamethyldisilazane and 250 g of water were charged, and 40 g of a 25% by weight aqueous sodium citrate solution was added thereto and stirred for 24 hours (hexamethyldisilazane). Equivalent ratio of sodium citrate to silazane 0.12). During this period, the temperature of the reaction solution hardly increased by 20°C, and no ammonia was generated. Furthermore, when the upper organic layer after separation was analyzed by gas chromatography, it was found that hexamethyldisilazane was hardly hydrolyzed.

Example 7 Using the same reactor as in Example 3, 161 g (1 mol) of hexamethyldisilazane and 250 g of water were charged, and 10 g of maleic acid was added thereto and stirred for 5 hours (the ratio of maleic acid to hexamethyldisilazane was Equivalence ratio 0.17). As the reaction progressed, ammonia was generated in the form of bubbles, and during this time the temperature of the reaction solution rose from 20°C to 28°C due to heat generation. The upper organic layer is separated by liquid separation.
180g was obtained and analyzed by gas chromatography, and it was found that trimethylsilanol was 99% by weight.
1% by weight of hexamethyldisiloxane
It was found that there are less than

Example 8 Using the same reactor as in Example 3, 161 g (1 mol) of hexamethyldisilazane, 100 g of toluene, and water were added.
To this was added 5 g of 25% by weight acetic acid aqueous solution and stirred for 10 hours (equivalent ratio of acetic acid to hexamethyldisilazane: 0.021). As the reaction progressed, ammonia was generated in the form of bubbles, and during this time the temperature of the reaction solution rose from 20°C to 32°C due to exothermic heat. After separation, the upper organic layer was analyzed by gas chromatography, and it was found that the components after removing the solvent contained 97% by weight of trimethylsilanol and 3% by weight of hexamethyldisiloxane, and the yield was
It was calculated to be 96.5 mol%.

Example 9 Equipped with a reflux condenser connected to a stirrer and a gas discharge pipe
1,3-divinyl-1,1,3- in a 200ml reactor
25 g (0.135 mol) of tetramethyldisilazane and 25 g of water
2 g of 25% by weight acetic acid aqueous solution was added dropwise to this, and the reaction was continued with stirring (1,3-divinyl-
The equivalent ratio of acetic acid to 1,1,3,3-tetramethyldisilazane is 0.062). As the reaction progresses, ammonia is generated as bubbles, and during this time the reaction solution is kept at 20℃.
The temperature ranged between 30℃ and 30℃. After 5 hours, stirring was stopped, and the upper organic layer was analyzed by gas chromatography, and it was found that 99% by weight of vinyldimethylsilanol was present, and 1,3-divinyl-1,1,
1% by weight of 3,3-tetramethyldisiloxane was found to be present.

Example 10 Using the same reactor as in Example 9, 1,3-diphenyl-1,1,3,3-tetramethyldisilazane
25 g (0.0876 mol) and 25 g of water were charged, and 2 g of a 25 wt% acetic acid aqueous solution was added dropwise thereto, followed by a reaction with continued stirring (acetic acid relative to 1,3-diphenyl-1,1,3,3-tetramethyldisilazane). equivalence ratio of
0.095). As the reaction progressed, ammonia was generated in the form of bubbles, and during this time the temperature of the reaction solution remained between 20°C and 30°C. After 5 hours, stirring was stopped and the upper organic layer was analyzed by gas chromatography, and it was found that 99% by weight or more of phenyldimethylsilanol was present, and 1,3-diphenyl-1,1,3,3-
Less than 1% by weight of tetramethyldisiloxane was found to be present.

Example 11 Using the same reactor as in Example 9, 25 g (0.109 mol) of 1,3-bis(chloromethyl)-1,1,3,3-tetramethyldisilazane and 25 g of water were charged, and citric acid was added to this. 1 g of ammonium was added to react (1,3-bis(chloromethyl)-1,1,
The equivalent ratio of ammonium citrate to 3,3-tetramethyldisilazane is 0.057). As the reaction progressed, ammonia was generated in the form of bubbles, and during this time the temperature of the reaction solution remained between 20°C and 30°C. After 5 hours, stirring was stopped, and the upper organic layer was analyzed by gas chromatography, and it was found that 98% by weight of chloromethyldimethylsilanol was present, and 1,3-bis(chloromethyl)-1,1,3,3-tetra It was found that 2% by weight of methyldisiloxane was present.

〔Effect of the invention〕

According to the present invention, silanol compounds can be produced using simple equipment and operations, and regardless of whether priority is given to reaction time, volumetric efficiency, or purification process, it is possible to simply produce a silanol compound by simply combining a carboxyl group-containing compound and water. The purpose can be achieved simply by adjusting the amount of . This is a remarkable effect of the fact that when a carboxyl group-containing compound or the like is used, the disilazane compound can be hydrolyzed even in a catalytic amount. Another great advantage is that by-product ammonia can be neutralized outside the system without affecting the reaction. Furthermore, according to the present invention, there is little or very little by-product of the disiloxane compound, so it can be used as a raw material for the next step without any purification such as washing with water or distillation.

Claims (1)

[Claims] 1 General formula [A] (Here, R ¹ , R ² , and R ³ are hydrogen atoms, with 1 to 1 carbon atoms.
18 alkyl groups, aliphatic double bond-containing groups having 2 to 7 carbon atoms, halogenated alkyl groups having 1 to 10 carbon atoms,
Represents a group selected from phenyl groups. ) is hydrolyzed to produce a silanol represented by the general formula [B] R ¹ R ² R ³ Si-OH (where R ¹ , R ² and R ³ have the same meanings as above). When producing a compound, the hydrolysis reaction is carried out in the presence of a water-soluble carboxyl group-containing compound or a water-soluble ammonium salt of a carboxyl group-containing compound (hereinafter referred to as "carboxyl group-containing compound, etc."). A method for producing a silanol compound, characterized by: 2. The method for producing a silanol compound according to claim 1, wherein the amount of the carboxyl group-containing compound, etc. used is in an equivalent ratio of 0.005 to 2 with respect to the disilazane compound. 3. The method for producing a silanol compound according to claim 1, wherein the amount of ammonium salt such as the carboxyl group-containing compound used is in an equivalent ratio of 0.01 to 0.2 with respect to the disilazane compound.