JP2001122965A - Polysilsequioxane compound containing hydrosilyl group, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hyrosilyl group containing polysilsesquioxane compound having a controlled mol.wt. and a controlled H equivalent, and to provide a method for producing the same, while although trials for producing the hydrosilyl group-having polysilsesquioxane as a raw material for incorporating the polysilsesquioxane into an organic resin have been carried out, the results have had defects such as largely restricted reaction conditions, the production of only unstable products and the absence of a description related to the control of the H equivalent. SOLUTION: The polysilsesquioxane compound, characterized by reacting a mixture of an organotrichlorosilane with an organomonochlorosilane in an amount of n-fold moles [(n) is a value in the range of 0.1 to 2.0] that of the organotrichlorosilane with water in an amount of (3+n)/2-fold moles that of the organotrichlorosilane to produce the polysilsesquioxane compound, and the method for producing the polysilsesquioxane compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hydrosilyl group-containing polysilsesquioxane compound and a method for producing the same.

[0002]

2. Description of the Related Art One silicon atom has 1.5 oxygen atoms per silicon atom.
The polyorganosiloxane composed of such a ratio is generally called polysilsesquioxane, and utilizes its excellent heat resistance and weather resistance to be used as a material such as a semiconductor insulating protective film, a flame retardant, or a paint additive. Use is expected. Attempts have been made to introduce functional groups for the purpose of incorporating these polysilsesquioxanes into organic resins. In particular, polysilsesquioxane having a hydrosilyl group is useful as an intermediate material that can easily introduce various functional groups by a hydrosilylation reaction with an olefin.

JP-A-60-86017 discloses a method for producing polysilsesquioxane into which a hydrosilyl group has been introduced by hydrolytic condensation of trichlorosilane. According to this method, hydrosilyl group-containing polysilsesquioxane is obtained by dissolving trichlorosilane in a solvent saturated with water and bubbling an inert gas accompanied with water vapor. When added and separated, the reaction conditions are severely restricted, such as causing a dehydrogenation reaction to cause gelation and a long reaction time, and there is no mention of controlling the H equivalent.

[0004] JP-A-4-353521, JP-A-1
0-237173 or JP-A-10-23717
In Japanese Patent Publication No. 4 (1994), a polysilsesquioxane is produced by hydrolytic condensation of organotrichlorosilane, and a silanol group remaining in the molecule is silylated with disilazane or monochlorosilane to introduce a hydrosilyl group. A method for doing so is disclosed. However, in such a method, it is practically impossible to arbitrarily control the remaining silanol groups, it is difficult to control the H equivalent, and since the silanol groups themselves are very unstable, There is a problem that the condensation reaction proceeds between them and the molecular weight changes with time.

[0005]

It is an important technique to easily introduce a hydrosilyl group into polysilsesquioxane, and to arbitrarily control the molecular weight and the H equivalent which influence the performance of polysilsesquioxane. Therefore, establishment of such a polysilsesquioxane and a method for producing the same are desired. The object of the present invention is to determine the molecular weight and H
An object of the present invention is to provide a controlled equivalent amount of a hydrosilyl group-containing polysilsesquioxane compound and a method for producing the same.

[0006]

Means for Solving the Problems The present inventors have determined the amount of a compound having active hydrogen in a molecule such as organotrichlorosilane, organomonochlorosilane, and alcohol used as a raw material, and the hydrolysis of SiCl groups in the system. The inventors have found that the molecular weight and the H equivalent of the obtained polysilsesquioxane can be arbitrarily controlled by controlling the amount of water necessary for decomposition and condensation, and have completed the present invention.

That is, the present invention relates to a method for preparing a mixture of an organotrichlorosilane represented by the following formula (1) and an n-fold molar amount of the organotrichlorosilane represented by the formula (2): (3 + n) / 2 times the molar amount of water, characterized by having a repeating unit represented by the formula (3) in the molecule, having a number average molecular weight of 500 to 5000, and an H equivalent of 100 to 500. 1
500 polysilsesquioxane compounds and a method for producing the same. R ¹ SiCl ₃ (1) R ² R ³ HSiCl (2) R ¹ Si (R ² R ³ HSiO) _n O _{(3-n) / 2} (3) (where R ¹ , R ² and R ³ are , Each independently,
A linear, branched or cyclic saturated hydrocarbon group having 1 to 18 carbon atoms, a linear, branched or cyclic unsaturated hydrocarbon group having 2 to 6 carbon atoms, or an aryl group having 10 or less carbon atoms. And n is a value in the range of 0.1 to 2.0. )

Further, the present invention also provides a compound having a hydrolyzable group introduced therein and a method for producing the compound by reacting the compound with an active hydrogen compound in the molecule before conducting the hydrolysis condensation reaction. That is, a mixture of an organotrichlorosilane represented by the following formula (1) and an n-fold molar amount of an organomonochlorosilane represented by the formula (2) is added to a mixture of an organotrichlorosilane having an m-fold molar amount of the organotrichlorosilane (4). After reacting at least one of the compounds represented by the formula (5), by reacting (3 + nm) / 2 times the molar amount of water with organotrichlorosilane. Having a repeating unit represented by the formula, a number average molecular weight of 500 to 5000, and an H equivalent of 100 to 5
000 polysilsesquioxane compounds and a method for producing the same.

R ¹ SiCl ₃ (1) R ² R ³ HSiCl (2) R ⁴ OH (4) R ¹ Si (R ² R ³ HSiO) _n (R ⁴ O) _m O _{(3-nm) / 2} ( 5) (wherein, R ¹ , R ² and R ³ are each independently a linear, branched or cyclic saturated hydrocarbon group having 1 to 18 carbon atoms, a linear chain having 2 to 6 carbon atoms, A branched or cyclic unsaturated hydrocarbon group or an aryl group having 10 or less carbon atoms, and R ⁴ is a linear or branched saturated hydrocarbon group having 1 to ⁴ carbon atoms, CH ₃ CO group, CH ₂ ＣＨCHCO group or CH ₂ ＣCCH ₃ CO group, m and n each independently represent a value in the range of 0.05 to 2.0,
n is a value in the range of 0.1 to 3.0. )

Hereinafter, the present invention will be described in more detail. In order to produce the hydrosilyl group-containing polysilsesquioxane of the present invention, first, an organotrichlorosilane represented by the above formula (1) and an n-fold molar amount of the above formula (2)
Is mixed. At this time, n is preferably in the range of 0.1 to 2.0. Here, R ¹ and R ² in the above formula (1) or (2)
And R ³ each independently represent a linear, branched or cyclic saturated hydrocarbon group having 1 to 18 carbon atoms, 2 carbon atoms,
To 6, a linear, branched or cyclic unsaturated hydrocarbon group or an aryl group having 10 or less carbon atoms. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, and an i-
Propyl, n-butyl, i-butyl, s-butyl, t-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, Vinyl group, allyl group,
Examples include a cyclopentyl group, a cyclohexyl group, a benzyl group, a phenethyl group, a phenyl group, a toluyl group, a xylyl group, and an ethylphenyl group.

Specific examples of the organotrichlorosilane include methyltrichlorosilane, ethyltrichlorosilane, n-propyltrichlorosilane, n-butyltrichlorosilane, i-butyltrichlorosilane, t-butyltrichlorosilane, pentyltrichlorosilane, hexyltrichlorosilane. Chlorosilane, n-heptyltrichlorosilane,
Examples thereof include n-octyltrichlorosilane, i-octyltrichlorosilane, nonyltrichlorosilane, n-decyltrichlorosilane, vinyltrichlorosilane, allyltrichlorosilane, phenyltrichlorosilane, and cyclohexyltrichlorosilane. Further, specific examples of the organomonochlorosilane include dimethylchlorosilane,
Examples thereof include diethylchlorosilane, ethylmethylchlorosilane, diisopropylchlorosilane, diphenylchlorosilane and the like.

The chlorosilane mixture may be diluted with a solvent. In this case, any solvent can be used as long as it is inert to chlorosilane. Usually, aromatic solvents such as toluene and xylene are used. Solvents, aliphatic hydrocarbon solvents such as hexane, and ethers such as diethyl ether and tetrahydrofuran are used. Subsequently, a predetermined amount of water is added to the chlorosilane mixture to carry out a hydrolytic condensation reaction.In the present invention, the amount of water to be added is adjusted to a necessary and sufficient amount for hydrolytic condensation of SiCl groups. It is characterized in that the molar ratio to organotrichlorosilane is (3 + n) / 2 times,
As shown in the following typical reaction formula, a polysilsesquioxane having a target structural formula is obtained.

[0013]

Embedded image

When the amount of water is (3) of the organotrichlorosilane
+ N) / 2 times less than the molar amount, SiCl groups remain in the obtained polysilsesquioxane, causing corrosive hydrochloric acid gas to be generated. Many silanol groups are generated,
Poor storage stability. The water to be added can be arbitrarily diluted using a solvent. The solvent that can be used at this time can be arbitrarily selected as long as it is inert to chlorosilane, but a solvent having affinity for both chlorosilane and water is preferable, and ethers such as tetrahydrofuran and dioxane; acetone; methyl ethyl ketone; Of these, ketones can be suitably used, and among them, tetrahydrofuran is more preferable.

The method of adding water is preferably such that the generation of a large amount of hydrochloric acid due to a rapid hydrolysis reaction is prevented, and diffusion of water into the system is not rate-determined.
It is preferable to add in about 4 hours. Similarly, the reaction temperature is preferably set to 15 ° C. or lower for the purpose of preventing rapid generation of hydrochloric acid. After completion of the addition, aging is preferably performed for about one hour to terminate the hydrolysis-condensation reaction. In this case, the reaction temperature may be increased to accelerate the hydrolysis-condensation reaction.

It is also possible to introduce a hydrolyzable substituent by reacting a compound having active hydrogen in the molecule before adding water to the chlorosilane mixture. That is, a mixture of an organotrichlorosilane represented by the formula (1) and an n-fold molar amount of the organomonochlorosilane represented by the formula (2) is added to a mixture of the organotrichlorosilane represented by the formula (4) having an m-fold molar amount of the organotrichlorosilane. After reacting at least one of the compounds shown, by adding (3 + nm) / 2 times the molar amount of water of organotrichlorosilane and subjecting to hydrolysis and condensation, the reaction is represented by the following typical reaction formula. Then, a polysilsesquioxane having a desired structural formula can be obtained. At this time, n and m are each in the range of 0.05 to 2.0, and n + m is 0.1 to
It is preferable to be within the range of 3.0.

[0017]

Embedded image(Where X is -SiR^TwoR^ThreeH group or -R^FourIn the base
And the ratio is -SiR^TwoR ^ThreeH: -R^Four= N: m
You. )

The condensation reaction of a compound having an active hydrogen in the molecule proceeds rapidly at an arbitrary temperature, so that there is no need to pay particular attention to the reaction temperature. The temperature is preferably set to 10 ° C. or less in consideration of safety. No special consideration is required for the rate of addition, but it is preferable to add over 0.2 to 2 hours for the above reasons. Subsequently, water is added to carry out a hydrolysis-condensation reaction.
The amount is (3 + nm) / 2 times the molar amount of organotrichlorosilane, which is a necessary and sufficient amount for hydrolytic condensation of Cl groups. The introduced hydrolyzable group is retained in the molecule due to the difference in hydrolysis rate, and the SiCl group having higher reactivity with water is selectively hydrolyzed.

Specific examples of R ^{4 in} the above formula (4) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, t-butyl group, CH ₃ CO group, CH ₂ ＣＨCHCO group,
CH ₂ ＣCCH ₃ CO groups. That is, specific examples of the compound having active hydrogen in the molecule include alcohols such as methanol, ethanol, 1-propanol, 2-propanol and 1-butanol, or acetic acid.
Examples thereof include carboxylic acids such as acrylic acid and methacrylic acid. An alkoxysilyl group can be introduced by reacting an alcohol, and a carboxysilyl group can be introduced by reacting a carboxylic acid.

After aging, it is preferable to add a basic compound to accelerate the hydrolysis and condensation reactions and to capture the hydrogen chloride present in the system. The basic compound is ammonia, a primary to tertiary amine, a metal hydroxide, and the like. Specific examples thereof include, in addition to ammonia, methylamine, ethylamine, ethylenediamine, dimethylamine, diethylamine, trimethylamine, triethylamine, lithium hydroxide, and water. Examples include sodium oxide, potassium hydroxide, calcium hydroxide, barium hydroxide and the like. Further, it is preferable to add water or a compound having active hydrogen in the molecule after adding the basic compound, thereby reacting and removing trace amounts of SiCl groups remaining in the system.

The hydrochloride generated by the addition of the basic compound is preferably removed by washing with water. At this time, it is preferable to use a dilute aqueous solution of an acidic compound for the purpose of removing excess basic compound remaining in the reaction system. The acidic compound used is preferably weakly acidic in order to suppress the hydrolysis of the hydrolyzable group of the siloxane compound. From this viewpoint, a dilute aqueous solution of a carboxylic acid such as acetic acid or formic acid is preferred.

The molecular weight of the hydrosilyl group-containing polysilsesquioxane synthesized according to the present invention can be determined in terms of polystyrene by gel permeation chromatography. In this case, the number average molecular weight Mn is obtained.
It is evident from the data of the Examples that there is a linear correlation with the theoretical molecular weight M obtained by the following formula. In addition, it is clear from the data of Examples that the H equivalent by the alkali decomposition method also has a linear correlation with the theoretical H equivalent obtained by the following formula. Therefore, the charging ratio for obtaining the required molecular weight and H equivalent can be obtained in advance by using these equations, and unnecessary labor and cost can be eliminated. M = [n / (n + m) × (R2 + R3 + 29.1) + m / (n +
m) × R4] × 4 + 32.0 + (104.2 + 2 × R1) × 2 / (n
+ M) Theoretical H equivalent = (n + m) / n × M / 4 (where R1, R2, R3 and R4 each represent the formula weight of R ¹ , R ² , R ³ and R ⁴ )

In the polysilsesquioxane of the present invention, the molecular weight and the H equivalent can be controlled by arbitrarily setting n and m. The polysilsesquioxane which does not use a compound having active hydrogen preferably has a number average molecular weight of 500 to 5000 and an H equivalent of 100 to 1500. In the case of polysilsesquioxane using a compound having active hydrogen, it is preferable that the number average molecular weight is 500 to 5000 and the H equivalent is 100 to 5000. When the number average molecular weight is 500 or less, it becomes difficult to exhibit performance such as heat resistance and weather resistance derived from the polysiloxane component.
Above, it becomes difficult to control the molecular weight. H equivalent is 10
If the molecular weight is 0 or less, the polysiloxane component is reduced due to the reduced molecular weight, so that it is difficult to exhibit properties such as heat resistance and weather resistance. A polysilsesquioxane having an H equivalent of not less than 1500 without using a compound having active hydrogen,
It is difficult to control the molecular weight, and when a compound having active hydrogen is used, components having no functional group in the molecule tend to increase when the H equivalent is 5,000 or more. Sesquioxane is less likely to be incorporated into the organic resin.

[0024]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which by no means limit the present invention. The polysilsesquioxane compound synthesized according to the present invention is identified by infrared absorption spectroscopy, ¹ H
-Performed by NMR method. The measurement conditions are as follows. Infrared absorption spectrum method: IR-70 manufactured by JASCO Corporation
0, liquid film method ¹ H-NMR method: FX-90 manufactured by JEOL Ltd.
Q, solvent CDCl _{3 The} number average molecular weight in terms of polystyrene was measured by a gel permeation chromatography method. The measurement conditions are as follows. Column: Tosoh columns G4000X, G3000X and G2000X were connected in this order and used. Column temperature: 40 ° C. Eluent: tetrahydrofuran Flow rate: 1 ml / min Pump: JASCO PU-980 Detector: JASCO 830 -RI

Example 1 A dropping funnel, a cooling tube, a sampling tube, and a thermometer were attached to a 500 ml four-necked flask sufficiently dried under a nitrogen stream, and 177.5 g of n-propyltrichlorosilane was attached.
(1.00 mol), 47.3 g of dimethylchlorosilane
(0.5 mol) and 46.1 g of toluene were mixed, and the inside of the system was sufficiently purged with nitrogen. The mixture was kept at 5 ° C. or lower on an ice bath while being stirred with a magnetic stirrer, and 63 g of THF and 31.5 g of water (1.75 mol) were added through a dropping funnel.
The mixture of 1) was added dropwise over about 4 hours. After dropping,
The mixture was heated to 80 ° C. in an oil bath and aged for 1 hour. The reaction solution was made basic by adding 20.2 g of triethylamine, and
After heating and stirring for 4.5 hours, 4.5 g of water was added to remove trace amounts of SiCl groups, and the mixture was aged for 2 hours. The obtained slurry was washed with an aqueous acetic acid solution, a saturated aqueous sodium hydrogen carbonate solution and pure water in this order, and then dried using anhydrous magnesium sulfate. The solvent is distilled off using a rotary evaporator, and 10
3 g of a clear, colorless liquid were obtained. When gel permeation chromatography analysis of this liquid was performed, it was found that a polystyrene equivalent number-average molecular weight of 1110 and a weight-average molecular weight of 1340 was generated. H-equivalent analysis by the alkali decomposition method gave a value of 320. The theoretical molecular weight M according to the above formula is 103
0, theoretical H equivalent is 260. The IR spectrum chart of this polymer is shown in FIG. 1, and the ¹ H-NMR spectrum chart is shown in FIG.

Example 2-5 The reaction was carried out in the same manner as in Example 1 except that the type of chlorosilane, the amount charged, and the amount of water charged were changed as shown in Table 1. Table 1 shows values of the number average molecular weight and the H equivalent of the obtained polymer by gel permeation chromatography analysis.

[Table 1] (The theoretical values of H equivalent weight and molecular weight M in the table are based on the above-mentioned calculation formula.)

Example 6 A dropping funnel, a cooling tube, a sampling tube, and a protective tube were attached to a 500 ml four-necked flask sufficiently dried under a nitrogen stream, and 177.5 g of n-propyltrichlorosilane was attached.
(1.00 mol), 23.7 g of dimethylchlorosilane
(0.25 mol) and 46.1 g of toluene, and the inside of the system was sufficiently purged with nitrogen. The solution was kept at 5 ° C. or lower on an ice bath while stirring with a magnetic stirrer, and 11.5 g (0.25 mol) of ethanol was added dropwise from the dropping funnel over about 30 minutes. Add 54g of THF to the dropping funnel.
And a mixture of 27.0 g (1.50 mol) of water and
This was added dropwise over about 4 hours. After completion of the dropwise addition, the mixture was heated to 80 ° C. in an oil bath and aged for 1 hour. The reaction solution was made basic by adding 20.2 g of triethylamine, heated and stirred for 1 hour, and then added with 9.2 g of ethanol to remove traces of SiCl groups, followed by aging for 2 hours. The obtained slurry was washed with an aqueous acetic acid solution, a saturated aqueous sodium hydrogen carbonate solution and pure water in this order, and then dried using anhydrous magnesium sulfate. The solvent was distilled off using a rotary evaporator to obtain 92.9.
g of colorless and transparent polysilsesquioxane was obtained. When gel permeation chromatography analysis of this liquid was performed, the number average molecular weight was 115 in terms of polystyrene.
It was found that polysilsesquioxane having a weight average molecular weight of 1530 was produced. H by alkali decomposition method
The equivalent analysis gave a value of 640. In addition,
According to the above formula, the theoretical molecular weight M is 970, and the theoretical H equivalent is 490. FIG. 3 shows an IR spectrum chart of this polymer, and FIG. 4 shows a ¹ H-NMR spectrum chart.

Example 7 The charged amount of dimethylchlorosilane was 9.5 g (0.10 m
ol) and the amount of ethanol charged was 4.6 g (0.10 mol).
The reaction was carried out in the same manner as in Example 6, except that l) was changed. As a result, the number average molecular weight of the obtained polymer determined by gel permeation chromatography was 227.
The value of 0 and the H equivalent were 1370. The theoretical molecular weight M according to the above formula is 2110, and the theoretical H equivalent is 1
060.

[0029]

According to the present invention, it is possible to produce a polysilsesquioxane compound having a controlled molecular weight and hydrosilyl group content. The hydrosilyl group-containing polysilsesquioxane synthesized according to the present invention can be arbitrarily introduced with a functional group by a hydrosilylation reaction with various olefins, and thus is useful as a reaction intermediate material.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum chart of a polysilsesquioxane compound obtained in Example 1.

FIG. 2 is a ¹ H-NMR spectrum chart of a polysilsesquioxane compound obtained in Example 1.

FIG. 3 is an infrared absorption spectrum chart of a polysilsesquioxane compound obtained in Example 6.

FIG. 4 is a ¹ H-NMR spectrum chart of a polysilsesquioxane compound obtained in Example 6.

Claims (4)

[Claims] 1. A mixture of an organotrichlorosilane of the formula (1) and an n-fold molar amount of the organotrichlorosilane of the formula (2) is added to a mixture of (3 + n) / 2 times the molar amount of the organotrichlorosilane. Characterized by being produced by reacting an amount of water with a repeating unit represented by the formula (3) in the molecule, and having a number average molecular weight of 500 to 500.
0 and a polysilsesquioxane compound having an H equivalent of 100 to 1500. R ¹ SiCl ₃ (1) R ² R ³ HSiCl (2) R ¹ Si (R ² R ³ HSiO) _n O _{(3-n) / 2} (3) (where R ¹ , R ² and R ³ are , Each independently,
A linear, branched or cyclic saturated hydrocarbon group having 1 to 18 carbon atoms, a linear, branched or cyclic unsaturated hydrocarbon group having 2 to 6 carbon atoms, or an aryl group having 10 or less carbon atoms. And n is a value in the range of 0.1 to 2.0. ) 2. A mixture of an organotrichlorosilane of the formula (1) and an n-fold molar amount of the organotrichlorosilane of the formula (2) is added to a mixture of (3 + n) / 2 times the mole of the organotrichlorosilane. Characterized by reacting an amount of water with a repeating unit represented by the formula (3) in the molecule, having a number average molecular weight of 500 to 5000, and H
A method for producing a polysilsesquioxane compound having an equivalent weight of 100 to 1500. R ¹ SiCl ₃ (1) R ² R ³ HSiCl (2) R ¹ Si (R ² R ³ HSiO) _n O _{(3-n) / 2} (3) (where R ¹ , R ² and R ³ are , Each independently,
A linear, branched or cyclic saturated hydrocarbon group having 1 to 18 carbon atoms, a linear, branched or cyclic unsaturated hydrocarbon group having 2 to 6 carbon atoms, or an aryl group having 10 or less carbon atoms. And n is a value in the range of 0.1 to 2.0. ) 3. A mixture of an organotrichlorosilane represented by the formula (1) and an n-fold molar amount of the organomonochlorosilane represented by the formula (2) is added to a m-fold molar amount of the organotrichlorosilane of the formula (2). After reacting at least one of the compounds represented by 4), the compound is produced by reacting (3 + nm) / 2 times the molar amount of water of organotrichlorosilane to produce the compound. ) Having a repeating unit represented by the formula (1), having a number average molecular weight of 500 to 5000,
And a polysilsesquioxane compound having an H equivalent of 100 to 5000. R ¹ SiCl ₃ (1) R ² R ³ HSiCl (2) R ⁴ OH (4) R ¹ Si (R ² R ³ HSiO) _n (R ⁴ O) _m O _{(3-nm) / 2} (5) ( Here, R ¹ , R ² and R ³ each independently represent a linear, branched or cyclic saturated hydrocarbon group having 1 to 18 carbon atoms, a linear, branched or cyclic saturated hydrocarbon group having 2 to 6 carbon atoms. A cyclic unsaturated hydrocarbon group or an aryl group having 10 or less carbon atoms, wherein R ⁴ is a linear or branched saturated hydrocarbon group having 1 to ⁴ carbon atoms, a CH ₃ CO group, or a CH ₂ ＣＨCHCO group; Or CH ₂ ＣCCH ₃ CO, wherein m and n each independently represent a value in the range of 0.05 to 2.0,
n is a value in the range of 0.1 to 3.0. ) 4. A mixture of an organotrichlorosilane represented by the formula (1) and an n-fold molar amount of the organomonochlorosilane represented by the formula (2) is added to a m-fold molar amount of the organotrichlorosilane of the formula (2). 4) reacting at least one of the compounds represented by formula (5), and then reacting with (3 + nm) / 2 times the molar amount of water of organotrichlorosilane. A method for producing a polysilsesquioxane compound having a repeating unit having a number average molecular weight of 500 to 5,000 and an H equivalent of 100 to 5,000. R ¹ SiCl ₃ (1) R ² R ³ HSiCl (2) R ⁴ OH (4) R ¹ Si (R ² R ³ HSiO) _n (R ⁴ O) _m O _{(3-nm) / 2} (5) ( Here, R ¹ , R ² and R ³ each independently represent a linear, branched or cyclic saturated hydrocarbon group having 1 to 18 carbon atoms, a linear, branched or cyclic saturated hydrocarbon group having 2 to 6 carbon atoms. A cyclic unsaturated hydrocarbon group or an aryl group having 10 or less carbon atoms, wherein R ⁴ is a linear or branched saturated hydrocarbon group having 1 to ⁴ carbon atoms, a CH ₃ CO group, or a CH ₂ ＣＨCHCO group; Or CH ₂ ＣCCH ₃ CO, wherein m and n each independently represent a value in the range of 0.05 to 2.0,
n is a value in the range of 0.1 to 3.0. )