JPS6017214B2 - Soluble methylpolysiloxane and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to soluble methylpolysilsesquioxanes.

As used herein, the term "silsesquioxane" means a siloxane in which the ratio of the number of oxygen atoms to the number of silicon atoms is 1.5. Until now, soluble polysilsesquioxanes having aryl stems such as phenyl groups and tolyl groups, and polysilsesquioxanes having higher alkyl groups such as isobutyl and isoamyl groups have been known (J. Amer.
Chem. S ratio. , vol. 82, p. 6194 (1960),
J. PolymerSci. , Volume C-1, page 83 (196
3), V$okomol, Soyed, AI Volume 2 663
Page (1970), Se v. Akad. NankSSSR
．． Ser. Khim. However, little is known about soluble polysilsesquioxanes having C,1C3 lower alkyl groups. Recently Tokusei Showa 50-11
No. 1198 proposes a method for obtaining organopolysiloxane by hydrolyzing organotrichlorosilane such as methyltrichlorosilane, but there is no description of any examples using methyltrichlorosilane. The present inventors used the method described in the above-mentioned Tokokukan Sho 50-111198, that is, by forming two layers with ketone (which cannot be mixed with water in any proportion) and water {B} containing an amine; When methyltrichlorosilane was hydrolyzed by adding methyltrichlorosilane and causing a hydrolysis and condensation reaction to occur at the interface between the two layers, immediately after the reaction was completed,
It is true that it is a soluble solid, and it can be obtained up to a degree of Fahrenheit with a molecular weight of about 500, but if it is left at room temperature, it becomes indestructible.

That is, the above method has the disadvantage that only extremely unstable polymers can be synthesized. Furthermore, the polymer obtained by the above method cannot be precipitated and recovered even if a non-solvent such as methanol is added, making it extremely difficult to handle. As such, the polymer obtained by the above method has the drawbacks of having too low a molecular weight and lacking storage stability, and therefore being of poor practical use. As a result of repeated research aimed at solving the drawbacks of the conventional methods as described above, the present inventors have discovered that methyltrichlorosilane has a molecular weight of about 9,000 to about 100.
000, which could not be synthesized before,
We succeeded in providing soluble methylpolysilsesquioxane with high molecular weight. That is, the present invention provides a soluble methylborisiloxane represented by the general formula and having a number average molecular weight of about 9,000 to about 100,000.

Further, in the present invention, C is represented by a general formula characterized in that SIC 3 is dissolved in a mixed solvent of ketone and ether in the presence of an amine, water is added dropwise thereto, hydrolyzed, and then heated and condensed. A method for producing a soluble methylpolysiloxane having a number average molecular weight of about 9,000 to about 10,000 is provided.

Furthermore, the present invention provides a method for dissolving methylpolysiloxane having a number average molecular weight in the range of about 9,000 to about 10,000 represented by the general formula in a mixed solvent of ketone and enal or a single solvent of ether, and then adding an ammonium salt as a catalyst to dehydrate it. The number average molecular weight characterized by condensation is about 10
000 to about 100,000.

The soluble methylpolysiloxane of the present invention does not show any gelation or deterioration even when stored at room temperature for a long period of time, and is a thermosetting resin, which can be molded and heated to produce resin products with excellent heat resistance. can be obtained.

Although the polymer 1) of the present invention is similar to conventionally known phenylpolysilsesquioxanes in its structure, that is, the Si-○ ladder structure, it has various characteristics compared to conventionally known phenylpolysilsesquioxanes. It is excellent in this respect.

In particular, the superiority of the polymer of the present invention is that
When fired, the weight residual rate reaches 88% (phenyl polysilsesquioxane, C6&S
For i○shi5, it is only 46.5% or less). Therefore, the present invention provides a material suitable for applications where flexibility is required at normal operating temperatures, and where it is desired to form a protective coating by ceramizing it if exposed to high temperatures. It is something to do.

In addition, looking at the production volume of raw material silanes, methylsilanes are significantly larger than phenylsilanes, and the raw materials for methylsilanes are cheap, so soluble polymers were essentially obtained from methyltrichlorosilane. This is extremely important in the field of silyl heat-resistant resin manufacturing technology.

Preferred embodiments of the present invention will be described below. The amines that can be present during the hydrolytic polymerization in the first production method of the present invention include various primary to tertiary amines, such as triethylamine, trinormalpropylamine,
Triisopropylamine, diethylamine, ethylamine, pyridine, ethylenediamine, etc. are used, but
Particularly preferred are triethylamine and diethylamine. Examples of ketones that can be used in the hydrolysis polymerization reaction in the first production method and the dehydration condensation reaction in the second production method of the present invention include methyl ethyl ketone, diethyl ketone, and methyl isobutyl ketone.

Examples of the ether include diethyl ether, tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, and the like.

Although there are no particular restrictions on the combination of ketone and ether to form a mixed solvent, a mixed solvent of methyl isobutyl ketone and tetrahydrofuran is particularly preferred for the hydrolytic polymerization reaction.

On the other hand, in addition to the above-mentioned mixed solvents, a single solvent of ethers can also be used in the dehydration condensation reaction.

In this reaction, a mixed solvent of methyl isobutyl ketone and tetrahydrofuran, and a single solvent such as dioxane or diethylene glycol dimethyl ether are particularly preferred. Examples of ammonium salts that can be used in the dehydration condensation reaction include salts of various amines, such as trimethylamine hydrochloride, triethylamine hydrochloride, triethylamine hydrochloride, diethylamine hydrochloride, ethylamine hydrochloride, and ammonium sulfamate.
Triethylamine hydrochloride is preferred.

As shown in Comparative Example 2 below, a polymer with a molecular weight of about 500 °F can be obtained by a slightly modified method of the present invention, that is, a method that does not use an amine; With a molecular weight of , it is not possible to precipitate and recover the polymer using a non-solvent such as methanol, and the storage stability of the polymer is also poor.

Next, a preferred embodiment of the method for producing soluble methylpolysiloxane of the present invention will be described. First, amine and then methyltrichlorosilane are dissolved in a mixed solvent of ketone and ether.

The appropriate amount of the solvent to be used is about 5 to about 1 part by volume per 1 part by volume of the raw material methyltrichlorosilane.

If the amount is less than about 5 parts by volume, an insoluble resin will be produced, and if it is more than about 1 part by volume, the molecular weight of the resulting polymer will be low. A particularly preferred amount of solvent used is about 7 to 8 parts by volume. The amount of ketone to be used relative to ether is suitably in the range of about 1 to about 5 parts by volume, preferably about 2 to 3 parts by volume, per 1 part by volume of ether.

The amount of amine used can be up to three times the mole of methyltrichlorosilane, but if more than three times the mole (the amount that converts all the hydrogen chloride generated by hydrolysis into the amine hydrochloride), an insoluble gel will form. I'll come.

The preferred amount of amine is approximately equimolar to methyltrichlorosilane. Now, the ketone ether layer in which the silane and amine are dissolved is ice-cooled, and water is gradually added dropwise while stirring.

A white precipitate of amine hydrochloride gradually forms, but as water is added dropwise, the white precipitate dissolves. The amount of water only needs to be enough to dissolve all of this hydrochloride. After the dropwise addition is completed, the reaction vessel is heated with oil. A temperature of about 120 qo or less can be arbitrarily selected as the temperature of the oil, but when the temperature is low, it is necessary to heat the oil for a long time. Preferably, the mixture is heated at about 11,000 ℃ for about 4 hours while the contents are gently refluxed. After the reaction is completed, the organic layer is washed with water until the water after washing becomes neutral, dried over anhydrous sodium sulfate, concentrated, and poured into methanol to precipitate the polymer. In this reaction, the molecular weight is about 9000 ~
Polymers with a sparsity of about 1000 degrees can be obtained.

In the second production method of the present invention, the polymer obtained as described above is further dissolved in the above-mentioned solvent.

In this case, the amount of solvent used is approximately 2 parts by weight of the polymer.
Suitably, the amount is within the range of from to about 2 parts by weight, preferably from 5 to 6 parts by weight. An aqueous or methanol solution of ammonium salt is added to this polymer solution and heated. When an aqueous solution is used, the amount of the salt to be used is suitably within the range of about 0.01 to about 2 parts by weight per 1 part by weight of the polymer, and preferably about 1.5 to 2 parts by weight. The concentration of the aqueous solution is suitably selected within the range of about 10 to about 50%, preferably about 40 to 45%. When using a methanol solution, the amount of salt to be used is suitably selected within the range of about 0.005 to about 0.05 part by weight, preferably about 0.0 part by weight, based on 1 part by weight of the polymer. That's about it. Also, the concentration of the methanol solution is about 1 to about 1
A range of 0% is suitable, but about 6-7% is preferred. The reaction temperature is suitably selected within the range of about 50°C to about 140°C, preferably around 100°C. The reaction time is longer as the reaction temperature is lower, but 90q
When the reaction is carried out at 0, there is almost no difference between the molecular weight of the polymer 4 hours after the start of the reaction and the molecular weight of the polymer 1 hour after the start of the reaction.

Therefore, a reaction time of about 4 hours is sufficient at a reaction temperature of 90 oo. After the reaction is completed, the polymer can be obtained as a precipitate by pouring the reaction product into methanol.

The molecular weight of the polymer obtained by this reaction is about 10,000~
It is about 10,000 degrees Fahrenheit. The polymer obtained in the present invention is soluble and does not become permanent even if left in a solid state, and has good storage stability.

When looking at the infrared absorption spectrum of this polymer, it was found that 1
275 Arc-1 (PCH3), 770 Enemy-1 (HiSi-C
), J Polym Sci, Volume C-1, page 83 (
1963) and Chikai Sho 50-139900, the mSiOSi-based absorption of HAS has been reported in 1130 Hada-1 and 103 & Ne-1 in solids, and in 1140 Hada-1 and 1040 Hada-1 in solutions. 1 (1050 arc-1
The structure of this polymer was found to be a ladder type as shown below.

Furthermore, it was confirmed that this soluble methylpolysiloxane has a hydroxyl group at its chain end, since absorption based on OH groups was observed in 3640 Hada-1 in the infrared absorption spectrum in carbon tetrachloride.

In addition to having the above-mentioned structure, the soluble methylpolysiloxane of the present invention has an extremely high residual weight when exposed to high temperatures as described above, so it is particularly suitable for fire-resistant heating. Useful as a curable silicone resin.

Example 1 Methyl isoptyl ketone (260 mm) and tetrahydrofuran (90 mm) were placed in a reactor equipped with a reflux condenser, a dropping funnel, and a stirring tube, and methyl trichlorosilane (47 mm, 0.4 mm) was charged into the reactor. mol) and triethylamine (56', 0.4 mol) are added.

Cool the reaction vessel with water and slowly add water dropwise while stirring. A white precipitate of triethylamine hydrochloride is gradually formed, but the white precipitate is dissolved again by further addition of water. The amount of water added is about 50 to 100 [degrees]. Next, use an oil scale to adjust the oil bath temperature to 100o ~ 11o.
Heat and reflux at 0qo for 4 hours.

After the reaction is completed, the organic layer is separated, washed with water until the washing water becomes neutral, and dried over anhydrous sodium sulfate.

Thereafter, the drying agent is removed, the mixture is concentrated to a point where the polymer precipitates, and the mixture is poured into methanol to precipitate the polymer. The obtained precipitate is thoroughly washed with methanol and dried under vacuum.

The yield was 18.8 mm, and the molecular weight (in benzene, Vapor
(according to pressure osmometer) is 900
It was 0:00. This polymer was dissolved in organic solvents such as tetrahydrofuran and toluene even after being left for one month, and no insoluble portion was observed to be formed.

Further, when this polymer was treated at 200° C. for 2 hours to perform dehydration condensation and harden, calorimetric analysis was performed, and the weight loss after 400 hours in air was only 5%. Example 2 Methyltrichlorosilane (11.7, 0.1 mol) and triethylamine (14, 0.1 mol) were dissolved in a mixed solvent of methyl isobutyl ketone (45) and tetrahydrofuran (45'). and hydrolyzed in the same manner as in Example 1.

The yield was 5.4 hours, and the molecular weight was 9500. Comparative Example 1 Methyltrichlorosilane was hydrolyzed according to the recipe described in Example 1 using the method described in JP-A-50-1,1119.

That is, a mixed solvent of methyl isobutyl ketone (26 M) and tetrahydrofuran (90 M) and water (50 M) pre-mixed with triethylamine (56 M)'
Two layers are formed with B), and methyltrichlorosilane (47') is added dropwise thereto, followed by heating for 4 hours to prevent the two layers from collapsing. The organic layer is separated, washed with water, and dried over anhydrous sodium sulfate. The solid obtained by distilling off all the solvent is soluble in methanol, so it cannot be purified by methanol coagulation. Therefore, dry it in vacuum. Yield is 2
It was 5.5 evening. Since this product contains gel, the remaining hydroxyl groups were trimethylsilylated with trimethylchlorosilane to obtain a benzene-soluble portion, and the molecular weight was measured.
The molecular weight was only 2200. I added this to toluene after 3 days, but it no longer dissolved. Comparative Example 2 Methyltrichlorosilane was hydrolyzed in the same manner as in Example 1 except that triethylamine was not added.

That is, methyltrichlorosilane (11.7) was added to a mixed solvent of methyl isobutyl ketone (65') and tetrahydrofuran (25 above) and heated to 10,000 ℃.
Slowly add water (50') dropwise. After the addition is completed, the mixture is heated for 4 hours, and then the organic layer is separated, washed with water, and dried over anhydrous sodium sulfate. The solvent is distilled off to obtain a solid,
Since this substance is soluble in methanol, it cannot be reprecipitated with methanol. Therefore, dry it in vacuum. The yield was 6.4 days. This stuff makes a gel easily.
Therefore, trimethylsilylation was carried out in the same manner as in Comparative Example 1, and when the molecular weight was measured, the molecular weight was only 5,000. This polymer was added to the turquoise after 3 days and no longer dissolved. Example 3 The methylpolysiloxane with a molecular weight of 9,000 obtained in Example 1 was dissolved in 20 parts of diethylene glycol dimethyl ether, 5 parts of water containing 3.8 parts of trimethylamine hydrochloride was added thereto, and the mixture was stirred at 130 qo for 4 hours. .

After the reaction is completed, the reaction product is poured into methanol to obtain a white precipitate.

Wash this well with methanol and vacuum dry it. The yield was 2.2 hours, and the molecular weight was 100,000. This polymer was well soluble in organic solvents such as toluene and tetrahydrofuran, and no formation of insoluble portions was observed even after it was left standing for one month.

Further, when this polymer was treated at 200 q0 for 2 hours to perform dehydration condensation and cure, thermogravimetric analysis was performed, and the weight loss at 400 oo in air was only 5%.
Example 4 Three parts of the polysiloxane with a molecular weight of 9,000 obtained in Example 1 were dissolved in a mixed solvent of methyl isobutyl ketone (15 parts) and tetrahydrofuran (6 parts), and methanol (1 part) containing 0.1 part of triethylamine hydrochloride was dissolved in this. Add 5') and stir at 90oo for 4 hours.

After the reaction was completed, the reaction solution was poured into methanol to obtain a white precipitate. Wash this well with methanol and vacuum dry.
The yield was 2.6 days, and the molecular weight was 25,000. Example 5 The polysiloxane having a molecular weight of 9,000 obtained in Example 1 was dissolved in diethylene glycol dimethyl ether, water (7') containing 5.5 parts of triethylamine hydrochloride was added thereto, and the mixture was heated at 90 minutes. Stir for 4 hours.

Claims (1)

[Claims] 1. A soluble methylpolysiloxane having a number average molecular weight of about 9,000 to about 100,000, represented by the general formula ▲ Numerical formulas, chemical formulas, tables, etc. are available. 2 A general formula characterized by dissolving CH_3SiCl_3 in a mixed solvent of ketone and ether in the presence of an amine, adding water dropwise to the solution, hydrolyzing it, and condensing it by heating ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ A method for producing a soluble methylpolysiloxane having a number average molecular weight of about 9,000 to about 10,000 as shown. 3 CH_3SiC in a mixed solvent of methyl isobutyl ketone and tetrahydrofuran in the presence of triethylamine
The method for producing soluble methylpolysiloxane according to claim 2, which comprises hydrolyzing l_3. 4 After dissolving methylpolysiloxane having a number average molecular weight of about 9,000 to about 10,000 represented by the general formula ▲Mathematical formula, chemical formula, table, etc.▼ in a mixed solvent of ketone and ether or a single solvent of ether, ammonium salt is used as a catalyst. A method for producing soluble methylborisiloxane having a number average molecular weight in the range of about 10,000 to about 100,000, which comprises addition and dehydration condensation.