JPS6034576B2 - Method for producing organosilicon polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a new and improved method for producing organosilicon polymers soluble in organic solvents by the reaction of silicic acid and organosilicon compounds.

Silicone resin, which has been known as a heat-resistant polymer, has excellent water resistance, antifoaming properties, scale-like properties, electrical insulation properties, etc., and has been used in a wide range of fields, but its manufacturing method is well-known.
This is due to the polymerization of organochlorosilane monomers.

However, the above production method requires a large amount of electrical energy to obtain the metal silicon as a starting material, and the yield of the polymer is also low, making the resulting silicone resin products expensive. On the other hand, as a more economical and inexpensive method for producing organosilicon polymers, a method of synthesizing it from sodium silicate or silicic acid has been proposed in Japanese Patent Publication No. 28-5699 and Samurai Publication No. 53-799, etc. .

However, these methods also have some problems. For example, according to Japanese Patent Publication No. 28-569, when reacting an organosilicon compound, the so-called organosilylating agent, with H-IJ-cahydrosol, even if the former is charged in large excess with respect to the latter, the organic solvent still remains. Insoluble organosilicon polymers are formed. Therefore, if this method is to be used industrially, a step of extracting the produced organic solvent-soluble matter with an organic solvent is necessary, and the yield is low, so it cannot be said to be an industrially satisfactory method. Also, according to the special public service 53-79 Jyukoyo,
Before reacting silicic acid with an organosilylating agent, it is generally necessary to carry out a step of extracting silicic acid with a gutter organic solvent.

Therefore, this process requires a salt-folding operation, which makes the process complicated, and the molecular weight of the obtained organosilicon polymer is low and limited. The present inventors have continued intensive research to resolve the problems in the production of these organosilicon polymers, and as a result, we have developed a combination of silicic acid and organosilicon compounds (hereinafter referred to as organosilylating agents).
When producing an organosilicon polymer by reacting with silicic acid, if the silicic acid is heat-treated under appropriate conditions in advance, an organic solvent-soluble organosilicon polymer having a desired molecular weight can be produced in high yield. They discovered that it could be easily manufactured, and completed the present invention.

That is, in the present invention, when producing an organosilicon polymer by reacting silicic acid with an organosilicon compound having a halogen atom or an alkoxy group bonded to it, the silicic acid is reacted with a silica in water or a mixed solvent of water and a polar organic solvent. This is a method for producing an organosilicon polymer, characterized by using silicic acid that has been heat-treated at a temperature of the boiling point of a solvent. By implementing the present invention, an organic-solvent-soluble organosilicon polymer can be produced stably and in high yield through a simple process that does not require a salt precipitation step.

Furthermore, any desired molecular weight, i.e. a weight average molecular weight of 50
It is possible to produce organosilicon polymers with high molecular weights ranging from 0.00 to 100,000 or even several hundreds of thousands. Furthermore, the organosilicon polymer obtained by the present invention is of course lipophilic,
It is extremely useful as a water repellent, antifoaming agent, mold release agent, electrical insulation agent, and various other raw materials. Furthermore, since the molecular weight can be made extremely high, film properties are also good. In the present invention, silicic acid that has been heat-treated in advance and an organosilylating agent are generally reacted together in a mixed solvent of water and a magnetic organic solvent.

As the reaction progresses, it gradually separates into two layers. The organosilicon polymer layer precipitated in the lower layer is thoroughly washed with liquid until the acid and the salt of the acid used are gone, and then dried to obtain a glassy or powdery product. In the present invention, it is extremely important to heat-treat silicic acid in advance in order to obtain an organosilicon polymer having a desired arbitrary molecular weight by reacting an inactive acid with an organosilylating agent.

The raw material silicic acid used in the present invention is not particularly limited as long as it is water-soluble silicic acid, and for example, sodium silicate and potassium silicate are preferably used. Generally, water glass is mixed with hydrochloric acid,
Since water-soluble silicic acid can be easily obtained by neutralizing with nitric acid, sulfuric acid, etc., this method can be advantageously employed industrially. However, depending on the conditions in this long reaction, it may turn into a gel, and even after the organosilylation reaction using the gelled silicic acid, it becomes insoluble in organic solvents, so the gelled silicic acid is used as the silicic acid raw material of the present invention. I can't. The raw silicic acid used in the present invention is prepared in water or a mixed solvent of water and a polar organic solvent, especially at pH. Preferably, the material is heat-treated at a temperature of 3,000 or higher under acidic conditions of 4 to 3.5.

That is, pH 0.4-3. Under conditions of a pH of ~3,
Silicic acid produced by neutralizing water glass is extremely stable and has a low degree of polymerization. Therefore, by heat-treating at a molecular weight of 3,000 or more, the molecular weight of the raw silicic acid can be easily adjusted, and any desired organosilicon polymer can be obtained. Further, the heat treatment time varies somewhat depending on the mixed solvent composition, the type of polar organic solvent, pH, heating temperature, etc., but generally a range of 2 minutes to 8 hours is most preferably employed.

Although it is not clear by what mechanism of action heat treatment of silicic acid in the present invention to a specific pH can increase the molecular weight of the organosilicon polymer obtained, it is possible to increase the molecular weight of the obtained organic silicon polymer.
It is presumed that this is due to the fact that the heat treatment under H atmosphere polymerizes the raw material silicic acid to produce high molecular weight silicic acid. Further, the concentration of silicic acid used in the present invention is not particularly limited as long as it is dissolved in a mixed solvent, and even sol-like silicic acid can be used. Generally, silicic acid having a silica concentration of about 1 to 10% can be used most preferably. As described above, the reaction between the heat-treated silicic acid and the organosilylating agent in the present invention can be carried out using a known method as is. Particularly preferred industrial conditions are to use 0.7 to 2.0 moles of the organosilylating agent per mole of silicic acid in a polar organic solvent containing water, and to carry out the reaction at a reaction temperature of 200° or higher.
At this time, as the polar organic solvent containing water, a suitable polar organic solvent/water volume ratio is 0.2 to 2.0. The above capacity ratio is 0. In the presence of salt, the organosilylation reaction may not proceed sufficiently, and as a result, silicic acid gel may co-precipitate to produce an organosilicon polymer insoluble in organic solvents. On the other hand, when the above-mentioned capacity ratio exceeds 2.0, both the silicic acid and the organosilylation agent become relatively stable, and as a result, the speed of organosilylation is slow and good results are not necessarily obtained. Moreover, the silica concentration as a whole decreases, which is industrially disadvantageous. The molar ratio of organosilylating agent/lotus acid used in the present invention is 0.
7 to 2.0 is preferred.

The lower limit of the above molar ratio also varies depending on the molecular weight of the raw material silicic acid used, and as long as it is soluble in water, the amount of organosilylating agent used may be smaller as a raw material with a higher molecular weight is used.
Generally, in order to obtain a silicon polymer soluble in an organic solvent, a molar ratio of 0.7 or more is required. When the molar ratio of organosilylating agent/silicic acid is large, it is observed that depending on the type of organosilylating agent used, the organosilylating agent becomes insoluble in organic solvents, contrary to expectations. Furthermore, since the organosilylating agent undergoes various processes during the reaction and undergoes decomposition and deterioration, it is not always possible to easily recover the excess organosilylating agent. I can't say that. Considering economic efficiency, a molar ratio of around 1 is sufficient. The reaction temperature is not particularly limited, but the higher the temperature, the faster the organosilylation reaction.

Generally, a temperature range of 2,000 to the boiling point of the solvent is favorable.
The organosilylating agent used in the present invention has the general formula RnSi
One or more of the compounds represented by Xrn and x(R2Si0)mSiR2x can be used. In the above formula, R is a saturated or unsaturated hydrocarbon group such as an alkyl group such as a methyl group, an ethyl group, or a propyl group, an aryl group such as a phenyl group or a naphthyl group, an alkenyl group such as a vinyl group or an allyl group, or y -aminopropyl group, 8-carpoxycetyl group, y-cyanof. It is a carbon-functional organic group such as a hydrocarbon residue having a substituent such as a lopyl group. Also, × is Ha. and/or an alkoxy group such as a methoxy group or an ethoxy group. Furthermore, although n is an integer of 1 to 3, depending on the mode of use, the average value of n may be a decimal number within the range of 1 to 3. Similarly, m is 3 or 4. Preferably used organosilylating agents include:

For example, trimethylchlorosilane, triethylchlorosilane, dimethyldichlorosilane, diethyldichlorosilane, methyltrichlorosilane, ethyltrichlorosilane,
1,4-dichlorooctamethyltetrasiloxane and the like are generally used. The organic solvents used in the present invention include alcohols such as methanol, ethanol, brobanol, and butanol, ethers such as dimethyl ether, jetyl ether, and tetrahydrofuran, ketones such as acetone and methyl isobutyl ketone, ethyl acetate, Esters such as butyl acetate, amides such as dimethylformamide,
It also includes alkyl sulfoxides such as dimethyl sulfoxide, and aromatic compounds such as benzene and toluene. Examples of the present invention are shown below, but the present invention also includes:
It is not limited to these.

The sodium silicate aqueous solution used in the following examples was prepared by diluting No. 4 sodium silicate (Si02/Na20 molar ratio 3.37) manufactured by Tokuyama Soda ■ with water and adjusting the silica concentration to 2% by weight. .

Furthermore, the measurement of molecular weight distribution and calculation of weight average molecular weight were performed as follows.

The measuring device used was Liquid Chromato Model 633 manufactured by Hitachi, Ltd. Column is ShodeXA-802, A-803A
-805 were connected (measured at room temperature. The solvent was tetrahydrofuran, which was flowed at a rate of 1 m/min. A differential refractometer was used as a detector. The sample was It was dissolved in tetrahydrofuran, and 0.5' of it was injected into the solvent by suction.The molecular weight (Mi) of each count was determined using a shark positive curve created using standard polyj styrene under the same measurement conditions. The chromatogram was divided by dividing the flow rate by 0.5 kite/min, and the Peter height (Hj) of each count was calculated.

The weight average molecular weight (Mw) was calculated using an electronic computer according to the following formula using these values.

Mw = Type 3 Kakuzan 2Hi Example 1 30% by weight sulfuric acid (specific gravity 1.27) 7.5 and water 22.5
Put 300 melons into a beaker and place in a magnetic star.
A solution prepared by diluting 15 parts of an aqueous sodium silicate solution with 15 parts of water was added within 1 minute while using a larder.

Then, it was heat-treated at 40 qo for 6 hours. On the other hand, trimethylchloride.

Luciran 6.4 was diluted to 60 q of inpropyl alcohol and perfused to 40 q. 40 qo of the former in the latter,
It was added within 1 minute under the box frame. Then, it was allowed to react for 30 minutes. At this time, the pH of the silicic acid solution during mixing is about 1, the volume ratio of isopropyl alcohol/water is about 1, and the molar ratio of trimethylchlorosilane/silicic acid is also about 1. As the reaction progresses,
The layers were separated. The lower organosilicon polymer layer was dissolved in toluene, washed with water, and then the toluene was removed under reduced pressure at 60° C. and dried. The product was a glassy powder and hydrophobic.

This product was dissolved in benzene, toluene, acetone, n-butanol, tetrahydrofuran, etc. From elemental analysis of the product, CI2.7%, day 3.3%, and the rest is Si0.
It was 2. The infrared absorption spectrum is at 1080 cm-1 and 1250 cm-1 attributed to Si-0-Si (CH
3) It showed remarkable characteristic absorption of 3Si. However, Si-O
The presence of H was not recognized in either the infrared absorption spectrum or NMR analysis. The product was dissolved in tetrahydrofuran and the weight average molecular weight determined by high performance liquid chromatography was 31,000. Example 2 Put 15 parts by weight of sulfuric acid (specific gravity 1.27) and 15 parts of water into a 300-ml beaker, and while using a magnetic stirrer, add 15 parts of sodium silicate aqueous solution to 15 parts of water. The diluted solution was added within 1 minute.

Then, at 30:00, heat treatment was performed for 2 hours. On the other hand, trimethylchloride. Lucilan 6.4 shout inpropyl alcohol 6
Dilute to 0° and warm to 40°. The former was added to the latter within 1 minute while stirring, and the reaction was allowed to proceed for 30 minutes at 40°C. At this time, the pH of the silicic acid solution during mixing is approximately 0.0.
The volume ratio of inpropyl alcohol/water is about 1, and the molar ratio of trimethylchlorosilane/silicic acid is about 1. As the reaction progressed, the layers were separated. The lower organosilicon polymer layer was dissolved in benzene, washed with water, and then the benzene was removed under 6000 vacuum and dried. The product obtained was a glassy powder and exhibited aqueous properties.

From elemental analysis, CI7.6%, day 4.8%, and the rest is Si0.
It was 2. This material was dissolved in benzene, toluene, acetone, n-butanol, tetrahydrofuran, etc.

The infrared absorption spectrum was obtained using Si-○-Si in the same machine as in Example 1.
(CH
3) It showed remarkable characteristic absorption of 3Si. However, Si-O
The presence of H was not recognized in either the infrared absorption spectrum or the NM old analysis. The product was dissolved in tetrahydrofuran and the weight average molecular weight determined by high performance liquid chromatography was 28,100. Examples 3-12 Example 1
Or, in the same manner as in 2, the pH of the silicic acid solution at the time of mixing as described in Table 1 by keeping the volume ratio of inpropyl alcohol/water constant at about 1 and the molar ratio of trimethylchlorosilane/silicic acid at about 1, The weight-average molecular weight of the products obtained was determined by varying the type of mineral acid and heat treatment temperature and time for boat conditioning.

The results are shown as Examples 3 to 12 in Table 1. The solubility of the products in organic solvents, infrared absorption spectra, etc. were the same as in Example 1. Example 13 3 weight percent sulfuric acid 15 parts, water 21 parts, and inpropyl alcohol 12 parts were placed in a 300ml beaker, and while stirring with a magnetic stirrer, an aqueous sodium silicate solution 152 parts was added within 1 minute. Ta.

Then, it was heat-treated at 30°C for 2 hours. On the other hand, 6.4' of trimethylchlorosilane was mixed with 35' of inpropyl alcohol.
The solution was diluted with 40 qo. The former was added to the latter within 1 minute while stirring, and the mixture was allowed to react for 3 minutes at 40:00. At this time, the pH of the silicic acid solution at the time of mixing is approximately 0.6.
, the inpropyl alcohol/water ratio is about 1, and the trimethylchlorosilane/silicate molar ratio is about 1. Also, isop during heat treatment of silicic acid. The ratio of alcohol/water is 1'3. Post-processing was carried out on the same machine as in Example 1. The product was a glassy powder and soluble in organic solvents. C from elemental analysis
I was 9.6%, I was 5.1%, and the rest was Si02.

The weight average molecular weight was 10,260. Example 14
30 parts by weight of 30% sulfuric acid, 5.6 parts of water, and 12 parts of inpropyl alcohol were placed in a beaker, and while stirring with a magnetic stirrer, 15 parts of an aqueous sodium silicate solution was added within 1 minute.

Then, it was heat-treated at 30 qo for 1 hour. On the other hand, 6.4' of trimethylchlorosilane was added to 35' of isopropyl alcohol.
The solution was diluted to 100% and flooded to 40°C. The former was added to the latter within 1 minute while stirring, and the reaction was allowed to proceed for 40 minutes. At this time, the pH of the silicic acid solution during mixing is approximately 0.4, the inpropyl alcohol/water ratio is approximately 1, and the molar ratio of trimethylchlorosilane/silicic acid is approximately 1. The water ratio is about 1/4. Post-treatment was carried out in the same manner as in Example 2. The product was soluble in organic solvents and had a weight average molecular weight of 26,600. Example
15-21 In the same manner as in Example 13, the molar ratio of trimethylchlorosilane/silicic acid was kept constant at about 1, and when carrying out the reaction, as shown in Table 1, inpropyl alcohol/water during the silicic acid heat treatment was carried out. The ratio of heat treatment temperature and heat treatment time, the pH of the solution at the time of mixing, and the weight average molecular weight of the product obtained by changing the type of mineral acid for pH adjustment were measured.

The results are shown in Table 1 as Examples 15-21. The solubility of the product in polar organic solvents, infrared absorption spectrum, etc., were the same as in Example 1. Examples 21-23 The method of Example 1, but varying the amount of trimethylchlorosilane, respectively.

Reactions were carried out at molar ratios of lucilane/silicic acid of 0.8, 1.4, and 1.8. All of the obtained products were soluble in organic solvents. Example 24 In the method of Example 22, the silicic acid heat treatment time was changed and the reaction was performed at 30° C. for 4 hours.

The resulting product was soluble in organic solvents. Example
25-27 In the method of Example 1, as an organosilylating agent,
The reaction was carried out using dimethylchlorosilane, diphenyldichlorosilane, 1,4-dichlorooctamethylsiloxane, and trimethylchlorosilane, respectively, at an organosilylating agent/silicic acid molar ratio of 1.0.

The product obtained was soluble in organic solvents. Example 2
8-31 The reaction was carried out in the same manner as in Example 1 except that ethator, dimethylformamide, methyl isobutyl ketone, and ethyl acetate were used as polar organic solvents.

All of the obtained products were soluble in organic solvents. Example 32 In the method of Example 1, as the sodium silicate raw material,
No. 3 sodium silicate (Si02/Na2) molar ratio 3.0
The reaction was carried out in the same manner except that 5) was used.

The obtained product had a weight average molecular weight of 29,500,
It was soluble in organic solvents. boat ship

Claims (1)

[Scope of Claims] 1. When producing an organosilicon polymer by reacting silicic acid with an organosilicon compound having a halogen atom or an alkoxy group bonded to it, the silicic acid is prepared in water or a mixed solvent of water and a polar organic solvent. 1. A method for producing an organosilicon polymer, comprising using silicic acid heat-treated at a temperature of 30° C. to the boiling point of a solvent. 2. The method according to claim 1, wherein the heat treatment is performed under acidic conditions of pH 0.4 to 3.5. 3 0.7 to 2.0% of the key organosilicon compound per 1 mole of silicic acid.
The method according to claim 1, in which 0 mol is used. 4. The method according to claim 1, wherein the reaction between silicic acid and an organosilicon compound is carried out in a mixed solvent of water and a polar organic solvent. 5. The method according to claim 1, wherein the silicic acid is water-soluble silicic acid. 6 The organosilicon compound has the general formula RnSiX_4_-_n or X(R_2SiO)_mSiR_2X (R is a hydrocarbon group or a carbon-functional organic group, or 4), the method according to claim 1. 7. The method of claim 1, wherein the heat treatment is carried out for at least 20 minutes. 8. The method according to claim 1, wherein the organosilicon polymer is soluble in an organic solvent. 9. The method according to claim 1, wherein the organosilicon polymer has a weight average molecular weight of 10,000 or more. 10. The method according to claim 1, wherein the reaction between silicic acid and the organosilicon compound is carried out at a pH of 5 or less. 11. The method according to claim 1, wherein the polar organic solvent is an alcohol, ether, ketone, ester, or aromatic compound. 12. The method according to claim 1, wherein the reaction between silicic acid and the organosilicon compound is carried out at 20° C. to the boiling point of the solvent.