JPS6348276B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing organosilanes, particularly organosilanes containing alkenyloxy groups and alkoxy groups in the molecule. Organosilanes containing alkenyloxy and alkoxy groups directly bonded to silicon atoms in their molecules are said to be useful as curing agents for room-temperature curable silicone rubber; A partial alkoxysilane is synthesized by reacting an organochlorosilane containing a bonded chlorine atom with an alcohol, and then a ketone compound is added to the remaining chlorine atom in the presence of a transition metal compound catalyst and a hydrogen chloride scavenger. It is produced by a method of reaction to form the corresponding organosilane. However, this method has the disadvantage that it is difficult to separate and purify the target product due to the large number of by-products, and the reaction yield is also low.Also, since the starting material is organochlorosilane, distillation alone is not enough to remove residual residue in the target product. Unable to reduce the amount of Chlor, this was reduced to 200ppm.
In particular, it is difficult to reduce the content to 20 ppm or less, which has the disadvantage that the industrial use of the room-temperature-curable silicone rubber added thereto is severely limited. The present invention relates to a method for producing an organosilane containing an alkenyloxy group and an alkoxy group, which solves these disadvantages, and is based on the general formula (R ¹ is a hydrogen atom, an unsubstituted or substituted alkyl group, an alkenyl group, or an aryl group,
R ² , R ³ , R ⁴ are hydrogen atoms or the same group as R ¹ , ^and a is an integer of 0 to ² ). Alkyl group, alkenyl group, aryl group or formula -
CH ₂ CH ₂ OR ⁶ (R ⁶ is the same as R ¹ above)] in the presence of a catalyst to form a compound of the general formula (Here, R ₁ , R ² , R ³ , R ⁴ , R ⁵ , a are the same as above, b is an integer of 1 to 3, and a+b≦3) containing an alkenyloxy group and an alkoxy group. It is characterized by obtaining silane. That is, as a result of various studies on efficient production methods of organosilanes containing alkenyloxy groups and alkoxy groups, the present inventors found that when an organosilane represented by the above general formula is reacted with an alcohol, it is possible to react in 11 steps. It has been discovered that the desired organosilane can be obtained in good yield, and the organosilane obtained by this method can significantly reduce the amount of residual chlorine. The present invention was completed after confirming that it can be advantageously used as various precision industrial materials. The organosilane used as an initiator in the method of the present invention has the general formula and this R ¹ is a hydrogen atom or a methyl group,
Alkyl groups such as ethyl, propyl, and butyl groups, alkenyl groups such as vinyl and allyl groups, aryl groups such as phenol groups, or some or all of the hydrogen atoms bonded to the carbon atoms of these groups are replaced by halogen atoms, Chloromethyl group substituted with cyano group etc., 3,3,3-trifluoropropyl group,
An unsubstituted or substituted monovalent hydrocarbon group selected from a cyanomethyl group, etc., where R ² , R ³ , and R ⁴ are hydrogen atoms or the same monovalent hydrocarbon group as R ¹ above, and a is 0 to 2. It is assumed to be an integer of

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Examples include [Formula]. Since this organosilane is generally synthesized from organosilane, it usually contains 100 to 1000 ppm of residual chlorine, but if this organosilane is used as it is as a starting material for the method of the present invention, it will not produce the desired organosilane. Since the amount of residual chlorine is large, washing with water, distillation, etc. will reduce the amount of remaining chlorine to 1
It is best to refine it to ~20ppm. Next, the alcohol to be reacted with this organosilane is represented by the general formula R ⁵ OH as described above, and R ⁵ is an unsubstituted or substituted alkyl group, alkenyl group, or aryl group, or has the formula -
CH ₂ CH ₂ OR ⁶ , where R ⁶ is the same unsubstituted or substituted alkyl group, alkenyl group, or aryl group as R ¹ described above, but this includes CH ₃ OH, C ₂ Straight chain alcohols such _{as H5OH} , _C3H7OH , _{C4H9OH ,} ( _CH3 ) _2CHOH ,
Branched alcohols such as ( _CH3 ) _3COH ,
Examples include cellosolve types such as CH ₃ OCH ₂ CH ₂ OH and C ₂ H ₅ OCH ₂ CH ₂ OH. The amount of this alcohol compound to be blended with the organosilane is preferably 80 to 120 mol% of the theoretical amount required for partial alkoxylation of the organosilane, but this amount should be determined based on the desired organosilane and starting material. It may be determined by considering the boiling point difference between the organosilane and the reaction by-product. The reaction between organosilane and alcohol described above must be carried out in the presence of a catalyst, such as an acidic catalyst such as p-toluenesulfonic acid, triethylamine, diethylhydroxyamine, a guanidyl group-containing silicon compound, etc. Any known basic catalyst containing an amino group may be used, but it is preferable to use triethylamine, which is industrially inexpensive and easily available, and can be easily separated during distillation. It may be added in an amount of 0.01 to 5% by weight based on the organosilane as a starting material. In the method of the present invention, a catalyst is added to the organosilane as the starting material, and the alcohol mentioned above is added dropwise thereto to cause the reaction. The reaction may be carried out in the presence of a solvent inert to the reaction. The method of the present invention is to obtain an organosilane having an alkenyl group and an alkoxy group through a one-step reaction between an organosilane represented by the above general formula and an alcohol, and can be obtained industrially easily and with high purity. In particular, it has the advantage of producing organosilane with a significantly reduced amount of residual chlorine, so room-temperature-curing silicone rubber using this as a curing agent is used as a seal for nuclear power generation, where contamination with impurities such as chlorine atoms is extremely difficult. It has the advantage of being useful as a material for the aerospace industry, an ultra-precision industrial material, and as a sealing material for electronics. Next, examples of the present invention will be given. Example 1 Methyltri(isopropenyloxy)silane with a residual chloride content of 220 ppm in a separable flask equipped with a reflux condenser, thermometer, stirring bar and dropping funnel.

[Formula] 428g (2 moles) and 4g of triethylamine were added at 35°C.
After heating to , 128 g (4 mol) of methanol was added dropwise from the dropping funnel over 1 hour while stirring.
Thereafter, the mixture was heated under reflux for 2 hours and then distilled under reduced pressure, yielding 188 g of a product with a boiling point of 74° C./114 mmHg. Next, when I analyzed this thing, I found that
This IR is as shown in Figure 1, and
Based on the NMR and GC-MS results, this is methyl(isopropenyloxy)dimethoxysilane.

It was confirmed that the formula was [Formula], the amount of residual chlorine in this product was 97 ppm, and the yield was 58%. Example 2 In the same equipment as Example 1, 428 g (2 mol) of methyltri(isopropenyloxy)silane, which had been washed with water and distilled to reduce the amount of residual chlorine to 5 ppm, was added.
After adding 4g of triethylamine and heating to 35℃, methanol was added from the dropping funnel while stirring.
64 g (2 mol) was added dropwise over 40 minutes, then 55-60
After heating to 1 hour at 0.degree. C. and distilling under reduced pressure, 20/g of the product with a boiling point of 98.degree. C./112 mmHg was obtained. Next, we examined this using IR, NMR, and GC-MS, and found that it was methyldi(isopropenyloxy)methoxysilane.

[Formula] was confirmed, and the residual amount of chlorine in this product was 3 ppm,
The yield was 53%. Comparative example: 64 g (2 moles) of methanol was added dropwise to 299 g (2 moles) of methyltrichlorosilane over about 50 minutes.
The mixture was heated to 0.degree. C. for 1 hour and then distilled under reduced pressure to obtain 160 g of methyldichloromethoxysilane. Next, 290 g of triethylamine, 900 g of acetone and 5.0 g of cuprous chloride were added to this, and the mixture was heated at 40℃ for 24 hours.
After reacting for an hour, the salts were removed by filtration, and distillation was performed under reduced pressure. As a result, 103
g was obtained. As a result of analysis, this product was confirmed to be the same methyldi(isopropenyloxy)methoxysilane as that obtained in Example 2, but the residual amount of chlorine was 260 ppm, and the yield was also 28%. It was hot. Examples 3 to 8 Using the same method as in Example 1, organosilane as a starting material was changed to methyltri(isopropenyloxy)silane with a residual chlorine content of 5 ppm and vinyltri(isopropenyloxy)silane with a residual chlorine content of 7ppm. , alcohol to methanol,
When silane was synthesized using ethanol, methyl cellosolve, and ethyl cellosolve, the results shown in Table 1 below were obtained. The IR values of the silanes obtained in Examples 3, 5, and 8 were as shown in FIGS. 2 to 4.

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[Brief explanation of the drawing]

Figures 1 to 4 all show the IR of the organosilane obtained in this example.
The figure shows the IR of the organosilanes obtained in Example 1, FIG. 2 in Example 3, FIG. 3 in Example 5, and FIG. 4 in Example 8.

[Claims]

1 General formula (R ¹ and R ² are the same or different lower alkyl groups or trimethylsiloxy groups, R ³ and R ⁴ are hydrogen atoms or the same or different lower alkyl groups, and R ⁵ is an alkyl group having 1 to 8 carbon atoms. , m is 0,
1, 2 or 3, n is 2, 3 or 4, m+n is 4 or 5). 2 R ¹ is a methyl group, ethyl group, propyl group, butyl group or trimethylsiloxy group, R ² is a methyl group, R ³ is a hydrogen atom or a methyl group, R ⁴ is a methyl group or an ethyl group, R ⁵ is a methyl group, ethyl group,
The organosilicon compound according to claim 1, which is a butyl group or an octyl group.

Claims (1)

A method for producing an organosilane, which comprises obtaining an organosilane containing an alkenyloxy group and an alkoxy group, where b is an integer of 1 to 3, and a+b≦3. 2 Claim 1 in which the catalyst is a basic catalyst
The method for producing organosilane described in Section 1. 3. The method for producing an organosilane according to claim 1, wherein in the general formula of the organosilane, R ² is a methyl group and R ³ and R ⁴ are hydrogen atoms.