JPH0786114B2 - Method for producing bis (mercaptoalkyl) tetraorganodisiloxane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for producing an organosilicon compound used for modifying the properties of a synthetic resin, and more specifically, an epoxy resin and an unsaturated polyester resin. , A polystyrene, polyphenylene sulfide, polyurethane rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, EPM or EPDM, and a novel method for producing a bis (mercaptoalkyl) tetraorganodisiloxane useful for modifying interfacial properties.

(Prior Art) Conventionally, a method for producing 1,3-bis (3-mercaptopropyl) -1,1,3,3-tetramethyldisiloxane, which is considered to be most useful among bis (mercaptoalkyl) tetraorganodisiloxanes. The following methods are known.

For example, first, 3-chloropropyl (dimethyl) methoxysilane is reacted with thiourea and ammonia in the presence of a catalytic amount of a tertiary amine such as N, N-dimethylformamide to give 3-mercaptopropyl (dimethyl) methoxysilane. (US Pat. No. 4,401,826) and then hydrolyzing the compound with dilute hydrochloric acid to obtain the target substance. Alternatively, in the above method, instead of 3-chloropropyl (dimethyl) methoxysilane, 1,3-bis (3-
A method is known in which chloropropyl) -1,1,3,3-tetramethyldisiloxane is used and the final hydrolysis step is omitted.

(Problems to be Solved by the Invention) However, since the former method uses ammonia gas in the first reaction, a bad odor is generated. Further, there are disadvantages that the process is long and time-consuming, and that the starting material, 3-chloropropyl (dimethyl) methoxysilane, has a poor production yield and is difficult to obtain on an industrial scale. On the other hand, apart from the problem of malodor, the latter method has solved the drawbacks of the former method, such as the simplification of the process and the use of readily available compounds as raw materials. However, since the number of chloropropyl groups involved in the reaction is reduced to 2, the heat generated during the reaction is intense and the reaction is difficult to control. In addition, the oxidation reaction between target substances and the target substance
Dehydrochlorination reaction with 3-bis (3-chloropropyl) -1,1,3,3-tetramethyldisiloxane occurred simultaneously, and in many cases most of the target substance was turned into resin, yield and purity Is giving rise to a new shortcoming. That is, the conventional methods have problems in terms of industrialization, purity of the target substance, and overall yield.

Thus, it has been extremely difficult to obtain highly pure 1,3-bis (3-mercaptopropyl) -1,1,3,3-tetramethyldisiloxane industrially in high yield.

The object of the present invention is to eliminate such problems, less odor is generated, simple operation, and can be mass-produced.
An object of the present invention is to provide an industrially advantageous method for producing high-purity bis (mercaptoalkyl) tetraorganodisiloxane.

[Structure of Invention]

(Means for Solving the Problem) As a result of earnest studies to achieve such an object, the present inventor has reacted thiourea with bis (chloroalkyl) tetraorganodisiloxane in a polar aprotic solvent. The present inventors have found that a bis (mercaptoalkyl) tetraorganodisiloxane can be obtained in high yield and high purity by producing an isothiuronium salt and then decomposing it with ethylenediamine, and arrived at the present invention.

That is, the present invention relates to thiourea and the general formula (In the formula, R ¹ and R ³ each represent an alkyl group or an aryl group, and R ² represents an alkylene group) and reacted with bis (chloroalkyl) tetraorganodisiloxane in a polar aprotic solvent. , General formula (Wherein R ¹ , R ³ and R ² are the same as described above), and an isothiuronium salt is produced, and then this is subjected to a decomposition reaction with ethylenediamine.

General formula (In the formula, R ¹ , R ³ and R ² are the same as the above), and is a method for producing a bis (mercaptoalkyl) tetraorganodisiloxane.

The chemical reaction formula of the production method of the present invention is as follows: thiourea and bis (chloroalkyl) tetraorganodisiloxane (I
And (I) with isothiuronium salt (III) formation reaction (1), and isothiuronium salt (III) decomposition reaction with ethylenediamine (2).

In the isothiuronium salt formation reaction (1), thiourea used as a raw material is commercially available and can be easily obtained.

In the bis (chloroalkyl) tetraorganodisiloxane (II), which is also used as a raw material,
Examples of the alkyl group of R ¹ and R ³ include methyl, ethyl, propyl, butyl, pentyl, hexyl and dodecyl, and examples of the aryl group include phenyl and tolyl. Further, methylene is used as the alkylene group of R ² ,
Examples are ethylene, trimethylene and tetramethylene. Of these, an alkyl group having 1 to 4 carbon atoms is used as R ¹ and R ³ because of easy availability of raw materials and production.
A methyl group is particularly preferable, and R ² is preferably a methylene or trimethylene group. Such bis (chloroalkyl)
Specific examples of tetraorganodisiloxane (II) include:
For example, 1,3-bis (chloromethyl) -1,1,3,3-tetramethyldisiloxane, 1,3-bis (3-chloropropyl)
-1,2,3,3-Tetramethyldisiloxane may be mentioned.

The ratio of thiourea and bis (chloroalkyl) tetraorganodisiloxane (II) used is not particularly limited, but a stoichiometric amount is economically preferable.

In the isothiuronium salt formation reaction (1), as the polar aprotic solvent used, N, N-dimethylformamide, N, N-dimethylacetamide, tetramethylurea, hexamethylphosphoric triamide, dimethylsulfoxide, sulfolane or N-methyl is used. Examples thereof include pyrrolidone. Of these, N, N-dimethylformamide is particularly preferable because it is easily available and handled, and the reaction is quick. The amount of polar aprotic solvent used is not particularly limited, but it is thiourea (melting point about 180
It is preferably in the range of 20 to 200% by weight for the reaction control.

In the isothiuronium salt formation reaction (1), reaction control is carried out by placing bis (chloroalkyl) tetraorganodisiloxane (II), thiourea and a polar aprotic solvent in a reaction vessel and heating the mixture to a predetermined temperature to start the reaction. Above all preferred. Further, this reaction is carried out at 80 to 180 ° C., preferably 100 to 160
It is carried out in the temperature range of ° C. The pressure during the reaction is usually atmospheric pressure, but it may be applied under pressure.
The reaction time depends on the reaction conditions, but 1 to 3 hours is usually sufficient. From the above, the isothiuronium salt (III) is obtained.

Next, the decomposition reaction (2) of the isothiuronium salt (III) with ethylenediamine can be achieved by adding ethylenediamine to either the reaction mixture obtained by the reaction formula (1) or a purified product thereof. The amount of ethylenediamine used is not particularly limited, but is preferably in the range of 1 mol or more and less than 10 mol per 1 mol of the isothiuronium salt (III). If it is less than 1 mol, the reaction is slow and a good yield cannot be obtained in a short time. Even if it is used in an amount of 10 mol or more, there is no particular effect, and it is economically disadvantageous.

In the decomposition reaction (2), the use of an organic solvent is not essential, but when used as desired, an alcohol such as methyl alcohol or ethyl alcohol; a ketone such as acetone; an aliphatic hydrocarbon such as hexane or heptane; a cyclohexane or the like. Alicyclic hydrocarbons; ethers such as ethyl ether; aromatic hydrocarbons such as toluene and xylene;
Alternatively, halogenated hydrocarbons such as 1,2-dichloroethane are preferable, and among them, controllability of reaction, smoothness, and liquid-liquid separation of a target substance after reaction and a guanidine derivative salt by-produced are easy. Methanol is particularly desirable. The amount of such an organic solvent used is not particularly limited, but is preferably in the range of 10% by weight or more and less than 500% by weight with respect to the isothiuronium salt (III).

The main decomposition reaction (2) is carried out at a temperature range of 0 to 150 ° C, preferably 40 to 100 ° C. The pressure during the reaction is not particularly limited, but is usually atmospheric pressure. The reaction time depends on the reaction conditions, but 0.5 to 3 hours is usually sufficient. After the reaction, if necessary, n-hexane or the like is added to extract the target substance layer, and further vacuum distillation is performed to obtain the target bis (mercaptoalkyl) tetraorganodisiloxane (I).

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.
The scope of the present invention is not limited to the following examples.

Example 1 1,3-bis (3-mercaptopropyl) 1,1,
Synthesis of 3,3-tetramethyldisiloxane In a flask having an internal volume of 1 equipped with a stirrer, a thermometer, a dropping funnel, a reflux condenser and an oil bath, 1,3-bis (3-chloropropyl) -1,1, 3,3-tetramethyldisiloxane 2
87 g (1.0 mol), thiourea 152 g (2.0 mol) and N, N-dimethylformamide 76 g were charged, stirring was started, and the liquid temperature was 1
When heated to 10 ° C, a rapid exotherm was observed and the liquid temperature rose to a maximum of 138 ° C. Then, the mixture was heated and stirred at a liquid temperature of 120 ° C. for 1 hour. A sample is taken out from the reaction vessel and subjected to gas chromatography analysis, ¹ H nuclear magnetic resonance absorption analysis and chloride ion titration to obtain 1,3-bis (3-chloropropyl) -1,1,3,3-tetramethyl. It was confirmed that the disiloxane was quantitatively consumed and the corresponding isothiuronium salt was formed.

Further, the mixture was cooled to 60 ° C. while continuing stirring, and 100 g of methanol was added through the dropping funnel. To this, ethylenediamine 12
0 g (2.0 mol) was added dropwise from the dropping funnel over 30 minutes while maintaining the liquid temperature at 50 to 70 ° C. After completion of dropping, the mixture was heated and stirred at a liquid temperature of 70 ° C for 1 hour. A sample was taken out of the reaction vessel and subjected to gas chromatography analysis to confirm that 1,3-bis (3-mercaptopropyl) -1,1,3,3-tetramethyldisiloxane was produced. After cooling the reaction product, 100 g of n-hexane was added to separate the target substance layer, and a fraction of 125 to 127 ° C / 4 Torr was collected by distillation under reduced pressure. As a result, 1,3-bis was obtained as a colorless transparent liquid. (3-mercaptopropyl) -1,1,3,3-tetramethyldisiloxane 2
I got 26g. This is 1,3-bis (3-chloropropyl)
The yield was 81% based on -1,1,3,3-tetramethyldisiloxane. The 1,3-bis (3-mercaptopropyl) -1,1,3,3-tetramethyldisiloxane thus obtained had a high purity of 98.1% as a result of gas chromatographic analysis, and was further analyzed by elemental analysis and infrared rays. As a result of absorption spectrum analysis, ¹ H nuclear magnetic resonance absorption analysis and mass spectrum analysis, it was confirmed that the molecular structure was represented by the following formula.

Comparative Example 1 1,3-bis (3-chloropropyl) -1,1,3,3 was placed in a flask having an inner volume of 1 equipped with a stirrer, a thermometer, a reflux condenser, a dip-type ammonia gas introduction line and an oil bath. −
287 g (1.0 mol) of tetramethyldisiloxane, 1 thiourea
52 g (2.0 mol) and 76 g of N, N-dimethylformamide were charged, and introduction of ammonia gas was started at a flow rate of 2.0 ml / sec. When the liquid temperature was heated to 100 ℃, including stirring, a rapid heat generation was observed and the liquid temperature rose to a maximum of 220 ℃, and a sharp increase in viscosity was also observed. After the exotherm disappeared, the mixture was heated and stirred at a liquid temperature of 110 ° C. for 1 hour. After cooling the reaction product, 100 g of methanol and 100 g of n-hexane were added to separate the target substance layer, and further vacuum distillation was performed. As a result, the target 1,3-bis (3-mercaptopropyl) -1 was obtained. 25.0 g of 1,1,3,3-tetramethyldisiloxane was obtained. The purity of this product was 90.0% by gas chromatography analysis, and 1,3-bis (3-chloropropyl)
The yield for -1,1,3,3-tetramethyldisiloxane is
It was confirmed to be 8.9%.

Example 2 1,3-bis (mercaptomethyl) -1,1,3,3-
Synthesis of tetramethyldisiloxane In a flask with an internal volume of 1 equipped with a stirrer, thermometer, dropping funnel, reflux condenser and oil bath, 1,3-bis (3-chloromethyl) -1,1,3,3-tetra Methyldisiloxane 231
g (1.0 mol), thiourea 152 g (2.0 mol) and N, N-dimethylformamide 76 g were charged, stirring was started, and the liquid temperature was 110
When it was heated to ℃, it rapidly generated heat and the liquid temperature rose to a maximum of 144 ℃. After that, the mixture was heated and stirred at a liquid temperature of 120 ° C. for 1 hour. A sample is taken out from the reaction vessel and subjected to gas chromatography analysis, ¹ H nuclear magnetic resonance absorption analysis and chloride ion titration to obtain 1,3-bis (chloromethyl) -1,1,
3,3-tetramethyldisiloxane is consumed quantitatively,
It was confirmed that the corresponding isothiuronium salt was produced.

Further, the mixture was cooled to 60 ° C. while continuing stirring, and 100 g of methanol was added through the dropping funnel. To this, ethylenediamine 12
0 g (2.0 mol) was added dropwise from the dropping funnel over 30 minutes while maintaining the liquid temperature at 50 to 70 ° C. After completion of dropping, the mixture was heated and stirred at a liquid temperature of 70 ° C. for 1 hour. A sample was taken out of the reaction vessel and subjected to gas chromatography analysis to confirm that 1,3-bis (mercaptomethyl) -1,1,3,3-tetramethyldisiloxane was produced. After cooling the reaction product, 100 g of n-hexane was added to separate the target substance layer, and the fraction at 82 to 84 ° C / 4 Torr was collected by vacuum distillation. As a result, 1,3-bis colorless transparent liquid was obtained. (Mercaptomethyl)
170 g of -1,1,3,3-tetramethyldisiloxane was obtained. This was a yield of 76% based on 1,3-bis (chloromethyl) -1,1,3,3 tetramethyldisiloxane. The 1,3-bis (mercaptomethyl) -1,1,3,3-tetramethyldisiloxane thus obtained had a high purity of 97.2% as a result of gas chromatography analysis, and further had an elemental analysis and an infrared absorption spectrum. As a result of analysis, ¹ H nuclear magnetic resonance absorption analysis and mass spectrum analysis, it was confirmed that the molecular structure was represented by the following formula.

Comparative Example 2 In a flask having an internal volume of 1 equipped with a stirrer, a thermometer, a dropping funnel, a reflux condenser, a dip-type ammonia gas introduction line and an oil bath, 1,3-bis (chloropropyl) -1,
231 g (1.0 mol) of 1,3,3-tetramethyldisiloxane, 152 g (2.0 mol) of thiourea and N, N-dimethylformamide
76 g was charged, and the introduction of ammonia gas was started at a flow rate of 2.0 ml / sec. When stirring and heating the liquid temperature to 100 ° C, a rapid heat generation was observed and the liquid temperature rose to a maximum of 260 ° C.
At the same time, a remarkable increase in viscosity was observed, and finally stirring became impossible. As a result, the desired 1,3-
Bis (mercaptomethyl) -1,1,3,3-tetramethyldisiloxane could not be recovered at all.

〔The invention's effect〕

According to the production method of the present invention, using readily available raw materials,
Moreover, as shown in Example 1, for example, highly pure (98% or more) 1,3-mercaptopropyl) -1,1,3,3 can be prepared by a simple operation.
-Because tetramethyldisiloxane can be obtained in a high yield (81% or more), and the problem of malodor due to ammonia gas, which is a defect of the conventional method, can be eliminated, it is suitable as an industrial production method.

Therefore, it is advantageous when the bis (mercaptoalkyl) tetraorganodisiloxane obtained by the method of the present invention is used as a reactive oligomer raw material for modifying an organic material,
Further, a material having extremely high reliability in terms of molecular design can be obtained. That is, when modified by reacting an organic monomer or a polymer thereof with a bis (mercaptoalkyl) tetraorganodisiloxane obtained by the method of the present invention, adhesion, adhesiveness, weather resistance and water repellency to conventional organic materials can be obtained. Excellent properties peculiar to silicone such as abrasion resistance and gas permeability can be imparted.

Claims (1)

[Claims] 1. Thiourea and the general formula (In the formula, R ¹ and R ³ each represent an alkyl group or an aryl group, and R ² represents an alkylene group) and reacted with bis (chloroalkyl) tetraorganodisiloxane in a polar aprotic solvent. , (Wherein R ¹ , R ³ and R ² are the same as described above), and an isothiuronium salt is produced, and then this is subjected to a decomposition reaction with ethylenediamine. General formula (In the formula, R ¹ , R ³ and R ² are the same as the above), and a process for producing bis (mercaptoalkyl) tetraorganodisiloxane.