CN1123283A

CN1123283A - Method for preparation of 3-chloropropyl trichloro-silane

Info

Publication number: CN1123283A
Application number: CN 94118297
Authority: CN
Inventors: 胡春野
Original assignee: Institute of Chemistry CAS
Current assignee: Institute of Chemistry CAS
Priority date: 1994-11-21
Filing date: 1994-11-21
Publication date: 1996-05-29
Anticipated expiration: 2014-11-21
Also published as: CN1040538C

Abstract

The preparation method uses trichlorosilane and chloropropylene (their mole ratio is 1.1:1.1-1.0:1.5) as raw materials, uses the solution of chloroplatinic acid and n-tribulylamine and n-tripropylamine or N,N-dimethyl benzylamine (their mole ratio is 1.0:0.5-1.0:1.0) in cyclohexanone, isopropanol and tetrahydrofuran or ethylene glycol methyl ether as catalyst and makes them quickly produce silicon-hydrogen addition reaction at room temp. so as to obtain the 3-chloropropyl trichlorosilane whose production rate is 70-76%.

Description

Preparation method of 3-chloropropyltrichlorosilane

The invention relates to a preparation method of an organosilane coupling agent.

3-chloropropyltrichlorosilane is an important intermediate in the production process of various silane coupling agents, and the most convenient preparation method is that trichlorosilane and chloropropene are synthesized by hydrosilylation under the action of a catalyst.

Catalysts for this reaction are reported in many cases, but chloroplatinic acid and other homogeneous platinum complex catalysts are of practical interest, but these catalysts have revealed many problems in practical use. Chloroplatinic acid (H)₂PtCl₆·6H₂O) is a widely used hydrosilylation catalyst [ see J.Amer.chem.Soc., 82,3602 (1960))]Such catalysts are usually used as isopropanol solutions. The disadvantages are that: 1. the reaction is difficult to initiate, it needs to be activated at 80 ℃ and the activity is shown after a long induction period. 2. The reaction speed is slow, and the reaction temperature is reduced during feeding, so that the feeding speed is limited, and the reaction time is prolonged. 3. Chloroplatinic acid catalyzes a side reaction, and when the reaction is carried out at a relatively high temperature for a long time, by-products increase, and the yield of 3-chloropropyltrichlorosilane decreases.

(1)

Product of

(2)

Byproduct 1 and byproduct 2

(3)

By-product 3

Many efforts have been made to improve on the problems of chloroplatinic acid catalysts.U.S. Pat. No. 3,925,434(1975) uses chloroplatinic acid as catalyst and phenothiazine as catalyst promoter, resulting in a shortened reaction induction period without increasing the product yield. Japanese patent JP87-18,916(1987) uses a chloroplatinic acid tetrahydrofuran solution as a catalyst, but the product yield is low although the reaction rate is increased, and the catalyst needs to be previously heat-treated. Czech patent CS187,167(1980) gives relatively high yields with a catalytic system consisting of chloroplatinic acid, N-dimethylaniline and diphenylsilane, which, however, requires a preliminary reaction treatment and diphenylsilane is not readily available and is therefore difficult to apply in practice. With respect to homogeneous platinum complex catalysts, U.S. Pat. No. 4,292,433(1981) reports the use of dichloro-bis- (triphenylphosphine) platinum (II) complex [ Pt (PPh)₃)₂Cl₂]High yields of 3-chloropropyltrichlorosilane are obtained, but the reaction needs to be carried out at high temperature and in an autoclave, the catalyst needs to be specially prepared, and the catalyst is large in dosage and high in cost.

In addition, for the addition reaction of trichlorosilane and chloropropene, the proportionof the two raw materials is also a factor influencing the yield of 3-chloropropyltrichlorosilane. It is common practice to use an excess of trichlorosilane, but the excess of trichlorosilane increases the formation of propyltrichlorosilane as a by-product, and the low boiling point and corrosiveness of trichlorosilane pollute the environment.

The invention aims to overcome the defects of high reaction initiation temperature, long induction period, low reaction speed, low yield of 3-chloropropyltrichlorosilane and the like in the catalysis of chloroplatinic acid and the problem of environmental pollution caused by improper mixture ratio of reactants, thereby providing a preparation method suitable for industrial production of the 3-chloropropyltrichlorosilane. According to the method, trichlorosilane and chloropropene with the molar ratio of 1.0: 1.1-1.0: 1.5, preferably 1.0: 1.1-1.0: 1.2 are used as raw materials, a solution of chloroplatinic acid and an organic amine compound in ketone, alcohol or ether is used as a catalyst, the rapid initiation of a silicon-chlorine addition reaction at room temperature is realized, and the 3-chloropropyltrichlorosilane with the yield of 70-76% is prepared.

The method is realized by the following steps that firstly, a high-efficiency catalyst is prepared, the catalyst consists of two solutions of chloroplatinic acid and organic amine, and the organic amine compounds are N-tributylamine, N-tripropylamine and N, N-dimethylbenzylamine. The chloroplatinic acid and the organic amine compound are required to have a proper proportion, the effective proportion range is that the mole ratio of the chloroplatinic acid to the organic amine is equal to 1.0: 0.5-1.0: 1.0, and when the mole ratio is more than or less than the proportion, the activity of the catalyst is reduced, the yield of the product is reduced, and particularly, when the mole ratio is more than the proportion, the catalyst even loses the activity. The dosage of the catalyst in the reaction is calculated by the molar ratio of chloroplatinic acid to trichlorosilane, and the dosage of the catalyst is quite small due to the high activity of the catalyst. The minimum effective dosage can reach the mole ratio of chloroplatinic acid/trichlorosilane of 10^-7In practical application, the molar ratio is preferably controlled to be 10^-4～10^-6。

Respectively dissolving the chloroplatinic acid and the organic amine compound in the calculated amount by using a ketone, alcohol or ether to prepare a solution with the concentration of 0.01-0.1M, wherein effective solvents are cyclohexanone, isopropanol, tetrahydrofuran and ethylene glycol monomethyl ether. The chloroplatinic acid is preferably cyclohexanone or isopropanol as a solvent, and the organic amine may be the same solvent as chloroplatinic acid or a different solvent.

The raw materials of trichlorosilane and chloropropene have a proper ratio, and excessive trichlorosilane can increase the byproduct of propyltrichlorosilane and pollute the environment, so the molar ratio of trichlorosilane to chloropropene is preferably 1.0: 1.1-1.0: 1.2. Further increasing the amount of chloropropene is advantageous to minimize the formation of by-products, but is not economically desirable.

The reaction is initiated firstly, the catalyst prepared by the method can rapidly initiate the reaction within the range of room temperature to 80 ℃, the reaction induction period is 0-3 minutes, and the reaction is exothermic and is easy to cause reaction overheating and volatilization of a large amount of low-boiling point reactants at high temperature, so the reaction initiation temperature is preferably controlled to be between room temperature and 60 ℃. After the reaction is initiated, the reaction temperature can be controlled by adjusting the feeding speed, the rule is that the temperature rises when the feeding speed is high, the reaction temperature is preferably controlled to be 65-75 ℃, and an external heating source is not needed in the feeding process. And after the addition is finished, continuously refluxing for 1 hour by using bath temperature to raise the reaction temperature to 80-90 ℃ to finish the reaction, wherein the reaction liquid is colorless and transparent, and the yield of the 3-chloropropyltrichlorosilane with the boiling point of B.P. ═ 181 ℃ obtained by normal pressure distillation can reach 70-76%. In conclusion, the invention overcomes the problems existing in the chloroplatinic acid catalytic process and has the following advantages:

1. the catalyst is simple to prepare and does not need pretreatment.

2. The catalyst has high activity, can quickly initiate reaction within the range of room temperature to 80 ℃, and eliminates the induction period.

3. The reaction speed is high, the rapid feeding can be realized, and the reaction time is shortened.

4. The reaction temperature is adjusted by the feeding speed, no external heat source is needed during the feeding period, and the energy conservation is realized.

5. The reaction by-products are less, and the 3-chloropropyltrichlorosilane with high yield is prepared.

6. After the reaction is finished, the reaction solution is colorless and transparent, so that alcoholysis can be carried out only by distilling off the front fraction, and the process is simplified.

The invention is further illustrated by the following examples:

examples 1,

1.0g of chloroplatinic acid was dissolved in 20ml of isopropanol to give a chloroplatinic acid isopropanol solution having a concentration of 0.1M, and 0.5g of n-tributylamine was dissolved in 27ml of cyclohexanone to give a n-tributylamine cyclohexanone solution having a concentration of 0.1M.

A reflux condenser tube group consisting of a charging funnel, a thermometer and an upper dry ice cold trap is arrangedInto a 250ml three-neck flask, 54.2g (0.4mol) of trichlorosilane and 33.7g (0.44mol) of chloropropene were put into an addition funnel and mixed,about 20ml of the reactants and a small amount of zeolite were added to a reaction flask, followed by 0.4ml each of the previously prepared 0.1M chloroplatinic acid isopropanol solution and 0.1M n-tributylamine cyclohexanone solution, the amount of catalyst being chloroplatinic acid/trichlorosilane equal to 1X 10^-4(molar ratio). The reaction was initiated immediately at 40 ℃ bath temperature, the reaction temperature rose rapidly and reflux occurred. When the temperature rises to 60 ℃, the feed liquid is dripped, the feeding speed is adjusted to control the reaction temperature to be about 70 ℃, the feeding is completed within 30 minutes, and the reflux is stopped quickly. The bath temperature is increased and the heating reflux is continued for 1 hour, the reaction temperature is finally raised to 82 ℃, and the reaction liquid is colorless and transparent. The reaction mixture was distilled at atmospheric pressure to collect the following fractions: unreacted substance and silicon tetrachloride (SiCl)₄)15.1g of propyltrichlorosilane (CH)₃CH₂CH₂SiCl₃)4.6g, 3-chloropropyltrichlorosilane (ClCH)₂CH₂CH₂SiCl₃B.p. ═ 181 ℃)60.2g, the yield was 71% based on trichlorosilane. Comparative example 1:

the experimental setup and procedure were the same as in example one, except that 0.4ml of 0.1M chloroplatinic acid isopropanol solution was used as the catalyst. The reaction can not be initiated at the bath temperature of 40 ℃, the bath temperature is increased to 80 ℃ to enable the reaction liquid to flow back, the color of the reaction liquid is gradually deepened to be brown, the temperature is slowly increased, the temperature is increased to 60 ℃ after 1 hour, the temperature of the reaction liquid is reduced after the feeding is started, the feeding is finished after 2 hours, the oil bath temperature is increased to continue flowing back for 1 hour, the reaction temperature is finally increased to 74 ℃, and the reaction liquid is dark brown. The reaction mixture was distilled at atmospheric pressure to collect the following fractions: unreacted substance and silicon tetrachloride (SiCl)₄)30.1g of propyltrichlorosilane (CH)₃CH₂CH₂SiCl₃)3.9g, 3-chloropropyltrichlorosilane (ClCH)₂CH₂CH₂SiCl₃)43.6g, 51% yield based on trichlorosilane.

Example 2:

the experimental setup was the same as in example one. 542g (4.0mol) of trichlorosilane and 337g (4.4mol) of chloropropene are put into an addition funnel to be mixed, 20ml of mixed feed liquid and a small amount of zeolite are firstly added into a 1-liter reaction bottle, and then 0.1M chloroplatinic acid isopropyl is added0.4ml of each of an alcohol solution and a 0.1M n-tributylamine cyclohexanone solution, the amount of the catalyst being chloroplatinic acid/trichlorosilane equal to 1X 10^-5(molar ratio). The reaction was initiated rapidly at room temperature (25 ℃), the reaction temperature was controlled at about 70 ℃ by adjusting the feed rate, the feed was completed within 1.5 hours, the reaction was heated with an oil bath for 1 hour under reflux, the temperature of the reaction finally rose to 83 ℃, the reaction was colorless and transparent, and thereaction mixture was distilled at atmospheric pressure to collect the following fractions: unreacted product and SiCl₄189g，CH₃CH₂CH₂SiCl₃36g，ClCH₂CH₂CH₂SiCl₃(b.p. ═ 181 ℃)621g of 3-chloropropyltrichlorosilane gave 73% yield based on trichlorosilane.

Example 3:

the experiment was carried out as in example 2, with the chloroplatinic acid/n-tributylamine molar ratio being changed to 1.0: 2.0, according to which the chloroplatinic acid isopropanol solution and the n-tributylamine cyclohexanone solution were used in amounts of 0.4ml and 0.8ml, respectively.

The reaction can not be initiated at room temperature, the reaction solution is heated by using an oil bath (80 ℃) to reflux, but the temperature of the reaction solution is always raised to about 40 ℃ and is not increased any more, which indicates that the reaction still does not occur, and 0.6ml of chloroplatinic acid isopropanol solution is supplemented to ensure that the chloroplatinic acid/n-tributylamine molar ratio is equal to 1.0: 0.8 and the reaction immediately occurs. The reaction mixture was treated in the same manner as in example two to obtain 609g of 3-chloropropyltrichlorosilane in a yield of 72%.

Example 4:

the process of example two was followed except that the n-tributylamine solution of example two was replaced with a 0.1M n-tripropylamine cyclohexanone solution. The reaction was initiated quickly at room temperature, the feed rate was adjusted to control the reaction temperature at about 65 ℃ and the feed was completed in 2 hours, then heated with an oil bath and refluxed for 1 hour, the temperature of the reaction solution finally increased to 81 ℃, and the reaction mixture was distilled to obtain 594g of 3-chloropropyltrichlorosilane in 70% yield.

Example 5:

the solution of chloroplatinic acid in isopropanol in example two was replaced with a 0.1M solution of chloroplatinic acid in cyclohexanone and the rest was carried out in the same manner as in example two. The reaction was initiated rapidly at room temperature, the feed rate was adjusted to control the reaction temperature at about 75 ℃ and the feed was completed in 1.2 hours, then heated with an oil bath and refluxed for 1 hour, the temperature of the reaction solution was finally raised to 82 ℃ and the reaction mixture was distilled to obtain 619g of 3-chloropropyltrichlorosilane in 73% yield.

Example 6:

the experiment was carried out as described in example 2, the catalyst solution being replaced by 0.4ml each of a 0.05M solution of chloroplatinic acid in isopropanol and a 0.05M solution of n-tributylamine in cyclohexanone in such an amount that the molar ratio chloroplatinic acid/trichlorosilane was 5X 10^-6. The reaction was initiated immediately at room temperature, the feed rate was adjusted to control the reaction temperature at about 70 ℃ and the feed was completed in 1.5 hours, then heated with an oil bath and refluxed for 1 hour, the temperature of the reaction solution was finally raised to 83 ℃ and the reaction mixture was distilled to obtain 626g of 3-chloropropyltrichlorosilane in 74% yield.

Example 7:

the experiment was carried out as in example 2, the molar ratio trichlorosilane/chloropropene starting material being changed to 1.0: 1.2. According to the proportion, the using amount of the trichlorosilane is 542g (4.0mol) and the using amount of the chloropropene is 367g (4.8mol), and 642g of 3-chloropropyltrichlorosilane is obtained, and the yield is 76 percent based on the trichlorosilane.

Claims

1. The preparation method of the 3-chloropropyltrichlorosilane is characterized in that trichlorosilane and chloropropene are used as raw materials and are subjected to hydrosilylation reaction, the molar ratio of trichlorosilane to chloropropene is 1.0: 1.1-1.0: 1.5, a ketone, alcohol or ether solution of chloroplatinic acid and organic amine is used as a catalyst, the molar ratio of chloroplatinic acid to organic amine is 1.0: 0.5-1.0: 1.0, the concentration of the catalyst solution is 0.01-0.1M, the molar ratio of chloroplatinic acid to trichlorosilane is 10-4-10-6, hydrosilylation reaction is initiated in a range of 80 ℃ askew at room temperature, the reaction induction period is 0-3 minutes, the reaction temperature is controlled to be 65-75 ℃ during charging, the reaction end point temperature is 80-90 ℃, and the yield of the 3-chloropropyltrichlorosilane is 70-76%.

2. The method for preparing 3-chloropropyltrichlorosilane according to claim 1, wherein the optimum molar ratio of trichlorosilane to chloropropene is 1.0: 1.1-1.0: 1.2.

3. The process according to claim 1, wherein the organic amine is selected from the group consisting of N-tributylamine, N-tripropylamine, and N, N-dimethylbenzylamine.

4. The method of claim 1, wherein the ketones, alcohols and ethers are cyclohexanone, isopropanol, tetrahydrofuran and ethylene glycol monomethyl ether.