CN1277834C - Technique for preparing preparing propyl chloride trialkoxyl silicane from trialkoxyl silicane - Google Patents

Abstract

The present invention discloses a technical method for directly preparing propyl chloride trialkoxyl silicane from trialkoxyl silicane. The method comprises the following steps: trialkoxyl silicane used as raw material is weighed and adopted; a transition metal compound which is 1 to 1000 ppm of the weight of trialkoxyl silicane according to metal ions or alcoholic solution of the transition metal compound is used as a catalyst, and the catalyst is added into silicane solvent which is 0.2 to 2 times as much as the weight of the trialkoxyl silicane; under protection of nitrogen gas, the catalyst and the silicane solvent are stirred; the trialkoxyl silicane is added and is activated for 1 to 10 hours at the room temperature; chloropropene which is equal to 1/3 to 10/3 of the mole number of the trialkoxyl silicane is added; the obtained mixture is heated to 25 DEG C to 150 DEG C, and a reaction is carried out for 2 to 4 hours; chloropropene which is equal to 1/5 to 1/20 of the mole number of the trialkoxyl silicane is continuously added; heat is preserved for 1 to 3 hours; through separation, propyl chloride trialkoxyl silicane is obtained. The present invention adopts the transition metal compound as the catalyst and carries out uniform phase catalysis. The technical method has the advantages that the catalytic reaction condition is moderate, the reaction easily happens, the use level of the catalyst is little, the cost is low, and the yield rate is high.

Description

Process for preparing chloropropyl trialkoxysilane from trialkoxysilane

Technical Field

The invention relates to a preparation process of chloropropyl trialkoxysilane, in particular to a process method for preparing chloropropyl trialkoxysilane from trialkoxysilane.

Background

Chloropropyltrialkoxysilanes are important intermediates in the silane coupling agent industry for the preparation of other silanes such as: bis (triethoxysilylpropyl) disulfide and other substituted trimethoxysilanes. In the prior art, chloropropyltrialkoxysilane is usually obtained by taking trichlorosilane as a raw material and carrying out hydrosilylation and alcoholysis.

The reaction equation is:

at present, most enterprises adopt the method, but the complex production process releases a large amount of hydrogen chloride gas, equipment is seriously corroded, the environment is polluted, the method is generally built in places with low environmental requirements, and trichlorosilane is an extremely unstable substance, has low flash point and boiling point, is easy to catch fire and decompose to generate hydrogen chloride gas, and has great difficulty in the transportation and processing processes. In addition, the chloropropyltrichlorosilane product obtained by the method contains a large amount of chloride ions, has strong acidity, limits the application range of the product, and has high raw material consumption and high production cost in the production process.

Technical content

The invention provides a process for preparing chloropropyl trialkoxysilane directly from trialkoxysilane, which fundamentally avoids the pollution of hydrogen chloride and has the advantages of high product quality and low production cost.

The invention adopts the following technical scheme: weighing trialkoxysilane raw materials, adding 1-1000ppm of transition metal compound or alcoholic solution thereof which is calculated by metal ions and is relative to the mass of trialkoxysilane into a silane solvent which is 0.2-2 times of the mass of trialkoxysilane as a catalyst, stirring under the protection of nitrogen, adding trialkoxysilane, activating for 1-10 hours at room temperature, adding chloropropene with the mole number of 1/3-10/3 relative to the trialkoxysilane, heating to 25-150 ℃ for reacting for 2-4 hours, continuously dropwise adding chloropropene with the mole number of 1/5-1/20 relative to the trialkoxysilane, preserving heat for 1-3 hours, and separating to obtain chloropropyltrialkoxysilane.

The invention has the following advantages;

① in the invention, the chloropropyl trialkoxysilane is prepared by directly reacting trialkoxysilane with chloropropene, namely:

the generation of hydrogen chloride gas is avoided.

② the invention adopts transition metal compound as catalyst, homogeneous catalysis, and the process has the advantages of mild catalytic reaction conditions, easy reaction, low catalyst consumption, low cost, and high yield.

③ the invention adds inhibitor, which inhibits the disproportionation of the reactant, prevents the side reaction, greatly improves the selectivity of the reaction, and improves the yield.

Detailed description of the preferred embodiments

Example 1 a process for the preparation of chloropropyltrialkoxysilane from trialkoxysilane: weighing trialkoxysilane raw material, adding 1-1000ppm transition metal compound or its alcohol solution as catalyst relative to trialkoxysilane mass based on metal ion into silane solvent 0.2-2 times of trialkoxysilane mass, stirring under the protection of nitrogen, adding trialkoxysilane, activating at room temperature for 1-10 hr, adding chloropropene with the mole number of 1/3-10/3 relative to trialkoxysilane, heating to 25-150 ℃ for reacting for 2-4 hours, continuously dripping chloropropene with the mole number of 1/5-1/20 relative to the trialkoxysilane, preserving the heat for 1-3 hours, separating to obtain chloropropyltrialkoxysilane, the separation method can adopt the rectification or decompression rectification commonly used in the prior art, and in the embodiment, the reaction temperature isbetween 60 and 120 ℃; the silane solvent can be chloropropyl trialkoxysilane, tetraalkoxysilane, etc.; the trialkoxysilane containing active hydrogen can adopt trimethoxy silane or triethoxy silane and the like; the transition metal compound used as the catalyst may be iridium chloride, iridium chloride hydrate, chloroiridic acid, rhodium dodecacarbonyl, ruthenium trichloride, (1, 5-cyclooctadiene) iridium chloride or rhodium chloride hydrate, the alcohol solution of the transition metal compound used as the catalyst may be an aliphatic alcohol such as n-butanol, isobutanol, isopropanol, etc., in this example, after the activation of trialkoxysilane, an inhibitor selected from cyanuric acid, urotropin, paraformaldehyde or triphenylphosphine may be added in an amount of 1/1000 to 1/100 based on the mass of trialkoxysilane.

Example 2 to a 2000L reactor equipped with a thermometer, stirrer and condenser, 2L of a catalyst solution containing 20g of chloroiridic acid was charged, nitrogen was introduced for protection, stirring was carried out, 300Kg of chloropropyltriethoxysilane was added, 800Kg of triethoxyhydrosilicon was then added, stirring and activation were carried out at room temperature (usually about 25 ℃) for 4 hours, 2Kg of triphenylphosphine and 380Kg of chloropropene were added, heating was carried out to 95 ℃ and the temperature of the solution increased up to 130 ℃ during the reaction, reaction was carried out for 4 hours, 80Kg of chloropropene was added dropwise, and heat was maintained at 100 ℃ for 3 hours. Sampling and analyzing, and detecting that the yield of the chloropropyl triethoxysilane can reach 82%. The mixture is decompressed and distilled to obtain 965Kg of chloropropyl triethoxysilane with content more than 97 percent.

Example 3 to a 2000L reactor equipped with a thermometer, stirrer, condenser, 2L of a catalyst solution containing 20g of chloroiridic acid was charged, nitrogen was introduced for protection, stirring was carried out, 300Kg of chloropropyltriethoxysilane was added, then 800Kg of triethoxyhydrosilicon was added, stirring was carried out at room temperature (usually about 25 ℃) for activation for 4 hours, 380Kg of chloropropene was added, heating was carried out to 95 ℃, the temperature of the solution increased during the reaction up to 130 ℃ for 4 hours, 80Kg of chloropropene was added dropwise, and heat was maintained at 100 ℃ for 3 hours. Sampling and analyzing, and detecting to obtain the yield of the chloropropyl triethoxysilane by 67 percent.

Example 4 in a 1000L reactor with a stirrer, a thermometer, a dropping device and a condenser, 15g of iridium chloride was added, 100kg of tetraethoxysilane was added, then 300kg of triethoxysilane was added, nitrogen was introduced as a shielding gas, stirring was carried out at room temperature for activation for 2 hours, 0.5kg of urotropine was added, 350kg of chloropropene was added, stirring was carried out, heating was carried out to 80 ℃ during the reaction, the temperature of the solution increased to 135 ℃ at the maximum, reaction was carried out for 4 hours, 20kg of chloropropene was added again, and heat was maintained at 80 ℃ for 2 hours. Sampling and analyzing, and detecting that the yield of the chloropropyl triethoxysilane can reach 85%.

Example 5 in a 200L reactor equipped with a stirrer, a thermometer, and a reflux condenser, 12g of rhodium dodecacarbonyl as a catalyst was charged, 40Kg of chloropropyltrimethoxysilane was charged, 80Kg of trimethoxysilane was charged, nitrogen was introduced as a shielding gas, the reaction was stirred and activated at room temperature for 5 hours, 70Kg of chloropropene was charged, the reaction was stirred and heated to 80 ℃ for 4 hours, the temperature of the solution increased during the reaction, 3Kg of chloropropene was added dropwise, and the reaction was terminated after 3 hours of heat preservation at 90 ℃. Sampling and analyzing, and determining that the yield of the chloropropyl trimethoxy silane can reach 85 percent.

Claims (6)

1. A process for preparing chloropropyl trialkoxysilane from trialkoxysilane is characterized in that trialkoxysilane raw materials are weighed, a transition metal compound or an alcohol solution thereof which is 1-1000ppm of the mass of trialkoxysilane based on metal ions and is relative to the mass of trialkoxysilane is added into a silane solvent which is 0.2-2 times of the mass of trialkoxysilane as a catalyst, the trialkoxysilane is stirred under the protection of nitrogen, the trialkoxysilane is added, the reaction is activated for 1-10 hours at room temperature, chloropropene with the mole number of 1/3-10/3 relative to the mole number of trialkoxysilane is added, the reaction is carried out for 2-4 hours at the temperature of 25-150 ℃, chloropropene with the mole number of 1/5-1/20 relative to the mole number of trialkoxysilane is continuously added dropwise, the temperature is kept for 1-3 hours, and chloropropyl trialkoxysilane is obtained through separation.

2. The process for preparing chloropropyltrialkoxysilane from trialkoxysilane according to claim 1, characterized in that the silane-based solvent can be selected from tetraalkoxysilane or chloropropyltrialkoxysilane.

3. The process of claim 1, wherein the transition metal compound or alcoholic solution thereof is selected from iridium chloride, iridium chlorohydrate, chloroiridic acid, ruthenium dodecacarbonyl, ruthenium trichloride, (1, 5-cyclooctadiene) iridium chloride, and rhodium chlorohydrate.

4. The process for obtaining chloropropyltrialkoxysilanes from trialkoxysilanes according to claim 1, characterised in that after activation of the trialkoxysilane an inhibitor is added in an amount of 1/1000-1/100 relative to the mass of the trialkoxysilane.

5. The process of claim 4, wherein said inhibitor is selected from cyanuric acid, urotropine, paraformaldehyde, triphenylphosphine.

6. The process for preparing chloropropyltrialkoxysilanes from trialkoxysilanes according to claim 1, characterized in that the reaction temperature is between 60 and 120 ℃.