CN102604099B - Method for effectively processing industrial waste n-propyl trifunctional silane - Google Patents

Abstract

The invention discloses a method for effectively treating industrial waste n-propyl trifunctional silane. The n-propyl trifunctional silane is processed into di-n-propyl difunctional silane and its derivatives through Grignard reaction. The use value of industrial waste is improved by preparing dipropyldifunctional silane and derivatives thereof. The prepared silicone resin, silicone oil, silicone rubber and their secondary products containing propyl group have outstanding performance and wide application. The method of the invention is stable in process, simple and reliable, high in yield and low in cost, can solve the problem of waste material treatment urgently needed in the current silane coupling agent industry, and turn waste into wealth while reducing environmental pollution.

Description

A method for effectively treating industrial waste n-propyl trifunctional silane

technical field

The invention relates to a method for effectively treating industrial waste n-propyl trifunctional silane, in particular to processing n-propyl trifunctional silane into dipropyl difunctional silane and further preparing hexapropylcyclotrisiloxane 1. A process for polysiloxane and silicone rubber containing dipropylsiloxane chain segments. the

Background technique

N-propyltrifunctional silane (including n-propyltrimethoxysilane, n-propyltriethoxysilane and n-propyltrichlorosilane) is a by-product in the industrial production of silane coupling agents, accounting for about 5% of the mixture, the production amount is very large, and it will seriously pollute the environment after being discarded. However, these by-products are currently not well utilized. The main treatment method on the market is to prepare fumed white carbon black by high-temperature calcination. This process consumes a lot of energy, the added value of the product is small, and it cannot reflect the unique performance of the material, resulting in great waste. Since such by-products cannot be discharged as sewage, and in the absence of better treatment methods and processes, many domestic silane coupling agent manufacturers now store such by-products for a long time, occupying a large storage area. The storage room even seriously affected the normal operation of the factory. However, some manufacturers give up the separation of such by-products and directly sell unpurified silane coupling agents on the market, which seriously affects the competitiveness of products in domestic and foreign markets. Therefore, the effective treatment of such by-products has become an important problem that needs to be solved urgently. the

The availability of n-propyl trifunctional silane is not high, mainly because there are three functional groups in it, which is very easy to hydrolyze, and the performance of the hydrolyzed product cannot be well controlled. If you want to improve its utilization value, the more convenient method is to convert the three functional groups it has into two functional groups. There are many methods used, one of which is to convert one of the functional groups into an inactive group, such as an alkyl group, through the Grignard Reaction. When the converted inactive group is n-propyl, the prepared silane is di-n-propyl difunctional silane, which is called dipropyl difunctional silane for short. the

For the preparation of dipropyldifunctional silane from n-propyl trifunctional silane, there are no reports at home and abroad. At present, only the research on the preparation of dialkyldialkoxysilane from the reaction of haloalkane and tetraalkoxysilane can be used for reference, which can be divided into one-step method and two-step method. The patent EP460590 introduces a two-step method, that is, the Grignard reagent is prepared by the reaction of chlorocyclopentane and magnesium chips in a tetrahydrofuran solvent, and then the obtained Grignard reagent is reacted with equimolar tetramethoxysilane to synthesize a bicyclic Pentyldimethoxysilane. Due to the two-step synthesis, it will naturally bring about complex operations, long process flow, and many reaction equipment problems, and the content of by-products in the synthesis liquid is high, and the reaction yield is low. the

In US4958041 and CN1183143 patents, the method for synthesizing dialkyldialkoxysilane in one step is introduced. The method is to prepare a small amount of Grignard in methyl-tert-butyl ether solvent with chloroalkane and magnesium chips. The reagent is used as an initiator, and then a mixed solution composed of chloroalkane, tetraalkoxysilane and methyl-tert-butyl ether is added dropwise to react to synthesize dialkyldialkoxysilane. Although the one-step synthesis process described in the patent is convenient, if it is to be applied to the research content involved in the present invention, there are still several problems to be solved. First of all, this one-step preparation process requires a small amount of Grignard reagent as an initiator, which is difficult to implement industrially; secondly, according to the method introduced in the patent, there will be a large amount of unreacted Grignard reagent remaining in the synthesis solution during the reaction, which will bring trouble to the post-processing. Again, the molar ratio of chloroalkane to tetraalkoxysilane is too large, which will increase the production cost, because in the research of dealing with n-propyl trifunctional silane involved in the present invention, n-propyl trifunctional Silane is an industrial waste with very low cost, while chloroalkane is relatively expensive and accounts for a large proportion of raw material cost. Calculated by chloroalkane, the reaction efficiency of the synthesis process is very low. the

In order to improve the product yield, CN1183143 also introduces a method for processing the filter cake, that is, the filtered filter cake is treated with dilute hydrochloric acid, and the product and solvent are recovered. Because organosiloxane is very sensitive to moisture, especially acidic aqueous solution, it is easy to hydrolyze, so the product and unreacted raw materials in the filter cake will be destroyed, and moisture will be brought into the product at the same time. the

JP 6-345781 provides a laboratory preparation method of dialkyldialkoxysilane. The reaction medium is expensive and unsuitable for industrial production. The post-treatment of this method is to add an aqueous solution of inorganic salt first, and then add acid to treat the reaction material, so that the solid material in the reaction material is dissolved into inorganic salt and enters the water phase. The target product in the reaction material remains in the organic phase, and the organic phase is removed. The solvent produces the product. This method eliminates filtration and corresponding washing of filter cake and other operations. But because the hydrolysis loss of dialkyldialkoxysilane is very serious, the yield of target product is very low. the

Patent CN101225090A provides a new method different from the above several processes: using the reactant tetraalkoxysilane as a solvent, in the presence of a catalyst, first initiate a Grignard reaction with a small amount of haloalkane and metal magnesium powder, and then dropwise add Dialkyldialkoxysilanes can be synthesized in one step by reacting haloalkanes diluted with hydrocarbon or ether solvents with tetraalkoxysilanes via Grignard reagents. But in the technology that this patent introduces, after reaction finishes and cools down, directly filters. Because the Grignard reagent is excessive in the chemical reaction involved in this process, when the reaction reaches a certain level, the target product has been obtained, but the excess reactant continues to exist, and the Grignard reagent will be mixed with the air in the process of filtration. Oxygen and water vapor react exothermicly, and the released heat will further prompt the excess Grignard reagent to continue to react with the target product, generating a series of by-products. During the implementation of the process, an increase in the temperature of the filter unit was observed. Since there are a large number of organic reagents in the system, the temperature rise will cause potential danger, so the quenching process is necessary. the

Based on the above research status, if you want to treat n-propyl trifunctional silane with Grignard reagent to prepare its derivatives, you can’t blindly copy the process conditions of similar research, and you need to learn from the relevant research content. Improvement can truly effectively deal with industrial waste, increase its use value, and turn waste into treasure. the

There are no reports on the properties and applications of dipropyldifunctional silane at home and abroad. Since dipropyl difunctional silane belongs to the category of dialkyl difunctional silanes, it has the general properties of dialkyl difunctional silanes, for example, it can be used as a structural control agent for silicone compounds, polypropylene Stereo modifiers for catalysts in production, chain extenders for room temperature vulcanized silicone rubber and synthetic reagents for silicone vinyl capping agents, etc., especially as the most basic raw materials for silicone oil and silicone rubber, the market demand is very high. Because the propyl group has a longer chain and greater steric hindrance than the methyl group, dipropyl difunctional silane is different from ordinary dimethyl difunctional silane, and has special properties and wider application space. the

Dipropyl difunctional silane can be hydrolyzed and condensed by itself or with other silanes with 1 to 3 Si-R' (R' is a non-hydrolyzable group) to form homopolymers or copolymers. The hydrolysis of dipropyldifunctional silane is the same as that of other hydrolyzable silanes. When the hydrolyzed group of these silanes is a halogen, the hydrohalic acid generated during hydrolysis will promote the further progress of hydrolysis. the

Formula 1: (Pr) _a (R') _b SiO _(4-ab)/2 (where Pr is a propyl group and R' is a non-hydrolyzable group)

The properties of the condensation product depend on the properties of Si-R' and the ratio of propyl group to R'. When the sum of a and b in formula 1 is less than 1.9, the obtained polysiloxane has the properties of resin. When the sum of a and b is 1.98-2.01. The resulting polysiloxane has a viscosity close to that of rubber. When the sum of a and b is greater than 2.1, the final product is a triorgano-terminated polysiloxane. The prepared resins, rubber-like fluids, and end-blocked polysiloxanes have the same applications as polysiloxanes with conventional organic groups as silicone materials with both conventional and propyl groups. In addition, these materials have special value in high and low temperature resistance. Due to the introduction of propyl groups, the properties of silicone elastomers and resins have changed, so they have a wider application space. the

Starting from dipropyl difunctional silane, polysiloxane containing dipropylsiloxane chains can be prepared. If all are dipropyl chains, it is called polydipropylsiloxane; if it is a dipropyl chain Copolymerized with other chain segments (such as dimethyl), it is called dimethyldipropyl copolymerized polysiloxane; all of the above can be referred to as propyl silicone oil (this abbreviation is used hereinafter). This new type of silicone oil also has the properties of ordinary silicone oil, such as water resistance, anti-adhesion, mold release, defoaming, emulsification, lubrication, low volatility, etc. After secondary processing, propyl silicone oil can also be made into secondary products such as silicone grease, silicone paste, defoamer, release agent, and paper release agent. the

However, the synthesis process of dipropyl silicone oil is quite different from that of ordinary silicone oil. Methyl silicone oil can be obtained by hydrolysis of dimethyl difunctional silane. High molecular weight dimethicone can be obtained by ring-opening polymerization of cyclosiloxane. However, the synthesis of diethyl silicone oil is more difficult. This is because the ring-opening activities of different side chain cyclic siloxanes are different, and the conditions for synthesizing polysiloxanes with different side chains are also different. Although the synthesis of propyl silicone oil has not been reported yet, it can still be determined that its synthesis conditions are completely different from those of methyl silicone oil and ethyl silicone oil. the

High molecular weight propyl silicone oil can be prepared by ring-opening polymerization of cyclosiloxane. This method requires the first preparation of hexapropylcyclotrisiloxane as a starting material. The synthetic process of hexapropylcyclotrisiloxane has not been reported either. The synthesis of hexamethylcyclotrisiloxane has become a consensus in the industry. It is generally prepared by a three-step method. The first step is the hydrolysis of dimethyldichlorosilane, followed by high-temperature cracking under the action of strong alkali, and then by rectification Hexamethylcyclotrisiloxane was isolated. But in this process, the main product is octamethylcyclotetrasiloxane, and the proportion of hexamethylcyclotrisiloxane is very low, and the yield is lower than 10% based on the original feed ratio. Patent CN101597303A discloses the preparation process of hexaethylcyclotrisiloxane, which is also prepared by a three-step method, namely hydrolysis, cracking and rectification. Both of the above-mentioned methods have the disadvantages of many steps, complex reactions, many raw materials and high energy consumption. Since the propyl group has a larger volume and greater steric hindrance than the methyl and ethyl groups, and the physical properties of the three are different, hexapropylcyclotrisiloxane can be obtained in one step by changing the reaction process. the

When starting from hexapropylcyclotrisiloxane to prepare polydipropyl silicone oil and (or) dimethyldipropyl copolysiloxane, as previously mentioned, the preparation process and the preparation of methyl silicone oil and ethyl silicone oil The difference in process is large, which is caused by the influence of propyl group. A strong catalyst must be used to open the ring of hexapropylcyclotrisiloxane. At the same time, an accelerator is used to promote the reaction. Finally, a chain stopper is added to terminate the reaction, so as to prevent the phenomenon of molecular weight reduction and wide molecular weight distribution caused by end group backbiting. . the

Like traditional polysiloxanes, Formula 1 can be converted to an insoluble resin by adding a curing agent. The properties of these resins can be precisely controlled with or without fillers. The organic group-terminated polysiloxane liquid can be used as a lubricant by adding additives. High viscosity rubber analogs can be converted into silicone elastomers by adding suitable fillers and vulcanizing agents. In this respect, the suitable filler referred to should be easy to disperse in the matrix, such as fumed silica, precipitated silica, and the like. Others such as titanium dioxide, alumina and carbon black can also be used as fillers. Preferred vulcanizing agents are those of benzoyl peroxide and cumene peroxide. the

Contents of the invention

The object of the present invention is to provide a method for effectively treating industrial waste n-propyl trifunctional silane, and the use value of industrial waste is improved by preparing dipropyl difunctional silane and derivatives thereof. Because the process is stable, simple and reliable, high in yield and low in cost, it can solve the urgent problem of waste disposal in the current silane coupling agent industry, and turn waste into treasure while reducing environmental pollution. the

The technical solution for the treatment of n-propyl trifunctional silane involved in the present invention is: in the same reactor, the reactant n-propyl trifunctional silane is used as the initial reactant, and the method for preparing Grignard reagent on site is synthesized in one step. target product. The method makes full use of the huge heat of reaction released when the Grignard reaction occurs, so that the reaction for preparing the dialkyldialkoxysilane can be carried out quickly and smoothly. the

Specific steps are as follows:

(1) by n-propyl trifunctional silane: chloropropane: magnesium is 0.8～1:1:1～1.5 molar ratio will magnesium, n-propyl trifunctional silane and the chloropropane of 10%～50% charging amount Add it to the solvent made by mixing ethers and hydrocarbons, the molar ratio of the amount of solvent to n-propyl trifunctional silane is 1-10:1; use iodine as catalyst, heat to 70°C-150°C to trigger reaction, and then drop the remaining chloropropane diluted by solvent to synthesize dipropyldifunctional silane; after the synthetic liquid is lowered to room temperature, it is quenched with a quenching agent in an ice-water bath, and after the solid is separated, Obtain high-purity product dipropyl difunctional silane by fractional distillation and rectification;

Among them: the above-mentioned magnesium is magnesium powder, magnesium chips or magnesium bars; the above-mentioned ethers are diethyl ether, tetrahydrofuran, methyl tert-butyl ether, propyl ether, butyl ether or 1,4-dioxane; the above-mentioned hydrocarbons are hexane , cyclohexane, heptane, benzene or toluene; the mixed volume ratio of ethers and hydrocarbons in the solvent is 0.2 to 1: 0 to 1; the molar ratio of the amount of the catalyst to the reactant magnesium is 0.0001 to 0.1: 1; Above-mentioned quenching agent is methyl alcohol or ethanol, and the molar ratio of its consumption and n-propyl trifunctional silane is 1～5: 1;

(2) Dissolve di-n-propyl difunctional silane in an inert solvent, then slowly add the mixed solution into a dilute acid solution to prepare a hydrolyzate, which is sequentially washed with saturated sodium carbonate, saturated sodium chloride and After washing with distilled water and drying, high-purity hexapropylcyclotrisiloxane is obtained by fractional distillation under reduced pressure, and the residue after fractionation is cracked at 150-350°C under a potassium alkali catalyst to obtain hexapropylcyclotrisiloxane ;

Wherein: the above-mentioned inert solvent is hydrocarbons or ethers, and the hydrocarbons are hexane, cyclohexane, heptane, benzene or toluene, and the ethers are ether, tetrahydrofuran, methyl tert-butyl ether, propyl ether, Butyl ether or 1,4-dioxane; above-mentioned dilute acid is dilute hydrochloric acid, dilute sulfuric acid or dilute acetic acid; above-mentioned potassium alkali catalyst is potassium hydroxide, potassium carbonate, potassium ethylate or potassium silanolate, and its consumption is: potassium in The mass percentage in siloxane is 0.1% to 5%;

(3) React hexapropylcyclotrisiloxane with catalyst and accelerator at 80°C to 150°C under nitrogen protection, and add end-capping agent hexamethyldisiloxane to obtain polydipropylsiloxane ;

or

(3) React hexapropylcyclotrisiloxane and octamethylcyclotetrasiloxane at 80°C to 150°C in the presence of catalysts and accelerators to obtain dimethyldipropylcopolysiloxane ;

Wherein: the catalyst described in step (3) is lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide or tetramethylammonium hydroxide, and the mass ratio of its consumption and hexapropyl cyclotrisiloxane is 0.001 ～0.05: 1; The accelerator is dimethyl sulfoxide, N, N-dimethylformamide, hexamethylphosphoramide, tetrahydrofuran, crown ether, cryptate, polyether or nitrobenzene, and its consumption is the same as The mass ratio of hexapropylcyclotrisiloxane is 0.01～0.20:1; the mass ratio of the amount of the end-capping agent hexamethyldisiloxane to hexapropylcyclotrisiloxane is 0.001～0.01: 1. The mass ratio of the hexapropylcyclotrisiloxane to the octamethylcyclotetrasiloxane is 0.05-100:1. the

(4) Co-hydrolyze dipropyl difunctional silane and other hydrolyzable silanes to prepare various resins and silicone oil products containing propyl groups, and further prepare various types containing Propyl-based products. the

(5) Blend propyl silicone oil with reinforcing filler, concentrated cross-linking agent, vulcanizing agent and other fillers, and undergo a vulcanization process to prepare silicone rubber containing propyl groups and blended rubber products of silicone rubber and other rubbers. the

The reactant ratios and reaction conditions used in the present invention can vary within a wide range. The purpose of the present invention is to convert one of the functional groups of the industrial waste n-propyl trifunctional silane into a propyl group, thus it needs to be reacted by one mole of n-propyl trifunctional silane and one mole of Grignard reagent, considering The activity of Grignard reagent is very high, and side reaction is easy to take place, so the preferred condition in the present invention is that the molar weight of Grignard reagent is slightly higher than n-propyl trifunctional silane; Grignard reagent is composed of one mole of chloropropane Prepare with one mole of magnesium, considering that magnesium is easily oxidized and the Grignard reagent generated will cover the surface of magnesium to stop the reaction when the dissolution situation is not good, so the preferred condition in the present invention is the molar amount of magnesium Slightly higher than chloropropane; In summary, the preferred condition in the present invention is that the amount of substance of n-propyl trifunctional silane is slightly less than the amount of substance of chloropropane and then less than the amount of substance of magnesium, the optimal ratio The weight ratio of n-propyltrifunctional silane:chloropropane:magnesium is 0.9:1:1.2. the

Since the reactants that do not participate in the reaction can be recovered and re-dosed for use after the reaction, the excessive use of any component in the reactant ratio is within the scope of the present invention. Within a certain range, simultaneous excess of both components is also advisable. For example, from 0.5 to 1.3 moles of chloropropane reacting with 1 mole of n-propyltrifunctional silane in the presence of an excess of magnesium gave satisfactory results. If considering the pretreatment situation and the feeding ratio of the reaction material magnesium (divided into three kinds of magnesium strips, magnesium powder, and magnesium chips), the ratio range of the above-mentioned chloropropane and n-propyl trifunctional silane can be further expanded, 0.1: 1 to 10:1 is also possible. In the case of activated magnesium in excess, 0.9:1 to 1.2:1 is preferred. In the reaction process, due to the existence of quenching reaction and excessive Grignard reagent will bring side reactions, large excess of chloropropane and magnesium powder will cause great waste at the same time, so it is not within the scope of the present invention. the

The magnesium that selects in the technology of the present invention has three kinds of magnesium powder, magnesium chips and magnesium bar, wherein because the particle size of magnesium powder is little, the specific surface area is big and active, thereby is most preferred; Magnesium chips and magnesium bar all need to use weak acid before use Soaking treatment to improve the activity; especially for magnesium strips, if the surface of the magnesium strips is dark, it needs to be polished in advance. The molar ratio of magnesium to alkyl halide after treatment is 1:1 to 2:1, preferably 1.1:1 to 1.3:1. the

The catalyst ratio can also be varied within a wide range. Based on the amount of substance of reactant magnesium, when the mol ratio of iodine and magnesium is 0.0001: 1 to 0.1: 1, all can react smoothly, preferably 0.01: 1.

The dissolution of the Grignard reagent in the present invention has a great influence on whether the reaction can be carried out smoothly, so the selection of the solvent is very important. The first condition for selecting a solvent is to have a certain solubility to the Grignard reagent, so ethers are the first choice, including any ethers routinely used in this field, such as diethyl ether, tetrahydrofuran, methyl tert-butyl ether, propyl ether, butyl ether or 1 , 4-dioxane, preferably tetrahydrofuran. The ethers involved in the technology of the present invention need to be dewatered before use, the purpose of which is to prevent the moisture in the ether solvent from quenching the reaction and reducing the yield. Due to the disadvantages of ethers such as difficult water removal operation, high price, and low boiling point, a mixture of ethers and hydrocarbon solvents can be selected as a solvent to reduce the amount of ethers used. The hydrocarbon solvents involved in the present invention are hexane, cyclohexane, heptane, benzene, toluene, etc., preferably toluene. The volume content of ethers in the mixed liquid is 100% to 20%, preferably 50%. the

The mol ratio of mixed solution and reaction raw material n-propyl trifunctional silane is 1: 1 to 10: 1, preferably 5: 1 to 9: 1.

The feeding of raw materials in the present invention is divided into two steps. As mentioned above, some raw materials are first put into the reactor as the "bottom material", and the rest of the raw materials are used as the "drop feed", which is added dropwise into the reactor after the reaction is started. In order to start the reaction smoothly and stably, the present invention attaches great importance to the amount of halogenated alkanes in the "base material", and has achieved satisfactory results in the industrial production of the target product. The chloropropane in the "bottom material" accounts for 10% to 50% of the total weight of the chloropropane feed, preferably 10-20%. The solvent in the primer accounts for 10% to 40% of the total weight of the solvent feed, preferably 15-25%. the

Because the reactions studied in the present invention are heterogeneous, agitation of the reactions is a primary consideration. The more effective method adopted in the present invention is: under mechanical stirring, after adding the reactant and the catalyst in the reaction vessel, heating the reaction mixture to reflux. The solid in the lower layer is mainly mixed by mechanical stirring, and the upper layer is mainly blended by liquid reflux. However, do not stir quickly, otherwise the heat will be lost quickly and the reaction cannot continue; nor can the mechanical stirring be stopped after the reflux occurs, and only rely on reflux, otherwise it will be unable to disperse due to the exothermic heat of the local reaction, resulting in local overheating and then flushing. the

The reaction temperature is generally from 0°C to 120°C, preferably from 70°C to 150°C, most preferably from 100°C to 130°C, according to the boiling point of the selected mixed solution. The higher the reaction temperature, the more violent the reaction, but when the temperature is too high, it is easy to cause the risk of flushing, so it is necessary to adjust the reaction temperature according to the selected solvent. The reaction of the present invention is preferably carried out at a slight reflux temperature all the time after the reaction is started. the

After completion of the reaction of n-propyltrifunctional silane with chloropropane in the presence of magnesium, the resulting reaction product is separated from the mixture by various methods. For example, the reaction mixture can be filtered to remove solids, and the filtrate can be subjected to fractional distillation to obtain the product. When using this method, it is often found that the yield is low due to the fact that the solid is relatively viscous and absorbs a large amount of product. A very effective solution is to dilute the product mixture with an inert solvent, then filter and wash the filter cake several times to increase the yield. the

There is a small amount of excess Grignard reagent residue in the residual solids of the Grignard reaction obtained in the present invention, and it is necessary to remove the unreacted Grignard reagent with a quencher after the reaction to avoid danger caused by oxidation during subsequent processing. The quencher also acts as a diluent. Because as the reaction progresses, the solids in the system gradually increase and the reaction materials become thicker. The added quenching agent can effectively disperse the solids at the same time and increase the fluidity of the reaction materials, which is conducive to the smooth progress of the reaction and is also beneficial to subsequent reactions. separation operation. Alcohols are usually selected as the quenching agent, and the Grignard reagent is converted into alkoxymagnesium salt by reaction, and then removed by filtration. If the raw material is n-propyltrimethoxysilane, the selected quenching agent is methanol, and if the raw material is n-propyltriethoxysilane, the selected quenching agent is ethanol. The molar ratio of the solvent amount of the quencher to n-propyltrifunctional silane is 1:1 to 5:1, preferably 1:1 to 3:1. the

When the reaction raw material is n-propyltrichlorosilane, since the product is dipropyldichlorosilane, its silicon-chloride bond is easy to react with the quenching agent, so it is generally first distilled out from the system, and then placed in an ice-water bath Adding quenching agent to the remaining solids under certain conditions, this process is simple and the yield is not very high. In order to improve the yield of dipropyl dichlorosilane, the reaction system can be diluted by adding the inert solvent diphenyl ether in the system earlier, and then the dipropyl dichlorosilane is distilled out from the system (the boiling point of diphenyl ether is higher than Dipropyl dichlorosilane, during distillation, dipropyl dichlorosilane is first evaporated), and then add the quenching agent to the remaining solids. In order to improve the processing efficiency of n-propyl trifunctional silane and obtain more products, another effective solution can be selected, which is to replace these chlorine atoms with ethoxy groups, so that the ethoxy derivatives formed will not It will be easily hydrolyzed and can be filtered in an open system. The filtrate was collected and the solvent was distilled off, and then the product dipropyldiethoxysilane was obtained by fractional distillation under reduced pressure. This can be achieved by adding triethylorthoformate at the end of the reaction. Triethyl orthoformate also acts as a quencher for the Grignard reagent. The ratio of triethyl orthoformate to silicon-chlorine bond is 1:1 to 3:1, preferably 2:1. the

In the technical scheme (2) related to the patent of the present invention, the inert solvent includes hydrocarbons and ethers. Hydrocarbons are hexane, cyclohexane, heptane, benzene or toluene; ethers are diethyl ether, tetrahydrofuran, methyl tert-butyl ether, propyl ether, butyl ether or 1,4-dioxane; preferably toluene. The dilute acid is dilute hydrochloric acid, dilute sulfuric acid or dilute acetic acid, preferably dilute hydrochloric acid. The potash base catalyst includes one of potassium hydroxide, potassium carbonate, potassium ethoxide or potassium siliconate, and its dosage is: the mass percentage of potassium in siloxane is 0.1% to 5%, preferably potassium hydroxide. the

The hydrolyzate prepared by the technical scheme (2) involved in the patent of the present invention has a very high content of hexapropylcyclotrisiloxane, and direct vacuum distillation can obtain a higher yield, which is different from that of hexamethylcyclotrisiloxane And the characteristics of the low content of the target product in the hydrolyzate of hexaethylcyclotrisiloxane. the

In the technical scheme (2), the cracking reaction temperature is 150 to 350°C, preferably 200 to 300°C. the

In the technical scheme (3) that the patent of the present invention relates to, the catalyst is lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide or tetramethylammonium hydroxide, preferably tetramethylammonium hydroxide; the preferred crown ether of the accelerator . the

In the technical solution (5) involved in the patent of the present invention, the reinforcing filler includes fumed silica, precipitated silica, titanium dioxide, alumina, and carbon black, preferably fumed silica; the vulcanizing agent includes benzene peroxide Vulcanizing agents such as formyl and cumene peroxide, preferably benzoyl peroxide. the

The achievements of the invention can solve the urgent problem of waste disposal in the current silane coupling agent industry, reduce waste liquid discharge, save production costs, and reduce industrial energy consumption. At the same time, it can also provide various new products containing propyl groups with superior performance, including Silicone oil, silicone resin and silicone rubber, etc., so as to comprehensively improve the industry research and development level and technical strength of my country's silane coupling agent industry and even the silicone industry. the

Detailed ways

Example 1

Add 7.2g of magnesium powder, 32.8g of n-propyltrimethoxysilane, 3g of chloropropane and 50mL of tetrahydrofuran (anhydrous treatment) to each reactant in a reaction vessel, put 0.025g of iodine particles, and heat This mixture was brought to 74°C, resulting in liquid reflux. A large number of bubbles are generated on the liquid surface, and the reaction is initiated. At this point, 16.62 g of chloropropane dissolved in 50 mL of tetrahydrofuran (need to be anhydrous treated) was slowly added dropwise. Control the heating temperature to keep the system in a slightly boiling state, and the temperature floats at about 76°C. Gas chromatography is used to monitor the residual amount of reactants. When the conversion rate of n-propyltrimethoxysilane is greater than 99%, the reaction ends (about four hours), the reaction is stopped, and natural cooling is performed. the

In an ice-water bath, 20 mL of anhydrous methanol was added to quench the reaction. Filter and wash the precipitate. The precipitate was washed with a small amount of anhydrous methanol. The filtrates were combined and the solvent was removed by rotary evaporation. The product mixture was subjected to fractional distillation. Infrared and NMR were used to confirm the product, dipropyldimethoxysilane, and the yield was 90% calculated according to the amount of n-propyltrimethoxysilane added. the

Example 2

The n-propyltrimethoxysilane in Example 1 was replaced with n-propyltriethoxysilane to obtain dipropyldiethoxysilane. the

Example 3

Replace the magnesium powder in Example 1 with magnesium bars (before use, it needs to be polished and soaked in dilute acid, dried and then fed), to obtain dipropyldimethoxysilane. the

Example 4

The magnesium powder in Example 1 was replaced with magnesium chips (before use, it needs to be soaked with dilute acid, dried and then fed), to obtain dipropyldimethoxysilane. the

Example 5

7.2g of magnesium powder, 37.0g of n-propyltrimethoxysilane, 6g of chloropropane and 60mL of tetrahydrofuran (need to be treated without water) were added to a reaction vessel, and after the reaction was triggered, slowly drop Add 14.64 g of chloropropane dissolved in 40 mL of tetrahydrofuran (need to be anhydrous treated), and when other conditions remain unchanged, the yield of the product dipropyldimethoxysilane is 87%. the

Example 6

When the tetrahydrofuran in Example 5 was replaced with an equal proportion mixture of tetrahydrofuran and toluene (both subject to anhydrous treatment), other conditions remained unchanged, and the yield of the product dipropyldimethoxysilane was 80%. the

Example 7

The ratio of 7.2g magnesium powder, 39.3g n-propyl trichlorosilane, 3g chloropropane and 50mL tetrahydrofuran (need to be treated without water) is added to each reactant in a reaction vessel, 0.025g iodine particles are put into it, and the mixture is heated. The mixture reaches 74 degrees Celsius, producing liquid reflux. A large number of bubbles are generated on the liquid surface, and the reaction is initiated. At this time, 16.62 g of chloropropane dissolved in 50 mL of tetrahydrofuran (requiring anhydrous treatment) was slowly added dropwise. Control the heating temperature to keep the system in a slightly boiling state all the time, and the temperature floats at about 76 degrees Celsius. After four hours, the reaction was stopped and allowed to cool naturally. the

After adding 50 mL of diphenyl ether, distill out the low-boiling solvent by ordinary distillation, and then distill under reduced pressure to obtain dipropyldichlorosilane with a product yield of more than 50%. the

Example 8

In Example 7, 50 mL of diphenyl ether was replaced with 100 g of triethyl orthoformate to replace the chloro-silicon bonds with ethoxy groups, and then filtered, the filtrate was collected and the solvent was evaporated. Fractional distillation under reduced pressure can obtain dipropyldiethoxysilane. The product is confirmed by infrared and NMR, and the calculated yield exceeds 60% based on the amount of n-propyltrichlorosilane initially added. the

Example 9

Add 10 mol of dipropyldichlorosilane, 10 mol of dimethyldichlorosilane and 0.1 mol of trimethylsilane into 1L of ice water, and neutralize the hydrolyzate with sodium carbonate. The obtained oil layer is separated from the water layer, and the organosilicon liquid substance contains dipropyl silicon-based units, dimethyl silicon-based units and trimethyl silicon-based units, and can be used as a lubricant and a heat-transfer fluid. the

Example 10

Dipropyldichlorosilane in Example 9 is replaced by dipropyldimethoxysilane or dipropyldiethoxysilane, and dimethyldichlorosilane is not replaced or dimethyldimethylsilane is replaced. Oxysilane or dimethyldiethoxysilane can be used to obtain a silicone liquid containing dipropylsilyl units, dimethylsilyl units and trimethylsilyl units. the

Example 11

Into the reaction vessel, 200 mL of 6 mol/L hydrochloric acid was added, and then 40 g of dipropyldimethoxysilane dissolved in 50 mL of toluene was slowly added while stirring. After the dropwise addition was complete, stirring was continued for 4 hours. Stand to separate layers, wash the oil layer with water, saturated potassium carbonate, saturated sodium chloride and distilled water respectively, and dry with anhydrous magnesium sulfate to obtain high-purity dipropylsiloxane hydrolyzate. the

The hydrolyzate is fractionated under reduced pressure, and the product is confirmed by infrared, NMR and mass spectrometry to obtain hexapropylcyclotrisiloxane with a purity of more than 99%. the

Example 12

The dipropylsiloxane hydrolyzate in Example 11 was pyrolyzed at 250° C. in the presence of potassium hydroxide and the low boilers were separated under reduced pressure to obtain a dipropylsiloxane mixture. The mixture was fractionated under reduced pressure, and the product was confirmed by infrared, NMR and mass spectrometry to obtain hexapropylcyclotrisiloxane with a purity of more than 99%. the

Example 13

The hydrolyzate obtained by fractionating hexapropylcyclotrisiloxane in Example 11 was pyrolyzed at 250° C. in the presence of potassium hydroxide and the low boilers were separated under reduced pressure to obtain a dipropylsiloxane mixture. The mixture was fractionally distilled, and the product was confirmed by infrared, NMR and mass spectrometry, and hexapropylcyclotrisiloxane could be obtained with a purity of more than 99%. the

Example 14

Polydipropylsiloxane, also known as propyl silicone oil, can be prepared by polymerizing 100 parts (parts by mass) of hexapropylcyclotrisiloxane with a purity of more than 99% under the catalysis of 1 part of potassium hydroxide. the

Example 15

The catalyst in Example 14 is replaced by tetramethylammonium hydroxide alkali gel to prepare polydipropylsiloxane. The catalyst in the product can be removed by raising the temperature. the

Example 16

100 parts (parts by mass) of hexapropylcyclotrisiloxane with a purity of 99% or more, 100 parts of octamethylcyclotetrasiloxane and 1 part of hexamethyldisiloxane were catalyzed by 1 part of potassium hydroxide Polymerization reaction can obtain high molecular weight copolymer of dimethylsiloxane and dipropylsiloxane. The catalyst in the product can be neutralized with silyl phosphate. the

Example 17

The catalyst in Example 16 is replaced by tetramethylammonium hydroxide alkali gel, and dimethylsiloxane dipropylsiloxane copolymer can also be obtained. The catalyst in the product can be removed by raising the temperature. the

Example 18

100 parts (parts by mass) of hexapropylcyclotrisiloxane with a purity of more than 99%, 100 parts of octamethylcyclotetrasiloxane, 10 parts of tetramethyltetravinylsiloxane and 1 part of hexamethyldi Siloxane is polymerized under the catalysis of 1 part of tetramethylammonium hydroxide alkali gel to obtain high molecular weight dimethylsiloxane dipropylsiloxane copolymer with vinyl groups. The catalyst in the product can be removed by raising the temperature. the

Example 19

Add an equal amount of white carbon black to 100 parts (mass parts) of the copolymer after removing the catalyst in Example 18, carry out blending on the mixer, then heat at 160 degrees Celsius for 30 minutes, then add 3 parts of peroxide Benzoyl, then heat treatment under pressure at 180 degrees Celsius for 20 minutes, and finally heat treatment at 160 degrees Celsius for 1 hour. Special silicone rubber with excellent performance in high and low temperature resistance can be obtained.

The unit of mass parts in the above-mentioned embodiments is gram. the

Claims (10)

1. a method for processing industrial waste n-propyl trifunctional silane is to process n-propyl trifunctional silane into di-n-propyl difunctional silane and derivatives thereof by Grignard reaction, characterized in that, The above processing method is: (1) Add magnesium, n-propyl trifunctional silane and 10% to 50% of chloropropane in the molar ratio of n-propyl trifunctional silane: chloropropane: magnesium in a molar ratio of 0.8 to 1:1:1 to 1.5 Add it to the solvent made by mixing ethers and hydrocarbons, the molar ratio of the amount of solvent to n-propyltrifunctional silane is 1-10:1; use iodine as catalyst, heat to 70°C-150°C to trigger reaction, and then drop the remaining chloropropane diluted by solvent to synthesize dipropyldifunctional silane; after the synthetic liquid is lowered to room temperature, it is quenched with a quenching agent in an ice-water bath, and after the solid is separated, Obtain high-purity product dipropyl difunctional silane by fractional distillation and rectification; Among them: the above-mentioned magnesium is magnesium powder, magnesium chips or magnesium bars; the above-mentioned ethers are diethyl ether, tetrahydrofuran, methyl tert-butyl ether, propyl ether, butyl ether or 1,4-dioxane; the above-mentioned hydrocarbons are hexane , cyclohexane, heptane, benzene or toluene; the mixed volume ratio of ethers and hydrocarbons in the solvent is 0.2～1:0～1; the molar ratio of the amount of the catalyst to the reactant magnesium is 0.0001～0.1:1; The above-mentioned quenching agent is methanol or ethanol, and the molar ratio of its consumption to n-propyltrifunctional silane is 1～5:1; (2) Dissolve di-n-propyl difunctional silane in an inert solvent, then slowly add the mixture into a dilute acid solution to prepare a hydrolyzate, which is sequentially washed with saturated sodium carbonate, saturated sodium chloride and After washing with distilled water and drying, high-purity hexapropylcyclotrisiloxane is obtained by fractional distillation under reduced pressure, and the residue after fractionation is cracked at 150-350°C under a potassium alkali catalyst to obtain hexapropylcyclotrisiloxane ; Wherein: the above-mentioned inert solvent is hydrocarbons or ethers, and the hydrocarbons are hexane, cyclohexane, heptane, benzene or toluene, and the ethers are ether, tetrahydrofuran, methyl tert-butyl ether, propyl ether, Butyl ether or 1,4-dioxane; above-mentioned dilute acid is dilute hydrochloric acid, dilute sulfuric acid or dilute acetic acid; above-mentioned potassium alkali catalyst is potassium hydroxide, potassium carbonate, potassium ethylate or potassium silanolate, and its consumption is: potassium in The mass percentage in siloxane is 0.1% to 5%; (3) React hexapropylcyclotrisiloxane with catalyst and accelerator under nitrogen protection at 80°C to 150°C, and add end-capping agent hexamethyldisiloxane to obtain polydipropylsiloxane ; or (3) Reaction of hexapropylcyclotrisiloxane and octamethylcyclotetrasiloxane in the presence of a catalyst and an accelerator at 80°C to 150°C to obtain dimethyldipropylcopolysiloxane ; Wherein: the catalyst described in step (3) is lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide or tetramethylammonium hydroxide, and the mass ratio of its consumption to hexapropylcyclotrisiloxane is 0.001 ～0.05:1; The accelerator is dimethyl sulfoxide, N, N-dimethylformamide, hexamethylphosphoramide, tetrahydrofuran, crown ether, cryptate, polyether or nitrobenzene, and its consumption is the same as The mass ratio of hexapropylcyclotrisiloxane is 0.01～0.20:1; the mass ratio of the amount of the end-capping agent hexamethyldisiloxane to hexapropylcyclotrisiloxane is 0.001～0.01: 1. The mass ratio of the hexapropylcyclotrisiloxane to the octamethylcyclotetrasiloxane is 0.05-100:1. the 2. the method for processing industrial waste n-propyltrifunctional silane according to claim 1, is characterized in that: step (1) described n-propyltrifunctional silane: chloropropane: the weight ratio of magnesium is 0.9:1 :1.2; The molar ratio of the consumption of catalyst and magnesium is 0.01:1. the 3. The method for treating industrial waste n-propyl trifunctional silane according to claim 1, characterized in that: ethers in the solvent of step (1) are selected from tetrahydrofuran, hydrocarbons are selected from toluene, ethers and hydrocarbons in the solvent The mixing volume ratio is 1:1. the 4. The method for treating industrial waste n-propyl trifunctional silane according to claim 1, characterized in that: the quenching agent in step (1) is selected from methanol, and the molar ratio of its consumption to n-propyl trifunctional silane It is 3:1. the 5. The method for treating industrial waste n-propyltrifunctional silane according to claim 1, characterized in that in step (2), the inert solvent is toluene; the dilute acid is dilute hydrochloric acid. the 6. The method for treating industrial waste n-propyltrifunctional silane according to claim 1, characterized in that: the potash base catalyst in step (2) is potassium hydroxide, and its consumption is: potassium in siloxane The mass percentage is 0.1%. the 7. The method for treating industrial waste n-propyltrifunctional silane according to claim 1, characterized in that: the cracking temperature in step (2) is 200-300°C. the 8. The method for treating industrial waste n-propyltrifunctional silane according to claim 1, characterized in that the catalyst in step (3) is tetramethylammonium hydroxide. the 9. The method for treating industrial waste n-propyltrifunctional silane according to claim 1, characterized in that the accelerator in step (3) is crown ether. the 10. The method for treating industrial waste n-propyl trifunctional silane according to claim 1, characterized in that the reaction temperature in step (3) is 100°C-130°C. the