KR102246599B1 - Method for producing chloropolysilane in high-yield - Google Patents

Abstract

_{The present invention includes the step of performing a chlorination reaction by supplying chlorine (Cl 2} ) gas to a solid calcium silicide (Ca-silicide) in a reactor, but when the chlorination reaction is performed, when the solid temperature in the reactor is 200° C. or higher. It relates to a method for producing a chloropolysilane represented by the following Formula 1, characterized in that the injection of chlorine gas is stopped and chlorine gas is injected when the solid temperature in the reactor is 200°C or less:
[Formula 1]
Si _n Cl _2n+2
(However, in Chemical Formula 1, n is an integer of 2 or more).
The method for producing a chloropolysilane according to the present invention includes a specific step for controlling an exothermic reaction, thereby producing a chloropolysilane having a high yield.

Description

Method for producing high-yield chloropolysilane {METHOD FOR PRODUCING CHLOROPOLYSILANE IN HIGH-YIELD}

The present invention relates to a method for preparing chloropolysilane, and more particularly, to a method for preparing chloropolysilane in high yield.

With the recent development of the electronics industry, the demand for silicon for semiconductors such as polycrystalline silicon and amorphous silicon has rapidly increased. Chloropolysilanes have recently been in the spotlight as a very important material for manufacturing semiconductor silicon.

As a method for preparing chloropolysilane, there is a method of distillation separation and purification using a by-product gas of polysilicon production, or a method of using a chlorination reaction. However, in the case of using a method of distillation separation and purification using a polysilicon production by-product gas, it is difficult to supply and supply raw materials without a polysilicon production process, and a wide variety of by-products are generated, so that the by-product post-treatment process is very complicated. In addition, in order to obtain chloropolysilane by using a polysilicon production by-product gas, a polysilicon production process and a purification process must be added, so the entire process is complicated. In addition, the method of distillation separation and purification using a by-product gas of polysilicon production has a carbon issue that has recently emerged as an important issue.

On the other hand, in the case of using the chlorination reaction, there is an advantage that the process is simple, but since the synthesis reaction of chloropolysilane corresponds to a very high exothermic reaction, there is a problem that it is difficult to control the exothermic reaction. Difficulties exist. In addition, when iron (Fe) is included as a metal component of the raw material, the treatment of _{FeCl 2 generated as an impurity is problematic.}

In addition, if the exothermic reaction is not controlled, the yield decreases due to the following side reactions.

Si ₂ Cl ₆ + Cl ₂ → 2SiCl ₄ (at temperatures above ^{300 o C)}

Si ₂ Cl ₆ → Si + SiCl ₄ (at temperatures above ^{350 o C)}

Patent Document 1 is a method for preparing hexachlorodisilane by distilling a mixture containing hexachlorodisilane with high purity, and in the distillation process, moisture is present in an amount of 10 ppbw (part per billion by weight) or less. Characterized by that. Patent Document 1, which is the aforementioned problem, corresponds to a method for obtaining high purity hexachlorodisilane in a mixture in which various by-products are mixed.

Patent Document 2 discloses that by heating a mixture of granular high-purity metallic silicon and metallic copper or a copper compound in an inert atmosphere, a catalyst body that is active in the reaction of metallic silicon and chlorine in advance is generated, and only metallic silicon is added after the chlorination reaction starts. By doing so, it is intended to obtain high-purity hexachlorodisilane continuously without causing a problem of accumulation of metallic copper or a copper compound, and Patent Document 2 is characterized by a copper catalyst body for obtaining high-purity hexachlorodisilane.

Korean Patent Application Publication No. 10-2010-0066528 (2010.06.17) Republic of Korea Patent Publication No. 10-2014-0105014 (2014.08.29.)

The present invention is to provide a method for producing a chloropolysilane capable of solving the problem of low yield by controlling the above-described problem, the exothermic reaction, and producing a high yield of chloropolysilane, and suppressing the progress of side reactions. do.

In order to achieve the above object, the present invention comprises _{the step of performing a chlorination reaction by supplying a chlorine (Cl 2} ) gas to a solid calcium silicide (Ca-silicide) in a reactor, but when performing the chlorination reaction, in the reactor It provides a method for producing a chloropolysilane represented by the following Formula 1, characterized in that the injection of chlorine gas is stopped when the solid temperature is 200°C or higher, and chlorine gas is injected when the solid temperature in the reactor is 200°C or less. :

[Formula 1]

Si _n Cl _2n+2

(However, in Chemical Formula 1, n is an integer of 2 or more).

The chloropolysilane represented by Formula 1 may be hexachlorodisilane.

The chlorine gas may be injected at 0.1 to 1.0 kg/hr/reactor.

Prior to the chlorination reaction, a pretreatment step of controlling the external temperature of the reactor to be maintained at 100°C to 180°C may be further included, and preferably, the external temperature of the reactor may be controlled to be maintained at 110°C to 130°C. .

When performing the chlorination reaction, the external temperature of the reactor may be controlled to 100°C to 180°C, and preferably, the external temperature of the reactor may be controlled to 110°C to 130°C when performing the chlorination reaction.

The external temperature of the reactor may be controlled through one or more temperature sensors outside the reactor, or through one or more temperature sensors inside the reactor.

The reactor is a reactor body; One or more trays disposed in the reactor body; One or more temperature sensors for measuring the temperature of a solid in one or more trays; A gas inlet for injecting gas into the reactor; And a gas exhaust port for discharging gas from the reactor.

The temperature sensor may be rotatable.

The temperature sensor may be movable through rotation between a first position inserted into one or more reactor trays and a second position moved out of one or more reactor trays.

The manufacturing method of chloropolysilane according to the present invention includes a specific step for controlling an exothermic reaction to prepare a high-yield chloropolysilane, and in the manufacturing method according to the present invention, the prepared chloropolysilane generates heat. There is an advantage in that it is possible to prevent re-breaking or side reactions from proceeding according to the reaction, and that it is easy to treat by-products generated in the reaction step for producing chloropolysilane.

1 is a schematic diagram of a manufacturing method according to an embodiment of the present invention.
2 is a schematic diagram of a manufacturing method when a heating temperature is separately controlled from outside according to an embodiment of the present invention.
3 is a schematic diagram of a manufacturing method in the case of controlling the external heating temperature by the internal temperature of the reactor according to an embodiment of the present invention.
4 is a graph showing an input amount of chlorine gas according to a temperature control method. _{(a) is the Cl 2} input amount of Example 1 that separately controls the external heating temperature, and (b) is the Cl of Example 2 that controls the external heating temperature through the internal temperature sensor without separately controlling the external heating temperature. _{2 is the} input amount.
5 is a schematic diagram of a reactor according to an embodiment of the present invention. (a) When the temperature sensor is inserted into the reactor tray (first position), and (b) the temperature sensor is moved out of the tray (second position).

Hereinafter, the present invention will be described in more detail.

In the present invention, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise specified.

In the present invention, when a component is positioned "on" another component, this includes not only a case where a certain component is in contact with another component, but also a case where another component exists between the two components.

One aspect of the present invention includes performing a chlorination reaction by supplying a _{chlorine (Cl 2} ) gas to a solid calcium silicide (Ca-silicide) in a reactor,

When performing the chlorination reaction, the injection of chlorine gas is stopped when the solid temperature in the reactor is 200° C. or higher, and chlorine gas is injected when the solid temperature in the reactor is 200° C. or less, represented by the following formula (1). The method of preparing chloropolysilane is:

[Formula 1]

Si _n Cl _2n+2

(However, in Chemical Formula 1, n is an integer of 2 or more).

In the present invention, when the solid temperature in the reactor is measured and the chlorination reaction is performed, the injection of chlorine gas is stopped when the solid temperature in the reactor is 200°C or higher, and chlorine gas is injected when the solid temperature in the reactor is 200°C or less. Characterized by that.

In the present invention, in consideration of the temperature of the solid in the reactor, the internal temperature in the reactor is controlled by controlling the injection or blocking of chlorine gas. Accordingly, the manufacturing method according to the present invention can very precisely control the amount of chlorine gas injected to prepare chloropolysilane, and it is possible to control the exothermic temperature of the method for manufacturing chloropolysilane corresponding to a very high exothermic reaction. .

In addition, the method for producing chloropolysilane according to the present invention is capable of controlling the heat generation temperature inside the reactor where the chlorination reaction occurs by controlling the injection or blocking of chlorine gas in consideration of the solid temperature in the reactor. It is possible to reduce the progress of side reactions that may occur at a high temperature such as the above, and prevent the yield of chloropolysilane from being lowered, such as cracking of the prepared chloropolysilane again.

In the present invention, the chloropolysilane represented by Chemical Formula 1 may preferably be hexachlorodisilane.

In an embodiment according to the present invention, the chloropolysilane represented by Chemical Formula 1 is hexachlorodisilane, and in this case, it may be prepared through Reaction Scheme 1 below.

[Scheme 1]

2CaSi ₂ + 9Cl ₂ → 2CaCl ₂ + Si ₂ Cl ₆ + 2SiCl ₄ (at temperatures above ^{100 o C)}

However, in the case of Scheme 1, since it is a very high exothermic reaction (thermodynamic enthalpy H ₂₉₈ (KJ/mol) = -3,601.9), side reactions such as Scheme 2 and Scheme 3 below proceed. Therefore, the present inventor considers the heating temperature control in the reactor as the most important factor in order to obtain a high yield of chloropolysilane.

[Scheme 2]

Si ₂ Cl ₆ + Cl ₂ → 2SiCl ₄ (at temperatures above ^{300 o C)}

[Scheme 3]

Si ₂ Cl ₆ → Si + SiCl ₄ (at temperatures above ^{350 o C)}

The present invention comprises a feature characterized in that the injection of chlorine gas is stopped when the solid temperature in the reactor is 200°C or higher, and chlorine gas is injected when the solid temperature in the reactor is 200°C or less, so that the exothermic temperature can be controlled, It is possible to prevent the internal temperature of the reactor from becoming a high temperature, which is a condition in which side reactions occur. For this reason, the present invention not only can effectively reduce the progress of side reactions that may occur in the production reaction of chloropolysilane, but also prevent a decrease in yield such as cracking of the finally produced chloropolysilane again. Accordingly, the manufacturing method of the present invention can increase the selectivity of chloropolysilane such as hexachlorodisilane, and a high yield of chloropolysilane can be obtained.

In the present invention, if the injection of chlorine gas is stopped when the solid temperature in the reactor is 200°C or higher, and chlorine gas is injected when the solid temperature in the reactor is 200°C or less, the chlorine gas is injected at 0.1 to 1.0 kg/hr/reactor. It is characterized in that, and preferably can be injected at 0.2 to 0.6 kg/hr/reactor, more preferably at 0.35 to 0.5 kg/hr/reactor, and most preferably at 0.4 kg/hr/ It can be injected into a reactor.

When the amount of chlorine gas injected is within the above range, it is possible to control the reaction temperature appropriately and thereby suppress side reactions.If _{the amount is less than the above range, the amount of Cl 2} injected is small, so the reaction completion time is very long and throughput (Throughput) may decrease, and if it exceeds the above range, side reactions may proceed due to inability to control the reaction temperature.

Since the method for preparing chloropolysilane according to the present invention includes the step of performing a chlorination reaction by supplying _{chlorine (Cl 2 ) gas to calcium silicide (Ca-silicide), calcium chloride (CaCl 2} ) may be generated as a by-product. However, calcium chloride produced as a by-product in the present invention exists as a stable solid material during the reaction, so it can be easily separated through gas/solid separation with chloropolysilane, and has a property that is well soluble in solid or water, so it is treated by water treatment method. Because it is possible, for example, iron silicide (FeSi ₂ ) has the advantage of being much easier to treat than a by- _{product (FeCl 2} ) obtained by performing a chlorination reaction.

One embodiment according to the present invention is to further include a pretreatment step of controlling the external temperature of the reactor to be maintained at 100°C to 180°C, prior to the chlorination reaction. Exemplarily, in the present invention, after the pretreatment step, the chlorination reaction is performed, and when the chlorination reaction is performed, chlorine gas may be injected or the injection of chlorine gas may be stopped depending on the solid temperature in the reactor. In addition, in this pretreatment step, pretreatment is performed for the purpose of removing moisture contained in calcium silicide.

The pretreatment step may be pretreated for 24 hours to maintain the external temperature, and heating devices generally used by a person skilled in the art as a method for raising the external temperature of the reactor are not particularly limited and all can be used, preferably Upper and lower heating rod (heating load) method can be used.

When the pretreatment step is performed before performing the chlorination reaction, more efficient temperature control can be performed than when the pretreatment step is not performed, and the generation of by-products (SiOH) can be suppressed by removing moisture contained in calcium silicide. There is an advantage.

During the pretreatment step, the external temperature of the reactor can be controlled to be maintained at 100°C to 180°C, preferably 110°C to 150°C, and more preferably 110°C to 130°C. Can be controlled to do.

When the external temperature of the reactor satisfies the above range during the pretreatment step, it is easy to remove the temperature when injecting the reactant, and there is an advantage of suppressing the generation of by-products through moisture control, and the external temperature of the reactor satisfies the above range. If not, it is difficult to remove the appropriate reaction temperature initially, and by-products may be generated under the influence of moisture.

In one embodiment according to the present invention, d) the external temperature of the reactor is controlled to 100°C to 180°C when performing the chlorination reaction. Exemplarily, the present invention may be to control the external temperature of the reactor while injecting chlorine gas or stopping the injection of chlorine gas according to the solid temperature in the reactor when performing the chlorination reaction.

At this time, the external temperature of the reactor can be controlled to be maintained at 100°C to 180°C, preferably 110°C to 150°C, and more preferably 110°C to 130°C. can do.

When performing the chlorination reaction, when the external temperature of the reactor satisfies the above range, there is an advantage of controlling the exothermic reaction occurring inside the reactor, and when the external temperature of the reactor is lower than the above range, the appropriate reaction temperature is not reached. If the reaction does not proceed and the external temperature of the reactor is higher than the above range, it may be difficult to control the excessive exothermic temperature.

In one embodiment according to the present invention, controlling the external temperature of the reactor is controlled through one or more temperature sensors outside the reactor.

When controlling the external temperature of the reactor through one or more temperature sensors outside the reactor, external heating so that the temperature sensor located outside the reactor measures the ambient temperature of the reactor and maintains the external temperature at (100°C to 180°C). The temperature can be adjusted, and the external heating temperature can be adjusted so that it can be maintained at preferably (110°C to 150°C), more preferably (110°C to 130°C). At this time, since the external temperature of the reactor may closely affect the yield of the chloropolysilane, it is important that the external temperature of the reactor is controlled to satisfy a specific temperature range.

In another embodiment according to the present invention, controlling the external temperature of the reactor is controlled through one or more temperature sensors inside the reactor.

In the case of controlling the external temperature of the reactor through one or more temperature sensors inside the reactor, one or more temperature sensors inside the reactor are inserted into the reaction material to measure the temperature inside the reactor, or located on the reaction material and inside the reactor. The temperature of can be measured. Illustratively, in the case of the present invention, since the reactant calcium silicide is in a solid form, the temperature sensor inside the reactor can be inserted into the reactant solid calcium silicide to measure the internal temperature of the reactor, or the reactant solid calcium silicide. It is located on the silicide to measure the internal temperature of the reactor. Preferably, in the case of the present invention, it is inserted into the solid calcium silicide to measure the internal temperature of the reactor.

Thereafter, in consideration of the internal temperature of the reactor measured through one or more temperature sensors located inside the reactor, the external heating temperature may be adjusted so that the external temperature of the reactor can be maintained at (100°C to 180°C), and preferably ( 110°C to 150°C), and more preferably (110°C to 130°C), the external heating temperature may be controlled. In this case, since it is possible to accurately measure the temperature of the inside of the reactor or the solid in the reactor where the reaction takes place, it is easier to control the exothermic reaction because it is possible to more precisely control the temperature of the inside of the reactor.

In the present invention, the reactor includes a gas inlet and a gas exhaust port, and it is preferable to use a reactor including one or more temperature sensors inside the reactor so as to measure the temperature inside the reactor. Illustratively, the reactor comprises a reactor body; One or more trays disposed in the reactor body; One or more temperature sensors for measuring the temperature of the reactants in one or more trays; A gas inlet for injecting gas into the reactor; And a gas exhaust port for discharging gas from the reactor. In addition, the reactor may further include a mass flow controller for measuring the flow rate of the material into the reactor body.

At least one tray disposed in the reactor body may contain a reactant, that is, solid calcium silicide in the present invention, and chlorine gas is injected by the step according to the present invention through the gas inlet and the gas outlet, or chlorine gas Can be stopped.

The temperature sensor may preferably be included in a form capable of rotating inside the reactor. Illustratively, the temperature sensor included in the reactor according to the present invention is movable between a first position inserted into one or more reactor trays and a second position moved out of one or more reactor trays.

The temperature sensor included in a rotatable form inside the reactor contains a solid as a reactant in one or more trays arranged in the reactor body, and then rotates the temperature sensor to insert it into the solid in the reactor tray. It may become possible to more precisely measure the temperature change that occurs during this exothermic reaction. On the other hand, when the temperature sensor is not inserted into the solid and moves out of the reactor tray, it is possible to remove the reactor tray from the reactor body through the open surface.

Hereinafter, examples will be described in detail to illustrate the present invention in detail. However, the embodiments according to the present invention may be modified in various forms, and the scope of the present invention is not construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art. In addition, "%" and "parts" indicating the content hereinafter are based on weight unless otherwise noted.

Examples and Comparative Examples

Example 1

84 kg of the CaSi ₂ raw material was dispersed and filled in the reactor, and the pretreatment was performed for 24 hours by setting the external heating temperature to 120°C through an external temperature sensor. Thereafter, the external heating temperature was fixed at 120°C, Cl ₂ gas was injected, the solid temperature in the reactor was measured through an internal temperature sensor, and _{the injection of Cl 2} gas was stopped when the internal temperature increased to 200°C or higher, When the temperature was lowered to 200° C. or lower, the Cl ₂ gas was re-injected. Table 1 shows the purity and yield of HCDS (hexachlorodisilane) obtained as a result. At this time, _{the amount of the injected Cl 2} gas is shown in Fig. 4 (a).

Example 2

84 kg of the CaSi ₂ raw material was dispersed and filled in the reactor, and the internal temperature of the reactor was adjusted to be 120°C through an internal temperature sensor, and pretreatment was performed for 24 hours. After that, Cl ₂ gas was injected, and the solid temperature in the reactor was measured through an internal temperature sensor. When the internal temperature rises above 200°C, _{the injection of Cl 2} gas is stopped, and when it falls below 200°C, the Cl ₂ gas is It proceeded in such a way that it is injected again. The resulting HCDS purity and yield (Yield) are shown in Table 1. At this time, _{the amount of the injected Cl 2} gas is shown in (b) of FIG. 4.

division HCDS purity (%) yield(%) Example 1 42% 70% Example 2 40% 98.9%

Comparative Examples 1 to 2

After packing 160 g of the CaSi ₂ raw material in a fixed bed reactor, pretreatment was performed at 150° C. for 24 hours, and then moisture was removed. Thereafter, the external temperature of each reactor was fixed at 120° C. (Comparative Example 1) and 200° C. (Comparative Example 2), and the amount of HCDS obtained by injecting _{Cl 2 was measured.}

division HCDS purity (%) yield(%) Comparative Example 1 50% 48% Comparative Example 2 48% 55%

As can be seen from Tables 1 and 2, according to the present invention, the injection of chlorine gas is stopped when the solid temperature in the reactor is 200°C or higher, and chlorine gas is injected when the solid temperature in the reactor is 200°C or less. In Examples 1 and 2, the yield was high, and it was confirmed that Example 2, in which the external heating was controlled according to the internal temperature, showed better yield. On the other hand, in Comparative Examples 1 and 2, which were not prepared by the manufacturing method according to the present invention, the yield was low.

Claims (12)

Including the step of performing a chlorination reaction by supplying _{chlorine (Cl 2} ) gas to solid calcium silicide (Ca-silicide) in the reactor,
When performing the chlorination reaction, the injection of chlorine gas is stopped when the solid temperature in the reactor is 200°C or higher, and chlorine gas is injected when the solid temperature in the reactor is 200°C or less,
The chlorine gas is injected at 0.1 to 1.0 kg/hr/reactor,
Prior to the chlorination reaction, a method for producing a chloropolysilane represented by the following Formula 1, comprising a pretreatment step of controlling the external temperature of the reactor to be maintained at 100°C to 180°C.
[Formula 1]
Si _n Cl _2n+2
(However, in Chemical Formula 1, n is an integer of 2 or more). The method of claim 1,
The chloropolysilane represented by Formula 1 is a method of producing a chloropolysilane, characterized in that it is hexachlorodisilane. delete delete The method of claim 1,
Prior to the chlorination reaction, the method for producing a chloropolysilane, characterized in that the external temperature of the reactor is controlled to be maintained at 110°C to 130°C. The method of claim 1,
A method for producing a chloropolysilane, characterized in that the external temperature of the reactor is controlled to 100°C to 180°C when performing the chlorination reaction. The method of claim 6,
The method for producing a chloropolysilane, characterized in that when performing the chlorination reaction, the external temperature of the reactor is controlled to 110°C to 130°C. The method according to claim 6 or 7,
The external temperature of the reactor is controlled through at least one temperature sensor outside the reactor. The method according to claim 6 or 7,
The external temperature of the reactor is controlled through at least one temperature sensor inside the reactor. The method of claim 1,
The reactor is a reactor body; One or more trays disposed in the reactor body; One or more temperature sensors for measuring the temperature of a solid in one or more trays; A gas inlet for injecting gas into the reactor; And a gas exhaust port for discharging gas from the reactor. The method of claim 10,
The temperature sensor is characterized in that rotatable, the method for producing chloropolysilane. The method of claim 11,
The temperature sensor is characterized in that it is capable of moving through rotation between a first position inserted into one or more reactor trays and a second position moved out of one or more reactor trays.

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