JP5828647B2 - Method for thermal stabilization of diethylzinc and diethylzinc composition - Google Patents

Description

The present invention relates to a diethylzinc composition excellent in thermal stability, a thermal stabilization method, and a thermal stabilization compound.

  Diethyl zinc is conventionally used as a reaction reagent for organic synthesis in polymerization catalyst applications such as polyethylene oxide and polypropylene oxide, and in the production of intermediates such as pharmaceuticals and functional materials, and is known as an extremely useful industrial material. ing.

In recent years, a method of forming a zinc oxide thin film by a technique called MOCVD (Metal Organic Chemical Vapor Deposition) method using diethyl zinc as raw materials and water vapor as an oxidizing agent has been studied. The zinc oxide thin film obtained by this MOCVD method has various functions in solar cells such as CIGS solar cell buffer layer, transparent conductive film, dye-sensitized solar cell electrode film, thin-film Si solar cell intermediate layer, and transparent conductive film. It is used in various functional films such as films, photocatalytic films, ultraviolet cut films, infrared reflective films, and antistatic films, compound semiconductor light emitting devices, electronic devices such as thin film transistors, etc., and has a wide range of uses.

  It is known that diethyl zinc is gradually decomposed and metal zinc particles are deposited when heat is applied (for example, see Non-Patent Document 1). Therefore, handling of diethyl zinc has problems such as a decrease in product purity due to precipitation of metal zinc particles generated by pyrolysis, contamination of storage containers, and blockage of manufacturing equipment piping.

  As a method for solving the above-mentioned problem relating to the precipitation of metal zinc particles generated by pyrolysis, for example, a method of adding a compound such as anthracene, acenaphthene, or acenaphthylene to obtain a composition in which diethyl zinc is stabilized is known. (For example, refer to Patent Documents 1 to 3).

U.S. Pat. No. 4,385,003 U.S. Pat. No. 4,402,880 U.S. Pat. No. 4,407,758

Yasuo Kuniya et al. , Applied Organometallic Chemistry, 5, 337-347, published in 1991

As disclosed in Patent Documents 1 to 3, even if anthracene, acenaphthene, and acenaphthylene are added, diethylzinc cannot be sufficiently stabilized, and diethylzinc having higher thermal stability is required.

On the other hand, diethyl zinc is important as a raw material for the production of zinc oxide thin films by MOCVD, and in use, generally, carrier gas such as nitrogen, argon or helium is circulated through diethyl zinc filled in a supply container. In general, a method in which diethyl zinc is present in a carrier gas as a saturated vapor gas to supply it to an external device such as a film forming apparatus is generally used.
Compounds such as anthracene, acenaphthene, and acenaphthylene, which have been known as additives for diethyl zinc, have boiling points of 342 ° C. (anthracene), 279 ° C. (acenaphthene), 265-275 ° C. (acenaphthylene), Since the compound also has a higher boiling point than diethyl zinc having a boiling point of 118 ° C., the diethyl zinc composition stabilized by adding anthracene, acenaphthene, and acenaphthylene to diethyl zinc is used in the above manner. Is supplied to an external device or the like for a long period of time, there is a problem that the added anthracene, acenaphthene, acenaphthylene and other compounds accumulate in the diethylzinc remaining in the supply container.

In other words, the present invention improves the thermal stability of diethyl zinc used for a raw material for producing a zinc oxide thin film by a polymerization catalyst, an organic synthesis reagent, MOCVD method, etc., and does not precipitate metallic zinc particles even when handled for a long time. It aims at providing the diethyl zinc composition excellent in property. Furthermore, in the above-mentioned supply over a long period of time in use in a method in which a carrier gas such as nitrogen, argon, helium, etc. is circulated through the diethylzinc composition and diethylzinc is supplied to the external device as a saturated vapor gas, The object is to reduce the accumulation of the added compound in diethylzinc remaining in the middle of the supply in the supply container.

As a result of intensive research and development to solve the above problems, the present inventor has found that a compound having a specific carbon-carbon double bond coexisted in diethyl zinc (CAS No. 557-20-0) and The thermal stability is remarkably improved, and the compound having a specific carbon-carbon double bond having a boiling point close to that of diethyl zinc is selected as a coexisting compound. In the use in a method in which a carrier gas such as nitrogen, argon, helium, etc. is circulated in the diethylzinc composition and diethylzinc is supplied to the external device as a saturated vapor gas, It was possible to reduce the accumulation of the added compound in the diethylzinc remaining during the supply, and the present invention was completed.

The method for thermal stabilization of the diethylzinc composition according to the present invention uses a compound having a carbon-carbon double bond represented by the following general formula (1) as an additive, and the additive rate of the additive to diethylzinc is 50 ppm to Added at 20 wt%.

The method of thermal stabilization of the diethylzinc composition according to the present invention uses a compound having a carbon-carbon double bond of the following general formula (2) as an additive, and the additive rate of the additive to diethylzinc is 50 ppm to Added at 20 wt%.

In the formula (2), n is an integer of 1 to 4, and each R is independently hydrogen, a linear or branched alkyl group having 1 to 8 carbon atoms, a linear or branched group having 1 to 8 carbon atoms. An alkenyl group, an allyl group having 6 to 14 carbon atoms, and a linear or branched alkoxy group having 1 to 8 carbon atoms.

R, which is a substituent represented by the above general formula (1) or (2), independently has 1 to 8 carbon atoms such as hydrogen, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group. Straight chain or branched alkyl group, vinyl group, propenyl group, isopropenyl group, etc., straight chain or branched alkenyl group having 1-8 carbon atoms, phenyl group, toluyl group, etc., C6-C14 allyl group, methoxy It may have various substituents such as an alkoxy group such as a group, an ethoxy group, an isopropoxy group, and a phenoxy group.

The compound having a carbon-carbon double bond of the compound represented by the general formula (1) has a cyclic hydrocarbon as a central skeleton, and the central skeleton of the cyclic hydrocarbon is, for example, when n = 1, 1,3-cyclohexadiene, when n = 2, 1,3-cycloheptadiene, when n = 3, 1,3-cyclooctadiene, when n = 4, 1,3-cyclononadiene. Therefore, the compound of the present invention is a compound having a central skeleton of the cyclic hydrocarbon and having hydrogen or a substituent R in the skeleton. That is, the compound of the present invention is a compound in which 1,3-cyclohexadiene, 1,3-cycloheptadiene, 1,3-cyclooctadiene, 1,3-cyclononadiene, and their side chains are substituted with a substituent R It is. Depending on the position of the substituent, the prefix number indicating the position of the above-described double bond may be from 1,3- to 2,4-, 3,5-, or 4,6-, but the general formula (1 ) Structure may be included.

Similarly, the compound having a carbon-carbon double bond of the compound of the general formula (2) has a cyclic hydrocarbon as a central skeleton, and the central skeleton of the cyclic hydrocarbon is, for example, n = 1. 1,4-cyclohexadiene when n = 2, 1,4-cycloheptadiene when n = 2, 1,4-cyclooctadiene when n = 3, 1,4-cyclononadiene when n = 4 is there. Therefore, the compound of the present invention is a compound having a central skeleton of the cyclic hydrocarbon and having hydrogen or a substituent R in the skeleton. That is, the compound of the present invention is a compound in which 1,4-cyclohexadiene, 1,4-cycloheptadiene, 1,4-cyclooctadiene, 1,4-cyclononadiene and their side chains are substituted with a substituent R It is. Depending on the position of the substituent, the prefix number indicating the position of the above-mentioned double bond may be 1,4-to 2,5- or 3,6--, but includes the structure of the general formula (1) It only has to be done.

  Examples of the compound having a carbon-carbon double bond represented by the above general formula (1) or (2) include 1,3-cyclohexadiene, 1,4-cyclohexadiene, 1-methyl-1,4- Cyclohexadiene, 2-methyl-1,4-cyclohexadiene, 3-methyl-1,4-cyclohexadiene, 4-methyl-1,4-cyclohexadiene, 5-methyl-1,4-cyclohexadiene, 1-methyl-1,3 -Cyclohexadiene, 3-methyl-1,3-cyclohexadiene, 4-methyl-1,3-cyclohexadiene, 5-methyl-1,3-cyclohexadiene, 2-methyl-1,3-cyclohexadiene, 2, 4-dimethyl-1,4-hexadiene, 1,1-dimethyl-2,5-hexadiene, 1,3-dimethyl-1,3-cyclohexadiene, -Methyl-1,3-cycloheptadiene, 5,5-dimethyl-1,4-cyclohexadiene, 1,2-dimethyl-1,3-cyclohexadiene, 1-ethyl-1,4-cyclohexadiene, α- Terpinene, γ-terpinene, 1,3,5,5-tetramethyl-1,3-cyclohexadiene, 1,3,5-trimethyl-1,4-cyclohexadiene, 1,3-cycloheptadiene, 1, Examples include 4-cycloheptadiene, 2-methyl-1,3-cycloheptadiene, 1,3-cyclooctadiene, 1,4-cyclooctadiene, 1,3-cyclononadiene, and the like.

  Among these compounds having a carbon-carbon double bond represented by the general formula (1) or (2), for example, 1-methyl-1,4-cyclohexadiene (CAS No. 4313-57-9) The substituent R such as hydrogen is a compound composed of hydrogen, a methyl group having 3 or less carbon atoms, an ethyl group, an isopropyl group, an isopropenyl group, and the like. The total carbon number is 6 to 10, preferably 7 to 9 is a liquid at room temperature and has a boiling point close to 118 ° C. which is the boiling point of diethyl zinc. Therefore, a carrier gas such as nitrogen, argon or helium is added to the diethyl zinc composition by MOCVD or the like. In use in the method of supplying diethylzinc as a saturated vapor gas to the external device through circulation, the compound added to the diethylzinc remaining in the supply container in the supply container for a long time as described above It is possible to reduce to excessively accumulate, it is possible to coexist in diethylzinc at moderate concentrations.

  The additive used in the present invention can provide a sufficient effect when added alone, but a plurality of additives may be used in combination.

  Here, the amount of the compound having a carbon-carbon double bond represented by the general formula (1) or (2) of the present invention is within a range in which the performance of diethyl zinc is maintained and a thermal stabilization effect is obtained. If there is no particular limitation, it is usually 50 ppm to 20 wt%, preferably 100 ppm to 10 wt%, more preferably 200 ppm to 5 wt%, based on diethyl zinc. Can be obtained.

If the amount of the compound having a carbon-carbon double bond represented by the general formula (1) or (2) of the present invention is too small, a sufficient effect of improving thermal stability may not be obtained, If the amount is too large, the effect of increasing the amount added may not be obtained, so it is desirable to add an appropriate amount for obtaining the desired effect of thermal stability.

  Diethyl zinc used in the present invention is generally known as an industrial material used as a reaction reagent for organic synthesis in polymerization catalyst applications such as polyethylene oxide and polypropylene oxide, and in the production of intermediates such as pharmaceuticals and functional materials. What is being used can be used.

  In the present invention, it is used in a method of forming a zinc oxide thin film by MOCVD or the like, and includes a buffer layer for CIGS solar cells, a transparent conductive film, an electrode film for dye-sensitized solar cells, an intermediate layer for thin-film Si solar cells, Various functional films in solar cells such as transparent conductive films, photocatalytic films, ultraviolet cut films, infrared reflective films, various functional films such as antistatic films, compound semiconductor light emitting devices, electronic devices such as thin film transistors, etc. Diethyl zinc having a purity higher than that of industrial materials can also be used.

In preparing the diethylzinc composition of the present invention, diethylzinc and an additive which is a compound having a carbon-carbon double bond represented by the general formula (1) or (2) of the present invention may be mixed. For example, there are no particular restrictions on the method of addition, such as adding the aforementioned additives to diethyl zinc.
For example, in order to improve storage stability, a method of adding an additive to diethyl zinc in advance can be used.

Further, for example, when used for a reaction or the like, an additive can be added to diethyl zinc immediately before use.

  In addition, the temperature for preparing the diethylzinc composition of the present invention is preferably 70 ° C. or less, which is less affected by the thermal decomposition of diethylzinc. Usually, the composition of the present invention can be prepared at -20 ° C to 35 ° C. Also, the pressure is not particularly limited. Except for special cases such as reaction, diethylzinc and the composition of the present invention can be usually prepared near atmospheric pressure, such as 0.1013 MPa.

  The equipment used and the atmosphere used in equipment such as storage / transport containers, storage tanks, and piping for the diethyl zinc composition of the present invention can be used as they are. For example, the material of the above-mentioned equipment can be a metal such as SUS, carbon steel, titanium, or hastelloy, or a resin such as Teflon or fluorine rubber. In addition, an inert gas such as nitrogen, helium, or argon can be used in the same manner as diethyl zinc.

  The diethyl zinc composition of the present invention can be used by dissolving in a known solvent that can be used when diethyl zinc is used. Examples of the solvent include, for example, saturated hydrocarbons such as pentane, hexane, heptane and octane, hydrocarbon compounds such as aromatic hydrocarbons such as benzene, toluene and xylene, diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane and diglyme. And ether compounds such as

  Examples of the use of the diethylzinc composition of the present invention include use as a polymerization catalyst such as polyethylene oxide and polypropylene oxide, use as a reaction reagent for organic synthesis in the production of intermediates such as pharmaceuticals and functional materials, , Used in a method of forming a zinc oxide thin film by MOCVD method, etc., and CIGS solar cell buffer layer, transparent conductive film, dye-sensitized solar cell electrode film, thin film Si solar cell intermediate layer, transparent conductive film, etc. Various functional films such as various functional films, photocatalytic films, ultraviolet cut films, infrared reflective films, antistatic films, etc. in batteries, oxide forming applications such as compound semiconductor light emitting devices, electronic devices such as thin film transistors, etc., ZnS List the same applications where diethyl zinc has been used so far, such as thin film formation applications for II-VI electronic devices. Can.

  The diethylzinc composition to which the compound having a carbon-carbon double bond represented by the general formula (1) or (2) of the present invention is added is excellent in thermal stability, and diethylzinc is thermally decomposed. There is very little precipitation of the metal zinc particle which generate | occur | produces. As a result, it is possible to prevent problems such as a decrease in product purity, contamination of storage containers, and blockage of manufacturing equipment piping. In addition, especially in use in a method of supplying a carrier gas such as nitrogen, argon, helium or the like as a saturated vapor gas of diethyl zinc to an external device such as MOCVD, etc., it was added to the diethyl zinc composition. Since the boiling point of the compound of the present invention and the boiling point of diethyl zinc are close, in the above-mentioned supply for a long time, in the diethyl zinc composition remaining in the supply container in the supply container for a long time, Accumulation of the added compound of the present invention can be reduced.

  EXAMPLES The present invention will be described in more detail with reference to examples below, but these examples do not limit the present invention.

[measuring equipment]
DSC measurement was performed using DSC6200 (manufactured by Seiko Instruments Inc.).

[Preparation of diethyl zinc composition]
Diethyl zinc (manufactured by Tosoh Finechem Co., Ltd.) and 1-methyl-1,4-cyclohexadiene (CAS No.4313-57-9) (commercially available reagent) in a glass container at a predetermined concentration at room temperature under a nitrogen atmosphere Weighed out. The additive was dissolved in diethyl zinc to prepare a diethyl zinc composition.

The addition rate (wt%) of the additive to diethyl zinc was defined by the following formula.
Addition rate of additive (% by weight) = (additive weight / (additive weight + diethyl zinc weight)) × 100

  DSC measurement (Differential Scanning Calorimetry) was performed about the diethyl zinc composition prepared by the above-mentioned method, and the thermal stability effect of the additive was evaluated.

[Reference Example 1]
[Thermal stability test by DSC measurement of diethyl zinc]
Diethyl zinc was weighed and sealed in a SUS DSC cell under a nitrogen atmosphere. The obtained sample was subjected to DSC measurement, and thermal analysis measurement was performed at a temperature increase rate of 10 ° C./min with a temperature range of 30 to 450 ° C. The decomposition temperature of each sample is observed at the initial exothermic temperature of DSC measurement. Table 1 shows the initial exothermic temperature of a sample containing only diethyl zinc with no additive added.

[Example 1]
[Thermal stability test of diethyl zinc composition by DSC measurement]
Diethyl zinc composition to which 1-methyl-1,4-cyclohexadiene (CAS No. 4313-57-9) (commercial reagent), which is an additive of the present invention, was added in the same manner as in Reference Example 1 The material was weighed and sealed in a SUS DSC cell. The obtained sample was subjected to DSC measurement, and the same thermal analysis measurement as in Reference Example 1 was carried out at a rate of temperature increase of 10 ° C./min with a temperature range of 30 to 450 ° C. Table 1 shows the initial heat generation temperature of each sample.
The initial exothermic temperature of the sample of the diethylzinc composition to which the additive of the present invention was added was higher than the initial exothermic temperature of the sample of only diethylzinc obtained in the reference example, and the composition of the present invention was composed of only diethylzinc. The decomposition start temperature is higher than that of the sample. From this result, the high thermal stability of the diethyl zinc composition to which the additive was added was confirmed. In addition, the boiling point of 1-methyl-1,4-cyclohexadiene, which is an additive of the present invention, is close to 115 ° C. and 118 ° C. which is the boiling point of diethyl zinc, and carrier gases such as MOCVD method, nitrogen, argon, helium, etc. In the use in the method of supplying the external device as a saturated vapor gas of diethyl zinc by circulating through the zinc zinc, in the diethyl zinc composition remaining in the supply container in the supply container for a long time, The problem of accumulation of compounds used as additives is reduced.

[Comparative Examples 1-3]
In the same manner as in Example 1, the same study was performed on a diethyl zinc composition to which anthracene, acenaphthene, and acenaphthylene, which are additives described in Patent Documents 1 to 3, were added. Table 1 shows the initial heat generation temperature of each sample.
These samples were lower than the initial exothermic temperature of the sample of the diethyl zinc composition to which the compound of the present invention was added, and the composition to which the existing additive was added was inferior in thermal stability to the composition of the present invention. .
The boiling point of the aforementioned additives is 342 ° C. (anthracene), 279 ° C. (acenaphthene), 265 to 275 ° C. (acenaphthylene) and higher than 118 ° C. which is the boiling point of diethylzinc. In the method of supplying a carrier gas such as helium to diethyl zinc as a saturated vapor gas of diethyl zinc and supplying it to an external device, diethyl zinc remaining in the supply container in the supply container after the above supply for a long period of time Problems arise in the accumulation of these compounds in the composition.

[Examples 2 to 4]
The same thermal analysis measurement as in Example 1 was performed by changing the addition concentration of 1-methyl-1,4-cyclohexadiene (CAS No.4313-57-9) (commercially available reagent) which is an additive of the present invention. It was. Table 1 shows the initial heat generation temperature of each sample.
The initial exothermic temperature of the sample of the diethylzinc composition to which the compound of the present invention was added was higher than the initial exothermic temperature of the sample of only diethylzinc obtained in the Reference Example even if the concentration of the compound added was lowered. The composition has a higher decomposition onset temperature than the diethylzinc only sample. From this result, the high thermal stability of the diethyl zinc composition to which the additive was added was confirmed.

[Comparative Examples 4 to 6]
In the same manner as in Example 3, the same study was performed on a diethyl zinc composition to which anthracene, acenaphthene, and acenaphthylene, which are additives described in Patent Documents 1 to 3, were added. Table 1 shows the initial heat generation temperature of each sample.
These samples were lower than the initial exothermic temperature of the sample of the diethyl zinc composition to which the compound of the present invention was added, and the composition to which the existing additive was added was inferior in thermal stability to the composition of the present invention. .

[Examples 5 to 8]
Specific examples of the additive of the present invention include 1,4-cyclohexadiene (CAS No. 628-41-1), α-terpinene (CAS No. 99-86-5), γ-terpinene CAS No. 99-85. -4), 1,3,5,5-tetramethyl-1,3-cyclohexadiene (CAS No. 4724-89-4) (all commercially available reagents), respectively, were used to prepare diethylzinc compositions. Thermal analysis measurement similar to 1 was performed. Table 1 shows the initial heat generation temperature of each sample.

The initial exothermic temperature of the sample of the diethylzinc composition to which the additive of the present invention was added was higher than the initial exothermic temperature of the sample of only diethylzinc obtained in the reference example, and the composition of the present invention was composed of only diethylzinc. The decomposition start temperature is higher than that of the sample. From this result, the high thermal stability of the diethyl zinc composition to which the additive was added was confirmed.
In addition, since the boiling point of these compounds of the present invention is lower than that of known compounds, a carrier gas such as MOCVD method, nitrogen, argon, helium, etc. is circulated through diethyl zinc and supplied to an external device as a saturated vapor gas of diethyl zinc. In the use in the method, the problem that the compound used as an additive accumulates in the diethyl zinc composition remaining in the supply container in the supply container by the above-mentioned supply for a long time is reduced.

Claims (11)

As a method for improving the thermal stability of diethyl zinc, a compound having a carbon-carbon double bond represented by the following general formula (1) is used as an additive, and the additive is added to diethyl zinc at an addition rate of 50 ppm to 20 wt%. A method for thermal stabilization of diethylzinc, characterized by:

In formula (1), n is an integer of 1 to 4, and each R is independently hydrogen, a linear or branched alkyl group having 1 to 8 carbon atoms, or a linear or branched group having 1 to 8 carbon atoms. An alkenyl group, an allyl group having 6 to 14 carbon atoms, and a linear or branched alkoxy group having 1 to 8 carbon atoms. As a method for improving the thermal stability of diethyl zinc, a compound having a carbon-carbon double bond represented by the following general formula (2) is used as an additive, and the additive is added to diethyl zinc at an addition rate of 50 ppm to 20 wt%. A method for thermal stabilization of diethylzinc, characterized by:

In the formula (2), n is an integer of 1 to 4, and each R is independently hydrogen, a linear or branched alkyl group having 1 to 8 carbon atoms, a linear or branched group having 1 to 8 carbon atoms. An alkenyl group, an allyl group having 6 to 14 carbon atoms, and a linear or branched alkoxy group having 1 to 8 carbon atoms.   In the compound having a carbon-carbon double bond represented by the general formula (1) or (2), the substituent R is a compound composed of hydrogen or an alkyl group or an alkenyl group having 3 or less carbon atoms, and the total carbon The method for thermal stabilization of diethylzinc according to claim 1 or 2, wherein the number is 6 to 10. The manufacturing method of the diethyl zinc composition formed using the method of the thermal stabilization of the diethyl zinc in any one of Claims 1-3.   The method for stabilizing diethylzinc according to any one of claims 1 to 3, wherein the saturated and / or unsaturated hydrocarbon having 5 to 25 carbon atoms is different from the additive having an effect on the thermal stability of diethylzinc. And a method of thermally stabilizing diethylzinc, characterized in that an aromatic hydrocarbon compound or an ether compound having 6 to 30 carbon atoms coexists in diethylzinc. The method for producing a diethylzinc composition according to claim 4, wherein the saturated and / or unsaturated hydrocarbon having 5 to 25 carbon atoms and the 6 to 30 carbon atoms of a different type from the additive constituting the diethylzinc composition. A method for producing a diethylzinc composition, wherein an aromatic hydrocarbon compound or an ether compound coexists.   A composition comprising diethyl zinc and a compound having a carbon-carbon double bond represented by the general formula (1) described in claim 1 as an additive, wherein the additive has an addition rate of 50 ppm to Diethyl zinc composition which is 20 wt%   In the compound having a carbon-carbon double bond represented by the general formula (1), the substituent R is a compound composed of hydrogen, an alkyl group or an alkenyl group having 3 or less carbon atoms, and a total carbon number of 6 to 6. The diethylzinc composition of claim 7, which is 10.   A diethyl zinc composition comprising diethyl zinc and an additive, wherein a compound having a carbon-carbon double bond represented by the general formula (2) described in claim 2 is added to diethyl zinc as an additive.   In the compound having a carbon-carbon double bond represented by the general formula (2), the substituent R is a compound composed of hydrogen or an alkyl group or an alkenyl group having 3 or less carbon atoms, and a total carbon number of 6 to 10. The diethylzinc composition of claim 9, which is 10. The diethyl zinc composition of Claim 9 and 10 whose addition rate of the additive to diethyl zinc is 50 ppm-20 wt%.