JP2008044878A - Method for producing n-alkylborazine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for stably producing an N-alkylborazine. <P>SOLUTION: The method for producing the N-alkylborazine comprises the step of reacting an alkali metal borohydride represented by ABH<SB>4</SB>(wherein A is a lithium atom, a sodium atom, or a potassium atom) with an alkylamine salt represented by RNH<SB>3</SB>X (wherein R is an alkyl group; and X is a halogen atom) in a solvent to synthesize an N-alkylborazine, wherein the rate of that portion of at least either of the alkali metal borohydride and the alkylamine salt used in the reaction which passes a mesh of an opening of 1.00 mm is not less than 99 mass%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing N-alkylborazine.

  As the performance of information equipment increases, LSI design rules become finer year by year. In the manufacture of LSIs with fine design rules, the materials that make up LSIs must also have high performance and function on fine LSIs.

  For example, regarding materials used for interlayer insulating films in LSIs, a high dielectric constant causes signal delay. In a fine LSI, the influence of this signal delay is particularly great. For this reason, development of a new low dielectric material that can be used as an interlayer insulating film has been desired. Further, in order to be used as an interlayer insulating film, it is necessary not only to have a low dielectric constant but also to be excellent in characteristics such as moisture resistance, heat resistance and mechanical strength.

As a response to such a demand, borazine compounds having a borazine ring skeleton in the molecule have been proposed (see, for example, Patent Document 1 and Patent Document 2). Since a borazine compound having a borazine ring skeleton has a low molecular polarizability, the formed film has a low dielectric constant. In addition, the formed film is excellent in heat resistance.
JP 2000-340689 A JP 2003-119289 A

  Among the borazine compounds, a method for producing an N-alkylborazine having a nitrogen moiety substituted with an alkyl group includes, for example, an alkali borohydride (for example, sodium borohydride) and an alkylamine salt (for example, methylamine hydrochloride). ) In a solvent is known.

  As a result of investigation by the present inventors, when the above-described method is used, the raw material alkali borohydride and the alkylamine salt are solids that are hardly soluble in an organic solvent, so that the powdery raw material was dispersed in each solvent. After mixing, N-alkylborazine is synthesized, and it has been clarified that the pipe is easily clogged during the raw material supply during the synthesis. Such clogging of piping causes a problem that it is difficult to efficiently and stably produce N-alkylborazine. That is, when the piping is blocked during the raw material supply, the reaction must be stopped at that time, and the desired amount of N-alkylborazine cannot be obtained, resulting in a decrease in yield. To do. Even in the case where clogging occurs, if a desired amount of N-alkylborazine is to be obtained, it is necessary to restart the supply of raw materials by a method such as replacing the pipe after stopping the reaction. In order to replace the piping, it is necessary to lower the temperature of the reaction kettle, and it is necessary to raise the temperature again when the reaction is restarted. This consumes extra time and energy.

  Then, an object of this invention is to provide the means which can manufacture N-alkyl borazine stably.

  In view of the above problems, the present inventors have examined the cause of clogging of piping that occurs when N-alkylborazine is synthesized. In the process, it was found that a certain amount of raw material aggregates are contained in the raw material powder, so that clogging can occur in the piping, particularly in the valve portion. Further, the present inventors have shown that N-alkylborazine can be stably produced by sieving an alkali borohydride and an alkylamine salt, which are raw materials for synthesizing N-alkylborazine, to remove aggregates. The headline and the present invention have been completed.

That is, the present invention relates to an alkali borohydride represented by ABH ₄ (A is a lithium atom, a sodium atom or a potassium atom) and RNH ₃ X (R is an alkyl group, and X is a halogen atom). ) To synthesize N-alkylborazine by reacting with an alkylamine salt represented by the following formula: at least one of the alkali borohydride or the alkylamine salt used in the reaction It is a manufacturing method of N-alkyl borazine whose ratio which passes a 1.00 mm mesh is 99 mass% or more.

  According to the present invention, N-alkylborazine can be produced stably.

The present invention relates to an alkali borohydride represented by ABH ₄ (A is a lithium atom, a sodium atom or a potassium atom) and RNH ₃ X (R is an alkyl group, and X is a halogen atom). And a step of synthesizing an N-alkylborazine by reacting the alkylamine salt represented in a solvent with an opening of at least one of the alkali borohydride or the alkylamine salt used in the reaction. It is a manufacturing method of N-alkyl borazine whose ratio which passes a 00 mm mesh is 99 mass% or more.

  Hereinafter, the production method of the present invention will be described.

First, a raw material, ABH ₄ (A is a lithium atom, a sodium atom or a potassium atom), an alkali borohydride represented by (RNH ₃ ) _n X (R is an alkyl group, and X is a halogen atom) An alkylamine salt represented by the formula (Atom).

In alkali borohydride (ABH ₄ ), A is a lithium atom, a sodium atom or a potassium atom. Examples of alkali borohydrides include sodium borohydride and lithium borohydride.

In the alkylamine salt (RNH ₃ X), R is an alkyl group, and X is a halogen atom. The halogen atom is preferably a chlorine atom. In consideration of the yield of the synthesis reaction and the ease of handling, R is preferably the same alkyl group. The alkyl group may be linear, branched or cyclic. Although carbon number which an alkyl group has is not specifically limited, Preferably it is 1-8, More preferably, it is 1-4, More preferably, it is one. Specific examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, heptyl group. Octyl group, nonyl group, decyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, and the like. Alkyl groups other than these may be used. Examples of alkylamine salts include monomethylamine hydrochloride (CH ₃ NH ₃ Cl), monoethylamine hydrochloride (CH ₃ CH ₂ NH ₃ Cl), monomethylamine hydrobromide (CH ₃ NH ₃ Br), mono And ethylamine hydrofluoride (CH ₃ CH ₂ NH ₃ F).

  The alkali borohydride and alkylamine salt to be used may be selected according to the structure of the N-alkylborazine to be synthesized. For example, in the case of producing N-trimethylborazine in which a methyl group is bonded to a nitrogen atom constituting a borazine ring, an alkylamine salt such as monomethylamine hydrochloride is used as an alkylamine salt. Use it.

  The amount of alkali borohydride and alkali amine salt to be used is not particularly limited, but preferably the amount of alkali amine salt used is 1 to 100 kg, more preferably 3 to 20 kg, still more preferably 5 to 10 kg. .

  The mixing ratio of alkali borohydride and alkylamine salt is not particularly limited, but when the amount of alkylamine salt used is 1 mol, the amount of alkali borohydride used is preferably 0.5-2. The amount is 0 mol, more preferably 0.8 to 1.5 mol, still more preferably 1.0 to 1.2 mol.

  In the present invention, as a raw material for synthesizing N-alkylborazine, a ratio of passing through a mesh having an opening of 1.00 mm of at least one of an alkali borohydride or an alkylamine salt as a raw material is 99% by mass or more. It is characterized by the use of things.

  Specifically, in the present invention, the amount of particles of alkali borohydride and / or alkylamine salt which are raw materials passing through a mesh having a mesh size of 1.00 mm is 99% by mass or more, preferably 99.9% by mass. It is above, More preferably, it is 100 mass%. In this way, N-alkylborazine is synthesized using sodium borohydride and / or an alkylamine salt from which aggregates aggregated to a certain size or more are removed, thereby preventing clogging of piping for supplying raw materials. And stable production of N-alkylborazine becomes possible. In addition, the size of the raw material sodium borohydride or alkylamine salt is preferably as small as possible, and the lower limit of the particle diameter is not particularly limited, but is practically 10 μm.

  In addition, the said ratio performs 100 mass of raw materials using the JIS standard sieve of 1.00 mm opening (JIS standard number JIS Z8801-1 test sieve), and measures the mass percentage of particle | grains with a particle diameter of 1.00 mm or less. Is required.

  In the present invention, the raw material having a ratio of passing through a mesh having a mesh size of 1.00 mm of 99% by mass or more may be used by either one or both of alkali borohydride and alkylamine salt. Preferably, a material having a ratio of passing through a mesh having an opening of 1.00 mm is 99% by mass or more in both raw materials.

  In order to obtain a raw material having a defined particle diameter as described above, although not particularly limited, the dried raw material is pulverized by an arbitrary pulverization method, if necessary, and then preferably classified by a sieve such as a vibration sieve, Classification is performed with a general classification apparatus such as inertia classification or centrifugal classification, and the particle size is controlled to a specific particle size.

  For the pulverization, for example, a bead mill, a ball mill, a roll mill, a hammer mill, a pin mill, a jet mill, a crusher, a cutter mill, a hammer crusher, a stamp mill, a screen mill, a tube mill, a vibrating ball mill, a stirring mill, a planetary mill, a mortar and the like are used.

  In addition, the obtained raw material is preferably stored in an atmosphere in which the amount of moisture is controlled in order to prevent aggregation due to moisture absorption.

  N-alkylborazine is synthesized by reacting the above alkali borohydride with an alkylamine salt in a solvent.

  The solvent for synthesis is not particularly limited, and examples thereof include tetrahydrofuran, monoethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), and tetraethylene glycol dimethyl ether (tetraglyme). .

  The amount of the solvent to be used is not particularly limited, but is preferably 2 to 10 times by mass with respect to the total amount of alkylamine salt and alkali borohydride.

  The reaction conditions between the alkali borohydride and the alkylamine salt are not particularly limited. Reaction temperature becomes like this. Preferably it is 20-250 degreeC, More preferably, it is 50-240 degreeC, More preferably, it is 100-220 degreeC. When the reaction is performed within the above range, the amount of hydrogen generation can be easily controlled. The reaction temperature can be measured using a temperature sensor such as a K thermocouple.

  The synthesized N-alkylborazine is a compound represented by the following formula.

  In the formula, R is as described for the alkylamine salt, and thus the description thereof is omitted here. Examples of N-alkylborazines include N, N ′, N ″ -trimethylborazine, N, N ′, N ″ -triethylborazine, N, N ′, N ″ -tri (n-propyl) borazine, N, N ', N ″ -tri (iso-propyl) borazine, N, N ′, N ″ -tri (n-butyl) borazine, N, N ′, N ″ -tri (sec-butyl) borazine, N, N ′, N ″ -tri (iso-butyl) borazine, N, N ′, N ″ -tri (tert-butyl) borazine, N, N ′, N ″ -tri (1-methylbutyl) borazine, N, N ′, N ″ -Tri (2-methylbutyl) borazine, N, N ', N "-tri (neo-pentyl) borazine, N, N', N" -tri (1,2-dimethylpropyl) borazine, N, N ', N "-Tri (1-ethylpropyl) borazine, N, N ', N" Tri (n-hexyl) borazine, N, N ′, N ″ -tricyclohexylborazine, N, N′-dimethyl-N ″ -ethylborazine, N, N′-diethyl-N ″ -methylborazine, N, N ′ -Dimethyl-N "-propylborazine and the like.

  The synthesized N-alkylborazine can be purified as necessary. As a purification method of N-alkylborazine, for example, distillation purification is used.

  The size and type of the distillation purification apparatus may be determined according to the environment and scale. For example, if a large amount of borazine compound is to be processed, an industrial scale distillation column can be used. If a small amount of N-alkylborazine is to be treated, distillation purification using a distillation tube can be used. For example, as a specific example of a distillation apparatus for treating a small amount of N-alkylborazine, a distillation apparatus in which a Liebig cooling pipe is attached to a three-necked flask with a Claisen type connecting pipe can be used. However, the technical scope of the present invention is not limited to the embodiment using such a distillation apparatus.

  The temperature at the time of distillation purification is not particularly limited, and can be appropriately set according to the kind of synthesized N-alkylborazine. For example, the temperature is usually about 100 to 150 ° C.

  The produced borazine compound such as N-alkylborazine is not particularly limited, but can be used for forming an interlayer insulating film for a semiconductor, a barrier metal layer, an etch stopper layer, and the like. In that case, the borazine compound may be used as it is, or a compound obtained by modifying the borazine compound may be used. A polymer obtained by polymerizing a borazine compound or a borazine compound derivative may be used as a raw material for an interlayer insulating film for a semiconductor, a barrier metal layer, or an etch stopper layer. Hereinafter, “N-alkylborazine”, “borazine compound”, “derivative of borazine compound”, and “polymer derived therefrom” are collectively referred to as “borazine ring-containing compound”.

  As a method for forming an interlayer insulating film for semiconductor, a barrier metal layer, or an etch stopper layer using a borazine ring-containing compound, for example, a solution-like or slurry-like composition containing a borazine ring-containing compound is prepared. A technique of forming a coating film by applying to a desired site can be used.

  Hereinafter, embodiments of the present invention will be described in more detail using examples and comparative examples. However, the technical scope of the present invention is not limited to the following embodiments.

<Example 1>
8.38 kg of dehydrated methylamine hydrochloride and 30.0 kg of triglyme as a solvent were charged into a reaction vessel equipped with a cooling tube while purging with nitrogen, and the reaction system was heated to 150 ° C. A mixture of sodium borohydride (5.25 kg) obtained by removing aggregates with a sieve having an opening of 1.00 mm (16 mesh) in a nitrogen atmosphere and 22.2 kg of triglyme as a solvent is supplied over 7 hours. did. That is, the ratio of the sodium borohydride used passing through a mesh having an aperture of 1.00 mm was 100% by mass. Thereafter, the reaction solution was heated to 170 ° C. and aged for 2 hours. There was no blockage of the slurry supply piping over the entire synthesis period, and 4.53 kg of N-trimethylborazine was obtained (yield 90%).

<Comparative Example 1>
The same operation as in Example 1 was performed except that the aggregate of sodium borohydride was not removed by sieving. The proportion of sodium borohydride used passing through a mesh having an aperture of 1.00 mm was 98% by mass. As a result, during the slurry supply, when 3.70 kg of sodium borohydride was supplied, the slurry supply piping was blocked and the slurry supply became impossible, so the reaction was stopped halfway. The yield of N-trimethylborazine at this time was 55%.

  From the results shown in the above Examples and Comparative Examples, borazine was removed without clogging the piping by sieving alkali borohydride and / or N-alkylamine, which are N-alkylborazine synthesis raw materials, and removing aggregates. It was revealed that the compound was synthesized.

  Therefore, according to the present invention, N-alkylborazine can be stably produced.

Claims (3)

Alkyl borohydride represented by ABH ₄ (A is a lithium atom, sodium atom or potassium atom) and an alkyl represented by RNH ₃ X (R is an alkyl group, and X is a halogen atom) It has a step of synthesizing an N-alkylborazine by reacting with an amine salt in a solvent, and the proportion of the alkali borohydride used in the reaction passing through a mesh having an opening of 1.00 mm is 99% by mass or more. A method for producing N-alkylborazine. Alkyl borohydride represented by ABH ₄ (A is a lithium atom, sodium atom or potassium atom) and an alkyl represented by RNH ₃ X (R is an alkyl group, and X is a halogen atom) A step of synthesizing an N-alkylborazine by reacting with an amine salt in a solvent, and the proportion of the alkylamine salt used in the reaction passing through a mesh having an opening of 1.00 mm is 99% by mass or more. A method for producing an N-alkylborazine. Alkyl borohydride represented by ABH ₄ (A is a lithium atom, sodium atom or potassium atom) and an alkyl represented by RNH ₃ X (R is an alkyl group, and X is a halogen atom) A step of synthesizing an N-alkylborazine by reacting with an amine salt in a solvent, and a ratio of the alkali borohydride used in the reaction and the alkylamine salt passing through a mesh having an opening of 1.00 mm The manufacturing method of N-alkyl borazine whose each is 99 mass% or more.