JPH10158247A - Imidation catalyst and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new compound enabling to imidate an amic acid at a low temperature in a short time by using a specific imidazolidinone compound and a hydrogen halide. SOLUTION: A 1,3-dialkyl-2-imidazolidinone-hydrogen halide complex of formula I [R1 , R2 are each an alkyl; X is a halogen; (n) is 0.5, 1, 2], e.g. 1,3-di-n- propanol-2-imidazolidinone-hydrogen chloride complex. The complex of formula I is obtained by mixing a 1,3dialkyl-2-imidazolidinone of formula II (e.g. 1,3- dimethyl-2imldazolidinone) with a hydrogen halide (e.g. HF, HCl) in a ratio of 1:1 and subsequently reacting the mixture in a state that the water content in the raw materials is <=1%, more excellent <=0.1%. The obtained complex is useful as an imidation catalyst, and can be used for the imidation reaction in a small amount even at a relatively low temperature of <100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an imidization catalyst which is a complex compound comprising 1,3-dialkyl-2-imidazolidinone and hydrogen halide, which can imidize amic acids at a low temperature in a short time. It relates to the manufacturing method.

[0002]

2. Description of the Related Art The imidization reaction of amic acid or polyamic acid is difficult to proceed. Generally, these amide acids are imidized by a thermal imidation method of dehydrating by heat, a dehydrating agent of acetic anhydride, or the like. A chemical imidation method using pyridine or the like as a catalyst is known.

In the thermal imidization method, French Patent 1,239,
491 (1960) and the like, generally requires a high temperature of 200 ° C. or higher, so that electricity must be used as a heat source industrially, and the reaction may take several hours depending on the type of imides to be produced. Therefore, there is a problem that the manufacturing cost is increased.

In the chemical imidization method, although imidization can be carried out at a low temperature of 100 ° C. or less, a long time is required for the reaction, and acetic anhydride in a molar amount equal to or more than the carboxyl group of the amide acid is required. In addition, when pyridine or the like is used as a catalyst and an industrial production method is used, a large amount of equipment is required for a solvent and a catalyst recovery system, which causes an increase in cost. In addition, when a high temperature treatment such as molding is performed on the produced polyimide, a problem often occurs such that the polyimide is colored black and the aesthetic appearance at the time of molding is impaired.

[0005] M. Oba, J .; Polym. Sci. ,
Part A, 34 (4), 651-58 (1996)
Discloses a method in which a compound having two functional groups selected from a hydroxyl group, a carboxyl group, a sulfonic acid group, and an amino group is used as a catalyst for thermally imidizing a polyamic acid. However, even when such a catalyst is used, a temperature of 140 ° C. or higher is required to achieve an imidization ratio of 100%, and imidization cannot be performed at a low temperature of 100 ° C. or lower.

[0006]

An object of the present invention is to provide a novel imidization catalyst capable of imidizing an amic acid compound at a low temperature of 100 ° C. or less in a short time.

[0007]

The present inventors have conducted intensive studies to solve the above problems, and as a result, have come to invent a novel imidization catalyst and a method for producing the same. That is, the present invention relates to general formula (1)

Embedded image (Wherein, R ₁ and R _{2 each} represent an alkyl group, X represents a halogen atom, and n represents a number selected from 0.5, ₁ , and ₂ ). A complex compound comprising an imidazolidinone and a hydrogen halide, wherein the compound is an imidization catalyst, wherein R ₁ and R ₂ in the general formula (1) are the same or different from each other;
An imidation catalyst characterized by being a complex compound comprising 1,3-dialkyl-2-imidazolidinone, which is an alkyl group of 1, and hydrogen halide; and 1,3 represented by the general formula (1). -Dialkyl-2-imidazolidinone,
An imidization catalyst characterized by being a complex compound comprising at least one or more hydrogen halides selected from hydrogen fluoride, hydrogen chloride, hydrogen bromide and hydrogen iodide, in the presence or absence of an organic solvent A method for producing the above imidation catalyst, comprising mixing 1,3-dialkyl-2-imidazolidinone represented by the general formula (1) and hydrogen halide below, -2- An imidization catalyst characterized by being a complex compound comprising imidazolidinone and hydrogen chloride, in the presence or absence of an organic solvent, 1,3-dimethyl-2- A method for producing an imidization catalyst, comprising mixing imidazolidinone and hydrogen chloride.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The present invention relates to an imidization catalyst which is a complex compound comprising 1,3-dialkyl-2-imidazolidinone and hydrogen halide and a method for producing the same, wherein the imidation catalyst is used for imidizing amic acids. It is a compound that effectively acts as a catalyst.

One of the raw materials of the present invention is represented by the general formula (2)

Embedded image (Wherein, R ₁ and R _{2 each} represent an alkyl group), which is a 1,3-dialkyl-2-imidazolidinone;
₁ and R ₂ may be the same or different, and the alkyl group includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a 1-methylpropyl group,
-Methylpropyl group and isobutyl group, which can be relatively easily produced, so that both R ₁ and R ₂ are methyl groups in 1,3-dimethyl-2-imidazolidinone (hereinafter abbreviated as DMi). 1,3-diethyl-2-imidazolidinone as an ethyl group, 1,3-di-n-propyl-2-imidazolidinone as an n-propyl group, n
1,3-Di-n-butyl-2-imidazolidinone, which is a -butyl group, is preferred. Among them, DMi is most preferred because it is particularly inexpensive and easily available.

Another raw material, hydrogen halide, is
Examples thereof include hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide, and hydrogen chloride is most preferable because it is inexpensive and can be used relatively easily.

Since the complex compound of the present invention is hygroscopic and dissociates in water into 1,3-dialkyl-2-imidazolidinone and hydrogen halide, the water content in the raw material used is preferably 1% or less, more preferably 1% or less. Preferably, it is 0.1% or less, more preferably 0.01% or less.

When these materials are mixed, they react immediately,
The complex compound can be easily produced. The reaction temperature is not particularly limited as long as the reaction solution does not solidify and the hydrogen halide is dissolved.

The mixing ratio of the 1,3-dialkyl-2-imidazolidinone and the hydrogen halide used may be any value as long as the hydrogen halide can be dissolved in the 1,3-dialkyl-2-imidazolidinone. However, when the product is isolated as crystals, the molar ratio of 1,3-dialkyl-2-imidazolidine to hydrogen halide is 1 to minimize the operation of removing unreacted raw materials. : 1 is preferred. .

In conducting the above reaction, a solvent may be used. Examples of usable solvents include diethyl ether, n-propyl ether, n-butyl ether, methyl-t-butyl ether, tetrahydrofuran, 1,4
-Ethers such as dioxane, alcohols such as methanol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, t-butyl alcohol, phenol, o-cresol, m-cresol, p-cresol, etc. Phenols, aromatic hydrocarbons such as benzene, toluene, and xylene, etc., and most organic solvents generally used can be used.

The solution of the complex compound thus obtained can be used as it is as a reaction solution containing a catalyst before imidizing amide acids.

When it is desired to isolate the produced complex compound, the molar ratio varies depending on the kind of the raw material, but is 1: 1.
, For example, a 1: 1 complex of 1,3-dimethyl-2-imidazolidinone and hydrogen chloride can be isolated as crystals. 1,3-dialkyl-2 during the reaction
If no solvent other than imidazolidine is used, crystals are deposited if left at room temperature.
Also, when a solvent is used, crystals can be precipitated by appropriately cooling. A complex compound in which the molar ratio of 1,3-dialkyl-2-imidazolidinone to hydrogen halide is not 1: 1 is usually liquid at room temperature, but it is often used as a liquid or as it is cooled and solidified. May be.

The complex compound comprising 1,3-dialkyl-2-imidazolidinone and hydrogen halide thus obtained is effective as an imidization catalyst, and can be used in a solution containing amic acid or polyamic acid. , Just add a small amount,
The imidization can be carried out at a relatively low temperature of 100 ° C. or higher and of course lower than 100 ° C.

[0019]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples.

Infrared Spectroscopy (hereinafter IR) IR analysis was performed by KBr tablet method using IR REPORT-100 manufactured by JASCO.

Differential Thermal Analysis (hereinafter, DSC) As for DSC, thermal behavior at -100 to 100 ° C was measured by using SSC / 5200 manufactured by Seiko Denshi Kogyo.

Example 1 100 g of DMi was charged into a flask, and hydrogen chloride gas 3
5.2 g was blown at a blowing start temperature of 30 ° C and at the end of 81 ° C. During this time, no particular temperature control was performed. When this solution was left at room temperature for 1 hour, crystals precipitated.
The obtained complex compound of DMi and hydrogen chloride was a colorless and transparent columnar crystal, and the yield was 98.4%. Since the obtained crystal dissociates in water, the crystal is dissolved in water, and the DMi content in the crystal is determined by high performance liquid chromatography (H
By PLC), the hydrogen chloride content was determined by titration with a 0.01 N-sodium methylate / methanol solution, respectively. As a result, the molar ratio of DMi to hydrogen chloride in the crystal was 1: 1.02. IR measurement of the obtained crystals was performed by the KBr tablet method. The chart is shown in FIG. DMi
In the absorption band of the absorption of the carbonyl stretching vibration of N-C = O found in 1690 cm ^-1 is shifted to 1660 cm ^-1. FIG. 2 shows a DSC chart of the obtained crystal.
The melting point of the obtained complex compound crystal was around 37 ° C., and was clearly different from DMi having a melting point of 8 ° C.

Example 2 100 g of DMi and 100 g of tetrahydrofuran were charged into a flask, and 32 g of hydrogen chloride gas was added to 30 g of the flask with stirring.
Blow below ℃. After evaporating off tetrahydrofuran and excess hydrogen chloride, the mixture was allowed to stand at room temperature, whereupon crystals were deposited. The obtained complex compound was a colorless and transparent plate-like crystal having a width of about 1 to 5 mm and a length of about 1 to 7 cm. The yield was 97%. The composition was measured in the same manner as in Example 1. As a result, the molar ratio of DMi to hydrogen contained in the crystals was 1: 1.01.

Example 3 100 g of 1,3-diethyl-2-imidazolidinone was charged into a flask, and 29.3 g of hydrogen chloride gas was blown at 80 ° C. or lower. When this solution was allowed to stand at 10 ° C. or lower for 2 hours, crystals precipitated. The obtained complex compound was a colorless and transparent columnar crystal, and the yield was 90.6%. The molar ratio of 1,3-diethyl-2-imidazolidinone to hydrogen chloride contained in the crystals was 1: 1.01.

Example 4 1,3-Di-n-propyl-2-imidazolidinone 10
0 g and 100 g of tetrahydrofuran were charged into a flask, and 31.1 g of hydrogen chloride gas was blown at 40 ° C. or lower. After distilling off tetrahydrofuran and excess hydrogen chloride by evaporation, the mixture was left at −5 ° C. to precipitate crystals. The yield was 90%. When the composition was measured in the same manner as in Example 1, the 1,3-
The molar ratio of di-n-propyl-2-imidazolidinone to hydrogen chloride was 1: 1.

Reference Example 1 p-phenylenediamine and phthalic anhydride (molar ratio 1:
30 g of the amic acid obtained in 2) and 150 g of 1-methyl-2-pyrrolidone were charged into a flask to dissolve the amic acid. The 1,3-dimethyl-2- obtained in Example 1 there.
3 g of a complex compound consisting of imidazolidinone and hydrogen chloride was charged and reacted at 80 ° C. for 1 hour. The amide acid was imidized to obtain a bisimide compound. The yield was 98.6%.

Reference Example 2 In 150 g of DMi, 20 g of 4,4'-bis (3-aminophenoxy) biphenyl, 11.25 g of pyromellitic anhydride dianhydride and 0.80 g of phthalic anhydride were charged, and
Reaction was carried out at 4 ° C. for 4 hours to obtain a polyamic acid solution. After injecting 1.3 g of hydrogen chloride gas into the solution at a temperature of 30 ° C. or lower, a reaction was performed at 90 ° C. for 1 hour. The polyamic acid was imidized, and yellow polyimide particles were generated immediately after the start of the reaction. This solution was filtered, washed with methanol, and dried under reduced pressure at 60 ° C. for 8 hours to obtain a yellow polyimide powder. The imidation ratio of the obtained polyimide was determined by M.I. Ob
a, J. et al. Polym. Sci. , Part A, 34
(4) As measured by the method described in 651-58 (1996), the imidation ratio was 100%. The strand obtained by melting this polyimide at 420 ° C. was yellow and transparent, and had the same aesthetic appearance as the polyimide obtained by a general thermal imidization method.

Reference Example 3 Into 100 g of tetrahydrofuran, 5 g of a complex compound obtained in Example 2 and composed of 1,3-dimethyl-2-imidazolidinone and hydrogen chloride was charged. To this solution, a polyamic acid powder comprising 20 g of 4,4-diaminodiphenyl ether, 20.7 pyromellitic dianhydride and 1.48 g of phthalic anhydride was charged and reacted at 60 ° C. for 3 hours. The obtained polyimide was a yellow powder, and the imidation ratio measured by the same method as in Reference Example 2 was 100%.

Reference Example 4 In 150 g of DMi, 20 g of 4,4'-bis (3-aminophenoxy) biphenyl, 11.25 g of pyromellitic dianhydride and 0.80 g of phthalic anhydride were charged.
Reaction was carried out at 4 ° C. for 4 hours to obtain a polyamic acid solution. This solution was heated and stirred at 90 ° C. for 10 hours. The imidation ratio measured by the same method as in Reference Example 2 was 6%, and a sufficiently imidized polyimide could not be obtained.

[0030]

The present invention relates to a novel imidization catalyst which can imidize an amic acid compound at a low temperature in a short time and a method for producing the same.

[Brief description of the drawings]

FIG. 1 is an IR chart of a complex compound obtained in Example 1.

FIG. 2 is a DSC chart of the complex compound obtained in Example 1.

Claims (7)

[Claims] 1. A compound of the general formula (1) (Wherein, R ₁ and R _{2 each} represent an alkyl group, X represents a halogen atom, and n represents a number selected from 0.5, ₁ , and ₂ ). A complex compound comprising imidazolidinone and hydrogen halide. 2. An imidization catalyst, which is a complex compound comprising 1,3-dialkyl-2-imidazolidinone represented by the general formula (1) and hydrogen halide. 3. A complex compound comprising 1,3-dialkyl-2-imidazolidinone in which R ₁ and R ₂ in the general formula (1) are the same or different and are C1-4 alkyl groups, and a hydrogen halide. An imidization catalyst characterized by the following. 4. A 1,3-dialkyl-2-imidazolidinone represented by the general formula (1), and at least one halogen selected from hydrogen fluoride, hydrogen chloride, hydrogen bromide and hydrogen iodide. An imidization catalyst, which is a complex compound composed of hydrogen iodide. 5. The method according to claim 1, wherein the 1,3-dialkyl-2-imidazolidinone represented by the general formula (1) is mixed with hydrogen halide in the presence or absence of an organic solvent. 2. A method for producing the compound according to 1. 6. An imidization catalyst, which is a complex compound comprising 1,3-dimethyl-2-imidazolidinone and hydrogen chloride. 7. In the presence or absence of an organic solvent,
The method for producing an imidation catalyst according to claim 6, wherein 1,3-dimethyl-2-imidazolidinone and hydrogen chloride are mixed.