JPH07316293A - Production of polyimide ester - Google Patents

Abstract

PURPOSE:To produce a thermoplastic polyimide ester having excellent mechanical strength through a simple process at a low cost. CONSTITUTION:The production process comprises producing a diamic acid- dicarboxylic acid from trimellitic anhydride and an aromatic diamine, adding an aromatic diacetoxy compound thereto, and heating the mixture to cause the acid to successively undergo ring closure and melt polymerization with the diacetoxy compound, the polymerization being conducted in the presence of an aromatic acetoxycarboxylic acid and/or a poly(alkylene terephthalate).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyimide ester suitable for industrial materials such as high strength fibers and films.

[0002]

BACKGROUND OF THE INVENTION Polyethylene terephthalate has been the most well known of saturated polyesters, and in order to improve its properties, polyethylene terephthalate has an acyloxy aromatic carboxylic acid. Has been proposed (Japanese Patent Laid-Open No. 49-72393).

However, there is a limit to the improvement of the mechanical strength only by the modification by the reaction of the acyloxy aromatic carboxylic acid, and a further excellent modified polyester has been demanded. Further, from the viewpoint of the manufacturing method, a manufacturing process is simplified and a manufacturing cost is desired to be low.

The present inventors have conducted intensive studies on a method for efficiently producing a novel polyester having improved mechanical strength by solving the above-mentioned problems, and as a result, trimellitic anhydride and aroma have been obtained. A diamic acid dicarboxylic acid is produced from an aromatic diamine, and then an aromatic diacetoxy compound is added to the diamic acid dicarboxylic acid. Then, a ring closure reaction of the diamic acid dicarboxylic acid and a melt polymerization reaction with the aromatic diacetoxy compound are sequentially performed to produce a polyimide ester. Hits the,
It was found that a polyimide ester excellent in mechanical strength can be efficiently produced in one pot by adding acetoxy aromatic carboxylic acid and / or polyalkylene terephthalate to the reaction during melt polymerization, and the present invention is based on this finding. completed.

[0005]

That is, the present invention is to produce a diamic acid dicarboxylic acid from trimellitic anhydride and an aromatic diamine, and then add an aromatic diacetoxy compound to the diamic acid dicarboxylic acid under heating. In producing a polyimide ester by sequentially performing a ring-closing reaction of and a melt polymerization reaction with an aromatic diacetoxy compound,
The present invention provides a method for producing a polyimide ester, which comprises adding and reacting acetoxy aromatic carboxylic acid and / or polyalkylene terephthalate during melt polymerization.

Here, trimellitic anhydride has the formula

[0007]

[Chemical 1]

It is represented by

The aromatic diamine has the formula [I]

[0010]

[Chemical 2]

[Wherein, X is -O-, -SO _2- , -CH _2- , -CH ₂ CH
_2- , m and n are 1-2, a is 0 or 1, and b is 0-2
Respectively, R ¹ and R ³ are the same or different hydrogen atoms,
Halogen atom, C1-C6 alkyl group, C1-C1
4 is an alkoxy group, a phenyl group or a cyclohexyl group, and R ² and R ⁴ are the same or different halogen atoms, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms,
A phenyl group or a cyclohexyl group is shown. ] Is represented.

In the above formula [I], X, m, n, a,
b and R ^{1 to} R ⁴ are as described above, but here, the alkyl group having 1 to 6 carbon atoms includes a methyl group and an ethyl group, and the alkoxy group having 1 to 4 carbon atoms is methoxy. Group, ethoxy group, etc.

Examples of the aromatic diamine represented by the above formula [I] include 1,4-diamino-2-chlorobenzene,
1,4-diamino-2-methylbenzene, 1,4-diamino-2,5-dichlorobenzene, 1,4-diamino-2,5-dimethylbenzene, 1,3-diaminobenzene, 4,4′-diamino -3,3'-Dimethyldiphenyl, 4,4'-diamino-3,3 '
-Dichlorodiphenyl, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane and the like.

In the present invention, the trimellitic anhydride and aromatic diamine are first reacted in a solvent. The reaction conditions in this case are not particularly limited, but it is preferable to react approximately twice the amount of trimellitic anhydride with the aromatic diamine represented by the above formula [I]. Reaction temperature is 0
-50 ° C, the pressure may be either normal pressure or pressurized condition, and the reaction time is usually 0.5 to 5 hours. The solvent used for the reaction is preferably a polar solvent such as methal, ethanol, acetone, methylethylketone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like, and is preferably carried out in an inert gas atmosphere such as nitrogen or argon.

By this reaction, diamic acid dicarboxylic acid is produced. Here, the diamic acid dicarboxylic acid has the formula [II]

[0016]

[Chemical 3]

Is represented by

In the above formula [II], X, m,
m, a, b, R ^{1 to} R ⁴ are as described in the description of the above formula [I].

Specific examples of this diamic acid dicarboxylic acid include 1,4-bis (2,5-dicarboxy) -benzamido-2-chlorobenzene; 1,4-bis (2,5-dicarboxy) -benz Amido-2-methylbenzene; 1,4-bis (2,5-dicarboxy) -benzamide-2,5-dichlorobenzene; 1,4-bis (2,5-dicarboxy) -benzamide-2, 5-dimethylbenzene; 4,4'-bis (2,
5-dicarboxy) -benzamido-3,3'-dichlorodiphenyl;4,4'-bis (2,5-dicarboxy) -benzamido-3,3'-dimethylphenyl;4,4'-bis ( 2,5-
Dicarboxy) -benzamide-diphenyl ether;
4,4'-bis (2,5-dicarboxy) -benzamido-diphenyl sulfone; 4,4'-bis (2,5-dicarboxy)
-Benzamide-diphenylmethane; 4,4'-bis (2,5
-Dicarboxy) -benzamido-diphenylethane.

In the present invention, an aromatic diacetoxy compound is added to the diamic acid dicarboxylic acid represented by the above formula [II] thus obtained, and the ring-closing reaction of the diamic acid dicarboxylic acid and the aromatic diacetoxy compound are heated. Melt polymerization reaction with a diacetoxy compound is sequentially performed.

Here, as the aromatic diacetoxy compound, 1,4-diacetoxybenzene, 1,3-diacetoxybenzene, 4,4'-diacetoxydiphenyl, 4,4'-diacetoxydiphenyl ether, 4,4 Examples thereof include'-diacetoxydiphenyl sulfone and 2,2-bis (p-acetoxyphenyl) propane.

The reaction in this case is carried out under heating. Usually, the temperature is raised to 250 to 300 ° C. over 1 to 5 hours to effect the ring-closing reaction of the diamic acid dicarboxylic acid, and subsequently, at the same temperature. It may be carried out by melt-polymerizing for 1 to 5 hours to carry out the transesterification reaction. The pressure during this reaction may be atmospheric pressure or reduced pressure. Further, it is preferable that the diamic acid dicarboxylic acid as a raw material and the aromatic diacetoxy compound are used in an approximately equimolar amount.

In the present invention, during the above-mentioned melt polymerization,
Acetoxy aromatic carboxylic acid and / or polyalkylene terephthalate is added and reacted. Here, as the acetoxy aromatic carboxylic acid, p-acetoxybenzoic acid, 4-acetoxy-4′-carboxydiphenyl,
2-acetoxy-5-naphthoic acid and the like can be mentioned. Examples of polyalkylene terephthalate include polyethylene terephthalate and polybutylene terephthalate.

In this case, the use ratio of the raw material is such that the diamic acid dicarboxylic acid and the diacetoxy compound are almost equimolar as described above, and the acetoxy aromatic carboxylic acid is used for the total amount of 20 to 95 mol%. The acid and the polyalkylene terephthalate are preferably used alone or in a total amount of 5 to 80 mol%. The amount of the diamic acid dicarboxylic acid used here may be less than 50 mol% and may be replaced with terephthalic acid or isophthalic acid.

The method for producing the polyimide ester of the present invention will be described in detail. The trimellitic anhydride and the aromatic diamine are charged in a ratio such that the former: the latter are approximately 2: 1 (molar ratio), and the solvent is used. Add 1 at below 50 ℃
Allow to react for ~ 5 hours. Then add the remaining monomer,
The temperature is raised to 250 to 300 ° C over 1 to 5 hours, the solvent is distilled off, the ring-closing reaction of diamic acid dicarboxylic acid is carried out, and the produced water is distilled off. Continuously, 250-300
React for 1 to 5 hours at ℃ to carry out transesterification reaction,
The acetic acid may be distilled off, and the pressure may be reduced to react for 1 to 15 hours to complete the polymerization.

According to the method of the present invention, the synthesis of diamic acid dicarboxylic acid and the polymerization of polyimide ester can be carried out in one pot, and since both are carried out at substantially the same temperature, there is no need to carry out reheating. The heating step can be omitted.

The polyimide ester can be produced as described above. This has a reduced viscosity [ηsp / C] of 0.2 dl / g or more at 60 ° C. in a solution of p-chlorophenol in a concentration of 0.2 g / dl of 0.2 dl / g or more, and the formula [A]

[0028]

[Chemical 4]

A repeating unit represented by the formula [B]

[0030]

[Chemical 5]

[In the formula, Ar is

[0032]

[Chemical 6]

[0033]

[Chemical 7]

[0034]

[Chemical 8]

Or

[0036]

[Chemical 9]

(X is -O-, -S-, -SO _2- , -CO-, -O (CH ₂ ).
_P O-,

[0038]

[Chemical 10]

Or

[0040]

[Chemical 11]

Is shown. However, p and q are 1-10. ) Is shown. ]

A repeating unit represented by the formula [C]

[0043]

[Chemical 12]

A repeating unit represented by the formula [D]

[0045]

[Chemical 13]

And a repeating unit represented by

In the above equation, X, m, n, a, b, R ¹
~ R ⁴ is as described above.

[0048]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto as long as the scope of the present invention is not exceeded.

Example 1 A reactor equipped with a stirrer and an argon gas inlet tube was charged with a solution of trimellitic anhydride (3.84 g, 0.02 mol) dissolved in methanol (10 ml), and the solution was placed in an argon gas atmosphere. A solution of 1.42 g (0.01 mol) of 1,4-diamino-2-chlorobenzene in 15 ml of methanol was added dropwise. The reaction solution was homogeneous at the beginning, but after 30 minutes, a precipitate was formed to be a slurry. After 1 hour 4,4'-biphenol diacetate 2.60 g
(0.01 mol), p-acetoxybenzoic acid 12.60
g (0.07 mol) and polyethylene terephthalate (3.84 g, 0.02 mol) were added, and the temperature was raised to 280 ° C. over 1 hour under an argon gas stream. During that time, methanol, water and acetic acid were distilled.

Further, the reaction was carried out at that temperature for 1 hour, and the acetic acid formed during this time was distilled off. Then 1 in the reactor
The pressure was reduced to mmHg, and the reaction was performed at 280 ° C. for 2 hours with stirring to obtain a copolymer.

This copolymer had a reduced viscosity [η sp / C] (hereinafter the same) of 0.65 dl / at 60 ° C. in a solution having a concentration of 0.2 g / dl using p-chlorophenol as a solvent.
It was g. Also, as a result of infrared absorption spectrum analysis,
Absorption by benzene ring at 1580 cm ^-1 and 1490 cm ^-1 , absorption by carbonyl group at 1650 cm ^-1 and further 1780-1680 cm ^-1 and 720 cm.
Absorption by the imide group was observed at the ^-1 position. From these facts, this copolymer has the following repeating unit [A '
], [B '], [C] and [D'].

[0052]

[Chemical 14]

[0053]

[Chemical 15]

[0054]

[Chemical 16]

[0055]

[Chemical 17]

Furthermore, it was confirmed by a polarizing microscope that this polyester exhibits liquid crystallinity at 310 ° C. or higher.
Next, this polyester was spun at 330 ° C. from a spinning nozzle having an inner diameter of 1 mm to obtain a fiber having a yarn diameter of 30 μm.
The properties of this fiber were measured according to JIS-L-1069. The results are shown in Table 1.

Example 2 The same as in Example 1 except that 1.36 g (0.01 mol) of 1,4-diamino-2,5-dimethylbenzene was used instead of 1,4-diamino-2-chlorobenzene. Example 1
A copolymer was obtained in the same manner as in.

The reduced viscosity [η sp / C] of this copolymer was 0.83 dl / g. In addition, as a result of infrared absorption spectrum analysis, absorption by the benzene ring at the positions of 1580 cm ⁻¹ and 1490 cm ⁻¹ , absorption by the carbonyl group at the position of 1650 cm ⁻¹ , further 1780 to 1680 cm ^−1.
And absorption by an imide group was observed at a position of 720 cm ^-1 . From these, it was confirmed that this copolymer was composed of the following repeating units [A ″], [B ′], [C] and [D ′].

[0059]

[Chemical 18]

[0060]

[Chemical 19]

[0061]

[Chemical 20]

[0062]

[Chemical 21]

Further, it was confirmed by a polarizing microscope that this polyester exhibits liquid crystallinity at 310 ° C. or higher. Next, this polyester was spun at 330 ° C. from a spinning nozzle having an inner diameter of 1 mm to obtain a fiber having a yarn diameter of 30 μm. The properties of this fiber were measured according to JIS-L-1069. The results are shown in Table 1.

[0064]

[Table 1]

[0065]

As described above, according to the present invention, a thermoplastic polyimide ester having excellent mechanical strength can be produced by a simple process and at low cost.

Claims (1)

[Claims] 1. A diamic acid dicarboxylic acid is produced from trimellitic anhydride and an aromatic diamine, and then an aromatic diacetoxy compound is added thereto, and the ring-closing reaction of the diamic acid dicarboxylic acid and the aromatic diacetoxy compound are added with heating. In producing a polyimide ester by sequentially performing the melt polymerization reaction of 1), a method for producing a polyimide ester, wherein acetoxy aromatic carboxylic acid and / or polyalkylene terephthalate is added and reacted at the time of melt polymerization.