JPH05140069A - Unsaturated group-containing aromatic polyazomethine oligomer and its production - Google Patents

Abstract

PURPOSE:To produce the subject oligomer capable of preventing gelation during molding, curable in a mild condition, excellent in solubility, moldability and thermal stability and useful, e.g. as an insulating material for an electric apparatus, etc., by reacting an aromatic diamine with an aromatic dialdehyde, an aliphatic unsaturated aldehyde, etc. CONSTITUTION:An aromatic diamine such as metaphenylenediamine is reacted with an aromatic dialdehyde such as isophthalic aldehyde and an aliphatic unsaturated aldehyde such as clotonaldehyde or an aromatic unsaturated aldehyde such as cinnamaldehyde to give the objective oligomer of the formula (R1 and R2 are divalent aromatic; A and B are aliphatic or aromatic polymerizable unsaturated group; n is 0-15).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oligomer useful as a raw material for a heat-resistant synthetic resin, especially a heat-resistant aromatic polyazomethine having a thermosetting property, and a method for producing the oligomer.

[0002]

2. Description of the Related Art As the demand for the plastics industry has increased, industrial materials having special properties have been required, and this tendency is rapidly developing in association with the sophistication of the industrial sector.

The demand for improved heat resistance is strongly demanded for plastic materials as well, and the market is expanded as a heat resistant industrial material in the fields where heat resistance is required such as films, fibers, laminates, laminates and adhesives. And to expand into a wide range of new fields with new functions.

In response to such demands, a group of synthetic resins called engineering plastics such as aromatic polyamide, polyimide, polysulfone, polyphenylene oxide, etc. have already been developed and have new functions different from conventional synthetic resins. Industrially produced as plastic, it is opening up new demand fields.

Among these polymer materials, a polymer having a --CH.dbd.N-- bond in the main chain repeating unit (polyazomethine) has excellent heat resistance, flame retardancy, conductivity, photochromism and the like. However, although many studies have been carried out from early on, a high molecular weight product could not be obtained due to the poor solubility of this polymer, and a molded product could not be obtained.

On the other hand, terephthalaldehyde and 3,
When 4-diaminodiphenyl ether and p-phenylenediamine derivative are used as main raw materials and these are reacted at a predetermined blending ratio, a predetermined amount of diamine component is added, for example, N-methylpyrrolidone (NMP), hexamethylphosphortriaside. A method has been proposed in which a polycondensate (polymer) is obtained by dissolving it in (HMPA), adding one of the raw materials, dialdehyde, as a solution, and adding and reacting the solution.

In this case, a metal halide such as lithium chloride or calcium chloride is added for solubilization (JP-A-63-234030).

However, since impurities such as metal ions remain in the molded product thus obtained, which adversely affects the electrical characteristics in particular, there is a drawback that its use is extremely limited.

That is, generally, this thermosetting resin is often used especially for insulating materials for electric and electronic devices, printed wiring boards, laminated plates, etc., but its electrical characteristics deteriorate due to the presence of lithium ions, calcium ions and chlorine ions. However, there are problems such as corrosion and corrosion of electrodes of electric / electronic devices and printed wiring boards, and therefore polyazomethine cannot be put to practical use despite having excellent heat resistance.

[0010]

DISCLOSURE OF THE INVENTION The present invention provides a polyazomethine which has excellent heat resistance of conventional polyazomethines, excellent mechanical strength at high temperatures, chemical stability, and solubility in a solvent. The object is to develop a polyazomethine oligomer that is a precursor for production, has a relatively low melting point, can be molded into a desired shape under heat and pressure, and can be cured under relatively mild conditions.

[0011]

The present invention has the general formula

[Chemical 2] And an unsaturated group-containing aromatic polyazomethine oligomer for producing the same, which is obtained by reacting an aromatic diamine, an aromatic dialdehyde and an aliphatic or aromatic unsaturated aldehyde We have developed a method for producing azomethine oligomers.

[0012] This product can be cured in the presence of a radical generating catalyst, and it was found that this cured aromatic polyazomethine has the above-mentioned excellent properties, and the present invention has been completed.

The aromatic polyazomethine oligomer having an unsaturated group of the present invention can be synthesized by the following reaction formula as an example.

[0014]

[Chemical 3]

A means for taking out the produced water to the outside of the reaction system is necessary for the above reaction to proceed smoothly, and for example, an organic solvent azeotropic with water may be added. In this case, as the azeotropic organic solvent, it is generally convenient to use a solvent such as benzene or toluene which is azeotropic with water but does not mix.

It is advantageous that the degree of polymerization n of the oligomer is 0 to 15, preferably about 3 to 7, because the moldability is easy, and the polymerization at this stage is not necessary at all. This reaction is generally dissolved and heated in a mixture of amines, an inert organic solvent that dissolves the dialdehyde, and an azeotropic solvent with water. It can be carried out by removing the water produced at this time by azeotropic distillation.

The aromatic diamine which can be used in the present invention is, for example, metaphenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane. , 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3 '
-Diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, dianisidine, 2,4-toluylenediamine, 2,4 / 2,6-toluylenediamine mixture, 1,3-bis (3-aminophenoxy) benzene, etc. Can be used, and a mixed use of two or more kinds is also possible.

Acrolein, crotonaldehyde, vinylacetaldehyde, α-methylacrolein, α-ethylacrolein, α-methylcrotonaldehyde, cyclohexenealdehyde as a precursor of an organic residue having a polymerizable unsaturated group at the terminal or inside of the chain. Unsaturated aldehydes such as cinnamaldehyde are mentioned, but unsaturated aldehydes such as acrolein, crotonaldehyde, and cinnamaldehyde are most commonly used from the viewpoints of stability, availability, price, etc. of the produced polyazomethine oligomer.

Typical examples of the aromatic dialdehyde that can be used in the present invention include phthalaldehyde, isophthalaldehyde, terephthalaldehyde or a mixture thereof.

Aromatic polyazomethines derived from phthalaldehyde are slightly insufficient in heat resistance, and when terephthalaldehyde is used, the heat resistance of the polymer after thermosetting is sufficient but it is obtained as a precursor. The aromatic polyazomethine oligomer has a high melting point and tends to be difficult to handle, and in terms of practicality, isophthalaldehyde has the best balanced property, which is consistent with the object of the present invention.

Since this synthetic reaction proceeds in a relatively stoichiometric manner, a desired value is put into n in the above formula [A] to calculate a desired amount of the aliphatic or aromatic unsaturated aldehyde. , An aromatic diamine and an aromatic dialdehyde may be reacted, and if precise adjustment is required, the molar ratio can be determined by a simple test.

As described above, the composition of the aromatic polyazomethine oligomer obtained by this reaction can be easily selected, and it can be easily molded at a temperature of 200 ° C. or lower.

The aromatic polyazomethine oligomer having an unsaturated group synthesized according to the present invention can be cured by the combined use of a radical generating catalyst, and the heat resistance can be remarkably improved.

The radical generating catalyst is not limited,
Industrially, the peroxide type is suitable, and when the molding temperature is 100 ° C. or higher, the so-called high temperature decomposition type,
For example, dicumyl peroxide type is used.

A suitable amount is 0.5 to 3 phr.
Further, the combined use of the unsaturated bond of the oligomer of the present invention and the copolymerizable monomer is possible when the monomer dissolves the aromatic polyazomethine oligomer, and particularly when the polymerization degree n of the oligomer is a small value, its applicable range Is wide. The combined use of polymerizable monomers promotes softening of the entire condensation system,
Although the moldability and workability are improved, the heat resistance of the cured aromatic polyazomethine tends to be lowered, so that it is necessary to adjust the addition amount according to the purpose.

In the production of a molded article using the aromatic polyazomethine oligomer having an unsaturated group according to the present invention, a reinforcing agent, a filler, a release agent, a coloring agent, another polymer as a low-shrinking agent, etc. are required. Of course, they can be used in combination. Next, in order to help understanding of the present invention, examples will be shown below.

[0027]

【Example】

 (Example 1)

[Chemical 4] In a 500 ml four-neck separable flask equipped with a reflux condenser, thermometer, and stirrer, isophthalaldehyde (IP
6.7 g, 3,4'-diaminodiphenyl ether (abbreviated as 3,4'-DAPE) 12 g, benzene 10
0 g and DMF 100 g are weighed and dissolved. After dissolution, 1.4 g of crotonaldehyde, 5 mg of toluquinone and 50 g of benzene are charged, the temperature is gradually raised, and heating is performed at 80 ° C. for 1 hour. Then, the reflux condenser is removed, a distillation apparatus is attached and the temperature is raised to distill off benzene. After distilling off benzene, the reaction product is gradually added to about 1 liter of water under vigorous stirring to precipitate crystals. The precipitated crystals were suction filtered, washed with water and dried to obtain an azomethine oligomer. This is m. p. It is 180 to 230 ° C., and its infrared absorption spectrum is shown in FIG. Elemental analysis values are C; 80.45%, H; 4.98%, N; 9.16%, and theoretical values are C; 80.27%, H; 5.02%, N; 9.36%. And showed a good agreement.

(Example 2)

[Chemical 5] Synthesis of Example 1 The same operation as in Example 1 was performed except that 1.12 g of acrolein was used instead of 1.4 g of crotonaldehyde. The azomethine oligomer obtained had m.p. p. 260 ° C
The above is the above, and the infrared absorption spectrum thereof is shown in FIG. Elemental analysis values are C; 80.31%, H; 4.85%, N; 9.30%, theoretical values are C; 80.18%, H; 4.87%, N; 9.51%. And showed a good agreement.

(Example 3)

[Chemical 6] Synthesis of Example 1 The same operation as in Example 1 was performed except that 2.64 g of cinnamaldehyde was used instead of 1.4 g of crotonaldehyde. The azomethine oligomer obtained had m.p. p. 110
˜140 ° C., and its infrared absorption spectrum is shown in FIG. Elemental analysis values are C; 81.49%, H; 4.91%, N; 8.62%, and theoretical values are C; 81.33%, H; 4.90%, N; 8.76%. And showed a good agreement.

(Example 4)

[Chemical 7] Synthesis of Dean Stark 5 equipped with a distillation tube, thermometer and stirrer
Add 3,4'-D to a 00 ml 4-neck separable flask.
APE (20 g), crotonaldehyde (14 g), hydroquinone (10 mg), DMF (100 g) and benzene (100 g) were added, and the mixture was stirred at room temperature for 30 minutes and then heated to reflux for 2 hours.
When the generation of condensed water was no longer observed, benzene was driven out, and the reaction product was gradually added to about 1.5 liters of water under vigorous stirring to precipitate crystals. The precipitated crystals are suction filtered, washed with water and dried. The azomethine oligomer obtained had m.p. p. It is 100 to 130 ° C., and its infrared absorption spectrum is shown in FIG. Elemental analysis values are C; 79.12%, H; 6.55%, N; 9.03%, and theoretical values are C; 78.95%, H; 6.58%, N; 9.21%. And showed a good agreement.

[0031]

Although the conventional aromatic polyazomethine is a thermoplastic resin, it has excellent chemical resistance and electrical characteristics due to its high melting point and poor solubility. The fact is that it has not been put to practical use due to its moldability problems.

The present invention has improved these drawbacks and can be used as a raw material for a thermosetting aromatic polyazomethine, which is the same aromatic polyazomethine but has excellent moldability and has little deterioration in mechanical strength even at high temperatures. We have succeeded in developing a novel aromatic polyazomethine oligomer having a novel unsaturated group.

This oligomer can be easily synthesized under mild conditions and, despite having a polymerizable double bond, is relatively stable and does not gel during the molding process.
Moreover, it has excellent properties that it can be easily cured even at a low temperature by the action of the radical generating catalyst.

The aromatic polyazomethine obtained by curing this oligomer is an aromatic polyazomethine which is excellent in heat resistance and does not deteriorate in strength even at high temperatures.

[Brief description of drawings]

1 is an infrared absorption spectrum diagram of the unsaturated group-containing aromatic polyazomethine oligomer obtained in Example 1. FIG.

2 is an infrared absorption spectrum diagram of the unsaturated group-containing aromatic polyazomethine oligomer obtained in Example 2. FIG.

FIG. 3 is an infrared absorption spectrum diagram of the unsaturated group-containing aromatic polyazomethine oligomer obtained in Example 3.

4 is an infrared absorption spectrum diagram of the unsaturated group-containing aromatic polyazomethine oligomer obtained in Example 4. FIG.

Claims (2)

[Claims] 1. A general formula: An unsaturated group-containing aromatic polyazomethine oligomer represented by: 2. A method for producing an unsaturated group-containing aromatic polyazomethine oligomer, which comprises reacting an aromatic diamine, an aromatic dialdehyde and an aliphatic or aromatic unsaturated aldehyde.