JPS63193925A - Aromatic polyazomethine - Google Patents

Abstract

PURPOSE:To obtain the titled polymer, containing specific constituent units prepared by reacting an aromatic dialdehyde with an aromatic diamine, having excellent heat and chemical resistance as well as melt moldability and suitable as high-tenacity and high-modulus fibers, films, etc. CONSTITUTION:The aimed polymer obtained by dissolving equimolar amounts of terephthalaldehyde and 3,4'-diaminodiphenyl ether capable of providing constituent units expressed by formula I in, e.g. a reaction medium (e.g. N- methylpyrrolidone, etc.), and adding (B) an aromatic diamine (e.g. p- phenylnediamine, etc.) capable of providing constituent units expressed by formula II (R is H, halogen, etc.; n is 1-4) and an equimolar amount of an aromatic dialdehyde to the resultant solution and carrying out reaction, preferably at ordinary temperature - 100 deg.C while flowing N2 gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel aromatic polyazomethine. More specifically, it is a novel method that uses terephthalaldehyde as one of the raw materials and reacts it with a specific aromatic diamine to produce a high-strength, high-modulus molded product with excellent melt moldability, heat resistance, and chemical resistance. This invention relates to aromatic polyazomethine.

[Prior Art] Polymers having an aromatic 10H=N- group have long been known as polyschiff bases, and are a type of high-performance polymer that can be made into heat-resistant, high-strength, and high-modulus molded products. It is expected to be used as a type of highly functional polymer with conductivity or semiconductivity.

For example, JP-A-51-138800 describes polyazomethine which can be melt-molded and provides a high-strength, high-modulus il cloth or film. Furthermore, JP-A No. 60-101122 discloses a polyazomethine that can be melt-molded and has cross-linking reactivity.
Publication No. 1123 describes heterocycle-containing polyazomethine,
Each is listed. And European Patent No. 1498
No. 35 discloses conductive polyazomethine.

As mentioned above, polyazomethine is a polymer with various useful properties, but on the other hand, it is difficult to increase the degree of polymerization, or the resulting polymer is stiff and has a high melting point. There are many problems with its moldability, and it cannot be said that it is necessarily easy to handle.

Various methods have been tried in the past to solve these problems with polyazomethine. For example, attempts have been made to lower the softening point by introducing lower alkyl groups or halogen atoms into the aromatic nucleus, and to lower the molding temperature by introducing flexible bonding groups into the polymer. In addition, the above-mentioned Japanese Patent Application Laid-Open No. 51-138
As described in Japanese Patent Application No. 800, in order to maintain heat resistance and high performance, there are examples in which symmetry is imparted to the molecular structure to prevent deterioration of physical properties.

However, these methods are insufficient in obtaining polymers with a high degree of polymerization, in achieving ease of melt molding, and in obtaining high-performance molded products.

In addition, as a special method, L B (L anc+m1
nur −B roge+jt) lI! There is also a method of obtaining a film-like molded product by an exchange reaction using amines (see LJAC8゜Tan 107.8308-8310).
, this method can hardly be called commercial.

[Object of the Invention] The main object of the present invention is to provide a molded product which does not have the above-mentioned drawbacks, has a high degree of polymerization, is easy to melt mold, has excellent heat resistance and chemical resistance, and has high strength and high modulus. The object of the present invention is to provide an aromatic polyazomethine that provides aromatic polyazomethine.

[Structure of the Invention] In order to achieve the above-mentioned object, the present inventors have conducted extensive research and found that terephthalaldehyde is used as an aldehyde component to form aromatic polyazomethine, and a very special diamine component is used as a diamine component to be combined with terephthalaldehyde. Compared to conventional products, it is easier to increase the degree of polymerization, has good melt moldability, and has excellent heat resistance and chemical resistance, making it possible to create molded products with good properties by melt molding. The inventors have discovered that a novel and useful aromatic polyazomethine can be obtained, and have arrived at the present invention.

That is, in the novel aromatic polyazomethine according to the present invention, the main structural unit of the polymer is the following (1).

A structural unit represented by (It), [However, R in the above formula <I[) is a hydrogen atom.

It is a halogen atom or a lower alkyl group, and n is an integer of 1 to 4. ] and the molar ratio of the structural units (I) and (II) [(I)
/(II) is within the range of 10/90 to 10010.

The most important feature of the aromatic polyazomethine of the present invention is the above (
The structural unit represented by the formula I), that is, the structural unit derived from terephthalaldehyde and 3,4'-diaminodiphenyl ether, is combined with the above-mentioned structural units (the sum of I>(II) [(I)+(II)]) By making the polymer contain at least 10 mol% of such special structural units, the various drawbacks of conventionally known aromatic polyazomethines can be overcome, and a high degree of polymerization can be achieved. It is completely unexpected that a polymer with good melt moldability would be formed in this manner.

On the other hand, in the structural unit represented by the above formula (n), R
is a hydrogen atom, a halogen atom such as chlorine or bromine, or a lower alkyl group such as a methyl group or an ethyl group. This R
does not need to be exactly the same in all the structural units (II>), for example, - aromatic nuclei may have two or more different substituents, and between the structural units in the polymer chain It may have two or more types of substituents that are different from each other.

Examples of diamine components providing such structural units include p-phenylenediamine, 2-methyl-p-phenylenediamine, 2,6-dimethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, chloro- 〇-Phenylenediamine, 2,6-dichloro-p-
7 enylenediamine.

2.5-dichloro-p-phenylenediamine.

2.3,5.6-tetramethyl-p-phenylenediamine, 2,3,5.6-titrac-O-phenylenediamine, 2,3,5.6-tetrabromo-p-
Examples include phenylenediamine.

In order to improve melt moldability, diamine components in which R is a halogen atom or a methyl group as described above are preferred, and 2,5-dimethyl-p-phenylenediamine is particularly preferred.

These diamine components may be used alone, but two or more may be used in combination as long as the conditions specified in the present invention are satisfied.

In the aromatic polyazomethine of the present invention, the molar ratio of the above-mentioned structural unit (I> and (n) varies depending on the type of substituent R in the structural unit (II), but in any case, (I)/( II) molar ratio is 10/90 to 10010
It is necessary to keep it within the range of . Outside of this range, poly! - becomes rigid and the melt formability becomes poor, and
The molten polymer tends to increase in viscosity and gel, making it difficult to obtain a good molding polymer.

The suitable molar ratio range is determined by the balance between moldability and physical properties of the molded product, but for example, when 2,5-dimethyl-〇-phenylenediamine is used as the diamine component of the structural unit (II), (I) / (n) =5015
The range of 0 to 90/10 is particularly preferable because melt moldability is excellent.

The main structural units of the aromatic polyazomethine according to the present invention are the above (I) and (II) structural units, but (I)
+ Less than 50 mol %, preferably 30 mol % based on (II)
A third structural unit can also be present in an amount less than mol %. In particular, only the main structural unit (for example, a single system)
If the resulting polymer has a high melting point and is difficult to mold, it is effective to introduce a third structural unit.

The third structural unit is derived from various aromatic dialdehydes such as terephthalaldehyde, chloroterephthalaldehyde, methylterephthalaldehyde, and known aromatic diamines. Such aromatic diamines include m-phenylene diamine and 4,4'-diaminodiphenyl ether.

3.4'- or 4,4'-diaminodiphenylmethane.

3.4'- or 4.4'-diaminodiphenylsulfone, benzidine, 1.4- or 1.5-diaminonaphthalene, 2.6- or 2.7-diaminophthalene.

Examples include diaminoanthraquinone.

Also, aromatic aminoaldehydes such as p-aminobenzraldehyde can be used as the component providing the third structural center.

When producing the aromatic polyazomethylene of the present invention, the above-mentioned aromatic dialdehyde and aromatic diamine are generally reacted in equimolar amounts, but in order to control the polymerization reaction, a monofunctional terminal capping agent such as Benzaldehyde, aniline, benzamide, p-aminobenzoic acid, 4-carboxybenzaldehyde, etc. may be used in combination.

In addition, when the diamine component is a salt (eg, hydrochloride, sulfate), a neutralizing agent (eg, lithium carbonate).

It goes without saying that lithium hydroxide, sodium carbonate) may be used in combination and directly supplied to the reaction system.

The method itself for synthesizing polyazimethine by reacting dialdehyde and diamine may be any method known for -11'2. For example, as a reaction medium, a method using a solvent such as N-methylphosphorolidone (abbreviated as NMP), hexamethylphosphotriamide (abbreviated as HMPA), dimethylsulfone, dimethylacetamide, dimethylformamide, etc., dehydration of polyphosphoric acid, concentrated sulfuric acid, etc. A method using a solvent, and a method using general solvents such as alcohols, petroleum solvents, benzene, toluene, etc. can be used. Alternatively, the reaction can be carried out directly with Molton without using a solvent.

When the reaction is carried out in a solvent, it is usually carried out at room temperature to 100°C or lower, but the reaction can proceed smoothly by removing the generated moisture from the system, for example under the flow of N2 gas. . Furthermore, in order to increase the solubility in the solvent, it is effective to include a metal salt such as lithium chloride or calcium chloride in the reaction system.

After the reaction is complete, the reaction solution is placed in a non-solvent (e.g., water, ether, methanol, etc.) to precipitate the polymer, and the polymer is separated by filtration and washing to obtain aromatic polyazomethine. .

The obtained polymer has a sufficiently high degree of polymerization and generally has an intrinsic viscosity (IV) of 0 when measured using concentrated sulfuric acid as a solvent.
．． It shows a value greater than 3, preferably greater than 0.5.

[Effects of the Invention] The aromatic polyazomethine of the present invention as described above has good melt moldability and excellent heat resistance and chemical resistance. , films, sheets, and other molded products).

In particular, although the aromatic polyazomethine of the present invention has good heat resistance, it has much better melt formability than conventional ones, which is due to the presence of ether in the molecular structure of the polymer. It is thought that this is because it has a bond and a part of it has meta-coordination, so it can impart flexibility to the entire polymer. It is thought that the structure becomes bulky due to the effect of the substituent of the diamine used as a copolymerization component, and the moldability is further improved.

Therefore, it can be melt-molded into a molded article of any shape, and can be widely used in various fields that take advantage of the characteristics of the aromatic polyazomethine.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Note that in the examples, "parts" simply indicate parts by weight.

Further, the intrinsic viscosity (IV), which is a measure indicating the degree of polymerization, is a value calculated based on the results of measurement at a concentration of 0.5 g/ρ using concentrated sulfuric acid as a solvent.

The transition temperature indicating liquid crystallinity is a value determined by DSC, and the thermal decomposition initiation temperature (Td) indicating heat resistance is the weight loss initiation temperature by TGA.

Regarding melt moldability, polymer dischargeability was checked using a flow tester and used as a measure of moldability. In this case, the temperature was -20°C, the transition temperature on the high temperature side in DSC, the pressure was 100 kg/C, the nozzle diameter was 0.3 mm, and the residence time in the polymer was 1 minute, and the judgment was made based on whether or not it could be discharged. .

Example 1 3. 8.0 parts of 4'-diaminodiphenyl ether.

25 parts of NMP, 25 parts of NMPA and 2 parts of anhydrous lithium chloride
．． After 5 parts were mixed under N2 gas atmosphere and stirred to dissolve, 5.36 parts of terephthalaldehyde was added, and the mixture was stirred and reacted at room temperature for 24 hours under N2 gas flow. After the reaction was completed, the reaction solution was poured into water, and the precipitated yellow powder was filtered, washed, and dried to obtain an aromatic polyazomethine having an IV of 0.83.

This polymer was measured at 330°C and 367°C by DSC.
It has a transition point, and microscopic observation in the molten state reveals that it is a cloudy, viscous, liquid crystalline polyazomethine. Furthermore, according to TGA, the thermal loss onset temperature was 453°C, which confirmed that the polymer had extremely high heat resistance.

The melt moldability of the polymer measured using a flow tester was also good, and the physical properties such as strength and modulus of the obtained molded product were also good.

Example 2 7.2 parts of 3.4'-diaminodiphenyl ether and 0.78 parts of 2.5-dimethyl-〇-phenylenediamine were mixed with 25 parts of NMP, 25 parts of HMPA and 2.5 parts of Ltci. s
Then, 5.36 parts of terephthalaldehyde was added thereto, and the mixture was stirred and reacted at room temperature for 12 hours under N2 gas flow. After the reaction is completed, the reaction solution is poured into water, and the precipitated yellow powder is filtered, washed, and dried to obtain 11.5 g of copolymerized aromatic polyazomethine with IV=1.2.
I got it.

This polymer was measured at 275°C and 311°C by DSC.
It has a transition temperature of , and microscopic observation reveals that it is a polymer with yellow, turbid liquid crystals. According to TGA, the thermal loss starting temperature was 449°C, confirming that it had good heat resistance. Furthermore, the melt moldability of the polymer was also good using a flow tester.

Example 3 A yellow polymer (copolymerized aromatic polyazomethine) was obtained in the same manner as in Example 2, except that the copolymerization ratio of 2.5-dimethyl-p-phenylenediamine was 20 mol% of the total diamine. .

This polymer has an IV=1.36 and a transition temperature of 2
The temperatures were 58°C and 298°C. In TGA, the weight loss initiation temperature was 443°C, and it was confirmed that the polymer had good heat resistance. Furthermore, the moldability at 278°C using a flow tester was good.

Example 4 2.4 parts (30 mol%) of 3,4'-diaminodiphenyl ether and 2,5-dimethyl- as diamine components
The reaction was carried out for 8 hours in the same manner as in Example 1 except that 3.8 parts (70 mol %) of p-phenylenediamine was used.

The obtained yellow-orange polymer (copolymerized aromatic polyazomethine) had an IV of 0.43, and the transition temperature by DSC showed broad peaks at 205°C and 239°C.

Further, the temperature at which TGA started to lose weight was 405°C.

The moldability determined by a flow tester was that the polymer flowed somewhat poorly, but it was possible to discharge and had melt moldability.

Comparative Example 1 A polymer (copolymerized aromatic Polyazomethine) was produced.

The obtained polymer had an IV of 3.0, and according to DSG, unclear peaks were observed at 200°C and 237°C.

When tested using a flow tester at 217°C, the polymer could not be discharged and solidified inside the flow tester, resulting in poor melt moldability.

in! ;! 4 P.

Procedural amendment 2nd day of March 1986

Claims (3)

[Claims] (1) The main structural units of the polymer are the following (I), (
II) It is a unit expressed by the formula, ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) [However, the above (II) formula R is a hydrogen atom, a halogen atom, or a lower alkyl group, and n is an integer of 1 to 4. ] An aromatic polyazomethine characterized in that the molar ratio of the structural unit (I) to the structural unit (II) is within the range of 10/90 to 100/0. (2) The aromatic polyester according to claim 1, wherein the molar ratio of the structural unit [I] to the sum of the structural units [I] and [II] is within the range of 50/50 to 90/10. Azomethine. (3) The aromatic polyazomethine according to claim (2), wherein the structural unit [II] is a unit represented by the following formula. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼