JPS5913533B2 - Houkozoku Polyamide No. Seizou Hohou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing aromatic polyamides.

More specifically, the present invention relates to a novel method for producing an aromatic polyamide by thermally condensing an aromatic dicarboxylic acid diaryl ester and an aromatic diamine.

Aromatic polyamides, such as poly m-phenylene isophthalamide, poly p-phenylene tereph. Talamide and the like are known to have a high degree of thermal stability and excellent properties such as high modulus of rigidity and high tensile strength.
Hitherto, various studies have been conducted on industrial production methods for such aromatic polyamides, such as m-phenylenedi.

A method is known in which an aromatic diamine such as an amine or p-phenylenediamine is reacted with an acid chloride such as isoptalol chloride or terephthaloyl chloride in the presence of a dehydrochlorination agent. In this method, the acid chloride must be handled in an anhydrous state because it easily reacts with water. 5 However, the above method cannot be said to be an industrially advantageous method for producing polyamide.

As a result of repeated research into a method for producing aromatic polyamide free from such drawbacks, the present inventors have found that aromatic dicarboxylic acid diaryl ester and aromatic 10 diamine are heated at 150°C or higher in the presence of a diarylsulfone solvent. It is known that an aromatic polyamide with excellent solubility can be easily obtained by heating and condensing at a high temperature, and that when this heating and condensation is carried out in the presence of a compound having two benzene nuclei or a naphthalene nucleus, the condensation reaction occurs. The present invention was achieved based on the discovery that this can be promoted.

That is, the present invention heats and condenses an aromatic dicarboxylic acid diaryl ester and an aromatic diamine at a temperature of 150° C. or higher in the presence of a diarylsulfone solvent, and at the same time produces a hydrocarbon having two benzene nuclei. Alternatively, it is a method for producing an aromatic polyamide characterized by allowing a hydrocarbon having an ether or naphthalene nucleus to coexist in the condensation system.

In the present invention, any diaryl ester of aromatic dicarboxylic acid that is used as a raw material for this type of aromatic polyamide can be used as the aromatic dicarboxylic acid diaryl 5 ester. Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, diphenyl-4,4'
-Dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, diphenooxyethane-4,4'-dicarboxylic acid, diphenylketone-954,4'-dicarboxylic acid acid, diphenylmethane-4,4'-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, and the like.

Examples of the aromatic oxy compound that forms an ester with the aromatic dicarboxylic acid include phenol, p-cresol, m-cresol, o-cresol, p-butylphenol, p-octylphenol, p-nitrophenol, p-cresol, and p-cresol. -Phenylphenol, α-naphthol,
Examples include β-naphthol.

Preferred aromatic dicarboxylic acid diaryl esters include diphenyl terephthalate, diphenyl isophthalate, diphenyl-4,4''-dicarboxylic acid diphenyl ester, diphenyl ether-4,4f-dicarboxylic acid diphenyl ester, and diphenooxyethane. 14,4
dicarboxylic acid diphenyl ester, diphenylketone-4,45-dicarboxylic acid diphenyl ester, diphenylmethane-4,4'-dicarboxylic acid diphenyl ester, naphthalene-2,6-dicarboxylic acid diphenyl ester, naphthalene-2,7- Dicarboxylic acid diphenyl ester, terephthalic acid diphenyl ester, isophthalic acid diphenyl ester, diphenyl-4,41-dicarboxylic acid diphenyl ester, diphenyl ether-4,4'-dicarboxylic acid diphenyl ester Tolyl ester, diphenylsulfone-4,4'-dicarboxylic acid di-p-tolyl ester, diphenoxyethane-4,4I-dicarboxylic acid bis p-t-butylphenyl ester, diphenylketone-4,42-dicarboxylic acid bis p-nitrophenyl ester, diphenylmethane-4,45-dicarboxylic acid bis p-phenyl phenyl ester, naphthalene-2,
Examples include 6-dicarboxylic acid diα-naphthyl ester and naphthalene-2,6-dicarboxylic acid diβ-naphthyl ester.

Particularly preferred aromatic dicarboxylic acid diaryl esters include terephthalic acid and/or isophthalic acid and molecular weight 150.
It is an ester consisting of the following aromatic oxy compounds.

In particular, when heated and condensed with aromatic diamines,
The polycondensation rate is fast, and an industrially useful aromatic polyamide can be easily obtained. Such an aromatic dicarboxylic acid diaryl ester can be produced by a conventionally known method.

A particularly preferred aromatic dicarboxylic acid diaryl ester is one obtained by subjecting the aromatic dicarboxylic acid and an aromatic oxy compound to an esterification reaction in the presence of a conventionally known esterification catalyst. In the method of the present invention, aromatic diamines used in the production of aromatic polyamides of this type can be used.

More specifically, p-phenylene diamine, m-phenylene diamine, 4-45-diaminodiphenyl ether,
Examples include 3,4-diaminodiphenyl ether and 4,4'-diaminobiphenyl. Among these, p-phenylene diamine, 4,45-diaminodiphenyl ether, and 3,45-diaminodiphenyl ether are particularly preferred. A preferred aromatic polyamide for the method of the present invention is an aromatic polyamide made from the above-mentioned aromatic dicarboxylic acid diaryl ester and the above-mentioned aromatic diamine,
The aromatic polyamide may be a homopolyamide or a copolyamide.

Particularly preferred aromatic polyamides contain terephthalic acid and/or isophthalic acid as an acid component, and a group consisting of p-phenylenediamine, 4-4I-diaminodiphenyl ether, and 3,4-diaminodiphenyl ether as a diamine component. A copolyamide containing one or more aromatic diamines selected from the following. The copolymerization ratio (base) is expressed by the following formula, where the ratio of the main acid component to the total acid components in the copolymerized polyamide is A mol %, and the ratio of the main diamine component to the total diamine components is B mol %. X (dry %) -200-(A+B) Here, is X 5 to 100 moles? , especially 25-75 mol%
It is preferable that

In the method of the present invention, the aromatic polyamide contains the aromatic dicarboxylic acid diaryl ester and the aromatic diamine in 1
It is produced by heating and polycondensing at a high temperature of 50°C or higher.

At that time, it is preferable that the charging ratio of aromatic diamine to aromatic dicarboxylic acid diaryl ester be 1.0 to 1.2 times by mole, more preferably 1 to 1.05 times by mole. The polycondensation reaction temperature is 150°C or higher. Preferably 160~
The temperature is 500°C, particularly preferably 180 to 400°C. In the initial stage of the polycondensation reaction, the polycondensation reaction can proceed sufficiently even if the aromatic oxy compound produced by the reaction remains in the reaction system, so it can be carried out under pressure (for example, 10 atm). It may also be carried out at normal pressure.

After the initial stage of polycondensation, the aromatic oxy compound produced by the reaction is removed from the reaction system. Preferably, such a method is carried out in a nitrogen stream. Although the reaction is carried out at a relatively low temperature at the initial stage of polycondensation, it is preferable to gradually raise the temperature as the reaction progresses. The reaction time varies depending on reaction conditions, such as reaction temperature, but is 1 hour or more, preferably 3 to 30 hours.

In the polycondensation reaction, it is not necessary to use a catalyst, but
Use of a catalyst can further shorten the polycondensation time.

Examples of such catalysts include those conventionally used as polyester transesterification or polycondensation catalysts. The amount of such a catalyst used is, for example, 0.01 mol based on the aromatic dicarboxylic acid diaryl ester. ~2 moles? and preferably 0.02 mol% to 0
．． It is 5 mol%. The polycondensation reaction is performed in a diarylsulfone solvent.

Such diarylsulfones include, for example, diphenylsulfone, phenyl-p-tolylsulfone, di-p-tolylsulfone, bis(3,4-dimethylpheno(c)-
Examples include sulfone, di-p-tert-butyl phenyl sulfone, and the like. The amount of the solvent to be used is 0.1 times to 100 times by weight, preferably 0.5 times to 50 times by weight, particularly preferably 2 times to 20 times by weight, based on the aromatic polyamide to be produced. By using diphenyl sulfone solvent, the polycondensation reaction rate increases significantly,
Moreover, the resulting aromatic polyamide has improved solubility.

In the method of the present invention, the following compounds are coexisting in the polycondensation system in order to further promote the polycondensation reaction of the aromatic polyamide.

Such compounds are, for example, hydrocarbons or ethers having two or more aromatic nuclei, such as biphenyl, diphenyl ether, tolylphenyl ether, ditolyl ether, naphthalene, methylnaphthalene, dimethylnaphthalene, etc., or hydrocarbons having a naphthalene nucleus. . These compounds may be added to the reaction system together with the raw materials from the initial stage of polycondensation, or may be added to the reaction system during polycondensation. The amount of these compounds to be used is 0.1 times to 1000 times, preferably 1 time to 500 times, particularly preferably 5 times to 500 times the weight of the aromatic polyamide to be produced. .

These compounds used here are distilled out of the reaction system together with aromatic oxy compounds produced by the polycondensation reaction of the aromatic polyamide.

Under such conditions, the polycondensation reaction of aromatic polyamide is promoted. The aromatic polyamide obtained by the polycondensation reaction can be further polycondensed in a solid phase to obtain an aromatic polyamide with a higher degree of polymerization.

At that time, the polycondensation temperature is 250°C or higher, preferably 50°C or higher.
0.C or less, more preferably 280 to 400 °C,
The reaction pressure is above atmospheric pressure, normal pressure, or 10 to 0.1
It can also be carried out under reduced pressure such as mmHg. At this time, an aromatic polyamide with a higher degree of polymerization can be obtained by passing an inert gas such as nitrogen through the reaction system.
Next, the method of the present invention will be explained with reference to Examples.

Note that parts in the examples mean parts by weight. In addition, the ring element viscosity (ηSp/c) is C=1.29/dl in concentrated sulfuric acid, 35
This is a value obtained by measuring at °C. Example 1 3.98 parts of diphenyl terephthalate, 3 parts of diphenyl isophthalate
．． 97 parts of p-phenylenediamine, 2.70 parts of p-phenylenediamine, 50 parts of diphenyl sulfone, and 50 parts of diphenyl ether were charged into a reactor equipped with a stirrer, and after reacting for 20 minutes at 250°C in a nitrogen stream, it took 120 minutes. gradually raise the temperature,
A polycondensation reaction was carried out at 360° C. for 240 minutes while distilling diphenyl ether and the phenol produced by the reaction out of the reaction system.

The obtained reaction product was taken out from the reactor after cooling, and then the diphenyl sulfone used as a solvent was extracted and removed with acetone.

The obtained polymer was soluble in sulfuric acid at 50°C, and the ηSp/c of this polymer was 9.52.

Example 2 7.95 parts of diphenyl terephthalate, p-
2.70 parts of phenylene diamine, 5 parts of diphenyl sulfone
A polycondensation reaction of an aromatic polyamide was carried out in exactly the same manner as in Example 1, except that 0 part and 50 parts of diphenyl ether were used.

The obtained polymer was soluble in sulfuric acid at 50°C, and the ηSp/c of this polymer was 4.13.

Comparative Example 1 Example 2 except that diphenyl sulfone and diphenyl ether were not used and the polycondensation reaction was carried out without a solvent.
A polycondensation reaction of aromatic polyamide was carried out in the same manner as described above.

The obtained polymer is insoluble in sulfuric acid at 50°C, and 10
Dissolved at 0°C. Moreover, ηSp/c of this polymer is 0.
It was only 65 years old. Example 3 Diphenyl terephthalate 7.95 parts p-phenylenediamine
1.35 parts 3,4'-diaminodiphenyl ether 2.50 parts diphenyl sulfone
50 parts diphenyl ether 5
0 part was charged into a reactor equipped with a stirrer, and a polycondensation reaction was carried out in the same manner as in Example 1.

The obtained polymer was soluble in sulfuric acid at 50°C, and the ηSp/c of this polymer was 5.82.

Example 4 Biphenyl instead of diphenyl ether,
5 each of ditolyl ether and α-methylnaphthalene
A polycondensation reaction was carried out in the same manner as in Example 1 except that 0 part was used.

At this time, biphenyl, ditolyl ether, α
-Methylnaphthalene, etc. were distilled out of the reaction system during polycondensation. All of the obtained polymers are soluble in sulfuric acid, and the ηSp/c of these polymers is 7.68 and 8.5, respectively.
It was 9.7.00.

Claims (1)

[Claims] 1 Aromatic dicarboxylic acid diaryl ester and aromatic diamine are heated at 150°C in the presence of a diarylsulfone solvent.
A method for producing an aromatic polyamide, which is characterized by carrying out thermal condensation at a temperature above, and at that time, allowing a hydrocarbon having two benzene nuclei or an ether or a hydrocarbon having a naphthalene nucleus to coexist in the condensation system.