JPH0813886B2 - Process for producing azo group-containing polymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyamic acid and a polyimide having an azo group in the polymer main chain, which is suitable for a polymerization initiator.

Generally, an azo compound is decomposed by heat to generate a radical, and thus serves as a polymerization initiator. It is also useful as a modifier and compatibilizer for various resins.

[Conventional technology]

As a method for synthesizing a polymer having an easily decomposable azo group, a method for producing a polymer having an azo group in the side chain by copolymerizing a vinyl monomer having an azo group in the side chain with another vinyl monomer (Makromol.Chem . 180 609 (1979)) Method for producing polymer having azo group in side chain by reaction of polymer having hydroxyl group and azo compound having carboxyl group (Makromol. Chem. 36 17 (1959)) Glycol having azo group Method for Producing Polyurethane Containing Azo Group in Main Chain by Reaction of Azo Group with Diisocyanate Compound (Angew. Makromol. Chem. 1 92 (1967)) Azo group-containing polyamide or polyester from dicarboxylic acid chloride containing an azo group and diamine or glycol (Synthesis of Polymers 33 (3) 131 (197
6), J. Polym. Sci. A Polym. Chem. 24 406 (1986) Method for synthesizing polycarbonate having azo group in main chain from azo group-containing dicarboxylic acid chloride and bisphenol A (JP-A-59-27908) Have been proposed.

[Problems to be solved by the invention]

Any azo group-containing polymer is useful for producing block copolymers and graft copolymers. However, in this method, the synthesis of the azo group-containing vinyl monomer is complicated, and in the method of (1), it is difficult to completely react the azo compound because it is a polymer reaction. Further, the methods (1) and (2) have the drawback that they are complicated because it is necessary to separately synthesize an azo group-containing dicarboxylic acid chloride.

[Means for solving problems]

The present inventors have arrived at the present invention as a result of extensive studies on a method for producing a polyamic acid and a polyimide having an azo group in the main chain without the above-mentioned drawbacks.

That is, 1 of the present invention is represented by the formula (I) (Here, R ¹ and R ² are each independently a C 1-2 alkyl group, and X is Or a compound represented by formula (II) (Here, R ¹ , R ² and X have the same meanings as in formula (I).) An azo group-containing compound selected from the compounds or salts thereof and a tetracarboxylic acid dianhydride are combined with an organic solvent. The present invention provides a method for producing an azo group-containing polymer for a polymerization initiator, which comprises polycondensing polyamic acid therein.

The second aspect of the present invention is to provide a method for producing a polyimide as a polymerization initiator by further chemically ring-closing the polyamic acid obtained above.

The compound having one azo group in the molecular main chain used in the present invention and having amino groups at both ends (hereinafter, referred to as azobisamine) is represented by the general formula (1). (Here, R ¹ and R ² are each independently an alkyl group having 1 to 2 carbon atoms, and X is Which are aromatic groups selected from the group) and salts thereof, such as The general formula (II) (Wherein R ¹ , R ² and X have the same meaning as in formula (I)) and salts thereof, for example, And the like.

These may be used alone or in combination of two or more.

As the tetracarboxylic dianhydride used for producing the polyamic acid used in the present invention, any aromatic tetracarboxylic dianhydride and aliphatic tetracarboxylic dianhydride and heterocyclic tetracarboxylic acid can be used. Although it is possible to use an anhydride, specific examples thereof include pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, and 3,3 ′, 4,4′-diphenyl. Tetracarboxylic acid dianhydride, 1,2,5,6-naphthalene tetracarboxylic acid dianhydride, 2,2 ', 3,3'-diphenyltetracarboxylic acid dianhydride, 2,2-bis (3,4 -Dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ) Ether dianhydride, ethylene tetracal Acid dianhydride, naphthalene-1,2,4,5-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) Ketone dianhydride, decahydronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2, 5,6-tetracarboxylic dianhydride,
2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3, 6,7-Tetrachlornaphthalene, 1,4,5,8-tetracarboxylic dianhydride, phenanthrene-1,8,9,10-tetracarboxylic dianhydride, cyclopentane-1,2,3,4 -Tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, 2,2-bis (2,
3-dicarboxyphenyl) propane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1
-Bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, benzene-1, 2,3,4-tetracarboxylic dianhydride,
Examples thereof include 1,2,3,4-butanetetracarboxylic acid dianhydride and thiophene-2,3,4,5-tetracarboxylic acid dianhydride, which are used alone or as a mixture.

In the present invention, when producing a polyamic acid, a part of the azo group-containing compound represented by the formula (I) or (II) may be replaced with a diamine containing no azo group, if necessary. As the diamine containing no azo group, any aromatic diamine, aliphatic diamine and heterocyclic diamine can be used, and specific examples thereof include metaphenylenediamine, paraphenylenediamine and 4,4 ′. -Diaminodiphenyl propane, 4,4'-diaminodiphenylmethane, benzidine, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-
Diaminodiphenyl ether, 2,6-diaminopyridine, bis- (4-aminophenyl) diethylsilane, bis- (4-aminophenyl) phosphine oxide, bis- (4-aminophenyl) -N-methylamine, 1,5
-Diaminonaphthalene, 3,3'-dimethyl-benzidine, 3,3'-dimethoxy-benzene, 2,4-bis- (β-
Amino-t-butyl) toluene, bis- (para-β-amino-t-butylphenyl) ether, para-bis (2
-Methyl-4-aminobenzyl) benzene, para-bis (1,1-dimethyl-5-aminopentyl) benzene, m
-Xylylenediamine, p-xylylenediamine, bis (para-amino-cyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, 3-methyl-heptamethylenediamine, 4, 4'-
Dimethylheptamethylenediamine, 2,11-diaminododecane, 1,2-bis- (3-aminopropoxy) -ethane, 2,2-dimethylpropylenediamine, 3-methoxy-hexamethylenediamine, 2,5-dimethylhexamethylene Diamine, 2,5-dimethylheptamethylenediamine, 5-methylnonamethylenediamine, 1,4-diamino-cyclohexane, 1,12-diaminooctadecane, 2,5
-Diamino-1,3,4-oxadiazole and the like,
These are used alone or as a mixture.

As the amounts of the azobisamine used in the present invention and optionally the azo group-free diamine, and the tetracarboxylic dianhydride, the ratio of the amino group and the acid anhydride is used in substantially equivalent amounts.

Azobisamine can be polycondensed with tetracarboxylic acid dianhydride in an equivalent amount alone, or diamine can be used in combination. When used in combination, the amount of azobisamine used should be 0.05 mol% or more based on the diamine. If the amount is less than this range, it is meaningless as a polymer containing an azo group. That is, when it is used as a radical polymerization initiator, its initiation ability becomes extremely poor.

The organic solvent used to produce the polyamic acid is such that it does not react with either the reactant diamine or the tetracarboxylic dianhydride. Further, this organic solvent must be one that does not react with the polyamic acid and dissolves the polyamic acid. Examples of such a solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, N-methylcaprolactam, dimethylsulfoxide, N-methyl-2-pyrrolidone. , Tetramethylurea, tetramethylthiourea, pyridine, dimethyl sulfone, hexamethylphosphoramide, tetramethylene sulfone, formamide, N-methylformamide, butyrolactone and N-acetyl-
Examples thereof include 2-pyrrolidone, but the present invention is not limited thereto.

The solvent can be used alone, or a combination of solvents can be used, or benzene, benzonitrile, dioxane,
It can also be used in combination with poor solvents such as xylene, toluene and cyclohexane. In this case, the concentration of the polyamic acid in the organic solvent is 1 to 50%, preferably 3 to 30%.

The polyamic acid is produced according to a conventional method. For example, it can be produced by mixing tetracarboxylic dianhydride with a solvent solution of azobisamine and another diamine and stirring the mixture at room temperature.

As a method of chemically ring-closing the polyamic acid to imidize, a method of imidizing by adding and mixing an imidization catalyst such as a base and an acid anhydride to a polyamic acid solution or an imidization catalyst such as a base and an acid anhydride, or those There is a method of imidization in an organic solvent containing. The imidization temperature needs to be a temperature at which the imide group in the polyamic acid is not substantially decomposed, but if the temperature is too low, the imidization time will be long and it is not industrial. It is usually carried out at around room temperature to 50 ° C or lower.

As the acid anhydride, any of aliphatic carboxylic acid monoanhydride, aromatic carboxylic acid monoanhydride, alicyclic carboxylic acid monoanhydride, and heterocyclic carboxylic acid monoanhydride can be used, but specific examples thereof include Acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, formic anhydride,
Malonic anhydride, succinic anhydride, maleic anhydride,
Phthalic anhydride, benzoic anhydride, o, m and p-toluic anhydride, m and p-ethylbenzoic anhydride, p
-N-propylbenzoic anhydride, p-isopropylbenzoic anhydride, anilic anhydride, o, m and p-nitrobenzoic anhydride, o, m and p-chlorobenzoic anhydride,
Various dibromo and dichlorobenzoic acid anhydrides, tribromo and trichlorobenzoic acid anhydrides, hemelic acid anhydrides, 3,4-xylyl acid anhydrides, isoxylic acid anhydrides, mesitrenic acid anhydrides, veratrumic acid anhydrides, trimethoxybenzoic acid Anhydrous, α- and β-naphthoic anhydride, p-phenylbenzoic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic acid anhydride, nadic acid anhydride, chlorendic anhydride , Nicotinic anhydride, isonicotinic anhydride, picolinic anhydride, quinolinic anhydride, and the like, but are not necessarily limited thereto.
The amount of the carboxylic acid monoanhydride used is 1/5 mol or more, preferably 1 mol or more, based on the amide bond of the polyamic acid.

As the base, an aliphatic N-containing compound, an aromatic N-containing compound,
Imidazoles are used. Examples of the aliphatic N-containing compound include triethylamine, tributylamine, triethylenediamine, dimethylbenzylamine, 4-methylmorpholine and the like.

Examples of aromatic N-containing compounds include pyridine, quinoline,
Isoquinoline, α-picoline, β-picoline, γ-picoline, 3,5 lutidine, 3,4 lutidine, 2,5 lutidine, 2,4 lutidine, 2,4,6 collidine, 1,2,4 triazine, pyrimidine, Pyrazine, 1,3,5 triazine, pyridazine, 4-dimethylaminopyridine, 4-morpholinopyridine, 4-
Examples thereof include pyrrolidinopyridine and 4-piperazinopyridine.

Examples of imidazoles include N-cyanoethyl-2-ethyl 4-methylimidazole, N-cyanoethyl 2-methylimidazole, N-cyanoethyl-2-phenylimidazole, 2-methylbenzimidazole, 5-methylimidazole, N-phenylimidazole, 2 -Phenyl-4-methylimidazole and the like can be mentioned.

The amount of these bases used is amide bond 1 of polyamic acid.
The amount is 0.001 to 5 mol, preferably 0.01 to 1 mol per mol.

The azo group-containing polymer of the present invention thus obtained is useful as a high molecular weight polymer initiator for producing various block copolymers.

Example 1 In a 300 ml four-necked flask, 2,2'-azobis [N- (4
-Aminophenyl) -2-methylpropionamidine]
5.263 g (10 mmol) of tetrahydrochloride, 4.048 g (40 mmol) of triethylamine and 50 g of N-methyl-2-pyrrolidone (abbreviated as NMP) were added. Next, 1.961 g (10 mmol) of 1,2,3,4-butanetetracarboxylic acid dianhydride was added and the reaction was carried out at room temperature for 24 hours with stirring to give a pale yellow viscous polymer solution. A part of this was put into a large amount of methanol to precipitate, wash, and vacuum dried at room temperature for 24 hours, and ηinh of the polymer was 1.5 dl / g (0.5 g / dl, NMP, 30 ° C.). From the infrared absorption spectrum, absorption of amic acid (N—H) was observed at 3280 cm ⁻¹ .

Next, a solution of 4.1 g (40 mmol) of acetic anhydride, 0.52 g (4 mmol) of isoquinoline and 50 g of NMP was added to the above polymer solution, and the mixture was stirred and reacted at room temperature for 48 hours to obtain a yellow polymer solution. This was put into a large amount of methanol to precipitate a polymer, which was washed several times with methanol and then dried at room temperature for 24 hours to obtain a pale yellow powdery polymer. The yield was over 95%. The ηinh of this polymer is 1.3dl / g (0.5g / d
l, NMP, 30 ° C) and the infrared absorption spectrum is 1780 cm ^-1
And a strong absorption of imide was newly observed at 730 cm ^-1 , while 3
Absorption of NH at 280 cm ^-1 was completely gone.

In the differential thermal analysis of the polyamic acid and the polyimide obtained as described above, a broad exothermic peak was observed at 100 to 160 ° C, but in the polymer preheated at 150 ° C for 3 hours, the exothermic peak was no longer observed in the above temperature range. I couldn't do it.
This exothermic peak coincided with that of the starting material, azobisamine.

Example 2 8.770 g (30 mmol) of 1,3-bis (4-aminophenoxy) benzene, 2,2'-azobis [N- (3-aminophenyl) -2-methylpropionamidine] tetrahydro in a 300 ml four-necked flask. Chloride 1.053g (2.0mmo
l), 0.81 g (8 mmol) of triethylamine and 150 g of NMP were added. Then, 9.415 g (32 mmol) of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride was added and the reaction was carried out at room temperature for 24 hours with stirring to give a viscous pale yellow polymer solution. A portion of this was placed in a large amount of methanol to precipitate, wash, and vacuum dried at room temperature for 24 hours.
h was 2.1 dl / g (0.5 g / dl, NMP, 30 ° C). From the infrared absorption spectrum, absorption of amic acid was observed at 3280 cm ^-1 .

Then, a solution of 20.4 g (200 mmol) of acetic anhydride, 0.49 g (4 mmol) of dimethylaminopyridine and 80 g of NMP was added to the above polymer solution, and the mixture was stirred and reacted at room temperature for 48 hours to obtain a yellow polymer solution. This was put into a large amount of methanol to precipitate a polymer, washed with methanol several times, and then vacuum dried at room temperature for 24 hours. The yield was over 95%. The ηinh of this polymer was 2.0 dl / g, and in the infrared absorption spectrum, strong imide absorption was newly observed at 1780 cm ^-1 and 730 cm ^-1 , while NH absorption at 3280 cm ^-1 was completely eliminated. .

In the differential thermal analysis of the polyamic acid and the polyimide obtained as described above, a broad exothermic peak was observed at 100 to 160 ° C, but in the case of the polymer which was previously heat-treated at 150 ° C for 3 hours, the exothermic peak was no longer in the above temperature range. I was not able to admit.

Example 3 In a 300 ml four-necked flask, 2,2'-azobis [N- (4
-Aminophenyl) -2-methylpropionamide] 0.
765 g (2.0 mmol), 1,3-diaminodiphenyl ether 6.
007 g (30 mmol) and 150 g NMP were added. Then 3,3 ', 4,
4'-benzophenone tetracarboxylic dianhydride 10.311g
(32 mmol) was added and the mixture was reacted under stirring at room temperature for 24 hours to obtain a pale yellow viscous polymer solution. A part of this was put into a large amount of methanol to precipitate, wash, and vacuum dried at room temperature for 24 hours. The polymer ηinh was 1.8 dl / g. From the infrared absorption spectrum, absorption of amic acid was observed at 3280 cm ^-1 .

Next, a solution of 20.4 g (200 mmol) of acetic anhydride, 2.58 g (20 mmol) of isoquinoline and 70 g of NMP was added to the above polymer solution, and the mixture was stirred and reacted at room temperature for 48 hours to obtain a yellow polymer solution. This was put into a large amount of methanol to precipitate a polymer, washed with methanol several times, and then vacuum dried at room temperature for 24 hours. The yield was over 95%.
The ηinh of this polymer was 1.8 dl / g, and in the infrared absorption spectrum, strong imide absorption was newly observed at 1780 cm ⁻¹ and 730 cm ⁻¹ , while absorption of amic acid at 3280 cm ⁻¹ was completely abolished.

In the differential thermal analysis of the polyamic acid and polyimide obtained as described above, a broad exothermic peak was observed at 100 to 160 ° C, but in the case of the polymer which was previously heat-treated at 150 ° C for 3 hours, the exothermic peak was no longer in the above temperature range. Was not recognized.

Reference Example 1 2.0 g of the azo group-containing polyimide obtained in Example 1, NMP3
0 g and butyl acrylate (50 g) were placed in a 300 ml four-necked flask, the atmosphere was replaced with nitrogen with stirring, and the mixture was polymerized at 70 ° C for 4 hours.
The polymerization solution was poured into a large amount of methanol, washed several times with methanol, and vacuum dried at room temperature for 24 hours to obtain a transparent rubber-like polymer. The polymerization rate was 49.5%.

Next, the rubber-like polymer 10 g, NMP 10 g and styrene 20 g
Was added and polymerized at 70 ° C for 4 hours in the same manner as above.
Polymerization was carried out at 130 ° C. for 1 hour to obtain a white powdery polymer. The styrene polymerization rate was 45%.

Reference Example 2 10 g of the azo group-containing polyimide obtained in Example 2, NMP10
0 g and 20 g of styrene were placed in a 300 ml four-necked flask, the atmosphere was replaced with nitrogen with stirring, and then polymerization was carried out at 70 ° C. for 8 hours. After pouring the polymerization solution into a large amount of methanol and washing it several times with methanol
It was vacuum dried at 100 ° C. for 5 hours to obtain a white powdery polymer. The polymerization rate of styrene is 43.5%,
Was 1.3 dl / g (0.5 wt%, NMP, 30 ° C).

Reference Example 3 When styrene was polymerized in exactly the same manner as in Reference Example 2 except that 10 g of the azo group-containing polyamic acid obtained in Example 3 was used, the polymerization rate of styrene was 40.8% and ηinh was 1.0.
dl / g.

〔The invention's effect〕

As described above, the azo group-containing polyamic acid or polyimide obtained in the present invention is relatively easily obtained and is preferably used as a polymerization initiator.

Continuation of the front page (56) Reference JP-A-55-60526 (JP, A) US Pat. No. 3597392 (US, A) US Pat. A) British patent 1147856 (US, A)

Claims (2)

[Claims] 1. A formula (I) (Here, R ¹ and R ² are each independently an alkyl group having 1 to 2 carbon atoms, and X is Or a compound represented by formula (II) (Wherein R ¹ , R ² and X have the same meanings as in formula (I)), or an azo group-containing compound selected from the salts thereof and a tetracarboxylic acid dianhydride. A process for producing an azo group-containing polymer for a polymerization initiator, which comprises polycondensing a polyamic acid in a solvent. 2. The polyamic acid obtained according to claim 1 is chemically closed to form a polyimide.
A method for producing an azo group-containing polymer for a polymerization initiator.