DE1495846A1 - Process for the production of polyimides containing azo groups - Google Patents

Description

PAINT FACTORY N E U S C H R I F T LEVERKUSEN-Bayerwerk ' P 14 95 846.4 »atint-aitiiiunc Appendix for input Le A 9135. "of July 3, 1968

G / Sh

Process for the preparation of polyimides containing azo groups

Bb is already known that polyimides can be obtained by reacting Can produce tetraarboxylic dianhydrides with primary diamines (cf. Bfitische Patent 903 271).

It has now been found that azo groups containing polyimides obtained when reacting a Azobenzoltetracarbonsäuredianhydrid with a diamine at temperatures of 0 to 35O ⁰ C, optionally in an organic solvent and optionally in the presence of a catalyst. All azobenzenetetraoarboxylic dianhydrides, e.g. B. azobenzene-3,3 ', 4,4 ^f -totraoarboxylic acid-, azobenzene-2,2 ¹ , 3 »3 ^f -> totracarboxylic acid or azobenzoi-3,4,2 ¹ ^« - tetracarboxylic dianhydride or mixtures thereof can be used .

Examples of suitable diamines are aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic diamines, for example 1,4-diaminobutane, 1,6-diaminohezane, 1,4-diamino-cyclohexane, 4,4-diamino-hexahydro-diphenylmethane, 4,4 ^t -Diamino-diphenylmethane, 4,4 * -diaiaino-diphenylether, 1,5-diaminonaphthalene, diamino-carbazole, 4,4 * -diaminodiphenyl-βulfon, HiH'-dimethyl-H ^ '- di-Cp-aminophonyli -urea,

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New documents (Ail. 7 S ι Ab ₈ ; 2 No.; f S «tt 3 dM Xndwvng ^ M. V.

H95846

H-methyl-N- (p-aminophenyl) -carbamic acid (p-amino phony1) -ether , p-aminobenzoic acid (p-aminophenyl) -ether, p-aminobenzoic acid (p-aminophenyl) -amide.

You have the general formula

H ₉ NR-NH ₉ "' _Λ <■ ί where R has two

Valuable organic radical means which is derived from a uronetic, heterocyclic, aliphatic, oyoloaliphfitieohekL or from a combination of an aromatic and an aliphatic group. Such groups are e.g. B. Alkylenreete, preferably with 1 to 6 carbon atoms, Cycloalkylenreete, preferably with 5 to 7 carbon atoms, Arylenreste, Of, ctf-Diarylenalkylreste, Diarylenätherreste, Diarylenesulfonreste, Diarylenurstoffreeie, Aryloarbonsäureearylesterreste and Arylcarbonsäure-N-arylaraidreste

The reaction of the present invention is carried out according to the following Reaction scheme

-N = N-

+ η HgN-R-NH ₂

[, ft ft Q1 ^^

HOOC

-HN-OO

COOH

CO-NH-R-

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In this reaction scheme, R has the meaning given above and η means an integer from 10 to about 1000.

The process is generally carried out at temperatures of 0 to 35O ° C, preferably 0 to 25O ⁰ C is performed. Dehydrating acidic or basic catalysts, for example Friedel-Crafts catalysts such as acetic anhydride / pyridine, acetic anhydride, propionic anhydride and zinc chloride, can also be used. However, the reaction also takes place without a catalyst.

The reactions according to the invention can be carried out with and without a solvent be performed. As a solvent, depending on the reaction conditions for example suitable: (halogenated hydrocarbons, phenols, esters, ketones, ethers, amides, sulfoxides, sulfones such as toluene, o-dichlorobenzene, phenol, cresol, acetophenone, acetone, Tetrahydrofuran, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, Dimethyl sulfoxide, tetramethylene sulfone.

In order to achieve the highest possible molecular weight reaction products, it is expedient to use the starting products used - azobenzenetetracarboxylic dianhydride and diamine - to be used in a molar ratio of 1: 1, but the reaction can in principle also be used an excess of one of the two components can be carried out up to about twice the molar amount. The response times can range from about 1 to 25 hours.

The implementation of the method can, for. B. be done so that to a solution of the diamine in one of the above

Lo A 9135 909819 / 115.6.

H95846

Solvent, the Azobenzoltetracarbonsäureanhydrid portione, with cooling inflicts to give a dark red · viscous solution · This solution can be used directly for the production of coatings, ·, for example, used on metals by a thin layer of solution is brought to the metal surface by heating to temperatures baked in between about 150 and 300 ^° C. *.

The products according to the invention - the polyimides containing azo groups - Surprisingly, they have an extremely high thermal stability, which is due to the presence of azo bridges was not to be expected. They are used for the production of coatings, especially of highly heat-resistant wire seals Production of films and foils used, which in addition to the excellent thermal stability also has good elasticity and have hardness.

Since the polyimides according to the invention are intensely colored red, can be produced with these products red laokartige coatings that are up to about 40O ⁰ C temperature resistant. Itote paints with such a high temperature resistance have not previously been known, since there are no red organic pigments suitable for coloring paints that can withstand such high temperatures. The few temperature-resistant inorganic red pigments z. B. iron oxide pigments, which are known up to now, are not suitable for paints because they have an unfavorable effect on the mechanical properties of the coatings.

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The compounds obtained according to the invention do not need to be added, since the red color is due to their chemical structure is given. So there is no stifling of the mechanical properties of the coatings through additives and the color remains unchanged up to such temperatures as the coating itself without Tolerates damage. -. '

example 1

To a solution of 10.0 Gewiohtsteilen 4,4'-diaminodiphenyl ether in 200 parts by volume of anhydrous dimethylformamide under cooling at 15 to 20 ⁰ C 16,1 parts by weight Azobenzoltetraearbonsäuredianhydrid prepared by cyclization of azobenzene tetracarboxylic means of acetic anhydride, was added portionwise. To complete the reaction, the mixture is stirred for a further 2 hours at room temperature and the reaction product obtained is a dark red, viscous solution with a viscosity of 9054 cP ₂ ^. It contributes to a fat-free sheet metal a thin film of this solution and heated in einem'Ofen 30 minutes 240 ⁰ C. An elastic, tough, resistant to the usual organic solvents, dyed red PoIyimidfilm. The IR spectrum of the film confirms the polyimide structure.

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With the lacquer solution produced, a wire 0.7 mm in diameter is lacquered to a thickness of 0.740 mm in the usual way. The vertical baking oven is 4.20 m · The temperature rises to 35O ⁰ C in the oven of the 220th The withdrawal speed for the wire can be varied from 5 m / min to 8 m / min. Work is carried out with 6 passages · The enamelled wire obtained is colored red and has excellent thermal properties. A heat shock stress of 26O ⁰ C of the wound on the own diameter wire coil is held without Difficult Celts. The softening temperature '(DIN 46453) is above 33O ⁰ C. Also, after aging at 200 ⁰ C, the windability of the wire remains around the own diameter 2 weeks and longer.

Example 2

To a solution of 52.5 parts by weight of 4,4-diamino-dicyclohexylmethane ¹ in 1000 parts by volume of anhydrous dimethylformamide at 15 to 20 ⁰ C portionwise 80.5 parts by weight Azobenzoltetracarbonsäuredianhydrid, prepared as described in Example 1 was added. An inhomogeneous reaction mixture is initially obtained, which gradually changes into a viscous, red solution in an exothermic reaction. By cooling keeping the reaction temperature at 20 to 25 ⁰ C. The mixture is stirred for volletändigen solution overnight at room temperature. The viscosity of the solution is 600 ^c ? 25 *

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An enamelled wire produced from this enamel solution according to the method described in Example 1 also has excellent properties, particularly with regard to its temperature resistance. The properties are of the quality level known for enamelled wires made of polyimides, for example the softening temperature (DIN 46 453) is above 330 ^° C.

Example 3 t

To a solution of 27.0 wt. Tin. H, M'-dimethyl-H, M'-di (p-aminophenyl) urea (P: 186 °) in 400 parts by volume of dimethyl sulfoxide are 32.2 parts by weight at room temperature with cooling. Azobenzene-3,3 ', 4,4 * -tetracarboxylic acid dianhydride was added in portions. The mixture is stirred for a further 2 hours at room temperature and a dark red, viscous solution is obtained. A thin film of this solution is applied to a grease-free sheet metal; followed by 30 minutes at 24O ⁰ C is heated in an oven. An elastic, hard, red polyimide film which is insoluble in the usual organic solvents is obtained. The IR spectrum of the polyimide film clearly shows the presence of the imide groups.

The viscous polyamide-polycarboxylic acid solution obtained is refluxed for 5 hours. A red colored one falls Polyimide, which has a melting point above 400 C.

The IR spectrum proves the polyimide structure.

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Example 4:

Analogously to Example 3, 25.7 wt. Tie. M-methyl-li (paminophenyl) carbamic acid (p-aminophenyl) ester (F: 142 °) with 32.2 wt. TIn. Azobenzene-3,3 ', 4,4'-tetracarboxylic acid dianhydride in 400 parts by volume of M-methylpyrrolidone, initially at room temperature, then under reflux conditions. A red-colored polyimide with a melting point above 400 ^° C. is obtained, which is used in all
agents is insoluble.

over 400 C, which is found in all common organic solutions

Example 5:

Aue 19.8 parts by weight. 4,4'-diamino-diphenylmethane and 32.2 parts by weight of azobenzene-tetracarboxylic acid dianhydride (mixture of isomers, temperature: 270 °) in 400 parts by volume of dimethylacetamide, a polyamide-polycarboxylic acid solution is prepared in the manner described. This red, viscous solution is poured onto a glass plate to form a film of 50 .mu.m thick, and this is heated in one

Baking oven 1 hour at 240 ° and receives an elastic, dark red polyimide film.

Example 6ι

322 parts by weight. Azobenzene tetracarboxylic acid dianhydride with 58 parts by weight. Hexarethylene diamine (1.6) in 1000 parts by volume Dimethylformamide reacted under reflux conditions in a 5-hour reaction. It is allowed to cool, filtered and dried at 100 ° in vacuo and the reaction product is then heated for 2 hours with 250 wt. tin. Acetic anhydride. 142 parts by weight are obtained. a red colored compound of the structure

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R = N

ifi 205 ° C. The IR spectrum shows the presence of the anhydride and iiaide groups.

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Claims (1)

H95846 Claim Process for the preparation of polyimides containing azo groups, characterized in that: 3 an azobenzenetetracarboxylic dianhydride is reacted with a diamine at temperatures from 0 to 35O ⁰ C, optionally in an organic solvent and optionally in the presence of a catalyst. Le A 9135 - 10 - 909 8.19 / 1156 New documents (Art. 7, Paragraph I, Paragraph 2, No. 1, Clause 3 of the "Amendment of 4. 9.19 (57)