DE2061360A1 - Storable solutions of reactive polyamides based on phenylogous carboxamides - Google Patents

Description

Badische Anilin- & Soda-Fabrik AG

Our reference: 0.Z.27 228 E / AR

6700 Ludwigshafen, December 10th, 1970

Storable solutions of reactive polyamides based on phenylogous carboxamides

The present invention relates to storage-stable solutions more reactive Polyamides based on phenylgic carboxamides /

Reactive polyamides for the purposes of the present invention are polyamide condensation products from phenylogenic aromatic diamines and aromatic dicarboxylic acids, the aromatic Nuclei carry substituents that are capable of further chemical reactions. ™

It is known to have reactive polyamide condensation products from chain-shaped polyamides, such as those used in Implementation of dicarboxylic acids with diamines or dicarboxylic acid chlorides and diamines are formed by condensation, by introducing functional groups in a polymer-analogous reaction to manufacture. The side reactions that take place simultaneously in polymer-analogous reactions lead to products that are not separated off because they are built into the same macromolecule. Polymer mixtures are generally obtained in this way. ^

It is also known that polyamides which carry reactive carboxyl groups on the aromatic nucleus as substituents can be prepared by diamines with aromatic tetraoarboxylic acid dianhydrides, tricarboxylic acid anhydride chlorides or carboxylic acid chlorides which contain more than two acid chloride groups in the molecule, in an organic, polar solvent reacts whose functional groups neither react with the diamine nor with the carboxyl substituents. This creates in a first stage, polymers which are usually still soluble in the solvent used for the reaction.

As a result of their reactivity, however, the solutions of such polyamides have a tendency to gel after a short time, with

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the responses responsible for this, both inter- and can be intramolecular in nature. For further processing, e.g. into fibers, films, foils or lacquers, these are gelling Solutions unusable.

The object was therefore to find solutions of reactive polyamides based on phenyllogous carboxamides that were stable over a long period of time. In relation to the subject matter of the invention, storage stability should be understood to mean that period of time during which the polyamide / solvent system does not gel on storage ^{at a given temperature, for example at 60, 80 or 100 ° C.}

It has now been found that solutions of polyamide condensation products from aromatic diamines and aromatic carboxylic acid compounds with reactive substituents on the aromatic Cores are stable in storage if the aromatic diamines are benzophenone diamines of the general formula R R

NH,

I,

where η is 1 or 2 and R is H, OH, OR, COOH and COOR ' and R 'is an alkyl radical having 1 to 12 carbon atoms, and the aromatic carboxylic acid compounds are tetracarboxylic acid anhydrides the general formula

... CO

where m is 0 or 1 and X is -CO-, -0-,

and -SOp- represent.

CH,

The polyamide addition products obtained from these starting components are characterized by their good solubility in polar organic solvents, in which they are characterized by a

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Addition reaction can be produced, and by a excellent compared to previously known solutions of related substances Storage stability of these solutions. The ones on the aromatic The reactive substituents in the core of these soluble polyamide condensation products enable further condensation to form insoluble, infusible products, which are made as thread-like or sheet-like plastic structures with increased temperature resistance find multiple technical uses. It was surprising that the two conflicting properties, viz the reactivity for further condensation and the inertia required for the stability of the solutions against gelling in the polyamide condensation products according to the invention could equally be united.

Suitable diamine components for the preparation of the storage-stable solutions of the polyamide condensation products according to the invention are the diamines derived from benzophenone or its next higher homologue, the amino groups in each case being in the 4-position on the aromatic nucleus, and preferably the nuclei bearing the amino groups in the still free positions can be occupied by another substituent R in each case. Such substituents R include OH, OR ¹ , GOOH, GOOR '. R ¹ is an alkyl radical with 1 to 12 carbon atoms. These compounds mentioned can be described by the general formulas

and

-CO

Particularly suitable are 3- _{oxy-3-amino-4'- /} / m-oxy-p-amino7-benzoylbenzophenone, 3-carboxy-4-amino-4 ^t, -carboxy-p-amino7-benzoylbenzophenone, 3,3 '-Dimercapto ^ -4,4' -diaminobenzophenone, 3-mercapto-4-amino-4 '- / m-mercapto-p-aminoZ-benzoylbenzophenone, 3,3'-dimethoxy-4,4'-diaminobenzophenone, 3- Methoxy-4-amino-4 '- ^ / m-methoxyp-aminoj-benzoylbenzophenone and especially 4,4'-diamino-benzophenone, 3,3'-dioxy-4,4'-diaminobenzophenone and 3,3'-dicarboxy -

4,4 ^I -diaminobenzophenone. 209 82 5/0943

-4-

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Aromatic tetracarboxylic anhydrides used as the carboxylic acid component for the production of the reactive polyamides according to Invention can be used advantageously are aromatic tetracarboxylic dianhydrides with at least one aromatic Core like them through the general formulas

can be described, where -X- equals -CO, -S-, -0-,

-C- and -SOp- can be. The compounds in question B CH ₃

of this type are pyromellitic anhydride, naphthalene tetracarboxylic acid dianhydride, Bisphenol tetracarboxylic anhydride, 3.3 ', 4.4 * - Benzophenone tetracarboxylic acid anhydride, 3,3 ', 4,4'-diphenylsulfonetetracarboxylic acid anhydride, 3,3 ', 4,4'-diphenylether tetracarboxylic anhydride and 3,3 ', 4,4'-diphenyl sulfide tetracarboxylic acid anhydride. 3,3 ', 4,4'-Benzophenonetetracarboxylic acid anhydride are particularly preferred and 3,3 ', 4,4'-diphenylsulfonetetracarboxylic acid anhydride.

The polycondensation reaction which leads to the reactive polyamides is preferably carried out with equimolar amounts of the reactants. But it is also possible to use one of the reactants in excess, for example, to 50 i "excess. This procedure allows the molecular weight of the reactive polyamides to be produced to be controlled within wide limits.

The polycondensation should expediently be carried out in a solvent which is compatible with the reactants is chemically inert. Organic, polar substances that are used in the setting have proven particularly useful as solvents Polycondensation temperature are liquid. In particular, N-methyl pyrrolidone, dimethyl sulfoxide, dimethylformamide, Dimethylacetamide, dimethoxyacetamide and hexamethylphosphonamide into consideration. These solvents can increase the solubility of the components still alkali and alkaline earth metal salts

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such as lithium chloride or magnesium chloride in amounts of 0.5 5 wt. 56 are added. Daa ratio of solids content to solvent is expediently in the range 5:95 "to 40:60, preferably 10:90 "to 30:70.

The reactants diamine and tetracarboxylic dianhydride are reacted in a manner known per se, as is described, inter alia, in French patent 1,239,491. For example, the amino compounds can be dissolved in an inert atmosphere in the solvent at room temperature and the tetracarboxylic anhydrides can be added in portions to this solution in an equimolar amount with stirring. The ä

Do not exceed the temperature of the reaction mixture + 30 ^{0 O.}

The reaction usually takes several hours. Their end is indicated by the fact that the viscosity of the solution does not increase any further. A solution of reactive polyamides is obtained which, despite its reactivity, is storage-stable within wide limits in the sense of the definition given at the beginning. The degree of polymerization of the polyamides obtained is, depending on the conditions used for the reaction, in the range of oligomers up to several hundred monomer units, corresponding to an inherent viscosity of II = 0.1 to -l dl / g measured as a 0.5 solution in N -Methylpyrrolidon be | - _i; 3: 0 ⁰ G. The products are not networked, so they are real solutions. The initial components are so reactive that high molecular weight polyamides are formed under normal condensation conditions, but on the other hand the reaction proceeds in such a way that no additional intra- and intermolecular conversions take place which lead to precipitation of the reaction products, ie to gelling of the solution. .

The storage-stable solutions of the reactive polyamides according to the invention can mainly be extended in two directions to process. Once can through intermolecular condensation reactions - if necessary crosslinked with the addition of crosslinkers and thus insoluble and infusible polyamides

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immeasurably high molecular weight can be obtained. On the other hand, the reaction can easily and clearly be carried out intramolecularly, especially in solution. For example, insoluble polyheterocycles are obtained by cyclization. The reactions can both by the usual method by thermal treatment (for example, evaporation of the solvent), and by chemical means (eg, precipitation) can be effected, normally a condensing by annealing at 140 to 32O ⁰ G, preferably 160 follows to 25O ⁰ C . The resulting secondary products can be described as high molecular weight, optionally crosslinked, aromatic polyimides.

Except for crosslinkers such as phenol-formaldehyde condensates or Silicone resins with functional groups can be mixed with the solutions of the reactive polyamides before or during further processing also additives such as toluene, xylene, Cresol, cyclohexanone, acetanilide, nitrobenzene, other thermoplastic or crosslinkable binders such as polyisocyanates and epoxy compounds, fillers and pigments such as graphite or Titanium dioxide, dyes such as zapone blue, celliton blue, zapone red etc., thioxotropic agents such as silica gel, basic substances such as secondary and tertiary amines to neutralize the acidic groups in the usual type and amount attached.

The uses of the solutions according to the invention The polyimides obtained are mainly used in the production of fibers, foils, films, wire and other varnishes, coatings, Linings of reaction vessels and thin-walled molded parts among others, where increased temperature resistance, good adhesion, elasticity and hardness are required.

The parts given in the examples below are parts by weight.

example 1

10.6 parts of 4,4'-diaminobenzophenone are dissolved in nitrogen under nitrogen 66 parts of N-methylpyrrolidone. The solution will then turn up to 18

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20 ⁰ G cooled and mixed with 16.195 parts 3.3 ^f , 4 »4'-Benzophenontetracarbonsäureanhydrid and 30 ropes of N-methylpyrrolidone. The anhydride is added in portions over the course of 15 minutes. After stirring for 8 hours at room temperature, a viscous solution has formed. The intrinsic viscosity of this solution is 0.451 dl / g (measured at 30 ⁰ G in a concentration of 0.5 wt .-? I in N-Methyl-pyrrolidone).

The storage stability of the solution is over 300 hours ^{at 100 °} C. and over 1000 hours ^{at 80 ° C.} After evaporation of the solvent at 25O ⁰ C to elastic films, the tear strength is measured to be 1000 kg / cm is obtained.

Example 2

21.2 parts of 4,4'-diaminobenzophenone are dissolved in 172 parts of N-methylpyrrolidone. The solution is ^{cooled to 20 °} C. and mixed with 21.8 parts of pyromellitic anhydride. The addition of the anhydride is added batchwise so that the temperature of the solution not exceeding 30 ⁰ C. The solution is then stirred for 12 hours at room temperature. It is thereby obtain a solution, the intrinsic viscosity to 0.56 dl / g at 3O ⁰ C at a concentration of 0.5 wt. -I "in N-Methyl-pyrrolidone is determined. The storage stability of the solution is at 10O ⁰ C for 300 hours, at 80 ⁰ C for 1000 hours.

Example 3

31.6 parts of 4-amino-4 '- (p-amino-benzoyl) -benzophenone are dissolved in 272 parts of dimethylformamide at room temperature. The solution is then treated portionwise with 35.8 parts of 3,3 ', 4>4'-Diphenylsulfontetracarbonsäureanhydrid in the course of 20 minutes while the temperature does not exceed 3O ⁰ G. After 15 hours of reaction time, a viscous solution having an intrinsic viscosity of 0.860 dl / g (in N-methylpyrrolidone -'f * measured at 30 ⁰ C at a concentration of 0.5 wt.) Is obtained. The gelation time of this solution is over 1000 hours at 100 ° C.

■ "- ■■■ -. ^JiIi!. ■ - ■ _8-

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After 20 minutes of storage at 220.degree obtained elastic films and coatings. The tear strength of the Films is 1000 kgf / cm on average.

Example 4

Under a nitrogen atmosphere, 31.0 parts of 3,3'-dicarboxyl-4,4'-diaminobenzophenone are dissolved in 232 parts of dimethylacetamide at room temperature. The solution is cooled to 18 to 20 ° C. and 26.8 parts of 2,3,6,7-maphthalenetetracarboxylic acid anhydride are added. The anhydride is added within 20 minutes in such a way that the temperature of the solution does not exceed 30.degree. A solution whose inner Yiskosität 0.865 dl / g (measured at 3O ⁰ C at a concentration of 0.5 wt .- ^ in N-Methylpyrrölidon) is obtained. The gel time of this solution is at 100 ⁰ C over 1000 hours. From the solution a 40 / u thick coating by evaporation of the solvent is produced at 22O ⁰ C on glass plates. It is elastic and resistant to scratches and even after 300 hours of storage at 300 ⁰ C still unchanged flexible.

209825/0943

Claims (3)

Patent claims ■ 1 * Storage-stable solutions made from polyamide condensation products Benzophenonediamines of the general formula R R where η is 1 or 2 and R is H, OH, OR ', GOOH and GOOR' and R ^{f is} an alkyl radical having 1 to 12 carbon atoms, and tetracarboxylic anhydrides of the general formulas where η is zero or 1 and X is CO, 0, S, and SO ₂ mean in polar solvents. 2. Preparation of storage-stable solutions according to claim 1, characterized in that compounds of the formula I are subjected to the polycondensation in a manner known per se with compounds of the formula II in polar organic solvents. 3. Use of storage-stable solutions according to claim 1 for the production of insoluble, infusible thread-like and sheet-like Plastic structures with increased temperature resistance by further condensation of the soluble polyamide condensation products by conventional methods. Badische Anilin- & Soda-Fabrik AG 2 09825/094 3