PROCESS OF PREPARING A POLY(ANTHRANILIDE), POLY(ANTHRANILIDE) AND ITS USE

Abstract

The present invention relates to a process of preparing a poly(anthranilamide) comprising the steps: (A) providing an anthranilate, and (B) reacting the anthranilate by polycondensation and separation of the alcohol on which the anthranilate is based in the presence of a catalyst to poly(anthranilamide), the poly(anthranilamides) obtained in this way and their use in the production of fibers of composite materials.

Claims

1. A process for preparing a poly(anthranilamide), comprising: (A) providing an anthranilic ester, (B) converting the anthranilic ester by polycondensation with elimination of alcohol in the presence of a catalyst to give the poly(anthranilamide).

2. The process as claimed in claim 1, in which the catalyst comprises: (1) an alkyl compound, an alkyl halide compound, an acetylacetonate, a carboxylate, an alkoxide, and/or a chloride of a metal of group 1, 4, 11, 12, 13 or 14 of the Periodic Table of the Elements or (2) a Brønsted acid.

3. The process as claimed in claim 2, in which the metal of group 1, 4, 11, 12, 13 or 14 of the Periodic Table of the Elements comprises Li, Ti, Cu, Zn, Al, Hf, Zr and/or Sn; and/or in which the alkyl compound comprises diethylzinc and/or triethylaluminum; and/or in which the alkyl halide compound comprises dichloro(ethyl)aluminum and/or chloro(diethyl)aluminum; and/or in which the acetylacetonate comprises titanium (monoxide) acetylacetonate, zinc acetylacetonate and/or aluminum acetylacetonate; and/or in which the carboxylate comprises zinc(II) acetate; and/or in which the alkoxide comprises methoxide, ethoxide, isopropoxide, butoxide, isobutoxide and/or phenoxide; and/or in which the alkoxide comprises aluminum triisopropoxide, titanium tetrabutoxide, titanium tetraisobutoxide and/or lithium methoxide; and/or in which the chloride comprises zinc dichloride and/or iron trichloride; and/or in which the Brønsted acid comprises sulfuric acid, hydrochloric acid, nitric acid and/or phosphoric acid.

4. The process as claimed in claim 1, in which the anthranilic ester comprises methyl anthranilate, ethyl anthranilate, propyl anthranilate, isopropyl anthranilate, butyl anthranilate and/or isobutyl anthranilate.

5. The process as claimed in claim 1, in which step (B) is conducted at a reaction temperature in the range from 120° C. to 300° C.; and/or in which step (B) is conducted at a pressure in the range from 0.10 bar.sub.(abs.) to <1.0 bar.sub.(abs.).

6. The process as claimed in claim 1, in which step (B) is conducted in the absence of a solvent, wherein step (B) is followed by a process comprising: (C)(i) dissolving the poly(anthranilamide) in a mineral acid to obtain a mineral acid solution of the poly(anthranilamide); and (D)(i) isolating the poly(anthranilamide) dissolved in the mineral acid from the mineral acid solution, comprising a step of precipitating in water.

7. The process as claimed in claim 1, in which step (B) is conducted in the presence of a solvent, wherein the solvent comprises an organic solvent which is in liquid form under the reaction conditions of step (B), an ionic liquid or a mixture thereof, and, in step (B), the poly(anthranilamide) is obtained such that it is suspended in the solvent, wherein step (B) is followed by a process comprising: (C)(ii) dissolving the poly(anthranilamide) suspended in the solvent in a mineral acid and separating off the solvent to obtain a mineral acid solution of the poly(anthranilamide); and (D)(ii) isolating the poly(anthranilamide) dissolved in the mineral acid from the mineral acid solution, comprising a step of precipitating in water.

8. The process as claimed in claim 1, in which step (B) is conducted in the presence of a solvent, wherein the solvent comprises an ionic liquid or a mixture of an ionic liquid and an organic solvent which is in liquid form at the reaction temperature, and, in step (B), the poly(anthranilamide) is obtained such that it is dissolved in the solvent, wherein step (B) is followed by a process comprising: (D)(iii) isolating the poly(anthranilamide) dissolved in the solvent from the solution in the solvent, comprising a step of precipitating in water.

9. The process as claimed in claim 7, in which the organic solvent comprises diphenyl ether, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, hexamethylphosphoramide, or a mixture thereof, and/or in which the ionic liquid comprises 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium butyrate, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium methylsulfonate, a dialkylimidazolium phosphate, or a mixture thereof.

10. The process as claimed in claim 1, in which step (A) comprises converting anthranilic acid to isatoic anhydride and reacting the isatoic anhydride with an alcohol to give the anthranilic ester; and/or in which step (A) comprises reacting anthranilic acid with an alcohol to give the anthranilic ester.

11. The process as claimed in claim 10, in which the reaction with the alcohol in step (A) is conducted in the presence of a catalyst, wherein step (B) is conducted without prior removal of the catalyst used in step (A) and no catalyst other than the catalyst used in step (A) is added.

12. A poly(anthranilamide) of the formula
RO—[O═C)(ortho-C.sub.6H.sub.4)—NH].sub.n—H in which R is an aliphatic organic radical and n denotes the number of repeat units.

13. A poly(anthranilamide) as claimed in claim 12, in which R is methyl, ethyl, propyl, isopropyl, butyl or isobutyl; and/or in which n is in the range from 20 to 2500.

14-15. (canceled)

16. A fiber comprising the poly(anthranilamide) of claim 12.

17. A composite comprising the poly(anthranilamide) of claim 12 and another material comprising a metal, a mineral material or a polymer other than poly(anthranilamide).

18. The process as claimed in claim 8, in which the organic solvent comprises diphenyl ether, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and/or hexamethylphosphoramide, and/or in which the ionic liquid comprises 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium butyrate, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium methylsulfonate and/or a dialkylimidazolium phosphate.

19. The poly(anthranilamide) as claimed in claim 13, in which n is in the range from 70 to 2000.

20. The poly(anthranilamide) as claimed in claim 19, in which n is in the range from 70 to 200.

21. The poly(anthranilamide) as claimed in claim 20, in which n is in the range from 70 to 100.

Description

EXAMPLES

[0126] Analysis

[0127] The number-average molar mass (M.sub.n) of the resulting poly(anthranilamide) was determined by means of .sup.1H NMR spectroscopy (from Bruker, AV Ill HD 600, 600 MHz; pulse sequence zg30, delay time d1: 10 s, 64 scans). Each sample was dissolved in deuterated sulfuric acid. The relevant resonances in the .sup.1H NMR spectrum (based on TMS=0 ppm) are as follows:

[0128] The signals at 8.5-7.1 ppm are used for the aromatic protons of anthranilamide (corresponding to an integral of 4 protons). The resonances of the protons of the methyl ester end group have a shift of 3.56 ppm (methyl group, corresponding to an integral of 3 protons).

[0129] The molar mass M.sub.n of the polymer is calculated according to formula (I) as follows, using the following abbreviations: [0130] F(A)=area of the resonance at 8.5-7.1 ppm of the aromatic protons (4 protons) [0131] F(M)=area of the resonance at 3.56 ppm of the methyl group of methyl anthranilate (3 protons)

[0132] The following formula (I) was used to calculate the number of repeat units from oAB (n) in the polymer:

[00001]$\begin{array}{cc}n=\frac{F\left(A\right)}{F\left(M\right)}.Math.\frac{3}{4}& \left(I\right)\end{array}$

[0133] The number n was used to calculate the molar mass M.sub.n of the polymer by the following formula (II):

M.sub.n=150.16.sup.g/.sub.mol+n.Math.120.14.sup.g/.sub.mol+1.sup.g/.sub.mol  (II)

Example 1 (Inventive): Preparation of Poly(Anthranilamide) by Polycondensation of Methyl Anthranilate in the Presence of Ti(OiPr).SUB.4 .as Catalyst

[0134] A 500 mL four-neck flask was equipped with a distillation system, precision glass stirrer, temperature probe, nitrogen feed and gas inlet/gas outlet with pressure relief valve. Subsequently, 50 g of methyl anthranilate and 9.4 g of Ti(OiPr).sub.4 were weighed in. Nitrogen was introduced at 10 L/h for 20 minutes, in the course of which the solution was stirred at 300 rpm. Thereafter, the solution was stirred at 180° C. for 9 h.

[0135] The molar mass M.sub.n was determined by means of NMR in D.sub.2SO.sub.4.

Example 2 (Inventive): Preparation of Poly(Anthranilamide) by Polycondensation of Methyl Anthranilate in the Presence of Ti(OiPr).SUB.4 .as Catalyst and Diphenyl Ether as Solvent

[0136] The reaction was conducted analogously to example 1, but in the presence of 50 mL of diphenyl ether.

Example 3: Preparation of Poly(Anthranilamide) by Polycondensation of Methyl Anthranilate Under Reduced Pressure in the Presence of Ti(OiPr).SUB.4 .as Catalyst and Diphenyl Ether as Solvent

[0137] The reaction was conducted analogously to example 2, but at a pressure of 0.80 bar.sub.(abs.).

Example 4 (Comparative): Preparation of Poly(Anthranilamide) by Polycondensation of Methyl Anthranilate in the Absence of Ti(OiPr).SUB.4 .as Catalyst

[0138] The reaction was conducted analogously to example 1, but in the absence of the catalyst. There was no conversion of the monomer here to resulting poly(anthranilamide).

[0139] The following table compares the results to one another:

TABLE-US-00001 Pressure Mn Example Catalyst Solvent (abs) Result [g/mol] 1 Ti(OiPr).sub.4 — 1.0 bar Polymerization 2554 2 Ti(OiPr).sub.4 Diphenyl 1.0 bar Polymerization n.d. ether 3 Ti(OiPr).sub.4 Diphenyl 0.8 bar Polymerization n.d. ether 4 — — 1.0 bar No conversion of n.d. the monomer (n.d. = not determined)