DE1495824A1 - Process for the production of thread-forming polyamides containing hydroxyl groups - Google Patents

Description

Process for the production of thread-forming polyamides containing hydroxyl groups Contrary to the assertion made in US Pat. No. 2,279,745 that high molecular weight, thread-forming, hydroxyl group-containing polyamides, due to their special properties because of technical interest, can only be obtained if one such hydroxyl-containing polyamide-forming starting materials, such as dicarboxylic acids and diamines and / or aminocarboxylic acids, used whose hydroxyl group by at least 5 atoms from a carboxyl group and by at least 3 atoms from an amino group is removed, it has been found that high molecular weight, thread-forming, hydroxyl-containing Polyamides are also obtained if they are used as starting materials containing hydroxyl groups Dihydroxyaryl-dicarboxylic acid ester, preferably aryl ester, is used and this with corresponding amounts of diamines, optionally in a mixture with hydroxyl group-free polyamide-forming starting materials, polycondensed at polyamide-forming temperatures.

Such esters which can be used in the present invention are z. 9. the alkyl and aryl esters, especially phenyl esters, of 3,6-dihydroxyphthalic acid, Resorcinol dicarboxylic acid-2,4, resorcinol dicarboxylic acid -4,6,2,5-dihydroxyterephthalic acid, 4,41 -dihydroxydiphenyl-dicarboxylic acid-3,3 ', 4,4 "-dihydroxydiphenylmethanedicarboxylic acid-3,3', 4,4'-dihydroxy-5,5'-dimethyldiphenylmethanedicarboxylic acid-3,3 'ulid 1,1- (4,4'-dihydroxy-5,5'-dimethyldiphenyl) -ethanedicarboxylic acid-3, 31 diamines that can be used are e.g. E.g .: 1,4-tetramethylenediamine, 1, 6-hexamethylenediamine, benzidine, 4,4'-diaminodiphenylmethane, m-xylylenediamine, p-xylylenediamine, Bis - m- (2-aminoethyl) -] - benzene and bis - [- p- (2-aminoethyl) -] - benzene.

Dicarboxylic acids, which are used in addition to the Dihydrr aryidicarbonsäureestern can be, bind z. B. adipic acid, pimelic acid, sebacic acid, isophthalic acid and terephthalic acid or its amide-forming derivatives.

Other polyamide-forming starting materials which may also be used are # -aminocarboxylic acid, such as # -aminocarboxylic acid, # -aminoundecanoic acid, and # -aminododecanoic acid.

The mixture of starting materials is melted together in a manner known per se and to polyamide-forming temperatures, d. H. to temperatures between about 150 and 35000, heated. Optionally, you can also use diluents such. B. a phenol, to add.

To promote the removal of what is released during the polycondensation Alcohol or phenol and optionally the diluent, it is appropriate to work with negative pressure towards the end of the implementation.

The new polyamides can be obtained from the melt or from solutions process into threads, films or other shaped bodies in a manner known per se. Their good solubility in alkalis made possible by the free hydroxyl groups also the production of such structures by regenerating the polyamides from aqueous-alkaline Solutions in acid felling baths. In addition, the polyamides are made by reacting the hydroxyl groups with z. B.

Formaldehyde or its derivatives, diisocyanates and the like of Networking and thus the transfer to the infusible and insoluble state accessible. Such crosslinking is due to only a few hydroxyl groups in the The original molecular lobes were very wide-meshed, so the products can still be melted and thermoplastically deformable, but the melts are highly viscous and stable, see above that they are particularly suitable for the manufacture of certain products, such as pipes or blown bodies, suitable.

The relative viscosities given in the examples below of the polyamides are measured on 0.5% m-cresol solutions at 25 ° C.

Example 1 Polyamide from 4,4'-dihydroxy-3,3'-dimethyldiphenylmethane-dicarboxylic acid diphenyl ester-5,5 ' and hexamethylenediamine-1,6.

A mixture of 97.36 g of 4,4'-dihydroxy-3,3'-dimethyldiphenylmenthandicarboxylic acid diphenyl ester-5,5 ', 24.87 g and 98.0 g of cresol DAB 6 is placed in a with a distillation attachment, template and stirrer equipped flask. The apparatus is opened three times, each time after evacuation to about 20 torr, charged with nitrogen. Then heat with stirring at normal pressure to 75 ° C and increases the temperature every 15 minutes by 250C. It is held for 30 minutes at about 25oC, with phenol and cresol distilling off. then the pressure is reduced by 150 torr every 15 minutes and the mixture is stirred at about lo Torr another 30 minutes. The melt obtained in this way is yellowish and highly viscous. The product obtained after cooling has a rel. Viscosity of 1.31. The polyamide can be obtained crystallized from a cresol solution by precipitation with methanol and then melts at 2150C. It dissolves in Dimethylformamti, Tetrahydrofuran, Dimethyl sulfoxide, cresol, pyridine and methanolic aqueous sodium hydroxide solution, however, is insoluble in z. B. ethylene chloride, chlorobenzene and benzene.

Example 2 Polyamide from 4,4'-dihydroxy-3,3'-dimethyldiphenylmethane-dicarboxylic acid diphenyl ester-5,5 ' and m-xylylenediamine.

A mixture of 100.33 g of 4,4'-dihydroxy-3,3'-dimethyldiphenylmethane dicarboxylic acid diphenyl ester-5,5 ', 30.04 m-xylylenediamine and loo g cresol DAB 6, as described in example 1, implemented. A pale yellow at 250 ° C is obtained, highly viscous melt. The product has a rel. Viscosity of 1.295. Through failures with methanol from a cresol solution, a crystalline product is obtained, which at 22o - 225 0C melts. It dissolves in dimethylformamide, tetrahydrofuran, dimethyl sulfoxide, Cresol, pyridine and methanolic aqueous Caustic soda, however, is insoluble in z. B. methylene chloride, ethylene chloride, tetrachloroethane, o-dichlorobenzene and benzene.

Example 3 Polyamide from 4,4'-dihydroxy-3,3'-dimethyldiphenylmethanedicarboxylic acid diphenyl ester-5,51 and bis-p- (2-aminoethyl) benzene.

A mixture of 97.17 -g 4.41-dihydroxy-3, 31 -dimethyldiphenylmethanedicarboxylic acid diphenyl ester-5,5 ', 35.11 g of bis-p-2-aminoethyl) benzene and 98 g of cresol DAB 6 is in a flask with Given the distillation attachment, receiver and stirrer. The apparatus is used three times, each time after evacuation to about 20 torr, filled with nitrogen.

The mixture is then heated to 75 ° C. with stirring and the temperature is increased after 15 minutes around 25 ° C. It is held at 25oC for 30 minutes, with phenol and Distill off the cresol. The pressure is then reduced every 15 minutes 150 Torr and stir at lo Torr for another 3/4 hour. The product crystallizes, when about 95% of the phenol-cresol mixture has distilled off, whereby it becomes milky-cloudy will. One dissolved in cresol in the heat and restored by adding methanol shows precipitated and thereby crystallized sample dried at 120 ° C. in a vacuum a melting point of 190 - 202 ° C. The rel. Viscosity is 1.2o. One of one Foil cast with phenol solution dissolves in cresol, pyridine and methanolic aqueous solution Caustic soda, however, is insoluble in z. B. methylene chloride, ethylene chloride, o-dichlorobenzene, Dioxane, dimethyl sulfoxide, benzene and acetone. with the slide in some cases through Crystallization becomes cloudy.

Example 4 The polyamides described below are made according to in Example 1 specified procedure prepared.

The table shows the change in solubility when the content is changed on phenolic hydroxyl groups. a) Mixed polyamide from 80 mol% 4,4'-dihydroxy-3,3'-dimethyldiphenylmzthandicarboxylic acid diphenyl ester-5,5 ' (I), 20 mol% isophthalic acid (II) and loc mol% hexamethylenediamine-1,6 (III) 18.73 Parts by weight I 0.80 mol 3.18 "" II o, 20 mol 5.980 "" III 1, o3 mol Rel. Viscosity 1,300. b) Mixed polyamide from 50 mol% I, 50 mol% II and 100 mol% III 11.79 parts by weight I 0.50 moles 8.01 "" II o.50 moles 6.25 "" III 1.03 moles Rel. Viscosity 1.312. c3 Mixed polyamide from 30 mol% I, 70 mol% II and 100 mol% III 7.45 parts by weight I 0.30 11.82 moles "" II 0.70 moles 6.347 III 1.03 moles REl. Viscosity 1.365 d) Mixed polyamide from 20 mol% I, 80 mol% II and 100 mol III 4.82 parts by weight I 0.20 Mol 13.09 "" II 0.80 Mol 6.153 "" III 1.03 Mol Rel. Viscosity 1.312 Table Solvent Polyamide according to Example 1 4a 4b 4c 4 d n-NaOH 1. n.l. n.l. n.l. n.l.

(oily) (crystalline) (crystalline) n-NaOH / CH3OH 1. 1. 1. swells to the left.

(1: 1) 3 (swells) n-NaOH / C2H5OH 1. 1. 1. swells to the left.

(1,1) (swells) n-NaOH / n-C3H7OH 1. 1. 1. 1. w.l.

(1,1) (slightly cloudy) (cloudy) n-NaOH / iso- 1. 1. 1. 1. w.l.

C3H7OH (1: 1) (cloudy) 1. = soluble w.l. = sparingly soluble n.l. = not soluble

Claims (1)

Claim method for the production of high molecular weight, thread-forming, polyamides containing hydroxyl groups by polycondensation of hydroxyl groups polyamide-forming starting materials, optionally in a mixture with hydroxyl group-free, polyamide-forming starting materials, at polyamide-forming temperatures and optionally reduced pressure, characterized in that the hydroxyl group-containing, polyamide-forming starting materials Dihydroxyaryl -di carbonsäurees ter, preferably Aryl ester, is used.