DE1123103B - Process for stabilizing high molecular weight, linear polycondensates containing amide groups - Google Patents

Description

Process for stabilizing high molecular weight, linear, amide groups containing polycondensates The mechanical properties of high molecular weight, linear, Polycondensates containing amide groups are known to be increased by the influence Temperatures, deteriorated by oxygen or light.

Polycondensates of this type are therefore stabilized by adding, for example Phenols, amines and urea derivatives. Polyamide compounds are also used as stabilizers secondary polyamines such as N, N'-diphenyl-1,4-phenylenediamine, N, N'-diphenyl-2,7-naphthylenediamine or N-phenyl-NI'-benzylphenylenediamine, are known. A disadvantage of that kind stabilized polycondensates containing amide groups. that the in it Sweat contained stabilizers, migrate in documents or even extracted can be.

It is also known that nitrogen-containing polycondensation products can be used can refine by reacting them with resinous aminoplasts. In this finishing process however, crosslinked nitrogen-containing polycondensation products and their aging resistance are obtained is only marginally improved and its flow behavior compared to non-crosslinked Polycondensate is deteriorated.

It has now been found that high molecular weight, linear, amide groups polycondensates containing can advantageously stabilize by adding to the polycondensates 0.01 to 5 percent by weight, preferably 0.1 to 2 percent by weight, based on the polycondensates, condensation products of aliphatic aldehydes with secondary ones aromatic amines of the general formula 1 Ar-NH R in which Ar is an aryl radical and R for an aromatic, aliphatic or cycloaliphatic radical, which optionally may be substituted by inert substituents, and / or the general Formula II incorporates R '- NH ~ NH-R ", in which R' and R" are the same or different aromatic, aliphatic or cycloaliphatic radicals, optionally through inert substituents may be substituted, mean. It's an advantage of the polycondensates stabilized according to the invention, that the stabilizers contained therein of the type mentioned do not wander or sweat and under the processing conditions practically cannot be extracted.

Linear polycondensates within the meaning of the invention are for example those that can be produced in the usual way Polyurethanes, polyureas, polythioureas and, in particular, polyamides, as are customarily made from lactams with more than 3 carbon atoms in the ring, such as pyrrolidone, piperidone, caprolactam, capryllactam, Dodecyllactam, undecyllactam and oenanthlactam, or from o, w'-diamines and c (), ct) '-dicarboxylic acids with more than 3 carbon atoms between the functional groups, such as tetramethylenediamine, Hexamethylenediamine, octamethylenediamine, 4,4'-diamino-di-cyclohexylmethane and adipic acid, Pimelic acid, suberic acid, azelaic acid, sebacic acid and undecanedicarboxylic acid can be, as well as polyester amides. Such polycondensates generally have K values between 60 and 85.

Secondary amines of the general formula 1 are within the meaning of the invention those which contain a phenyl or naphthyl radical as aryl radicals, such as, for example Phenyl-B-naphthylamine, phenyl-A-naphthylamine, phenyl-isopropylamine, diphenylamine and, p'-dinaphthylamine.

Suitable secondary amines of the general formula II, in which R ' and R ″ denote aromatic radicals are, for example, N, N'-diphenyl-p-phenylenediamine and N, N'-di-B-naphthyl-p-phenylenediamine.

A corresponding suitable secondary amine in which R 'and R "are one Cycloaliphatic radical is, for example, N, N'-dicyclohexyl-p-phenylenediamine. Corresponding secondary amines in which R 'an aromatic and R "denotes a cycloaliphatic radical are, for example, N-phenyl-N'-cyclopentyl - p - phenylenediamine, N - phenyl - - cyclohexylp-phenylenediamine, N-phenyl-N'-cycloheptyl-p-phenylenediamine, N-phenyl-N'-cyclooctyl-p-phenylenediamine, N-phenyl-N'-cyclododecyl-p-phenylenediamine and N- (p-naphthyl) -N'-cyclohexyl-p-phenylenediamine. As a corresponding suitable secondary Amines in which R 'and R "are aliphatic radicals come, for example, N, N' - Di - sec.butyl - p - phenylenediamine and N, N'-diisoamyl-p-phenylenediamine in question.

Inactive substituents for the purposes of the invention are those those under the conditions of the production of polycondensates of the above Type or at their processing temperatures neither with the monomeric starting materials enter into a reaction with the finished polycondensates.

Such substituents are, for example, alkoxy groups, such as methoxy, Ethoxy and isopropoxy groups, as well as halogen atoms, such as fluorine, chlorine and bromine atoms, and alkyl, cycloalkyl and aryl groups.

Aliphatic aldehydes in the context of the invention are for example Monoaldehydes, such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde and 2-ethyl caproaldehyde, as well as dialdehydes such as glyoxal, malondialdehyde and succindialdehyde.

Amines and aldehydes of the type mentioned can be used in the customary manner equimolar amounts or using an excess of one component in an acidic or alkaline medium at room temperature or at an elevated temperature be converted to the products used as stabilizers.

Such reaction products can already be used during manufacture the polycondensates of the type mentioned above are added. But you can too add to the finished polycondensates. It is also possible to use the polycondensates In addition to such reaction products from amines and aldehydes, there are also customary additives, such as fillers, dyes, pigments and opacifiers to be added. The mixing can using conventional mechanical mixing devices, for example screw presses or kneaders. The conversion products the polycondensates optionally also in the form of their solution in suitable organic Solvents are added.

Polycondensates stabilized according to the invention, in particular polyamides, are suitable for the production of moldings, such as threads, fibers, bristles, foils, Films and structural parts such as gears, as well as coatings and household items. For example, polycaprolactam stabilized according to the invention is ideally suited for the production of tire cord.

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

EXAMPLE 1 To 100 parts of caprolactam, 1 part of a conventional one is added Way from 100 parts of N, N'-diphenyl-p-phenylenediamine and 27 parts of paraformaldehyde reaction product produced in an acidic medium. You then polycondense that Lactam in the usual way and spun the stabilized melt into threads of 320den. The threads are then converted into residues of monomers and oligomers in the usual way washed out.

The breaking load of the polycaprolactam threads (1) obtained is 2.1 kg, the elongation 21 01o and the tear length 59.2 km. The K value of the polycaprolactam is 70.7.

For comparison, polycaprolactam threads from 320 den (II) below Addition of 1 part of N, N'-diphenylp-phenylenediamine to 100 parts of caprolactam in otherwise produced in a corresponding manner.

Samples of the threads are used to examine the thermal stability I and II are each held for 3 hours at a temperature of 190 ° C. Then sample I shows a residual strength of 870 / o, sample II of 430 / o.

The residual strength is the ratio of in kilograms measured strength after exposure to strength before exposure in Percent.

Example 2 As described in Example 1, caprolactam is converted from 100 parts with the addition of 1 part of a conventional 100 parts phenyl-ß-naphthylamine and 32 parts of paraformaldehyde in an acidic medium obtained reaction product in Otherwise, threads of 344 den (III) are produced. Their breaking load is 1.93 kg, its elongation 26% and its tear length 50.4 km. The polycaprolactam has the K value 71.

For comparison, polycaprolactam threads from 344 den (IV) from 100 Parts of caprolactam and 1 part of phenyl-ß-naphthylamine under otherwise identical conditions manufactured.

The threads III and IV show after storage for 3 hours at 190 ° C Residual strength of III 760 / o and IV = 220 / o.

Example 3 As described in Example 1, 100 parts are converted into caprolactam with the addition of 1 part of a conventional 100 parts phenyl-ß-naphthylamine and 67 parts of 400 / dger aqueous formaldehyde solution in an alkaline medium Reaction product, which was then crosslinked in an acidic medium, threads (V) manufactured by 367 den. Their breaking load is 1.77 kg, their elongation 25% and their tear length 43.4 km. The K value of the polycaprolactam is 69. The threads have after 3 hours of storage at 190 "C a residual strength of 440 / o.

Example 4 100 parts of commercially available granulated polycaprolactam, whose relative viscosity is 2.68, are mixed with 1 part of a finely powdered, conventionally prepared condensation product from cyclohexylphenyl-p-phenylenediamine and formaldehyde mixed.

The mixture is smoked in a screw press at 2500 C and with a spinning pump through a nozzle, the ten openings, each 0.25 mm in diameter has pressed. The threads obtained are cooled and wound up in the usual way and stretched.

The threads have a residual strength after storage at 190 ° C. for 3 hours from 920 / ,.

Threads made from the same polycaprolactam without the addition of a stabilizer otherwise in the same way are produced, show after 3 hours Storage at 190 ° C has a residual strength of only 38O / o.

Claims (2)

PATENT CLAIMS: 1. Process for stabilizing high molecular weight, linear polycondensates containing amide groups with derivatives of secondary aromatic amines, characterized in that the derivatives of secondary aromatic amines are condensation products of aliphatic aldehydes with secondary aromatic amines of the general formula 1 Ar -NH-R in the Ar stands for an aryl radical and R stands for an aromatic, aliphatic or cycloaliphatic radical, which can optionally be substituted by inert substituents, and / or of the general formula II in which R 'and R "are identical or different aromatic, aliphatic or cycloaliphatic radicals, which may optionally be substituted by inert substituents, used in an amount of 0.01 to 5 percent by weight, based on the polycondensate. 2. Embodiment according to claim 1, characterized in that the Condensation products of aliphatic aldehydes and secondary aromatic amines already used in the polycondensation of the polycondensate-forming starting materials will. Publications considered: German Patent No. 865 058.