AU654611B2

AU654611B2 - Aromatic copolyamides, processes for their preparation and structures formed therefrom

Info

Publication number: AU654611B2
Application number: AU31995/93A
Authority: AU
Inventors: Karl Heinrich; Holger Jung; Peter Klein; Georg-Emerich Miess
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1992-01-27
Filing date: 1993-01-25
Publication date: 1994-11-10
Anticipated expiration: 2013-01-25
Also published as: BR9300290A; EP0553755A3; MX9300408A; ATE180806T1; EP0553755B1; EP0553755A2; SK383792A3; CZ383792A3; ES2134222T3; JPH05339369A; DE59309617D1; AU3199593A; CA2088115A1

Abstract

The invention relates to aromatic copolyamides which are soluble in organic polyamide solvents and contain the recurring structural units of the formulae Ia, Ib, Ic and optionally Id: [-OC-R<1>-CO-NH-R<2>-NH-] (Ia) <IMAGE> [-OC-R<1>-CO-NH-R<3>-NH-] (Id) where R<1> and R<2> are principally unsubstituted divalent aromatic radicals whose valence bonds are in the para-position or in a comparable coaxial or parallel position to one another, X is a group of the formula -S-, -SO2-, -CO- or -O-, Y has one of the definitions given for X, R<3> is a radical of the formula II, of the formula III, of the formula IV and/or of the formula V <IMAGE> in which Hal is a halogen atom, and R<4> is C1-C6-alkyl, C1-C6-alkoxy or halogen, and where the molar proportions of the recurring structural units Ia, Ib, Ic and Id are fixed within selected limits. Shaped articles made from the copolyamides according to the invention are distinguished by good mechanical properties; in particular, fibres can be produced which have extremely high tear strengths and knot strengths.

Description

Rlogjulalon 32(2)

AUSTRALIA

Patents Act 1990 654611

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged:

S

S S

S

Invention Title: AROMATIC COPOLYAMIDES, PROCESSES FOR THEIR PREPARATION AND STRUCTURES FORMED THEREFROM *5 S. 55555*

S

S.

S S 555 S. S

S*

S.

The following statement is a full description of this invention, including the best method of performing it known to :-US 1'IOCHST AKTIENGESELLSCHAFT HOE 92/F 020 K Dr.AC/PP Desc:ciption Aromatic copolyamides, processes for their preparation and structures formed therefrom The invention relates to novel aromatic copolyamides of the dicarboxylic acid-diamine type, which can be spun from their solutions in organic solvents, and also to shaped structures produced therefrom, such as fibers, films and coatings which have a very high initial modulus (modulus of elasticity), and to processes for their preparation.

As is known, aromatic polyamides (aramids) are raw materials which have high stability to heat and high chemical stability as well as low combustibility. Thus, for example, fibers and films composed of such raw materials have very good mechanical properties, such as high strength and a high initial modulus (modulus of elasticity) and are very suitable for industrial fields of application for example for reinforcing plastics or as filter materials.

It is known that filaments or fibers composed of polyaramides which have high strengths and a high initial modulus can be produced if the amide bonds to the aromat- :ic nuclei are oriented coaxially or virtually parallel to one another, as a result of which rigid, rod-shaped 25 polymer molecules are formed.

A typical polyamide of this type is, for example, poly(pphenyleneterephthalamide). Filaments composed of this material are described, for example, in German Patent 22 19 703.

This polyamide has a number of advantages, but its preparation and its processing are very difficult.

Because of the insolubility in polar organic solvents ,0 J I 2 and specifically also in the presence of inorganic salts, such as calcium chloride or lithium chloride, as solubilizing agents, this polymer will precipitate out of the reaction medium shortly after it has formed. It must be isolated, washed, dried and then redissolved in a spinning solvent. The preferred solvent for the preparation of the spinning solutions is concentrated sulfuric acid, which gives rise to particular problems in relation to handling (safety at work, corrosion) and waste disposal.

Attempts have therefore been made to circumvent these difficulties by developing copolyamides which have good solubility in the known amide solvents and which can also readily be spun and the filaments of which, after stretching, are distinguished by high strength values and initial moduli.

S. Thus, for example, copolyamides obtained from terephthalic acid, p-phenylenediamine and 3,4'-diaminophenyl ether, which in amide solvents yield isotropic solutions 20 which can readily be spun, have been described in German Patent 25 56 883 and in German Offenlegungsschrift (German Published Specification) 30 07 063. As a result of very high stretching, the filaments acquire high strengths and moduli. Here it is the meta orientation and 25 the oxygen atom which give rise to the increased solubility. However, there is still a need for aramids which can be processed from known amide solvents to give fibers .which have high strengths and moduli.

It has now been found that selected aromatic copolyamides 30 of high molecular weight can be processed to give shaped structures which are distinguished by surprisingly good mechanical properties, such as high tear strengths, high initial moduli and low elongation at break.

3 The object on which the present invention is based is, therefore, to provide further aromatic copolyamides which are distinguished by good solubility in polyamide solvents and by good spinnability and which can be processed to give shaped structures which have good mechanical properties.

The copolyamides according to the invention are characterized by the presence of selected aromatic diamine components in selected proportions.

The present invention relates to aromatic copolyamides which are soluble in organic polyamide solvents and have an inherent viscosity of at least 3.5 dl/g, in particular at least 4.5 dl/g, measured at 25 0 C in solutions of 0.25 by weight of copolymer in N-methylpyrrolidone, containing the recurring structural units of the formulae Ia, Ib, Ic and optionally Id I-OC-R '-CO-N H-R-NH-] (ia), 0 -OC- R-CO-NH X NH (Ib) N H (Ib), CRiCO-NNH- (c) (Id)

-OC-R

1 -CO-NH-R (Id) 4 in which at least 80 mol of all radicals R 1 with respect to the amount of these radicals in the copolymer, are an unsubstituted divalent aromatic radical, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position with respect to one another, and up to 20 mol of all radicals R 1 with respect to the amount of these radicals in the copolymer, are an unsubstituted divalent aromatic radical, the valency bonds of which are in the meta-position or in a comparable angled position with respect to one another,

R

2 is an unsubstituted divalent aromatic radical, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position with respect to one another, X is a group of the formula -SOz-, -CO- or, in particular, Y assumes one of the definitions given for X, in particular and S. 3 is a radical which differs from R 2 and is of the formula II and/or of the formula III and/or of the formula IV and/or of the formula V CO NH (III), Ho I R 4 4 0(IV),

S

in which Hal is a halogen atom and R 4 is C -C-alkyl,

C

1 -C6-alkoxy and/or halogen, and the proportion of recurring structural units Ia, Ib, Ic and Id, with respect to the sum of these structural units in the copolymer, is within the following limits: 5 recurring structural unit of the formula Ia: 40 to mol preferably 45 to 55 mol recurring structural unit of the formula Ib: 5 to mol preferably 35 to 45 mol recurring structural unit of the formula Ic: 5 to mol preferably 5 to 25 mol and recurring structural unit of the formula Id: 0 to mol preferably 0 or 5 to 20 mol If a copolymer comprises radicals in the meta-position, such as radicals R 1 or radicals of the formula IV in the meta-position, the amount of the recurring structural units of the formula Ib preferably ranges within the lower range of the indicated amount, for example 5 to mol If the copolymer according to the invention comprises recurring structural units of the formula Id, in particular those which comprise radicals of the formula IV, the amount of said units is preferably 5 to 15 mol and very particularly preferably 5 to 10 mol with respect to 20 the sum of the structural units Ia, Ib, Ic and Id.

Structural units of the formula Id can also comprise different radicals of the formulae II to V, for example radicals of the formula III and V, IV and V or III, IV and V.

If any radicals are divalent aromatic radicals the valency bonds of which are in the para-position or in a comparable coaxial or parallel position with respect to one another, said radicals are mononuclear or polynuclear aromatic hydrocarbon radicals or heterocyclic-aromatic 30 radicals, which can be mononuclear or polynuclear. In the case of heterocyclic-aromatic radicals, said radicals comprise, in particular, one or two oxygen, nitrogen or sulfur atoms in the aromatic nucleus.

6 Polynuclear aromatic radicals can be fused with one another or linearly bonded to one another via C-C bonds or via a -CO-NH- group.

The valency bonds which are in a coaxial or parallel position with respect to one another are in opposing directions. An example of coaxial bonds in opposing directions are the biphenyl-4,4'-ene bonds. Examples of parallel bonds in opposing directions are the naphthalene or 2,6-bonds, whilst the naphthalene 1,8-bonds are parallel and in the same direction.

Examples of preferred divalent aromatic radicals, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position with respect to one another, are mononuclear aromatic radicals which have free valencies in the para-position with respect to one another, in particular 1,4-phenylene, or binuclear, fused aromatic radicals which have parallel bonds in opposing directions, in particular 1,5- and 2,6-naphthylene, or binuclear aromatic radicals which are linked via a 20 C-C bond and have coaxial bonds in opposing directions, in particular 4,4'-biphenylene.

Particularly preferred radicals R 2 and R 2 are i" 1,4-phenylene.

If any radicals denote divalent aromatic radicals which 25 have valency bonds which are in the meta-position or in a comparable angled position with respect to one another, said radicals are mononuclear or polynuclear aromatic hydrocarbon radicals or heterocyclic-aromatic radicals, which can be mononuclear or polynuclear. In the case of heterocyclic-aromatic radicals, said radicals comprise, in particular, one or two oxygen, nitrogen or sulfur atoms in the aromatic nucleus.

7 Polynuclear aromatic radicals can be fused with one another or can be linked to one another via C-C bonds or via bridge groups, such as, for example, -CH 2 -CO-NH-, -CO- or -SO 2 Examples of polynuclear aromatic radicals in which the valency bonds are in an angled position comparable to the meta-position are 1,6-naphthylene, 2,7-naphthylene or 3,4'-biphenylene.

A preferred example of a mononuclear aromatic radical of this type is 1,3-phenylene.

Examples of Hal substituents in radicals of the formula II or V are bromine and in particular chlorine.

R

4 is preferably methoxy, and in particular methyl.

In order to prepare the copolyamides comprising the 15 recurring structural units Ia, Ib, Ic and, optionally, Id, a dicarboxylic acid dichloride of the formula X is appropriately reacted with a mixture of the diamines of the formulae VI, VII, VIII and, optionally, IX C I-OC-R -COC I HN-R 2

-NH

2

(VI),

Hp X H HN Y YR NH 20 H 2 (VII), (VIII),

H

2 N-R-NH2

(IX),

in which the radicals R 1 to R 3 as well as X and Y have the AN meaning defined further above.

The dicarboxylic acid dichloride of the formula X and the S 5 individual diamine types can also be used in the form of 8 mixtures.

For this reaction, the proportions of the diamines VI, VII and VIII and, optionally, IX are in each case to be chosen such that polyamides are formed which have the above-defined proportions of structural units of the formulae Ia, Ib, Ic and, optionally, Id.

It is self-evident to a person skilled in the art that the sum of all structural units derived from aromatic acids and the sum of all structural units derived from aromatic amines are essentially identical, i.e. that they differ by at most about 1 preferably by at most 0.2 and in particular are identical within the framework of the practical measurement and metering possibilities.

The molecular weight of the polyamides formed can be controlled, inter alia, via the selection of the propor- :.tions of aromatic acids to aromatic amines. These selection criteria are known to those skilled in the art in the polycondensi.ion field.

9999* 9 Examples of suitable aromatic dicarboxylic acids from which the dicarboxylic acid dichlorides of the formula X are derived are naphthalene-1,4-dicarboxylic acid, naphthalene-l,5-dicarboxylic acid, naphthalene-2,6dicarboxylic acid, biphenyl-4,4' -dicarboxylic acid 25 adE and in particular terephthalic acid.

Up to 10 mol of the dicarboxylic acid dichlorides can also be derived from divalent aromatic meta-radicals.

Examples of acids from which such dicarboxylic acid dichlorides are derived are naphthalene-1,6-dicarboxylic acid, naphthalene-1,7-dicarboxylic acid, naphthalene-2,7dicarboxylic acid, biphenyl-3,4'-dicarboxylic acid and in particular isophthalic acid.

-D)

I -9 Examples of suitable diamines of the formula VI are naphthalene-1, 4-diamine, naphthalene-1, 5-diamine, naphthalene-2,6-diamine, benzidine and in particular p-phenylenediamine.

The diamines of the formula VII (3,4'-diaminodiphenyl ether) and of the formula VIII (1,4-bis-(4-aminophenoxy)benzene) are known per se.

Examples of suitable diamines of the formula IX are 2chloro-1,4-phenylenediamine, 4,4'-diaminobenzanilide and m-phenylenediamine, 3,5'-dimethylbenzidine, chlorobenzidine or The copolymerization of the monomer compounds described above is generally carried out as solution polymerization.

15 To this end, the aromatic monomer compounds to be reacted .9 with one another are as a rule dissolved in an organic *solvent. The organic solvent preferably comprises at least one solvent of the amide type, such as, for ex- S. ample, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, tetramethylurea, N-methyl-2-piperidone, N,N'-dimethylethyleneurea, -tetramethylmaleimide, N-methyl- .q caprolactam, N-acetylpyrrolidine, N,N-diethylacetamid.

N-ethyl-2-pyrrolidone, N,N'-dimethylpropionamide, NI,' dimethylisobutylamide, N-methylformamide or N,N'-dimeth- 25 ylpropyleneurea. The preferred organic solvents N-methyl- 2-pyrrolidone, N,N-dimethylacetamide and a mixture of these compounds are of importance for the process according to the invention.

In a preferred embodiment of the solution polymerization, the aromatic monomer diamines are dissolved in an amide solvent. The solution thus obtained is then mixed with the at least one aromatic monomer compound in the form of an aromatic dicarboxylic acid dihalide, with vigorous 10 stirring, in order to initiate the copolymerization.

In this process the amide solvent i sed not only as solvent for the aromatic monomer compounds and the aromatic copolyamide obtained therefrom but also as acid acceptor for a hydrogen halide, for example for hydrogen chloride, which is formed as a by-product of the copolymerization of the aromatic monomer compounds. In some cases it can be advantageous to use an additive which promotes the solubility, for example a metal halide of one of the metals of Group I or II of the Periodic Table, which halide is added to the copolymerization mixture before, during or after the copolymerization.

Examples of such additives are alkali metal halides, such as lithium chloride, or alkaline earth metal halides, such as calcium chloride.

The polycondensation temperatures for the solution polymerization are usually between -20 0 C -nd +120 0

C,

preferably between +10 0 C and +100 0 C. Particularly good results are obtained with reaction temperatures of between +10°C and The sum of the concentrations of the aromatic monomer compounds in the polymerization mixture solution can be adjusted taking into account the desired degree of polymerization, the desired viscosity of the polymeriza- 25 tion mixture, the nature of the aromatic monomer compounds used, the nature of the solvent used and the desired polymerization temperature. The most favorable sum of the concentrations can be determined on the basis of a number of preliminary experiments for the course of the polymerization.

Polycondensation reactions are preferably carried out in such a way that 2 to 15, preferably 5 to 12, by weight of polycondensation product are present in the solution 11 after the reaction is complete. Particularly good results are obtained with concentrations of 5.0 to 8 by weight.

The molecular weight of the polymer, and thus also the viscosity of the reaction batch, increase in the course of the polycondensation reaction.

An adequate molecule chain length is reached if the viscosity of the polymer solution obtained from the polycondensation reaction corresponds to an inherent viscosity of the polymer greater than 3.5, preferably greater than 4.5 and particularly preferably greater than dl/g, in particular 5.5 to 8.0 dl/g.

Inherent viscosity is understood to mean the expression In 7rel -ir c In this expression, l,.L is the relative viscosity and c the concentration used, in g/100 ml.

For the purposes of the present invention, it is determined for solutions of, in each case, 0.25 of polymer in N-methylpyrrolidone at 25 0

C.

Insofar as it is used to prepare the aromatic polyamides according to the invention which have been described above, the process for the preparation of aromatic polyamides which has been outlined and is known per se is also a subject of the invention.

If the polymer solution has reached the viscosity required for further processing, the polycondensation reaction can be stopped in the conventional manner by adding monofunctional compounds, such as, for example, acetyl chloride. The hydrogen chloride formed, which is 12 bound in salt form to the amide solvent, can then be neutralized by adding basic substances.

Substances suitable for this purpose are, for example, lithium hydroxide and calcium oxide, but in particular calcium hydroxide.

The aromatic copolyamide obtained on carrying out the process according to the invention can be separated off from the copolymerization mixture by means of a separation process, for example by precipitation. In order to prepare a solution for shaping the copolyamide, the aromatic copolyamide obtained in this way is then dissolved in a suitable organic solvent, this process being designated the dissolving process for the preparation of .the shaping solution.

However, in those cases in which the solution polymerization process is used to prepare the aromatic copolyamide according to the invention, the copolyamide is completely dissolved in the solvent for the polymerization, because it is outstandingly soluble in said solvent. Therefore, 20 if the process according to the invention is used industrially it is advantageous to use the mixture obtained from the polymerization immediately as shaping solution for the aromatic copolyamide.

The aromatic copolyamide according to the invention is .i 25 outstandingly soluble in an organic solvent, for example in organic solvents of the amide type, and has outstanding resistance to heat and superior resistance to chemicals. The aromatic copolyamide according to the invention is particularly useful for the production of diverse shaped articles, for example fibers, films and coatings, which are likewise a subject of the invention.

Within the framework of this description the term "fibers" is to be understood in its broadest meaning; 13 thus, the term also covers, for example, filaments or staple fibers of any desired denier.

Within the framework of this description, the term "films" is likewise to be understood in its broadest meaning; thus, it also covers, for example, embodiments of diverse thickness, such as sheets or membranes.

The shaped structures not only have outstanding resistance to heat and resistance to chemicals but also have superior mechanical properties, for example in respect of the tensile strength, the abrasion resistance and the modulus of elasticity. The solution of the aromatic copolyamide can also be used in diverse ways, for example for the production of fibers, sheets, sheet-like elements, fibrous materials and other shaped articles.

The solvent used in the process for the preparation of the shaping solution of the aromatic copolyamide is preferably a solvent of the amide type, in particular the solvents of the amide type which have been mentioned S"further above, or a mixture of two or more of the said compounds.

I For the preparation of the shaping solution it is advanto ageous if the concentration of the aromatic copolyamide is kept within a range between 4 and 15 by weight, in particular between 5 and 12 by weight. If necessary, 25 the shaping solution can comprise an additive to promote the solubility, it being possible to use at least one metal halide of a metal of Groups I and II of the Periodic Table, for example lithium chloride, calcium chloride or magnesium bromide, specifically in a concentration of between 0.2 and 10 preferably of between and 5 with respect to the total weight of the shaping solution. The additive to promote the solubility also promotes the stability of the shaping solution at elevated temperature.

14 Shaping of the shaping solution to give a shaped article can be carried out by any suitable dry process, wet process or dry/wet process. In the cases in which a wet process is used in order to shape the shaping solution, for example to give filaments, the shaping solution or in this case the spinning solution is extruded through a die, for example a spinneret, into a coagulating liquid. With this procedure it is usually advantageous if the coagulation liquid is composed of water or of an aqueous solution containing a polar organic solvent. The polar organic solvent can be selected from the same amide solvents which are customarily used for dissolving the aromatic copolyamide.

The polar organic solvent used in the coagulation liquid is preferably the same solvent as is contained in the shaping solution. The coagulation liquid is preferably used at a temperature between 0 0 C and the boiling point of the coagulation liquid under atmospheric pressure.

The polar organic solvent is preferably present in the coagulation liquid in a concentration of less than 70 "*by weight, in particular less than 50 by we.ight.

The shaping process explained above is particularly suitable for the production of films or fibers from a shaping solution.

25 When producing fibers from the aromatic copolyamide, the shaping or spinning solution is extruded through a spinning head which has multiple spin orifices, the filament-form streams of the spinning solution being solidified in one of the coagulation liquids indicated above (wet process) or in an atmosphere promoting evaporation (dry process). A variant which is also suitable is the "dry jet/wet spinning process", as is described, for example, in US-A-34 14 645. A conventional horizontal or vertical wet spinnin(. machine, a dry jet wet spinning 15 machine or a spinning machine in which the material flow is downward under stress can be used for spinning.

In the case of wet spinning of an aromatic copolyamide according to the invention, the coagulation is preferably effected using a coagulation liquid containing an additive to promote coagulation, this coagulation being followed by a further coagulation step, in the course of which the coagulating filaments of the aromatic copolyamide are passed into a water bath which is kept at a temperature of between 0 and 100 0

C.

The additional coagulation step serves to complete the coagulation by removal of the solvent. In addition, additives to promote coagulation, if such substances are used, are washed out of the coagulated filaments.

It is clear from the above description that the aromatic copolyamide according to the invention can be processed to give filaments without any problems, using conventional spinning processes and equipment, without a .S hazardous or harmful solvent, such as, for example, S 20 concentrated sulfuric acid, having to be used.

I Consequently, the risks for the operating personnel are reduced. In addition, the filaments produced from the copolyamide according to the invention have a dense internal structure.

The shaping solution can also be processed to give a film using conventional fanning or extruding processes.

Fibers or films which are produced by the shaping processes indicated above are usually subjected to a stretching operation, by means of which not only the mechanical properties, such as, for example, the tensile strength and the modulus of elasticity, but also the thermal properties, such as, for example, the stability 16 to heat, of the filaments or films produced in this way are improved.

Filaments composed of the aromatic copolyamides according to the invention are as a rule stretched in order to obtain a high mechanical strength and a high modulus of elasticity. The stretching ratio is usually about 1:6 to 1:20. The stretching temperature is as a rule between 250 and 550°C, preferably between 350 and 500"C.

Stretching can be carried out in a single step, in two steps or in several steps and a hotplate or a cylindrical heating device can be used for heating. In addition, the stretched filaments or films can be subjected to a further heat treatment at the same temperature or a higher temperature in order to improve the crystalline 15 structure. In this context it is pointed out that the aromatic copolyamide according to the invention is not only surprisingly advantageous with respect to its solubility in conventional organic solvents but can also be stretched under "mild" operating conditions without 20 any problems after the production of the fibers or films.

The fibers obtainable from the copolymers according to the invention are distinguished by high tear strengths and initial moduli and by low elongations at break.

A further preferred subject of the present invention S* 25 comprises fibers composed of the copolymers according to the invention, which have a tear strength of about 90 to 250 cN/tex, in particular 150 to 250 cN/tex, an initial modulus, with respect to 100 elongation, of about 25 to N/tex, in particular 35 to 50 N/tex, and an elongation at break of about 3 to 7 in particular 4 to 6 It has been found, surprisingly, that fibers which have high transverse strength values not obtained hitherto for aramides and which have a combination of exceptionally 17 high tear strength and transverse strength can be produced from the copolyamides according to the invention by using particular stretching conditions. The loop strength (in accordance with DIN 53843) or the knot strength (in accordance with DIN 53842 Part 1) can be used as a criterion for the transverse strengths.

Preferred fibers composed of the copolyamides according to the invention have knot strengths of 25 to 80 cN/tex, in particular of 50 to 80 cN/tex, and/or loop strengths of 40 to 130 cN/tex, in particular of 85 to 120 cN/tex.

Very particularly preferred fibers composed of the copolyamides according to the invention have tear strengths of more than 200 cN/tex, in particular of 200 to 250 cN/tex, and loop strengths of more than 80 cN/tex, 15 in particular of 85 to 120 cN/tex.

S: These particularly preferred fibers are obtainable by stretching the spun fibers at elevated temperature and using a spin finish preparation which is stable under the stretching conditions. Such preparations essentially 20 contain a particulate, inert inorganic material which lowers the sliding friction between the fibers during the stretching process. These preparations are usually applied to the fibers from an aqueous suspension and a uniform layer of said inorganic material is then produced 25 around the fibers by drying. Examples of suitable inorganic and inert particles are graphite, talc, colloidal silica, water-repellent silica, mica, hydrated magnesium silicate or aqueous dispersions containing magnesium silicate and an aqueous gel-forming inorganic compound, such as aluminum silicate.

Examples of such preparations are described in JP-A-60-239,522, JP-A-60-239,523 and EP-A-121,132.

18 Stretching of the aramid fibers pretreated in this way is generally carried out at fiber temperatures of higher than 300'C, preferably at 350 to 550°C. The degrees of stretching for the production of these particularly preferred aramide fibers are usually 1:8 to 1:20, preferably 1:9 to 1:15.

The invention also relates to such fibers and a process for their production.

The fibers composed of an aromatic copolyamide according to the invention, which have outstanding mechanical and thermal properties and are distinguished by a high stretchability, can be used industrially in very diverse ways, for example for reinforcing plastics, in particular as reinforcing materials for the fabric inserts in car 15 tires and other rubber articles, as heat-resistant insulating materials, for the production of filter fabrics and as lightweight insulating materials. Films composed of an aromatic copolyamide according to the invention can be used as heat-resistant electrical 20 insulating materials, in particular for the production of S'membranes, for example as support material for separation membranes.

Further features and advantages of the invention are explained in more detail below with the aid of examples.

25 However, it is to be understood that the invention is not restricted to the illustrative examples. On the contrary, numerous possibilities for modifications and/or supplements are available to a person skilled in the art, taking the illustrative examples as a basis, without having to go beyond the basic concept of the inventicn.

19 Example 1 Aromatic copolyamide obtained from 100 mol of terephthalic acid dichloride, 50 mol of p-phenylenediamine, mol of 1,4-bis-(4-aminophenoxy)-benzene and 25 mol of 3,4'-diaminodiphenyl ether.

162.2 g (1.5 mol) of p-phenylenediamine, 150.2 g (0.75 mol) of 3,4'-diaminodiphenyl ether and 219.3 g (0.75 mol) of 1,4-bis-(4-aminophenoxy)-benzene are dissolved, under nitrogen, in 14042 g of N-methylpyrrolidone and 607.3 g (3 mols) of terephthalic acid dichloride are added in the course of 20 minutes at between 35 0 C and 55"C. When the desired viscosity 5.5 dl/g) is obtained, the polycondensation reaction is stopped by adding 4.7 g of acetyl chloride and the reaction mixture is then neutralized with 328.2 g of calcium oxide (55 strength suspension in NMP). The solution is stirred further at 120*C. The solution is filtered, degassed and spun wet. To this end, it is spun at a rate of 16 m/min from a die which has 100 orifices 20 each 0.1 mm in diameter into a coagulation bath comprising a 35 solution of N-methylpyrrolidone in water, which is at 80"C. The resulting filaments are stretched to 11 times their length through two water baths, a washing machine, via a dryirlg godet and finally over a hot plate at temperatures of 400 to 440 0

C.

The filament linear density is 1.91 dtex for a tear strength of 190 cN/tex, an elongation of 4 and an initial modulus of 41 N/tex, with respect to 100 elongation.

Examples 2 to 37 Further aromatic copolyamides are produced, spun and tested in accordance with the procedure described in Example 1. The diamines used, the proportions thereof, the solution viscosities of the resulting polymers, the 20 spinning conditions and properties of the resulting f ibers are given in Table 1 below. The following abbreviations are used for the monomers in Table 1:

TPC

Ipc

NDC

PPD

3,4 '-DADPE

BAPOB

4,4'-DABA Cl-PPD DM B =terephthalic acid dichloride =isophthalic acid dichloride 6-naphthalenedicarboxylic acid dichloride =p-phenylenediamine =3,4'-diaininodiphenyl ether =1 ,4-bis- (4-aminophenoxy) -benzene =4,4 '-diaminobenzanilide =chloro-para-phenylenediamine =m-phenylenediamine 3,5 '-dimethylbenzidine 4.

4 4 44 .4 4 .4 4. 4 4 *4 44 4 4 4 4 .44.

4 4.

4 44 4 444 4 4. 4 4 44

I

21

S

4

S

.5 S. *4

S

Example No. 2 3 4 5 6 7 8 9 TPC (mol 100 100 100 100 100 100 100 100 IPO (mol 0 0 0 0 0 0 0 0 NDC (nol 0 0 0 0 0 0 0 0 PPD (mol 55 50 50 50 50 50 50 3141-DADPE (mol 22.5 20 40 30 20 30 20 BAPOB (mol 22.5 30 10 20 20 10 20 4,4'-DABA (mol 0 0 0 0 0 0 10 0 Cl-PPD (mol 0 0 0 0 10 10 0 0 Spinning solution 6 6 6 6 6 6 6 6 concentration Inherent viscosity 6.2 6.5 6.3 4.3 6.5 5.8 6.0 5.9 (dl/g) in NMP4 0.25 strength at 250C Strength (cN/tex) 143 134 184 160 124 170 163 190 Elongation 3.8 3.5 3.4 3.0 3.3 3.7 Modulus (N/tex) 41 34 50 44 41 52 41 41 Stretching 1: 8 9 10 15 14 10 14 14 S. iS S S

S

SSS*

S S S S. S

S

S.

S S S. S 22 *6 0* 6O Example No. 10 11 12 13 14 15 16 17 TPC (mol 100 100 100 100 100 100 100 100 IPC (mol 0 0 0 0 0 0 0 0 NDC (mol 0 0 0 0 0 0 0 0 PPD (mol 50 60 50 50 45 40 45 3,4'-DADPE (mol 17.5 10 45 35 40 50 45 BAPOB (mol 17.5 30 5 15 15 10 10 4,4'-DABA (mol 15 0 0 0 0 0 0 0 Cl-PPD (mol 0 0 0 0 0 0 0 0 Spinning solution 6 6 10 8 10 10 6 12 concentration(% inherent viscosity 6.4 6.1 4.5 4.6 3.6 3.8 6.1 6.3 (dl/g) in NMP 0.25 strength at 25 0

C

Strength (cN/tex) 164 98 203 197 188 184 165 176 Elongation 4.3 3.8 3.7 3.5 3.5 3.4 3.1l Modulus (N/tex) 45 27 52 '48 52 50 48 Stretching 1: 7 4 14 12111 t18 9 13 *0 0 *600: .00.

23 o oo oooo• Example No. 18 19 20 21 22 23 24 TPC (mol 100 80 85 85 80 80 75 100 IPC (mol 0 20 15 15 10 10 10 0 NDC (mol 0 0 0 0 10 10 15 0 PPD (mol 50 60 60 60 60 65 60 3,4'-DADPE (mol 22.5 10 10 15 15 10 10 BAPOB (mol 22.5 30 30 25 25 25 30 4,4'-DABA (mol 5 0 0 0 0 0 0 0 C1-PPD (mol 0 0 0 0 0 0 0 0 Spinning solution 6 6 6 6 8 6 6 12 concentration Inherent viscosity 7.0 6.1 6.1 5.6 5.4 5.8 6.1 6.3E (dl/g) in NMP 0.25 strength at Strength (cN/tex) 169 99 94 94 96 94 95 182 Elongation 3.8 4.8 4.3 4.2 3.9 3.8 4.3 3.2 Modulus (N/tex) 40 24 27 29 30 29 27 Stretching 1: 15 5 4.5 4.5 4.6 5.3 4.2 18 r 24

S

*SSS**

S S Example No. 26 27 28 29 30 31 32 33 TPC (mol 100 100 100 100 100 100 100 100 P -mo 0 0- IPC (mol 0 0 0 0 0 0 0 0 PPD (mol 50 50 45 45 45 50 45 3,4'-DADPE (mci 35 35 50 35 30 30 30 BAPB (mol 15 15 5 15 15 10 10 4,4'-DAB3A (mci 0 0 0 0 0 0 0 0 MPD (mol 0 0 0 5 10 10 15 Spinning solution 6 8 10 6 6 6 6 6 concentration Inherent viscosity 6.8 5.01 4 5.4 4.8 4.5 5 5.1 (dl/g) in NMP Strength (cN/tex) 248 223 203 210 188 202 160 170 Elongation 5 4.4 3.8 5 5.4 5.6 5 5.2 Modulus (N/tex) 50 48 52 42 36 38 35 36 Stretching 1: 12 9 10 95 8 7 10 Loop strength 114 86 87 84 42 (cN/tex) Knot strength 69 59 53 63 27 (cN/tex) o".S 0. go 0 25 Example No. 34 35 36 37 TPC (mol.% 100 100 100 100 IPC (mol 0 0 0 NDC (mci 0 0 0 0 PPD (mol %)45 35 40 3,4'-DADPE (mol 30 30 25 BAPOB (mol 10 10 5 4,4'-DABA (mol 5 5 0 MPD (mol 0 0 5 0 DMIB (mol 20 20 20 Spinning solution 6 6 6 6 concentration(% Inherent viscosity 6.32 6.10 6.30 6.33 (dl/g) in NI4P Strength (cN/tex) 189 174 198 146 Elongation 3.2 3.6 Modulus (N/tex) 59 60 60 67 Stretching 1: 7 11 10 7 *9

Claims

1. An aromatic copolyamide which is soluble in organic polyamide solvents and has an inherent viscosity of at least 3.5 dl/g, in particular 4.5 dl/g, measured at 25"C in solutions of 0.25 by weight of copolymer in N-methylpyrrolidone, containing the recurring structural units of the formu- lae Ia, Ib, Ic and optionally Id i-OC-R'-CO-NH-R -NH-1 I a), -OC-R'-CO-NH -X -NH- (Ib), -OC-R'-CO-NH Y Y NH- I c [-OC-R'-CO-NH-R (Id) in which at least 80 mol of all radicals R 1 with respect to the amount of these radicals in the copolymer, are an unsubstituted divalent aromatic radical, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position with respect to one another, and up to mol of all radicals R 1 with respect to the amount of these radicals in the copolymer, are an unsubstituted divalent aromatic radical, the valency bonds of which are in the meta-position or in a S S .9 L i -27 comparable angled position with respect to one another, R 2 is an unsubstituted divalent aromatic radical, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position with respect to one another, X is a group of the formula -SO 2 -CO- or, Y assumes one of the definitions given for X, and R 3 is a radical which differs from R 2 and is of the formula II and/or of the formula III and/or of the formula IV and/or of the formula V o CO-NH-- (III), Ho i S S o 4 S R 4 R 4 in which Hal is a halogen atom and R 4 is C,-C-alkyl, 15 Cl-C-alkoxy and/or halogen, and the proportion of q recurring structural units Ia, Ib, Ic and Id, with respect to the sum of these structural units in the copolymer, is within the following limits: recurring structural unit of the formula Ia: 40 to 65 mol recurring structural unit of the formula Ib: 5 to mol recurring structural unit of the formula Ic: 5 to mol and recurring structural unit of the formula Id: 0 to mol 4 3 28

2. The aromatic copolyamide as claimed in claim 1, wherein X and Y are

3. The aromatic copolyamide as claimed in claim 1, wherein at least 90 mol of all radicals R 1 preferably 100 mol of the radicals R 1 with respect to the amount of these radicals, are 1,4-phenylene and up to 10 mol of all radicals R 1 with respect to the amount of these radicals, are 1,3-phenylene.

4. The aromatic copolyamide as claimed in claim 1, wherein R 2 is 1,4-phenylene.

The aromatic copolyamide as claimed in claim 1, wherein at least 90 mol of all radicals R 1 preferably 100 mol of the radicals R 1 with respect to the amount of these radicals, are 1,4-phenylene 15 and the proportion of recurring structural units Ia, Ic and Id, with respect to the sum of these structural units, is within the following limits: recurring structural unit of the formula Ia: 45 to 55 mol recurring structural unit of the fornula Ib: 35 to 45 mol recurring structural unit of the formula Ic: 5 to mol and recurring structural unit of the formula Id: 0 or S 25 to 20 mol

6. The aromatic copolyamide as claimed in claim 1, wherein R 3 is a radical of the formula IV and wherein the proportion of the recurring structural unit of the formula Id is 5 to 15 mol very particularly preferably 5 to 10 mol with respect to the sum of the structural units Ia, Ib, Ic and Id. J 29

7. A process for the preparation of the copolyamide as claimed in claim wherein a dicarboxylic acid dichloride of the formula X is reacted with a mixture of the diamines of the formulae VI, VII, VIII and, optionally, IX CI-OC-R -COC H 2-R 2 (VI), HN -X-NH HzN- /-NH (VII), (VIII), H 2 N-R3-NH 2 (ix), in which the radicals R 1 to R 3 as well as X and Y 10 have the meaning defined in claim 1 and wherein the molar proportions of the diamines of the formulae VI to IX, with respect to the sum of the proportions of these diamines, are selected within limits such that a copolyamide having the proportions of recurring 15 structural units of the formulae Ia, Ib, Ic and Id defined in claim 1 is formed. 9* S

8. A shaped structure composed of an aromatic copolyamide as claimed in claim 1.

9. The shaped structure as claimed in claim 8, which is 20 a fiber, film or coating.

The shaped structure as claimed in claim 8, which is a fiber which has a tear strength of about 90 to 250 cN/tex, an initial modulus, with respect to 100 elongation, of about 25 to 60 N/tex and an elongation at break of 3 to 7

11. The shaped structure as claimed in claim 8, which is Sa fiber which has a tear strength of more than 200 cN/tex, in particular of 200 to 250 cN/tex, and a loop strength of more than 80 cN/tex, in particular of 85 to 120 cN/tex.

12. A process for the production of fibers as claimed in claim 11, comprising the measures: i) production of fibers composed of an aromatic copolyamide as claimed in claim 1, ii) application of an aqueous suspension of a preparation which is stable under the stretching conditions and which essentially comprises a particulate, inert inorganic material which lowers the sliding friction between the fibers during the stretching operation, 15 iii) drying of the fibers pretreated in this way, so that a layer of said inorganic material forms around the fibers, and iv) stretching the fibers pretreated in this way at temperatures of higher than 300°C, in 20 particular 350 to 550"C. 80006

13. The use of fibers composed of an aromatic copolyamide as claimed in claim 1 to reinforce plastics, in particular to reinforce elastomers.

14. The use of a film composed of an aromatic 25 copolyamide as claimed in claim 1 for the production of membranes. DATED this 25th day of January

1993. HOECHST AKTIENGESELLSCHAFT WATERMARK PATENT TRADEMARK ATTORNEYS "THE ATRIUM" 290 BURWOOD ROAD HAWTHORN. VIC. 3122. -31 HOE 92/F 020 K Abstract Aromatic copolyamides, processes for their preparation and structures formed therefrom Aromatic copolyamides are described which are soluble in organic polyamide solvents and which comprise the recurring structural units of the formula la, Ib, Ic and, optionally, Id S-OC-R -CO-NH-R NH- (Ia), 9 -OC-R -CO-NH X N (Ib), ^NH- (Ic) [-OC-R -CO-NH-R (Id) in which R 1 and R 2 are mainly unsubstituted divalent aromatic radicals, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position with respect to one another, X is a group of the formula -SOz-, -CO- or Y assumes one of the definitions given for X, and R 3 is a radical of the formula II, of the formula III, of the formula IV and/or of the formula V Ho I (II) f O 0 N (III) I (IV), S. 0 sa *040 0 00 0 in which Hal is a halogen atom and R 4 is Cl-C-alkyl, Ci-C-alkoxy or halogen, and the molar proportions of recurring structural units Ia, Ib, Ic and Id are fixed within selected limits. Shaped structures composed of the copolyamides according to the invention are distinguished by good mechanical properties and in particular fibers can be produced which have exceptionally high tear 10 strengths and knot strengths. 0 e so