DE1929694B2 - OPTICALLY ANISOTROPIC MASSES OF AROMATIC POLYAMIDES - Google Patents

Description

30th

The invention relates to new, optically anisotropic masses consisting essentially of carbocyclic Aromatic polyamides exist in suitable liquid media. These masses are used to manufacture used by usable threads, fibers and foils. In particular, threads or fibers with exceptional Internal structure and extremely high tensile properties created.

The optically anisotropic compositions according to the invention contain components selected from the group of carbocyclic aromatic polyamides whose chain extending bonds are selected by each aromatic nucleus are essentially coaxial or parallel and oppositely directed, in appropriate liquid media, which are illustrated below, which may contain additives. The amount of polyamide in the mass exceeds the critical concentration point and is preferably at least about 5 percent by weight of the mass. These anisotropic masses are structurally and functionally of known polyamide "solutions" and are used for the production of high-strength moldings (e.g. threads or fibers), often without post-treatment after shaping (e.g. stretching), exceptionally suitable.

Threads or fibers produced from the above optically anisotropic masses are exceptional Internal structure and extremely high tensile properties characterized either in the state after Extrusion or after a heat treatment. The threads <> o or fibers have a low angle of orientation and / or high speed of sound. Threads or fibers according to the invention have orientation angles below 45 °, preferably below 35 ° and most preferably below 25 °, and / or sound velocity values of <«, at least 4 km / sec., preferably at least

6 km / sec. and most preferably at least

7 km / sec.

F i g. 2 and 3 further phase diagrams of masses according to the invention,

4 and 5 critical concentration points of special compositions according to the invention as a function of the inherent viscosity and

6 and 7 show the relationship between the Thread structure parameters orientation angle or speed of sound and an important physical one Property (initial modulus) of the thread.

The term "aromatic nucleus" used in the description of the invention is intended to be individual in a chain include linked aromatic rings and divalent aromatic radicals with fused rings. to the preferred polymers include carbocyclic aromatic polyamides with up to two aromatic polyamides Rings, including non-fused rings linked in a chain (e.g. 4,4'-diphenylene) or fused rings (e.g. 1,5-naphthalene), per amide linkage. The chain-lengthening ones Bonds of these aromatic rings are p-oriented and / or substantially coaxial or parallel and oppositely directed.

Polyamides which are highly preferred are those due to repeating units of the formula I

O O H H

Il Il 1 i

hC-R-C-N-R'-Nd

characterized where R and R '(when the chain extending bonds are substantially coaxial) under

- <f> - 1.4-phenylene and

- <> - <f> ■ 4.4'-diphenylene

are selected and wherein R and R '(when the chain extending bonds are substantially parallel are) under

1.5-naphthylene and

2.6-Naphlh> lcn

are selected, where R and R 'are the same or

can be different and can contain substituents on the aromatic nuclei.

Further highly preferred polyamides used in accordance with the invention are repeating Units of the formula II

C-R "-characterized, where R" under

I.
-N-

Hl)

1,4-phenylene and

4.4'-Diphenylenes

is selected. R ″ can also contain substituents on the aromatic nuclei.

Any substituents should and should not be reactive during the polymerization preferably also during the subsequent processing of the polymer, for example the heat treatment an object formed therefrom (for example, thermally), be non-reactive. One Such reactivity is undesirable in that they cause crosslinking of the polymer and the Can adversely affect mass and / or thread properties. Among the preferred non-reactive Substituents can be halogens (e.g. chlorine, bromine and fluorine), lower alkyl (e.g. Methyl, ethyl, isopropyl and n-propy!), Lower alkoxy (for example methoxy and ethoxy), cyano, acetyl and nitro should be mentioned. In general, it is preferred that no more than two suitable substituents (and more preferably no more than one suitable substituent) per aromatic nucleus.

Both homo- and mixed polyamides with substituted or unsubstituted aromatic cores, as described above, are well suited for the compositions according to the invention and the threads made therefrom. Copolymers with random distribution are preferred copolymers. The expression "with random distribution" means that the copolymer consists of molecules which contain a large number of units, which consist of two or more different types, in an irregular sequence. The units can be of the type AB (for example from p-aminobenzoyl chloride hydrochloride), AA (for example from p-phenylenediamine or 2,6-dichloro-p-phenylenediamine) or BB (for example from terephthaloyl- or 4,4'-bibenzoyl chloride) or mixtures thereof always under the condition that the stoichiometric requirements for high polymer formation are met. It is not necessary that the relative number of different types of unit in different molecules ode · ¹ of a single molecule is the same in different parts.

One or more of these polymers can be used in a suitable manner in the compositions according to the invention and filaments or fibers made therefrom are used, d. i.e., a single homopolymer Individual copolymer or homopolymer and / or mixed polymer mixtures are suitable.

Although the polymer chains described above are essentially composed of amide linkages (-CONH-) and aromatic ring nuclei, as described above, can be used to produce the Products according to the invention usable polymers also contain up to about 10% (molar basis) units, which do not meet the description cited above, for example aromatic polyamide-forming units, their kettenverlängerniie bonds other than coaxial or parallel and oppositely directed are, which can be m-oriented, for example, or ίο other links than amide linkages, for example Urea or ester groups.

Suitable aromatic polyamides include

Poly (p-benzamide),
Poly (p-phenylene terephthalamide),

Poly (2-chloro-p-phenylene terephthalamide),
Poly (2,6-dichloro-p-phenylene-2,6-naphthalamide),
Poly- (p-phenylene-p, p 'diphenyldicarbonamide),
Poly- (p, p'-phenylenbenzair.id),

Poly (1,5-naphthylene terephthalamide), ordered

aromatic mixed polyamides, for example
Mixed poly- (p, p'-diaminobenzanilide-terephthalamide) and mixed polyamides with random
Distribution, such as
Mixed poly (p-benzamide / m-benzamide) (95: 5)
be mentioned.

The designation of the positions of substituent groups on the aromatic nuclei of the polymers, useful in the present invention relates to the position (s) of the or the Substituents on the diamine, diacid or other reactants from which the polymer is made will. For example, there is a random end / end distribution of polymer-forming units in of the chain, if possible, encompassed by the name by which any given polymer is referred to herein will.

The polyamides have an inherent viscosity (such as

described below) of at least about 0.7 and preferably above about 1.0 and are thread-forming.

Polyamides with lower inherent viscosities can be used for films.

A preferred polyamide in the compositions of the invention is an essentially homopolymer Poly (p-benzamide), which consists essentially of repeating units of the formula III

C)

consists. It can easily be obtained from suitable monomers by certain polymerization processes which are dissolved in special solvents, which if desired lithium chloride and chain terminators may contain.

Polyamides useful in the invention can be prepared from suitable reactants by low temperature solution polymerization processes (i.e. under

(, o 60 "C and preferably from -10 to 30 ⁰ C) similar to the procedures described in US Pat. No. 30 63 966 for the preparation of poly (p-phenylene terephthalamide). For example, such polyamides can be prepared, by doing

6_s p-phenylenediamine or 2-chloro-p-phenylenediamine with polyamide-forming derivatives of terephthalic acid is made to react. This dicarboxylic acid will expediently in the form of their dihalides

which are readily prepared by known procedures, the diacid chloride usually is preferred.

The production of other useful polymers and copolymers is illustrated in the following examples.

To liquid media which can be used for the production of the anisotropic compositions according to the invention are include:

(1) Concentrated sulfuric acid, the concentration is greater than about 90 percent by weight, usually greater than 98 to 100 percent by weight H2SO4, or Oleum (i.e., concentrated sulfuric acid containing up to 20% or more free SCb), the additives may contain (e.g. NaHPCK Na2SÜ4, Potassium acetate, which can be present in an amount of 2 to 3 percent by weight of the total mass). Choosing the sulfuric acid concentration best suited for a particular mass production, based in part on the inherent viscosity of the polymer used.

(2) hydrofluoric acid, either alone or in combination with additives such as water (1 to 2 Percent by weight of the total mass), NaF or KF (1 to 2 percent by weight of the total mass), one inert chlorinated hydrocarbon (e.g. CH2Cl2) or mixtures thereof is used (in an amount up to 5 percent by weight of the total mass).

(3) chlorine, fluorine or methanesulfonic acids, alone or in combination with additives such as lithium chloride (up to about 2.5 weight percent) can be used.

Mixtures of two or more of the above liquid media can be used in suitable combinations can be used, for example mixtures of hydrofluoric acid and fluorosulfonic acid, of methanesulfonic acid and sulfuric acid or of oleum and chloro-, fluoro- or methanesulphonic acid.

The usual additives such as dyes, fillers, matting agents, UV stabilizers, antioxidants and the like., Can be incorporated with the polymer or copolymer or in the inventive Masses for the intended purposes are dispersed before molded articles are produced therefrom will.

Compositions according to the invention can expediently be produced by, for example, polyamide and the liquid medium (and, if present, additives) in a conventional manner (e.g. with stirring) are combined. Numerous suitable working methods used for the manufacture of specific compositions according to the invention are useful are illustrated in the examples.

The anisotropic compositions according to the invention can consist of a single anisotropic phase or of a Emulsion of anisotropic and isotropic phases in any dispersion ratio or degree of dispersion exist. Tiny amounts of undissolved polyamide can be present in these phases or in the emulsion. A "mass" is a molded body (for example thread or fiber-forming or film-forming) Polyamide / solvent system containing at least one of the above phases.

Anisotropic masses

When the constituents forming the compositions according to the invention are in specific concentration ranges are combined, the resulting masses are optically anisotropic; i.e., microscopic areas of the Masses are birefringent, larger mass samples depolarize linearly polarized light because of the light transmission properties the microscopic areas of the mass vary with direction. This property is linked to the fact that at least a part the mass is in a liquid crystalline or mesomorphic state. In "Industrial Research", May 1966, Pages 53 to 57 (G. H. Brown) describe that In many of their properties, liquid crystals lie between the liquid and the solid state. They have thus extraordinary structural arrangements, partly the order of crystals and the fluidity of liquids lend.

The compositions according to the invention show anisotropy while they are in the relaxed state. Conventional polyamide materials can indeed depolarize linearly polarized light if they are more substantial Shear effects are subjected (e.g. flow birefringence, whereby molecules in a solution are hydrodynamically oriented), but in the case of resting (i.e. stationary) samples, only those according to the invention show Masses of this phenomenon.

It is assumed that the elongated, stiff-chain aromatic polymers which are present in the anisotropic compositions according to the invention form essentially rod-like units (aggregates or bundles) in the liquid medium. This elongated, stiff-chain configuration of the polymer is indicated by the values of the exponent «in the Mark-Houwink equation [η] = KM * for dilute solutions of polymer with a lower molecular weight. In this known equation, [η] denotes the intrinsic viscosity, M the molecular weight and K and α constants for a given polymer / solvent system. The vast majority of polymers for which this equation has been applied in the literature have values below 0.9. Among the polymers that are used in the compositions according to the invention, an α value of 1.6 has been determined for poly (p-benzamide), measured on unfractionated polymer with an inherent viscosity in the range from 0.4 to 2 and at weight average molecular weight determinations made in sulfuric acid (95 to 98 weight percent). If a given system exceeds a certain critical concentration point, an anisotropic phase is formed which gives rise to the properties of the anisotropic compositions according to the invention.

A given polyamide / liquid medium composition of the invention is isotropic under a special polyamide concentration. When the concentration de ·; As the polyamide increases, the viscosity of the mass increases. At one point when describing the present invention is referred to as the "critical concentration point", but occurs in the course of the Curve of viscosity versus concentration shows a sharp discontinuity when the mass is without formation of a solid phase changes from isotropic to partially anisotropic. The further addition of polyamide leads to a Decrease in the viscosity of the mass, as the mass becomes more anisotropic. An example of a curve from Viscosity versus concentration is described in Example 14 and in FIG. 1 illustrates.

A given mass of the invention is. As already mentioned above, anisotropic if the components of the

Mass are present in special concentration ranges. Between the concentration of the polymer or copolymer, its inherent viscosity and temperature, there is a complicated relationship that generally determines the areas in which a given mass of polymer or mixed polymer and liquid medium is anisotropic. Exemplary phase relationships are in example 15 and F i g. 2 and 3 shown. Such relationships can easily be established for other compositions of the invention by routine experimentation to be determined.

The "critical concentration point" varies with the specific polyamide and its weight percentage and its inherent viscosity, the particular liquid medium and temperature. Of the Influence of the percentage by weight of polymer and the temperature on the masses of two different Polyamides are shown in Example 16. The Influence of Inherent Viscosity on Two Different Polyamides is in Example 15 and FIG. 4 and 5 shown.

The anisotropic compositions according to the invention contain the polymers and copolymers described above, which have up to about 10% (molar basis) aromatic units, their chain-extending bonds are not substantially coaxial or parallel and oppositely directed. For example, can Mixed poly (p-benzamide / -m-benzamide) (95: 5) with high molecular weight and random distribution p-aminobenzoyl chloride hydrochloride and m-aminobenzoyl chloride hydrochloride using the low temperature solution polymerization processes described above getting produced. A mass produced from such a mixed polyamide shows optical anisotropy.

Anisotropic masses of aromatic mixed polyamides, in which all chain-extending bonds of each aromatic nucleus are substantially coaxial or parallel and oppositely directed also encompassed by the present invention. For example kf.nn an ordered mixed polyamide, made from 4 / i'-diaminobenzanilide and terephthaloyl chloride or:!, 6-naphthaloyl chloride, incorporated into an anisotropic mass, which is the copolymer and contains a suitable sulfuric acid or oleum.

Compositions containing poly (2-chloro-p-phenylene terephthalamide) can be separated into two layers, an isotropic, upper layer and a denser, anisotropic, lower layer. This separation can be achieved, for example, by letting a spinning mass stand for a period of time sufficient for MTA to achieve separation (e.g. 1 week), or it can be achieved, for example, by centrifugation. An isotropic poly (2-chloro-p-pheny-lenterephthalamide) composition can be converted into an anisotropic composition by changing the polymer concentration while maintaining the inherent viscosity of the polymer. Likewise, a change in the volume of a given anisotropic phase in a mass system with two layers can be achieved by producing the mass from a polymer with a higher inherent viscosity at a constant concentration

The combinations of the above-mentioned ingredients were chosen so that an anisotropic mass is obtained receives. It is possible that with certain combinations of components none are anisotropic Mass is obtained. For example, poly- (p-phenyien-p.p'-dipher.yldicarboxamide) and poly (p, p'-phenylenebenzamide), which form anisotropic masses in oleum, but no anisotropic masses in HF. Whether a given mass is anisotropic is easily determined by the methods described below.

Determination of the optical anisotropy

In the following examples, the anisotropic character of the compositions according to the invention is exemplified described in the following way:

(1) by graphing the relationship of bulk viscosity to polymer concentration to Determination of the "critical concentration point",

is (2) by numerical values for the light transmission through crossed polarizers, identified as "DDA",
(3) by observing the bright field seen in a polarizing microscope; and (4) by visually determining the "stirred rheumatism".

Critical focus point

The anisotropic masses according to the invention are characterized by a "critical concentration point", d. That is, at the rise in the curve of mass viscosity versus polymer concentration a sharp discontinuity. When the concentration exceeds this point, the mass is anisotropic, and further addition of polymer leads to a reduction in viscosity while the mass becomes more anisotropic. This "point" (as well as the full viscosity versus concentration curve) becomes routinely determined using conventional concentration and viscosity measurement methods (see example 14).

"DDA" test

A measurement that distinguishes anisotropic masses from isotropic masses is described in the examples. This measurement is based on the degree of depolarization anisotropy (DDA and is used in the context of the present invention. This quantity is a measure of di < Depolarization of the linearly polarized light passing through a sample and is caused by di < following equation

DDA =

100

defines, in which the symbol "'" for measurements on a final sample (completely isotropic), e an opacity factor in the sense that a given adsorber with double thickness has an ε-value twice as large as b <single thickness, and π and σ measurements mean that have been carried out with a parallel or vertical polarizer and analyzer. This equation is essentially a percent difference equation. 1 in practice, the incident light intensity is set i.-nmer s that a measurement of ε * (and ε * '), which corresponds to d <unit (i.e. a transmittance display of 100 ° /, with parallel polarizers for both (blank and (2) sample is obtained, which represents (a complete lack of depolarization and (2) eil complete depolarization for the observed Fe

609 517/4

ίο

indicates. In this case the DDA equation simplifies to

DDA =

KM)

The scale ranges from 0 to 100, with the former being complete isotropy and the latter being complete Show anisotropy for the observed field.

The device used for the DDA measurements consists of a Bausch and Lomb polarization microscope (rotatable polarizer, fixed analyzer). The light source is a Silge and Kuhne Ortho Illuminator B with a 100 W GE BMY lamp operated constantly at 115 V. The change in light intensity to regulate επ (and ε * ') takes place through the neutral density filter and the iris diaphragm of the light source. The light which passes through is picked up by a photosensitive resistor GEB-1036 operated at 22 1/2 volts, and a 50 ^ ammeter is used to indicate the relative intensity. The light passes through the following components in the following order: light source, polarizer, condenser, sample, microscope objective (2Ox, Leitz NA = 0.33, FL long), analyzer, eyepiece (1Ox, compensating) to the photoresistor.

All measurements are carried out with red light, which is filtered through a red waveband filter (with a Permeability range from about 600 ΐτ.μ to one Maximum of about 650 τημ in the visible range) is generated in the lighting fixture. The photoresistor comes with a range of color compensating filter films (Kodak Color Compensating filter films CC50R) with an opacity of 1 (100% transmittance on the Measuring device), two films are assigned an opacity of 2, etc. During the calibration, the Films are placed on the microscope stage, and the microscope is placed approximately in the center of the filter film stack (vertically) in focus. The working conditions envisaged for the photoresistor are designed in such a way that a linear calibration curve with logarithmic measured values is plotted against the Opacity is preserved. The opacity values of the sample are then taken directly from the calibration curve. this gives a relative "red opacity value" for each sample.

Samples for di <~ measurement are made by a Drops of the mass are taken from inside the larger sample. This drop is on a Pyrex glass pane applied. An annular spacer made of fluorocarbon with a thickness of 51 μ is used placed on the pane, and a second pane of glass closes the cell. This unit is turned into a special Brought screw structure that holds the glass in contact with the spacer to a constant sample thickness of 51 μ (with the sample essentially filling the cell). These samples are before the Taking measurements, allowed to relax for 1 to 1.5 hours. Blank samples are used in the made in the same way with pure solvent.

When performing visual observations (in the microscope with crossed polarizers) the Masses whose DDA is measured each shows positive Value for DDA the presence of anisotropic phase. The higher the DDA, the greater the amount of anisotropic phase, which is present in the mass, apart from the extreme borderline cases with less than about 5% an existing phase. This is partly due to the sensitivity of the apparatus. Aucl if the proportion of the anisotropic phase is small and not evenly distributed or dispersed, small « Fields of observation are selected that have less than the average or no anisotropic phases. exhibit. A 100% anisotropic mass does not always result in a DDA = 100, probably on the ground of irregularities in the structure.

Observation between the light polarizing elements

The DDA test described above quantitatively describes the light transmission of anisotropic materials. Appropriately, however, a qualitative determination can also be carried out, with a light source, an analyzer and a crossed polarizer

(or equivalents thereof) as described in these tests can be used. If such polarizing Elements are crossed, leaving a resting (relaxed) bulk sample between the polarizer and the analyzer is brought through, substantially no light when the mass is isotropic. When the sample however, is anisotropic, light is transmitted and a relatively bright field is observed (with the The intensity of the light depends on the degree of anisotropy of the sample).

Rühropalescence

The term "Rühropaleszenz" is used in describing the invention to mean a for Describing anisotropic masses characteristic property that is visually observed with the naked eye will. Many of the compositions of the present invention appear when placed in bulk in a clear container be observed, cloudy or hazy and yet contain no or practically no undissolved

₄ c solid. If the mass is disturbed when viewed in reflected ordinary light by tilting or rolling the container or even just by slowly stirring it, a characteristic, easily observable satin-like shimmer or glow is generated which is also observed after the disturbance has ceased and then in intensity subsides. With some compositions, no color sensation is evoked, while others may show a bluish tone or even a degree of chroma which observers describe as pearly or iridescent. Color coming from the outside in the mass, such as yellow discolouration due to smaller amounts of impurities or as an inherent color in some polymers, modify the observation of the color

developed under shear. Crowds that are disturbed in the manner described above indicate the Surface often has the appearance of striations and / or grain. These visual effects are in accordance with the invention anisotropic masses observed. Although such effects do not conclusively prove that the mass is anisotropic, then such masses are generally anisotropic or become with the addition of more polymer (provided that the solubility limits allow this) anisotropically. Of the For the sake of brevity, the examples provide visual observation of all of the variations described above of the phenomenon referred to as the occurrence of "Rühropaleszenz".

Masses which are described below as anisotropic can show this rhropalescence effect or can prove to be anisotropic according to the qualitative or quantitative methods mentioned above prove d. That is, the critical concentration point is determined or the sample is placed between the light polarizing elements, for example in a microscope for the depolarization of linearly polarized Light, either qualitative or quantitative, is observed as described above. Any of the above described qualitative or quantitative methods indicates anisotropy in a suitable manner, although one or more such working methods are more appropriate and / or for a given mass can be more precise. The determination of the critical concentration point is the preferred test for the Determination of the anisotropy, since it is expedient and accurate for all anisotropic masses according to the invention can be used. The qualitative test (visual observation between the polarizing light Elements) is preferred for convenience when examining a large number of samples. Observation of agitation ralescence is also convenient and generally indicates anisotropy. Of the DDA test is preferred for sulfuric acid masses because it is at the limit for such masses anisotropic measurements is more sensitive. Although the DDA test in general for all according to the invention Bulk is suitable, because hydrofluoric acid (in HF bulk or generated by the fluorosulfonic acid in other masses) glass attacks, in such cases precautionary measures and / or modified Test methods may be necessary (for example, replacing the glass slide with a tension-free one HF-resistant slide and protection of the microscope lens from HF gas).

Usability of the masses and thread manufacture

The above-described compositions or masses according to the invention can easily be used Production of threads or fibers and foils are used.

Compositions according to the invention which contain at least 5 percent by weight of polymer are insofar preferred as they are particularly useful for the production of threads or fibers. This anisotropic It is true that masses can also be used for the production of other moldings, the preferred use however, these masses are used in the manufacture of threads or fibers by conventional means Working methods and / or the procedures described below.

The compositions or compositions according to the invention are conventional wet and dry Dry spinning methods and extruded as threads with conventional devices of this type. At the Wet spinning is a suitably prepared mass containing the polymer and, for example, sulfuric acid contains, in a suitable coagulation bath, for example a water bath kept at 0 to 50 ° C, extruded, the coagulation bath depending on the solvent used in the manufacture of the Mass is used. Other useful coagulants include mixtures of water and alcohols and aqueous salt baths, these for example at a temperature of about -20 to + 50 ° C. Dry spinning can be achieved by placing the compositions or masses according to the invention in a heated gas stream are extruded, whereby evaporation occurs and filaments of the polyamide are formed.

After their production, the threads can be passed over a sizing roller and wound onto spools will. The development of maximum thread and yarn property values can be supported by the coils in water or in mixtures of water and water-miscible inert organic

ίο liquids are immersed to remove residues of acidic Remove solvents, followed by drying. The removal of the remaining solvents and / or Salts can also be obtained by passing the thread or yarn on its way through aqueous baths by rinsing the bobbins with water while the yarn is being formed and by removing the strands of yarn washed or dipped instead of the spools of thread. Dry spun yarn can go through Wash by itself with a small amount of water can be solidified.

The physical meaning of the orientation angle is that it forms an angle (i.e. half the Orientation angle) around the thread axis in which a given percentage of crystallites is aligned. A high percentage (i.e. greater than about 50%, im generally about 77%) of the crystallites within this angle (one half of the orientation angle) around the Thread axis aligned. This percentage is obtained from an intensity curve of the diffraction pattern of the thread determined (as described below). For example, the intensity curve for most of the filaments made according to the invention (i.e. for essentially all heat treated filaments and for most filaments in the post-extrusion state) essentially a Gaussian curve. at of such a curve, about 77% of the diffraction intensity falls into this angle, which is interpreted as that this shows that a similar percentage of crystallites are oriented at this angle. Both few threads (for example with some threads in the state after extrusion) for which the curve does not can be Gaussian (for example, the curve can be composed of several curves, the show partially resolved peaks) more than about 50% of the crystallites are aligned at this angle (cf. Example 17).

The threads or fibers produced from the compositions according to the invention are in addition to that characteristic Orientation angle characterized by the speed of sound. The speed of sound is a structural parameter related to the molecular orientation of the thread along the thread axis A higher value of the speed of sound is the result of a higher level of molecular egg Orientation along the thread axis. Sound speed and related parameters are in »Textile Research Journal ", Volume XXIX, No. 7. pp. 525 to 53! (1959) (C h a r c h and M ο s e 1 e y) and in »Journal ο Applied Polymer Science ". Volume III, No. 9, pp. 266 to 27 ((1960) (M o s e 1 e y).

Orientation angle and / or speed of sound show the extraordinary internal structure of the thread; These structural parameters each relate to dii

(15 orientation and each show their unusual features opportunity. The speed of sound is a measure of the overall molecular orientation, in contrast to zi crystalline orientation. This entire molecular

Orientation differ *, differ from the orientation, which is described by the orientation angle, d. That is, the orientation angle is a measure of the orientation of the crystals, which is determined by X-ray measurements is determined. The extraordinary internal structure of the threads that can be produced shows itself through one of these orientation parameters or both.

The threads produced from the compositions according to the invention have high tensile strength properties in the spun state. Threads in the spun state are threads that are used in normal spinning processes are formed, but have not yet been subjected to drawing (elongation) or heat treatment that changes the molecular order or the arrangement of the polymer molecules. The threads can however, it may have been subjected to washing and drying steps necessary to remove solvents or to remove impurities. To other work steps that can be carried out without changing the fundamental character of the threads belong

(1) Application of finishes, dyes, coatings or adhesives,

(2) physical treatment of the thread by twisting, crimping, cutting into stacks,

(3) Use of the thread in the manufacture of shaped objects, fabrics, papers, Resin or rubber compounds.

Threads from the masses according to the invention are in the spun state for special end uses, for example for tire cord, preferred. For such applications it is generally desirable that the In addition to a high modulus and a high strength or tear length value, the thread has an elongation of shows about 5%. Post-shaping treatments (such as heat treatments) that make up the module and improve strength, but often reduce elongation (e.g., below 5%).

The tensile strength properties of wet or dry spun threads can be improved by subjecting the undrawn threads to a heat treatment. Hot air ovens, heated bars, slots and plates, and liquid heating baths are useful for such treatments. The tensile strength properties of the spun threads are preferably improved by placing the taut or stretched thread in a nitrogen atmosphere which is kept at a temperature in the range from about 300 to 1000 ^° C., preferably from 500 to 600 ^° C., about 0.1 Heated for seconds to 5 minutes, preferably 0.1 to 10 seconds, as shown below.

The threads produced from the compositions according to the invention have excellent chemical and thermal properties. They retain their tensile strength properties when heated for 0.5 hours and boiled in 1% aqueous hydrochloric acid solution and 1% alkali solution. The threads are after 1 hour immersion at 6O ⁰ C in commercially used dry cleaning solvents such as perchlorethylene and trichlorethylene, substantially unaffected. The threads will not sustain the combustion if removed from an open flame.

The excellent tensile properties of the threads make them particularly useful as reinforcing agents for plastics, tire cord, V-ribbons and the like.

The compositions or compositions of the invention can be prepared by a conventional wet extrusion method be deformed into foils. Such films are usually under a holding force if they are then dried and washed.

An anisotropic mass can generally be used to make a thread which is im spun state has properties that are superior to the properties of threads made from a

ίο otherwise corresponding: mass are made, the is isotropic or less anisotropic (i.e. from an emulsion of isotropic and anisotropic phases in which the isotropic phase predominates). The opposites of the properties of a thread from one to a high degree

anisotropic mass versus the properties of a thread made from a mass that is something is anisotropic or isotropic are shown in the examples.

Measurements and tests

The inherent viscosity (ijinh) is given by the following equation

defined, in which (η «ι) the relative viscosity and (C) a concentration of 0.5 g of the polymer in 100 ml of solvent. The relative viscosity (Tjrei) is determined by dividing the flow time of a dilute solution of the polymer in a capillary viscometer by the flow time for the pure solvent. The dilute solutions used here to determine (for free) have the concentration represented by (C) , the flow times

are determined at 30 ^° C., with concentrated (95- to 98% strength) sulfuric acid being used as solvent, unless otherwise stated.

Tensile properties of the thread

The thread properties strength, elongation and initial modulus are denoted by T / E / Mi and are expressed in their conventional units; d. H. as g / den,% and g / den. These properties are expediently measured in accordance with ASTM work regulations D 76-53 (October 1962), using a test machine such as an Instron tester (a product of Instron Engineering Corp., Canton, Mass.), Which has a constant rate of expansion supplies. If nothing else

is specified, samples with an elongation at break up to about 8% with an expansion rate of 10% / min. tested, while samples with higher elongation at break rwii 60% / min. be tested. The samples are threads with a length of 2.54 cm or yarns with 3 turns / 2.54 cm and 25.4 cm length, and the tests are carried out at 21 ^° C. and 65% relative humidity.

The samples are not boiled (pickled), but generally at 2TC and 65% relative Moisture conditioned for at least 16 hours (which is sometimes referred to hereafter as "self-state" unless otherwise specified. If a boil-out treatment is mentioned, then there is them in 30 minutes of boiling the threads or yarns in

_6s 0.1% aqueous sodium lauryl sulfate, rinsing, 1 hours of drying at 4O ⁰ C and at least Kistündigem conditioning at 21 ° C and 65% relative humidity, unless otherwise specified.

Heat treatment of the thread

The heat treatment process after extrusion, which is applied to the threads and yarns obtained from the flowable compositions of the present invention and compositions obtained include, unless otherwise specified in the examples, washing or submerging the spun filaments or yarns in water until they are substantially removed from the spinning media and / or are free of salt, after which they are dried and then described in one of the following Devices are heated.

Device A

This device consists of a stainless steel inner tube that is 81.3 cm long and 7.94 mm Inner diameter, which is arranged concentrically in a second tube with an outer diameter of 2.69 cm, with the entire assembly centered in a 30.48 cm electric furnace. Divided by two Nipples in the outer tube spaced 10 inches from each side of the tube center Nitrogen gas introduced so that the entering nitrogen through the annular space between the passes through both tubes. The nitrogen escapes from the ring-shaped space through a small opening that is arranged in the center of the wall of the inner tube, into the inner tube and then out of the inner tube ends outward at such a rate that the atmosphere in the heated 30.48 cm zone of the Inner tube is replaced at least once a minute. The ones protruding from the oven The outer ends of the device are covered with asbestos fiber and glass tape to within about two inches from each end wrapped around. The temperature of the oven is regulated by a thermocouple placed in the center of the Outer wall is fixed by soldering and with a Minneapolis-Honeywell "Pyrovane" regulator in connection stands. The heated tube has a temperature profile with the maximum temperature in the middle range. The nominal heat treatment temperature is given by determines a thermocouple soldered to the outer center surface of the inner tube. At the By guiding threads through the pipe, guiding devices are used to guide the threads centered and kept out of contact with the pipe walls.

Device B

This device is identical to the above device A in terms of pipe dimensions, furnace type and the like and operates in the same general manner. However, this device B differs from that above device A in the amount of insulation wound at the ends and by the fact that the nitrogen inlets in device A are on opposite sides of the outer tube, while in device B they are on the same side. Between the two devices can There are differences in nitrogen flow rates.

Device C

This device consists of a stainless steel inner tube 89 cm long and 1.27 cm Inside diameter, which is concentric in a second stainless steel tube with a diameter of 2.54 cm and 45.7 cm in length with the entire assembly centered in a 30.48 cm electric oven. Through two nipples connected to the ends of the outer tube (one to each end of the outer tube), nitrogen gas enters such that the entering nitrogen through the annular space between the passes through both tubes. The nitrogen comes out of the ring-shaped space through two small ones in the Inner pipe wall arranged in the middle of openings in the inner pipe and then out of the inner pipe ends

ίο such a speed to the outside that the atmosphere in the heated 30.48 cm zone of the inner tube is changed at least once per minute. The outer ends of the device protruding from the oven are wrapped with glass wool about two inches from each end. The temperature of the oven is regulated by a Minneapolis-Honeywell "Pyrovane" regulator, using a thermocouple in contact with the center of the outer surface of the inner tube. The heated tube has a temperature profile with the maximum temperature in the middle range. The nominal heat treatment temperature is determined by a second thermocouple in contact with the outer central surface of the inner tube. When threading threads through the pipe, guide devices are used to keep the threads centered and out of contact with the pipe walls.

The use of devices A, B and C at the treatment of threads is indicated accordingly in the following examples, together with the nominal heat treatment temperature at the central portion (approximately 2.5 to 5.1 cm) of the inner tube for the device is observed.

Crystallinity

The degree of crystallinity indicated by the X-ray diffraction diagram becomes qualitative estimated by visual inspection and using the following expressions:

amorphous: has only diffuse rings or arcs;

Traces: very diffuse scattering area with a certain sharpening of the main spots;

low: moderate degree of sharpness in the spots with considerable surrounding diffuse scattering area;

medium: completely sharp spots, but with retention of a certain diffuse character;

high: very sharp diffraction spots and essentially no presence of diffuse Scattering.

As the crystallinity increases, the number of diffraction spots usually increases.

It should be noted that these ratings are only intended as a differentiation of the range of Crystallinities are intended to be those of the types of thread produced from the compositions according to the invention are observed, and are not intended to constitute a limitation in this regard.

Orientation angle

The orientation angle of the thread or the fiber is determined according to the general procedure described in "Textile Research Journal", Vol. 21. pp. 805 to 822 (1951) (K r i m 111 and T ο b ο 1 s k y) is described. It will be a

White angle X-ray diffraction diagram
(Permeability diagram) of the thread.

using a Warhus pinhole camera. The camera consists of a 7.6 cm long collimator tube with two lead (Pb) holes 0.0635 cm in diameter at each end and has a sample-to-film distance of 5 cm. During the ί exposure, a vacuum is created in the camera. The radiation is generated by a Philips X-ray unit (Catalog No. 12 045) with a copper fine adjustment diffraction tube (Catalog No. 32 172) and a Nickel-JS filter, the unit operating at 40 kV and 16 mA. A thread sample holder 0.051 cm thick is filled with the sample, with all threads lying in the X-ray beam being kept parallel. The diffraction diagram is recorded on Kodak No-Screen® medical X-ray film (NS-.54T) or equivalent. The film is exposed for a sufficient period of time to give a diagram: £ u which is considered acceptable according to conventional standards (e.g. a diagram in which the diffraction spot to be measured has a sufficient photographic density, e.g. between 0.2 and 1.0, to be legible). In general, an exposure time of about 45 minutes is suitable, but a shorter exposure time may be suitable and also desirable for highly crystalline and oriented samples in order to obtain a more accurately readable diagram. The exposed film is x-rayed for 3 minutes at a temperature of 20 ± 1.1 ⁰ C (68 ± 2 ° F) Processed in General Electric Supermix® X-ray Fixing and Curing Solution for minutes. The film is washed in running water for 0.5 hours and dried.

The arc lengths in degrees be. half the maximum intensity (the angle which includes locations with 50% of the maximum intensity) of the equatorial main spot is measured and taken as the orientation angle of the sample. The special arcs that are used to determine the orientation angle for threads that are described in the following examples (in the order given in the following section) occur at the following ₄ , positions, 20 (degrees):

Thread of example

> Θ (degrees)

A.
H

9 (A) 22.17

9 (H) 22.15

10 (A) 21.31

10 (H) 20.28

11 (H) 23.41

12 (A) 22.98 12 (H) 22.44

= Thread as if spun.
= heat-treated thread.

Thread of example (A-I) 1 (HI) 1 (A-2) 1 (H-2) 1 (A) 3 (A) 4th (H) 4th (A) 6th (H) 6th (A) 7th (H) 7th (A) 8th (H) 8th

2 Θ (degrees)

22.56

22.41

22.56

22.51

22.73

22.10

22.19

22.44

22.46

22.44

22.32

22.93

22.59

A-I = first thread as extruded in the example.

A-2 = second thread as extruded in example.

H-I = first heat-treated filament in example.

H-2 = / further heat-treated "adcn in example.

so

SS

λ s, the orientation angle of the threads are ir various ways by three related Densito metermethcden (or equivalents thereof) from derr X-ray film is determined, whose development has been described above.

In one method (Method 1), the azimuthal intensity distribution of the diffraction arc is obtained using a Joyce-Loebl automatic recording microdensitometer (Model MK III C with a rotating stage, manufactured by Joyce, Loebl and Co., Gateshead, England). Typical instrument settings that are used are: Lever ratio 1: 1,
Objective lens 5 / 0.10,
Recorder speed: integrating, slot setting: 187,
Wedge: 0.087 density units / cm. Variations on these settings, which may be required due to the nature of a given diffraction diagram, are made in accordance with the manufacturer's instructions for that device (dated August 1963). In operation, the film is brought onto the stage, the instrument is focused on the film, and the center of the diffraction diagram is brought into alignment with the center of the stage, these two centers being brought into congruence with the aid of the light beam from the instrument. The stage and attached film are moved to allow the light beam to pass through the most intense area of the diffraction spot, the opposite spot is checked to ensure proper centering, and after any fine adjustments are made, the azimuthal intensity curve is recorded by a 360 ° rotation of the film on suitable coordinate paper with a linear scale. A curve is obtained which has two main peaks. A baseline is drawn under each peak such that the background blackness of the film extends under the peak. A plumb line is dropped on the baseline from each peak maximum. A line parallel to the base line is drawn through the midpoint of each perpendicular (that is the point at "half the height") and intersects each leg of the respective curve. The leg to leg length of each "half-height" horizontal line is converted to degrees of arc in the following manner. The horizontal distance (ie parallel to the base line) between the two peak maxima is measured and represents 180 ° of the curve. By forming a direct ratio to this distance from peak to peak, the distance from leg to leg at "half the height" is converted into a degree. Converted value. The diameter is formed from the values for the two arcs, and this is Jen

Orientation angle to which reference is made in the description of the invention.

The percentage of crystallites that are relative to the filament axis within one half of that through the above The calculated angle is determined in the following manner. For each peak of the curve described above are drawn from the points of contact at the peak of the horizontal Leg-to-leg line at "halfway up" perpendicular like the baseline. This creates a rectangle that goes through the baseline, the two vertical lines and the horizontal line is connected "halfway up". Using a planimeter, the relative area of the rectangle plus the area of the peak under the curve and above the horizontal line »in half height «'(total = area 1). The total area under the peak above the baseline is then determined with the planimeter (area 2). The percentage of crystallites that are within the orientation angle is aligned, corresponds to:

Area 1
Area 2

100.

A second method (Method 2) used to determine the orientation angle used for the threads uses an improved version of the "Flying-spot" densitometers, which in "Acta Cryst.", 10, pp. 560 to 562 (1957) (Owens and S tat ton) is described. The equipment used is that in the referenced reference in FIG. 1 described Equipment similar, with the following differences:

(1) Sola constant voltage transformer No. 80 808 is replaced by Catalog No. 23-22-112, and this unit is only connected in series between the ^3S main switch of the regulated 500 V outlet.

(2) The display oscilloscope Dumont No. 304 A and the subsequent calibration signal generator are through a Tektronix 532 display oscilloscope in combination with a Tektronix preamplifier 53/54 K replaced. The combined units are only in series between the main switch and switched to the photo amplifier.

(3) The flying-spot oscilloscope (Dumont No. 304 A) and its cathode ray tube are through a Tektronix 536 oscilloscope with a cathode ray tube 536 P 5 replaced.

50

(4) The regulated 500 V outlet is with the Photo amplifiers and also with the circular generator (a type of device developed by Owens and Equip is referred to as a sampling frequency generator connecting.

(5) The circular generator is in one place through a Tektronix type horizontal preamplifier 53/54 K and at a second point by a line circuit switch and a vertical preamplifier of the Tektronix 53/54 K type connected to the Tektronix 536 oscilloscope.

The operation of this device is carried out according to the instructions of Owens and Stat ton, with the Exception that calibration with a square wave from a signal generator is not necessary. Appropriately, as described in the literature reference mentioned, a metal block forms the infinite

(10 borrowed density value from the display graph. A clear portion of the film provides a reference for zero density.

In the cited reference it is stated that the "flying spot" densitometer a quick measurement of the orientation angle and the photographic one Blackening (optical density) delivers.

A third method (method 3), by which the orientation angles of the threads are determined, includes a Leeds & Northrup photometer (Catalog No. 6700-P1), its electronic components by a Keithley 410 micro-micro-ammeter (Keithley Instruments Ina, Cleveland, Ohio) have been replaced. The output of this device becomes a Leeds & Northrup Speedomax Recorder, Type G, directed. From the from this device to for example The curve recorded on the semi-logarithmic chart can show the orientation angle and the Crystallite alignment can be obtained by procedures comparable to those used in the Joyce-Loebl device described above can be used.

Of the above three methods or instrument systems, Methods 1 and 3 described above provide 3 the most precise determinations of the orientation angle. The accuracy of the "flying spot" method is approximately ± 1.5 ° of the specified angle value. The angles of orientation given in the following examples are determined using method 2 of the "flying spot" device), if nothing otherwise stated, due to the speed and convenience of measuring the large number of analyzed threads that made this method possible.

Speed of sound

In the examples below, the speed is of the sound in the threads, referred to as the speed of sound (SV) of the thread, determines by using a dynamic module test device KLH (in a conventional manner according to the manufacturer's instructions) PPM-5 (manufactured by KLH Research and Development Corp., Cambridge, Mass.), The following as »PPM-5«, in connection with a potentiometric recorder Speedomax type G (manufactured by Leeds & Northrup Co., Philadelphia, Pa.), hereinafter referred to as the "recorder" is used. The latter instrument operates as a 10 millivolt recorder. These devices allow! performing measurements as graphs of sound propagation time as a function the distance.

The mode of operation by which the sound velocity measurements are carried out in the invention, can be summarized in the following manner, with all measurements in an air atmosphere which is maintained at 21.1 ° C and 65% relative humidity (r. F.). The yarns under these conditions for at least 16 hours before determining the speed of sound exposed.

The range switch on the PPM-5's modular unit is set to 100, causing the Recorder at full deflection 100 microseconds or 10 microseconds per 2.54 cm of paper perpendicular to the paper direction. The recorder is set so that the recording paper

(Leeds & Northrup Co., No. 690 489) is advancing at the rate of 17.5 mm per minute emotional.

The yarn sample is placed in the scanning unit of the PPM-5 and is suitably loaded to to cause the yarn to have a tension of 0.1 g / denier. The power switch, the zero control and the Threshold adjusters are actuated (in a conventional manner according to the manufacturer's instructions). Then while the movable transducer (or thread probe) of the PPM-5 scanner is cycled from the stationary transmitter (yarn probe) at a speed of 7.62 cm per minute away and up Moved to this, a sound surge signal of 10,000 Hertz is fed to the yarn. While the probe is along of the yarn is moved, a diagonal line is drawn on the recording paper that separates the paper from the crossed one side to the other. The pen of the recorder changes the direction w: nn the probes at the places of greatest and least separation from each other.

Since the recording paper is moved forward at the speed of 17.5 mm per minute, the Probe speed along the yarn corresponding to a ratio of 3 / 0.688 or 4.36 / 1 faster than that Forward speed of the recording paper (i.e., per 2.54 cm of recording paper movement, the moving probe covered 11.05 cm along the yarn).

The speed of sound between two points in the yarn (the speed of sound SV) is then determined by taking the slope of the recorded chart paper line in the following manner at 11.05 km / sec. is multiplied:

SV =

\ crtikalcr distance in
/ wipe two points on the registricipapicrlinic

horizontal offshore in
2.54 cm units between two points on the regulatory paper line

1.05 km sec.

The factor 11.05 km / sec. results from the combination of registration paper and probe speed. and the necessary details are shown in the following derivation:

4.36 x 2.54 cm / 2.54 cm vertically

(Rcgislricrpapicr)

10 microseconds / 2.54 cm horizontally
(Rcgislricr paper)

2.54 cm 2.54 cm x 10 'km.cm
H) "'' sec. Microsc

1.05 km sec.

Sound velocity values given in describing the present invention are based on a measurement of the slope of the chart line taken while the two are moving Separate probes (i.e., while the moving Probe moved away from the yarn tension weight). Usually the incline value is that of 11.05 km / sec. is multiplied by the average of three separate inclination determinations made at three separate diagonal chart paper lines can be made.

example 1

This example illustrates the preparation of anisotropic and isotropic oleum compositions from poly (pphenylene terephthalamide) and making threads from it.

A mixture of 36.0 grams of poly (p-phenylene terephthalamide with an inherent viscosity of 2.64 and 264 g of fuming sulfuric acid (3% free SO3) will under anhydrous condition using a disk-type air-driven stirrer in a 500 ml resin making vessel mixed while cooling with an ice / water bath. The mixture is stirred overnight and at room temperature for 15 days ditched. The resulting mass shows agitated tropalescence and depolarized linearly polarized Light.

A portion of the dope prepared above is centrifuged to remove trapped air. Then it is applied by means of a mechanically driven syringe through a 0.254 cm thick precious metal spinneret extruded with 20 holes of 0.076 mm diameter in an aqueous coagulating bath, the one Temperature of 41 ° C. The bath is about 5.1 cm wide and about 2.54 cm deep. After going through a For a distance of about 0.61 m, the yarn comes out of the water and closes at an angle of about 45 ° an electrically driven winder. The thread is on a perforated bobbin with 19.8 m / min, collected. Then the yarn is soaked in cold running water for several hours (i.e. 3 Hours) and dried in air at room temperature. The threads show low crystallinity and an orientation angle of 34 ° and a speed of sound of 4.56 km / sec. (Boiled) threads show the following T / E / Mi / den values: 5.3 / 10.4 / 171 / 5.0.

4s The above yarn is run through a at 7.63 m / min 600 ° C heated pipe (device A) passed and collected at 8.34 m / min. The resulting threads show high crystallinity, an orientation angle of 15 ° and a speed of sound of 8.37 km /

so sec. (Boiled) threads show the following T / E / Mi / den values: 12.8 / 1.9 / 817 / 4.84.

A mixture of 9.0 g of the same polymer and 111.0 g of fuming sulfuric acid (2% free SO3) is operated under anhydrous conditions with an air-driven disc-type stirrer in one 500 nil resin making tank mixed while is cooled with an ice / water bath. The mixture is left overnight, or until a clear viscous mass is obtained, stirred, during which time the

ί, ο the Kühibad is allowed to warm to room temperature. A portion of the clear dope prepared above is centrifuged to remove trapped air. Then it is with the help of a mechanically driven syringe through a 0.0254 cm thick precious metal spinneret with 20 holes 0.076 mm in diameter in an aqueous coagulating bath at room temperature extruded. The bath is about 5.1 cm wide and about 2.54 cm deep. After going through a bathing section

2! 3

from about 0.61 m, the yarn is at an angle of about 45 ° out of the water and becomes an electric one driven winder out. The yarn is fed to a perforated bobbin at 11.3 m / min, It is then collected in cold running water for several hours (el. h. 3 hours) and washed in Air dried at room temperature. The threads show low crystallinity and an orientation angle of about 50 °, determined from a wide-angle X-ray diagram. (Boiled) threads show the following T / E / Mi / den values: 3.1 /20.8/106/7.0.

The above yarn is passed through a tube heated to 550 ° C. (device A) at 7.63 m / min and with 8.34 m / min, collected. The resulting filaments show high crystallinity and an angle of orientation from 19 °. Filaments (cooked out) show the following T / E / Mi / den values: 5.3 / 1.4 / 401 / 5.7.

Example 2

The present example illustrates the preparation of an anisotropic mass of poly (2-methyl-p-phenylene-2,6-naphthalamide).

A mixture of 7.5 g of poly (2-methyl-p-phenylene-2,6-naphthalamide) with an inherent viscosity of 2.08 and 45.0 grams of 99.5 weight percent sulfuric acid is made under anhydrous conditions with a mechanically driven paddle-type stirrer in mixed in a 200 ml round bottom flask while cooling with an ice / water bath. The mixture will be over Stirred overnight, during which time the cooling bath is allowed to warm to room temperature. Which resulting flowable mass shows agitated tropalescence and depolarized linearly polarized light.

Example 3

The present bet illustrates the manufacturing process an anisotropic mass of a copolymer with random distribution, which consists of 54.7 percent by weight Poly (p-phenylene-2,6-naphthalamide) and 44.3 percent by weight poly (p-phenylene-terephthalamide), and of threads from it.

A mixture of 7.5 g of an interpolymer with random distribution consisting of 54.7 percent by weight Poly (p-phenylene-2,6-naphthalamide) and 44.3 percent by weight poly (p-phenylene terephthalamide) and has an inherent viscosity of 5.51, and 67.5 grams of 99.2 weight percent sulfuric acid is under anhydrous conditions with a mechanically driven paddle-type stirrer in a 200 ml round bottom flask mixed while cooling with an ice / water bath. The mixture is overnight stirred, during which time the cooling bath is allowed to warm to room temperature. Which The resulting Mpsse is extremely viscous, shows Rühropaleszenz and depolarized linearly polarized Light.

The spinning mass produced above is used for removal centrifuged by entrapped gases. It is then driven mechanically by means of a Syringe through a 0.064 cm thick precious metal spinneret with 20 holes 0.076 mm in diameter into one Aqueous coagulation bath maintained at 25 ° C extruded. The water bath is about 5.1 cm wide and about 2.54 cm deep. After passing through a bath length of about 0.61 m, the yarn is at an angle of about 45 ° out of the water and fed to an electrically powered winder. The yarn is on a perforated spool at 6.1 m / min.

collected while it is wetted on the bobbin by passing it through a tank of water that is arranged on the lower part of the collecting coil. The yarn is then cold flowing overnight Water washed, and a part is removed for heat treatment. The rest will be on the Coil dried in air at room temperature. The dry threads show traces of crystallinity and an orientation angle of 37 ° and a speed of sound of 5.92 km / sec. The threads show the the following T / E / Mi / den values: 8.7 / 8.4 / 327 / 4.79 (stretching rate 10%).

The above wet (washed) yarn as spun at 7.63 m / min, through a to 547 ° C

is heated pipe (device B) passed and with 8.84 m / min, collected. The resulting threads show high crystallinity and an orientation angle of 11 °, determined * from a wide-angle X-ray diagram. The yarn shows the following T / E / Mi / den values: 12.7 / 1.8 / 895 / 87.3. In addition, the above dry yarn is as extruded with 7.62 m / min, heated to 535 ° C by nitrogen filled pipe structure passed and collected at 8.54 m / min. The threads show the following T / E / Mi /

2s den values: 9.5 / 1.8 / 633 / 4.67.

Example 4

The present example illustrates the preparation of an anisotropic oleum composition of poly- [p-phenylene-bis- (iminocarbonyl-p-phenylene) terephthalamide] and of threads of it.

A blend of 5.0 grams of the above polyamide having an inherent viscosity of 2.4 and 45.0 grams fuming sulfuric acid (0.8% free SO3) is under anhydrous conditions with a mechanically driven paddle-type stirrer in a 200 ml round bottom flask mixed while cooling with an ice / water bath. The mixture is overnight or until solid particles can no longer be visually observed, during which time the The cooling bath is allowed to warm to room temperature. The resulting mass is flowable and shows Rühropaleszenz and depolarized linearly polarized light.

The spinning mass produced above is centrifuged to remove entrapped gases. she is then passed through a 0.064 cm thick stainless steel spinneret with 20 holes of 0.0076 cm Diameter in an aqueous coagulation bath mi

so 27 ⁰ C extruded. The bath is about 5.1 cm wide and about 2.54 cm deep. After passing through a bath section of about 0.61 m, the yarn is led out of the water at an angle of 45 'and to an electrically driven winder. The Gan

SS is collected on a perforated spool at 10.7 m / Mir. It is then used for several (i.e. 3) hours ii Washed in cold running water and dried in air at room temperature. The threads point medium Crystallinity, an orientation angle of about 40 and a speed of sound of 4.22 km / sec determined from a Wehwinkel x-ray diagram. The threads show the following T / E / Mi / der Values: 4.8 / 12.4 / 167 / 6.06.

Made in a similar manner to the yarn above

6s threads are at 7.62 m / min, through a 550 ° i heated tube (device A) passed and m 8.54 m / min, collected. The resulting thread show high crystallinity and an orientation

609 517/41

angle of 10 °. determined from a wide angle x-ray diagram. The threads show the following r / E / Mi / den values: 5.4 / 0.9 / 583 / 6.3.

Example 5

The present example illustrates the preparation of an anisotropic oleum composition of a mixed polyamide with random distribution, that: ius repeating units of the formulas

NII

-NH - <

and

■■ - CC)

CO

NH

IS

CO

(relative molar ratio 1: 3: 3), and of threads therefrom.

A mixture of 7.5 grams of the above polyamide having an inherent viscosity of 6.22 and 67.5 grams fuming sulfuric acid (0.8% free SO3) is used under anhydrous conditions with a mechanical powered paddle-type stirrer in a 200 ml mass: Round bottom flask mixed while with an ice / what sample

water bath is cooled. The mixture will be for several

Stirred for hours until there are no more solid particles visually '35 can be observed, during which time the cooling bath is allowed to warm to room temperature will. The resulting mass shows agitated tropalescence and depolarized linearly polarized light.

The spinning mass prepared in the above manner is centrifuged to remove entrapped gases. It is then applied by means of a mechanically driven syringe through a 0.064 cm thick precious metal spinneret extruded with 20 holes 0.005 cm in diameter in a water coagulation bath at 27 ° C. That The water bath is about 5.1 cm wide and about 2.54 cm deep. After going through a bath section of about 0.61 m the yarn comes out of the water at an angle of about 45 ° and becomes an electrically driven one Winder out. The yarn is collected on a perforated bobbin at 9.45 m / min. It will then washed for several (3) hours in cool running water, and one part is in air on one Coil dried at room temperature. The dry threads show low crystallinity and orientation angle of 28 °, determined from a white angle X-ray diagram. The threads show the following T / E / Mi / den values: 9.2 / 10.1 / 268 / 3.41.

Table Il

Caden as exlrtidierl

F'adensammelyeschu indigkcil

The above wet (washed) yarn is passed through a ^{tube heated to 610 °} C. at 7.62 m / min (device B) and collected at 8.1 m / min. The resulting filaments show high crystallinity and an orientation angle of 10 ° as determined from a wide-angle X-ray diagram. The threads show the following T / E / Mi / den values: 20.1 / 2.0 / 1069 / 2.78.

Examples 6 to 8

The following three examples illustrate the preparation of anisotropic oleum compositions, the blends of poly (p-benzamide) and poly (p-phenylcntcrephthalamide) included, as well as the production of threads from these masses.

Poly-1,4-benzamide with an inherent viscosity of 2.83 and poly- (p-phenylene terephthalamide) with an inherent viscosity of 3.67 are used in the amounts given in Table I along with 45.0 g of fuming Sulfuric acid (0.8% free SO3) in a 200 ml round bottom flask mixed, which is equipped with a mechanically driven paddle-type stirrer, while cooling with an ice / water bath. The mixture is stirred overnight, during this time the cooling bath is allowed to warm to room temperature. The masses are fluid and show Rühropalescence.

Table 1
Crowds

Poly (pbenza mid)

Poly - (p-pliciulcn /
lcrcphihulamid)

2.5 g
1.25 g
3.75 g

2.5 g
3.75 g
1.25 g

Any dope prepared in the above manner is centrifuged to remove entrapped gases remove, and then by means of a mechanically driven piston through a 0.064 cm thick Precious metal spinneret with 20 holes 0.0076 cm in diameter in a coagulation water bath at 25 ° C extruded. The water bath is about 5.1 cm wide and about 2.54 cm deep. After going through a bathing section from about 0.76 m, the yarn becomes an electrical one at an angle of about 45 ° out of the water driven winder out. The thread is wound on a perforated bobbin with the method shown in Table II specified speed collected. It is then placed in cold running water for several (3) hours washed, and part of it is removed for heat treatment. The rest will be in air at Room temperature dried. The threads show the angles of orientation given in Table II below (O.A.) and T / E / Mi / den values (all with 10% stretch rate).

Dimensions:
example

9.1 m / min.
10.7 m / min.
10.7 m / min.

I ailencii-'cnsch I. Wed the O. T ii> 5 4.98 28 5.8 10.0 220 4.11 25th 7.1 10.8 161 5.42 31 4.8

The above wet (washed) yarn in the state as extruded is passed at 7.64 m / min through a ^{tube heated to 640 °} C. (device B) and collected at the speeds given in Table III. The resulting threads show the angles of orientation and T / E / Mi / den values given in Table III. That spun from Compound 6 (Table II)

dry yarn is carried out at 7.63 m / min, through which to 600 ° heated, nitrogen-filled pipe structure passed and collected at 8.1 m / min. The resulting threads show high crystallinity and an orientation angle of 12 ° as determined from a wide-angle X-ray diagram. The threads show the following T / E / Mi / den values: 11.8 / 1.3 / 889 / 4.80.

Table 111
Heat treated ^{F: adcn}

Thread out
Dimensions

ad collection speed thread properties
T E

Wed

the

O.A.

6th 8.7 m / min. 7th 8.2 m / min. 8th 8.4 m / min.

15.9 1.8 946 5.98 8 ° 14.3 1.4 1056 3.58 9 ° 10.2 1.4 805 3.76 10 °

Example 9

The present example illustrates the preparation of an anisotropic oleum mass of mixed poly (p-

phenylene-p.p'-diphenyldicarboxamide / isophthalamide)
(90: 10) and threads from it.

In a centrifuge flask equipped with a stirrer yields 25.812 g of the above polyamide with an inherent viscosity of 2.51 and 146.27 g 100.72% sulfuric acid (3.2% free SO3) combined. The mixture is stirred at about 25 ° C to obtain a to form anisotropic mass, which is 15 percent by weight of the Contains copolymer. The DDA value of a 15 weight percent mass in 100.81% sulfuric acid is 98.2.

The mass produced in the above manner is placed in a Carpenter 20 stainless steel cell at 25 ° C. and extruded through a spinneret with 20 holes 0.076 mm in diameter into 10 percent strength by weight sulfuric acid at 25 ° C. The coagulated threads are wound onto a bobbin at a speed of 13 m / min, with water being dripped onto it. These threads are immersed in water (25 ° C), which is changed, until the water is no longer acidic. The leached with water, air-dried (21.1 ⁰ C, 65% relative humidity) yarns exhibit low crystallinity at an orientation angle of 28 ° and a velocity of sound of 6,10km / sec. Threads (in their own state) have the following T / E / Mi / den values: 5.2 / 4.7 / 273 / 10.72.

The dry threads produced above are passed through a pipe at a speed of 7.62 m / min passed at 600 ° C (device A). The threads drawn to 1.04 times show a high degree of crystallinity and have an orientation angle of 12 °. The threads have the following T / E / Mi / den properties (cooked thread): 8.8 / 1.4 / 706 / 12.26.

Example 10

The present example illustrates the production of an anisotropic oleum mass from mixed

poly-ip-phenylene-p.p'-diphenyldicarboxamide / terephthalamide) (55 : 45) and from threads dp out.

24.80 g of the above polyamide having an inherent viscosity of 6.47 are added in one with a stirrer Equipped centrifuge flask combined with 223.2 g of 100.70% sulfuric acid. The mixture is stirred at about 25 ° C until an anisotropic Mass results, which contains 10 percent by weight of the mixed polyamide. The DDA value of a 10.0 percent by weight The mass in 100.81% sulfuric acid is 100.

The above anisotropic mass is placed in a Carpenter 20 stainless steel cell at about 25 ° C. and extruded into 10 weight percent sulfuric acid at 29 ° C. through a spinneret with 20 holes 0.076 mm in diameter. The threads reach a take-up spool via a guide at a speed of 30.5 m / min. These extruded threads are ^{soaked in water (25 °} C.) which is changed until it is no longer acidic. The water-leached, air-dried (21.1 ° C, 65% relative humidity) threads are amorphous and have an orientation angle of about 40 °. The threads (in their own state) have the following T / E / Mi / den values: 9.7 / 8.7 / 256 / 3.42.

The above dried threads are fed into a tube with a rate of 7.62 nV min Has a temperature of 600 ° C (device A).

Filaments drawn 1.07 times show low crystallinity and an orientation angle of 18 ° The threads (in their own state) have the following T / E / Mi / den values: 22.5 / 3.2 / 668 / 2.77.

Be i s ρ i e I 11

The present example illustrates dry spinning an anisotropic HF mass containing poly (pbenzamide).

20 g of poly (p-benzamide) (ηπ * = 3.04) and 105 m anhydrous HF are placed in a polyethylene screw deckeifiasehe (180 ml volume) and 2 to ^ For hours the shaft was stirred with a Hastelloy stirrer through a hole in the top of the bottle stands out. The bottle is cooled from the outside by an ice / water bac. There will be a Rühropaleszen; showing, anisotropic mass is formed, which contains 16 percent by weight polymer (a similar 18% ig < Ground is birefringent when viewed between crossed polarizers). The 16% mass

f> o which has approximately the viscosity of glycerin is poured into eini cooled from the outside (at about 10 ⁰ C) Inconel Zelli, and a piston above the Lösunj pressure is applied to the Ausdüsen a yarn from a platinum spinnerette hole with 0 .0152 cm in diameter and 0.0076 cm in length in a 0.9 m long »Luche®» column with 15.2 cm ² , which byc! a warm stream of nitrogen, which is directed in the opposite direction to the thread flow, is heated to about 70 ° C

will. The pressure applied is about 1.8 kg / cm ² and the take-up speed is 140 m / min. The bobbin with the collected filament is boiled in water for 15-30 minutes, after which the filaments are sampled and dried prior to testing. The dry sample shows the following yarn tensile properties T / E / Mi / den: 4.7 / 2.8 / 276 / 3.2. The thread shows average crystallinity and an orientation angle] of 23 °. Been after the yarn 1 continuous to 2 seconds, successive Behänd- Ungen over a hot bar (350 ⁰ C, air atmosphere, tight, l, 008fache stretching)! And in a hot tube (device A, no stretching) subjected at 540 ° C the following thread tensile properties exist: T / E / Mi = 5.6 / 1.7 / 396. The thread has high crystallinity and an orientation angle of 25 °.

Example 12

20th

The present example illustrates the wet spinning of an anisotropic HF mass, the poly (p-phenylene terephthalmide) contains

28 g of poly (p-phenylene terephthalamide) (? Jinh = 4.0) are combined with 110 ml of anhydrous HF to form an anisotropic mass which shows Rühropalescence and contains 20 percent by weight of the polymer. This mass is placed in an Inconel cell, cooled to 10 ° C., and extruded through a 100-hole spinneret, each hole 0.063 mm in diameter. The threads are passed through a water bath (6 ^° C.) for a distance of 210 cm, after which they are at 71 m / m: n. be wound up. The pressure on the piston in the cell is 9.1 to 9.6 kg / cm ² . After washing overnight in running water and drying, the threads show the following thread tensile properties T / E / Mi / den = 8.7 / 5.4 / 260 / 1.72. The threads show medium crystallinity and an orientation angle of 21 °. The speed of sound is 6.35 km / sec. After stretching 1.05 times at 15 m / min. Hurch a. nitrogen-filled, heated tube (device C) in which the 5 cm central portion has a temperature of 562 "C, these threads show the following thread tensile properties T / E / Mi = 17.1 / 2.2 / 817. The threads have high crystallinity and an orientation angle of 11 °.

Example 13

The present example illustrates the preparation of anisotropic oleum compositions from poly (3,3'-dimethoxy-4,4'-diphenylene-4,4'-diphenyldicarboxamide).

2.0 g of the polyamide are dissolved in 8.0 ml of 100.95% strength sulfuric acid under anhydrous conditions dissolved by stirring slowly for 24 hours. It ss a clear isotropic solution forms. The addition of 0.2 g of the polymer and its dissolution provides one uniform, viscous, anisotropic mass showing a high degree of agitation rheumatism.

In another mass production, a similarly produced polymer sample (2.0 g, ? / inh = 1.67) under anhydrous conditions for 24 hours long at room temperature with 18 ml technical methanesulfonic acid (water content 0.30%, refractive index = 1.4293) stirred. The resulting viscous 6s mass is anisotropic, shows Rühropaleszenz and depolarized linearly polarized light when viewed through crossed polarizers.

Example 14

The present example illustrates determinations of anisotropic and isotropic phase relationships for HF, FSQ3H and CISOaH materials, which au different according to the invention useful Polymeri seeds and copolymers are produced. For a hurry System is given an exact determination while for the other systems summarized! Results (which are obtained in a similar manner, but ohm viscosity determinations) are tabulated are put together.

Part A

From the results given below and from FIG. 1 it can be seen that there is a discontinuity in the slope of a curve for mass viscosity versus polymer concentration for exemplary compositions according to the invention which contain poly (benzamide) in HF. The slope of the curve changes when the polymer concentration in the compositions is about 14 percent by weight ( ie, at the critical concentration). At lower polymerisa concentrations, the mass is clear and isotropic. However, if more polymer is added beyond the critical point, a second phase is formed which becomes visible at 15 ± 0.5% and is of lower viscosity and opaque and shows Rühropalescence. This anisotropic phase separates from the original clear phase with high viscosity.

The results relating to the above observations are summarized below. Two poly (benzamide) compounds in HF are produced by combining samples of the polymer with HF, either in a polyallomer test tube 3.82 cm in diameter and 10.2 cm deep, which is nearly transparent and equipped with a Teflon ®-TFÄ fluorocarbon cap through which a viscometer spindle extends into the mass, or in a polyethylene bottle approximately 4.45 cm in diameter and 10.8 cm deep capped through which a viscometer spindle extends. By Using an external ice / water bath, a constant temperature of 0 ° C is maintained. the The viscosity of the stirred mass is measured with a Brookfield Synchro-Lectric viscometer (model RV. manufactured by Brookfield Engineering Laboratories, Inc. Staughton, Mass.), with that of the Spindles No. 4 and 6 supplied by the manufacturer named above can be used. The viscosity calculations are performed at various concentrations by using the spindle indicator readings (obtained with different spindle settings, the spindle speeds and thus the amount of shear) can be correlated with the table values in the Brookfield Factor Finder. If more polymer is added the viscosity of the solution increases until a maximum value of about 3600 poise is measured when 13.4 percent by weight of polymer are present in the tube. If 20 ± 1.0 percent by weight polymer are present in the tube, the original clear phase disappears completely and it is only the anisotropic one Phase visible. The anisotropic phase (1) depolarizes when viewed through crossed polarizers in a microscope shows the plane of linearly polarized light, (2) shows a high degree of stirring tropalescence when stirred, and (3) is thixotropic.

Specific results from these determinations are compiled in Table IV below.

Table IV

g polymer /

Weight percent

Polymer

Spindle setting /

Spindelan / own

Reading

Calculated bulk viscosity in poise

Mass no.
free HI ".

(using ih = 3.9)

50 *) / 11.5
O.5 *) / 21.5

ml

water-

4/1 3.4 "Zn
14 / 19.4 "Ai

4h

"10

HN)

ifoOO

200

Mass no. 2 (using \ 9OmI on anhydrous HI ", the same polymer as in mass Ni. 1)

4 / 4.2% 100 ^s1 ) /10.5 2.1 6 / 6.2% 5 () *) / 48 19th «/8.1"/ ,, 2 (> *) / 90 90 10. 10.0 "'II P) / 51 1020 12/1 1.8 "/" O.5 *) / 44 1760 14/1 3.5 "/ ii 2.5 **) / HO 3200 Ib / 1 j. 1"/" l **) / 28 2800 19-17.5 "/ ii I * ¹ ) / 17th 1700 21 / 18.9 "/ ,, l ") / 8 800 22 / I9.b "/ i, 1 "*) / 4 400 24.'2I.O "/ (i ] **) / i 300

25th

^r ) Is wiril Spir.ce! KV No. 4 used. ^: *) If spindle RV No. h is used.

If in Fig. 1 the viscosity is plotted against the polymer concentration (both results in Table V
Phase relationships of anisotropic and isotropic masses are plotted in a curve, in which X represents the results with mass No. 1 and the results with mass No. 2 are represented by dots), it can be seen that the critical point is about 14 percent by weight Polymer occurs. The final viscosity of 200 to 400 poise is about 4 to 6% of the highest bulk viscosity measured or determined from Fig. 1 from the viscosity at the discontinuity in the curve.

(The above viscosity determinations are in containers with an uncalibrated viscometer spindle system have been carried out, which do not have optimal dimensions. Such are the relative viscosity determinations for the masses, it is accurate, but the absolute values are not necessarily correct.)

part B

By using the working methods described above the results given in Table V below for the given systems obtain. For the systems of Table V, viscosity decreases (similar to those shown above) observed qualitatively when any given mass changes from isotropic to anisotropic when the polymer concentration the mass is increased. The anisotropic masses show visual Rühropaleszenz and as above When viewed with a microscope through crossed polaroids depolarize the plane of linear polarized light. In Table V, the column headed "Polymer from" shows the polymer or copolymer indicated, its mass by the procedures of the present example Is evaluated. The inherent viscosity is also given for each polymer or copolymer.

Polymer of 7 / inh iiles / cn / solvent (0/0) It) Poly (p-phenylene terephthalamide) 4.0 visible HF 13th 20 to 21 Poly- (p-benzam: d) 2.86 FSOiH 9 12 to! 3 Poly- (p-benzam d) 3.9 HF 15 + 0.5 19th Poly- (p-benzam d) 2.8b HF 17th 18 to 19 Poly- (p-benzamd) 3.9 FSOiH 8th 10 Poly- (p, p'-phen5 lenbenzamide) 2.0 FSO3H 11 to 12 14 to 15 Poly- (p-phenylea-p, p-biphenyldicarboxamide) 1.55 FSO 3 H 9 15b Pory- (p-phenylene terephthalamide) 3.4 FSO 3 H 7 to 8 9 to 10 Poly- (p-benzam d) 2.8b CISO3H 8th 10 Poly (p-phenyl conductor terephthalamide) 3.4 CISO) H 7th 9 Poly- (p.p'-phen) lenbenzamide) 2.0 CISOiH 9 - Copoly-ip-phenylen-p.p-biphenyldicarboxamide / C-I 3.2 FSO3H 9 11th terephtha'amid) the same C-I 3.5 FSObH 8th 10 the same C-I 3.2 CISOiH 9 10 the same C-2 3.5 CISOiH 8th 10 Explanations: ^a ) A: Polymerisatkon / entralion in the mass, at dci visible op, or a / while Phase (anisotn ip) occurs. B: polymer concentration at which only one Pha se (anisotropic) ISI ^b ) Seems to form two anisotropic phases / u, one at about Γ> (icw ichtspro / enl uml a bei 14 to 2 (1 C cw ι hispm / cni

IC-I) Mnhcrlialtnr ion

(O

lc-21 MiilM.'1'li.illni 'um

Example 15

The present example illustrates the influence of the parameters (1) acid strength and polymer concentration, (2) the inherent viscosity of the polymer and (3) added salts on the inventive anisotropic sulfuric acid and oleum compounds, the poly (p-benzamide) and poly (p-phenylene terephthalamide) contain.

Acid strength and polymer concentration

The results of solubility tests on poly (p-benzamide) in sulfuric acid and oleum are summarized in Tables VI and VII. The solubility results are obtained as follows: An excess of polymer is added to the acid or oleum in a round-bottomed flask fitted with a stirring rod with ground glass bearing, at the end of which is attached a Teflon®-TFA fluorocarbon paddle stirrer. The temperature of the contents of the flask is moderate with a room temperature water bath. Portions of acid or oleum are added after long (e.g., 2 to 16 hour) periods of agitation and the maximum concentrations are determined visually as the point at which no solid material can be seen. Further proportions of acid or oleum are added to the liquid, anisotropic masses exhibiting stirring tropalescence until the mass is visibly clear. The polymer concentration which is present when the mass becomes visibly clear is taken as the critical concentration point. The results shown are for poly (p-benzamide) samples with inherent viscosities of 2.72 and 1.53

Using the results from the above tables, phase diagrams can be drawn as shown in FIG.

Results from similar determinations be; eir 5 poly (p-phenylenerephthalamide) sample with an inr Rent viscosity of 3.32 is shown in Table V. One derived from these results. The phase diagram is shown in FIG. 3 shown.

10 Table VIII

Solubility of poly- (p-phenylene terephthalamici)
(rjinh = 1.53) in sulfuric acid

'5 H2SO4
(%)

Maximum solubility ¹ )

Kr, table-Pur.KiM

97.3

99.2

100.5

4.6

7.8

11.7

8.65

(a) Visually as a concentration (percent by weight Polymeric at which no solid particles are observed

(b) Weight percent polymer in the mass.

Inherent viscosity of the polymer

Table VI

Solubility of poly (p-benzamide) (// mh = 2.72) in sulfuric acid

H 2SO4

Maximum solubility ¹¹ }

96.3

97.3

99.2

100.5

102.3

104.5

4.5
7.14

10.3

12.7

14.4

14.5

Critical point ^c )

none

none

8.67

8.67

8.55

8.76

(b) Is determined visually as the concentration (percent by weight polymer) at which no solid particles are observed will.

(c) Weight percent polymer in the mass.

It is expected that the critical concentration for a given polymer in a given sauna with the molecular weight (or the apparent inherent viscosity) of the polymer: varies. Results for poly (p-phenylene terephthalamide) samples with different inherent viscosities are shown in Table IX. The following procedure is used to achieve these results: One a sufficient and known amount of polymer is completely dissolved. The resulting anisotropic Masses are then (while mixing with a spatula) with the same acid or with oleum titrated until the masses are visually clear if one

Subject to shear stress. This procedure can be used due to the very high bulk viscosity Require dissolution of the polymer from several days to several weeks. In general, this is the way of working more satisfactory for polymers, their inherent ones

^A ^ viscosity is below 3.5.

Table IX

Critical points (or concentrations) of
Poly (p-phenylene terephthalamides) in 100.2% strength
sulfuric acid

Table VIl

Solubility of
sulfuric acid

H.'SO.

Polymer,

7 / inh

Critical
Concentration ⁸ )

Poly- (p-bcnzamicl) (7 / mh = 1.53)

in

Maximum solubility ¹ )

(1.7
11th
I 5.5

Critical point ^H )

1.24
2.23
2.64
2.70
2.76
2.80
3.06
3.37

10.81
9.47
9.52
9.13
8.92
8.95
8.77
8.39

4.60

(a) Determined visually as the concentration (percent by weight polymer) at which no solid particles are observed.

(b) Weight percent polymer in the mass.

(aj weight percent polymer in the mass.

In Table X are similar results for
Polv- (p-bcnzamid) indicated. The results of this
Tables show a trend towards lower critical

Concentrations as the inherent viscosity of the polymer increases. The results of Tables IX and X are in FIG. 4 and 5 respectively.

Table X

Critical points (or concentrations) of poly- [p-benzamide) in sulfuric acid

Polymer, 7 / inh H 2SO., Critical (%) Concentration ⁴ )
(%) 1.67 99.5 9.88 1.67 i00.3 9.55 1.75 99.7 9.74 1.75 100.5 8.57 1.75 100.5 -10.00 2.16 100.2 9.67 2.66 100.2 9.22 2.76 100.2 9.30 2.76 100.3 9.69

(a) Weight percent polymer in the mass.
Added salts

the

i ^ n. Addition of salts has the consequence that Oleum masses of (I) poly (p-phenylene terephthalamide) (? Jinh = 2.80) and (II) poly (p-benzamide) (ijinh = 2.7?) each turn into a solid slurry after a given amount of salt has been added. The for the The amount of salt required to form the pulp is shown in Table XI below for compositions which initially contained 3.0 g of the polymer and 27.0 g of 100.2% strength sulfuric acid.

Table Xl

Mass / salt solidification relationships

Polymer
in bulk

salt

Salt mengc for
the appearance
of a Keststoll mash

Na ₂ H PCM 0.6 g Na ₂ HPOi 0.8 g Potassium acetate 0.6 g Na ₂ SOi 0.8 g

The salts are added in proportions of 0.2 g. The masses remain flowable and show rühropalescence, if smaller amounts of salt than indicated in the table are present in any mass.

Example 16

The present example illustrates the influence of temperature and percentage by weight of polymer on the critical concentration points for poly (p-benzamide) and poly (p-phenylene terephthalamide).

Poly (p-benxamide) with an inherent viscosity of about 2.72 is used in the following compositions. There are masses with different concentrations,

namely 9.2, 10.0 and 12.0% in 99.5 percent by weight H2SO4 produced at room temperature. Each of these masses is anisotropic at this temperature. If the If the temperature is gradually increased, they change three bulk samples at 29, 53 and 77 "C, respectively, into essentially isotropic masses.

Poly (p-phenylene terephthalamide) having an inherent viscosity of about 3.16 is used in the following compositions. Masses with different concentrations, namely 9.2, 10.0 and 12.0%, are produced in 100.3 percent by weight H2SO4 at room temperature. Each of these masses is anisotropic at this temperature. As the temperature is gradually increased, the three mass samples at 41, 67 and 109 ⁰ C, respectively, are converted into essentially isotropic masses.

The points at which each of the above samples transitions into a substantially isotropic mass are the critical volume concentration points for each sample.

The present example shows that for a particular polymer / liquid medium this point is different from the Temperature of the mass and the percentage by weight of polymer depends on it.

Example 17

This example illustrates the percentage of crystallites oriented at an angle, which is half as large as the orientation angle of the thread axis, in the case of special polymer samples some of the above examples in the as-extruded state. The intensity curve of the diffraction diagram of the thread is not necessarily a curve similar to the Gaussian curve for each of these samples.

Using the as-extruded orientation angle of each of the following samples of Method 1 described above, and the percentage of crystals is also determined in the determined manner described above. The difference, if any, in the specified Orientation angle value in comparison with the values given in the preceding examples according to Method 2 is due to the greater degree of accuracy of Method 1. The values for the

4s orientation angle and the percentage of crystallites given in Table XII below. As the table shows in each case, more than about 50% are the Crystallites in half of the orientation angle! aligned.

Table XIl example

Orientation angle

"/ 0 to

aligned

Crystals

30 ^u

24 °

25 ° 20 "

70
64
6b
56

IΪ ic ι / 'Lt 7 l'latl Zcichnumien

Claims (3)

(Π) Claims: 1. Optically anisotropic mass, consisting essentially of (I) polymer which consists essentially of at least one type of carbocyclic aromatic homo- or mixed polyamide with chain-extending bonds of each aromatic nucleus which are coaxial or parallel and oppositely directed, and
at least one liquid medium, namely (A) concentrated sulfuric acid, (B) hydrofluoric acid and / or (C) chlorine, fluorine or methanesulfonic acids,
wherein the polymer is present in a concentration above the critical concentration point. 2. Composition according to claim 1, characterized in that the liquid medium is concentrated sulfuric acid at a concentration above about 98 weight percent that free SCb may contain. 3. Composition according to claim 1, characterized in that the concentration of the polymer is at least about 5 percent by weight of the mass. The threads or fibers have excellent tensile properties, especially an initial modulus of at least 200 g / denier, preferably at least 300 g / denier, and most preferably above about 400 g / denier and / or a tenacity of at least about 5 g / denier. Have preferred threads or fibers in the state after extrusion, an elongation at break in addition to a high initial modulus and high strength of at least about 5%. The invention is explained in detail below with reference to the drawings. It shows Fig. 1 shows a typical relationship between viscosity and polymer concentration in the compositions according to the invention which is the critical concentration point 15th