KR20010014109A - Polyester fibres and filaments and method for producing them - Google Patents

Abstract

The invention relates to fibres or filaments consisting mainly of polyethylene terephthalate as a fibrous polymer, containing 0.1 to 4 wt. % in relation to said fibrous polymer of a polyamide from the following group: polyepsiloncaprolactam, polyamide 12 and amorphous polyamide 6I/6T; mainly in the form of intercalations. The polyamides have a relative viscosity in certain areas and the polyepsiloncaprolactam has a particle size of less than 3 mum in the melt. 0.02 to 1.0 wt. % of an organic phosphorous stabiliser selected from the class of phosphonic compounds is also provided in the polymer mixture for preventing yellowing. The winding speed for the filaments is up to 8000m/min. for producing partially oriented yarns. The invention also relates to a method for producing novel polyester fibres and filaments.

Description

Polyester fibers and filaments and methods for producing them

Fibers, or filaments, each containing a small amount of additives can be processed into melt spinning depending on the composition of the mixture and are known to induce an increase in elongation at break for undrawn yarns at partially the same draw-off speed. have. For example, EP 0 041 327 B1 describes mixtures of polyesters with liquid crystal materials (LC polymers). Such added liquid crystal materials, however, are expensive and cause problems in radiation. Moreover, irregularities in the yarns and breakage of the fibers are expected.

EP 0 080 274 B1 describes the addition of polyhexamethylene adipamide and polyethylene glycol to fiber forming polymers (polyethylene terephthalate). This increases elongation at break. However, such mixtures have been found to be problematic during spinning. That is, as shown in Tables 1 and 2 below (see Additive Types AS2503, A3 and A4), breakage of the fibers occurs frequently. EP 0 080 274 B1 explicitly mentions that in addition to polyolefins such as polyethylene or polypropylene and polyethylene glycol, poly-epsilon-caproamide cannot be mixed with polyethylene terephthalate as a major component in the polymer. According to the examples and claims, in addition to polyethylene glycol, polyhexamethylene adipamide poses a question as an added polymer, which suggests to those skilled in the art that polyamide 6 has other properties such as radiation behavior and product properties than polyamide 66. It means that it leads to a much worse result with respect to the requirements, and in the end it is no longer considered as an additive.

As used herein, the term “insoluble polymer” means a fiber forming thermoplastic polymer and a polymer that forms a melt of two phases at spinning temperature. Such melts were examined under a microscope and the micrographs show a two phase system in which finely divided droplets of insoluble polymer were continuously dispersed in a fiber forming polymer matrix.

The above conditions under which an insoluble polymer is located in the fiber forming matrix are fundamentally different from the so-called anisotropic melts being formed in the temperature range in which the thermoplastic polymer is melt spun. Such anisotropic conditions can occur if the liquid crystal material has a polyester spinning polymer, for example, as described in European Patent Publication No. 0 041 327, and is conditioned by the action of shear force.

Aslan et al. J. Appl. Polym. Sci., Vol. 55, 57-67 (1995) describes spinning a mixture of polyethylene terephthalate and nylon 6. Spinning speeds up to 3600 m / min were found at 5% by weight of polyamide 6. In this case, a decrease in trimming strength was observed compared to the unmodified control.

J. Appl. Evstatiev et al. Polym. Sci., Vol. 67, 723-737 (1998) The molecular behavior of the mixture was studied to determine the compatibility of the mixture of PET / PA6 in a 40/60 weight ratio. It has been shown that fibers with a 60% proportion of PA6 in the polyester are, however, completely uneconomical.

Many Japanese publications cited by Aslan et al. And considered to be in the field of basic technical background relate to the mixing of polyesters and polyamides. J61266616-A (Derwent Abstract Form) describes the prevention of fibrillation in polyester / polyamide mixtures in high concentration relations and J56015414-A (Derwent Abstract Form) is used for nylon 6 The addition of 10 to 30% of polyester to this is described. As an additive, European Patent Publication No. 0 047 464 B1 describes polymethacrylic acid esters as polymerization additives for various acrylic polymers, more particularly polyethylene terephthalate (PET).

As shown in European Patent Publication No. 0 047 464 B1 and European Patent Publication No. 0 631 638 B1, the latter publication discloses imidized additives, radiation reliability is limited to such cases. Use of these materials means increased fiber breakage.

European Patent Publication No. 0 631 638 B1 discloses a fibrous polymer comprising, in percentage terms, 0.1 to 5% by weight of 50 to 90% imidized polymethacrylic acid ester in the form of an inclusion essentially. Such a fibrous polymer has a better spinning aspect than the fibrous polymer disclosed in European Patent Publication No. 0 047 464 B1, although no numerical examples have been given in connection with the spinning. A serious disadvantage of polymethacrylic acid ester additives is their relatively high price. In particular, because of the price of such imidized polymethacrylic acid esters, processes requiring such additives are not economical. Moreover, the described additives are not available on a large scale and their use also depends on several producers.

It should be further pointed out that the production of partially oriented and trouble-free yarns suitable for draw-texturing as well as their subsequent processing are described by way of example in European Patent Publication No. 0 631 638 B1. It is not. Elongation at break is given at spinning speeds of 3500, 6000, 7000 and 8000 m / min. In this case, however, the elongation value is not suitable for use advantageously in subsequent processing in texturing. For example, elongation at break of 65% is mentioned at a spinning speed of 6000 m / min. Yarns with such elongation, however, cannot be used for trouble-free draw-texturing and its use will tend to be done exceptionally rather than routinely. In fact, the typical elongation at break in draw-texturing is about 120%. The elongation value at spinning speeds above 3500 m / min relates to highly oriented yarns for industrial and textile applications.

According to the details given in European Patent Publication No. 0 530 652 B1, if a spinning speed of 6000 m / min is exceeded, a special purpose spinning apparatus is required. This patent document features a porous tube under the spinneret that delays cooling and stabilizes the spinning process. Such a method, based on passive cooling by drawing air, due to the movement of the filaments, is known as a difficult spinning process. A serious disadvantage of the described device is the lack of flexibility or limited flexibility, especially in spinning processes.

It is somewhat surprising that in the examples of European Patent Publication No. 0 530 652 B1, no critical spinning speed range of 4000 to 6000 m / min is mentioned. This is however the very scope in which radiation crystallization is clearly beginning to play a role and thus is of great interest. In this speed range, given the details, we are using a transverse blowing process. Surprisingly, even at spinning speeds of 6000 m / min or less, this extremely important speed range is not described and because passive cooling techniques are used at higher speeds, which are fairly stable for difficult and / or difficult to spin polymers. It is believed that problematic conditions may occur in the spinning process. In this case, the lateral blowing process is only used to a limited extent for the polymer mixture described and the process as a whole is thereby substantially limited.

Although the prior art documents describe a limited number of polymer mixtures that may be suitable for making fibers with improved elongation at break. The acceptable spinning properties of the mixtures, if any, are based on the European Patent Publication No. 0 631 638 B1; In order to ensure good spinning properties in this publication, special spinning devices are additionally needed, as at certain spinning speeds (see European Patent Publication No. 0 530 652 B1).

Mixtures of polyester and polyhexamethylene adipamide (see European Patent Publication No. 0 080 274) are not described in the prior art with reference to European Patent Publication No. 0 631 638 B1.

Moreover, the prior art does not consider the problem recognized by the inventors of the present invention, namely that the melt is somewhat markedly yellowed when the polyamide is mixed with polyethylene terephthalate. The product emitted from this can only be rejected as unprocessable and consequently unusable due to yellowing.

The present invention relates to polyester fibers and filaments comprising a small amount of additives and methods of making them.

One object of the present invention is very economical due to the large increase in elongation at break and the use of small amounts of ready-to-use additives and polymer mixtures for producing polyester fibers and filaments, which have good spinning properties and comprise up to 5% polyamide as an additive. And yellowing is reduced or eliminated to provide a process by which the product can be marketed.

This object can be achieved by fibers and filaments as claimed in claim 1 and by a method as claimed in claim 12.

The dependent claims relate to further developed advantages of the present invention.

Surprisingly, fibers and filaments, which can be prepared from polymer mixtures of polyethylene terephthalate and small amounts of poly-epsilon-caprolactam (polyamide 6), polyamide 12 or polyamide 6I / 6T, are very particularly when produced at high spinning rates It has been found that it can have a high elongation at break and at the same time exhibit excellent spinning behavior. Although mixtures of polyethylene terephthalate and polyamide 6 are known, they are new to the effect of inducing an increase in elongation at break in combination with good spinning properties.

In addition, even at relatively low additive concentrations, elongation very well suited for subsequent processing of the filaments in draw-texture processing was obtained. For polyamide 12 and polyamide 6I / 6T such effects are not yet known.

As a further important feature of the invention, such polymer mixtures may comprise organic phosphorus stabilizers selected from the group consisting essentially of the phosphorus compound family. This is related to the removal of yellowing in a surprising way.

The polymer mixtures used in the process of the present invention can also be spun at high spinning speeds using conventional lateral blowing without any problem.

Other well-known cooling means are also suitable, for example, devices that passively cool by drawing air in order to quickly move the fibers or devices that direct air to the fibers, located in the middle of the fiber array.

Still, using a mixture of polyethylene terephthalate / polyamide 6, polyethylene terephthalate / polyamide 12, and polyethylene terephthalate / polyamide 6I / 6T to improve the elongation at break in products spun at high speeds significantly improves productivity. It is possible and it has not yet been found that the mixture has excellent radioactivity despite its high elongation. Moreover, for polyamide 6 and polyamide 6I / 6T, they are considerably cheaper and more readily available than additive components (polymethacrylic acid alkyl esters) as described in EP 0 631 638 B1.

More specifically, Grilon, EMS-CHEMIE AG, Chem-7013 Domat, Switzerland Commercially available polyamide 6 products such as forms F34, F40, F47 and F50 have proven to be good additives. More preferably, the relative viscosity is in the range of 2.5 to 5.2 when measured at a concentration of 1% concentrated sulfuric acid at 20 ° C. These lead to significant increases in elongation at break.

As for the effect of increasing the elongation at break, the relative viscosity of the additive polyamide 6 does not play a decisive role over a wide range. Usually, the range of 2.5 to 5.2 is preferred. At the same time taking into account good spinning behavior, the relative viscosities of 2.8 to 4.1 appear to be very suitable. Especially suitable are relative viscosities in the range of 2.8 to 3.7.

Particularly suitable additives for polyamide 12 are commercially available Grilamid, produced by EMS-Chemie AG. It is type L20 and its relative viscosity is in the range of 1.85 to 1.95 as measured in m-cresol containing 0.5% concentration at 20 ° C. Polyamide 12 having a relative viscosity in the range of 1.6 to 2.3 is generally suitable. The range of 1.8 to 2.0 is preferred.

The third type of polyamide, polyamide 6I / 6T, is partly an aromatic copolyamide, consisting of the monomers hexamethylenediamine, isophthalic acid and terephthalic acid, as indicated by the nomenclature. For use in accordance with the present invention, with respect to the variable composition range (ratio of isophthalic acid to terephthalic acid), it has been found that polyamide 6I / 6T grades give good results if they have an amorphous structure. Within this population, from the point of view of the relative viscosity at low range, as opposed to the description in the prior art with respect to nylon additives in PET, an item having such an unexpected thing is preferred (see European Patent Publication No. 0 080 274, supra). B1, page 9, lines 30 and 31 of Example 8.). When measured at a concentration of 0.5% in m-cresol at 20 ° C, the maximum relative viscosity is preferably 1.50. The range of 1.35-1.45 is preferable. Corresponding commercial product is Grivory of SM-CHEmie AG. G16 is suitable, which is amorphous with a 70:30 isophthalic acid to terephthalic acid ratio and has a relative viscosity of about 1.42.

In order to stabilize the polymer mixture to prevent yellowing, the following groups of phosphorus compounds are preferred: 2-phosphono propionic acid (= 2-carboxyethanephosphonic acid), ethoxycarbonyl-methanephosphonic acid ethyl ester and Irganox 1222. Such compounds are advantageous because they can be added during polycondensation of the polyester, in part because they can reduce the molecular weight of the polyester. Small additions can be made with the polyamide additive.

The concentration of phosphorus compound for use according to the invention is in the range of 0.02 to 1.0% by weight. Preferably it is 0.05 to 0.6 weight%.

The addition of the polyamide additive to the polyethylene terephthalate can be carried out, for example, using a so-called "melt conditioning" method of continuous modification of the polymer melt (see German Patent Publication No. 4,039,857 C7). The contents of this German Patent Publication No. 4,039,857 C2 are incorporated herein by reference. In this German patent publication, some of the melt is withdrawn from the main melt stream. This portion of the melt is administered to a secondary flow extruder and is acted upon and dispersed by additives in the form of granules, beads or preferably powders. The dispersed and mixed melt concentrate is then directed to the main melt conduit where it is diluted to final concentration.

Instead of such a "melt control" method, it is possible to produce a pure additive melt, for example using a preliminary plasticizer / compressor, and to inject it into the main melt stream. The mixing elements are arranged correspondingly to ensure homogenization and dispersion of the additive in the base polymer (polyethylene terephthalate = PET).

If the starting product is PET granules which are melted in the spinning extruder, it is possible to add the additives directly to the PET granules in the spinning extruder, to disperse the additives in polyethylene terephthalate and to spin the melt mixture. The additive is preferably in powder form to obtain a satisfactory dispersion.

The additives may be added as pure substances or in the form of a master batch. In addition, further additives (eg stabilizers according to the invention) can be spun together with other materials. The polyethylene terephthalate itself may already comprise additives such as matting agents (titanium dioxide), stabilizers (more particularly those necessary for the invention), catalysts and the like according to the invention. In the context of the present invention, "polyethylene terephthalate" (PET) or "polyester" means at least 80% polyethylene terephthalate and diols other than ethylene glycol, such as diethylene glycol, tetramethylene glycol, or acids other than terephthalic acid, By polyester is meant for example 20% units derived from isophthalic acid, hexahydroterephthalic acid and dibenzoic acid.

If necessary, polyethylene terephthalate with branched preparations with small amounts of 3 to 4 functional alcohols or acid groups, trimethylpropane, trimethylethane, pentaeryrite, glycerol, tremesin acid, trimellitic acid or pyromellitic acid Can be modified.

The starting polyester may contain well-known additives such as sodium-3,5-dicarboxybenzene sulfonate in order to reactively modify the depigmentation.

In melt conduits, for example, dynamic and / or static mixers can be used. To this end, a dynamic and / or static mixer can be placed directly upstream of the spinneret.

In particular, the droplet size of polyamide 6 in the polyethylene terephthalate matrix, as investigated in the examples of the present invention, is from 250 to 400 nm, ie less than 0.5 μm. On the other hand, the droplet size mentioned in European Patent Publication No. 0 080 274 B1 is between 0.5 and 3 μm. Thus, if the droplets in the matrix are very finely divided, the polymer mixture is better than the large inclusions, which are relatively far from each other because of their large size at the same concentration and thus have a less homogeneous distribution. It shows radiation behavior. Particle size was measured with a sample from a molten mixture that was not spun yet, with the particles still spherical.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but is not limited thereto.

Conventional radiators, such as those well known to those skilled in the art, have been used and are described, for example, in Ullman's Encyclopedia of Industrial Chemistry, vol. 10, Fibers, 3, General Production Technology, page 535 is illustrated in Figure 26.

Example 1

Table 1 shows the results of the spinning test at a winding speed (Vwick) of 4950 m / min. Spinning temperature is 292 ° C for PA6 and Grilamid L20 and Grivory In the case of G16 and G21, it was 295 degreeC, and the range of 280-295 degreeC is preferable. Conventional lateral blowing processes were used to cool the filaments. After the lateral blow wind, the yarn is wound into a cold double bobbin. The bobbin or curling speed, ie the true spinning speed, was 5000 m / min in all cases. To prepare the yarn, a conventional, quenched polyethylene terephthalate, which is normally used in the textile industry, used M764 supplied from EMS-Chemie AG. The additives used were poly-epsilon-caprolactam having the product names A23, F34, F40, F47 and F50 of EMS-Chemage and polyhexamethylene adipamide having the product names of AS2503, A3, A4 and A5 from BASF. . The additive in powder form was kneaded onto polyethylene terephthalate granules. The concentrations of additives PA6 and PA66 were added in each case up to 1.25% of the polyethylene terephthalate weight. For PA12 and PA6I / 6T, up to 3% by weight was added as a chip.

Comparing between the various additives, the use of A23, F34, F40, L20 and G16 is no problem and the radiation behavior is good while the use of polyhexamethylene adipamide, as shown in the direct comparison, shows four It happens frequently. In the case of the mixture of polyethylene terephthalate and A5, trimming occurred even in connection with a pirn, so that no bobbin could be wound up. In the case of G21 having a higher viscosity than G16, there was no increase in elongation.

Example 2

The results in Table 2 were obtained from experiments with 6 threaded spinning units. Spinning temperature and winding speed (Vwick) were 288 ° C. and 4950 m / min, respectively. Zero speed test Except for the "zero 2" bobbin speed was 5000 m / min. In the "zero 2" test (typical, no additives), the bobbin speed was 3225 m / min. In this case, the "melt control" method commonly used for melt reforming in continuous polyester polycondensation plants with directly connected spinners was used. Additives F34, F40 and AS2503 were used at concentrations of 1.5 and 2% by weight. Also in this case, F34 and F40 showed no problem radiation mode, but frequent use of AS2503 caused frequent trimming. Of all the polyhexamethylene adipamide types of Example 1, AS2503 has the relatively best running aspect, but such aspect is still substandard.

Table 3 shows the spinning data of the texture yarns. The qualitative data of the modified polyester is the same as that of a good, conventionally made texture yarn. A huge increase in productivity in the spinning portion is an advantage, so that the POY yarns are spun at only about 3200 m / min.

In the case of fiber (staple fiber) production, there is an increase in productivity, in which case the melt spinning operation is significantly reduced, but later the stretching is considerably larger (see the field technicians in Ullmann's Encyclopedia of Industrial Chemistry, 5th edition 10, Fibers, 3). , As understood in General Production Technology, pages 550-561). The increase in productivity in fiber production, in particular, is associated with a correspondingly higher discharge rate in melt spinning as well as an increase in the draw ratio in the fiber production line.

Legend of Tables 1 to 3

The abbreviations in Tables 1 to 3 have the following meanings.

brand producer polymer Relative viscosity (1% concentration in sulfuric acid) A23 Grilon A23 Ems-chemie PA6 2.40-2.55 F34 Grilon F34 Ems-chemie PA6 3.35-3.50 F40 Grilon F40 Ems-chemie PA6 3.60-3.75 F47 Grilon F47 Ems-chemie PA6 4.00-4.20 F50 Grilon F50 Ems-chemie PA6 5.00-5.40 L20 Grilamid L20 Ems-chemie PA12 1.85-1.95 *** G16 Grivory G16 Ems-chemie PA61 / 6T (70/30) 1.42 *** G21 Grivory G21 Ems-chemie PA61 / 6T (70/30) 1.52 *** AS2503 Ultramid BASF PA66 2.5 AS2503 A3 Ultramid A3 BASF PA66 2.5 A4 Ultramid A3 BASF PA66 2.5 Zero: * Grlene M764 Ems-chemie PET ** Zero-1: * Grlene M764 Ems-chemie PET ** Zero-2: * Grlene M764 Ems-chemie PET **

* Base polymer = unmodified PET (quenching) for conventional textile applications

** Relative viscosity of PET granules 1.64 as measured in 1% solution in m-cresol

*** Relative viscosity measured in m-cresol 1% solution at 20 ° C

Table 1 (Pilot Factory)

Additive type A23 F34 F40 F47 F50 AS2503 A3 A4 zero L20 G16 G21 amount(%) 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25 - 3.0 3.0 3.0 stabilizator**(%) - 0.15 - - - - - - - 0.3 0.3 0.3 EB (%) 69.6 103.8 106 106.3 107.1 101.9 114.8 123.9 64.7 155.8 141.2 39.8 TS (cN / drex) 2.89 2.63 2.5 2.47 2.49 2.4 2.3 1.81 3.07 1.64 1.54 1.75 Titer 126.4 126.8 126.5 126.2 126.5 127.1 126.2 125.2 124.9 126.1 125.1 125.1. Winding speed (m / min) 4950 4950 4950 4950 4950 4950 4950 4950 4950 4950 4950 4950 Relative Viscosity * 2.475 3.425 3.675 4.1 5.2 2.5 2.6 3.4 - 1.90 1.42 1.52 Radiation pattern Very good Very good Very good Good middle Bad Bad Very bad Good Very good Good middle color yellow White yellow yellow yellow yellow yellow yellow White White White White

Relative viscosity of the PA additive, measured at a concentration of 1% concentrated sulfuric acid; L20, G16, and G21 relative viscosities measured at m-cresol 0.5% concentration

** 2-phosphono propionic acid

(EB = Elongation at Break, TS = Tensile Strength)

Table 2 (6 dread items in the production plant)

Additive type F34 F34 F40 F40 AS2503 AS2503 Zero-1 Zero-2 amount(%) 1.5 2 1.5 2 1.5 2 - - EB (%) 121.6 151.6 122.9 153 120.3 137.5 65.8 121.2 TS (cN / dtex) 2.11 1.84 2.1 1.81 2.14 1.98 3.1 2.34 Titer (dtex) 124.1 124.3 124 124.9 124.6 124.9 124.1 125.1 Winding speed (m / min) 4950 4950 4950 4950 4950 4950 4950 3170 Radiation pattern Very good ** Very good ** Very good ** Very good ** Bad *** Bad *** Good Very good color yellow yellow yellow yellow yellow yellow White White

** No problem for 240 minutes of travel time

*** Problems every 13 minutes on average

TABLE 3

Additive type F34 F40 Zero-2 amount(%) 1.5 1.5 - EB (%) 26.9 26.1 21.2 TS (cN / dtex) 3.92 3.96 4.05 Titer 75.1 75.4 75.9 Vlex (m / min) 800 800 800 Elongation 1.7 1.705 1.695 Driving characteristics Very good Very good Very good Particle size 250-400 250-400 -

Claims (19)

In essence, in fibers and filaments consisting of polyethylene terephthalate as a fiber or filament forming polymer, polyamide as an additive polymer, and at least one stabilizer, the fibers and filaments are polyamides predominantly in the form of inclusion bodies, In relation to 0.1 to 4% by weight, the polyamide is selected from the group consisting of poly-epsilon-caprolactam, polyamide 12 and amorphous polyamide 6I / 6T, said poly-epsilon-caprolactam being 3 μm in the melt It has a particle size of less than and has a relative viscosity in the range of 2.5 to 5.2 when measured at a concentration of 1% of concentrated sulfuric acid, the polyamide 12 has a relative viscosity in the range of 1.6 to 2.3 when measured at a concentration of 0.5% of m-cresol. The amorphous polyamide 6I / 6T has a phase up to 1.50 when measured at a 0.5% concentration of m-cresol. Having a large viscosity, at least one organic phosphorus stabilizer is present in the molten spinning polymer mixture in an amount of 0.02 to 1.0% by weight, the stabilizer being selected from the group consisting of phosphorus compounds, the filament winding speed being 8000 m / min Fibers and filaments, characterized in that to reach to produce a partially oriented yarn. The method of claim 1, wherein the phosphorus compound is 2-phosphono propionic acid, ethoxycarbonyl-methanephosphonic acid diethyl ester and Igranox Fibers and filaments selected from the group consisting of 1222. The fiber and filament of claim 1 or 2, wherein the phosphorus compound is comprised in an amount equal to 0.05 to 0.6 wt% of the polymer mixture. Fiber and filament according to any one of claims 1 to 3, wherein said polyamide is added in an amount equal to 0.5 to 3% by weight of said fiber polymer. The method according to any one of claims 1 to 4, wherein the relative viscosity in the case of poly-epsilon-caprolactam is in the range of 2.8 to 4.1 as measured at 1% concentration of concentrated sulfuric acid. Fibers and filaments. 6. The fiber and filament of claim 5, wherein the relative viscosity of the poly-epsilon-caprolactam is in the range of 2.8 to 3.7. The fiber and filament of any one of claims 1 to 6, wherein the melt particle size of the poly-epsilon-caprolactam is less than 1 μm. 8. The fiber and filament of claim 7, wherein the melt particle size of the poly-epsilon-caprolactam is less than 0.5 μm. The method according to any one of claims 1 to 4, wherein the relative viscosity of polyamide 12 is in the range of 1.8 to 2.0 when measured at a concentration of 0.5% of m-cresol. 10. The method of claim 9, wherein the relative viscosity of the polyamide 12 is in the range of 1.85 to 1.95. The relative viscosity of the amorphous polyamide 6I / 6T according to any one of claims 1 to 4, characterized in that it is in the range of 1.35 to 1.45 as measured at a concentration of 0.5% of m-cresol. Fiber and filament. A method for producing melt spun fibers and filaments consisting essentially of polyethylene terephthalate by polycondensation or melting of polyester fiber polymers followed by melt spinning, wherein the fiber polymer is subjected to poly-epsilon-caprolactam, poly 0.1 to 4% by weight of a polyamide selected from the group consisting of amide 12 and amorphous polyamide 6I / 6T, 0.02 to 1.0% by weight of a stabilizer selected from the group consisting of phosphorus compounds, and if necessary additional additives, The poly-epsilon-caprolactam has a relative viscosity in the range of 2.5 to 5.2 when measured at a concentration of 1% of concentrated sulfuric acid, and the polyamide 12 has a relative viscosity of 1.6 to 2.3 when measured at a concentration of 0.5% of m-cresol. Wherein the amorphous polyamide 6I / 6T has a maximum relative of 1.50 when measured at a 0.5% concentration of m-cresol Having a viscosity, in the case of poly-epsilon-caprolactam, melt dispersion is carried out with a particle size of less than 3 μm, and the winding speed of the filaments is set to 8000 m / min to produce partially oriented yarns , Melt spun fiber and filament manufacturing method. 13. The process of claim 12 wherein polyethylene terephthalate is selected as the fiber polymer. The method according to claim 12 or 13, wherein 0.5 to 3% by weight of polyamide is added to the fiber polymer. The compound of claim 12, wherein the phosphorus compound is 2-phosphono propionic acid, ethoxycarbonyl-methanephosphonic acid diethyl ester, and Irganox. 1222 and the phosphorus compound is added to the fiber polymer in the course of polycondensation or with polyamide. 17. The process according to any one of claims 12 to 16, wherein for the continuous modification of the polyethylene terephthalate melt, a portion of the melt is taken from the main melt stream and placed in a secondary flow extruder for polyamides, if necessary stabilizers and / or other additives. After being dispersed and dispersed, the dispersed and mixed melt concentrate is transferred back from the auxiliary flow to the main melt conduit, diluted to a final concentration and then spun the melt mixture. The additive melt of any one of claims 12 to 15, wherein the additive melt consisting of polyamide and any additional additives is prepared using a preliminary plasticizer and injected into the main melt flow of polyethylene terephthalate. Then homogenizing and dispersing in the base polymer using a mixer followed by spinning the resulting melt mixture. 16. The polyethylene terephthalate granules according to any one of claims 12 to 15, wherein the polyethylene terephthalate granules are used as starting materials, melted in a spinning extruder and the polyamide and any additives directly Adding to the spinning extruder to disperse in polyethylene terephthalate and spin the resulting melt mixture. 19. The method of claim 16 or 18, wherein the polyamide is added in powder form.