RU2602883C2 - Low-pill polyester fibre - Google Patents

Abstract

FIELD: textile.

SUBSTANCE: group of inventions relates to textile industry. Fibre is based on polyester, consisting of aromatic dicarboxylic acids and aliphatic diols. Fibre contains from 0.5 to 10 wt% of inorganic particles with size from 0.5 to 5 mcm. Particles are metal salts of first and second main groups of periodic table. Salts contain chlorides, fluorides, bromides, iodides, carbonates, phosphates, nitrates, hydrocarbonates, sulphites and mixed salts thereof. Polyester is extruded and moulded to produce filaments, drawn, twisted, fixed and cut to required length. Non-dyed raw fibre needs from 200 to 700 flex abrasion tours. Fibres have strength of 25 cN/tex.

EFFECT: higher quality of fibre due to low piling, which is maintained at next stages.

19 cl

Description

The invention relates to polyester fiber with low pilling, to a method for its production, sheet textile materials produced from it, and, in particular, to its use in the field of dyed textile products.

After relatively long periods of use, numerous textile products show a phenomenon known as pilling. Pilling means unwanted clusters of fibers in the form of balls (pills) on the surface of textile products, which adversely affect the appearance of textile products. In this case, individual fibers are knocked out of the thread and, as a result of friction, undergo deformation on the surface of the product with the formation of pills. This occurs, in particular, with synthetic fibers, but also with natural fibers, regardless of the type of sheet material production.

Due to the high strength of the polyester fibers, such pills cannot tear off the surface, but remain on it and look unsightly for the observer. Therefore, in the physical sense, this phenomenon means that the polyester fibers have a higher strength compared to natural fibers and, in particular, also high resistance to bending.

Of course, in principle, the pills can be removed mechanically, for example, using a brush or by scraping. Such cleaning is very tiring and expensive and cannot prevent the formation of new pills forever.

Pilling can be reduced as a result of modifications. The purpose of such modifications is to prevent the formation of pills or to accelerate the separation and removal of the resulting pills from the surface. Such modified fibers are referred to as low pilling fibers. An object of the present invention is to provide such a fiber with low pilling properties.

Numerous attempts have been made to overcome the aforementioned disadvantages. In this case, the emphasis, in particular, is on reducing the bending resistance of polyester fibers, which must be taken care of, but it must be ensured that the tensile strength of the fibers is not too reduced, so that the additional processing process can be carried out without causing significant damage to the fibers, for example, as in the case of standard types of cotton fibers.

As mentioned in the introduction, the usual way to reduce bending resistance is to reduce the molecular weight of the polymer. In order to obtain good technological characteristics of the polymer, in spite of the lower molecular weight, the melt viscosity of the polymer is increased by means of crosslinking agents. As cross-linking agents, multifunctional molecules are used that can be integrated into the molecular chain during the polycondensation process. Examples of such molecules include multifunctional alcohols (pentaerythritol), polybasic acids, and silicon compounds or phosphorus compounds. Another approach that has been implemented is the subsequent hydrolysis of the polyester. For this purpose, hydrolytically active compounds (acids, bases and organic derivatives) are added to the polyester.

The principle of temporary cross-linking or branching is that the ester chain is provided with a thermally or hydrolytically unstable bond in the polymer chain, which is hydrolytically broken after the fiber forming process, for example, during dyeing of a textile sheet or flocking. An example of polyesters that can undergo temporary cross-linking in this manner can be found, for example, in FR-A-2290511, where 0.01 to 2% by weight of diphenylsilanediol based on the weight of dimethyl terephthalate (DMT) is introduced before transesterification. However, in this case, the elongation at break is too high to provide technological characteristics with cotton fibers and, in addition, the tensile strength is too low to carry out the process of weaving yarn from the corresponding staple fiber.

A similar idea related to temporary branching can be found in FR-A-1589057, according to which fibers with the same disadvantages as in the aforementioned French document are still obtained.

Additional approaches to the production of low pilling polyester fibers can be found in EP-A-1425444. Here, during the production of the polyester, organosilicon compounds based on tetrahydrofurfuryl alcohol are added.

Commercially available low pilling polyesters, for which silicic esters are used as temporary crosslinkers, are already known on the market. As a result of the proper level of modification, very good pilling behavior (low bending resistance) with sufficient strength after staining can be obtained. However, in the case of a mixture of dyes or in the case of modified or variable dyeing conditions, such fibers react again, therefore, such products require high process stability. In this case, even relatively small fluctuations or deviations of the process lead to problems.

Methods that utilize irreversible “chain splitters” include manufacturing methods that employ, for example, a compound such as pentaerythritol. In this case, the effect is used, as a result of which the fibers formed from low molecular weight, branched, rigid materials in the final product break up earlier than the fibers formed from the corresponding linear, higher molecular weight, flexible chain polymers. However, the effectiveness of this method is limited. Due to crosslinking, the melt viscosity can be increased and, therefore, lower molecular weight polymers can also be molded. Despite the modification, a natural limit is reached at which the melt can no longer be molded, and thus the resulting effect of low pilling cannot be further enhanced.

Despite the fact that a number of methods are already known by which it is possible to produce polyester fibers with low pilling properties, there is still a need for improved methods and fibers with improved properties for pilling and other good properties, in particular, properties that are stored on subsequent processing steps, such as dyeing fibers.

Therefore, the aim of the invention is to obtain a new polyester fiber with low pilling, which has the desired properties in relation to the formation of low pilling, in particular, even after dyeing the fiber, and which can additionally be produced and processed using known means.

The present invention relates to a fiber with low pilling on the basis of a complex polyester containing from 0.1 to 10 wt.% Inorganic particles with a particle size in the range from 0.5 μm to 5 μm.

The addition of inorganic or mineral particles to polyester fibers is a well-known method for modifying the resulting fibers. In this way, the desired properties can be achieved, such as a matte surface, opacity, color, radiation absorption, fire resistance and antibacterial activity.

It was unexpectedly found that by adding particles according to the invention, which were not previously described in this way, it is possible to improve the behavior of polyester fiber pills.

By adding particles according to the invention during the process of forming a fiber from a melt of low molecular weight starting materials, the fiber can also be modified in this way. Moreover, an additional improvement in the behavior of the pills is possible even in the case of starting materials, which, due to their previously obtained low molecular weight, cannot be improved further, since they are no longer suitable for processing in another way.

The additives according to the invention are integrated into the polyester matrix in such a way that unforeseen events cannot occur during further processing. Subsequent selective hydrolysis to improve the behavior of pills in some circumstances has the disadvantage associated with the difficulty in providing and reproducing the required property profiles. But not in the case of the present invention.

In principle, all known types of polyester materials suitable for fiber production can be considered as a polyester material. Polyesters that can be molded from melt mainly consist of components that are derived from aromatic dicarboxylic acids and aliphatic diols. Typical components of aromatic dicarboxylic acids are bivalent residues of benzenedicarboxylic acids, in particular terephthalic acid and isophthalic acid; conventional diols contain from 2 to 4 carbon atoms, among which ethylene glycol and / or propane-1,3-diol are particularly suitable.

Polyesters that contain at least 85 mol% of polyethylene terephthalate (PET) and / or polytrimethylene terephthalate (PTT) are particularly preferred. The remaining 15 mol% are formed from dicarboxylic acid units and glycol units, which act as so-called modifying agents, and which allow a person skilled in the art to selectively influence the physical and chemical properties of the resulting filaments. Examples of such dicarboxylic acid units are residues of isophthalic acid or aliphatic dicarboxylic acid, such as glutaric acid, adipic acid, sebacic acid; examples of diol residues that act in a modifying manner include those of longer chain diols, for example propanediol or butanediol, di- or triethylene glycol or polyglycol (if present in small amounts) with a molecular weight of from about 500 to 2000.

Polyesters that are modified to impart flame retardant properties are also particularly preferred. Polyesters of this type are also already well known. Polyesters modified to give flame retardant properties and used according to the invention are polyesters in which phosphorus compounds are introduced into the polyester chain, in other words, are present in covalently bound form.

It should be understood that such phosphorus elements introduced into the chain are chain elements that are located in the linear chain of the polymer molecule (the longest chain), but are also possibly present in the side chains and branches.

Polyesters modified to give flame retardant properties that contain an element introduced into the chain contain blocks of formula (I) and / or (II)

in which R is alkylene or polymethylene containing from 2 to 6 carbon atoms, or phenyl; and R ¹ means alkyl containing from 1 to 6 carbon atoms, aryl, arylalkyl or alkylaryl are preferred. In formula (I), R is preferably ethylene, and R ^{1 is} preferably methyl, ethyl, phenyl, or o-, m- or p-methylphenyl, in particular methyl or phenyl. Polyesters of this type are described, for example, in document DE-A-3940713.

In addition, suitable polyesters modified to give flame retardant properties in which the polyester contains phosphorus chain elements introduced into the chain are known, for example, from DE-A-2236037, DE-A-2242002, DE-A-232800343, DE-A-2346787 and DE-A-2454189.

Polyesters that contain at least 95 mol% of polyethylene terephthalate (PET), in particular polyesters that are modified with a crosslinking agent, are particularly preferred.

Polyesters of this type typically have a molecular weight corresponding to a relative viscosity change (η _spec ) of from 0.6 to 0.9, measured on solutions containing 1 g / l of polymer in dichloroacetic acid at 25 ° C.

The polyesters used to make the fibers of the invention are sufficiently dry and typically contain less than 500 ppm of residual moisture.

The inorganic particles used according to the invention are, in particular, mineral materials.

Among the mineral materials, metal salts of the first and second main groups of the Periodic Table of Elements are preferred. Particularly preferred are salts of lithium, sodium, potassium, rubidium, beryllium, magnesium, calcium, strontium, barium and their mixed salts, in particular salts found naturally or mixed salts.

Among the salts, chlorides, fluorides, bromides, iodides, carbonates, sulfates, phosphates, nitrates, hydrocarbons, sulfites, nitrates and their mixed salts are preferred, in particular, naturally occurring salts or mixed salts are preferred.

Carbonate salts and / or bicarbonate salts of calcium and / or magnesium are particularly preferred.

The mineral materials used according to the invention, and in particular, the carbonate salts and / or hydrocarbonate salts of calcium and / or magnesium, have a surface of particles that has been surface treated, or a surface coated with a higher fatty acid, preferably a higher fatty acid, containing from 10 up to 28 carbon atoms.

The mineral materials used according to the invention, and in particular the carbonate salts and / or hydrocarbonate salts of calcium and / or magnesium, have an average particle diameter in the range from 0.5 to 5 μm, preferably from 1.0 to 4 μm, in particular from 1.0 to 3.0 microns. The average particle diameter, also referred to as the average particle size (= d ₅₀ ), is in the range preferably from 0.5 μm to 5 μm, preferably from 1.0 to 4 μm, in particular from 1.0 to 3.0 μm .

The percentage of particles with a particle size of more than 5 μm cannot exceed 1 wt.%, In order to prevent a violation of the stability of the process of forming the fiber.

It is particularly preferred if the mineral materials used according to the invention, and in particular the carbonate salts and / or hydrocarbonate salts of calcium and / or magnesium, have an average particle diameter in the range from 0.5 to 5 μm, preferably from 1.0 to 4 μm, in particular, from 1.0 to 3.0 microns, and are present in amounts of from 0.5 to 10 wt.%, preferably from 0.5 to 5 wt.%, in particular from 0.5 to 2.5 wt. .%. In this case, the average particle diameter, also expressed as the average particle size (= d ₅₀ ), is preferably in the range from 0.5 μm to 5 μm, preferably from 1.0 to 4 μm, in particular from 1.0 to 3.0 μm

The average particle diameter or average particle size (= d ₅₀ ) was determined using a laser diffraction method according to the international standard ISO 13320-1. A measuring device suitable for particle size analysis is, for example, a Microtrac S 3500 laser analyzer.

The mineral materials used according to the invention, and in particular the carbonate salts and / or hydrocarbonate salts of calcium and / or magnesium, are mainly particles that are obtained by grinding, for example, by crushing and / or precipitation or crystallization of the substrate-forming salts.

The above surface treatment of the particles with a higher fatty acid prevents aggregation of mineral materials and provides the most possible uniform distribution of particles in the polyester fiber material.

Examples of the higher fatty acids may include saturated higher fatty acids [CH ₃ (CH _2), COOH, n = 8-26] , such as decanoic acid, undecanoic acid, lauric acid, tridecyl acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, cerotinic acid, heptacosanoic acid; and unsaturated higher fatty acids such as oleic acid (cis), elaidic acid (trans), cetoleic acid, erucic acid (cis), brassidic acid (trans), linoleic acid, linolenic acid and arachidonic acid. Among such saturated fatty acids, stearic acid is particularly preferred.

The fiber according to the invention preferably contains from 0.5 to 10 wt.% Carbonate salts and / or hydrocarbonate salts of calcium and / or magnesium with a particle size in the range from 0.5 μm to 5 μm. Among the aforementioned fibers, fibers that contain about 1 wt.% Of the aforementioned salts are particularly preferred. Among the aforementioned fibers, fibers that contain no more than 2.5% by weight of the aforementioned salts are particularly preferred since otherwise precipitation may occur during the production of the fibers.

The fibers of the invention are preferably low pilling fibers. This property is determined by measuring, known as the number of bending abrasion cycles, and it is a measure of the fiber's resistance to bending. In this case, a constant transverse force is applied to the individual fiber. This is repeated until the fiber breaks. In such tests, an average value of 50 measurements is established. Thus, the arithmetic number of cycles required before rupture is an appropriate measure of the fiber's resistance to bending. The measurement, known as bending abrasion cycles, is carried out according to the Grünewald CHEMIEFASERN test, 1963, p. 853 (the test is carried out on a bending abrasion device using 20 μm wire and a load of 1100 mg). The fibers according to the invention (raw white fiber, without dyeing) require only not more than 800 bending cycles, preferably not more than 700 bending cycles, in particular not more than 600 bending cycles, while polyester without additives according to the invention (raw white fiber, unpainted) requires a minimum of 1500 bending cycles before the fiber breaks. The minimum number of cycles of abrasion by bending, in other words, until the fiber is broken, is 200 cycles of abrasion by bending, preferably 250 cycles of abrasion by bending. Thus, the fibers according to the invention usually require from 200 to 700 cycles of abrasion by bending, preferably from 200 to 600 cycles of abrasion by bending, in particular from 250 to 600 cycles of abrasion by bending.

The fibers according to the invention, in particular, exhibit a very good combination of the lack of pilling and at the same time good strength. The fibers of the invention (unpainted raw white fiber) preferably have a strength of at least 25 cN / tex in combination with the aforementioned bending resistance (bending abrasion cycles).

The fiber according to the invention can be produced using well-known methods and devices, in other words, can be obtained essentially without additional investment. The mineral material added according to the invention is introduced into the polyester, for example, using a mixing extruder. Such a composition, depending on the degree of its filling, can serve both as a masterbatch and as a single feedstock.

First, polyester and mineral materials or the previously described composition (casting mixture) are provided, which are subjected to melt spinning to produce polyester filaments. In this case, standard devices containing the appropriate die are used. The flow rate of the mixture at the exit of the spinnerets is matched to the fiber spinning speed so that a fiber with a desired linear density is obtained.

It should be understood that the term "fiber spinning speed" means the speed at which cured filaments are drawn. The threads elongated in this case can either be fed directly to the hood, or also twisted a little, or deposited and pulled later. Fibers and filaments elongated in the usual way can then be crimped, they can be fixed and / or cut to the required length to form staple fibers according to widely known methods. The spinning speed of the fiber or the speed of drawing upon receipt of staple fibers is usually at least 500 meters per minute and not more than 2200 meters per minute. To get filaments, they can be pulled at a significantly higher speed, up to 8000 meters per minute. The fiber spinning temperature is usually 255 ° C or more and 305 ° C or less. The fiber forming is particularly preferably carried out at approximately 275-295 ° C.

A spinneret is a conventional spinneret used in the case of conventional polyesters, in which the size, location and number of holes depend on the desired fiber and fiber forming apparatus.

The linear density of an individual fiber according to the invention at the end of its formation is in the range from 0.6 to 30 dtex, preferably from 0.9 to 13 dtex, in particular from 0.9 to 8 dtex, while the linear density increases with increasing particle dosage due to the higher density of inorganic particles present. Linear density was determined according to the international standard DIN EN ISO 1973.

In this regard, it was found that when the content of inorganic particles is more than 5 wt.%, The material has a tendency to breaks of filaments and the formation of winding. The formation of deposits on parts of the stationary device is also observed, so that the life of the devices used is reduced.

The hardening of fibers formed in this way from a melt, in particular, the hardening of polyester filaments, can be carried out in the usual way using air or other fluids, as described in the art (for example, using nitrogen). Transverse, radial, asymmetric flow methods or other cooling methods may be used. For quenching, air blowing is preferably used.

After cooling, conventional additives or brighteners can be used using standard methods.

The formed fibers can have round, oval and additional suitable cross-sections or other shapes, such as dumbbell-shaped, kidney-shaped, triangular cross-sections or cross-sections in the form of a trefoil or polyfoil. Hollow fibers are also possible. You can also apply fibers formed from two or more polymers. The geometry of the bicomponent fibers can be ″ core / cladding ″ (centered and eccentric), ″ side by side ″ or ″ island in the sea ”geometry.

The filaments thus obtained are combined to form filaments, and the filaments, in turn, are combined to form bundles. The bundles are first laid in a basin by means of a bundle for additional processing. Harnesses temporarily stored in basins are combined and receive a common large tourniquet.

Then, the fibers of a large tow (typically from 10-600 ktex) can be pulled using conventional methods along the conveyor line, preferably at a feed speed of 10-110 m / min. In this case, it is still possible to use preparations that accelerate the hood without adversely affecting the subsequent characteristics.

The drawing ratios are preferably in the range from 1.25 to 4, particularly preferably from 2.5 to 3.5. The temperature during drawing is in the range of glass transition temperature of the drawn tow, and in the case of polyester, it is preferably from 40 ° C to 80 ° C, particularly preferably 50-70 ° C.

The hood can be carried out in one stage or selectively using a two-stage drawing process (in this regard, see, for example, US patent 3816486). Before the drawing process and during the drawing process, one or more surface finishes can be applied using well-known methods.

In order to impart optionally crimped / textured fibers to the fibers thus drawn, well-known mechanical crimping methods can be applied using essentially known crimping machines. Preferred is a mechanical device for crimping the fiber with steam treatment, such as a camera for crimping the fiber. However, it is also possible to use fibers crimped according to other methods, for example, fibers with three-dimensional crimping. To carry out the crimping process, the tow is first heated to a temperature in the range from 50 ° to 100 ° C, preferably from 70 ° to 85 ° C, particularly preferably to about 78 ° C, and is treated with a roll feed roller in a pressure range from 1.0 to 6.0 bar, particularly preferably about 2.0 bar, wherein the pressure in the chamber for crimping the fiber is from 0.5 to 6.0 bar, particularly preferably 1.5 to 3.0 bar, at a steam feed rate of from 1.0 to 2.0 kg / min, particularly preferably 1.5 kg / min.

Smooth or optionally crimped fibers are then relaxed and / or fixed at a temperature of 120 ° to 170 ° in an oven or stream of hot air.

To obtain staple fibers, smooth or optionally crimped fibers are combined, followed by cutting and optionally curing and stacking in pressed balls in the form of a flock. The staple fibers of the present invention are preferably cut into a mechanical cutting device (chopping) after the relaxation step. Cutting can be skipped if different types of tow are produced. These types of tow are stacked and pressed in uncut form into balls.

In the fibers according to the invention, a very good crimp index (degree of tortuosity) K1, which is a measure of the filling of the fiber and is obtained as a result of mechanical crimping of the fiber, is additionally found. The crimp index is a key characteristic that is important both for fiber processing and for the distinctive properties of textile and fiber-filled products, in particular products formed from staple fibers. When evaluating the tortuosity index, the fiber elasticity characteristic is measured, which is transmitted by changing the tortuosity mechanically. In this case, the tortuosity affects the technological properties of the fiber and the processing during subsequent stages of the process.

Within the scope of the invention, the degree of tortuosity should be understood as the following relation:

in which L _k represents the length of the crimped staple fibers in a relaxed state, and L _v represents the length of the same fiber, but after stretching, in other words, in this case, the fiber is almost in a straight line without crimping. The drawing process is carried out using a load, which is known as a straightening load. Such a load is established in preliminary tests using a tangent line attached to the curve of the dependence of elongation on load for the corresponding fiber.

The fibers obtained according to the invention preferably have a degree of crimp of at least 3 curls (curls) per cm, preferably from 3 curls per cm to 9.8 curls per cm, and particularly preferably from 3.9 curls per cm to 8 , 9 curls per cm. In applications related to the production of sheet textile materials, meandering values of approximately 5 to 5.5 curls per cm are particularly preferred.

The crimp index K1 according to the invention is preferably 15% or more, preferably 17% or more.

As already mentioned, with an increase in the content of inorganic particles, the fiber suffers losses in terms of strength and elongation. However, with an increase in the degree of modification, bending resistance also decreases as desired.

However, of particular interest are the characteristics of textile materials obtained after high temperature dyeing. The reason is that such fiber properties affect the final product. To this end, the polyester fibers according to the invention were dyed under ordinary conditions, in other words, dispersed at 130 ° C for 60 minutes in an acetic medium. In such a case, after the aforementioned dyeing, the polyester fibers according to the invention showed an additional decrease in bending resistance, more specifically, a decrease in the number of bending abrasion cycles to 400 bending abrasion cycles, and at least at least one dyed polyester without adding particles according to the invention requires 700 bending cycles before the fiber breaks.

Fibers according to the invention, which are dyed in the manner described above, require only not more than 400 cycles of abrasion by bending, preferably not more than 300 cycles of abrasion by bending, while polyester fiber without adding particles according to the invention (dyeing as described above) requires at least at least 700 bending cycles before the fiber breaks. In other words, the minimum number of bend abrasion cycles before the fiber breaks is 150 bend abrasion cycles, preferably 190 bend abrasion cycles. Thus, the fibers according to the invention (after dyeing) usually require from 150 to 400 cycles of abrasion by bending, preferably from 190 to 400 cycles of abrasion by bending, in particular from 190 to 300 cycles of abrasion by bending.

When using water-soluble, alkaline inorganic particles during the staining process, an increase in pH can be detected. This indicates that water-soluble, alkaline, inorganic particles present in the fiber react with the dye solution. It is not possible to establish the effect of pH on the characteristics of dyed fiber textile materials, although an increase in pH is observed when dyeing with acid dyes.

Examination of the fiber according to the invention after dyeing using a microscope (scanning electron microscope) shows that slight surface damage is observed, but it does not depend on the pH of the solution. Such data indicate the fact that individual particles on the surface break out of the fiber due to the mechanical load on the material. The polyester fiber matrix contains enough particles to protect them from degradation by the dye solution.

As previously discussed, fibers according to the invention, dyed as described above, require only no more than 400 cycles of abrasion by bending, preferably no more than 300 cycles of abrasion by bending, while polyester fiber without adding particles according to the invention (dyeing as described above) at least 700 bending cycles are required before the fiber breaks. In other words, the minimum number of bend abrasion cycles before the fiber breaks is 150 bend abrasion cycles, preferably 190 bend abrasion cycles. Thus, the fibers according to the invention (after dyeing) usually require from 150 to 400 cycles of abrasion by bending, preferably from 190 to 400 cycles of abrasion by bending, in particular from 190 to 300 cycles of abrasion by bending.

For the dyed fibers according to the invention, in particular, a very good combination of properties is found, consisting in the absence of pilling and the simultaneous presence of good strength. The fibers of the invention (dyed as described above) preferably have a strength of at least 23 cN / tex in combination with the aforementioned bending resistance (number of bending abrasion cycles).

From the fibers according to the invention, corresponding sheet textile materials can be produced which also form part of the invention.

The term "sheet textile material" should be understood in its broadest sense within the scope of the present description. Such a material may include all materials containing fibers according to the invention, which are obtained using the method of forming sheet material. Examples of such sheet textile materials are woven materials, rovings, knitwear, warp knitwear and non-woven materials.

The nonwoven material according to the invention can be formed from endless synthetic fibers (filaments) or from staple fibers. To obtain a nonwoven material, staple fibers according to the invention are preferably used, the length of which is usually from 1 to 200 mm, preferably from 3 to 120 mm, particularly preferably from 3 to 60 mm.

The invention will be illustrated by the following example, although the scope of the invention is not limited to this example.

EXAMPLES

The low molecular weight crosslinked starting PET material was modified with alkaline earth metal carbonates. In the usual manner for PET, the starting material was dried to a residual moisture content of at least less than 500 ppm.

Then, fibers were formed from the starting material, and the following table shows the most important parameters of the process of forming fibers from the melt:

Feed rate g / min 556 Material temperature ° C 264 Molding temperature ° C 268 Number of holes 702 Draw speed m / min 1200 Linear density of individual fibers dtex 6.69 or 6.77 Dosage during modification % 2.5 or 5

Alkaline earth carbonate was added in the form of a masterbatch. The resulting linear density of the molded product increased with increasing particle dosage due to the high density of the additive.

With a degree of modification of 2.5%, the technological characteristics of the material were comparable with unmodified material or only slightly deteriorated compared to unmodified material. However, with a degree of modification of 5%, the material is prone to breakage of filaments and the formation of winding. First of all, the formation of deposits on parts of a stationary device led to a deterioration in technological characteristics. The obtained molded material was jointly oriented by double addition to form a cord of 59 ktex. The material could be pulled, crimped and fixed along the conveyor line similarly to unmodified fiber. Recycling was common.

The following table shows the most important conveyor line parameters.

Linear Density ctex 59.3 Feed rate m / min thirty Hood ratio 3.0 Cord temperature before crimping ° C 55 Fixation temperature ° C 135

The following table shows the characteristics of textile materials, as well as two unmodified types of PET for comparison.

Units 0% supplement 1.25% supplement 2.5% supplement 3.75% supplement 5.0% supplement Linear density dtex 2.40 2.67 2,55 2.60 2.48 Strength SN / Tex 29.6 25.52 25.24 25.15 27.32 Elongation at break % 42.1 31.07 38.16 28.04 30.74 Degree of tortuosity % 17.4 15.0 15.6 12.5 14.6 Number of curls cm ^-1 5,6 5,4 5,0 4.7 5,0 Relative change in sample thickness % 0.24 0.24 0.27 0.20 0.22 The number of cycles of abrasion by bending 1540 406 568 346 267

Linear density was determined according to the international standard DIN EN ISO 1973; fiber strength and elongation were determined according to the international standard DIN EN ISO 5079.

The number of bending abrasion cycles was determined as described in Grünewald's document (CHEMIEFASERN, 1963, p. 853) by testing on a bending abrasion apparatus with a 20 μm wire and a load of 1100 mg.

Fibrous samples were stained by dispersion at 130 ° C for 60 minutes in acetic acid under the conditions commonly used for PET. The following table shows the characteristics obtained for dyed textile samples;

Units 0% supplement 1.25% supplement 2.5% supplement 3.75% supplement 5.0% supplement Linear density dtex 2.63 2.68 2.70 2.72 2.82 Strength SN / Tex 28.6 24.7 25.0 24.4 23.5 Elongation at break % 31.1 24.7 28.1 23.9 26,4 The pH value of the solution after staining 4.77 - 4.9 5.2 The number of cycles of abrasion by bending 745 233 281 228 198

It can be clearly seen that for all samples the resistance to bending, more precisely, the number of cycles of abrasion by bending, decreased by about half as a result of staining. A decrease in strength and elongation is also present and increases with increasing degree of modification. However, differences from the unmodified type after staining are less pronounced than in the case of a raw white product.

It is well known that the pH value increases deliberately during the staining process. This indicates that the alkaline earth metal carbonate present in the fiber reacts with the dye solution. This leads to the assumption that the pH value of the dye solution can affect the characteristics of textile materials and the nature of the fiber. Therefore, staining processes were carried out at different pH values. The following table shows the obtained characteristics of textile materials obtained by such dyeing processes.

Units Alkaline staining Acetic acid staining; Twice the amount of acetic acid PH value of the solution before staining 9.3 4,56 4.37 Linear density dtex 2.63 2.70 2.73 Strength SN / Tex 25.0 25.0 24.1 Elongation at break % 26.5 28.1 28.0 The pH value of the solution after staining 8.1 4.9 4.64 The number of cycles of abrasion by bending 282 281 300

Based on the obtained measured values, it is impossible to determine the effect of pH on the characteristics of textile materials even despite the fact that the pH increases when colored in an acidic environment. Therefore, the pH value is not a suitable parameter to influence the characteristics of textile materials. Tests performed on a scanning electron microscope showed that the surface is slightly damaged, but such damage does not depend on the pH of the solution.

The PET matrix of the fiber contains enough carbonate particles to protect them from degradation by the dye solution.

The staining temperature and staining time were investigated as further influencing parameters.

The following table shows the characteristics of textile materials obtained for different dyeing times at 130 ° C:

Staining time Units 30 minutes 45 min 60 min 90 min Linear density dtex 2.67 2.66 2.70 2.61 Strength SN / Tex 25.1 25.1 25.0 24.9 Elongation at break % 31.9 30.1 28.1 27.0 The number of cycles of abrasion by bending 340 326 281 338

The following table shows the characteristics of textile materials obtained at different dyeing temperatures after 60 minutes.

Staining temperature Units 100 ° C 115 ° C 130 ° C 135 ° C Linear density dtex 2.66 2.65 2.70 2.67 Strength SN / Tex 24.8 24.4 25.0 25.3 Elongation at break % 34.2 32.1 28.1 25.5 The number of cycles of abrasion by bending 462 391 281 304

The number of bending abrasion cycles decreases with increasing temperature. However, staining conditions of 130 ° C and 60 minutes are usually sufficient for PET. An additional increase in two such parameters did not lead to an additional decrease in bending resistance. In addition, it can be determined that the strength of the fiber does not deteriorate as a result of the dyeing process. The strength of the fiber is maintained regardless of the duration of dyeing, dyeing temperature and pH.

The characteristics achieved for the obtained fibers are comparable with those of other low pilling polyester fibers manufactured by the industry. The following table provides some key fiber characteristics for comparison.

Units 2.5% supplement Comparison 1 Comparison 2 Crosslinking agent constant temporary constant Carbonate dosage % 2.5 without without The number of cycles of abrasion by bending for raw fiber white 568 978 1540 Strength of raw white fiber SN / Tex 25,2 27.1 29.6 Elongation (at break) of raw white fiber % 38.1 44.7 42.1 The number of cycles of abrasion by bending for dyed fiber 281 149 745 Dyed Fiber Strength SN / Tex 25.0 23.7 28.6 Elongation (at break) of the dyed fiber % 28.1 22.1 31.1

Claims (19)

1. A fiber with low pilling ability based on a polyester, in which the polyester consists of aromatic dicarboxylic acids and aliphatic diols; the fiber contains from 0.5 to 10 wt.% inorganic particles with a particle size in the range from 0.5 μm to 5 μm; inorganic particles contain mineral materials and are metal salts of the first and second main groups of the Periodic table of elements; salts contain chlorides, fluorides, bromides, iodides, carbonates, phosphates, nitrates, bicarbonates, sulfites and their mixed salts; and unpainted raw white fiber, 200 to 700 bending cycles are required before the fiber breaks; and fiber strength is at least 25 cN / tex. 2. The fiber according to claim 1, characterized in that the polyester contains at least 85 mol.% Polyethylene terephthalate (PET) and / or polytrimethylene terephthalate (PTT). 3. The fiber according to claim 1, characterized in that the polyester has a molecular weight corresponding to a relative change in viscosity (ŋ _spec ) in the range from 0.6 to 0.9, measured in solutions containing 1 g / l of polyester in dichloroacetic acid at 25˚C. 4. The fiber under item 1, characterized in that the mineral materials contain metal salts of the first and second main groups of the Periodic table of elements, that is, in other words, salts of lithium, sodium, potassium, rubidium, beryllium, magnesium, calcium, strontium, barium and mixed salts thereof, in particular naturally occurring salts or mixed salts. 5. The fiber according to claim 4, characterized in that the salts contain salts found in nature, or mixed salts. 6. The fiber under item 1, characterized in that the inorganic particles contain carbonate salts and / or bicarbonate salts of calcium and / or magnesium. 7. The fiber according to claim 1, wherein the inorganic particles are carbonate salts and / or bicarbonate salts of calcium and / or magnesium with a surface of particles that has been surface treated with a higher fatty acid, preferably a higher fatty acid containing from 10 to 28 carbon atoms. 8. The fiber according to claim 1 or 7, characterized in that the inorganic particles are carbonate salts and / or hydrocarbonate salts of calcium and / or magnesium, which have an average particle diameter of from 0.5 to 5 μm, preferably from 1.0 to 4 microns, in particular from 1.0 to 3.0 microns. 9. The fiber under item 1 or 7, characterized in that the inorganic particles are carbonate salts and / or hydrocarbonate salts of calcium and / or magnesium, which have an average particle diameter of from 0.5 to 5 μm, preferably from 1.0 to 4 μm, in particular from 1.0 to 3.0 μm, and are present in amounts of from 0.1 to 10 wt.%, Preferably from 1.0 to 5 wt.%, In particular from 1.0 to 2.5 mass%. 10. The fiber according to claim 1, characterized in that the unpainted raw white fiber requires from 200 to 600 cycles of abrasion by bending, in particular from 250 to 600 cycles of abrasion by bending, before the fiber breaks. 11. The fiber according to claim 1, characterized in that the linear density of the individual fiber is in the range from 0.6 to 30 dtex, preferably from 0.9 to 13 dtex, in particular from 0.9 to 8 dtex. 12. The fiber under item 1, characterized in that the content of inorganic particles with a particle size in the range from 0.5 μm to 5 μm is in the range from 0.5 to 5 wt.%, Preferably from 1.0 to 2.5 mass%. 13. The fiber under item 1, characterized in that the fiber is pulled and give the fiber crimp. 14. The fiber according to claim 1, characterized in that the fiber is dyed by high temperature dyeing in an acidic environment, and the fiber requires no more than 400 cycles of abrasion by bending, preferably not more than 300 cycles of abrasion by bending, before the fiber breaks. 15. The fiber according to claim 1, characterized in that the fiber is dyed by high-temperature dyeing in an acidic environment, and the fiber requires at least 150 cycles of abrasion by bending, preferably at least 190 cycles of abrasion by bending, before the fiber torn apart. 16. The fiber according to claim 1, characterized in that the fiber is dyed by high-temperature dyeing in an acidic environment, and the fiber requires from 150 to 400 cycles of abrasion by bending, preferably from 190 to 400 cycles of abrasion by bending, in particular from 190 to 300 cycles of abrasion by bending before the fiber breaks. 17. The fiber according to claim 1, characterized in that the fiber is dyed by high-temperature dyeing in an acidic environment, and the fiber requires from 150 to 400 cycles of abrasion by bending, preferably from 190 to 400 cycles of abrasion by bending, in particular from 190 to 300 cycles of abrasion by bending before the fiber breaks, wherein the fiber strength is at least 23 cN / tex. 18. The method of production of fiber with low pilling in PP. 1-17, characterized in that the complex polyester, which consists of aromatic dicarboxylic acids and aliphatic diols and contains from 0.5 to 10 wt.% Inorganic particles with a particle size in the range from 0.5 μm to 5 μm, while inorganic particles contain mineral materials and are metal salts of the first and second main groups of the Periodic table of elements; wherein the salts contain chlorides, fluorides, bromides, iodides, carbonates, phosphates, nitrates, bicarbonates, sulfites and their mixed salts; subjected to extrusion and molding to obtain filaments, stretched, crimped, fixed and, if necessary, cut to the desired length. 19. Sheet textile material containing fiber with low pilling in one or more paragraphs. 1-17.