WO2013023985A2

WO2013023985A2 - Process for producing surface-modified polyolefin filament yarns, the polyolefin filament yarns obtainable accordingly, and their use

Info

Publication number: WO2013023985A2
Application number: PCT/EP2012/065583
Authority: WO
Inventors: Rainer Gutmann; Winfried Schuler; Rolf Neupert
Original assignee: Deutsche Institute Für Textil- Und Faserforschung Denkendorf
Priority date: 2011-08-12
Filing date: 2012-08-09
Publication date: 2013-02-21
Also published as: EP2742174B1; WO2013023985A3; DE102011110154A1; EP2742174A2

Abstract

A process is described for producing surface-modified polypropylene filament yarns that are dyeable from aqueous liquors. This process is characterized in that the filament yarns, comprising standard commercial PP, in the course of their formation in a melt spinning procedure, undergo treatment with a hydrogen peroxide solution. The invention further relates to polyolefin filament yarns obtainable by this process, and to the use of these polyolefin filament yarns for producing sheetlike textile structures, with the possibility of advantageous subsequent dyeing with vat dyes. The treatment referred to or the upgrading step, which in accordance with the prior art normally takes place at a much later point in the production chain, therefore yields a hydrophilized filament yarn without an additional downstream treatment step, such as by plasma treatment, for example, and also without any other additional energy input. The resulting filament yarn can be processed and upgraded in the same way as has hitherto been the case in the industrial practice. Without the aftertreatment of the prior art, the textiles obtained in accordance with the invention exhibit a desirable dyeability. This can be achieved without further pretreatment, by means of vat dyeing by the Thermosol process in deep shades, and the vat dyeing at the same time possesses the high light fastness known for vat dyeings.

Description

METHOD FOR THE PREPARATION OF SURFACES OF MODIFIED POLYOLEFIN FILAMENT YARN, THEN AVAILABLE IN POLYOLEFIN FILAMENT YARN E AND

THEIR USE

description

The invention relates to a process for the preparation of surface-modified polyolefin filament yarns dyeable from aqueous dyeing liquors, to the polyolefin filament yarns obtainable by this process and to their use for the production of textile fabrics.

It is known that unmodified polypropylene is difficult to dye because it is poorly wetted by an aqueous dyeing liquor due to its non-polar structure, thereby hindering the transition of the dye from the liquid phase into the polymeric solid. In addition, the diffused dye can only build weak van der Waals interactions with the polymer.

The annually increasing worldwide demand for textiles made of polypropylene (PP) would certainly not be found in this form, had it not been possible to modify the originally non-functionalized, water-repellent fiber polymer at least on the filament or fiber surface so that as a result Performance and performance properties result with fibers or filaments from others polymeric raw materials are comparable. Improved interaction possibilities of the PP filament yarns with their immediate - mostly aqueous - environment on their surface are not only of decisive importance for the consumer, but are already invaluable in the production, processing and finishing of PP filament yarns or textiles ,

For this reason, the focus in the further development of PP filament yarns has always been on functionalization. This takes place either on the polymeric raw material d. H. on the chemical skeleton and is thus distributed in the fiber over its entire volume. Or it is carried out only on the fiber surface, which has no decisive influence on the structure formation in the fiber and the resulting mechanical-physical properties in contrast to the former variant. If you pay with a modification of the entire raw material for an effect required only on the fiber surface in proportion to much, on the other hand requires a modification that is performed exclusively on the fiber surface, usually an additional process step, of course, with appropriate energy and Investment costs is connected.

This additional process step is according to the current state of the art ua. As a result, reactive radicals are generated by the action of high-energy radiation substantially at the polymer surface. These can be z. B. with oxygen or oxygen-containing compounds, in the simplest case, water, and thus lead to the formation of hydroxyl groups on the PP surface. Today, UV, X-ray or γ-rays as well as electron beams (β-radiation) are often used as sources for recording the necessary radiant energy into the textile. In addition, however, treatments are frequently carried out with different gas plasmas which, depending on the gas used, can produce not only hydroxy groups but also other reactive functional groups. Common to all methods is that they are generally used on the finished textile and that a special system for radiation or plasma treatment is required for this. This represents an increasing cost-effectiveness problem that must be addressed today, regardless of whether or not this technique is capable to produce a broad spectrum of interesting surface properties. These include, for example, the improvement of wettability, hydrophilicity, antistatic, dyeability or adhesion to the polymer interface. These property improvements are therefore always the content and goal of all approaches that generate functional (reactive) groups on the PP surface independently of the method used, which are then often used to chemically bind or graft low molecular weight compounds or oligomers / polymers ,

The various approaches mentioned can be divided into physically or chemically initiated processes according to their method of use. Thus, after Erst- rem z. B. PP fiber exposed to UV or short-wave radiation, wherein radicals are generated along the polymer chain, which then react in different subsequent reactions to form polar, functional groups or volatile, low molecular weight compounds (S. Aslanzadeh, M. Haghighat Kish "Photooxidation of polypropylene fibers exposed to short wavelength UV radiations", Fibers and Polymers (2010), 11 (5), 710-718). In many practical applications, the radiation treatment of the polymer in the presence of air, singlet oxygen or ozone (RL Clough, KT Gillen, Polymer degradation under ionizing radiation: The role of ozone, Journal of Polymer Science: Part Al 27 (1989 ), 2313-2324). performed, which increases the yield of functional groups, but on the other hand makes a reaction control more difficult. This may just make the controlled change in surface properties difficult. The spectroscopic methods (FTIR, NMR, MS) used to identify the groups generated indicated that alcohol, peroxide, ketone, aldehyde, ester, ester, perrester, carboxylic acid and anhydride groups are formed. Among the most significant in terms of volume are the alcohol, peroxide and carbonyl functions, which can not only be used to react with corresponding performance chemicals, but can also be detected by wet-chemical analysis (D. Knittel, E. Schollmeyer, " Functional group analysis on oxidized surfaces of synthetic textile polymers ", Talanta (2008), 76 (5), 1136-1140). Naturally, any polymer degradation, even if it takes place only on the surface of a fiber, leads to structural changes and to a loss of mechanical properties (EP 1825052, "Colored polyolefin fibers, their use and methods for their preparation"). The extent of these changes also depends on the structure present in the polymer. Thus, UV treatment of an unoriented or poorly oriented PP filament yarn in air leads to a significant reduction in elongation at break, while a drawn PP yarn shows no change (YJ Hwang, JS An, MG McCord, SW Park, BC Kang, The "The effect of etching on low-stress mechanical properties of polypropylene fabrics under hot / oxygen atmospheric pressure plasma", Fibers and Polymers (2003), 4 (4), 145-150). Another frequently observed phenomenon of radiation- and oxygen-treated PP materials is an aging effect. Ie. the produced filament yarn loses strength after completion of the treatment when stored. The reason for this lies in the different degradation kinetics of the different peroxide structures produced in the treatment. Thus, in contrast to the rapidly degrading acid peroxide, the tertiary hydroperoxide is held responsible for the observed effect on storage (P. Gijsman M. Kroon, M. van Oorschot, "The role of peroxides in the thermooxidative degradation of polypropylene", "Polymer Degradation and Stability (1996), 51 (1), 3-13).

Although the plasma discharge is a physically initiated method for the treatment of PP, it can also be regarded as a chemical process, since the actual modification of the polymer surface is carried out by the gas of the plasma and thereby already modified before possibly a reaction with further reactive compounds takes place. The investigations are so numerous that only one example should be mentioned to make it clear that the planned in this project innovative process for the oxidation of the PP surface in terms of the result, of course, in competition with the established plasma processes. Even with the use of plasma technology, a surface modification is again to be achieved especially in the case of PP as a textile substrate, which brings about a better wettability, moisture absorption and dyeability (P. Cocolios, F. Coeuret, F. Forster, J.-L. Gelot, B. Martens, E. Prinz, G. Rames-Langlade, A. Villermet, Method for Surface Treatment of Polymeric Substrates, PCT Int. Appl. (2001), WO 2001058992). As mentioned, the plasma treatment is usually used in combination with a subsequent chemical reaction of the generated functional groups, but this is not absolutely necessary. Thus, for example, it is possible to dye a PP fabric after treatment with an argon plasma and subsequent reaction with acrylic compounds, diamines or aminocarboxylic acids with anionic or cationic dyes. However, this already succeeds without the described reaction with the compounds mentioned. Here, the improved wettability owing to the more hydrophilic surface evidently suffices to facilitate the adsorption of the dye on the fiber surface and thus the diffusion into the fiber.

In order to achieve good hydrophilicity, intensive plasma treatment is required or new techniques are used, such as the underwater plasma technique. But this is with a z.T. significant change in the fiber morphology associated (etching), which may well be desired in the direction of absorbency, but may also have an undesirably high effect on the mechanical properties. To achieve the right balance, you can already take into account in the composition of the gas mixture used in the plasma, this effect by using a gas mixture of an oxidizing and a reducing gas, the mixing ratio is in each case to the surface tension of the polymeric Substrate tuned.

In addition to the two options described above to achieve a surface modification of the PP fiber, this is in principle also by a direct treatment with suitable chemicals, usually usually peroxides or oxygen, possible (VE Caudill, GW Halek, "Polypropylene surface characteristics after exposure to hydrogen peroxide and heat processing "Journal of Plastic Film & Sheeting (1992), 8 (2), 140-54). Investigations have been made for quite some time and concern both reactions in the gas phase and in solution, all work in common is the result that oxidation of the PP takes place only at elevated temperature. The reactions in the gas phase use oxygen or ozone as the oxidant, both fibers and fabrics being used as substrates (S. Honda, H. Shimizu, "Surface oxidation of polyolefin fibers with ozone during melt spinning" Jpn. Kokai Tokyo Koho (1973), JP 48018519). Although temperatures of over 100 ° C are usually given for the treatment, the treatment times of several minutes are very long with regard to modern production methods. Therefore, sometimes oxidation promoting agents such. B. Metal salts (DE Bergbreiter, N. White, J. Zhou, "Modification of polyolefin surfaces with iron cluster oxidants" Journal of Polymer Science, Part A: Polymer Chemistry (1992), 30 (3), 389-96) applied to the polymeric substrate which should increase the oxidation yield.

A first description of the treatment of staple fibers with ozone or an ozone-air mixture can be found in patent applications in the 60s and 70s. Lazer, J. Pavlinec, D. Berek, Z. Manasek, M. Micko, "Oxidation of polypropylene to cumulate peroxide and hydro-peroxide functional groups", is described herein as a ten minute exposure to a 100 ° C filament. , (1963), CS 106425, Application: CS 19610313) and / or an action during the stretching process (F. Geleji, G. Odor, "Modified polypropylene fiber", (1964), HU 151336). The mechanical strength of the fibers should drop only slightly in the first method.

In the known attempts to achieve the oxidation of a PP surface via the liquid phase, hydrogen peroxide or organic peroxides are usually used (C. Marco, C. Biancas, "Degradation of isotactic polypropylene in solution with organic peroxide" Revista de Plasticos Modernos ( 2002), 84 (554), 176-184, CAN 138: 288070). Here, too, the reaction is supported by increased temperature, but due to the aqueous systems, these are below 100 ° C. Although this u. If ATR-FTIR spectroscopy does not detect oxygen on the PP surface, contact angle measurements and electron micrographs indicate a change. If the oxidation is carried out with hydrogen peroxide in an organic solvent and at the same time the resulting water removed, the process can be improved and applied to a variety of organic substrates (M. Emsenhuber, G. Kwant, K. Van Straaten, M. Janssen , P. Alsters, H . Hoving, "Process for singlet oxygen oxidation of organic substrates", Eur. Pat. Appl. (2004), EP 1403234 A2).

Based on the above-described prior art, the invention is based on the complex object to further develop the method described above so that the known aftertreatment of textiles by plasma treatment, which currently represents the state of the art, is no longer necessary. Rather, the invention "inline", d. H. in the melt-spinning process, propose a suitable treatment with the result that the filament yarns or the textiles produced therefrom can advantageously be dyed with vat colors, in particular according to a standard dyeing process, and that high use fastnesses, in particular high light fastnesses, are obtained.

According to the invention, the above-described object is achieved by a process for producing surface-modified polyolefin yarns which can be dyed from aqueous dyeing liquors, characterized in that polyolefin filament yarns based on homo- and / or copolymers of propylene and / or ethylene, optionally with one or more comonomers, during the thread formation in the melt-spinning process for hydrophilizing the surface below the melting point of the polyolefin materials with a hydrogen peroxide solution, in particular with an aqueous hydrogen peroxide solution treated. The surface treatment with hydrogen peroxide takes place below the respective melting point of the filament yarn material. If these were carried out above the melting point, consequently in the liquid state of the material, the filament yarns or threads would be destroyed. Also, the thread must not be largely cooled. Subsequent heating and treatment with hydrogen peroxide would not lead to the desired result.

It is preferred that an aqueous hydrogen peroxide solution is used whose concentration of hydrogen peroxide is less than about 35% by weight, especially about 0.5 to 35% by weight. It is particularly preferred if the concentration of aqueous hydrogen peroxide solution of hydrogen peroxide at about 1 to 30 wt .-%, in particular 1.5 to 10 wt .-%, is located.

For the process according to the invention, it is essential that the treatment of the surface of the polyolefin filament yarns takes place with a hydrogen peroxide solution. It is particularly preferred if this treatment is carried out in the blowing shaft of the spinning device below the spinneret by means of a preparation pen with forced dosing. This is expediently a preparation device or a preparation pin, which is usually used for spin finishing. The aforementioned forced dosing is therefore expedient in order to achieve a uniform surface application of the hydrogen peroxide solution, with the result that the later intended coloration appears uniform. If, by the way, the application device with which hydrogen peroxide is introduced according to the invention, in particular with the preparation pin, is too close to the spinneret, then this leads, if the thread is still liquid, to sticking in the application device or the preparation pin. This leaves the frame according to the invention. Thus, it can now be determined expertly and easily when the earliest treatment with hydrogen peroxide solution can be started in the process according to the invention. The further parameter on how far one should distance from the nozzle could, for example, also be determined by determining the dyeability in a later test. If the dyeability is poor, then the order of the hydrogen peroxide solution on the threads or the filament yarn must be made at a closer distance to the spinneret. A temperature indication is not possible or reproducible here. The thread tears due to its high speed still air with it, so that ultimately with, for example, a thermal imaging camera, the thread is not measured as such, but the air envelope of the thread.

It has proven to be particularly expedient that the application distance (between the spinneret and the application site) of the hydrogen peroxide solution in the blower shaft is less than about 4 m, in particular less than about 2 m. It is particularly preferred if the application distance is up to about 1.5 m. In order to achieve the desired object to a desirable extent, it is appropriate to pay attention to the amount of applied (pure) hydrogen peroxide attention. It is advantageous if the amount of (pure) hydrogen peroxide applied, based on the filament yarn weight, is adjusted to up to about 10% by weight, in particular to more than about 0.1% by weight. It is particularly preferred if the amount of (pure) hydrogen peroxide applied, based on the filament yarn weight, is adjusted to about 0.2 to 2% by weight. Incidentally, the temperature of the hydrogen peroxide solution used is not critical. For example, it can have room temperature. Heating does not make sense, since ultimately the temperature on the surface of the filaments is decisive for the action of the hydrogen peroxide in the sense of the invention.

To optimize the process according to the invention, it is useful to strip the filament yarns under the spinneret at a speed of between about 300 and 3000 m / min, in particular between about 750 and 2700 m / min, and then to stretch it.

In the context of the invention and in all embodiments described above, it is furthermore advantageous if the process according to the invention, in particular via the polymer throughput in the upstream extruder, is controlled such that the filament titer of the filament yarns produced is adjusted to 0.1 dtex to 20 dtex becomes . The adjustment of the filament titer is preferably such that during later use of the filament yarns in carpets the filament titer is between about 10 and 20 dtex, in clothing between about 1 and 5 dtex and in textiles based on microfibers less than about 1 dtex, especially about 0, 1 to 0.8 dtex.

The following should also be stated with regard to the starting materials: The process according to the invention is particularly preferably to be applied to polyolefin filament yarns which are homopolymers of propylene (PP). Here are particularly those homopolymers of polypropylene of importance, the melt flow rate M FR [g / 10 min], measured according to IS01133, at 230 ° C and 2.16 kg load, between about 1 and 600, in particular between about 10 and 45, is , As an advantageous framework for the temperature of the polymer melt suitable for processing (PP) can here a range of about 230 to 270 ° C, in particular from 235 to 265 ° C, defined.

Also advantageous in the context of the invention as starting material are homopolymers of ethylene. For this are considered as preferred M FR values [g / 10 min], measured at 190 ° C and 2, 16 kg load, about 0.5 to 150, especially about 5 to 20.

Copolymers of propylene and also ethylene with at least one further comonomer are important for the purposes of the invention. In the preparation of the copolymer, at least one further comonomer with an olefinic double bond is expediently used in addition to propylene or ethylene. These may be, for example, vinyl acetate, butadiene, cyclic olefins and the like. Optionally, the polymers or copolymers used according to the invention, which are based on propylene and / or ethylene, may contain one or more further polymers or copolymers. These may be, for example, chemically identical polymers of propylene or ethylene or copolymers thereof but with different molecular weights or chemically different polymers or copolymers. The proportion of these other components is expediently subject to the following conditions in these polymer mixtures: their mixing proportions are always lower than that of the starting polymer or copolymer for each individual component. The present invention also provides polyolefin filament yarns obtainable by the process of the invention described above. It has been found that the polyolefin filament yarns according to the invention are in good agreement with the object of the invention. Thus, they show a color depth, expressed as K / S value, which is at least twice as large as the corresponding value which is achieved with a non-hydrogen peroxide-treated sample. Thus, a color depth is achieved, which is comparable or higher with the commercial products, as shown below. This is associated with the particular advantage of the invention that no disadvantageous after-treatment of the polyolefin filament yarns according to the prior art is associated with a complex plasma treatment. This particular dyeability of the polyolefins obtainable according to the invention makes these advantageous uses available. The invention thus also relates to the use of the polyolefin filament yarns according to the invention for the production of textile fabrics, in particular of wovens, fabrics, nonwovens and knitted fabrics, the advantageous properties of which in particular being that advantageous subsequent dyeing with vat dyes can take place. It is particularly preferred if the dyeing of the textile fabrics obtained according to the invention with conventional vat dyes, in particular according to the thermosol method, is carried out from an aqueous dyeing liquor.

The invention will be explained in more detail below, in particular with regard to technological aspects: Accordingly, it is sufficient for the invention, without having to make a change in the entire polymeric starting material wet-chemically described in the described in the thread formation in the melt spinning process fiber surface wet Modify way and thus leave the bulk phase, ie the fiber interior, unchanged. The treatment provided for this purpose accordingly takes place according to the invention "inline", d. H. in the melt spinning process just below the spinneret, this with a hydrogen peroxide solution, whereby partial oxidation at the fiber surface and the generation of functional groups with i.a. hydrophilic properties is achieved. As a result, it is possible to dispense with a separate process step, as is usually required in the later course of the processing chain according to the prior art (eg plasma treatment), in order to achieve a comparable effect.

The approach according to the invention described above has not previously been described and thus differs in principle from a post-treatment process by means of plasma treatment of textiles, which currently constitutes the state of the art. In contrast, the inventive peroxidic degradation of the homo- and copolymers of the type described above by reactive extrusion, which is also primarily used in industrial practice to produce a more processable polymer with controlled rheology, also leads to the fact that the formed functional, oxygen-containing groups after thread formation not only in the filament interior, but, assuming a homogeneous distribution, can also be found on the filament surface. The resulting surface concentration, however, is comparatively minimal, so that no appreciable changes in the interfacial properties are recorded. If one wanted to achieve effective functionalization of the filament surface by means of peroxide decomposition, the starting homo- or copolymer would have to be degraded so strongly that the necessary mechanical properties and spinnability would no longer exist. For this reason, peroxidic degradation and any other type of bulk modification can not be considered as a true alternative to surface treatment of the described filament yarns. From this point of view, the use of the above-mentioned and from the method completely new type of modification of the filament surface - as described in this invention - particularly advantageous because the intrinsic reactivity of the still hot forming thread is used under the spinneret to by reaction with the inexpensive oxidizing agent to bring about the functionalization. As a byproduct, only water is formed, which makes this process attractive for ecological reasons.

According to the invention, in the implementation of the method described here, two aspects play an equal role: the chemistry of the modification and the position in the process flow at which the modification must take place. Both are necessarily connected in the melt spinning process because the position determines the reaction d. H. the thread temperature, which is exploited at the application site for the chemical modification of the filament surface, and thus the reactivity and the conversion. With regard to the first aspect, as with many of the methods used today, the chemical modification of the filament surface, in particular of the PP filament surface, takes place via an oxidation of the filament / polymer surface. Crucial for this and thus fundamentally different from the applied methods is that this oxidation reaction is carried out in the present process solely with dilute hydrogen peroxide solution (H ₂ 0 ₂ ). Normally, this boundary condition alone is sufficient for oxidation of the textile surface, in particular the PP textile surface, in practice, which is why usually the use of an initiator in the form of radiation or thermal energy or in the form of a radical generator is necessary. Only so far is it possible to include a radical site. For example, to generate in the PP chain, which can then react to the desired functionality (hydroxy group, carbonyl group, etc.).

In carrying out the method according to the invention, it has now surprisingly been found that initiation can already be achieved by advancing the treatment step from the stage of textile finishing to the stage of thread formation in the melt spinning process. Under the conditions prevailing there and the structures formed in and on the thread, which are characterized by the process variables, the desired functionalization of the filament surface is achieved, which then makes it possible to realize the properties and effects of the filament yarns which are important for further processing and application ,

As important physico-chemical properties occur on the filament yarns u. Changes in the moisture absorption capacity, the yarn friction coefficients and the filament mechanical data, while the textile fabric also changes in surface resistance and the dyeing behavior are recorded. Especially in the dyeing behavior with vat dyes very good effects in terms of dye absorption are observed according to the invention. Carrying out the method according to the invention opens up a novel possibility of integrating the modification of polyolefin filament yarns, in particular PP filament yarns, into the existing production technology during the production process, without necessitating a fundamental change in the construction of the production plant or in the settings of the production parameters , This represents a hitherto unknown innovation in which compared to the previous practice only in or after the blow shaft to about four feet below the spinneret, ie where usually the spin finish is applied, a dilute H ₂ 0 ₂ solution on the filament bundle is applied. The surface of the filaments which is still hot at this point is directly oxidized by the attacking oxygen of the hydrogen peroxide without further initiation, and the attacked site in the polymer chain reacts further to the hydroxyl group. This increases the hydrophilicity and the wettability of the polyolefin filament yarns, in particular the PP Filament yarns, also all related properties are improved. To what extent this is in addition to the H ₂ 0 ₂ concentration of the different variables in the extrusion process is done depends. The most important variables are the processing / melt temperature, the filament titer, the application height (distance to the melt spinning nozzle) and the blowing and the drawing speed under the nozzle. The application of the hydrogen peroxide takes place via a preparation pen (also referred to as a preparation nozzle) with forced dosing, as is usually used for applying spin finishes in melt spinning processes. The apparatus for applying the spin finish is an indispensable part of the extrusion plant, as used in any production plant customary, and consists of a ceramic nozzle, which is supplied by a precision gear pump with the liquid to be applied from a storage tank out. These liquids are solutions, emulsions or pure spin fining oils; in the present invention, these are hydrogen peroxide solutions.

The extrusion and winding conditions in filament yarn production are within the usual values for the production of LOY, POY or FDY materials from polypropylene. In this case, the following have proven to be particularly favorable: Melt temperatures in the extrusion spinning plant in the range of about 220 ° C. to 290 ° C. and / or nozzle hole numbers of about 10 to 100 holes and / or take-off speeds of about 300 m / min to 3000 m / min , With these, preferably filament titres of about 0.1 dtex to 20 dtex are spun, with the achieved tear strengths being in the range of up to about 60 cN / tex. The filament yarns according to the invention can be further processed under conventional conditions into textile fabrics, preferably knitted fabrics.

As already explained above, a further subject of the present invention is the use of the resulting polyolefin filament yarns, in particular polypropylene filament yarns, and the sheets obtainable therefrom for an advantageous dyeing. In this case, the polyolefin filament yarns according to the invention or the fabrics obtained therefrom can now be dyed in a simple manner from an aqueous dyeing liquor by a standard method. This is based on vat dyeing achieved, which are carried out by a thermosol and which have high use fastness, in particular light fastness in the inventive method. The invention will be explained in more detail by way of examples. example 1

Lyondell / Basell commercial polypropylene granules Moplen H P561R (MFR [230 ° C / 2, 16 kg] 25 g / 10 min to ISO 1133) are fed to the extrusion spinning line and melted at a melt temperature of 260 ° C. Filament yarn spun with 24 filaments and a filament yarn denier of 90 dtex. The concentration of the hydrogen peroxide solution used was 3.5%. The amount of hydrogen peroxide applied to the filament yarn denier was 0.77%, applied at a distance of 1.2 m below the spinneret and the filament yarn was produced at a take-off speed of 1000 m / min.

Example 2

Lyondell / Basell commercial polypropylene granules Moplen H P561R (MFR [230 ° C / 2, 16 kg] 25 g / 10 min to ISO 1133) are fed to the extrusion spinning line and melted at a melt temperature of 260 ° C. Filament yarn spun with 24 filaments and a filament yarn denier of 90 dtex. The concentration of the hydrogen peroxide solution used was 35%. The amount of hydrogen peroxide applied to the filament yarn denier was 7.7%, applied at a distance of 1.2 m below the spinneret and the filament yarn was produced at a take-off speed of 1000 m / min.

Example 3

Lyondell / Basell commercial polypropylene granules Moplen H P561 R (MFR [230 ° C / 2, 16 kg] 25 g / 10 min to ISO 1133) are fed to the extrusion spinning line and melted at a melt temperature of 260 ° C to a POY. Filament yarn spun with 24 filaments and a filament yarn denier of 120 dtex. The concentration of the hydrogen peroxide solution used was 3.5%. The fila mentgarntiter applied, applied hydrogen peroxide amount was 0.35%, wherein applied at a distance of 1.2 m below the spinneret and the filament yarn was produced at a take-off speed of 2500 m / min. Example 4

Lyondell / Basell commercial polypropylene granules Moplen H P561S (M FR [230 ° C / 2, 16 kg] 33 g / 10 min to ISO 1133) are fed to the extrusion spinning line and melted to a FDY at a melt temperature of 240 ° C. Filament yarn spun with 24 filaments and a filament yarn denier of 100 dtex. The concentration of the hydrogen peroxide solution used was 3.5%. The amount of hydrogen peroxide applied to the filament yarn denier was 1.45%, applied at a distance of 1.2 m below the spinneret and the filament yarn was produced at a delivery rate of 2800 m / min. Example 5 to 8

Lyondell / Basell commercial polypropylene granules Moplen H P561S (M FR [230 ° C / 2, 16 kg] 33 g / 10 min to ISO 1133) are fed to the extrusion spinning line and melted at a melt temperature of 260 ° C into a POY. Filament yarn spun with 32 filaments and a filament yarn denier of 120 dtex. The concentration of the hydrogen peroxide solution used was 3.5%. The amount of hydrogen peroxide applied to the filament yarn was 0.35%, applied at a distance of 1, 1 m, 1.2 m, 1.35 m and 1.45 m below the spinneret and producing the filament yarn at a drawing speed of 2500 m / min has been.

The most important production parameters and the associated mechanical data of the undrawn and drawn filament yarns are summarized in Table 1. Therein, the data for the mechanical properties of the filament yarns prepared by the various methods are preceded by the results of a reference filament yarn prepared by the same method without hydrogen peroxide application. In the case of the LOY and POY processes, besides the values of the bobbins, the values of the post-stretched filament yarns are indicated as well. as they are achieved by a separate drawing process on a stretch-winding unit with setting a residual elongation of 20-30%. In the case of the FDY process, the fully drawn filament yarn is already available at the end of the process, ie the intermediate stage of the undrawn filament yarn can not be isolated or characterized.

In comparison to the filament yarn properties of the corresponding reference filament yarns, it is apparent, in particular for the fully hidden filament yarns, that the hydrogen peroxide application does not lead to a deterioration of the yarn-mechanical properties. That is, the ongoing modification of the filament surface only results in achieving a functionalization sufficient to improve its hydrophilicity and to desirably improve the dyeability of the filament yarns. The improved dyeability is just the decisive indicator of the teaching of the invention and a measure of the achieved modification.

Table 1:

Ref. Ref. Ref.

Example 1 2 3 4

(1-2) (3) (4)

Process LOY LOY LOY POY POY FDY FDY

Melt [° C] 260 260 260 260 260 240 240

Application distance [m] - 1.2 1.2 - 1.2 - 1.2

Hydrogen peroxide application _ [%] _ - 0.77 7.7 - 0.35 - 1.45

Tear strength unstr. [cN / tex] 26,6 23, 1 23, 1 26,6 27,2 - -

Elongation at break unstr. [%] 198 281 271 192 184 - -

Titre unstretched [dtex] 120 90 90 120 121 - - A module unstr. [cN / tex] 233 155 175 233 238 - -

Tear strength verstr. [cN / tex] 54.5 52.7 57.6 54.6 53.7 52.2 50, 1

Elongation at break stretched [%] 26 29 24 26 27 45 48

Titers stretched [dtex] 58 38 37 59 60 102 102

A-module stretched [cN / tex] 583 509 678 583 555 n. B. 394

For the practical implementation of the dyeings commercial vat and disperse dyes are therefore used according to the recipes of the manufacturer. Specifically, the following conditions are used to dye the knitted stockings made from the drawn filament yarns. First, the knits are washed according to manufacturer's instructions at 60 ° C in the dyeing machine for 30 min, including 0.5 g / l Kieralon OLB (surfactant compound) (manufacturer: BASF SE) and 0.5 g / l of soda are used in the wash liquor. It is then rinsed three times, spun and dried in air. The mixture is then heat-set in a steamer at 120 ° C. for 30 seconds: the actual staining is carried out as a thermosol staining, a dye liquor consisting of 20 g / l of dyestuff strain with 10 g / l avolan IS (surfactant compound) (manufacturer. Bayer AG) and 10 g / l Primasol AMK (surfactant compound) (manufacturer: BASF SE) is used. This is applied to the textile in two passages in a padder (contact pressure: 1.6 bar, throughput speed: 1.5 m / min) and then dried at 120 ° C. for 90 seconds. The mixture is fixed for five minutes at 145 ° C and 50% relative humidity before the textile is washed four times at 80 ° C with water and then dried in air. The dispersion dyes Dianix Yellow CC, Dianix Red CC and Dianix Blue CC as well as the indanthrene dyes: Indanthrene Yellow 5GF, Indanthrene Red FGL, Indanthrene Navy Blue G, Indanthrene Gold Orange G, Indanthrene Red LGG and Indanthren Blue RS used. The assessment of dyeability is based on the K / S values, which are determined with the aid of a commercial colorimeter from the colorimetric values measured there. The K / S value is given by the formula (100-R) ² / 200R. Where R is the percentage of light reflected from the colored sample which is measured at the maximum absorption wavelength. In the following table these values are compared with the corresponding values of a non-hydrogen peroxide treated sample. Table 2:

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Explanation of the results: All samples treated with hydrogen peroxide show a deeper staining (higher colorant uptake). This depends on the type of dye and the color and reaches about 1.5 to 5 times higher values than the comparison sample.

The following explanation of the invention serve the following explanations to the subsequent FIGS. 1 and 2. It is shown in FIG

1 shows a plant for the production of LOY, POY or FOY filament yarns;

Fig. 2 shows a plant for the production of FDY filament yarns.

In Fig. 1 mean: (1) granules container, (2) extruder, (3) spinner head with pump and nozzle, (4) threading, (5) forced hydrogen peroxide dosing, (6) hydrogen peroxide application, (7) chute, (8 ) Godet 2, (9) godet 1, (10) winding head, (11) spool.

The plant described in FIG. 1 can be described as follows with regard to the process sequences taking place therein: The spinning plant for the production of filament yarns consists of two parts, which are located on different constructional levels. The extrusion part (extruder with periphery and the application device) is connected via the chute with the connected. Depending on the set winding speed, the different processes are realized: at winding speeds of up to about 1000 m / min of the LOY, up to about 4000 m / min of the POY and with overlying winding speeds the FOY process. In Fig. 2 mean: (1) granules container, (2) extruder, (3) spinner head with pump and nozzle, (4) thread formation, (5) hydrogen peroxide forced dosing, (6) hydrogen peroxide application, (7) chute, (8 ) Winder (winding head with godets 1 + 2), (9) delivery godet duo, (10) drawing unit with three heatable godet duos, (11) withdrawal godet with printing roll. The plant described in FIG. 2 can be described as follows with regard to the process sequences taking place therein: The spinning plant for the production of fully drawn filament yarns, like the spinning plant of FIG. 1 of two parts. The extrusion part and the connection to the winding plane are identical. The yarn coming from the extruder is withdrawn from the godet at low speed (less than 1000 m / min) and then stretched on the following godets at increasing speeds under heating. The delivery duo delivers the finished drawn yarn to the winder at a constant speed, as used in the above POY / FOY process. The winding speed is in the range of 2000 to 5000 m / min.

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Claims

claims

1. A process for the preparation of surface-modified polyolefin dyeable from aqueous dyeing liquors, characterized in that polyolefin filament yarns based on homopolymers and / or copolymers of propylene and / or ethylene, optionally with one or more comonomers, during the Filamentgarnbil- formation in Melt spinning process for hydrophilizing the surface below the melting point of the polyolefin materials are treated with a hydrogen peroxide solution.

2. The method according to claim 1, characterized in that the surface treatment of the filament yarns is achieved by the chemical reaction of an aqueous hydrogen peroxide solution with the polymer molecules on the filament surface.

3. The method according to claim 2, characterized in that an aqueous hydrogen peroxide solution is used whose concentration is less than 35 wt .-%, in particular 0.5 to less than 35 wt .-%, is.

4. The method according to claim 3, characterized in that the concentration of the aqueous hydrogen peroxide solution is 1 to 30 wt .-%, in particular 1.5 to 10% by weight.

5. The method according to any one of claims 1 to 4, characterized in that the treatment of the surface of the polyolefin filament yarns with the hydrogen peroxide solution in the blower shaft of the spinning device is carried out below the spinneret by means of a preparation pin with forced dosing.

6. The method according to claim 5, characterized in that the application distance (between spinneret and application site) of the hydrogen peroxide solution in the blower shaft is less than 4 m, in particular less than 2 m.

7. The method according to claim 6, characterized in that the application distance is up to 1.5 m.

8. The method according to at least one of claims 2 to 7, characterized in that the amount of applied (pure) hydrogen peroxide, based on the filament yarn weight, up to about 10 wt .-%, in particular more than 0, 1 wt .-%, is set.

9. The method according to claim 8, characterized in that the amount of applied (pure) hydrogen peroxide, based on the Filamentgarngewicht, is adjusted to 0.2 to 2 wt .-%.

10. The method according to at least one of the preceding claims, characterized in that the filament yarns are withdrawn under the spinneret at a speed between 300 and 3000 m / min, in particular between 750 and 2700 m / min, and then stretched and wound on bobbins.

11. The method according to at least one of the preceding claims, characterized in that the method, in particular over the polymer passage in the upstream extruder, is controlled so that the filament titer of the filament yarns produced is adjusted to 0, 1 dtex to 20 dtex.

12. The method according to claim 11, characterized in that the setting of the filament titer is such that in the subsequent application of the filament yarns in carpets of filament titer between 10 and 20 dtex, in garments between 1 and 5 dtex and in textiles based on microfibers less is about 1 dtex.

13. The method according to at least one of the preceding claims, characterized in that the homo- and / or copolymer used for Filamentgarnherstellung is set with respect to a melt flow rate that the thread formation sets as usual, especially in the case of polypropylene (PP) the Melt flow rate MFR [g / 10 min], measured according to IS01133, at 230 ° C and 2, 16 kg load, between 1 and 600, in particular between 10 and 45, lies.

14. Polyolefin filament yarns obtainable by a process according to at least one of the preceding claims and dyed with vat dyes following their preparation, wherein the polyolefin filament yarns have a color depth, indicated as K / S value, which is at least twice as large as that Value achieved with a non-hydrogen peroxide treated and colored sample.

15. Use of the polyolefin filament yarns, produced according to at least one of claims 1 to 13, for the production of textile fabrics, in particular of crocheted fabrics, woven fabrics, nonwovens and knitted fabrics.

16. Use of the textile fabric according to claim 15 for subsequent dyeing with vat dyes.

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