WO2006000197A1

WO2006000197A1 - Method and device for the production of molded cellulose bodies

Info

Publication number: WO2006000197A1
Application number: PCT/DE2005/001118
Authority: WO
Inventors: Christoph Michels; Birgit Kosan; Frank Meister
Original assignee: Thüringisches Institut für Textil- und Kunststoff-Forschung e.V.
Priority date: 2004-06-26
Filing date: 2005-06-23
Publication date: 2006-01-05
Also published as: EP1763596A1; CN1977072A; DE112005002138A5; CN100564621C; DE102004031025B3; EP1763596B1

Abstract

The invention relates to a method for producing molded cellulose bodies by using ionic liquids, especially 1,3-dialkylimidazolium halides, as solvents. According to said method, the cellulose is dissolved, the solution is shaped into fibers or foils/membranes, the cellulose is regenerated with the aid of a precipitation process in aqueous solutions, the solvent is separated by washing, and the molded bodies are dried.

Description

Method and device for the production of shaped articles from cellulose

The invention relates to a process for the production of moldings from Cellu¬ loose with "ionic liquids", in particular 1, 3-Dialkylimidazoliumhalogeni- the solvent, in which one dissolves the cellulose, the solution to fibers or films / membranes deformed, the Cellulose is regenerated by precipitation in aqueous solutions, the solvent is separated by washing and the shaped bodies are dried.

For forming cellulose - as a non-meltable polymer - into filaments, staple fibers or films / membranes under industrial conditions, three different solution spinning processes have been developed to the technical maturity, namely the spinning of stable derivatives, e.g. Cellulose 2,5-acetate dissolved in acetone without regeneration (acetate method - Ullmann's Encyclopedia Weinheim: VCH Verlagsgesellschaft 1986 Vol. A5 p. 438-448), the spinning of semistable derivatives, e.g. Cellulose xanthogenate, dissolved in sodium hydroxide solution with regeneration (Götze K. "Man-made fibers by the viscose process" Berlin / Heidelberg / New York: Springer Verlag 1967) and the spinning of solutions of cellulose and Aminoxidhydraten and regenerating by precipitating the celluloses in aqueous amine oxide solutions [Lyocell - Woodings C. "Regenerated Cellulose Fibers" Woodhead Publishing LTD Cambridge 2001; DE-A 29 13 589 and 28 48 471, US-A 4 246 221].

It is also known to form cellulose in chelate-forming metal complexes, for example in copper tetramine hydroxide (cuoxam), copper ethylenediamine (Cuen), nickel tris (2-aminoethyl) amine (nitrene), zinc diethyltriamine, dimethyl acetamide / lithium chloride [Klüfers P. "Which Metals Form Complexes with Cellulose Dianions" Lecture DFG / Bad Herrenalb 16.03.1999]. These solvents, apart from the copper tetramine hydroxide for spinning "copper silk", probably have a broad analytical interest, but hitherto have not found any technical application. Although ionic liquids have been known since 1914, they have only recently gained in importance as solvents or reaction media for many syntheses. Of particular interest are compounds with a positive nitrogen atom such as the ammonium; Pyridinium and imidazolium cation [Schilling G. "Ionic liquids" GIT Laboratory Journal 2004 (4) 372 - 373].

It is known from WO 03/029329 and US-A 2003/0157351 that certain ionic liquids, predominantly consisting of cyclic nitrogen cations and halogen anions, dissolve cellulose in the absence of water and at elevated temperature and precipitate again on addition of water , In the preparation of the cellulose solution, dry cellulose is dissolved in largely anhydrous ionic liquids while supplying energy, for example by heating with microwaves. No statements are made about the properties of the starting and regenerated cellulose, the cellulose solution and the possible conditions of deformation of the cellulose solution.

For a use of ionic liquids as solvents for the deformation of the cellulose to filaments, staple fibers and films / membranes speaks a possible higher thermal stability compared to Aminoxidhydraten and a much better environmental performance compared to the viscose, acetate and copper process. As solvents, the ionic liquids should permit working in a closed solvent circuit.

Object of the present invention is to provide a method by which one bleaches at high process safety and environmental friendliness in a simple manner, cellulose (pulp, Elementarchlorfrei ECF or total chlorine-free TCF) while substantially preserving the molecular parameters to filaments, staple fibers and films / membranes deformed and a corresponding device. With this method and this device molded body made of cellulose with new or improved properties can be herge¬ provides. The object is achieved with a method for the production of shaped articles from cellulose by dissolving them in an ionic liquid, shaping the viscous solution to the molding and regenerating the cellulose, characterized in that

a) cellulose or a cellulose mixture dispersed in water with shearing down to the individual fiber, pressed, and the press-moist cellulose or cellulose mixture, b) dispersed in the ionic liquid, with the addition of basic substances and, if appropriate, further stabilizers, under shear, rising Tem¬ temperature and decreasing pressure (from about 800 to 850 mbar to about 10 to 30 mbar), the water removed and the dispersion in a homogeneous solution Lö¬, c) the solution via (a) temperature-controlled pipe (s) and a Druckaus d) the solution in the spin pack feeds a filter, a distributor plate preferably designed as a heat exchanger and the spinning capillary (s) or the slot of the spinneret (s), e) the solution jets deformed into capillaries or to the film passing through an air-conditioned gap, f) the oriented solution jets by treatment with a tempered Lösun g, which is miscible with the ionic liquid, but represents a precipitant for the cellulose precipitates, at the end of the Fällbadstrecke by removing or diverting separates from the precipitation bath and g) the shaped body as filament yarn, fiber cable or foil / membrane deducts one - or multi-stage Fällmittelwäsche subjects, possibly aviviert and dried or cut into staple fibers, aviviert and dried.

The spinning solution preferably reaches the spinning temperature only when passing through the distributor plate designed as a heat exchanger. - A -

In a preferred embodiment of the process according to the invention, the spinning solution is divided into spinning capillaries of 0.4 to 5 mm overall length (I), with a cylindrical part (L = 0.5 to 3D), a conical part (I-L) and an exit diameter ( D) of 0.05 to 0.25 mm with a circular arrangement of the spinning capillaries for Filamentgame and rectangular arrangement of Spinnkapilla¬ ren for spun fibers deformed.

The deformation of the spinning solution into a flat film is expediently carried out with a slot die with a gap width of 0.1 to 2.0 mm thickness. Ring slit nozzles with a gap width of approximately 0.1 to 1.5 mm are suitable for the production of blown films.

The dispersion and dissolution of dry cellulose, without upstream consuming grinding processes, in anhydrous ionic liquids, eg. For example, in 1-butyl-3-methylimidazolium chloride does not lead to a "nodule-free" suspension and even after very long dissolution times to a homogeneous solution that meets the requirements of a spinning process.Fine-milled cellulose is very voluminous, not free-flowing and tends in the presence Furthermore, it has been found that the dissolution of the cellulose in this manner is associated with a significant degradation of the molar mass. Fraud of the cuoxam-DP of a spruce sulphite pulp prior to dissolution under microwave heating was 550 for the cellulose regenerated from the solution, a cuoxam-DP of 172 was found, and spinning of such solutions into fibers is not possible.

In the process according to the invention, pulps of wood or cellulosic fibers of annual plants, in particular cotton linters, produced by the sulfite, sulfate hydrolysis sulfate or organosolv process with elemental chlorine-free (ECF) or totally chlorine-free (TCF) bleach, be used. Preference is given to using mixtures of celluloses having an average molar mass (Cuoxam DP 400 to 800) with high molecular weight celluloses (Cuoxam DP 800 to 3,000) or low molecular weight celluloses (Cuoxam DP 20 to 400). Preferred θ ionic liquids are melts of 1, 3-dialkylimidazolium halides. For stabilization before and / or during the dissolution of the cellulose, basic substances having a low vapor pressure may be added to the ionic liquid in an amount which causes a pH of 8 or more in the suspension containing cellulose and aqueous ionic liquid. The basic compound having a low vapor pressure is particularly preferably an alkali hydroxide such as KOH or NaOH.

In the method according to the invention, the pulp is whipped up to a single fiber under high shear in water. After pressing gequolle¬ ne cellulose is present with about 50% by mass of water. For example, in aqueous 1-butyl-3-methylimidazolium chloride, which contains at the same time as much alkali metal hydroxide as achieves a pH of> 8, the cellulose which is moist with respect to the press can easily be converted into a homogeneous suspension which undergoes shear, increases in temperature and reduces pressure after distilling off the water into a homogeneous spinning solution. Under these conditions, the dissolution time is only a fraction of that required to dissolve dry cellulose in water-free 1-butyl-3-methylimidazolium chloride. The reduction in molecular weight is less than 10%. The spinning solution quality can analogously to the lyocell process by determining particle content c _ppm and bezoge¬ on the class width

Particle distribution [# 3X = / (Λ :)] by means of laser diffraction [see Kosan B. Michels Ch. Chemical Fibers International 48 (1999) 4 pp. 50-54], as well as zero-scratch viscosity ηl and relaxation time λ ⁹ _m [see Michels Ch. Paper 52 (1998) 1 pp. 3-8]. In practice, relaxation time spectra [H = f (X)] are present in these solutions since the cellulose has a molecular weight distribution. λf _n is then the relaxation time at the frequency maximum in the weighted relaxation time spectrum [H * λ = f (λ)]. In contrast to the cellulose / amine oxide hydrate solutions, the solvation of the cellulose in 1-butyl-3-methylimidazolium chloride or 1-ethyl-3-methylimidazolium chloride is significantly slower and the achievement of the minimum zero shear viscosity (complete solvation) is much more dependent on the dissolution temperature and dissolution time. The temperature function of zero shear viscosity and relaxation time is given by the relationship (1)

\ nη (λ) = \ nK _{η {λ) +} ^ - (1) K • 1 given. Their knowledge is essential for the deformation of highly elastic solutions in the spinneret channel and gap.

The cellulose concentration and the molecular weight of the cellulose or Cellulosemi- research are expediently selected such that at 85 ⁰ C a Nullschervis¬ viscosity by the spinning solution from 1,000 to 100,000 Pa s, preferably from 10,000 to 80,000 Pa s, is established.

For a high stability of the molecular weight over a long time at elevated temperature, in addition to the addition of bases, such an antioxidant has been proven. These are, in particular, organic compounds having at least one conjugated double bond and two hydroxyl or amino groups, such as hydroquinone, p-phenylenediamine, gallic acid esters, tannins, etc. As is apparent from DTA / DSC and reaction calorimetric measurements, the thermal stability of the invention is Spinning solutions compared to stabilized lyocell spinning solutions significantly higher. While in stabilized cellulose / Aminoxidhydrat- solutions above 13O ⁰ C, the risk of explosive decomposition, the 1-butyl-3-methyl-imidazolium is stable to at least 25O ⁰ C and the stabilized spinning solution, the cellulose begins above 213 ° C. decompose.

The deformation of the solution into filaments, staple fibers and films / membranes takes place in a modified dry-wet extrusion process such that the solution via a temperature-adjustable pipe and Druckausgleichs¬ device the spin pack with dissolving temperature 3 _L , here by a Sicherheitssspinnfilter presses, in a temperature-adjustable heat exchanger, the required spinning temperature 3 _Sp sets the solution according to their Relaxa¬

tion time λ ^& _m at spinning temperature can relax, through spinnerets to Filamen- th or foils deformed and leads with delay through a gap to the precipitation bath. Between the heat exchanger outlet and spin capillaries, a volume V should remain in cm ³ which is at least equal to or greater than the product of the volume flow V ₁ in cm ³ / s and the relaxation time λ _m in s at the spinning temperature. V ≥ v _L -λ _m (2)

In the gap, which consists of an air-conditioned zone, the yarn sheet is perpendicular to the thread running direction and surface-treated with conditioned air of vor¬ preferably 15 to 25 ° C and 20 to 80% relative humidity.

The thread formation can be represented as a two-stage process. In the spin capillary, a tapering of the solution jet from the inlet A _E to the outlet cross section A _A of the spinning capillary takes place predominantly under the influence of the shearing stress τ _D at a constant temperature, ie the draft in the nozzle SV _D follows

DE and D _A corresponds to the entry or exit diameter of the spinning capillary. In the gap of length a, under the influence of the axial expansion stress σ _a, as the temperature decreases, a further tapering of the solution jet in the ratio of withdrawal v _a and injection velocity v 1, the spinning distortion occurs

SV, -

D _κ corresponds to the capillary diameter at the transition gap / precipitation bath. The delay of the solution jet in the gap is simultaneous with an increase of the thread surface according to (5)

connected. In this formula, 0 _A denotes the surface of the thread at the spinning capillary naus- and O _κ the surface of the thread at the precipitation bath inlet. The Oberflächen¬ magnification per unit time AO _a in the gap of length a then results with

o _A - - DA ^■ π -v _s and o _κ = D _κ -π to A ΔÖO _βa = = Ö ό _κ -Ö _Ä = = DD _ΛA --ππ - v, [J WSVΪ _n - -lι )) (6)

and with ^V s = 3,6 - κr ² ⁾ A ² - K - PL - ^C Cell. V follows Δ AÖQ _a . = 3, 66 - -11 (0T - ² _' . Α ₀ - ^ "^ a ψK - iI)) \ ≡f- [I) D _A - P _L - ^C Cell.

for the surface increase of a capillary per unit time. Where T _{10 is} the fiber denier in dtex, p _{L is} the density of the spinning solution in g / cm ³ and c _{Cell is} the cellulose concentration in% by mass. It is easy to see that the rebuilding of surfaces during the thread consolidation in the gap should be associated with disturbances in the fiber cladding and adversely affect the fibrillation behavior of the fibers. In addition, the solution jets are highly hygroscopic, absorb water from the air-conditioned environment and take place in the peripheral areas of a partial precipitation of the cellulose.

In the method according to the invention, it has been found that very good fiber properties are achieved when the surface area increase AÖ _{a reaches} values of <200 cm ² / min, in particular <20 cm ² / min.

Another important factor is the surface increase normalized to the gap a = 1.

v _{α / I} = 10 - - [mm I min] a With AÖ _a in cm ² / min and a in cm. It is a measure of the rate of surface change and should be as small as possible. Good fiber properties are obtained for values v _m <500 mm / min, in particular for v _m <50 mm / min.

The climatization of the gap, preferably by air with a certain temperature and temperature, has, in addition to a cooling and stabilizing effect of the yarn path, a partial precipitation of the cellulose, preferably in the edge zones of the filaments. This increases the spinning reliability, especially with high capillary densities, promotes the formation of a core / shell structure and improves the fiber properties. When passing the air-conditioned draft zone, the group of threads is preferably additionally subjected to a likewise conditioned gas stream.

In the process according to the invention, the oriented solution jets for regenerating the cellulose are passed through an aqueous precipitation bath which contains up to 50% by mass, preferably up to 25% by mass, of the ionic liquid used for dissolving.

Furthermore, it was found that when using, for example, 1, 3-dialkyl imidazolium halides as a solvent, the discolor slightly brown precipitation bath by treatment with alkaline hydrogen peroxide at 60 to 80 ⁰ C and the entrained by the pulp and other auxiliary products cations on cation exchanger can remove. The precipitation bath thus purified can be recirculated as a solvent after distillative concentration.

The inventive method and apparatus will now be explained with reference to the drawings and by examples. Show it

FIG. 1 shows a graph of the particle distribution of a typical cellulose / 1-butyl-3-methylimidazolium chloride spinning solution with 11.5% by weight of cotton linter pulp; FIG. 2 is a graph of the weighted relaxation time spectrum of a spinning solution containing 12.5% by weight of eucalyptus prehydrolysulfate pulp at 85 ^° C.; FIG. 3: a graphic representation of the temperature function of zero shear viscosity and relaxation time for the spinning solution according to FIG. 2; FIG. 4 shows the enthalpy determined by DSC analysis as a function of the temperature for 1-butyl-3-methylimidazolium chloride and for a spinning solution containing 12% by weight of spruce sulphite pulp and 1-butyl-3-methylimidazolium chloride as solvent; Figure 5: the schematic representation of an apparatus for carrying out the method for producing filament yarns and staple fibers; FIG. 6 is a schematic representation of a preferred apparatus for the production of staple fibers and films; Figure 7: a schematic representation of the distribution plate designed as a heat exchanger.

FIG. 1 shows the density distribution q3 * (x) determined by laser diffraction versus the particle size in μm for a spinning solution of 11.5% by weight cotton linters pulp stabilized with 0.22% by mass NaOH (based on the solvent) (cuoxam DP 650) and 88.5% by mass of 1-butyl-3-methyl-imidazolium chloride with a zero shear viscosity of 31650 Pas and a relaxation time of 5.3 s at 85 ⁰ C. The particle content of 20 ppm, divided in 81% <12 μm and 19% <40 μm equivalent particle diameter. This corresponds to a solution quality that is suitable for spinning fibers.

FIG. 2 shows the weighted relaxation time spectrum (H * λ) = f (λ) for a spinning solution of 12.5% by mass of a spinning solution stabilized with 0.22% by mass of NaOH and 0.04% by mass of gallic acid propyl ester (based on the solvent) eucalyptus tus-Vorhydrolysesulfatzellstoffes (cuoxam DP 569) and 87.5% by mass of 1-butyl-3-methyl-imidazolium chloride with a zero shear viscosity of 27010 Pas and a relaxation time of 9.5 s at 85 ⁰ C. The particle content was 22 ppm with a share of 40% <12 microns and 60% <40 microns. Figure 3 contains the temperature function of zero shear viscosity and Relaxations¬ time (at the frequency maximum) in the temperature range 70 -130 ⁰ C for Spinnlö¬ solution in Figure 2. The comparison of the spinning solutions in Figures 1 veran¬ to 3 illustrates the influence of pulp provenance, molar mass (Cuoxam DP), cellulose concentration, stabilization and temperature on the zero shear viscosity, relaxation time and the solution state.

FIG. 4 shows the results for the thermal analysis of the solvent 1-butyl-3-methylimidazolium chloride and a stabilized spinning solution of 12 mass% eucalyptus pre-hydrolysis sulfate pulp and 88 mass% 1-butyl-3-methylimidazolium chloride. While the solvent has no changes in addition to the endothermic melting peak to 250 ⁰ C, the curve of the spinning solution next to the endothermic melting peak, an exothermic peak starting at 213 ° C. Obviously, here begins the thermal degradation of cellulose.

FIG. 5 shows a spinning device for carrying out the method according to the invention. It consists of a temperature-controlled pipe (1), pressure equalizer (2), spin pack (3), draft zone (9), precipitation bath (11) and take-off godet (18). The spin pack (3) comprises a distribution plate designed as a heat exchanger (5) with a solution filter (4), an inflow chamber (6) and at least one spinneret (7). Between spin pack (3) and precipitation bath (11) is the conditioned draft zone (9) with gas supply / distribution (10) whose length is adjustable by vertical movement of the precipitation bath (11). The Fällbadbehälter (11) comprises the inflow chamber (12) for forming a laminar Fällbadströmung, the overflow (13) by a existing existing ceramic thread guide bottom opening (14), the collecting trough (15), Fällbadpumpe (16) and thermostat (17 ). About the thread guide in the bottom opening (14) and the Abzugsgalette (18) separates the filament bundle (19) from the precipitation bath (11) by peeling at the angle ß, which is preferably less than 70 °. FIG. 6 shows a spinning device which preferably serves for spinning spun fibers and films. The structure up to the spinneret (7) largely corresponds to that of Figure 5. The spinneret (7) here forms a rectangle and contains arranged in rows spinning capillaries or a slot for spinning films. The conditioned draft zone (9) and the gas supply / distribution (10) are adapted to this rectangular shape. The length of the draft zone (9) is adjusted by vertical displacement of precipitation bath (11). As indicated by the dotted line, the draft zone (9) is largely closed. Opposite to the gas supply / distribution (10) are openings for discharging the conditioned blowing gas. The precipitation bath (11) is again formed from inflow or settling chamber (12), overflow (13), deflection roller or roller (14), collecting pan (15), pump (16) and thermostat (17). The separation of yarn sheet (19) and precipitation bath (11) by deflecting at an angle> 90 ° and deduction on the Galettenduo (18). When spinning films, a driven roller (14) takes over the deflection and further guide rollers transport to the godet pair (18).

Figure 7 shows schematically the structure of the heat exchanger (5) formed distribution plate with solution filter (4), seals (8) and heaters (H). The spinning solution with the temperature T1 (3 _L ) passes through the solution filter (4), flows through a plurality of holes (R) with simultaneous heating to the spinning temperature T2 (3 _Sp ) and passes with this temperature upstream chamber (6) and nozzle (7 ). The heat exchanger (5) is preferably made of nickel-plated or chromium-plated aluminum, copper or brass. In addition, it expediently comprises a well sealed off by seals (8) for receiving the filter pack (4), a separate heater (H) and flow duct (R).

EXAMPLES 1 to 7 A spruce sulphite pulp (Cuoxam DP 550, ECF-bleached) was beaten in water at a liquor ratio of 1:20 and dehydrated by pressing to 40% by mass. By dispersing 75 g of moist cellulose into 275 g of 1 Butyl-3-methyl-imidazoliumchloricl (BMIMCI) with 20% by mass of water and stabilizer additives according to Table 1 gave 350 g of homogeneous Sus¬ pension, after entry into a vertical kneader under high shear, slowly rising temperature of 85 to 120 ⁰ C and decreasing pressure of 850 to 20 mbar was transferred with complete removal of water in a homogeneous solution. The release time was uniformly 60 minutes. The solution containing 12% cellulose by mass and 88% by mass BMIMCI (refractive index 1, 5228 at 50 ⁰ C) was measured immediately after dissolving and after spinning (corresponding to a time of 20 hours at 85 ⁰ C) was investigated. The results are included in Table 1.

Table 1

¹⁾ based on BMIMCI ²⁾ gallic acid propyl ester ³⁾ p-phenylenediamine; ⁴⁾ p-hydroquinone

The addition of alkali resulted in a significant stabilization of the cellulose. Obviously, the BMIMCI cleaved off traces of hydrochloric acid at a higher temperature, which led to a cleavage of the 1.4 acetal bond of the cellulose. By low addition of radical scavengers as in Examples 5 to 7, the thermal long-term stability of the spinning solutions could be further improved. Example 8 375 g of eucalyptus prehydrolysis sulphate pulp (Cuoxam DP 569, TCF-bleached) were beaten in a liquor ratio 1:15 in water, separated from the liquor by a centrifuge to 50% by mass, coarsely crushed and pressed dry in 3088 g i-butyl-3-methyl-imidazolium chloride (BMIMCI) with 15% by mass of water, which at the same time contained 0.22% by mass of sodium hydroxide and 0.036% by mass of gallic acid propyl ester. By introducing the suspension into a vertical kneader, evaporation of 838 g of water for 60 minutes under high shear, elevated temperature (85 to 130 ⁰ C) and vacuum (800 to 15 mbar), a homogeneous solution of 12.5 mass% of cellulose and 87.5 mass% BMIMCI with a zero-shear viscosity of 32 680 Pa s, a relaxation time of 9.8 s at 85 ⁰ C and a Temperatur¬ function according to In η _o = 16.9874 + 9799 * 1 / T

The particle content of the solution was 18 ppm with a content of 65% <12 μm and 35% <40 μm.

The spinning of the solution took place in a test apparatus according to FIG. 5. The required amount of spinning solution m _L was fed to the spin pack at 85 ° C. melt temperature via a temperature-controlled pipe at the same temperature by means of a spin pump (0.10 ml / Umd.), Filtered, in a heat exchanger on spinning tuft Heat S _Sp , relax in the inflow chamber with approx. 8 ml volume and through nozzles with 30 resp. At Vers. Nr. 7.12 60 spinning capillaries with an L / D _A - ratio of 1 resp. At verse 2 and the exit diameter D _A pressed. The solution jets passed through the air gap of the length a under the delay SV ₃ and additionally with 25 (staple fibers) or 1001 / min (filament yarn) air of 25 ° C. and moisture was blown according to the table. The oriented bundle of threads passed under simultaneous precipitation of the cellulose, the spinning bath at a temperature of 2O ⁰ C was separated at the Abzugsgeschwin¬ speed v _a at an angle ß = 40 ° from the precipitation bath, withdrawn via godets and fed to the aftertreatment. For the spun fiber samples the aftertreatment was carried out batchwise and without tension and in the case of the filament yarn (Vers. No. 7.12) continuously under minimum tension (<2 cN / tex) by washing, drying with 2.5% shrinkage, softening and tangential winding onto cylindrical coils.

The spinning conditions and the spun fiber or filament yarn properties are listed in Tables 2 and 3 below. Table 2 also shows the calculated surface increase AÖ _a as well as the velocity v _on which the surface increase took place.

Table 2 (spinning conditions)

¹⁾ filament yarn 100 dtex (60); ²⁾ pf ^c = 1, 11 g / cm ² Table 3 (fiber properties)

¹⁾ The method for determining the wet scrub resistance is described by Mieck KP et al. In Melliand Textilberichte 74 (1993) 945 u. Lenzinger reports 74 (1994) 61-68 described in detail.

The dissolved cellulose cuoxam DP was 531 and that of the fiber was 529. The fiber properties had high tensile and moduli in the conditioned and wet state, as well as increased wet scrub resistance over lyocell fibers.

Example 9 A cotton linter pulp (Cuoxam DP 650) was analogously to Example 8 in a spinning solution with 11, 5 mass% cellulose, zero shear viscosity 31650 Pas at 85 ° C, relaxation time 5.3 s at 85 ° C, particle content 20 ppm, particles <12 μm 81% and particles <40 μm 19% transferred. The spinning was carried out in an apparatus according to FIG. 5 under the following conditions:

Flow rate 1, 35 g / min Diameter D _A 100 microns (30 capillaries) spinning temperature 100 ⁰ C late SV _a 9.3 mm air gap 12 Rel. Moisture 7.5% spin bath 20 ⁰ C-off speed 50.2 m / min

Fibers with very high tensile strengths and moduli were obtained in the conditioned and wet state:

Fineness 1, 27 dtex tensile strength cond. 67.7 cN / tex wet 60.9 cN / tex Elongation at break cond. 9.0% wet 8.8% initial modulus cond. 1366 cN / tex Wet 511 cN / tex Wet Scrub Resistance 43 T Cuoxam DP Fiber 624

Example 10 A mixture of 85% by weight of beech hydrolysis sulphate pulp (Cuoxam DP 390, TCF bleached) and 15% by weight of spruce sulphite pulp (Cuoxam DP 780, ECF bleached) was beaten together in water to a monofilament by means of a jet mixer and passed through a sieve belt press Fleet separated. 1020 g of the wet cellulose with a water content of 52% by mass were mixed thoroughly in 3478 g of BMIMCl with 15% by weight of water, which simultaneously contained 0.22% sodium hydroxide and 0.036% propyl gallate, in a vertical kneader and under shear, elevated temperature (85 / 13O ⁰ C) and vacuum (700/20 mbar) distilled off during 60 minutes 1044 g of water and then dissolved for 60 minutes. The resulting solution contained 14.0% by mass of cellulose with a cuoxam DP of dissolved cellulose of 465. The zero-shear viscosity at 85 ° C. was 13 100 Pas, the relaxation time 5.5 s. The particle analysis showed a content of 28 ppm with a particle distribution of 82% <12 μm; 16% <40 μm and 2%> 40 μm. For spinning the 19.1 g / min spinning solution of 90 ⁰ C in the spin pack, filtered through a sieve filter (mesh size 25 microns), heated in the heat exchanger to 110 ⁰ C and through a rectangular nozzle with 900 Spin capillaries (arranged on an area of 1 x 3 cm) were pressed 75 microns exit diameter. The yarn passage passed the air-conditioned gap of 2.8 cm length under a draft of 5.1 and was flowed over a width of 9 cm with 160 l / min of air at 23 ° C. and 70% relative humidity. The surface increase on warpage was 0.128 cm ² / min + capillary, its velocity 0.46 mm / min.

After precipitation of the cellulose in the spinning bath of 23 ⁰ C and deflecting the Faden¬ flocking reached this one pair of godets to a take-off speed of 22 m / min .. After cutting the fiber tow into staple of 40 mm length, washing and preparing by drying at 9O ⁰ C to a residual moisture of 10% by mass. For the mechanical fiber properties, the following values were obtained:

Fineness 1, 50 dtex tensile strength cond. 44, 1 cN / tex tensile strength wet 40, 0 cN / tex elongation at break cond. 12, 1% elongation at break wet 12, 0% loop tearing force cond. 32, 2 cN / tex module cond. 920 cN / tex module wet 340 cN / tex NSB 130 tours

Example 11 A mixture of cotton linters pulps (80% by mass of Cuoxam DP 465 and 20% by mass of Cuoxam DP 650) was prepared analogously to Example 9. The press-moist cellulose mixture had a water content of 45% by mass. In a horizontal single-shaft mixing / kneading reactor of the type Diskotherm B (LIST AG ARISDORF Switzerland) were in the first shear zone continuously via a precision gear pump 819 g / min preheated to 90 ° C 1-ethyl-3-methyl-imidazoliumchlorid (EMIMCI), the 10% by mass of water, 0.28% Natri¬ hydroxide and 0.04% tannin contained, and metered via a belt scale and control piston pump 200 g / min crushed cellulose, mixed and heated under a vacuum of 30 mbar to 120 ⁰ C and distilled off 172 g / min of water. The resulting in the second shear zone light yellow homogeneous solution with 13 mass% cellulose (zero shear viscosity 11450 Pas at 85 ° C) was cooled to 110 ⁰ C, taken from a vertical double-skid conveyor and fed to a wide-film laboratory. This corresponded to the structure of the arrangement in figure 6, via a pressure-balancing device and precision gear pump was 847 g / supplied to the spin pack min spinning solution, filtered exchanger homogenized in Wärme¬ to 110 ⁰ C and through a sheet of 100 mm slot width and 1, 2 mm - thick pressed. The solution, which was deformed into a flat film, passed a conditioned air gap (20 ^° C., 55% relative humidity) of 15 mm in length, passed into the precipitation bath (an aqueous solution containing EMIMCI), and was deflected by means of a driven roller and tightened by the roller duo at 20 m / min. After washing, drying and preparation, a conditioned film of 40 μm thickness and a basis weight of 61 g / m ^{2 was obtained} . The longitudinal tear strength of the film was 27.2 cN / tex, its elongation 16.8%.

Example 12 234 g of eucalyptus prehydrolysis sulphate pulp (Cuoxam DP 569, TCF-bleached) were dissolved in water with an Ultramischer in a liquor ratio of 1:25, adjusted to a pH of 10 with sodium hydroxide, by pressing down to 26.7% by mass. separated from the liquor, coarsely crushed and pressed moist in 1520.5 g of 1-butyl-3-methyl-imidazolium chloride (BMIMCI) containing 22% by mass of water, 1.4 g of sodium hydroxide and 1.2 g of gallic acid propyl ester. By adding the suspension (2400 g) to a horizontal two-shaft kneader of the CPR 2.5 batch type (List-AG Arisdorf), evaporate 980 g of water for 90 minutes under high shear (shaft speed 30/24 to 90/72 rpm) Melt temperature (85 to 145 ° C) and vacuum (800 to 10 mbar) resulted in a homogeneous concentrated solution of 16.5% by mass of cellulose and 83.5% by mass BMIMCI (molar ratio of cellulose: BMIMCI // 1: 4.67) with a zero shear viscosity of 72,560 Pas, a relaxation time of 4.8 s at 85 ° C and a temperature function according to

In η ₀ = -15.35831 + 9505 ^* 1 / T

The particle content of the solution was 33 ppm with a proportion of 61% <12 .mu.m and 39% <40 .mu.m.

The spinning of the solution was carried out in a test apparatus according to Figure 5. The required spinning solution amount m _L was fed with 95 ⁰ C melt temperature via a temperature-controlled pipe at the same temperature by spin pump (0.10 ml / Umd.) The spin pack, filtered, in the heat exchanger on spinning tuft 3 _Sp heated, relaxed in the inflow chamber with about 8 ml volume and pressed through nozzles with 60 spinning capillaries with an L / D _A ratio of 1 and the exit diameter DA. The solution jets passed under the delay SV ₃ the air-conditioned air gap of length a and were additionally blown with 85 l / min air of 25 ° C and 2.5 g / m ^{3 of} water. The oriented Faden¬ flocking happened with simultaneous precipitation of the cellulose, the spinning bath with a temperature of 20 ⁰ C was treated with the withdrawal speed V _A at the angle ß = 40 ° separated from the coagulation bath, drawn off via godets and the diskon¬ tinuous aftertreatment supplied. Spinning conditions and fiber properties are shown in Tables 4 and 5 below. Table 4 (spinning conditions)

1) 60 capillaries in 4 rows a 15; ²⁾ SV _Da = ^ SV _D -SV _a Table 5 (Fiber properties)

The cuoxam DP of the dissolved cellulose was 509, that of the fiber 510.

Claims

claims

1. A process for the production of moldings from cellulose by dissolving the same in an ionic liquid, forming the viscous solution to the molding and regenerating the cellulose, characterized in that

a) cellulose or a cellulose mixture dispersed in water with shearing down to the individual fiber, pressed, and the press-moist cellulose or cellulose mixture, b) dispersed in the ionic liquid with the addition of basic substances under shear, rising temperature and decreasing pressure of the water c) the solution is fed to at least one spin pack via (a) heatable pipe (s) and a pressure compensation device, d) the solution in the spin pack a filter, a distributor plate designed as a heat exchanger and the spinning capillary (n e) the solution jets deformed into capillaries or to the foil, passing through an air-conditioned gap, f) the oriented solution jets by treatment with a tempered solution which is miscible with the ionic liquid is, for the cellulose but a precipitant, fails, at the end d he separates Fällbadstrecke by turning off or diverting from the precipitation bath and g) the shaped body as filament yarn, fiber cable or film / membrane ab¬ pulls, a single or multi-stage Fällmittelwäsche subjects, aviviert and dried or cut into staple fibers, aviviert and dried.

2. The method according to claim 1, characterized in that pulps of wood or cellulosic fibers of annual plants, such as cotton linters, prepared by the sulfite, sulfate A / orhydrololyse sulfate or Organosolvverfahren with Elementarchlor- (ECF) and / or Total Chlorine Free (TCF) bleaching.

3. The method according to claim 1, characterized in that one uses celluloses of average molecular weight (Cuoxam DP 400-800) in mixture with hochmolekula¬ Ren (Cuoxam DP 800 -3000) or low molecular weight (Cuoxam DP 20 - 400) celluloses.

4. The method according to claim 1, characterized in that are used as ionic liquid 1, 3-dialkyl-imidazolium halides.

5. The method according to claim 1, characterized in that the ionic liquid for stabilization before and / or during the dissolution of basic substances low vapor pressure zu¬ sets in such an amount that the suspension cellulose / aqueous ionic liquid has a pH> 8 has.

6. The method according to claim 1 and 5, characterized in that the basic substances are low vapor pressure alkali metal hydroxides.

7. The method according to claim 1, characterized in that the Spinnlö¬ solution further stabilizers in the form of organic compounds having at least one conjugated double bond and two hydroxyl, or amino groups, preferably hydroquinone, phenylenediamine, gallic acid esters or tannins.

8. The method according to claim 1, characterized in that the ionic liquid consists of a recycled precipitation bath.

9. The method according to claim 1, characterized in that the aqueous precipitation bath is treated with alkaline hydrogen peroxide solution in the heat, removed via ion exchanger entrained metal ions and concentrated by distillation, the ionic liquid.

10. The method according to claim 1, characterized in that one cellulosic concentration and molecular weight of the cellulose or cellulose mixture so selects that sets at 85 ° C, a zero shear viscosity of the spinning solution of 1,000 to 100,000 Pa s, preferably 1,000 to 80,000 Pa s, and a relaxation time of 0.5 to 90 s.

11. The method according to claim 1, characterized in that the spinning solution reaches the spinning temperature only when passing through the distributor plate designed as a heat exchanger.

12. The method according to claim 1, characterized in that the spinning solution in spinning capillaries of 0.4 to 5 mm total length (I), with ei¬ NEM cylindrical part (L = 0.5 - 3 D), a conical part (I L) and an initial diameter (D) of 0.05 to 0.25 mm with circular arrangement of the spinning capillaries for filament yarns and rectangular arrangement of the spinning capillaries for staple fibers.

13. The method according to claim 1, characterized in that one deforms the spinning solution in slot dies of 0.1 to 2.0 mm thickness to the flat film or in circular slit dies of 0.1 to 1, 5 mm gap width to the blown film.

14. The method according to claim 1, characterized in that additionally applied to the yarn sheet when passing through the air-conditioned draft zone with an air-conditioned gas stream.

15. The method according to claim 1, characterized in that the surface increase per unit time AÖ _a during deformation of the cellulose solution in the gap a of the relationship ΔÖ _fl = 3.6 -1 (T ² - ^^ - ÜSVΪ -l) <200 cm ² / min ^D A - P _L - Ccell. where T _{10 is} the fiber denier in dtex, v _a the draw speed in m / min, D _A the exit diameter of the spinning capillary in cm, p _L the density of the spinning solution in g / cm ³ and c _Cell the cellulose concentration in mass% mean.

16. The method according to claim 1, characterized in that the Geschwin¬ speed of the surface increase v _on in the gap a of the relationship

v = 10 ^ ² - <500 mm / min a, where AÖ _{a is} the surface increase in cm ² / min and a is the gap length in cm.

17. The method according to claim 1, characterized in that the thread yarn forming a filament yarn passes through the precipitation bath and an opening formed in the bottom of the precipitating bath container by a yarn guide element and separated from the precipitating bath stream by being deflected at an angle β <70 ° Galette is transported.

18. The method according to claim 1, characterized in that the fiber cable forming yarn sheet passes the precipitation bath, separated by deflecting a rod or a roll at an angle> 90 ° ge from the precipitation bath and transported via a godet duo.

19. The method according to claim 1, characterized in that one passes the flat film over a roller through the precipitation bath, with the same at the angle> 90 ° deflects and separated by a second roller from the precipitation bath and transported.

20. Apparatus for producing cellulose fibers or filament yarns from pulps and ionic liquids as solvent (FIG. 5) consisting of a temperature-controllable pipe (1) and pressure compensation device (2)

A spin pack (3), solution filter (4), temperature-controllable heat exchanger (5) with seals (8), inflow chamber (6) and spinneret (7) • a delay zone (9) with gas supply A distribution (10) • a precipitation bath (11) with inflow chamber (12), overflow (13), Fadenleit¬ element / bottom opening (14), drip pan (15), pump (16) and Ther¬ mostat (17) and • a Abzugsgalette (18).

21. Device for the production of cellulose fibers or foils from pulps and ionic liquids as solvent (FIG. 6) consisting of • a rectangular spinning nozzle (7), • a delay zone (9) with gas supply / distribution (10) • a precipitation bath (11 ) with inflow chamber (12), overflow (13), Umlenkrol¬ le (14), drip pan (15), pump (16) and thermostat (17) and • a godet duo (18).

22. Device according to claim 18 or 19 (FIG. 7), characterized in that the heat exchanger (5) consists of • nickel-plated or chromium-plated aluminum, copper or brass • a cavity sealed off by seals (8) for receiving the filter pack (4). • a separate heater (H) • and the flow channels (R) consists.

23. The device according to claim 18, characterized in that the Volu¬ men V in cm ^{3 of} the inflow chamber (6) between the heat exchanger (5) and spinneret (7) of the relationship V = v _L - λ _m (I) is sufficient, wherein v _{L is} the volume flow of the cellulose solution in cm ³ / s and / l _m mean the relaxation time at the maximum frequency of the relaxation time spectrum of the spinning solution.