FI91089C - Fiber based on at least one cellulose derivative - Google Patents

Description

FIELD OF THE INVENTION The invention relates to a fiber consisting at least in part of a filament based on a cellulose derivative having cellulose ester groups, wherein at least some of the ester groups are formate groups.

The fiber according to the invention is characterized by the following properties: a) the degree of substitution DS for the formate groups of the cellulose is at least 2% and the degree of polymerization DP of the cellulose is more than 150 but less than 1,500; b) the fiber strength T and the initial modulus MA implement the following 15, where T and MA are expressed in cN / tex: T> 20; and MA> 1,000; c) the filament is morphologically such that it consists of at least partially overlapping layers surrounding the axis of the filament, and that in each layer the optical direction and the direction of crystallization vary substantially periodically along the axis of the filament.

The composition from which the fiber of the invention is obtained is prepared by dissolving cellulose, whereby this dissolution can be carried out without significantly reducing the degree of polymerization of the cellulose.

In this process, called the "dissolution method", the following steps are essential: a) preparing a mixture of at least three materials using: (I) a cellulosic material, (II) a material comprising at least a compound selected from the group consisting of organic monocarboxylic acids; anhydrides and halides of these acids, wherein this material is formed at least 2 parts of formic acid and / or formic anhydride and another organic acid, (III) a material containing either phosphoric anhydride or at least one phosphoric acid or phosphoric acid-hydride (b) in order to obtain a mixture, the amount of water is zero or such that the ratio

Pe - Pr Rr * - 10 P, + PIX + PIXX ♦ P. - Pr is less than 15.0% and greater than 7.5%, and Rer is given as a percentage (%), Pe is the weight of any water present, Per is the weight of water that can react with material (II) and / or (III), Px is the weight of cellulose in material (I), Ptt is the weight of material (II) and Pm is the weight of material (III); (c) the ratios R:, Rt1 and RjU are defined as follows:

Pi 20 R: = - PI + PII + PIII + P. - P.r

SILICON

Ru - - 25 PI + PII + PIII + P. - P.r

Pm PI I I =

p + p + P + P-P

ΓΙ II III e e r 30 relations Rj, RIir R! x z and Rtr, whose sum Rj + R1X + Rni + Rer is equal to 100% by definition, satisfy the following equations, the values of which are given as a percentage:

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91089 3 if Rer implements a total of: 12.5 £ Rer <15.0 a total of 10.0 £ Rz £ 14.5 is obtained; 2.0 £ Rzz £ 10.0 δ and equation: RIZ £ 0.89 Rz - 2.89; if Rer implements a total of: 10.0 <Rer <12.5 a total of 10 is obtained: 10 10.0 £ Rz £ 19.5; 2.0 £ RZI £ 17.0 and equals: RZI £ 1.78 Rx - 8.78 if Rz implements a total of:

Rj £ 14.5; 15 or equation: RIZ £ -1.40 Rz + 37.30 if Rz implements equation:

Rz;> 14.5; if Re r implements the same; £ 7.5 Rer <10.0 gives a total of: 10.0 £ Rz £ 31.0; 2.0 £ Rz z £ 23.0 and equals:

Rlz £ 4.40 Rj - 32.00 25 if Rj implements the following:

Rj £ 12.5 or equation: RZI £ 1.19 Rz + 41.50 if Rz implements together: 30 Rz}> 15.5; if Rer implements a total of: 5.0 £ R. r <7.5 a total of 10.0 £ Rz £ 37.0 is obtained; £ 2.0 RZI £ 27.5 4 and equals:

Rjj i 4.17 R, - 26.67 if Rj implements together:

Rj 5 13.0; 5 tal gives the equation: RIX <1.14 Rx + 49.14 if Rj implements the equation:

Rx> 19.0; if Rer implements the same: 10 2.5 S Rer <5.0 the same is obtained: 10.0 <Rj ^ 37.0; 2.0 £ Rj 1 S 36.5 and the sum: RXI <4.63 Rj - 28.25 15 if Rj implements the equation:

Rj <14.0 or the same is obtained: RZ1 ^ 1.23 Rj +55.60 if Rj is combined; 20 Rj &15.5; if Rer implements the equation: - 2.5 <Rer <2.5 the equation is obtained: 10.0 <Rj <38.0; 2.0 <R1X S 40.0 25 and co;

Rj j S 2.80 Rj + 5.00 if Rj simultaneously implements:

Rj S 12.5 or equation: 30 Rj j <- 1.14 Rj + 62.14 if Rj is combined;

Rj S 19.5; if Rer implements the equation: - 5.0 <R.r S - 2.5

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91089 5 gives: 10.0 <Rj £ 35.0; 2.0 £ RZ1 £ 45.0 and combined S1B: RXI £ - 1.30 RI + 64.50; 5 if Rer implements the same: - 7.5 <R.r S - 5.0 the same is obtained: 10.0 <Rj S 32.0; 2.0 S Rn <36.0 and total O; 10 Rj S 4.00 Rj - 22.00 if Rj implements the same;

Rj * 14.5; d) the degree of polymerization of the cellulose DP of the material (I) is greater than 150 and the plenempl 1,500; E) the esterification of the cellulose is allowed to take place in this mixture for a sufficiently long anlsotropic mixture.

Cellulose derivatives A. Preparation and method implementation 20 1. Preparation of spinning solution

The solution can be conveniently prepared with any thermostated mixer, preferably in a vacuum. If it is not possible to start the vacuum in the mixer el, it is inevitable to burn the gases from the spinning solution 25 in a suitable manner.

For the preparation of the spinning solution according to the invention, the following method is used, for example.

Use a double-vigorous reaction vessel with a regular volume of zero 4 liters.

The paste is placed in the first material (II) and material-11a (III) and homogenized by mixing. The material (I) is then added with stirring, a vacuum of zero 5-10 mBar (500-1000 Pa) is drawn into the reaction vessel. Stirring is initiated and esterification and dissolution begin at the same time. The temperature of the mixture during mixing is preferably 5 to 20 ° C.

It should be noted that other methods would be possible. For example, premix 5 could be prepared by impregnating material (I) with material (II) by solidifying a mixture (preferred temperature: -15 to 0 ° C) and solidifying material (III) by solidifying the whole mixture to prepare a premix which is klint, and then stirring the tStS premix at 5 to 20 ° C as described above to initiate the esterification reaction and dissolution.

It would also be possible to prepare a solution using an extruder with one or more screws, in which case the base material would be continuously added to the nozzle press of tShSn and the preparation would preferably take place in a vacuum.

2. Ceramic solutions for obtaining fibers

To prepare the fibers, the solutions 20 prepared by the method described in point 1 above are used directly without extracting it before the cellulose derivative. The spinning technique used is a technique called dry air jet-wet, described in U.S. Patent 3,414,645. A solution is introduced into the spinning drum, which may, for example, come directly from the solution-forming reaction vessel. The solution is then pressed through a die with a hole. The orifice of the nozzle is set horizontally at a distance which may be from a few millimeters to several centimeters above the surface of the coagulation bath. Before the solution enters the coagulation bath, the spray is directed into the air to orient the molecules according to the flow and to obtain the mechanical properties before the coagulation. A cult of cellulose derivative is formed in a coagulation bath. The coagulation bath should be such that the cellulosic material 35 precipitates and the organic and inorganic acidic materials are soluble. The coagulation bath is preferably acetone-based and has a temperature ranging from 10 to -20 ° C. The product spun into the coagulation bath and having several filaments is placed in a drawing device. The ratio of the speed of the spun product in the drawing device to the speed of the spun product from the device is the tensile strength factor (FEF) of the yarn.

It should be noted that the invention is applicable to cases where non-coagulating liquids other than air are used in the so-called "airspace technology", for example nitrogen or other gases, and that the invention is applicable to cases where other spinning techniques are used, e.g.

B. Defining the properties of articles 15 1. Mechanical properties of spun articles

As used herein, the term "spun yarn" means an assembly formed solely of filaments obtained by the same spinning operation through the same die 20.

For the purposes of this description, "conditioning" means the treatment of spun fibers in accordance with DIN standards 53802-20 / 65 of July 1979 of the Federal Republic of Germany.

The wire number is determined in accordance with Federal Republic of Germany 25 DIN 53830 of July 1965, where the wires have previously been conditioned. The measurement is performed on at least three samples, each 50 m long, by weighing the wire of this pit.

The number of filaments is determined from the variability of the individual filaments by measuring the frequency of the resonance given by the individual filament at a given voltage of the order of 0.5 cN / tex. The absolute error is less than 0.01 dtex.

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The mechanical properties of the wires are measured using a Zwick GmBH & Co (RFA) type 1435 tensile device, which complies with the standards of the Federal Republic of Germany DIN 51220 of October 1976 and 51221 of August 1976, the methods described in 5 German standard DIN 53834 of January 1979. in the measurement, the protective thread is 100 turns per min and they are stretched to an initial length of 400 nun. All results are obtained as the average of 10 measurements.

10 The mechanical properties of the filaments are measured using a Tex-techno (RFA) type FAFEGRAPH-T traction device in accordance with the Federal Republic of Germany standard DIN 53816 of July 1976. The results are given as the average of 10 measurements.

Strength (T) and initial modulus (Mt) are given in cN / tex. 15 The elongation at break (Ar) is given as a percentage. The initial modulus (Mt) is defined as the angle coefficient of the linear part of the fracture-elongation curve starting just at the 0.5 cN / tex bias fraction.

Determination of the sound modulus 20 The sound propagation speed in the fibers is determined using a "dynamic Modulus Tester" PPM-5R type measuring device manufactured by Morgan Co., Inc .; Cambridge, Mass., USA.

The samples to be measured are pre-air-conditioned 25 wires. Measurements are performed in the same environment as the air conditioning.

A bias of about 2 cN / tex is applied to the wire at about 2 meters. Two M0RGAN-WTRT-5 FB type probes with a constant light 30 support pressure are then placed against the wire. The resonant frequency of the piezoelectric ceramics of the probes is 5 kHz. L is the silent distance of the two probes in meters. The absolute ground error of this distance is less than a millimeter; "t" is the time in seconds that elapses from the source pulse from the 35 probes to be transmitted to the receiving probe.

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91089 9

The relative error of the measurements is less than 3% for the travel time "t". Xanimodule M, defined by the equator: Μβ «V2 x 10'4 cN / tex where V is the sound propagation velocity (m / s) given as the inverse of the reg-5 slope of the regression line given to N by L and" t ": n for measuring paper, where N is vfl-hlnta 3.

2. Chemical properties of spun articles 10 Substitute grade (DS) and polymer grade (DP)

The spun article is conditioned at room temperature (e.g., about 22 ° C) and at the humidity of the room where the DS and DP measurements were made. The water content of the spun article is determined, for example, by thermogravimet-15.

The substitution grade DS and the polymerolation grade DP of the cellulose derivative are determined by the same methods as for the compositions mentioned in section I.C of the basic application without acetone extraction.

20 3. Physical properties of spun articles 3.1. Optical properties

The optical anisotropy of the spun articles is detected and measured with an Olympus BH2 type polarization-25 microscope. In particular, birefringence is determined by Berek's compensation method.

3.2. Structure measured by X-ray beam (a) Apparatus and test arrangements

Equipment: determinations have been performed with two types of 30 Silia equipment:

With high power generator11a (generator A). TailOin is a Rikagu RU-200 PL equipment equipped with a pyirirai or anode that operates under the following conditions: 40 kV; 200 mA: focal point 0.5 x 10 mm 2 with ano-35 d, apparent point focal point 0.5 x 1 mm 2; 10 copper precipitation, from which K β-sSde is removed, which is filtered through a Ni membrane and whose energy is limited.

Siemens brand with a classic generator with a closed tube and dusted under the following conditions: 40 kV; 30 mA: hleno linear focal point 0.04 x 8 mm2; copper K αχ precipitation initiated by a CGR monochromator prepared from ground crystals (R - 1,400 nun); burning is D * 510 now. (DGF = Compagnle Générale de Radioloque, France).

10 Each generator is used for four different test arrangements.

Experimental arrangements 1

Large-angle goniometer Rlkagu SG-9R (rain 250 15 nun) equipped with Eulerl pllrllia and liquid scintillation disc; sweep speed in 2 Ø 2 ° / nun; Rotational speed of Eulerln circuit: 2 ° / nun fixed 2 0: 11a. Selection of the collimation level of the Rdntgens rain beam

Pedal: ø 1 mm for point collimator.

Analysis: cross-shaped slits 0.9 x 0.9 mm 2 (angular aperture 0.5 ° x 0.5 °) 110 mm from the plane of the sample.

arrangement 2

Rlkagu SG-9R goniometer equipped with a rotary sample holder (rotation speed 100 rpm) and a nes-25 scintillation counter that is stepped to 0.1 ° with respect to 11-sayx 0 0.

Selection of the collimation level of the X-ray rain beam: cross-section gap 1/6 °; diffusion gap 1 °; an analytical gap of 0.15 mm placed in a sample of a 250 mm head.

30 Arrangement 3

Siemens large-angle goniometer equipped with Eulerl pllrll and liquid scintillation counter. Sweep speed 0.1 ° / min in 2 Ø.

Monochromator CGR, combustion or 510 mm.

35 Analysis gap 0.4 mm to 155 mm of the sample.

li 91089 11

Jfirjestely 4

Central diffusion goniometer Rlkagu SASG equipped with a Leti-type linear goniometer and an Ortec multichannel analyzer.

5 Selection of the collimation level of the X-ray bundle: first gap 15 x 0.1 nun; tolnen gap 15 x 0.05 nun -250 mm.

NB and distance between detector and detector: 360 mm. Silent distance between sample & tolsen gap: 105 mm.

10 The following Table 15 shows the arrangements used, the angular ranges, and the generator used as a function of the measured parameters.

Table 15 15 Measured Used RO-X-rays Used Parameters and System Angle Generation Market

Crystal orientation

20 thioindex (1-0) 1 large angles A

crystallinity

index (I.C) 2 large angles A

Longitudinal (Tj) 25 Horizontal axis

Directional (Tt)

naiveSizes 3 large corners B

Period length

(L.P.) 4 small angles A

30 Half-width

(Δ tp) 4 small angles A

integrated

intensity 4 small angles A

12 b) KReflected reflectors for the determination of various structural parameters by high-angle diffraction

The light-5 images of the rbntgendiffraction phenomenon of the studied paths show a certain amount of Kaarla on the horizontal axis, on the vertical axis and outside the two axes. The characteristics of Charles N3i are related to the characteristics of the material structure.

The angular gap of the vertical axis arc, which is located at a diffraction angle 2 -Θ- of about 34.7 °, depends on the statistical orientation of the crystallites with respect to the fiber axis. This reflection at an angle of 2 · θ: η to about 34.7 ° is selected to determine the orientation index (0-1) and the apparent longitudinal dimension (Tx) of the crystallites.

The horizontal axis uses an arc located at about 11 ° at 29 to determine the apparent horizontal axis size (Tt) of the crystallites.

If special reflections are used to determine the above parameters, it is necessary to consider the entire diffraction gram to determine the crystallinity index.

c) Methods used to determine the various parameters 25 All measurements have been made on one or more fibers, each of which is composed of several filaments, i.e. non-twisted fibers, parallel to the central Ken.

Crystal Orientation Index (1-0) 30 The orientation of a crystal can be characterized by an angle between the axis of the fiber and the perpendicular plane of the diatropic planes.

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91089 13

By measuring the aperture of the directional angle of the arc along the vertical axis, which is located at about 20 = 34.7 °, the orientation degree of the crystallites with respect to the driven axis is obtained directly.

5 Orlentaatlolndeksl is a ground roll of formula 180 - a 1.0 - - x 100 180 where a is the half-width of kSyr & n obtained by sweeping the direction of the angle of direction 10; a is expressed in degrees.

Quality Code (I-C)

Relative crystallinity index in the land-based Wake-lin method (Journal of applied Physics, Vol. 30, no. 11, p. 1654, November 1959).

15 Before comparing the rintgent diffraction pattern of any sample to two standards: one that is 100% amorphous and the other that is 100% crystalline, correct the original experimental values for the various parameters, pulse frequency, X-ray rainfall stability. -20 diffusion, airborne diffusion, polarization and absorption effects.

The patterns are then normalized before examining methods called "relative."

The crystallinity indices obtained are, of course, a function of the choice of amorphous and crystalline standard. These standards are made as follows:

Crystalline standard! treated with acid-regenerated fiber using cellulose formate, which is already strongly crystalline (24 hours in 30 N hydrochloric acid at 60 ° C), is obtained.

Amorphous standard: amorphous cellulose formate.

14 The characteristic spectra of these two standards are shown in Fig. 5. In Fig. 5, the spectrum S1 corresponding to the crystalline standard is shown by a solid line and the spectrum S2 corresponding to the amorphous standard is shown by 5 dashed lines. In the NSissS spectra, the vertical axis corresponds to an angle of 2 β in degrees and the horizontal axis corresponds to the corrected intensity I, expressed in pulses per second (cps).

The spectra are recorded as "pyiSriva nSytteesté" 10 as rainfall of 2 - 10 ° - 20 0 - 38 °. By "rotating sample" is meant a layer of parallel and adjacent fibers; this layer rotates the axis ym-pSri, which is perpendicular to it, and this occurs as a bundle of rfintenses form.

15 The present size of the crystallites

The Oebye-Scherrer formula is used to calculate the apparent dimension of the crystallites in one direction associated with the selection of the sweep reflection. The sweep as a function of 2 · θ: η following the perpendicular axis of the 20 reflections at about 34.7 ° produces a diffraction-curvature curve as a function of the angle 2 · θ ·. The half-width of the profile, which is βο and is expressed in radians, makes it possible to determine the apparent longitudinal dimension of the crystallites by 25 λ.

Tj - - - - β2. cos © where β corresponds to the determined "equipment size" determined by the diffraction in the hexamethylenetethan-30 raamine powder.

The angle & is half the angle 2 -Θ, which is the maximum of the curve. λ is the wavelength of the X-ray transmission used.

A similar method applied to horizontal sweep at a level of 35 reflections at about 11 ° 2 kohti per horizontal plane gives

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91089 Apparent perpendicular size (Tt) of crystallites. The increase in the apparent size of the crystal joints should be considered as a result of the increase in the actual size and / or the improvement of the local order.

5 Long period Experiment with central diffusion of X-ray precipitation with organic fibers may reveal in the photograph a diffusion around a perpendicular rain bundle extending in the horizontal direction and two diffractions at small angles, from the perpendicular to the central diffusion perpendicular. This possible diffraction at small angles means the periodicity of the electron density in the material under study. This periodicity was mSåri-equated to 15 λ L.P. - -—- sin £ where A is the wavelength of the X-ray beam and & is an angle 2 θ # which follows a perpendicular plane and which is the maximum of the in-20 intensity of the diffraction.

Recording the intensity of this diffraction at small angles, which follows a perpendicular plane as a function of &, gives a Kayra whose half-width Αφ represents the uniformity of the periodicity and the area under the curve (integrated intensity) represents the amplitude of the periodic phenomenon. Parameters describing the possible long-term phenomenon L.P., ACf and 1.1.

3.3. Morphology

The morphological properties of the spun articles have been determined with an optical microscope and a scanning electron microscope.

c) Examples The following examples illustrate the preparation of esterified cellulosic fibers obtained in A.l. in accordance with. In all NaissM examples, the references, Rj x, Rx x z and Rer, denote the same angle precedent, and are calculated in the same manner as the former. Spinning is performed as before in A.2. has been described. Example II-1.

5 Prepare a mixture of the following basic ingredients:

Material (I): cellulosic material containing 99.3% by weight of holocellulose (45.7% by weight of α-cellulose and 53.6% by weight of hemicellulose).

10 Material (II): formic acid.

Material (III): orthophosphoric acid.

At the beginning of the preparation of the mixture, the ratios are as follows: Rx = 19.8%; Rxτ - 18.1%; Rt11 »61.05% and

Rer = Re = 1'05% · After 20 minutes a solution is obtained having the following composition: Cellulose derivative (cellulose formate): 23.65% by weight; organic acid (formic acid): 11.8% by weight; inorganic acid (orthophosphoric acid): 61.05% by weight; and water: 3.5% by weight. The solution is anisotropic-20 pin.

From the dissolution vessel, the solution is placed directly on the spinning pump wood. From the pump, the solution is pressed through a die with 100 holes, each with a diameter of 0.005 cm. The mouthpiece is placed 2 cm above the coagulation bath, which is acetone at -17 ° C. In the traction unit, the fiber speed is 90 m / min, which corresponds to a FEF of 4.5. The resulting spool is washed with liquid and then air dried. N3in is obtained from a spun yarn formed of 100 filaments and the fiber formed from this spun yarn.

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Example II-2

Prepare a mixture in which the basic ingredients are as follows:

Material (I): cellulosic material containing 99.3% by weight of holocellulose (52.2% by weight of α-cellulose and 47.1% by weight of hemicellulose).

Materials (II) and (III): same as in the example

II-L.

Upon completion of the mixture, S has the following ratios: 10 Rj <19.8%; RIX - 18.1%; R11Z - 61.05% and R. r - R. - 1.05%.

After 20 minutes, an anisotropic solution having the following composition is obtained: Cellulose formate: 24.05% by weight; formic acid: 11.1% by weight; orthophosphoric acid: 61.05% by weight; and water S: 3.8% by weight.

The Tfist solution is made into a fiber according to Example II-1 above.

Example II-3

A mixture is prepared by placing 368.6 g of Cx (Cx * α-cellulose 50.97%, hemicellulose 45.91%, resin 0.02%, ash 0%, water 3.1%; holocellulose 96.88%; DP 270.0; pulp pH> = 6.98), partially dried, 442.6 g formic acid and 1,500 g orthophosphoric acid.

25 When the mixture is ready, it has the following ratios:

R t = 15.85%; R1Z - 19.0%; R11Z - 64.05% and Rtr «R.« 1.1%.

After 20 minutes, an anisotropic solution with the following composition is obtained (in% by weight): cellulose 30 formate: 19.6%; formic acid: 12.85%; orthophosphoric acid: 64.05%; and water: 3.5%.

From this solution, fiber is made according to Example II-1 above.

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Example II-4

A solution of Example II-2 is prepared analogously to Silia by separating the mixture in the following ratios: Rx * 23.75%; Rx x 17.2%; Rr ττ * 5 58.0% and R.r - R. - 1.05%.

After 20 minutes, an anisotropic solution with the following composition is obtained (in% by weight): cellulose formate: 28.5%; formic acid: 9.4%; orthophosphonic acid: 58.0%? and water: 4.1%.

10 This solution is made into a fiber according to Example II-1 above with the following differences: traction speed: 81 m / min; FEF * 5.4.

Example II-5

A mixture is prepared from the following basic materials: Material (1): a cellulosic material containing 99.4% by weight of holocellulose (91.3% by weight of α-cellulose and 8.1% by weight of hemicellulose).

Material (II) and (III): same as in Example II-1.

20 When the mixture is ready, it has the following ratios:

R t = 15.85%; R t = 19.0%; RT 2 x = 64.05% and Rer = R. = 1.1%.

After 90 minutes, an anisotropic solution having the following composition (by weight) is obtained: cellulose 25 formate: 19.35%; formic acid: 13.25%; orthophosphoric acid: 64.05%; and water: 3.35%.

This solution is made into a fiber according to Example II-1 above with the following differences: traction speed: 90 m / min; FEF = 3.6.

30 Example II-6

Prepare a mixture of the following basic ingredients:

Material (I): cellulosic material containing 99.1% by weight of holocellulose (89.4% by weight of α-cellulose 35 and 9.7% by weight of hemicellulose).

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91089 19

Material (II) and (III): same as in Example II-1.

Once the mixture is ready, the M has the following ratios:

Rx - 19.75%; R1 x - 18.1%; R11z - 61.05% and Rer - R. -5 1.1%.

After 90 minutes, an anisotropic solution having the following composition (by weight) is obtained: cellulose formate: 24.95%; formic acid: 9.6%; orthophosphoric acid: 61.05%; and water: 4.4%.

This solution is made into a fiber according to Example II-1 above.

Example II-7

A solution is prepared under the same conditions in gold grade II-2, but using a mixture of formic acid and acetic acid as the material (II), the formic acid / acetic acid ratio being 9 and the value of the ratio Rx r being the same in gold grade II-2.

After 30 minutes, an anisotropic solution with the following composition is obtained (in% by weight): cellulose-20-azoacetate: 23.45%; mixture of formic acid and acetic acid: 12.1%; orthophosphoric acid: 61.05%; and water: 3.4%. The term "cellulose acetoformate" means a mixed ester of cellulose having formate and acetate groups.

This solution is made into a fiber according to the method of Example II-1 above.

Example II-8

Prepare a mixture of the following basic substances:

Material (I): cellulosic material containing 97.4% by weight of holocellulose (95.1% by weight of α-cellulose and 2.3% by weight of hemicellulose).

Materials (II) and (III): same as in Example II-1.

20

Once the mixture is ready, it has the following ratios:

Rx = 15.55%; Rz z = 19.0%; Rin = 64.05% and Rer = R. * 1.4%.

After passing through a twin-screw mixer and after 30 minutes, an anisotropic solution having the following composition (in% by volume) is obtained: cellulose formate: 18.85%; formic acid: 13.6%; orthophosphoric acid: 64.05%; and water: 3.5%.

This solution is cultured in Example II-1 by removing it from the solution before keeping the solution under vacuum for 30 minutes.

Example II-9

Prepare a mixture of the following basic substances:

Material (I): cellulosic material containing 98.7% by weight of holocellulose (89% by weight of α-cellulose and 9.7% by weight of hemicellulose).

Materials (II) and (III): same as in Example II-1.

Upon completion of the mixture, it has the following ratios: 20 R, - 19.7%; Rz z - 18.1%; Rzzl - 61.05% and Rer = Re -1.15%.

After 90 minutes, an anisotropic solution having the following composition (in% by weight) is obtained: cellulose formate: 13.75%; formic acid: 11.4%; orthophos-25 foric acid: 61.05%? and water: 3.8%.

The TS solution is made into a fiber according to Example II-1.

In all of the above examples, the degree of polymerization of the cellulose of the material (I) II-1-II-9 is greater than 150 and less than 1,500, and the variation of DP in the preparation of the compositions is always less than 20%.

The mechanical properties and chemical characteristics of the spun articles are given in the following Table 16. The properties T, Ar, DP and DS have been determined in all experiments, Ma has been determined in most experiments.

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In Table 16 kThe abbreviations used are as follows: F = spun yarn; Ft = filament; T1 = thread number;

T »number; Ar «murtovenyma; Mt «initial modulus; Me - aani module; DS * total cellulose substitution rate; DP

5 degree of cellulose polymerization of cellulose derivatives.

Table 16 _Features___ 10 Mechanical properties Chemical

Present TA T Ar Mb

Characteristics of the character (F) (Ft) cN / tex (%) cN / tea cN / tex No. tex dtex DP DS

15 II-l F 18.5 24 2.3 1550 2570 167 37.2 II-l Ft 1.96 30 3 2160 II-2 F 19.7 47 3.4 2330 262 41.6 II-3 F 16, 8 41 3.3 2030 2814 246 45.6 11-4 F 19.9 48 3.0 2430 3179 254 38.7 20 II-5 F 20.7 56 4.2 2130 2812 380 42.6 II-6 F 20.6 57 3.7 2410 3277 284 50.7 II-6 HUF 1.96 60 3.7 2780 II-7 F 20.7 46 3.6 2210 3041 526 35.3 * II-8 F 16.9 65 4.0 2390 3082 420 40.7 25 II-8 Ft 1.72 72 4.0 2780 II-9 F 20.5 58 3.7 2460 3720 326 39.8 II-9 Ft 2.13 64 3, 7 2780 *) In Example II-7, the relative DS of the formate groups is 34.4%, the relative DS of the acetate groups is 0.9.

The physical properties of the obtained articles in Experiments II-1 to II-9 are summarized in the following Table 17. The property An is defined in all experiments; other omi-35 femininity has been identified in most experiments.

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The abbreviations used in Table 17 have the following meanings: Δη = birefringence; I.O. = crystal orientation index; I. C. * crystallinity index; Tj “crystallites size 5 horizontally; Tt = size of crystallites in the vertical plane.

Table 17 10 Physical properties

Example Δη 1.0. I. C. Tt Tt No. (%) (%) (A) (A) II-1 0.0379 15 II-2 0.0400 92.00 130 35 II-3 0.0365 91.35 49 123 32 II-4 0.0404 92.65 55 130 37 II-5 0.0325 92.10 54 132 31 II-6 0.0400 93.20 54 144 36 20 II-7 0.0400 92.55 51 142 31 II-8 0 , 0400 II-9 0,0389 25 Notes on experiments II-1 to II-9:

All experiments are in accordance with the invention. Polarization microscopic examination of the filaments formed by the spun yarns obtained in the nSissS examples shows that each filament has a complex morphology, and the morphology varies from edge to center when viewed. The filament 1 is schematically shown in Figures 6 and 7.

Fig. 6 shows a cross-section of the filament 1 in the plane with the axis xx 'of this filament, which is assumed to be straight; and Figure 7 shows the filamentous

II

91089 23 a cross-section of a tin 1 parallel to a plane perpendicular to the axis xx 'shown in the diagrams by the letter O in Fig. 7.

Filament 1 has an outer thread 2, called 5 "shell", and an inner thread 3, called "core". In a polarizing microscope, the shell 2 has a uniform morphology and resembles, for example, rayon filament.

The core 3 is contrasted from the palm kernel and is formed of parallel layers 4; The nSma layers are practically centered perpendicular to the plane of the axis xx 'as shown in Figure 7. This filament thus consists, at least in part, of overlapping layers which surround the axis of the filament. The layers 4 are less than 1 μm thick and va-15 roll in the plane of Fig. 6 parallel to the axis xx '. In each layer, the optical axis (optical direction) and the crystallization direction vary in space nSennSis periodically in the xx 'direction of the axis. These directions are not shown in the drawing for simplicity.

The fibers obtained have the values T and MA realized by the equations given in the defining of the fibers of the cellulose derivatives (s) according to the invention.

The following combinations are obtained: DS 2 2%; 150 <DP <1,500; T> 20; and> 1,000, where T and M1 are expressed as cN / tex.

NSilia fibers thus have better mechanical properties and in this implementation without the addition of spinning to the jaw.

The NSma findings are valid such that the degree of substitution of the cellulose-30 as DS formate groups is at least 2%, whereby the values of natna DS are obtained, for example, by partially regenerating the cellulose of the cellulose derivatives.

On the other hand, the following facts from Examples II-1 to II-9 must be stated: 24

The birefringence of An is high because it is mouth-rempl than 0.03.

The phenomenon of such a long period is not observed by analyzing the fibers by X-ray.

The degree of cellulose substitution of the fibers according to the invention as formate groups is preferably at least 30.0% and at most 70.0% and the degree of substitution DS of the cellulose as black ester groups is 0.0% or less.

The polymerization rate DP of the cellulose talulose derivatives of the fibers according to the invention is at least 200 and at most 1,200.

II

Claims (4)

91089 A fiber consisting at least in part of a filament based on a cellulose derivative having cellulose-5 ester groups, wherein at least some of said ester groups are formate groups, characterized in that the fiber has the following characteristics: a) the degree of cellulose substitution DS for formate groups is at least 2 % and the degree of polymerization of the cellulose OP is greater than 150 but less than 1,500; (b) the fiber strength T and the initial modulus M1 implement the following equations, where T and are expressed in cN / tex: T> 20, and M *> 1 000; c) the morphology of the filament is such that the filament consists at least in part of overlapping layers surrounding the axis of the filament, and that in each layer the optical direction and the crystallization direction vary considerably periodically along the axis of the filament. Fiber according to Claim 1, characterized in that the sitd is stretched other than that resulting from the manufacture. Fiber according to Claim 1 or 2, characterized in that its birefringence An is greater than 0.03. Fiber according to one of Claims 1 to 3, characterized in that the degree of polymerization of the cellulose of the cellulose derivative or derivatives is at least 200 and at most 1,200.