DE202017007095U1 - Modified viscose fiber - Google Patents

Abstract

wobei T der Titer der Faser in dtex ist.

A modified viscose fiber incorporating an algal material characterized by a wet modulus at a 5% elongation in the wet state satisfying the following formula: $$\text{wet modulus}\left(\text{cN}\right)\ge 0.5*\surd \text{T}.$$

where T is the titer of the fiber in dtex.

Description

The present invention relates to a modified viscose fiber.

In particular, the invention relates to a modified viscose fiber with incorporated algae material having improved performance for textile applications, particularly in the knitwear sector, which meet consumer expectations of unrestricted washability or industrial laundry requirements, their use in the manufacture of yarns and fabrics, and a process for producing these fibers.

EP 1 259 564 describes the production of fibers and moldings according to the NMMO process from a polymer solution comprising a biodegradable polymer - usually cellulose - and a material from marine plants and / or shells of marine animals and optionally other additives. Moldings produced in this way are loud EP 1 259 564 a fibrillation tendency lower than that of corresponding moldings after the NMMO process without additives. This conclusion was drawn on the basis of the changed fiber structure recognizable in SEM images, more precisely a reduced longitudinal orientation.

EP 1 259 564 also discloses the production of fibers and shaped articles modified by the addition of a material from marine plants and / or shells of marine animals by a viscose process. By way of example, 15% (Example 7) and 1.7% (Example 8) of a brown algae material are added to cellulose. Thus produced fibers or molded articles have similar or slightly deteriorated physical fiber properties compared to a viscose fiber without additives (Comparative Example 3).

In addition, describes EP 1 259 564 in Examples 9 and 10, the production of fibers and moldings with the addition of a material from marine plants and / or shells of marine animals by the carbamate method. According to this method, a very low fineness-related dry breaking strength is achieved, which is further reduced by the addition of algal material depending on the amount of incorporation.

It is known that the addition of material from marine plants, in particular sea algae, fibers and cellulosic moldings and textiles produced therefrom gives a particularly soft feel and causes an enrichment with vitamins, micronutrients and trace elements, and that alginate containing algae has moisture-retaining properties. It has also been shown that algae and fibers made from it have antioxidant properties [http://www.smartfiber.de/index.php/seacellde/zertifizierungen, retrieved on 17 April 2016]. For these reasons, a material from marine plants, in particular seaweed containing products are considered to be particularly kind to the skin.

Alone EP 1 259 564 disclosed fibers, both the NMMO process, the viscose process and the carbamate produced fiber types, but also commercially available under the Trademark SeaCell ™ Lyocell type meet for various reasons, the requirements of the modern textile industry only poorly:

The lyocell-based grades tend to fibrillate without subsequent refining or additional cross-linking, despite the somewhat shorter fiber longitudinal orientation, and consequently, after repeated washes, to form unsightly, white-scrubbed textile surfaces. On the other hand, fiber types produced by the viscose process have a somewhat poorer wet-strength (wet strength and BISFA wet modulus) than conventional viscose fibers. The grades produced by the carbamate process have too low dry tensile strength for commercial yarn production. In addition, this process has no economic importance, there is still no industrial fiber production by the carbamate process.

Compared to this prior art, the object was to produce a cellulosic fiber, in which a perceptible for the consumer amount of material from algae is incorporated in order to achieve the desired properties of natural softness, moisture storage capacity and a skin friendliness, but in addition increased textile mechanical requirements satisfy both dimensional stability and wash resistance and low Fibrillationsverhalten.

This object is achieved by a modified viscose fiber according to claim 1. Preferred embodiments are given in the subclaims. The term "fiber" is intended for the purpose of present invention fibers of defined, relatively short length (for example, so-called "staple") as well as fibers of very large length, also referred to in the art as "filament" include.

list of figures

• 1 illustrates the fibrillation dynamics of cellulosic fibers determined according to an adapted Canadian Standard Freeness test.
• 2 shows the microscopic assessment of the fibrillation behavior of a fiber according to Example 3.
• 3 shows the fibrillation behavior of a fiber according to Example 4.
• 4 shows the fibrillation behavior of a SeaCell ™ fiber.

Detailed description of the invention:

The present invention solves the above-mentioned problem by providing non-fibrillating cellulosic regenerating fibers with incorporated algal material, which after one EP 1 259 564 modified viscose process can be produced. The fibers according to the invention are distinguished by the known special softness of cellulose fibers with incorporated material from algae, but have a significantly reduced tendency to wet fibrillation compared with solvent-spun fibers based on the NMMO process.

Surprisingly, the minor procedural changes compared to those in EP1 259 564 B1 described manufacturing processes in that the fibers of the invention in comparison with the fibers of the viscose type with incorporated brown algae according to EP 1 259 564 Example 7 (with 15% brown algae) and Example 8: (with 1.67% brown algae on cellulose) and even compared to Comparative Example 3 of EP 1 259 564 (without admixture of algae) have significantly improved physical fiber properties, in particular a higher fineness-related breaking strength and a higher wet modulus.

wobei T der Titer der Faser in dtex ist.The fibers according to the invention have a wet modulus at an elongation of 5% in the wet state, which satisfies the following formula: $$\text{wet modulus}\left(\text{cN}\right)\ge 0.5*\surd \text{T}.$$

where T is the titer of the fiber in dtex.

This wet module corresponds to the wet modal fiber module as defined by BISFA (The International Bureau for the Standardization of Man-Made Fibers) and is hereinafter also referred to as "BISFA Wet Module" or "BISFA Module". The wet modulus and the other textile-physical properties mentioned in the present application are measured according to the measurement methods defined by the BISFA.

In a preferred embodiment, the fiber according to the invention has a fiber strength in a conditioned state which satisfies the following formula: $$\text{fiber strength}\left(\text{cN}/\text{tex}\right)\ge \mathrm{27,38}-1.4*\text{T}\text{,}$$

This strength is significantly higher than that in the EP 1 259 564 described modified viscose fibers.

The fibers according to the invention may contain, based on cellulose, 0.5% by weight to 6% by weight, preferably 2% by weight to 6% by weight, particularly preferably 3% by weight to 4% by weight, of algae material.

The algae can come from both salt and fresh water. It is both the use of microalgae and macroalgae, especially kelp, possible.

The algae used preferably have an alginic acid content of 15% by weight to 50% by weight. In a preferred embodiment, the fibers according to the invention contain algae material of the type Ascophyllum nodosum.

In addition, the fibers according to the invention also have, without complementary additions of metal ions, an increased zinc content compared to lyocell fibers and / or viscose fibers with the same addition of algae to algae.

The content of zinc ions is preferably at least 200 ppm, more preferably 200 ppm to 700 ppm.

The zinc content is also significantly higher than modal fibers and is at least partially present in the fiber according to the invention as Zn alginate. Zinc is an essential trace element with skin care properties and is therefore used in skin care products. Zinc alginates are used in wound dressings, among others. It is believed that the combined action of alginate (as a moisture storage and natural softening agent) with alginate-releasable zinc ions provides even better skincare properties.

To produce the viscose fiber according to the invention, a process is used by spinning a viscose with a content of 4% by weight to 7% by weight of cellulose, 5% by weight to 10% by weight of NaOH, 34% by weight to 42% by weight (based on Cellulose) carbon disulphide and from 1% to 5% by weight (based on cellulose) of a modifier in a spinning bath, stripping off the coagulated threads; wherein a viscose is used whose Spinngamma value 50 to 68, and whose spinning viscosity is 50 ball falling seconds to 150 ball falling seconds; wherein the alkali ratio (= cellulose concentration / alkali content) of the ready-to-use viscose is 0.7 to 1.5, and the temperature of the spinning bath 34 ° C to 48 ° C, wherein the following spin bath concentrations are used: H ₂ SO ₄ 68 g / l - 90 g / l Na ₂ SO ₄ 90 g / l - 160 g / l ZnSO ₄ 30 g / l - 65 g / l, wherein the final withdrawal from the spinning bath is at a rate between 15 m / min and 60 m / min, and wherein an algal material is spun in the form of an aqueous dispersion.

The numerical values given for the composition of the viscose refer to their state before addition of the dispersion of the algae material.

A similar procedure with regard to the parameters of the viscose used, the spinning bath and spinning was in the WO 2011/026159 A1 described so that you can refer to this document for more details on the spinning process.

The modifier used causes a sheath structure of the fiber according to the invention in a conventional manner. The modifier may be, for example, an ethoxylated amine.

The material used from algae is preferably pulverized and dried, with a residual water content of <15%, better <10%, in a particle size of x ₉₉ of ≤ 20 microns, better <15 microns before. In order to achieve the desired fiber properties, the algal material should preferably have an alginic acid content of at least 15%. The material is preferably dispersed in water immediately before use, if appropriate with the addition of a dispersing aid, in order to give a dispersion having a solids content of preferably from 2% by weight to 15% by weight. The aqueous dispersion can be deaerated as required in vacuo and optionally after the previous filtration to remove undissolved particles in the desired ratio of viscose may be added, taking care to intimate mixing with conventional mixing equipment, homogenizers or the like. After mixing in the viscose, filtration can be carried out by candle filter before spinning.

The spinning can be done by spinnerets with a hole diameter of 50 microns - 100 microns depending on the desired titre of the fibers.

The present invention also relates to the use of the viscose fiber of the present invention for the production of yarns and fabrics.

The invention will now be explained by way of examples. These are to be understood as possible embodiments of the invention. By no means is the invention limited to the scope of these examples.

A detailed listing of the process parameters of all examples can be found in Table 9 at the end of the example section.

Example 1: Preparation of a modified algae-incorporated modified viscose fiber according to the invention

From dried, powdered plant material of Ascophyllum nodosum, a 10% dispersion in deionized water was prepared, which was deaerated for 6 hours. By spinnerets with 50 microns hole diameter was prepared with a deduction of 30 m / min a viscose without or with 2.5% or 5% algae material on cellulose. The dosage of the algae dispersion was carried out immediately before the homogenizer, with a residence time of <1 min in front of the spinneret. Table 1: Fiber properties of a modified viscose fiber, Example 1 Alga [%] on Cell. Titre [dtex] FFk [cN / tex] Fdk [%] FFn [cN / tex] FDn [%] Wet module (Bisfa module) [cN / tex] 0 (without) 1.72 39.0 11.8 23.2 13.5 6.4 2.5 1.71 31.3 10.6 18.6 12.1 5.6 5 1.79 31.3 11.4 17.2 12.1 5.3

Legend (also applies to the following tables):

• Titer [dtex]: fineness (conditioned)
• FFk [cN / tex]: denier-based tear strength dry or conditioned
• FDk [%]: maximum tensile strength dry or conditioned
• FFn [cN / tex]: denier-based tear strength wet
• FDn [%]: maximum tensile strength wet
• Wet Module (Bisfa Module) [cN / tex]: Fineness Wet Modulus at 5% Elongation

EXAMPLE 2 Preparation of a modified algae-incorporated viscose fiber according to the invention using differently concentrated powder dispersions

From dried, powdered plant material of Ascophyllum nodosum, a 10%, a 5% and a 2.5% dispersion were prepared in demineralized water, the dispersions were not vented. By spinnerets with 50 microns hole diameter and with a deduction of 30 m / min, a viscose fiber without or with 5% algae material was prepared on cellulose. Table 2: Fiber properties of a modified viscose fiber, Example 2 Alga [%] on Cell. Concentration of algae dispersion [g / kg] Titre [dtex] FFk [cN / tex] Fdk [%] FFn [cN / tex] FDn [%] Wet module (Bisfa module) [cN / tex] WRV [%] 0 (without) 1.76 36.6 12.6 22.7 14.9 5.9 66 5 100 1.83 23.5 11.2 11.1 12.2 4.1 81 5 50 1.98 28.4 12.7 15.3 14.8 4.5 79 5 25 1.89 29.1 11.8 17.4 13.2 5.6 86 Legend (also applies to the following tables): WRV [%]: water retention capacity.

Due to the high viscosity, the highest concentration of algae dispersion still contained many air bubbles, which often led to thread breaks during spinning. Therefore, in this case, no good Drawing and no higher strengths are achieved. When metering thinner algae dispersions, this problem did not occur - the resulting fineness-related strengths are at a significantly higher level than with a viscose fiber accordingly EP 1 259 564 ,

The alginic acid content of the algal material used and the fibers thus spun was analyzed after total hydrolysis of the fiber via HPLC on the basis of the mannuronic acid and guluronic acid content against an alginic acid standard (Fluka). The alginic acid content of the algal powder used was 25%, the alginic acid content of the fibers was between 0.95% and 1.2%, corresponding to an algae content of 3.8% to 4.8%.

As can be seen from Table 2, the fibers thus produced also have a significantly increased water retention capacity (WRV) compared to a modified viscose fiber without addition of algae. This shows the moisture storage capacity of the algae additive.

EXAMPLE 3 Preparation of a modified algae-incorporated modified viscose fiber according to the invention - incorporation of 4% algae powder (Ascophyllum nodosum) onto cellulose, dosed as a 6% dispersion in water.

By spinnerets with 60 microns hole diameter and with a deduction of 20 m / min, a viscose fiber without or with 4% algae material was prepared on cellulose. Table 3: Fiber properties of a modified viscose fiber, Example 3 Alga [%] on Cell. Titre [dtex] FFk [cN / tex] Fdk [%] 0 (without) 1.79 31.2 14.6 4 1.75 27.4 13.5

The alginic acid content of the fibers thus spun was 0.77% to 0.83%, corresponding to an algae content of 3.35% - 3.60%, the algal powder used had an alginic acid content of 23%.

Example 4 Production of a modified algae-incorporated modified viscose fiber according to the invention - incorporation of 4% algae powder (Ascophyllum nodosum) onto cellulose, dosed as a 6% dispersion in water.

By spinnerets with 60 microns hole diameter and with a deduction of 19 m / min according to the invention modified viscose fibers were prepared with 4% algae material on cellulose for about 40 hours. Table 4: Fiber properties of algae-incorporated modified viscose fibers, Example 4 Alga [%] on Cell. Titre [dtex] Titre Cv [%] FFk [cN / tex] Fdk [%] FFn [cN / tex] FDn [%] Bisfa (5%) module wet [cN / tex] SFk [cN / tex] SDk [%] Kfk [cN / tex] 4 1.67 9 27.5 12.6 14.2 12.6 4.5 9 2.8 18.1 Legend (also applies to the following tables) Titer Cv: [%]: standard variation coefficient SFk [cN / tex]: fineness-related loop strength conditioned SDk [%]: Leaning-out conditioned

The alginic acid content of the fibers thus spun was 0.80% - 1.0%, corresponding to an algae content of 3.2% - 4.0%; the algae powder used had an alginic acid content of 25%.

Zinc contents of the modified algae-incorporated modified viscose fibers according to the invention:

The zinc content was measured on fiber samples from Example 3 and Example 4 in comparison to a standard viscose fiber (manufacturer: Lenzing AG), a modal fiber (manufacturer: Lenzing AG) and one with algae modified fiber produced by the lyocell method (SeaCell ™, manufacturer: Smartfiber AG), determined by ICP analysis after fiber pulping.

It was found that the modified algae-incorporated modified viscose fibers according to the invention have a zinc content of 330 ppm to 530 ppm, while standard viscose fibers and modal fibers have significantly lower zinc contents. Table 5: Zn content of the alginin-modified modified viscose fibers and comparative fibers according to the invention Alga [%] Zn [mg / kg] Fiber sample Example 3 4 410 Example 4, fiber sample 1 4 530 Example 4, fiber sample 2 4 330 Example 4, fiber sample 3 4 400 Example 4, fiber sample 4 4 360 Example 4, fiber sample 5 4 380 Standard viscose fiber (textile type) 0 41 Modal fiber A 0 73 Modal fiber B 0 165 SeaCell ™ fiber 3 - 5 5

Comparison of the fibers produced according to the invention with the prior art from EP 1 259 564:

Comparison of fibrillation tendency with a commercially available SeaCell ™ fiber.

This fiber is one after EP 1 259 564 manufactured lyocell type with 3% -5% incorporated material of Ascophyllum nodosum.

1. a) Nassscheuerwert - Verfahren gemäß EP 0 943 027 B1 [0030]
2. b) Adaptierte CSF-Prüfung in Anlehnung an die Norm Canadian Standard Freeness T 227 om-99
3. c) Schütteltest und mikroskopische Bewertung der Fibrillationsneigung - Verfahren gemäß EP 0 943 027 B1 [0029]

To study the fibrillation tendency of the fibers, the following procedures were used:

1. a) Wet abrasion value - Method according to EP 0 943 027 B1 [0030]
2. b) Adapted CSF test based on the Canadian Standard Freeness T 227 om-99 standard
3. c) Shake test and microscopic assessment of fibrillation tendency - according to EP 0 943 027 B1 [0029]

Test of wet abrasion value (also wet abrasion resistance or 'NSF'):

20 individual fibers are weighted with a titer-dependent pretension weight to a metal roller with 1 cm in diameter. The roll is covered with a Viskosefilamentgarnstrumpf and is moistened continuously. During the measurement, the roller is rotated at a speed of 500 rpm. The roller simultaneously performs a pendulum movement transverse to the fiber axis with about 1 cm deflection. The number of rotations is determined until the fibers rub through. The stronger the fibrillation tendency in the wet state, the lower the number of revolutions U achieved which, based on the titer [dtex], gives the value of the wet abrasion resistance. Table 6: Wet scrub test results on fibers with incorporated algae, all 1.7 dtex Nasscheuer worth (NSF) Fiber type / manufacture NSF [U / dtex] CV [%] Example 2, 5% alga owc 2954 2 Example 4, 4% algae owc 2151 26 Seacell ™, Smartfiber AG, Lyocell method 18 27 Legend: CV [%]: coefficient of variation (standard deviation in% of the mean value)

Adapted CSF Exam Canadian Standard Freeness (CSF):

The adapted Canadian Standard Freeness test uses a mixer as a measure of fibrillation tendency, in which fiber samples cut to 5 mm in length are beaten in water until they begin to fibrillate. The CSF apparatus itself consists of a funnel with overflow and a strainer inserted in it. As the degree of fibrillation increases, the screen located in the CSF apparatus clogs, allowing more water to pass into the overflow and less into the pass. In a standardized measuring cylinder, the volume of water in ml is determined in the passage after different mixing times, which is higher the less the fiber fibrillates.

1 illustrates the determined according to these experiments fibrillation dynamics. The abscissa indicates the mixing time in minutes, the ordinate the volume of water in milliliters.

A

Standard-Lyocellfaser 1,7 dtex

B

Viskosefaser ohne Alge 1,7 dtex aus Beispiel 2

C

algeninkorporierte modifizierte Viskosefaser aus Beispiel 2

D

algeninkorporierte modifizierte Viskosefaser aus Beispiel 4

E

Normalviskosefaser 1,7 dtex 1,7 dtex SeaCell™ (Smartfiber AG), lyocellbasierte algeninkorporierte

F

Type

In accordance with 1 investigated fiber types A to F were the following fibers:

A

Standard lyocell fiber 1.7 dtex

B

Viscose fiber without alga 1.7 dtex from example 2

C

algae-modified modified viscose fiber from Example 2

D

algae-modified modified viscose fiber from example 4

e

Normal Viscosity Fiber 1.7 dtex 1.7 dtex SeaCell ™ (Smartfiber AG), lyocell-based algal-incorporated

F

grade

As in 1 As shown, both lyocell types, both the standard Lyocell fiber and the SeaCell ™, fibrillate after only 10 minutes of mixing time. All fiber types based on a viscose process, including the algae-incorporated fibers according to the process modified according to the invention, show no signs of fibrillation in the CSF test even after a mixing time of 45 minutes.

Fibrillation degree by shaking test and microscopic evaluation

The friction of the fibers together during washing or finishing operations in the wet state is simulated by the following test: 8 fibers are placed in a 20 ml sample vial with 4 ml of water and for 3 hours in a laboratory shaker type RO-10 from Gerhardt, Bonn (FRG) shaken at level 12. The fibrillation behavior of the fibers is then evaluated under the microscope by counting the number of fibrils per 0.276 mm fiber length and is reported in a fibrillation value of 0 (no fibrils) to 6 (strong fibrillation). Table 7: Splice test after shaking test, number of fibrils and note after 3 hours fibrils grade Fiber type / manufacture Sample A Sample B Sample A Sample B Fiber from example 3, 4% algae owc 0 0 0 0 Fiber from Example 4, 4% algae owc 0 8th 0 0 SeaCell ™, Smartfiber AG, Lyocell method > 50 > 50 3 3

• 2 zeigt das Fibrillationsverhalten der Faser gemäß Beispiel 3.
• 3 zeigt das Fibrillationsverhalten der Faser gemäß Beispiel 4.
• 4 zeigt das Fibrillationsverhalten der SeaCell™-Faser.

The 2 to 4 show the result of the microscopic examination of the fibers:

• 2 shows the fibrillation behavior of the fiber according to Example 3.
• 3 shows the fibrillation behavior of the fiber according to Example 4.
• 4 shows the fibrillation behavior of the SeaCell ™ fiber.

It can be clearly seen that the fibers according to the invention do not or practically do not fibrillate.

Comparison of the physical fiber properties of the alginin-incorporated modified viscose fibers produced by the process according to the invention with the viscose fibers described in EP 1 259 564 B1.

Table 8: Overview of physical fiber data in comparison Titre [dtex] FFk [cN / tex] Fdk [%] FFn [cN / tex] FDn [%] SFk [cN / tex] KFk [cN / tex] Bisfa module [cN / tex] EP 1 259 564 Example 7 1.7 21.7 14.2 12.4 15.8 6.0 kA 2.9 EP 1 259 564 Example 8 EP 1 259 564 1.7 23.7 16.9 14.1 18.5 6.5 kA 3.0 Comparative Example 3 1.7 24.8 17.2 14.2 21.1 6.4 kA 2.9 Ex.1, 2.5% alga owc 1.71 31.3 10.6 18.6 12.1 kA kA 5.6 Fiber Beisp.1, 5% algae owc 1.79 31.3 11.4 17.2 12.1 kA kA 5.3 Fiber Example 2, 5% algae owc, 100 g / l dispersion 1.83 23.5 11.2 13.2 12.2 kA kA 4.1 Fiber Example 2, 5% algae owc, 50 g / l dispersion 1.98 28.4 12.7 15.3 14.8 kA kA 4.5 Fiber Example 2, 5% algae owc, 25 g / l dispersion. 1.89 29.1 11.8 17.4 13.2 kA kA 5.6 Fiber example 3, 4% algae owc 1.75 27.4 13.5 kA kA kA kA kA Example 4, fiber sample 1, 4% algae owc 1.8 27.6 13.1 14.5 13.7 8.8 17.6 4.2 Example 4, fiber sample 2, 4% algae owc 1.7 27.1 12.9 14.3 12.6 9.0 17.7 4.3 Example 4, fiber sample 3, 4% algae owc 1.7 26.3 12.7 13.5 12.3 9.0 18.6 4.4 Example 4, fiber sample 4, 4% algae owc 1.5 28.9 11.9 14.4 11.7 9.0 18.5 5.1 Legend: owc: on weight of cellulose - Weight fraction on cellulose n / a: Not available

As can be seen from Table 8, with the exception of a fiber sample of Example 2 where, as mentioned above, good tenacities were not achieved due to thread breaks, the fineness of tenacity in the dry state is greater than 25 cN for all fibers made with algal material incorporated according to the present invention / tex, ie significantly higher than that of the viscose fibers EP 1 259 564 Examples 7 and 8 and even higher than the reference viscose fiber EP 1 259 564 Comparative Example 3.

In particular, the wet modulus according to BISFA, ie the tear strength at 5% elongation in the wet state, is higher than 4.0 cN / tex for all fibers produced according to the invention with incorporated algae material, while the wet modulus for the viscose types EP 1 259 564 does not exceed 3.0.

As far as the wet modulus is concerned, all algae-incorporated types produced by the modified viscose process meet the minimum values defined by BISFA for a modal fiber.

With respect to dry strength, only the fibers of Examples 1 and 2 (except Example 2.1 with the 100 g / l aldehyde dispersion) achieve the values required in the BOSTFA mode definition.

Although the modified viscose fibers with incorporated algae according to the invention are not modal fibers in the true sense of the word, they can still be used in comparison to the substantially improved physical fiber properties EP 1 259 564 Example 7 and 8 significantly improved utility values are closed. The connection between the wet modulus of fibers and the surface shrinkage of fabrics made therefrom has long been known (Szegö, L., Faserforsch., Text. Techn. 21.10 (1970).) Puchegger has confirmed this relationship for viscose and modal fibers (Puchegger, F Lenzinger Ber., 55, 32-36 (1983) and Puchegger, F., Lenzinger Ber. 58, 94-99 (1985)).

The following table summarizes the process parameters of Examples 1-4: Table 9: viscose composition: Ex. 1 Ex. 2 Ex. 3 Ex. 4 Cellulose concentration [% by weight] 5.8 5.8 5.6 5.4 R18 content [%] 97.5 95 96 97 NaOH concentration in the viscose wt. [%] 6.2 6.1 6.5 6.7 Alkali ratio (cellulose: NaOH, both g / l) 0.9 1.0 0.9 0.8 CS ₂ in viscose [% by weight on cellulose] 37 39 36 38 Modifier [wt.%] 3 3 4 4 Maturity level (gamma value) 58 58 57 59 Spinning Viscosity [bullet fall seconds] 96 80 95 82 Nozzle hole diameter 50 μm 50 μm 60 μm 60 μm Spinnbadzusammensetzung: H ₂ SO ₄ [g / l]: 75 73 74 72 Na ₂ SO ₄ [g / l]: 128 123 125 120 ZnSO ₄ [g / l]: 60 65 65 60 T spin bath [° C]: 38 38 37 37 T second bath [° C] 97 97 97 97 Final discharge from the spinning bath [m / min] 30 30 20 19

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1259564 [0003, 0004, 0005, 0007, 0011, 0012, 0016, 0034, 0043, 0052, 0053, 0054, 0057]
• EP 1259564 B1 [0012]
• WO 2011/026159 A1 [0025]
• EP 0943027 B1 [0044]

Claims (4)

A modified viscose fiber incorporating an algal material characterized by a wet modulus at a 5% elongation in the wet state satisfying the following formula: $$\text{wet modulus}\left(\text{cN}\right)\ge 0.5*\surd \text{T}.$$

where T is the titer of the fiber in dtex. Viscose fiber according to Claim 1 characterized by a fiber strength in a conditioned state which satisfies the following formula: $$\text{fiber strength}\left(\text{cN}/\text{tex}\right)\ge \mathrm{27,38}-1.4*\text{T}\text{,}$$

Viscose fiber according to Claim 1 or 2 , characterized by a content of zinc ions of at least 200 ppm, preferably 200 ppm to 700 ppm. Viscose fiber according to one of the preceding claims, characterized by a content of algal material of at least 0.5% by weight, preferably 2% by weight to 6% by weight.

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