FI78126C - Process for manufacturing chitosan viscose fibers - Google Patents

Description

78126

Manufacture of chitosan viscose fibers - Förfarande för tillverkning av fibrer av kitosanviskos

The invention relates to a process for the preparation of chitosan viscose fibers.

Hitherto, chitosan-containing viscose fibers and chitin / chitosan fibers have been prepared using the viscose method. 5 Chitin or chitosan is mercerized and reacted with carbon disulphide using a cooling method in the temperature range of -30 to 0 ° C. Only by the cooling method can chitin or chitosan derivatives which are soluble in aqueous sodium hydroxide solution be obtained, enabling their use in the manufacture of modified viscose fibers as an additive or as a spinning solution in the production of polyaminosaccharide fibers. In the case of polyaminosaccharides, the cooling process has simultaneously obtained favorable reactivity with carbon disulphide, inter alia, due to suitable changes in the supermolecular structure of chitin / chitosan.

As described above, the preparation of the polyaminosaccharide viscose takes place in practice in a suitable length of time. However, the use of cooling in industrial conditions poses a number of difficulties that in practice often cannot be overcome.

Known methods for preparing chitosan-containing viscose fibers as well as polyaminosaccharide fibers by the viscose method have been described e.g. R.A.A. In Muzzarelli's book "Chitin", Pergamon Press, New York 1977.

Other known methods for preparing polyaminosaccharide fibers are based on spinning the dissolved polymers into a regeneration bath or air.

Japanese Patent 81/112937 describes the production of chitosan fibers and films from an acidic aqueous solution of chitosan. The spinning solution is filtered and spun through holes, nozzles or 2,781 26 pores and precipitated in an aqueous solution of anionic surfactants. Alternatively, the spinning solution is sprayed onto a flat surface, after which it is dipped in a precipitation bath to form a film.

Japanese Patent 84/116418 describes the production of chitosan films and fibers by dissolving chitosan in a solvent containing water and dichloroacetic acid. The solution is formed into fibers or films in an aqueous solution of metal salts and the products formed are treated with a chelating metal.

Japanese Patent 80/123635 describes a process for producing isocyanate chitosan films and fibers. The acetic acid salt of chitosan is treated with sodium cyanate and the reaction product is mixed with acetic acid and spun into dilute sodium carbonate solution to form fibers.

Japanese Patent 81/106901 describes a process for producing chitosan fibers. Chitosan and its salts are separated from the aqueous solution using a basic, chelating bath. The chitosan flakes are dispersed in water and heated in acetic acid at 40 ° C to give a spinning solution containing 3% chitosan and 0.5% acetic acid. The spinning solution is spun into 5% aqueous sodium hydroxide solution at 30 ° C, washed and dried to give 3.5-denier fibers with a strength of 2.44 g / denier, an elongation at break of 10.8% and a loop strength of 1.75 g / denier.

Japanese Patent 85/235691 describes the preparation of chitosan fibers used as pure water filters. Chitosan is dissolved in 0.1 M acetic acid solution and spun into 2-deier filaments in an alkaline bath.

European patent application EP 77.098 describes a process for the production of porous chitosan fibers useful in ultrafiltration and dialysis, having a pore diameter of 0.1-1 mm and a thickness of 0.005-0.025 mm. The fibers are prepared by spinning solutions into an alkaline precipitation bath through spinning heads for spinning porous fibers using gaseous ammonia as the internal precipitant.

Japanese Patent 85/059123 describes the wet spinning of chitosan fibers by a method in which chitosan dissolved in an aqueous solution of acetic acid and urea is spun into an aqueous solution containing a mixture of alcohol and base. The acetic acid-10 and urea contents of the spinning solution are 0.5-20% by weight and 0.1-10% by weight. The base may be, for example, sodium hydroxide, potassium hydroxide or ammonium hydroxide, which are used in a concentration of 1 to 50% by weight. The volume ratio of aqueous base to alcohol is in the range of 95: 5 to 30:70.

Japanese Patent 85/40224 describes a method of manufacturing chitosan fibers which achieves improved breaking load and strength. The fibers are prepared by spinning an acetic acid solution of chitosan into air at a pressure of more than 10 kg / cm2. For example, a 20% acetic acid solution containing chitosan is spun into air 20 at a pressure of 15 kg / cm 2, treated with gaseous ammonia and washed to give fibers with a strength of 2 g / denier dry and 0.82 g / denier wet, an elongation of 11% and a strength of 100 g / denier.

U.S. Patent 4,309,534 also describes the manufacture of regenerated chitosan-25 fibers and films. Vigorous mixing in the presence of acetic acid, glycolic acid and pyruvic acid for 2-14 days at room temperature produces said compounds which can be used in the production of transparent films and birefringent fibers.

Microcrystalline chitosan and a process for its preparation based on a precipitation process are known from Polish patent 125,995. According to this method, the product is prepared in the form of a gel-like dispersion or powder. Microcellan chitosan has increased reactivity and water retention (WRV) in powder form in the range of 200-500% and in gel dispersion in the range of 500-2000%, respectively, with an average molecular weight in the range of 10-10 and a degree of deacetylation of at least 5-30%.

Microcrystalline polymers are described in O.A. Battista: "Microcrystalline Polymers Science", McGraw Hill Pub., New York 1975.

Chemically, microcrystalline chitosan is similar in structure to the standard chitosan used as a raw material. However, it differs from this raw material in its structure * of polymer chains (supermolecular structure).

Known methods for making chitosan-containing viscose fibers as well as polyamine saccharide fibers often involve a number of complex methods and chemicals for making the fibers.

Known chitosan-containing viscose fibers are characterized by special properties such as better colorability, especially when using acid dyes.

Known polyamine saccharide fibers are characterized by different mechanical properties, improved colorability, bacteriostatic and biodegradability.

The object of the present invention is to prepare chitosan-containing viscose fibers using a derivative based on microcrystalline chitosan as an additive, in particular in the form of a gel-like dispersion.

According to the present invention, there is provided a process for preparing chitosan-containing viscose fibers which comprises the use of a chitosan derivative based on the reaction of mercerized microcrystalline chitosan with carbon disulphide.

li 5 78126

According to a preferred embodiment of the invention, the derivative is added to the viscose solution at a concentration of at least 0.1% by weight based on the weight of c <.- cellulose, in particular 0.5-25% by weight, and the addition is carried out primarily by mixing or injecting the derivative into the viscose solution before spinning.

According to a preferred embodiment of the process according to the invention, the microcrystalline chitosan used as starting material for preparing the chitosan derivative, in particular in the form of a gel-like dispersion in water, has a water retention (WRV) in gel form in the range of 500-2000% and in powder form in the range of 500-800% 4 6 10 -10, degree of deacetylation at least 30%, preferably 40-80% and primarily particle size in the range 0.1-100 μπι.

According to a preferred embodiment of the process according to the invention, a chitosan derivative based on microcrystalline chitosan is prepared by mercerizing microcrystalline chitosan in an alkaline solution, in particular aqueous sodium hydroxide solution, after which the excess solution is optionally filtered off, in particular by filtration or centrifugation, and mercerized microcrystalline chitosan. 10% by weight of polymer and 5-20% by weight of sodium hydroxide are reacted with carbon disulphide to give an alkali-soluble derivative.

According to a further preferred embodiment of the process according to the invention, the reaction with the carbon disulphide is carried out at a temperature of at least 10 ° C, preferably at a temperature of 15-40 ° C.

Furthermore, according to a preferred embodiment of the process according to the invention, the mercerization is carried out at a temperature of 10-50 ° C, preferably at a temperature of 15-40 ° C.

6 78126

According to the invention, there is also provided a novel chitosan derivative obtained by mercerizing microcrystalline chitosan and reacting it with carbon disulphide, said derivative containing mainly urea groups according to the following formula 5:

Chit-NH-C

II

0 where Chit-N represents the monomer unit of chitosan, where N is the nitrogen atom of the amino group of chitosan in the raw material.

To illustrate the invention, figures are shown showing the microcrystalline raw material and the derivative based thereon.

Figures 1a and Ib are optical microscopic photographs of a microcrystalline chitosan raw material (magnification 400 times).

Figure 1a is a scanning electron micrograph of a microcrystalline chitosan raw material (magnification 1000 times), Figures 2a and 2b are images of an optical microscope with the derivative dissolved in an alkaline solution (magnification 400 times).

The microcrystalline chitosan used as a raw material in the preparation of the chitosan derivative can be characterized as consisting of small particles of average size. . in the range 0.01-100 μm, especially in the form of a dispersion (Fig. 1), in which case it has special properties, e.g. gel-like shape, higher reactivity, high water retention, etc.

The main advantage of the production of modified viscose fibers is related to the use of 25 microcrystalline chitosan, especially in gel form, as evidenced by e.g. higher reactivity due directly to its special structure.

li 7 78126

The mercerization process of microcrystalline chitosan carried out by the process according to the invention / gives the product a typical gel form suitable for reaction with carbon disulphide. Mercerization of the microcrystalline chitosan is performed in order to effect appropriate macromolecular changes in its structure, which are mainly related to swelling and gel formation.

The mercerization of microcrystalline chitosan is also carried out according to the invention at the standard temperature used in the viscose process. In contrast to known methods, cooling is not required to produce mercerized microcrystalline chitosan.

At the same time, the mercerization can be carried out in a very short time, in the order of a few minutes, while the known methods for carrying out the mercerization of standard chitosan require 10-24 hours at -30 to 0 ° C.

The reaction of mercerized microcrystalline chitosan with carbon disulfide according to the invention is carried out under standard viscose processing conditions in contrast to known methods which require a low temperature and a longer time to prepare an alkaline, soluble derivative.

The microcrystalline chitosan and sulfur carbon derivative formed according to the invention do not contain xanthate groups or contain only a very low amount thereof. Based on the infrared spectral study of the structure, a carbonyl group attached to the amide units in the wavelength range 1765-1745 cm-1 is seen in the spectrum. At the same time, no absorption peak is observed in the infrared spectrum of the raw material in this wavenumber range.

Simultaneously, according to infrared spectrometric studies, the typical absorption peak due to the vibration of the NH group in the raw material is in the range of 1560-1555 cm and is not visible in the spectrum of the chitosan derivative. As a result, it can be stated that the amino groups of chitosan form the corresponding amide groups during the preparation of the chitosan derivative.

The infrared spectrum of the derivative also shows new absorption peaks in the wavelength range of 865 cm * and 795 cm. In this case, the first absorption peak can be assumed to be related to the oscillation of C-S groups, while the second absorption peak may be related to the oscillation of N-C = 0 units.

From the studies carried out, it can be concluded that the reaction of mercerized microcrystalline chitosan with carbon disulphide under the conditions of the invention has mainly led to the formation of urea groups in the final product.

The derivative obtained according to the invention, based on microcrystalline chitosan, is dissolved in an alkaline aqueous solution, in particular sodium hydroxide solution (Figure 2). At the same time, the obtained solution of the chitosan-15 derivative mixes infinitely with the viscose solution and does not affect its stability.

The modification of viscose fibers according to the invention makes it possible to produce chitosan-containing fibers by the commonly used viscose technique also on an industrial scale.

Upon spinning in a precipitating spinning bath, the chitosan derivative regenerates to form chitosan, which is still in the structure of the viscose fibers.

The modified viscose fibers produced by the process of the invention have several advantages over standard fibers. They are more suitable for dyeing, especially when using acid dyes. In this case, in accordance with this advantage, a common dyeing process can be carried out with the modified viscose fibers and the wool or polyamide fibers.

n 78126

At the same time, modified viscose fibers have a higher dye absorption capacity, especially when using acid, dispersion and direct dyes.

Modified viscose fibers also suitably have a higher water absorption capacity than standard viscose fibers. Modified, chitosan-containing viscose fibers have a significantly higher coefficient of swelling than standard fibers. The value of the swelling factor for modified viscose fibers is greater than 100% depending on the amount of chitosan used. The swelling factor of Standar-10 diviscose fibers is in the order of 60-80%, while the value of viscose fibers typically used as superabsorbents is in the range of 130-150%, respectively.

The modified viscose fibers prepared according to the invention can be used as superabsorbent fibers.

The addition of a chitosan derivative according to the invention to a viscose solution to form modified viscose fibers makes it possible to influence their structure depending on the chitosan content and the spinning parameters used.

The modified viscose fibers containing chitosan prepared according to the invention have the additional property of having a bacteria-resistant effect.

An important advantage of the invention is the high efficiency of relatively small amounts of chitosan, whereby chitosan is introduced into the structure of viscose fibers by suitable modification of the viscose solution with a chitosan derivative, thereby achieving considerable effects on the properties of the fibers to be produced, such as colorability, swelling, supermolecularity.

Further research could focus on the further development of 30 specialty chitosan viscose fibers, 10,78,126 that could be used in the textile industry in the manufacture of fabrics, knitwear and nonwovens.

The following methods have been used to determine the properties of chitosan derivatives and chitosan viscose fibers: 5 - average molecular weight of chitosan: determined according to the method described in "Chitin", Pergamon Press, New York, 1977 - degree of deacetylation of chitosan: determined by infrared spectrometry, 1 ° International Journal of

Biological Macromolecules ", Vol. 2, p. 115, 1980 - crystallinity index of chitosan (in film form) and viscose fibers: determined by infrared spectrometry as described in" Textile Research

Journal ", Vol. 29, p. 786, 1959 - hydrogen bonding energy E": Π was determined according to the infrared spectrometric method described in "Cellulose 20 Chemistry and Technology", Vol. 7, p. 173, 1973 - nitrogen content: determined by Kjehdhal- according to standard method - mechanical properties of viscose fibers thickness, breaking load and elongation at break: 25 determined according to Finnish standards number SFS 3984 and SFS 4639 - carbon disulphide content: determined according to standard sulfur method commonly used in viscose fiber industry 7812 6 - sodium hydroxide the swelling factor of the viscose fibers: 5 was determined as follows: 200 mg of the sample was placed in 200 ml of distilled water for 20 hours at 20 ° C, after which the liquid was filtered off and the sample was centrifuged for 80 seconds at 3000 rpm (mo). t was dried at 105 ° C to constant weight (m 2). The swelling factor was calculated according to the following equation: swelling factor = mQ ~ ml (x100%) ml - viscosity fiber degree of organization 10: determined according to the method described in "Paper and Wood", Vol. 47 (5), ss. 311-322, 1965, using X-ray diffractometric measurement.

- colorability of chitosan viscose fibers and suitable viscose fibers used as reference fibers: examined by measuring the amount of 20 dyes absorbed from the dye bath by UV spectrophotometry compared to the original amount. The study used different types of dyes under different conditions as follows:

Straight color? Solophenylblau AGFF

25 Solophenylblau AGFF 0.4% by weight sodium sulphate 3.4% by weight broth ratio 1:18

temperature 95 ° C

staining time 30 min.

12 78126

Acid Color; Lanasyn olivegrun S-4 GL

Lanasyn olivegrun S-4 GL 2.0% by weight ammonium sulfate 3.0% by weight acetic acid 1.0% by weight 5 broth ratio 1: 200

temperature 90 ° C

staining time 30 min.

Dispersion color: Resolinblau GRL

Resolinblau GRL 2.0% by weight 10 Polegal SP 2.0 g / l acetic acid 0.5% by weight broth ratio 1: 200

temperature 100 ° C

staining time 30 min.

15 - Reaction color: Drimarenbrill. blue K-BL

Drimarenbrill.blau K-BL 0.4% by weight sodium sulphate 30 g / l sodium carbonate 5 g / l broth ratio 1:30

20 temperature 50 ° C

staining time 30 min.

Base color: Maxilonblau GRL

Maxilonblau GRL 2.0% by weight sodium acetate 2.0% by weight 25 sodium sulfate 10.0% by weight acetic acid 0.5% by weight broth ratio 1: 200

temperature 95 ° C

staining time 30 min.

The electrical conductivity and resistance of chitosan viscose fibers and viscose fibers used as a reference were measured in accordance with the Finnish standard SFS 5155.

13,781 26

The chitosan-containing viscose fibers were formed using a standard method known for the production of conventional viscose fibers.

The invention is further illustrated by the following examples, which are not intended to limit the scope of the claims.

EXAMPLE 1

13% by weight of a 25% by weight sodium hydroxide solution was added to 37.9 parts by weight of a microcrystalline chitosan dispersion containing 5.27% by weight of a polymer having a water retention in gel form (WRVg) of 698%, an average molecular weight of 4.02 x 105, a degree of deacetylation of 62 %, crystallinity index IKj 0.840 and hydrogen bonding energy 19.3-23.5 kJ / mol. The mercerization of microcrystalline chitosan was performed by stirring the solution for 10 ml to 15 minutes at 20 ° C. The mercerized microcrystalline chitosan solution was then poured into a filter bag made of a polyester fabric having a basis weight of 130 g / m 2 and excess sodium hydroxide was removed by centrifugation.

74 parts by weight of a mercerized microcrystalline chitosan-20 gel containing 2.06% by weight of polymer were poured into a xanthogenation vessel and the xanthogenation was performed under reduced pressure at 30 ° C for 1 hour using 0.58 parts by weight of carbon disulphide.

The product obtained was a pale yellow, very clear viscose solution containing 2.04% by weight of chitosan and 8.19% by weight of sodium hydroxide. According to infrared spectrometric studies, an absorption peak was observed in the wavelength range typical of the vibration of the carbonyl group associated with the amide unit in the range of 1765 cm. The microcrystalline chitosan used as raw material had no absorption peak in the wavelength range studied.

14,781 26

Simultaneously, based on infrared spectrometric studies, it was found that the product did not have an absorption peak typical of NH_ (amino) group oscillation in the range -1 ^ 1560-1555 cm, which in turn was observed in the infrared spectrum of the 5 raw materials used. According to infrared spectral studies, new absorption peaks were also observed in the wavelength range of 865 cm and 795 cm. The former absorption may apparently be related to the vibration of the C-S groups, while the second absorption peak is related to the vibration of the N-C = O groups.

The obtained product was dissolved in aqueous sodium hydroxide solution and had no effect on the stability of the viscous solution during mixing.

EXAMPLE 2

15% by weight of 25% by weight sodium hydroxide solution IS was added to 23.9 parts by weight of a dispersion of microcrystalline chitosan, which in turn contained 8.37% by weight of a polymer with a water retention (GRV) of 1076%, an average molecular weight of 2.12 x 10, a degree of deacetylation. 64%, crystallinity index IKj 0.912 and hydrogen bond energy E „16.47 - 25.41 kJ / mol. Mercerization of 20 microcytes of chitosan was performed for 10 minutes with stirring at 20 ° C. The mercerized microcrystalline chitosan was then transferred to a filter bag according to Example 1, and excess sodium hydroxide was removed by centrifugation.

2S 37.0 parts by weight of mercerized microcrystalline chitosan in the form of a gel containing 5.70% by weight of polymer in a xanthogenation vessel was added, and the xanthogenation process was carried out under reduced pressure at 30 ° C for 1 hour using 0.73 parts by weight of carbon disulphide.

The product obtained was a yellow, suitably clear viscose solution containing 5.59% by weight of chitosan and 11.36% by weight of sodium hydroxide. According to infrared spectrometric studies, an absorption peak of 15,78,126 was observed in the wavenumber range of 1760 cm, which is typical for the vibration of the carbonyl group associated with the amide group. The other absorption peaks were similar to those obtained in the study of the product prepared according to Example 1.

5 The product obtained was dissolved in sodium hydroxide solution and did not affect the stability of the viscose solution during mixing.

EXAMPLE 3

13.4% by weight of a 20% sodium hydroxide solution was added to 386.7 parts by weight of a microcrystalline chitosan dispersion containing 1.65% by weight of a polymer having a water retention capacity in the gel form of WRVg of 665% and having supermolecular properties as in Example 1. For 10 minutes at 20 ° C. The mercerized microcrystalline chitosan 15 was then poured into a filter bag as in Example 1 and excess sodium hydroxide was removed by centrifugation.

383 parts by weight of mercerized microcrystalline chitosan in the form of a gel containing 1.6% by weight of polymer in a xanthogenation vessel were poured and the xanthogenation process was carried out under reduced pressure at 33 ° C for 1 hour using 4 parts by weight of carbon disulphide.

386 parts by weight of a pale yellow, very clear viscous solution containing 1.58% by weight of chitosan were obtained. The structure of the product was similar to Example 25 1.

220 parts by weight of the product obtained were poured into 860 parts by weight of a viscose sieve containing 10.45% by weight of σ (.- cellulose having a '? -30 to remove bubbles A standard viscose spinning process was applied to produce modified chitosan viscose fiber.

16 78126

At the same time, normal viscose fiber was prepared as a reference material by a standard method.

Spinning of the viscose fibers was performed at a speed of 23 m / min in a first bath containing a solution of sulfuric acid and zinc sulphate at 45-50 ° C, then a second bath containing a sulfuric acid solution at 95 ° C and then a third bath containing a sulfuric acid solution at 60 ° C. . The resulting fibers were washed 3 times in water at 80 ° C and dried under standard conditions.

The obtained modified viscose fibers contained 1.0% by weight of chitosan and had a thickness of 1.42 dtex, a breaking load of 2.34 cN / dtex and an elongation at break of 16.3 *. The swelling coefficient of these fibers was 116%, the crystallinity index IK_ 0.255 and the hydrogen bond energy E „

Z 1U

15.03 kJ / mol. The electrical resistance of these fibers was 4.5 x 10; 15 ohms and electrical conductivity 2.25 x 10 A.

Conventional viscose fibers prepared by the same method that did not contain chitosan had a thickness of 1.68 dtex, a breaking load of 2.68 cN / dtex, and an elongation at break of 21.2%. The swelling coefficient of these fibers was 86.7%, the crystallinity index IK ^ 0.243 20 and the hydrogen bond energy E „14.31 kJ / mol. Standard viscose fibers H 10 -9

the electrical resistance was 4.8 x 10 Ohm and the electrical conductivity 2.45 x 10 A

respectively.

Chitosan-containing viscose fibers had better coloring properties with acid dyes, dispersion dyes, and .25 direct dyes than standard fibers.

The color absorbency of the modified viscose fibers from the dye solution was as follows: direct color Solophenylblau AGFF: 87.5% acid dye for Lanasy olivegrin S-4 GL: 80.0% dispersion dye Resolinblau GRL: 83.7% reaction dye Drimarenbrill. blue K-BL: 55.6% and base color Maxilonblau GRL: 78.7% 17 781 26

The color absorbency of the standard viscose fibers used as reference fibers at the same time was, respectively: direct color Solophenylblau AGFF: 82.5% acid color for Lanasy olivegrin S-4 GL: 67.5% 5 dispersion color Resolinblau GRL: 82.5% reaction color Drimarenbrill.blau emvla Gla %

The color absorbance of the wool and nylon 6.6 samples used in the reference dye was as follows: 10 direct color Solophenylblau AGFF: 80.0% and 80.0% acid color for Lanasy olivegri S-4 GL: 88.7% and 91.5% dispersion color Resolinblau GRL: 96.2% and 93.2% reaction color Drimar blue K-BL; 55.6% and 51.2% and base color Maxilonblau GRL: 82.0% and 70.0% 15 The percentage of color absorption is compared with the amount of color used.

EXAMPLE 4

13% by weight of a 20% sodium hydroxide solution was added to 251 parts by weight of a microcrystalline chitosan dispersion containing 1.92% by weight of a polymer having the properties described in Example 3. The microcrystalline chitosan mercerization process was carried out with stirring at 20 ° C for 12 minutes. The mercerized microcrystalline chitosan was then poured in gel form into a filter bag as in Example 1 and excess sodium hydroxide was removed by centrifugation.

111 parts by weight of mercerized microcrystalline chitosan in the form of a gel containing 4.05% by weight of polymer in a xanthogenation vessel were poured and the xanthogenation process was carried out under reduced pressure at 30 ° C for 1 hour using 1.64 parts by weight of carbon disulphide.

18,781 26

112.6 parts by weight of a very clear, yellow viscose solution containing 3.98% by weight of chitosan were obtained. The structure of the product was similar to Example 1.

65 parts by weight of the product obtained were poured into 1000 parts by weight of a viscose solution containing 10.5% of CL cellulose with stirring at 20 [deg.] C. for 1 minute. The contents of the vessel were then evacuated to remove air bubbles. A standard spinning process was used as in Example 3 to form viscose fibers containing chitosan as well as to form viscose fibers used as standard 10.

The modified viscose fibers contained about 0.5% by weight of chitosan and had a thickness of 1.70 dtex, a breaking load of 2.71 cN / tex and an elongation at break of 20.7%. The swelling coefficient of the modified fibers was 113.9% and the crystallinity index KT_ 0.225 and the hydrogen bond energy 10 · .: 15 E „14.37 kJ / mol. The electrical resistance of the fibers was 13 x 10 Ohm and the electrical conductivity H -9 was 0.8 x 10 A, respectively.

The order state index (10) of the viscose fibers modified according to X-ray diffractometric measurements was -0.02 and the order state index -0.20 of the normal viscose fibers used as reference fibers.

The standard viscose fibers, which did not contain chitosan, had a thickness of 1.54 dtex, a breaking load of 2.71 cN / tex and an elongation at break of 21.1%. The swelling factor was 66.5%, the crystallinity index IKjj 0.228 and the hydrogen bond energy E „14.31 kJ / mol.

n The dye absorption capacity of the modified viscose fibers from the dye solution was as follows: direct dye Solophenylblau AGFF: 84.4% reaction dye Dimarenbrill.blau K-BL 60.0% and base dye Maxilonblau GRL: 80.0% is 78126

The color absorption capacities of the standard viscose fibers used simultaneously as reference fibers were as follows: direct color Solophenylblau AGFF: 78.1% reaction color Drimarenbrill.blau K-BL 51.2% 5 and base color Maxilonblau GRL: 80.5%

The absorbency of the dye solution of wool and nylon 66 fibers from the dyeing solution was determined for comparison and was as follows: direct dye Solophenylblau AGFF: 80.0% and 80.0% reaction dye Drimarenbrill.blau K-BL: 55.6% and 51.2% 10 and base dye Maxilonblau GRL: 82.0% and 70.0% The percentage of color absorption is calculated compared to the amount of color used in the staining solution.

Claims (10)

20,781 26 A process for preparing chitosan viscose fibers, which comprises using a chitosan-based additive in a viscose solution before spinning, characterized in that the additive is a chitosan derivative based on the reaction of a gelatinized microcrystalline chitosan dispersion in mercerized water with carbon disulphide. Process according to Claim 1, characterized in that the additive is added to the viscose solution in a concentration of at least 0.1% by weight based on the weight of α-cellulose, in particular in the range from 0.5 to 25% by weight. Process according to Claim 1 or 2, characterized in that the chitosan-based additive is prepared from a gel-like microcrystalline chitosan dispersion prepared in water, in particular with a water retention capacity of 500-2000% in gel form and 200-800% in powder form, 4 6 average molecular weight in the range 10-10 , a degree of deacetylation of at least 30%, preferably 40-80%, and a particle size preferably in the range of 0.01-100 μm. Process according to one of Claims 1 to 3, characterized in that the chitosan derivative based on microcrystalline chitosan is prepared by mercerizing the microcrystalline chitosan in an alkaline solution, in particular aqueous sodium hydroxide solution, after which the excess solution is optionally pressed off, in particular by filtration. or by centrifugation, and the mercerized microcrystalline chitosan, preferably containing 1-10% by weight of polymer and 5-20% by weight of sodium hydroxide, is reacted with carbon disulphide to give an alkali-soluble derivative. Process according to Claim 4, characterized in that the reaction with the carbon disulphide is carried out at a temperature of at least 10 ° C, preferably in the range from 15 to 40 ° C. li 781 26 Process according to Claim 5, characterized in that the reaction with the carbon disulphide is carried out for 1 to 120 minutes, preferably for 30 to 90 minutes. Process according to one of Claims 2 to 6, characterized in that the mercerization is carried out using a chitosan concentration of 0.01 to 10% by weight and a sodium hydroxide concentration in the range from 1 to 50% by weight, preferably in the range from 1 to 20% by weight. %. Process according to Claim 7, characterized in that the mercerization is carried out at a temperature of 10 to 50 ° C, preferably in the range from 15 to 40 ° C. Process according to Claim 8, characterized in that the mercerization is carried out using at least 30 seconds, preferably 5 to 60 minutes. 10. A chitosan derivative for use as an additive in viscous pre-spinning chitosan viscose fibers, characterized in that the chitosan derivative is obtained by mercerizing a gel-like microcrystalline crystalline dispersion in water and reacting the product with carbon disulphide 20, and that said derivative contains mainly: urea; - »O 25 where Chit-N represents the monomer unit of chitosan, where N represents the nitrogen atom in the amino group of chitosan in the raw material. 22 7 81 2 6 Patent scrap;