CN100545325C - Cellulose form having functional effect and method for producing same - Google Patents

Abstract

The invention relates to a method for producing cellulose moldings having a functional effect. The method is characterized in that the incorporated ion exchangers with bactericidal metal ions and/or ionic pharmaceutical active substances are fed into the cellulosic fibers or films in such a way that precipitates of these active substances accumulate in the fibres. When the fibers and films are used in an aqueous solution, the precipitate releases the active substance periodically in an amount corresponding to the normality. The invention also relates to moldings produced according to the method according to the invention.

Description

Forms of cellulose with functional effects and methods for their manufacture

technical field

The present invention relates to cellulosic forms with improved and enhanced functional effects, especially for use in medicine, hygiene, clothing, paper and packaging, and a method for producing a cellulose form by a dry-wet process in industry.

The functional effect is directed towards a stable and finely adjustable bactericidal effect, especially for wound contact materials, sports and leisure wear, hospital textiles, filters and wrapping paper.

Background technique

It is well known that heavy metal ions such as silver, mercury/mercury, copper, zinc and zirconium ions kill or inhibit the growth of bacteria, viruses, fungi or spores (Thurman et al., CRC Crit. Rev. In Environ. Contr. 18(4 ), pp. 295-315 (1989)). Silver ions are of particular interest with regard to biocidal effects. An important advantage of silver ions over other biocidal metal ions such as Hg ²⁺ is the insensitivity of human metabolism to silver. The fungicide action concentration of silver is expressed as 0.01-1 mg/l (Ullman's Encyclopedia of Industrial Chemistry (fifth edition), VCH1993, Vol. A 24, p. 160).

Berlin，第124ff页)。This effect of silver ions is used in different applications. In the manufacture of textile fibers, for example, silver is electrodeposited on the surface of polyamide filaments. The handling of the silver plated polyamide filaments on the weaving and molding machines was problematic because the silver layer of the polyamide filaments partially deposited on the yarn guides, causing the devices to stop several times. It is further known to incorporate metallic silver, silver-zeolites or silver-glass ceramics into the fiber matrix of melt-spun fibers such as polypropylene fibers, polyester fibers and polyamide fibers (Taschenbuch für die Textilindustrie 2003, Schiele and

Berlin, p. 124ff).

The use of silver-zeolites or silver-glass ceramics has also been proposed for acrylic fibers. Cellulose fibers with bacteriostatic and bactericidal properties are commercially available. Incorporation of triclosan (2,4,4-trichloro(II)-hydroxyphenylene ether) into cellulose fibers resulted in permanently bacteriostatic fibers (ITB International Textile Bulletin 3/2002). The substance is effective against bacteria normally present on the skin, including pathogenic Staphylococcus aureus types.

DE 10 140 772 discloses a method for producing a form of cellulose with incorporated algae. Said form is capable of adsorbing metals from media containing heavy metals. Forms loaded with heavy metals can be used as antibacterial and/or fungicidal materials. The amount of heavy metal adsorbed in the cellulose form is given as at least about 70 mg/kg relative to the total weight of the cellulose form.

It further revealed that a silver content of 1855 mg/kg per fiber was obtained by dipping fibers having a brown algae content of 11.39% by weight based on fiber weight in a 0.05M AgNO ₃ solution. Since algae are natural products, the ability to bind the heavy metals varies. During the binding of heavy metals to algae, different binding mechanisms are involved, such as ion exchange, complexation and other unknown reactions. Therefore, the binding of the heavy metals to the algae is non-specific. Another advantage of the fibers is that only cations are available for the bactericidal effect and no bactericidal anions such as benzoic acid and sorbic acid are present.

WO 00/63470 relates to a method for producing cellulose forms with high adsorption capacity, wherein ordinary ion exchange particles having a particle size >= 25 μm are added to said forms produced by the Lyocell method. Furthermore, the adsorption of heavy metals (ie, copper and lead) using an anion exchanger of styrene-divinylbenzene copolymer, having a capacity of 0.01 mmol/g, is disclosed.

The patent abstract of JP 3054234, Japanese 0152 Edition No. 01 (C-0834), discloses the manufacture of cellulose compositions comprising ion-exchanger functionality, suitable for use as binders for metal ions, wherein the manufacturing process consists of specific The resulting cellulose is mixed with an anionic polymer, followed by solidification of the mixture.

Contents of the invention

It is an object of the present invention to provide a cellulose form having a functional effect and a process for the preparation of said cellulose form, especially for use in medicine, hygiene and clothing, wherein said form has a bactericide Effects and among other things said advantages favor breathable clothing. Another object is to keep the active agent in the textile deposit and further obtain a sufficient release of the active agent from the deposit over a period of time. The release concentration of the active agent should be controllable. Furthermore, the forms obtainable by the process according to the invention, especially fibers or foils, should be such that they are suitable for the production of wound coverings, band-aids, hygiene products, textiles, special papers due to the high adsorption capacity of the active agent and packaging materials to form. Finally, it should be possible to manufacture composites comprising different fibers.

Other advantages appear in the following description.

Combining the methods according to the invention discussed above, the object is achieved by feeding a cellulose form spun according to the dry-wet extrusion method and having incorporated weakly linked cationic active ions with active agents exchange agent. Surprisingly, we found that the binding capacity of the active agent depends on the degree of crosslinking of the ion exchanger. Thus, if polyacrylates that are weakly crosslinked by multifunctional crosslinkers are used, the binding capacity of cationic active agents, such as silver, can be increased by more than double the amount.

A weakly crosslinked ion exchanger according to the invention is an ion exchanger with a reduced amount of crosslinking. Common ion exchanger resins exhibit crosslinking amounts of 4 to 12% by weight, based on the weight of the ion exchanger resin. The weakly crosslinked ion exchangers according to the invention have a crosslinking amount in the range of 0.1 to 2.0% by weight, preferably 0.3 to 1.5% by weight, particularly preferably 0.5 to 1.2% by weight.

Weakly crosslinked ion exchanger resins are characterized by a remarkable ability to swell significantly in aqueous solutions. Ordinary ion exchange resins with the aforementioned amounts of crosslinker show only a small degree of swelling.

Fibers made with incorporated weakly crosslinked cation exchangers show a capacity to bind silver ions which exceeds that of fibers with brown algae according to DE 10 140 772 by up to 28 times. Thus, an opportunity is given to make fibers or foils that can be loaded in large quantities with cationically active biocides such as silver ions. A fiber with 15% by weight of incorporated weakly cross-linked cation ion exchanger can be loaded with about 80 g of silver. Silver loadings of fibers of greater than 100 gAg/kg of fibers are possible if the amount of weakly crosslinked cation exchanger that has been incorporated is correspondingly increased.

The concentration of the biocidal metal ion and/or anionic active agent may be in the range of 0.005 g to 100 g per kg of cellulose form.

Fibers that have been loaded with biocidal metal ions and/or anionic active agents can be blended with textile fibers and processed into a material whose area has been measured.

The fibers can be blended with other fibers, such as those of cotton, wool or synthetic fibers, to produce yarns with the desired silver content. This procedure allows germicidal yarns to be manufactured in a very economical way.

The textile fibers are selected from the group comprising cotton, wool, polyester fibers, polyamide fibers, polyacryl-fibers, polypropylene fibers and cellulosic synthetic fibers. Cellulosic synthetic fibers especially refer to freshly prepared fibers from dissolved cellulose after manual treatment, for example by extrusion processes.

An area-measured material at least partially comprises a form of cellulose. Paper can be made from this area-measured material. Sausage wraps can be made from this area-measured material. Nonwovens can be made from this area-measured material. However, incorporation of ion exchangers leads to adverse effects on textile physical parameters such as strength, elongation and interlocking strength with increasing amounts within the fibers. In detail, strength and interlocking strength decrease with increasing amount of ion exchanger incorporated.

Accordingly, it would also be of economic interest to provide silver-loaded fibers that exhibit textile physical properties, such as strength and interlocking strength, close to those of fibers without incorporated ion exchangers.

Fibers having a sufficient silver content per fiber to exhibit a sufficient biocidal effect without disadvantages in view of the physical parameters of the textile are obtainable by the present invention. According to the invention, 5000 to 10,000 mg Ag/kg of fiber may be bound with 0.5 to 1.5% by weight of the incorporated weakly crosslinked cation exchanger, based on the weight of the cellulose of the fiber. The fibers have a sufficient biocidal effect in the known fields of use and are equal to unmodified fibers with regard to their textile physical parameters. The fibers and yarns made therefrom can be processed on a wide variety of textile machines.

If instead of the weakly crosslinked cation exchangers as described in DE 19 917 614 on the basis of carboxyl groups bound to acrylic-divinylbenzene-copolymers or on the basis of chelate-forming subunits bound to styrene-divinylbenzene-copolymers Amino-diacetic acid is used as an ion exchanger, then fibers comparable in their bactericidal effect are obtained. However, the capacity of silver ions is less than 50% of that of the aforementioned weakly cross-linked cation exchangers.

One measure of the bactericidal effect on the fibers or yarns is the equilibrium concentration of the active agent in the aqueous solution, eg the concentration of silver ions.

For this purpose, the fibers or yarns loaded with silver ions are placed in distilled water at a temperature of 20° C., followed by measuring the equilibrium concentration of silver ions after 24 hours. Table 1 shows the equilibrium concentration of silver ions and the silver loading in the fibers using weakly cross-linked cation exchangers or ion exchangers known to cross-link with divinyl-benzene. As indicated, the equilibrium concentration of silver ions is at a level above the concentration of 0.01 to 1 mg/l required to obtain a biocide effect. The equilibrium concentration can be controlled to each desired concentration level by mixing with other types of fibers.

Table 1

The content of ion exchanger is 7% by weight Ag content of fiber [g/kg] Equilibrium concentration [mg/l Ag⁺] Ion exchangers with -COOH- groups 13.5 2.9  Ion exchangers with chelating groups 17.5 3.6 Weakly linked cation exchangers (invention) 36.5 2.7

As shown in Figure 1, the fibers according to the present invention provide the equilibrium concentration required to obtain the antimicrobial effect at the same time at the increased Ag content of the fibers. The advantages are obvious.

During use of the fibers, free Ag ions are permanently released, whereby an equilibrium concentration is maintained by Ag deposited in the fibers. Due to the improved storage properties of the fibers of the present invention, said equilibrium concentration can be maintained for an extended period of time.

Fibers can be loaded with cations if weakly crosslinked cation exchangers based on styrene-divinylbenzene-copolymers with trialkylammonium groups in chloride form and strongly basic anion exchangers are incorporated into the fibers Active and anionic active fungicide ions such as silver ions and benzoic or sorbic acid.

Sterilisation，Desinfektion，Konservierung，第4版，时间1988年，第396页)。加工造纸中的所述纤维或由其制成的箔为食品提供抗菌包装。Thus, silver ions can be used with anionic active agents such as benzoic acid and sorbic acid. As shown in several publications, the substance is toxicologically unobjectionable and therefore it qualifies for direct use in food (

Sterilisation, Desinfektion, Konservierung, 4th edition, dated 1988, p. 396). Processing said fibers in papermaking or foils made from them provides antimicrobial packaging for food products.

Furthermore, the functionalized fibers with cationic active agents can be used within medical applications. The fibers may bind agents such as nicotine. The fibers can be made into bonds and used in transdermal therapeutic systems.

The advantageous loading of the functional fibers can be performed by dipping the fibers in a solution of suitable ions. The impregnation can be carried out in continuous or batch mode. When impregnating in continuous mode, it is preferred to load the short fibers in a separate tank during subsequent processing.

Detailed ways

The invention and its characteristics will be more clearly illustrated by the following examples:

Example 1

A pulverulent weakly crosslinked cation exchanger based on a crosslinked copolymer of acrylic acid and sodium acrylate, having a particle size of less than 10 μm, was added to N-methylmorpholine-N monohydrate in a proportion of 15% by weight based on the proportion of cellulose - 12% by weight cellulose solution in oxide. The spinning solution was homogenized in a kneader and spun at a temperature of about 90° C. with a spinning nozzle having 480 holes and a spinning hole diameter of 80 μm. The withdrawal speed was about 30 m/min. The multifilament fibers are directed through several wash tanks to wash off residual N-methylmorpholine-N-oxide. The fibers were slipped and loaded in 10 L of 0.1 M silver nitrate solution per kg of fiber. After loading, the fibers were slid and washed to remove residual silver nitrate. Finally, the fibers are dried at a temperature of about 80°C.

Table 2

Yarn count dtex 0.7 Tensile tear resistance related to yarn count (dry) cN/tex 22.5 Elongation (dry) % 14.8 Yarn count-dependent tear resistance of interwoven loops cN/tex 7.5 silver content g/kg fiber 80

Table 2 shows the parameters of the fibers and the silver content per fiber. Fibers that are already highly loaded offer the advantage that silver loaded yarns can be obtained economically by blending this fiber with other textile fibers such as cotton. For a content of about 5000mg Ag/kg yarn, silver fibers constitute only one sixteenth of the yarn.

In contrast to polyamide fibers that have been plated, the yarns thus produced show good processability on weaving or molding machines.

Example 2

Fibers were produced according to Example 1 with a titer of 0.17 tex and a content of weakly crosslinked cation exchanger of 6% by weight, based on the cellulose content. These fibers were loaded with silver according to Example 1. Fiber parameters are given in Table 3.

Example 3

Fibers were produced according to Example 1 with a titer of 0.5 tex and a content of weakly crosslinked cation exchanger of 0.5% by weight, based on the cellulose content. Silver ion loading was performed according to Example 1. The parameters of the fibers are shown in Table 3. Furthermore, in Table 3, fibers without weakly crosslinked cation exchangers are shown for comparison.

table 3

Example 2 Example 3 Fibers without weakly cross-linked cation exchangers Yarn count dtex 0.17 0.5 0.5 Tensile tear resistance related to yarn count (dry) cN/tex 35.8 37.6 38.1 Elongation (dry) % 13.0 11.4 11.8 Tear resistance cN/tex of interwoven loops related to yarn count 8.2 9.1 9.5 silver content g/kg fiber 36.6 4.6 -

From Examples 1 to 3 it is evident that the silver content on the fibers can be adjusted over a wide range via the content of weakly crosslinked cation exchangers. Even high silver contents of 0.5% by weight are achievable. The effect of 0.5% by weight of weakly crosslinked cation exchanger on the textile parameters of the fibers is insignificant.

Example 4 (comparative example)

Aqueous suspensions of weakly acidic macroporous cation exchangers based on styrene-divinylbenzene-copolymers with chelating groups of iminodiacetic acid were prepared such that the spun fibers reached a concentration of 6% by weight, based on the cellulose content. Concentration of content added to cellulose slurry in 60% aqueous N-methylmorpholine-N-oxide. After spinning, the fibers were washed and loaded with silver ions according to Example 1. Table 4 shows the parameters of the fibers.

Table 4

Example 4 Example 5 Yarn count dtex 0.5 0.5 Tensile tear resistance related to yarn count (dry) cN/tex 31.2 30.9 Elongation (dry) % 14.2 13.5 Yarn count-dependent tear resistance of interwoven loops cN/tex 9.1 8.5 silver content g/kg fiber 17.5 13.6

Example 5 (comparative example)

Operating correspondingly to Example 4 and adding 6% by weight of a weakly acidic macroporous cation exchanger based on cross-linked polyacrylate in sodium form to the slurry, so that the spun fibers contained 6% by weight, based on the cellulose content, of Ion exchanger, the fibers were washed and loaded with silver ions according to Example 1, the operator obtained fibers with 13.6 g Ag/kg per fiber. Example 5 surprisingly shows that polyacrylate-based ion exchangers bind approximately half the amount of silver ions compared to polyacrylate-based weakly crosslinked cation exchangers. An increase in the binding capacity of more than 100% leads to technical and economical advantages, because on the one hand, small amounts of weakly crosslinked cation exchangers in the fibers hardly affect the physical parameters of the textile, and on the other hand, the high incorporation of silver ions based , economical production is possible by blending with other fibers.

Example 6

Fibers made according to Examples 1 to 5 with weakly crosslinked cation exchangers as well as conventional ion exchangers of the prior art were loaded with silver, copper(II) and zinc ions. The results are shown in Table 5.

table 5

Fibers loaded with copper ions, silver ions, or a combination of silver and zinc ions can be used as biocide fibers.

Example 7

A weakly crosslinked cation exchanger based on a crosslinked copolymer of acrylic acid and sodium acrylate and a strongly basic anion exchanger based on a styrene-divinylbenzene copolymer with trialkylammonium groups in the chloride form were placed on N - Suspension in methylmorpholine-N-oxide in such a way that the spinning solution contains 11% by weight of cellulose, 8% by weight of weakly crosslinked cation exchanger and 8% by weight of all The stated amount of anion exchanger was added to an 11% by weight solution of cellulose in N-methylmorpholine-N-oxide monohydrate. After homogenization, the spinning solution was spun according to Example 1 to have a titer of 0.5 tex. The fiber exhibited a tenacity of 26.3 cN/tex, an elongation of 12.1% and a tear resistance of 8.6 cN/tex for the loops associated with the yarn.

The silver loading was 52.4 g silver/kg fiber and the benzoate loading was 16.6 g benzoate/kg fiber. These fibers have a very strong fungicide effect. The examples show the suitability of the fibers according to the invention in combination with fibers loaded with anion exchangers and cation exchangers known from the prior art.

Example 8

An ion exchange fiber or foil according to the invention with an incorporated cation exchanger made corresponding to Example 2 was loaded with nicotine. The loaded fibers or foils are washed and dried. These fibers or foils can be processed into textile deposits and can be applied as transdermal therapeutic systems.

Example 9

The biocidal properties of fibers made according to Example 1 were determined according to European Pharmacopaeia (EP 2002) 'Bioburden determination'.

Papers were tested that contained fibers according to Example 1 in amounts that resulted in progressively changing silver contents in papers of 190 mg Ag/kg paper, 760 mg Ag/kg paper and 3800 mg Ag/kg paper. The tests were carried out with the following microorganisms (Tables 6-9):

Pseudomonas aeruginosa ATCC 9027

Staphylococcus aureus ATCC 6538

Bacillus subtilis spore ATCC 6633

Fusarium solani spore ATCC 36031

Table 6 - Pseudomonas aeruginosa

Table 7 Staphylococcus aureus

Table 8 Spores of Fusarium solani

Table 9 Bacillus subtilis spores

All results for microbial counts are subject to a 10% measurement error.

The control sample was paper without silver containing fibers. For all microorganisms, a dependence of the biocide effect on the duration of treatment and the concentration of silver loading could be found. Bacillus subtilis spores showed the highest resistance as expected. However, such microorganisms can also achieve a reduction in the microbial population.

Example 10

The fibers made according to Example 1 were combined with cotton to be spun into knitting yarns with a denier of Nm 68/1 and a silver content of 1300 mg Ag/kg of yarn. A hose was knitted from this yarn and its antiseptic effect was tested (sample 31444083). The assay was performed according to SN195924. The test microorganism was Lactobacillus brevis DSM 20054. Cotton fabrics equipped with antimicrobial properties were not used as test samples (Table 10). Five measurements were carried out on each sample as well as the test sample.

Table 10-test results of antibacterial effect in bacteria when experimenting with Lactobacillus brevis as test bacteria

KBE = number of colonies - building blocks of test bacteria

AE = antibacterial effect

Evaluation Criteria:

The 24-hour value of the growth control (control, ie the standard fabric) must be at least two orders of magnitude greater than the initial value (AE<-2).

An antimicrobial effect is imparted if the KBE value is at most 0.5 decilog above the mean value of the KBE at zero contact time, ie AE _5,24 >-0.5.

The effectiveness of the antimicrobial device is given if a single KBE value for each contact time shows an antimicrobial property for 4 out of 5 tested bacteria. These requirements are met by the results of sample number 3144408 (knitted socks).

Claims (23)

1. A process for the production of functionally effective cellulose forms according to the wet-dry extrusion process, characterized in that it comprises at least one incorporated exchange A dose of cellulose fibers or foils of cross-linked cation-active ion exchangers loaded with bactericide metal ions and/or one of benzoic acid and sorbic acid, the bactericide metal ions and and/or one of benzoic acid and sorbic acid in such a way that a precipitate of the bactericide metal ion and/or one of benzoic and sorbic acid is produced within the fibers and upon application of these fibers or foils to an aqueous solution The latter precipitate is loaded in such a way that the bactericide metal ion and/or one of benzoic acid and sorbic acid is released in an equilibrium concentration amount. 2. The method according to claim 1, characterized in that: the cross-linked cationic active ion exchanger is a cross-linked polyacrylate. 3. The method according to claim 1, characterized in that: silver ions are used as bactericide metal ions. 4. The method according to claim 2, characterized in that: silver ions are used as bactericide metal ions. 5. The method according to claim 3, characterized in that copper ions, mercury ions, zirconia ions or zinc ions are used as additional bactericide metal ions. 6. The method according to claim 4, characterized in that copper ions, mercury ions, zirconia ions or zinc ions are used as additional bactericide metal ions. 7. according to the arbitrary described method of claim 1-6, it is characterized in that: the concentration of a kind of in described bactericide metal ion and/or benzoic acid and sorbic acid is at the 0.005g of every kg described cellulose form to the range of 100g. 8. according to the method described in any one of claim 1-6, it is characterized in that: the described fiber that has been loaded with a kind of in bactericide metal ion and/or benzoic acid and sorbic acid is blended with textile fiber and processed into The material whose area has been measured. 9. The method according to claim 7, characterized in that said fibers loaded with bactericide metal ions and/or one of benzoic acid and sorbic acid are blended with textile fibers and processed into area-measured Material. 10. The method according to claim 8, characterized in that said textile fibers are selected from the group comprising cotton, wool, polyester fibers, polyamide fibers, polyacrylic fibers, polypropylene fibers and cellulose synthetic fibers. 11. The method according to claim 9, characterized in that said textile fibers are selected from the group comprising cotton, wool, polyester fibers, polyamide fibers, polyacrylic fibers, polypropylene fibers and cellulose synthetic fibers. 12. The method according to any one of claims 1-6, characterized in that the cellulose form further comprises an anionically active ion exchanger. 13. The method of claim 7, wherein the cellulose form further comprises an anionically active ion exchanger. 14. The method of claim 8, wherein the cellulose form further comprises an anionically active ion exchanger. 15. The method of claim 9, wherein the cellulose form further comprises an anionically active ion exchanger. 16. The method of claim 10, wherein the cellulose form further comprises an anionically active ion exchanger. 17. The method of claim 11, wherein the cellulose form further comprises an anionically active ion exchanger. 18. A cellulose form having a functional effect, characterized in that the form contains a crosslinked cation-active ion exchanger having a crosslinking amount of 0.1 to 2.0% by weight, based on the weight of the ion exchanger, wherein the The ion exchanger is loaded with the bactericide metal ion and/or one of benzoic acid and sorbic acid and said form always releases said metal ion and/or benzoic acid and sorbic acid in aqueous solution at a concentration corresponding to the equilibrium concentration One of. 19. The cellulose form of claim 18, wherein the metal ions are at least in part silver ions. 20. An area-measured material, characterized in that it at least partially comprises a cellulose form according to any one of claims 18-19. 21. A paper made from the area measured material of claim 20. 22. A sausage wrap made from the area-measured material of claim 20. 23. A nonwoven article made from the area measured material of claim 20.