U.S. patent application number 10/552086 was filed with the patent office on 2006-12-21 for cellulosed molded article having a functional effect and method for producing the same.
Invention is credited to Ralf Bauer, Reiner Buettner, Carmen Knobelsdorf, Hardy Markwitz, Frank Meister.
Application Number | 20060283567 10/552086 |
Document ID | / |
Family ID | 32981104 |
Filed Date | 2006-12-21 |
United States Patent
Application |
20060283567 |
Kind Code |
A1 |
Buettner; Reiner ; et
al. |
December 21, 2006 |
Cellulosed molded article having a functional effect and method for
producing the same
Abstract
The invention relates to a method for producing cellulosed
molded articles having a functional effect. The method is
characterized by charging cellulosed fibers or films with
incorporated ion exchangers having bactericidal metal ions and/or
ionic pharmaceutical active substances in such a manner that a
depot of these active substances is built up in the fiber. Said
depot time releases the active substances in the amount of the
corresponding equivalent concentration when the fibers and films
are used in aqueous solutions. The invention also relates to molded
articles produced according to the inventive method.
Inventors: |
Buettner; Reiner;
(Rudolstadt, DE) ; Markwitz; Hardy; (Rudolstadt,
DE) ; Knobelsdorf; Carmen; (Saalfeld, DE) ;
Bauer; Ralf; (Rudolstadt, DE) ; Meister; Frank;
(Rudolstadt, DE) |
Correspondence
Address: |
INTELLECTUAL PROPERTY / TECHNOLOGY LAW
PO BOX 14329
RESEARCH TRIANGLE PARK
NC
27709
US
|
Family ID: |
32981104 |
Appl. No.: |
10/552086 |
Filed: |
April 1, 2004 |
PCT Filed: |
April 1, 2004 |
PCT NO: |
PCT/EP04/03466 |
371 Date: |
December 23, 2005 |
Current U.S.
Class: |
162/157.6 ;
162/161; 162/182; 264/103; 264/187; 264/203; 264/211; 428/359;
428/360 |
Current CPC
Class: |
D06M 13/188 20130101;
D06M 11/42 20130101; D21H 11/20 20130101; Y10T 428/2905 20150115;
Y10T 428/2904 20150115; D06M 11/44 20130101; D01F 1/103 20130101;
D01F 2/00 20130101; D06M 15/263 20130101; D21H 21/36 20130101; D06M
11/46 20130101 |
Class at
Publication: |
162/157.6 ;
264/187; 264/203; 264/103; 264/211; 428/359; 428/360; 162/182;
162/161 |
International
Class: |
D01F 2/02 20060101
D01F002/02; D02G 1/20 20060101 D02G001/20; D21F 11/00 20060101
D21F011/00; D21H 11/00 20060101 D21H011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 4, 2003 |
DE |
103 15 749.2 |
Claims
1. A method for producing a cellulosic form that releases active
agents in an amount that reaches equilibrium in an aqueous
solution, the method comprising: incorporating within a cellulosic
solution a weakly linked cation-active ion exchanger loaded with
bactericide metal ions and/or with ionic, pharmaceutic agents in
such a manner, that a depot of said agents is created within the
fiber and that said depot releases the agents in an amount of the
equilibration concentration upon application of these fibers or
foils in aqueous solutions.
2. The method according to claim 1, wherein the weakly linked,
cation-active ion exchanger is a poly-acrylate.
3. The method according to claim 1, wherein the metal ions comprise
silver ions.
4. The method according to claim 3, further comprising additional
bactericidally active metal ions, including copper-, mercury-,
zirconia- or zinc ions.
5. The method according to claim 1, wherein the ionic pharmaceutic
agents are anion-active agents, including benzoic acid or sorbic
acid.
6. The method according to claim 1, wherein the concentration of
the active agents is in the range of 0.005 g to 100 g per kg of the
cellulosic form.
7. The method according to claim 1, wherein the cellulosic form is
a fibre, which has been loaded with active agents, blended with
textile fibers and processed into area-measured material.
8. The method according to claim 7, wherein the textile fibers are
selected from the group comprising cotton, wool, polyester-fibers,
polyamide-fibers, polyacryl-fibers, polypropylene-fibers or
cellulosic synthetic fiber.
9. The method according to claim 2, wherein the cellulosic form
further comprises cation-active and/or anion-active
ion-exchangers.
10. A cellulosic form, characterised in that said form contains
weakly linked cation-active ion exchangers, wherein the ion
exchanger is loaded with bactericidal metal ions and/or ionic
pharmaceutic agents and that said form releases in aqueous
solutions the metal ions and/or agents at a concentration
corresponding to the current equilibration concentration.
11. The cellulosic form according to claim 10, characterised in
that the metal ions are at least in part silver ions.
12. The cellulosic form according to claim 11, wherein the form is
a fiber and is intermixed with a compatible material to form a
mixture.
13. The cellulosic form according to claim 12, wherein the mixture
is used to form a paper, a sausage casing or a non-woven
fabric.
14. A lyocell-type cellulosic form containing an active agent that
is released from the material relative to the concentration of the
active agent in an aqueous solution contacting the material, the
material comprising: a mixture of a cellulosic material, active
agent and a polymeric resin with cross-linkers in an amount from
about 0.1 to 2.0 weight % of the resin and wherein the amount of
active agent in the material is proportional to the amount of
polymeric resin in the mixture.
15. The lyocell-type cellulosic form according to claim 14, wherein
the polymeric resin is polyacrylate and the active agent is silver
ions.
16. The lyocell-type cellulosic form according to claim 15, wherein
the form is a fiber for producing a woven or non-woven fabric.
17. A method of producing a lyocell-type cellulosic form containing
an active agent that is released from the material relative to the
concentration in an aqueous solution contacting the material, the
method comprising: providing a cellulosic material comprising
cellulose homogenized in N-methylmorpholine-N-oxide monohydrate;
mixing in a polyacrylate polymer in a form that is intermixed with
the cellulosic material; forming cellulosic/polymer fibres;
removing residual N-methylmorpholine-N-oxide monohydrate from the
cellulosic/polymer fibres; contacting the cellulosic/polymer fibers
to a solution of silver nitrate for a sufficient time to load the
cellulosic/polymer fibers with silver ions in an amount
proportional to the amount of polyacrylate polymer introduced into
the cellulosic material.
Description
[0001] The invention relates to cellulosic forms as well as a
method for producing cellulosic forms by the dry-wet extrusion
process with improved and enhanced functional effects, especially
applicable in medicine, hygiene, garment, paper manufacturing and
packaging industry.
[0002] The functional effect is directed to a steady and
meticulously adjustable bactericide effect, especially for wound
contact material, sports and leisure clothing, hospital textiles,
filter and packaging papers.
PRIOR ART
[0003] It is well known that heavy metal ions like e.g. silver,
quicksilver/mercury, copper, zinc and zirconium ions are deadening
or growth inhibiting to bacteria, viruses, fungi or spores (Thurman
et al., CRC Crit. Rev. In Environ. Contr. 18 (4), P. 295-315
(1989)). With respect to the bactericide effect silver ions are of
particular interest. The important advantage of silver ions against
other bactericide metal ions, like e.g. Hg.sup.2+, is the
insensibility of the human metabolism against silver. The
bactericide acting concentration is denoted for silver as 0.01-1
mg/l (Ullman's Encyclopedia of Industrial Chemistry (5. Edition),
VCH 1993, Volume A 24, P. 160).
[0004] This effect of silver ions is used in different
applications. In the manufacture of textile fibres silver is for
example galvanically deposited on the surface of polyamide silk.
Working up of said galvanically silver-plated polyamide silk on
knitters and moulders is problematical, since the silver layer of
the polyamide silk is partially deposited on the yarn leading
devices leading to numerous shut downs of said devices. It is
further known to introduce metallic silver, silver-zeolite or
silver-glass ceramics into the matrix of the fibre of melt spun
fibres like polypropylene fibres, polyester fibres and polyamide
fibres (Taschenbuch fur die Textilindustrie 2003, Schiele &
Schon Berlin, P. 124 ff).
[0005] The use of silver-zeolite and silver-glass ceramics was also
proposed for acrylic fibres. Also cellulosic fibres with
bacteriostatic and bactericidal properties are available on the
market. Incorporation of triclosan
(2,4,4-trichloro(II)-hydroxyphenyleneether) into cellulosic fibres
leads to a permanently bacteriostatic fibre (ITB International
Textile Bulletin 3/2002). Said substance is active against bacteria
usually occurring on skin, including pathogenic
staphylococcus-types.
[0006] DE 10 140 772 discloses a method for producing cellulosic
forms with incorporated algae. Said forms are able to adsorb metals
from heavy metal containing media. The heavy metal loaded forms may
be used as antibacterial and/or fungicidal material. The content of
adsorbed heavy metals in said cellulosic forms is given as at least
about 70 mg/kg, related to the total weight of the cellulosic
forms.
[0007] It is further disclosed that by dipping a fibre with a
content of brown algae of 11.39 weight-%, based on the weight of
the fibre, into a 0.05 M AgNO.sub.3-solution a silver content of
1855 mg/kg per fibre was obtained. Since algae are natural products
the capacity for binding said heavy metals varies. During binding
of heavy metals onto algae different binding mechanisms are
relevant, like ion exchange, complexing and further unknown
reactions. The binding of said heavy metals onto said algae is
therefore non-specific. A further disadvantage of said fibre is
that only cations may be used for a bactericidal effect, but no
bactericidal anions, e.g. benzoic acid and sorbic acid.
[0008] WO 00/63470 relates to a method for the production of
cellulosic forms with a high adsorption ability, wherein usual ion
exchange particles with grain size of >=25 .mu.m are added to
said forms prepared by the Lyocell method. Furthermore, the
adsorption of heavy metal ions is disclosed, namely of copper and
lead, with a capacity of 0.01 mmol/g, using an anion exchanger of a
styrene-divinyl benzene copolymer.
[0009] Patent Abstracts of Japan, Edition 0152, No. 01 (C-0834) of
JP 3 054234 discloses the production of a cellulosic composition
comprising an ion exchanger functionality, useful as binder for
metal ions, wherein said production process consists of mixing a
specifically generated cellulose and an anionic polymer followed by
solidification of said mixture.
AIM OF THE INVENTION
[0010] Aim of the present invention is to provide a cellulosic form
with functional effect as well as a method for preparing said
cellulosic form, especially for the use in medicine, hygiene and
garment, wherein said forms have a bactericide effect and wherein
especially said advantages go along with breathable clothing. A
further aim is to keep said active agents in a textile depot and
further to obtain sufficient release of said agents from said depot
over a period of time. The released concentrations of said agent
should be controllable. Further the forms, especially fibres or
foils, obtainable by the method of the invention, should be formed
thus, that they are useful for preparing wound overlays, band-aids,
sanitary products, textiles, special papers and packaging material,
because of the high adsorption ability of active agents. Finally
composites including differing fibres should be producible.
[0011] Further advantages are shown in the following
description.
[0012] The aim is reached in combination with the aforementioned
discussed method according to the present invention by charging the
cellulosic forms, wherein said forms are spun according to the
dry-wet extrusion method and having incorporated weakly linked
cationic active ion exchangers with active agents. Surprisingly it
was found that the binding capacity for said active agents depends
on the degree of cross-linking of the ion exchanger. Thus, the
binding capacity for the cationic active agents, like e.g. silver
could be increased by more than the double amount, if polyacrylates
are used, which were weakly cross-linked by a multifunctional
cross-linker.
[0013] Weakly cross-linked ion exchangers according to the present
invention are ion exchangers with a decreased amount of
cross-linkers. Usual ion exchanger resins show an amount of
cross-linkers of 4 to 12 weight-%, based on the weight of the ion
exchanger resin. Weakly cross-linked ion exchangers according to
the present invention have an amount of cross-linkers ranging from
0.1 to 2.0 weight-%, preferably 0.3 to 1.5 weight-%, particularly
preferably 0.5 to 1.2 weight-%.
[0014] Weakly cross-linked ion exchanger resins are characterized
by the pronounced ability to swell considerably in aqueous
solutions. Usual ion exchange resins with the aforementioned amount
of cross-linkers show only a minor degree of swelling.
[0015] Fibres made with incorporated weakly cross-linked cation
exchangers show a capacity for binding silver ions which surpasses
the capacity of fibres with brown algae according to DE 10 140 772
up to the 28-fold. Thus, the opportunity is given to produce fibres
or foils which may be heavily loaded with cationic active
bactericide agents like silver ions. A fibre with 15 weight-%
incorporated weakly cross-linked cationic ion exchanger may be
loaded with about 80 g silver. Silver loads of fibres of >100 g
Ag/kg fibre are possible, if the amount of the incorporated weakly
cross-linked cation exchanger is increased accordingly.
[0016] Said fibres may be mixed with other fibres, e.g. cotton,
wool or synthetic fibres, to produce yarns with the desired silver
content. This procedure allows the production of bactericidic yarns
in a very economic way.
[0017] However, incorporation of ion exchangers leads with an
increasing amount within the fibre to a disadvantageous influence
on the textile physical parameters like strength, elongation and
loop strength. In particular strength and loop strength will be
reduced with an increasing amount of incorporated ion
exchanger.
[0018] Thus, it is also of economic interest to provide silver
loaded fibres showing textile physical properties, like strength
and loop strength which come close to the properties of fibres
which do not contain incorporated ion exchangers.
[0019] With the present invention it is possible to obtain fibres
with a sufficient content of silver per fibre to show an adequate
bactericide effect, but no disadvantages in view of the textile
physical parameters. According to the present invention it is
possible with 0.5 to 1.5 weight-%, based on the cellulose weight of
the fibres, of incorporated weakly cross-linked cation exchanger to
bind 5000 to 10.000 mg Ag/kg fibre. Such fibres have a sufficient
bactericide effect in the known field of use and are equal to
non-modified fibres concerning their textile physical parameters.
Processing of such fibres and yarns made thereof is possible on all
kind of textile machinery.
[0020] If, instead of weakly cross-linked cation exchangers, ion
exchangers are used on the basis of acrylic
acid-divinylbenzene-copolymer-bound carboxyl groups or on the basis
of a styrene-divinylbenzene-copolymer bound chelat forming
imino-diacetic-acid as described in DE 19 917 614, fibres are
obtained, which are comparable in their bactericide effect.
However, the capacity for silver ions is less than 50% of the
aforementioned weakly cross-linked cation exchangers.
[0021] A measure for the bactericide effect of the fibres or yarns
is the equilibration concentration of the active agent in aqueous
solutions e.g. the concentration of the silver ions.
[0022] For this purpose fibres or yarns loaded with silver ions are
put into distilled water at a temperature of 20.degree. C.,
followed by a measurement of the equilibration concentration of the
silver ions after 24 h. Table 1 shows the equilibration
concentrations of silver ions and the load of silver in the fibres,
while using weakly cross-linked cation exchangers or known ion
exchangers cross-linked with divinyl-benzene. As shown the
equilibration concentration of silver ions is on a level which is
above the necessary concentration of 0.01 to 1 mg/l to obtain a
bactericide effect. The equilibration concentration may be
controlled to each desired concentration level by mixing with other
kinds of fibres. TABLE-US-00001 TABLE 1 content of ion exchanger
Ag-content of the fiber equilibration-concentration 7 weight %
[g/kg] [mg/l Ag.sup.+] ion exchanger with 13.5 2.9 --COOH-groups
ion exchanger with 17.5 3.6 chelating groups weakly linked cation
36.5 2.7 exchanger (inventive)
[0023] As shown in table 1, the fibres according to the present
invention provide the equilibration concentration which is
necessary to obtain an antimicrobial effect, at an increased
Ag-content of the fibre at the same time. The advantages thereof
are obvious.
[0024] During the use of the fibres free Ag-ions are permanently
released, whereby the equilibration concentration is uphold by the
Ag deposited in the fibre. Due to the improved storing properties
of the inventive fibres the equilibration concentration may be
uphold over an extended period of time.
[0025] If weakly cross-linked cation exchangers and strongly basic
anion exchangers, based on styrene-divinylbenzene-copolymer with
trialkylammonium-groups in chloride-form are incorporated into the
fibre, said fibres may be loaded with cation-active and
anion-active bactericide ions, like silver ions and benzoic acid or
asorbic acid.
[0026] Thus, it is possible to use silver ions together with anion
active agents like e.g. benzoic acid and asorbic acid. Said
substances are toxicologically unobjectable as shown in several
publications and therefore they are qualified for a direct use in
foods (Wallhau.beta.er, Sterilisation, Desinfektion, Konservierung,
4.sup.th edition, time 1988, P. 396). Processing of such fibres in
paper manufacturing or foils made thereof provide antimicrobial
packages for food.
[0027] Further, the use of said functionalised fibres with cation
active agents within medical applications is possible. Such fibres
may bind agents, like nicotine. Said fibres may be manufactured
into band-aids and used for transdermal, therapeutic systems.
[0028] Advantageously loading of said functional fibres may proceed
by dipping the fibres into a solution of appropriate ions. Said
dipping may be carried out continuously or in batch mode. When
dipping in continuous mode it is preferred to load the cut fibre in
a separate bath during subsequent treatment.
[0029] The invention and its properties will be illustrated more
clearly by the following examples:
EXAMPLE 1
[0030] Powdery weakly cross-linked cation exchanger, based on a
cross-linked copolymerisate of acrylic acid and sodium acrylate,
having a grain size<10 .mu.m, is added to 12 weight-% cellulose
solution in N-methylmorpholine-N-oxide monohydrate, in a weight
proportion of 15 weight-%, based on the cellulose proportion. This
spinning solution was homogenised in a kneader and spun with a
spinning nozzle with 480 holes and a spinning hole diameter of 80
.mu.m at a temperature of about 90.degree. C. The draw off speed
was about 30 m/min. The multifile fibre was led through several
washing baths to wash out the residual N-methylmorpholine-N-oxides.
The fibres were skidded and loaded in 10 L of 0.1 M silver nitrate
solution per kg fibre. After loading the fibres were skidded and
washed to remove residual silver nitrate. Finally the fibres are
dried at a temperature of about 80.degree. C. TABLE-US-00002 TABLE
2 yarn-count dtex 0.7 yarn-count related tensile tear resistance
(dry) cN/tex 22.5 elongation (dry) % 14.8 yarn-count-related tear
resistance of interwoven loops cN/tex 7.5 Silver content g/kg fiber
80
[0031] Table 2 shows the parameters of the fibres as well as the
silver content per fibre. A highly loaded fibre offers the
advantage, that by blending this fibre with other textile fibres,
e. g. cotton, silver loaded yarns can be economically obtained. For
a content of roughly 5000 mg Ag/kg yarn the silver-fiber
constitutes only a sixteenth of the yarn.
[0032] In contrast to the galvanised polyamide-fibres thus produced
yarns show a good processability on knitting machines or
moulders.
EXAMPLE 2
[0033] Fibres are produced according to example 1 with a titre of
0.17 tex and a content of weakly cross-linked cation exchanger of 6
weight-%, based on the content of cellulose. These fibres are
loaded with silver according to example 1. The fibre-parameters are
given in table 3.
EXAMPLE 3
[0034] Fibres are made according to Example 1 with a titre of 0.5
tex and a content of weakly cross-linked cation exchanger of 0.5
weight-%, based on the cellulosic content. The loading with silver
ions is carried out according to Example 1. The parameters of the
fibres are shown in table 3. Further, in table 3 a fibre without
weakly cross-linked cation exchanger is shown for comparison.
TABLE-US-00003 TABLE 3 fiber without weakly linked cation example 2
example 3 exchanger yarn-count dtex 0.17 0.5 0.5 yarn-count related
cN/tex 35.8 37.6 38.1 tensile tear resistance (dry) elongation
(dry) % 13.0 11.4 11.8 yarn-count-related tear cN/tex 8.2 9.1 9.5
resistance of loops silver content g/kg fiber 36.6 4.6 --
[0035] It is evident from examples 1 to 3, that the silver content
on a fibre is adjustable over a wide range via the content of
weakly cross-linked cation exchanger. Even with 0.5 weight-% a high
silver content is obtainable. The influence of 0.5 weight-% of the
weakly cross-linked cation exchanger on the textile parameters of
the fibre is marginal.
EXAMPLE 4 (COMPARATIVE EXAMPLE)
[0036] To a cellulose slurry in 60% aqueous
N-methylmorpholine-N-oxide an aqueous suspension of weakly acid
macro-porous cation exchanger, based on
styrene-divinylbenzene-copolymer with chelating groups of
iminodiacetic acid, is added in such a concentration, that the
spinned fibres reach a content of 6 weight-%, based on the
cellulosic content. After spinning said fibres are washed and
loaded with silver ions according to Example 1. Table 4 shows the
parameters of the fibres. TABLE-US-00004 TABLE 4 example 4 example
5 yarn-count dtex 0.5 0.5 yarn-count related tensile tear cN/tex
31.2 30.9 resistance (dry) elongation (dry) % 14.2 13.5
yarn-count-related tear cN/tex 9.1 8.5 resistance of loops silver
content g/kg fiber 17.5 13.6
EXAMPLE 5 (COMPARATIVE EXAMPLE)
[0037] Working corresponding to Example 4 and adding to the slurry
6 weight-% of a weakly acid macroporous cation exchanger, based on
cross-linked polyacrylate in its sodium-form, so that the spun
fibre contains 6 weight-% ion exchanger based on the cellulose
content, washing said fibre and loading it with silver ions
according to Example 1, one obtains fibres with 13.6 g Ag/kg per
fibre. Example 5 surprisingly shows that the ion exchanger on the
basis of polyacrylate binds about half the amount of silver ions
compared to the weakly cross-linked cation exchanger based on
polyacrylates. The rise of the binding capacity of more than 100%
leads to technical and economical advantages in that on one hand
small amounts of the weakly cross-linked cation exchanger in the
fibre barely influence the textile physical parameters, while on
the other hand, based on the high incorporation of silver ions, an
economical production by blending with other fibres is
possible.
EXAMPLE 6
[0038] Fibres with weakly cross-linked cation exchangers as well as
common ion exchangers of the prior art, made according to Examples
1 to 5 are loaded with silver, copper (II) and zinc ions. The
results are shown in Table 5. TABLE-US-00005 TABLE 5 metal content
g/kg fiber fiber incorporated with copper silver silver/zinc 20
weight-% ion exchanger according to 23.7 57.1 23.9/27.5 example 4
(comparative example) 20 weight-% ion exchanger according to 11.5
41.7 36.4/24.5 example 5 (comparative example) 15 weight-% weakly
linked cation 25.5 85.5 59.3/30.5 exchanger as in example 1 to
3
[0039] Fibres loaded with copper ions, silver ions or a combination
of silver ions and zinc ions may be used as bactericide fibres.
EXAMPLE 7
[0040] A suspension of weakly cross-linked cation exchanger based
on a cross-linked copolymerisate of acrylic acid and sodium
acrylate and a strong basic anion exchanger, based on a
styrene-divinylbenzene-copolymer with trialkylammonium-groups in
chloride form, in 85% N-methylmorpholine-N-oxide is added in such
an amount to a 11 weight-% cellulose solution in
N-methylmorpholine-N-oxide-monohydrate, such that the spinning
solution contains 11 weight-% cellulose, based on the cellulose
content, 8 weight-% of the weakly cross-linked cation exchanger and
8 weight-% of said anion exchanger. After homogenisation the
spinning solution is spun according to Example 1 with a titre of
0.5 tex. The fibres show a strength of 26.3 cN/tex, an elongation
of 12.1% and a yarn-count related tear-resistance of loops of 8.6
cN/tex.
[0041] The silver load is at 52.4 g silver/kg fibre and the load
with benzoate at 16.6 g benzoate/kg fibre. These fibres possess a
very strong bactericide effect. The example shows the
appliccability of fibres according to the invention in combination
with loaded fibres with anion exchangers and cation exchangers
known from the prior art.
EXAMPLE 8
[0042] Ion-exchanging fibres or foils according to the invention
with incorporated cation exchangers, produced corresponding to
example 2, are loaded with nicotine. The loaded fibres or foils are
washed and dried. These fibres or foils can be processed into
textile depots and can be applied as transdermal, therapeutic
system.
EXAMPLE 9
[0043] The bactericide properties of fibres, produced according to
example 1, were determined following the European Pharmacopaeia (EP
2002), `Bioburden determination`.
[0044] Papers were examined, which contain fibres according to
example 1 in such an amount, that gradually altered silver contents
in the paper of 190 mg Ag/kg paper, 760 mg Ag/kg paper and 3800 mg
Ag/kg paper resulted. The examination was carried out with the
following micro-organisms (Tables 6-9):
[0045] Pseudomonas aeruginosa ATCC 9027
[0046] Staphylococcus aureus ATCC 6538
[0047] Bacillus subtilis spores ATCC 6633
[0048] Fusarium solani spores ATCC 36031. TABLE-US-00006 TABLE 6
Pseudomonas aeruginosa microbial count after respective incubation
time silver content 0 minutes 1 day 3 days 7 days comparative 6.9
.times. 10.sub.4 7.8 .times. 10.sup.4 5.9 .times. 10.sup.5 4.5
.times. 10.sup.4 sample 190 mg Ag/kg 8.9 .times. 10.sup.4 4.5
.times. 10.sup.3 77 <10 760 mg Ag/kg 7.7 .times. 10.sup.4 1.3
.times. 10.sup.3 <10 <10 3800 mg Ag/kg 8.7 .times. 10.sup.4
3.3 .times. 10 <10 <10
[0049] TABLE-US-00007 TABLE 7 Staphylococcus aureus microbial count
after respective incubation time silver content 0 minutes 1 day 3
days 7 days comparative 1.1 .times. 10.sup.5 1.2 .times. 10.sup.5
1.4 .times. 10.sup.5 9.6 .times. 10.sup.4 sample 190 mg Ag/kg 1.3
.times. 10.sup.5 1.1 .times. 10.sup.5 4.6 .times. 10.sup.3 36 760
mg Ag/kg 1.4 .times. 10.sup.5 8.8 .times. 10.sup.4 4.8 .times.
10.sup.3 <10 3800 mg Ag/kg 1.2 .times. 10.sup.5 4.9 .times.
10.sup.4 1.1 .times. 10.sup.3 <10
[0050] TABLE-US-00008 TABLE 8 Fusarium solani spores microbial
count after respective incubation time silver content 0 minutes 1
day 3 days 7 days comparative 1.6 .times. 10.sup.5 1.7 .times.
10.sup.5 1.6 .times. 10.sup.5 1.7 .times. 10.sup.5 sample 190 mg
Ag/kg 1.6 .times. 10.sup.5 1.2 .times. 10.sup.5 1.0 .times.
10.sup.3 <10 760 mg Ag/kg 1.2 .times. 10.sup.5 7.8 .times.
10.sup.4 7.3 .times. 10.sup.3 <10 3800 mg Ag/kg 1.6 .times.
10.sup.5 8.8 .times. 10.sup.4 1.4 .times. 10.sup.3 <10
[0051] TABLE-US-00009 TABLE 9 Bacillus subtilis spores microbial
count after respective incubation time silver content 0 minutes 1
day 3 days 7 days comparative 1.3 .times. 10.sup.5 1.2 .times.
10.sup.5 1.2 .times. 10.sup.5 1.3 .times. 10.sup.5 sample 190 mg
Ag/kg 1.1 .times. 10.sup.5 9.5 .times. 10.sup.4 9.7 .times.
10.sup.4 1.6 .times. 10 .sup.4 760 mg Ag/kg 1.2 .times. 10.sup.5
1.1 .times. 10.sup.5 8.4 .times. 10.sup.4 1.7 .times. 10 .sup.4
3800 mg Ag/kg 1.3 .times. 10.sup.5 8.8 .times. 10.sup.4 7.7 .times.
10.sup.4 1.1 .times. 10 .sup.4
[0052] All results of the microbial count are afflicted with an
error of measurement of 10%.
[0053] The comparative sample was a paper without silver-containing
fibres. For all micro-organisms a dependency of the microbicidal
effect on duration of treatment and concentration of the
silver-load could be found. The bacillus subtilis spores showed the
highest resistance as expected. But also with these micro-organisms
a decrease in microbial count could be achieved.
EXAMPLE 10
[0054] Fibres produced according to example 1 were spun in
combination with cotton to stocking-yarn with a titre of Nm 68/1
and a silver content of 1300 mg Ag/kg yarn. With this yarn a hose
was knitted and examined on its bactericide effect (sample
31444083). The examination was carried out according to SN195924.
The test-organism was lactobacillus brevis DSM 20054. As test
sample a not anti-microbially equipped cotton fabric was used
(Table 10). Five measurements were carried out on each sample as
well as the test sample. TABLE-US-00010 TABLE 10 Results of the
examination of the anti-bacterial effect in a germ carrying
experiment with Lactobacillus brevis as examinated germ Ig KBE
after X hours of contact 0- AE-values sample 0 average 2 6 24 AE6
AE24 rating test 1 7,0 6,9 7,3 8,0 9,3 -1,1 -2,4 test 2 6,8 7,2 8,0
9,3 -1,1 -2,4 test 3 7,0 7,3 8,0 9,3 -1,1 -2,4 test 4 7,0 7,0 8,0
9,4 -1,1 -2,5 test 5 6,7 6,9 8,1 9,2 -1,2 -2,3 3144408.1 6,9 6,9
6,2 3,0 4,2 3,9 2,7 + 3144408.2 6,9 6,4 3,5 6,1 3,4 0,8 + 3144408.3
6,9 6,2 4,5 4,0 2,9 2,9 + 3144408.4 7,0 6,2 3,0 6,2 3,0 0,7 +
3144408.5 7,0 6,1 3,5 6,2 3,4 0,7 + KBE = number of colony-building
units of test-bacteria AE = antimicrobial effect
[0055] Evaluation-Cirteria:
[0056] The 24-hours-value of the growth-control (control, i. e.
standard-fabric) has to be larger than the initial value by at
least two orders of magnitude (AE<-2).
[0057] An antimicrobial effect is given, if a KBE-value is at most
0.5 decadic logarithms above the average value of the KBE at zero
contact time, i. e. AE.sub.5.24>-0.5.
[0058] The effect of an antimicrobial equipment is given, if for
the test-bacteria 4 of 5 single KBE-values of each contact time
show an antimicrobial property. These requirements are met by the
results of sample number 3144408 (knitted hose).
* * * * *