U.S. patent application number 11/232273 was filed with the patent office on 2006-01-26 for bristle with an antimicrobial finish, brushware with such bristles and pack for such bristles or brushware.
Invention is credited to Georg Weihrauch.
Application Number | 20060019097 11/232273 |
Document ID | / |
Family ID | 7633489 |
Filed Date | 2006-01-26 |
United States Patent
Application |
20060019097 |
Kind Code |
A1 |
Weihrauch; Georg |
January 26, 2006 |
Bristle with an antimicrobial finish, brushware with such bristles
and pack for such bristles or brushware
Abstract
A bristle with an antimicrobial finish is proposed, which is
preponderantly made from thermoplastic material and which is doped
with an antimicrobial substance, which, during use, diffuses to the
bristle surface. The bristle is manufactured in a multicomponent
extrusion process and has at least one first cross-sectional area
of a plastic component determining the mechanical use
characteristics of the bristle and at least one further
cross-sectional area of the other plastic component. The other
cross-sectional area or the sum of all the other cross-sectional
areas controls the diffusion rate of the antimicrobial
substance.
Inventors: |
Weihrauch; Georg;
(Wald-Michelbach, DE) |
Correspondence
Address: |
Lichti + Partner GbR;Patentanwalte
Postfach 41 07 60
Karlsruhe
D-76207
DE
|
Family ID: |
7633489 |
Appl. No.: |
11/232273 |
Filed: |
September 22, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10204968 |
Aug 27, 2002 |
|
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PCT/EP01/01289 |
Feb 7, 2001 |
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11232273 |
Sep 22, 2005 |
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Current U.S.
Class: |
428/375 ;
428/34.1 |
Current CPC
Class: |
Y10T 428/13 20150115;
A46D 1/00 20130101; Y10T 428/2933 20150115 |
Class at
Publication: |
428/375 ;
428/034.1 |
International
Class: |
D02G 3/00 20060101
D02G003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 3, 2000 |
DE |
100 10 572.6 |
Claims
1. A bristle comprising: a first cross sectional region made from a
first plastic component, said first cross sectional region defining
mechanical use characteristics of the bristle, said first cross
sectional region forming a portion of an outer surface of the
bristle; and at least one second cross sectional region made from a
second plastic component, said at least one second cross sectional
region containing an antimicrobial substance doped into said second
plastic component, said at least one second cross sectional region
forming a remaining portion of said outer surface of the
bristle.
2. The bristle of claim 1, wherein said second cross sectional
region is disposed substantially within said first cross sectional
region.
3. The bristle of claim 1, wherein said second cross sectional
region is Y-shaped, X-shaped, cross-shaped, or star-shaped.
4. The bristle of claim 1, wherein said first cross sectional
region defines a jacket which substantially surrounds said second
cross sectional region.
5. The bristle of claim 1, wherein said first cross sectional
region retards diffusion of said antimicrobial substance toward
said outer surface of the bristle during use.
6. The bristle of claim 1, wherein said at least one second cross
sectional region is located on a cirumference of said first cross
sectional region.
7. The bristle of claim 1, wherein said first cross sectional
region is doped with said antimicrobial substance and said at least
one second cross sectional region retards diffusion of said
antimicrobial substance from said first cross sectional region.
8. The bristle of claim 1, wherein said at least one second cross
sectional region is doped with said antimicrobial substance to
control said diffusion of said antimicrobial substance and said
first cross sectional region retards said diffusion of said
antimicrobial substance from said at least one second cross
sectional region.
9. The bristle of claim 1, wherein said first and said second
cross-sectional regions are made from different materials or
differently finished materials.
10. The bristle of claim 1, wherein said first and said second
cross-sectional regions have different cross sectional areas.
11. The bristle of claim 1, wherein only said at least one second
cross-sectional region is doped with said antimicrobial substance
in high concentration.
12. The bristle of claim 1, wherein said first cross-sectional
region is doped with the antimicrobial substance in a concentration
not impairing mechanical use characteristics thereof.
13. The bristle of claim 1, wherein said second cross-sectional
region forms a sector of said first cross-sectional region.
14. The bristle of claim 1, wherein said second cross-sectional
region forms a layer on a surface of said first cross-sectional
region.
15. The bristle of claim 1, wherein said second cross-sectional
region subdivides said first cross-sectional region into
sectors.
16. The bristle of claim 1, wherein at least one of said first and
said cross-sectional region has silver of oxidation level 0 as the
antimicrobial substance.
17. The bristle of claim 1, wherein said first cross-sectional
region has an antimicrobial substance comprising silver of
oxidation level 0 and said at least one second cross-sectional
region has a same antimicrobial substance of higher
concentration.
18. The bristle of claim 17, wherein said first cross-sectional
region has silver of oxidation level 0 with a content of
500<c<100,000 ppm and said further cross-sectional region has
a content of c<100%.
19. The bristle of claim 17, wherein said at least one second
cross-sectional region has silver of oxidation level 0 with a
content of 500<c<100,000 ppm.
20. The bristle of claim 1, wherein at least one of said first and
said second cross-sectional regions has antimicrobial substance
comprising silver of oxidation level 1.
21. The bristle of claim 20, wherein the antimicrobial substance is
selected from the group consisting of silver halides, silver
sulphates, silver carbonates and organic silver salts.
22. The bristle of claim 1, wherein at least one of said first and
said at least one second cross-sectional region contains silver of
oxidation level 0 and an other one of said first and said at least
one second cross-sectional region contains silver of oxidation
level 1.
23. The bristle of claim 1, wherein said second cross-sectional
region contains silver of oxidation level 0 in a form of at least
one thread.
24. The bristle of claim 1, wherein silver of oxidation level 0 or
1 is present in disperse form in a plastic matrix of the
bristle.
25. The bristle of claim 1, wherein silver of oxidation level 0 is
applied as a layer to at least one of said first and said second
cross-sectional regions.
26. The bristle of claim 1, wherein said at least one second
cross-sectional region comprises a thermoplastic elastomer.
27. The bristle of claim 1, wherein said first cross-sectional
region has one of a first surface color and a first body color
which differs from one of a second surface color and a second body
color of said at least one second cross-sectional region.
28. The bristle of claim 1, wherein the thermoplastic material has
a water absorptivity of at least 0.1 mass %.
29. The bristle of claim 28, wherein the thermoplastic material is
one of polyamide, polyester and polyurethane.
30. The bristle of claim 1, wherein said first cross-sectional
region has a first water absorptivity which differs from a second
water absorptivity of said second cross-sectional region.
31. The bristle of claim 1, wherein each of at least two combined
monofilaments forms one of said first and said at least one second
cross sectional region.
32. Brushware having a plastic bristle carrier and bristles
according to claim 1, wherein at least portions of said bristle
carrier are antimicrobially treated.
33. The brushware of claim 32, wherein said bristle carrier is made
from plastic and contains particulate silver of oxidation level 0
and/or 1.
34. The brushware of claim 32, wherein said bristle carrier is made
from two different or different types of plastics in multicomponent
injection molding, at least one component being filled with
particulate silver of oxidation level 0 and/or 1.
35. The brushware of claim 32, wherein the bristle carrier is
filled with particulate silver of oxidation level 0 and/or 1 in a
region of attachment of the bristles.
36. The brushware of claim 32, wherein the bristles are
individually fastened on or in the bristle carrier.
37. The brushware of claim 32, wherein the bristles are joined in a
gap-free manner to said bristle carrier by thermal processes.
38. A pack for the brushware of claim 32, wherein the pack is
finished with an antimicrobial substance.
39. The pack of claim 38, wherein pack material contains
antimicrobial substance in disperse form.
40. The pack of claim 38, wherein a side forming an inside of the
pack is coated with the antimicrobial substance.
41. A method for producing the bristle of claim 1, the method
comprising the steps of: a) preparing a first plastic component for
extrusion; b) doping a second plastic component with an
antimicrobial substance; c) co-extruding, following step b), said
first plastic component together with said second plastic component
in a multi-component extrusion process to form a bristle having an
outer surface with a portion thereof occupied by said second
plastic component and with a remaining portion thereof occupied by
said first plastic component.
Description
[0001] This application is a continuation of Ser. No. 10/204,968
filed Aug. 27, 2002 as the national stage of PCT/EP01/01289 filed
on Feb. 7, 2001 and also claims Paris Convention priority of DE 100
10 572.6 filed Mar. 3, 2000.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a bristle with an antimicrobial
finish, which is mainly of thermoplastic material and which is
doped with an antimicrobial substance, which during use diffuses to
the bristle surface. The invention is also directed at brushware
having such bristles and to a pack for such bristles or
brushware.
[0003] Bristles having an antimicrobial finish have long been
known, but have scarcely been used in practice. Thus, at a very
early date the known antimicrobial action of silver in colloidal
form and its possibility of use in toothbrushes was recognized (GB
446 303), in that oligodynamic, colloidal silver was embedded in
bristle monofilaments or applied to the bristle carrier. It is also
known to embed in the bristle material or apply to the bristle
monovalent or polyvalent ion forming agents, including silver and
silver compounds (EP 678 548), silver being proposed in particle
form <10 .mu.m with a content of 100 ppm to 10 mass %. It is
finally known (DE 195 08 539) to fill a bristle with particles of
different size, the larger particles being of silver with the
oxidation number 0 and having a size of 1 to 50 .mu.m.
[0004] It is also known (EP 413 833) to coat bristle monofilaments
with a solution or emulsion of a polymer with free acid radicals
and a mixed in, cationic antibactericide, e.g. chlorohexidine and
to then dry the coating. Production is very complicated and the
adhesion of the coating to the bristle core is inadequate. The
antibactericide also diffuses out too rapidly.
[0005] It is also known in textile fiber technology to bind silver
to carrier materials, e.g. zeolite (U.S. Pat. No. 4,525,410, EP 275
047) and to disperse the thus doped zeolite in particle form in the
polymer melt for the monofilament and extrude it with the latter.
The fiber comprises a polymer core with a higher melting point and
an outer layer of a polymer with a low melting point, which
contains the silver-doped zeolite particles. It is also known (EP
116 865) to coextrude a fiber having a Nylon core and outer
segments or layers, which contain silver-doped zeolite
particles.
[0006] In all known systems the antimicrobial action is based on
the fact that in a moist environment antimicrobially active cations
diffuse out of the bristle or fiber and penetrate the thin cell
wall of microorganisms, particularly bacteria and block their
protein metabolism.
[0007] When used as bristles or in brushware monofilaments of the
aforementioned type suffer from the disadvantage that if pure
silver is used as the antimicrobial substance this necessarily
leads to a correspondingly high filling of the bristle with the
particulate silver. This leads to a reduction in the stability of
the bristles and consequently to a deterioration of the use
characteristics (flexibility, recovery capacity, etc.). Thus, such
monofilaments have not been adopted in practice.
[0008] Other microbial substances, particularly in the form of
metal salts or silver doped zeolite, due to the high ballast
material percentage, also lead to a weakening of the bristle. This
weakening can only be partly compensated by a diameter increase,
which is highly undesired in the case of much brushware,
particularly toothbrushes. This is often accompanied by an
undesired, high bristle roughness. All the known proposals suffer
from the further disadvantage that, even prior to use, particularly
in a moist atmosphere, the antimicrobial substance is given off, so
that the substance is used up prematurely.
SUMMARY OF THE INVENTION
[0009] On the basis of the prior art of EP 413 833, the problem of
the present invention is to propose a bristle for brushware, e.g.
for toothbrushes, body care, cosmetic and hygienic brushes or the
like, which has an adequate antimicrobial action and at the same
time unchanged, highly satisfactory use characteristics. The
invention must also ensure that the antimicrobial action is not
prematurely used up.
[0010] According to the invention this problem is solved in that
the bristle is produced in a multicomponent extrusion process and
has at least one first cross-sectional area determining the
mechanical use characteristics of the bristle of a plastic
component and at least one further cross-sectional area of the
other plastic component, and that the further cross-sectional area
or the sum of all further cross-sectional areas controls the
diffusion rate of the antimicrobial substance.
[0011] As a result of the construction according to the invention
the first cross-sectional area guarantees the use characteristics
of the bristle, whereas the further cross-sectional area or areas
are of minor significance for the use characteristics of the
bristle. The doping with the antimicrobial substance takes place
exclusively or preponderantly in one of the cross-sectional areas,
whereas the other cross-sectional area or areas act in
diffusion-controlling manner for the antimicrobial substance. The
control of the diffusion rate of the microbial substance can take
place by different doping of the cross sectional areas with the
substance or in that a non-doped cross-sectional area acts as a
diffusion brake or as a reflector for the ionized atoms or
molecules. This makes it possible to simultaneously control the
action period of the antimicrobial substance.
[0012] The use characteristics of the bristle on the one hand and
the diffusion rate on the other can also be influenced in that the
cross-sectional areas are made from different or differently
finished plastics or have different cross-sectional surfaces and/or
different cross-sectional contours.
[0013] Preferably the further and appropriately smaller
cross-sectional area of the bristle is doped with the substance in
high concentration, so that an adequate charge carrier quantity
diffuses into the moist atmosphere. In this embodiment this can be
further assisted in that the larger cross-sectional area acts as a
diffusion brake, so that the substance mainly diffuses out at the
surface of the highly doped cross-sectional area and only with a
significant time lag at the surface of the large cross-sectional
area.
[0014] The large cross-sectional area of the monofilament can also
be doped with the substance in a concentration not impairing its
mechanical use characteristics, the further, smaller
cross-sectional area acting exclusively as a microbially inert
diffusion brake and for regulating the active substance delivery
from the larger cross-section. However, the smaller cross-section
can also be highly doped with the antimicrobial substance and then
there is also diffusion into the larger cross-sectional area, so
that the ions diffusing out there on the surface are constantly
replaced from the other cross-sectional area. However, at the same
time the large cross-sectional area forms a diffusion brake,
because the ions preferably pass out at the free surface of the
smaller cross-sectional area, where the lower diffusion resistance
exits.
[0015] According to a preferred development, the further
cross-sectional area is located on the circumference of the large
cross-sectional area and either forms part of the bristle surface
or completely embraces the bristle. This on the one hand ensures a
comparatively rapid delivery of the ions at the free surface of the
smaller cross-sectional area and on the other hand the
cross-sectional area decisive for the stability and bending
behavior of the bristle is only slightly weakened, so that even
very thin bristles can be adequately doped with antimicrobial
substance. In the case of thin bristles, particularly with
diameters smaller than 0,75 mm, the bristle can be completely
surrounded by a thin layer acting as a diffusion brake.
[0016] The further, smaller cross-sectional area can form a sector
in the larger cross-sectional area or also a layer on the surface
thereof. In the first case said further cross-sectional area can be
highly doped, whereas when constructed in the form of a layer it
acts exclusively as a diffusion brake through a corresponding
material choice. This layer can be extruded with the monofilament
or can be subsequently applied.
[0017] In another embodiment the further, smaller cross-sectional
area can be located in the interior of the large cross-sectional
area, e.g. in the form of coextruded, thin monofilaments with a
random cross-sectional shape (circular, polygonal, cruciform,
etc.). The further cross-sectional area can also subdivide the
large cross-sectional area into sectors, e.g. can be in the form of
a star-shaped layer of limited thickness. In this embodiment the
diffusion of the antimicrobial substance also takes place into the
larger cross-sectional area. To the extent that the surface of the
smaller cross-sectional area is exposed, an increased diffusing out
takes place.
[0018] Preferably at least one further cross-sectional area has
silver of oxidation level 0 as the antimicrobial substance. Instead
of this or in addition thereto the large cross-sectional area can
contain silver of oxidation level 0 and then preferably the
further, smaller cross-sectional area has the same substance in a
higher concentration.
[0019] An advantageous embodiment is characterized in that the
large cross-sectional area has silver of oxidation level 0 with a
content of 0<c<50,000 ppm and the further cross-sectional
area a content of c<100%.
[0020] In a preferred development the further, smaller
cross-sectional area has silver of oxidation level 0 with a content
of 500<c<100,000 ppm. Practical tests with such a bristle
have shown that the combination of a high concentration in the
further, smaller cross-sectional area and a lower concentration in
the large cross-sectional area ensures a diffusion of the
antimicrobial substance at an adequate speed and over an adequate
period of time roughly corresponding to the use period of a
toothbrush.
[0021] Another embodiment of the invention is characterized in that
at least one cross-sectional area has silver of oxidation level 1
and it can be in the form of silver halides, sulphates, carbonates
or organic silver salts, in which cation formation takes place as a
function of the solubility product to a greater extent.
[0022] The aforementioned antimicrobial substances can also be
combined with one another in such a way that one cross-sectional
area has silver of oxidation level 0 and at least one further
cross-sectional area silver of oxidation level 1.
[0023] If silver of oxidation level 0 is used, it can be contained
in the further, smaller cross-sectional area in the form of at
least one thread, which, during the extrusion of the monofilament,
also follows. Preferably the silver of oxidation level 0 or 1 is
present in disperse form in the plastic matrix and is extruded
together with the plastic melt. For this purpose it is possible to
use a granulate, which already contains the particles. Instead of
this silver-containing polymer particles can be extruded together
with the polymer. Since as a result of the silver content the
polymer particles have a better dimensional stability, they largely
maintain their particle form. Bristles of this type without an
antimicrobial finish and their production are e.g. described in WO
17/09906, the entire disclosure of which is hereby incorporated by
reference.
[0024] Instead of this it is possible for the silver of oxidation
level 0 to be applied to one of the cross-sectional areas in layer
form.
[0025] All the cross-sectional areas of the bristle can comprise
the same thermoplastic material. However, it is also possible to
form the further, smaller cross-sectional area from a thermoplastic
elastomer, which has a lower diffusion resistance to the
antimicrobial substance.
[0026] In order to provide a use indication, the cross-sectional
areas can also be differently surface or through-dyed, wherein
increasing wear on the free bristle end or bristle jacket is
indicated by a corresponding color change.
[0027] The preferred thermoplastic materials are those having a
water absorptivity of at least 0.1 mass % and more particularly
polyamides, polyesters and polyurethanes.
[0028] The diffusion rate can also be controlled in that the
cross-sectional areas of the bristle or the polymers forming them
have different water absorptivity, so that the cations are more
rapidly formed in the cross-sectional area with the higher water
absorptivity and more rapidly diffuse out than in the other
cross-sectional area.
[0029] The cross-sectional areas of the bristle can also be formed
by two or more combined monofilaments, whereof each forms one of
the cross-sectional areas.
[0030] The invention also relates to brushware having a plastic
bristle carrier and bristles constructed according to the
invention. Such brushware is characterized in that also the bristle
carrier is at least zonally antimicrobially finished. Thus, in the
case of toothbrushes, the invention takes account of the
scientifically proven finding that as a result of the permanently
moist atmosphere, as well as the cavities which have evolved in the
bristle configuration area, a relatively high bacterial attack
occurs on the bristle carrier.
[0031] If, as is usually the case, the bristle carrier is made from
plastic, it preferably has particulate silver of oxidation level 0
or 1.
[0032] If, as is also known, the bristle carrier is made from two
different or different types of plastic, which are produced by
multicomponent injection molding, at least one of the components is
filled with particulate silver of oxidation level 0 or 1.
[0033] In a preferred development the bristle carrier is solely or
preponderantly filled in the vicinity of the fastening of the
bristles with particulate silver of oxidation level 0 or 1, i.e. in
the area which is particularly endangered by bacterial attack and
the establishment of bacteria.
[0034] Finally, in the case of such brushware, the bristles are
preferably individually fastened to or in the bristle carrier,
which compared with a bundle-like arrangement of the bristles aids
free diffusion, because on the one hand moisture has uniformly
rapid access to all the bristles and on the other the bristle
configuration dries more rapidly after use, which prevents
bacterial attack and blocks diffusion.
[0035] Moreover, either individually or in bundle form, the
bristles are joined to the bristle carrier in gap-free manner by
thermal processes in order to prevent the establishment of bacteria
and in order to prevent excessively rapid consumption of the
antimicrobial substance. Such processes more particularly include
injecting in, welding or thermal bonding.
[0036] Bristles and brushware, particularly when used for hygienic
purposes, such as toothbrushes, cosmetic brushes, etc., reach the
processor or final consumer in packs. Frequently they are in the
form of plastic packs or blister packs with a cardboard support and
a transparent plastic blister. As packing cannot take place under
sterile clean room conditions, it is also not possible to exclude
that during packing germs can enter the pack. Despite the air-tight
seal germ growth can occur if moisture is present in the pack,
particularly if as a result of temperature changes the moisture
condenses on the inside of the pack and which reacts more rapidly
to temperature changes than the actual packed article.
[0037] To prevent contamination of the packed bristles or brushware
with germs, according to the invention the pack is characterized in
that it is finished with an antimicrobial substance. Said substance
is preferably silver or silver salts and can be incorporated in
disperse form into the material of the pack or can be applied in
layer form to the inside of the pack.
[0038] The invention is described in greater detail hereinafter
relative to embodiments represented in the drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0039] FIG. 1 shows a cross section through a bristle in a first
embodiment of the invention;
[0040] FIG. 2 shows a perspective view of the bristle of FIG.
1;
[0041] FIG. 3 shows a cross section through a bristle in a second
embodiment of the invention;
[0042] FIG. 4 shows a cross section through a bristle in a third
embodiment of the invention;
[0043] FIG. 5 shows a cross section through a bristle in a fourth
embodiment of the invention;
[0044] FIG. 6 shows a cross section through a bristle in a fifth
embodiment of the invention;
[0045] FIG. 7 shows a cross section through a bristle in a sixth
embodiment of the invention;
[0046] FIG. 8 shows a cross section through a bristle in a seventh
embodiment of the invention;
[0047] FIG. 9 shows a cross section through a bristle in an eighth
embodiment of the invention;
[0048] FIG. 10 shows a cross section through a bristle in a ninth
embodiment of the invention;
[0049] FIG. 11 shows a cross section through a bristle in a tenth
embodiment of the invention; and
[0050] FIG. 12 shows a cross section through a bristle in an
eleventh embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0051] FIG. 1 is a cross section through a bristle 1, whose first,
larger cross-sectional area 2 comprises a thermoplastic material,
e.g. polyamide, polyester or polyurethane and which has a further
cross-sectional area 3 with a much smaller cross-section and which
forms a partly cylindrical sector of the overall cross-section. The
cross-sectional area 2 has the use characteristics necessary for a
bristle with respect to the bending behavior and recovery capacity
and at least to a limited extent this is aided by cross-sectional
area 3. Cross-sectional area 3 can be made from a different
plastic, particularly a different thermoplastic or an
elastomer.
[0052] As can be gathered from FIG. 2, the smaller cross-sectional
area 3 passes over the entire length of the bristle 1 and
production preferably takes place by the extrusion of both material
components for cross-sectional areas 2 and 3. The smaller
cross-sectional area 3 is filled with an antimicrobial substance in
particle form, preferably silver of oxidation level 0 or 1. A high
doping of the antimicrobial substance takes place. The larger
cross-sectional area 2 can also be filled with an antimicrobial
substance 5 in particle form. The thermoplastic material of the
larger cross-sectional area 2 forms in this embodiment a diffusion
brake for the highly doped, antimicrobial substance in the smaller
cross-sectional area 3 and which diffuses out more rapidly on its
free surface, whereas the substance from the larger cross-sectional
area diffuses out at a lower speed and more slowly due to the
longer diffusion paths.
[0053] The bristle 1 according to FIG. 3 once again has a large
cross-sectional area 2, which determines the use characteristics
thereof. In said cross-sectional area 2 the small cross-sectional
area 3 is present as a core and is produced, optionally together
with the larger cross-sectional area 2, by coextrusion. It can once
again comprise a different plastic and is in this case highly doped
with the antimicrobial substance 4. In this case the larger
cross-sectional area 2 acts as a diffusion brake or conversely the
smaller cross-sectional area 3 forms a slow and continuously
flowing source of antimicrobial substance.
[0054] In the embodiment according to FIG. 4 the larger
cross-sectional area 2 determining the bristle use characteristics
contains three smaller cross-sectional areas 3 in the form of
strands and which are once again highly doped with the
antimicrobial substance. Once again the larger cross-sectional area
2 acts as a diffusion brake.
[0055] In the embodiment according to FIG. 5 the further, smaller
cross-sectional area 3 is incorporated in the form of a cruciform
cross-section in the larger cross-sectional area 2. In this
embodiment the cruciform cross-sectional area 3 is highly doped and
the larger cross-sectional area 2 less highly doped with the
antimicrobial substance.
[0056] FIG. 6 shows an embodiment in which the larger
cross-sectional area 2 is subdivided in star-like manner into
sectors by the smaller cross-sectional area 3 and only the smaller
cross-sectional area 3 is highly doped with the antimicrobial
substance.
[0057] FIG. 7 shows a bristle 6 with a polygonal, namely square
cross-section leading to a higher mechanical cleaning action than
with a circular bristle. The bristle 6 once again has a larger
cross-sectional area 2 of a thermoplastic material and a smaller
cross-sectional area 3 in the form of a segment, which is more
highly doped with the antimicrobial substance than the large
cross-sectional area 2. The bristle 7 according to FIG. 8 differs
from that of FIG. 7 only in that it has two segmental, smaller
cross-sectional areas 3 at diagonally positioned corners. In both
cases the antimicrobially acting cations are mainly delivered at
the free surface of the smaller cross-sectional area 3. However,
part thereof is diffused into the larger cross-sectional area 2 and
to this extent a diffusion brake is formed, because the cations
must firstly migrate through this cross-sectional area in order to
arrive at the free surface thereof.
[0058] In the embodiment according to FIG. 9 the smaller
cross-sectional area 3 forms a layer on the larger cross-sectional
area 2 only extending over a small part of the circumference. The
cross-sectional area 3 is preferably diffusion-tight with respect
to the antimicrobial substance 4 in the large cross-sectional area
2, so that the inherently slow diffusion on the larger, free
surface of cross-sectional area 2 is intensified. According to FIG.
10 this can optionally take place in locally oriented form, in that
the outer layer 3 forming the diffusion brake covers a larger part
of the circumference of the large cross-sectional area 2 or, as in
the embodiment of FIG. 11, the entire circumference. In both cases
the antimicrobial substance is exclusively housed in the large
cross-sectional area 2.
[0059] FIG. 12 shows a star-shaped bristle 8, whose bearing
cross-sectional area 2 has a four-arm construction. At the ends of
each arm are located the smaller cross-sectional areas 3, which are
highly doped with the antimicrobial substance 4, whereas the
cross-sectional area 2 is less highly doped.
* * * * *