Skin barrier product with discontinuous adhesive layer

An adhesive, flat skin barrier product for use as semi-manufacture in the production of, a.o., dressings, wound-care devices, electrodes and fastening means for ostomy equipment and catheters, consists of alternating zones of material of at least two different kinds (26,28,30) at least one of which is a skinfriendly self-adhesive material. The zones are parallel and extend in a direction usually at right angles to the main surfaces of the product. The zones may for instance be parallel strips, co-axial rings, co-wound Archimedean spirals or short strands. The skin barrier product offers the advantage that in a simple way it may be produced to comprise, besides the sealing material itself, other components for special purposes, e.g. having contents of antiseptics, medicaments or others biologically active substances of liquid-transporting or electrically conductive structures.

FIELD AND BACKGROUND OF THE INVENTION 
The present invention relates to an adhesive, flexible flat skin barrier 
product for use as a semi-manufacture in the production of dressings, skin 
and wound care devices, fastening means for dressings, ostomy equipment, 
wound drains and catheters, e.g. for incontinence equipment for men and 
for similar applications, and for use in electrodes for application to the 
skin. 
A large number of flexible skin barrier products of this general type are 
known, and many of them have as a main component a sealing material 
comprising a continuous phase containing an adhesive and for instance 
being built from an elastomer, an emulsifier for the elastomer, a resin 
promoting the adhesive capacity and optionally an oil-based extender as 
well as an antioxidant. In this there is in many cases dispersed a 
discontinuous phase comprising one or more water-soluble or 
water-swellable hydrocolloids, starch derivatives or cellulose derivatives 
or hydrophilic polymers. 
Examples hereof are those known from U.S. Pat. Nos. 4,231,369 and 
4,367,732. They consist of a continuous phase comprising a physically 
cross-linked elastomer in the form of one or more styrene-olefin-styrene 
block copolymers or ethylene-propylene block copolymers, a hydrocarbon 
tackifier in the form of a polymer or copolymer from cyclopentadiene, 
dicyclopentadiene, .alpha.-pinene and/or .beta.-pinene, an antioxidant and 
optionally a liquid paraffin as an emulsifier; and in this a discontinuous 
phase comprising one or more water-swellable hydrocolloids, preferably gum 
guar and/or sodium carboxymethyl cellulose. Known skin barriers may also 
contain other elastomers, e.g. natural rubber, synthetic resins of a 
similar nature as natural rubber and silicone rubbers. As adhesive 
material and structure-forming component in skin barriers polyisobutylene 
of a suitable molecular weight distribution is also frequently used, e.g. 
as stated in U.S. Pat. No. 3,339,546. In principle, all known 
skin-friendly self-adhesive sealants may be present in the skin barrier 
product according to the invention. 
In the majority of the known skin barriers the composition thereof is 
substantially uniform over the whole of the width and length dimension 
(hereinafter sometimes together called the surface dimension, i.e. seen as 
passing from one edge to an opposite edge thereof), incidentally as a rule 
also in the thickness dimension, as regards the adhesive composition. This 
is often an advantage but in a number of instances varying properties in 
the surface direction may be desirable, for instance in such a way that 
regions or portions of adhesive material forming an angle to the flat 
surfaces of the product alternate with regions or portions of another kind 
equally forming an angle to the surfaces of the skin barrier product, e.g. 
made of another kind of adhesive material, of less adhesive or of 
non-adhesive material; or materials having more or less pronounced barrier 
properties, having liquid-conducting or electrically conducting 
properties, materials containing wound-healing substances or medicaments, 
or absorbing materials. 
U.S. Pat. No. 3,885,559 discloses a process for the reduction of pain in 
the removal of adhesive tapes or bandages. This is achieved by using an 
adhesive tape or bandage comprising a flexible backing with an adhesive 
portion distributed and adhered thereon in the form of adhesive layers 
alternately spaced with regions of lesser or even no adhesiveness. The 
backing is needed to hold the regions assembled, and the individual 
regions do not extend through the entire thickness of the product, viz. 
because of the backing. 
European published Patent Application No. 134,437 A1 discloses a flexible 
magnetic foil for therapeutic purposes. It has a flexible rubber-like foil 
in which permanent magnetic ferrites have been embedded, whereby the 
active surface of the foil has been magnetized with poles having 
alternating polarity. In order to attach the foil to the skin of a 
patient, it is provided with self-adhesive coating which is tolerable to 
the skin. Thus, no kind of material extends through the entire thickness 
of the product. 
SUMMARY OF THE INVENTION 
It is the object of the invention to provide a semi-manufacture skin 
barrier product with properties changing in the width and/or length 
dimension so as to suit varying needs with one product not needing some 
uniform cover layer or backing unless the ultimate use of the 
semi-manufacture calls for the application of such a uniform layer on a 
surface of the product. According to the invention this is achieved if the 
product consists of a number of alternating zones of material of at least 
two different kinds, at least one kind of zone consisting of a 
skin-friendly self-adhesive material, the zones of material extending 
substantially parallelly through the entire thickness of the product in a 
direction intersecting its flat surfaces. Preferably the zones are 
substantially at right angles to the flat surfaces of the product and 
hence are parallel to the edges. All the kinds of material present in the 
product have to be substantially non-irritating to skin or mucous 
membranes and must also be substantially non-allergenic. 
According to the invention at least one kind of zone consists of a 
self-adhesive material of the kind which comprises a continuous phase 
containing a self-adhesive elastomer mass and one or more water-soluble or 
water-swellable hydrocolloids substantially evenly dispersed as a 
discontinuous phase in the continuous phase. The self-adhesive sealing 
agent may thus advantageously be one of the kinds described in the 
abovementioned U.S. Pat. Nos. 4,231,369 and 4,367,732 and which in the 
continuous phase also comprise an emulsifier for the elastomer and 
normally an antioxidant. 
The self-adhesive material or one of them may, however, have no contents of 
hydrocolloid and, e.g., be based on styrene-isoprene-styrene block 
copolymers, polyisobutylenes, polyvinylether or polyacrylates, 
polymethacrylates or copolymers thereof. 
The skin barrier product preferably has the same thickness as known skin 
barriers, for instance 0.5-2 mm. 
DETAILED EXPLANATION OF THE INVENTION 
The various zones of material may be grouped in various ways. 
In principle, thus, one or more zones may be entirely surrounded at all 
edges by one or more other zones, said other zones being of mutually 
different or identical materials. The geometrical arrangement may vary 
widely. Thus, as seen from the surface, one zone of one material may form 
an "island" in a matrix formed by another material; or a plurality of 
zones of the same material or different materials may form such islands in 
the matrix. Also, a plurality of thin platelets made of materials of two 
or more kinds and having irregular or regular shapes may be joined 
together so as to fill up the semi-manufacture. 
According to another variant, two or more kinds of material are spirally 
wound together to form (two or more) neighbouring zones each substantially 
in the shape of an Archimedean spiral which may, however be more or less 
deformed. Such a product may be formed by stacking sheets or lengths, each 
having a constant thickness, of the desired materials, rolling the stack 
as one rolls a carpet and slicing the roll thus formed substantially 
perpendicularly to its axis. 
In a further geometrical arrangement of the product according to the 
invention, the zones of material, seen from the surface of the product, 
are rectilinear, curved or wavy, substantially parallel and all extend 
from one edge of the product to another. It will be understood that each 
individual zone, be it rectilinear, curved or wavy, has a substantially 
constant width, i.e. that its edges, bordering a neighbouring zone or the 
outer world, are substantially equidistant. 
A variant of this embodiment is one in which all of the zones form a closed 
curve, e.g. a circle or an elliptic curve, seen from the surface of the 
product. In that case the zones are cylinders of, for instance, a length 
of 0.5-2 mm, a central cylinder being in its entirety surrounded by one or 
more other and larger cylinders. Any two adjacent zones or cylinders 
consist of different materials. Such cylinders may be deformed. 
A further variant is one in which the zones of material, seen from the 
surface of the product, are rectilinear, curved or wavy, substantially 
parallel and all extend from one edge of the product to another, at least 
one such zone having a function other than an adhesive function. Any zone 
having a function other than an adhesive function may well have, but need 
not have, that other function in addition to an adhesive function. For 
example a medicament or some liquid-transported structure may be embedded 
in an adhesive material. 
Thus, in the present product the zones may be mainly parallel or co-axial 
alternating strips of identical or different thicknesses. In that case the 
product is a sort of laminate the layers of which are quite short and 
upright or at least form an angle to the main faces of the product. 
Preferably the strips may have a thickness of for instance 0.5-2 mm, 
whereby they are easily produced by slicing from a roll or a stack of 
layers of a usual skin barrier, alternating with layers of a different 
material. The zones may, however, also be thicker, especially in annular 
semi-manufactures of the kind in question, for instance 1-5 cm. In this 
case the skin barrier product may for instance be produced by extrusion, a 
process which may also be used in the production of a product having 
narrow zones, and subsequent slicing into thin sheets. 
According to the invention at least one of the kinds of zones may be made 
of a material hampering or preventing migration of matter to and from 
adjacent self-adhesive zones. In other words it is a question of a more or 
less efficient barrier zone. These barrier zones may be of several 
different kinds and their presence does not exclude the presence of zones 
of quite another kind in the product. 
This embodiment notably has importance in cases where zones of the 
self-adhesive sealing agent alternate with zones of another kind and it is 
wanted to prevent migration of matter from or into said zones of another 
kind. At least one of the kinds of zones may consist of a material 
hampering or preventing passage of aqueous liquids to adjacent 
hydrocolloid-containing self-adhesive materials. 
The zones hampering or impeding migration of matter may for instance be 
films or foils of plastic or metal. Such barrier foils or films may for 
instance have a thickness of 10-100 .mu.m and for instance consist of 
polyolefins, polyester, poyvinylchloride, aluminium or laminates thereof. 
The zones hampering or preventing migration of matter could alternatively 
consist of a material which is ductile under the influence of low forces 
and also more or less hydrophobic and containing a self-adhesive elastomer 
mass, but no hydrocolloid. A main function of self-adhesive skin barriers 
containing hydrocolloid is to absorb sweat and/or wound exudates while 
retaining their adhesive capacity. Due to the absorption capacity thereof, 
such skin barrier product may, however, unwantedly absorb liquid from the 
edges, for instance water from bathing or secretion from stomas in case of 
its application for fastening ostomy equipment. When it comprises a 
material hampering migration of matter and especially a material hampering 
migration of water, the movement of the water across the edges of the 
zones of the skin barrier product (a movement parallel to its flat 
surfaces) will become very slow and the product will retain its adhesive 
capacity for a long period of time and thus obtain an increased life time. 
When the adhesive material without or poor in colloids is ductile under 
the influence of low forces, it will keep up with the thickness increase 
of the product and thereby still form a barrier against unintentionally 
being decomposed by water from the edges. 
Since moreover materials of the kind in question may be composed in a 
manner so as to absorb water to a certain degree, but substantially slower 
than does the hydrocolloid-containing adhesive, it will be able to keep up 
with even very considerable increases in volume caused by the absorption 
of liquid. 
Although the zone hampering migration of matter generally does not contain 
hydrocolloid, it is possible that zones of adhesive material of the kind 
in question and having a high content of hydrocolloid alternate with zones 
having a lower content of hydrocolloid instead of zones entirely devoid of 
hydrocolloid. 
In another grouping of the zones of material they may in accordance with 
the invention be strands of identical or different cross-sectional shapes 
and sizes and substantially fill up the product. The lengths of the 
strands are normally the thickness of the product so that they are at 
right angles to the main surfaces thereof, but they may also be longer and 
thus be at an oblique angle to the main surfaces of the product and the 
edges thereof. 
The strands may have any regular or irregular cross-section, but should 
fill up the product so that there will be no air ducts where they abut on 
each other. They may be prismatic and thereby in a simple manner fulfil 
the requirement for filling up the product if their cross-sections are 
either identical equilateral triangles, squares or regular hexagons. 
Normally they will, however, be round strands. A skin barrier product 
having its zones in the form of strands may be produced by co-extrusion of 
for instance prismatic, circular or oval, long, parallel strands of the 
materials in question, and subsequent slicing of the composite strand thus 
formed into thin pads. If the cross-sections of the strands do not by 
themselves ensure the complete filling up of the cross-sectional area of 
the product formed, one may after the extrusion but before the slicing 
press the single strands together into a composite strand, for instance by 
passing them through a slightly funnel-shaped compressing device. 
At another grouping of the zones of material a number of strands are 
distributed evenly or unevenly in a strand of a self-adhesive material of 
the kind comprising a continuous phase containing a self-adhesive 
elastomer mass and a water-soluble or water-swellable hydrocolloid 
dispersed therein as a discontinuous phase, said latter strand filling up 
the interspaces between the former. The distribution may possibly also be 
the opposite: single strands of an adhesive material as mentioned, 
distributed in a larger strand surrounding all of them and forming a sort 
of matrix for them. 
In the embodiment having the single strands distributed in a surrounding 
strand there may be strands of various kinds, i.e. strands of mutually 
different kinds, for instance the kinds referred to later in this 
specification. 
The skin barrier product according to the invention may advantageously be 
in the form of an annular pad for affixing drains, ostomy pouches or other 
equipment, in which case according to the invention the alternating zones 
of material may be substantially co-axially cylindrical or form an 
Archimedean spiral, and the product may be provided with a central 
aperture. Further, the product may be provided on both the inner edge and 
the outer edge with a water-impermeable barrier layer, such as e.g. a film 
or foil of plastic or metal or a laminate thereof, or of a self-adhesive 
elastomer mass free from hydrocolloid or poor in hydrocolloid. It is 
thereby attained that water from the outer edge or secretion from stomas 
from the inner edge only slowly penetrate into the adhesive ring whereby 
the lifetime thereof will be substantially increased. 
Such products may be produced in a far more economic way than current 
annular pads, which are manufactured by punching from sheets or lengths, 
thus causing a considerable waste of material. In contradistinction hereto 
an annular product as just mentioned may be manufactured by co-extrusion 
of materials for the zones to form a hollow cylinder having co-axial 
layers of material and subsequent slicing of the cylinder thus formed; or 
by spirally coiling assembled lengths of the materials and subsequent 
slicing of the hollow roll thus formed. 
It is observed that by the expression "annular" reference is made to any 
embodiment of the product having a defined outer delimitation and a 
central or eccentric aperture suitable for engaging a drain or a stoma. 
The aperture needs not be circular but most frequently is. The outer shape 
may be circular, elliptic or polygonal, e.g. quadrangular, or have any 
other desired shape. Even products having an outer shape differing from 
that of the circle may be produced in the manner described above, most 
conveniently by performing a suitable deformation before the hollow 
cylinder or roll is sliced; a desired shape of the aperture may be 
maintained by means of a mandrel which is removed successively as the 
slicing proceeds. 
An annular product may conveniently comprise zones that hamper or prevent 
migration of matter or contain a self-adhesive elastomer mass free from 
hydrocolloid or poor in hydrocolloid, and such zones may advantageously 
form the outer zone and/or inner zone; but may additionally be partition 
zones within a hydrocolloid-containing self-adhesive elastomer mass. 
A long series of other materials may form parts of the product according to 
the invention, either as separate zones or as parts of zones containing an 
adhesive. As examples may be mentioned that one or more kinds of zones 
expediently may consist of a foam material having open or closed cells. In 
the foam material a biologically active substance may be present, for 
instance a medicament or an antiseptic or antibiotic. The biologically 
active substance may be present within the cells of a foam with open cells 
or be present in the very foam material, i.e. as a component of the walls 
of open or closed cells which for instance may consist of a foamed gel 
material such as gelatin. 
Biologically active substances may also be present in other materials than 
foam materials. For instance one or more zones of material may comprise 
hydrophilic gel substance containing an agent effective against warts, 
e.g. cantharidine, salicylic acid, silver nitrate, podophyllin, or an 
anti-metabolitic cytostatic such as cytarabine, fluorouracil or 
mercapto-purine. 
One or more zones of the product may be made from a hydrophilic gel 
substance containing one or more keratolytically active substances, for 
instance carbamide, salicylic acid and/or lactic acid. 
Furthermore, one or more zones may for instance contain one or more 
compounds inhibiting mitosis, e.g. anthracene, silver nitrate or 
glucocorticoids such as mildly, medium strongly or strongly active 
corticosteroids such as hydrocortisone, triamcinolone acetonide or 
betametasone. 
The gel substances mentioned above may be hydrophilic or hydrophobic, 
optionally of a desired HL-balance (hydrophilic-lipophilic balance), and 
optionally a supporting structure may be incorporated therein in the form 
of a foam of, e.g.,a polyether, collagen or gelatin, or in the form of 
fibres, filaments or woven or nonwoven textile material, e.g. of a 
polyester or cotton. Hydrophilic gels may for instance be mixtures of 
karaya and glycerol; of pectin, lower molecular weight polyethylene glycol 
and glycerol; or mixtures of gelatin, glycerol and water. 
Hydrophobic gels may for instance consist of mixtures of 
styrene-isoprene-styrene blockcopolymers and paraffin; mixtures of 
styrene-isoprene-styrene blockcopolymers, liquid paraffin and 
dioctyladipate; or mixtures of nitrocellulose, ricinus oil and rosin. 
As examples of active substances which may be incorporated into the gel 
substances may be further mentioned antiseptics such as iodophors, silver 
compounds, hexidine or chlorohexamine; vitamins; and antibiotics, 
wound-healing agents and growth-promoting substances. 
Foam materials which may be present as a special kind of zone or form a 
supporting structure in the gel substances just mentioned, may for 
instance be of a polyether, polyethylene, polyvinyl chloride, gelatin or 
collagen. 
The skin barrier product according to the invention may further comprise 
liquid-transporting structures. They may for instances be fibres, 
filaments or woven or nonwoven textiles; and optionally tubular structures 
may be present in the form of capillaries or bodies having ducts, the 
capillaries or ducts being substantially at right angles to the surfaces 
of the skin barrier product. Bodies containing ducts may for instance be 
of plastics or rubber-like materials. 
The skin barrier product may also incorporate layers with so-called 
superabsorbing materials; such materials are well-known in connection with 
absorption products such as sanitary towels and diapers. 
According to a special embodiment of the skin barrier product it comprises 
zones or strands of (a) a self-adhesive material preferably without 
hydrocolloid and (b) a hydrophilic, electrically conductive gel substance, 
optionally separated by an aluminium foil. This embodiment is especially 
suitable for the production of electrodes for use in transneurocutaneous 
stimulation (TNS). Contrary to electrodes for electrocardiographs, which 
transmit specific voltage differences, the TNS-electrodes should only be 
electrically conductive and this is achieved by means of the conductive 
gel substance which is preferably the more structure-forming component in 
this embodiment. It possesses the advantage of utilizing self-adhesive 
technology proper so that an electrode manufactured therefrom because of 
the self-adhesive zones may be fixed in a given position for many days. 
The electrially conductive gel may be a hydrophilic basal polymer such as 
polyacrylamide, salts of polymethacrylic and polyacrylic acids, polyvinyl 
alcohol or Na-CMC, softened by means of an emollient of low viscosists, 
e.g. a liquid polyol such as glycerol and optionally with an addition of 
typically 0.1-1.5% of NaCl, KCl or another biologically harmless, readily 
soluble salt and if desired 1-10% of water. 
A product of this kind is preferably made from a stack of alternating 
sheets or lengths rather them from strands. The zones in the finished 
product of the invention may be straight, curved or wavy, but may 
especially be approximately circular. In that case, the product may be 
made from a stack as alternating layers in the same manner as described in 
connection with the annular products, only omitting the aperture in the 
middle. The production may be performed in analogy with that described for 
the annular products.

DETAILED DESCRIPTION OF SOME EMBODIMENTS 
FIGS. 1 and 6 show a skin care product 10 consisting of alternating strips 
or zones 18 and 20 of material, all extending in a direction substantially 
perpendicular to the surfaces of the product. They are shown as flat, 
rectilinear strips but might for instance be curved or wavy. As shown they 
are also substantially parallel, which here as in other parts of the 
specification means that the individual layers have substantially 
equidistant boundary surfaces or edges 22. 
The zones 18 consist of an agent adhesive to the skin and comprising 
hydrophilic components, especially of the kind consisting of a continuous 
phase containing a self-adhesive elastomer mass and one or more 
hydrocolloids dispersed therein as a discontinuous phase. The zones 20 
consist of a continuous phase of a self-adhesive elastomer mass, 
preferably of the same kind as in the zones 18, but without any 
hydrophilic discontinuous phase. Thus the zones 20 will act as barriers 
which to a high degree will counteract migration of aqueous liquids from 
the zones 18 to the zones 20. The zones 20 do not, or only to a small 
degree, absorb water from the skin or wound surface to which a finished 
product produced from this semi-manufacture is attached. 
The skin care product shown in FIGS. 1 and 6 may be produced by alternately 
joining long strips of material 18 and material 20 to form a block which is 
subjected to light pressure to ensure full contact between the surfaces of 
the layers, after which the block is sliced into pads having a thickness 
of, e.g., 0.5-2 mm. It is expedient that the widths and numbers of the 
strips correspond to the desired surface dimensions of the product. It is 
observed that the thickness dimension shown in FIG. 6 is not necessarily 
correct relative to the length dimension. The lines 24 in FIG. 6 mark 
surfaces, but might as well represent detachable protective covers, for 
instance of siliconized paper, which may be placed on the semi-manufacture 
before it is worked up to form a final product. 
Slicing of the block of layers 18,20 may be carried out with a cutting wire 
but preferably takes place with a knife the sides of which are constantly 
moistened with a solvent which does not affect the materials of the block 
and which evaporates rapidly after the cutting. When the skin adhesive is 
one of the kinds described in the U.S. Pat. Nos. 4,231,369 and 4,367,732 
ethanol or isopropanol is preferably used as the solvent. 
FIGS. 2 and 7 show a skin barrier product 11 also built up from parallel, 
rectilinear thin zones 26 and 28. The zones are of different widths and 
can optionally be separated by barriers of foil 30. The zones 26 consist 
of a skin adhesive material of for instance the same kind as the zones 18 
or 20 in FIG. 1. The zones 28 consist of or contain a material active in 
some desired respect, here exemplified by an electrically conductive, 
hydrophilic gel material; in that case the zones of elastomer mass 26 
preferably do not contain hydrophilic components and the barriers of foil 
30 are preferably of aluminium. The electrically conductive material may 
for instance consist of karaya, glycerol, propylene glycol, NaCl and water 
in the weight ratio 42:53:3:0.25:3; or polyacrylate, glycerol, water and 
NaCl in the weight ratio 62:36:2:0.15; or polyoxyethylene, propylene 
glycol, water NaCl and KCl in the weight ratio 11:45.5:43:0.45:0.05; or 
gelatin, glycerol, water and NaCl in the weight ratio 47:47:4.8:1.2. 
The skin care product 12 shown in FIG. 3 consists of two alternating kinds 
of zones of material, viz. zones 32 of a skin adhesive, for instance of 
the same kind as the zones 18 in FIG. 1, and zones 34 of a material 
particularly suitable for transporting liquid through the thickness 
dimension of the product, viz. perpendicular to the plane of the paper. 
The structure permitting the transportation is shown as capillaries 36 but 
the transportation capacity may also be caused by, e.g., an open-cell foam 
material constituting or forming part of the zones. The capillaries may be 
incorporated into a hydrocolloid-free skin adhesive of, e.g., the same kind 
as the adhesive in zones 20 in FIG. 1 so that liquid will not migrate in 
the surface direction of the product. This product is especially suitable 
for the production of dressings for suppurating wounds. Migration of 
liquids parallelly to the surfaces may also be prevented by impermeable 
barrier layers, for instance foils between layers 32 and 34. 
The products shown in FIGS. 2 and 3 may be produced in the same way as that 
shown in FIG. 1. 
On the other hand, FIG. 4 shows a skin care product 13 built up and 
produced in another way. Its zones are short prismatic strands 40,42,44,46 
extending in a direction intersecting the surface of the product and being 
of two or more different kinds. Such a product is produced by extruding 
long strands of the respective kinds of material through nozzles, then 
preferably through a funnel-shaped tube in order to ensure that there will 
be no airfilled interstices between the strands, and subsequent slicing of 
the composite strand thus formed into thin pads. It will be understood 
that the final semi-manufacture will not have planar boundary surfaces 
between the strands as shown for the sake of clearness. Instead of being 
prismatic the nozzles may be round and of identical or different sizes, 
just as the prismatic strands may all have the same size and may 
advantageously have the cross-section as equilateral triangles, squares or 
regular hexagons. The slicing preferably is carried out at right angles to 
the longitudinal dimension of the long strands but might be oblique 
thereto. 
In the product shown in FIG. 4 the strands 40 of skin adhesive are of the 
same kind as are the zones 18 in FIG. 1; the strands 42 are 
liquid-transporting as are the zones 34 in FIG. 3, preferably with 
capillaries embedded in a hydrocolloid-free skin adhesive; the strands 44 
consist of a hydrocolloid-free adhesive like the zones 20 in FIG. 1; and 
the strands 46 contain a substance biologically active in skin care, e.g. 
an antiseptic or antibiotic, a growth-promoting agent or a wound-healing 
agent. 
The skin care product 14 shown in FIG. 5 contains a plurality of 
comparatively wide circular-cylindrical strands 50 of a skin adhesive of 
the same kind as that of the zones 18 in FIG. 1, viz. a self-adhesive 
elastomer mass containing a hydrocolloid embedded in a common strand 54 
consisting of a skin adhesive of the same kind as that in the zones 20 in 
FIG. 1, i.e. without a hydrocolloid or with a low content of hydrocolloid. 
This product may be produced by extrusion through a nozzle for the material 
for the strand 54 containing channels through which the material for the 
strands 50 is conveyed. 
It will be appreciated that the strands referred to in FIG. 4 and 5 are 
quite short, i.e. as the thickness of the product. 
FIG. 8 shows an annular skin barrier product for use in the production of 
ostomy appliances. It consists of three annular zones of material, outer 
and inner zones 56 of a skin adhesive of for instance the same 
hydrocolloid-containing kinds as the material of the zones 18 in FIG. 1, 
and therebetween a hydrocolloid-free zone 58. Inside the inner zone 56 
there is an aperture 60, and penetration of liquids from said aperture to 
the inner zone of sealing agent 56 is prevented by a cover of liquid-tight 
film or foil 62; the entire annular product is encased in a corresponding 
liquid-barrier 64. 
The number of annular zones may be greater, and annular zones consisting of 
or comprising other materials may also be present, e.g., 
liquid-transporting zones or zones containing biologically active 
substances. 
An annular product as shown in FIG. 8 may be produced by co-extrusion and 
slicing. 
Another embodiment of an annular skin barrier product is shown in FIG. 9. 
The zones of material here are in the form of layers 66,68 of Archimedean 
spirals surrounding a central aperture 60. There are two such "co-current" 
spirals extending from an inner end to an outer, but there might be more. 
One of the spirals 66,68 consists of a hydrocolloid-containing adhesive as 
that in the layer 18 in FIG. 1, the other of a hydrocolloid-free material 
of the same kind as that in the layer 20 in FIG. 1. Innermost adjacent the 
aperture 60 and outermost facing the outer world a barrier foil or film as 
the foils or film 62,64 in FIG. 8 may be provided. 
This product may be produced by uniting two wide lengths corresponding to 
the zones 66 and 68, optionally providing the laminate thus formed with 
barrier foil or film on one side, and winding them around a suitable 
cylindrical object on which the roll may slide. Then the roll is moved 
forward in its length direction (the width direction of the lengths) and 
is sliced into thin pads just in front of cylindrical core. It will be 
understood that the ring formed may nave a barrier foil for every two 
layers, seen radially. The line 74, however, only marks the boundary 
surface between the two spirals, but might also represent a barrier foil. 
By producing blanks for sealing rings for ostomy pouches as explained in 
connection with FIG. 8 and FIG. 9 there is achieved the advantage of 
avoiding the waste of material that will inevitably occur in the known 
production of such sealing rings by punching from sheets or lengths of the 
skin adhesive. 
By rolling into spirals and slicing, an electrically conductive skin 
barrier product may be advantageously produced. In that case one of the 
layers of material 66,68 consists of a self-adhesive elastomer mass mainly 
of hydrophilic components, and the other of an electrically conductive, 
hydrophilic gel material as described hereinbefore. A thin aluminium foil 
may further be placed between the lengths of material. 
In order to prevent flow of the edges the skin barrier products described 
may be bevelled along their edges as described in European patent 
application publication No. 264,299. 
EXPERIMENTS 
In the field of ostomy bandages the so-called two-piece bandages gain an 
increasing popularity, i.e. for economic reasons because it is possible to 
change and discard the parts at different frequencies. 
In two-piece ostomy equipment an ostomy bag or ostomy stopper is firmly 
attached to one member of an annular two-part coupling ring and a skin 
barrier and sometimes also other equipment firmly attached to the other. 
The rings can be hermetically united to each other by some snap-like 
closing structure and comparatively easily disjoined from each other. 
Thus, during function the skin barrier keeps the bag or stopper in place 
around or in the ostomy opening. Numerous examples of such ring coupling 
systems are known, e.g. from European patent application publication No. 
188,776 (FIG. 7) and Danish patent specification No. 151,044 corresponding 
to U.S. patent application Ser. No. 987,523 of May 27, 1986. 
In such two-piece systems the part with the ostomy bag or stopper must 
necessarily be discarded and replaced frequently, commonly several times a 
day, whereas there is no reason to replace the skin barrier with its 
coupling ring as long as the skin barrier itself is intact. 
Adhesive materials as those described in the introducing parts of the 
present specification and disclosed in, i.a. U.S. Pat. Nos. 3,339,546, 
4,321,369 and 4,367,632, normally function excellently for periods of one 
to two days, but during the period following that the juices escaping from 
the ostomy opening will usually penetrate into the skin barrier and cause 
it to leak, which is very unpleasant for the user of the ostomy closing 
system. 
By experiments it has been shown that a skin barrier according to the 
present invention will greatly prolong the lifetime of the coupling part 
provided with the skin barrier and belonging to a two-piece ostomy system. 
A. 1. An adhesive mass as described in the Example of U.S. Pat. No. 
4,367,632 applied as a melt to a thickness of 1 mm on siliconized paper 
and a film of EVA (ethylene-vinylacetate copolymer) having a thickness of 
70 .mu.m was laminated onto its free surface. From this there was in the 
usual manner punched circular discs having an outer diameter of 100 mm and 
varying inner diameters (25 to 50 mm, individually adapted to the sizes of 
the stomas of the volunteers participating in the tests). The center parts 
and the material between the discs were discarded as waste material. 
A. 2. The same kind of adhesive mass as above was applied as a melt to a 
thickness of 1.5 mm to a length of siliconized paper. Another adhesive 
mass, having the same composition as the first one except for its content 
of hydrocolloid (30% Na-CMC) was applied as a melt to a thickness of 0.5 
mm onto another length of siliconized paper. 
The two lengths, each having a width of 1 meter, were wound together, the 
surfaces not provided with the siliconized paper facing each other, while 
pulling the siliconized papers off. In this manner there was formed 1 m 
long cylinders having an outer diameter of 100 mm; the winding was made 
around re-usuable cylindrical, silicone -coated rods of varying diameters 
(25-50 mm) to accommodate various sizes of stomas. The result was a 
spirally coiled roll having a cross-section largely as the disc shown in 
FIG. 9 of this specification. The layers of the roll alternated throughout 
its thickness between layers with and layers without hydrocolloid in the 
adhesive mass. 
The roll was sliced into annular discs each having a thickness of 1 mm by 
the aid of a specially designed slicing machine with a rotating steel 
blade which was constantly moistened with ethanol from a felt pad. The 
machine could cut 60 such discs per minute. 
The machine was adapted to catch the thin, flexible discs formed (which 
each is a skin barrier product according to the invention on a sheet or 
length of EVA film which may serve as a carrier or packing material for 
the product or may even be a part of an ultimate product produced from the 
semi-manufacture. 
It should be noted that the hydrocolloid-containing adhesive mass lost its 
self-adhesive properties in the surface immediately upon the cutting 
operation because the particles of hydrocolloid appeared in the very 
surface. After storage, however, the material regained its surface 
self-adhesive properties. The 0.5 mm zones of hydrocolloid-free adhesive 
mass sufficed to permit the immediate adhering to the EVA film and other 
suitable surfaces. 
A. 3. Thereafter both types of skin barrier, 1 and 2, were worked up with a 
ring coupling to form a stopper system as illustrated by FIG. 7 in European 
patent application publication 188,776 (Danish patent specification No. 
153,122). 
The two stopper systems were comparatively tested by 25 colostomy patients 
who were users of such stopper systems. 
A significant difference was found between the two different kinds of skin 
barriers. Skin barriers No. 1, that comprising only the 
hydrocolloid-containing adhesive, could be used in average only 
approximately 2 days, whereas skin barrier No. 2, that comprising 
alternating zones of hydrocolloid-containing and hydrocolloid-free 
adhesive could be used in average about 10 days. 
B. Another experiment was made with 20 volunteers who were accustomed to 
using ileostomi bags attached to the body by the aid of a skin barrier 
according to A. 1. above. 
The test skin barriers were made to dimensions as described under A.2. 
above, but with alternating zones, viz. 1 mm wide zones of a 
hydrocolloid-free adhesive mass as described under A.2., alternating with 
non-self-adhesive zones (3 mm wide) of gelled karaya/glycerol 1:1. 
The preparation took place in analogy to what is described in U.S. Pat. No. 
4,062,261 (DK 132,645), only with the difference that the elastomer mixture 
there shown was replaced by the abovementioned self-adhesive mass. In this 
process the sheet material, having a width of 1 meter, only had to be 
wound alone while at the same time removing a single sheet of siliconized 
paper. 
The skin barrier product was confectioned as described under A., and tested 
by use in a two-piece bag system with an ileostomy bag mounted by the aid 
of a two-piece coupling. 
Again, there was found an outspoken improvement of the lifetime of the skin 
barrier in comparison with that of the usual skin barrier. Moreover, the 
users much appreciated the presence of karaya which is known as an 
extremely skin-friendly material but which suffers from the inconveniency 
that it disintegrates too quickly. 
INDUSTRIAL USE OF THE INVENTION 
It is expected that the invention will attain an almost immediate use in 
the manufacture of skin barriers for attaching ostomy equipment, drains 
and catheters to the human body; and later also in highly specialized skin 
and wound care products.