Note: Descriptions are shown in the official language in which they were submitted.
CR119/AA 2159965
AHSORHENT ARTICLE HAVING.ADHESIVE FASTENING MEANS
This invention relates to an absorbent article
having adhesive fastening means for attaching such an
article to an undergarment. The invention is
particularly concerned with a pantiliner, and, more
particularly, a thin pantiliner, which, in use, is
attached to the crotch region of the user's panty by
means of adhesive. The following description is
particularly concerned with pantiliners. It is to be
understood, however, that the invention is also
applicable to sanitary napkins, incontinent pads, and
other articles which are designed to absorb and retain
liquid and other discharges from the human body.
The use of an adhesive, usually referred to as
panty fastening adhesive, is well known in the above
context, and attention is directed to International
Patent Publications Nos. WO 92/04000 (Papa et al) and WO
93/01785 (Osborn et al) which include descriptions of
various patterns in which the panty fastening adhesive
may be applied. It is objects of the present invention
to provide an absorbent article in which the panty
fastening adhesive is applied thereto in a pattern which
is particularly advantageous. In one particular aspect
thereof, the invention is concerned with patterns which
are suitable for use on a very thin pantiliner which is
stretchable, and which is preferably elastic.
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The Osborn patent publication identified above
describes sanitary articles which are elastic, and some
of
which have a thickness of as little as about 3mm.
Such articles
are highly flexible and, because of their elasticity,
are potentially able to follow the stretch of the panty
in use.
However, these very characteristics pose
potential problems in relation to the panty fastening
adhesive. The adhesive connection between the panty and
the pantiliner must be such that it does not impair the
elastic properties of the pantiliner, or at least does
not do so to any significant extent. It is an object of
one aspect of the present invention to provide an
adhesive pattern which is able to deal with these
problems. It should be noted, however, that the
adhesive patterns described herein are also applicable
to non-elastic adhesive articles, and has advantages in
relation to these also. This is to deal with the fact
that there is a tendency for the panty movement to cause
A
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bunching of the pantiliner so that it tends to separate
itself from the panty, and to curl and stick to itself.
According to the present invention there is
provided an absorbent articlES for adhesive attachment to
an undergarment, wherein adhesive is applied to a
surface of
the article, said surface be=ing outwardly defined by a
perimeter, the adhesive being applied only to at least
one portion the said surface of at or adjacent the said
perimeter, the remainder of the surface being
substantially adhesive-free.
Preferably at least: 25~ of the said surface is
adhesive-free, and more preferably at least 50~.
Preferably, the adriesive extends completely to
the perimeter or, if there i;s a gap between the edge of
the adhesive and the perimeter, the gap is not more than
3mm, and more preferably from 1 to 2mm in width.
In some embodiments, the adhesive is applied
in the form of one or more strip-shaped regions which
extend around at least a major portion of the periphery
of the article, at or adjacent the periphery.
Some embodiments oi: the invention will now be
described with reference to Figures 1 to 7 of the
accompanying drawings, which are plan views of
pantiliners of hourglass shape, showing that face of the
pantiliner which carries the panty fastening adhesive.
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Each of Figures 1 to 7 shows a pantiliner of
the-same shape and size. In one embodiment, it has a
length of about 153mm, a maximum width of about 67mm,
and a minimum width of about Slmm. It is to be
understood that the pantiliner could have other
dimensions and/or be of some other shape, e.g.
rectangular.
The pantiliner has an absorbent layer of which
one face is adhesively bonded to a liquid-impermeable
backsheet and the other face may be covered by a liquid-
permeable topsheet to which it is adhesively bonded.
The absorbent layer may itself consist of a plurality of
sub-layers having different characteristics. At least
one of the layers of the pantiliner, and for this
purpose the term "layer" includes the adhesive
connection between the absorbent layer and the backsheet
and, if present, the adhesive connection between the
absorbent layer and the topsheet, is elastic, and all
layers which are not elastic are at least stretchable.
By this means the article as a whole is rendered
elastic. Further details of this can be found in our
Italian Patent Application identified above.
For present purposes, however, it is sufficient to
note that the pantiliner just described has panty
fastening adhesive applied. to the aforementioned
backsheet, and it is the disposition of this panty
fastening adhesive which is shown in Figures 1 to 7.
The panty fastening adhesive is applied only to one or
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more regions of the backshe:et which are adjacent the
periphery thereof. A substantial portion of the
backsheet, preferably at least 25~ thereof, and more
preferably at least 50$, has no adhesive applied
thereto. As supplied to the user, the face of the
backsheet to which the panty fastening adhesive is
applied is covered by a protective release layer but
this is removed by the user prior to use.
In the case of Figure 1, the adhesive is
applied in a narrow perimetral strip the width of which
is preferably from 4mm to lOmm, and more preferably
about 5mm. In the case of Figure 2, the
adhesive is applied in the form of two longitudinally
extending strips, one extending along each lateral edge.
There is thus a central strip which is free of adhesive,
and which is preferably at least 15mm wide, more
preferably from 29mm to 43mm wide, for example about
35mm wide. Given the overall dimensions of the
pantiliner set out above, an adhesive-free strip 35mm
wide thus corresponds to having two adhesive strips,
each with a maximum width of 16mm and a minimum width of
8mm.
The adhesive pattern of Figure 3 is the same
as that of Figure 1, except that a narrow gap, which is
not more than 3mm, and is preferably from 1 to 2mm, is
left adhesive-free between the perimeter of the
pantiliner and the outer edge of the adhesive strip.
The presence of this gap makes it easier for a user to
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grasp the edge of the pantiliner when the time comes to
remove it from the panty. It also makes it easier for
the user to remove the protective silicone-coated film
by which the adhesive- coated side of the pantiliner is
normally covered in the condition in which it is
purchased by the user.
A similar effect, is achieved with the
embodiment of Figure 4, where, instead of having a
continuous, narrow, adhesive--free area around the entire
perimeter of the pantiliner, the adhesive strip has two
breaks in it, one at each end, the breaks being
preferably from 15mm to ~35mm in length, and more
preferably 20mm in length.
Figures 5 to 7 show some further possible
adhesive patterns. Figure 5 is similar to Figure 1, but
has small adhesive-free areas at each of its four
corners. Each of these areas is preferably from 1 to
2mm in width at the point where its width is greatest.
Figure 6 combines the adhesive-free periphery of Figure
3 with the adhesive- free gaps of Figure 4. Figure 7 is
also similar to Figure 3, except that it has a small
area at each end where the .adhesive extends completely
to the edge of the pantilin.er. I will be understood
that many other variations in the adhesive pattern are
possible within the scope of the present invention.
Using the adhesive patterns shown in Figures 1 to 7, the
pantiliner is attached to the panty over what is
preferably only a small part of its area.
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It will be seen that in each of the patterns
shown in Figures 1, 2, 4 and 5, the adhesive extends to
the very edge of the pantil.iner over at least a major
portion of the perimeter thereof, i.e. more than 50~,
preferably more than about 65~. In the case of the
pattern of Figure 1 the proportion is 100$. In the case
of Figure 2 the proportion is preferably from 75~ to
90$, and more preferably from 80~ to 85~. In the case
of Figure 4 the proportion is preferably from 80~ to
95~, and more preferably from 85~ to 95~. In the case
of Figure 5 the proportion is preferably at least 95~.
In the case of the' patterns of Figures 3 and
6, the adhesive does not extend to the very edge of the
pantiliner, but extends to .a point very close to that
edge over the whole (Figure' 3), or substantially the
whole (Figure 6) of the perimeter. In the case of
Figure 7 the adhesive extends to a point very close to
the edge of the pantiliner over substantially the whole
of the perimeter, and actually to the edge over a small
portion of the perimeter.
It has been found that the provision of
adhesive only at or adjacent a major portion of the
periphery of the pantiliner, enables the pantiliner to
retain a secure grip on the panty during movement of the
latter, and avoids, or at least reduces, the tendency of
the pantiliner to bunch and wrinkle and, not
infrequently, stick to itself. The effect thus provided
is particularly advantageous in the context of an
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elastic pantiliner, such as the very thin elastic
pant:iliner described in our above-mentioned Italian
Patent Application. In those embodiments of the
invention where the adhesive is applied to a relatively
small area (preferably not more than 50~ of the total
surface are), the adhesive used need not be stretchable,
even though the pantiliner i;; stretchable, and this in
itself represents an advantage.
Suitable panty fastening adhesives which can
be used include SAVARE LA203 * (produced by Savare
I.C.S.r.l.) and KORAMELT 86~9* produced by Kommerling
Chemische Fabrik K.G.. Both of these are SEBS
(styrene-ethylene-butylene- atyrene block copolymer
based, hot melt adhesives.
The adhesive is pi:eferably applied with a
basis weight of about 24g/m2 by coating, for example
using a slot die coater, or by spraying or by printing.
The description thus far has largely dealt with
articles which are elastic. However, as mentioned
briefly above, the adhesive patterns according to the
invention are also advantageous when applied to
non-elastic articles.
Firstly, articles, for example pantiliners,
which are stretchable but non-elastic, give rise to
similar problems of bunching arid wrinkling as do elastic
articles, and these may indeed be even more acute.
Accordingly, the patterns according to the invention may
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215996
advantageously be applied to stretchable but non-elastic
articles.
Secondly, whether the articles are elastic,
stretchable but non-elastic, or non-stretchable, it is
desirable that, where they are adhesively fastened to a
panty, they should be gas-permeable, though liquid-
impermeable, so as to allow water vapour to pass through
them. To this end, not only must the backsheet be gas-
permeable, but its permeability must not be too greatly
impaired by the panty fastening adhesive.
