Note: Descriptions are shown in the official language in which they were submitted.
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GLASS FIBRE MAT AND PRODUCTS CONTAINING GLASS FIBRE MATS
BACKGROUND OF THE INVENTION
The present invention relates to a glass fibre mat. It further relates to
products containing
glass fibre mats, particularly a CV floor covering comprising a glass fibre
mat as a
structural layer.
Glass fibre mats are known in multifarious embodiments and for various
applications.
Also known are customary methods of producing glass fibre mats from glass
fibres and
binders. A significant application of glass fibre mats is their use as a
carrier material in
floor coverings, particularly in CV (Cushioned Vinyl) floor coverings. During
the production
of CV floor coverings, the glass fibre mat is typically initially impregnated
in a first step
with a PVC paste (particularly Plastisol). For this purpose, the PVC paste is
usually
applied to the glass fibre mat by means of a coating knife in a predetermined
layer
thickness or with a predetermined surface weight (e.g. approx. 400 g/m2). A
further layer
of PVC paste is then applied to the glass fibre mat impregnated in such a way,
wherein
the surface weight of this second layer can typically lie roughly within the
same order of
magnitude as the impregnating coating. The back foaming, i.e. the application
of an
elastically flexible coating to the back side of the glass fibre mat, then
takes place. The
usable side can then receive a final finishing, for example by means of a
coating of clear
varnish or other special coatings. This kind of production of CV floor
coverings has been
known in the PVC industry for some time and is widely used in different
variants.
Various requirements are made of the glass fibre mat forming the carrier layer
in this
respect, some of which are to some extent in conflict with one another. Hence,
the glass
fibre mat should exhibit good mechanical strength, namely both during the
processing
and also during the use of the floor covering designed and produced using said
glass
fibre mat. It is therefore important for both the PVC paste and also the back
foaming to
create an optimal mechanical connection with the glass fibre mat, so that
these layers are
prevented from separating from the glass fibre mat when the floor covering is
in use. On
the other hand, the PVC paste, which is applied to the glass fibre mat by
means of a
coating knife, as described above, must be prevented from penetrating through
said glass
fibre mat. This is because otherwise more or less noticeable lumps of PVC form
on the
back side of the glass fibre mat, where the backing foam is to be applied
subsequently,
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which has a substantially adverse effect on the level of comfort when walking
on the CV
floor covering. Furthermore, as usual cost considerations play a part, both in
relation to
the production of the glass fibre mat and also in relation to the impregnation
thereof with
PVC paste, in which case the consumption of PVC paste for impregnation is
crucially
dependent on the thickness and the properties (pore volume, permeability,
absorbability,
pore size distribution) of the glass fibre mat.
BRIEF SUMMARY OF THE INVENTION
The present invention is aimed at providing a glass fibre mat which is ideally
suited for
use as a carrier material in a CV floor covering, in that is satisfies all the
requirements
described above in a practical manner and, to this extent, is superior to the
prior art in its
overall properties.
DETAILED DESCRIPTION OF THE INVENTION
This problem is solved according to the present invention by a glass fibre mat
comprising
glass fibres of a first kind, glass fibres of a second kind and a binding
agent, wherein the
glass fibres of the first kind are characterized by a mean fibre diameter of
under 6pm and
compliance with the EC Protocol "ECB/TM/27 rev. 7" and the glass fibres of the
second
kind are characterized by a mean fibre diameter of over 6pm, wherein
furthermore the ratio
between the weight component of glass fibres of the first kind and the weight
component of
glass fibres of the second kind is between 0.01 and 0.15 and, in addition, the
surface
weight of the glass fibre mat is between 25 g/m2 and 80 g/m2.
In other words, therefore, a specific combination of synergistically
interacting features is
characteristic of the glass fibre mat according to the invention, such that it
comprises
various glass fibres connected to one another by means of a binding agent,
namely
relatively thin glass fibres of the first kind on the one hand, i.e. those
with a mean fibre
diameter of under 6 pm and, on the other hand, relatively thick glass fibres
of the second
kind, i.e. those with a mean fibre diameter of over 6 p, wherein the weight
component of
glass fibres of the first kind in the glass fibre composition is significantly
smaller than the
weight component of glass fibres of the second kind, in that the ratio between
the weight
component of glass fibres of the first kind and that of glass fibres of the
second kind lies
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between 0.01 and 0.15, wherein furthermore glass fibres of the first kind
within the
meaning of the criteria according to the EC Protocol "ECB/TM/27 rev. 7"
(Biopersistence
of Fibres; Intratracheal Instillation) are not biopersistent and the surface
weight of the
glass fibre mat lies between 25 g/m2 and 80 g/m2. The properties of the
corresponding
glass fibre mat make it particularly suitable, especially with regard to the
use described
above, although they also allow a use of the glass fibre mat according to the
invention
associated with significant advantages in a series of other applications, in
which similar
requirements are made of the glass fibre mat (see below). One aspect which is
to this
extent significant and entirely surprising in this context is that despite its
relatively low
surface weight of between 25 g/m2 and 80 g/m2, which is even lower than the
typical
surface weight of known glass fibre mats used and suitable for similar
applications, which
contain no microfibres, and therefore despite the smaller proportion of
stronger glass
fibres to this extent, compared with traditional glass fibre mats with only
one kind of glass
fibres, the glass fibre mat according to the invention exhibits no significant
loss in terms of
mechanical properties such as strength, in particular, wherein at the same
time, however,
the risk that (in the preferred application described above) PVC paste
penetrates through
the glass fibre mat and forms lumps on the back side is significantly reduced
compared
with the relevant prior art. At the same time, when the glass fibre mat
according to the
invention is used, compared with the state of the art, the surface of the
finished floor
covering can be improved by minimizing irregularities on the usable side. It
should
furthermore be emphasized that the need for PVC paste, which is required in
order to
impregnate the glass fibre mat, can be reduced when using the glass fibre mat
according
to the invention, namely without the bond between the glass fibre mat and the
impregnation being adversely affected as a result of this. Because the
microfibres, i.e.
glass fibres of the first kind exhibiting a mean fibre diameter of under 6 pm
are
furthermore not biopersistent (see above), the glass fibre mat according to
the invention
and the products manufactured using it are non-hazardous from a health
perspective; this
is because the glass fibres released particularly during processing
(particularly at raw
edges) can cause no harm in the human body, because they are either not
respirable
(this is the case with glass fibres of the second kind) or, however, are
dissolved in the
body by bodily fluids (this is the case with glass fibres of the first kind).
To this extent,
although glass fibres of the second kind may likewise be non-biopersistent,
they need not
necessarily be so, which is an important aspect both with regard to
flexibility, which
concerns the glass used for glass fibres of the second kind, and also with
regard to
production costs.
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Although the use of the glass fibre mat according to the invention, as
discussed in detail
above, is paramount when it comes to the manufacture of floor coverings, as
far as the
particular suitability of the glass fibre mat according to the invention is
concerned, this is
in no way the only possible use. Various aspects presented above, which
characterize
the glass fibre mat according to the invention, mean that this can also be
used instead
particularly advantageously for a series of other applications. Something to
be particularly
mentioned in this case is its use (in the manner of a traditional wallpaper)
as a paintable
ceiling and wall covering, with which an outstanding surface quality can be
achieved with
a very small (subsequent) application of paint, wherein furthermore the
extremely low
tendency for the paint to pass through the mat has a very favourable effect on
the bond
between the glass fibre mat acting as a ceiling or wall covering and the base
concerned.
The fact that a very good surface quality can be achieved with a very small
amount of
wall or ceiling paint is not only an economic aspect in this case. It also
means that the
weight of the ceiling and wall covering plus the coat of paint, i.e. the
painted ceiling and
wall covering, is relatively small, which for its part accommodates the bond
of the glass
fibre mat to the base. These advantageous criteria apply in a very similar
manner when
using the glass fibre mat according to the invention as the surface coating on
a sheet of
building material, particularly a mineral ceiling or wall panel, such that the
glass fibre mat
is applied to the preformed board at the factory (particularly by adhesion or
surface
lamination). This is because the specific structure of the glass fibre mat
according to the
invention prevents the adhesive from penetrating through from the back side to
the front
surface, i.e. the visible side, so that the surface quality of the visible
side and the paint
adhesion are not adversely affected by adhesive tracks. Likewise, due to its
favourable
properties, as described, the glass fibre mat according to the invention can
be used
particularly advantageously as a cover for interior elements, particularly of
a motor
vehicle, particularly as a cover panel or other interior facing.
The particular advantages of the glass fibre mat set out above are
particularly distinct
when the mean fibre diameter of glass fibres of the first kind is between 0.5
pm and 6 pm,
preferably between 0.6 pm and 3.0 pm, particularly preferably between 0.6 pm
and 1.5
pm.
Furthermore, according to another preferred development of the present
invention, it is
particularly favourable for the mean fibre diameter of the glass fibres of the
second kind to
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be between 6 pm and 13 pm. Particularly in combination with the preferred
dimensions of
the glass fibres of the first kind, as indicated above, particularly
outstanding material
properties result, which make the corresponding glass fibre mat particularly
attractive for
the uses set out above.
Glass fibres of the second kind particularly preferably comprise C-glass
and/or E-glass,
wherein T-glass for glass fibres of the second kind is also highly suitable
for various
applications. It is particularly advantageous in this case for glass fibres of
the second kind
to comprise a mixture of at least two different kinds of glass fibre. If the
mixture of glass
fibres of the second kind in this respect comprises both C-glass and also E-
glass, it is
preferable for the proportion of glass fibres comprising C-glass in the
mixture of glass
fibres of the second kind to be greater than the proportions of glass fibres
comprising E-
glass, wherein the proportion of glass fibres comprising C-glass in the
mixture of glass
fibres of the second kind may even be substantially greater within the
framework of the
present invention than the proportions of glass fibres comprising E-glass. The
ratio
indicated above is in turn favourable with regard to the particular properties
of the glass
fibre mat according to the invention described above, as they are useful,
particularly in
flooring applications. For other applications, however, other ratios may also
be entirely
favourable, even up to a proportion of 100 % of glass fibres comprising E-
glass
accounting for fibres of the second kind.
According to yet another aspect of the present invention, glass fibres of the
second kind
particularly preferably have a mean length/diameter ratio of between 500 and
2000. This
proportion of glass fibres of the second kind bears a special relationship to
the particular
function thereof within the glass fibre mat, particularly with regard to
mechanical strength
(see above).
According to yet another preferred development of the present invention, the
ratio
between the weight component of glass fibres of the first kind and the weight
component
of glass fibres of the second kind for typical applications of the glass fibre
mat according
to the invention is preferably between 0.03 and 0.08, particularly preferably
between 0.04
and 0.06. The aforementioned ratio is favourably less than 0.055, ideally less
than 0.048.
In turn, there result in this case quite particularly advantageous properties
of the glass
fibre mat according to the invention, particularly with regard to the possible
use thereof as
a carrier material in CV floor coverings with outstanding properties. In this
respect, it is
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furthermore favourable for typical applications if the surface weight of the
glass fibre mat
lies between 40 g/m2 and 60 g/m2. For specific applications, very good results
can be
achieved, however, with values that differ from these, e.g. a ratio between
the weight
component of glass fibres of the first part and the weight component of glass
fibres of the
second kind of less than 0.03.
As far as the binding agent of the glass fibre mat according to the invention
is concerned,
there is significant latitude here, which may particularly take account of the
subsequent
use of the glass fibre mat according to the invention. Particularly
advantageous binding
agents are urea resins and polyacrylic acid binders. The binding agent may,
however,
also comprise polyacrylic acid. Outstanding properties result when the binding
agent
comprises a mixture of urea resin and a polymer dispersion or a mixture of
polyacrylic
acid binders and a polymer dispersion.
Likewise, considerable latitude exists on the other hand in relation to the
weight
component of the binding agent in the glass fibre mat, wherein to this extent
the specific
binding agent used in each case and also the use of the glass fibre mat can
play a part.
For the possible use of a CV floor covering as a carrier material, which is
paramount in
this case, a weight component of the binding agent of between 15 % and 35 %,
preferably of between 20 % and 30 %, of the total weight of the glass fibre
mat is
advantageous.
The binder may, depending on the designated subsequent use of the glass fibre
mat in
each case according to the invention, contain an additive (or a plurality of
additives),
which may account for up to 50% of the total weight of the binder. The
additive (or
additives) may specifically modify or else optimize the properties of the
binder in this case
with regard to the individual determination of the glass fibre mat. Typical
additives are, for
example, kaolin and TiO2. However, not only can the binder be technically
optimized by
additives, but additives are also capable of reducing costs by being able to
make an
expensive binding agent "go further".
With regard to the relationships described above, it is advantageous for
typical
applications if the porosity of the glass fibre mat lies within the range of
roughly 1000
1/m2s and roughly 3000 1/m2s, wherein a porosity of between roughly 1500 1/m2s
and
roughly 2500 1/m2s is particularly favourable. The above values for a
preferred porosity
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are based on the measurement standard DIN EN IS09237, namely for a
differential
pressure of 100 Pa.
The present invention according to the above embodiments does not relate
exclusively to
the untreated glass fibre mat. Instead, the invention also relates
particularly to a glass
fibre mat pretreated for subsequent specific further processing, particularly
provided with
additional impregnation, wherein the impregnating agent may be particularly a
plastisol or
another PVC-based means. Furthermore, the present invention also extends to
the
finished CV floor covering produced using the glass fibre mat according to the
invention,
which CV floor covering comprises a usable layer and a structural layer,
wherein the
structural layer comprises a glass fibre mat according to the invention
provided with
impregnation (see above).
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