ECARTEUR POUR VITRAGE ISOLANT A VITRES MULTIPLES

SPACER FOR MULTIPLE-GLAZED INSULATING GLAZING

Abrégé français

L'invention concerne un écarteur pour vitrage isolant à vitres multiples, comprenant un corps de base (5) présentant deux surfaces d'appui (9, 11) pour les vitres (1, 3), s'étendant parallèlement entre elles, et une surface de collage (19), orientée à l'opposé de l'espace intérieur du vitrage et reliant les deux surfaces d'appui, le corps de base (5) étant fabriqué en matière plastique renforcé aux fibres de verre. Cet écarteur est caractérisé en ce qu'une feuille métallique (21) est collée sur toute la surface de collage (19), et en ce qu'en choisissant la proportion de fibres de verre dans la matière plastique du corps de base, il est possible d'équilibrer mutuellement les coefficients de dilatation thermique du corps de base et de la feuille métallique. Un tel écarteur permet d'obtenir une excellente étanchéité et une liaison durable entre l'écarteur en matière plastique et la feuille métallique, ainsi qu'entre cette feuille et le produit d'étanchéité se trouvant entre les vitres.

Abrégé anglais

The invention relates to a spacer for multiple-glazed
insulating glazing, comprising a base element (5), which has two
parallel contact surfaces (9, 11) for the glazing panels (1, 3), and
an adhesive surface (19) which is turned away from the inner
space of the glazing unit and connects the two contact surfaces.
The base element (5) is made of fibreglass reinforced plastic.
Said spacer is characterized in that a metal foil (21) is glued
against all of the adhesive surface (19), and in that by selecting the
proportion of fibreglass in the plastic matter of the base element
it is possible to match the coefficients of thermal expansion of
the base element and the metal foil. This type of spacer ensures
especially good leak tightness and lasting bonding between the
plastic spacer and the metal foil, and between said metal foil and
the sealant between the glazing panels.

Revendications

7
CLAIMS:
1. A spacer for a multiple glass pane insulating
glazing assembly, comprising a base body (5) having two
mutually parallel contact surfaces (9, 11) for glass panes
(1, 3) and an adhesion surface (19) which connects the two
contact surfaces and faces away from the interior space of
the glazing, said base body (5) consisting of glass-fiber
reinforced plastic material, and a metal layer (21) being
disposed on the adhesion surface (19), characterized in that
the metal layer (21) is bonded or vapor-deposited on the
entire adhesion surface (19) and the proportion of short
glass fibers in the plastic material is selected such that
the coefficient of thermal expansion of the base body (5)
corresponds to that of the metal layer (21).
2. A spacer according to claim 1, characterized in
that the metal layer (21) is a metal foil, and in that it is
bonded to the base body (5) by a non-gassing adhesive curing
with humidity.
3. A spacer according to claim 1 or 2, characterized
in that the base body (5) comprises a hollow space (29).
4. A spacer according to one of claims 1 to 3,
characterized in that said adhesion surface (19) has an
essentially U-shaped configuration in cross-section.
5. A spacer according to one of claims 1 to 4,
characterized in that the metal foil is made of aluminum.

8
6. A spacer according to one of claims 1 to 5,
characterized in that the base body (5) is made of a
thermoplastic material.
7. A spacer of claim 6 wherein said thermoplastic
material is a SAN plastic
8. A spacer according to one of claims 1 to 5,
characterized in that the wall (31) of the base body (5)
facing the interior space (7) of the multiple glazing
assembly is provided with openings (35).
9. A spacer according to claim 3, characterized in
that the hollow space (29) of the base body (5) contains a
desiccant.
10. A spacer according to one of claims 1 to 9,
characterized in that the metal foil has first and second
edges adjacent respective ones of said glass panes (1, 3)
and disposed at a distance from said adjacent respective
glass panes (1, 3).

Description

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SPACER FOR MULTIPLE-GLAZED INSULATING GLAZING
The invention relates to a spacer for a multiple pane
insulating glazing assembly.
Such spacers are especially utilized for double pane
insulating glass in order to provide a spaced connection
of the two individual glass panes. Moreover, they serve
the function of sealing the interior space between the
panes from the ambient so that, for example, a gas
introduced therein cannot escape. Furthermore, by an
appropriate configuration, they are intended to prevent
moisture or air from the ambient from penetrating into the
interior space, which would cause the glass panes to
become opaque over a longer period of time.
However, many spacers of the prior art present the
disadvantage that. they exhibit a higher thermal
conductivity compared to the gas or air enclosed in the
interior space. I3ecause of this, the inner glass pane is
strongly cooled :in the immediate region of the spacer when
outside temperatures are low, thus resulting in unwanted
moisture condensation at these locations.
An improvement of the insulating properties of
spacers has been obtained by the use of a plastic
material. However, this presents the problem that the
adhesive and sealing mass introduced between the edges of
the two glass panes, usually polysulphide or silicone,
poorly adheres to the plastic material since these
adhesives were usually developed especially for metallic
spacers. This results in leakage between the interior

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space and the ambient as well as hollow spaces between the
spacer and the sealing mass where moisture can collect and
further deteriorate the seal.
It is further known to reinforce the strength of
the plastic material by the use of glass fiber or mineral
powder reinforcements, e.g. according to US-A-5 260 112 or
EP-B-127 739.
According to the latter patent specification, on
which the preamble is based, the free surface of the spacer
in the assembled condition is provided with a metal coating
for the purpose of inhibiting the diffusion of water vapor.
The metal layer is coextruded with the spacer. This coating
method only allows a poor adhesion of the metal layer,
particularly in the case of great temperature variations.
This is especially important if, in contrast to the spacer
according to this patent specification, a sealing mass is
applied around the free part of the spacer, i.e. around the
metal layer, which should adhere both to the metal layer and
to the glass panes in order to obtain a good and durable
stability overall.
On the background of this prior art, it is the
object of the present invention to provide a spacer which,
having a low thermal conductivity, allows a reliable
adhesive bond and seal and in particular, a good adherence
of the metal layer to the plastic body.
According to the present invention there is
provided a spacer for a multiple glass pane insulating
glazing assembly, comprising a base body (5) having two
mutually parallel contact surfaces (9, 11) for glass panes
(1, 3) and an adhesion surface (19) which connects the two
contact surfaces and faces away from the interior space of

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the glazing, said base body (5) consisting of glass-fiber
reinforced plastic material, and a metal layer (21) being
disposed on the adhesion surface (19), characterized in that
the metal layer (21) is bonded or vapor-deposited on the
entire adhesion surface (19) and the proportion of short
glass fibers in the plastic material is selected such that
the coefficient of thermal expansion of the base body (5)
corresponds to that of the metal layer (21).

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The invention will now be explained in more detail
with reference to the single drawing which shows a cross-
section of the edge area of a double glazing.
Two glass panes 1, 3, of which only sections are
shown, are disposed in parallel to and at a distance from
each other by means of a spacer 5. This spacer 5 extends
along the non-represented edges of the two glass panes l,
3 so as to form an interior space 7 between the glass
panes. This interior space 7 is usually filled with air
and preferably with gas.
The spacer 5 includes contact surfaces 9 and 11, each
of which faces one of glass ~>anes 1 and 3, respectively.
In order to seal interior space 7, the contact surfaces 9
and 11 are provided with groove-shaped recesses 13 and 15,
respectively, into which a p~_astic sealing mass is
introduced, e.g. a butyl compound such as butyl rubber
(hereinafter shortly called butyl). Recesses 13 and 15
always ensure a minimum contact surface and minimum
thickness of butyl on the glass panes.
An outwardly facing, free surface 19 (hereinafter
referred to as the adhesion ;surface) extends from contact
surface 9 to exterior surface 11. This adhesion surface
19 has an essentially U-shaped cross-section while its
legs, seen in cross-section, are tapered from contact
surfaces 9 outwards.
A thin metal. foil 21, more particularly an aluminum
foil, is applied to this adhesion surface 19. The bond is
ensured by a non-gassing adhesive 23, e.g. a PUR-hotmelt
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adhesive curing with humidity. If a conventional adhesive
is used, gases diffuse through the spacer into the
interior space 7, where they :may lead to a chemical
condensate on the glass pane.
It is also possible to obtain a good adhesion of the
metal layer by vapor deposition, and other metals than
aluminum or steel can also be used in the process.
In order to obtain a good and durable bond of the
metal foil or metal layer to the plastic body, the
difference of the temperature expansion coefficients of
both parts should be as small as possible; otherwise, the
foil may chip off. In order to achieve the best possible
adjustment of both thermal expansion coefficients, an
appropriate amount of glass fibers is admixed to the
plastic material. It is evident that according to the
type of foil, e.g. aluminum c>r steel, a smaller or greater
amount of short glass fibers is admixed, preferentially
already to the plastic granu7_ate. Furthermore, the amount
admixed also depends on the kind of plastic material.
In order to allow a good processing, it is
advantageous to utilize a thermoplastic plastic material,
e.g. a SAN plastic material comprising glass fibers from
BASF known under the trademark LURAN. If such a plastic
material and an aluminum foi.L are used, the glass fiber
proportion amounts to approx. 350.
An adhesive resp. seali:zg mass 27, preferably
polysulphide or silicone, is introduced into the space 25
defined by the two glass panes 1 and 3 and adhesion
surface 19 in order to cement the two glass panes to the
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spacer, on one hard, and in order to obtain a further
sealing of interior space 7, on the other hand.
Since adhesion surface 19 is completely covered
outwardly by metal foil 21, this sealing mass 27 does not
come into direct contact with the plastic material of the
spacer but with the metal. Since the adhesion of
polysulphide or silicone to metal is significantly greater
than to plastic, an improved adhesive bond of the
individual parts is obtained. Furthermore, sealing mass
27 does no longer separate from foil 21, so that the
formation of hollow spaces i~. prevented.
The figure further shows that spacer 5 comprises a
hollow space which, viewed in cross-section, is enclosed
by the two contact surfaces ~j, 11, adhesion surface 19,
and by a wall 31 facing interior space 7. The good
stability of the spacer on account of the glass fibers is
thereby further increased. F?referably, a desiccant 33,
e.g. silica gel, molecular s__eves, or a mixture of the two
means, is introduced into this hollow space 29 in order to
draw moisture/water vapor oui~ of interior space 7. In
order to establish a connect_i.on between interior space 7
and hollow space 29, wall 31 is provided with openings 35.
The figure does not show that in the longitudinal
direction, spacers 5 are bent at an angle of 90° at the
corners of the glass panes. This is possible since the
base body is made of a thermoplastic material. This
allows either a corner connection to be used or to bend a
corner.
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The figure further shows that the longitudinal edges
of metal foil 21 do not come into contact with the
adjacent glass panes 1 resp. 3. Thereby it is ensured
that an insulating gap filled with sealing mass 27 is
formed between the glass pane and heat-conducting metal
foil 21. In addition, the transmission of heat or cold by
metal foil 21 is reduced by the fact that the thickness of
the metal foil is smaller than 0.1 mm, and that the path
between the two glass panes 1 and 3 is increased by the U-
shaped or V-shaped configuration of adhesion surface 19.
Other shapes of the plastic profile are also conceivable.
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