Note: Descriptions are shown in the official language in which they were submitted.
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WO 97/04037 PCT/EP96/03016
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Fire-retardant sealing system based on hotmelt
adhesives and process ~or the flameproof sealing of
articles or apertures
The present invention relates to a fire-
retardant sealing system based on hotmelt adhesives and
a process for the flameproo~ sealing of articles or
apertures by applying such a sealing system
Known fire-retardant sealing systems are, for
example, fireproof laminates. Fireproof laminates
usually consist of a fireproof material which is
laminated with a carrier web, for example a nonwoven
glass fiber, textile fiber or carbon fiber fabric, and
are used, for example, for the production of door
seals, window seals or other seals. Furthermore,
fireproof laminates are also employed between glass and
frame in ~ireproo~ glazing and inside ~ireproof doors
To permit fixing, some o~ the fireproo~ laminates are
provided with an adhesive layer. In the absence of an
adhesive layer, application can also be e~ected, ~or
example, by screwing on or by means of nails.
However, the disadvantage of the fireproof
laminates known to date is the method o~ application,
since either the additional provision of an adhesive
layer or the additional work o~ screwing on or nailing
on i5 required. A further disadvantage is the loss of
laminate resulting ~rom the exact adaptation of
predetermined laminate sizes to the article to be
sealed in each case.
It was accordingly the object of the present
invention to provide a fire-retardant sealing system
which can be installed, readily and without losses, in
the article to be rendered fire-retardant.
Unexpectedly, it was possible to achieve this
object by the combination of fireproof components with
hotmelt adhesives.
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The present invention accordingly relates to
~ire-retardant sealing systems based on hotmelt
adhesives, which contain
a) a hotmelt adhesive,
b) binders,
c) substances ~orming a carbon skeleton in the event
o~ a fire,
d) flameproo~ing agents and
e) a component which is intumescent in the event o~ a
~ire.
The novel sealing systems are based on hotmelt
adhesives. Suitable hotmelt adhesives are, ~or
example, those based on synthetic rubbers, pre~erably
based on so-called thermoplastic rubber grades, such
as, ~or example, block copolymers o~ styrene and
butadiene or isoprene or butyl rubber. Hotmelt
adhesives based on low molecular weight polyethylenes
(PE) and polyethylene waxes, those based on high
molecular weight ethylene/vinyl acetate copolymers,
those based on atactic polypropylene, those based on
ethylene/acrylate copolymers, with or without a low
content o~ carboxyl groups, those based on polyamides
and polyaminoamides, those based on polyurethanes and
those based on aliphatic or aromatic polyesters are
also suitable.
These hotmelt adhesives may contain
conventional additives, such as, ~or example,
antioxidants, plasticizers, pigments ~or coloring, such
as those ~or imparting whiteness, ~illers and the like.
According to the invention, binders, ~or
example polymeric binders, or ~ibers are added to the
hotmelt adhesive used ~or the preparation o~ the
sealing system. Examples of polymeric binders are
polyvinyl acetate, polyvinyl acrylate, polyvinyl
chloride copolymers or polychloroprenes. Pre~erred
~ibers are mineral ~ibers Mineral ~ibers are
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understood, depending on their starting materials, as
glass, rock or slag ~ibers, as well as ceramic ~ibers.
The terms mineral wool, glass wool, rock wool and slag
wool are also commonly used. Pre~erably used binders
are ~ibers, and mixtures o~ dif~erent ~ibers may also
be employed.
Furthermore, a substance ~orming a carbon
skeleton or carbon crust in the event o~ a ~ire is
added to the hotmelt adhesive. Suitable substances
are, ~or example, thermosetting plastics, such as, for
example, formaldehyde resins, urea resins, phenol
resins, phenol/~ormaldehyde resins, polyacrylonitrile,
polyimides, melamine resins, sugar, molasses, cellulose
or derivatives thereo~. The resins used should
pre~erably have a melting point between 100 and 200~C.
Phenol resins and phenol/~ormaldehyde resins prove to
be particularly advantageous. During the heating in
the event o~ a ~ire, these substances initially
crosslink, the strong intermolecular bonds also being
retained during the ~urther thermal load which leads to
pyrolytic decomposition and ~inally to the ~ormation o~
a paracrystalline carbon skeleton (Chemie-Ing.-Tech. 41
No. 9/10 (1970), pages 659-669).
As a third component, a ~lameproofing agent is
mixed with the hotmelt adhesive to render the latter
~lameproo~. Examples of suitable ~lameproo~ing agents
are aluminum hydroxide, aluminum oxide trihydrate,
magnesium hydroxide, calcium carbonate, boron
compounds, ammonium sulfamate or urea. For example,
oxides and carbonates o~ metals, such as, ~or example,
bismuth, tin, iron, antimony or molybdenum oxides or
bismuth carbonate, and other conventional flameproo~ing
agents may ~urthermore be used.
A component which is intumescent in the event
o~ a ~ire is also added. Suitable intumescent
components are all components or substances which ~oam
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in the event of a fire and are present in solid form,
for example as powder or granules. These are, for
example, components based on expanded graphite,
silicates, polyurethanes, nitrogen compounds or
phosphorus compounds, as disclosed, for example, in EP-
B-153 564 or EP-B-338 347. Expanded graphite or a
component based on phosphorus compounds is preferably
used.
The amounts of the individual components in the
sealing systems according to the invention depend on
the requirements which their properties have to meet
and on the required behavior in the event of a fire, a
high content of intumescent component having an
advantageous effect on the fire behavior, a high
content of binders having an advantageous effect on the
flexibility and a high content o~ substances which ~orm
a carbon skeleton in the event of a fire having an
advantageous ef~ect on the strength of the sealing
systems in the event of a fire.
The sealing systems according to the invention
preferably contain
a) 30 to 70~ by weight, particularly preferably 40 to
60% by weight, of hotmelt adhesive,
b) 1 to 15~ by weight, particularly preferably 3 to
10~ by weight, of binder,
c) 1 to 15~ by weight, particularly preferably 3 to
10~ by weight, of substances forming a carbon skeleton
in the event of a fire,
d) 1 to 25~ by weight, particularly preferably 1 to
15~ by weight, of ~lameproofing agents and
e) 10 to 40~ by weight, particularly preferably 15 to
30~ by weight, of intumescent components.
The preparation of the sealing systems
according to the invention is carried out by simply
mixing together and melting together the individual
components, for example in a heatable stirred vessel.
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The melt thus obtained is then ~abricated in a
tabletting or granulating apparatus. The melts are,
for example, dripped onto a cooling belt or applied as
a ~ilm to a cooling belt ~or solidi~ication and then
cut. Heatable kneaders or extruders, downstream o~
which appropriate ~abrication means are connected, are
pre~erably used.
The ~lameproo~ sealing o~ the articles or
apertures to be protected is then preferably e~ected
by means o~ apparatuses usually used for applying
hotmelt adhesives, ~or example a so-called jet
applicator or a hotmelt hand gun The granular or
tablet-like sealing system is pre~erably lique~ied in a
premelt container under atmospheric pressure at a
temperature o~ between 100 and 200~C and then applied
through the applicator nozzles. The application can be
adjusted in a very exact and variable manner by means
o~ the type and bore o~ the nozzle, the pressure o~ the
~ireproo~ laminate and the control o~ the nozzle
ori~ice After cooling and solidi~ying, the sealing
system adheres ~irmly, by means o~ the hotmelt adhesive
present, to the article to be protected.
By means o~ the ~ire-retardant sealing system
according to the invention, imparting ~lame-retardancy,
~or example, ~ireproo~ glazing, ~ireproo~ doors and
other apertures to be sealed, ~or example, joints or
cable ducts, is substantially facilitated, and
~urthermore there are no losses as in the adaptation o~
conventional sealing systems in laminate ~orm.
Exam~le
For the preparation o~ a ~ire-retardant sealing
system, 50~ by weight of a commercial hotmelt adhesive
based on vinyl acetate (~rom Fuller), 10~ by weight o~
a phenol resin (Resin 122, ~rom Ceca), 5~ by weight o~
Inorphil (mineral ~ibers), 15~ by weight o~ aluminum
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hydroxide and 20~ by weight of expanded graphite are
melted together in a heated stirred vessel. The melt
is then applied as a ~ilm to a cooling belt ~or
solidi~ication and is then cut, a~ter which the sealing
system in granular ~orm is obtained.
