Note: Descriptions are shown in the official language in which they were submitted.
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F ~ L ~ r o ~
BIT~N SHEETING
The presen~ in~en~ion concerns a sheeting compos~d of
several layers, specifically a ~upporting layer and at least two
layers of ~itumen applie~ one on top of another to one ~ide. Such
sheeting are in the~selves k~ow~ and are described in German 2
735 823 Al for example. A ~ethod of manufacturing su~h a sheeti~
is known from ~erman 3 413 ~4 C2.
Standard bitumen sheeting comprises a support imp~egnated
with bitufflen or poly~e~-modified bitumen and with outer layers ~n
each side. The oute~ l~ye~s can be c~umb-filled oxidized ~itumen,
bltumen modified with thermoplastic polymers (SBS~ or bitumen
modi~ied with thermoplastics ~AP~). Bitumen sheeting must
es~entially satisfy two basic d~m~n~. The sheeti~g must provide
long-la~ting tightness d~e to the outer layers, usually on each
side o~ the support. ~his ~m~n~ is satisfied by using ~igh-
quality polymer-modified layers. The effectiveness of the bond at
the o~erl~ps $s also very important. Elasticity and low-
temperature ~lexibilit~ are significant properties of SBS-
modified layers, and are usually present in a ~heeting with
laye~s on each side They are not, however, always the best
indicators of ~ood hot o~ cold overlzp bonding. Another draw~ack
of SBS-modifled layers is that they co~sume a ~ot of power to
soften them f~r hot laying. T~ e~sure satisfactory bonding, the
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outex l~yers ~u~t be heated so hot that the~ can damage ~he
suppor~ing l~yer.
One known approach to ~limi~ating this draw~ack is to a~ply
another layer of bitumen to the bottom o~ the ~heeting as
des~ribed for example in Ger~an 3 413 264 C2 The ~isco3ity o~
the ex~ra Layer must be at leask ~000 m~Z~sec lower during the
manufacturi~g p~ocess than th~t o~ the layer dire~tly below the
supporting layer. One ad~ntage o~ ~his approa~ is that, since
the hot bonding will ~equire less heat, the 3upporti~g layer will
~e exposed to les~ da~age. The extra laye~ must ~e just thi~k
enough to pro~ide enough bi~umen ~or bon~ing but ~o more, to keep
¢osts lo~ Experien~e ~mo~.~trates that ~he extra layer ~u~t be
a~ least O.8 m~ to ensure satis~actory ~onding.
A succession o~ two layer.~ of bitu~en ~an aLso be app~ied ~o
each side o~ the supporting layer ~n the known bLtumen sheeting.
It is ~lso possikle to apply two layers to one si~e and one laye~
to the other.
Such bitumen sheets are laid next to ea~h other with a strip
of prescribed width overla~ping ~t each adja~ent edge. The
overlaps a~e t~en bond~d together hot or co~d~ One drawba~k here
is ~at the re~dlly hot-~ondin~ lower layer is often not
optimall~ ~onded to the poorly hot-bonding upper layer, leading
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to defe~ts i~ the ~oint The p~ohlem was veri~ied b~ peali~g the
layers apar~
~ he ohje~t o~ the present invention is ~ccordin~Ly an
bitumen sheeting o~ the a~ores~ld type th~t ~ill ensure long-term
pro~ç~ion ac~ompanied by i~eal ~on~ing a~ the ovexlaps~
This object is at~ai~ed in the ~eneri~ sheeting in
accordance wi~h the pre~ent in~enti~n as recited ~ the ~o~y of
~laim 1. Advantageous a~a~ced em~diments of the sheeting in
accordance ~i~h the present inven~io~ are re~ted in ~he
subsidiary ~laims. Claim 6 concerns a met~od o~ l~y~ng ~n bitumen
sheeti~s in acco~da~ce with the presen~ invention.
The st~ip~ that ove~l~p when a sheeting o~ bi~umen in
accordan~e with the present i~vention i~ lai~ will all be o~ the
same mate~ial. Iden~ical laye~ing m~sses will accord~ngly ~e
bo~ded to~ethe~ when the seams are ~oined in ~he overla~pi~g
areas The re~ult will ~e optimal adhesio~ ln the vicinit~ o~ the
~e~m. That equally r~dily ~onding layers will be ~onded together
n that vicinity will ensure a particula~ly tight seal.
~ he ~esired quality o~ such layers of bit~men can be
attained by adding hi~h-quality :cesins. The viscosity o;~ a l~Lyer
o~ SBS-modi~ied bitl~men car~ be consicleral~ly decreased and its
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sof~ening point lower~d by a~ least 10~K simult~neously.
The t~o layers of ~itwmen on each side o~ the overlap will
melt simultaneously a~d with less energy ConsUmp~Lo~ pr~viding
an op~imal bond~ An ~itu~en ~heetin~ in accord~nce with the
Rresent inVen'CLon will be particularly useful when o~ly one laye~
is to ~e lai~ ~ecause the thickne~s of the seam will be e~en more
si~ni~ic~nt.
~ he s~rip bordering the longit~ldl n~l edge w~ e
e~;sentially as wide as the o~terlap
~ n one ~van~ag~ous embo~iment o~ the pres~nt in~ention, ~t
lea$t o~e layer of bi~umen is applied to the other side o~ the
supporting layer, with ~he strip applied to its outer su~ace and
along t~e longit~ l edge of ~e shee~in~. The areas out~ide
the strip on the outside o~ the outer~os~ layer of bi~umen on the
othe~ sLde O:e the supporting layer can }~e p~otectecl by a
protecti~e layer. The protective layer can be a con~ention~l
scat~e~ing o~ stone chips, granules etc ~ sheet o~ metal o~
pl~stic, or a fabri~ pad
O~e exa~ple of a~ bit~men shee~ing in accordance with the
present invention will now be spe~i~ied with re~erence to ~he
accomp~nying ~awing, wherein
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Figu~es 1~ and 1~ are highly schem~ti~ large~-~cale ~e~tio~s
through two embodiment~ of ~ sheeting in the vicinit~ of their
longitu~.tn~l edge an~
Figure ~ is a highly sche~a~i¢ but not as large-scale
lo~gitl~; n~ I side view o~ three ~heets like those illustrated in
Figure lA lai~ overlapping
The sheeting illustr~ted in Figure lA in~ludes a supporting
la~ex 1. Applled to its bottom, in terms o~ the ~igu~e bu~ also
constituting the boktom ~hen the sheeting ls laid, is an inner
l~yer 2 o~ ~itume~ Also applied to the bottom is a~ ~ute~ layer
3.1 of bitumen ~pplied along the longi~udinal edge o~ the top of
the sheetin~ is a strip 3.2 o~ ~itumen. ~t's width ~ is narrow in
~elation to the total lenqt~ B of t~e ~heeting. Strip 3.2 is o~
the same materi~l as the o~t~r layer 3.1 o~ bitumen on th~ botto~
o~ ~he sheeting. A~acent to s~rip 3.2 on the ~op of supporting
layer 1 i5 ano~her l~e~ 4 of hitumen tha~ extends f~om whe~e it
ad~oins st~ip 3 2 to the other and unillustrated longitudi~al
edge o~ the sheeting. hayer 4 is of a di~erent ~itum~n ~han
outer laye~ 3.1 and strip ~.2 Lay~rs 2 and 4 ~an be of the sam~
or of differen~ m~terials. I~ t~ey are of ~i~fer2n~ materials,
layers 2 and 3.1 can be of the sa~e ma~erial. The out~ides o~
outer laye~ 3.1 a~d ~trip 3.2 are conventionally provt.ded wit~ a
layer ~.1 and 6.2 of separ~tor, ~alc, s~nd, or she~,
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corlv~n~ion~ll y removed as the sheeting iS laid.
Ou~side strip 3 :~, the top o~ the la~er 4 appliec~ dlrectly
to supporting layer 1 is pr~vic3ed ~rith a sça~tering 5.
lt has also l:~een pro~en practic~l for layers 2, 3 1, a~d 3.2
to }:~e o:E APP-modi~ied bi~umen ~nd for layer 4 to he o~ SBS-
modi~ied bitumen APP~modi:l~ied bitumen is conslderably less
vis~oUs as it melts than ~BS-modified bitumen, even though its
so f tening po illt i s hi g~er .
Figure 11~ illustr~tes anothe~ embodiment o;E an bitumen
sheeting, which ~ e~s ~o~ the em~odiment illustrate~ in ~igure
lA only in the po~itio~ of the strip Other~lse ~he sheeti~g is
struc~urally identi~al to the sheeting in Fi.gure lA, and the sa~e
re~erence n~bers ar~ e~ployed ~ith an added apostrophe for the
equivalent layers.
An ex~ra l~yer 4' ~ ~itumen has ~een applied at the top in
Figure 1~ to the upper sur~ace of supporting layer 1' and ex~en~s
over the total width o~ t~e sheetlng. ~pplied to the top o~ layer
4' ~lo~g the longitudinal ed~e of the sheeti~g is a strip 3.2' of
bitum~ o~ width b and o~ the same ~aterial ~s the outermost
layer 3.1' on the ~ottom o~ the sheeting.
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.
Vario~s examples of how ~n bitumen sheeti~g of the type
illu.~trated in Figu~es lA and lB will now be provided, the
individual laye~s ~einq identi~ied by their reference num~ers.
~mrle 1
Upper su~faci~g in ~he ~olm o~ a po~ymer-modi~ied ~itu~en
impermeable ~Fig 1~.
~ ayer 1: Suppor~i~g layer of 2S0 g poly~er felt imp~egnated
wit~ S~S-modified bi~umen.
~ ayer 2: Botl~om l~yex of SB$-~nodi~ied bi~umen.
~ ayer 3 1: ~xtra ~otto~ polymer l~yer like layer 2 with no
~illers b~t wi~h an added 5 ~ resin.
Layer 3.2 : Layer, of the same material as layer 3 1, on
overlap s~rip.
La~er 4: Top layer like layer 3, but with 0.5 ~ ~o~e S3S-
modi f ied bi ~en
Layer 5: Sc:~ttered slate chips
Layer ~.1 Sheet of PE la~nated ~o bottom
L~er 6. 2: Strips of PE laminated to bottom
Exz~ple 2
Polymer-modi~ied bitumen as an interffle~iate ~ig. 1~)
Layer 1: Glass-fel~ or glas~-~trix co~posite s~ppor~
layer i~pregnated with S~S-modi~i~d ~i~umen.
Layer 2; Botto~ lay~r of SBS-modi~ie~ bitumen.
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Layer 3 1: Additional bo~tom layer like layer 2 without
filLers ~nd ~ith 5 % r~in added.
Layer 3.2: Layer o~er overlap strip of th~ sa~e material as
layer 3.1.
Layer 4. Top laye~ lik~ layer 2.
Lay~r 5: Thin PP-~elt la~lnation.
Layer 6.1: PE she~t lamina~ed to ~ottom
Layer 6.2: T ~i n~ted strips of PP.
Cu~renk effo~ts to develop bitume~ ~heets for appli~tions
ln the imp~rmeables ~ield a~ i~creasingly concen~rated on cold
honding. Sheets o~ the aforesaid ge~era ~an ~e employed in this
are~ as w~ll Rellable adhesion on the part of the seams in the
vi~inity of ~he overlap and hence their permanent ti~h~n~s~ is
en.~ured b~ the use of adjacent layers ~ the s~e propertles.
Cold-adheslve ~aye~s can be thinn~r. Extra layer 3 1 can now
usu~ he O 5 mm thick. Layer 3.2 can have th~ same t~ickness
and c~n ~e ~pplie~ in the form of a strip of width b to the now
~ntinuous layer 4.
E~a~ple 3
Polymer-modified ~itumen impermea~le as an interme~iate
~ig. lB)
Layer 1': Glass-~elt or glass-matrix ~mpo~ite su~po~ting
l~yer impregnateq with SBS-mo~ified ~ltumen.
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Layer 2': Botto~ layer o~ SBS-mo~ified bitumen
Layer 3.1 r: Extra ~attOffl ~old-adhe~ive layer o~ polymer-
modifie~ bitu~e~ with 10 ~ of a blend o~ various ~esins.
Layer 3.~': Laye~ over overlap strip of the s~me material as
layer 3.~'
Layer 4': Top layer like layer 2'.
L~yer ~': Thin PP-~elt l~ination
Layer 6.1~; Bottom l~ina~ion o~ sili~onlzed PE, to be
peeled off when the sheeting is laid.
Layer 6 2'; 1amin~ed strip of sili~oni~ed PE, to be peeled
o~f wherl the sheeti~g i-~ laid
Example 4
Upper sur~ in the form o~ a polymer-modi~ied bitumen
impermea~le ~Fig. ~B~
Layer 1' 5uppor~ing layer of ~SO-g PE-fel~ impregna~e~ with
SBS-modi~ie~ bitumen
I.ayer 2' Bottom layer o~ APP--modified bit~men
Layer 3~1'. Additional ~cttom layer like layer 2'
Layer 3.2': L~yer over overLap strip like layer 3.1'.
L~yer 4': To~ layer o~ S~S-modifie~ bitumen
Layer 5': Scattered slate chips
Layer 6.1': P~ ~heet lamina~ed ~o hottom.
La~er ~ 2' T.~mi~ted s~rip~ of PP.
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Adj acent }:~ltumen sheets are }~osi~ioned when la;Ld with the
lower sur:Eace, bikumen laye~ ~.1, of the sheeting to the right in
the drawing, o~e~lappi~g the top of the shee~ing to width }~ i~or
example, outer l~yer 3.1 accor~in~ly resti~g directly on strip
3 ~ 2 ~ Two sheets will acco:rdingly l~e homogeneously bonded together
that area.
This app~oach to layi~g the sheets is ~epre~ente~ highly
sche~Ltically in Figur0 2 . For simplicit~' s sake the displac~ent
thell~ OCCULS in the vicinity of the overlap is ~epresentecl ~ 904,
although in reality i~ slopes, o~ course.
Three laid sheets ~1, D2, ~d ~3 are illustrated. T~ey
overlap one another at their adj ~cent edges as hereiDbefore
specified su~h that, ~s indicated a~ the txan3ition between D1
and D2, s~me o~ the strip 3.~ on the bottom o~ a ~he~ti~ will
rest against the strip 3.1 on ~h2tever sh~eting i9 below it,
allowlng the hot bon~ing to oc~ur at that site. The top of the
3heeting is provided wi~h ~cattering 5 ~s hereinbe~ore speci~ied
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ProvisionaL international office action
The do~uments cited in the sear~h ~eport in no way suggest
modifytng ~n bitumen sheeting of the type recited in ~laim 1 to
adapt 1~ to the task cited on page 4 of the description.
These documents contain ln particula~ no suggestion th~t the
strip applied to the other side of the supporting layer should be
of the s~me bitumen as the outermost layer on ~he first side of
the ~upportlng layer.
