Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Tho invontion relate- to a la~inat-d ~f-t~ pane~
for e~ample for u~o aa the windscro-n Or a motor v-hiclo~
the pane being Or th- kind whloh co~pri~-~ an out-r pan-~
an inner pane~ and a laminating matorial whioh glue~ th-
two pano~ togeth-r.
Laminated safety pan-s of th- kind ~p-oifi-d ar-
beco~ing u~od to an e~-r-incroaJing e~t-nt aa ~ohiol-
wlnd-creen~, I ~uoh la~l~ated safoty pane~ a~ a rule~
both th- outer and inn-r panOJ ar- made of ailioato ~laa~
and th- laminating mat-rial~ intercon~-cting the t~o
~ilicate glasJ paneB~ i~ fr-quontly a lamlnating foil of
vi~co--la~tic pla~ticJ~ such a- poly~inylbutyral (PVB)~
polyvinylal¢ohol (PVA)~ polyr-thaa- (PU)~ polyoarbonate (PC),
poly~inrlchlorid- (PVC) or th- lik-. The ~af-ty of peopl-
trav-llin6 in v-hiclo~ ha- b--n ahewn to b- con-ld-rably
incr-a~-d a~ a r-ault of th- u~e o~ ~uoh wind-or--n~,
Should a por~on travelling in a vehicl- having a wind~cro-n
compri-ing a laminat-d ~a~oty pan- of th- kind ~p-ci~i-d~
be thrown towardJ th~ wind~cr--n in an accid-at~ th-r- i~
~uch 1-~ risk of th- per~on p-netrating the wind~or-en than
with oth-r kind~ of wind~creen~ ev-n if tho por~on i~
thrown quite viol-ntly toward~ the wind-ore-n. The ri-k
i8 ev-n low-r if the per~on i~ ~ecured by a ~afety bolt
in the vehi¢l-, The ro~i~tanco of ~uoh wind~cr--ns to
p-netration i~ achieved without making the wind~or--n~
~o tough that tho forco o~ tho blow roquirod to cau~-
da~ag- to th- wind~cre-n~ i~ gr-at nough~ if applied by a
'-- human head~ to caus- soriou~ ~kull or brain in~uri--.
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The risk Or pormanont brain damage brought about by
impact of tho head with a windscreon can thus b-
aubatantially eliminated.
~owover~ with windacroon~ compri~ing la inat-d safoty
pane- of tho kind ~pecified~ when~in an acoident, the
hoad of a person travelling in the vohicl- ¢omea into
contact with the alightly fractur-d laminated ~afoty pan-
disfiguring cut~ may occur to th- pa-songor's h-ad.
A ~yatom o~ claaaifying ~uch outs according to s-riou~nos~
and indicating th- degr-e of seriouoneaa by a numb-r
ref-rred to aa th- laceration indo~ (TLI) ha~ been dovisod.
Clearly~ of cours-~ th- dang-r Or auch laoerationff
occurring ia con~idorably roduced if th- inner pano of
the laminated safety pan-~ prea-nted to tho intorior of
the vohicle~ br-ak~ into vory fino frag~-ntJ when struck.
For thia purpoae~ it has already beon ~uggeat-d that a
toughened gla~a ohould b- us-d for the inn-r pan-.
E~amploa Or tho compon-nt~ used in lamlnat-d af-ty panea
which break into fine frag~-nta ar- the o-callod
Ten-Twonty and VHR glas~. Th- u-o of a toughonod gla8a
Or thia kind aa tho innor pane incr-aa-a tho numb-r of
cracks which in¢ur on imp$ng-ment of a paaa-ngera hoad
on the laminated saf-ty pane~ th- r-sult being that the
p~no breaka up into finer frag~ont~. The numbor of cra¢ka
dep-nd~ on th- energy abaorbed by the laminatod aafoty pan-
The number of crac~s incroaaod by tho u~o of a toughened
$nner pano haH howev-r not yet produced aati~faotory
rosults~ ainc~ vory flno fragment~ can b- obtained only if
tho strength of the toughonod innor pane ia ~ery hlgh.
As a result howevor~ it b-comes pos~ible for seriou~
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lO90~i90
Jkull or brain in~uries to bc cau~ed when a p-raona
h~ad ~trikea the pane since th- pane will not gi~-
way unle~ the blo~ struck by the head i~ ~e~-re.
The ~tr-ngth Or the panes ~u~t b- kept within v-r~ ~arrow
limits~ sinc- both panea Or th~ laminat-d aafety pan-
~u~t break slightly with an impingemont ~-locity of
20 km/h (ST~Z0) otherwis~ th-re i~ a riak that th-
s-~-r- skull or brain in~urie~ may be oau~-d. Sinc- it
ia dif~icult to control the ~tr-n~th Or the toughenod
inner pane ~o acourately~ in manufaotur-~ that on the
one hand th- panelwh-n it br-aks~ broaks into fine
~ragment~ while on th- other hand the str-ngth Or the
blo~ r-quirad to br-ak tha inn-r pan- i~ low enough~
pan-- of th- kind ape¢ified, ~e-ting th- two conflicting
r~quir-ments ~et out abo~-~ could not hith-rto b- produo-d
r-liably on an industrial ~calo.
It is Xnown that br-ak-ge into fine rra~-nt~ c~n be
obtainod i~ th- inn-r pan- i~ made aa thiD a~ poasibl- in
pan-~ Or th- kind ap-¢ifi~d. As a re~ult th- ~a6ging Or
th- whole pan- whea strucX and broken by a per~ons head
incr-a-o~ a~ compar-d with th- ca~- in which th- innor pane
i~ not made thin~ ao that th- inner pan- br-aka up into
fragment~ og relat~-lr fine ~tructur-~ and as a r-~ult
the laGcration ind-s i~ roduc-d - in oth-r worda th-r-
i~ lo~- riak of disri~uri~g lacoration~. Even wlth
asy~-trlcal windaor-en~ of thi~ klnd~ ~n w~ich t~e i~n-r
pane ia ~ub~tantiall~ thinn-r th~n th- outer p~n-~ how-~er~
~t has not ~et be-n po~ibl- howe~er to r-duo- th-
"- lac~ration indes to ~alue~ low enough to be co~pl-t-ly
satis~actory. On th- con~ary~ in both ca~ both
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109U~gO
with the u~e of a toughened (aic') inner pane and a
~ery thin inner pane - the re~ult ha~ be-n an improv-m-nt
of the laceration inde~ by only 1 to 2 unit~. Another
di~ad~antage of the u~o of toughoned pano~ i~ that it
call~ for e~tra operation~ in th- manufactur- of the
laminated safety panes~ 80 that uch pane- ar- mor-
e~pensi~- than pano~ in whioh no toughon-d glHJa1i- u~od.
Starting from the knowledgo that th- laceratlon inde~
of laminated saf-ty pano~ of tho kind specifiod can be
further roduced only if tho fragment~ into which the innor
pane broaka aro made e~en finer~ it i8 an ob~-ct of tho
in~ontion to provid- a la~inat-d ~afoty pane in which~
when tho aafoty pano ia brokon by imping-m-nt of an ob~-ct
the inner pane
on th- i l-r pane~/br-ak~ up into individual pi-c-~ aa
small as po~iblo which ox¢lud- lacoration~ to the ma~imum
xtent.
To this end~ according to th- in~ontion~ th-ro ia
providod a laminat-d ~a~oty pan- compriaing an outor pano,
an inncr pane~ and a laminating material which gluo~ the
two pane~ togcth-r~ in which tho adh-aiv- ~trongth of th-
conn-ction between the inn-r pane and the laminating
material i~ mad- ~ub~tantially highor than that betw--n
tho outer pane and the laminating material
At l-ast one of th- pane~ may be made o~ ~ilicate gla~
Preferably the inner pane is mad- of non-preatro~aod
~ilicato glaaa.
According to anoth-r proferrod foatur~ tho innor p~ne
may bo thinnor than th- outor pane.
Pr~forably thc inner pane iA ~ubatantial-~y thinn-r
than th- outer pano~ being more particularly at most
2 mm in thicknoss.
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lO~O~i~U
According to the present invention the laminated safety pane ~ay
inclute inner and outer panes wherein the thickness of the inner pane is at
st 1 mm and the thickness of the outer pane is at least 2 mm.
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1090~
Tho laminating matorial connecting th- inn-r and
out-r panes may b- a layor Or ~ls¢o-ela~ti¢ plastics~
e.g. one of tho numbor Or such pla-tics pr-~iou~ly
mentioned. Tho lay-r Or vi~co_ola~tic plaati¢a is
pr-f-rably in the form Or a laminating foil.
It ha- b--n found that with a laminat-d saf-ty pano
ac¢ording to th- inv-ntlon, th- inner pane can br-ak into
particularly fine fra~ments whi¢h do not ¢aus- la¢-rationa,
with a ¢onsidorabl- con~equent redu¢tion in thc laooration
index. Pr-f-rably~ th- adhesiv- str-ngth of the
¢onne¢ti~n botwe-n th- inn-r pane and tho laminating
foil is from 4 to 10 Pumm-l unit~ and that of the
connection betwo-n the outer pano and th- laminating foil
is from 1 to 2 Pummel units. Th- ffect of a safoty pano
according to the in~-ntion~ parti¢ularly in thos-
mbodim-ntff in whi¢h tho strongth of adhe~ion b-twe-n
tho 1 inating foil and the inn-r pane is in¢rea~od over
th- valu-s of atr-n~th of adhesion stron~th normally
achie~able using laminating rOil~, i9 pre~umably due to
the fact that a~ a r-~ult of the intimat- connection to
tho laminating foil th- inner pano iJ for¢od to shar- any
bulging or b-nding deformation of the foll without
be¢oming detached from the foil when some ob~e¢t~ ~u¢h
a~ a human h-ad~ atrik~J the innor pane. The result is that
a large numbor of 0108ely spa¢od crac~s or broakage lines
are formed in th- inner pan-~ i.o. the inner pan- breaka
into extrom~ly fine fra~mont-, sin¢- th- inn-r pane i9 not
ablo to bond to the same e~t-nt as the laminating mat-rial~
which i~ both rosiliontly and plaatically d-formable.
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1(~9~;90
Embodi~ents of the invention are described below
with roforence to tho accompanying drawing~.
In the drawlngs~
Fig. 1 i~ a diagrammatic cro~ eotional viow of a
fir~t form of laminated saf-ty pane embod~ing tho ln~ontion~
~ig. 2 is a diagrammatic oroa~ ctlonal vl-w of a
socond form ot laminat-d afety pane embodylng th-
invention~ and
Fig. 3 i~ a diagra atio cro~s-~ectional ~iow of a
third form of laminatod ~afoty pane mbodying ths inv-ntion.
In the ombodimont illu~trat-d in ~ig. 1 a laminated
safety glas~ pan- compri~-~ an outer iliGate glaJ~ pane 10
an inner sillcate gla~J pan~ 12 aad a laminating foil l4
for in~tance~ of polyvinylbutyral~ whioh gluo~ the two
silicate glass panes 10~ 12 togother. The adh-~ion of the
laminating foil 14 to the inn-r pane 12 i~ ~o ad~ustod
that the adhe~ive ~tr-ngth i~ 6 Pummol unit~ whllo tho
adhe~ive strength of the co oction botweon th- out-r pane
10 and th- laminating foil 14 is 1.5 Pummol unit~.
In the embodimont of Fig.l~ th- pano~ lO and 12 aro
o~ mu¢h tho same thickne3~. The mbod~uont illu~tratod
in Fig. 2 difrer~ from that illu~trat-d in Fig. 1 in that
in the embodiment Or Fig. 2 the innor pano 12 i~ much
thinnor than tho outor pano lO. In both tho pano of Fig, 1
and that of Fig, 2 tho laminating foil 14 can b- ot a matorial
capablo ot ~ory high adho~ion to untroatod gla~ tho urtaoo
of the outer pan- lO which i~ adJac-nt tho laminating toil
14 ha~ing becn gi~on an alkalino tr~atm-nt during ~anufacturo
of tho laminatod pano~ prior to lamination~ in ordor to
~n~ur~ that tho strength of adho~ion of tho foil 14 to the
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109()~ 0
pane 10 is less than to the pane 12. The said alkaline treatment of said
surface may consist in washing it down with a suitable soap solution.
Alternatively, if laminating foils capable only of a lesser a & esion to
untreated glass are used, such as, for instance, polyvinylbutyral foils,
preferably that surface of the inner pane 12 which is adjacent the laminating
foil 14 has been treated, in manufacture of the laminated safety pane and
prior to lamination, in such a way as to ensure that the respective surface
layer of pane 12 is impoverishet in alkali metal and alkaline earth metal
atons. In this case the treatment may consist, for instance, in boiling the
pane 12 in acidified water. Of course, a primer, preferably a washing primer
which is added to the washing water, can also be applied to that surface of
the inner pane 12 which is adjacent the laminating foil 14. An a & esion
increasing coating, re particularly an adhesion increasing primer, may be
applied to the surface of the pane 12 adjacent the foil 14 before lamination
is performed.
Fig. 3 shows a variant embodiment in which the laminating foil 14
of the embodiments illustrated in Figs. 1 and 2 is replaced by a double
foil consisting of an outer foil 15 and an inner foil 16. The principle
underlying this use of the double foil is to provide, in effect, a foil
of which one surface is capable of adhering to glass with a greater strength
than the other surface. This mdght, of course, be achieved by means other
than the use of a double foil, but a double foil is a convenient
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moan~ of achle~ing the de~ired effoct. In tho embodimont
of ~lg. 3, the foil ~urfaco capablo Or high adho~i~o
~trength i~ providod by the foil 16~ whil~t the foil
~urfaco capable only of low-r adhe~i~e strongth 1~ pro~ided
by tho foll 15. The outer foil 15 can b- mado, for
instance, of ~oft PV~ whilo the innor foil 16 can b-
mado of a copolymer of ~inylchlorido and glycidyl
mothacrylate with a contont of about 40% by woight Or a
high-molocular~ non-migrating pla~ticizor which do-~ not
ab~orb wator. Such a combination of outor and innor foil~
increa~oJ tho adh-sion b-two-n tho laminating foil and
the gla~. Moroo~or~ a compoJito laminating foil con~i~ting
of a out-r foil 15 and i~nor foil 16 for u~e in th-
mbodisont illu~trat-d in Fig. 3 can of cour~o eithor b-
obtainod from foil supplior~ or altornati~oly the foll~ 15
and 16 can b- pr-~-d and bond-d tog-thor only during th-
laminating prooo~,
Tho laminatlng layor 14 can of cour~o also bo producod
by pouring the ro~pectivo plaatic~ material in a liquid
~orm~ for e~aspl- molt-n or in ~olution~ onto the pano 10
or 12~ The invention can of cour~e al~o bo appliod to
multi-layor laminated ~a~oty ~la~ sy~tem~ - e,6, ~y~tem~
in whi¢h moro than two ~ilicate gla~ pano~ ar- intor_
conn-¢tod by ~uitable laminating foil~. In ~uch a caJo
the strength of adhe~ion of the inner-mo~t pane to the
ad~oining laminating foil ~hould bo mado greater than that
of tho other pan-~ to the re~pecti~e laminating foil~ ~o
that the innormo~t pano i~ forcod to ~haro e~actly in tho
bulging movement of the laminating foil neare~t to the
interior of the ~ehicle~ 80 that the innermo~t pano broak~
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1090~90
into a largo number of very ~mall fragmentJ.
If de~irod, in all the embodiments do~cribod a
furth-r lay-r of tough~ ~-ft pla~tic~ preforably a
solf-ropairing layer is disposod on that Jido of tho
inner pane 12 which is romoto from tho laminating foil
14 or 15, 16. Thi~ ~urthor roduces tho ri~k of in~ury
to tho head of a porson striking tho laminatod pane from
the inner ~ido. Plasti¢J lay-rs of this kind are di~clo~ed,
for instanco~ in German Offenlo6ungsschrift No. 2,228,299
and German Auslogeschrift No. 2,220,753~ to which referonce
can bo mado for furthor detailJ.
In ombodimentff of tho invontion~ ~uch a~ those deJcribed
with roference to FigJ. 1 to 3~ in which two glass panos
are bondod togothor by an interposed laminating layor of
plaJtic~ the adhesive strongth of the connection between
the innorpane and tho laminating layor i~ preferably
botween 4 and 10 Pummol unit~, and moro proforably botweon
4 and 6 Pum~el units~ while the adhesive strongth of the
connection botweon tho outor pane and the larinating layer
iJ preferably botwoen 1 and 2 Pummel units.
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