Note: Descriptions are shown in the official language in which they were submitted.
', . .~ ~
- 2078787
W0 91/1~739 PCT/EP91/00469
polyurethane seal~t ~ontaining epoxy compou~d~
','''
; This invention relates to UV-stabilized joint sealan~s
.
;~; based on polyurethane prepolymerc, fillers and, optionally,
other auxiliaries and to their use.
Joint sealants based on polyurethane prepolymers have
acquired some significance in the building industry and
also in the DIY field. As the name uggests, they are used
mainly for sealing joints between structural elements o~
the same material or of different materials. For exampl~,
`~ they may be used to seal joints between structural compo-
; 10 nents and ma~erials, for example o~ concrete, masonry,
asbestos cement and gas concrete, metals, wood, plaster and
many plastics, such as PVC. They are also used for flexib-
ly bonding metals in locksmithing, roofing and plumbing and
~or sealing joints and overlaps. The sealing of metal
: 15 facings on mantelshelves and window sills, eves flashing
connections, on flat roofs and balconies, the connection
. . i
; and sealing of eaves guttering and gulleys are further
examples~
Elastic sealants are preferably used in the manufac-
ture of glazing, screens and windows and also the associ~
`~ ated frames. In this field, they have been successfully
;~ used for the sealing of glass joints, for the manufacture
~; of two-pane and three-pane insulating glass and in its
'`!i`;`' installation in frames and window walls. Accordingly, one
~; ` 25 particular application for sealants is pane sealing in
;~ window construct~on.
~i The sealants are generally packed and marketed in
cartridges. A~ter application, the sealants applied cure
to form elastic materials. Curing generally takes place in
30- ~ the course of ~a crosslinking prooess~initiated~by~oxida~
tion, moistur~ ~or polyaddition.~;~ Joint sealants~ have~to
, ~ ~ meet stringent teahnical requirements. After~application,
7~87
W0 91/1~739 2 P5T/EP91/00~69
they are required to cure rapidly, but to remain highly
elastic. These properties should not b~ affected to any
significant extent, if at all, by ageing or by weathering.
Not only for aesthetic reasons should the ~ur~aces of the
; 5 cured joint sealants remain largely tack-free, crack-free
and homogeneous.
Joint sealants based on various polyurethane systems
are known to the expert. For example there are one-compo-
nent systems and two-component systems. One-component
systems include moisture~curing ioint sealants. In their
case, the polyurethane prepolymers are terminated by water-
reactive groups, such as for example isocyanate or alkoxy-
silane groups. Moisture-curing joint sealants based on
alkoxysilane-terminated polyurethane prepolymers are
described, for example, in ~E-OS 36 19 2370 Moisture-
curing joint sealants based on isocyanate-terminated
polyurethane prepolymers are known to the expert, for
example, from DE 37 26 547. Two-component systems are, for
example, systems based on mercapto-terminated polyurethane
prepolymers. A process for the production of such com-
pounds and their use in joint sealants are known to the
expert ~nter ~lLa from DE-OS 36 01 189. In addition, a
~ process for the production of polyurethane prepolymers
; containing (meth~acrylate groups and their use in anaerobi-
~5 cally curing adhesives and joint sealants are described in
DE-OS 32 45 563.
- ~he weather resistance of khe above-mentio~ed joint
sealants has to meet particularly stringent requirements,
particularly for external applicat~ons. W stability is
~ 30 particularly important in the case of joint sealants baæed
i~ on polyur~thane prepolymers. Accordingly, so-called UV
3~ stabilizers are normally added to such joint sealants.
~j Suitable W ~stabilizers, also known as W absorb~rs, are
f .
,~ ~ ~described, ~or example, in DE-OS~32 21 655.
~t~ 35 In addition, moisture-curing polyurethane joint
~ . : ~,
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`` ` 20787~7
. ~0 91fl~739 3 PC~P91~00~69
sealants having improved properties, more particularly
improved long-term stability under weathering con~itions,
are described in hitherto unpublished German patent appli-
cation P 38 43 090.1.
~owever, particul~r significance is attributed not
, only to weather resistance in general, but in particular
to the permanent adhesion of the joint sealants to the sur-
faces under weathering conditions. Hitherto known poly-
urethane joint sealants have deficiencies i~ this regard.
This applies in particular in cases where one of the sub-
strate~ is glass or has a glass-like surface. T~e perma-
~ nent adhesion of onventional joint sealants based on poly-
- urethane prepolymers under weathering conditions is not
~; entirely satisfactory, particularly in the sealing of
glass.
It has now surprisingly been fouynd that weather-
resistant adhesion to gla~s can be signi~icantly improved
~ effective quantities of epoxy compounds are added to the
.~ W -stabilized joint sealants. It is remarkable that,
although the addition of W stabilizers alone and the
addition of epoxy compou~ds alone to joint sealants based
l on polyurethane prepolymers improves weather-resistant
?-~ adhesion to glass, a combination of W stabilizers and
epoxy compounds produces a considerable împrovement in that
~ 25 property so that it is possible to speak in terms of the:. syn rgistic effect.
. Although combinations of, ~or example, isocyanate-terminated polyurethane prepolymers with epQxy compounds,
such as glycidyl eth-rs, are known from the patent litera-
l 30 ture, for example from JP ~5/217255, there is no re~erence
,~: to the fact that system~ such as these can be speci~ically
used as ~oint sealants. ~n addition, a synergistic ef~ect
:~ ~ - on combination with W stabilizers leading to improved~
~ ~ weather-resistant adhesion:to glass has never been de-
. ~ 35 scribed in:the literature.
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WO 91J14~3g 4 PCT/~P91/00~69
The problem addressed by the present inventiQn was to
provide joint sealants based on polyurethane prepolymers
which would reprPsent an improvement over the prior art and
which, in particular, would show improved weather-resistant
adhesion to glass or glass like surfaces. At the same
time, the other desirable, positive proper~ies o* such
,; joint sealants would at least not be signi~icantly im-
~: paired.
- This problem has been solve~ in accordance with the
: 10invention by W -stabilized joint sealants based on polyure-
thane prepolymers, fillers and, optionally, other auxilia-
ries, characterized in that epoxy compounds are present to
. improve weather-resistant adhesion to glass or glass~like
,~ sur~aces.
~: 15Joint sealants based on polyurethane prepolymers are
known from the patent literature cited above. ThPy may
contain W stabilizers, fillers and~or other auxiliaries,
as also mentioned in the cited literature. The quantities
- adding up to 100% by weight - of W stabilizers, polyure-
.~ 20thane prepolymers, fillers, auxiliaries and epoxy compounds
present in the joint sealants according to the invention
' are preferably selected so that the joint sealants contain
,~ approximately 20~ by weight to 75% by weight polyurethane
. . prepolymers, 0% by weight to 20~ by weight auxiliaries and,
;. 25as the balance to ~00% by weight, fillers, W stabilizers
: and epoxy compounds, the minimum ~iller content being
approximat~ly 20% by weight. The expert will not be able
to use very much less than 20% by weight polyurethane
:,~;............prepolymers because an excessively low binder content would
~''" 30 result in an unsuitable joint sealant. A filler content
:;~ much lower than 20% by weight would also be.inappropriate
:~ :~ because, in:that case, ~he joint sealants in er alia would
~, : ~ not:have the necessary consistency. ~n general,.the expert
.will not work at:these limit~. Accordingly, a polyurethane
3sprepolyDer content -of~approximately 30% by weight to ~0~ by
-~ .! : .
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~WO 91/14739 5 PCT/BPgl/00469
weight and a filler content of approximately S0~ by weight
to 70% by weight are preferred. If desired, up to 20% by
weight auxiliaries may be present.
: Polyurethane prepolymers can be prepared by mixing
alcohols having a functionality of ~ or more with isocya-
nate compounds having a functionality of 2 or more. The
properti~s o~ the products can be influenced both through
. the type and through the quantity of compounds used~ Suit-
.- able polyol components are both low molecular wei~ht and
- 10high molecular weight compounds. Low molecular weiyht
.~ compounds which may be used as polyol oomponents for poly-
urethane prepol~mers are, for example, ethylene glycol,
propylene glycol, neopentyl glycol, butane-1,4-diol,
. hexane-1,6-diol and also triols, such as glycerol, tri
; 15~ethylol propane or trimethylol ekhane, and also hydroxy
~i~ compounds of relatively high functionality, such as penta-
erythritol.
Polyether polyols and/or polyester polyols are gener-
ally used as the relatively high molecular weight polyol
20compon~nt. Polyether polyols can be obtained by reaction
of an epoxide or tetrahydrofuran with a low molecular
.5~ weight polyol component, the epoxide being, for example,
. ethylene oxide, propylene oxide, butylene oxide, styrene
~: oxide, cyclohexene oxide, trichlorobutylene oxide and
¦ 25epichlorohydrin and the polyol being select~d, for example,
.` from such compounds as ethylene, diethylene and propylene
;~. glycol.
. Polyesters as starting matarials for polyurethane
.~ ¦ ; ~prepolymers are no~maIly obtained by reaction QP hydroxyl
¦ 30compounds with carboxylic ~cids. The low molecular weight
¦~ polyfunctional hydroxyl compounds already mentioned may be
~; ~ ~u ed.as the hydroxyl:compounds.;~The acid component may be
.` ¦~ -.se}ected from:such compounds as adipic acid, phthalic acid,
- ~ oxalic aci~,~ maleic acid, succinic acid, glutaric acid,
;~ ~ 35 ~azelaic acid, sebacic acid and tricarboxylic acids. Suit-
~'
~ . ~
` ~ 20787~7
`t ' ~ `'
~O 91J14739 6 PC~/~P91~00~69
able polyesters fo~ the production of polyurethane prepoly-
mers can also be obtained by ring-opening polymerization
of, for example, ~-caprolactone or methyl-~-caprolactone.
In addition to polyesters and polyethers, however, natural
substances, so-called oleochemical polyols or, for example,
castor oil, may also be used as the polyol component.
According to the invention, preferred polyols are
polyether polyols, more particularly polyether polyols
which may be obtained by reaction of glycerol to propylen~
oxide adducts, such as polypropylene glycol.
~` Both aromatic and aliphatic and/or cycloaliphatic
isocyanates may be used as the isocyanate component.
Suitable isocyanates having a functionality o~ 2 or more
are, for example, the isomers of tolyl~ne diisocyanatef
isophorone diisocyanate, dicyclohexyl methane diisocyanate,
tetramethyle~e diisocyanate, trimethyl hexamethylene
- ! diisocyanate, trimethyl xylene diisocyanate, hexamethylene
dii~ocyanate and diphenyl methane dii~ocyanate or even
triisocyanates, such as for example 4,4',4"-triphenyl
~'20 methane triisocyanate. According to the invention, aroma-
jl tic diisocyanates, more particularly technical diphenyl
methane-4,4'-diisocyanate (MDI) and 2,4-tolylene diisocya-
nate (TDI), are preferred.
In one pre*erred embodiment, the polyurethane prepoly-
mer is prepared by reaction of a glycerol/propylene oxide
adduct and/or a polypropylene glycol with technical diphen-
yl methane diisocyanate and/or technical tolylene diisocya-
nate. If the isocyanate is used in excess, the polyure-
thane prepolymer formed contains reactive NCO groups.
The durability of joint sealants is generally achieved
by addition of ~ine-particle solids, also known as ~illers.
i~ Both organlc and inorganic fillers are used. Pre~erred
inorganic fillers are, for example, chalk (coatéd~ or
~uncoated)~and/or zeolltes.~In addition, zeolîtes ~ay al50
~ ~ 35 ~be~serve as a drying agent. PVC powder, ~or example,~is a ~
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~ 2078~7
WO 91/1~739 7 PCT/~P91/00~9
~ suitable organic filler. The fillers generally contribute
: significantly towards ensuring that, after application, the
sealing compound has the internal cohesion required to
prevent it. from running or bulging from vertical joints.
5 The additives or fillers mentioned may be divided into
pigments and thixotropicizing fillers, also known in short
as thixotropic agents. In the case of joint sealants based
on moisture-curing polyurethane prepolymers, these thixo-
tropic agents hav~ to meet additional requirements. In the
case of isocyanate-terminated prepolymers, for example,
thexe must ba no danger of unwanted reactions with the
isocyanate yroups. Accordingly, ~he thixotropic agents are
essentially selected from swellable polymer powders of
which examples are polyacrylonitrile~ polyurethane, poly-
~inyl chloride, polya~rylates, polyvinyl alcohols, poly-
~ vinyl acetates and the corresponding copolymers. Particu-
: larly good resul~s can be obtained with fine-particle
~` polyvinyl chloride powder.
The properties of the polyurethane joint sealant can
be further improved by adding other components to the
. polymeric powder used as thixotropic agent. The other
,~ components in question are substances which come under the
category of the plasticizers or swelling agents and swel-
ling aids used for plastics. It is necessary in this
;. 25 regard to determine the optimal composition of the prepoly-
., mer/polymer powder/plasticizer/swelling aid systems. For
,,.j example, neither the plasticizer nor .the swelling aid
.~ should react with the isocyanate groups of the prepolymer.
.~; Accordingly, suitable thixotropic agents for polyvinyl
.`:` 30 chloride powder, ~or example, are plasticizers from the
. class of phthalic acid esters. Examples of suitable
,,` . compounds~from this class are dioctyl phthalate, dibutyl
.~ - ~ ~ phthalate~and~benzyl butyl phthalate. Other classes^ of
~ :compounds which have the desired properties are chloro~
:!~ ~ ~5 paraffins, allcyl su~fon~c acid esters,; ~or example ;of~:
~i,
i',., :
- .
`. ~t~`~ 2~7~7~
Wo 91/14739 8 PCT~BP9lJ00~69
phenols or cresols, and fa~ty acid es~ers. According to
the invention, plasticizers based on alkyl sulfonic acid
esters and polyvinyl chloride are particularly preferred as
the swellable polymer powder.
.l 5 Suitable swelling aids are low molecular weight or-
ganic compounds which are miscible with th~ polymer powder
and the plasticizer, but which do not react with the reac-
-~ tive terminal groups, for example isocyanate groups, of the
polyurethane prepolymer. Swelling aids of this type axe
known to the expert from the relevant textbooks on plastics
and polymexs. Preferred swelling aids for polyvinyl
chloride powder are esters, ketones, aliphatic hydrocar-
bons, aromatic hydrocarbons and alkyl-substituted aromatic
hydrocarbons. The latter, particularly xylene, are prefer-
ably used as swelling aids for polyvinyl chloride powders
in accordance with the present invention.
The pigments and dyes in the joint sealant according.
to the invention are the known substances used for this
purpose, such as titanium dioxide or iron oxides and carbon
., 20 black. It is known that stabilizers, such as benzoyl
chloride, acetyl chloride, toluenesulfonic acid methyl
,~ ester, carbodiimides and/or polycarbodiimides, can be added
to the joint sealants to improve their sta~ility in stor-
l. age. Particularly effective stabilizers are olefins
-¦ 25 containing 8 to 20 carbon atoms. In addition to their
stabilizing effect, they can also act as plasticizers or
.~ ¦ swelling agents. Olefins containing 8 to 18 carbon atoms
: are preferred, particularly when the double bond ls in the
.:~ . 1,2-position. The best results are obtained when the
molecular st~ucture of these stabilizers is linear.
. ¦ Epoxy compounds are known to the expert not only from
::~ ~ the patent li~erature, bu~ also ~rom encyclopedias. For
j~ ~ example, the production of epoxides, their properties and~
r~; ~ . uses,are described in~detail~in Encyklopadie der techni~
~ ~ 35 schen Chemio, 4th Edition, Vol. ~lO, Verlag~.Chemie,~Wein~
.~'.'.. : : :
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WO 91/~739 9 PcT/~psl/oo46s
heim/BergstraBe 1974, pages 563 et seq. Technically the
- most important epoxy compounds include epichlorohydrin and
those based on bisphenol A. Liquid epoxy compounds and/or
epoxy compounds readily soluble in at least one of the
other components of the joint sealant are particularly
suitable for the purposes of the invention. Non-volatile
or substantially non-volatiIe epoxy compounds are preferab-
ly used for safety reasons. Polyfunctional epoxy compounds
are paxticularly suitable. The average number o~ epoxy
~roups per mol~cule is preferably 1 5 to 3Ø
Glycidyl compounds, such as glycidyl esters or glyci
dyl ethers, are eminently suitableO Glycidyl esters can be
obtained, for example, by esterification of glycidol, also
known as 2,3-epoxy-1-propanol, with acids, for example
carboxylic acids. However, glycidyl ethers are preferred
for the purposes of the invention. Glycidyl ethers are in
particular compounds which, in theory or practice~ repre-
sent reackion products of epichlorohydrin wlth OH-function-
al substances. 0~ these, both phenolic compounds and
1 20 alcohols are suitable. Among the particularly suitable
i polyfunctional phenolic compounds, bisphenol A, also known
i! as 2,2 bis-(4-hydroxyphenyl)-propane, is preferred. Among
the alcohols, low molecular waight polyhydric alcohols
containin~ 2 to 6 carbon atoms a~e particularly pre~erred.
Pentaerythritol and dimethylol propane are particularly
suitable. Accordingly, epoxy compounds preferably present
in accordance with the invention are, for example, tri-
methylol propane, triglycidyl ethers, diglycidyl ethers
baæed on bisphenol A and/or pentaerythritol diglycidyl
ether.
The last-mentioned compound is commercially available
i~ and is known to the expert, for example as the principal
constituent~o~ optionally~filled casting resins for the
encapsulation and sheathing o~ electronic componants in the~
ir . .
~; 35 electrical industry. Like most epoxy compounds, lt lS
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2~7~7~
~0 91/14739 10 PCT~EP91/OO~C9
distinguished by high reactivity to compounds containing
amino, hydroxyl and/or carboxyl or anhydride groups. These
substances can be cured with organic polyamines at room
temperature and with dicarboxylic anhydrides, phenolic
resins, urea and melamine resins at relatively high temper-
atures. According to the present invention, however, there
is no need for such curing agents and~or accelerators for
epoxy compounds. On the contrary, it has proved to be
favorable in the interests of weather-resistant adhesion to
glass or glass-liXe surfaces for epoxy compounds to be
present to only a minor extent ~n the joint sealant and for
the actual curing process to take place at least predomi-
~;~ nantly by linkage of the polyurethane prepolymers to one
- another.
Accordingly, the joint sealants according to the
inv~ntion preferably contain no more than 15% by weight
~
: epoxy compound, based on polyurethane prepolymer. In order
to obtain a su~ficient improvement in weather-resistant
adhesion to glass, the expert will add no less than 1% by
weight epoxy compounds. A pre~erred range is from 3 to 8%
by weight, in which optimal results can be obtained.
r~! Suitable W stabilizers are known~ for example, ~rom
~t;''~ the above-cited DE-OS 32 21 655 and/or are commercially
obtainable. Representatives of the benzophenones, benztri-
azoles and sterically hindered amines are of particular
importance. So far as the problem addressed by the inven-
`, tion is concerned, particularly good results are obtained
with a preferred ratio o~ epoxy compound to W stabilizers
¦ of 3:1 to 1:2. Particularly good results are obtained in
:1 30 particular ln the range` from 2:1 to 1:1.
`~ ~owever; it has been found that not all W stabilizers
~are equally suitable. For example, less favorable results
are obtained with benzophenone or ~tris-nonyl phosphide.
Co ~ inations of W stabilizers also differ from one another
3~5 in their effeotiveness. Combinations of benztriazoles with
~. ~ ~
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`~ 207~8~
wo 9~ 73g ll pcT/~p9l/oo45s
sterically hindered amines have proved ts~ be eminently
suitable, particularly where the two components are used in
a ra~io to one another of 2: 1 to l: 2. Subs~antially equal
quantities of be~ztriazoles and sterically hindered amines
are pre~erred. The ratios mentioned above are quantitative
ratios. Suitable benxtriazoles are, in particular, 2-(2-
hydroxy-5-methylphenyl) - 2~-benztriazole and 2- (2-hydroxy-
3,5-ditert. amylphenyl)-2H-benztriazole. Among ~he suitable
; sterically hindered amines, bis-~2,2,6,6-tetramethyl-4-
piperidyl)-sebacate, for example, is particularly ~uitable.
- Suitable sterically hindered amines are also known to the
expert in short as l'HALS'I~
Polyurethane prepolymers with the basic molecular
structures described above suitable for the purposes o~ the
.~: ! 15 invention may contain various reactive terminal groups.
~`~' These terminal groups largely determine the curing process
-, of the joint sealants. Polyurethane prepolymers containing
mercaptan and/or alkoxysilane groups as reactive terminal
functional groups are preferred. Suitable mercaptan- or
, 20 alkoxysilane-terminated polyurethanes can be produced from
i corresponding isocyanate-te~minated polyurethanes.
~,1 Suitable isocyanate-terminated polyurethane prepoly-
, mers can be produced relatively easily. In general, the
isocyanate component merely has to be used in a stoichio-
j 25 metric excess in the above-described production o~ the
¦ polyurethane prepolymers from polyfunctional isocyanates.
Polyurethanes containing reactive NC0 groups are formed in
this way. Isocyanate-terminated polyurethane prepolymers
are preferably used in moisture-curing one-component joint
sealants, a~ desaribed for example in the above-cited DE-
OS 37 26 547.
In the same way as the isocyanate-terminate~ polyure-
,~ thanes, alkoxysilane-terminatied polyurethanes are pre~er-
p;~ ably ;used -in l-component moisture-curing jointing com-
-:~ ~5pounds. Polyurethane prepolymer~ aontainlng rcactive
;;:.
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207~7~
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wo g~ 739 12 ~C~/~Pgl~00~69
alkoxysilane groups can ha produced, for example, from
reactive isocyanate-funct~onal polyurethane prepolymers.
These polyurethane prepolymers are reacted with NCO-reac-
tive alkoxysilanes which leads to the required alkoxy-
silane-functional polyurethane prepolymers. If isocyanate
terminated prepolymers are used, it is obvious that the
alkoxysilane group introduced is also terminally position
in the reaction products. Suitable alkoxysilane-terminated
polyurethanes and their production are described, for
lo example, in ~he above-~îted DE-OS 36 2~ 237 and in DE OS 25
51 275.
Polyurethane prepolymers containing mercapto groups
can also be produced from the corresponding isocyanate
prepolymers. To this end, the isocyanate prepolymers are
reacted, for example, with mercaptoalcohols. Corresponding
SH-terminated prepolymers can thus be produced, for ex-
ample, from NCO-terminated polyurethane prepolymers. SH-
terminated prepolymers may be used with advantage in
oxidatively curing two-component sealants. Further partic-
ulars on this sub~ect can be found, for example, in the
above-cited DE-OS 36 01 189.
In a two~componen~ mercaptofunctional polyurethane
joint sealant of the type in question, the epoxy compound
is preferably present in the curing component. Two-compo-
1 25 nent systems are divided by the expert in~o a so~called
¦ prepolymer component or even resin component and a so-
I ¢alled curing component. The prepolymer component at least
predominantly contains the prepolymers capable of ~urther
polymerization. The term "curing component" is sel~--
explanatory. ~or example, in ~oint sealants based on SH-
terminated polyurethane prepolymer~, an oxidic curing
agent, such as~ma~ganese dioxide, is present in the curing
component. Accordingly, the curing agent is pre~èrably
, present in admixture with epoxy compounds in the curing
component.
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W0 91/~739 13 pcT/~psl~oo~6s
- The jolnt sealants generally contain other auxil-
iaries, preferably catalysts, plasticizers, solvents and/or
other auxiliaries known per se to the expert on joint
; sealants. Catalysts may be, for example, tin compound~i,
such as dibutyl dilaurate or dibutyl tin acetyl acPtonate.
Of the plasticizers, phthalate plasticizers, such as benzyl
butyl phthalate, are suitable. In the case of the SH-
: functional prepolymers, mercaptosilanes may be used as
:, coupling agents and/or thiuram disulfides as accelerators.
; 10 Xetoxime silanes are known as crosslinking agents for
silane-functional prepolymers. The auxiliaries and par-
ticularly the catalysts may dif~er in their suitahility
according to the different chemical modi~ication of the
~ polyurethane prepolymers suitable for the purposes of the
,; 15 invention. ~owever, this is also known to the expert.
Suitable auxiliaries can also be found in the paten~
literature cited above. .
~he joint sealants according to the invention are
pre~erably used for pane sealing in window manufacture, by
which is meant sealing of the window frame to the glass~
.: An important standard in Germany which describes the
requirements joint sealants o~ the type in question are
expected to satisfy is DIN 18545. An important test is the
so-called "Adhesion and Elasticity Test After Exposure to
~ight" which is described in DIN 52455. According to these
.' test criteria, the joint sealants according to the inven-
: tion described in the foregoing are eminently suitable ~or
' pane sealing, partiaularly so far as parmanent adhesion to
: glass is concerned. Accordingly, they open up a field of
~i 30 application which~ hitherto, has largely been reserved for
:,; the less economical joint sealants based on silicone or
: polysulfide~
The invention is illustrated by the following Ex-
~: amples. . ~;
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r ~ ~ .
:'~',',.' ~
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2~787~7
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- W0 91/1~739 14 PCT/EP91~00~9
m p 1 c
Exampl~ 1
Joint sealant based on SH-terminated polyurethane prepoly-
; 5 mer (PUR):
~o~po~t ~ A1A2
: ! 1. SH-term. PUR32.0 32.0
2. Benztriazole1.0
: 10 3. HAL31~0
4. Tin catalyst0.1 0.1
5. Phthalate pla~ticizer 10.0 10.0
6. Chalk54.3 56,9
. 7. Titanium dioxide0.5 0.5
~ 158. Coupling agent0.5 0.5
' ~ 100. 0 100 . 0
.
~ 20 Component B ~curing age~t) Bl B2
.. 1. Manganese dioxide (curing agent) 35.0 35.0
. 2. Phthalate plasticizer 20.0 45~0
3. Pentaerythritol diglycidyl ethèr 25.0
~`, 4. Chalk 13.0 13~0
-5. Carbon black 5.0 5.0
6. Accelerator ~.0 2.0
: . ,
, .
:, 100. 0 100. 0
,l.
, .
.~ 30 All quantities in % by weight
,:6 Mixing ratio o~ ~ : B ~ 1 : 0.10
, . ~
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~'" .' ' ' '
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', ' ~
` ` 2~787
: ` f~
wo 9~ 739 15 ~C~/BP91/00469
Ex~mpl~ 2
One-component joint sealant based on siloxane-terminated
polyurethane prepolymers ~PUR)
Bl B2 B3
1. Siloxane-term. PUR 40.040.040.0
2. Chalk 45.543.541.0
3. Titanium dioxide 5.05.0 5.0
4. Solvent 7~07.0 7.0
5. Crosslinking agent 2.02.0 2.0
: 6. Tin catalyst 0.50.5 0.5
7. ~ALS - 1.0 1.0
~ 8~ Benztriazole - 1.0 1.0
-- 9. Pentaerythritol diglycidyl ether - - 2.5
_ _
-~" 100.010~.O100.O ~,
All quankities in ~ by weight
.~, 20 Te~t re~ults
The test specimens were produced in accordance with
l DIN 18545 or DIN 42455, Sheet 1.
.~
Ad E~ampl~ 1
~l :25 The test specimens were conditioned as follows:
, : :
: . - 7 days normal atmosphere (23C/50% relative humidity)
~:, - 1 day drying cabinet, 50C
, - 7 day~ W/water storage (DIN 5~455, Sheet 3)
.. '' . :
'~`; : ~
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-.-'
.
.....
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,~, 1 . .
-~ 2~78~7
,;.~. ~,
.,;...... ~.,;,.
.: Wo 9l/1473g 16 PCT/~P'91/OOf~69
Aahe~lon test
Adhesion to glass Comparison Inven-
: tion
:
Component A: A1 A2 A1
Component B: B2 B1 Bl
,,
Breaking force: 0.13 0.46 1.0 N/mm2
... .
Elongation at break: 22 32 133 %
'
~a 13:a~ampl~Q~f 2
, - 7 days normal atmosphere (23~CJ50% relative humidity)
- 7 days drying cabinet, 50C
7 days storage under water (DIN 52455, Sheet 3
'`. !- .
- A~hs~io~ test
:
Adhesion to glass Comparison Inven-
tion
Bl B2 B3
~:i.,
~ Breaking ~orce: 0.25 0.36 0.63 N/mm'~
,i........ 25 Elongation at break: 57 129 203 %
: The results of the adhesion t,e,st for Examples 1 and 2
. demonstrate the improved e~'fect of the joint sealants
~, ~according to the invention.
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