Note: Descriptions are shown in the official language in which they were submitted.
~~~"~'~l
O.Z. 0050/43297
Preparation of resilient elastomers containing
bonded urethane groins or urethane and urea rour~s
in the presence of N-perethoxylated ~olyoxlralkylene
pohyamines as a formative component
The present invention relates to a process for
the preparation of resilient, cellular or preferably
compact elastamers containing bonded urethane groups or
urethane and urea groups, preferably elastomer moldings,
in particular airbag covers, by reacting organic,
modified or unmodified polyisocyanates (a) which are
known per se, with relatively high-molecular-weight
compounds containing at least two reactive hydrogen atoms
(b), at least one I~-perethoxylated polyoxyalkylene-
polyamine (c) and at least one low-molecular-weight chain
extender and/or crosslinking agent (d), in the presence
or absence of catalysts (e), auxiliaries (f) and blowing
agents (g), in a mold.
The preparation of elastomers containing bonded
urethane groups, urea groups or urethane and urea groups
2U and processes for the production of resilient, compact or
cellular moldings from these elastomers by the RII~
(reaction injection molding) method are known from
numerous patents and other publications.
According to DE-B-2622951 (US-A-4,218,543),
cellular or compact, resilient moldings having a closed
surface layer of polyurethane-polyurea elastomers can be
produced by the principle of reaction injection molding.
The formulations which are suitable for this purpose
essentially comprise organic polyisocyanates, polyols,
reactive aromatic diamines or polyamines which are
substituted in the o-position to the amino group by alkyl
groups, and strong catalysts for the reaction between
hydroxyl groups and isocyanate groups. It is essential
here that the aromai:ic diamines or polyamines are
infinitely miscible with polyols having a molecular
weight of from 12000 to 1800 and containing alkyl
- 2 ° O.Z, 0050/43297
substituents having 1 to 3 carbon atoms, where at least
two of the alkyl substituents have 2 to 3 carbon atoms
and each of the o-positions to the amino groups is
substituted. Systems of this type have initiation times
of down to less than one second; the transition from the
liquid phase to the solid phase takes place virtually
instantaneously, which results in the liquid reaction
mixture as it were solidifying on the walls of the mold.
It is furthermore known that the reactivity of
aromatically bonded amino groups toward isocyanates can
be greatly reduced by electron-withdrawing substituents.
According to DE-C-12 16 538 (British Patent 981,935),
examples of aromatic diamines of this type are 3,3'
dichloro-~,~'-diaminodiphenylmethane, 3,3'-dinitro-4,4'
diaminodiphenylmethane and 3,3°-dichloro-4,4'-diamino-
diphenyl; however, processing of these compounds requires
complex and inconvenient equipment due to reservations
about the health risk posed by them. Eiowever, the highly
electronegative substituents of these compounds reduce
the reactivity of the aromatically bonded amino groups so
much that full curing in moldings produced by reaction
injection molding requires up to 15 minutes and thus
becomes uneconomic.
Polyurethane-polyurea formulations having,
compared with the systems of DE-B-26 22 951,
somewhat reduced reactivity axe obtained, according
to EP-A-026 915, if the aromatic diamines used are
3,3',5,5'-tetraalkyl-substituted 4,~'-diaminodiphenyl
methanes in which the alkyl radicals are identical or
different and are methyl, ethyl, isopropyl, sec- or tert-
butyl, it being necessary for at least one of the
substituents to be isopropyl or sec-butyl. The tetra-
alkyl-substituted diaminodiphenylmethanes described are
readily miscible with the polyols in the required amounts
at room temperature and have little or no tendency
towards crystallization, so that formulations are easy to
handle under the usual conditions for conventional 1~IM
-- 3 - O.Z. 0050/43297
systems. However, it has been found that the tetraalkyl-
substituted 4,4'-diaminodiphenylmethanes described may
not be reactive enough for specific applications.
Polyurethane-polyurea formulation's which are
somewhat more reactive than those described in
EP-A-026 915 are described in EP-A-069 286. Th.e aromatic
diamines used are trialkyl-substituted aneta-phenylene
diamines in which two of the alkyl substituents are
identical or different, linear or branched alkyl having
1 to 4 carbon atoms, and the third alkyl radical has 4 to
12 carbon atoms or is five- or six-membered cycloalkyl.
Even with a relatively high content of diamines, the
formulations have adequate flowability and give moldings
having high heat distortian resistance and no progressive
fall in the shear modulus curves from 100 to 200°C.
All these processes have the disadvantage that
the difference in reactivity between the relatively high-
molecular-weight compounds containing at least two
primary hydroxyl groups and the aromatic diamines when
isocyanate groups are adducted is significant, in spite
of steric hindrance of the amino groups, and can only be
overcome by using synergistic catalyst combinations of
tertiary amines and metal salts, eg. dibutyltin
dilaurates, in order to accelerate the hydroxyl-
isocyanate polyaddition reaction. However, polyurethane-
polyurea elastomers prepared using metal salt catalysts
depolymerize at above 150°C, and extended exposure to
high temperatures can result in total loss of the
mechanical properties of the material.
It is furthermore known to partly or exclusively
use polyoxylene-polyamines having molecular weights of
from 1100 to 16000 for the preparation of resilient
polyurethane-polyurea or polyurea elastomers, for example
from EP-A-033 498 (US-A-4,269,945), EP-A-81 701,
EP-A-93 861 (US-A-4,396,729), EP-A-92 672, EP-A-93 862
(US-A-4,444,91.0 and US-A-4,433,067), EP-A-93 334 and
EP-A-93 336.
- 4 - O.Z. 0050/43297
According to EP-A-81 701 mentioned above as an
example, relatively high-molecular-weight
polyoxyalkylene-polyamines containing amino groups bonded
to aliphatic or aromatic radicals are used. I3owever,
aliphatic polyoxyalkylene-polyamines are known to be
extremely reactive, so that processing of RIM
formulations based on these compounds can result in
considerable problems associated with the machines, in
particular in the production of bulky moldings, for
ZO example due to short shot times and consequently output
of a small amount of material. Somewhat slower to react
than aliphatic polyoxyalkylene-polyamines are
polyoxyalkylene-polyamines containing aromatically bonded
amino groups. These compounds have the disadvantage of an
expensive preparation in multistep processes .and, in
particular, relatively high viscosities, for example of
mare than 20,000 mPas at 25°C, which can cause
considerable problems in the processing of formulations
containing reinforcing agents.
Furthermore, US Patents 4,048,105, 4,102,833 and
4,374,210 disclose the use of isocyanate group-containing
prepolymers and quasiprepolymers having NCO contents of
from 9 to 31~ by weight, prepared using unmodified or
modified 4,4'-diphenylmethane diisocyanates, in
polyurethane systems and the preparation of alkoxylated
polyoxyalkylene-polyamines. According to DE-E-1 917 408,
DE-A-1 966 059 and DE-A-1 966 058 (CA-A-914,850), poly-
oxypropylene-diamines and -triamines can be reacted with
ethylene oxide or propylene oxide at from 125 to 170°C,
and the resultant polyoxyalkylene-polyamine/alkylene
oxide adducts can be further reacted with polyisocyanates
to give polyurethane foams. According to US-A-4,465,858
and US-A-4,479,010, alkpxylated polyoxyalkylene-poly-.
amines having a tertiary amino group content of more or
less than 90$ are prepared by reacting polyoxyalkylene-
polyamines with alkylene oxides at from 75 to 85°C in the
presence of from 5 to 15~ by weight of water, based on
- C7.Z. 0050143297
the. polyoxyalkylene-polyamine, and then treating a
reaction product at from 75 to 135°C. The resultant
alkoxylated polyoxyalkylene-polyamines are suitable for
the production of flexible polyurethane f~ams, as poly-
5 urethane catalysts containing tertiary amino groups, or
as crosslinking agents for polyurethane foams, elastomers
and adhesives.
Hy selecting suitable relatively high-molecular-
weight compounds containing at least two reactive
hydrogen atoms, eg. polyether-polyols andJor polyester-
polyols, polyoxyalkylene-polyamines containing primary
amino groups bonded to aliphatic or aromatic radicals,
or, in particular, appropriately substituted aromatic
primary diamines as chain extenders and specific
catalysts or catalyst systems, attempts have been made to -
match the RIM formulations to the given requirements, eg.
volume and geometry of the mold. However, this method has
the disadvantage that the starting compounds employed
affect not only the reactivity of RIM formulations, but
also the mechanical properties of the resultant moldings.
This means that moldings having certain spatial shapes
and relatively large dimensions can in soma cases only be
produced with impaired mechanical properties, or not at
all, since the reaction mixtures have, for example,
inadequate flowability or cannot be introduced into the
mold in the necessary amounts.
The increasing use of low-density materials in
industry means that the mechanical demands made on
plastic moldings are often so high that they can only be
met, in particular in the case of cellular moldings, if
mechanical reinforcing elaareants, known as inserts, are
additionally used. This is no less true of processes for
the production of resilient, cellular or compact moldings
containing urethane groups or urethane and urea groups;
processing of polyurethane°(PU) or polyurethane-polyurea
(PU-PH) formulations of this type in the presence of
inserts is particularly difficult and, due to the high
~~~~ab"l'~
- 6 - O.Z. 0050/43297
reject rate, is also expensive. Only by using inserts in
cellular moldings, eg. airbag covers, can, for example,
the rec,~uiredl high flexibility arid high tear strength away
from the defined predetermined breaking poiait be ensured.
However, compact moldings, for example PU-PH
elastomer external parts of motor vehicles produced by
RIM, also frer~uently exhibit undesired brittieness after
demolding and are therefore very fragile. This low-
temperature brittleness, which occurs, in particular, in
IO moldings made from formulations containing a high
proportion of chain extenders and/or crosslinking agents,
can in some cases only be reduced or el.uninated by
extended storage and/or conditioning. The increased
fracture sensitivity of compact moldings of this type for
a certain time after demolding likewise causes increased
production costs.
It is an object of the present invention to
overcome the abovementioned disadvantages, at least in
part, but expediently in full, and to develop PU or PU-PH
formulations for the production of compact or cellular
moldings which have improved mechanical properties, in
particular h9.gh flexibility and simultaneously high tear
strength and, in the case of PU-PIi moldings, have reduced
or no low--temperature brittleness, ie. have greater
flexibility after demolding, with retention of the
excellent mechanical properties without the use of
inserts.
We have found that, surprisingly, this object is
achieved by the additional use of certain
polyoxyalkylene-polyamines which have been fully
oxyalkylated at the amino groups, in addition to the
known relatively high-molecular-weight compounds and low
molecular-weight chain extenders and/or crosslinking
agents, as 'the compound containing reactive hydrogen
atoms.
The present invention accordingly provides a
process for the preparation of resilient elastomers
2~9~fi7~
- 7 - 9,Z. 0050/43297
containing bonded urethane groups or urethane and urea
groups, by reacting
a) at least one organic and/or modified organic
polyisocyanate with
b) at least one relatively high-molecular-weight
compound containing at least two reactive hydrogen
atoms,
c) at least one oxyalkylated polyoxyalkylene-polyamine
and
d) low-molecular-weight chain extenders and/or
crosslinking agents,
in the presence or absence of
e) catalysts and/or
f) auxiliaries,
wherein the oxyalkylated polyoxyalkylene-polyamines (c)
used are N-perethoxylated polyoxyalkylene-polyamines.
In a preferred embodiment of the invention, the
process is particularly suitable for the production of
resilient airbag covers as claimed in claim 9 containing
bonded urethane groups or urethane and urea groups.
The process according to the invention
expediently uses N-perethoxylated polyoxyalkylene-
polyamines prepared from polyoxyalkylene-polyamines
containing at least 2, preferably 2 or 3, primary amino
groups and having a molecular weight of at least 200,
pref$rably from 2~0 to 5850.
The additional use of the N-perethoxylated
polyoxyalkylene-polyamines which can be used according to
the invention and which can be regarded as relatively
high-molecular-weight crosslinking agents with respect to
their structure and molecular weight, and which engage in
a particular way in the polyisocyanate polyaddition
reaction at a certain time due to their specific
reactivity, surprisingly gives elastomers having
increased tear strength, higher flexibility and lows:.
brittleness. PIE-Pty formulations give, by the RIM method,
moldings which no longer have low-temperature
~o~~~~~
- 8 - O.Z. U050/432~7
brittleness, but fully retain their very good mechanical
properties. There is no need to use inserts, as are
required, for example, for the production of airbag
covers for automobiles. The process acao~ding to the
invention is therefore preferably used to produce insert-
free moldings which, can be used as airbag covers in motor
vehicles.
The following applies to the preparation of the
N-perethoxylated polyoxyalkylene-polyamines which can be
used according to the invention and to the other starting
materials which can be used in the process according to
the invention for the preparation of the resilient
elastomers or elastomer moldings containing bonded
urethane groups or urethane and urea groups:
a) Suitable organic polyisocyanates are conven-
tional aliphatic, cycloaliphatic and, preferably,
aromatic polyisocyanates. Specific examples which
may be mentioned are 1,6-hexamethylene diisocyanate,
1-isocyanato-3,5,5-trimethyl-3-isocyanatomethyl-
cyclohexane, 2,4- and 2,6-hexahydrotolylene
diisocyaanate and the corresponding isomer mixtures,
4,4'-, 2,2'- and 2,4'-dicyclohexylmethane
diisocyanate and the corresponding isomer mixtures,
mixtures of 4,4°-, 2,2'- and 2,4'-dicyclo-
hexylmethane diisocyanates and polymethylene-
polycyclohexylene polyisocyanates, 2,4- and
2,6-tolylene diisocyanate and the corresponding
isomer mixtures, 4,4'-, 2,4'- and 2,2'-diphenyl-
m~thane diisocyanate and the corresponding isomer
mixtures, mixtures of 4,4'-, and 2,4'- and
2,2'-diphenylmethane diisocyanates and polyphenyl-
polymethylene polyisocyanates (crude MDT) and mix-
tures of crude MDI and tolylene diisocyanates.
Modified polyisocyanates, ie. products obtained
by chemical reaction of the above diisocyanates
and/or polyisocyanates, are frequently also used.
examples which may be mentioned are diisocyanates
- O.Z. 0050143297
and/or polyisocyanates containing ester, urea,
biuret, allophanate and, preferably, carbodia.mide,
isocyanurate and/or urethane groups. Specific
examples are aromatic polyisocyanat'es containing
urethane groups and having NCO contents of from
33.6
to 8% by weight, preferably from 31 to 21% by
weight, for example 4,4'-diphenylmethane diiso-
cyanate or tolylene diisocyanate modified with
low-
molecular-weight dials, trials, oxyalkylene glycols,
dioxyalkylene glycols, polyoxyal~cylene glycols
having molecular weights of up to 800, the following
being examples of dioxyalkylene glycols or poly-
oxyalkylene glycols, which can be employed
individually or as mixtures: diethylene glycol,
dipropylene glycol, polyoxyethylene glycols, poly-
oxypropylene glycols and polyoxypropylene-polyoxy-
ethylene glycols. Frepolymers containing NCO groups
and having NCO contents of from 25 to 8% by weight,
preferably 21 to 14% by weight, are also suitable.
Also suitable are liquid polyisocyanates containing
carbodiimide groups and/or isocyanate rings and
having NCO contents of from 33.6 to 8% by weight,
preferably from 31 to 21% by weight, fax example
based on 4,4'-, 2,4'- and/or 2,2-diphenylmethane
diisocyanate and/or 2,4- and/or 2,6-tolylene
diisocyanate and, preferably, 2,4- and 2,6-tolylene
diisocyanate, and the corresponding isomer mixtures,
4,4'-a 2,4'- and 2,2'-diphenylmethane diisocyanate
and the corresponding isomer mixtures, for example
of 4,4'- and 2,4'-diphenylmethane diisocyanates,
crude 1~IDI and mixtureo of tolylene diisocyanates
and
crude MDI, are also suitable.
However, the following are used in particular:
(i) carbodiimide- and/or urethane-containing polyiso-
cyanates made from 4,4'-diphenylmethane diisocyanate
or a mixture of 4,4'- and 2,4'-diphenylmethane
diiso-
cyanates and having an NCO content of from 33.6
to 8%
7
- 10 - O.Z, 0050/43297
-by weight, (ii) NGO-containing prepolymers having
an
NCO content of from 8 to 25~ by weight, based on
the
prepolymer weight, and prepared by reacting polyoxy-
alkylene-polyols having a functionality of from
2 to
4 and having a molecular weight of from 600 t~ 6000
with 4,4'-diphenylmethane diisocyanate or a mixture
of 4,4'- and 2,4'-diphenylmethane diisocyanates,
and
mixtures of (i) and (ii).
As stated above, suitable compounds for the
preparation of the NCO-containing prepolymers are
polyoxyalkylene-polyols having a functionality of
from 2 to 4, preferably of 2 or 3, and having a
molecular weight of from 600 to 6000, preferably
from
1000 to 4500. Analogous polyoxyalkylene-polyols
having molecular weights of at least 200, preferably
from approximately 240 to 5850 can be employed,
for
example, for the preparation of polyoxyalkylene-
polyamines, which are themselves suitable starting
materials for the preparation of the N-perethoxyl-
ated polyoxyalkylene-polyamines which are suitable
according to the invention or in combination
therewith for the preparation of the elastomers
or
elastomer moldings containing bonded urethane and
urea groups. Polyoxyalkylene-polyols of this type
can
be prepared from one or more alkylene oxides having
from 2 to 4 carbon atoms in the alkylene radical
and
an initiator molecule containing from 2 to 4,
preferably 2 or 3, reactive hydrogen atoms in bound
form, by canventional processes, for example by
anionic polymerization using alkali. metal hydroxides,
such as sodium hydroxide or potassium hydroxide,
or
alkali metal alcoholates, such as sodium methyla~te,
sodium ethylate, potassium ~ethylata or potassium
isopropylate, as catalysts or by cationic
polymerization using ~,ewis acids, such as antimony
pentachloride, boron trifluoride etherate inter
alia,
or bleaching earths as catalysts,
21~~~(i"~~
- 11 - o.z. 0050/43297
- Examples of suitable alkylene oxides are tetra-
hydrofuran, 1,3-propylene oxide, 1,2- or 2,3-butylene
oxide and, preferably, ethylene oxide and
1,2-propylene oxide. The alkylene oxides may be used
individually, one after the other in an alternating
manner or as mixtures. Examples of suitable initiator
molecules are water, organic dicarboxylic acids, such
as succinic acid, adipic acid, phthalic acid and
terephthalic acid, aliphatic and aromatic,
unsubstituted or N-monosubstituted or N,N- and N,N'-
dialkyl-substituted diamines having from 1 to 4
carbon atoms in the alkyl radical, such as
unsubstituted or mono- and dialkyl-substituted
ethylenediamine, diethylenetriamine, triethylene-
tetramine, 1,3-propylenediamine, 1,3- and 1,4-buty-
lenediamine, 1,2-, 1,3-, 1,4-, 1,5- and 1,6-hexa-
methylene diamine, phenylenediamines, 2,3-, 2,4-,
3,4-and 2,6-talylenediamine and 4,4'-, 2,4'- and
2,2°-diaminodiphenylmethane.
Furthermore, suitable initiator molecules are
alkanol~unines, eg. ethanolamine, diethanolamine,
N-methyl- and N-ethylethanolamine, N-methyl- and
N-ethyldiethanolamine and triethanolamine, and also
ammonia. Polyhydric, in particular dihydric and /or
trihydric alcohols and dialkylene glycois, such as
ethaned3.ol, propane-1,2-diol, propane-1,3-diol,
butane-1,4-diol, hexane-1,6-diol, glycerol,
trimethylolpropane, pentaerythritol, diethylene
glycol and dipropylene glycol are preferably used.
The polyoxyalkylene-polyols can be used indi-
vidually or in the form of mixtures.
b) The relatively high-molecular-weight compounds b)
containing at least two reactive hydrogen atoms can
be, for example, those having a functionality of 2 to
4, preferably from 2 to 3, and a molecular weight of
from 1200 to 8000, preferably from 1800 to 6000.
Examples of compounds which have proven successful
- 12 - O.Z. 0050/43297
-are polyoxyalkylene-polyaznines containing primary
and/or secondary amino groups, polyoxyalkylene-
polyalda.mines and/or polyketimines and/or preferably
polyols, expediently selected from' the group
S consisting of polyoxyalkylene-polyols, polyester
polyols, polythioether polyols, hydroxyl-containing
polyester-amides, hydroxyl-containing polyacetals and
hydroxyl-containing aliphatic golycarbonates, or
mixtures of at least 2 of said relatively high-
molecular-weight compounds containing at least 2
reactive hydrogen atoms. Preference is given to
polyoxyalkylene-polyamines containing primary or
secondary amino groups, and polyoxyalkylene-polyols.
Suitable polyester-polyols may be prepared, for
example, from organic dicarboxylic acids having from
2 to 12 carbon atoms, preferably aliphatic
dicarboxylic acids having from 4 to 6 carbon atoms,
and polyhydric alcohols, preferably diols, having
from 2 to 12 carbon atoms, preferably from 2 to s
carbon atoms. Examples of suitable dicarboxylic acids
are succinic acid, glutaric acid, adipic acid,
suberic acid, azelaic acid, sebacic acid,
decanedicarboxylic acid, malefic acid, fumaric acid,
phthalic acid, isophthalic acid and terephthalic
acid. The dicarboxylic acids may be used either
individually or mixed with one another. The free
dicarboxylic acids may also be replaced by the
corresponding dicarboxylic acid derivatives, for
example dicarboxylates with alcohols having from 1 to
4 carbon atoms or dicarboxylic anhydrides . Preference
is given to dicarboxylic acid mixtures comprising
succinic acid, glutaric acid and adipic acid in
ratios of, for example, from 20 to 35 : 35 to 50 : 20
to 32 parts by weight, and in particular
adipic acid. Examples of dihydric and
polyhydric alcohols and dialkylene glycols, in
particular diols, are ethanediol, diethylene glycol,
- 13 - O.Z. 0050143297
.1,2- and 1,3-prapanediol, dipropylene glycol,
1,4-
butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-
decanediol, glyceral and tramethylolpropane. Pref-
erence is given to ethanediol, dieth~,ilene glycol,
1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol
and
mixtures of at least two of said diols, in particular
mixtures of 1,4-butanediol, 1,5-pentanediol and
1,6-
hexanediol. furthermore, polyester-polyols made
from
lactones, eg. ~-caprolactone, or hydroxycarboxylic
acids, eg. ~-hydroxycaproic acid, may also be
employed.
The polyester-polyols may be prepared by polycon-
densing the organic, eg. aromatic and preferably
aliphatic polycarboxylic acids and/or derivatives
thereof and polyhydric alcohols without using a
catalyst or preferably in the presence of an ester-
ification catalyst, expediently in an inert gas
atmosphere, eg, nitrogen, carbon monoxide, helium,
argon, inter alia, in the melt at from 150 to 250C,
preferably from 180 to 220C, at atmospheric pressure
or under reduced pressure until the desired acid
number, which is advantageously less than 10,
preferably less than 2, is reached. In a preferred
embodiment, the esterification mixture is
polycondensed at the abovementioned temperatures
under atmospheric pressure and subsequently under
a
pressure of less than 500 mbar, preferably from
50 to
150 mbar, until an acid number of from 80 to 30,
preferably from 40 to 30, has been reached. Examples
of suitable esterification catalysts are iron,
cadmium, cobalt, lead, zinc, antimony, magnesium,
titanium and tin catalysts in the form of metals,
metal oxides or metal salts. however, the
polycondensation may also be carried out in the
liquid phase in the presence of diluents and/or
entrainers, eg. benzene, toluene, xylene or
chlorobenzene, for removal of the water of
14 - O.Z. x050/43297
-condensation by azeotropic distillation.
The polyester-polyols are advantageously prepared
by polycondensing the organic polycarboxylic acids
and/or d~rivat.ives thereof with polyhydric alcohols
in a molar ratio of from 1:1 to 1:8, preferably fro
m 1:1.05 to 1.2.
The polyester-polyols obtained preferably have a
functionality of from 2 to 3, in particular from 2 to
2.4, and a molecular weight of from 480 to 3000,
preferably from 1200 to 3000 in particular from 1800
to 2500.
However, the polyols used are in particular poly-
oxyalkylyene-polyols prepared by the above processes,
for example by anionic polymerization using alkali
metal hydroxides or alkali metal alkoxides as -
catalysts and with addition of at least one initiator
molecule containing at least 2 bonded reactive
hydrogen atoms, or by cationic polymerization using
Lewis acids or bleaching earth as catalysts, from
one
or more alkylene oxides having from 2 to 4 carbon
atoms in the alkylene moiety.
The polyoxyalkylene-polyols, preferably
polyoxypropylene-polyols and polyoxypropylene-
polyoxyethylene-polyols, preferably have a
functionality of from 2 to 4, in particular from
2 to
3, and molecular weights of from 1200 to 8000,
preferably 1800 to 6000, in particular from 2400
to
4800, and suitable polyoxytetramethylene-glycols
having a molecular weight of up to approximately
3500.
Other suitable polyoxyalkylene-polyols are poly-
mer-modified polyoxyalkylene-polyole, preferably
graft polyoxyalkylens-polyols, in particular those
based on styrene and/or acrylonitrile and prepared
by
in-situ polymerization of acrylonitrile styrene,
or
preferably mixtures of styrene and acrylonitrile,
for example in a weight ratio of from 90 : 10
- 15 - 0,~. 0050/43297
-to 10 . 90, preferably 70 . 30 to 30 . 70,
expediently in the abovementioned polyoxyalkylene-
polyols, .similar to the methods described in Cterman
Patents 11 11 394, 12 22 669 (US-A-3,304,273,
3,383,351, 3,523,093), 11 15 536 (GB-A-1,040,452)
and
11 52 537 (GB-A-987,618), and polyoxyalkylene-polyol
dispersions Containing, for example, as the disperse
phase, usually in an amount of from 1 to 50~C by
weight, preferably from 2 to 25~ by weight, poly-
areas, polyhydraxides, polyurethanes containing
bonded tent-amino grougs and/or melamin,
and described, for example, in EP-B-011 752
(US-A-4,304,708), US-A-4,374,209 and DE-A-32 31
497.
Like the polyester-polyols, the polyoxyalkylene
polyols can be used individually or in the form
of
mixtures. Furthermore, they may be mixed with the
graft polyoxyalkylene-polyois or polyester-polyols
and the hydroxyl-containing polyester-amides,
polyacetals, polycarbonates, polyoxyalkylene-
polyamines, polyoxyalylene polyaldimines and/or
polyoxyalkylene polyketimines.
Examples of suitable hydroxyl-containing
polyacetals are the compounds which can be prepared
from dihydroxyl compounds, such as diethylene glycol,
triethylene glycol, 4,4'-dihydroxyethoxydiphenyl-
dimethylmethane, hexanediol and formaldehyde.
Suitable polyacetals can also be prepared by poly-
merizing cyclic acetals.
Suitable hydroxyl-containing polycarbonates are
those of a conventional type, which can be prepared,
for example. by reacting diols, such as 1,3-
propanediol, 1,4-butanediol and/or 1,6-hexanediol,
diethylene glycol, triethylene glycol or
tetraethylene glycol, with diaryl carbonates, eg.
diphenyl carbonate, o~ phosgen~.
The polyester-amides include, for example, the
predominantly linear condensates obtained from
°
16 - 0.~. 0050/43297
. polybasic, saturated and/or unsaturated carboxylic
acids or anhydrides thereof and polyhydric saturated
and/or unsaturated amino alcohols, or mixtures of
polyhydr.ic alcohols and amino alCohols and/or
polyamines.
Suitable polyoxyalkylene-polyamines can, as
stated above, be prepared from the abovementioned
polyoxyalkylene-polyols by known processes. Examgles
which may be mentioned are the cyanoalkylation of
polyoxyalkylene-polyols and subsequent hydrogenation
of the resultant nitrite (US-A-3,267,050), or the
partial or complete amination of polyoxyalkylene-
polyols by means of amines or ammonia in the presence
of hydrogen and catalysts (DE-A-12 15 373).
The preparation of golyoxyalkylene-polyamines
containing primary or secondary amino groups is
furthermore described in EP-A-81 701 and EP-A-438 695
(CA-A-2,033,444), and that of polyazomethine-contain-
ing. eg. polyaidimine- or polyketimine-
containing, polyoxyalkylene-polyamines is described
in EP-A-438 696 (U'S-A-5,0$4,487).
c) As an additional compound containing reactive
hydrogen atoms for the preparation of resilient
elastomers or elastomer moldings containing urethane
groups or urethane and urea groups, N-perethoxylated
polyoxyalkylene-polyamines are used according to the
invention. Suitable polyoxyalkylene-polyamines which
are fully sthoxylated on the primary amino groups can
b~ obtained by known procQSSes, for example by
reacting ethylene oxide with polyoxyalkylene-
polyamines in the presence of catalysts, preferably
basic catalysts, or in particular without using a
catalyst, at elevated temperatures and at atmospheric
or superatmospheric pressure, the reaction being
carried out until all the free -NH-groups
have been ethoxylated. The starting materials
for the preparation of the I~-perethoxylated
- 17 - Q.~. 0050/43297
.polyoxyalkylene-polyamines are expediently polyoxy-
alkylene-polyamines containing at least 2 and/or
3
primary amino groups having a molecular weight of
at
least 20~, preferably from 240 to 5850. In a pre-
y ferred embodiment, the N-perethoxylated polyoxy-
alkylene-polyamines which can be used according
to
the invention can be prepared by reacting polyoxy-
alkylene-diamines and/or triamines with from 1.0
to
1.2 mol, preferably from 1.05 to 1.15 mol, of ethy-
lane oxide per -NH-group in the absence of catalysts
at from 90 to 1.20C, preferably from 100 to 120C,
and at from 1 to 8 bar, preferably from 4 to 6 bar.
N-perethoxylated polyoxyalkylene-polyamines which
have proven particularly successful and are therefore
preferred are di[N,N-di(2-hydroxyethyl)amino]-
polyoxyalkylenes, tri[N,N-di(2-hydroxyethyl)amino]_
polyoxyalkylenes, or mixtures thereof, having a
molecular weight of from 400 to 6000, preferably
from
560 to 3200.
In order to produce moldings by the process
according to the invention, the N-perethoxylated
polyoxyal.kylene-polyamines ( c ) can be employed
in any
desired amounts. In order to achieve specific
mechanical properties, it has proven expedient,
for
technical reasons associated with processing and
on
cost grounds, and depending on the formative
components (a), (b) and (d), to determine the
necessary amounts experimentally by means of simple
experimental series. In order to produce resilient
moldings having high flexibility and tear strength
and very low brittleness, the N-perethoxylated
polyoxyalkylen~-polyamines axe expediently used
fn an
amount of from 1 to 50 parts by weight, preferably
from 1 to 25 parts by weight, based on 100 parts
by
weight of the relatively high-molecular-weight
compounds containing at least two reactive hydrogen
atoms (b) and the low-molecular-weight chain
~0°~~~~~
18 - O.Z. 0050/43297
. extenders and/or crosslinking agents (d),
d) Suitable chain extenders and/or crosslinking
agents usually have molecular weights of less than
500. Preferably from 50 to 400. Example~ which can be
used are alkanediols having 2 t~ 12 carbon atoms,
preferably 2, 4 or 6 carbon atoms, eg, ethanediol,
1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol,
1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol,
1,10-decanediol and preferably 1,4-butanediol,
dialkylene glycols having 4 t~ 8 carbon atoms, eg.
diethylene glycol and dipropylene glycol, and
difunctional to tetrafunctional polyoxyalkylene-
poiyols having a molecular weight of up to 500.
However, other suitable compounds are branched and/or
unsaturated alkanediols, usually having not more than
12 carbon atoms, eg. 1,2-gzopanediol, 2-methyl or
2,2-dimethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-
propanediol, 2-butane-1,4-diol and 2-butyne-1,4-diol,
diestezs of terephthalic acid with glycols having 2
to 4 carbon atoms, eg. bis(ethylene glycol) or
bis(1,4-.butanediol) terephthalate, hydroxyalkylene
ethers of hydroquinone or resorcinol, eg. 1,4-di(~-
hydroxyethyl)hydroquinone or 1,3-di(~-hydroxZrethyl)-
resorcinol, alkanolamines having 2 to 12 carbon
atoms, eg. ethanolamine, 2-aminopropanol and 3-amino-
2,2-dimethylpropanol, and N-alkyldialkanolamines, eg.
N-methyl- and N-ethyldiethanolamine.
Examples of higher-functional czosslinking agents
which may be mentioned are trifunctional and higher
functional alcohols, eg, glycerol, trimethylolpro
pane, pentaerythritol and trihydroxycyclohexanes, and
trialkanolamines, eg. triethanolamine.
Chain extenders which have proven highly
successful and arc then~fore preferred are alkyl
substituted aromat:Cc polyamines, preferably having
molecular weights of from 122 to 400, in particular
primary aromatic diamines which contain, in the
- 19 - O.Z. 0050/43297
-ortho-position to the amine groups, at least one
alkyl substituent which reduces the reactivity of the
amino group due to static hinderance, and which are
liquid at room temperature and are partially
miscible, but preferably infinitely miscible, under
the processing conditions with the relatively high-
molecular-weight, at least difunctional compounds (b)
and N-perethoxylated polyoxyalkylene-polyamines (c).
Examples of suitable compounds are alkyl-
substituted mete-phenylenediamines of the formula
z
R NH2 R2 NH2
and/or
HEN , ~ R1 / ~ RI
R3 R3 NH2
where R' and Rz are identical or different and are
methyl, ethyl, propyl or isopropyl, and R1 is linear
or branched alkyl having 1 to 10, preferably 1 to 6,
carbon atoms. Also highly successful are branched
alkyl radicals R1 having 4 to 6 carbon atoms in which
the branching point is on the C1 carbon atom.
Specific examples of Rl radicals are methyl, ethyl,
isopropyl, 1-methyloctyl, 2-ethyloctyl, 1-methyl-
hexyl, 1,1-dimethylpentyl, 1,3,3-tri.nnethylhexyl, 1-
ethylpentyl, 2-ethylpentyl, cyclohexyl, 1-methyl-n-
propyl, tart-butyl, 1-ethyl-n-propyl, 1-methyl-n-
butyl and i,l-dimethyl-n-propyl.
Specific examples of alkyl-substituted m-phenyl
enediamines area 2,4-dimethyl-6-cyclohexyl-, 2-cyclo
hexyl-4,6-diethyl-, 2-chyclohexyl-2,6-isopropyl--,
2,4-dimethyl-6-(1-ethyl-n-propyl)-, 2,4-dimethyl-6
(1,1-dimethyl-n-propyl)- and 2-(1-methyl-n-butyl)
4,6-dimethyl-1,3-phenylenediamine. Preference is
given to 1-methyl-3,S-diethyl-2,4- and/or -2,6-
ghenylenediamines, 2,4-dimethyl-6-tent-butyl-, 2,4-
~~~~7~
- 20 -- O.Z. 0050/43297
dimethyl-6-isooctyl- arid 2,4-dimethyl-5-cyclohexyl-
1,3-phenylenediamine.
Also suitable are 3,3'-di- and/or 3,3',5.5'-tetra
n-alkyl-substituted4,4'-diaminodiphenyimethanes,eg.
3,3'-dimethyl-, 3,3'-diethyl-, 3,3'-di-n-propyl-,
3,3',5,5'-tetramethyl-, 3,3',5,5'-tetraethyl- and
3,3',5,5°-tetra-n-propyl-4,4'-diaminodiphenylmethane.
Preferred alkyl-substituted4,4'-diaminodiphenyl-
methanes are those of the formula
R5 R6
H2N ~ ~ CHZ ~ ~ NHZ
Ra ~R7
where R°, R5, R6 and R' are identical ar different and
are methyl, ethyl, propyl, isopropyl, sec-butyl or
tert-butyl, but where at least one of the radicals
must be isopropyl or sec-butyl. ~°he 4,4'-diaminodi-
phenylmethanes may also be used as a mixture with
isomers of the formula
HzN RS R6 HzN RS
and/or
R4 ~ ~ CH2 ~ ~ ~z R4 ~ ~ CHZ l ~ R6
R7 R~ NH2
where R', R°, R6 and R' are as defined above.
Specific examples are: 3,3',5-trimethyl-5'-iso-
propyl-, 3,3',5-triethyl-5'-isopropyl-, 3,3',5-
trimethyl-5'-sic-butyl-, 3,3°,5-triethyl-5'-sec -
butyl-, 3,3'-dim~ethyl-5,5'-diisopropyl-, 3,3'-
diethyl-5,S'-diisopropyl-, 3,3'-dimethyl-5,5'-di-sec-
butyl-, 3,3'-diethyl-5,5'-di-sec-butyl-, -3,5-di-
- 21 - 0.~. 0050/43297
-methyl-3',5'-diisopropyl-, 3,5-diethyl-3,5'-di-
isopropyl-, 3,5'-dimethyl-3',5-di-sec-butyl-, 3,5-
diethyl-3',5'-di-sec-butyl-, 3-methyl-3'-5,5-tri-
isopropyl-, 3-ethyl-3',5,5'-triisopropy~-, 3-methyl-
3'-ethyl-5,5'-diisopropyl-, 3-methyl-3',5,5'-tri-sec-
butyl-, 3-ethyl-3',5,5'-tri-sec-butyl-, 3,3'-di-
isopropyl-5,5-di-sec-butyl-, 3,5-diisopropyl-3',5'-
di-sec-butyl-, 3-ethyl-5-sec-butyl-3',5'-diisopropyl-
3-methyl-5-tart-butyl-3',5-diisopropyl-, 3-ethyl-
5-sec-butyl-3'-methyl-5'-tart-butyl-, 3,3'-5,5'-
tetraisopropyl- and 3,3',5,5'-tetra-sec-butyl-4,4'-
diamino-diphenylmethane. Preference is given to 3,5-
dimethyl-3',5'-diisopropyl- and 3,3',5,5'-
tetraisopropyl-4,4'-diaminodiphenylmethane. The
Z5 diaminodiphenylmethanes can b2 employed individually
-
or in the form of mixtures.
In order to prepare therefrom elastomers and
resilient moldings containing bonded urethane and
urea groups, it is expedient to use the following,
which are readily available industrially: 1,3,5-
triethyl-2,4-phenylenediamine, 1-methyl-3,5-diethyl-
2,4-phenylenediamine, mixtures of 1-methyl-3,5-
diethyl-2,4- and -2,6-phenylenediamines, known as
DETDA, mixtures of 3,3'-di- or 3,3',5,5'-tetraalkyl-
substituted 4,4'-diaminodiphenylmethane isomers
having 1 to 4 carbon atoms in the alkyl moiety, in
particular 3,3',5,5'-tetraalkyl-substituted 4,4'-
diaminodiphenylmethanes containing bonded methyl,
ethyl and isopropyl radicals, and mixtures of the
said tetraalkyl-substituted 4,4'-diaminodiphenyl-
methanes and DETDA.
In order to achieve specific mechanical
properties, it may also be expedient to use the
alkyl-substituted aromatic polyamines as a mixture
with the abovementioned low-molecular-weight
polyhydric alcohols, preferably dihydric and/or
trihydric alcohols, or dialkylene glycols.
2~~~~°~7
- 22 - O.Z, 0050/43297
The low-molecular-weight chain extenders and/or
crosslinking agents are thus selected, in particular,
from the group consisting of law-molecular--weight
difunctional and/or trifunctional' alcohols,
difunctional to tetrafunctional polyoxyalkylene-
polyols having a molecular weight of up to 500, and
alkyl-substituted aromatic diamines, or mixtures of
at least two of said chain extenders and/or cross-
linking agents.
zn order to prepare the resilient elastomers
containing bonded urethane groups or urethane and
urea groups, the organic polyisocyanates and/or
modified organic polyisocyanate mixtures (a),
relatively high-molecular-weight compounds containing
at least two reacta.ve hydrogen atoms (b), N-pere-
thoxylated polyoxyalkylene-polyamines (c) and low-
molecular-weight chain extenders and/or crosslinking
agents (d) are advantageously reacted in such amounts
that the ratia between number of equivalents of RICO
groups in component (a) and the total number of
reactive hydrogen atoms in components (b) to (d) is
from 0.85 to 1.25:1, preferably from 0.95 to 1.15:1,
in particular from 0.98 to 1.05:1, and the ratio
between the number of reactive hydrogen atoms in
components (b) and (d) is expediently in the range
from 1:2 to 1:15, preferably from 1:2.9 to 1:10.
e) The elastomers containing bonded urethane and
urea groups and the moldings produced therefrom are
preferably prepared in the absence of catalysts,
while the formation of the elastomers containing
urethane groups and the moldings produced therefrom
is expediently carried out in the presence of cata-
lysts.
The catalysts, where used, are, in particular,
highly basic amines. In order to produce heat-resist
ant moldings which can be painted on-line, it is
expedient to completely omit synergistic
- 23 - ~.~. 0050J432~7
-organometallic compounds, eg. organotin compounds.
Specific examples of suitable catalysts are: ami-
dines,eg,2,3_dimethyl-3,4,5,5-tetxahydropyrimidine,
and tertiary amines, eg. triethylamirie, tributyl-
amine, dimethylbenzylamine, N-methyl-, N-ethyl- and
N-cyclohexylmorpholine, N,N,N',N'-tetramethylethyl-
enediamine, N,N,N°,N°-tetramethylbutanediamine,
N,N,N',N " ,N " -pentamethyldisthylenetriamine,
N,N,N',N'-tetramethyldiaminoethyl ether, N,N,N',N'-
tetramethyl-4,4°-diaminodicyclohexylmethane, bis-
(diznethylaminopropyl)urea, dimethylpiperazine, 1,2-
dimethylimidazole, 1-azabicyclo[3.3.0]octane and
preferably 1,4-diazabicyclo[2.2.2]octane.
Other suitable catalysts area tris(dialkylamino
alkyl)-s-hexahydrotriazines, in particular tris(N,N
dimethylaminopropyl)-s-hexahydrotriazine, tetraalkyl
ammonium hydroxides, eg. tetramethylammonium
hydroxide, alkali metal hydroxides, eg. sodium
hydroxide, and alkali metal alkoxides, eg. sodium
methoxide and potassium isoprogropoxide, and alkali
metal salts of long-chain fatty acids having 10 to 20
carbon atoms, with or without lateral Oki groups. It
is usual to use from 0.001 to 5% by weight,
preferably from 0.05 to 2% by weight of catalysts,
based on the weight of the components (b) to (d).
f) Specific examples of suitable auxiliaries (f)
are surfactants, foam stabilizers, cell regulators,
fillers, flameproofing agents, external and/or
internal release agents, dyes, pigments, hydrolysis-
protection agents, and fung.ista~t.ic and bacteriostatic
substances.
Suitable surfactants are compounds which are used
to support homogenization of the starting materials
and may also be suitable for regulating the cell
structure. Specific examples are emulsifiers, such as
the sodium salts of castor oil sulfates or of fatty
acids, and salts of fatty acids with amines, eg.
- 24 .~ O.Z. 0050/43297
diethylamine oleate, diethanolamine stearate and
diethanolamine ricinoleate, salts of sulfonic acids,
eg. alkali metal or ammonium salts of dadecylbenzene-
or dinaphthylmethanedisulfonic acid and ricinoleic
acid; foam stabilizers, such as siloxane-oxaalkylene
copolymers and other organopolysiloxanes, oxyethyl-
ated alkylphenols, oxyethylated tatty alcohols,
paraffin oils, castor oil esters, ricinoleic acid
esters, turkey red oil and groundnut oil, and cell
regulators, such as paraffins, fatty alcohols and
di-
methylpolysiloxanes. the surfactants are usually
used
in amounts of from 0.01 to 5 parts by weight, based
on 100 parts by weight of components (b) to (d).
For the purposes of the present invention,
fillers, are conventional organic and inorganic
fillers. Specific examples are inorganic fillers,
such as silicate minerals, for example phyilosili--
cates, such as antigorite, serpentine, hornblendes,
amphiboles, chrysotile, talc and zeolites, metal
oxides, such as kaolin, alumina, titanium oxides
and
iron oxides, metal salts, such as chalk and barytes,
and inorganic pigments, such as cadmium sulfide
and
zinc sulfide. Preference is given to kaolin (china
clay) , a:Luminum silicate and coprecipitates of
barium
2S sulfate and aluminum silicate, and natural and
synthetic fibrous minerals, such as wollastonite
or
glass fibers of various lengths, which may be sized.
Examples of suitable organic f~.llers are carbon
black, melamine, collophony, cyclopentadienyl resins
and graft polymers based on styrene-acrylonitrile
,
which are prepared by in-situ polymerization of
acrylo-
n.itrile/styrene mixtures in polyoxyalkylene-polyols
in a similar manner to those given in German Patents
11 11 394, 12 22 669 (US 3,304,273, 3,383,351, and
3 , 52.3, 093 ) , 11 52 536 ( GH 1, 040, 452 ) and
11 52 537
(GB 987,618) and then aminated if desired, and also
filler-polyoxyalkylene-polyols or polyamines in
which
- 25 - o.Z. 0050143297
aqueous polymer dispersions are converted into
polyoxyal.kylene-polyol or polyamine dispersions. The
inorganic and organic fillers can be used
individually or as mixtures.
The inorganic and/or organic fillers can
advantageously be incorporated into the reaction
mixture in amounts of from 0.5 to 35~ by weight,
preferably from 3 to 20~ by weight, based on the
weight of components (a) to (d).
Examples of suitable flameproofing agents are
tricresyl phosphate, tris-2-chloroethyl phosphate,
trischloropropyl phosphate and tris-2,3-dibromopropyl
phosphate.
In addition to the abovementioned halo-sub-
stituted phosphates, it is also possible to use
inorganic flameproofing agents, eg. aluminum oxide
hydrate, antimony trioxide, arsenic oxide, ammonium
polyphosphate and calcium sulfate, or melamine,
expandable graphite or mixtures thereof, for example
mixtures of melamine, expandable graphite and/or
ammonium polyphosphate, for flameproofing the
moldings. In general, it has proved expedient to
use
from 5 t,o 50 parts by weight, preferably from 5
to 25
parts by weight, of the flameproofing agents
mentioned per 100 parts by weight of components
(b)
to (d).
Further details on the other conventional aux-
iliaries mentioned above can be obtained from the
literature, for example from the monograph by ~'.H.
Saunders and K.C. Frisch, High Polymers, Volume
XVI,
Polyurethanes, Parts 1 and 2, Interscience Pub-
lishers, 1962 and 1964 respectively, or Kunststoff-
Handbuch, Polyurethane, Volume VIT, Hanser-Verlag,
Munich, Vienna, 1st and 2nd Editions, 1966 and
1983.
g) In order to produce resilient moldings based on
the novel elastomers containing urethane groups or
- 26 - O.Z. 0050/43297
-urethane and urea groups, blowing agents (g) may be
introduced into the reaction mixture comprising
components (a) to (d) and possibly catalysts (e)
and/or auxiliaries (f), in order to produce cellular
moldings.
An example of a suitable blowing agent for the
production of cellular moldings is water, which
reacts with isocyanate groups to form carbon dioxide)
The amount of water which can expediently be used
is
from 0.01 to 5~ by weight, preferably from 0.1 to
1.0~ by weight, in particular from 0.2 to 0.4~ by
weight, based on the weight of components (b) to
(d).
Other blowing agents which can be used are low-
boiling liquids which evaporate during the exothermic
polyaddition reaction. Suitable liquids are those
which are inert toward the organic polyisocyanate
and
have a boiling point of less than 100C. examples
of
preferred liquids of this type are halogenated,
preferably fluorinated, hydrocarbons, such as
methylene chloride and dichloromonofluoromethane
,
perfluorinated or partially fluorinated hydrocarbons,
such as trifluoromethane, difluoromethane,
difluoroethane, tetrafluoroethane and hepta-
fluoropropane, hydrocarbons, such as n- and iso-
butane, n- and iso-pentane and technical-grade mix-
tures of these hydrocarbons, propane, propylene,
hexane, heptane, cyclobutane, cyclopentane, cyclo-
hexane, dialkyl ethers, such as dimethyl ether,
diethyl ether and furan, carboxylic acid esters,
such
as methyl formats and ethyl formats, ketones, such
as
acetone, and/or fluorinated and/or perfluorinated
tertiary alkylamines, such as perfluorodimethyliso-
propylamine. Mixtures of these low-boiling liquids
with one another and/or with other substituted or
unsubstituted hydrocarbons can also be used.
The most expedient amount of low-boiling liquid
27 ° ~.Z. 0050/43297
-for the production of resilient, cellular moldings of
this type from elastomers containing bonded urethane
groups or urethane and urea groups depends on the
desired density and, where appropriate, on the
presence of water. In general, amounts of from 1 to
15~ by weiglxt, preferably from 2 to 11~ by weight,
based on the weight of components (b) to (d) give
satisfactory results.
The resilient, compact moldings based on the
elastomers according to the invention containing urethane
and urea groups are expediently produced by the orie-shot
process using the low-pressure method or in particular by
reaction injection molding (RIM) in open or preferably
closed molds. Cellular moldings are produced by carrying
out the reaction, in particular, with compaction in a
closed mold. Reaction injection molding is described, for
example, by H. Piechota and H. Rbhr in Integral-.
schaumstoffe, Carl ~Ianser-verlag, Munich, Vienna, 1975;
D.J. Prepelka and J.L. Wharton in Journal of Cellular
Plastics, March/Apr_il 1975, pages 87 to 98, and U. ICnipp
in Journal of Cellular Plastics, March/April 1973, pages
76-84.
If a mixing chamber having several teed nozzles is
used, the starting components can be fed in individually
and mixed vigorously in the mixing chamber. It has proven
particularly advantageous to use the two-component
method, combining formative components (b) to (d) and, if
used, (e) to (g) in component (A) and using, as component
(B), organic polyisocyanates or modified polyisocyanate
mixtures. It is advantageous her~, for example, that
components (A) and (B) can be stored separately and
transported using a minimum of space and merely need to
be mixed in the appropriate amounts during processing.
The amount of reaction mixture introduced into the
mold is such that the moldings obtained, which may be
cellular, have a density of from 250 to 1400 kg/m', the
compact moldings preferably having a density of from 1000
- 28 - O.Z. 0050/43297
to 1400 kg/m', in particular from 1000 to 1200 kg/m', and
the cellular and microcellular moldings preferably having
a density of from 400 to 1100 kg/rn', for example from 450
to 750 kg/m', in particular from 550 to 6'SO kg/m', for
shoe soles, and from 700 to 1200 kg/m', in particular
from 950 to 1150 kg/m', for panelling elements. The
starting components are introduced into the mold at from
to 80°C, preferably from 30 to 65°C. The mold temper-
ature is expediently from 20 to 110°C, preferably from 35
10 to 95°C and in particular from 35 to 75°C. The degree of
compaction for the production of microcellular or cellu-
lar moldings is from 1.1 to 8, preferably from 2 to 6.
In order to improve demolding of the elastomer
moldings produced by the novel process, it has proven
15 advantageous to coat the internal surfaces of the mold,
at least at the beginning of a production run, with
conventional external mold-release agents, for example
based on wax or silicone, or, in particular, with. aqueous
soap solutions. However, internal mold-release agents, as
described, for example, in EP-A-153 649, EP-A-180 749
(AU 85/47,498), EP-A-173 888 (US 4,519,965), WO 84/03,288
(EP-A-119 47:L) and WO 86/01,215, have proven particularly
successful and are therefore preferred. The mold dwell
times are on average from 3 to 60 seconds, depending on
the size and geometry of the molding.
The compact moldings obtainable by the process
according to the invention are preferably used in the
automotive and aircraft industries, for example as bumper
covers and in particular as airbag covers, bump strips,
body parts, eg. rain gutters, mudguards, spoilers, wheel
arch extensions and for other industrial housing parts
and rollers. Cellular moldings are suitable for shoe
soles, armrests, headrests, sun visors, safety covers in
vehicle cabins, and as motorcycle, tractor and bicycle
saddles, seat cushions and top layers in composite
elements.
- 2~ - 0.2. 0050/43297
ExAMPLES
Preparation of N,N,N~-.P1~_tetra(2-hydroxyethyl)_
polyoxypropylene-diamine mixtures
EXAMPLE 1
3560 g (8.9 mol) of a polyoxypropylene-~diamine
having the structure
HEN- CH - CH2 ~ OCH~ --- CH ~ NHS
n
CH3 CH3
and a mean molecular weight of 400 (,Teffamine~ D 400 from
Texaco AG) was treated for one hour in a 10 1 autoclave
at 105°C under reduced pressure (1.33 mbar) in order to
remove the volatile constituents. The autoclave was then
filled with nitrogen to an absolute pressure of 3 bar,
and 1722 g (39.14 mol) of ethylene oxide were metered in
over a period of 4 hours at 105°C. After a reaction time
of 10 hours at 105°C, all the unreacted ethylene oxide
was remaved by distillation under reduced pressure at 33
mbar for 30 minutes and then at 1.33 mbar for 60 minutes.
The N-perethoxylated polyoxypropylene-diamine prepared in
this way had a hydroxyl number of 344, a viscosity of
1110 mPas at 25°C (by the Ubbelohde method), a residual
water content of 0.015 by weight and a pH of 11.7.
EXAMPLE 2
The procedure was similar to that in Example 1,
but 5260 g (2.63 mol) of a polyoxypropylene.~diamine
having a mean molecular weight of 2000 (,7effamine~ D 2000
from Texaco AG) and 509 g (11.568 mot) of ethyleize oxide,
which were metered in over a period of 2 hours at 105°C,
were used.
This gave an N~~perethoxylated polyoxypropylene
diamine having an hydroxyl number of I01, a viscosity of
720 mPas at 25°C (by the Ubbelohde method), a residual
~~~a~'~~
° 30 - O.Z. 0050/43297
water content of 0.07 by weight and a pH of 11.7.
Production of moldings containing bonded urethane
and urea groups
EXAMPLE 3
Polyoxyalkylene-polyamine component (A):
Mixture of
66.5 parts by weight of polyoxypropylene-diamine
(,Teffamine~ D 2000 ) ,
3.0 parts by weight of N-perethoxylated polyoxypropylene
diamine prepared as described in
Example 1,
30.0 parts by weight of a mixture of 1-methyl-
3,5-diethyl-2,4-phenylenediamine
and -2,6-phenyl-enediamine in a
weight ratio of 80:20 (DETDA1 and
0.5 part by weight of oleic acid.
Isocyanate component (Component B):
An NCO-containing prepolymer, having an NCO
cantent of 20~ by weight, prepared by reacting a
carbodiimide group-containing 4,4'-diphenylmethane
diisocyanate having an NCO content of 29.5 by weight and
a dipropylene glycol-initiated polyoxypropylene-diol
having an hydroxyl number of 56.
The polyoxyalkylene-polyamine (A) and the
isocyanate (B) components were mixed in an A:B mixing
ratio of 100:97.7 parts by weight in a Puromat~ 30 high
pressure metering unit from Elastogran Polyurethane GmbH,
Machine Construction Division, and irr~ected into a
metallic mold having the internal dimensions 400 x 200 x
2 mm which was held at 90°C. Component A was at 65°C and
B was at 50°C.
After a mold dwell time of 20 seconds, the molding
was removed. No low-temperature brittleness, ie. fracture
of the test sheet, was observed up to 30 minutes after
demolding. The test was then terminated.
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Comparative Example I
Polyoxyalkylene-polyamine component (A):
Mixture of
69.5 parts by weight of polyoxypropyle'ne-diamine
(Jeffamine~ D 2000),
30.0 parts by weight of a mixture of 1-methyl
3,5-diethyl-2,4-phenylenediamine
and -2,6-phenylenediamine in a
ratio by weight of 80:20 (DETDA)
and
0.5 part by weight of an oleic acid.
Isocyanate component (E): as in Example 3
The procedure was similar to that of Example 3,
but a mixing ratio between the polyoxyalkylene-polyamine
component (A) and isocyanate component (E) of
100:94.2 parts by weight was used. Low-temperature
brittleness occurred after only 10 minutes after the
molding had been removed, causing the test sheet to
break.
2 0 E~~AMPLE 4
Polyoxyalkylene-polyamine component (A):
Mixture of
43.5 parts by weight of N,N°-dibenzylpolyoxypropylene
diamine having a molecular weight
of approximately 2180 (prepared as
described in EP-A-4389 695,
Example 1)
20.0 parts by weight of N-perethoxylated polyoxypropyl-
ene-diamine, prepared as described
in Example 2,
30.0 parts by weight of a mixture of 1-methyl-3,5-
diethyl-2,4-phenylenediamine and -
2,6-phenylenediamine in a weight
ratio of 80:20 (DETDA),
2~~~6'~'~
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4.1 parts by weight of N,N'-polyoxypropylene-
dicyclopentylimine having a
molecular weight of from 350 to
700,
1.9 parts by weight of zinc stearate and
0.5 parts by weight of oleic acid.
Isocyanate comgonent (B): as described in Example 3.
First, ground glass fibers as filler were added
to polyoxyalkylene-polyamine component (A) in such an
amount that the glass fiher content in the molding
produced was 20~ by weight.
The glass fiber-containing polyoxyalkylene-
polyamine (A) and isocyanate (B) components were mixed in
a A:B mixing ratio of 100:66.9 parts by weight in a
Puromat~ 30 high-pressure metering unit and in~ecaed into
a metallic mold having the internal dimensions
400 x 200 x 2 mm kept at 65°C. Component A was at 65°C
and component B was at 50°C.
After a mold dwell time of 20 seconds, the
molding was removed. No low-temperature brittleness, ie.
fracture of the test sheet, was observed up to 30 minutes
after demolding. The remainder of the test was then
terminated.
Comparative Example II
Polyoxyalkylene-polyamine component (A):
Mixture of
63.5 parts by weight of N,N'-dibenzylpolyoxypropylene--
diamine having a molecular weight
of approximately 2180 (prepared as
described in EP-A-438 695, Example
1)
30.0 parts by weight of a mixture of 1-methyl-3,5-
diethyl-2,4-phenylenediamine and -
2,6-phenylenediamine in a weight
ratio of 80:20 (DETDA),
4.1 parts by weight of N, N' -polyoxypropylene-
dicyclopentylimine having a
20~~~'~~~
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_ molecular weight of from 350 to
700,
1.9 parts by weight of zinc stearate and
0.5 parts by weight of oleic acid. ,
Isocyanate component (B): as described in Example 3.
The procedure was similar to that of Example 4,
but a mixing ratio between the polyoxyalkylene-polyamine
(A) and isocyanate (B) components of 100:64.6 parts by
weight was used. Low-temperature brittleness occurred
after only one minute after the molding had been
demolded, causing the test sheet to break.
The N,N'-polyoxypropylene-dicyclopentylimine used
in Example 4 and Comparative Example II was prepared as
follows:
520 g of polyoxypropylene-diamine having a mean
molecular weight of 230 (Jeffamin~T~ 230 from Texaco AG)
were mixed at room temperature with 675 g of a solution
comprising 425 g of cyclopentanone and 250 g of toluene,
and the resultant reaction mixture was heated under
reflux on a water separator until water no longer
separated out (after about 9 hours). The toluene and
excess cyclopentanone were then removed by distillation
under reduced pressure at from 100 to 120°C, leaving, as
residue, 810 g of polyoxypropylene-dicyclopentylimine,
which was used without further purification.
EXAMPLE 5
The production of an airbag cover
Component A: mixture of
40.2 parts by weight of a glycerol-initiated polyoxy
propylene (86~ by weight)-polyoxy
ethylene (14~ by weight)-polyol
having a hydroxyl number of 26,
37.5 parts by weight of a tra.msthylolpropane-initiated
po:lyoxypropylene (BO~k by weight)
polyoxyethylene (20~ by weight)
polyol having a hydroxyl number of
- 34 - O.Z. 0050143297
27,
5.0 parts by weight of a N-perethoxylated polyoxy-
propylene-diamine prepared as
described in Example~2,
5.0 parts by weight of ethylene glycol,
5.0 parts by weight of polyoxytetramethylene glycol
having a hydroxyl number of
approximately 112,
0.5 Bart by weight of a 33~ strength by weight
solution of diazabicyclooctane in
ethylene glycol,
1.8 parts by weight of diazabicyclooctane-based
catalyst (DABCO~ 8154 from Air
Products) and
5.0 parts by weight of black paste (carbon black).
Component B:
NCO-containing prepolymer having an NCO content
of 26$ by weight, prepared by reacting 4,4'-
diphenylmethane diisocyanate and a carbodiimide group
containing 4,4'-diphenylmethane diisocyanate having an
NCO content of 29.5~c by weight with trioxypropylene
glycol.
Components A and B were mixed in a mixing ratio
of 100:41 parts by weight in a Puromat~ 30 high-pressure
metering unit, and the mixture was injected into a
metallic mold (airbag cover from Chrysler AG, internal
dimensions 260 x 175 x 50 mm) kept at 50°C. Companent A
was at 40°C and component B was at 30°C. After 100
seconds, the polyurethane molding was removed. After
storage for 48 hours, the molding was clamped in a holder
device for penetration testing, and a stamp measuring
120 x 20 mm and weighing 20.8 kg was allowed to act on
the molding at a speed of 16 km/h at -40°C, 25°C and
80°C. The polyurethane molding was penetrated and only
broke, as desired, at the predetermined breaking point.
~~~~~7~
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COMPARISON E~CAMphE III
The production of an airbag cover
Component A: mixture of
45.2 parts by weight of a glycerol-initiated polyoxy
propylene (86~ by weight)-.polyoxy
ethylene (14~ by weight)-polyol
having a hydroxyl number of 26,
37.5 parts by weight of a trimethylolpropane-initiated
polyoxypropylene (80~ by weight)_
polyoxyethylene (20~ by weight)
polyol having a hydroxyl number of
27,
5.0 parts by weight of ethylene glycol,
5.0 parts by weight of polyoxytetramethylene glycol
having a hydroxyl number of
approximately 112,
0.5 part by weight of a 33~ strength by weight
solution of diazabicyclooctane in
ethylene glycol,
1.8 parts by weight of diazabicyclooctane-based
catalyst (OABCO~ 8154 from Air
Products) and
5.0 parts by weight of black paste (carbon black).
Component B: as described in Example 5
The airbag cover was produced as described in
Example 5, but using an A:B mixing ratio of 100:40 parts
by weight.
A polyurethane molding was obtained which did not
pass the penetration test described in Example 5 since it
broke at a random point.
