Note: Descriptions are shown in the official language in which they were submitted.
1331~38
- Mo-2943
LeA 23,291
POLY-a-OLEFIN/POLYURETHANE BLOCK COPOLYMERS,
PROCESSES FOR THEIR PRODUCTION AND THEIR USE
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to new poly-a-olefin/
polyurethana block copolymers (PAO/PU block copolymers),
characterized in that they are synthesized from iso-
cyanate-reactive functionalized poly-(C2-C10-~-olefins)
(hereinafter abbreviated to PAO), preferably polypro-
ylene, di- or polyisocyanates or isocyanate prepolymers
and polyols and/or low molecular weight chain extending
agents.
The present invention also relates to a process
for the production of the PAO/PU block copolymers and to
their use as polymer dispersants for the production of
polymer blends, as primers or modifiers or for the
production of moldings or coatings.
Description of the Prior Art
Methods to obtain functionalized PAOs lie in
the degradation of high molecular weight non-functional
polyolefins ir. the presence of oxygen, air or ozone, or
by grafting with unsaturated carboxylic acids or acid
anhydrides for example. Carboxy-modified or carboxylic
anhydride-modified PAOs such as these are know per se,
but have never been used for the production of PAO/PU
block copolymers.
~-2943
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.
By contras~, PAO/PU blends and mixtures formed
~- solely by physical mixing and not by chemical linkage
are known. For example, DE-A 2,720,534 describes
PU/polyethylene or PU/polypropylene mixtures for
insulating panels.
According to DE-A 2,309,508, polyurethanes
having improved flex life are obtained by the addition
of rom 2 to 30~ polyethylene or polypropylene.
US-A 3,670,049 claims inter alia polyethylene and
polypropylene as lubricants for PU prepolymers.
US-A 3,272,890 describes polyethylene or
polypropylene molding mixtures containing from 15 to 25X
o a thermoplastic polyurethane (TPU).
Polyolefin mixtures with polycondensates or
- 15 polyurethanes are described in JA 25,175/70 (Toray~ .
In FR-A 2,163,530, GB-A 1,163,266, GB-A
1,181,727, DE-A 2,740,711/GB-A 1,070,105 and FR-A
1,330,784, polypropylene is modified inter alia by the
addition of polyurethanes to improve its dyeability.
Polypropylene-modified PU (prepolymers) are
described as hotmelt adhesives in DE-A 2,441,645, JA
~:: 56 033 ,139 and JA 51 114,438.
According to US-A 3, 432,451, polyurethanes are
synthesized in the presence of a polyolefin and used as
coatings and lacquers.
All of these patents are concerned with
physical mixtures of the particular components. There
are no covalent bonds between the polyolefins and the
polyurethane segments. Accordingly, the basic incompat-
ibility between these chemically very different polymercomponents cannot be eliminated. This is reflected, for
example, in the inadequate mechanical properties of
these blends.
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According to the present invention, this
problem is solved by chemical bond of the polyole~in
(PAO) with the PU component. Accordingly, PAO/PU block
copolymers such as ~hese may be directly used as moldings
or coatings, but more advantageously as primers or
compatibility promoters.
SUMMARY OF THE INVENTTON
The present invention is directed to poly-~-
olefin/polyurethane (PAO/PU) block copolymers which are
prepared by reacting
A) isocyanate-reactive functionalized poly-(C2-C10-~-
olefins) having a weight average molecular weight
Mw of about 1000 to 350,000,
B) polyisocyanates, isocyanate prepolymers or modified
polyisocyanates and, optionally,
C) isocyanate-reactive compounds containing -~
Zerewitinoff-active hydrogen atoms and having a molec-
ular weight of 400 to about 5000 and, optionally,
~- D) low molecular weight isocyanate-reactive chain
extending agents having a molecular weight of 32 to 399,
wherein at least one of the two isocyanate-reactive ~ -
compounds C) or D) must be present.
The present invention is also directed to this process
for preparing the poly-~-alkylolefin/polyurethane block
copolymers and to their use as polymer dispersants for
the production of polymer blends, as primers or compat- -~
ibility modifiers or for the production of moldings or
coatings.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to poly-~-
olefin/polyurethane block copolymers (PAO/PU block
copolymers), characterized in that they are obtained by `~
the reaction of
~: :
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A) isocyana~e-reactive functionalized poly-(C2-C10-~-
ole~in~) having a weight average molecular weight
of about 10~0 to 350,000, preferably about 2000 to
200,000 and more preferably about 2000 to 100,000,
B) polyisocyanates, isocyanate prepolymers or modified
organic di- or polyisocyanates and, optionally,
C) isocyanate-reactive compounds having a molec-
ular weight of 400 to abou~ 5000 and containing Zere-
witinof-active hydrogen atoms, such as polyether
polyols, polyester polyols, polycarbonate polyols,
polylactones, amino group-containing modified polyols
and, optionally,
D3 lo~ molecular weight compounds having a molecular
weight of from 64 to 399 as chain extending agents, for
example organic di- or polyhydroxy compounds and di- and
polyfunctional aminoalcohols or amines having a molec-
ular weight in the range of from 32 to 399,
in a single-stage or multistage process, -
wherein at least one of the two isocyanate-reactive
20 compounds C) or D) must be present.
The isocyanate-reactive, functionalized poly-
~-olefins (PAOs) mentioned in A) having a weight
average molecular weight Mw of about 1000 to 350,000,
preferably aboue 2000 to 200,000 and most preferably
about 2000 to 100,000 are polyolefins, preferably
polypropylenes, which contain functional groups capable
of reacting with isocya~ate groups. A review of s~itable functi~
groups ~an be fcund for example in Houben ~ yl, Suppl~E~tary Vol. 4,
pp. 768-784. These functionalized PAOs are preferably
poly-~-alkylolefin carboxylic acids, anhydrides,
alcohols and amines. The polyolefins in A) are homopoly-
mers or copolymers of C2-ClO-~-olefins, preferably poly-
propylene.
Functionalized PAOs are known in principle.
Thus, polypropylenes containing carboxylic acid groups
may be obtained in accordance with U.S. Patents
Mo-2943 - 4 ~
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3,416,990, 3,437,550 and 3,483,276 by modifying crystal-
line or amorphous polypropylene with an ethylenically
unsaturated carboxylic acid or polycarboxylic acid,
anhydride, amide or alkylester. Examples of acids or
5 anhydrides such as these are maleic acid, fumaric acid,
itaconic acid, acrylic acid, methacrylic acid, crotonic
acid, maleic acid anhydride or itaconic acid anhydride.
Maleic acid anhydride is preferably used.
lo An example of crystalline, carboxylated
polypropylene polymer which may be used in accordance with
the invention is Hercoprime* G, obtainable from Hercules,
Inc., Wilmington, Delaware 19894. An example of
amorphous carboxylated polypropylene polymer is
15 Epolene* E 43, obtainable from Eastman Kodak Company,
Tennessee.
Another method of obtaining functionalized
polyolefins is described in Canadian Patent Application
537,523. This patent application describes a process for
20 the production of poly-(C2-C10-~-alkylolefin) dicarboxylic -~-
acids having molecular weights Mw of about 70,000 to
350,000, preferably about 70,000 to 100,000, and most
preferably about 70,000 to 80,000, characterized in that
poly-(C2-C10-x-olefins) having a Mw of approximately
25 355,000 and a polydispersity M~ Mn f approximataly 10 are
oxidatively treated at about 200 to 300~C and optionally
degraded. -~
For example, 6000 g/h of isotactic polypropylene -~
having a Mw of 355,000 and a polydispersity M~ Mn of 10 ;~
30may be introduced into an extruder (ZSK 32) having an LD ~-~
(length-to-diameter ratio) of 40, heated to 250-260C and
mixed with 1500 normal liters/hour (Nl/h) air under
pressure, the cylinder temperature of the
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1 33 1 238
extruder being kept at about 210C after the zone where
the air is introduced. (~ = weight average molecular
weight; Mn = number average molecular weight).
In the degassing zvne, the excess air escapes
and the polypropylene carboxylic acid obtained is
extruded through the nozzle. After this first oxida-
tion, the resulting polypropylene carboxylic acid has a
of about 113,000, a polydispersity of 5 and a
carboxyl group content of 0.? carboxyl groups per
10 molecule.
This product may again be oxidatively extruded
in the same way, resulting in a polypropylene carboxylic
acid having ~ Mw of 94.000. a polydispersity of 4 and a
carboxyl group content of 1.3 carboxyl groups per
15 molecule.
This product may be oxidatively extruded a
third time. The resulting polypropylene carboxylic acid
has a Mw of 70,000, a po1ydispersity of 5 and a car-
boxyl group content of 1.5 to 2 carboxyl groups per
molecule.
The carboxyl group content is determined by
acidimetric titration using a methanolic potassium
hydroxide solution. The oxidative extrusion is
preferably carried out under pressures of about 1
25 bar to lOO bar.
This oxidation proces~ according to the above-
cited patent application to form polyolefin carboxylic
acids may also be carried out in a kneader at temper-
atures of about 150 to 300C using reaction times of
30 about 1 to 1000 minutes, preferably 10 to 1000 minutes,
with air throughputs of about 10 to 1000 l/h, and
pressures of about 1 to 100 bar.
Mo-2943 - 6 -
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The above-cited application also relates to a
process for the production of poly-(C2-C10-~-
olefin) carboxylic acids, characterized in that C2-C10
olefins are polymerized in known manner with known
orsanometallic mtxed catalysts, for example vanadium (III) crganic
c~unds and alu~m~iumaIky ~ lides especiall~ vanadium ~acetylacetonate)3/
Al(Cl) (C2H5)2, to molecular weights ~ of about 50,000 to
350,000 and then treated with C02 for 6 to 20 hours at t ~ eratures
of about -50 to -70C under a C02 pressure of up to about5 bar.
The reactionnuxture is subsequently acidified with aqueous
acid and the polyolefin carboxylic acid obtained is
separated off.
The PAO carboxylic acids or PAO carboxylic
acid anhydrides may then be directly reacted with isocyanate groups.
The reaction of isocyanate groups containing compounds
with low molecular weight carboxylic acids or carboxylic -~
acid anhydrides is known in principle and is described,
for example, in R.L. Zapp, G.E. Serniuk, K.S. Mickler,
Rubber Chem. Technol. 43, 1154 (1970); S. Motoki, T.
Saito, H. Ka~ami, Bull. Chem. Soc. Jpn. 47, 775 (1974);
C. Naegli, A. Tyabij, Helv. Chim. Acta. 17, 931 (1934).
Depending on how the reaction is conducted,
either hydroxamic acid anhydrides (formula I)
O O H O H
" '
R-COOH + R'-NCO - > R-C-O-C-N-R' R-C-N-R' + C0
(I) (II~
or with elimination of C02, amide linkages (formula II) -
are obtained.
Reaction of functionalized PAO with mono-
or polyisocyanates or isocyanate prepolymers to form
isocyanate-group-containing PAO and the resulting
preparation of PAO/PU block copolymers showing the
properties advantageously obtainable in accordance with
the invention is new.
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1 33 1 238
However, the above-mentioned PAOS carboxylic
acids or PAOS carboxylic acid anhydrides may also first
be converted into other isocyanate-reactive groups by
known organochemical reactions w~ich have not been used
for functionalized PAOs. Conversion into alcohol
groups, amino groups, epoxide groups etc. is mentioned
by way of example without limiting the invention in any
way.
This conversion of the carboxylic acid groups ..
or anhydride groups may be effected ~i~her directly by
reduction or rearrangement into other NCO-reactive
groups or by reaction of the PAO-carboxylic acid or
anhydride groups with other low molecular weight or
high molecular weight, at least bifunctional compounds
corresponding to the formula
An-R-Bm
wherein
R is an organic radical, for example an alkyl,
aralkyl, or aryl radical
having a molecular weight of 14 to about 1000,
A is a functional group capable of reacting with
carboxylic acid groups or anhydride groups~ such as
hydroxyl or amino groups, thus forming ester, amide
or imide bonds,
B is a functional group capable of reacting with
asocyanate groups, such as the groups set forth in
~ouben-Weyl E4, pp. 768-784, preferably hydroxy,
: amino, thio and epoxide groups,
n > 1 and
m > 1
Examples of these compounds include diols,
polyols and aminoalcohols such as ethylene glycol,
1,4-butanediol, 2,2-dimethyl-1,3-propanediol, ethanol-
amine, diethanolamine, etc.
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The reactivity of the polyolefin carboxylic
acid groups may have to be increased for this reaction
to be successfully performed. Any of the activating
agents normally used in organic chemistry may be used
S for this purpose. Conversion into carboxylic acid
halides is preferred. Conversion into carboxylic acid
chlorides is particularly preferred.
These polyolefin carboxylic acid chlorides may
be obtained in accordance with the already cited German
10 Patent Application (P 36 18 378) by reaction of poly-
olefin carboxylic acids having a Mw of about 1000 to ~-
350,000 with halogenating agents, preferably with
chlorinating agents such as thionyl chloride, optionally
in organic solvents such as aliphatic, cycloaliphatic or
15 aromatic solvents. Organic solvents are, preferably,
halogenated or alkylated aromatic hydrocarbons such as
toluene or chlorobenzene. In the absence of solvents,
the halogenation takes place as such using a suspension
of the carboxylic acid in the halogenating agent.
Organic polyisocyanates B) suitable for pre~
paring the PAO/PU block copolymers by reaction with the
functionalized PAO according to the invention are any
organic compounds containing at least two free iso-
cyanate groups. It is preferred to use diisocyanates
25 X(NCO)2 where X is in particular an aliphatic hydro-
carbon radical containing 4 to 12 C-atoms, a cyclo-
aliphatic hydrocarbon radical containing 6 to 15 C-
atoms, an aromatic hydrocarbon radical containing 6 to
15 C-atoms or an araliphatic hydrocarbon radical con-
30 taining 7 to 15 C-atoms.
Examples of particularly preferred diiso-
cyanates include tetramethylene diisocyanate, hexa-
methylene diisocyanate, dodecamethylene diisocyanate,
1,4-diisocyanato-cyclohexane, 1-isocyanato-3,3,5-tri-
Mo-2943 - 9 -
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.
methyl-5-isocyanatomethyl cyclohexane, 4,4'-methylene-
- bis-cyclohexyl diisocyanate, 4,4'-diisocyanato-2,2-di-
cyclohexyl propane, 1,4-diisocyanatobenzene, 2,4-diiso-
cyanatotoluene and/or 2,6-diisocyanatotoluene, 4,4'-di-
isocyanatodiphenylmethane, p-xylylene dii~ocyanate,
~ '-tetramethyl-m- or -p-xylylene diisocyanate and
mixtures of ~hese diisocyanates because thermoplastic
block copolymers are formed therefrom.
It is of course also possible to use the
10 polyisocyanates of higher functionality known per se
from polyurethane chemistry or even modified polyiso-
cyanates known per se, for example polyisocyanates
containing carbodiimide groups, allophanate groups,
isocyanurate groups, urethane groups and/or biuret
groups, either exclusively or in admixture with the
diisocyanates.
The isocyanate-reactive polyols containing
Zerewitinoff-active hydrogen atoms suitable as starting
material (C) for the production of PA0/PU block co-
20 polymers according to the invention are syn~hesis unitsknown per se from polyurethane/polyurea chemistry having
molecular weights of 400 to about 5000 such as polyether
polyols, polyester polyols, polycarbonate polyols,
polylactones and amino group-containing modified
25 polyols. In this case, too, difunctional compounds are
particularly preferred.
The compounds serving as chain extenders which
are suitable as starting material D) for the production
of the PA0/PU block copolymers according to the in-
30 vention are organic polyhydroxy compounds having amolecular weight of 62 to 399. The chain extenders are
: preferably difunctional and have a molecular weight 62
: to 399, preferably 62 to about 250. While trifunctional
chain extending agents are less preferred, they may be
Mo-2943 - 10 -
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1331238
co-used in small quantities with the difunctional chain
extenders.
Suitable compounds include in particular, simple
polyhydric alcohols such as ethylene glycol,
sl,2-propanediol, 1,3-propanediol, 1,4-butanediol,
1,6-hexanediol, trimethylol propane or glycerol. Low
molecular weight polyester diols such as adipic acid-
bis-(hydroxyethyl)-ester; low molecular weight diols
containing ether groups such as diethylene glycol,
triethylene glycol, tetraethylene glycol, dipropylene
glycol, tripropylene glycol or tetrapropylene glycol; and
also difunctional or polyfunctional amines having a
molecular weight of 32 to 399 may also be used as chain
extending and crosslinking agents.
15 ~ Compounds C) and D) are described in detail in
DE-A 2,832,253 (U.S. Patent 4,263,408), pages 11 to 20.
Rhein and Ingham (Polym. Prep. Amer. Chem. Soc.
Div. Polym. Chem. 15 (1974) 60-65 and Polymer 16, ~1975),
799-804) describe the production of prepolymers,
20 ethylene-propylene copolymers or atactic propylene
homopolymers by controlled subsequent introduction of
doublP bonds and subsequent ozonolysis. The terminal
groups formsd are converted into OH groups with alkyl
aluminum hydride reagents. These OH-functional pre-
25 polymers may be subsequently crosslinked with diiso-
cyanates. `
These products differ from the PAO/PU blockcopolymers according to the invention in that there is no
proportional co-use of organic polyhydroxyl compounds
30 having a molecular weight of 62 to about 5000 and/or no
use of alcoholic, aminic or hydrazinic chain extending or
crosslinking agents. Accordingly, there can be no
Mo-2943 -11- `
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I 33 1 238
formation of relaeively long and significant PU segments
- or domains in the products described in Rhein and Ingham
although ehis is crucial to compatibility with poly-
urethanes. However, it is precisely these segments or
domains which are essential according to the invention
for achieving the desired properties of the compat-
ibility-promoting PA0/PU block copolymers. In addition,
this method described by Rhein et al is not workable on
an industrial scale because the metal hydrides are
difficult to separate after the reaction and their
activity to isocyanates would be a problem, quite apart
rom their high cost.
By dispensing with the polyols serving as
fle~cibilizing soft segments in accordance with the
invention, whether in the form of the segments C) or in
the form of NC0 prepolymers B) based on relatively high
molecular weight polyols, rigid crosslinked, non-melting
and thermoplastically non-formable and non-processible
products are obtained by the process described by Rhein
and Ingham. However, it is precisely the thermoplastic
properties of the PA0IPU block copolymers according to
the invention that are crucial to their use as dis-
persants and primers for the production of polymer
blends.
The present invention also relates to a process
for the production of poly-a-olefin/polyurethane
(PA0/PU) block copolymers, characterized in that
A) isocyanate-reactive, functionalized poly-(C2-C10~ -
ol~ins) having a Mw of about 1000 to 350,000
are reacted, optionally in stages, with
B) organic di- or polyisocyanates, modified polyiso-
cyanates or isocyanate prepolymers based on
relatively high molecular weight polyols (C), and,
optionally,
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C) isocyanate-reactive synthesis units containing
Zerewitinoff-active hydrogen atoms having a molec-
ular weight of 400 to about 5,000 such as polyether
polyols, polyester polyols, polycarbonate polyols,
polylactones, amino group-containing modified
polyols and, optionally,
D) low molecular weight compounds having a molecular
weight of 62 to 399 as chain extending agents such
as organic di- or polyhydroxy compounds and di- and
polyfunctional amines having a molecular weight of :
32 to 399 as chain extending or crosslinkin~ a~ents
wherein at least one of the two isocyanate-reactive
compounds C) or D3 must be present.
One of the embodiments of the process according
lS to the invention for the production of PAO/PU block
copolymers is a process which is characterized in that
~ the functional PAOs A) are first reacted with the di- or
: polyisocyanates or with the isocyanate prepolymers B) in
:: the melt or in the presence of an inert organic solvent
(such as acetone, N-methyl pyrrolidone, toluene, chloro-
: benzene, dichlorobenzene, etc.) to form a prepolymer
still containing free isocyanate groups; the remaining
free NCO groups are completely or partly reacted in a
second step with the organic polyhydroxy compounds C)
25 having a molecular weight of 400 to about 5000 and any
remaining free isocyanate groups are optionally reacted
in a third step with organic di- or polyhydroxy com-
pounds D) having a molecular weight of 62 to 399 and/or
with aminic or hydrazinic chain extending or cross-
linking agents having a molecular we~ght of 32 to 399.
Mo-2943 - 13 -
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Anoth~r embodiment of the process for the
- production of PAOIPU block copolymers is characterized
in that the functional PAOs A) are first reacted with
the di- or polyisocyanates or with the isocyanate pre-
polymers B) in the melt or in the presence of an inert
organic solvent ~such as acetone, N-methyl pyrrolidone,
toluene, chlorobenzene, dichlorobenzene, etc.) to form a
prepolymer still containing free isocyanate groups and,
in a second step, the remaining free NCO groups are
completely reacted with a mixture of the organic poly-
hydroxy compounds C) having a molecular weight af 400 to
about 5000 and the organic di- or polyhydroxy campounds
D) having a molecular weight of 62 to 399 and/or aminic
or hydrazinic chain extending or crosslinking agents
. 15 having a molecular weight of 32 to 399.
j The present invention also relates to a process
for the production of PAO/PU block copolymers which is
characterized in that the di- or polyisocyanates B) are
first reacted with the organic polyhydroxy compounds C)
having a molecular weight of 400 to about 5000 in the
melt or in the presence of an inert organic solvent such
as acetone, N-methyl pyrrolidone, toluene, chloro-
benzene, dichlorobenzene, etc. to form a prepolymer
still containing free NeO groups and, in a second step,
the remaining free NCO groups are completely or partly
reacted with the functionalized PAOs A) and, in a third
step, any remaining free NCO groups are optionally
reacted with organic di- or polyhydroxy compounds D)
having a molecular weight of 62 to 399 and/or aminic or
hydrazinic chain extending or crosslinking agents having
a molecular weight of 32 to 399.
, In the process for the production of PAO/PU
block copolymers, the functional polypropylene car- ,.
boxylic acids may first be converted into the poly-
Mo-2943 - 14 -
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1 33 1 238
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propylene carboxylic acid halides, more especially
chlorides (as in Canadian Patent Application 537,523)
and, finally, reacted with aliphatic diols, preferably
ethylene glycol, butanediol or hexanediol, in the melt or
in an inert organic solvent such as toluene to form a
hydroxyalkyl polypropylene carboxylic acid ester as
functional PAOs.
Hydroxy-functional polypropylene carboxylic
acid derivatives are also preferably obtained by the
lo reaction of functional polypropylene carboxylic acid
anhydrides with aminoalcohol, preferably ethanolamine, in
an inert solvent which preferably forms an azeotrope with
water and azeotropically removing water to form
hydroxyalkyl polypropylene carboxylic acid diimides.
These hydroxy-functional polypropylene
carboxylic acid derivatives are then reacted with
isocyanates, preferably diphenylmethane diisocyanate,
- more preferably diphenylmethane diisocyanate, naphthylene
diisocyanate, toluylene diisocyanate, isophorone
diisocyanate or hexamethylene diisocyanate, more
preferably diphenylmethane-4,4-diisocyanate, in an inert
solvent at about 50 to 150C, preferably about 70 to
120C, or in the melt at about 100 to 200C, preferably
about 130 to 170C to form NC0 prepolymers and the NC0
prepolymers thus formed are subsequently reacted with a
chain extending agent such as butanediol, hexanediol,
more preferably butanediol, and/or relatively high
molecular weight polyhydroxyl compounds C), in a quantity
substantially equivalent to the quantity of NC0 present.
The mixture may then be kept at the temperature indicated
until no more free NC0 can by analytically detected.
In another preferred process, the above-
mentioned NC0 prepolymers of the hydroxy-functional PP
carboxylic acid esters or imides may first be reacted
Mo2942 -15-
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1331238
wi~h or~anic polyhydr~xy ccmpo~ds havin~ a mo1ecu1i~ weight of 400
to about 5000, preferably with polyesters, polypropylene glyool ether
or poly(tetramethylene)-g1ycol ether having a moleculi~ weight of
about 1000 to 3000 in such a quantity that, on completion
of this re~ction, free isocyanate groups are still present.
The frea isocyanate groups are then
reacted as described above with a substantially
equivalent quantity of a chain extending agent. The
polyesters prefarably used are aliphatic or aliphatic-
aromatic linear polyesters of dicarboxylic acids anddiols, of the type normally used for thermoplastic
polyurethanes.
In another preferred process for the production
of functionalized PA0-NC0 prepolymers, the PAOs car-
- 15 boxylic acids or anhydrides (preferably polypropylene
carboxylic acid or anhydrides) are directly reacted with
the aromatic or aliphatic isocyanates, preferably
diphenylmethane diisocyanate or toluylene diisocyanate
or NC0 prepolymers thereof, in a high-boiling solvent or
preferably in the melt at a temperature above the
melting point of the PA0 (preferably PP) carboxylic acid
or anhydride (i.e. above about 150C but to avoid
unwanted secondary reactions, not significantly above
the melting point, i.e. below about 200C). In this
reaction, amide bonds of the polypropylene residue to
the diisocyanate are formed with elimination of C02 in
accordance with formula (II). After the evolution of
C2 has stopped, the reaction mixture may be further -~
processed by one of the variants mentioned above. The
particular advantage of conducting the reaction in this
way lies in the simplicity of the procedure and in the
elimination of the preliminary stages for the prepa-
ration of the hydroxy-functional PA0 (preferable PP)
carboxylic acid esters or imides.
Mo-2943 - 16 -
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White to pale yellowish, crystalline or
amorphous solids which melt at about 150 to 2~0C
without decomposition are obtained in these processes.
Thermoanalytical investigations reveal the presence of
undisturbed crystallizations of ~he PAO and PU segments.
IR-spectra show both the signals for the functional PAOS
and also the characteristic absorption bands for
urethane and amide bonds. A considerable proportion of
block copolymers may be detected, while only negligible
quantities of pure PA0 (polypropyl~ne) or pure PU may be
isolated by the method of separating liquids (cf. R.
Kuhn, Makromol. Chem. 181. 725 (1980)).
The reactions take place at a temperature of
about 20 to 200C, preferably about 50 to 190C. The
standard catalysts normally used for isocyanate re-
actions may optionally be used in quantities of about
0.1 to lOZ, based on the total quantity of reactants.
The described reactions are complete when no more free
isocyanate groups can be analytically detected lIR).
The optionally dissolved PAO/PU block co-
polymers are isolated in known manner either by removal
of the solvent, preferably in vacuo, at elevated temper-
ature or by precipitation of the solution by the use of
a solvent in which the polymer is insoluble.
~5 To complete the reaction and to improve the
mechanical properties of the end product, it may be
advisable to condition the PAO/PU block copolymers
according to the invention for about 0.1 to 24 h,
preferably about 1 to 5 h at a temperature of about 50
to 150C, preferably about 70 to 120C.
After purification and drying and, optionally,
conditioning, the PAO/P~ block copolymers obtainable in
accordance with the invention may be processed in
standard mixing units, such as mixing rolls, kneaders,
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single-screw and multiscrew extruders and Brabender
mixers, to form moldings. The processing temperature
should preferably not excead about 250C.
The PA0/PU block copolymers according to the
S invention may also be mixed in any ratio with thermo-
plastic polyurethanes, such as Desmopan*, a product of
Bayer AG, or with isotactic and/or atactic polypropylenes
such as Vestolen*, a product of Huls A~.
In this case, the PA0/PU block copolymers
according to the invention may be used with particular
advantage as primers, compatibility promoters or dis-
persants in otherwise incompatible or poorly compatible
thermoplastic polymer mixtures such as polypropylene/
thermoplastic polyurethane elastomer blends. The PA0/PU
15 block copolymers are present in these mixtures in an
amount of 0.1 to 20% by weight.
The technological advance which may be achieved
by using th~ PA0/PU block copolymers according to the
invention may be demonstrated by measurement of the
20 torsional separation strength between polypropylene and
polyurethane sandwich panels. When a mixture of poly-
propylene (PP) and PU is used as the adhesive layer ~-
; between such panels, a torsional separation strength of
8 MPa is obtained in this comparative test. An addition
25 of 10~ of the PA0/PU block copolymers according to the
invention to the adhesive layer increases the torsional
separation strength to 13 MPa. For comparison, the
torsional separation strength between two polypropylene
panels is 4 MPa and between two PU panels is 16 MPa. The
30 comparative procedure adopted is to bond two panels of the
pure materials with a mixture of PU and PP (1:1) by fusion
bonding; whereas, in the test according to the invention
the block copolymer of Example 4 is added in a quantity of
10% to the PP/PU mixture as polymer dispersant and bonded
35 by holding for 15 minutes at 240C.
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The torsional separation streng;h impar~ed by
the PAO/PU block copolymer is reflected in considerably
increased compatibilizing of the PP and PU materials
because ehe strength is increased by 60~.
The effect of the PAO/PU block copolymers
according to the invention as polymer dispersants ~s
also apparent when PP/PU blends are viewed under an
optical microscope. Whereas, in the absence of polymer
dispersants, an irregular distribution consisting of
10 more or less large units of PU and PP is observed in
these blends, the phases are made uniform an~ smaller
by addition of the PAO/PU block copolymers according
to the:::invention.
The invention is further illustrated, but is
- 15 not intended to be limited by the following examples in
which all parts and percentages are by weight unless
otherwise specified.
EXAMPLES
Example 1
20 Preparation of the PP carboxylic acids (in accordance
with German Patent Application P 36 18 378.4):
6000 g/h isotactic polypropylene having a
weight average molecular weight of 340,000 were intro-
duced into an extruder (Werner u. Pfleiderer ZSK 32)
25 with a length-to-diameter ratio (LD) of 40, heated to
250-260C and mixed with 1500 Nl/h air under pressure.
After the zone where the air was introduced,
~he cylinder temperature of the extruder was kept at
210C. In the degassing zone, the excess air escaped
and the degraded polypropylene was extruded through the
nozzle.
Carboxy-functionalized polypropylene having a
molecular weight of approx. 80,000 and a functionality
of approx. 1 was obtained. Accordingly, the substance
35 had an acid number of approx. 0.7 g KOH/g substance.
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Example 2
Preparation of the hydroxy-functional PP carboxylic acid
esters:
100 g isotactic polypropylene degraded by
thermal oxidation (acid number approx. 0.7 mg KOH/g
5 substance) were dissolved in 200 ml abs. toluene and
refluxed for 2 hours with 20 g (excess) thionyl chloride.
Unused thionyl chloride and some toluene was distilled off
in vacuo. The quantity of tolune removed was added again
and 20 g o* ethylene glycol were added to the acid
~0 chloride. After another 3 hours under reflux, the product
was precipitated in an excess of methanol, filtered under
suction, washed with methanol and dried.
Example 3
Preparation of the bis-(hydroxyimide) of Epolene* E 43
polymer (a product of Eastman Kodak Company):
45 g (0.01) Epolene* E 43 polymer and 1.22 g
(0.02) ethanolamine were refluxed for 2 hours in 100 ml
toluene in a water separator. The product was then
precipitated in methanol, filtered under suction, washed
~oand dried.
OH number = 24 mg KOH/g substance (theor. 22.5).
Example 4
Preparation of the PAO/PU block copolymers:
80 g of the hydroxy-functional polypropylene of Example 2
25were dissolved in toluene and reacted with 25 g
diphenylmethane diioscyanate (MDI) in the quantity
calculated for the intended quantity of PU component.
After 2 hours at 80C. a stoichiometric quantity of
1,4-butanediol was slowly added, followed by stirring for
3012 hours at 80C until no more free isocyanate could be
detected. The product was precipitated in methanol,
filtered under suction, washed and dried.
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Example 5
The hydroxy-functional PP carboxylic acid esters
or imides of Examples 2 or 3 were dissolved in toluene and
reacted with toluylene diisocyanate (2,4-toluylene
5 diisocyanate~ in the quantity calculated for the intended
quantity of PU component NCO/OH-ratio = lOO/l. After
2 hours at 80C, a polyester of adipic acid and hexanediol
(OH number 56, molecular weight 2000) was slowly added in
half the quantity stoichiometrically corresponding to the
10 free isocyanate group content. After 2 hours at 80C,
1,6-hexanediol was slowly added in the quantity
corresponding to the remainder of free isocyanate groups,
followed by stirring for 12 hours at 80C until no more
free isocyanate could be detected. The product was
precipitated in methanol, filtered under suction, washed
and dried.
Example 6
100 g of the polypropylene carboxylic acid of
Exampla 1 (acid number 0.7) were melted under nitrogen at
20 150C. 25 g MDI were then slowly added at that
temperature. There was an evolution of gas (CO2) which ;
stopped after about 15 minutes. After another 30 minutes,
112 g of a polyester of adipic acid and butanediol (OH
number 50 mg KOH/g substance) were added, followed by
25 stirring for another 2 hours at 150C. 4.5 g butanediol
were then added to this NCO prepolymer containing
polypropylene blocks, followed by rapid stirring, after
which the mixture was poured into a Teflon pan and held
for 2 hours at 80C.
30 Exàmple 7
450 g (0.1) Epolene* E 43 polymer were melted at
160C, followed by the gradual addition of 34.8 g (0.2)
2,4-toluylene diisocyanate. Evolution of CO2 was observed
and slowly abated. After 30 min., 9 g of
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butanediol were added, followed by rapid stirring. The
product solidified and was then held for 2 hours at 80OC.
Example 8
Preparation of the PP carboxylic acids by thermal oxi-
s dation in an autoclave.
15.000 g isotactic polypropylene having a weight average
molecular weight of 340.000 were introduced in an auto-
clave (45 1~ It is heated to 200C and mixed with 600
l/h air under pressure (1,5 bar). The mixture is
lo stirring for 12 hours. Carboxyfunctionalized
polypropylene having a molecular weight Mw f
approximately 2.000 and a functionality of 2 - 2,5 was
obtained. ~'
Example 9
1.050 g of the polypropylene carboxylic acid of Example 8
were melted under nitrogen at 150C.
323 g methanediphenyldiisocyanate were then added at that
temperature. There was an evolution of gas (CO2). After
about two hours 1.627 g of a polyester of adipic acid and
butanediol ~molecular weight Mw about 2250) were added,
followed by stirring for 10 minutes at 160-170C.
Increasing of viscosity was observed and the product was
poured into a Teflon-pan and held for two hours at 120C.
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~xample 10
Mixing of the PAO~PU block copolymers with Vestolen* 5200
(Huls AG) polymer and Desmopan*thermoplastic (Bayer AG):
Brabender* Plastograph, Brabender OHG, Duisburg
s Model 8~ II 00 No. 179535
Procedure: temperature = 240C (~5C)
quantity = 50 g
compounding time = 15 mins.
r.p.m. = 25.
The compounded samples were removed with a
spatula while still hot and soft and dried in vacuo for
1 hour at 130C. Whereas, in the absence of polymer disper-
sants, an irregular distribution consisting of more or less
1arge units of PU and PP is observed in these blends, the
phases are made uniform and smaller by addition of the
PAO/PU block copolymers according to the inventionU.
Example 11
20Measurement of torsional separation strength
Sandwich samples of PU (Desmopan* 359 thermo-
plastic, Bayer AG) and PP (Vestolen* 5200 polymer) were
prepared using an intermediate film of 100-200~m thickness
by pressing for 15 minutes at 240DC in a heating press.
When the intermediate film consisted of a PU/PP
blend (ratio by weight 1:1), a separation strength of 8 MPa
was measured. When 10% of the PP/PU block copolymer of
Example 4 was added to the PU/PP blend for the intermediate
film, a torsional separation strength of 13 MPa was obtained.
For comparison: the strength of a sandwich
panel of two identical Desmopan* thermoplastic PU
elastomer panels (Bayer AG, D 5090 Leverkusen) was approx.
16 MPa; the strength of a sandwich panel of two identical
Vestolen* polymer panels was 4 MPa.
Although the invention has been described in
detail in the foregoing for the purpose of illustration,
it is to be understood that such detail i5 solely for
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that purpose and that variations can be made therein bythose skilled in the art without departing from the
spirit and scope of the invention except as it may be
limited by the claims.
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