U.S. patent application number 10/658915 was filed with the patent office on 2004-03-18 for thermoplastic molding compositions.
Invention is credited to Guntherberg, Norbert, Lindenschmidt, Gerhard, Niessner, Norbert.
Application Number | 20040054078 10/658915 |
Document ID | / |
Family ID | 7897415 |
Filed Date | 2004-03-18 |
United States Patent
Application |
20040054078 |
Kind Code |
A1 |
Guntherberg, Norbert ; et
al. |
March 18, 2004 |
Thermoplastic molding compositions
Abstract
Thermoplastic molding compositions essentially comprise (A) from
20 to 99% by weight of at least one graft copolymer, (B) from 1 to
80% by weight of a copolymer obtainable from at least one
alpha-olefin and from at least one polar comonomer, with the
proviso that the monomers used are not vinyl acetate or any
vinylaromatic monomer, and (C) from 0 to 80% by weight of a
thermoplastic polymer, obtainable by polymerizing a monomer
mixture, essentially consisting of (c1) from 50 to 100% by weight
of at least one vinylaromatic monomer and/or of a
C.sub.1-C.sub.8-alkyl (meth)acrylate, and (c2) from 0 to 50% by
weight of at least one monofunctional comonomer, and (D) from 0.1
to 15% by weight of a three-block polymer made from (d1) from 5 to
90% by weight of polyethylene oxide and (d2) from 95 to 10% by
weight of polypropylene oxide and having a central polypropylene
oxide block with a molar mass of from 800 to 5 000 g/mol and
terminal blocks made from polyethylene oxide, where components A to
D give 100% by weight in total. A process for preparing the
thermoplastic molding compositions is also described, as is their
use.
Inventors: |
Guntherberg, Norbert;
(Speyer, DE) ; Lindenschmidt, Gerhard; (Leimen,
DE) ; Niessner, Norbert; (Friedelsheim, DE) |
Correspondence
Address: |
KEIL & WEINKAUF
1350 CONNECTICUT AVENUE, N.W.
WASHINGTON
DC
20036
US
|
Family ID: |
7897415 |
Appl. No.: |
10/658915 |
Filed: |
September 11, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10658915 |
Sep 11, 2003 |
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09913184 |
Aug 9, 2001 |
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6649117 |
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09913184 |
Aug 9, 2001 |
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PCT/EP00/00962 |
Feb 7, 2000 |
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Current U.S.
Class: |
525/64 |
Current CPC
Class: |
C08F 265/04 20130101;
C08L 23/08 20130101; C08L 51/003 20130101; C08L 23/08 20130101;
C08L 25/14 20130101; C08L 23/08 20130101; C08L 71/02 20130101; C08L
2666/02 20130101; C08L 2666/22 20130101; C08L 51/003 20130101; C08L
2666/24 20130101 |
Class at
Publication: |
525/064 |
International
Class: |
C08L 065/00; C08L
071/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 12, 1999 |
DE |
19906066.5 |
Claims
We claim:
1. A thermoplastic molding composition, essentially comprising (A)
from 20 to 99% by weight of at least one graft copolymer,
essentially obtainable from (a1) from 30 to 90% by weight of a
core, obtainable by polymerizing a monomer mixture, essentially
consisting of (a11) from 80 to 99.99% by weight of at least one
C.sub.1-C.sub.10-alkyl acrylate, (a12) from 0.01 to 20% by weight
of at least one copolymerizable, poly-functional, crosslinking
monomer, and (a13) from 0 to 40% by weight, based on the total
weight of components (a11) and (a12), of at least one other
copolymerizable, monoethylenically unsaturated monomer, and (a2)
from 10 to 70% by weight of a graft shell, obtainable by
polymerizing a monomer mixture in the presence of the core (a1),
and essentially consisting of (a21) from 50 to 100% by weight of at
least one styrene compound of the formula (I) 5 where R.sup.1 and
R.sup.2 independently of one another, are hydrogen or
C.sub.1-C.sub.8-alkyl and/or of a C.sub.1-C.sub.8-alkyl
(meth)acrylate, and (a22) from 0 to 50% by weight of at least one
monofunctional comonomer, and (B) from 1 to 80% by weight of a
copolymer obtainable from at least one alpha-olefin and from at
least one polar comonomer, with the proviso that the monomers used
are not vinyl acetate or any vinylaromatic monomer, and (C) from 0
to 80% by weight of a thermoplastic polymer, obtainable by
polymerizing a monomer mixture, essentially consisting of (c1) from
50 to 100% by weight of at least one vinylaromatic monomer and/or
of a C.sub.1-C.sub.8-alkyl (meth)acrylate, and (c2) from 0 to 50%
by weight of at least one monofunctional comonomer, and (D) from
0.1 to 15% by weight of a three-block polymer made from (d1) from 5
to 90% by weight of polyethylene oxide and (d2) from 95 to 10% by
weight of polypropylene oxide and having a central polypropylene
oxide block with a molar mass of from 800 to 5 000 g/mol and
terminal blocks made from polyethylene oxide, where components A to
D give 100% by weight in total.
2. A thermoplastic molding composition as claimed in claim 1,
wherein the particle size of the graft copolymers (A) as given by
the average diameter (d.sub.50) is from 60 to 1500 nm.
3. A thermoplastic molding composition as claimed in claim 2,
wherein the particle size as given by the average diameter
(d.sub.50) is from 150 to 700 nm.
4. A thermoplastic molding composition as claimed in any one of
claims 1 to 3, wherein the particle size distribution of component
(A) is bimodal.
5. A thermoplastic molding composition as claimed in claim 4,
wherein the component (A) used comprises a mixture of from 0.5 to
99.5% by weight of a graft copolymer (A) whose particle size as
given by the average diameter (d.sub.50) is from 200 to 1000 nm and
from 99.5 to 0.5% by weight of a graft copolymer (A) whose particle
size as given by the average diameter (d.sub.50) is from 60 to 190
nm.
6. A thermoplastic molding composition as claimed in any one of
claims 1 to 5, wherein the glass transition temperature of the core
(a1) is selected to be below 0.degree. C.
7. A process for preparing thermoplastic molding compositions as
claimed in any one of claims 1 to 6 in a manner known per se, which
comprises mixing the components of claim 1 and, if desired,
conventional additives in a mixing apparatus.
8. The use of the thermoplasic molding compositions as claimed in
any one of claims 1 to 6, or prepared as claimed in claim 7, for
producing moldings, films or fibers.
9. The use of the thermoplastic molding compositions as claimed in
any one of claims 1 to 6, or prepared as claimed in claim 7, for
coating sheet-like structures to give sheet-like structures with a
reduced-gloss surface and antistatic properties, via
coextrusion.
10. A molding, a film or a fiber obtainable by way of the use as
claimed in claim 8.
11. A coating or film with leather-like appearance, produced by
mixing (A) from 20 to 99% by weight of at least one graft
copolymer, essentially obtainable from (a1) from 30 to 90% by
weight of a core, obtainable by polymerizing a monomer mixture,
essentially consisting of (a11) from 80 to 99.99% by weight of
n-butyl acrylate, and (a12) from 0.01 to 20% by weight of
tricyclodecenyl acrylate, and (a2) from 10 to 70% by weight of a
graft shell, obtainable by polymerizing a monomer mixture in the
presence of the core (a1), and essentially consisting of (a21) from
60 to 90% by weight of styrene and (a22) from 40 to 10% by weight
of acrylonitrile, and (B) from 1 to 80% by weight of a copolymer,
prepared from from 67 to 96% by weight of ethylene, from 1 to 20%
by weight of n-butyl acrylate, from 3 to 10% by weight of
(meth)acrylic acid, and from 0 to 3% by weight of maleic anhydride,
and (C) from 0 to 80% by weight of a copolymer, prepared by
continuous solution polymerization of (c1) from 65 to 85% by weight
of styrene and (c2) from 15 to 35% by weight of acrylonitrile, and
(D) from 0.1 to 15% by weight of a three-block polymer made from
(d1) from 5 to 90% by weight of polyethylene oxide and (d2) from 10
to 95% by weight of polypropylene oxide and having a central
polypropylene oxide block with a molar mass of from 800 to 5 000
g/mol and terminal blocks made from polyethylene oxide, where
components A to D give 100% by weight in total, and then
calendering or extruding to give films.
12. The use of coated sheet-like structures or of films with
leather-like appearance as claimed in claim 11 for the internal
fitting-out of houses, utility vehicles, aircraft, ships or trains,
or in the furniture industry or in the sanitary sector.
Description
[0001] The invention relates to thermoplastic molding compositions
based on ASA (acrylonitrile-styrene-acrylate) with improved
flowability and improved extrusion properties. The invention
further relates to a process for preparing these thermoplastic
molding compositions, their use, and also, produced therefrom,
reduced-gloss and antistatic films and moldings, and coatings with
reduced gloss, and the use of these.
[0002] There is a wide variety of application sectors for
thermoplastic molding compositions, and there is therefore a wide
variety of known molding compositions with differing mixes for
different application sectors.
[0003] EP-A 0 526 813 describes polymer blends for flexible films.
These are made from a graft copolymer of vinyl monomers as graft
shell on an acrylate rubber as graft base, a partially crosslinked
copolymer rubber based on acrylate, an uncrosslinked polymer based
on styrene compounds and/or on acrylic compounds and an
ethylene-vinyl acetate copolymer. The plastic material which can be
obtained, in which no PVC is present, is suitable for producing
leather-like films. However, these mixtures tend to discolor
undesirably during processing and have a disadvantageous
relationship between tensile strength and elongation at break.
Films of this type also exhibit relatively severe fogging when
processed by methods similar to those conventionally used.
[0004] DE-A 31 49 358 relates to thermoplastic molding compositions
obtainable from a graft copolymer with a core made from a
crosslinked alkyl acrylate and, if desired, comonomers and a shell
obtainable by polymerizing a vinylaromatic monomer, with an
ethylenically unsaturated monomer and with a copolymer obtainable
by polymerizing a vinylaromatic monomer and with an ethylenically
unsaturated monomer. Films produced from these thermoplastic
molding compositions have the disadvantage of excessively low
elongation at break together with excessively high hardness.
Molding compositions of this type are moreover unsuitable for soft
coextrusion compositions.
[0005] Plastic films with reduced-gloss surface and leather-like
appearance are used, for example, for interior trim in motor
vehicles, in the construction of buildings and in the sanitary and
furniture sectors. The plastic usually used nowadays is PVC, mixed
with a variety of vinyl polymers and plasticizers. These films are
not fully aging-resistant at high temperatures, and they comprise
volatile constituents and naturally contain halogen (see DE-A 42 11
415).
[0006] The use of alkylene oxide polymers (component (D)) in
thermoplastic molding compositions is known.
[0007] AU-A 93 52 355 relates to thermoplastic synthetic mixtures
for producing degradable single-use plastic products. These
mixtures comprise from 65 to 95% by weight of high-molecular-weight
polyethylene oxide, at least one high-molecular-weight
thermoplastic polymer selected from the group consisting of
nylon-11, nylon-12, polyethylene-co-acrylic acid,
polyethylene-co-methacrylic acid, polyethylene-co-vinyl acetate and
polyethylene-co-vinyl alcohol.
[0008] EP-A 0 603 147 describes antistatic thermoplastic styrene
(co)polymers which comprise high-molecular-weight polyethylene
oxide (average molecular weight from 100,000 to 400,000), a lithium
salt and ethylene glycol, diethylene glycol or triethylene
glycol.
[0009] The use of alkylene oxide polymers in thermoplastic molding
compositions based on SAN and/or ABS is disclosed in a number of
documents.
[0010] FR-B 1 239 902 describes the use of additives for rendering
polymers antistatic. Examples of additives used are ethylene
oxide-propylene oxide three-block copolymers. These antistats can
be used in PVC, polymethacrylate, polyethylene, polystyrene or
molding compositions made of ABS
(acrylonitrile-butadiene-styrene).
[0011] EP-A 0 018 591 describes molding compositions which comprise
styrene-acrylonitrile copolymers. These molding compositions also
comprise linear three-block copolymers built up from two terminal
ethylene oxide blocks and from a central propylene oxide block. The
alkylene oxide three-block copolymers are used as lubricants. They
affect the processing properties of styrene-acrylonitrile
copolymers, in particular processing properties in injection
molding. Adding the three-block polymers has no substantial effect
on the mechanical properties.
[0012] There has been no previous disclosure of the use of alkylene
oxide polymers in molding compositions which comprise mainly ASA
graft rubber with SAN, and comprise at least one olefin
copolymer.
[0013] It is an object of the present invention, therefore, to
provide thermoplastic molding compositions which may be used either
as films or else as soft, reduced-gloss surface coatings of hard,
brittle or impact-resistant thermoplastics. These molding
compositions are applied to coatings, for example by coextrusion,
and for this have to have good flowability. A further object was to
provide a process for preparing these thermoplastic molding
compositions, as well as the use of the novel molding compositions
for producing moldings or films, and as coextrusion compositions.
The films should have reduced susceptibility to electrostatic
charging and reduced Shore hardness. Further objects are the
provision of films and moldings made from the novel molding
compositions which have good and balanced mechanical properties,
and the use of these.
[0014] We have found that this object is achieved by thermoplastic
molding compositions, essentially comprising
[0015] (A) from 20 to 99% by weight of at least one graph
copolymer, essentially obtainable from
[0016] (a1) from 30 to 90% by weight of a core, obtainable by
polymerizing a monomer mixture, essentially consisting of
[0017] (a11) from 80 to 99.99% by weight of at least one
C.sub.1-C.sub.10-alkyl acrylate,
[0018] (a12) from 0.01 to 20% by weight of at least one
copolymerizable, polyfunctional, crosslinking monomer, and
[0019] (a13) from 0 to 40% by weight, based on the total weight of
components (a11) and (a12), of at least one other copolymerizable,
monoethylenically unsaturated monomer, and
[0020] (a2) from 10 to 70% by weight of a graft shell, obtainable
by polymerizing a monomer mixture in the presence of the core (a1),
and essentially consisting of
[0021] (a21) from 50 to 100% by weight of at least one styrene
compound of the formula (I) 1
[0022] where R.sup.1 and R.sup.2, independently of one another, are
hydrogen or C.sub.1-C.sub.8-alkyl and/or of a C.sub.1-C.sub.8-alkyl
(meth)acrylate, and
[0023] (a22) from 0 to 50% by weight of at least one monofunctional
comonomer, and
[0024] (B) from 1 to 80% by weight of a copolymer obtainable from
at least one alpha-olefin and from at least one polar comonomer,
with the proviso that the monomers used are not vinyl acetate or
any vinylaromatic monomer, and
[0025] (C) from 0 to 80% by weight of a thermoplastic polymer,
obtainable by polymerizing a monomer mixture, essentially
consisting of
[0026] (c1) from 50 to 100% by weight of at least one vinylaromatic
monomer and/or of a C.sub.1-C.sub.8-alkyl (meth)acrylate, and
[0027] (c2) from 0 to 50% by weight of at least one monofunctional
comonomer, and
[0028] (D) from 0.1 to 15% by weight of a three-block polymer made
from
[0029] (d1) from 5 to 90% by weight of polyethylene oxide and
[0030] (d2) from 95 to 10% by weight of polypropylene oxide
[0031] and having a central polypropylene oxide block with a molar
mass of from 800 to 5 000 g/mol, and terminal blocks made from
polyethylene oxide,
[0032] where components A to D give 100% by weight in total.
[0033] These molding compositions feature excellent flowability and
very good extrusion properties. They may be extruded to give films,
or coated thermoformed sheets with a soft, mat surface, with
consistent product quality or they may be processed to give
moldings, for example by injection molding. The molding
compositions have a high level of mechanical strength and heat
resistance. They give good coextrusion. Films and moldings made
from these molding compositions have reduced surface gloss and
reduced electrostatic charging. They are suitable for internal trim
of motor vehicles and for use in the construction of houses and in
the sanitary and furniture sectors.
[0034] This type of combination of properties is achieved by the
novel molding compositions. The fundamental properties here for
application in films are achieved by the mixture of components (A)
to (C) and the overall property profile for application in
coextrusion is achieved by the mixture of components (A) to (D). As
well as reducing susceptibility to electrostatic charging,
component (D) improves flowability and reduces Shore hardness.
[0035] The amount of component (A) present in the novel molding
compositions, based on the total of components (A) to (D), is from
20 to 99% by weight, preferably from 30 to 98% by weight and
particularly preferably from 60 to 95% by weight. This component is
a particulate graft copolymer built up from an elastomeric graft
core (a1) (soft component) and, grafted onto this, a shell (a2)
(hard component).
[0036] The amount of the graft core (a1), based on component (A),
is from 30 to 90% by weight, preferably from 35 to 80% by weight
and particularly preferably from 40 to 75% by weight.
[0037] The graft core (a1) is obtained by polymerizing a monomer
mixture made from, based on (a1),
[0038] (a11) from 80 to 99.99% by weight, preferably from 90 to
99.85% by weight and particularly preferably from 97 to 99% by
weight, of at least one C.sub.1-C.sub.10-alkyl acrylate,
[0039] (a12) from 0.01 to 20% by weight, preferably from 0.2 to 10%
by weight and particularly preferably from 0.5 to 5% by weight, of
at least one crosslinking monomer, and
[0040] (a13) from 0 to 40% by weight, preferably from 0 to 10% by
weight based on the total weight of components (a11) and (a12), of
at least one other copolymerizable, monoethylenically unsaturated
monomer.
[0041] Particularly suitable C.sub.1-C.sub.10-alkyl acrylates
[component (a11)] are methyl acrylate, ethyl acrylate, propyl
acrylate, n-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate,
n-heptyl acrylate, n-octyl acrylate, 2-ethyl-hexyl acrylate,
n-nonyl acrylate and n-decyl acrylate, and also mixtures of these,
particularly preferably ethyl acrylate, 2-ethylhexyl acrylate,
n-butyl acrylate or mixtures of these, and very particularly
preferably n-butyl acrylate.
[0042] The copolymerizable, polyfunctional crosslinking monomers
(a12) used are generally those which contain two, three or four,
preferably two, copolymerizable double bonds which are not
conjugated in 1,3 positions. Examples of monomers of this type
suitable for crosslinking are ethylene glycol diacrylate, ethylene
glycol dimethacrylate, butanediol diacrylate, butanediol
dimethacrylate, hexanediol diacrylate, hexanediol dimethacrylate,
divinylbenzene, diallyl maleate, diallyl fumarate, diallyl
phthalate, triallyl cyanurate, triallyl isocyanurate,
tricyclodecenyl acrylate, dihydrodicyclopentadienyl acrylate,
triallyl phosphate, allyl acrylate, allyl methacrylate and
dicyclopentadienyl acrylate (DCPA) (cf. DE-C-12 60 135).
[0043] Other examples which may be mentioned of copolymerizable,
monoethylenically unsaturated monomers (component (a13)) are
butadiene, isoprene;
[0044] vinylaromatic monomers, such as styrene or styrene
derivatives of the formula I;
[0045] methacrylonitrile, acrylonitrile;
[0046] acrylic acid, methacrylic acid, dicarboxylic acids, such as
maleic acid and fumaric acid, and also anhydrides of these, such as
maleic anhydride;
[0047] nitrogen-functional monomers, such as dimethylaminomethyl
acrylate, dimethylaminoethyl acrylate, vinylimidazole,
vinylpyrrolidine, vinylcaprolactam, vinylcarbazole, vinylaniline,
acrylamide;
[0048] C.sub.1-C.sub.4-alkyl methacrylates, such as methyl
methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl
methacrylate, n-butyl methacrylate, isobutyl methacrylate,
sec-butyl methacrylate and hydroxyethyl acrylate;
[0049] aromatic or araliphatic (meth)acrylates, such as phenyl
acrylate, phenyl methacrylate, 2-phenylethyl acrylate,
2-phenylethyl methacrylate, benzyl methacrylate, benzyl acrylate,
2-phenoxyethyl methacrylate and 2-phenoxyethyl acrylate;
[0050] unsaturated ethers, such as vinyl methyl ether,
[0051] and also mixtures of these monomers.
[0052] The amount of the graft shell (a2) present, based on
component (A), is from 70 to 10% by weight, preferably from 65 to
20% by weight, particularly preferably from 60 to 25% by weight,
and it is obtainable by polymerizing a monomer mixture in the
presence of the core (a1).
[0053] The graft shell (a2) is obtained by polymerizing a monomer
mixture made from, based on (a2),
[0054] (a21) from 50 to 100% by weight, preferably from 55 to 95%
by weight, particularly from 60 to 90% by weight, of at least one
styrene compound of the formula (I) 2
[0055] where R.sup.1 and R.sup.2, independently of one another, are
hydrogen or C.sub.1-C.sub.8-alkyl and/or of a C.sub.1-C.sub.8-alkyl
(meth)acrylate, and
[0056] (a22) from 0 to 50% by weight, preferably from 45 to 5% by
weight, particularly preferably from 40 to 10% by weight, of at
least one monofunctional comonomer.
[0057] The styrene compound used of the general formula (I)
(component (a21)) is preferably styrene, .alpha.-methylstyrene or
ring-C.sub.1-C.sub.8-alkyl-alkylated styrenes, such as
p-methylstyrene or tert-butylstyrene, particularly preferably
styrene or .alpha.-methylstyrene.
[0058] According to the invention, the C.sub.1-C.sub.8-alkyl
(meth)acrylates used are methyl methacrylate (MMA), ethyl
methacrylate, n- or isopropyl methacrylate, n-butyl methacrylate,
isobutyl methacrylate, sec-butyl methacrylate, tert-butyl
methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl
methacrylate, octyl methacrylate or 2-ethylhexyl methacrylate,
particularly preferably methyl methacrylate, or mixtures of these
monomers, methyl acrylate (MA), ethyl acrylate, propyl acrylate,
n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl
acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl
acrylate or 2-ethylhexyl acrylate, particularly preferably n-butyl
acrylate, or else a mixture of these monomers with one another or
with the methacrylates and/or styrene compounds of the formula I,
where the amount of the acrylates in the graft shell is preferably
subordinate.
[0059] Possible monofunctional comonomers (component (a22)) are
monomers selected from the group consisting of methacrylonitrile,
acrylonitrile and mixtures of these, N-C.sub.1-C.sub.8-alkyl-,
N-C5-C.sub.8-cycloalkyl- and N-C.sub.6-C.sub.10-aryl-substituted
maleimides, such as N-methyl-, N-phenyl-, N-dimethylphenyl- and
N-cyclohexylmaleimide, and maleic anhydride. Acrylonitrile is
preferred.
[0060] It is preferable for the graft shell (a2) to have been built
up from styrene or from a mixture comprising from 65 to 85% by
weight of styrene, the remainder being acrylonitrile.
[0061] In a preferred embodiment the graft shell (a2) is built up
using a mixture of styrene (S) and acrylonitrile (AN) (molar ratio
S/AN usually from 4.5:1 to 0.5:1, preferably from 2.2:1 to 0.65:1),
styrene on its own, a mixture of acrylontrile and methyl
methacrylate (MMA) or MMA on its own.
[0062] Component (A) is prepared by methods known per se, for
example as described in DE-A 31 49 358.
[0063] For this, the core (a1) is first prepared, by polymerizing
the acrylate(s) (a11) and the polyfunctional crosslinking monomers
(a12), if desired together with the other comonomers (a13), in
usually aqueous emulsion, in a manner known per se at from 20 to
100.degree. C., preferably from 50 to 80.degree. C. Use may be made
of the usual emulsifiers, such as alkali metal alkyl- or
alkylarylsulfonates, alkyl sulfates, fatty alcohol sulfonates,
salts of higher fatty acids having from 10 to 30 carbon atoms,
sulfosuccinates, such as Aerosol.RTM. OT (Cyanamid), ether
sulfonates, such as Disponil.RTM. FES61 (Henkel) or resin soaps
(Dresinate). Preference is given to the use of the sodium or
potassium alkylsulfonates, or of salts of fatty acids having from
10 to 18 carbon atoms.
[0064] The usual amounts of emulsifiers may be used. Advantageous
amounts of emulsifiers are from 0.3 to 5% by weight, in particular
from 1 to 2% by weight, based on the monomers used in preparing the
core (a1).
[0065] The dispersion is preferably prepared using sufficient water
to give the finished dispersion a solids content of from 20 to 60%
by weight.
[0066] Preferred polymerization initiators are free-radical
generators, for example peroxides, preferably peroxosulfates, such
as potassium peroxodisulfate, and azo compounds, such as
azodiisobutyronitrile. However, it is also possible to use redox
systems, in particular those based on hydroperoxides, such as
cumene hydroperoxide. Concomitant use may also be made of from 0 to
3% by weight of molecular weight regulators, such as ethylhexyl
thioglycolate, tert-dodecyl mercaptan, terpinols or dimeric
.alpha.-methylstyrene.
[0067] The amount of the initiators generally depends on the
desired molecular weight and is usually from 0.1 to 1% by weight,
based on the monomers used in preparing the core (a1).
[0068] To maintain a constant pH, preferably from 6 to 9, buffer
substances may be used as polymerization auxiliaries, for example
Na.sub.2HPO.sub.4/NaH.sub.2PO.sub.4 or sodium hydrogencarbonate.
The usual amounts of the buffer substances are used, and further
details in this connection are therefore unnecessary.
[0069] The precise polymerization conditions, in particular the
type, method of addition and amount of the emulsifier, are
generally determined individually within the ranges given above in
such a way as to give the resultant latex of the crosslinked
acrylate polymer (a1) a d.sub.50 of from 60 to 1000 nm, preferably
from 80 to 800 nm, particularly preferably from 100 to 600 nm. The
particle size distribution of the latex here should preferably be
narrow.
[0070] The graft core (a1) may particularly preferably also be
prepared by polymerizing the monomers (a11) to (a13) in the
presence of a fine-particle latex made from elastomeric or hard
polymers (seed-latex polymerization). The seed latex used may, for
example, have been made from crosslinked poly-n-butyl acrylate or
from polystyrene.
[0071] It is also in principle possible to prepare the graft core
(a1) by a process other than emulsion polymerization, e.g. by bulk
or solution polymerization, and then to emulsify the resultant
polymers. Microsuspension polymerization is also suitable,
preferably using oil-soluble initiators, such as lauroyl peroxide
or tert-butyl perpivalate. The processes for this are known.
[0072] In a preferred embodiment the core (a1) has a glass
transition temperature below 0.degree. C.
[0073] The graft-rubber particles (A) usually have a particle size
(d.sub.50) of from 60 to 1500 nm, preferably from 100 to 1200
nm.
[0074] In a particularly preferred embodiment, graft-rubber
particles (A) with a particle size (d.sub.50) of from 150 to 700 nm
are used in order to give the molding composition high
toughness.
[0075] In another preferred embodiment, a mixture of graft-rubber
particles (A) of different sizes which has a bimodal particle size
distribution is used. In a particularly preferred mixture of this
type, from 0.5 to 99.5% by weight of the mixture has a particle
size, as given by the average diameter (d.sub.50), of from 200 to
1000 nm, and from 0.5 to 99.5% by weight of the mixture has a
particle size, as given by the average diameter (d.sub.50), of from
60 to 190 nm.
[0076] The chemical structure of the two graft copolymers is
preferably the same, although the shell of the coarse-particle
graft copolymer may in particular also have a two-stage
structure.
[0077] The graft shell (component (a2)) is generally likewise
prepared by known polymerization processes, such as emulsion, bulk,
solution or suspension polymerization, preferably in aqueous
emulsion in the presence of an aqueous emulsion of the core (a1)
(see DE-A 12 60 135, DE-A 31 49 358 and DE-C 11 64 080). In a
preferred embodiment, the graft copolymerization is carried out in
a system which is the same as that used for the polymerization of
the core (a1) with addition, if required, of further emulsifier and
initiator. These do not have to be the same as the emulsifiers or
initiators used for preparing the core (a1). The emulsifier, the
initiator and the polymerization auxiliaries may each be charged on
their own or in a mixture to the dispersion of the core (a1). Any
of the possible combinations of, on the one hand, charging and
feeding and, on the other hand, initiator, emulsifier and
polymerization auxiliaries may be used. Preferred embodiments are
those known to the skilled worker. The monomer or, respectively,
monomer mixture to be grafted on may be added to the reaction
mixture all at once, batchwise in two or more stages or else
continuously during the polymerization.
[0078] The amount of component (B) present in the novel molding
compositions, based on the total of components (A) to (D), is from
80 to 1% by weight, preferably from 60 to 3% by weight,
particularly preferably from 50 to 4% by weight.
[0079] Alpha-olefins used to prepare component (B) may be
C.sub.2-C.sub.8-alpha-olefins, such as ethene, propene, 1-butene,
1-pentene, 1-hexene, 1-heptene or 1-octene, or mixtures of these,
preferably ethene or propene.
[0080] Examples of polar comonomers, which according to the
invention should not include vinyl acetate or vinylaromatic
monomers, are:
[0081] alpha- or beta-unsaturated C.sub.3-C.sub.8 carboxylic acids
and the available anhydrides of these, for example acrylic acid,
methacrylic acid, maleic acid, maleic anhydride, fumaric acid,
itaconic acid, and glyceride esters thereof and also esters with
C.sub.1-C.sub.8-alkyl alcohols whose alkyl radicals may have
monosubstitution by phenyl groups or by naphthyl groups,
unsubstituted or mono- or di-C.sub.1-C.sub.4-alkyl- -substituted
phenol or naphthol, methyl methacrylate, ethyl methacrylate,
n-butyl acrylate, isobutyl acrylate, pentyl acrylate, hexyl
acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate,
glycidyl methacrylate, phenyl acrylate, phenylethyl methacrylate,
phenylethyl acrylate, benzyl methacrylate, benzyl acrylate,
phenylpropyl methacrylate, phenylpropyl acrylate, phenylbutyl
methacrylate, phenylbutyl acrylate, 4-methylphenyl acrylate,
naphthyl acrylate, phenoxyethyl methacrylate and phenoxyethyl
acrylate;
[0082] methacrylonitrile, acrylonitrile;
[0083] carbon monoxide.
[0084] In a preferred embodiment, copolymers used as component (B)
can be prepared from (I) 40 to 75% by weight of ethylene, from 5 to
20% by weight of carbon monoxide and 20 to 40% by weight of n-butyl
acrylate, for example the commercially available ELVALOY.RTM.
HP-4051 (DuPont), or preferably from (II) 50 to 98.9% by weight of
ethylene, 1 to 45% by weight of n-butyl acrylate and 0.1 to 20% by
weight of (meth)acrylic acid and/or maleic anhydride or from (III)
96 to 67% by weight of ethylene, 1 to 20% by weight of n-butyl
acrylate, 3 to 10% by weight of (meth)acrylic acid and 0 to 3% by
weight of maleic anhydride.
[0085] The copolymers (B) are prepared in a manner known per se
(see U.S. Pat. No. 2,897,183 and U.S. Pat. No. 5,057,593). They are
usually prepared by free-radical polymerization. The initiators
usually used are peroxides, such as lauroyl peroxide, tert-butyl
peracetate, tert-butyl peroxypivalate, di-tert-butyl peroxide,
di(sec-butyl) peroxydicarbonate, tert-butyl peroctanoate and
tert-butyl perisononanoate, preferably tert-butyl peroxypivalate
and tert-butyl perisononanoate. Initiators containing azo groups,
such as azobisisobutyronitrile, are also suitable.
[0086] The choice of the suitable inititor usually depends on the
polymerization temperature to be selected, which is generally from
100 to 300.degree. C., preferably from 130 to 280.degree. C. The
pressure during the polymerization is usually selected within the
range from 100 to 400 MPa, preferably from 150 to 250 MPa. The
amount of initiator is generally chosen within the range from 1 to
50 mol, preferably from 2 to 20 mol, for each 10.sup.6 mol of the
polar copolymer used.
[0087] The polymerization is generally carried out in a
continuously operating tubular reactor. A reactor of this type is
described, for example, in U.S. Pat. No. 2,897,183. The reaction
time is generally from 30 to 1 min, preferably from 5 to 2 min. The
use of a solvent has hitherto been found to be optional.
[0088] The proportion of component (C), a thermoplastic polymer, in
the molding compositions is from 0 to 80% by weight, preferably
from 5 to 60% by weight, particularly preferably from 10 to 30% by
weight, based on the total of components (A) to (D). This polymer
is obtainable by polymerizing a monomer mixture essentially
consisting of
[0089] (c1) from 50 to 100% by weight, preferably from 60 to 95% by
weight, particularly preferably from 65 to 80% by weight, of at
least one vinylaromatic monomer and/or of a C.sub.1-C.sub.8-alkyl
(meth)acrylate, and
[0090] (c2) from 0 to 50% by weight, preferably from 0 to 40% by
weight, particularly preferably from 5 to 35% by weight, of at
least one monofunctional comonomer,
[0091] based in each case on component (C).
[0092] The vinylaromatic monomer (component (c1)) used comprises
styrene, the substituted styrenes of the formula (I) mentioned
above as component (a21) or the C.sub.1-C.sub.8-alkyl
(meth)acrylates mentioned under component (a21), preferably methyl
methacrylate. Preference is given to the use of styrene,
.alpha.-methylstyrene and p-methylstyrene.
[0093] Monomers which may be used as monofunctional comonomers
(component (c2)) are those mentioned above as component (a22). The
component (c2) used may also, if desired, be a mixture of the
C.sub.1-C.sub.8-alkyl (meth)acrylates mentioned under component
(a21) and the monomers mentioned under component (a21). Preference
is given to monoethylenically unsaturated nitrile compounds, in
particular acrylonitrile, methacrylonitrile and mixtures of these.
Acrylonitrile is particularly preferred.
[0094] In a preferred embodiment use is made of a mixture of
styrene (S) and acrylonitrile (AN), S and .alpha.-methylstyrene, if
desired mixed with methyl methacrylate or with maleimides, or of
methyl methacrylate, if desired with methyl acrylate. Particular
preference is given to SAN polymers whose principal components are
styrene and acrylonitrile.
[0095] The polymers of component (C) are generally known. In some
cases they are also commercially available, or can be prepared by
known methods (see Kunststoff-Handbuch, Vieweg-Daumiller, Vol. V
(Polystyrol), Carl-Hanser-Verlag, Munich 1969, page 118 et seq.).
The polymerization is generally carried out by a free-radical route
in emulsion, or in suspension, solution or bulk, and the latter two
methods are preferred. The polymers (C) generally have viscosity
numbers (VNs) (measured to DIN 53 726 on a 0.5% strength solution
in dimethylformamide at 25.degree. C.) of from 40 to 160 ml/g,
corresponding to average molar masses M.sub.w of from 40,000 to
2,000,000.
[0096] The proportion of component (D) in the molding compositions,
based on the total of components (A) to (D), is from 0.1 to 15% by
weight, preferably from 0.2 to 12% by weight and in particular from
0.3 to 10% by weight. Component (D) is a three-block copolymer made
from polyethylene oxide and polypropylene oxide and having a
central polypropylene oxide block with a molar mass of from 800 to
5 000 g/mol and terminal blocks made from polyethylene oxide. The
proportion of ethylene oxide is from 5 to 90% by weight, preferably
from 10 to 80% by weight.
[0097] Component (D) is particularly preferably a three-block
polymer having a portion of about 20% by weight of polypropylene
oxide and a proportion of about 80% by weight of polyethylene
oxide.
[0098] The molecular weights given are average molecular weights
and are given as a number average M.sub.n determined from the OH
number in accordance with DIN 53240.
[0099] Component (D) is prepared by known polymerization processes,
as described, for example, in N. Schonfeld, Grenzflchenaktive
Ethylenoxid-Addukte, Wissenschaft-liche Verlagsgesellschaft mbH,
Stuttgart, 1976, pp. 53 et seq. This first produces a central
polypropylene oxide block, to each of whose ends a block made from
polyethylene oxide is added. The lengths of these two blocks do not
have to be the same.
[0100] Besides components (A), (B), (C) and (D), the thermoplastic
molding compositions may also comprise additives, such as
lubricants, mold-release agents, pigments, dyes, flame retardants,
antioxidants, stabilizers to protect against the action of light,
fibrous or pulverulent fillers, fibrous or pulverulent reinforcing
agents, and antistats in the amounts usual for these agents.
[0101] The invention also provides a process for preparing
thermoplastic molding compositions in a manner known per se, by
mixing, in a mixing apparatus,
[0102] (A) from 20 to 99% by weight of at least one graft
copolymer, essentially obtainable from
[0103] (a1) from 30 to 90% by weight of a core, obtainable by
polymerizing a monomer mixture, essentially consisting of
[0104] (a11) from 80 to 99.99% by weight of at least one
C.sub.1-C.sub.10-alkyl acrylate, 3
[0105] where R.sup.1 and R.sup.2, independently of one another, are
hydrogen or C.sub.1-C.sub.8-alkyl and/or of a C.sub.1-C.sub.8-alkyl
(meth)acrylate, and
[0106] (a22) from 0 to 50% by weight of at least one monofunctional
comonomer, and
[0107] (B) from 1 to 80% by weight of a copolymer obtainable from
at least one .alpha.-olefin and from at least one polar comonomer,
with the proviso that the monomers used are not vinyl acetate or
any vinylaromatic monomer, and with
[0108] (C) from 0 to 80% by weight of a thermoplastic polymer,
obtainable by polymerizing a monomer mixture, essentially
consisting of
[0109] (c1) from 50 to 100% by weight of at least one vinylaromatic
monomer and/or of a C.sub.1-C.sub.8-alkyl (meth)acrylate, and
[0110] (c2) from 0 to 50% by weight of at least one monofunctional
comonomer, and with
[0111] (a12) from 0.01 to 20% by weight of at least one
copolymerizable, polyfunctional, crosslinking monomer, and
[0112] (a13) from 0 to 40% by weight, based on the total weight of
components (a11) and (a12), of at least one other copolymerizable,
monoethylenically unsaturated monomer, and
[0113] (a2) from 70 to 10% by weight of a graft shell, obtainable
by polymerizing a monomer mixture in the presence of the core (a1),
and essentially consisting of
[0114] (a21) from 50 to 100% by weight of at least one styrene
compound of the formula 4
[0115] where R.sup.1 and R.sup.2, independently of one another, are
hydrogen or C.sub.1-C.sub.8-alkyl and/or of a C.sub.1-C.sub.8-alkyl
(meth)acrylate, and
[0116] (a22) from 0 to 50% by weight of at least one monofunctional
comonomer, with
[0117] (B) from 1 to 50% by weight of a copolymer obtainable from
at least one .alpha.-olefin and from at least one polar comonomer,
with the proviso that the monomers used are not vinyl acetate or
any vinylaromatic monomer, and with
[0118] (C) from 0 to 80% by weight of a thermoplastic polymer,
obtainable by polymerizing a monomer mixture, essentially
consisting of
[0119] (c1) from 50 to 100% by weight of at least one vinylaromatic
monomer and/or of a C.sub.1-C.sub.8-alkyl (meth)acrylate, and
[0120] (c2) from 0 to 50% by weight of at least one monofunctional
comonomer, and with
[0121] (D) from 0.1 to 15% by weight of a three-block polymer made
from
[0122] (d1) from 5 to 90% by weight of polyethylene oxide and
[0123] (d2) from 95 to 10% by weight of polypropylene oxide
[0124] and having a central polypropylene oxide block with a molar
mass of from 800 to 5 000 g/mol and terminal blocks made from
polyethylene oxide,
[0125] where components A to D give 100% by weight in total,
[0126] and, if desired, with conventional additives.
[0127] The novel molding compositions may be prepared by mixing
processes known per se, for example by melting in a mixing
apparatus, e.g. an extruder, Banbury mixer or kneader, or on a roll
mill or calender at from 150 to 300.degree. C. It is also possible,
however, for the components to be mixed "cold" without melting and
for the mixture, composed of powder or pellets, not to be melted
and homogenized until it is processed.
[0128] The novel thermoplastic molding compositions may be used to
produce moldings, films or fibers. The invention therefore also
provides the corresponding moldings, films and fibers.
[0129] The invention also provides the use of the novel
thermoplastic molding compositions for coating sheet-like
structures to give sheet-like structures with a reduced-gloss
surface and antistatic properties, via coextrusion.
[0130] The novel molding compositions may be used to produce
moldings of any type, in particular films. The films may be
produced by extrusion, rolling, calendering or other processes
known to the skilled worker, usually at from 150 to 280.degree. C.
Preference is given to the production of films from the molding
compositions via extrusion. The novel molding compositions are
molded here by heating and/or friction, on their own or with
concomitant use of plasticizing or other additives, to give a
processable film. Examples of equipment suitable for this purpose
are extruders with slot dies. The films usually have a thickness of
from 0.05 to 2 mm. An example of a process used to make finished
products from films of this type is thermoforming at, for example,
from 120 to 170.degree. C.
[0131] In a preferred embodiment, coatings or leather-like films
are produced by mixing
[0132] (A) from 20 to 99% by weight of at least one graft
copolymer, essentially obtainable from
[0133] (a1) from 30 to 90% by weight of a core, obtainable by
polymerizing a monomer mixture, essentially consisting of
[0134] (a11) from 80 to 99.99% by weight of n-butyl acrylate,
and
[0135] (a12) from 0.01 to 20% by weight of tricyclodecenyl
acrylate, and
[0136] (a2) from 10 to 70% by weight of a graft shell, obtainable
by polymerizing a monomer mixture in the presence of the core (a1),
and essentially consisting of
[0137] (a21) from 60 to 90% by weight of styrene and
[0138] (a22) from 10 to 40% by weight of acrylonitrile, and
[0139] (B) from 1 to 80% by weight of a copolymer, prepared
from
[0140] from 67 to 96% by weight of ethylene,
[0141] from 1 to 20% by weight of n-butyl acrylate,
[0142] from 3 to 10% by weight of (meth)acrylic acid, and
[0143] from 0 to 3% by weight of maleic anhydride, and
[0144] (C) from 0 to 80% by weight of a copolymer, prepared by
continuous solution polymerization of
[0145] (c1) from 65 to 85% by weight of styrene and
[0146] (c2) from 15 to 35% by weight of acrylonitrile, and
[0147] (D) from 0.1 to 15% by weight of a three-block polymer made
from
[0148] (d1) from 5 to 90% by weight of polyethylene oxide and
[0149] (d2) from 10 to 95% by weight of polypropylene oxide
[0150] and having a central polypropylene oxide block with a molar
mass of from 800 to 5 000 g/mol and terminal blocks made from
polyethylene oxide,
[0151] where components A to D give 100% by weight in total,
[0152] and then calendering or extruding to give films.
[0153] The novel molding compositions may also be used for
coextrusion together with other polymers, giving coextruded
moldings or coextruded films. Examples of these other polymers are
ABS (acrylonitrile-butadiene-- styrene polymers), PBT (polybutylene
terephthalate), ASA (acrylonitrile-styrene-acrylate), PVC
(polyvinyl chloride), SAN (styrene-acrylonitrile copolymers), MABS
(methyl methacrylate-acrylonitri- le-butadiene-styrene polymers),
polymethyl methacrylate, polycarbonate and others.
[0154] Coextruded sheets may be further processed by thermoforming,
for example for use in the sanitary sector, for producing
containers (e.g. hard-shell suitcases) or for decorative purposes,
e.g. in the furniture sector.
[0155] The coated sheet-like structures and the films with
leather-like appearance have a wide variety of applications, in
particular in the automotive industry for the construction of
automotive interiors, for decorative purposes, as a leather
substitute in producing suitcases or bags and in the furniture
industry as a coating material for the lamination of furniture
surfaces, and also for the internal fitting-out of houses,
aircraft, ships or trains, and in the sanitary sector.
[0156] The present invention therefore also provides the use of
coated sheet-like structures or of films with a leather-like
appearance for the internal fitting-out of houses, utility
vehicles, aircraft, ships or trains, in the furniture industry and
in the sanitary sector.
[0157] The molding compositions may moreover be coextruded to give
tubes or profiles, and/or injection molded to give other
moldings.
[0158] The novel thermoplastic molding compositions are preferably
halogen-free. They are very substantially free from constituents
which escape by evaporation or bleed-out, and exhibit practically
no disadvantageous changes during processing, for example
discoloration. In particular, even without the concomitant use of
appropriate stabilizers or other additives, they have excellent
heat-aging resistance and light resistance, and also good
mechanical properties.
[0159] In particular, the novel molding compositions feature good
flowability, especially when processed by extrusion. The good
extrusion properties of the molding compositions bring about very
consistent product quality of the films. These molding compositions
are also antistatic and reduced-gloss to markedly matt.
EXAMPLES
[0160] The following constituents were prepared (all % given are by
weight):
[0161] Preparation of a Component A:
[0162] Particulate Graft Copolymer Made from Crosslinked
Poly-n-butyl Acrylate (Core) and Styrene-acrylonitrile Copolymer
(Shell)
[0163] A mixture made from 98 g of n-butyl acrylate and 2 g of
dihydrodicyclopentadienyl acrylate and also, separately, a solution
of 1 g of Na C.sub.12-C.sub.18-paraffin-sulfonate in 50 g of water
were added at 60.degree. C. over the course of 4 hours to a mixture
made from 3 g of a polybutyl acrylate seed latex, 100 g of water
and 0.2 g of potassium persulfate. The polymerization was then
continued for a further 3 hours. The average particle diameter
d.sub.50 of the resultant latex was 430 nm with a narrow particle
size distribution (Q=0.1).
[0164] 150 g of this latex were mixed with 60 g of water, 0.03 g of
potassium persulfate and 0.05 g of lauroyl peroxide, and then
firstly 20 g of styrene were grafted onto the latex particles over
the course of 3 hours at 65.degree. C., followed by a mixture of 15
g of styrene and 5 g of acrylonitrile over the course of 4 hours.
The polymer was then precipitated by a calcium chloride solution at
95.degree. C., separated off, washed with water and dried in a
stream of warm air. The degree of grafting in the polymer was 35%
and the average diameter d.sub.50 of the particles was 510 nm.
[0165] The makeup of the graft copolymer was as follows (rounded
values):
[0166] 65% by weight of a graft core made from from polybutyl
acrylate, crosslinked,
[0167] 15% by weight of an inner graft made from styrene polymer,
and
[0168] 20% by weight of an outer graft made from
styrene-acrylonitrile copolymer with an S/AN weight ratio of
3:1.
[0169] The seed polymer used at the outset was prepared by the
process of EP-B 6503 (column 12, line 55 to column 13, line 22) by
polymerizing n-butyl acrylate and tricyclodecenyl acrylate in
aqueous emulsion, and had a solids of 40%.
[0170] The average particle size mentioned in describing component
(A) is the weight average of the particle sizes.
[0171] The average diameter is the d.sub.50, denoting that 50% by
weight of all the particles have a smaller diameter, and 50% by
weight a larger diameter, than the diameter corresponding to the
d.sub.50. To characterize the breadth of the particle size
distribution the d.sub.10 and d.sub.90 values are frequently given
in addition to the d.sub.50. 10% by weight of all the particles are
smaller, and 90% by weight are larger, than the d.sub.10 diameter.
In a similar way, 90% by weight of all of the particles have a
smaller diameter, and 10% by weight a larger diameter, than the
diameter corresponding to the d.sub.90. The quotient
Q=(d.sub.90-d.sub.10)/d.sub.50 is a measure of the breadth of the
particle size distribution. A smaller Q indicates a narrower
distribution.
[0172] Component B:
[0173] A copolymer was prepared from 67-96% by weight of ethylene,
1-20% by weight of 4-butyl acrylate, 3-10% by weight of acrylic
acid and 0-3% by weight of maleic anhydride.
[0174] Component B is a product commercially available from BASF as
a grade of Lupolen.RTM..
[0175] Preparation of a Component C:
[0176] Copolymer Made from Styrene and Acrylonitrile
[0177] A copolymer made from 65% by weight of styrene and 35% by
weight of acrylonitrile (component C) was prepared by continuous
solution polymerization, as described in Kunststoff-Handbuch, ed.
R. Vieweg und G. Daumiller, Vol. V "Polystyrol", Carl-Hanser-Verlag
Munich 1969, pp. 122-124. The viscosity number VN (determined in
accordance with DIN 53 726 at 25.degree. C., 0.5% by weight in
dimethylformamide) was 60 ml/g.
[0178] Component D:
[0179] The components (D) used was a three-block copolymer with a
proportion of about 20% by weight of polypropylene oxide and a
proportion of about 80% by weight of polyethylene oxide.
[0180] Component (D) is prepared by known polymerization processes,
as described, for example, in N. Schnfeld, Grenzflchenaktive
Ethylenoxid-Addukte, Wissenschaft-liche Verlagsgesellschaft mbH,
Stuttgart, 1976, pp. 53 et seq. This first produces a central
polypropylene oxide block, to each of whose ends a block made from
polyethylene oxide is added. The lengths of these two blocks do not
have to be the same.
[0181] Molding Compositions Prepared and their Properties
[0182] Components A to D were intimately mixed, with melting, at
240.degree. C. and 250 rpm in a Werner+Pfleiderer ZSK30 twin-screw
extruder, discharged and pelletized. The pellets were extruded in a
Rheocord 90 single-screw 3:1 Haake extruder at 220.degree. C. and
from 160 to 220 rpm to give a film of thickness 0.6 mm, using a
slot die with 0.5 mm gap.
[0183] The following properties were determined for the films:
[0184] Shore hardness: the Shore hardness was determined to DIN 43
505 using test apparatus D.
[0185] The flowability of the molding compositions was determined
on pellets, by measuring the melt volume rate (MVR) at 220.degree.
C. or 200.degree. C. with a load of 10 kp or 21.6 kp. The amount
discharged from a standard die in 10 min is given in ml.
[0186] The mixes for the films produced and the results of the
tests are given in Table 1.
1 TABLE 1 Example/Component 1 (comparison) 2 A/pts. by wt. 70 70
B/pts. by wt. 20 20 C/pts. by wt. 10 10 D1/pts. by wt. -- 3 MVR 41
108 220/21.6/ml/10 min MVR 20 40 200/21.6/ml/10 min MVR <0.2 3.6
220/10/ml/10 min Shore D/.degree. 41 31
[0187] The novel mixture is seen to have considerably better
flowability and markedly lower Shore hardness.
* * * * *