Title of Invention

A HETEROPHASIC ALPHA-OLEFIN RANDOM COPOLYMER COMPOSITION AND PROCESS FOR ITS PREPARATION

Abstract The invention relates to a heterophasic alpha-olefin random copolymer composition with a melting temperature (Tm) of at least 130°C and a flexural modulus of not higher than 1000 MPa, whereby the inventive composition comprises an alpha-olefin random copolymer component (A) of at least two alpha-olefin (co)polymer fractions (i) and (ii) having a different comonomer content, whereby at least one of the fractions is an alpha- olefin random copolymer, and a rubber component (B).
Full Text The invention relates to a heterophasic alpha-olefin random copolymer composi-
tion having a low stiffness and an improved thermal behaviour. Moreover, the
present invention is related to the process for the manufacture of the new poly-
mer composition as well as its use.
Background art
Polymers are increasingly used in different demanding applications. At the same
time there is a continuous seek for tailored polymers which meet the require-
ments of these applications. The demands can be challenging, since many poly-
mer properties are directly or indirectly interrelated. For instance, it has been
problematic to develop polymers with the combination of low stiffness together
with high melting temperature. E.g. EP 991 719 of the Applicant discloses pro-
pylene polymers having tensile modulus of 420 MPa or less. However, there is
still need to control or to improve the thermal behaviour of the polymer together
with the low stiffness.
Summary of the invention
Hence, the object of the present invention is to provide further heterophasic al-
pha-olefin random copolymer compositions which broaden the product window
of polymers for wide variety of end applications.
Another object of the present invention is to provide a process for obtaining fur-
ther alternatives for the polymer compositions.
It has surprisingly been found that a heterophasic alpha-olefin random copolymer
composition having a high melting temperature (Tm) and at the same time a low
flexural modulus, i.e. low stiffness, can be obtained with a copolymer composi-
tion as tailored according to the invention.
Accordingly, the heterophasic alpha-olefin random copolymer composition of the
invention comprises
- an alpha-olefin random copolymer component (A) of at least two alpha-olefin
(co)polymer fractions (i) and (ii), and
- a rubber component (B), whereby the comonomer content between the alpha-
olefin polymer fractions (i) and (ii) is different and whereby at least one of frac-
tions (i) and (ii) is a random copolymer. The other of said two fractions (i) and
(ii) can be a homopolymer or a copolymer. This tailored combination of compo-
nents (A) and (B) provides a heterophasic alpha-olefin random copolymer com-
position having a melting temperature (Tm) of at least 130°C and a flexural
modulus of not higher than 1000 MPa.
Unexpectedly, it has been found that the melting temperature can be controlled
with the different comonomer content between fractions (i) and (ii), so that said
combination of high melting temperature (Tm) and, at the same time, low flexural
modulus, i.e. low stiffness, can be achieved. Also unexpectedly, rubber compo-
nent (B) can be incorporated to the random copolymer component (A) of the in-
vention and still the improved thermal behaviour together with the low stiffness
of the final composition can be maintained.
The present invention thus provides feasible means to control and adjust the
combination of low stiffness (modulus) and thermal behaviour.
Preferably, with the present invention it is also possible to obtain heterophasic
alpha-olefin copolymers i.a. with good impact strength at low temperatures and,
optionally, advantageous optical or sealing properties or both, depending on the
needs of the end use application.
The "heterophasic alpha-olefin random copolymer composition" is referred
herein below also shortly as "random-heterophasic copolymer".
By the term "random copolymer" is meant herein that the comonomer in said co-
polymer is distributed randomly, i.e. by statistical insertion of the comonomer
units, within the copolymer chain. Said term "random" copolymer is generally
known and used in the art.
The "random copolymer component (A)" forms "matrix (A)" of the random-
heterophasic copolymer. Both terms are used herein below.
The term "rubber, component" is well known in the field and means herein an
elastomeric alpha-olefin copolymer component (B) of the random-heterophasic
copolymer produced separately and dispersed in matrix (A). Preferably, said rub-
ber component (B) is produced separately in a multistage process in the presence
of matrix (A) as described herein below. Typically rubber component (B) is thus
a copolymer of at least two alpha-olefms and is mainly in amorphous (= xylene
soluble, XS) form. Rubber component (B) is suitably an elastomeric propylene
copolymer with one or more alpha-olefin comonomers, preferably at least with
ethylene and optionally with one or more higher alpha-olefms.
As known, also matrix (A) comprises an amorphous (= xylene soluble, XS) part.
The amount of said amorphous part of matrix (A) can be increased by increasing
the comonomer content of matrix (A). Accordingly, the amorphous part of matrix
(A) and the amorphous rubber component (B) are dispersed as an "amorphous
phase" in matrix (A).
Brief Description Of The Accompanying Drawings
Figure 1 is a plot showing ethylene content in matrix (A) versus melting point for
polymers of examples 1, 2, 5 and 8 of the invention; and
Figure 2 shows a plot of stiffness versus xylene solubles in matrix composition of
the polymers of examples 3, 4, 6, 7, 9, 10 and 14 of the present invention.
Description of the invention
Preferably, the present invention provides a heterophasic alpha-olefin random
copolymer composition comprising
(a) an alpha-olefin random copolymer component (A) which comprises at least
one fraction (i) comprising a homopolymer of an alpha-olefin or a co-
polymer of an alpha-olefin with one or more alpha-olefin comonomers,
and at least one fraction (ii) comprising a copolymer of an alpha-olefin
with one or more alpha-olefin comonomers, and
(b) a rubber component (B) dispersed in the random copolymer component (A),
whereby
-the amount (wt%) of comonomer in fraction (ii) is higher than the amount
(wt%) of comonomer in fraction (i), and wherein
-the heterophasic alpha-olefin random copolymer composition has a melting
temperature (Tm) of at least 130°C and a flexural modulus of not higher
than 1000 MPa.
Accordingly, fraction (i) can either comprise a homopolymer or a random co-
polymer as defined above, or a mixture of a homo and/or (co)polymer(s), pro-
vided that, if there is any comonomer present in fraction (i), the amount (wt%) of
the comonomer in fraction (i) is lower than the amount (wt%) of the comonomer
in fraction (ii), and thus also lower than the total amount (wt%), i.e. the total co-
monomer content (wt%), of matrix (A).
It has been surprisingly found that the melting temperature (Tm) of the random-
heterophasic copolymer is controlled and determined with fraction (i) of matrix
(A): It is believed that fraction (i) of the homo or random copolymer with a lower
comonomer content determines or contributes to the final melting temperature of
the random-heterophasic copolymer composition, even though the second random
copolymer fraction (ii), and as a result matrix (A) of fractions (i) and (ii), has
higher comonomer content than fraction (i). The low flexural modulus, i.e. de-
creased stiffness, is in turn due to the total comonomer content of matrix (A),
which decreased stiffness can be advantageously tailored further with rubber
component (B).
Furthermore, within the present concept it is possible to vary one or both of the
properties of said combination, ie. either to decrease the stiffness further or to
increase the Tm further, or both to decrease the stiffness and increase the Tm fur-
ther, depending on the desired end application.
It is understood herein that the values of Tm of more than 130°C and flexural
modulus of less than 1000 MPa of the random-heterophasic copolymer of the
invention can be obtained and controlled at least with the comonomer contents of
fractions (i) and (ii) preferably in the presence of rubber component (B) as de-
fined above.
Therefore, as a further aspect the invention provides also a use of a random co-
polymer component (A), which comprises at least two alpha-olefin (co)polymer
fractions (i) and (ii), wherein at least one of fractions (i) and (ii) is an alpha-
olefin copolymer and wherein fractions (i) and (ii) have different comonomer
contents (wt%), for controlling and adjusting, i.e. tailoring, the combination of
thermal behaviour and stiffness of the random copolymer component (A) by
means of a different comonomer content between the two fractions (i) and (ii).
Preferably, fraction (ii) has higher comonomer content than fraction (i) as de-
fined above. In one preferable embodiment of said use the comonomer difference
between said fractions (i) and (ii) is chosen to obtain a flexural modulus less than
1000 MPa and Tm of more than 130°C of the random copolymer component (A).
In another embodiment of said use a rubber component (B) is incorporated into
said matrix (A) and, optionally, the stiffness is further controlled by said rubber
component (B). More preferably, the random-heterophasic copolymer of the in-
vention as defined above or below is used for the tailoring of said property com-
bination.
If desired, Tm and stiffness may be tailored further within the limits of the inven-
tion by means of other features, e.g. by adding further polymer compounds or
additives in a manner known in the field.
Furthermore, the heterophasic-random copolymer composition of the invention
may preferably also exhibit a good impact strength at low temperatures. More-
over, rubber component (B) provides highly feasible means for further tailoring,
e.g. further increasing, the impact strength at low temperatures, if desired.
In addition to said impact strength at low temperatures, the invention enables a
wide flexibility in other properties of the random-heterophasic copolymer to meet
the demands in various end applications. As an example e.g. optical properties
and sealing properties or both can be varied within the invention. The tailoring
can be effected e.g. by adjusting the crystalline and amorphous part of the ran-
dom-heterophasic copolymer in a known manner to optimize the desired optical
properties. As an example of the means for tailoring the copolymer composition
include one or more of the following: the type and the number of the comono-
mer(s) used in matrix (A) and in rubber component (B); the total amount of the
comonomer in matrix (A); the amount of the comonomer in each of fractions (i)
and (ii) within the limits of the invention; the amount of the comonomer in rub-
ber component (B); the weight ratio between matrix (A) and rubber component
(B); as well as the weight ratio, i.e. split, between fractions (i) and (ii).
Accordingly, matrix (A) of the random-heterophasic copolymer is multimodal
with respect to the comonomer distribution due to the difference in the comono-
mer contents between fractions (i) and (ii). The "multimodal comonomer distri-
bution" is further defined in the under "definitions and determination methods"
below.
The following definitions and specific ranges represent either individually or in
any combinations some of the feasible or preferable general subgroups or em-
bodiments of the random-heterophasic polymer of the invention:
Matrix (A) can be unimodal or multimodal with respect to the molecular weight
distribution (MWD). The "multimodal MWD" is further defined under the ex-
perimental part below and includes the bimodal matrix (A). The two fractions (i)
and (ii) provide also a feasible means to obtain said "multimodal, e.g. bimodal,
MWD". Furthermore, the MWD can be narrow or broad in a manner well known
in the art.
In one embodiment, fraction (i) of matrix (A) comprises a homopolymer compo-
nent, and preferably is comprised of a homopolymer component of one alpha-
olefin. This embodiment is referred herein also as H/R-matrix (A). Preferably, in
H/R-matrix (A) fraction (i) is a homopolymer propylene, and fraction (ii) is a
random copolymer of propylene with one or more alpha-olefins.
In a second embodiment fraction (i) of matrix (A) comprises a random copoly-
mers) of an alpha-olefin(s) with at least one alpha-olefin comonomer, and pref-
erably is comprised of a copolymer of one alpha-olefin with at least one alpha-
olefin comonomer. This embodiment is referred herein also as R/R-matrix (A).
Preferably, in R/R-matrix (A) fraction (i) is a random copolymer of propylene
with one or more alpha-olefins and fraction (ii) is a copolymer of propylene with
one or more alpha-olefins.
Similarly, fraction (ii) of matrix (A) comprises a random copolymer(s) of an al-
pha-olefin(s) with at least one alpha-olefin comonomer, and preferably is com-
prised of a copolymer of one alpha-olefin with at least one alpha-olefin comono-
mer, such as a copolymer of propylene with one or more alpha-olefins.
Preferably, matrix (A) is comprised of fractions (i) and (ii) and, optionally, of a
prepolymer fraction in a conventional manner. Alternatively, as indicated above,
fractions (i) and (ii) may comprise further (co)polymer components or matrix (A)
may comprise further fractions within the limits of the invention.
The melting temperature (Tm) of the heterophasic polymer composition is at least
130°C, preferably at least 131°C, more preferably at least 133°C. On the other
hand, the melting temperature is typically not higher than 170°C. The present Tm
describes the improved thermal behaviour.
Preferably, also fraction (i) of matrix (A) has a melting temperature of at least
130°C, preferably of at least 131°C, e.g. of at least 133°C. Furthermore, fraction
(i) of matrix (A) has suitably a melting temperature of not higher than 170°C. In
practice, the melting temperature of fraction (i) of matrix (A) is essentially in the
same level as the melting temperature of the random-heterophasic copolymer,
and if Tm of fraction (i) is higher, then it is typically not higher than up to 15°C
of the Tm of the final random-heterophasic copolymer, the Tm of fraction (i) be-
ing e.g. between 0 to 12°C, suitably between 1 to 8°C, higher.
Typically, fraction (i) of matrix (A) has thus a higher melting temperature than fraction
(ii) of matrix (A) and fraction (i) contributes to the Tm of matrix (A) and to the Tm of
the final random-heterophasic copolymer as well.
In one embodiment (i), the melting temperature (Tm) of the random-heterophasic
copolymer is of at least 130°C, preferably of at least 132°C. Preferably, the melt-
ing temperature (Tm) of said random-heterophasic copolymer may then not be
higher than 165°C, suitably not higher than 155°C. In this embodiment said Tm
may e.g. range between 130 to 165°C, preferably it ranges from 132 to 155°C. In
this embodiment (i) matrix is preferably a R/R-matrix (A).
In another embodiment (ii), the melting temperature (Tm) of the random-
heterophasic copolymer is of at least 130°C, preferably of at least 135°C. Said
melting temperature (Tm) may not be higher than 170°C. Preferably, said melting
temperature (Tm) ranges from 135 to 160°C. Preferably, also in this embodiment
(ii) matrix is a R/R-matrix (A).
In still another preferred embodiment (iii), the melting temperature (Tm) of the
random-heterophasic copolymer may be of at least 130°C, preferably of at least
135°C, suitably of at least 140°C and in some cases even of at least 145°C may
be desired. In this embodiment said Tm is preferably not higher than 170°C, such
as not higher than 165°C. The melting temperature (Tm) of the random-
heterophasic copolymer may thus range e.g. from 145 to 165°C. Preferably, in
this embodiment (iii) matrix is a H/R-matrix (A).
The flexural modulus describes the stiffness (softeness) of the random-
heterophasic copolymer. The flexural modulus of the random-heterophasic co-
polymer is thus not higher than 1000 MPa, typically not higher than 990 MPa,
preferably not higher than 900 MPa, suitably not higher than 800 MPa.
The lower limit is not critical, however it may be preferable that the flexural
modulus is not lower than 100 MPa. Accordingly, the flexural modulus of the
random-heterophasic copolymer preferably ranges from 100 to 1000, e.g. to 990
or to 800 MPa.
In one embodiment (iv) a considerably low stiffness may be desired, whereby the
flexural modulus of the random-heterophasic copolymer is not higher than 600
MPa, preferably not higher than 500 MPa, suitably not higher than 450 MPa, and
even may not be higher than 400 MPa. In this embodiment (iv), the heterophasic
polymer composition may have a flexural modulus e.g. in the range of 100 to 600
MPa, suitably of 100 to 500 MPa, preferably of 100 to 450 MPa, and may even
be of 150 to 400 MPa. This embodiment (iv) may preferably be combined with
the embodiment (i) above, so that the flexural modulus is as given in this para-
graph, and the melting temperature of the random-heterophasic copolymer is at
least 130°C, suitably of at least 132°C, and preferably not higher than 165°C, e.g.
not higher than 155°C. For instance, matrix (A) is a R/R matrix (A) and the ran-
dom-heterophasic copolymer thereof has a Tm in a range of 130 to 165°C, pref-
erably in the range of 132 to 155°C.
In another embodiment (v), the flexural modulus and the melting temperature of
the random-heterophasic copolymer may be: the flexural modulus is not higher
than 600 MPa, preferably not higher than 500 MPa, suitably not higher than 450
MPa, and even may not be higher than 400 MPa. Typically, the flexural modulus
may range from 100 to 600 MPa, such as from 100 to 500 MPa, preferably from
100 to 450 MPa, e.g. from 150 to 400 MPa. This embodiment (v) may preferably
be combined with the embodiment (ii) above, so that the flexural modulus is as
given in this paragraph, and the melting temperature of the random-heterophasic
copolymer is at least 130°C, preferably at least 135°C. Suitably, the melting tem-
perature (Tm) shall not be higher than 170°C, preferably not higher than 160°C.
Tm may range e.g. between 135 to 160°C. This embodiment is particularly suit-
able for an R/R-matrix (A).
In further embodiment (vi), the flexural modulus of the random-heterophasic co-
polymer is lower than 350 MPa and preferably the melting temperature (Tm) of at
least 130°C, suitably of at least 132°C. The melting temperature (Tm) of this em-
bodiment may not be higher than 165°C, preferably not higher than 155°C. For
instance, matrix (A) is typically an R/R-matrix (A) and the melting temperature
for this embodiment ranges from 130 to 165°C, preferably from 132 to 155°C.
In yet another embodiment (vii), the flexural modulus of the random-
heterophasic copolymer is lower than 1000 MPa, typically may range between
300 to 990 MPa, preferably between 300 to 900 MPa, suitably between 400 to
800 MPa. In this embodiment (vii) the melting temperature (Tm) of the random-
heterophasic copolymer varies typically in the range of 130 to 170°C, preferably
in the range of 140 to 170°C, such as in the range of 140 to 160°C. Preferably,
matrix (A) is a H/R-matrix (A).
In still another embodiment (viii), the flexural modulus of the random-
heterophasic copolymer is not higher than 1000 MPa, and is typically in the
range of 300 to 990 MPa, preferably in the range of 300 to 900 MPa, such as in
the range of 400 to 900 MPa, and may even be in the range of 400 to 800 MPa. In
this embodiment (viii) the melting temperature of the random-heterophasic co-
polymer is at least 130°C, preferably of at least 135°C, suitaly of at least 140CC,
such as at least 145°C. The melting temperature (Tm) in this embodiment (viii) is
typically not higher than 170°C, preferably not higher than 165°C, an may be
e.g. in a range of 145 to 165°C. Preferably, matrix (A) is a H/R-matrix (A).
As defined above, the comonomer contents are different in fraction (i) and (ii) of
matrix (A). Said difference is defined herein as the difference between the
amount (wt%) of comonomer in fraction (i) and the total amount (wt%) of the
comonomer in matrix (A), whereby said comonomer content (wt%) of fraction (i)
is lower than that of matrix (A). The "difference in comonomer content between
fraction (i) and matrix (A)" (in wt%) is thus calculated by subtracting the "co-
monomer content of fraction (i)" (in wt%) from the "total comonomer content of
matrix (A)" (in wt%), i.e.:
"difference in comonomer content between fraction (i) and matrix (A)" = "total
comonomer content of matrix (A)" - "comonomer content of fraction (i)".
E.g. in case of a multistage polymerisation process of the random-heterophasic
copolymer as further described below, the comonomer content of fraction (i) or
(ii), which is prepared first, preferably fraction (i), and matrix (A) can be deter-
mined by Fourier transform infrared spectroscopy (FTIR) in a known manner,
and the secondly prepared fraction (i) or (ii), preferably fraction (ii), can be cal-
culated from the measured values of the firstly prepared fraction and matrix (A)
taking account the weight ratios, i.e. split, of fractions (i) and (ii). Similarly the
comonomer content of rubber (B) can be calculated from the measured (by FTIR)
comonomer content of matrix (A) and the final random-heterophasic copolymer
taking account the weight ratios of matrix (A) and rubber (B).
Typically, the difference in the comonomer content between fraction (i) and ma-
trix (A) is at least 0.5 wt%, preferably at least 1 wt%. The difference in said co-
monomer content is e.g. up to 15 wt%, suitably up to 10 wt%, such as 8 wt%, for
example up to 6 wt%.
In one embodiment (I), preferably in case of R/R-matrix (A) said difference in
the comonomer content between matrix (A) and random copolymer fraction (i) is
0.5, e.g. at least 1 wt%, preferably at least 2 wt% or higher, e.g. may be up to 6
wt%, e.g. up to 4 wt%.
In another embodiment (II), preferably in case of H/R-matrix, higher difference
may be desired, whereby the difference in said comonomer content between ma-
trix (A) and the homopolymer fraction (i) may vary in broader range, being e.g.
at least 2 wt%, typically at least 3 wt%, preferably at least 4 wt %, even at least 5
wt%. The upper limit in said difference may be up to 10 wt%, for example up to
8 wt%, in some embodiments e.g. in the range of 3 to 6 wt%.
Furthermore, the comonomer content in matrix (A), i.e. the total amount of the
comonomer in matrix (A), is typically at least 1 wt%, and may be e.g. up to 13
wt%, suitably between 2 to 12 wt%, e.g. between 3 to 12 wt% or even between 5
to 12 wt%.
In one embodiment (ix) said total comonomer content in matrix (A) is up to 13
wt%, e.g. in a range of 4 to 12 wt%, preferably in a range of 6 to 12 wt%, more
preferably in a range of 7 to 10 wt%.
In another embodiment (x), the total comonomer content in matrix (A) may be up
to 12 wt%, preferably shall range from between 1 to 12 wt% and suitably in the
range of 2 to 10 wt%.
Furthermore, the homo- or random copolymer of fraction (i) can have a comono-
mer content of up to 15 wt%, suitably of up to 10 wt%, depending i.a. on the type
of matrix (A) (H/R- or R/R-) and on the Tm and stiffness levels desired. Thus in
one embodiment (xi) the amount of comonomer in fraction (i) may varied e.g.
within any of the ranges: 0 to 1, 0 to 2, 0 to 3, 0 to 4, 0 to 5, 0 to 6, 0 to 7, 0 to 8,
0 to 9 or even up to 10 wt%, such as 0 to 6 wt %.
It may be preferable for some end applications, that the comonomer content of
fraction (i) in R/R-matrix (A) may vary between 1.5 to 6 wt%, such as 1.5 to 4
wt%. Alternatively, for some other end applications comonomer content of frac-
tion (i) of 4 to 6 wt% may be desired.
One feasible range of the amount of comonomer in fraction (i) for adjusting the
Tm within the limits of the invention may vary from 0 to 10 wt%, preferably from
0 to 6 wt%, but is not limited thereto.
It is in turn, preferable that the copolymer of fraction (ii) has a comonomer con-
tent of up to 20 wt%.
In one embodiment (xii) the amount of the comonomer in fraction (ii) is not
lower than 2 wt%, more preferably not lower than 3 wt%, e.g. between 3 to 15
wt%, for some end applications even below 10 wt% may be desirable.
In another embodiment (xiii) the copolymer of fraction (ii) has a comonomer
content in the range of 2 to 20 wt%, preferably in the range of 5 to 20 wt%, e.g.
in the range of 6 to 17 wt%.
In a further embodiment (xiv) the amount of the comonomer in fraction (ii) is
not lower than 10 wt% and preferably in the range of 10 to 15 wt%.
Also the amount of the comonomer in rubber component (B) and the amount of
rubber (B) in the random-heterophasic copolymer can be varied within the limits
of the invention to adjust i.a. one or more of the stiffness, impact strength at low
temperatures and optical properties of the final random-heterophasic copolymer
to the level desirable of the end application in question.
Typically, the comonomer content of rubber component (B) is in the range of 10
to 60 wt%, more preferably in the range of 15 to 50 wt%.
In one embodiment (xv), the amount of comonomer in rubber component (B) is
in a range of 15 to 40 wt%.
In another embodiment (xvi), rubber component (B) has a comonomer content in
the range of 20 to 40, preferably in the range of 20 to 35 wt%.
As a preferable embodiment of the invention matrix (A) comprises a propylene
homopolymer or propylene random copolymer as fraction (i) and/or propylene
random copolymer as fraction (ii). Still more preferably, the random copolymer
in fraction (i) and/or in fraction (ii) is a random copolymer of propylene and one
or more alpha-olefins.
The term "alpha-olefins" includes herein ethylene and higher alpha-olefins and
may be selected e.g. from the group consisting of ethylene, C4 alpha-olefin, C5
alpha-olefin, C6 alpha-olefin, C7 alpha-olefin, C8 alpha-olefin, C9 alpha-olefin,
C10 alpha-olefin, Cn alpha-olefin, C12 alpha-olefin. Preferably, the comonomers
are selected from the group consisting of ethylene, 1-butene, 1-pentene, 4-
methyl-1-pentene, 1-hexene, 1-heptene or 1-octene. The preferred comonomer is
ethylene.
Preferably, rubber component (B) is a propylene copolymer, more preferably a co-
polymer of propylene and another alpha-olefin as defined above. In particular,
rubber (B) is a copolymer of propylene with ethylene and, optionally, with an-
other alpha-olefin. In one embodiment, rubber (B) is a copolymer of propylene
and ethylene.
Accordingly, as a further embodiment (1) the invention provides a random-
heterophasic propylene copolymer comprises
(a) a propylene random copolymer component (A) which comprises at least one
fraction (i) comprising a propylene homopolymer or a propylene copoly-
mer with one or more alpha-olefin comonomers and at least one fraction
(ii) comprising a propylene copolymer with one or more alpha-olefin co-
monomers, and
(b) a rubber component (B) of a propylene copolymer with one or more alpha-
olefin comonomers, dispersed in the random copolymer component (A),
whereby
- the amount of comonomer in fraction (ii) is higher than the amount of co-
monomer in fraction (i), and wherein
- the random-heterophasic copolymer has a melting temperature (Tm) of at
least 130°C and a flexural modulus of not higher than 1000 MPa.
The above defined options and subgroups for 'the comonomer content in fraction
(i), fraction (ii) and matrix (A) apply particularly suitably for the polypropylene
random copolymer component (1).
The split, i.e. the weight ratio, between fraction (i) and (ii) in matrix (A) is pref-
erably 30:70 to 70:30, more preferably between 40:60 to 60:40.
Moreover, the amount of matrix (A) in the random-heterophasic copolymer may
be at least 30 wt%, suitably at least 40 wt%, and preferably at least 50 wt%.
Typically, the amount of matrix (A) in the random-heterophasic copolymer
ranges from 60 to 90 wt%, more preferably ranges from 70 to 90 wt%, for some
end applications, however, range from 60 to 85 wt% may be desired.
Accordingly, the amount of rubber component (B) in the random-heterophasic
copolymer may thus be up to 70 wt%, preferably up to 60 wt% and more prefera-
bly up to 50 wt% depending on the property combination desired for the end ap-
plication.
Thus in one embodiment (xvii) rubber (B) in the random-heterophasic copolymer
may range between 5 to 70 wt%, preferably between 5 to 40 wt%, more prefera-
bly in the range of 5 to 30 wt%, and even 10 to 30 wt%.
In another embodiment (xviii), the amount of rubber (B) in said random-
heterophasic copolymer is in the range of 10 to 50 wt%, preferably in the range
of l5 to 40 wt%.
Preferably the amount of matrix (A) in the total random-heterophasic copolymer is at
least 30 wt% and the amount of rubber (B) is not higher than 70 wt%.
In the present invention, the random-heterophasic copolymer may have an MFR2
(measured according to ISO 1133) of 0.01 to 500 g/10 min, preferably in the
range of 0.1 to 100 g/10 min, and more preferably in a range of 1 to 50 g/10 min.
Preferably, the MFR2 of fraction (i) of matrix (A) is lower than the MFR2 ef frac-
tion (ii), i.e. fraction (i) has the higher molecular weight than fraction (ii), or,
alternatively, vice versa.
The falling weight impact (measured according to ISO 6603-2), which describes
the ductile behaviour is preferably down to (-20)°C
Accordingly, the xylene solubles (XS, wt%, as defined below under definitions
and determination methods) of the random-heterophasic copolymer may be up to
60 wt%. Moreover, the xylene solubles in fraction (i) of matrix (A) may be up to
15 wt%, preferably in the range of 0.5 to 15 wt%. In turn, the xylene solubles in
fraction (ii) of matrix (A) may be up to 70wt%, e.g. in the range of 3 to 70 wt%.
The xylene solubles of matrix (A), which is preferably comprised of fractions (i)
and (ii) together, may be up to 50 wt%, e.g. in a range of 3 to 50 wt%.
The xylene solubles in rubber component (B) may be up to 100 wt%, e.g. 10 to
100 wt%, preferably in a range of 50 to 100 wt%.
In one embodiment (xix), the xylene solubles (XS) in fraction (i) of matrix (A)
are in a range of 3 to 15 wt%, preferably 4 to 13 wt%, whereas the xylene solu-
bles (XS) in fraction (ii) of matrix (A) are in a range of 10 to 70 wt%, preferably
in a range of 30 to 70 wt%.
It a further embodiment (xx) the xylene solubles (XS) in matrix (A), which is
preferably comprised of fractions (i) and (ii), are in a range of 4 to 50 wt%, pref-
erably in a range of 15 to 40 wt%.
Moreover, in one embodiment (xxi), the xylene solubles (XS) in rubber compo-
nent (B) may be in the range of 70 to 100 wt%, preferably in the range of 80 to
100 wt%.
In another embodiment (xxii), the random-heterophasic copolymer may have xy-
lene solubles (XS) in the range of 20 to 70 wt%, preferably 30 to 55 wt%.
In a preferable embodiment, the random-heterophasic copolymer is any combina-
tion of embodiments (xx), (xxi) and (xxii).
The intrinsic viscosity of the amorphous part (IV/AM) of the random-
heterophasic copolymer may be up to 5 dl/g, preferably 1 to 4 dl/g, preferably 1
to 2 dl/g, such as 1 to 1.5 dl/g. And for some end applications embodiments
IV/AM of 1 to 3 dl/g may be desired.
The matrix (A) and/or the random-heterophasic copolymer of the invention may
be produced by blending at least part of the components in-situ during the po-
lymerisation process thereof or, alternatively, by blending mechanically one or
more of the separately produced components.
Preferably, matrix (A) and the random-heterophasic copolymer of the invention
is produced by in-situ blending in a multistage polymerisation process, also
called in-situ process. Matrix (A) may be produced first as a multistage process,
wherein fractions thereof are produced in two or more reactors which may be the
same or different and, optionally, in same or different the polymerisation condi-
tions, or, alternatively, in one reactor by changing the catalyst and/or polymerisa-
tion conditions. Furthermore, fractions (i) and (ii) of matrix (A) may be produced
in any order, preferably in different reactors.
In a preferable embodiment, fraction (i) is produced first in a first reactor and
then fraction (ii) is produced in a subsequent reactor in the presence of fraction
(i).
If desired the polymerisation process may include a prepolymerisation step in a
manner known in the field.
Without limiting the invention to any process, rubber component (B) may pref-
erably be produced as a further process step after the formation of matrix (A) in
the same multistage process system as matrix (A). Accordingly, after the forma-
tion of matrix (A), rubber component (B) is preferably produced in. the subse-
quent one or more reactor(s), preferably at least in one gas reactor, in the pres-
ence of matrix (A). Such rubber processes are known in the field.
Preferably, fractions (i) and (ii) of matrix (A) as well as rubber (B) may be pro-
duced using a different or the same polymerisation method including slurry, bulk,
solution and gas phase polymerisation methods.
Preferably, fraction (i) of matrix (A) is formed in a slurry process, in solution or
as bulk polymerisation, preferably as bulk polymerisation. Such process is pref-
erably carried out in a loop reactor.
Fraction (ii) of matrix (A) is preferably performed in a first gas phase reactor,
whereas rubber (B) is typically formed in one or more subsequent reactor, e.g. in
second or further subsequent gas phase reactor(s).
Accordingly, it is preferred that the random-heterophasic copolymer is produced
in an in-situ process, more preferably, fraction (i) of matrix (A) is produced in a
loop reactor, whereas fraction (ii) of matrix (A) is produced in a subsequent first
gas phase reactor in the presence of fraction (i) and rubber (B) is then produced
in a subsequent one or more gas phase reactors, preferably in the presence of
fraction (i) and (ii).
Such process is preferably effected in a "loop"-"first gas phase"-"second or fur-
ther rubber gas phase" -multistage reactor system, preferably such as developed
by Borealis A/S, Denmark, and known as BORSTAR® technology. Such process
is known and described i.a. in W092/12182.
Alternatively, part of the components of the random-heterophasic copolymer may
be made in a multistage process and then blended with the remaining compo-
nents).
The invention thus further provides a "process for producing the random-
heterophasic copolymer as defined above" comprising a matrix (A) with at least
two fractions (i) and (ii) as defined above, wherein the comonomer content of
fraction (i) is lower than the comonomer content of fraction (ii), comprising the
steps of:
-producing matrix (A) by
(a) (co)polymerising in a slurry reactor, e.g. a loop reactor, an alpha-olefin, pref-
erably propylene, and optionally one or more comonomers in the presence of a
polymerisation catalyst, to produce fraction (i), transferring the reaction product
of step (a) to a subsequent gas phase reactor,
(b) copolymerising in a gas phase reactor an alpha-olefin, preferably propylene,
with one or more comonomers in the presence of the reaction product of step (a)
to produce fraction (ii) for obtaining matrix (A), and then
- producing rubber component (B) by
(c) copolymerising in a subsequent second or further gas phase reactor(s) an al-
pha-olefin, preferably propylene, with one or more alpha-olefin comonomers,
preferably at least with ethylene, in the presence of matrix (A) obtained from step
(b),
and recovering the obtained random-heterophasic copolymer.
The process is preferably a continuous process. The comonomer is at least ethyl-
ene, more preferably ethylene.
According to one embodiment of the invention the polymerisation conditions for
the slurry reactor of the first stage may be as follows:
the temperature is within the range of 40°C to 110°C, preferably between
60°C and 90°C,
the pressure is within the range of 20 bar to 80 bar, preferably between 30
bar to 60 bar,
hydrogen can be added for controlling the molar mass in a manner known
per se.
The reaction mixture from the slurry (bulk) reactor is transferred to the first gas
phase reactor (second stage). The polymerisation conditions in the first gas phase
reactor may be as follows:
the temperature is within the range of 50°C to 130°C, preferably between
60°C and 100°C.
the pressure is within the range of 5 bar to 50 bar, preferably between 15-
35 bar, in some embodiments also 20 bar to 35 bar may be desired,
hydrogen can be added for controlling the molar mass in a manner known
per se.
The polymerisation conditions in the subsequent one or more gas phase reactors
for preparing rubber component (B), e.g. in the second gas phase reactor in the
third stage of the process, can be the same as in the first gas phase reactor of the
second stage. Typically, in case of ethylene-propylene, the ratio of ethylene to
propylene is 0.1 to 1.5, e.g. 0.3 to 1.0 mol per mol in the reactor.
The process of the invention enables highly feasible means for tailoring matrix
(A) of the invention. The properties of the final polymer, i.a. MW, MWD and
thus MFR2 and IV (intrinsic viscosity) of matrix (A) and rubber component (B),
can be controlled e.g. with one or more of the following process parameters: hy-
drogen feed, comonomer feed, alpha-olefin feed in the gas phase reactor, pref-
erably propylene and comonomer feeds, catalyst, the type and amount of an ex-
ternal donor (if used), split between fraction (i) and (ii) and the weight ratio of
matrix (A) to rubber component (B).
Furthermore, the crystallinity of the random-heterophasic copolymer can be fur-
ther modified during or after the polymerisation step with nucleating agents in a
manner known in the art, e.g. using nucleating systems are described i.a. in WO
9924478 and WO 9924479.
The obtained copolymer product may also be subjected to an extrusion and/or a
further treatment steps in a known manner to obtain pellets.
The produced random-heterophasic copolymer of the invention may, if desired,
be thus subjected to different treatment steps for further modifying the polymer
properties in a known manner, e.g. to a visbreaking, for adjusting, i.e. increasing,
the MFR of the product by using conventional methods and organic peroxides.
The random-heterophasic copolymer can be produced by using any suitable po-
lymerisation catalyst.
Preferably, a coordination catalyst is employed, more preferably of the group of
transition metals, still more preferably of the transition metals of Group 3 to 10, ac-
tinides and lanthanides of the Periodic Table (IUPAC, 1989), such as a Ziegler-
Natta-catalyst, a metallocene-catalyst, a non-metallocene-catalyst, or any mxture
thereof. Most preferably, Ziegler-Natta catalyst comprising titanium and chlorine
is used.
Preferred catalysts are those as disclosed e.g. in US 5234879, W092/19653,
W092/19658, W099/33843, WO03/000754 and WO03/000757. The documents
are included herewith by reference. The preferred catalyst used in the above
process is a high activity, stereoselective Ziegler-Natta type polymerisation cata-
lyst system comprising a solid catalyst component, cocatalyst and an external
donor. The catalyst may or may not be supported with an external support, e.g.
silica. Alternatively, a Mg-based support system may be used.
In one preferred embodiment for producing a heterophasic polymer copolymer as
defined above, a procatalyst is used which has been prepared by bringing to-
gether MgC12, a lower alcohol, a titanium compound and an ester of phthalic
acid, whereby a transesterification has been carried out at a temperature between
110 und 150 °C between the lower alcohol and the ester of the phthalic acid,
whereby the alcoxy group of the phthalic acid ester comprises at least five carbon
atoms. Such catalyst is known and can be prepared according or analogously to
the literature e.g. as described in US 5234879, WO 92/19653, W092/19658 or
W099/33843 which are included herewith by reference.
In another preferred embodiment a catalyst is used as described in detail below.
This catalyst is known in the field and can be prepared according or analogously
to the so called emulsion method described e.g. in WO 03/000754 and WO
03/000757. Preferably the catalyst has a low surface area, whereby the catalyst
component comprises a compound of a transition metal of Group 3 to 10 of the
Periodic Table, or actinide or lanthanide. The most preferred catalysts for this
embodiment and their preparation.
The present invention is also related to a random-heterophasic copolymer obtain-
able by the "process for preparing the random-heterophasic copolymer" as de-
fined above.
According to a first embodiment, the random-heterophasic copolymer is obtain-
able by the "process for preparing the random-heterophasic copolymer" as de-
fined above using a polymerization catalyst as disclosed in US 5234879,
W092/19653, W092/19658 or W099/33843.
According to a second embodiment, the random-heterophasic copolymer is ob-
tainable by the "process for preparing the random-heterophasic copolymer" as
defined above using a polymerisation catalyst as disclosed in WO 03/000754 or
WO 03/000757, which catalyst comprises a compound of a transition metal of
Group 3 to 10 of the Periodic Table (IUPAC), or of an actinide or lanthanide, and
is prepared according to a "catalyst preparation method" comprising
(a) forming a liquid/liquid emulsion system, which contains a homogeneous
solution of at least one catalyst component, said solution being dispersed in
a solvent immiscible therewith and forming the dispersed phase of the liq-
uid/liquid emulsion system,
(b) solidifying said dispersed droplets to form solid catalyst particles having a
predetermined size range,
(c) removing the solvent from the reaction mixture in order to obtain said solid
catalyst particles.
Hence, according to the second embodiment of the "process for preparing the
random-heterophasic copolymer" as defined above, the polymerisation catalyst
used is a ZN-catalyst which is prepared by the "catalyst preparation method" as
defined above.
The invention also provides a random-heterophasic copolymer as defined above
which is obtainable by the "process for preparing the random-heterophasic co-
polymer" as defined above, wherein a polymerisation catalyst is used which is a
ZN-catalyst prepared by the "catalyst preparation method" as defined above.
The ZN catalyst which is prepared by the "catalyst preparation method" as de-
fined above enables to produce a random-heterophasic copolymer with very low
stiffness. Said catalyst is very suitable for producing a random-heterophasic co-
polymer of one or more the embodiments (i), (iv) and (vi).
The flexural modulus (stiffness, FM, MPa) can be expressed with the following
formula (I) for a specific subgroup (I) of a random-heterophasic propylene co-
polymer with ethylene as the comonomer:
FM = 426 - 22,3 x C20n + 1.71 x C2AM - 6.76 x R + 85.1 x IVAM (I),
wherein:
C2(ii) is ethylene, content in fraction (ii) of matrix (A) in wt%,
C2AM is ethylene content in the amorphous part of the random-heterophasic co-
polymer in wt%,
R is the amount (wt%) of rubber component (B), preferably material produced in
the second gas phase reactor, based on consumption of ethylene and propylene,
given in wt% of the random-heterophasic copolymer,
IVa.m is the intrinsic viscosity of the amorphous part of the random-heterophasic
copolymer in dl/g;
provided that the calculated flexural modulus FM is above 100 MPa, and
that the random-heterophasic propylene copolymer has the following combina-
tion:
(a) ethylene content in fraction (i) is 4 to 5 wt%,
(b) split between fractions (i) and (ii) is 55/45 - 65/35 per weight, and
(c) C2(ii) is 4 to 20 wt%, said formula (I) being particularly suitable in the range
of 5.5-13 wt%,
(d) C2AM is 15 to 50 wt%, said formula (I) being particularly suitable in the range
of 15 to 40 wt%,
(e) R, preferably obtained from 2nd gas phase reactor of a multistage process, is
10 to 40 wt%, said formula (I) being particularly suitable in the range of 18 to 35
wt%, and
(f) IVAM is 1.0 to 3.5 dl/g, said formula (I) being particularly suitable in the
range of 2 to 3 dl/g.
Furthermore, MFR2 (ISO 1133) is typically 1 to 2 g/10 min, but it is apparent for
a skilled person that copolymer compositions with MFR2 higher than 1-2 will
also result in very low FM values.
Such subgroup (I) of FM of formula (I) is preferably a subgroup of a random-
heterophasic copolymers obtainable by the "process for preparing the random-
heterophasic copolymer" as defined above using the ZN polymerisation catalyst
that is obtainable by the "catalyst preparation method" as defined above.
Moreover, the random-heterophasic copolymer of subgroup (I) has preferably a
melting temperature (Tm) of at least 130°C.
As to the further definition of the catalyst component, the catalyst, e.g. as de-
scribed in WO 03/000754, may include, in addition to said transition metal com-
pound, also any additional cocatalyst(s) (e.g. additional transition metal com-
pounds and/or activators and/or poison scavengers and/or any reaction product(s)
of a transition compound(s) and a cocatalyst(s). Thus the catalyst may be acti-
vated in situ to from the catalyst components in said solution in a manner known
in the art.
In one preferable "catalyst preparation method" a solution of a complex of Group
2 metal and an electron donor is prepared by reacting a compound of said metal
with said electron donor or a precursor thereof in an organic liquid reaction me-
dium; reacting said complex, in solution, with a compound of a transition metal
to produce an emulsion, the dispersed phase of which contains more than 50
mol% of the Group 2 metal in said complex: maintaining the particles of said
dispersed phase within the average size of 5 to 200 micro meter by agitation pref-
erably in the presence f an emulsion stabilizer and solidifying said particles.
For said catalyst particles, the compound of a transition metal is preferably a
compound of a Group 4 metal. The Group 4 metal is preferably titanium, and its
compound to be reacted with the complex of a Gp 2 is preferably a halide. In a
still further embodiment of the invention a compound of a transition metal can
also be selected from Group 5 metals, Group 6 metals, Cu, Fe, Co, Ni and/or Pd.
The complex of the Group 2 metal is preferably a magnesium complex.
In the "catalyst preparation method" also a turbulence minimizing agent (TMA)
or mixtures thereof may be used, which are preferably polymers having linear
aliphatic carbon backbone chains, which might be branched with short side
chains only in order to serve for uniform flow conditions when stirring, Said
TMA is in particular preferably selected from a-olefin polymers having a high
molecular weight of MW about 1-40 x 106, or mixtures thereof. Especially pre-
ferred are polymers of alpha-olefin monomers with 6 to 20 carbon atoms, and
more preferably polyoctene, polynonene, polydecene, polyundecene or polydode-
cene or mixtures thereof, having the molecular weight and general backbone
structure as defined before, and most preferable TMA is polydecene.
As electron donor compound to be reacted with the Group 2 metal compound is
preferably a mono- or diester of an aromatic carboxylic acid or diacid, the latter
being able to form a chelate-like structured complex. Said aromatic carboxylic
acid ester or diester can be formed in situ by reaction of an aromatic carboxylic
acid chloride or diacid dichloride with a C2-C16 alkanol and/or diol, and is pref-
erable dioctyl phthalate. The reaction for the preparation of the Group 2 metal
complex is generally carried out at a temperature of 20° to 80°C and in case that
the Group 2 metal is magnesium, the preparation of the magnesium complex is
carried out at a temperature of 50° to 70°C
The electron donor is preferably an aromatic carboxylic acid ester, a particularly
favoured ester being dioctyl (2-ethyl-hexyl) phthalate. The donor may conven-
iently be formed in situ by reaction of an aromatic carboxylic acid chloride pre-
cursor with a C2-C16 alkanol and/or diol. The liquid reaction medium preferably
comprises toluene.
The emulsion stabiliser is typically a surfactant, of which the preferred class is
that based on acrylic polymers.
The alkoxy magnesium compound group is preferably selected from the group
consisting of magnesium dialkoxides, complexes of a magnesium dihalide and an
alcohol, and complexes of a magnesium dihalide and a magnesium dialkoxide, it
may be a reaction product of an alcohol and a magnesium compound selected
from the group consisting of dialkyl magnesiums alkyl magnesium alkoxides,
alkyl magnesium halides and magnesium dihalides. It can further be selected
from the group consisting of dialkyloxy magnesiums diaryloxy magnesiums alky-
loxy magnesium halides, aryloxy magnesium halides, alkyl magnesium alkox-
ides, aryl magnesium alkoxides and alkyl magnesium aryloxides.
The magnesium dialkoxide may be the reaction product of a magnesium dihalide
such as'magnesium dichloride or a dialkyl magnesium of the formula R^Mg
wherein each one of the two Rs is a similar or different C1-C20 alkyl, preferably a
similar or different C4-C10 alkyl, Typical magnesium alkyls are ethylbutyl mag-
nesium, dibutyl magnesium, dipropyl magnesium, propylbutyl magnesium,
dipentyi magnesium, butylpentylmagnesium, butyloctyl magnesium and dioctyl
magnesium. Most preferably, one R of the formula RjMg is a butyl group and the
other R is an octyl group, i.e. the dialkyl magnesium compound is butyl octyl
magnesium.
Typical alkyl-alkoxy magnesium compounds RMgOR, when used, are ethyl mag-
nesium butoxide, butyl magnesium pentoxide octyl magnesium butoxide and oc-
tyl magnesium octoxide.
Dialkyl magnesium, alkyl magnesium alkoxide or magnesium dihalide can react
with a polyhydric alcohol R'(OH)m or a mixture thereof with a monohydric alco-
hol R'OH.
Typical C2 to C6 polyhydric alcohols may be straight-chain or branched and in-
clude ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butylene glycol,
1,3-butylene glycol, 1,4-butylene glycol, 2,3-butylene glycol, 1,5-pentanediol,
1,6-hexanediol, 1,8-octanediol, pinacol, diethylene glycol, triethylene glycol, and
triols such as glycerol, methylol propane and pentareythritol. The polyhydric al-
cohol can be selected on the basis of the activity and morphology it gives the
catalyst component.
The aromatic reaction medium may also contain a monohydric alcohol, which
may be straight- or branched-chain. Typical C1-C20 monohydric alcohols are
methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec.butanol,
tert.butanol, n-amyl alcohol, iso-amyl alcohol, sec-amyl alcohol, tert.amyl alco-
hol, diethyl carbinol, akt.amyl alcohol, sec.isoamyl alcohol, tert.butyl carbinol.
Typical C5-C10 monohydric alcohols are hexanol, 2-ethyl-lbutanol, 4-methyl-2-
pentanol, l-heptanol, 2-heptanol, 4-heptanol, 2,4-dimethyl-3pentanol, 1-octanol,
2-octanol, 2-ethyf-i-hexanol, 1-nonanol, 5-nonanol, dilsobutyl carbinol, 1-decanol
and 2,7-dimethyl-2-octanol. Typical >C10 monohydric alcohols are n-1-
undecanol, n-1-dodecanol, n-l-tridecanol, n-l-tetradecanol, n-1-pentadecanol, 1-
hexadecanol, n-1-heptadecanol and n-1 octadecanol. The monohydric alcohols
may be unsaturated, as long as they do not act as catalyst poisons.
Preferable monohydric alcohols are those of formula R'OH in which R' is a C2-
C16 alkyl group, most preferably a C4-C12 alkyl group, particularly 2-ethyl-l-
hexanol.
Preferably, essentially all of the aromatic carboxylic acid ester is a reaction prod-
uct of a carboxylic acid halide, preferably a dicarboxylic acid dihalide, more
preferably an unsaturated a,P-dicarboxylic acid halide, most preferably phthalic
acid dichloride, with the monohydric alcohol.
The finally obtained catalyst component is desirably in the form of particles hav-
ing an average size range of 5 to 200 µm, preferably 10 to 100, more preferably
20 to 50 µm. Especially the catalyst particles obtainable by "the catalyst prepara-
tion method" are typically non-porous, i.e. their surface area is very small com-
pared to prior art Ziegler-Natta catalysts supported on an external donor. The
surface area of the catalyst used in the present invention may be smaller than 20
m2/g, preferably less than 10 m2/g, and more preferably less than 5 m2/g, and
may even be not measurable by normal measurement apparatus. This applies also
to the porosity. The active components of the catalysts are evenly distributed
thorough the whole catalyst particles.
The catalyst used in the present invention comprises a catalyst component pre-
pared as aforesaid, preferably in association with an alkyl aluminium cocatalyst
and donors, such as an external donor.
The random-heterophasic copolymer as defined in the present invention can be
used in wide variety of end applications, i.a. for molded and extruded articles,
films including blown and cast films, fibers without limiting to these.
Depending on the end application various additives and/or other polymer compo-
nents may be added to the random-heterophasic copolymer in a conventional
manner.
Additionally, the present invention provides an article, such as film, which com-
prises a random-heterophasic copolymer according to this invention.
Preferably, the film modulus (for a film below 200 um) is 80 to 700 MPa, more
preferably 80 to 400 MPa and most preferably 80 to 300 MPa.
Definitions and determination methods
The following definitions for the used terms as well as the determination methods
for the characterizing values/parameters used herein to describe the random-
heterophasic copolymer of the invention and the properties thereof apply gener-
ally for the description part above and for the examples below, unless otherwise
stated:
- Weight-% is abbreviated as w% or wt-%
- The xylene solubles (XS) -fraction contains amorphous polymer chains. It is
preferable that fraction (i) has a lower XS-fraction than fraction (ii). Low stiff-
ness and impact strength increases with increasing the fraction of xylene solubles
in the fraction (ii) and/or in the rubber component (B).
-XS (xylene solubles) and AM (amorphous part) were analyzed by the known
method:
2.0 g of polymer was dissolved in 250 ml p-xylene at 135°C under agitation. Af-
ter 30±2 minutes the solution was allowed to cool for 15 minutes at ambient tem-
perature and then allowed to settle for 30 minutes at 25±0.5°C. The solution was
filtered with filter paper into two 100 ml flasks.
The solution from the first 100 ml vessel was evaporated in nitrogen flow and the
residue dried under vacuum at 90°C until constant weight is reached.
XS%=(100 x m1 x v0) / (m0 x V1), wherein
mo= initial polymer amount (g)
m1= weight of residue (g)
v0= initial volume (ml)
V1= volume of analyzed sample (ml)
The solution from the second 100 ml flask was treated with 200 ml of acetone
under vigorous stirring. The precipitate was filtered and dried in a vacuum oven
at 90°C.
AM%=(100 x m2 x v0) / (m0 x v1), wherein
m0= initial polymer amount (g)
m1= weight of precipitate (g)
v0= initial volume (ml)
V1= volume of analyzed sample (ml)
- The intrinsic viscosity (IV) value is increasing with the molecular weight of a
polymer. IV of AM: measured according to ISO 1628.
- MFR2: measured according to ISO 1133 (230°C, 2.16 kg load).
- Comonomer content (wt%) was determined in a known manner based on Fou-
rier transform infrared spectroscopy (FTIR) determination calibrated with C13-
NMR.
- Multimodality, including bimodality, with respect to the comonomer distri-
bution, is demonstrated herein with the different comonomer content (wt%) be-
tween the components of the random-heterophasic copolymer, e.g. between the
fractions (i) and (ii) of the matrix (A), which comonomer content is determined
using said FTIR method described above.
-The optional multimodality, including bimodality, with respect to the mo-
lecular weight distribution (MWD) means that the molecular weight profile of
e.g. the random copolymer component (A) does not comprise a single peak but
instead comprises two or more distinct maxima, a maximum and one or more
shoulders centered about different average molecular weights, or in some cases a
distinctly broadened curve. The fraction (i) may comprise a higher MW compo-
nent than fraction (ii), or vice versa. E.g. it is possible to produce the fraction (i)
as the HMW component in the preferable loop-gas phase process of the invention
and the fraction (ii) in the subsequent gas phase reactor as the LMW component.
The MWD can be determined e.g. by using a size exclusion chromatography
(SEC) in a manner known in the art.
- Thermal properties of polymer was analyzed with a differential scanning calo-
rimeter and according to the method:
Melting temperature Tm, crystallization temperature Tc, and the degree of
crystallinity were measured with Mettler TA820 differential scanning calo-
rimetry (DSC) on 3±0.5 mg samples. Both crystallization and melting curves
were obtained during 10°C/min cooling and heating scans between 30°C and
225°C. Melting and crystallization temperatures were taken as the peaks of endo-
therms and exotherms. The degree of crystallinity was calculated by comparison
with heat of fusion of a perfectly crystalline polypropylene, i.e. 209 J/g.
- Instrumental falling weight impact (IFWI): was measured according to ISO
6603-2.
- Flexural modulus: was measured according to ISO 178 (room temperature, if
not otherwise mentioned) by using injection moulded test specimens as described
in EN ISO 1873-2 (80x10x4 mm).
- Charpy notched impact: was measured accoding to ISO 179 (room tempera-
ture, if not otherwise informed) and at -20 °C by using injection moulded test
specimens as described in EN ISO 1873-2 (80x10x4 mm)
- Tensile strength: (tensile stress at yield) was measured according to ISO 572-2
(cross head speed = 50 mm/min)
- Tensile modulus: was measured according to ISO 572-2 (cross head speed = 1
mm/min)
The present invention will now be described by way of examples: The raw mate-
rials are e.g. commercially available or can be produced according or analo-
gously to the known methods described in literature, unless otherwise specified.
Example 1
All raw materials were essentially free from water and air and all material addi-
tions to the reactor and the different steps were done under inert conditions in a
nitrogen atmosphere. The water content in propylene was less than 5 ppm.
The polymerisation (bulk polymerisation step) was done in a 5 litre reactor,
which was heated, vacuumed and purged with nitrogen before use. 407 ul TEA
(triethyl aluminium, from Witco used as received), 69 ul external donor (dicyclo
pentyl dimethoxy silane, from Wacker, dried with molecular sieves) and 30 ml
pentane (dried with molecular sieves and purged with nitrogen) were mixed and
allowed to react for 5 minutes. Half of the mixture was added to the reactor and
the other half was mixed with 20,1 mg highly active and stereo specific Ziegler
Natta catalyst (ZN catalyst). The ZN catalyst was prepared according to patent
WO03/000754, example 7, and had Ti content 2,84 w%. After about 10 minutes
the ZN catalyst/TEA/external donor/pentane mixture was added to the reactor.
The AI/Ti molar ratio was 250 and the Al/Do molar ratio was 10. 80 mmol hy-
drogen, and 1400 g were added to the reactor. Ethylene was added continuously
dur+ing polymerisation and 27 g was added in total. The temperature was in-
creased from room temperature to 70°C during 18 minutes. The reaction was
stopped, after 30 minutes at 70°C by flashing out unreacted monomer. Finally the
polymer powder was taken out from the reactor and analyzed and tested. The
MFR of the product (fraction (i) of the matrix (A)) was 2,9, and ethylene content
4,3 w%. The other polymer details are seen in table 1.
Example 2
This example was done in accordance with Example 1, but after having flashed
out unreacted propylene after the bulk polymerisation step, the polymerisation
was continued in gas phase. After the bulk phase the reactor was pressurized up
to 5 bar and purged three times with a 0,042 mol/mol ethylene/propylene mix-
ture. 70 mmol hydrogen was added and the temperature was increased to 70°C
and pressure with the aforementioned ethylene/propylene mixture up to 20 bar
during 13 minutes. Consumption of ethylene and propylene was followed from
scales. The reaction was allowed to continue until a 60/40 split between polymer
amount produced in the bulk stage (fraction (i)) and polymer amount produced in
the gas phase (fraction (ii)) was reached. The MFR of the final product was 2,7
and the total ethylene content 5 w%. The ethylene content in the gas phase mate-
rial can be calculated to be 6,1 w%. Other details are seen in table 1.
Example 3
This example was done in accordance with Example 2. but after having flashed
out unreacted monomer after the gas phase polymerisation the polymerisation
was continued in the second gas phase (rubber stage). The hydrogen amount in
the rubber stage was 120 mmol and ethylene/propylene molar ratio in the feed to
the reactor was 0,65. The temperature was 70 °C. The reaction was allowed to
continue until a rubber content of 20 w%, based on consumption of ethylene and
propylene from the scales, in the final product was reached. MFR of the final
product was 1,8, the total ethylene content 13,9 w%, XS 28 w%, and flexural
stiffness 444 MPa. The other details are shown in table 1.
Example 4
This example was done in accordance with Example 3, with the exception that
the reaction was allowed to continue until the rubber content in the final product
was 34 w%. MFR of the final product was 1,2, the total ethylene content 19,2
w%, XS 38,6 w%, and flexural stiffness 326 MPa. The other details are shown in
table 1.
[ Example 5
This example was done in accordance with Example 2, with the exception that
the ethylene/propylene molar ratio in the feed was 0,084 and hydrogen amount 75
mmol. MFR of the final product was 2,5, the total ethylene content 6,6 w%, and
XS 24,3 w%. The ethylene content in the gas phase material can be calculated to
be 10,2 w%, The other details are shown in table 1 .
Example 6
This example was done in accordance with Example 5, but after having flashed
out unreacted monomer after the first gas phase stage the reaction was continued
in the second gas phase stage. The hydrogen amount was 120 mmol, ethyl-
ene/propylene molar ratio in feed 0,65 and amount of rubber according to mono-
mer consumption 20 w%, MFR of the final product was 1,5, the total ethylene
content 15,3 w%, XS 34,1 w%, and flexural modulus 327 MPa. The other details
are shown in table 1,
Example 7
This example was done in accordance with Example 6, with the exception that
the reaction in the rubber stage was allowed to continue until the rubber content
in the final product was 34 w%, MFR of the final product was 1,1, the total eth-
ylene content 20,6 w%, XS 43,8 w%, and flexural modulus 240 MPa. The other
details are shown in table 1.
Example S
This example was done in accordance with Example 2, with the exception that
the ethylene/propylene molar ratio in the feed was 0,126 and hydrogen amount 80
+mmol. MFR of the fial product was 2,5, the total ethylene content 7,6 w% and XS
29,5 w%. The ethylene content in the gas phase material can be calculated to be
12,8 w%. The other details are shown in table 1
Example 9
This example was done in accordance with Example 8, but after having flashed
out unreacted monomer after the first gas phase stage the reaction was continued
in the second gas phase stage. The hydrogen amount was 120 mmol, ethyl-
ene/propylene molar ratio 0,65. The reaction was allowed to continue until the
rubber content in the final product was 20 w%. MFR of the final product was 1,5,
the total ethylene content 16,6%, XS 41,5 w% and flexural modulus 271 MPa.
The other details are shown in table 1.
Example 10
This example was done in accordance with Example 9, with the exception that
the reaction was allowed to continue until the rubber content in, the final product
was 34 w%. MFR of the final product was 1,0, ethylene content 22,2 w%, XS
49,6 w% and flexural modulus 197 MPa. The other details are shown in table 1.
Example 11
This example was done in accordance with Example 10, with the exception that
the ethylene/propylene molar ratio in the feed was 0,30 and hydrogen amount 110
mmol. MFR of the final product was 1,3, the total ethylene content 16,0 w%, XS
51,1 w% and flexural modulus 159 MPa.
Example 12
This example was done in accordance with Example 1, with the exception that
the catalyst used in this test can be described as a typical 4th generation Ziegler
Natta catalyst for producing high isotacticity and high stiffness products. The
catalyst was prepared in accordance with W092/19653. The catalyst contained
2,1 w% titanium. The product produced in bulk contained 4,8 w% ethylene and
MFR was 1,8. Other details are shown in table 2.
Example 13
This example was done in accordance with Example 12, but after the bulk stage
the polymerisation was continued in gas phase. The temperature was 80°C, hy-
drogen 60 mmol and ethylene/propylene molar ratio 0,11 in feed. Ethylene con-
tent in the product was 6,4 w% MFR 2,4 and XS 20,6 w%. The split between
bulk and first gas phase was 50/50. The ethylene content in the gas phase mate-
rial was 7,7 w%. Other details are seen in table 2.
Example 14
This example was done in accordance with Example 13, but after the first gas
phase stage the reaction was continued in the second gas phase stage (rubber
stage). The temperature was 70°C, hydrogen 70 mmol and ethylene/propylene
molar ratio in feed 0,57. MFR of the final product was 0,80, the total ethylene
content 16,4 w%, XS 37,5 w% and flexural modulus 350 MPa. Other details are
shown in table 2.
Comparative Example 1
This example was done in accordance with Example 13, except that ethyl-
ene/propylene molar ratio in feed was 0,07. MFR of the product was 2,2, ethyl-
ene content 5,1 w% and XS 9,9 w%. The split between bulk and first gas phase
was 54/46. The ethylene content in the first gas phase material was adjusted to
correspond to the ethylene content of the bulk product (within the limits of the
measurement accuracy), so that there were no difference in the comonomer con-
tents between the bulk product (fraction i) and the product of the first gas phase
reactor (fraction ii) and thus no difference between the ethylene content of the
bulk product and the obtained matrix ("one phase matrix"). Other details are seen
in table 2.
Comparative Example 2
This example was done in accordance with Comparative Example 1, but after the
first gas phase stage the reaction was continued in the second gas phase stage
(rubber stage) as described in example 14. MFR of the product was 0,8, ethylene
content 14,9 w%, XS 31 w% and flexural modulus 480 MPa.
The experiments of tables 1 and 2 below were made in laboratory scale, thus due
to the small-scale measurement accuracy, slight variations in the measured values
may occur between individual examples and when compared to the results ob-
tained from the pilot plant experiments shown in below tables 3 to 5.
The examples show the improved combination of the high Tm and low flexural
modulus achieved with the present composition comprising "the matrix of two
fractions with different comonomer contents". Furthermore, the table 2 shows a
comparison between the products of example 14 of the invention and the Com-
parative example 2 representing the prior art. The product of Comparative exam-
ple 2 corresponds to that of example 14, except that, although the total ethylene
content in the matrix of Comparative example 2 is comparable (within the meas-
urement accuracy) with that of example 14, however there is no difference be-
tween the comonomer content of the bulk product (fraction (i)) and the first gas
phase product (fraction (ii)) in the matrix of Comparative example 2, and thus no
difference between the comonomer content of the bulk product (fraction (i)) and
the obtained final product (matrix (A)) thereof. As a result, the product of exam-
ple 14 has the same melting temperature (about 138 °C), but clearly lower flexu-
lar modulus (350 MPa) over that of Comparative example 2 (480 MPa).
Generally, the melting temperature of the random copolymers, preferably ethyl-
ene-propylene random copolymers, decreases with increasing comonomer, pref-
ereably ethylene, content in case of a matrix of "one phase material". This is also
shown by the continuous curve ("one phase material, general") in figure 1 using
ethylene as the comonomer in the random copolymer. The figure 1 shows the
different behaviour of the "matrix of two fractions with different comonomer
content", wherein the fraction (i) (Bulk material, Ex 1) with lower ethylene con-
tent controls the melting temperature of the obtained "two fraction matrix"
(Bulk/gas phase material, ex 2, 5 and 8). In Examples 2, 5 and 8 a bulk/gas phase
reactor configuration was used.
In the present case, the melting point of the polymer is not controlled by the total
ethylene content in the copolymer, but by the ethylene content of the material
produced in the bulk. The melting point of the bulk/gas phase materials in this
experiment was a few degrees lower than that of the bulk material (the differ-
ences may also due to the measurement accuracy, see above), but, in general, the
melting point does not decrease markedly with increasing comonomer content.
This is because in all three examples the bulk part of the bulk/gas phase material
is the same (Example 1). It is only the comonomer, e.g. ethylene, content in the
gas phase part that increases. Accordingly, the comonomer, e.g. ethylene, content
of fraction (ii) can be increased enabling to increase the total amount of the co-
monomer, which will increase XS and decrease stiffness (as shown in figure 2),
while still keeping melting point on an unchanged high level.
As examples show different catalyst can be used for producing the random co-
polymer of the invention. Furthermore, it was also found, as shown from figure
2 that with the catalyst prepared according to the emulsion system described in
WO03/000754 ("catalyst preaparation method") and used in the examples 1-11
even more decreased stiffness can be obtained for the polymer products com-
pared e.g. to the catalyst described in W092/19653 and used in examples 12 to
14. The stiffness in the examples 3, 4, 6, 7 and 9-11 with 20 wt% rubber is on the
same level as in example 14 with 30 wt% rubber.
Examples 15 to 23
The examples 15 to 23 were prepared in a continuous multistage process in pilot
scale comprising a loop reactor and a fluidised bed gas phase reactor as follows:.
The catalyst used was a known, highly active, stereospecific transesterified
MgCb-supported Ziegler-Natta catalyst prepared according to US 5234879. The
catalyst was contacted with triethylaluminium (TEAL) as a cocatalyst and an ex-
ternal donor (dicyclopentyl dimethoxysilane). The catalysts used in the examples
are further characterized in the tables 3, 4 and 5. The catalyst was prepolymer-
ised in a known manner in the presence of propylene and the cocatalyst in a sepa-
rate prepolymerisation step. Then propylene, ethylene and hydrogen were fed
together with the activated catalyst into the loop reactor which operated as a bulk
reactor at conditions given in tables 3 to 5 (production of fraction (i)). Then the
polymer slurry stream was fed from the loop reactor into the gas phase reactor
and more propylene, ethylene and hydrogen were fed in the gas phase reactor
(production of fraction (ii) in the presence of fraction (i) to obtain the matrix
(A)). The polymerisation conditions therein are given in tables 3 to 5. The rubber
was produced with a C2/C3 ratio 500 mol per kmol and the IV was adjusted with
the hydrogen feed.
The products of examples were subjected to visbreaking after the polymerisation
of the random-heterophasic copolymer to increase the MFR from 1.5 to 8 g/10
min. The visbreaking was effected in a known manner.
Tables 3, 4 and 5 the properties obtained for the polymer products of examples
15 to 23.
As already mentioned the invention enables the increase the comonomer content
in fraction (ii) of the random PP produced e.g. in a first gas phase reactor,
whereby higher ethylene content and higher amount of XS in the final polymer
can be achieved, and thus the stiffness (flexural modulus) be decreased, while
keeping the melting point essentially in the same level determined by the fraction
(i). Furthermore, the stiffness may also be decreased i.a. by means of the amount
and/or comonomer content (and thus XS) of the rubber part (B) (e.g. the product
of the second or further gas phase reactor) in the final random-heterophasic co-
polymer composition. Accordingly, in case of example 15, for instance, the in-
crease in the ethylene content in the fraction (ii) (in product of the first gas phase
reactor) and/or the increase of the amount and/or XS value of the rubber (B) (the
product of the second gas phase reactor) would decrease the flexural modulus
further.
As shown in table 5, visbreaking causes a slight decrease in the flexural modulus
over the non-visbreaking products enabling the further tailoring of the product.
WECLAIM:
1. A heterophasic alpha-olefin random copolymer composition of the invention
comprising:
(a) an alpha-olefin random copolymer component (A) of at least two alpha-
olefin (co)polymer fractions (i) and (ii), and
(b) a rubber component (B),
characterized in that
- at least one of fractions (i) and (ii) is an alpha-olefin random copolymer,
- the comonomer content (wt%) of fraction (i) is different from the comonomer
content (wt%) of fraction (ii), and
- the heterophasic alpha-olefin random copolymer composition has a melting
temperature (Tm) of at least 130°C and a flexural modulus of not higher than 1000 MPa,
wherein the weight ratio between fraction (i) and (ii) of matrix (A) is 30:70 to 70:30,
and
wherein the amount of matrix (A) in the random-heterophasic copolymer is at least
30 wt% and the amount of rubber (B) is not higher than 70 wt%.
2. The composition as claimed in claim 1 comprising:
(a) an alpha-olefin random copolymer component (A) which comprises:
- at least one fraction (i) comprising a homopolymer of an alpha-olefin or a
copolymer of an alpha-olefin with one or more alpha-olefin comonomers, and
- at least one fraction (ii) comprising a copolymer of an alpha-olefin with one or
more alpha-olefin comonomers, and
(b) a rubber component (B) dispersed in the random copolymer component (A),
wherein
- the amount (wt%) of comonomer in fraction (ii) is higher than the amount (wt%) of
comonomer in fraction (i), and wherein
- the heterophasic alpha-olefin random copolymer composition has a melting
temperature (Tm) of at least 130°C and a flexural modulus of not higher than 1000 MPa.
3. The composition as claimed in claim 1 or 2, wherein matrix (A) is a H/R-matrix (A)
wherein fraction (i) is a homopolymer fraction as claimed in claim 2, preferably a
homopolymer fraction of propylene.
4. The composition as claimed in claim 1 or 2, wherein matrix (A) is a R/R-matrix (A)
wherein fraction (i) is a copolymer fraction as claimed in claim 2, preferably a copolymer
fraction of propylene with one or more alpha-olefin comonomers.
5. The composition as claimed in any of the preceding claims, which has a melting
temperature (Tm) of at least 130°C, suitably of at least 131°C, preferably of at least 132°C.
6. The composition as claimed in any of the preceding claims, which has a melting
temperature (Tm) of at least 135°C, preferably of at least 140°C, and not higher than 165°C.
7. The composition as claimed in any of the preceding claims, wherein fraction (i) of
matrix (A) has a melting temperature of at least 130°C, preferably of at least 131°C, e.g. of
at least 133°C.
8. The composition as claimed in any of the preceding claims, which has a flexural
modulus of lower than 1000 MPa, typically between 300 to 990 MPa, preferably between
300 to 900 MPa, suitably between 400 to 800 MPa.
9. The composition of any of the preceding claims, which has a flexural modulus e.g.
in the range of 100 to 600 MPa, suitably of 100 to 500 MPa, preferably of 100 to 450 MPa,
and may even be of 150 to 400 MPa.
10. The composition as claimed in any of preceding claims, which has a flexural
modulus lower than 350 MPa.
11. The composition as claimed in any of the preceding claims, wherein the difference in
the comonomer content between fraction (i) and matrix (A) is at least 0.5 wt%, preferably at
least 1 wt%.
12. The composition as claimed in any of the preceding claims, wherein the difference in
said comonomer content is e.g. up to 15 wt%, suitably up to 10 wt%, such as 8 wt%, for
example up to 6 wt%.
13. The composition as claimed in any of the preceding claims 1, 2, 4-12, wherein the
comonomer content between matrix (A) and the random copolymer fraction (i) is 0.5, e.g. at
least 1 wt%, preferably at least 2 wt% or higher, e.g. up to 6 wt%, such as up to 4 wt%.
14. The composition as claimed in any of the preceding claims 1-3, and 5-12, wherein
the difference in the comonomer content between matrix (A) and the homopolymer fraction
(i) is at least 2 wt%, typically at least 3 wt%, preferably at least 4 wt %, even at least 5 wt%,
the upper limit in said difference being up to 10 wt%, for example up to 8 wt%, such as in
the range of 3 to 6 wt%.
15. The composition as claimed in any of the preceding claims, wherein total amount of
the comonomer in matrix (A), is typically at least 1 wt%, and may be e.g. up to 13 wt%,
suitably between 2 to 12 wt%, e.g. between 3 to 12 wt% or even between 5 to 12 wt%.
16. The composition as claimed in any of the preceding claims, wherein fraction (i) has
a comonomer content from 0 and up to 15 wt%, suitably of up to 10 wt%.
17. The composition as claimed in any of the preceding claims, wherein the amount of
the comonomer in fraction (ii) is between 2 to 20 wt%.
18. The composition as claimed in any of the preceding claims, wherein the comonomer
content of rubber component (B) is in the range of 10 to 60 wt%, more preferably in the
range of 15 to 50 wt%.
19. The composition as claimed in any of the preceding claims, wherein the xylene
solubles (XS, wt%) of matrix (A), which is preferably comprised of fractions (i) and (ii), is
up to 50 wt%, e.g. in a range of 3 to 50 wt%.
20. The composition as claimed in any of the preceding claims, wherein the xylene
solubles in rubber component (B) may be up to 100 wt%, e.g. 10 to 100 wt%, preferably in
a range of 50 to 100 wt%.
21. The composition as claimed in any of the preceding claims, which is a random-
heterophasic propylene copolymer and which comprises:
(a) a propylene random copolymer component (A) comprising at least one
fraction (i), which comprises a propylene homopolymer or a propylene copolymer with one
or more alpha-olefin comonomers, and at least one fraction (ii), which comprises a
propylene copolymer with one or more alpha-olefin comonomers, and
(b) a rubber component (B) of a copolymer of propylene with one or more alpha-
olefin comonomers.
22. The composition as claimed in any of the preceding claims, wherein the comonomer
is at least ethylene, preferably ethylene.
23. A method for controlling the combination of thermal behaviour and stiffness of a
random-heterophasic copolymer component (A), which comprises at least the two alpha-
olefin (co)polymer fractions (i) and (ii), wherein at least one of the fractions (i) and (ii) is an
alpha-olefin copolymer and wherein fractions (i) and (ii) have different amounts (wt%) of
comonomer, by providing the different comonomer content between the two fractions (i)
and (ii), preferably in the presence of rubber component (B).
24. The method as claimed in claim 23 wherein random copolymer component (A) is a
matrix (A) of the heterophasic random alpha-olefin copolymer as defined in any one of the
previous claims 1 to 22, and the optional rubber (B) is as claimed in any one of the previous
claims 1 to 22.
25. A process for producing the random-heterophasic copolymer as claimed in any of
the claims 1 to 22, comprising:
- producing matrix (A) by
(a) (co)polymerising in a slurry reactor an alpha-olefin, preferably propylene, and
optionally one or more comonomers in the presence of a polymerisation catalyst, to produce
fraction (i), transferring the reaction product of step (a) to a subsequent gas phase reactor,
(b) copolymerising in a gas phase reactor an alpha-olefin, preferably propylene, with
one or more comonomers in the presence of the reaction product of step (a) to produce
fraction (ii) for obtaining matrix (A), and then
- producing rubber component (B) by
(c) copolymerising in a subsequent second or further gas phase reactors of an alpha-
olefin, preferably propylene, with one or more alpha-olefin comonomers, preferably with at
least ethylene, in the presence of matrix (A) obtained from step (b),
and recovering the obtained random-heterophasic copolymer.
26. The process as claimed in claim 25, wherein the polymerisation catalyst catalyst
used in the above process is a high activity, stereoselective Ziegler-Natta type
polymerisation catalyst comprising a solid catalyst component of a transition metal
compound of Group 3 to 10 of the Periodic Table (IUPAC, 1989) or of an actinide or
lanthanide, cocatalyst and an external donor.
27. A process as claimed in claim 25 or 26, wherein the polymerisation catalyst catalyst
comprises a compound of a transition metal of Group 3 to 10 of the Periodic Table (IUPAC,
1989), or of an actinide or lanthanide, and is obtainable by method comprising:
(a) forming a liquid/liquid emulsion system, which contains a homogeneous solution
of at least one catalyst component, said solution being dispersed in a solvent immiscible
therewith and forming the dispersed phase of the liquid/liquid emulsion system,
(b) solidifying said dispersed droplets to form solid catalyst particles having a
predetermined size range,
(c) removing the solvent from the reaction mixture in order to obtain said solid
catalyst particles.
28. A random-heterophasic copolymer composition obtainable by the process of any of
claims 25 to 27.
29. An article comprising the composition as claimed in any of preceding claims 1 to 22
or 28.


The invention relates to a heterophasic alpha-olefin random copolymer composition
with a melting temperature (Tm) of at least 130°C and a flexural modulus of not higher than
1000 MPa, whereby the inventive composition comprises an alpha-olefin random
copolymer component (A) of at least two alpha-olefin (co)polymer fractions (i) and (ii)
having a different comonomer content, whereby at least one of the fractions is an alpha-
olefin random copolymer, and a rubber component (B).

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2397-KOLNP-2007-FORM 1.pdf

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Patent Number 250438
Indian Patent Application Number 2397/KOLNP/2007
PG Journal Number 01/2012
Publication Date 06-Jan-2012
Grant Date 03-Jan-2012
Date of Filing 28-Jun-2007
Name of Patentee BOREALIS POLYMERS OY
Applicant Address P.O. BOX 330, FIN-60101 PORVOO, FINLAND
Inventors:
# Inventor's Name Inventor's Address
1 VESTBERG TORWALD VARIKSENMARJANPOLKU 12, 0610 PORVOO FINLAND
2 JAASKELAINEN PIRJO KASKITIE 20, 06150 PORVOO FINLAND
3 MALM BO HARJUVIITA 16 A 27, 02110 ESPOO FINLAND
PCT International Classification Number C08L 23/10
PCT International Application Number PCT/EP2006/000227
PCT International Filing date 2006-01-12
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 05000737.6 2005-01-14 EUROPEAN UNION