1
DESCRIPTION
THERMOPLASTIC POLYMER COMPOSITION, PRODUCTION METHOD THEREOF,
AND SHAPED ARTICLE AND ELECTRIC CABLE OBTAINED THEREFROM
TECHNICAL FIELD
[0001]
The present invention relates to a thermoplastic polymer
composition and a shaped article obtained from the composition.
More particularly, the present invention relates to a
thermoplastic polymer composition which contains an inorganic
filler in a high ratio and is excellent in flexibility, mechanical
strength, elongation at break, heat resistance, scratch
resistance, whitening resistance and flame retardancy, and
further to a shaped article obtained by using the thermoplastic
polymer composition.
BACKGROUND ART
[0002]
Sheath materials and some insulating materials for electric
cables are frequently polyvinyl chloride and crosslinked
polyethylene, and their flexibility, flame retardancy and
insulation property are appreciated. However, there are
difficulties in their disposition or recycling because of the
2
generation of chlorine gases by heating and the lack of
thermoplasticity. For this reason, there has been known a shaped
article comprising a crystalline homopolymer or copolymer of
polyethylene which is non-crosslinked and is recyclable and has
mechanical and electrical properties fit for usual use conditions
as disclosed in Patent Document 1. The shaped article used in
Patent Document 1 is excellent in flexibility, impact resistance
and low-temperature property, but is insufficient in scratch
resistance and tensile strength.
Patent Document 1: Japanese Patent Laid-Open Publication No.
Hll-111061
DISCLOSURE OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
[0003]
An object of the present invention is to provide a
thermoplastic polymer composition which contains an inorganic
filler in a high ratio and is excellent in flexibility, mechanical
strength, elongation at break, heat resistance, scratch
resistance, whitening resistance and flame retardancy. It is
another object of the present invention that flexibility and heat
resistance are ensured without significantly reducing the brittle
temperature and the scratch resistance is improved by increasing
hardness. In other words, an object of the present invention is
3
to provide a method of producing a thermoplastic polymer
composition which is excellent in flexibility, mechanical
strength, elongation at break, heat resistance, whitening
resistance and flame retardancy and is especially excellent in
scratch resistance. In addition, an object of the present
invention is to provide a shaped article comprising the
composition, and an electric cable having an insulation material
and/or sheath comprising the composition.
MEANS TO SOLVE THE PROBLEMS
[0004]
[First Thermoplastic Polymer Composition]
A first thermoplastic polymer composition related to the
present invention comprises the following (A) , (B) , (C) and (D) :
(A) 5 to 64 . 9 % by weight of a propylene-based polymer having
a melting point, as measured by differential scanning calorimetry
(DSC), in the range of 120°C to 170°C;
(B) 0 to 59. 9 % by weight of a propylene-based polymer having
a melting point, as measured by differential scanning calorimetry
(DSC), of less than 120°C or having no observed melting point;
(C) 0.1 to 30 % by weight of a graft-modified propylene-based
polymer obtained by graft modifying a propylene-based polymer
(C-l) having a melting point as measured by differential scanning
calorimetry (DSC) of less than 120°C or having no observed melting
4
point with at least one compound selected from the group consisting
of a vinyl compound containing a polar group and a silane compound;
and
(D) 35 to 75 % by weight of an inorganic filler.
Here, the total amount of (A), (B), (C) and (D) is 100 %
by weight.
[0005]
The inorganic filler (D) is preferably one or more kinds
selected from the group consisting of talc, metal hydroxides,
metal carbonates and metal oxides.
[0006]
The first thermoplastic polymer composition of the present
invention preferably contains 0.1 to 20 parts by weight of an oil
(F) relative to the total 100 parts by weight of the
propylene-based polymer (A), the propylene-based polymer (B) , the
graft-modified propylene-based polymer (C) and the inorganic
filler (D). Further, the thermoplastic polymer composition of
the present invention preferably contains 0.1 to 20 parts by weight
of an ethylene-based polymer (E) relative to the total 100 parts
by weight of the propylene-based polymer (A) , the propylene-based
polymer (B) , the graft-modified propylene-based polymer (C) and
the inorganic filler (D).
[0007]
A method of producing the thermoplastic polymer composition
5
containing the ethylene-based polymer (E) comprises
melt-kneading the graft-modified propylene-based polymer (C)
with the ethylene-based polymer (E) to produce a propylene-based
polymer composition (G), and melt-kneading the propylene-based
polymer composition (G) with components including the inorganic
filler (D), the propylene-based polymer (A) and optionally the
propylene-based polymer (B).
A first shaped article is preferably an insulating material
for an electric cable or an electric cable sheath.
[0008]
A first electric cable of the present invention has an
insulating material comprising the thermoplastic polymer
composition and/or a sheath comprising the thermoplastic polymer
composition. The electric cable is preferably an electric cable
for an automobile or an electric cable for an instrument.
[Second Thermoplastic Polymer Composition]
A second thermoplastic polymer composition related to the
present invention comprises the following (A), (BB) and (D):
(A) 5 to 64 . 9 % by weight of a propylene-based polymer having
a melting point, as measured by differential scanning calorimetry
(DSC), in the range of 120°C to 170°C;
(BB) 0.1 to 60.0 % by weight of a modified propylene-based
polymer which is partly or fully graft-modified with at least one
compound selected from the group consisting of a vinyl compound
6
containing a polar group and a silane compound, and which has a
melting point, as measured by differential scanning calorimetry
(DSC), of less than 120°C or has no observed melting point; and
(D) 35 to 75 % by weight of an inorganic filler.
Here, the total amount of (A), (BB) and (D) is 100 % by weight.
[0009]
The inorganic filler (D) is preferably one or more kinds
selected from the group consisting of talc, metal hydroxides,
metal carbonates and metal oxides.
[0010]
The second thermoplastic polymer composition of the present
invention preferably contains 0.1 to 20 parts by weight of an
ethylene-based polymer (E) relative to the total 100 parts by
weight of the propylene-based polymer (A), the graft-modified
propylene-based polymer (BB) and the inorganic filler (D) .
Further, the second thermoplastic polymer composition of the
present invention preferably contains 0.1 to 20 parts by weight
of an oil (F) relative to the total 100 parts by weight of the
propylene-based polymer (A) , the graft-modified propylene-based
polymer (BB) and the inorganic filler (D).
[0011]
Furthermore, a method of producing the second thermoplastic
polymer composition containing the ethylene-based polymer (E)
comprises melt-kneading the graft-modified propylene-based
7
polymer (BB) with the ethylene-based polymer (E) to produce a
propylene-based polymer composition (GG), and melt-kneading the
propylene-based polymer composition (GG) with components
including the inorganic filler (D) and the propylene-based polymer
(A) .
[0012]
A second shaped article of the present invention comprises
the second thermoplastic polymer composition. The second shaped
article is preferably an insulation material for an electric cable
or an electric cable sheath.
[0013]
A second electric cable of the present invention has an
insulating material comprising The second thermoplastic polymer
composition and/or a sheath comprising the second thermoplastic
polymer composition.
[0014]
The second electric cable is preferably an electric cable
for an automobile or an electric cable for an instrument.
EFFECT OF THE INVENTIONS
[0015]
The first and second thermoplastic polymer compositions of
the present invention contain the inorganic filler in a high ratio
and have good flexibility as well as excellent mechanical strength,
8
elongation at break, whitening resistance and scratch resistance.
[0016]
In the case where the oil is contained in the first and second
thermoplastic polymer compositions of the present invention, the
compositions are excellent especially in scratch resistance and
low temperature brittleness resistance. In addition, in the case
where the ethylene-based polymer is contained in the thermoplastic
polymer compositions of the present invention, the compositions
are excellent especially in scratch resistance. Further,
according to the methods of producing the first and second
thermoplastic polymer compositions of the present invention,
there may be obtained thermoplastic polymer compositions which
are excellent in flexibility, mechanical strength, elongation at
break and flame retardancy as well as in scratch resistance.
[0017]
Since the first and second thermoplastic polymer
compositions of the present invention contain the inorganic filler
in a high ratio, they are suited for producing shaped articles
excellent in flame retardancy, especially electric cables.
BEST MODE FOR CARRYING OUT THE INVENTION
[0018]
Hereinafter, the present invention will be explained in
detail.
9
[First Thermoplastic Polymer Composition]

As the propylene-based polymer (A) used in the present
invention, there may be mentioned a propylene homopolymer or a
copolymer of propylene with at least one olefin selected from
ethylene and α-olefins having 4 to 20 carbon atoms. Here, as
ethylene and the α-olefins having 4 to 20 carbon atoms, there may
be mentioned ethylene, 1-butene, 1-pentene, 1-hexene,
4-methyl-l-pentene, 1-octene, 1-decene, 1-dodecene,
1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene, and
preferable are ethylene and the α-olefins having 4 to 10 carbon
atoms. These α-olefins may form a random copolymer or a block
copolymer with propylene.
[0019]
The constituent units derived from ethylene and the
α-olefins having 4 to 20 carbon atoms may be contained in an amount
of 35 mol% or less, preferably 30 mol% or less in the whole
constituent units of the propylene-based polymer (A).
[0020]
The propylene-based polymer (A) usually has a melt flow rate
(temperature: 230°C, load: 2.16 kg) of 0.01 to 1000 g/10 min,
preferably 0.05 to 100 g/10 min, more preferably 0.1 to 50 g/10
min and further more preferably 0.1 to 10 g/10 min, as measured
according to ASTM D1238.
10
[0021]
The propylene-based polymer (A) used in the present
invention has a melting point as measured by -α- differential
scanning calorimeter (DSC) of 120°C or higher, preferably from
120 to 170°C and more preferably from 125 to 165°C. The
measurement of the melting point (Tm) is carried out as follows.
That is, the melting point is a peak temperature in an endothermic
curve observed when a sample in an aluminum pan is heated to 200°C
at an elevation rate of 100°C/min and maintained at 200°C for 5
minutes and then cooled to -150°C at a cooling rate of 10°C/min
and subsequently heated again to 200°C at an elevation rate of
10°C/min.
[0022]
The propylene-based polymer (A) may have an isotactic
structure or a syndiotactic structure, but preferably has an
isotactic structure in terms of heat resistance and the like.
[0023]
Further, a plurality of propylene-based polymers (A) may
be used simultaneously if needed. For example, two or more
components which are different in melting point and rigidity may
be used.
[0024]
Depending on desired physical properties, the
propylene-based polymer (A) may be selected from the group
11
consisting of a homopolypropylene excellent in heat resistance
(in which a comonomer other than propylene typically accounts for
3 mol% or less) , a block polypropylene excellent in balance between
heat resistance and impact resistance (which typically has 3 to
30 % by weight of a n-decane-soluble rubber component) , and a
random polypropylene excellent in balance between flexibility and
transparency (which typically has a melting peak of 120°C or higher
and preferably in the range of 125°C to 150°C, as measured by
The propylene-based polymer (B) optionally used in the
present invention is a copolymer of propylene with at least one
olefin selected from ethylene and α-olefins having 4 to 20 carbon
atoms. The polymer typically contains 40 to 99 mol%, preferably
12
40 to 92 mol% and more preferably 50 to 90 mol% of constituent
units derived from propylene, and 1 to 60 mol%, preferably 8 to
60 mol% and more preferably 10 to 50 mol% of constituent units
derived from ethylene and the α-olef ins having 4 to 20 carbon atoms
(here, the total of propylene, ethylene and the α-olefins having
4 to 20 carbon atoms is 100 mol%).
[0026]
The propylene-based polymer (B) used in the present
invention is preferably a copolymer of propylene with at least
one olefin selected from ethylene and α-olefins having 4 to 20
carbon atoms. As ethylene and the α-olefins having 4 to 20 carbon
atoms, there may be mentioned specifically ethylene, 1-butene,
1-pentene, 1-hexene, 3-methyl-l-butene, 3-methyl-l-pentene,
3-ethyl-l-pentene, 4-methyl-l-pentene, 4-methyl-l-hexene,
4,4-dimethyl-l-pentene, 4-ethyl-l-hexene, 1-octene,
3-ethyl-l-hexene, 1-octene, and 1-decene. These may be used
alone or in combination of two or more kinds . Of these, especially
preferably used is at least one of ethylene, 1-butene, 1-hexene
and 1-octene.
[0027]
The propylene-based polymer (B) used in the present
invention usually has a melt flow rate (temperature: 230°C and
load: 2.16 kg) of 0.1 to 50 (g/10 min) . In addition, the
propylene-based polymer (B) has a melting point as measured by
13
differential scanning calorimetry (DSC) of less than 120°C or has
no observed melting point, and preferably has a melting point of
100°C or lower or has no observed melting point. Here, that a
melting point is not observed means that a crystal fusion peak
with a heat of crystal fusion of 1 J/g or higher is not observed
in the range of -150 to 200°C. The measurement conditions are
described in Examples.
[0028]
A method of producing the propylene-based polymer (B) is
not particularly limited. For example, the propylene-based
polymer (B) may be produced by a method described in WO 04/87775.
[0029]
As the specific examples of the propylene-based polymer (B)
having the characteristics as mentioned above, there may be
mentioned a random copolymer (B-1) of propylene and the α-olefin
having 4 to 20 carbon atoms and a random copolymer (B-2) of
propylene, ethylene and the α-olefin having 4 to 20 carbon atoms.
[0030]
By using the random copolymer (B-1) of propylene and the
α-olefin having 4 to 20 carbon atoms, the obtainable thermoplastic
polymer composition shows excellent mechanical strength,
elongation at break, scratch resistance and whitening resistance.
[0031]
By using the random copolymer (B-2) of propylene, ethylene
14
and the α-olefin having 4 to 20 carbon atoms, the obtainable
thermoplastic polymer composition shows excellent flexibility,
scratch resistance and whitening resistance.
[0032]
Hereinafter, there will be explained the random copolymer
(B-l) of propylene and the α-olefin having 4 to 20 carbon atoms,
and the random copolymer (B-2) of propylene, ethylene and the
α-olefin having 4 to 20 carbon atoms.
[Random copolymer (B-l) of Propylene and α-olefin having
4 to 20 Carbon Atoms]
The random copolymer (B-l) of propylene and the α-olefin
having 4 to 20 carbon atoms preferably used in the present
invention contains constituent units derived from propylene,
constituent units derived from ethylene, and constituent units
derived from the α-olefin having 4 to 20 carbon atoms, and
satisfies the following (a) and (b).
(a) The molecular weight distribution (Mw/Mn) as measured
by gel permeation chromatography (GPC) is in the range of 1 to
3.
(b) The melting point (Tm) (°C) and the content M (mol%) of
constituent units derived from the comonomer as determined by
l3C-NMR spectrum satisfy the following relation (1) . The melting
point Tm is less than 120°C and preferably less than 100°C. The
value M is not particularly limited but, for example, may be from
15
5 to 45.
[0033]
14 6exp(-0.022M) ≥Tm≥l25exp(-0.032M) (1)
The melting point (Tm) of the random copolymer (B-l) of
propylene with the α-olef in having 4 to 20 carbon atoms is measured
by DSC as follows. The measurement is carried out by filling an
aluminum pan with a sample, (i) heating the sample to 200°C at
an elevation rate of 100°C/min and maintaining the sample at 200°C
for 5 minutes, (ii) cooling the sample to -150°C at a cooling rate
of 10°C/min and subsequently (iii) heating the sample to 200°C
at an elevation rate of 10°C/min. The temperature of an
endothermic peak observed at the stage (iii) is the melting point
(Tm) . The melting point (Tm) is typically less than 120°C,
preferably 100°C or lower, more preferably in the range of 40 to
95°C and further more preferably in the range of 50 to 90°C. If
the melting point (Tm) is within this range, the obtainable shaped
article shows excellent balance between flexibility and strength,
and also shows reduced surface stickiness to permit easy
processing.
[0034]
The random copolymer (B-l) of propylene with the α-olefin
having 4 to 20 carbon atoms desirably satisfies:
(c) the degree of crystallinity measured by X-ray
diffraction is preferably 40 % or less and more preferably 35 %
16
or less.
[0035] #
In the random copolymer (B-l) of propylene with the α-olefin
having 4 to 20 carbon atoms, the content of constituent units
derived from the α-olefin having 4 to 20 carbon atoms is preferably
5 to 50 mol% and more preferably 10 to 35 mol%. As the α-olefin
having 4 to 20 carbon atoms, 1-butene is preferably used.
[0036]
Such random copolymer (B-l) of propylene with the α-olefin
having 4 to 20 carbon atoms may be obtained by a method described
in WO 04/87775.
[Random copolymer (B-2) of Propylene, Ethylene and α-olefin
having 4 to 20 Carbon Atoms]
The random copolymer (B-2) of propylene, ethylene and the
α-olefin having 4 to 20 carbon atoms preferably used in the present
invention contains constituent units derived from propylene,
constituent units derived from ethylene and constituent units
derived from the α-olefin having 4 to 20 carbon atoms, and
satisfies the following (m) and (n).
(m) The molecular weight distribution (Mw/Mn) as measured
by gel permeation chromatography (GPC) is in the range of 1 to
3.
(n) The random copolymer (B-2) contains 40 to 85 mol% of
constituent units derived from propylene, 5 to 30 mol% of
17
constituent units derived from ethylene and 5 to 30 mol% of
constituent units derived from the α-olefin having 4 to 20 carbon
atoms (here, the total of constituent units derived from propylene,
constituent units derived from ethylene and constituent units
derived from the α-olefin having 4 to 20 carbon atoms is 100 mol%.
Further, the total of constituent units derived from ethylene and
constituent units derived from the α-olefin having 4 to 20 carbon
atoms is preferably 60 to 15 mol%).
[0037]
Further, the random copolymer (B-2) of propylene, ethylene
and the α-olefin having 4 to 20 carbon atoms preferably satisfies
ax. least one, more preferably both of the following (o) and (p) .
(o) The Shore A hardness is 30 to 80 and preferably 35 to
60.
(p) The degree of crystallinity measured by X-ray
diffraction is 20 % or less and preferably 10 % or less.
[0038]
In addition, the melting point (Tm) of the random copolymer
(B-2) of propylene, ethylene and the α-olefin having 4 to 20 carbon
atoms measured by DSC is preferably 50°C or lower or is preferably
not observed. The measurement of the melting point may be carried
out by the same method as that of the copolymer (B-i).
[0039]
As regards the amounts of the propylene component and other
18
comonomer components, more particularly, the random copolymer
(B-2) preferably contains 60 to 82 mol% and more preferably 61
to 75 mol% of constituent units derived from propylene; 8.0 to
15 mol% and more preferably 10 to 14 mol% of constituent units
derived from ethylene; and 10 to 25 mol% and more preferably 15
to 25 mol% of constituent units derived from the α-olefin having
4 to 20 carbon atoms. As the α-olefin having 4 to 20 carbon atoms,
1-butene is especially preferably used.
[0040]
Such random copolymer (B-2) of propylene, ethylene and the
α-olefin having 4 to 20 carbon atoms may be obtained, for example,
by a method described in WO 04/87775.
[0041]
By using the random copolymer (B-2) of propylene, ethylene
and the α-olefin having 4 to 20 carbon atoms in the present
invention, the obtainable shaped article has improved flexibility
and excellent low temperature brittleness resistance. The shaped
article, for example electric cable, has an advantage that the
coating of the electric cable is unlikely to be broken even when
exposed to a low temperature.

As the polymer used as a raw material of the graft-modified
propylene-based polymer (C), a propylene-based polymer (C-I)
having a melting point as measured by differential scanning
19
calorimetry (DSC) of less than 120°C or having no observed melting
point is preferable in terms of improvement in tensile elongation
at break and abrasion resistance.
[0042]
The propylene-based polymer (C-l) is a copolymer of
propylene with at least one olefin selected from ethylene and
α-olefins having 4 to 20 carbon atoms. The polymer usually
contains 40 to 99 mol%, preferably 40 to 92 mol% and more preferably
50 to 90 mol% of constituent units derived from propylene; and
1 to 60 mol%, preferably 8 to 60 mol% and more preferably 10 to
50 mol% of constituent units derived from ethylene and the
α-olefins having 4 to 20 carbon atoms used as comonomers (here,
the total of propylene, ethylene and the α-olefins having 4 to
20 carbon atoms is 100 mol%.).
[0043]
The propylene-based polymer (C-l) used in the present
invention is preferably a copolymer of propylene with at least
one olefin selected from ethylene and α-olefins having 4 to 20
carbon atoms. As ethylene and the α-olefins having 4 to 20 carbon
atoms, ethylene and the α-olefins described in the propylene-based
polymer (B) may be used singly or in combination of two or more
kinds. Of these, especially preferably used is at least one of
ethylene, 1-butene, 1-hexene and i-octene.
[0044]
20
The propylene-based polymer (C-l) used in the present
invention typically has a melt flow rate (temperature: 230°C,
load: 2.16 kg) of 0.1 to 50 (g/10 min) . In addition, the
propylene-based polymer (C-l) has a melting point of less than
120°C as measured by differential scanning calorimetry (DSC) or
has no observed melting point, and preferably has a melting point
of 100°C or lower or has no observed melting point. Here, that
a melting point is not observed means that a crystal fusion peak
with a heat of crystal fusion of 1 J/g or higher is not observed
in the range of -150 to 200°C. The measurement conditions are
as described in Examples.
[0045]
A method of producing the propylene-based polymer (C-l) is
not particularly limited. For example, the propylene-based
polymer (C-l) may be produced by a method described in WO
04/087775.
[0046]
As specific examples of the propylene-based polymer (C-l)
having the characteristics as mentioned above, there may be
mentioned a random copolymer (C-la) of propylene with the α-olef in
having 4 to 20 carbon atoms, and a random copolymer (C-lb) of
propylene, ethylene and the α-olef in having 4 to 20 carbon atoms.
[Random copolymer (C-la) of Propylene with α-olefin having
4 to 20 Carbon Atoms]
21
The random copolymer (C-la) of propylene with the α-olef in
having 4 to 20 carbon atoms preferably used in the present
invention contains constituent units derived from propylene and
constituent units derived from the α-olef in having 4 to 20 carbon
atoms, and satisfies the following (al) and (bl).
(al) The molecular weight distribution (Mw/Mn) as measured
by gel permeation chromatography (GPC) is in the range of 1 to
3.
(bl) The melting point (Tm)(°C) and the content M (mol%)
of constituent units derived from the comonomer as determined by
13C-NMR spectrum satisfy the following relation (1) . The melting
point Tm is less than 120°C and preferably less than 100°C.
[0047]
146exp(-0.022M)>Tm≥l25exp(-0.032M) (1)
The random copolymer (C-la) of propylene with the α-olefin
having 4 to 20 carbon atoms usually has a melting point (Tm) of
less than 120°C, preferably 100°C or lower, more preferably in
the range of 40 to 95°C and further more preferably in the range
of 50 to 90°C. If the melting point (Tm) is within this range,
the obtainable shaped article shows particularly excellent
balance between flexibility and strength, and also shows reduced
surface stickiness to permit easy processing. As the measurement
method of the melting point (Tm) of the random copolymer (C-la)
of propylene with the α-olefin having 4 to 20 carbon atoms, there
22
may be mentioned the same method as described in the random
copolymer (B-l) of propylene with the α-olefin having 4 to 20
carbon atoms.
[0048]
The random copolymer (C-la) of propylene with the α-olefin
having 4 to 20 carbon atoms preferably satisfies the following
(cl):
(cl) the degree of crystallinity measured by X-ray
diffraction is preferably 40 % or less and more preferably 35 %
or less.
[0049]
In the random copolymer (C-la) of propylene and the α-olefin
having 4 to 20 carbon atoms, the content of constituent units
derived from the α-olefin having 4 to 20 carbon atoms is preferably
5 to 50 mol% and more preferably 10 to 35 mol%. As the α-olefin
having 4 to 20 carbon atoms, 1-butene is preferably used.
[0050]
Such random copolymer (C-la) of propylene with the α-olefin
having 4 to 20 carbon atoms may be obtained, for example, by a
method described in WO 04/87775.
[0051]
By use of a modified product of the random copolymer (C-la)
of propylene with the α-olefin having 4 to 20 carbon atoms, the
obtainable thermoplastic polymer composition shows excellent
23
mechanical strength, elongation at break, scratch resistance,
whitening resistance and low temperature brittleness resistance.
In addition, such thermoplastic polymer composition can give a
shaped article, for example an electric cable, which has an
advantage that the coating of the electric cable is unlikely to
be broken even when exposed to a low temperature.
[Random copolymer (C-lb) of Propylene, Ethylene and
α-olefin having 4 to 20 Carbon Atoms]
The random copolymer (C-lb) of propylene, ethylene and the
α-olefin having 4 to 20 carbon atoms preferably used in the present
invention contains constituent units derived from propylene,
constituent units derived from ethylene and constituent units
derived from the α-olefin having 4 to 20 carbon atoms, and
satisfies the following (ml) and (nl).
(ml) The molecular weight distribution (Mw/Mn) as measured
by gel permeation chromatography (GPC) is in the range of 1 to
3.
(nl) The random copolymer (C-lb) contains 40 to 85 mol% of
constituent units derived from propylene, 5 to 30 mol% of
constituent units derived from ethylene and 5 to 30 mol% of
constituent units derived from the α-olefin having 4 to 20 carbon
atoms (here, the total of constituent units derived from propylene,
constituent units derived from ethylene and constituent units
derived from the α-olefin having 4 to 20 carbon atoms is 100 mol%.
24
Further, the total of constituent units derived from ethylene and
constituent units derived from the α-olefin having 4 to 20 carbon
atoms is preferably 60 to 15 mol%).
[0052]
Further, the random copolymer (C-lb) of propylene, ethylene
and the α-olefin having 4 to 20 carbon atoms preferably satisfies
at least one, more preferably both of the following (ol) and (pi) .
(ol) The Shore A hardness is 30 to 80 and preferably 35 to
60.
(pi) The degree of crystallinity measured by X-ray
diffraction is 20 % or less and preferably 10 % or less.
[0053]
In addition, the melting point (Tm) of the random copolymer
(C-lb) of propylene, ethylene and the α-olefin having 4 to 20
carbon atoms measured by DSC is preferably 50°C or less or is
preferably not observed. The measurement of the melting point
may be carried out by the same method as that of the copolymer
(B-l).
[0054]
As regards the amounts of the propylene component and other
comonomer components, more particularly, the random copolymer
(C-lb) preferably contains 60 to 82 mol% and more preferably 61
to 75 mol% of constituent units derived from propylene; 8.0 to
15 mol% and more preferably 10 to 14 mol% of constituent units
25
derived from ethylene; and 10 to 25 mol% and more preferably 15
to 25 mol% of constituent units derived from the α-olefin having
4 to 20 carbon atoms. As the α-olefin having 4 to 20 carbon atoms,
1-butene is especially preferably used.
[0055]
Such random copolymer (C-lb) of propylene, ethylene and the
α-olefin having 4 to 20 carbon atoms may be obtained, for example,
by a method described in WO 04/87775.
[0056]
Further, by use of a modified product of the random copolymer
(C-lb) of propylene, ethylene and the α-olefin having 4 to 20
carbon atoms, the obtainable thermoplastic polymer composition
is excellent in flexibility, scratch resistance, whitening
resistance and low temperature brittleness resistance. In
addition, the thermoplastic polymer composition can give a shaped
article, for example electric cable, which has an advantage that
the coating of the electric cable is unlikely to be broken even
when exposed to a low temperature.
[0057]
Meanwhile, when the propylene-based polymer (B) is used,
the propylene-based polymer (B) and the propylene-based polymer
(C-l) which is a raw material before modification may be the same
or different from each other.
[0058]
26
The graft-modified propylene-based polymer (C) used in the
present invention may be obtained by graft modifying the
propylene-based polymer (C-1) having a melting point as measured
by differential scanning calorimetry (DSC) of less than 120°C or
having no observed melting point, with at least one compound
selected from the group consisting of a vinyl compound containing
a polar group and a silane compound. Examples of the vinyl
compounds include vinyl compounds having an oxygen-containing
group such as acid, acid anhydride, ester, alcohol, epoxy and
ether; and vinyl compounds having a nitrogen-containing group such
as isocyanate and amide. Examples of the silane compounds include
vinylsilane, aminosilane and
Y-methacryloxypropyltrimethoxysilane. Of these, preferable are
the vinyl compounds having an oxygen-containing group,
specifically unsaturated epoxy monomers, unsaturated carboxylic
acids and derivatives thereof.
[0059]
The unsaturated epoxy monomers include an unsaturated
glycidyl ether and an unsaturated glycidyl ester (for example,
glycidyl methacrylate).
[0060]
The unsaturated carboxylic acids include acrylic acid,
maleic acid, f umaric acid, tetrahydrophthalic acid, itaconic acid,
citraconic acid, crotonic acid, isocrotonic acid, and nadic acid™
27
(endocis-bicyclo[2.2.1]hepto-5-ene-2,3-dicarboxylic acid).
[0061]
Further, as the derivatives of the unsaturated carboxylic
acids, there may be mentioned acid halide compounds, amide
compounds, imide compounds, acid anhydrides and ester compounds
of the unsaturated carboxylic acids, and specifically there may
be mentioned malenyl chloride, maleimide, anhydrous maleic acid,
anhydrous citraconic acid, monomethyl maleate, dimethyl maleate,
and glycidyl maleate.
[0062]
Of these, preferable are the unsaturated dicarboxylic acids
and acid anhydrides thereof, and especially preferably used are
maleic acid, nadic acid™ and acid anhydrides thereof.
[0063]
The graft position of the unsaturated carboxylic acid or
its derivative grafted on the unmodified propylene-based
copolymer is not particularly limited. The unsaturated
carboxylic acid or its derivative may be bonded to an arbitrary
carbon atom of the ethylene-based polymer.
[0064]
The graft-modified propylene-based polymer (C) as mentioned
above may be prepared by various conventionally known methods,
for example, by using the following methods.
(1) The unmodified polymer is melted.by an extruder or the
28
like. The unsaturated carboxylic acid or the like is added and
grafted to the polymer.
(2) The unmodified polymer is dissolved in a solvent. The
unsaturated carboxylic acid or the like is added and grafted to
the polymer.
[0065]
In either case, in order to effectively graft copolymerize
the graft monomer such as the unsaturated carboxylic acid, the
graft reaction is preferably carried out in the presence of a
radical initiator. As the radical initiator, for example,
preferably used are an organic peroxide, an azo compound and the
like.
[0066]
As the organic peroxide, there may be mentioned benzoyl
peroxide, dichlorobenzoyl peroxide and dicumyl peroxide. As the
azo compound, there may be mentioned azobisisobutyl nitrile and
dimethyl azoisobutyrate.
[0067]
As such radical initiator, specifically, preferably used
is a dialkyl peroxide such as dicumyl peroxide, di-tert-butyl
peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexyne,
2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and
1, 4-bis(tert-butylperoxyisopropyl)benzene.
[0068]
29
These radical initiators are typically used in an amount
of 0.001 to 1 parts by weight, preferably 0.003 to 0.5 parts by
weight and more preferably 0.05 to 0.3 parts by weight, relative
to 100 parts by weight of the unmodified polymer.
[0069]
The reaction temperature of the graft reaction using or
without using the radical initiator as mentioned above is
typically in the range of 60 to 350°C and preferably 150 to 300°C.
[0070]
The graft amount of the vinyl compound having a polar group
in the graft-modified propylene-based polymer (C) thus obtained
is not particularly limited, but is typically 0.01 to 10 % by weight
and preferably 0.05 to 5 % by weight, provided that the mass of
the graft-modified polymer is 100 % by weight. In the present
invention, by use of the graft-modified polymer (C) as mentioned
above, the obtainable shaped article is especially excellent in
the balance between tensile strength and scratch resistance.

The inorganic filler (D) used in the present invention is
not particularly limited. For example, metal compounds and
inorganic compounds such as glass, ceramic, talc and mica may be
widely used. Among these, preferably used are talc, metal
hydroxides, metal carbonates (carbonates) and metal oxides. In
the present invention, the inorganic fillers (D) may be used alone
30
or in combination of two or more kinds. As the metal hydroxides
used in the present invention, there may be mentioned aluminum
hydroxide, magnesium hydroxide, calcium hydroxide, barium
hydroxide, manganese hydroxide, zinc hydroxide, hydrotalcite,
and mixtures thereof. In particular, magnesium hydroxide alone
or a mixture containing magnesium hydroxide is preferable.
[0071]
The average particle size of the inorganic filler (D) is
not particularly limited but is typically 0.1 to 20 um and
preferably 0.5 to 15 um. Here, the average particle size is a
value determined by a laser method.
[0072]
In addition, the inorganic filler (D) used in the present
invention may be surface treated with a fatty acid such as stearic
acid or oleic acid, an organosilane or the like. The inorganic
filler may be an aggregate of fine particles having the above
average particle size.

The ethylene-based polymer is an ethylene-based elastomer
having at least 61 mol% of constituent units derived from ethylene
relative to the total constituent units. As the ethylene-based
polymer, especially preferable are an ethylene homopolymer and
ethylene/α-olefin copolymers comprising constituent units
derived from ethylene and constituent units derived from an
31
α-olefin. Among the ethylene/α-olefin copolymers, preferable is
a copolymer (E-1) of ethylene with an α-olefin having 3 to 10 carbon
atoms. As the α-olefins having 3 to 10 carbon atoms, there may
be specifically mentioned propylene, 1-butene, 1-pentene,
1-hexene, 3-methyl-l-butene, 3-methyl-l-pentene,
3-ethyl-l-pentene, 4-methyl-1-pentene, 4-methyl-l-hexene,
4,4-dimethyl-l-pentene, 4-ethyl-l-hexene, 1-octene,
3-ethyl-l-hexene, 1-octene, and 1-decene. These may be used
alone or in combination of two or more kinds. Among these, it
is especially preferable to use at least one of propylene, 1-butene,
1-hexene and 1-octene.
[0073]
As regards the content of each constituent unit in the
ethylene-based copolymer, the content of constituent units
derived from ethylene is preferably 7 5 to 95 mol% and the content
of constituent units derived from at least one olefin selected
from the α-olefins having 3 to 10 carbon atoms is preferably 5
to 25 mol%.
[0074]
The ethylene/α-olefin copolymer has:
(i) a density of 0.855 to 0.910 g/cm3 and preferably 0.857
to 0.8 90 g/cm3;
(ii) a melt flow rate (temperature: 190°C, load: 2.16 kg)
of 0.1 to 100 g/10 min and preferably 0.1 to 20 g/10 min; and
32
(iii) an index of the molecular weight distribution (Mw/Mn)
as evaluated by GPC of 1.5 to 3.5, preferably 1.5 to 3.0, and more
preferably 1.8 to 2.5. The ethylene/α-olefin copolymer may be
a graft-modified ethylene-based polymer (E-l) grafted with a vinyl
compound having a polar group.
[0075]
In that case, the vinyl compound having a polar group is
as described with respect to the graft-modified propylene-based
polymer (C). Further, the graft amount of the vinyl compound
having a polar group in the graft-modified ethylene-based polymer
(E-l) is not particularly limited but is typically 0.01 to 10 %
by weight and preferably 0.05 to 5 % by weight provided that the
mass of the graft-modified polymer is 100 % by weight.

Examples of the oils (F) used in the present invention
include various oils such as paraffin oil, naphthenic oil,
aromatic oil and silicon oil. Among these, preferably used are
paraffin oil and naphthenic oil.
[0076]
The oil (F) is not particularly limited but typically has
a kinematic viscosity at 40°C of 20 to 800 est (centistokes) and
preferably 40 to 600 est. In addition, the oil (F) typically has
a fluidity of 0 to -40°C and preferably 0 to -30°C, and has a flash
point (COC method) of 200 to 400°C and preferably 250 to 350°C.
33
By use of the oil (F), the obtainable thermoplastic polymer
composition of the present invention shows excellent low
temperature characteristics such as low temperature brittleness
resistance, and scratch resistance.
[0077]
The naphthenic process oil suitably used in the present
invention is a petroleum-based softening agent which is commonly
used in rubber processing in order to obtain softening effect,
component-dispersing effect, lubricating effect and improved low
temperature characteristics, and contains 30 to 45 % by weight
of a naphthenic hydrocarbon. If such process oil is added, the
melt fluidity in shaping the resin composition and the flexibility
and low temperature characteristics of the shaped article may be
further improved, and the surface stickiness of the shaped article
due to bleeding may be reduced. In the present invention, among
naphthenic process oils, those having an aromatic hydrocarbon
content of not more than 10 % by weight are suitably used. If
such oils are used, bleeding on the surface of the shaped article
is unlikely to occur, although the reason is not clarified.

The thermoplastic polymer composition of the present
invention contains 5.0 to 64.9 % by weight of the propylene-based
polymer (A) , 0 to 59.9 % by weight of the propylene-based polymer
(B) , 0.1 to 30 % by weight of the graft-modified propylene-based
34
polymer (C) , and 35 to 75 % by weight of the inorganic filler (D)
(here, the total amount of (A) , (B) , (C) and (D) is 100 % by weight) .
[0078]
When the propylene-based polymer (B) is used, the
thermoplastic polymer composition preferably contains 5.0 to
64. 9 % by weight of the propylene-based polymer (A) , 1.0 to 59. 9 %
by weight of the propylene-based polymer (B) , 0.1 to 29 % by weight
of the graft-modified propylene-based polymer (C) , and 34 to 75 %
by weight of the inorganic filler (D) (here, the total amount of
(A), (B), (C) and (D) is 100 % by weight).
[0079]
Further, the thermoplastic polymer composition may contain
the ethylene-based polymer (E) . For example, the copolymer (E-1)
of ethylene with the α-olefin having 3 to 10 carbon atoms or the
graft-modified ethylene-based polymer (E-2) may be used in an
amount of 0.1 to 20 parts by weight relative to 100 parts by weight
of the total amount of the components (A) , (B) , (C) and (D) . If
the amount of the ethylene-based polymer (E-1) is within this range,
low temperature characteristics are significantly improved.
[0080]
The oil (F) may be used in the present invention in an amount
of 0.1 to 20 parts by weight relative to 100 parts by weight of
the total amount of the components (A) , (B) , (C) and (D) . If the
amount of the oil (F) is within this range, low temperature
35
characteristics are significantly improved and the oil is unlikely
to bleed out on the surface of the shaped article.
[0081]
The thermoplastic polymer composition of the present
invention may contain additives as required while still achieving
the objects of the invention. Examples of the additives include
synthetic resins, rubbers, antioxidants, heat stabilizers,
weather stabilizers, slip agents, antiblocking agents,
nucleating agents, pigments, hydrochloric acid absorbers and
copper inhibitors. The amounts of such synthetic resins, rubbers
and additives are not particularly limited so long as the objects
of the present invention are not impaired. In a preferred
embodiment, the components (A), (B), (C) and (D) are contained
so that the total of them is 60 to 100 % by weight of the
thermoplastic polymer composition. The balance is accounted for
by the above-mentioned components such as synthetic resins,
rubbers, additives, ethylene-based polymer (E), and oil (F).
[Second Thermoplastic Polymer Composition]
The second thermoplastic polymer composition of the present
invention includes the following (A), (BB) and (D):
(A) 5 to 64 . 9 % by weight of a propylene-based polymer having
a melting point, as measured by differential scanning calorimetry
(DSC), in the range of 120°C to 170°C;
(BB) 0.1 to 60.0 % by weight of a modified propylene-based
36
polymer which is partly or fully graft-modified with at least one
compound selected from the group consisting of a vinyl compound
containing a polar group and a silane compound, and which has a
melting point, as measured by differential scanning calorimetry
(DSC), of less than 120°C or has no observed melting point; and
(D) 35 to 75 % by weight of an inorganic filler.
Here, the total amount of (A), (BB) and (D) is 100 % by weight.
[0082]
Here, the component (A) and preferred embodiments thereof
are as described with respect to the first thermoplastic polymer
composition.

The graft-modified propylene-based polymer (BB) used in the
present invention is preferably a partly or fully graft-modified
copolymer of propylene with at least one olefin selected from
ethylene and α-olefins having 4 to 20 carbon atoms. As the at
least one olefin selected from ethylene and α-olefins having 4
to 20 carbon atoms, there may be specifically used ethylene and
the α-olefins described in the propylene-based polymer (B) , and
they may be used alone or in combination of two or more kinds.
Of these, especially preferably used is at least one of ethylene,
1-butene, 1-hexene and 1-octene.
[0083]
The copolymer of propylene with ethylene and the α-olef in (s)
37
having 4 to 20 carbon atoms typically contains 40 to 99 mol%,
preferably 40 to 92 mol% and more preferably 50 to 90 mcl% of
constituent units derived from propylene, and 1 to 60 mol%,
preferably 8 to 60 mol% and more preferably 10 to 50 mol% of
constituent units derived from ethylene and the α-olefin (s) having
4 to 20 carbon atoms used as comonomer(s) (here, the total of
propylene, ethylene and the α-olefin (s) having 4 to 20 carbon atoms
is 100 mol%).
[0084]
The graft-modified propylene-based polymer (BB) has a
melting point as measured by differential scanning calorimetry
(DSC) of less than 120°C or has no observed melting point, and
preferably has a melting point of 100°C or lower or has no observed
melting point. Here, that a melting point is not observed means
that a crystal fusion peak with a heat of crystal fusion of 1 J/g
or higher is not observed in the range of -150 to 200°C. The
measurement conditions are as described in Examples.
[0085]
The graft-modified propylene-based polymer (BB) usually has
a melt flow rate of 0.01 to 100 g/10 min, preferably 0.1 to 50
g/10 min, more preferably 1 to 40 g/10 min, and especially
preferably 5 to 30 g/10 min, as measured at 190°C under a load
of 2.16 kg.
[0086]
38
Such graft-modified propylene-based polymer (BB) may be
produced, for example, by graft-modifying the propylene-based
polymer (C-l) described in the section of the first thermoplastic
polymer composition with at least one compound selected from the
group consisting of a vinyl compound containing a polar group and
a silane compound. Alternatively, the graft-modified
propylene-based polymer (BB) may be produced by blending a
graft-modified product of the propylene-based polymer (C-l) with
the propylene-based polymer (B) described in the section of the
first thermoplastic polymer composition. In the production of
the graft-modified propylene-based polymer (BB), the
propylene-based polymer (C-l) described in the section of the
first thermoplastic polymer composition, and the optional
propylene-based polymer (B) each preferably have a triad tacticity
(mm percentage) of 85 % or higher, more preferably 85 to 97.5 %,
further more preferably 87 to 97 % and especially preferably 90
to 97 %, as measured according to 13C-NMR method. If the triad
tacticity (mm percentage) is within this range, the polymer (BB)
is excellent especially in balance between flexibility and
mechanical strength. The mm percentage may be measured by the
method described in page 21, line 7, to page 26, line 6, in WO
04/8/1775
[0087]
Preferably, the graft-modified propylene-based polymer
39
(BB) is a graft-modified product (BB-la) of a random copolymer
of propylene with the α-olefin having 4 to 20 carbon at cms i n which
the content of constituent units derived from the α-olefin having
4 to 20 carbon atoms is in the range of 5 to 50 mol% (relative
to 100 mol% of the total of constituent units derived from
propylene and constituent units derived from the α-olefin having
4 to 20 carbon atoms).
[0088]
In the graft-modified random copolymer (BB-la) of propylene
with the α-olefin having 4 to 20 carbon atoms, the degree of
crystallinity measured by X-ray diffraction is preferably 40 %
or less and more preferably 35 % or less.
[0089]
In the graft-modified random copolymer (BB-la) of propylene
and the α-olefin having 4 to 20 carbon atoms, the content of
constituent units derived from the α-olefin having 4 to 20 carbon
atoms in the random copolymer of propylene with the α-olefin having
4 to 20 carbon atoms is preferably 5 to 50 mol% and more preferably
10 to 35 mol% (the total of constituent units derived from
propylene and constituent units derived from the α-olefin having
4 to 20 carbon atoms is 100 mol%). Especially, 1-butene is
preferably used as the α-olefin having 4 to 20 carbon atoms.
[0090]
Such graft-modified random copolymer (BB-la) of propylene
40
with the α-olefin having 4 to 20 carbon atoms may be produced,
for example, by graft-modifying the random copolymer (C-la) of
propylene and the α-olefin having 4 to 20 carbon atoms described
in the section of the first thermoplastic polymer composition with
at least one compound selected from the group consisting of a vinyl
compound containing a polar group and a silane compound.
Alternatively, the graft-modified random copolymer (BB-la) may
be produced by blending a graft-modified product of the random
copolymer (C-la) of propylene and the α-olefin having 4 to 20
carbon atoms with the random copolymer (B-l) of propylene and the
α-olefin having 4 to 20 carbon atoms described in the section of
the first thermoplastic polymer composition.
[0091]
By use of the graft-modified random copolymer (BB-la) of
propylene and the α-olefin having 4 to 20 carbon atoms, the
obtainable thermoplastic polymer composition is more excellent
in mechanical strength, elongation at break, scratch resistance
and whitening resistance, and also excellent in low temperature
brittleness resistance. In addition, the thermoplastic polymer
composition can give a shaped article, for example electric cable,
which has an advantage that the coating of the electric cable is
unlikely to be broken even when exposed to a low temperature.
[0092]
Further, in the second thermoplastic polymer composition
41
of the present invention, the graft-modified propylene-based
polymer (BB) is preferably a graft-modified product (BB-lb) of
a random copolymer of propylene, ethylene and the α-olefin having
4 to 20 carbon atoms which satisfies the following conditions:
The random copolymer contains 40 to 85 mol% of constituent
units derived from propylene, 5 to 30 mol% of constituent units
derived from ethylene, and 5 to 30 mol% of constituent units
derived from the α-olefin having 4 to 20 carbon atoms (here, the
total of constituent units derived from propylene, constituent
units derived from butene and constituent units derived from the
α-olefin having 4 to 20 carbon atoms is 100 mol%).
[0093]
The graft-modified random copolymer (BB-lb) of propylene,
ethylene and the α-olefin having 4 to 20 carbon atoms preferably
satisfies at least one, more preferably both of the following (ol)
and (pi).
(ol) The Shore A hardness is 30 to 80 and preferably 35 to
60.
(pi) The degree of crystallinity measured by X-ray
diffraction is 20 % or less and preferably 10 % or less.
[0094]
Preferably, the graft-modified random copolymer (BB-lb) of
propylene, ethylene and the α-olefin having 4 to 20 carbon atoms
has a melting point (Tm) as measured by DSC of 50°C or less or
42
has no observed melting point. The measurement of the melting
point may be carried out by the same method as that of the first
graft-modified propylene-based polymer (BB) and the like.
[0095]
As regards the amounts of the propylene component and other
comonomer components in the random copolymer of propylene,
ethylene and the α-olefin having 4 to 20 carbon atoms in the
graft-modified random copolymer (BB-lb) of propylene, ethylene
and the α-olefin having 4 to 20 carbon atoms, the random copolymer
preferably contains 60 to 82 mol% and more preferably 61 to 75
mol% of constituent units derived from propylene; 8.0 to 15 mol%
and more preferably 10 to 14 mol% of constituent units derived
from ethylene; and 10 to 25 mol% and more preferably 15 ~o 25 mol%
of constituent units derived from the α-olefin having 4 to 20
carbon atoms (here, the total of constituent units derived from
propylene, ethylene and the α-olefin having 4 to 20 carbon atoms
is 100 mol%) . As the α-olefin having 4 to 20 carbon atoms, 1-butene
is especially preferably used.
[0096]
Such graft-modified random copolymer (BB-lb) of propylene,
ethylene and the α-olefin having 4 to 20 carbon atoms may be
produced, for example, by graft-modifying the random copolymer
(C-lb) of propylene, ethylene and the α-olefin having 4 to 20
carbon atoms described in the section of the first thermoplastic
43
polymer composition, with at least one compound selected from the
group consisting of a vinyl compound containing a polar group and
a silane compound. Alternatively, the graft-modified random
copolymer (BB-lb) may be produced by blending a graft-modified
product of the random copolymer (C-lb) of propylene and the
α-olefin having 4 to 20 carbon atoms with the random copolymer
(B-2) of propylene and the α-olefin having 4 to 20 carbon atoms
described in the section of the first thermoplastic polymer
composition.
[0097]
By use of the modified random copolymer (C-lb) of propylene,
ethylene and the α-olefin having 4 to 20 carbon atoms, the
obtainable thermoplastic polymer composition is more excellent
in flexibility, scratch resistance and whitening resistance, and
also excellent in low temperature brittleness resistance. In
addition, the thermoplastic polymer composition can give a shaped
article, for example electric cable, which has an advantage that
the coating of the electric cable is unlikely to be broken even
when exposed to a low temperature.
[0098]
As described above, the graft-modified propylene-based
polymer (BB) is partly or fully graft-modified with at least one
compound selected from the group consisting of a vinyl compound
containing a polar group and a silane compound, and has a melting
44
point, as measured by differential scanning calorimetry (DSC) ,
of less than 120°C or has no observed melting point. Examples
of the vinyl compounds containing a polar group and silane
compounds used in the production of the graft-modified
propylene-based polymer include those used in the production of
the graft-modified propylene-based polymer (C) in the first
thermoplastic polymer composition of the invention. The
graft-modifying (graft copolymerizing) methods and the radical
initiators are as described in the section of the production of
the graft-modified propylene-based polymer (C) in the first
thermoplastic polymer composition of the present invention.
[0099]
The graft-modified propylene-based polymer (BB) used in the
present invention is partly or fully graft-modified with at least
one compound selected from the group consisting of a vinyl compound
containing a polar group and a silane compound, and has a melting
point, as measured by differential scanning calorimetry (DSC) ,
of less than 120°C or has no observed melting point. The graft
amount of the vinyl compound containing a polar group and the
silane compound is not particularly limited but is typically 0.01
to 10 % by weight and preferably 0.05 to 5 % by weight relative
to 100 parts by weight of the modified propylene-based polymer
(BB) . By use of the graft-modified propylene-based polymer (BB)
in the present invention, the obtainable shaped article is
45
excellent especially in balance between tensile strength and
scratch resistance.
[0100]
The inorganic filler (D), and optional components such as
ethylene-based polymer (E) and oil (F) are as described in the
first thermoplastic polymer composition.

The second thermoplastic polymer composition of the present
invention contains 5. 0 to 64 . 9 % by weight, preferably 5. 0 to 49. 9 %
by weight of the propylene-based polymer (A) ; 0 .1 to 60 % by weight,
preferably 10.1 to 40 % by weight: of tine graft-modified
propylene-based polymer (BB) ; and 35 to 75 % by weight, preferably
40 to 60 % by weight of the inorganic filler (D) (here, the total
amount of (A), (BB) and (D) is 100 % by weight).
[0101]
Further, the thermoplastic polymer composition may contain
the ethylene-based polymer (E) . For example, the copolymer (E-l)
of ethylene with the α-olefin having 3 to 10 carbon atoms or the
graft-modified ethylene-based polymer (E-2) may be used in an
amount of 0.1 to 20 parts by weight relative to 100 parts by weight
of the total amount of the components (A) , (BB) and (D) . If the
amount of the ethylene-based polymer (E-l) is within this range,
low temperature characteristics are significantly improved.
46
[0102]
Further, the oil (F) may be used in the present invention
in an amount of 0.1 to 20 parts by weight relative to 100 parts
by weight of the total amount of the components (A) , (BB) and (D) .
If the amount of the oil (F) is within this range, low temperature
characteristics are significantly improved and the oil is unlikely
to bleed out on the surface of the shaped article.
[0103]
The second thermoplastic polymer composition of the present
invention may contain additives as required while still achieving
the objects of the invention. Examples of the additives include
synthetic resins, rubbers, antioxidants, heat stabilizers,
weather stabilizers, slip agents, antiblocking agents,
nucleating agents, pigments, hydrochloric acid absorbers, and
copper inhibitors. The amounts of such synthetic resins, rubbers
and additives are not particularly limited as long as the objects
of the present invention are not impaired. In a preferred
embodiment, the components (A), (BB), and (D) are contained so
that the total of them is 60 to 100 % by weight of the thermoplastic
polymer composition. The balance is accounted for by the
above-mentioned components such as synthetic resins, rubbers,
additives, ethylene-based polymer (E), and oil (F) .

The first and second thermoplastic polymer compositions of
47
the present invention may be produced by conventionally known
methods. For example, they may be produced by melt-kneading the
components described above.
[0104]
In producing the first thermoplastic polymer composition,
it is preferable that the graft-modified propylene-based polymer
(C) and the ethylene-based polymer (E) are melt-kneaded to produce
a propylene-based polymer composition (G), and the
propylene-based polymer composition (G) is melt-kneaded with
components including the inorganic filler (D), propylene-based
polymer (A) and optional propylene-based polymer (B) . The
production in this manner is preferable because the scratch
resistance may be further improved while maintaining other
physical properties.
[0105]
Part of (C) or (E) may not be melt-blended beforehand, and
may be supplied together with the component (A) and the like
separately from the propylene-based polymer composition (G)
(melt-kneaded product). However, the highest effects may be
achieved when the components (C) and (E) are all melt-kneaded into
the propylene-based polymer composition (G) (melt-kneaded
product).
[0106]
Further, in producing the second thermoplastic polymer
48
composition, it is preferable that the graft-modified
propylene-based polymer (BE) and the ethylene-based polymer (E)
are melt-kneaded to produce a propylene-based polymer composition
(GG) , and the propylene-based polymer composition (GG) is
melt-kneaded with components including the inorganic filler (D)
and propylene-based polymer (A) . The production in this manner
is preferable because the scratch resistance may be further
improved while maintaining other physical properties.
[0107]
Part of (BB) or (E) may not be melt-blended beforehand, and
may be supplied together with the component (A) and the like
separately from the propylene-based polymer composition (GG)
(melt-kneaded product). However, the highest effects may be
achieved when the components (BB) and (E) are all melt-kneaded
into the propylene-based polymer composition (GG) (melt-kneaded
product).

First and second shaped articles of the present invention
comprise the thermoplastic polymer compositions as mentioned
above. The thermoplastic polymer compositions may be formed into
various shapes by conventionally known melt-forming methods.
Examples of the melt-forming methods include, for example,
extrusion, rotational molding, calendering, injection molding,
compression molding, transfer molding, powder molding, blow
49
molding, and vacuum forming. The shaped articles maybe composite
products with shaped articles comprising other materials, for
example, layered products.
[0108]
The first and second shaped articles may be suitably used
as, for example, electric cable coatings such as an insulator of
an electric cable and an electric cable sheath. The coating
layers such as the insulator of an electric cable and the electric
cable sheath may be formed around electric wires by conventionally
known methods, for example, extrusion.
[0109]
First and second electric cables of the present invention
have an insulator comprising the thermoplastic polymer
composition as mentioned above and/or a sheath comprising the
thermoplastic polymer composition as mentioned above.
Especially, the electric cable is preferably an electric cable
for an automobile or an electric cable for an instrument.
The thermoplastic polymer compositions as mentioned above
may be suitably used for building materials.
[0110]
Hereinafter, the present invention will be explained in more
detail with reference to Examples. However, the present
invention is not limited to these Examples.
[Examples]
50
[Components (A) t o (F)]
(A) Propylene-based Polymer
As an isotactic random polypropylene (r-PP), a
propylene/ethylene/1-butene random copolymer (Tm: 140°C, melt
flow rate (temperature 230°C, load 2.16 kg): 7 g/10 min, mmmm
(stereoregularity, pentad isotacticity): 0.96, Mw/Mn: 4.8) was
used.
(B) Propylene-based Polymer
(B-l) Propylene/1-Butene Copolymer (PBR)
To a 2000 ml polymerization device thoroughly purged with
nitrogen were added 866 ml of dried hexane, 90 g of 1-butene and
triisobutylaluminum (1.0 mmol) at room temperature. After the
inside temperature of the polymerization device was elevated to
65°C, propylene was fed so that the pressure inside the device
became 0.7 MPa. Subsequently, to the polymerization device was
added a toluene solution in which 0.002 mmol of
dimethylmethylene(3-tert-butyl-5-methylcyclopentadienyl)fluor
enyl zirconium dichloride was contacted with 0.6 mmol in terms
of aluminum of methylaluminoxane (manufactured by Tosoh Finechem
Corporation). The polymerization was performed for 30 minutes
while keeping the inside temperature at 65°C and the propylene
pressure at 0.7 MPa, followed by addition of 20 ml of methanol
to stop the polymerization. After depressurizing, the polymer
was precipitated from the polymerization solution in 2 L of
51
methanol and dried under vacuum at 130°C for 12 hours. The
resulting polymer had a weight of 12.5 g, a butene content of 2.9
mol%, a melting point of 74.4°C, a MFR (temperature 230°C, load
2.16 kg) of 7 g/10 min, a Mw/Mn of 2.10 and an mm value of 90 %.
[0111]
In the present invention, a copolymer (B-1) obtained by
scaling up the above method was pelletized for use. The
properties of the propylene/1-butene copolymer (B-1) (PBR) used
are shown in Table 1.
[0112]
[Table 1]
[Table 1]
Propylene/1-butene copolymer (PBR)
MFR (g/10 min)(Temperature 230°C, Load 2
Melting Point (°C)
Mw/Mn
1-Butene content (mol%)
16 kg)
(B-1)
7.0
75
2.1
26
[0113]
(B-2) Propylene/Ethylene/1-Butene Copolymer (PBER)
To a 2000 ml polymerization device thoroughly purged with
nitrogen were added 917 ml of dried hexane, 85 g of 1-butene and
triisobutylaluminum (1.0 mmol) at room temperature. After the
inside temperature of the polymerization device was elevated to
65°C, propylene was fed so that the pressure inside the system
became 0.77 MPa. Subsequently, ethylene was fed so that the
pressure inside the system became 0.7 8 MPa.
[0114]
52
Next, to the polymerization device was added a toluene
solution in which 0.002 mmol of
dimethylmethylene(3-tert-butyl-5-methylcyclopentadienyl)fluor
enyl zirconium dichloride was contacted with 0.6 mmol in terms
of aluminum of methylaluminoxane (manufactured by Tosoh Finechem
Corporation). The polymerization was performed for 20 minutes
while keeping the inside temperature at 65°C and the pressure
inside the system at 0.78 MPa with ethylene, followed by addition
of 20 ml of methanol to stop the polymerization. After
depressurizing, the polymer was precipitated from the
polymerization solution in 2 L of methanol and dried under vacuum
at 130°C for 12 hours. The resulting polymer had a weight of 60.4
g-
[0115]
In the present invention, a copolymer (B-2) obtained by
scaling up the above method was pelletized for use. The
properties of the propylene/ethylene/1-butene random copolymer
(B-2) (PBER) used are shown in Table 2. The mm value was 92 %.
53
[0116]
[Table 2]
[Table 2]
Propylene/ethylene/1-butene random copolymer
(PBER)
MFR (g/10 min) (Temperature 2 30°C, Load 2.16 kg)
Melting Point (°C)
Mw/Mn
Ethylene content (mol%)
1-Butene content (mol%)
(B-2)
8.5
Not
observed
2.0
13
19
[0117]
(C) Graft-modified Propylene-based Polymer
(C-X) Maleic anhydride-grafted propylene/1-butene
copolymer (Modified C-la)
The propylene/1-butene copolymer (B-l) having the
properties described in Table 1 was used as a propylene-based
polymer (C-la) which was a raw material for modification. 6 kg
of this propylene/1-butene copolymer was blended with a solution
of 30 g of maleic anhydride and 5.4 g of
2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne in 50 g of acetone.
[0118]
Subsequently, the resulting blended product was introduced
into a single-screw extruder having a screw diameter of 40 mm and
an L/D of 26 through a hopper of the extruder. The blended product
was extruded into a strand shape at a resin temperature of 250°C
and a throughput of 6 kg/h. Next, the extruded product was cooled
with water and pelletized to produce a maleic anhydride-grafted
54
propylene/1-butene copolymer (C-X) . This (C-X) had a Tm as
measured by DSC of 70°C and a melt flow rate (temperature 190°C,
load 2.16 kg) of 15 g/10 min.
[0119]
The unreacted maleic anhydride was extracted from the
resulting maleic anhydride-grafted propylene/1-butene copolymer
(C-X) with acetone, and the graft amount of the maleic anhydride
in this copolymer was measured to be 0.17 % by weight.
(C-Y) Maleic anhydride-grafted
propylene/ethylene/1-butene copolymer (Modified C-lb)
The propylene/ethylene/1-butene copolymer (B-2) having the
properties described in Table 2 was used as a propylene-based
polymer (C-lb) which was a raw material for modification. 6 kg
of this propylene/ethylene/1-butene copolymer was blended with
a solution of 30 g of maleic anhydride and 5.4 g of
2,5-dimethyl-2, 5-di(t-butylperoxy)-3-hexyne in 50 g of acetone.
Subsequently, the resulting blended product was introduced into
a single-screw extruder having a screw diameter of 40 mm and an
L/D of 26 through a hopper of the extruder. The blended product
was extruded into a strand shape at a resin temperature of 250°C
and a throughput of 6 kg/h.
[01201
Next, the extruded product was cooled with water and
pelletized to produce a maleic anhydride-grafted
55
propylene/ethylene/1-butene copolymer (C-Y). This (C-Y) had no
melting point as measured by DSC and a melt flow rate (temperature
190°C, load 2.16 kg) of 23 g/10 min. The unreacted maleic
anhydride was extracted from the resulting maleic
anhydride-grafted propylene/ethylene/1-butene copolymer (C-Y)
with acetone, and the graft amount of the maleic anhydride in this
copolymer was measured to be 0.17 % by weight.
(C-Z) Modified Polypropylene
A modified PP obtained by modifying a homopolypropylene
having a Tm of 157°C and an intrinsic viscosity [n] of 0.4 dl/g
with maleic anhydride was used. The graft amount of maleic
anhydride was 3.0 % by weight.
(D) Inorganic Filler
Magnesium hydroxide (Mg(OH)2, product name: KISUMA 5P,
produced by Kyowa Chemical Industry Co., Ltd.) was used.
(E) Ethylene-based Polymer
An ethylene/1-butene copolymer (E-l) having the properties
described in Table 3 was blended with a solution of 50 g of maleic
anhydride and 3 g of di-tert-butyl peroxide in 50 g of acetone.
Subsequently, the resulting blended product was introduced into
a single-screw extruder having a screw diameter of 40 mm and an
L/D of 26 through a hopper of the extruder. The blended product
was extruded into a strand shape at a resin temperature of 250°C
and a throughput of 6 kg/h.
56
[0121]
Next, the extruded product was cooled with water and
pelletized to produce a maleic anhydride-grafted
ethylene/1-butene copolymer (E-2).
[0122]
[Table 3]
[Table 3]
Ethylene/1-butene copolymer (EBR)
Density (kg/m3)
MFR (g/10 min) (Temperature 230°C, Load 2
Melting Point (°C)
Mw/Mn
16 kg)
(E-l)
870
1.2
59
2.1
[0123]
The unreacted maleic anhydride was extracted from the
resulting maleic anhydride-grafted ethylene/1-butene copolymer
(E-2) with acetone, and the graft amount of the maleic anhydride
in this copolymer was measured to be 0.43 % by weight.

Physical properties of each component were measured as
follows.
(1) The comonomer (ethylene and 1-butene) contents and mmmm
(stereoregularity, pentad isotacticity) were determined by the
analysis of 13C-NMR spectra.
(2) Melt Flow Rate (MFR)
The MFR was measured at 190°C or 230°C under a load of 2.16
kg, in accordance with ASTM D-1238.
(3) Melting Point (Tm)
57
Exothermic and endothermic curves were obtained by DSC, and
the Tm was defined as a temperature at a maximum melting peak where
AH in the temperature rising was 1 J/g or higher. The exothermic
and endothermic curves were recorded by a series of steps in which
a sample in an aluminum pan was heated to 200°C at an elevation
rate of 100°C/min and held at 200°C for 5 minutes, and then the
sample was cooled to -150°C at a cooling rate of 10°C/min and heated
again to 200°C at an elevation rate of 10°C/min.
(4) Molecular Weight Distribution (Mw/Mn)
The molecular weight distribution (Mw/Mn) was measured as
follows by using gel permeation chromatograph Alliance GPC-2000
System manufactured by Waters Corp. The separation column
consisted of two TSK gel GNH6-HT columns and two TSK gel GNH6-HTL
columns (each 7.5 mm in diameter x 300 mm in length) . The column
temperature was 140°C. The mobile phase consisted of
o-dichlorobenzene (Wako Pure Chemical Industries Inc.) and 0.025%
by weight of BHT (Takeda Pharmaceutical Co., Ltd.) as an
antioxidant, and was flowed at a rate of 1.0 ml/min. The sample
concentration was 15 mg/10 mL, the sample injection amount was
500 μL, and a differential refractometer was used as a detector.
Polystyrene standards manufactured by Toso Co., Ltd. were used
for Mw<1000 and Mw>4x10°, and those manufactured by Pressure
Chemical Co., Ltd. were used for 1000≥Mw≥4x106.
(5) Density
58
The density was measured in accordance with a method
described in ASTM D1505.
(6) Degree of Crystallinity
By using RINT2500 (manufactured by Rigaku Corp.) as a
measurement device, the degree of crystallinity was determined
by the analysis of a wide-angle X-ray profile measured using CuKa
as an X-ray source.
(7) Shore A Hardness
The Shore A hardness was measured under the following
conditions in accordance with JIS K6301. A sheet was prepared
with a press molding machine. The sheet was tested on an α-type
hardness meter, and a reading was taken immediately after a
pressure needle contacted the sheet.
(8) Intrinsic Viscosity [n]
A polymer sample was dissolved in decalin, and the solution
was measured for viscosity at 135°C with an Ubbelohde type
viscometer. The intrinsic viscosity was determined from the
measurement value.

(1) Tensile Strength at Break (TS) and Elongation at Break
(EL)
The tensile strength at break (TS) and elongation at break
(EL) were measured for a test piece prepared with an injection
59
molding machine in accordance with JIS K7113-2.
(2) Brittle temperature (Btp)
The brittle temperature was measured for a sheet 3 mm in
thickness prepared with an injection molding machine in accordance
with ASTM D74 6.
(3) D Hardness (HD-D)
A sheet prepared with an injection molding machine was
tested using a D-type hardness meter in accordance with ASTM D2240,
and a reading was taken immediately after a pressure needle
contacted the sheet.
(4) Scratch Resistance
A scrape abrasion tester (manufactured by Yasuda Seiki
Seisakusho Ltd.) was used. A SUS abrasion indenter weighing 700
g was attached at the tip of the tester. A test piece with a
thickness of 3 mm was abraded with a piano wire fixed to the tip
of the abrasion indenter at room temperature by reciprocating the
indenter 1000 times at a reciprocation speed of 60 cpm with a stroke
of 10 mm. The test sample was weighed before and after abrading,
and the abraded weight loss was determined. The smaller the value
is, the more excellent the scratch resistance is.
[Examples 1 to 5]
The material components in the amounts described in Table
4 were dry blended using a Henschel mixer, and the blended product
was melt-kneaded with a twin-screw extruder having a diameter of
60
30 mm at 210°C to produce a composition. The pellets obtained
were formed into a test piece by using an injection molding machine.
The tensile properties, brittle temperature, scrape abrasion and
D hardness were tested. The results are shown in Table 4.
[Example 6]
The maleic anhydride-grafted propylene/1-butene copolymer
(C-X) as graft-modified propylene-based polymer (C) and the
ethylene/1-butene copolymer (E-l) as ethylene-based polymer (E)
were kneaded together at 190°C by using a Labo Plastomill
(manufactured by Toyo Seiki Co., Ltd.). As a result, a
propylene-based polymer composition (G) shown below was produced.
(G) Propylene-Based Polymer Composition
Maleic anhydride-grafted propylene/1-butene copolymer
(C-X)/Ethylene/1-butene copolymer (E-l) = 80/20 (% by weight)
A composition was prepared and evaluated in the same manner
as in Example 1, except that the components and amounts thereof
were changed as described in Table 4. The results are shown in
Table 4.
[0124]
[Table 4]
[Table 4]
'A> r-PP
,B-I) PBR
(C-X) Modified PBR
'C-Y) Modified PBER
(C-Z) Modified PP
(E-l) EBR
(E-2) Modified EBR (G)
Unit
% by weight
% by weight
% by weight
% by weight
% by weight
% by weight
% by weight
Ex. 1
30
16
4
Ex. 2
30
16
4
Ex. 3
30
20
Ex. 4
45
5
Ex. 5
40
5
5
Ex. 6
30
&o
M
61
(D) Mg(OH)2
Tensile Strength at Break
Elongation at Break
Brittle temperature
D Hardness
Abraded Weight Loss
% by weight
MPa
%
°c
-
mg
50
32.0
491
-40
54
0.2
50
18.0
470
-35
50
1.1
50
35
500
-21
57
0.1
50
26
270
-16
61
0.1
50
25
390
-17
59
0.1
50
34
510
-40
54
0.2
[0125]
[Comparative Examples 1 to 4]
Compositions were prepared and evaluated in the same manner
as in Example 1, except that the components and amounts thereof
were changed as described in Table 5. The results are shown in
Table 5.
[0126]
[Table 5]
[Table 5]
(A) r-PP
(B-l) PBR
(C-X) Modified PBR
(C-Y) Modified PBER
(C-Z) Modified PP
(E-l) EBR
(E-2) Modified EBR
(D) Mg(OH)2
Tensile Strength at Break
Elongation at Break
Brittle temperature
0 Hardness
Abraded Weight Loss
Unit
% by weight
% by weight
% by weight
% by weight
% by weight
% by weight
% by weight
% by weight
MPa
%
°C
-
mg
Comp.
Ex. 1
30
20
50
16.0
280
-74
43
2.8
Comp.
EX. 2
29
16
1
4
50
23.1
440
-32
54
1.6
Comp.
Ex. 3
30
16
4
50
20.6
500
-43
51
1.9
Comp.
Ex. 4
30
16
4
50
23
440
-42
52
0.8
[0127]
The propylene-based resin compositions according to the
present invention proved excellent tensile strength at break,
elongation at break and scratch resistance when they contained
the inorganic filler (for example, magnesium hydroxide) , compared
with the ethylene-based resin compositions of Comparative
Examples.
62
INDUSTRIAL APPLICABILITY
[0128]
The thermoplastic polymer compositions of the present
invention contain the inorganic filler in a high ratio and have
good flexibility as well as excellent mechanical strength,
elongation at break and scratch resistance. Further, because the
thermoplastic polymer compositions of the present invention
contain the inorganic filler in a high ratio, the compositions
may be widely used for the production of flame retardant shaped
articles, for example electric cables and building materials.

WE CLAIM:
1. A thermoplastic polymer composition comprising the following (A), (BB) and (D):
(A) 5 to 64. 9 % by weight of a propylene-based polymer having a melting point, as measured
by differential scanning calorimetry (DSC), in the range of 120°C to 170°C;
(BB) 0.1 to 60.0 % by weight of a graft-modified propylene-based polymer which is partly or
fijUy graft-modified with at least one compound selected from the group consisting of a vinyl
compound containing a polar group and a silane compound, and which has a melting point, as
measured by differential scanning calorimetry (DSC) , of less than 120°C or has no observed
melting point; and
(D) 35 to 75 % by weight of an inorganic filler, wherein the total amount of (A), (BB) and (D) is
100% by weight.
2. The thermoplastic polymer composition as claimed in claim 1, wherein said graftmodified
propylene-based polymer (BB) has a melt flow rate in the range of 0.01 to 100 g/10
min, as measured at 190 C under a load of 2.16 kg
3. The thermoplastic polymer composition as claimed in claim 1 or 2, wherein said graftmodified
propylene-based polymer (BB) is a graft-modified product (BB-la) of a random
copolymer of propylene with an a-olefin having 4 to 20 carbon atoms, the random copolymer
containing 5 to 50 mol% of constituent units derived from the a-olefin having 4 to 20 carbon
atoms relative to 100 mol% of the total of the constituent units derived from propylene and the
constituent units derived from the a-olefin having 4 to 20 carbon atoms.
4. The thermoplastic polymer composition as claimed in claim 1 or 2, wherein said graftmodified
propylene-based polymer (BB) is a graft-modified product (BB-lb) of a random
copolymer of propylene, ethylene and an a-olefin having 4 to 20 carbon atoms, the random
copolymer containing 40 to 85 mol% of constituent units derived fi-om propylene, 5 to 30 mol%
of constituent units derived fi-om ethylene and 5 to 30 mol% of constituent units derived fi-om the
a-olefin having 4 to 20 carbon atoms relative to 100 mol% of the total of the constituent units
derived fi"om propylene, the constituent units derived from ethylene and the constituent units
derived from the a-olefin having 4 to 20 carbon atoms.
5. The thermoplastic polymer composition as claimed in any of claims 1 to 4, wherein said
inorganic filler (D) is one or more kinds of fillers selected from the group consisting of talc,
metal hydroxides, metal carbonates and metal oxides.
6. The thermoplastic polymer composition as claimed in any of claims 1 to 5, wherein the
composition fijrther includes 0.1 to 20 parts by weight of an ethylene-based polymer (E), relative
to the total 100 parts by weight of the propylene-based polymer (A) , the graft-modified
propylene-based polymer (BB) and the inorganic filler (D).
7. The thermoplastic polymer composition as claimed in to any of claims 1 to 6, wherein the
composition fiirther includes 0.1 to 20 parts by weight of oil (F), relative to the total 100 parts
by weight of the propylene-based polymer (A), the graft-modified propylene-based polymer
(BB) and the- inorganic filler (D).