Propylene resin composition

A propylene resin composition comprising: a polypropylelne having specific physical properties, 25.about.40% by weight; a propylene-ethylene block copolymer, 25.about.45% by weight; an ethylene-propylene rubber, 5.about.15% by weight; an ethylene-.alpha.-olefin copolymer, 5-15% by weight; and a talc, 5-30% by weight; is superior in all of the following properties concurrently: rigidity, heat resistance, impact resistance, surface hardness, etc.; and is suited for use in machine parts such as automobile parts; electric and electronic parts; packaging materials, engineering plastic substitutes, etc.

BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION 
The present invention relates to a propylene resin composition which is 
superior in all of the following properties concurrently: rigidity, heat 
resistance, impact resistance, surface hardness, etc.; and which is suited 
for use in machine parts, electric and electronic parts, packaging 
materials, engineering plastic substitutes, etc. 
2. Background Art 
Polypropylene is widely used, for example, in industrial materials for 
vehicle parts, electric and electronic parts, etc., and in various 
packaging materials, since it is generally inexpensive, and has the 
advantages of light-weight characteristics, mechanical strength, heat 
resistance, chemical resistance, etc. 
In recent years, there has been a strong demand for improvements in quality 
along with increased functionality and reduced costs for these materials. 
As ways to improve the rigidity, impact resistance, heat resistance, etc., 
of polypropylene, methods have been proposed such as incorporating an 
ethylene-propylene rubber and a nucleating agent into an 
ethylene-propylene block copolymer (Japanese Patent Application, Second 
Publication, No. Sho 60-3420), and incorporating an ethylene-propylene 
rubber, an ethylene copolymer, and an inorganic filler into an 
ethylene-propylene block copolymer (Japanese Patent Application, First 
Publication, No. Hei 4-275351, Japanese Patent Application, First 
Publication, No. Hei 5-5051, Japanese Patent Application, First 
Publication, No. Hei 5-98097, Japanese Patent Application, First 
Publication, No. Hei 5-98098). 
However, in the above-mentioned methods, although some characteristics have 
been improved, heat resistance and rigidity still have not been adequately 
improved. 
SUMMARY OF THE INVENTION 
In view of the above, it is an object of the present invention to provide a 
propylene resin composition which is superior in all of the following 
properties concurrently: rigidity, heat resistance, impact resistance, 
surface hardness, etc. 
The inventors, through long and careful research, have discovered that the 
above-mentioned object can be achieved by incorporating an 
ethylene-propylene rubber and an ethylenic polymer into a specific 
polypropylene. The present invention is based on this discovery and 
completely achieves these objects. 
More specifically, the present invention provides a propylene resin 
composition comprising 
(A) a polypropylene, 25.about.40% by weight, the polypropylene having the 
following physical properties (i) to (iv): 
(i) a portion insoluble in xylene at 25.degree. C. by solvent extraction 
method of not less than 99.0% by weight; 
(ii) an isotactic pentad fraction of not less than 98.5%; 
(iii) an isotactic number-average sequence length of not less than 500; and 
(iv) a total amount of fractions each of which has an isotactic 
number-average sequence length of not less than 800, according to a column 
fractionation method, of not less than 10% by weight; 
(B) a propylene-ethylene block copolymer, 25.about.45% by weight; 
(C) an ethylene-propylene rubber, 5.about.15% by weight; 
(D) an ethylene-.alpha.-olefin copolymer, 5.about.15% by weight; and 
(E) a talc, 5.about.30% by weight; 
(in which (A)+(B)+(C)+(D)+(E)=100% by weight). 
The propylene resin composition of the present invention is superior in all 
of the following properties concurrently: rigidity, heat resistance, 
impact resistance, surface hardness, etc.; and is suited for use in 
machine parts such as automobile parts; electric and electronic parts; 
packaging materials, engineering plastic substitutes, etc.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A detailed explanation of the present invention follows. 
In the present invention polypropylene (A) is substantially a propylene 
homopolymer; however, it must have the following properties. 
The polypropylene used for the present invention has a portion insoluble in 
xylene at 25.degree. C. by solvent extraction method (this portion is 
hereinafter referred to as "xylene-extraction-insoluble portion"; the 
amount of the xylene-extraction-insoluble portion is hereinafter referred 
to as "XI") of at least 99.0% by weight, preferably at least 99.5% by 
weight, and more preferably 99.7% by weight. When XI is less than 99.0% by 
weight, rigidity and heat resistance of the propylene resin composition 
are inferior. The determination of XI herein uses a method in which a 
polypropylene is dissolved in o-xylene at 135.degree. C.; then, by cooling 
to 25.degree. C., a polymer is precipitated. 
It is essential that the isotactic pentad fraction (ii) (hereinafter 
referred to as "IP") be at least 98.5% by weight, preferably at least 
99.0% by weight, and more preferably at least 99.5% by weight. When IP is 
less than 98.5% by weight, the heat resistance and rigidity properties of 
the propylene resin are inferior and undesirable. 
In addition, IP is the isotactic fraction with respect to pentad units in a 
polypropylene molecular chain, which is determined using 
carbon-isotope-based nuclear magnetic resonance (.sup.13 C-NMR). The 
method for this determination herein follows the method published in A. 
Zambelli; Macromolecules, 6, 925 (1973), 8, 687 (1975), and 13, 267 
(1980). 
An isotactic number-average sequence length (iii) (hereinafter referred to 
as "N") of at least 500, preferably of at least 700, and more preferably 
of at least 800, is necessary. When N is less than 500, the heat 
resistance and rigidity of the propylene resin composition are inferior. 
N indicates an average length of isotactic portions with respect to methyl 
groups in a polypropylene molecule. The method for determining N herein 
follows the method described in J. C. Randall, Polymer Sequence 
Distribution, Academic Press, New York, 1977, Chapter 2. 
In more detail, a polypropylene is dissolved in a 
1,2,4-trichlorobenzene/benzene deuteride solvent mixture which is heated 
to 130.degree. C. so that the polymer concentration is 10% by weight. This 
solution is put into a 10 mm diameter glass test tube and a .sup.13 C-NMR 
spectrum is taken using a method similar to that used for IP. This 
spectrum is shown in FIG. 1. In FIG. 1, "a" indicates the spectrum of the 
methyl group domain of the polypropylene, and "b" is an enlargement of the 
spectrum. The spectrum was obtained by pentad unit, i.e., by units of five 
adjacent methyl groups. The absorption peaks vary depending on the 
isotacticity (which consist of 10 structures: mmmm, mmmr, etc.) with 
respect to the methyl groups. In addition, "b" indicates the 
correspondence between the absorption peaks and the isotacticity. 
Shan-Nong ZHU, et al., Polymer Journal, Vol. 15, No. 12, pp 859.about.868 
(1983) describes the "bi-catalytic site model" as a polymerization theory. 
It proposes that, during polymerization, there are two kinds of active 
sites; a site on the catalyst side and a site at the end of a polymer; 
"catalyst-controlled polymerization" takes place on the catalyst side, 
while "chain end-controlled polymerization" takes place at the end of the 
polymer. (Details of this theory are described in Junji Furukawa; 
Macromolecule Essence and Topics 2, Macromolecule Syntheses, p. 73, 
published by Kagakudojin (1986) 
In conclusion, the bi-catalytic site model of the above-mentioned 
publication, in which 
.alpha. is the probability that in catalyst-controlled polymerization 
(enantiomorphic process), D and L will be added to the polymerization 
terminal; that is, an index of the degree of disorder within the isotactic 
sequence; 
.sigma. is the probability that in chain end-controlled polymerization 
(Bernoullian process), a mesoisomer is formed in which a monomer of the 
same configuration as that of the polymerization terminal is added 
thereto; and 
.omega. is the proportion of .alpha. sites; 
can theoretically be used to calculate the isotactic intensity of the 10 
different kinds of isotacticity of the pentad unit. In addition, .alpha., 
.sigma., and .omega., are calculated by least squares method so that the 
above-mentioned theoretical intensity and the above-mentioned NMR measured 
intensity agree. On the basis of the following equation, the mole fraction 
of each kind of pentad units is calculated. 
TABLE 1 
__________________________________________________________________________ 
MESOISOMER 
A.sub.1 : 
mmmm = .omega. (1 - 5.beta. + 5.beta..sup.2) + (1 - .omega.) 
.sigma..sup.4 
A.sub.2 : 
mmmr = .omega. (2.beta. - 6.beta..sup.2) + 2 (1 - .omega.) 
.sigma..sup.3 (1 - .sigma.) 
A.sub.3 : 
rmmr = .omega..beta..sup.2 + (1 - .omega.) .sigma..sup.2 (1 - 
.sigma.).sup.2 
RACEMIC A.sub.4 : 
mmrr = .omega. (2.beta. - 6.beta..sup.2) + 2 (1 - .omega.) 
.sigma..sup.2 (1 - .sigma.).sup.2 
STRUCTURE 
A.sub.5 : 
mmrm = 2.omega..beta..sup.2 + 2 (1 - .omega.) .sigma..sup.3 
(1 - .sigma.) 
A.sub.6 : 
rmrr = 2.omega..beta..sup.2 + 2 (1 - .omega.) .sigma. (1 - 
.sigma.).sup.3 
A.sub.7 : 
rmrm = 2.omega..beta..sup.2 + 2 (1 - .omega.) .sigma..sup.2 
(1 - .sigma.).sup.2 
A.sub.8 : 
rrrr = .omega..beta..sup.2 + 2 (1 - .omega.) (1 
- .sigma.).sup.4 
A.sub.9 : 
mrrr = .omega..beta..sup.2 + 2 (1 - .omega.) .sigma. (1 - 
.sigma.).sup.3 
A.sub.10 : 
mrrm = .omega. (.beta. - 3.beta..sup.2) + (1 - .omega.) 
.sigma..sup.2 (1 - .sigma.).sup.2 
__________________________________________________________________________ 
Provided that .beta. = .alpha.(1 - .alpha.). 
Next, the number-average sequence length (N) can be determined by applying 
the above result to the following defining equation described in the 
above-mentioned Randall publication: 
##EQU1## 
In practice, N can be determined according to the following equation. 
EQU N=1+(A1+A2+A3)/0.5(A4+A5+A6+A7) 
Furthermore, according to the physical property (iv) of the polypropylene 
(A), it is essential that the total amount of fractions each of which has 
an isotactic number-average sequence length (herein after referred to as 
"N.sub.f ") of not less than 800 according to a column fractionation 
method be at least 10% by weight of the whole, preferably 30% by weight of 
the whole, and more preferably at least 50% by weight of the whole. When 
the total amount of fractions each of which has N.sub.f of at least 800 is 
less than 10% by weight of the whole, the advantages of the improvement in 
rigidity, surface hardness, and heat resistance of the propylene resin 
composition are degraded. 
Here, the column fractionation method is carried out by dissolving in 
p-xylene at 130.degree. C. the above-mentioned xylene-extraction-insoluble 
portion; adding Celite to the solution; lowering the temperature at a rate 
of 10.degree. C./hour until reaching 30.degree. C. so as to allow the 
solution to adsorb to the Celite to form a slurry; filling a column with 
the Celite slurry; and obtaining different fractions of a polypropylene 
separately by using p-xylene as a developer and by raising the 
temperature, which is 30.degree. C. at the beginning, by 2.5.degree. C. at 
a time. This method is described in more detail in Masahiro Kakugo et al, 
Macromolecules, Vol. 21, pp 314.about.319 (1988). The N.sub.f of each 
fraction of the polypropylene is determined using the above-described 
method for determining N. 
A preferred example of component (A) for the present invention is a 
propylene homopolymer which is obtained by a polymerization using a 
modified solid catalytic composition which is obtained by: treating a 
solid catalyst containing, for example, a magnesium compound, a titanium 
compound, a halogen containing compound, and an electron donative compound 
as its essential components with a titanium compound of general formula 
TiXa.Yb (wherein X is a halogen atom selected from Cl, Br, and I, Y is an 
electron donative compound, and a is 3 or 4, b is an integer of 3 or 
less); then, washing the treated catalyst with a halogen-containing 
compound; and then further washing with a hydrocarbon. A mixture of such 
propylene homopolymer is also a preferred example of component (A) for the 
present invention. 
Among these examples of component (A), a mixture of a polypropylene having 
a melt flow rate (measured in conformity with Japan Industrial Standard 
(JIS) K7210, Table 1, Condition 14; which closely corresponds with ASTM 
D1238) (hereinafter referred to as "MFR") of 20.about.50 g/10 minutes, 
50.about.80% by weight, and a polypropylene having an MFR of 3.about.15 
g/10 minutes, 50.about.20% by weight, is preferred, since such a component 
(A) gives the propylene resin composition of the present invention a 
balance of superior properties with regard to rigidity and impact 
resistance. 
In addition, the propylene-ethylene block copolymer (B) for the present 
invention (hereinafter referred to as "BPP") is a copolymer which can be 
obtained by using a commonly-known multi-step polymerization method. In 
this method, a first-step reaction of the first step is carried out in 
which a propylene is allowed to polymerize, and then, a reaction of the 
second step is carried out in which the propylene-ethylene copolymer is 
formed. Examples of the multi-step polymerization method are described in 
U.S. Pat. Nos. 4,576,994, 4,761,461, and 4,337,326 (which are all 
incorporated herein by reference), etc. 
The propylene-ethylene copolymer rubber content of the above BPP is 
generally 5.about.25% by weight, preferably 8.about.21% by weight, and 
more preferably 10.about.18% by weight. In addition, the propylene content 
of the rubber component is generally 40.about.65% by weight, preferably 
42.about.63% by weight, and more preferably 45.about.60% by weight. 
The MFR of the BPP is not particularly limited, but generally a BPP with an 
MFR of 15 g/10 minutes or greater may be useful. 
In addition, when a BPP which contains a propylene homopolymer portion, 
generated in the first-step reaction, having the following properties (i), 
(ii), (iii), and (iv) is used, the propylene resin composition will tend 
to have superior properties in terms of rigidity and heat resistance: 
(i) a portion insoluble in xylene at 25.degree. C. by solvent extraction 
method of not less than 99.0%; 
(ii) an isotactic pentad fraction of not less than 98.5%; 
(iii) an isotactic number-average sequence length of not less than 500; and 
(iv) a total amount of fractions each of which has an isotactic 
number-average sequence length of not less than 800, according to a column 
fractionation method, of not less than 10% by weight. 
In addition, the ethylene-propylene rubber (C) (hereinafter called "EPR") 
used for the present invention is not particularly limited, but one having 
an MFR of 0.1.about.5.0 g/10 minutes, and preferably 0.5.about.4.0 g/10 
minutes, is suitable. Furthermore, the propylene content of the EPR is 
generally 15.about.35% by weight, and preferably 20.about.30% by weight. 
The EPR used for the present invention can also be a 
ethylene-propylene-unconjugated diene rubber (EPDM), or a mixture of 
EPDMs, in which an unconjugated diene such as ethylidenenorbornene, 
dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, and methylenenorbornene, 
is further copolymerized as a third component with an EPR. 
The ethylene-.alpha.-olefin copolymer (D) for the present invention is a 
copolymer of ethylene and an .alpha.-olefin having a carbon number of 
4.about.12. The ratio of the .alpha.-olefin in this copolymer is usually 
25% by mole or less, preferably 20% by mole or less, and more preferably 
5.about.15% by mole. Specific examples of the .alpha.-olefin are 1-butene, 
3-methyl-l-butene, 3-methyl-1-pentene, 4-methyl-l-pentene, 
4,4-dimethyl-l-pentene, vinylcyclopentane, vinlycyclohexane, etc. One, or 
a mixture of two or more, of these .alpha.-olefins can be used. 
A suitable MFR for this copolymer is generally 0.5.about.15.0 g/10 minutes, 
preferably 1.about.13 g/10 minutes, and more preferably 2.about.10 g/10 
minutes. In addition, a suitable density (measured in conformity with JIS 
K7112, which closely corresponds with ASTM D792) for this copolymer is 
generally not more than 0.920 g/cm.sup.3, preferably not more than 0.915 
g/cm.sup.3, and more preferably not more than 0.910 g/cm.sup.3. 
As the talc (E) for the present invention, any talc (which is also called 
magnesium silicate) can be employed. Talcs are widely used as fillers in 
synthetic resins and synthetic rubbers, and can be manufactured by the dry 
method by which a natural ore is coarsely crushed, and then classified and 
refined. Examples of the use of such a talc is described in U.S. Pat. Nos. 
4,480,055, 5,219,913, 5,252,659, and 5,308,908 (which are all incorporated 
herein by reference), etc. A suitable average particle size for the talc 
is generally not more than 5 .mu.m. preferably 0.3.about.3.0 .mu.m, and 
more preferably 0.4.about.2.8 .mu.m. 
In addition, for the purpose of improving the dispersability or the 
adhesion of the talc, the talc to be used may be treated with an 
organotitanate coupling agent, a silane coupling agent, an aluminium 
coupling agent, a fatty acid, a metallic salt of a fatty acid, fatty acid 
ester, or the like. 
The proportion of component (A) with respect to the composition of the 
present invention is 25.about.40% by weight, preferably 27.about.38% by 
weight, and more preferably 28.about.35% by weight. When the proportion of 
component (A) is less than 25%, the rigidity and heat resistance of the 
propylene resin composition are degraded. On the other hand, when the 
proportion exceeds 40% by weight, the impact resistance of the propylene 
resin composition is degraded. 
The proportion of component (B) with respect to the propylene resin 
composition is 25.about.40% by weight, preferably 26.about.38% by weight, 
and more preferably 27.about.36% by weight. When the proportion of 
component (B) is less than 25% by weight, the impact resistance of the 
propylene resin composition is degraded. On the other hand, when the 
proportion exceeds 40% by weight, the rigidity and heat resistance of the 
propylene resin composition are degraded. 
The proportion of component (C) with respect to the propylene resin 
composition is 5.about.15% by weight, preferably 6.about.14% by weight, 
and more preferably 7.about.13% by weight. When the proportion of 
component (C) is less than 5% by weight, the impact resistance of the 
propylene resin composition is degraded. On the other hand, when the 
proportion exceeds 15% by weight, the rigidity and heat resistance of the 
propylene resin composition are degraded. 
The proportion of component (D) with respect to the propylene resin 
composition is 5.about.15% by weight, preferably 6.about.13% by weight, 
and more preferably 7.about.11% by weight. When the proportion of 
component (D) is less than 5% by weight, the impact resistance of the 
propylene resin composition is degraded. On the other hand, when the 
proportion exceeds 15% by weight, rigidity and heat resistance of the 
propylene resin composition are degraded. 
In addition, the proportion of component (E) with respect to the propylene 
resin composition is 5.about.30% by weight, preferably 10.about.28% by 
weight, and more preferably 15.about.25% by weight. When the proportion of 
(E) is less than 5% by weight, the rigidity and heat resistance of the 
propylene resin composition are degraded. On the other hand, a proportion 
exceeding 30% by weight is undesirable, since when this is the case, the 
impact resistance of the propylene resin composition is degraded, and the 
mold will be contaminated by component (E) as it bleeds out. 
In addition, the propylene resin composition of the present invention may 
contain a nucleating agent (F), which is a phosphate compound defined by 
the following formula: 
##STR1## 
wherein R.sub.1 is selected from the group consisting of oxygen, sulfur, 
and a hydrocarbon group having a carbon number of 1.about.10; R.sub.2 and 
R.sub.3, which may be identical to or different from each other, are 
selected from the group consisting of hydrogen and a hydrocarbon group 
having a carbon number of 1.about.10; M is a metal atom selected from the 
group consisting of univalent, divalent, and trivalent metal atoms; n 
represents an integer from 1 to 3; one R.sub.2 and another R.sub.2 are 
separate groups or are linked to form a ring; one R.sub.3 and another 
R.sub.3 are separate groups or are linked to form a ring; and an R.sub.2 
and an R.sub.3 are separate groups or are linked to form a ring. 
Concrete examples of a preferred nucleating agent are sodium 
2,2'-methylenebis(4,6-di-t-butylphenyl)phosphate, sodium 
2,2'-ethylidenebis(4,6-di-t-butylphenyl)phosphate, lithium 
2,2'-methylenebis(4,6-di-t-butylphenyl)phosphate, lithium 
2,2'-ethylidenebis(4,6-di-t-butylphenyl)phosphate, sodium 
2,2'-ethylidenebis(4-i-propyl-6-t-butylphenyl)phosphate, lithium 
2,2'-methylenebis(4-methyl-6-t-butylphenyl)phosphate, lithium 
2,2'-methylenebis(4-ethyl-6-t-butylphenyl)phosphate, calcium 
bis[2,2'-thiobis(4-methyl-6-t-butylphenyl)phosphate], calcium 
bis[2,2'-thiobis(4-ethyl-6-t-butylphenyl)phosphate], calcium 
bis[2,2'-thiobis(4,6-di{-t-}butylphenyl)phosphate], magnesium 
bis[2,2'-thiobis(4,6-di-t-butylphenyl)phosphate], magnesium 
bis[2,2'-thiobis(4-t-octylphenyl)phosphate], sodium 
2,2'-butylidenebis(4,6'-dimethylphenyl)phosphate, sodium 
2,2'-butylidenebis(4,6-di-t-butylphenyl)phosphate, sodium 
2,2'-octylmethylenebis(4,6-di-t-butylphenyl)phosphate, calcium 
bis[2,2'-methylenebis(4,6-di-t-butylphenyl)phosphate], magnesium 
bis[2,2'-methylenebis(4,6-di-t-butylphenyl)phosphate], barium 
bis[2,2'-methylenebis(4,6-di-t-butylphenyl)phosphate], sodium 
2,2'-methylenebis(4-methyl-6-t-butylphenyl)phosphate, sodium 
2,2'-methylenebis(4-ethyl-6-t-butylphenyl)phosphate, sodium 
(4,4'-dimethyl-5,6'-di-t-butyl-2, 2'-biphenyl)phosphate, calcium 
bis[(4,4'-dimethyl-6,6'-di-t-butyl-2,2'-biphenyl)phosphate], sodium 
2,2'-ethylidenebis(4-n-butyl-6-t-butylphenyl)phosphate, sodium 
2,2'-methylenebis(4,6-dimethylphenyl)phosphate, sodium 
2,2'-methylenebis(4,6-diethylphenyl)phosphate, potassium 
2,2'ethylidenebis(4,6-di-t-butylphenyl)phosphate, calcium 
2,2'-ethylidenebis(4,6-di-t-butylphenyl)phosphate, magnesium bis [2,2 
'-ethylidenebis (4,6-di-t-butylphenyl)phosphate], barium bis [2,2 
'-ethylidenebis (4,6-di- t-butylphenyl ) phosphate], aluminium tris [2,2 
'-methylenebis (4,6-di-t-butylphenyl)phosphate], aluminium 
tris[2,2'-ethylidenebis(4,6-di-t-butylphenyl)phosphate], etc. One of these 
nucleating agents can be used, or two or more can be used in conjunction. 
In these, sodium 2,2'-methylenebis(4,6-di-t-butylphenyl)phosphate or 
sodium 2,2'-ethylidenebis(4,6-di-t-butylphenyl)phosphate is particularly 
preferred. 
A suitable amount of the nucleating agent to be added is 0.05.about.0.40 
parts by weight, preferably 0.08.about.0.30 parts by weight, and more 
preferably 0.1.about.0.2 parts by weight, with respect to the total amount 
of components (A) through (D) of 100 parts by weight. 
In order to obtain the resin composition of the present invention, all the 
components are mixed according to a commonly-known method such as a method 
using a ribbon blender, a tumbler, a Henschel mixer, or the like; and then 
the mixture is melt-mixed by using a kneader, mixing roll, banbury mixer, 
extruder, or the like. A suitable temperature for the melt-mixing is 
usually 170.degree..about.300.degree. C., and preferably 
190.degree..about.280.degree. C. The obtained composition can be molded 
into films, sheets, tubes, bottles, or the like, by a commonly-known 
method such as a melt molding method or a compression molding method. The 
molded article can be used alone, or it can be used in a laminated body 
with another material being laminated together therewith. 
Furthermore, any additive used by one having ordinary skill in the art such 
as an antioxidant, a weatherproof stabilizer, an anti-static agent, a 
lubricant, an antiblocking agent, an anti-fogging agent, a pigment, a 
plasticizer, a flexibilizer, or the like may be arbitrarily incorporated 
into the resin composition of the present invention, as long as the 
addition of the additive does not obstruct the above-mentioned object of 
the present invention. 
EXAMPLES 
The present invention will be explained further in detail referring to the 
following examples. 
In the following, the MFRs of propylenes and the ethylene-propylene rubbers 
were measured in conformity with JIS K7210, Table 1 Condition 14, which 
closely corresponds with ASTM D1238. The MFRs of ethylene-.alpha.-olefin 
copolymers were measured in conformity with Condition 4 of the same table. 
Flexural moduli were measured in conformity with JIS K7203, which closely 
corresponds with ASTM D790. Values of Izod impact strength were measured 
with test pieces having a notch in conformity with JIS K7110, which 
closely corresponds with ASTM D256. Deflection temperatures under load 
were measured with a load of 4.6 kg in conformity with JIS K7207B, which 
closely corresponds with ASTM D648. Values of Rockwell hardness were 
measured with scale R in conformity with JIS K7202, which closely 
corresponds with ASTM D785. 
In addition, an example of the production of the used polypropylene is 
shown below. 
(a) Preparation of Solid Catalyst 
56.8 g (597 mmol) of anhydrous magnesium chloride were completely dissolved 
in a liquid mixture of 100 g (174 mmol) of anhydrous ethanol, 500 ml of 
vaseline oil (CP15N; manufactured by IDEMITSU KOHSAN CO., LTD.), and 500 
ml of silicone oil (KF96; manufactured by SHINETSU SILICONE CO.), at 
120.degree. C. in nitrogen atmosphere. This mixture was stirred at 3000 
r.p.m. for 3 minutes at 120.degree. C. using a TK Homomixer manufactured 
by TOKUSHU KIKA KOGYO CO. Next, while maintaining the stirring and while 
cooling, the mixture was transferred into 2 liters of anhydrous heptane in 
such a manner that the anhydrous heptane was kept at 0.degree. C. or 
lower. The obtained white solid was thoroughly washed with anhydrous 
heptane and vacuum-dried at room temperature. 
30 g of the obtained white solid were suspended in 200 ml of anhydrous 
heptane, and while stirring, 500 ml (4.5 mol) of titanium tetrachloride 
were added dropwise over a one hour period. Next, the mixture was heated. 
When the temperature reached 40.degree. C., 4.96 g (17.8 mmol) of 
diisobutyl phthalate were added. The mixture was further heated to 
100.degree. C. over about an hour. Next, after the mixture was allowed to 
react at 100.degree. C. for 2 hours, the solid portion was collected by 
hot filtration. 500 ml (4.5 mol) of titanium tetrachloride were added to 
the obtained solid portion. The mixture was allowed to react at 
120.degree. C. while stirring, and then hot filtration was again conducted 
to collect the obtained solid portion. The collected solid portion was 
washed 7 times with 1 liter of hexane at 60.degree. C., and 3 times with 1 
liter of hexane at room temperature. 
(b) Preparation of TiCl.sub.4 [C.sub.6 H.sub.4 (COO.i-C.sub.4 
H.sub.9).sub.2 ] 
27.8 g (100 mmol) of diisobutyl phthalate were added dropwise to a solution 
of 19 g (100 mmol) of titanium tetrachloride in 1 liter of hexane over 30 
minutes, while the temperature of the mixture was maintained at 0.degree. 
C. After the addition was finished, the mixture was heated to 40.degree. 
C., and was allowed to react for 30 minutes. When the reaction was 
completed, the solid portion was collected and washed 5 times with 500 ml 
of hexane, and thus the desired product was obtained. 
(c) Preparation of catalytic composition for polymerization 
20 g of the solid catalyst obtained in (a) above were suspended in 300 ml 
of toluene, and were treated for 1 hour with 5.2 g (11 mmol) of TiCl.sub.4 
[C.sub.6 H.sub.4 (COO.i-C.sub.4 H.sub.9)2]obtained in (b) above, so as to 
support the catalyst. When this treatment for supporting the catalyst was 
completed, the solid portion was collected by hot filtration, and was 
suspended again in a mixture of 300 ml of toluene and 10 ml (90 mmol) of 
titanium tetrachloride, in which the solid portion was washed by stirring 
at 90.degree. C. for 1 hour. After collecting the solid portion, it was 
washed 5 times with 500 ml of toluene at 90.degree. C. and 3 times with 
500 ml of hexane at room temperature. 
Prepolymerization 
In nitrogen atmosphere, 500 ml of n-heptane, 6.0 g (53 mmol) of 
triethylaluminium, 3.9 g (17 mmol) of dicyclopentyldimethoxysilane, and 10 
g of the catalytic composition for polymerization obtained in (c) above 
were put in an autoclave having a volume of 3 liters, and stirred for 5 
minutes at a temperature in the range of 0.about.5.degree. C. Next, a 
propylene was supplied into the autoclave in such an amount that 10 g of 
the propylene would be polymerized for each 1 g of the catalytic 
composition for polymerization. Prepolymerization was then carried out at 
a temperature range of 0.about.5.degree. C. for 1 hour. The obtained 
prepolymerized solid catalytic composition was washed 3 times with 500 ml 
of n-heptane, and was used in the main polymerization below. 
Main polymerization 
In nitrogen atmosphere, 2.0 g of the prepolymerized solid catalytic 
composition prepared by the above method, 11.4 g (100 mmol) of 
triethylaluminium, and 6.84 g (30 mmol) of dicyclopentyldimethoxysilane 
were put in an autoclave with a stirring device having a volume of 60 
liters. After the autoclave was heated to 70.degree. C., a propylene was 
fed thereto, and polymerization was carried out for 1 hour. The unreacted 
propylene and hydrogen were removed thereafter, and thus the 
polymerization was terminated. As a result, a polypropylene (hereinafter 
referred to as "PP1") with an MFR of 25.1 g/10 minutes was obtained. 
In the same way, except that an amount of hydrogen charged during 
polymerization was varied, a polypropylene (hereinafter referred to as 
"PP2") with an MFR of 43.7 g/10 minutes, a polypropylene (hereinafter 
referred to as "PP3") with an MFR of 7.0 g/10 minutes, and a polypropylene 
(hereinafter referred to as "PP4") with an MFR of 12.4 g/10 minutes were 
obtained. 
In addition, the following 5 kinds of polypropylene were used for 
comparative examples: 
a polypropylene (hereinafter referred to as "PP5") with an MFR of 32.2 g/10 
minutes; a polypropylene (hereinafter referred to as "PP6") with an MFR of 
3.2 g/10 minutes; and a polypropylene (hereinafter referred to as "PP7") 
with an MFR of 0.8 g/10 minutes; PP5, PP6, PP7 being obtained by using as 
catalytic components titanium trichloride manufactured by TOSOH AKZO CO., 
and diethylaluminium chloride, and by varying the concentration of 
hydrogen; and a polypropylene (hereinafter referred to as "PP8") with an 
MFR of 6.8 g/10 minutes; a polypropylene (hereinafter referred to as 
"PP9") with an MFR of 10.8 g/10 minutes; PP8 and PP9 being obtained via 
prepolymerization and main polymerization by using the solid catalyst 
obtained in (a) instead of the catalytic composition obtained according to 
the operations of (a).about.(c) above; in the polymerization for PP8, 
dicyclopentyldimethoxysilane and triethylaluminium in the molar ratio of 
0.01 being used; and in the polymerization for PP9, 
dicyclopentyldimethoxysilane and triethylaluminium in the molar ratio of 
0.3 being used. 
With regard to the above polypropylenes, XI, IP, N, and N.sub.f were 
measured. The results are shown in Table 2. 
The conditions for the measurement of IP are shown below: 
Measuring device: JNM-GSX400 manufactured by JEOL LTD. 
Measuring mode: proton decoupling method 
Pulse width: 8.0 .mu.s 
Pulse repetition time: 3.0 s 
Cumulative number of repetitions: 20000 times 
Solvent: a mixture of 1,2,4-trichlorobenzene and benzene deuteride (75/25% 
by weight) 
Internal Circulation: hexamethyldisiloxane 
Sample concentration: 300 mg/3.0 ml solvent 
Measuring temperature: 120.degree. C. 
In addition, propylene-ethylene block copolymers were obtained carrying out 
preparation of catalyst and prepolymerization in the same manner as for 
PP1 above, and then carrying out the following main polymerization. 
First-step Polymerization: polymerization for propylene homopolymer 
In nitrogen atmosphere, 2.0 g of the prepolymerized solid catalytic 
composition prepared by the above-mentioned method, 11.4 g of 
triethylaluminium, 6.84 g of dicyclopentyldimethoxysilane were put in an 
autoclave with a stirring device having a volume of 60 liters. Next, the 
propylene and hydrogen were put into the autoclave, the temperature was 
raised to 70.degree. C., and polymerization was carried out for 1 hour. 
Then, the unreacted propylene was removed, and thus the reaction was 
terminated. After the reaction had finished, the reaction product was 
sampled. 
Second-step Polymerization: polymerization for propylene-ethylene copolymer 
Next, hydrogen was supplied to the autoclave while the ethylene/propylene 
mixture ratio were being controlled, and reaction took place at 70.degree. 
C. for 40 minutes. After the reaction, the unreacted gas was removed, and 
a copolymer (hereinafter referred to as "BPP1") was obtained in which the 
rubber component content was 14.5% by weight, and the propylene content in 
the rubber component was 55.1% by weight. 
Similarly, by changing the ethylene/propylene mixture ratio, a copolymer 
(hereinafter referred to as "BPP2") with a rubber component content of 
19.3% by weight and a propylene content in the rubber component of 62.4% 
by weight; and a copolymer (hereinafter referred to as "BPP3") with a 
rubber component content of 28.6% by weight and a propylene content in the 
rubber component was 67.9% by weight were obtained. 
XI, IP, N, and N.sub.f were measured with regard to each sample of 
propylene homopolymer taken during the preparation of the copolymer. The 
results are shown in Table 2. 
TABLE 2 
______________________________________ 
Type of XI (% by IP N N.sub.f (% by 
Polypropylene 
weight) (%) (-) weight) 
______________________________________ 
PP1 99.5 99.5 801 80 
PP2 99.5 99.5 790 73 
PP3 99.2 99.4 783 65 
PP4 99.7 99.5 698 72 
(Comparative) 
PP5 98.6 97.7 225 1 or less 
PP6 98.4 97.4 108 1 or less 
PP7 98.3 96.9 72 1 or less 
PP8 97.9 96.7 152 30 
PP9 97.1 95.8 93 21 
BPP1 99.5 99.5 821 82 
BPP2 99.5 99.5 790 78 
BPP3 98.1 98.1 123 7 
______________________________________ 
As ethylene-propylene rubbers, a rubber (hereinafter referred to as "EPR1") 
with an MFR of 4.5 g/10 minutes and a propylene content of 30.3% by 
weight; a rubber (hereinafter referred to as "EPR2") with an MFR of 1.1 
g/10 minutes and a propylene content of 26.1% by weight; and a rubber 
(hereinafter referred to as "EPR3") with an MFR of 6.5 g/10 minutes and a 
propylene content of 36.8% by weight were used. 
As ethylene-.alpha.-olefin copolymers, a copolymer (hereinafter referred to 
as "PEC1") with an MFR of 1.4 g/10 minutes, a density of 0.905 g/cm.sup.3, 
and a 1-butene content of 8.7% by mole; a copolymer (hereinafter referred 
to as "PEC2") with an MFR of 7.5 g/10 minutes, a density of 0.899 
g/cm.sup.3, and a 1-butene content of 10.9% by mole; and a copolymer 
(hereinafter referred to as "PEC3") with an MFR of 18.7 g/10 minutes, a 
density of 0.915 g/cm.sup.3, and a 1-butene content of 26% by mole were 
used. 
As talcs, a talc (hereinafter referred to as "TALC1") with an average 
particle size of 2.3 .mu.m, and a specific surface area of 4.0 m.sup.2 /g; 
and a talc (hereinafter referred to as "TALC2") with an average particle 
size of 11.0 .mu.m, and a specific surface area of 3.4 m.sup.2 /g were 
used. 
In addition, sodium 2,2'-methylenebis(4,6-di-t-butylphenyl)phosphate was 
used as a nucleating agent. 
Examples 1.about.7, and Comparative Examples 1.about.7 
For each Example and Comparative Example, a polypropylene, a 
propylene-ethylene block copolymer, an ethylene-propylene rubber, an 
ethylene-.alpha.-olefin copolymer, a talc, and a nucleating agent (types 
and proportions of these components being shown in Table 3; the 
proportions being expressed in parts by weight with respect to 100 parts 
by weight of the total amount of the resin) were mixed using a Supermixer 
(model SMV20) manufactured by KAWATA MFG. CO., LTD., and the mixture was 
palletized using a biaxial extruder (model AS30) manufactured by NAKATANI 
MACHINE CO., LTD). Each pellet obtained was made into a test piece using 
an injection molding machine manufactured by TOSHIBA MACHINE CO., LTD., at 
220.degree. C., with a mold cooling temperature of 50.degree. C. After 
leaving the obtained test piece in a thermostatic chamber for 2 days at 
23.degree. C. with the relative humidity of 50% temperature, flexural 
modulus, Izod impact strength (using the test piece with a notch), the 
deflection temperature under load, and Rockwell hardness were measured. 
The results obtained are shown in Table 4. 
TABLE 3 
__________________________________________________________________________ 
Propylene- 
Ethylene- Ethylene-.alpha.- 
ethylene block 
propylene olefin Nucleating 
Polypropylene 
copolymer rubber copolymer Talc agent 
Proportion 
Proportion 
Proportion 
Proportion 
Proportion 
Proportion 
Type 
(% by wt) 
Type 
(% by wt) 
Type 
(% by wt) 
Type 
(% by wt) 
Type 
(% by 
(Parts by 
__________________________________________________________________________ 
wt) 
Example 1 
PP1 
35 BPP1 
28 EPR1 
10 PEC1 
10 TALC 
17 -- 
1 
Example 2 
PP2 
31 BPP2 
31 EPR2 
11 PEC3 
13 TALC 
14 -- 
1 
Example 3 
PP3 
30 BPP3 
27 EPR1 
11 PEC1 
10 TALC 
22 0.1 
1 
Example 4 
PP4 
35 BPP2 
30 EPR3 
10 PEC2 
11 TALC 
14 -- 
1 
Example 5 
PP2 
38 BPP2 
36 EPR2 
9 PEC2 
8 TALC 
9 -- 
2 
Example 6 
PP1 
17 BPP1 
31 EPR1 
7 PEC1 
9 TALC 
22 0.15 
PP3 
14 1 
Example 7 
PP2 
20 BPP1 
28 EPR1 
8 PEC2 
8 TALC 
18 -- 
PP4 
18 1 
Comparative 
PP5 
37 BPP3 
34 EPR2 
13 PEC3 
12 TALC 
4 -- 
Example 1 2 
Comparative 
PP6 
20 BPP1 
50 EPR2 
9 PEC1 
8 TALC 
13 -- 
Example 2 1 
Comparative 
PP8 
30 BPP2 
25 EPR3 
17 PEC2 
18 TALC 
10 -- 
Example 3 2 
Comparative 
PP9 
25 BPP3 
22 EPR1 
18 PEC3 
18 TALC 
17 -- 
Example 4 1 
Comparative 
PP1 
20 BPP1 
40 EPR3 
15 PEC2 
15 TALC 
10 -- 
Example 5 1 
Comparative 
PP2 
52 BPP2 
27 EPR3 
4 PEC2 
3 TALC 
13 0.2 
Example 6 
Comparative 
PP7 
20 BPP3 
17 EPR1 
6 PEC1 
6 TALC 
31 -- 
Example 7 
PP9 
20 1 
__________________________________________________________________________ 
TABLE 4 
__________________________________________________________________________ 
Izod 
Impact 
Strength 
Deflection 
Flexural 
(test piece 
Temperature 
Rockwell 
MFR Modulus 
with notch) 
Under Load 
Hardness 
(g/10 min) 
(kg/cm.sup.2) 
(kg .multidot. cm/cm) 
(.degree.C.) 
(R Scale) 
__________________________________________________________________________ 
Example 1 
13 28100 
3.9 147 91 
Example 2 
17 27500 
4.8 141 90 
Example 3 
19 28500 
4.3 144 88 
Example 4 
18 27300 
4.5 146 89 
Example 5 
18 28900 
5.1 146 87 
Example 6 
20 28800 
5.3 148 89 
Example 7 
16 27800 
4.8 144 90 
Comparative 
16 16500 
4.8 109 75 
Example 1 
Comparative 
17 17200 
5.5 112 78 
Example 2 
Comparative 
15 17500 
6.1 108 71 
Example 3 
Comparative 
18 19100 
4.6 122 82 
Example 4 
Comparative 
20 19200 
4.5 106 69 
Example 5 
Comparative 
15 28300 
2.6 140 94 
Example 6 
Comparative 
18 28600 
2.1 142 92 
Example 7 
__________________________________________________________________________