Thermoplastic polymer composition

A thermoplastic polymer composition comprising: (i) 100 parts by weight of a thermoplastic polymer component which comprises an ethylene-propylene rubber, an ethylene copolymer and a propylene polymer (including an ethylene-propylene block copolymer), and (ii) 0 to 7 parts by weight of talc, the thermoplastic polymer component being composed of, according to fractionation using o-dichlorobenzene as a solvent, component (A) which is a component soluble in the solvent at 40.degree. C., component (B) which is a component insoluble in the solvent at 40.degree. C. but soluble at 110.degree. C., and component (C) which is a component insoluble in the solvent even at 110.degree. C. in such a proportion that the total amount of the components (A) and (B) is from 50 to 70 parts by weight, the weight ratio of the component (A) to the component (B) being from 0.5 to 1.5, and the amount of the component (C) is from 50 to 30 parts by weight.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a specific thermoplastic polymer composition 
which comprises an ethylene-propylene rubber, an ethylene copolymer, a 
propylene polymer (including a propylene-ethylene block copolymer) and 
talc, shows good processability on injection molding, can give a molded 
product having a good appearance, is excellent in the surface hardness, 
impact resistance and adhesion of coating, and thus is suited for the 
production of injection-molded products such as automobile parts. 
2. Background Art 
Heretofore, many attempts have been made to enhance the value of molded 
products of various rubbers such as an ethylene-propylene copolymer rubber 
by improving their fluidity and imparting rigidity to them. For instance, 
compositions prepared by incorporating polypropylene to rubber have been 
known as disclosed in Japanese Patent Publications Nos. 57-57049, 62-5460 
and 62-5461. However, the proportion of polypropylene in these 
compositions is generally small, and polypropylene having high fluidity 
and high crystallinity is not particularly employed, so that the 
compositions have low crystallization rates. A long cooling time is 
therefore required when large-sized molded products of the compositions 
are produced by means of injection molding. The productivity is thus 
extremely low. In addition, since the compositions contain neither 
ethylene copolymers nor talc, they can give only such molded products that 
are poor in the surface smoothness and surface hardness. 
The composition disclosed in Japanese Patent Publication No. 61-19651 
comprises a relatively large amount of polypropylene. However, this 
composition also contains neither ethylene copolymers nor talc. Moreover, 
a partially crosslinked rubber is used as a rubber component. For these 
reasons, the composition is also confronted with the same problems as in 
the above compositions in the productivity upon producing molded products, 
and in the surface smoothness and surface hardness of molded products. 
On the other hand, Japanese Patent Publication No. 60-3420 discloses a 
composition prepared by incorporating an ethylene-propylene rubber and 
talc into a propylene-ethylene block copolymer. This composition is 
excellent in adhesion of coating and low-temperature impact resistance. 
Further, Japanese Patent Laid-Open Publication No. 1-204946 discloses a 
composition comprising an ethylene-propylene rubber, a propylene-ethylene 
block copolymer, an ethylene copolymer and talc. This composition can give 
molded products having an improved dimensional stability. These 
compositions are, however, still insufficient in the surface hardness and 
smoothness of molded products. The molded products will be easily flawed 
due to their low surface hardness and have a poor appearance due to their 
poor surface smoothness. 
It is therefore an object of the present invention to solve the above 
problems in the prior art and provide a thermoplastic polymer composition 
which shows good processability on injection molding, can give an 
injection-molded product having a good appearance and a low density, and 
is excellent in the surface hardness, impact resistance and adhesion of 
coating. 
SUMMARY OF THE INVENTION 
It has now been found that the above object can be achieved by blending an 
ethylene-propylene rubber, an ethylene copolymer, a propylene polymer and 
talc in a specific proportion. 
Thus, the present invention provides a thermoplastic polymer composition 
comprising (i) 100 parts by weight of a thermoplastic polymer component 
which comprises an ethylene-propylene rubber, an ethylene copolymer and a 
propylene polymer (including a propylene-ethylene block copolymer), and 
(ii) 0 to 7 parts by weight of talc, the thermoplastic polymer component 
being composed of, according to fractionation using o-dichlorobenzene as a 
solvent, component (A) which is a component soluble in the solvent at 
40.degree. C., component (B) which is a component insoluble in the solvent 
at 40.degree. C. but soluble at 110.degree. C., and component (C) which is 
a component insoluble in the solvent even at 110.degree. C. in such a 
proportion that the total amount of the components (A) and (B) is from 50 
to 70 parts by weight, the weight ratio of the component (A) to the 
component (B) being from 0.5 to 1.5, and the amount of the component (C) 
is from 50 to 30 parts by weight. 
The composition of the present invention shows good processability when 
subjected to injection molding, can give molded products which have a good 
appearance, and is excellent in the surface hardness, impact resistance 
and adhesion of coating. 
More specifically, the present invention provides, for instance, a 
composition having a melt flow rate (MFR) of 10 g/10 min or more, a 
density of 0.95 g/cm.sup.3 or lower, a flexural modulus of 6,000 
kg/cm.sup.2 or more, a Rockwell hardness of 50 or more, an Izod impact 
strength at -30.degree. C. of 5 kg.cm/cm or more, and a peeling strength 
of a coated film, which will be described later, is 700 g/cm or more. 
Moreover, since the proportion of a high-crystalline component (C) and a 
relatively high-crystalline component (B) in the composition of the 
present invention is larger than that in the conventional thermoplastic 
polymer compositions, the composition of the invention can be solidified 
by cooling in a shorter time than before. The cooling time required in the 
process of injection molding can thus be shortened. This brings about a 
remarkable increase in the production speed of molded products. 
The composition of the present invention, which has the above-described 
advantageous properties, is suitably utilized for injection-molded 
automobile parts, especially for large-sized parts which needs coating and 
require a good appearance and flaw-resistance, such as a bumper, an air 
dam spoiler and a fascia. 
DETAILED DESCRIPTION OF THE INVENTION 
The ethylene-propylene rubber for use in the present invention should have 
an MFR (at 230.degree. C.) of 0.3 to 3 g/10 min, preferably 0.5 to 2 g/10 
min, and contain a proper amount of crystalline segment in the molecule. 
In the present invention, an ethylene-propylene rubber which contains 12% 
to 30% by weight, preferably 15% to 25% by weight, of propylene, and has a 
melting point determined by a differential scanning calorimeter of 
30.degree. to 60.degree. C., preferably 35.degree. to 55.degree. C., is 
preferred from the viewpoint of surface hardness and adhesion of coating. 
The ethylene-propylene rubber may be an EPDM containing ethylene 
norbornene, dicyclopentadiene, 1,4-hexadiene or the like as a third 
component. The ethylene-propylene rubber may also be a mixture of EPM and 
EPDM. 
It is desirable that the ethylene copolymer to be used in the present 
invention have an MFR (at 230.degree. C.) of 1 to 10 g/10 min, preferably 
2 to 8 g/10 min, from the viewpoint of processability and impact 
resistance; a melting point determined by a differential scanning 
calorimeter of 60.degree. to 100.degree. C., preferably 65.degree. to 
90.degree. C., because it is important that the crystallinity of the 
ethylene copolymer be not too high when the compatibility between the 
ethylene-propylene rubber and the ethylene copolymer is taken into 
consideration; and a density of 0.92 g/cm.sup.3 or less, preferably 0.91 
g/cm.sup.3 or less, more preferably 0.87-0.89 g/cm.sup.3, from the 
viewpoint of surface hardness, impact resistance and adhesion of coating. 
The above-described ethylene copolymer can be prepared by copolymerizing 
ethylene and an .alpha.-olefin in the presence of an ionic polymerization 
catalyst such as a Ziegler catalyst, a Phillips catalyst or a Kaminsky 
catalyst. Production methods applicable to the above copolymerization may 
be a gas phase fluidized bed method, a solution method, a slurry method, 
and a high pressure ionic polymerization method in which polymerization is 
carried out under a pressure of 200 kg/cm.sup.2 or more at a temperature 
of 150.degree. C. or higher. As long as the melting point of the resulting 
copolymer falls within the above range, the .alpha.-olefin content in the 
copolymer is not particularly limited; however, it is generally 12-30% by 
weight, preferably 15-25% by weight. The .alpha.-olefin to be 
copolymerized with ethylene should be a 1-olefin having 4 to 8 carbon 
atoms. Examples of the 1-olefin include butene-1, 3-methylbutene-1, 
pentene-1, 4-methylpentene-1, hexene-1, heptene-1 and octene-1. Such 
.alpha.-olefins may be used singly or as a mixture of two or more. 
From the viewpoint of processability and impact resistance, it is preferred 
that the propylene polymer for use in the present invention be a resin 
having an MFR (at 230.degree. C.) of 30 to 150 g/10 min, preferably 50 to 
100 g/10 min, and containing 1.5% to 8% by weight, preferably 2% to 7% by 
weight, of ethylene. It is further preferred that the resin contain a 
crystalline propylene polymer moiety with a density of 0.907 g/cm.sup.3 or 
more, preferably 0.908 g/cm.sup.3 or more, when surface hardness is taken 
into consideration. Among such preferable resins, a propylene-ethylene 
block copolymer is especially preferred. 
The above mentioned MFR of the propylene polymer may be controlled at the 
time of polymerization, or adjusted by an organic peroxide such as a 
diacyl peroxide or a dialkyl peroxide after the polymerization is 
completed. 
The propylene polymer may also be a copolymer with other unsaturated 
monomer such as maleic anhydride, methacrylic acid or 
trimethoxyvinylsilane which is introduced thereto by graft or random 
copolymerization. In particular, the use of a mixture of the propylene 
polymer and a crystalline polypropylene grafted with maleic anhydride or 
trimethoxyvinylsilane can improve the surface hardness of the resulting 
composition. 
A stereospecific catalyst is employed for the production of the above 
propylene polymer. Typical preparation methods of the catalyst are a 
method as disclosed in Japanese Patent Laid-Open Publication Nos. 
56-100806, 56-120712 and 58-104907, in which a titanium trichloride 
composition prepared by reducing titanium tetrachloride with an 
organoaluminum compound and then treating with various electron donors and 
electron acceptors is combined with an organoaluminum compound and an 
aromatic carboxylic acid ester; and a method as disclosed in Japanese 
Patent Laid-Open Publications Nos. 57-63310, 63-43915 and 63-83116, in 
which titanium tetrachloride and various electron donors are brought into 
contact with a magnesium halide to give a carrier-type catalyst. 
The above three kinds of polymer components are mixed so that the resulting 
polymer mixture (thermoplastic polymer component) can be composed of, 
according to fractionation using o-dichlorobenzene as a solvent, component 
(A) which is a component soluble in the solvent at 40.degree. C., 
component (B) which is a component insoluble in the solvent at 40.degree. 
C. but soluble at 110.degree. C., and component (C) which is a component 
insoluble in the solvent even at 110.degree. C. in such a proportion that 
the total amount of the components (A) and (B) is from 50 to 70 parts by 
weight, the weight ratio of the component (A) to the component (B) is from 
0.5 to 1.5, and the amount of component (C) is from 50 to 30 parts by 
weight. 
In the case where the total amount of the components (A) and (B) is less 
than the above range, that is, the amount of the component (C) is in 
excess of the above range, the resulting composition has a poor impact 
resistance. On the other hand, when the total amount of the components (A) 
and (B) is more than the above range, the resulting composition cannot 
have a sufficiently high flexural modulus. Further, when the weight ratio 
of the component (A) to the component (B) [component (A)/component (B)] is 
less than the above range, the resulting composition will exhibit a poor 
adhesion of coating; while when the weight ratio is in excess of the above 
range, a molded product of the composition will have a poor surface 
smoothness. 
When the intrinsic viscosity ([.eta.]) of the component (C) is high, the 
resulting composition requires a high molding temperature, leading to an 
increase in molding cycle. It is therefore desirable that the intrinsic 
viscosity of the component (C) be 2.0 dl/g or less, preferably 1.7 dl/g or 
less. 
The crystallinity of the propylene polymer can be shown by the proportion 
of highly-crystalline polypropylene, an index of which can be given by the 
following formula: 
##EQU1## 
wherein component (D) indicates a polypropylene moiety contained in the 
component (B), determined by .sup.13 C-NMR. In the present invention, it 
is preferred that the above index be 0.70 or more, preferably 0.75 or 
more, from the viewpoint of surface hardness. 
In the present invention, use may be made of a mixture of two or more kinds 
of the ethylene-propylene rubber, two or more kinds of the ethylene 
copolymer, and two or more kinds of the propylene polymer, as long as the 
components (A), (B), (C) and (D) of the resulting thermoplastic polymer 
component can satisfy the aforementioned conditions. 
The talc usable in the present invention should preferably have an average 
particle size of 5.0 .mu.m or less, preferably from 0.5 to 3.0 .mu.m, and 
a specific surface area of 3.5 m.sup.2 /g or more, preferably from 3.5 to 
6.0 m.sup.2 /g. Such talc may be prepared by a dry pulverization and the 
subsequent dry classification. When the average particle size of talc is 
in excess of 5.0 .mu.m, the resulting composition is likely to exhibit a 
poor impact resistance. The average particle size of talc herein is a 
particle size at a cumulative amount of 50% by weight in a cumulative 
particle size distribution curve obtained by a liquid phase sedimentation 
light transmission method using, for instance, Model CP manufactured by 
Shimadzu Corp. The specific surface area can be measured by an air 
permeation method using, for instance, a specific surface area measuring 
apparatus Model SS-100 manufactured by Shimadzu Corp. 
To impart high adhesion of coating to a molded product of the composition 
of the invention, it is preferable to control the amount of a 
non-crystalline moiety in the molded product to 50% by weight or more of 
the total amount of the resin components contained therein. Specifically, 
it is preferable that the thermoplastic polymer component comprising the 
ethylene-propylene rubber, the ethylene copolymer and the propylene 
polymer have a degree of crystallinity, determined by pulsed NMR, of 50% 
or less. 
The amount of talc to be used is from 0 to 7 parts by weight, preferably 
from 0 to 5 parts by weight, for 100 parts by weight of the total amount 
of the ethylene-propylene rubber, the ethylene copolymer and the propylene 
polymer. When the amount of talc is in excess of 7 parts by weight, the 
density of the resulting composition is too high, giving a molded product 
of too much weight. 
The talc can be used without subjecting to any treatment. However, in order 
to improve the adhesion between the talc and the polymers, or the 
dispersibility of the talc in the polymers, the talc may be treated with 
various organic titanate coupling agents, silane coupling agents, fatty 
acids, metal salts of fatty acid, fatty acid esters, and the like. 
Other auxiliary components may be added to the composition of the present 
invention unless they substantially impair the advantageous properties of 
the composition. 
Examples of the auxiliary components usable in the present invention 
include additives which are conventionally employed in thermoplastic 
polymer compositions, for example, a processing stabilizer, an 
antioxidant, an ultraviolet absorber, a light stabilizer, various soaps 
such as metal soaps, an antistat, a lubricant, a nucleator, a pigment and 
a dispersant for pigment. In addition, whiskers such as fibrous potassium 
titanate, fibrous magnesium oxalfate and fibrous aluminum borate, and 
carbon fibers, which are known as materials capable of imparting higher 
flexural modulus than that imparted by talc, can be employed, if 
necessary. 
The composition of the present invention can be prepared by kneading the 
polymer components, the talc, and, if necessary, the auxiliary components 
by any of an ordinary extruder, a Banbury mixer, a roller, a Brabender and 
a kneader. However, the use of a twin-screw extruder is desirable in the 
present invention. 
From the composition of the present invention, molded products may be 
prepared by any known molding method such as an injection molding method, 
an extrusion molding method and a blow molding method. However, an 
injection molding method will be most advantageously employed in view of 
the inherent properties of the composition.

This invention will now be explained in more detail with reference to the 
following examples, which are given merely for illustration of this 
invention and are not intended to be limiting thereof. 
In the examples, solvent fractionation was carried out in the following 
manner: 
(1) 5 g of a sample and 1.5 g of 2,6-di-t-butyl-p-phenol as an antioxidant 
were dissolved in 1.5 l of o-dichlorobenzene at 140.degree. C. The 
resulting mixture was filtrated through a 0.45-.mu.m Teflon filter at 
140.degree. C. to remove insoluble components such as a filler. 
(2) After redissolving the filtrate at 140.degree. C., 300 g of Celite 
(#545) was added to the solution. While stirring, the resulting mixture 
was cooled to room temperature at a cooling rate of 10.degree. C./hour to 
provide a coating on the surface of the Celite. 
(3) The coated Celite was filled in a cylindrical column. To this column, 
o-dichlorobenzene containing the above antioxidant in the same 
concentration as above was introduced, and fractionation was carried out 
by heating the column to temperatures of 40.degree. C., 110.degree. C. and 
140.degree. C. thereby to elute the coating. 
(4) After the fractionation was completed, a large amount of methanol was 
added to each fraction, followed by filtration through a 0.45-.mu.m Teflon 
filter. After drying in vacuum, each fraction was weighed. The proportion 
of each fraction was determined on the basis of the total weight of the 
three fractions. 
Measuring methods used in the examples are as follows: 
(i) Melting Point: 10 mg of a sample was placed in a differential scanning 
calorimeter, for instance, Model 910 manufactured by Du Pont Corp. After 
heating to a temperature of +180.degree. C., the sample was cooled to 
-100.degree. C. at a constant cooling rate of 10.degree. C./min. 
Thereafter, the sample was heated again at a constant heating rate of 
20.degree. C./min. A temperature corresponding to the peak of the 
thermogram obtained was taken as the melting point of the sample. 
(ii) Intrinsic Viscosity: A sample polymer was dissolved in 
o-dichlorobenzene containing 0.2% by weight of the above-mentioned 
antioxidant to give solutions of various concentrations, ranging from 0.1 
to 0.3 g/dl, of the polymer. Measurements of viscosity were carried out at 
a temperature of 140.degree. C. The intrinsic viscosity of the polymer was 
determined by extrapolating to a point of zero concentration of the 
solution. 
(iii) Propylene Content in Component (B): The propylene content was 
determined by an integrated intensity of signals deriving from a 
polypropylene carbon, which appear in the vicinity of 46.5 ppm from TMS 
(tetramethylsilane) in a .sup.13 C-NMR spectrum. 
(iv) Total Crystallinity of Resin: Determined by pulsed NMR (see Kobunshi 
Jikkengaku 18, "Magnetic Resonance of Polymer", pp. 143-144, Kyoritsu 
Shuppan Kabushiki Kaisha). 
(v) MFR: Measured in accordance with ASTM-D1238 with application of a load 
of 2.16 kg at a temperature of 230.degree. C. 
(vi) Density: Measured in accordance with ASTM-D1505 at a temperature of 
23.degree. C. 
(vii) Flexural Modulus: Measured in accordance with ASTM-D790 at a 
temperature of 23.degree. C. 
(viii) Surface Hardness: Evaluated by a Rockwell hardness (Scale R), 
measured in accordance with ASTM-D785 at a temperature of 23.degree. C. 
(ix) Impact Resistance: Evaluated by an Izod value at a temperature of 
-30.degree. C., measured in accordance with ASTM-D256. 
(x) Adhesion of Coating: Evaluated by the peeling strength of a coated 
film, determined in accordance with the following manner: 
&lt;1&gt; Coating Method 
a. An injection-molded specimen was exposed to the vapor of boiling 
1,1,1-trichloroethane for 30 seconds, and then allowed to stand at room 
temperature for 30 minutes for drying. 
b. The lower half of the surface of the specimen was covered with a masking 
tape while the upper half thereof remained uncovered. 
c. A polyurethane-modified polyolefin primer for polypropylene, "Soflex 
2500" manufactured by Kansai Paint Co., Ltd., was coated onto the specimen 
by means of spray coating to form a primer layer with a thickness of 
approximately 10 .mu.m. After drying the primer at room temperature for 30 
minutes, the masking tape was peeled off the specimen. 
d. A one-can urethane coating containing an isocyanate hardening agent, 
"Flexen 105" manufactured by Nihon B-Chemical K.K., was then coated onto 
the specimen by means of spray coating to form a coating layer with a 
thickness of approximately 80 .mu.m. The specimen was placed in an air 
oven adjusted to a temperature of 120.degree. C. for 30 minutes to bake 
the coating, and then allowed to stand at room temperature for 48 hours. 
The specimen thus obtained was used in the peeling strength test described 
below. 
&lt;2&gt; Measurement 
a. A cellophane adhesive tape was adhered to the entire surface of the test 
specimen obtained above. On the surface of the adhesive tape, cuts 
reaching to the base were made by a cutter in the long direction of the 
specimen at 10-mm intervals. 
b. The coating layer formed on the surface not coated with primer was 
peeled, together with the cellophane adhesive tape adhered thereon, off 
the specimen, and bent to the 180-degree direction. The specimen in this 
state was set in a tensile tester. 
c. The tester was operated at 23.degree. C. at a rate of pulling of 50 
mm/min. From the curve obtained on the recorder, a value corresponding to 
the peak was determined. The average of such values for ten peaks was 
taken herein as the value indicating the peeling strength of coating of 
the specimen. 
EXAMPLES 1 TO 8 AND COMATIVE EXAMPLES 1 TO 6 
Materials shown in Table 1 were mixed in accordance with the formulation 
shown in Table 2. To the resulting mixtures, 0.1 part by weight of 
2,6-di-t-butyl-p-phenol, 0.1 part by weight of 
tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane 
and 0.5 part by weight of carbon black were added, and mixed by a "Super 
Mixer" manufactured by Kawada Seisakusho K.K. for 5 minutes. The mixtures 
thus obtained were kneaded and granulated at 210.degree. C. by a 
twin-screw kneader, "FCM" manufactured by Kobe Steel Ltd., to give 
thermoplastic polymer compositions. 
Injection-molded specimens of the thus obtained thermoplastic polymer 
compositions were respectively prepared by an injection molding machine 
with a clamp pressure of 100 ton at a molding temperature of 220.degree. 
C. The properties of the specimens were evaluated in accordance with the 
above-described measuring methods. Furthermore, evaluation of the 
appearance (surface smoothness) of molded products was made in the 
following manner: 
Automobile bumpers (weight: 5 kg) were prepared by an injection molding 
machine with a clamp pressure of 4,000 ton at a molding temperature of 
220.degree. C. On the bumpers thus obtained, coating was conducted in the 
following manner: 
a. The bumper was exposed to the vapor of boiling 1,1,1-trichloroethane for 
60 seconds. 
b. A chlorinated polypropylene primer for polypropylene, "R-117" 
manufactured by Nihon B-Chemical K.K., was then coated onto the bumper by 
means of spray coating to form a primer layer with a thickness of 
approximately 15 .mu.m. The bumper was placed in an air oven adjusted to a 
temperature of 80.degree. C. for 10 minutes to bake the coating. 
c. A melamine-acrylate coating, "R-320" manufactured by Nihon B-Chemical 
K.K., was then coated onto the bumper by means of spray coating to form a 
coating layer with a thickness of approximately 35 .mu.m. The bumper was 
placed in an air oven at 120.degree. C. for 20 minutes to bake the 
coating. 
The surface smoothness of the coated bumper was evaluated by visual 
observation in comparison with a sheet metal having the same coating. 
The results are shown in Tables 3 and 4. 
TABLE 1 
______________________________________ 
Materials for Use in Examples and Comparative Examples 
______________________________________ 
&lt;Ethylene-Propylene Rubber&gt; 
MFR Melting Point 
Propylene Content 
Type (g/10 min) (.degree.C.) 
(% by weight) 
______________________________________ 
EPR-1 1.0 79 12 
EPR-2 1.8 53 16 
EPR-3 0.6 39 24 
EPR-4 0.9 19 32 
______________________________________ 
&lt;Ethylene Copolymer&gt; 
Melting 
MFR Point Density 
Butene Content 
Type (g/10 min) 
(.degree.C.) 
(g/cm.sup.3) 
(% by weight) 
______________________________________ 
PEX-1 3.5 105 0.915 10 
PEX-2 2.3 88 0.900 15 
PEX-3 7.5 68 0.882 24 
PEX-4 5.2 55 0.890 32 
______________________________________ 
&lt;Propylene-Ethylene Block Copolymer&gt; 
Ethylene Density of Propylene 
MFR Content Polymer Moiety 
Type (g/10 min) 
(% by weight) (g/cm.sup.3) 
______________________________________ 
PP-1 16 4.5 0.907 
PP-2 55 7.2 0.905 
PP-3 53 4.0 0.908 
PP-4 87 5.5 0.907 
PP-5 142 2.7 0.911 
______________________________________ 
&lt;Talc&gt; 
Average Particle Size 
Specific Surface Area 
Type (.mu.m) (m.sup.2 /g) 
______________________________________ 
Talc-1 2.1 4.1 
Talc-2 6.7 2.6 
______________________________________ 
TABLE 2 
__________________________________________________________________________ 
Formulation 
EPR PEX PP Talc 
Parts Parts Parts Parts 
Type by Weight 
Type 
by Weight 
Type 
by Weight 
Type 
by Weight 
__________________________________________________________________________ 
Ex. 1 
EPR-2 
20 PEX-2 
20 PP-3 
60 Talc-1 
5 
Ex. 2 
EPR-3 
15 PEX-3 
15 PP-3 
70 Talc-1 
5 
Ex. 3 
EPR-3 
15 PEX-2 
20 PP-3 
65 Talc-1 
5 
Ex. 4 
EPR-3 
20 PEX-2 
15 PP-3 
65 Talc-1 
5 
Ex. 5 
EPR-3 
20 PEX-2 
15 PP-4 
65 Talc-1 
5 
Ex. 6 
EPR-3 
20 PEX-2 
15 PP-3 
65 -- 0 
Ex. 7 
EPR-3 
15 PEX-3 
20 PP-3 
65 Talc-1 
5 
Ex. 8 
EPR-3 
20 PEX-2 
15 PP-3 
65 Talc-1 
3 
Comp. 
EPR-1 
25 PEX-1 
25 PP-3 
50 Talc-1 
5 
Ex. 1 
Comp. 
EPR-4 
10 PEX-4 
10 PP-3 
80 Talc-1 
5 
Ex. 2 
Comp. 
EPR-3 
5 PEX-2 
30 PP-3 
65 Talc-1 
5 
Ex. 3 
Comp. 
EPR-3 
30 PEX-2 
5 PP-5 
65 Talc-1 
5 
Ex. 4 
Comp. 
EPR-3 
20 PEX-2 
15 PP-2 
65 Talc-1 
10 
Ex. 5 
Comp. 
EPR-3 
20 PEX-2 
15 PP-1 
65 Talc-2 
5 
Ex. 6 
__________________________________________________________________________ 
TABLE 3 
______________________________________ 
Examples 
1 2 3 4 5 6 7 8 
______________________________________ 
component 
68 54 60 61 61 58 62 59 
(A) + 
component 
(B) 
parts by 
weight 
component 
0.8 0.8 0.6 1.4 1.5 1.2 0.8 1.3 
(A)/ 
component 
(B) 
[.eta.] of 
1.3 1.2 1.1 1.4 0.9 1.2 1.2 1.3 
component 
(C) dl/g 
Proportion of 
0.79 0.82 0.82 0.77 0.72 0.81 0.83 0.79 
high- 
crystalline PP 
(*1) 
Total cry- 
39 47 45 44 43 45 44 45 
stallinity of 
resin % 
MFR g/10 19 21 25 24 26 28 24 26 
min 
Density 0.93 0.93 0.93 0.93 0.93 0.90 0.93 0.92 
g/cm.sup.3 
Flexural 6,900 8,800 8,200 
8,100 
7,200 
6,500 
8,200 
7,600 
modulus 
Kg/cm.sup.2 
Rockwell 53 64 60 57 55 57 60 58 
hardness 
Izod value 
8.7 5.6 6.4 6.9 6.8 6.9 8.5 6.8 
(at -30.degree. C.) 
Kg .multidot. cm/cm 
Peeling 980 800 710 810 850 860 950 840 
strength of 
coating g/cm 
Surface .smallcircle. 
.smallcircle. 
.smallcircle. 
.smallcircle. 
.smallcircle. 
.smallcircle. 
.smallcircle. 
.smallcircle. 
smoothness 
(*2) 
______________________________________ 
(Note) 
*1: Proportion of highcrystalline PP = Amount of component (C)/(Amount of 
component (C) + Amount of component (D)) 
*2: .circleincircle. . . . Superior to sheet metal 
.smallcircle. . . . Almost equal to sheet metal 
x . . . Inferior to sheet metal 
TABLE 4 
______________________________________ 
Comparative Examples 
1 2 3 4 5 6 
______________________________________ 
component (A) + 
74 46 59 55 61 60 
component (B) parts by 
weight 
component (A)/ 
1.2 0.9 0.3 2.3 1.4 1.2 
component (B) 
[.eta.] of 1.3 1.1 1.5 0.8 1.6 2.3 
component (C) dl/g 
Proportion of high- 
0.81 0.80 0.80 0.86 0.67 0.78 
crystalline PP (*1) 
Total crystallinity of 
37 47 43 53 41 45 
resin % 
MFR g/10 min 16 26 27 34 19 6.9 
Density g/cm.sup.3 
0.93 0.93 0.93 0.93 0.96 0.93 
Flexural modulus 
5,000 10,600 8,600 
7,500 
9,300 
7,300 
Kg/cm.sup.2 
Rockwell hardness 
51 48 65 52 45 53 
Izod value (at -30.degree. C.) 
8.2 4.2 6.0 5.3 6.6 4.8 
Kg .multidot. cm/cm 
Peeling strength of 
450 760 390 520 880 800 
coating g/cm 
Surface smoothness (*2) 
.smallcircle. 
.smallcircle. 
.circleincircle. 
x .smallcircle. 
.smallcircle. 
______________________________________ 
(Note) 
*1: Proportion of highcrystalline PP = Amount of component (C)/(Amount of 
component (C) + Amount of component (D)) 
*2: .circleincircle. . . . Superior to sheet metal 
.smallcircle. . . . Almost equal to sheet metal 
x . . . Inferior to sheet metal