Heat-resistant, propylene resin-based molding materials and molded products obtained therefrom

There is provided a heat-resistant, propylene resin-based molding material, comprising the following components (A) and (B): PA1 component (A): 3 to 97% by weight of a resin-impregnated glass fiber bundle comprising: PA1 constituent (a.sup.1): 20 to 80 parts by weight of glass fibers having a length of at least 3 mm and an average diameter of 20 .mu.m or less, and PA1 constituent (a.sup.2): 80 to 20 parts by weight of a crystalline propylene polymer at least partly modified with an unsaturated carboxylic acid or a derivative thereof, the MFR of the modified polymer being 50 g/10 min or more, in which the glass fibers are present in the constituent (a.sup.2) in such a state that they are arranged almost in parallel with one another; and PA1 component (B): 97 to 3% by weight of a crystalline propylene polymer having an MFR of 50 g/10 min or more.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to heat-resistant, propylene resin-based molding 
materials which are excellent in moldability, and which can produce less 
warped, lightweight molded products having high heat resistance and high 
strength. 
2. Background Art 
Molded products obtained from a propylene resin are excellent in mechanical 
strength, processability and economical efficiency, so that they have been 
widely used in the field of industrial parts such as automotive parts. 
Further, in such a field where high rigidity and high heat resistance are 
especially required, high-performance composite materials composed of a 
propylene resin and an inorganic filler such as talc or glass fibers have 
been practically used. Such composite materials have been widely used, for 
example, for automotive parts, in particular, interior parts such as a 
trim and an instrument panel, exterior parts such as a bumper, and 
functional parts such as a fan shroud. 
The conventional composite materials composed of a propylene resin and 
glass fibers possess a high level of heat resistance. However, there is a 
problem with the conventional composite materials that when they are 
subjected to injection molding and then cooled, the resulting molded 
product tends to thermally shrink to warp. As a method for preventing the 
molded product from warping, it is known to increase the fluidity of the 
composite molding material. It is also known to additionally use 
flat-shaped fillers such as talc and mica in the composite molding 
material. However, these methods are not satisfactory in that the 
prevention of warping in the molded product is insufficient, or in that 
the required use of a large amount of filler increases the density of the 
composition, leading to a heavier molded product. 
It is therefore an object of the present invention to provide a propylene 
resin-based molding material which has high heat resistance and good 
moldability and which can produce lightweight molded products with very 
little warping. 
SUMMARY OF THE INVENTION 
It has now been found by the present inventors that the above object can be 
attained by using a specific resin-impregnated glass fiber bundle together 
with a specific propylene resin. 
Thus, the present invention provides a heat-resistant, propylene 
resin-based molding material, comprising the following components (A) and 
(B): 
component (A): 3 to 97% by weight of a resin-impregnated glass fiber bundle 
comprising: 
constituent (a.sup.1): 20 to 80 parts by weight of glass fibers having a 
length of at least 3 mm and an average diameter of 20 .mu.m or less, and 
constituent (a.sup.2): 80 to 20 parts by weight of a crystalline propylene 
polymer at least partly modified with an unsaturated carboxylic acid or a 
derivative thereof, the MFR of the modified polymer being 50 g/10 min or 
more, in which the glass fibers are present in the constituent (a.sup.2) 
in such a state that they are arranged almost in parallel with one 
another; and 
component (B): 97 to 3% by weight of a crystalline propylene polymer having 
an MFR of 50 g/10 min or more. 
The molding material of the present invention, because of its lightweight 
and its excellent heat resistance, moldability and anti-warping property, 
can be advantageously used for the production of various industrial parts, 
especially automotive parts for which lightweight, high level of heat 
resistance and dimensional stability upon molding are strongly desired.

DETAILED DESCRIPTION OF THE INVENTION 
[I] Heat-Resistant, Propylene Resin-Based Molding Material 
(1) Essential Components 
(A) Resin-impregnated Glass Fiber Bundle (Component (A)) 
The resin-impregnated glass fiber bundle, the component (A), comprises 20 
to 80 parts by weight of glass fibers (constituent (a.sup.1)) having a 
length of at least 3 mm and an average diameter of 20 .mu.m or less, and 
80 to 20 parts by weight of a crystalline propylene polymer (constituent 
(a.sup.2)) at least partly modified with an unsaturated carboxylic acid or 
a derivative thereof, the MFR (melt flow rate) of modified polymer being 
50 g/10 min or more. In the component (A), the glass fibers are present in 
the constituent (a.sup.2) in such a state that they are arranged almost in 
parallel with one another, and generally from 100 to 8,000 fibers, 
preferably from 500 to 5,000 fibers are bound into a bundle to form a 
strand. 
(a) Constituent (a.sup.1) 
The glass fibers, the constituent (a.sup.1), have a length of at least 3 
mm, preferably 5 to 20 mm, and an average diameter of 20 .mu.m or less, 
preferably 1 to 17 .mu.m, more preferably 3 to 14 .mu.m. 
When the length of the glass fibers is too short, the resulting molding 
material is poor in heat resistance and anti-warping properties. When the 
average diameter of the glass fibers is too large, the resulting molding 
material is poor in heat resistance and anti-warping properties. On the 
other hand, when the glass fibers are too thin, the resulting molding 
material has poor mechanical strength. 
It is not necessary to apply, to the surface of the glass fiber, a binding 
agent, or a surface treating agent for improving the adhesion or 
compatibility between the glass fibers and the propylene resin. However, a 
surface treatment of the glass fibers with a silane coupling agent, for 
instance, an epoxy-silane such as .gamma.-glycidoxypropyl trimethoxy 
silane, a vinyl-silane such as vinyltrichlorosilane or an amino-silane 
such as .gamma.-aminopropyl triethoxy silane, can improve the heat 
resistance, strength and anti-warping properties of the resulting molding 
material. 
(b) Constituent (a.sup.2) 
The modified crystalline propylene polymer, the constituent (a.sup.2), is a 
crystalline propylene polymer at least partly modified with an unsaturated 
carboxylic acid or with a derivative thereof, the MFR of the modified 
polymer being 50 g/10 min or more. 
Crystalline Propylene Polymer 
Examples of the crystalline propylene polymer to be modified include 
propylene homopolymers; and block, random or graft copolymers of propylene 
with a minor amount of an .alpha.-olefin (for example, ethylene, butene, 
pentene, hexene, heptene, 4-methylpentene or octene), a vinyl ester (for 
example, vinyl acetate), an aromatic vinyl monomer (for example, styrene), 
or a vinylsilane (for example, vinyltrimethoxysilane or 
vinyltrimethylsilane); and mixtures thereof. 
The MFR of the crystalline propylene polymer can be controlled either by 
the conditions for polymerization of the polymer or by a treatment using a 
peroxide. 
Examples of the peroxide usable for the above treatment include peroxides 
such as methyl ethyl ketone peroxide and methyl isobutyl ketone peroxide; 
peroxyketals such as n-butyl-4,4-bis(t-butylperoxy)valerate; 
hydroperoxides such as cumene hydroperoxide and diisopropylhydrobenzene 
peroxide; dialkyl peroxides such as 
1,3-bis(t-butylperoxy-isopropyl)benzene and dicumyl peroxide; 
percarbonates such as benzoyl peroxide and bis(4-t-butylcyclohexyl)peroxy 
dicarbonate; and peroxy esters such as t-butylperoxy acetate and 
t-butylperoxy laurate. 
Of these crystalline propylene polymers, those polymers which contain a 
propylene homopolymer moiety having a density of 0.9080/cm.sup.3 or more 
are preferably used from the viewpoint of heat resistance. 
Modification 
Examples of the unsaturated carboxylic acid or a derivative thereof to be 
used for the modification of the above crystalline propylene polymer 
include unsaturated organic acids such as acrylic acid, methacrylic acid, 
maleic acid and itaconic acid; anhydrides of unsaturated organic acids 
such as maleic anhydride, itaconic anhydride and citraconic anhydride; 
esters of unsaturated organic acids such as methyl acrylate and monomethyl 
maleate; amides of unsaturated organic acids such as acrylic amide and 
fumaric monoamide; and imides of unsaturated organic acids such as 
itaconic imide. 
Of these modifiers, acrylic acid and maleic anhydride are preferred from 
the viewpoint of the dispersibility and the reinforcing effect of the 
glass fibers. Maleic anhydride is most preferred. 
The modification can be achieved by grafting the modifier onto the 
crystalline propylene polymer. 
The amount of the modifier is generally from 0.01 to 20 parts by weight, 
preferably from 0.05 to 15 parts by weight, more preferably from 0.05 to 
10 parts by weight for 100 parts by weight of the crystalline propylene 
polymer. 
It is possible to adjust the degree of modification of the propylene 
polymer to a desired one by diluting a highly modified crystalline 
propylene polymer with non-modified one. 
Modified Crystalline Propylene Polymer 
The modified crystalline propylene polymer should have an MFR (JIS-K7210, 
230.degree. C., 2.16 kg) of 50 g/10 min or more, preferably 100 g/10 min 
or more, more preferably 200 g/10 min or more. 
When the MFR of the modified crystalline propylene polymer is lower than 50 
g/10 min, the reinforcing glass fibers cannot be uniformly dispersed in 
the resin-impregnated glass fiber bundle, whereby the resulting molding 
material has poor physical properties. 
(c) Other Constituents (Optional Constituents) 
Other constituents such as various resins, fillers and elastomers can also 
be incorporated into the resin-impregnated glass fiber bundle, the 
component (A), in such an amount that the advantages of the present 
invention are not appreciably impaired. 
(d) Weight Ratio between the Constituents 
The weight ratio between glass fibers (constituent (a.sup.1)) and the 
modified crystalline propylene polymer (constituent (a.sup.2)) in the 
resin-impregnated glass fiber strand is 20 to 80 (parts by weight):80 to 
20 (parts by weight), preferably 40 to 80 (parts by weight):60 to 20 
(parts by weight), more preferably 45 to 75 (parts by weight):55 to 25 
(parts by weight), provided that the total of the constituents (a.sup.1) 
and (a.sup.2) is 100 parts by weight. 
In the case where the ratio of the constituent (a.sup.2) is too small, a 
molded product in which the glass fibers are poorly dispersed will be 
obtained. On the other hand, when the ratio of the constituent (a.sup.2) 
is too large, the resulting molded product will have poor strength. 
(e) Preparation of the Resin-impregnated Glass Fiber Bundle 
As the starting glass fibers for the preparation of the resin-impregnated 
glass fiber bundle, continuous glass fibers (filaments) prepared by any 
known methods (as disclosed, for example, in British Patent No. 1,302,048 
and U.S. Pat. No. 4,439,387) may preferably be used. 
The subject bundle may be prepared by a method comprising the step of 
impregnating the continuous glass fibers (usually called "roving") with 
the modified crystalline propylene polymer, the constituent (a.sup.2), 
while the glass fibers are being drawn. 
More specifically, the continuous glass fibers are passed through a 
crosshead die attached to an extruder, while the modified crystalline 
propylene polymer in the molten state is supplied from a cylinder or the 
like to impregnate the glass fiber. The glass fiber strand thus obtained 
is cooled, and then cut into predetermined lengths. 
(B) Crystalline Propylene Polymer (Component (B)) 
The same crystalline propylene polymer as is used as the above constituent 
(a.sup.2) can be used as the crystalline propylene polymer, the component 
(B), having an MFR of 50 g/10 min or more. Thus, any one of the following 
polymers can be used as the component (B): propylene homopolymers; and 
block, random or graft copolymers of propylene with a minor amount of an 
.alpha.-olefin (for example, ethylene, butene, pentene, hexene, heptene, 
4-methylpentene or octene), a vinyl ester (for example, vinyl acetate), an 
aromatic vinyl monomer (for example, styrene), or a vinylsilane (for 
example, vinyltrimethoxysilane or vinyltrimethylsilane); and mixtures 
thereof. 
Of these crystalline propylene polymers, a propylene homopolymer 
(polypropylene) or a copolymer of propylene and ethylene is preferably 
used. It is particularly preferred to use a propylene-ethylene block 
copolymer of which the propylene homopolymer moiety has a density of 
0.9080/cm.sup.3 or more. The MFR of the crystalline propylene polymer is 
preferably 100 g/10 min or more, more preferably 200 g/10 min or more. 
When the MFR is too low, the resulting molding material is poor in heat 
resistance, moldability and anti-warping properties. 
Other components such as various resins, fillers and elastomers may be 
incorporated into the crystalline propylene polymer insofar as the 
advantages of the present invention are not significantly impaired. In 
particular, it is preferable to add, in advance, any of the 
below-described optional components to the propylene polymer when the 
qualities of the resulting molded product (warping and mechanical 
strength) are taken into consideration. 
(2) Weight Ratio between Components (A) and (B) 
In the heat-resistant, propylene resin-based molding material according to 
the present invention, the weight ratio between the resin-impregnated 
glass fiber bundle and the crystalline propylene polymer is 3 to 97 (% by 
weight):97 to 3 (% by weight), preferably 10 to 90 (% by weight):90 to 10 
(% by weight), more preferably 20 to 80 (% by weight):80 to 20 (% by 
weight). 
When the amount of the resin-impregnated glass fiber bundle is less than 3% 
by weight, the resulting molding material has poor heat resistance. On the 
other hand, when the amount is in excess of 97% by weight, the resulting 
molding material has poor moldability. 
(3) Other Components (Optional Components) 
Besides the above-described essential components (A) and (B), any of the 
conventional additives such as a pigment, an antioxidant, an antistatic 
agent, a flame-retardant and a dispersant may be incorporated into the 
molding material according to the present invention. Further, as component 
(C), use may also be made of a filler having an aspect ratio of 3 or more, 
or at least one elastomer selected from ethylene elastomers and styrene 
elastomers. These optional components may be used in combination. 
The optional component (C) can be fed as it is to a molding machine 
together with the components (A) and (B). It is, however, preferred that 
the component (C) be blended with the component (B) in advance. 
(a) Filler Having an Aspect Ratio of 3 or More (Component (C.sup.1)) 
An inorganic or organic filler can be used as the filler having an aspect 
ratio of 3 or more. Specific examples of such a filler include talc, mica, 
carbon fibers, glass flakes, magnesium sulfate fibers, aluminum borate 
fibers, potassium titanate fibers, wollastonite, calcium carbonate fibers, 
titanium oxide fibers, and aromatic polyamide fibers. Of these, mica and 
glass flakes are preferably used. It is particularly preferable to use 
water-ground or wet-classified mica. 
It is preferable to use a filler having an aspect ratio of 10 or more, 
particularly 15 or more. 
Those fillers which are surface-treated with a surface active agent, a 
coupling agent, a metallic soap or the like may also be used. The above 
fillers, especially surface-treated fillers, can further improve the heat 
resistance, anti-warping properties, appearance and strength of the molded 
product. 
(b) Elastomer Component (Component (C.sup.2)) 
At least one elastomer selected from ethylene elastomers and styrene 
elastomers can be used as the elastomer component. 
When such an elastomer component is used, the resulting molding material 
has improved impact strength and anti-warping properties. 
Ethylene Elastomer 
Examples of the ethylene elastomer include ethylene-propylene copolymer 
rubber (EPM), ethylene-propylene-diene terpolymer rubber (EPDM), 
ethylene-butene-1 copolymer rubber (EBM) and ethylene-propylene-butene-1 
terpolymer rubber (EPBM). These elastomers can be used in combination. 
In the case of the above ethylene-propylene copolymer rubber, it is 
preferable to use one having a propylene content of 20 to 55% by weight 
and a Mooney viscosity (ML.sub.1+4 100.degree. C.) of less than 100, 
preferably less than 50. 
In the case of the above ethylene-propylene-diene terpolymer rubber, it is 
preferable to use one having an iodine value of 20 or less. 
In the case of the above ethylene-propylene-butene-1 terpolymer rubber, it 
is preferable to use one having a propylene content of 5 to 50% by weight 
and a butene content of 5 to 50% by weight. 
Styrene Elastomer 
Examples of the styrene elastomer include hydrogenated styrene-butadiene 
block copolymers and hydrogenated styrene-isoprene block copolymers, more 
specifically, fully or partially hydrogenated styrene-butadiene and 
styrene-isoprene block copolymers, such as a 
styrene-ethylene/butylene-styrene block copolymer, a 
styrene-ethylene/propylene block copolymer and a 
styrene-ethylene/propylene-styrene block copolymer. It is preferable to 
use those styrene elastomers which have a degree of hydrogenation of 95% 
or more, particularly 99% or more. Further, it is preferable to use those 
styrene elastomers which have a styrene content of 5 to 50% by weight, 
particularly 15 to 40% by weight. 
(c) Amount of Component (C) 
The above-described filler or elastomer may be used generally in an amount 
of 50 parts by weight or less, preferably from 3 to 50 parts by weight, 
more preferably from 5 to 30 parts by weight for 100 parts by weight of 
the total of the components (A) and (B). 
When the amount of the filler is in excess of 50 parts by weight, the 
resulting molding material has poor moldability. In addition, the density 
of the molding material becomes high, so that the weight of the resulting 
molded product becomes large. When the amount of the elastomer is in 
excess of 50 parts by weight, the resulting molding material has poor heat 
resistance. 
(4) Production of the Molding Material 
The heat-resistant, propylene resin-based molding material can be obtained 
by blending the above-described essential components (A) and (B) and, 
according to necessity, the above optional component (C). 
It is preferred that the component (B) or a mixture of the components (B) 
and (C) be kneaded and granulated in advance, using an ordinary kneading 
machine such as a single-screw extruder, a twin-screw extruder, a Banbury 
mixer, a roller, a Brabender Plastograph or a kneader, although it is 
possible to directly feed it as it is along with the component (A) to a 
molding machine. 
When the kneading and granulation of a mixture of the components (B) and 
(C) is conducted, as the case may be, it may be conducted in a stepwise 
manner in view of the properties of the resulting molding material. Thus, 
for example, all of the component (B) and a part of the component (C) is 
first kneaded, the remainder of component (C) is then added, and the 
resulting mixture is further kneaded and granulated. 
Kneading is conducted at a temperature of generally from 190.degree. to 
250.degree. C., preferably from 200.degree. to 240.degree. C. 
When the above-described surface-treating agent for component (C)(C.sub.1) 
is used, this agent may be added at the time of kneading of components (B) 
and (C). In this case, the kneading and surface treatment of component (C) 
can be conducted at the same time. 
The molding material thus obtained generally has an MFR of 20 g/10 min or 
more, and thus exhibits good moldability. 
[II] Molded Product 
(1) Molding 
Molded products can be obtained from the heat-resistant, propylene 
resin-based molding material by various molding methods such as injection 
molding, compression molding, and extrusion molding (sheet-extrusion, blow 
molding). Among others, injection molding and press-injection molding are 
preferred since these methods can best make use of the advantageous 
properties of the molding material. 
(2) Intended Use 
The molded products obtained from the heat-resistant, propylene resin-based 
molding material, according to the present invention have excellent heat 
resistance and strength, exhibits very little warping, and are light in 
weight. They preferably have a density of 1.10 g/cm.sup.3 or less. 
Therefore, they can be advantageously used as various industrial parts, in 
particular, as high-functional or large-sized molded products, for 
example, automotive exterior and interior parts such as a bumper, a 
fender, a spoiler, an instrument panel, a trim, a fan shroud and a glove 
compartment; parts of household electric appliances, such as a TV cabinet, 
a VTR cabinet, a washing machine cover and a vacuum cleaner housing; and 
parts of audio appliances such as a stereo case. 
[III] Experimental Examples 
The following examples further illustrate the present invention but are not 
intended to limit it. 
In the examples, the following measurements were conducted: 
Heat Resistance 
The flexural modulus of a test piece of molded product was measured in 
accordance with JIS-K7203 at a temperature of 100.degree. C. 
Warping in Molded Product 
A discal sheet (200 .phi..times.2.0 mmt) was prepared by injection molding 
(with a pin gate). The degree of warping (deformation) of the sheet was 
measured in the following manner: While one end of the discal sheet placed 
on a mold platen was being pressed down, the degree of warping of the 
sheet, that is, the degree of lifting of the opposite end of the sheet 
from the mold platen was measured with a clearance gauge and a slide 
caliper. 
Density 
The density of a sheet (120.times.120.times.3 mm) obtained by injection 
molding was measured in accordance with JIS-K7112. 
MFR of Molded Product 
The same sheet as used in the measurement of density was crushed, and the 
MFR was measured in accordance with JIS-K7210 (230.degree. C., 2.16 kg). 
It is considered that the moldability is better as this value is higher. 
The following starting materials are used in the examples: 
(a) Component (A) 
(A)-1: 50 parts by weight of a propylene homopolymer modified With maleic 
anhydride (0.08% by weight), having an MFR of 230 g/10 min and a density 
of 0.9083 g/cm.sup.3, and 50 parts by weight of continuous glass fibers 
having an average diameter of 10 .mu.m, surface-treated with 
.gamma.-aminopropyl triethoxy silane were fed to an extruder. Glass fibers 
were impregnated with the modified propylene homopolymer while they were 
being drawn at the crosshead part of the extruder heated to a temperature 
of 200.degree. C. The glass fiber strand thus obtained was cooled, and 
then cut into a length of 12 mm to obtain pellets of a resin-impregnated 
glass fiber bundle. 
(A)-2: 30 parts by weight of a propylene-ethylene block copolymer modified 
with maleic anhydride (0.09% by weight), having an MFR of 250 g/10 min, a 
density of 0.9081 g/cm.sup.3 and an ethylene content of 3% by weight, and 
70 parts by weight of continuous glass fibers having an average diameter 
of 10 .mu.m, surface-treated with .gamma.-glycidoxypropyl triethoxy silane 
were fed to an extruder. The glass fibers were impregnated with the 
modified propylene-ethylene block copolymer while they were being drawn at 
the crosshead part of the extruder heated to a temperature of 200.degree. 
C. The glass fiber strand thus obtained was cooled, and then cut into a 
length of 12 mm to obtain pellets of a resin-impregnated glass fiber 
bundle. 
(A)-3: 50 parts by weight of a propylene homopolymer modified with maleic 
anhydride (0.09% by weight), having an MFR of 30 g/10 min and a density of 
0.9082 g/cm.sup.3, and 50 parts by weight of continuous glass fibers 
having an average diameter of 17 .mu.m, surface-treated with 
.gamma.-aminopropyl triethoxy silane were fed to an extruder. The glass 
fibers were impregnated with the modified propylene homopolymer while they 
were being drawn at the crosshead part of the extruder heated to a 
temperature of 200.degree. C. The glass fiber strand thus obtained was 
cooled, and then cut into a length of 12 mm to obtain pellets of a 
resin-impregnated glass fiber bundle. 
(A)-4: 30 parts by weight of a propylene-ethylene block copolymer modified 
with acrylic acid (0.7% by weight), having an MFR of 40 g/10 min, a 
propylene homopolymer moiety whose density is 0.9079 g/cm.sup.3 and an 
ethylene content of 3% by weight, and 70 parts by weight of continuous 
glass fibers having an average diameter of 17 .mu.m, surface-treated with 
.gamma.-glycidoxypropyl trimethoxy silane were fed to an extruder. The 
glass fibers were impregnated with the modified propylene-ethylene block 
copolymer while they were being drawn at the crosshead part of the 
extruder heated to a temperature of 200.degree. C. The strand thus 
obtained was cooled, and then cut into a length of 12 mm to obtain pellets 
of a resin-impregnated glass fiber bundle. 
(A)-5: 80 parts by weight of a propylene homopolymer modified with maleic 
anhydride (0.08% by weight), having an MFR of 230 g/10 min and a density 
of 0.9083 g/cm.sup.3, and 20 parts by weight of chopped glass fiber 
strands having an average diameter of 10 .mu.m and a length of 6 mm, 
surface-treated with .gamma.-aminopropyl triethoxy silane were fed to a 
twin-screw extruder (the glass fibers were separately fed at the latter 
half part of the extruder), and kneaded at 200.degree. C. and granulated 
to obtain pellets. 
(b) Component (B), or Component (B) Containing Component (C) 
(B)-1: Pellets of a propylene homopolymer having an MFR of 210 g/10 min and 
a density of 0.9082 g/cm.sup.3. 
(B)-2: Pellets obtained by feeding 78 parts by weight of a 
propylene-ethylene block copolymer (component (B)) having an MFR of 340 
g/10 min adjusted by the treatment with a peroxide, 
1,3-bis(t-butylperoxyisopropyl)benzene, a propylene homopolymer moiety 
whose density is 0.9080 g/cm.sup.3 and an ethylene content of 3% by 
weight, and 22 parts by weight of water-ground mica (component (C)) having 
an aspect ratio of 18 and an average particle size of 35 .mu.m to a 
twin-screw extruder (the mica was separately fed at the latter half part 
of the extruder), and kneading at 200.degree. C. and granulating them. 
(B)-3: Pellets obtained by feeding 75 parts by weight of the same 
propylene-ethylene block copolymer as used in (B)-2 above (component (B)), 
and 25 parts by weight of an ethylene-propylene copolymer rubber 
(component (C)) having a propylene content of 3% by weight and a Mooney 
viscosity (ML.sub.1+4 100.degree. C.) of 18 to a twin-screw extruder, and 
kneading at 200.degree. C. and granulating them. 
(B)-4: Pellets obtained by feeding 63 parts by weight of the same 
propylene-ethylene block copolymer as used in (B)-2 (component (B)); 12 
parts by weight of the same mica as used in (B)-2 (component (C)); and 25 
parts by weight of a styrene-ethylene/butylene-styrene block copolymer 
(component (C)) having a styrene content of 20% by weight, a 
number-average molecular weight of 30,000 and an MFR (230.degree. C., 2.16 
kg) of 150 g/10 min to a twin-screw extruder (the mica was separately fed 
at the latter half part of the extruder), and kneading at 200.degree. C. 
and granulating them. 
(B)-5: Pellets of a propylene homopolymer (component (B)) having an MFR of 
30 g/10 min and a density of 0.9080 g/cm.sup.3. 
(B)-6: Pellets obtained by feeding 63 parts by weight of a 
propylene-ethylene block copolymer (component (B)) having an MFR of 40 
g/10 min, a propylene homopolymer moiety whose density is 0.9076 
g/cm.sup.3 and an ethylene content of 3% by weight; 12 parts by weight of 
the same mica as used in (B)-4; and 25 parts by weight of the same 
styrene-ethylene/butylene-styrene block copolymer as used in (B)-4 
(component (C)) to a twin-screw extruder (the mica was separately fed at 
the latter half part of the extruder), and kneading at 200.degree. C. and 
granulating them. 
EXAMPLES 1-4 AND COMATIVE EXAMPLES 1-3 
The above-described components (A)-1 to (A)-5 and components (B)-1 to (B)-6 
were dry-blended as shown in Table 1. Each mixture obtained was fed to a 
screw-in-line type injection molding machine, and discal sheets for the 
measurement of warping and test pieces for the measurements of physical 
properties were prepared by molding at a temperature of 220.degree. C. The 
molding cycle was 45 seconds. 
The results of the above measurements are shown in Table 1. 
TABLE 1 
__________________________________________________________________________ 
Formulation 
Component (B), or 
component (B) 
Evaluation 
Component (A): containing 
Heat 
Resin- component (C): 
resistance 
impregnated Crystalline 
[flexural MFR of 
glass fiber propylene modulus at molded 
bundle polymer, etc. 
100.degree. C.] 
Warping 
Density 
product 
Type wt % Type wt % (kg/cm.sup.3) 
(mm) (g/cm.sup.3) 
(g/10 min) 
__________________________________________________________________________ 
Example 1 
(A)-1 
40 (B)-1 
60 28,400 
2.2 1.03 23 
Example 2 
(A)-1 
20 (B)-2 
80 24,700 
0.5 1.10 31 
Example 3 
(A)-2 
30 (B)-3 
70 21,900 
1.0 1.04 38 
Example 4 
(A)-2 
20 (B)-4 
80 21,000 
0.8 1.06 45 
Comp. (A)-3 
40 (B)-5 
60 20,300 
9.3 1.03 5 
Example 1 
Comp. (A)-4 
20 (B)-6 
80 18,300 
5.8 1.06 8 
Example 2 
Comp. (A)-5 
100 -- -- 24,900 
12.5 1.03 16 
Example 3 
__________________________________________________________________________ 
As is apparent from the data shown in Table 1, the injection-molded 
products obtained from the resin compositions shown in Examples 1 to 4 
have excellent heat resistance and moldability, had extremely small 
warping, and are light in weight. 
In contrast, the molded products obtained from the resin compositions shown 
in Comparative Examples 1 to 3 are poor in heat resistance or in warping.