JP3467895B2 - Modified polypropylene resin composition and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified polypropylene resin composition, a method for producing the same, a molding material for mold stamping and an injection-molded article comprising the modified resin composition, and more particularly, having high fluidity, Moreover, the present invention relates to a modified polypropylene resin composition excellent in impact strength and rigidity, a method for producing the same, a molding material for mold stamping and an injection molded article comprising the modified resin composition.

[0002]

2. Description of the Related Art Regarding automobile parts, it is indispensable to reduce their weight in order to cope with global environmental problems and the like. In particular, the properties required of the base resin for producing a thin and lightweight product by a molding method such as mold stamping include high fluidity, high rigidity and excellent impact strength. Conventionally, in order to meet such demands, various improvements have been made and various polyolefin resin compositions have been developed. For example, a polyolefin resin composition having improved fluidity has been obtained by adding an organic peroxide to a polyolefin resin and performing heat treatment. However, the polyolefin resin thus obtained has the problems of low rigidity and low impact strength.

Further, in JP-A-60-42448 and JP-A-61-233047, an ethylene / propylene copolymer rubber, an inorganic filler and an organic peroxide are added to a crystalline ethylene / propylene block copolymer. Blended,
It is described that a heat treatment at 170 to 280 ° C. gives a polypropylene resin composition having high fluidity and excellent rigidity and low temperature impact resistance.
However, when this polypropylene resin composition is treated as described above, the crystalline ethylene / propylene block copolymer is decomposed to increase the fluidity, but the rigidity and impact resistance are not sufficiently improved. There is a problem.

[0004]

In order to solve the above problems, the present invention provides a modified polypropylene resin composition having high fluidity and excellent rigidity and impact resistance, and a method for producing the same. With the goal. Further, the present invention is
An object of the present invention is to provide a molding material for mold stamping, which can be easily molded by the mold stamping molding method and can obtain a molded product excellent in strength even with a thin wall. A further object of the present invention is to provide an injection-molded article that is molded by an injection molding method and has excellent strength even with a thin wall.

[0005]

The present invention provides the following modified polypropylene resin composition, a method for producing the same, and a molding material for mold stamping and an injection molded product comprising the modified resin composition. (1) (A) Melt flow rate at 230 ° C is 1
50 to 90 parts by weight of polypropylene of 0 to 70 g / 10 minutes, and 0 to 25 parts by weight of (B) olefin-based copolymer rubber,
(C) 0.01 to 0.2 parts by weight of organic peroxide and (E) 0.05 to 1 part by weight of a crosslinking aid, relative to 100 parts by weight in total of 5 to 40 parts by weight of the inorganic filler. A modified polypropylene resin composition obtained by heat-treating a polypropylene resin composition containing the compound, characterized in that the melt flow rate at 230 ° C. is in the range of 50 to 150 g / 10 minutes. Polypropylene resin composition. (2) (A) Melt flow rate at 230 ° C is 1
50 to 90 parts by weight of polypropylene of 0 to 70 g / 10 minutes, and 0 to 25 parts by weight of (B) olefin-based copolymer rubber,
(C) 0.01 to 0.2 parts by weight of organic peroxide and (E) 0.05 to 1 part by weight of a crosslinking aid, relative to 100 parts by weight in total of 5 to 40 parts by weight of the inorganic filler. Which is a modified polypropylene resin composition obtained by heat-treating a polypropylene resin composition in which the melt flow rate at 230 ° C. is in the range of 50 to 150 g / 10 minutes, and the melt flow rate and Izod The relationship with the impact strength is the following formula (1)

## EQU3 ## Y ≧ −4.7878 logX + 13.8829 (1) [wherein, X represents melt flow rate (g / 10 minutes), and Y represents Izod impact strength (kg · cm / cm). ] The modified polypropylene resin composition characterized by being in the range which satisfy | fills these. (3) The relationship between the melt flow rate and the Izod impact strength is expressed by the following mathematical formulas (2) and (3).

## EQU4 ## Y ≧ −4.7878 logX + 14.3329 (2) Y ≦ −4.7878 logX + 16.8829 (3) [wherein, X is melt flow rate (g / 10 minutes), Y is Izod impact strength (kg cm / cm) is shown. ] The modified polypropylene resin composition according to the above (2), characterized in that (4) Polypropylene (A) is 60 to 80 parts by weight, olefinic copolymer rubber (B) is 5 to 15 parts by weight, and inorganic filler (C) is 10 to 30 parts by weight based on 100 parts by weight in total. Any of the above (1) to (3), wherein 0.02 to 0.1 part by weight of the peroxide (D) and 0.1 to 0.6 part by weight of the crosslinking aid (E) are blended. A modified polypropylene resin composition according to claim 1. (5) The polypropylene (A) is a propylene / ethylene block copolymer or homopolypropylene, the olefin copolymer rubber (B) is an ethylene / propylene / diene copolymer rubber or a propylene / ethylene copolymer rubber, and the inorganic filler (C) is The above-mentioned (1) to (4), wherein the talc and the crosslinking aid (E) are divinylbenzene.
The modified polypropylene resin composition according to any one of 1. (6) The modified polypropylene resin composition according to any one of (1) to (5) above, wherein the modified polypropylene resin composition has a melt flow rate of 70 to 120 g / 10 minutes. (7) (A) Melt flow rate at 230 ° C is 1
50 to 90 parts by weight of polypropylene of 0 to 70 g / 10 minutes, and 0 to 25 parts by weight of (B) olefin-based copolymer rubber,
(C) 0.01 to 0.2 parts by weight of organic peroxide and (E) 0.05 to 1 part by weight of a crosslinking aid, relative to 100 parts by weight in total of 5 to 40 parts by weight of the inorganic filler. Using a twin-screw extruder, the polypropylene resin composition in which the screw was used had a screw front stage temperature of 120 to 200 ° C. and a rear stage temperature of 18
The method for producing a modified polypropylene resin composition according to the above (1) or (2), characterized in that the kneading is carried out at 0 to 270 ° C. and the latter temperature is higher than the former temperature. (8) The method according to (7) above, wherein the temperature of the front stage of the screw is 140 to 160 ° C and the temperature of the rear stage is 200 to 260 ° C. (9) A molding material for mold stamping, comprising the modified polypropylene resin composition according to the above (1) or (2). (10) An injection-molded article obtained by injection-molding the modified polypropylene resin composition according to (1) or (2).

Melt flow rate (MF) in the present invention
R) is ASTM D 1238 (230 ° C, load 21)
It is the value measured by 60 g). Izod (I
ZOD) Impact strength is ASTM D-628 with notch
It is the value measured according to. The polypropylene (A) used in the present invention is a polypropylene having an MFR of 10 to 70 g / 10 minutes, preferably 20 to 60 g / 10 minutes. The type of polypropylene is not particularly limited, but it is preferable to use a propylene homopolymer or a propylene / ethylene block copolymer having an ethylene content of up to 20 mol% because excellent rigidity can be obtained.

The olefin copolymer rubber (B) used in the present invention is an amorphous random elastic copolymer containing olefin as a main component, and is mixed with an organic peroxide and heated,
It is a rubber that is crosslinked by kneading. Examples of such an olefin copolymer rubber (B) include ethylene / propylene copolymer rubber, ethylene / butene-1 copolymer rubber, propylene / ethylene copolymer rubber, and other olefin copolymer rubbers containing no diene component; ethylene. -Propylene / cyclopentadiene copolymer rubber, ethylene / propylene / 1,4-hexadiene copolymer rubber, ethylene /
Ethylene / propylene / non-conjugated diene copolymer rubber such as propylene / cyclooctadiene copolymer rubber, ethylene / propylene / methylene norbornene copolymer rubber, ethylene / propylene / ethylidene norbornene copolymer rubber.
Examples thereof include ethylene / butadiene copolymer rubber. These may be used alone or in appropriate combination of two or more.

Among the above olefin copolymer rubbers (B), it is preferable to use ethylene / propylene / non-conjugated diene copolymer rubber or ethylene / propylene copolymer rubber because excellent impact strength can be obtained.

As the inorganic filler (C) used in the present invention, talc, silica, mica, calcium carbonate, glass fiber, glass beads, barium sulfate, magnesium hydroxide, wallacenite, calcium silicate fiber, carbon fiber, magnesium oxy Examples thereof include sulfate fiber, potassium titanate fiber, titanium oxide, calcium sulfite, white carbon, clay and calcium sulfate.
These may be used alone or in appropriate combination of two or more.

Of the above-mentioned inorganic fillers (C), it is preferable to use talc because it increases rigidity and impact strength. In particular, talc having an average particle size of 0.1 to 3.0 μm, preferably 0.5 to 2.5 μm is desirable because it contributes significantly to the improvement of rigidity and impact strength.

The organic peroxide (D) used in the present invention has a decomposition temperature of 150 to 270 for a half-life of 1 minute.
C., preferably in the range of 170 to 190.degree. C., specifically benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl. −
2,5-di (peroxide benzoate) hexyne-
3,1,3-bis (t-butylperoxyisopropyl) benzene, lauroyl peroxide, t-butylperacetate, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,2 , 5-dimethyl-
2,5-di (t-butylperoxy) hexane, t-butylperbenzoate, t-butylperphenylacetate, t-butylperisobutyrate, t-butylpersec-octate, t-butylperbivalate, kumi Examples thereof include luper vivarate and t-butyl perdiethyl acetate.

Of these, 1,3-bis (t-butylperoxyisopropyl) benzene, digyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexyne-
Use of 3,2,5-dimethyl-2,5-di (t-butylperoxy) hexane or the like is preferable because the fluidity is remarkably improved.

The crosslinking aid (E) used in the present invention is crosslinked by reacting with the polypropylene (A) and the olefinic copolymer rubber (B) which are cleaved or activated by the organic peroxide (D). Is a substance that does. Examples of the crosslinking aid (E) include sulfur; divinyl compounds such as divinylbenzene; diallyl compounds such as diallylphthalate; p-quinonedioxime, p, p'-.
Oxime compounds such as dibenzoylquinone dioxime; Maleimide compounds such as phenylmaleimide; In addition, triallyl cyanurate, triallyl isocyanurate, ethylene glycol methacrylate, polyethylene glycol methacrylate, 1,3,5-triacryloyl hexahydro- s-triazine, liquid 1,
Examples thereof include oligomers having a double bond in the main chain or side chain such as 2-polybutadiene, and polymers having a double bond in the main chain or side chain such as syndioctatic-1,2-polybutadiene.

Of these, the use of divinyl compounds, maleimide compounds, quinone dioxime compounds, especially divinylbenzene, is preferable because the above-mentioned physical properties are balanced.

The best effects can be obtained by combining the above-mentioned preferred components of the components (A) to (E), but the preferred components are selected only for the specific components, and a wide range of other components are selected. Even when blended with the components, excellent effects can be obtained within a certain range.

The proportion of each component in the raw material composition used in the present invention is 50 to 90 parts by weight of polypropylene (A), preferably 60 to 80 parts by weight, and 0 to 25 parts by weight of olefin copolymer rubber (B). Parts, preferably 5 to 15 parts by weight, and the inorganic filler (C) is 5 to 40 parts by weight, preferably 10 to 30 parts by weight. And these (A)-(C)
Organic peroxide (D) based on 100 parts by weight of the total components
Is 0.01 to 0.2 part by weight, preferably 0.02 to 0.
1 part by weight, the crosslinking aid (E) is 0.05 to 1 part by weight, preferably 0.1 to 0.6 part by weight.

When each of the components (A) to (E) is used in a compounding amount within a preferable range, the resin composition has the greatest modification effect, and the resulting modified polypropylene composition has fluidity and rigidity. Although the impact resistance is greatly improved, even if only a specific component is set in a preferable range and this is mixed with a wide range of other components, excellent effects can be obtained in a certain range. That is, in the raw material composition used in the present invention, 60 to 80 parts by weight of polypropylene (A), 5 to 15 parts by weight of olefinic copolymer rubber (B) and 1 part of inorganic filler (C).
0.02 to 0.1 parts by weight of an organic peroxide (D), and a crosslinking aid (E) to 100 parts by weight of a total of 0 to 30 parts by weight.
It is particularly preferable to add 0.1 to 0.6 part by weight.

The modified polypropylene resin composition of the present invention contains, in addition to the above essential components (A) to (E), other components such as a colorant, a heat stabilizer and a weather stabilizer. Does not matter.

The modified polypropylene resin composition of the present invention is obtained by heat-treating a composition containing each of the above components and has an MFR of 50 to 150 g / 10.
Min, preferably 70 to 120 g / 10 min.
Alternatively, if the MFR is within such a range and the MF is
R and Izod impact strength satisfy the above-mentioned mathematical expression (1), preferably the above-mentioned mathematical expressions (2) and (3).
If the MFR is in the range of 50 to 150 g / 10 minutes, the modifying effect is obtained, but if the MFR is in the range of 70 to 120 g / 10 minutes, a larger modifying effect is obtained.

In the heat treatment, the temperature of the front stage of the screw is 120 to 200 ° C., preferably 140 using a twin-screw extruder.
˜160 ° C., the latter stage temperature is 180 to 270 ° C., preferably 200 to 260 ° C., and the latter stage temperature is higher than the former stage temperature, and melt kneading can be performed.

In the production method of the present invention, a polypropylene resin composition containing the above-mentioned components (A) to (E) and optionally other components is mixed with a twin-screw extruder at a screw front temperature. Is 120 to 200 ° C., preferably 140 to 160 ° C., the latter stage temperature is 180 to 270 ° C.,
The temperature is preferably 200 to 260 ° C., and the temperature of the latter stage is higher than the temperature of the former stage, and the mixture is melt-kneaded and reformed. In this case, the MFR of the modified polypropylene resin composition is 50 to 15
0 g / 10 minutes, preferably 70 to 120 g / 10 minutes, or the MFR is in such a range, the MFR and the Izod impact strength are represented by the formula (1),
Preferably, the melt kneading is performed so as to satisfy the mathematical expressions (2) and (3).

If the temperature in front of the screw is less than 120 ° C., the melting of the resin will be insufficient, and if it exceeds 200 ° C., the kneading of polypropylene (A), olefin copolymer rubber (B) and inorganic filler (C) will be unsuccessful. Will be enough. Further, when the temperature after the screw is less than 180 ° C, the organic peroxide (D) is not completely decomposed, and when it exceeds 270 ° C, the decomposition reaction is prioritized and the physical properties are deteriorated. By the temperature conditions, it is possible to obtain a modified polypropylene resin composition having high fluidity and avoiding such problems and having excellent rigidity and impact strength, but by melt-kneading under the preferable temperature conditions. Thus, a modified polypropylene resin composition that is more stable and has a greater modifying effect can be obtained.

Each component is preferably dry blended in advance before being melt-kneaded using a twin-screw extruder. The MFR of the resin composition before modification is 3 to 70 g / 10 minutes, preferably 8 to 60 g / 10 minutes. Further, the specific energy of the twin-screw extruder is 0.1 to 0.5 kWh / kg, preferably 0.1 to 0.3 kWh / kg.

As described above, polypropylene (A), olefin copolymer rubber (B) and inorganic filler (C)
By subjecting a composition consisting of the above to a heat treatment in the presence of an organic peroxide (D) and a crosslinking aid (E) to perform modification,
The modified polypropylene resin of the present invention that can improve the fluidity and rigidity of the polypropylene resin composition without lowering the impact strength, has high fluidity, and is excellent in rigidity and impact strength. A composition is obtained.

The modified polypropylene resin composition of the present invention is characterized in that the Izod impact strength is remarkably improved as compared with the conventional polypropylene resin composition having the same MFR as that of the present invention. Moreover, there is a significant technical significance that this advantage has been achieved in a composition containing polypropylene as a major component.

In general, the melt flow rate and the Izod impact strength of an olefinic elastomer have a relationship that the smaller the melt flow rate, the greater the Izod impact strength. For a given raw material resin, the absolute value of the melt flow rate is The Izod impact strength has a linear relationship with a negative slope as shown in FIG. When it is attempted to improve the impact resistance strength of the elastomer having such a relationship, the melt flow rate of the elastomer must be reduced to a small value, the flowability and processability of the elastomer are deteriorated, and the impact resistance strength and the melt flowability are deteriorated. It is difficult to achieve both.

However, according to the present invention, the relationship between the impact strength and the melt flow rate is completely different from that of the conventional elastomer, that is, the same melt flow rate is compared, and the impact strength is high. It is possible to achieve both high impact strength and excellent melt fluidity. Also, mechanical properties such as elastic modulus and elongation can be improved. Moreover, mainly using polypropylene (A) that is inexpensive and easily available,
Do not use expensive olefin copolymer rubber (B),
Alternatively, even if it is used, a small amount can be used, so that there is an advantage that the manufacturing cost of the elastomer can be reduced.

In producing the modified polypropylene composition of the present invention, the combined use of a specific amount of the organic peroxide (D) and a specific amount of the crosslinking aid (E) improves the above-mentioned impact strength. is important. Further, in the production of the modified polypropylene composition of the present invention, it is also important that the melt-kneading in the first stage is carried out at a relatively low temperature, and the melt-kneading in the second stage is carried out at a relatively high temperature. Provides a combination of flow rate and relatively high impact strength. The reason for this does not impose any limitation on the present invention, but since the former stage of melt-kneading is performed at 120 to 200 ° C., the olefin copolymer rubber (B) may be finely dispersed in the polypropylene (A) phase. It is considered that this is possible because the latter step is performed at 180 to 270 ° C., so that the polypropylene (A) has a low molecular weight and the polypropylene (A) and the olefin copolymer rubber (B) are crosslinked.

Since the modified polypropylene resin composition of the present invention has high fluidity and is excellent in rigidity and impact resistance, it is used in applications where thinness and light weight are required, particularly in a mold employing a mold stamping molding method. It can be suitably used as a molding material for stamping. Specific examples include automobile parts such as door trims, instrument panels, rear packages, and seat back garnishes.
Further, a molded product can be easily obtained by a molding method such as an injection molding method.

The molding material for mold stamping of the present invention comprises the modified polypropylene resin composition of the present invention and is a molding material which is a base material for molding by the mold stamping molding method. Since the modified polypropylene resin composition of the present invention has high fluidity, it is possible to easily obtain a molding material for mold stamping, which is required to be thin and lightweight. Such a molding material is used for mold stamping molding. As a base material, a stamped product can be easily formed, and a final product excellent in rigidity and impact resistance can be obtained even if it is thin. Specific examples of molded articles include the above-mentioned automobile parts.

The injection-molded article of the present invention is a molded article obtained by injection-molding the modified polypropylene resin composition of the present invention. Since the modified polypropylene resin composition of the present invention has a high fluidity, it can be filled into the details of the injection mold, and the injection molded product thus obtained is excellent in rigidity and impact resistance even in a thin portion.

[0032]

The modified polypropylene resin composition of the present invention is obtained by subjecting a polypropylene resin composition comprising a specific composition to heat treatment and has a specific melt flow rate value. Since it has fluidity and excellent rigidity and impact resistance, it is possible to reduce the thickness and weight of molded products. In particular, when the above mathematical expression (1) is satisfied, excellent melt fluidity and high impact strength can both be achieved.

The production method of the present invention comprises blending a specific polypropylene resin composition with an organic peroxide and a crosslinking aid,
Since it is melt-kneaded under a specific temperature condition by a twin-screw extruder, it has a specific melt flow rate value, high fluidity,
Moreover, the modified polypropylene resin composition excellent in rigidity and impact resistance can be easily and efficiently produced. In particular, it is possible to easily and efficiently produce the above-mentioned modified polypropylene resin composition having high fluidity and excellent in rigidity and impact resistance, which satisfies the above mathematical expression (1).

Since the molding material for mold stamping of the present invention comprises the above modified polypropylene resin composition,
It can be made thin and lightweight, can be easily molded by the mold stamping molding method, and a molded product excellent in strength can be obtained even if it is thin.

Since the injection-molded article of the present invention comprises the above modified polypropylene resin composition, it can be made thin and lightweight,
It has excellent rigidity and impact resistance.

[0036]

EXAMPLES Next, examples of the present invention will be described. Examples 1 to 6 and Comparative Examples 1 to 5 As polypropylene, homopolypropylene (MFR =
50 g / 10 minutes) 70 parts by weight, and as the olefin-based copolymer rubber, propylene / ethylene copolymer rubber (MFR =
0.5 g / 10 min) 15 parts by weight and 15 parts by weight of talc were used as the inorganic filler. As the organic peroxide, 2,5-dimethyl-2,5-di (t-
Butyl peroxy) hexyne-3 and divinylbenzene as a crosslinking aid were used to produce a modified polypropylene resin composition as follows.

The organic peroxide and the crosslinking aid were blended in the blending amounts shown in Table 1 with respect to 100 parts by weight of the total amount of the homopolypropylene, the olefinic copolymer rubber and the inorganic filler, and dry blended. Extruder (made by Toshiba
TEM, cylinder diameter = 53 mm, L / D = 45, screw speed = 250 rpm, specific energy = 0.1
6-0.25 kWh / kg, extrusion rate = 45 kg / Hr)
Cylinder set temperature by using the
℃, 140 ℃, 140 ℃), the latter stage (4 places 240 ℃,
240 ° C., 200 ° C., 200 ° C.) and melt kneading was performed to obtain pellets. A test piece was prepared from this pellet and evaluated. The results are shown in Table 1. The relationship between MFR and Izod impact strength is shown in FIG. The evaluation method is as follows. 1) MFR: ASTM D 1238 (temperature 230 ° C,
The load was 2160 g). 2) Tensile elongation: According to ASTM D-638. 3) Initial flexural modulus: According to ASTM D-790. 4) Izod impact strength (with notch): ASTM D
According to -628.

Example 7 80 parts by weight of homopolypropylene (MFR = 10 g / 10 minutes), propylene / ethylene copolymer rubber (MFR = 0.
5 g / 10 minutes) 5 parts by weight, talc 15 parts by weight, 2,5-
Dimethyl-2,5-di (t-butylperoxy) hexyne-3 0.08 parts by weight and divinylbenzene 0.2
Using 0 part by weight, mixing and melt-kneading were performed under the same conditions as in Example 1 to obtain pellets. Test pieces were prepared from the pellets and evaluated in the same manner as in Example 1. The results are shown in Table 1. The modified polypropylene resin composition obtained had a density of 1.0 g / cm ³ .

Example 8 Propylene / ethylene block copolymer (MFR = 55
g / 10 minutes) 70 parts by weight, ethylene / propylene / diene copolymer rubber (ethylene content = 78 mol%, Mooney viscosity ML _{1 + 4} (121 ° C.) = 64, iodine value = 7) 15 parts by weight, 2,5 -Dimethyl-2,5-di (t-butylperoxy) hexyne-3 (0.08 parts by weight) and divinylbenzene (0.20 parts by weight) were mixed and melt-kneaded under the same conditions as in Example 1 to obtain pellets. Got Test pieces were prepared from the pellets and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 9 Example 1 was repeated except that 0.50 parts by weight of triallyl isocyanurate was used in place of divinylbenzene in Example 1. The results are shown in Table 1.

[0041]

[Table 1]

From Table 1, in each example, the tensile elongation, the initial flexural modulus and the IZOD impact strength show high values even when the total MFR is 50 to 100 g / 10 min. It can be seen that a modified polypropylene resin composition in which the elongation and the rigidity are dramatically improved without lowering the impact strength is obtained.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the melt flow rate (MFR) and the Izod impact strength (IZ) of the resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 5, in which the black circles are the examples. is there.

Continuation of the front page (56) References JP-A-61-152754 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 23/00-23/36 C08J 3/24

Claims (10)

(57) [Claims] 1. (A) Polypropylene 50-9 having a melt flow rate at 230 ° C. of 10-70 g / 10 min.
0 parts by weight, (B) 0 to 25 parts by weight of olefin-based copolymer rubber, and (C) 5 to 40 parts by weight of a total of 100 parts by weight, and (D) organic peroxide 0.01. A modified polypropylene resin composition obtained by heat-treating a polypropylene resin composition containing 0.1 to 0.2 parts by weight and (E) 0.05 to 1 part by weight of a crosslinking aid, and having a melt flow at 230 ° C. A modified polypropylene resin composition having a rate in the range of 50 to 150 g / 10 minutes. 2. (A) Polypropylene 50-9 having a melt flow rate at 230 ° C. of 10-70 g / 10 minutes
0 parts by weight, (B) 0 to 25 parts by weight of olefin-based copolymer rubber, and (C) 5 to 40 parts by weight of a total of 100 parts by weight, and (D) organic peroxide 0.01. A modified polypropylene resin composition obtained by heat-treating a polypropylene resin composition containing 0.1 to 0.2 parts by weight and (E) 0.05 to 1 part by weight of a crosslinking aid, and having a melt flow at 230 ° C. The rate is in the range of 50 to 150 g / 10 minutes, and the relationship between the melt flow rate and the Izod impact strength is represented by the following mathematical formula (1): Y ≧ −4.7878 logX + 13.8829 (1) [wherein X represents the melt flow rate (g / 10 minutes), and Y represents the Izod impact strength (kg · cm / cm). ] The modified polypropylene resin composition characterized by being in the range which satisfy | fills these. 3. The relationship between the melt flow rate and the Izod impact strength is expressed by the following mathematical formulas (2) and (3): Y ≧ −4.7878 logX + 14.3329 (2) Y ≦ −4.7878 logX + 16.8829 (3) (In the formula, X represents a melt flow rate (g / 10 minutes), and Y represents an Izod impact strength (kg · cm / cm). ] The modified polypropylene resin composition according to claim 2, wherein the modified polypropylene resin composition is in a range satisfying the above condition. 4. A total of 10 to 80 parts by weight of polypropylene (A), 5 to 15 parts by weight of olefin copolymer rubber (B) and 10 to 30 parts by weight of inorganic filler (C).
The organic peroxide (D) is added in an amount of 0.02 to 0 parts by weight.
The modified polypropylene resin composition according to any one of claims 1 to 3, wherein 0.1 part by weight and 0.1 to 0.6 part by weight of the crosslinking aid (E) are blended. 5. The polypropylene (A) is a propylene / ethylene block copolymer or homopolypropylene, and the olefin copolymer rubber (B) is ethylene / propylene.
The modified polypropylene according to any one of claims 1 to 4, wherein the diene copolymer rubber or propylene / ethylene copolymer rubber, the inorganic filler (C) is talc, and the crosslinking aid (E) is divinylbenzene. Resin composition. 6. The modified polypropylene resin composition according to any one of claims 1 to 5, wherein the modified polypropylene resin composition has a melt flow rate of 70 to 120 g / 10 minutes. 7. (A) Polypropylene 50-9 having a melt flow rate at 230 ° C. of 10-70 g / 10 min
0 parts by weight, (B) 0 to 25 parts by weight of olefin-based copolymer rubber, and (C) 5 to 40 parts by weight of a total of 100 parts by weight, and (D) organic peroxide 0.01. To 0.2 parts by weight and (E) 0.05 to 1 parts by weight of a cross-linking aid were used to prepare a polypropylene resin composition using a twin-screw extruder, the screw front stage temperature was 120 to 200 ° C., and the rear stage temperature was 180. ~ 27
The method for producing a modified polypropylene resin composition according to claim 1 or 2, wherein the mixture is melt-kneaded at 0 ° C and with the latter temperature higher than the former temperature. 8. The temperature in front of the screw is 140 to 160.
8. The method according to claim 7, wherein the second stage temperature is 200 to 260 ° C. 9. A molding material for mold stamping, comprising the modified polypropylene resin composition according to claim 1 or 2. 10. An injection-molded article obtained by injection-molding the modified polypropylene resin composition according to claim 1.