JPH09216975A - Polypropylene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene resin composition having high rigidity, excellent impact resistance and elongation, and an excellent balance among the properties. SOLUTION: This composition comprises 50-70wt.% polypropylene, 3-15wt.% polystyrene-ethylene/propylene-polystyrene triblock copolymer having a styrene content of 15-40wt.% 3-15wt.% polystyrene-ethylene/butene-polystyrene triblock copolymer having a styrene content of 15-40wt.%, and 10-30wt.% talc. The ratio of the polystyrene-ethylene/propylene-polystyrene triblock copolymer component to the total weight of the polystyrene-ethylene/propylene-polystyrene triblock copolymer component and the polystyrene-ethylene/butene-polystyrene triblock copolymer components is 20-80wt.%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polypropylene resin composition which is excellent in impact resistance and rigidity and is suitable as a material for automobile parts and the like.

[0002]

2. Description of the Related Art Polypropylene resin compositions having excellent impact resistance and rigidity have been conventionally used as materials for three-dimensional molded articles such as interior and exterior parts of automobiles. Such polypropylene-based resin compositions include polypropylene homopolymers, propylene block copolymers, blends of polypropylene and ethylene-propylene rubber such as propylene random copolymers, polypropylene, ethylene-propylene rubber and ethylene-butene rubber. Blend polymer with.

[0003]

The mechanical properties such as excellent rigidity, impact resistance, and tensile elongation are required for automobile instrument panels and interior parts such as door trims and pillars. Further, since these interior parts may be textured so as to have a good surface appearance, a material having a good texture transfer property is desired. In addition, exterior parts such as automobile side moldings are required to have excellent low temperature impact resistance capable of withstanding use in cold regions. However, a material composed of a blend polymer of polypropylene and ethylene-propylene rubber has a drawback that the impact resistance is sufficient but the elongation and rigidity are not sufficient. On the other hand, a material composed of a blend polymer of polypropylene, ethylene-propylene rubber, and ethylene-butene rubber has improved elongation and rigidity, but has a drawback of low impact resistance at low temperature. Therefore, there has been a strong demand for a propylene-based resin composition having excellent mechanical properties such as rigidity, impact resistance, tensile elongation, and grain transferability, and having sufficient performance as a material for interior and exterior parts of automobiles.

The present invention has been made in order to solve these problems and has high rigidity, excellent impact resistance and elongation, excellent balance of physical properties, and good moldability.
Moreover, it is an object to provide a polypropylene resin composition suitable as a material for a molded product having a beautiful surface appearance.

[0005]

[Means for Solving the Problems] The above-mentioned problems are addressed by the following: (A) 50 to 70% by weight of polypropylene and (B) styrene content of 15 to 40% by weight of polystyrene-ethylene / propylene-polystyrene triblock copolymer. 3 to 15
% By weight, (C) 3-15% by weight of polystyrene-ethylene / butene-polystyrene triblock copolymer having a styrene content of 15-40% by weight, and (D) 1 of talc.
0-30% by weight, and the polystyrene-ethylene / propylene-polystyrene triblock copolymer component (B) and the polystyrene-ethylene / butene-polystyrene triblock copolymer component (C) based on the total amount of polystyrene- The ratio of the ethylene / propylene-polystyrene triblock copolymer component (B) is 20 to 80.
The problem can be solved by a polypropylene-based resin composition characterized in that the content is wt%.

The above polypropylene resin composition is
The polyethylene-ethylene / butene-polyethylene triblock copolymer (E) may be contained in an amount of 1 to 5% by weight.

Hereinafter, the present invention will be described in detail. (A) Polypropylene As the polypropylene used in the present invention, any one of a propylene homopolymer (homopolypropylene), a block copolymer, a random copolymer, or a combination of two or more thereof may be used. it can.
As the comonomer of the block copolymer or the random copolymer, α-olefins other than propylene such as ethylene, butene-1, pentene-1, and hexene-1 are used, and among them, ethylene is particularly preferable. The propylene content in these copolymers is preferably 60 to 100 mol%, particularly preferably 80 to 99 mol%. In the block copolymer using ethylene as the α-olefin, the ethylene-propylene block in the molecule is dispersed in the homopolypropylene block and exhibits rubber elasticity, and functions as a rubber component. The content of the rubber component is preferably 10 to 25% by weight of the block copolymer. More preferably, it is 10 to 20% by weight of the block copolymer.

Melt flow rate of polypropylene (J
It is preferably 5 to 500 g / 10 minutes as measured by IS K6758 and hereinafter also referred to as MFR) at 230 ° C. and a load of 2.16 kg. This MFR is 5g / 10
If it is less than the minute, the fluidity of the obtained resin composition is poor and the moldability is deteriorated. If the MFR exceeds 500 g / 10 minutes, the impact resistance of the resin composition will be poor. These polypropylenes may be those having a low MFR within the above range by kneading and bisbreaking with an organic peroxide. Further, two or more kinds of polypropylenes having different fluidity may be mixed and the MFR may be within the above range.

(B) Polystyrene-ethylene / propylene-polystyrene triblock copolymer (hereinafter referred to as "SE
The polystyrene-ethylene / propylene-polystyrene triblock copolymer used in the present invention has an ethylene / propylene alternating copolymer block located at the center of the molecule, and is located on both sides of the block. This is where the polystyrene block is located. The content of the polystyrene block in this SEPS is preferably 15 to 40% by weight. When the content of the polystyrene block is less than 15% by weight, the rigidity and surface hardness of the obtained polypropylene resin composition are lowered, and when it exceeds 40% by weight, the low temperature impact resistance of the polypropylene resin composition is lowered.

The fluidity of SEPS is 230 ° C. and the load is 2.1.
The MFR at 6 kg is preferably 0.5 to 70 g / 10 minutes. This is because if the MFR is less than 0.5 g / 10 minutes, poor dispersion will occur and the low-temperature impact resistance will be deteriorated, and if the MFR exceeds 70 g / 10 minutes, the elastic modulus and elongation will decrease. The MFR at 230 ° C. and a load of 2.16 kg is larger than 5 g / 10 minutes and more preferably 40 g / 10 minutes or less. Alternatively, the MFR at 200 ° C. and a load of 5 kg is preferably larger than 2 g / 10 minutes and 40 g / 10 minutes or less. This MFR
If the value is 2 g / 10 minutes or less, the texture transfer property of the molded product tends to be poor, and inconvenience may occur depending on the application (for example, when used as an automobile interior material without coating). is there.

SEPS can be produced by hydrogenating a copolymer of styrene and isoprene. For this, a method of sequentially polymerizing styrene, isoprene, and styrene, followed by hydrogenation, and a styrene-isoprene diblock copolymer were first produced, and a coupling agent was used to form a triblock copolymer. Later, hydrogenation method and 2
There is a method in which a triblock copolymer is directly polymerized using a functional initiator and then hydrogenated. In any case, a diblock copolymer will be produced, but this proportion is preferably less than 40% by weight of the whole. 40
This is because if it exceeds the weight%, the rigidity and the surface hardness decrease.

(C) Polystyrene-ethylene / butene-
Polystyrene triblock copolymer (hereinafter referred to as "SEB
Sometimes referred to as "S") Polystyrene used in the present invention-ethylene / butene-
The polystyrene triblock copolymer is a block in which an ethylene / butene alternating copolymer block is located in the center of the molecule and polystyrene blocks are located on both sides of the block. The content of polystyrene block in SEBS is 1
It is preferably 5 to 40% by weight. When the content of the polystyrene block is less than 15% by weight, the rigidity and surface hardness of the obtained polypropylene resin composition are lowered, and when it exceeds 40% by weight, the low temperature impact resistance of the polypropylene resin composition is lowered. Moreover, the fluidity of SEBS is 0.5 to 70 in terms of MFR at 230 ° C and a load of 2.16 kg.
It is preferably g / 10 minutes. If the MFR is less than 0.5 g / 10 minutes, poor dispersion may occur, resulting in deterioration of low temperature impact resistance.
This is because when R exceeds 70 g / 10 minutes, the elastic modulus and elongation decrease. M at 230 ° C and a load of 2.16 kg
It is more preferable that the FR is greater than 5 g / 10 minutes and 40 g / 10 minutes or less. Alternatively, the MFR at 200 ° C. and a load of 5 kg is preferably larger than 2 g / 10 minutes and 40 g / 10 minutes or less. If the MFR is 2 g / 10 min or less, the embossed transfer property of the molded product tends to be deteriorated, which causes inconvenience depending on the application (for example, when used as an automobile interior material without coating). There are cases.

SEBS can be produced by hydrogenating a triblock copolymer of styrene and butadiene. For this, a method in which styrene, butadiene, and styrene are sequentially polymerized and then hydrogenated, and a styrene-butadiene diblock copolymer is first produced, and a coupling agent is used to form a triblock copolymer. After that, there are a method of hydrogenating and a method of directly polymerizing the triblock copolymer by using a bifunctional initiator and then hydrogenating. In either case, a diblock copolymer will be produced,
This proportion is preferably less than 40% by weight of the total. This is because if it exceeds 40% by weight, the rigidity and the surface hardness decrease.

(D) Talc The talc used in the present invention preferably has an average particle size of 0.3 to 3.5 μm. 0.5-2.5
More preferably, it is μm. Also, 0.5 or more, 1 μm
If it is less than, it is preferable. If the average particle size is less than 0.3 μm, talc is likely to agglomerate and the rigidity and impact resistance are deteriorated, which is not preferable. If the particle size is larger than 3.5 μm, the rigidity and impact resistance are deteriorated, which is not preferable. Further, it is desirable that the aspect ratio of talc used in the present invention (defined by the ratio of the longest portion of the plate-like particles of talc to the thickness thereof) is 5 or more. More preferably, it is 7 or more. If the aspect ratio of talc is less than 5, rigidity becomes difficult to develop. Further, in the use thereof, the dispersibility of talc may be improved by using a surface treatment of talc or a dispersant.

(E) Polyethylene-ethylene / butene-
Polyethylene triblock copolymer (hereinafter referred to as "CEB
It may be referred to as "C") Polyethylene-ethylene / butene-used in the present invention
The polyethylene triblock copolymer has an ethylene / butene alternating copolymer block located at the center of the molecule, and crystalline polyethylene blocks located on both sides of the block. The content of polyethylene block in CEBC is preferably 15 to 40% by weight. When the content of the polyethylene block is less than 15% by weight, rigidity, heat resistance and surface hardness of the obtained polypropylene resin composition are lowered, and when it exceeds 40% by weight, the low temperature impact resistance of the polypropylene resin composition is low. descend.

The fluidity of CEBC is preferably such that the MFR at 230 ° C. and a load of 2.16 kg is 0.5 to 70 g / 10 minutes. Further, it is preferably 0.5 to 10 g / 10 minutes. Further, it is more preferably 1 to 5 g / 10 minutes.
This is because if the MFR is less than 0.5 g / 10 minutes, poor dispersion will occur and the low-temperature impact resistance will be deteriorated, and if the MFR exceeds 70 g / 10 minutes, the elastic modulus and elongation will decrease.

CEBC can be produced by hydrogenating a triblock copolymer of 1,4-polymerized polybutadiene and 1,2-polymerized polybutadiene. For this, there is a method in which a diblock copolymer of butadiene is first produced, a triblock copolymer is formed using a coupling agent, and then hydrogenated. In this case, a diblock copolymer is produced, but this proportion is 40% by weight of the whole.
It is preferred to be less than. This is because if it exceeds 40% by weight, it will be dissolved in polypropylene and the rigidity and surface hardness will decrease.

(Composition ratio) The ratio of the component (A) in the polypropylene resin composition of the present invention is 50 to 70.
% By weight. If the proportion of the component (A) is less than 50% by weight, the heat resistance will decrease, and if it exceeds 70% by weight, the impact resistance will decrease. On the other hand, the proportion of the component (B) in the polypropylene resin composition of the present invention is 3 to 15% by weight. When the composition ratio of the component (B) in the resin composition is less than 3% by weight, the low temperature impact resistance and surface hardness of the obtained polypropylene resin composition are lowered, and when it exceeds 15% by weight, the elongation is lowered. Similarly, the proportion of the component (C) in the polypropylene resin composition of the present invention is 3 to 15% by weight. When the composition ratio of the component (C) in the resin composition is less than 3% by weight, the elongation of the obtained polypropylene resin composition is lowered, and when it exceeds 15% by weight, the low temperature impact resistance and the elongation are lowered.

Further, the ratio of the total amount of the (B) component and the (C) component in the total amount of the (A) component, the (B) component, and the (C) component is 8% by weight or more and less than 25% by weight. Preferably there is. If the ratio of the total amount of the components (B) and (C) is less than 8% by weight, the resulting composition has poor impact resistance, and if it is 25% by weight or more, the surface hardness tends to decrease. There is a narrower range of uses.

Further, the proportion of the talc (D) component in the polypropylene resin composition of the present invention is 10 to 30% by weight. If it is less than this range, the desired rigidity and heat resistance cannot be obtained, and if it is more than 30% by weight, the specific gravity becomes heavy and the hardness decreases.

When the component (E) is used in combination, the proportion of the component (E) in the polypropylene resin composition of the present invention is 1 to 5% by weight. When the composition ratio of the component (E) in the resin composition is less than 1% by weight, the effect of improving the tensile elongation of the obtained polypropylene resin composition is small, and when it exceeds 5% by weight, the rigidity and the surface hardness decrease.

Further, the ratio of the component (B) to the total amount of the component (B) and the component (C) needs to be 20 to 80% by weight. More preferably, it is 30 to 70% by weight. More preferably, it is 35 to 65% by weight. In the present invention, it has been found that the combined use of the component (B) and the component (C) in the above proportion makes it possible to synergistically improve the impact resistance. For example, when the proportion of the component (B) is less than 20% by weight, not only synergistic improvement in impact resistance due to the combined use of the components (B) and (C) can be expected, but also low temperature impact resistance A decline occurs. On the other hand, if the proportion of the component (B) exceeds 80% by weight, not only synergistic improvement in impact resistance due to the combined use of the component (B) and the component (C) cannot be expected, but the tensile elongation is the same as before. Is inferior. Even when the ratio of the component (B) and the component (C) is within the above range, the low temperature impact resistance tends to be excellent when the amount of the component (B) is relatively larger than that of the component (C). on the other hand,
When the amount of the component (C) is relatively larger than that of the component (B), the tensile elongation tends to be excellent. Further, when the components (B) and (C) are almost equal in amount, impact resistance at room temperature tends to be excellent.

When component (E) is used in combination, (B)
(E) with respect to the total amount of the component, the (C) component, and the (E) component
The proportion of the components is preferably 5 to 25% by weight. Furthermore, it is preferable that it is 7 to 20% by weight. Thus, by further using the component (E) in combination, it is possible to more effectively exhibit the synergistic improvement in impact resistance due to the combined use of the components (B) and (C) described above. Become. Furthermore, the tensile elongation is improved as compared with the combined system of the component (B) and the component (C). If the proportion of the component (E) is less than 5% by weight, such an effect cannot be exhibited. Further, when the proportion of the component (E) exceeds 25% by weight, the tensile elongation is improved but the rigidity and heat resistance are seriously deteriorated.

(Production Method of Polypropylene Resin Composition) In producing the polypropylene resin composition of the present invention, a stabilizer against heat, oxygen and light and a flame retardant which are widely used in the field of synthetic resins and synthetic rubbers. Additives such as a filler, a colorant, a lubricant, a plasticizer, and an antistatic agent may be added depending on the purpose of use within a range that does not essentially impair the characteristics of the polypropylene resin composition of the present invention.

Examples of the antioxidant include the following. Dibutyl hydroxytoluene, alkylated phenol, 4,4'-thiobis- (6-t-butyl-3-methylphenol), 4,4'-butylidenebis- (6-t-butyl-3-methylphenol), 2, 2'-methylenebis- (4-
Methyl-6-t-butylphenol), 2,2'-methylenebis- (4-ethyl-6-t-butylphenol), 2,6-di-t
-Butyl-4-ethylphenol, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, n
-Octadecyl-3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, tetrakis [methylene-3-
(3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, dilaurylthiodipropionate,
Distearyl thiodipropionate, dimyristyl thiopropionate. Further, as the hindered phenol type, triethylene glycol-bis [3- (3-t-
Butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-
t-butyl-4-hydroxyphenyl) propionate],
2,4-bis- (n-octylthio) -6- (4-hydroxy-3,
5-di-t-butylanilino) -1,3,5-triazine, pentaerythritol-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-
Thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 3, 5-the-
t-Butyl-4-hydroxy-benzylphosphonate-
Diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5, -di-t-butyl- There are 4-hydroxybenzyl) -isocyanurate, octylated diphenylamine, 2,4-bis [(octylthio) methyl] -O-cresol. Examples of the hydrazine type include N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine. Besides, a phenol-based antioxidant, a phosphite-based antioxidant, a thioether-based antioxidant, a heavy metal deactivator, etc. can be applied.

Examples of the ultraviolet absorber include 2 (2'-
Hydroxy-5'-methylphenyl) benzotriazole,
2 (2'-hydroxy-3'-t-butyl-5'-methylphenyl) 5chlorobenzotriazole, 2 (2'-hydroxy-
3 ', 5-di-t-butylphenyl) 5chlorobenzotriazole, 2-hydroxy-4-n-octoxybenzophenone, phenyl salicylate, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [ 2-hydroxy-
3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-
Benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2 -(3,5-di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5
-Di-t-amyl-2-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl)
Examples include benzotriazole and hydroxyphenyl benzotriazole derivatives. Or dimethyl succinate
1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6
-Tetramethylpiperidine polycondensate, poly [{6- (1,
1,3,3-Tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-
Hyperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], N, N'-bis
(3-Aminopropyl) ethylenediamine ・ 2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4piperidyl) amino] -6-chloro-1,3,5-triazine Condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis ( 1,2,2,6,6-pentamethyl-4-piperidyl), 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate and the like.

As the flame retardant, for example, the following can be applied. Polybromodiphenyl oxide, tetrabromobisphenol A, brominated epoxy hexabromocyclododecane, ethylenebistetrabrimophthalimide, brominated polystyrene dechlorane, brominated polycarbonate, polyphosphonate compound, halogenated polyphosphonate, triazine, red phosphorus, Tricresyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, triallyl phosphate, trixylyl phosphate, trialkyl phosphate, trischloroethyl phosphate, trischloropropyl phosphate, tris (dichloropropyl) phosphate, antimony trioxide, aluminum hydroxide , Magnesium hydroxide. Alternatively, silicone oil, stearic acid, calcium stearate, magnesium stearate, carbon black, titanium dioxide, silica, mica, montmorillonite and the like.

In the polypropylene resin composition of the present invention, the components (A), (B), (C) and (D) and the component (E) when the component (E) is used in combination, the component (E) is used together with the additive. It can be produced by uniformly blending. The method of mixing (mixing method) is not particularly limited, and a method generally used in the field of synthetic resins may be applied. As a mixing method, generally used is a method of dry blending using a mixer such as a Henschel mixer, a tumbler and a ribbon mixer, and a melting method such as an open roll, an extrusion mixer, a kneader and a Banbury mixer. There is a method of mixing. Of these methods, two or more of these mixing methods may be used in combination to obtain a more uniform resin composition (for example, after dry-blending in advance, the mixture is melt-mixed). Even when using dry blending together, even when using one or two or more methods of melt-mixing, in producing a molded article by the molding method described below, it is particularly preferable to use pelletizing by manufacturing pellets. .

Among the above-mentioned mixing methods, it is necessary to carry out at a temperature at which the resin used is melted, whether in the case of melt mixing or in the case of molding by the molding method described later. However, if it is carried out at a high temperature, the resin is thermally decomposed or deteriorated, so that it is generally carried out at 170 to 350 ° C, preferably 180 to 260 ° C.

M of the polypropylene resin composition of the present invention
FR can be appropriately set according to the molding method, physical properties of the molded body, etc., but is usually 1 to 100 g / 10 minutes, preferably 5 to 60
g / 10 minutes, more preferably 10-40 g / 10 minutes. 1g /
If it is less than 10 minutes, the workability is poor, and if it exceeds 100 g / 10 minutes, the mechanical properties are poor.

The polypropylene resin composition of the present invention is molded into a desired shape by applying a molding method such as an injection molding method, an extrusion molding method, a compression molding method and a hollow molding method which are generally used in the field of synthetic resins. You may let me. Alternatively, after being formed into a sheet using an extrusion molding machine, this sheet may be formed into a desired shape by a secondary processing method such as a vacuum forming method or a pressure forming method. Among these molding methods,
In order to exhibit good texture transferability, a method of passing a web formed from a calender or an extrusion machine between a texture roll and a rubber roll while in a molten state, a method of intermittently pressing, an embossed belt A method of casting the resin composition on the above is preferable.

The Izod impact strength of the molded article made of the polypropylene resin composition of the present invention is usually 5 kgf · cm / cm.
Or more, preferably 15 kgf · cm / cm or more, and more preferably 18 kgf · cm / cm or more. If it is less than 5 kgf · cm / cm, the use of the material may be restricted.

The flexural modulus of the molded article made of the polypropylene resin composition of the present invention is usually 15,000 to 400.
00 kgf / cm ² , preferably 18,000 to 35,000 kgf
/ cm ² , more preferably 20,000 to 35,000 kgf / cm
² If it is less than 15,000 kgf / cm ² , the use of the material may be restricted.

The tensile elongation of the molded product made of the polypropylene resin composition of the present invention is usually 100% or more, preferably 200% or more, and more preferably 300% or more. If it is less than 100%, the use of the material may be restricted.

The polypropylene resin composition of the present invention is
It is particularly suitable as a material for three-dimensional molded articles such as automobile parts. For example, it is suitable as an interior material for automobile instrumental panels and door trims, pillars and the like, which are required to have excellent rigidity, room temperature impact resistance, tensile elongation and grain transferability. Also, because it has excellent low temperature impact resistance,
It is also suitable as an exterior material such as a side molding.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on Examples, but it goes without saying that these Examples do not limit the present invention.

[0037]

[Example] (A), (B), (C),
Various properties were tested for a molded body using a polypropylene resin composition comprising each of the components (D) and (E).

(A) Polypropylene As polypropylene (PP-1), MFR manufactured by Showa Denko K.K. is a homotype polypropylene "MA810B" of 35 g / 10 min, (PP-2) manufactured by MFR manufactured by the same company. Was 45 g / 10 minutes and the rubber content was 10% by weight. A block type polypropylene "MK711H" was used.

As the polystyrene-ethylene / propylene-polystyrene triblock copolymer (SPS) (B), four kinds shown in Table 1 were used.

[0040]

[Table 1]

(C) Polystyrene-ethylene / butene-
The polystyrene triblock copolymer (SEBS) is shown in Table 2.
The following three types were used.

[0042]

[Table 2]

The talc (D) used had a particle size of 2.2 μm measured by a laser sedimentation method and an aspect ratio of 7 measured by a transmission electron microscope. Further, talc having the same particle size of 0.7 μm and having the same aspect ratio of 5.5 was also used.

(E) Polyethylene-ethylene / butene-
Table 3 shows polyethylene triblock copolymer (CEBC).
Two types were used.

[0045]

[Table 3]

For comparison, instead of the triblock copolymer (TBC), ethylene / propylene rubber (intrinsic viscosity [η] = 2.5 dl / g, propylene content 25% by weight, hereinafter referred to as EPR), ethylene / butene rubber (Intrinsic viscosity [η] = 3.5 dl / g, butene content 15% by weight,
Hereinafter referred to as EBR). Further, a polystyrene-ethylene / propylene diblock copolymer (referred to as SEP) was also used for comparison. Styrene content is 37
% By weight, MFR (230) = 0.7 g / 10 minutes, MFR (2
00) = 0.6 g / 10 minutes.

These respective components were blended in the proportions (unit: weight%) shown in Tables 4 and 5 and dry blended for 5 minutes with a Henschel mixer. The resulting mixture is
Pellets were manufactured by kneading using a same-direction twin-screw extruder (diameter 30 mm) set at 80 ° C. Put these pellets in 2
Injection molding was performed using an injection molding machine set at 00 ° C., and test pieces for Izod impact test, flexural modulus and tensile elongation were prepared and tested. In addition, the grain transfer property was evaluated.

In the following examples and comparative examples, each physical property was measured by the following methods. The Izod impact strength (unit: kgf · cm / cm) was measured with a notch at room temperature and −30 ° C. according to ASTM D256. Flexural modulus (kgf / cm ² ) is ASTM D7
90 at a temperature of 23 ° C. Tensile elongation (%) was measured at a temperature of 23 ° C. according to ASTM D638. In addition, M of the components (B) and (C)
FR was measured under the conditions of 230 ° C, load 2.16kg and 200 ° C, load 5kg, and MFR (230) and MFR respectively.
(200). Regarding the grain transferability, a grained flat plate was molded at a mold temperature of 40 ° C. and a cylinder temperature of 230 ° C., and the grain transferability was visually determined. The transferability was evaluated as ⊚, the good transfer was evaluated as ◯, the inferior transfer property was evaluated as Δ, and the bad transfer property was evaluated as x.

[0049]

[Table 4]

[0050]

[Table 5]

[0051]

[Table 6]

[0052]

[Table 7]

From Tables 6 and 7, it is understood that in Examples 1 to 25, various properties such as impact resistance, rigidity, tensile elongation, and grain transferability are exhibited in a high dimension and in good balance. In particular, in Examples 12 to 25 in which CEBC was added, the tensile elongation was further improved.

[0054]

The polypropylene resin composition of the present invention has the following effects. (1) Excellent impact resistance. (2) Excellent elongation. (3) High rigidity. (4) The texture transfer property is excellent.

From these effects, the polypropylene resin composition of the present invention is particularly suitable as a material for three-dimensional molded articles such as automobile parts. For example, it is suitable as an interior material for automobile instrumental panels and door trims, pillars and the like, which are required to have excellent rigidity, room temperature impact resistance, tensile elongation and grain transferability. Further, since it has excellent low temperature impact resistance, it is also suitable as an exterior material for a side molding or the like.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Takenouchi 2-3-2 Yokou, Kawasaki-ku, Kawasaki City, Kanagawa Japan Polyolefin Co., Ltd. (72) Takayuki Beppu 2-3-3 Yokou, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture No. 2 in Japan Polyolefin Co., Ltd. (72) Inventor Yoshihiro Mogi 2-3-3 Yokou, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Polyolefin Co., Ltd. (72) Kazuhiko Sakai 2-3-3 Yokou, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 2 in Japan Polyolefin Co., Ltd. (72) Inventor Iku Minoru Jinagawa 1 Toyota-cho, Toyota-shi, Aichi Toyota Automobile Co., Ltd. (72) In-house Takao Nomura 1 Toyota-cho, Toyota-shi, Aichi Toyota Automobile Co., Ltd. (72) Inventor Takesumi Nishio 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto The Corporation

Claims (10)

[Claims] 1. A polypropylene containing 50 to 70% by weight,
A polystyrene-ethylene / propylene-polystyrene triblock copolymer having a styrene content of 15 to 40% by weight and a polystyrene-ethylene / butene-polystyrene triblock copolymer having a styrene content of 15 to 40% by weight are used. 3-15 wt% polymer and 1 talc
0 to 30% by weight of polystyrene-ethylene / propylene-polystyrene triblock copolymer component and the total amount of polystyrene-ethylene / butene-polystyrene triblock copolymer component of polystyrene-ethylene / propylene-polystyrene triblock. A polypropylene resin composition, wherein the proportion of the block copolymer component is 20 to 80% by weight. 2. The polypropylene resin composition according to claim 1, further comprising 1 to 5% by weight of a polyethylene-ethylene / butene-polyethylene triblock copolymer. 3. The polyethylene-ethylene / butene-
The polyethylene triblock copolymer has a temperature of 230 ° C,
Melt flow rate at a load of 2.16 kg is 0.5 g / 10
Minutes or more and 70 g / 10 minutes or less, 3.
The polypropylene-based resin composition described in 1. 4. The polyethylene-ethylene / butene-
The polypropylene-based resin composition according to claim 2, wherein the polyethylene triblock copolymer has a polyethylene block content of 15% by weight or more and 40% by weight or less. 5. The polystyrene-ethylene / propylene-polystyrene triblock copolymer has a 200
The polypropylene resin composition according to claim 1, wherein the melt flow rate at a temperature of 5 ° C and a load of 5 kg is more than 2 g / 10 minutes and 40 g / 10 minutes or less. 6. The polystyrene-ethylene / butene-
The polystyrene triblock copolymer has a temperature of 200 ° C,
The polypropylene resin composition according to claim 1, wherein the melt flow rate at a load of 5 kg is more than 2 g / 10 minutes and not more than 40 g / 10 minutes. 7. The talc has an average particle size of 0.3 μm.
2. The thickness is not less than m and not more than 3.5 μm.
The polypropylene-based resin composition described in 1. 8. The talc has an average particle size of 0.5 μm.
The polypropylene-based resin composition according to claim 1, wherein the polypropylene-based resin composition has a thickness of m or more and less than 1 μm. 9. The polypropylene, the polystyrene-ethylene / propylene-polystyrene triblock copolymer, and the polystyrene-ethylene / butene-
The ratio of the total amount of the polystyrene-ethylene / propylene-polystyrene triblock copolymer and the polystyrene-ethylene / butene-polystyrene triblock copolymer in the total amount of the polystyrene triblock copolymer is 8% by weight or more. The polypropylene resin composition according to claim 1, which is less than 25% by weight. 10. The total amount of the polystyrene-ethylene / propylene-polystyrene triblock copolymer, the polystyrene-ethylene / butene-polystyrene triblock copolymer, and the polyethylene-ethylene / butene-polyethylene triblock copolymer. The polypropylene-based resin composition according to claim 2, wherein the content of the polyethylene-ethylene / butene-polyethylene triblock copolymer in the content is 5% by weight or more and 25% by weight or less.