JPH10101888A - Propylene-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a propylene-based resin composition having excellent impact resistance, coating property and release resistance and suppressed in occurrence of flow mark. SOLUTION: This resin composition contains (A) a polypropylene-based polymer containing a propylene-ethylene block copolymer, (B) an ethylene-octene- based rubber, (C) a triblock copolymer and (D) talc. In the component A, melt flow rate(MFR) is 5-100g/10min, a ratio of xylene extract component is 15-60wt.% and propylene content in xylene extract component is 40-60wt.% and intrinsic viscosity in decalin is 2.0-5.0g/dl. In the component B, the octene content is 15-35wt.%. Critical energy release ratio (Gc) between the ethylene- octene-based rubber and xylene-insoluble component of the polypropylene polymer of the component A is >=30J/m<2> . In the component C, MFR is 5-40g/10min and viscosity at 230 deg.C becomes constant (0 shear viscosity) in an area having <=1rad/sec angular frequency and the 0 shear viscosity is 2,000-10,000 poise. Gc between the triblock copolymer and xylene-insoluble component of the polypropylene-based polymer of the component A at 100 deg.C is >=30J/m<2> and the content ratio is 2-10wt.%. In the component D, the average particle diameter is <=5μm and the content ratio is 5-25wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition which is excellent in impact resistance and paintability and does not generate flow marks. For example, the present invention relates to a resin composition suitable as a material for automobile bumpers and interior and exterior parts of automobiles. Things.

[0002]

2. Description of the Related Art As a technique for improving the impact resistance of materials for automobile bumpers and interior / exterior parts, propylene-based polymers such as propylene homopolymer, propylene-ethylene block copolymer, and propylene random copolymer have been used. Ethylene-propylene copolymer (JP-A-57-55952), ethylene-α-olefin copolymer (JP-A-4-372637),
JP-A-5-331348, JP-A-6-192500, JP-A-Hei.
JP-A-6-192506) and blending of a hydrogenated product of a block copolymer of styrene and a diene (JP-A-7-53842) are reported. In order to impart coatability to the above composition, a method of adding an EPR having an extremely low molecular weight is generally used. In addition, a method of adding a polyolefin modified with a compound having a polar group (Japanese Patent Application Laid-Open No. 6-57838)
JP-A-5-39), especially a method of adding a polyolefin modified with a compound having an unsaturated hydroxyl group.
No. 383) and a method of adding an oligomer having a polar group at the terminal (JP-A-3-157168, JP-A-5-117458, JP-A-5-320442).

[0003]

However, in the case of a material formed by the above method, a large amount of an ultra-low molecular weight ethylene-propylene copolymer or a chemically modified compound is required in order to exhibit sufficient paintability. It has to be added, and mechanical properties such as impact resistance tend to be greatly reduced. In particular, when the molded product is released from the mold, there is often a problem that the surface of the molded product is peeled off. Further, even if a material having a good balance of paintability, impact resistance and peeling resistance is obtained, a large molded product such as a bumper of an automobile has a defect that a flow mark is easily generated and the product is defective. The present invention has been made in order to solve such problems, and provides a propylene-based resin composition having excellent impact resistance, paintability, and peeling resistance, and in which generation of a flow mark is suppressed. The purpose is to do so.

[0004]

The propylene resin composition of the present invention comprises a component (A): a polypropylene polymer having a propylene-ethylene block copolymer, and a component (B): ethylene-octene rubber. And a component (C): a triblock copolymer, and a component (D): talc, and the polypropylene polymer having the component (A) propylene-ethylene block copolymer has a temperature of 230 ° C. MFR measured under the condition of a load of 2.16 kg at 5 to 100 g / 10 minutes, 2
The proportion of the xylene extractable component at 0 ° C. is 15-60% by weight
And the propylene content in the xylene extraction component is
The intrinsic viscosity in decalin at 40 to 60% by weight and 140 ° C. is 2.0 to 5.0 g / dl, and the ethylene-octene rubber of the component (B) has an octene content of 15 to 35% by weight. Critical energy release when the phase angle of the flat interface between the ethylene-octene rubber and the xylene insoluble component at 100 ° C. of the polypropylene polymer of component (A) is −2 ° to −12 ° Rate is 30 J / m ² or more, and the triblock copolymer of the component (C) has a load of 2.16 k at 230 ° C.
The MFR measured under the condition of g is 5 to 40 g / 10 minutes, and the viscosity at 230 ° C. becomes a constant zero shear viscosity in a region where the angular frequency is 1 rad / sec or less, and the zero shear viscosity is 2000 to 10,000.
Poise, said triblock copolymer and component (A)
The critical energy release rate when the phase angle of the flat interface between the polypropylene-based polymer and the xylene-insoluble component at 100 ° C is -2 ° to -12 ° is 30 J / m ² or more, The proportion is 2 to 10% by weight, and the talc of the component (D) has an average particle size of 5 μm or less, and has a content of 5 to 25% by weight in the whole. In this case, the component (C) is preferably a hydrogenated styrene-butadiene-styrene triblock copolymer having a styrene content of 12 to 25% by weight.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Component (A): Polypropylene Polymer] The polypropylene polymer in the present invention needs to contain at least a propylene-ethylene block copolymer in its component. That is, the polypropylene-based polymer in the present invention may be the propylene-ethylene block copolymer alone,
In addition to the ethylene block copolymer, a random copolymer or a homopolymer of propylene (also referred to as homopolypropylene or polypropylene homopolymer) can be used in combination. As the comonomer of the random copolymer, α-olefins other than propylene such as ethylene, butene-1, hexene-1, octene-1, and 4-methylpentene-1 are preferable, and ethylene is particularly preferable.

In a block copolymer using ethylene as an α-olefin, that is, a propylene-ethylene block copolymer, an ethylene-propylene component in a molecule is dispersed in homopolypropylene, and the rubber component has a high impact resistance. Contributes to the development of sex. Melt flow rate of the polypropylene polymer (230 ° C, load 2.16 kg: JIS K72
10 According to Condition 14. Hereinafter, it is called MFR. ) Is 5-100g
/ 10 minutes is preferred, and 15 to 50 g / 10 minutes is preferred. MFR,
If less than 5 g / 10 minutes, the fluidity of the obtained resin composition is poor,
Moldability deteriorates, and generation of flow marks in particular becomes remarkable. On the other hand, if the MFR exceeds 100 g / 10 minutes, there arises a problem that the impact resistance and coatability of the resin composition are reduced. The polypropylene-based polymer is obtained by melting and kneading a material having a low MFR (for example, MFR is 0.5 g / 10 min) in the presence of an organic peroxide (bisbreak), so that the MFR is within the above range. It can also be used.

The proportion of the xylene extractable component at 20 ° C. in the polypropylene polymer is preferably 15 to 60% by weight. More preferably, it is 25 to 50% by weight. This component corresponds to the rubber component. The ratio of the xylene extractable component at 20 ° C. of the polypropylene-based polymer is 15
If the amount is less than 10% by weight, a large amount of a rubber component needs to be added in order to develop impact resistance, and thus there are problems such as an increase in cost and poor dispersion. On the other hand, if the content exceeds 60% by weight, there is a problem that cohesion tends to occur during the production of the polypropylene-based polymer, which is likely to cause trouble.

Further, the propylene content in the xylene extraction component at 20 ° C. of the polypropylene-based polymer is 40%.
Preferably it is 6060% by weight. More preferably, the content is 45 to 58% by weight. If the propylene content in the xylene extraction component is less than 40% by weight, there is a problem that the resulting resin composition does not exhibit impact resistance. On the other hand, if it exceeds 60% by weight, heat resistance and surface hardness are reduced.

Further, the polypropylene-based polymer is heated at 20 ° C.
The intrinsic viscosity of the xylene-extracted component in decalin at 140 ° C. is preferably 2.0 to 5.0 g / dl. More preferably, it is 2.0 to 3.5 g / dl. If the intrinsic viscosity of the component is less than 2.0 g / dl, the resulting resin composition does not exhibit impact resistance. On the other hand, if it exceeds 5.0 g / dl, there is a problem that not only the coatability of the obtained resin composition is inferior, but also poor dispersion is likely to occur and the impact resistance is lowered. Further, there is a problem that the flow mark is deteriorated.

Further, the content of the polypropylene polymer in the whole propylene resin composition is preferably 55 to 85% by weight. Further, the content is preferably 60 to 80% by weight. If the content is less than 55% by weight, as a result, the amount of added rubber increases, leading to an increase in cost. On the other hand, if it exceeds 85% by weight, the coatability of the obtained resin composition tends to be poor.

[Component (B): Ethylene-octene rubber] The octene content of the ethylene-octene rubber used in the present invention is preferably 15 to 35% by weight. When the octene content is less than 15% by weight, there is a problem that low-temperature impact resistance is not exhibited. On the other hand, if it exceeds 35% by weight, heat resistance, surface hardness and peeling resistance will be reduced. Further, the critical energy release when the phase angle of the flat interface between the ethylene-octene rubber and the xylene-insoluble component at 100 ° C. of the propylene polymer of the component (A) is −2 ° to −12 °. Rate (hereinafter referred to as Gc)
It needs to be 30 J / m ² or more. If Gc is less than 30 J / m ² , there is a problem that the resulting resin composition has reduced impact resistance and the like and also has reduced peel resistance.

Further, the ethylene-octene rubber may contain 230
The MFR at 0 ° C is preferably 0.5 to 10 g / 10 minutes.
Furthermore, 0.5 to 8 g / 10 minutes is suitable. If the MFR is less than 0.5 g / 10 minutes, poor dispersion is caused, the surface appearance of the molded product is deteriorated, and the mechanical performance is also reduced. On the other hand, 10
If it exceeds g / 10 minutes, there is a problem that impact resistance is not exhibited.

The content of the ethylene-octene rubber in the whole propylene resin composition is preferably 5 to 20% by weight. If the content is less than 5% by weight,
Impact resistance and paintability are reduced. On the other hand, if it exceeds 20% by weight, the cost increases. The ethylene-octene rubber can be produced using a known metallocene catalyst. For example, it can be obtained by the methods described in US Pat. No. 5,278,272, US Pat. No. 5,272,236, JP-T-7-500622, and JP-T-8-501343.

[Component (C): Triblock copolymer] The triblock copolymer used in the present invention has the effect of improving the flow mark during molding. The MFR of the triblock copolymer measured at 230 ° C. under a load of 2.16 kg is preferably 5 to 40 g / 10 minutes. MFR is 5g / 10
If it is less than minutes, the effect of improving the flow mark during molding is inferior. On the other hand, if it exceeds 40 g / 10 minutes, there is a problem that impact resistance, tensile elongation and the like are reduced.

The viscosity of the triblock copolymer at 230 ° C. becomes constant (called zero shear viscosity) in a region where the angular frequency is 1 rad / sec or less, and the zero shear viscosity at that time is 2000 to 10,000 poise. Preferably, there is. 230
The viscosity at ℃ is not constant in the region where the angular frequency is 1 rad / sec or less, that is, the viscosity decreases with the decrease of the angular frequency
If it increases by 20% or more, there is a problem that the improvement effect of the flow mark is inferior and the paintability is also deteriorated. Further, if the zero shear viscosity is less than 2000 poise, there is a problem that impact resistance, tensile elongation and the like are reduced. On the other hand, 10000
If it exceeds poise, there is a problem that the effect of improving the flow mark is inferior and the paintability is also deteriorated.

Further, the triblock copolymer comprises:
The phase angle of the flat interface between the component (A) and the xylene-insoluble component at 100 ° C. of the propylene-based polymer is from −2 ° to −12.
It is preferable that the critical energy release rate (Gc) at 30 ° is 30 J / m ² or more. Gc is, if less than 30 J / m ^2,
There is a problem that the impact resistance and the like of the obtained resin composition are reduced.

Further, the content of the triblock copolymer in the propylene resin composition is preferably 2 to 10% by weight. Further, 2 to 5% by weight is preferable.
If the content of the triblock copolymer in the propylene-based resin composition is less than 2% by weight, there is a problem that the effect of improving the flow mark is small. On the other hand, if it exceeds 10% by weight, the cost increases, and there is a problem that the improvement of various physical properties cannot be expected for the high cost.

Further, the triblock copolymer is a hydrogenated product of a styrene-butadiene-styrene triblock copolymer (hereinafter referred to as SEBS), and the styrene content is 12 to 25% by weight. preferable. In this case, if the styrene content is less than 12% by weight, there is a problem that impact resistance and heat resistance are reduced. On the other hand, 25% by weight
Is exceeded, there is a problem that the effect of improving the flow mark is small.

These triblock copolymers can be produced by a commonly used anionic living polymerization method. This includes sequentially styrene, butadiene,
After polymerizing styrene and producing a triblock copolymer, a method of hydrogenation and after first producing a diblock copolymer of styrene-butadiene, and then forming a triblock copolymer using a coupling agent, How to hydrogenate,
Further, there is a method in which butadiene and styrene are sequentially polymerized using a bifunctional initiator and then hydrogenated. In either case, a diblock copolymer, a homopolymer, or the like is produced, but the content thereof must be less than 10% by weight of the entire triblock copolymer. If the content of the diblock copolymer or homopolymer exceeds 10% by weight, there is a problem that rigidity is reduced.

[Component (D): Talc] The average particle size of talc used in the present invention is preferably 5 μm or less.
If the average particle size exceeds 5 μm, there is a problem that impact resistance, tensile elongation and the like are reduced. The content of talc in the propylene-based resin composition is 5 to 25% by weight. If it is out of this range, it is difficult to satisfy the elastic modulus, impact resistance, and the like suitable for automotive materials.

In producing the resin composition of the present invention,
Additives such as heat, oxygen, and light stabilizers, flame retardants, fillers, coloring agents, lubricants, plasticizers, and antistatic agents that are widely used in the synthetic resin and synthetic rubber fields. Accordingly, the resin composition of the present invention may be added in a range that does not substantially impair the properties of the resin composition.

For example, examples of the antioxidant include the following. Dibutylhydroxytoluene, 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, dilauryl thiodipropionate, distearyl thiodipropionate, and dimyristylyl thiopropionate. Hindered phenol-based compounds include 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,
Pentaerythryl-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-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester,
3,5-trimethyl-2,4,6-tris (3,5-di-t
-Butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl)
-Isocyanurate, octylated diphenylamine,
There is 2,4-bis [(octylthio) methyl] -o-cresol. Hydrazines include N, N'-bis [3
-(3,5-di-t-butyl-4-hydroxyphenyl)
[Propionyl] hydrazine. In addition, a phenolic antioxidant, a phosphite antioxidant, a thioether antioxidant, a heavy metal deactivator and the like can be applied.

As the ultraviolet absorber, for example, 2-
(2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-
5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2-hydroxy-4-n-oct Xybenzophenone, 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-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-amyl-
2-hydroxyphenyl) benzotriazole, 2-
(2′-hydroxy-5′-t-octylphenyl) benzotriazole, hydroxyphenylbenzotriazole derivatives and the like. 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-piperidyl) 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-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, Bis (1,2,2,2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate
6,6-pentamethyl-4-piperidyl), 2,4-di-
t-butylphenyl-3,5-butyl-4-hydroxybenzoate and the like.

Further, as the flame retardant, for example, the following can be applied. Polybromodiphenyl oxide, tetrabromobisphenol A, brominated epoxy hexabromocyclododecane, ethylene bistetrabromophthalimide, brominated polystyrene dechlorane, brominated polycarbonate, polyphosphonate compound, halogenated polyphosphonate, triazine, red phosphorus, Tricresyl phosphate, triphenyl phosphate, crediphenyl phosphate, triallyl phosphate, trixylyl phosphate, trialkyl phosphate, trischloroethyl phosphate, trischloropropyl phosphate, tris (dichloropropyl phosphate), antimony trioxide, aluminum hydroxide, water An example is magnesium oxide. Further, silicone oil, stearic acid, calcium stearate, barium stearate, aluminum stearate, zinc stearate, magnesium stearate, carbon black, titanium dioxide, silica, mica, montmorillonite and the like may be added.

In addition to these additives, inorganic fillers may be added. Examples of the inorganic filler include fibrous materials such as barium titanate whiskers, calcium carbonate whiskers, magnesium sulfate whiskers, boron-based whiskers, carbon fibers and glass fibers, and particulate materials such as calcium carbonate and magnesium carbonate.

[Gc Measurement Method] In the present invention, Gc exists at a flat interface between an ethylene-octene rubber or a triblock copolymer and a xylene-insoluble component of a propylene-ethylene block copolymer at 100 ° C. It is defined by the critical energy release rate of the cracks. To measure Gc, an asymmetric double cantilever beam method (hereinafter referred to as ADCB method; see: Costantino-Creton, dissertation, Cornell University, 1992) is used. This is to allow cracks to grow along the interface. Conventionally, in a peel test that was sometimes used, a crack could not be grown along an interface. For this reason, the crack penetrated into a softer material (that is, in the ethylene-octene rubber or the triblock copolymer), and the Gc at the interface could not be measured accurately.

A parameter that determines the crack growth direction is a phase angle Ψ defined by the following equation. Ψ = tan ⁻¹ (K _II / K _I ) Here, K _I and K _II are stress intensity factors corresponding to mode I (tensile) and mode II (in-plane shear), respectively. Ψ depends on the geometry of the ADCB method, the elastic modulus of each material, Poisson's ratio, and crack length. Actually, evaluation is made by the boundary element method (BEM method) and the finite element method (FEM method).

In the present invention, it is necessary to measure Gc in the range of -2 ° to -12 °. Here, Ψ is defined to be negative when the crack proceeds in the direction of the thin beam. If Ψ is smaller than -12 °, cracks at the interface penetrate into a thin beam, and there is a problem that Gc at the interface cannot be measured accurately. On the other hand, if Ψ is -2 ° to 0 °,
Crack growth at the interface is unstable and, as before,
There is a problem that Gc of the interface cannot be measured accurately. Further, if Ψ exceeds 0 °, cracks penetrate into the ethylene-octene rubber or the triblock copolymer, and there is a problem that Gc at the interface cannot be measured accurately.

[Production Method] The resin composition of the present invention is produced by uniformly mixing the above-mentioned components, additives and the like. There is no particular limitation on the mixing method, and a method generally used in the field of synthetic resins may be applied. As a mixing method, a method of dry blending using a commonly used mixer such as a Henschel mixer, a tumbler, and a ribbon mixer, and a mixer such as an open roll, an extrusion mixer, a kneader, and a Banbury are used. And mixing while melting.

Of these methods, in order to obtain a more uniform resin composition, two or more of these mixing methods may be used in combination. For example, after dry-blending in advance, the mixture is melt-mixed. Even when dry blending is used in combination, or when one or two or more types of melt-mixing methods are used in combination, a pelletized product must be produced using a pelletizer before producing a molded product by a molding method described below. Is particularly preferred. Of the above mixing methods, even when melt mixing,
Even when molding is performed by a molding method described later, the molding must be performed at a temperature at which the resin used is melted. However, when the reaction is carried out at a high temperature, the resin is thermally decomposed or deteriorated. Therefore, the reaction is generally carried out at 180 to 350 ° C, preferably 190 to 260 ° C.

The resin composition of the present invention may be formed into a desired shape by using an injection molding method, an extrusion molding method, a compression molding method, a hollow molding method, etc., which are generally performed in the field of synthetic resins. Alternatively, after forming into a sheet using an extruder, the sheet may be formed into a desired shape by a secondary processing method such as a vacuum forming method or a pressure forming method.

[0032]

The present invention will be described below in detail with reference to examples. A propylene-based resin composition was produced using (A) a polypropylene-based polymer, (B) an ethylene-octene-based rubber (EOR), (C) a triblock copolymer, and (D) talc. (A) Five kinds of propylene-ethylene copolymer and polypropylene homopolymer (MFR: 30 g / 10 min., Hereinafter abbreviated as PP-6) shown in Table 1 were used as the polypropylene-based polymer.

[Table 1] In Table 1, MFR was measured according to JIS K7210 condition 14. CE / P is the amount of xylene extracted from the propylene-ethylene block copolymer, Fp is the propylene content measured by NMR, and [η] E / P (dl / g) is the limit of the xylene extracted component. Viscosity.

(B) As the ethylene-octene rubber,
Three types of ethylene-octene rubber shown in Table 2 were used.

[Table 2] In Table 2, Fo is the octene content measured by NMR. Further, the critical energy release rate when the phase angle of the flat interface between the PP-1 and the xylene-insoluble component at 100 ° C. is −2 ° to −12 ° is also shown.

(C) As a triblock copolymer, Table 3
The following five types were used.

[Table 3] In Table 3, SEBS is a hydrogenated product of a styrene-butadiene-styrene triblock copolymer, SEPS is a hydrogenated product of a styrene-isoprene-styrene triblock copolymer, CE
BC indicates a hydrogenated product of 1,4-butadiene-1,2-butadiene-1,4-butadiene block copolymer. Also, MFR
Was measured according to JIS K7210 condition 14. Further, the zero shear viscosity (η.) At 230 ° C. of these triblock copolymers is measured in the range of angular frequency (ω) of 0.1 to 10 rad / sec by RSAII manufactured by Rheometrics, and extrapolated to ω = 0. Sought by. (D) Talc having a particle size of 2 μm (T-1)
(T-2) having a particle size of 5.6 μm. still,
The particle size of talc was measured using a laser sedimentation method.

Using these components (A) to (D), Table 4
After dry blending for 3 minutes using a Henschel mixer, the same direction 2 set at 210 ° C.
The mixture was kneaded using a screw extruder (diameter 30 mm) to produce pellets of the resin composition. Pellets of each obtained resin composition
Molding was performed using an injection molding machine set at 210 ° C., and test pieces for measuring physical properties were prepared. Table 4 shows the test results. In Comparative Example 11, an ethylene-propylene copolymer (EPR) having a propylene content (Fp) of 50% by weight was used instead of EOR.

In Table 4, for each propylene resin composition, the flatness between (B) the ethylene-octene rubber and the xylene-insoluble component of the polypropylene polymer of the component (A) at 100 ° C. was determined. Interface phase angle is -2 ° to -12
° C critical energy release rate (Gc1) and (C)
The same critical energy release rate (Gc2) between the triblock copolymer and the xylene-insoluble component at 100 ° C. of the polypropylene polymer of the component (A) is also shown. These measurements were performed by the asymmetric double cantilever beam method described in JP-A-7-286088 and JP-A-7-292175. That is, first, two flat plates of xylene-insoluble components at 100 ° C. of the propylene-ethylene block copolymer serving as a reference having different thicknesses are prepared. And
An ethylene-octene rubber or a triblock copolymer is press-molded to form a sheet having a thickness of about 1 mm, and the sheet is superimposed on the above flat plate as shown in FIG. And press-bonded with a press molding machine. Thereafter, a crack was formed in the interface with a razor blade having a thickness of 0.25 mm, the interface strength was measured, and the critical energy release rate by the ADCB method was obtained. At this time, the thickness ratio of both beams was calculated and set by the boundary element method so that Ψ became −7 °.

Each physical property in Table 4 is based on the following test. (1) Low Temperature Impact Test (IZOD) Izod impact strength was measured with a notch at a temperature of -30 ° C. according to ASTM D265. The unit is (J / m). (2) Flow mark test (mark) A flat plate of 80 mm x 240 mm x 3 mm was formed, and the appearance of the flow mark was visually observed and evaluated. In Table 4, も の indicates no flow mark, ○ indicates a slight flow mark, and × indicates a marked flow mark.

(3) Paintability Test First, the flat plate formed in the above flow mark test was washed and dried with ion-exchanged water, coated with a chlorinated polypropylene primer at 10 μm, and dried at 80 ° C. for 30 minutes.
Thereafter, a 30 μm two-component urethane paint is applied and
Bake for a minute. Then, cuts at 2 mm intervals intersecting at an angle of 90 ° were made in the coating film surface, and 100 grids were made. Next, a cellophane adhesive tape was strongly adhered thereon, and the adhesive tape was quickly peeled off. In Table 4, ○ indicates that there was no peeling of the coating film, △ indicates that the coating film was partially peeled, and X indicates that more than half of the coating film on the grid crossed. (4) Peeling resistance test When a 1 cm wide cut was made in the above-formed flat plate with a cutter, a part of the flat plate surface was peeled off from the cut portion, and the flat plate was peeled off at a speed of 10 mm / min using a tensile tester. Was measured. The thickness of the surface portion to be peeled at this time was about 100 μm.

[0039]

[Table 4]

From the results shown in Table 4, it can be seen that any of the resin compositions of Examples 1 to 4 can provide molded articles having excellent low-temperature impact resistance, flow mark properties, coating properties, and peel resistance. We can see that we can do it. On the other hand, as in Comparative Example 1, [η] E / P
When using PP-3 (5.5dl / g) with large flow mark,
And the paintability deteriorates. On the other hand, as in Comparative Example 2, contrary to Comparative Example 1, when PP-4 having an intrinsic viscosity as small as 1.8 dl / g is used, the flow mark and the paintability are good, but the impact strength and the resistance to The peelability is significantly reduced. Furthermore, as shown in Comparative Example 3, the Fp of the xylene extracted component was small (Fp = 3
0) If PP-5 is used, IZOD, flow mark, and peel resistance tend to decrease. In Comparative Example 4, when EOR-2 having a low Fo was used, IZOD was significantly reduced, and the flow mark also tended to be poor. When EOR-3 having a small Gc1 (Gc1 = 20) is used as in Comparative Example 5, IZOD and peel resistance deteriorate.

The amount of the triblock copolymer added was reduced (1
(wt%) In Comparative Example 6, the flow mark, the coating property, and the peeling resistance were significantly reduced. Η as in Comparative Example 7. It was found that those with a remarkably large (TBC-3) deteriorated the flow mark and paintability. On the other hand, η as in Comparative Examples 8 and 9. Do not have
When SEPS (TB-4) and CEBC (TBC-5) were used, the results showed that the flow mark deteriorated. When talc having a large particle diameter is used as in Comparative Example 10, IZOD is reduced. Furthermore, when EPR is used instead of EOR as in Comparative Example 11, the peeling resistance is significantly reduced.

[0042]

According to the present invention, it is possible to provide a resin composition having excellent low-temperature impact resistance, flow mark properties, coating properties, and peeling resistance, and can be used in a wide range of fields such as automobile interiors, bumpers, and home appliances.

[Brief description of the drawings]

FIG. 1 is a side view for explaining a measurement example of a critical energy release rate.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 23:10 53:02) (72) Inventor Hideo Yamamoto 2-2-2, Yakko, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Polyolefin Co., Ltd. Kawasaki Research Laboratories (72) Inventor Kunihiko Asai 2-3-2 Yakko, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Japan Polyolefin Co., Ltd. Kawasaki Research Laboratories

Claims (2)

[Claims] 1. A component (A): a polypropylene-based polymer having a propylene-ethylene block copolymer; a component (B): an ethylene-octene-based rubber; and a component (C): a triblock copolymer. Component (D): A polypropylene-based polymer containing talc and the propylene-ethylene block copolymer of Component (A) has a MFR of 5 to 5 measured at 230 ° C. under a load of 2.16 kg. 100g / 10min, 20 ℃
And the propylene content in the xylene extractable component is 40 to 60% by weight.
~ 60 wt%, the intrinsic viscosity in decalin at 140 ° C
2.0 to 5.0 g / dl, the ethylene-octene rubber of the component (B) has an octene content of 15 to 35% by weight, and the ethylene-octene rubber and the polypropylene weight of the component (A) 100 of united
Critical energy release rate is 30 J / m when the phase angle of the flat interface with xylene-insoluble components at ℃ is -2 ° to -12 °
² or more, a triblock copolymer of the component (C), MFR was measured under the conditions of at a load 2.16kg its 230 ° C. is 5 to 40 g / 10 min, is in viscosity 230 ° C. corners A constant zero shear viscosity is obtained in the frequency range of 1 rad / sec or less, and the zero shear viscosity is
2000 to 10,000 poise, and the phase angle of the flat interface between the triblock copolymer and the xylene-insoluble component at 100 ° C. of the polypropylene polymer of the component (A) is -2.
The critical energy release rate at the time of ° to -12 ° is 30 J / m ² or more, the content ratio in the whole is 2 to 10% by weight, and the talc of the component (D) has an average particle size of 5 μm or less. Wherein the content of the propylene resin composition is 5 to 25% by weight based on the total weight of the propylene resin composition. 2. The component (C) is a hydrogenated styrene-butadiene-styrene triblock copolymer,
2. The propylene resin composition according to claim 1, wherein the styrene content is 12 to 25% by weight.