JPH10139960A - Polyolefin composition for automotive exterior parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyolefin compsn. for automotive exterior parts which is satisfactory in mechanical characteristics such as strength, impact resistance, hardness, and ductility, excellent in moldability, and suitable for automotive exterior parts such as a bumper. SOLUTION: This compsn. comprises 55-75 pts.wt. crystalline propylene- ethylene copolymer (A) having a melt flow rate (230 deg.C, 2.16kg) of 70g/10min or higher and a limiting viscosity number of 4 or higher, 12-22 pts.wt. ethylene- octene copolymer elastomer (B) having a melt index (190 deg.C, 2.16kg) of 0.5g/10min or higher and comprising 20-30wt.% octene units and the rest substantially being ethylene units, 2-8 pts.wt. polyethylene (C) having a melting peak (with a differential scanning calorimeter) at 100 deg.C or higher, 0-10 pts.wt. ethylene- propylene copolymer rubber (D), and 5-15 pts.wt. talc (E), the sum of ingredients B and D being 22 pts.wt. or lower and the sum of ingredients B, C and D, 20-30 pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin composition for automobile exteriors having good ductility, hardness and impact resistance and excellent moldability due to high fluidity.

[0002]

2. Description of the Related Art Polypropylene resins have been widely used for bumpers and exterior members of automobiles from the viewpoint of mechanical properties and recyclability. In order to obtain mechanical properties suitable for bumpers and exterior members, various polymers or elastomers and additives are usually blended instead of polypropylene alone, but considering the recyclability, each component should have the same or similar composition as much as possible. It is preferable to form with the material of. From such a viewpoint, there have been proposed a large number of polyolefin compositions for automobile exteriors, which are mainly composed of a propylene-ethylene block copolymer.

For example, JP-A-5-59251 discloses (A) an ethylene content of 0.5 to 10% by weight, a boiling n-heptane-insoluble content of a polypropylene component of 97% by weight or more, and a p-xylene soluble content of 5 at room temperature.
-20% by weight, intrinsic viscosity (decalin, 135 ° C) 2 or more, melt flow index 30-100, and flexural modulus
18,000 kgf / cm ² or more highly crystalline propylene-ethylene block copolymer 45-70% by weight, (B) ethylene content 70-
90% by weight and 10-20% by weight of an amorphous ethylene-propylene copolymer having a Mooney viscosity of ML _{1 + 4} (100 ° C.) of 5-60, (C)
Melt flow index (230 ° C) with α-olefin content of 4 to 10 carbon atoms of 5 to 15 mol% and density of 0.91 or less
2 to 50 g / 10 min ethylene / α-olefin copolymer 5
15% by weight, (D) 10 to 25% by weight of butene, 1 to 10% by weight of an amorphous ethylene / butene copolymer having Mooney viscosity ML 1 _{+ 4} (100 ° C.) 5 to 20, and (E) average particle Diameter D is 1.0 to 3.0
Disclosed is a resin composition for a bumper comprising 8 to 15% by weight of talc having a particle size of not more than 10 μm and having a particle size of 10 μm or more, wherein the component (B) is present as a rubber component reinforced by a polyethylene lamella. doing.

JP-A-6-9852 discloses that (A) an ethylene content of 0.5 to 10% by weight, a boiling n-heptane insoluble content of a polypropylene component of 97% by weight or more, and a p-xylene soluble content of 5 to 20% at room temperature.
Weight%, intrinsic viscosity (decalin, 135 ° C) 2 or more,
Melt flow index 30-100 and flexural modulus 18,0
45-80% by weight of a highly crystalline propylene-ethylene copolymer of 00 kgf / cm ² or more, (B) amorphous ethylene having an ethylene content of 70-90% by weight and a Mooney viscosity ML _{1 + 4} (100 ° C.) 5-70 -10 to 20% by weight of propylene block copolymer, (C) 5 to 15 mol% of α-olefin having 4 to 10 carbon atoms and density
Melt flow index (230 ° C) 2.2 with 0.91 or less
~ 50 g / 10 min ethylene / α-olefin copolymer 5-15
Wt%, (D) 10 to 25 wt% butene content, _{1 to} 10 wt% amorphous ethylene / butene copolymer with Mooney viscosity ML _{1 + 4} (100 ° C) 5 to 20 and (E) average particle size D50 is 1.0 to 3.
Disclosed is a resin composition for a bumper comprising less than 8% by weight of talc having a particle size of 0 μm and containing no particles having a particle size of 10 μm or more, wherein the component (B) is present as a rubber component reinforced by a polyethylene lamella. doing.

[0005] In these resin compositions for bumpers, in order to improve the balance between impact resistance and rigidity, a highly crystalline propylene-ethylene block copolymer is used as a rubber component in the form of an amorphous ethylene-propylene copolymer and an amorphous rubber. An ethylene / butene copolymer is blended, and ethylene / α-
An olefin copolymer is also included. However,
With such a composition, there is a problem that when the composition is made highly fluid, the tensile elongation at break and impact resistance of the composition are reduced.

JP-A-5-230321 discloses that the MFR is 30 to 150 g /
Ethylene-propylene block copolymer having an MFR of propylene homopolymer of 50 to 300 g / 10 minutes and an isotactic pentad fraction (P) of 0.98 or more in 10 minutes (230 ° C., 2.16 kg load) 55 to 75% by weight, 100 parts by weight of a thermoplastic polymer composition composed of 25 to 45% by weight of an ethylene copolymer having a melting temperature of 30 to 100 ° C. as measured by a differential scanning calorimeter, and an average particle size of Less than 5μm and specific surface area is 3.5m
² / g or more of a composition comprising 7 to 25 parts by weight of talc, wherein the propylene homopolymer region in the composition,
It discloses a thermoplastic polymer composition characterized in that the average value of the thickness of the crystal lamella observed by an electron microscope from the normal direction of the (100) or (010) plane is 8 nm or more. However, this thermoplastic polymer composition has a drawback that the composition is simple, but the elastomeric properties are insufficient, and the impact resistance and the like are poor.

Accordingly, it is an object of the present invention to provide an automobile exterior having sufficient mechanical properties such as strength, impact resistance, hardness, and ductility and excellent moldability, and suitable for use as an automobile bumper or exterior member. It is to provide a polyolefin composition for use.

[0008]

Means for Solving the Problems In view of the above problems, as a result of intensive studies, the present inventors have found that crystalline propylene-ethylene copolymers have a specific ethylene / octene copolymer elastomer and polyethylene / ethylene / propylene copolymer. When combined rubber and talc, good strength, impact resistance,
Having hardness and ductility, it has been discovered that a polyolefin composition for automotive exterior with excellent moldability can be obtained,
The present invention has been made.

That is, the polyolefin composition for automotive exterior of the present invention comprises (a) a crystalline propylene-ethylene copolymer having a melt flow rate (230 ° C., 2.16 kg) of 70 g / 10 min or more and an intrinsic viscosity of 4 or more. 55-75 parts by weight,
(b) 20 to 30% by weight of octene and the balance substantially consisting of ethylene;
(C, 2.16 kg) is 0.5 g / 10 min or more, and 12 to 22 parts by weight of an ethylene / octene copolymer elastomer, and (c) 2 to 8 parts by weight of polyethylene having a melting peak of 100 ° C. or more as measured by a differential scanning calorimeter. And (d) 0 to 10 parts by weight of an ethylene / propylene copolymer rubber, and (e) 5 to 15 parts by weight of talc, wherein the component (b) + the component (d) is 22 parts by weight or less. Wherein the component (b) + the component (c) + the component (d) are 20 to
It is characterized by being 30 parts by weight.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [1] Components of Polyolefin Composition for Automotive Exterior The polyolefin composition for automotive exterior of the present invention comprises a crystalline propylene-ethylene copolymer, an ethylene / octene copolymer elastomer, polyethylene, and an ethylene / propylene copolymer. Contains rubber and talc.

[A] Crystalline Propylene-Ethylene Copolymer The crystalline propylene-ethylene copolymer (ICP) used in the present invention has a melt flow rate of 70 g / 10 min or more in order to obtain high fluidity. MFR, 230 ° C, 2.16 kg). If the MFR of the crystalline propylene-ethylene copolymer is 70 g / 10 minutes or less, the resulting polyolefin composition for automotive exterior will have low fluidity and poor moldability. The preferred MFR is between 75 and 120 g / 10 minutes. If the MFR exceeds 150 g / 10 minutes, the impact resistance decreases.

(1) Structure The crystalline propylene-ethylene copolymer basically comprises (i)
70-90% by weight of a propylene homopolymer part and (ii) 30-10% by weight of a propylene-ethylene copolymer part,
In addition, an ethylene homopolymer part may be slightly contained. In addition, each part may exist as a single polymer, or may be in a state where they are bonded in a block shape. Each of the above-mentioned parts is basically composed of propylene and / or ethylene, but may contain a small amount of another α-olefin, a diene monomer or the like.

The propylene homopolymer portion preferably has a high stereoregularity with an isotactic pentad fraction of 97% or more determined by ¹³ C-NMR in order to improve the rigidity of the whole composition. Here, the isotactic pentad fraction is measured using the method described in Macromolecules, 6 , 925 (1973), that is, using a ¹³ C-NMR spectrum.

The propylene-ethylene copolymer portion preferably has a propylene / ethylene weight ratio of 25/75 to 75/25. When the weight ratio of propylene / ethylene is less than 25/75, the ductility and impact resistance of the crystalline propylene-ethylene copolymer are low, while the weight ratio of propylene / ethylene is 75/75.
If it exceeds / 25, the elastic modulus of the crystalline propylene-ethylene copolymer decreases. The preferred propylene / ethylene weight ratio is between 35/65 and 65/35. The bonding mode of propylene-ethylene in the propylene-ethylene copolymer portion is not particularly limited, but it is considered that a random copolymer portion is often formed by supplying a mixed gas of propylene and ethylene.

The intrinsic viscosity [η] of the propylene-ethylene copolymer part is 2 to 5 dl / g, preferably 3 to 5 dl / g. When the intrinsic viscosity [η] is less than 2 dl / g, the effect of improving the impact resistance is not sufficient. It becomes bad.

With respect to the proportion of each of the above parts, the propylene homopolymer part is 70 to 90% by weight,
The ethylene copolymerized portion is 10 to 30% by weight. Even if it contains a crystalline homopolyethylene portion, its content is 3% by weight or less. Propylene homopolymer part
If it is less than 70% by weight (the propylene-ethylene copolymer
If it exceeds 30% by weight), the rigidity of the crystalline propylene-ethylene copolymer is low. On the other hand, if the proportion of the propylene homopolymer exceeds 90% by weight (the proportion of the propylene-ethylene copolymer is less than 10% by weight), the impact resistance decreases. The ethylene content in the entire crystalline propylene-ethylene copolymer is preferably 2 to 30% by weight.

(2) Production method The crystalline propylene-ethylene copolymer can be produced by a mechanical blending method or a reactor blending method of a propylene homopolymer portion and a propylene-ethylene copolymer portion. A block copolymerization method of ethylene and propylene is preferred.

In the multistage polymerization method, first, propylene is supplied and polymerized in the presence of a Ziegler catalyst or the like to produce a crystalline propylene homopolymer portion (which may contain a small amount of a comonomer portion). At this stage, the mixture is switched to a mixed gas of ethylene and propylene to produce an ethylene-propylene copolymerized portion. Among them, particularly, a highly crystalline propylene-ethylene copolymer having a propylene homopolymer portion having an isotactic pentad fraction of 97% or more is described in, for example, JP-A-6-271616 and JP-A-6-298830.
No. 7,620,047, and 7-70266.

[B] Ethylene / octene copolymer elastomer The ethylene / octene copolymer elastomer is preferably an ethylene / octene copolymer obtained by copolymerizing octene and ethylene in the presence of a metallocene catalyst.

(1) Content of Octene The content of octene is 20 to 30% by weight. When the octene content is less than 20% by weight, impact resistance is reduced, and
If it exceeds 30% by weight, the rigidity is reduced.

(2) Metallocene Catalyst The metallocene catalyst used for producing the ethylene / octene copolymer elastomer preferably comprises (a) a metallocene compound and (b) alumoxane. Details of the metallocene catalyst are described in JP-A-60-35006.

(A) Metallocene Compound The metallocene compound comprises a mono-, di-, or tri-cyclopentadienyl derivative of a 4b, 5b or 6b transition metal. The transition metal is preferably titanium or zirconium. Preferred examples of such a metallocene compound include bis (cyclopentadienyl) titanium diphenyl, bis (cyclopentadienyl) titanium dimethyl, bis (cyclopentadienyl) zirconium diphenyl,
Bis (cyclopentadienyl) zirconium dimethyl and the like can be mentioned.

(B) Alumoxane Alumoxane is a polymerized aluminum compound and can be produced, for example, by dissolving a trialkylaluminum in an organic solvent and then contacting it with water.

(3) Properties The density of the ethylene / octene copolymer elastomer is 0.91 g /
cm ^{3 or} less, and particularly 0.85～0.88G / cm ³ preferred. The ethylene / octene copolymer elastomer preferably has a melt index (MI, 190 ° C., 2.16 kg) of 0.5 to 30 g / 10 minutes. If the MI is less than 0.5 g / 10 minutes, the moldability is low, and if it exceeds 30 g / 10 minutes, the impact resistance is reduced. A more preferred MI is from 0.5 to 5 g / 10 minutes.

[C] Polyethylene As the polyethylene (component (c)), those generally called low-density polyethylene, linear low-density polyethylene or ultra-low-density polyethylene are preferred. 0.91 for low density polyethylene
A density of ~0.93g / cm ^3, linear low density polyethylene
It has a density of 0.91 to 0.93 g / cm ³ , and ultra low density polyethylene has a density of 0.88 to 0.91 g / cm ³ .

Polyethylene (c) is a differential scanning calorimeter (D
The melting peak in SC) is above 100 ° C. If the melting peak is lower than 100 ° C., the hardness is low. Preferably, the melting peak of polyethylene (c) is in the range of 110-130 ° C.

The polyethylene of component (c) preferably has an MI of 1 to 30 g / 10 minutes. If the MI is less than 1 g / 10 minutes, the moldability is low, and if it exceeds 30 g / 10 minutes, the impact resistance is reduced.

[D] Ethylene / Propylene Copolymer Rubber Ethylene / propylene copolymer rubber (EPR) is an amorphous copolymer of ethylene and propylene. The ethylene content is 50 to 90 mol%. , Propylene content is 50 ~
Preferably it is 10 mol%. More preferably, ethylene is 70-80 mol% and propylene is 30-20 mol%. MFR of ethylene-propylene copolymer rubber (230
(° C, 2.16 kg) is preferably 0.5 to 20 g / 10 min, more preferably 0.5 to 10 g / 10 min.

[E] Talc The talc used in the present invention preferably has an average particle size of 10 μm or less. When the average particle size of talc exceeds 10 μm,
The effect of improving the mechanical properties is poor, and the impact resistance and the like are reduced. A more preferred average particle size of talc is 0.5 to 5 μm.

From the viewpoint of improving mechanical strength, heat resistance and weather resistance, it is preferable to use talc which has been surface-treated with silicone such as organopolysiloxane (polydimethylsiloxane or the like) or a modified product thereof. The modified silicone is obtained by adding a silazane compound to an organopolysiloxane or the like. Examples of the silazane compound include silazane, disilazane, trisilazane, and hexacyclosilazane. The surface treatment of talc with silicone or modified silicone is carried out in such a manner that 0.1 to 5 parts by weight, particularly 0.2
１1 part by weight and mechanically mixing with a Henschel mixer or the like.

[2] Compounding ratio The compounding ratio of each component in the polyolefin composition for automotive exterior is as follows: (a) the crystalline propylene-ethylene copolymer
75 parts by weight, (b) 12 to 22 parts by weight of ethylene / octene copolymer elastomer, and (c) 2 to 2 parts by weight of polyethylene.
8 parts by weight, (d) 0 to 10 parts by weight of ethylene / propylene copolymer rubber, (e) 5 to 15 parts by weight of talc, (b) + (d) ≦ 22 parts by weight. Yes, (b) + (c) + (d)
= 20 to 30 parts by weight.

Crystalline propylene-ethylene copolymer (a)
If the amount is less than 55 parts by weight, the mechanical properties such as strength and impact resistance of the polyolefin composition for automobile exterior are low, while if it exceeds 75 parts by weight, the ductility and the like are reduced. The preferred amount of the crystalline propylene-ethylene copolymer is from 60 to 70 parts by weight.

Ethylene / octene copolymer elastomer
If the amount of (b) is less than 12 parts by weight, the fluidity, impact resistance and ductility of the automotive exterior polyolefin composition are insufficient, and if it exceeds 22 parts by weight, strength, heat resistance, rigidity, etc. The mechanical properties of

If the amount of the polyethylene (c) is less than 2 parts by weight, the resulting polyolefin composition for automotive exterior will have low hardness, and if it exceeds 8 parts by weight, the mechanical properties such as strength and rigidity will decrease. .

If the amount of the ethylene / propylene copolymer rubber (d) exceeds 10 parts by weight, mechanical properties such as strength and rigidity are reduced. The lower limit may be 0, and a polyolefin composition for automobile exteriors containing no ethylene / propylene copolymer rubber is also within the scope of the present invention.

However, the total amount ((b) + (d)) of the ethylene / octene copolymer elastomer and the ethylene / propylene copolymer rubber must be not more than 22 parts by weight. Total amount of other polyethylene and ethylene-propylene copolymer rubber ((b)
+ (C) + (d)) should be 20 to 30 parts by weight. (b)
If + (d) exceeds 22 parts by weight, the flexural modulus of the polyolefin composition for automotive exterior will decrease. (B) + (c) +
If (d) is less than 20 parts by weight, the impact resistance of the polyolefin composition for automotive exterior is low, and if it exceeds 30 parts by weight, the flexural modulus of the polyolefin composition for automotive exterior decreases.

If the amount of talc is less than 5 parts by weight, the effect of improving rigidity and heat resistance is insufficient, and if it exceeds 15 parts by weight, fluidity and impact resistance decrease.

[3] Other Components The polyolefin composition for automotive exterior of the present invention may contain other additives (for example, heat stabilizer, antioxidant, light stabilizer, flame retardant, plasticizer) for the purpose of modification. , Antistatic agent, release agent,
Foaming agents, coloring agents, pigments, etc.).

[4] Characteristics of Polyolefin Composition for Automotive Exterior [A] Fluidity The polyolefin composition for automotive exterior of the present invention having the above composition has an MFR (230 ° C., 2.16 kg) of 18 g / 10 minutes or more. . If the MFR is less than 18 g / 10 minutes, the fluidity is not sufficient. The preferred MFR is 30 g / 10 min or more. In addition,
The upper limit of the MFR is preferably 60 g / 10 minutes.
If the FR is high, the mechanical strength of the composition becomes insufficient.

[B] Impact Resistance The polyolefin composition for automotive exterior of the present invention has an elongation at break of 150% or more (according to JIS K7113). If the elongation at break is less than 150%, the impact resistance is insufficient.

[C] Embrittlement Temperature The polyolefin composition for automotive exterior of the present invention has an embrittlement temperature of -25 ° C. or lower (according to JIS K7216). When the embrittlement temperature exceeds -25 ° C, the impact resistance is insufficient. The preferred embrittlement temperature is between -30 and -50C.

[D] Hardness The polyolefin composition for automotive exterior of the present invention preferably has a Rockwell hardness of 57 or more. When the Rockwell hardness is less than 57, the appearance is inferior when used for exterior parts of automobiles. Preferred Rockwell hardness is 59 or higher.

[E] Rigidity The polyolefin composition for automotive exterior of the present invention is 1100 MPa
It has the above flexural modulus (according to JIS K7203). If the flexural modulus is less than 1100 MPa, the rigidity is insufficient.

[0044]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto.

Synthesis Example 1 Synthesis of crystalline propylene-ethylene copolymer (ICP1)
Synthesis (1) Formation of Propylene Homopolymer Part Preparation of Catalyst Component (A) Pre-activated metallic magnesium was sequentially reacted with n-butyl magnesium chloride and n-butyl chloride in an n-butyl ether solvent, and the resulting reaction was performed. HC (O
C ₂ H ₅ ) ₃ was added dropwise and reacted. The obtained solid is n-
After washing with hexane and drying under reduced pressure, a magnesium-containing solid containing magnesium and chlorine was obtained. Under a nitrogen gas atmosphere, this magnesium-containing solid suspension in n-heptane and 2,2,2-trichloroethanol were reacted at 80 ° C. for 1 hour, and the obtained solid was filtered off, and n-hexane and toluene And washed several times to obtain solid components. This solid component was sequentially reacted with titanium tetrachloride and di-n-butyl phthalate in toluene, and the obtained solid substance was separated by filtration and washed.
Further, titanium tetrachloride was newly added to carry out a reaction, and the resultant was washed with n-hexane to obtain a catalyst component (A).

Pre-polymerization The above catalyst component (A) was cooled to 5 ° C. in an n-heptane solvent under a nitrogen gas atmosphere, and triethylaluminum (TEAL) and
2,3,4-Trimethyl-3-azacyclopentyltrimethoxysilane was added and reacted. After the pressure in the system was reduced, propylene gas was continuously introduced, and propylene was polymerized for 2.2 hours. After completion of the polymerization, propylene in the gas phase was purged with nitrogen gas, the solid phase was washed, and dried under reduced pressure to prepare a prepolymerized catalyst.

Under an atmosphere of the polymerization nitrogen gas, an n-heptane solvent was added to an autoclave.
After TEAL and t-butoxycyclopentyldimethoxysilane were charged and a prepolymerization catalyst was charged, hydrogen gas and propylene as a molecular weight controlling agent were introduced, and propylene was polymerized at 70 ° C. for 1 hour.

(2) Production of Propylene-Ethylene Copolymer Part After hydrogen gas was introduced into the vessel, a mixed gas having a molar ratio of propylene to ethylene of 1.03 was supplied.
Propylene and ethylene were copolymerized for 5 hours to obtain a propylene-ethylene copolymer (ICP1) in the form of a white powder. Table 1 shows the manufacturing conditions.

As a result of analyzing the obtained crystalline propylene-ethylene copolymer (ICP1), the propylene homopolymer portion was 87.0% by weight, and the propylene-ethylene copolymer portion was 13.0% by weight. The isotactic pentad fraction of the propylene homopolymer portion was determined to be ¹³ C-NM
As a result of measurement by the R method, it was found to be 97.5%. As a result of measuring the melt flow rate (MFR, 230 ° C., load 2.16 kg) of the propylene homopolymer part,
It was 50 g / 10 minutes. On the other hand, for the propylene-ethylene copolymer portion, the weight ratio of propylene / ethylene was 60 /
The intrinsic viscosity [η] (measured in decalin at 135 ° C.) was 3 dl / g. Further, the MFR of the whole propylene-ethylene copolymer (ICP1) was 80 g / 10 minutes.
Table 2 shows the measurement results.

Synthesis Example 2 The first-stage and second-stage polymerizations were performed immediately without the prepolymerization under the same conditions as in Synthesis Example 1 except for the conditions shown in Table 1, to obtain a propylene-ethylene copolymer (ICP2). .

The MFR of the obtained propylene-ethylene copolymer (ICP2), the content ratio of the propylene homopolymer part and the propylene-ethylene copolymer part, the IPF and MFR of the propylene homopolymer part, and the propylene-ethylene copolymer part The propylene / ethylene weight ratio and intrinsic viscosity [η] were measured in the same manner as in Synthesis Example 1.
Table 2 shows the results.

[0052] Table 1 Polymerization conditions ICP1 ICP2 first stage liquid propylene (liters) 3.0 3.0 hydrogen gas amount (propylene homopolymerization) (liters) 18 12.5 (copolymerization of propylene / ethylene) second stage C ₃ / C ₂ ^{( 1)} 1.03 0.84 Hydrogen gas amount (liter) 0.2 0.3 Pressure in container (kgf / cm ² G) 6.0 6.1 Polymerization time (h) 1.5 1.5 Note (1) Molar ratio of propylene to ethylene.

[0053] Note: (1) Isotactic pentad fraction. (2) Propylene / ethylene weight ratio.

Examples 1-4 and Comparative Examples 1-3 Raw Materials (a) Crystalline propylene-ethylene copolymer ICP1: MFR = 80 g / 10 min (230 ° C., 2.16 kg), produced in Synthesis Example 1. ICP2: MFR = 100 g / 10 min (230 ° C., 2.16 kg), manufactured in Synthesis Example 2.

(B) Ethylene / octene copolymer elastomer POE1: ethylene / octene copolymer elastomer (manufactured by Dow Chemical Japan Co., Ltd.) Octene content = 24% by weight, MI = 5 g / 10 min (190 ° C., 2.16 kg) , Density = 0.87 g / cm ³ . POE2: ethylene / octene copolymer elastomer (manufactured by Dow Chemical Japan Co., Ltd.) Octene content = 24% by weight, MI = 1 g / 10 min (190 ° C., 2.16 kg), density = 0.87 g / cm ³ .

(C) Other polyethylene LDPE: low density polyethylene (Nihon Unicar Co., Ltd.)
Density = 0.92 g / cm ³ , MI = 20 g / 10 min (190 ° C., 2.16 kg). VLDPE: Ultra low density polyethylene (manufactured by Nippon Unicar Co., Ltd.) Density = 0.90 g / cm ³ , MI = 20 g / 10 min (190 ° C., 2.16 kg).

(D) Elastomer EPR1: Ethylene / propylene copolymer rubber (EP02P
MFR = 3.2 g / 10 min. EPR2: Ethylene / propylene copolymer rubber (EP912
P, manufactured by Nippon Synthetic Rubber Co., Ltd.) MFR = 8.6 g / 10 min.

(E) Talc: LMS300, manufactured by Fuji Talc Co., Ltd. Average particle size = 1.25 μm, no surface treatment.

2. Kneading and injection molding method The above raw materials were blended in the ratio shown in Table 3 and dry blended using a super mixer, and then melted at 200 ° C and 200 rpm with a twin screw extruder (PCM-45, manufactured by Ikegai Co., Ltd.). Kneaded. The pellets of the obtained polyolefin composition for automobile exterior were injection molded at a resin temperature of 210 ° C., an injection pressure of 900 kgf / cm ² and a mold temperature of 60 ° C. to obtain a test piece.

3. Physical property measurement The following mechanical properties were measured for each test piece. The measurement results are shown in Table 4 together with the MFR (230 ° C., load 2.16 kg). Elongation at break (%): Measured according to JIS K7113. Embrittlement temperature (° C): Measured according to JIS K7216. Rockwell hardness: measured according to JIS K7202. Flexural modulus (kgf / cm ² ): Measured at 23 ° C. according to JIS K7203.

Table 3 Example weight parts 1 2 3 4 5 6 ICP1 65-62 65 6760 ICP2-65----POE1 17 17 17 17 22 22 POE2------LDPE 3 36-6 3 VLDPE − − − 3 − − EPR15 − 55 − − − EPR2 − 5 − − − − − Talc 10 10 10 10 5 15

Table 3 (continued) Comparative Example 1 part by weight 1 2 3 4 5 6 ICP1 65 65 − 73 53 65 ICP2 − − 65 − − − POE1 − − − 22 22 15 POE2 − − 25 − − − LDPE − − − 5 5 10 VLDPE − − − − − − EPR1 − 25 − − − − EPR2 25 − − − − − − Talc 10 10 10 0 20 10

Table 4 Example properties 1 2 3 4 5 6 MFR (g / 10 min) 40 50 35 40 42 35 Elongation at break (%) ≧ 300 ≧ 300 ≧ 300 250 ≧ 300 ≧ 300 Embrittlement temperature (° C.) −35 −35 −40 −35 −37 −33 Hardness ⁽¹⁾ 60 60 59 60 59 61 Flexural modulus (MPa) ≧ 1100 ≧ 1100 ≧ 1100 ≧ 1100 ≧ 1100 ≧ 1100 Formability ⁽²⁾ ◎ ◎ ◎ ◎ ◎ ◎ ◎ Notes: (1) Rockwell hardness. (2) Evaluation of the moldability is as follows. A: Very good. ：: good. X: Poor.

Table 4 (continued) Comparative Example Properties 1 2 3 4 5 6 MFR (g / 10 min) 40 30 40 40 30 33 Elongation at break (%) 80 85 ≧ 300 ≧ 300 95 100 Embrittlement temperature (° C.) −25 −25 −35 −35 −25 −25 Hardness ⁽¹⁾ 55 55 55 60 62 65 Flexural modulus (MPa) ≧ 1100 ≧ 1100 ≧ 1100 <1100 ≧ 1100 ≧ 1100 Formability ⁽²⁾ ◎ ◎ ◎ ◎ ◎ ◎ Note: (1) and (2) Same as above.

As is clear from Table 4, the polyolefin compositions for automotive exterior of Examples 1 to 6 have a good combination of elongation at break, embrittlement temperature, hardness and flexural modulus and excellent moldability. ing.

[0066]

As described in detail above, the polyolefin composition for automotive exterior of the present invention comprises a crystalline propylene-ethylene copolymer, an ethylene / octene copolymer elastomer, polyethylene, and ethylene / propylene copolymer. Since it is made of united rubber and talc, it has good strength, impact resistance, hardness, rigidity, etc. and excellent moldability.
It has sufficient strength and impact resistance even as a molded product as thin as 3 mm. Therefore, it can be widely used not only for automobile bumpers but also for various exterior parts.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 23:06) (72) Inventor Takeshi Takeshi 3-1 Chidoricho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Tonen Chemical Co., Ltd. (72) Invention Inventor Masakatsu Suetsugu 3-1 Chidori-cho, Kawasaki-ku, Kawasaki-city, Kanagawa Prefecture (72) Inventor Yuji Fujita 3-1 Tori-cho, Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa

Claims (4)

[Claims] (A) 55 to 75 parts by weight of a crystalline propylene-ethylene copolymer having a melt flow rate (230 ° C., 2.16 kg) of 70 g / 10 min or more and an intrinsic viscosity of 4 or more;
(b) 20 to 30% by weight of octene and the balance substantially consisting of ethylene;
(C, 2.16 kg) is 0.5 g / 10 min or more, and 12 to 22 parts by weight of an ethylene / octene copolymer elastomer, and (c) 2 to 8 parts by weight of polyethylene having a melting peak of 100 ° C. or more as measured by a differential scanning calorimeter. And (d) 0 to 10 parts by weight of an ethylene / propylene copolymer rubber, and (e) 5 to 15 parts by weight of talc, wherein the component (b) + the component (d) is 22 parts by weight or less. Wherein the component (b) + the component (c) + the component (d) are 20 to 3
A polyolefin composition for automobile exteriors, which is 0 parts by weight. 2. The polyolefin composition for automotive exteriors according to claim 1, wherein the crystalline propylene-ethylene copolymer has (i) an isotactic pentad fraction of 97% as determined by ¹³ C-NMR. 70-90% by weight of the propylene homopolymer portion described above and (ii) 30-10% by weight of a propylene-ethylene copolymer portion having a weight ratio of propylene / ethylene of 25 / 75-75 / 25. Characteristic polyolefin composition for automotive exterior. 3. The polyolefin composition for automotive exteriors according to claim 1, wherein the ethylene / octene copolymer elastomer is obtained by copolymerizing octene and the balance of ethylene in the presence of a metallocene catalyst. Polyolefin composition for automobile exteriors. 4. The polyolefin composition for automotive exterior according to claim 1, wherein said polyethylene (c) is selected from the group consisting of low-density polyethylene, linear low-density polyethylene and ultra-low-density polyethylene. A polyolefin composition for automobile exteriors, characterized in that the composition is at least one selected from the group consisting of: