JP3418957B2 - Polypropylene resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene resin composition. More specifically, bumpers for automobiles, etc.
The present invention relates to a polypropylene resin composition suitably used as a buffer material such as a flexible structure front and an antiglare material. 2. Description of the Related Art Crystalline polypropylene is excellent in rigidity, heat resistance, surface gloss and the like, but has a problem in that impact strength, particularly impact strength at low temperature, is inferior. For the purpose of remedying these drawbacks, there has been proposed a method of mixing a crystalline polypropylene with a rubbery polymer such as polyethylene, polyisobutylene, polybutadiene, and an amorphous ethylene / propylene copolymer. However, this method has a problem that the rigidity is reduced. In order to solve this problem, a method of adding an inorganic filler such as talc has been proposed. However, in this method, impact strength is impaired, silver streaks are easily generated on the surface of the molded product, and flow marks and voids are easily generated. There has been a problem of inferior appearance. Nevertheless, there have been many proposals using a method of adding an inorganic filler for the purpose of improving the balance between physical properties of rigidity and impact strength (for example, Japanese Patent Application Laid-Open No. 57-5595).
No. 2 and Japanese Patent Publication No. 60-16982). However, the balance of physical properties between rigidity and impact strength, particularly low-temperature impact strength, has not yet reached a satisfactory level. The present invention has been made in view of the above problems, and has as its object to provide a polypropylene-based resin composition having an excellent balance of physical properties between rigidity and impact resistance (particularly, low-temperature impact strength). According to the present invention, there is provided, according to the present invention, a polypropylene comprising the following components (A) and (B) in the following composition ratios: A resin composition is provided. (A): 95 to 50% by weight of an ethylene / propylene block copolymer having the following properties: Melt index (MI): 1 to 70 g / 10 minutes Ethylene content: 25% by weight or less (B): Having the following properties and Ethylene ・ α
-5 to 50% by weight of olefin (C6 to C20) and / or non-conjugated diene copolymer Melt index (MI): 0.05 to 70 g / 1
0 minute maximum melting point (Tm _max ): 90 ° C. or less Hexane soluble component at 25 ° C .: 2.0% by weight or less [0006] The polypropylene resin composition of the present invention will be specifically described below. 1. Ethylene / propylene block copolymer (A) (1) Composition ratio The composition ratio of the ethylene / propylene block copolymer (A) used in the present invention in the composition of the present invention is as follows:
It is 95 to 50% by weight, preferably 90 to 60% by weight. If it exceeds 95% by weight, the impact strength decreases. If it is less than 50% by weight, the rigidity is reduced. (2) The characteristic melt index (MI) of the block copolymer (A) The melt index (MI) of the block copolymer (A) used in the present invention is 1 to 70 g / 10 min, preferably 3 ６０60 g / 10 min. If it is less than 1 g / 10 minutes, the moldability will decrease. If it exceeds 70 g / 10 minutes, the fluidity is improved, but the impact strength is reduced. Measurement method is JI
SK-7210 (Measurement conditions: load 2160 g, temperature 2
30 ° C.). Ethylene content The ethylene content of the copolymer (A) used in the present invention is:
It is at most 25% by weight, preferably at most 20% by weight. 2
If it exceeds 5% by weight, the rigidity is reduced. (3) Production Method The method for producing the block copolymer (A) used in the present invention is not particularly limited, but a so-called Ziegler-Natta catalyst can be used as a catalyst system. Specifically, a transition metal compound (eg, a titanium-containing compound) as a main catalyst, or a carrier-supported catalyst obtained by supporting a transition metal compound on a carrier (eg, a magnesium-containing compound, a processed product thereof), and a co-catalyst as a co-catalyst Organometallic compounds (eg organoaluminum compounds)
Can be used. Further, a homogeneous catalyst may be used, and examples thereof include a conventionally known catalyst composed of a vanadium compound and an organoaluminum compound, and a new homogeneous catalyst such as a Kaminski catalyst or a metallocene catalyst recently discovered. Any of these copolymers may be produced by any process such as a slurry polymerization method, a solution polymerization method, and a gas phase polymerization method. Further, the copolymer is not necessarily limited to one kind of polymer obtained by polymerization in one polymerization reaction system, and may be two or more kinds of ethylene-propylene block copolymers separately polymerized. [0009] 2. Ethylene / α-olefin and / or non-conjugated diene copolymer (B) (1) Composition ratio Ethylene / α-olefin and / or
Alternatively, the composition ratio of the non-conjugated diene copolymer (B) in the composition of the present invention is 5 to 50% by weight, preferably 10 to 4% by weight.
0% by weight. If it exceeds 50% by weight, the rigidity is reduced. If it is less than 5% by weight, the impact strength will be reduced. (2) α-olefins and / or non-conjugated dienes, and their contents α-olefins and α-olefins used in the non-conjugated diene copolymer (B) include:
Examples thereof include α-olefins having 6 to 20, preferably 8 to 18 carbon atoms, which are linear, branched, or substituted with an aromatic nucleus. Specifically, 1-hexane, 1-octene, 1-nonene, 1-decene, 1-undecene,
Linear monoolefin such as dodecene, 3-methylbutene-1, 3-methylpentene-1, 4-methylpentene-
1,2-ethyl-1,2-ethylhexene-1,2,2
Examples include branched-chain monoolefins such as 2,4-trimethylpentene, and monoolefins substituted with an aromatic nucleus such as styrene. In addition, examples of the non-conjugated diene include a linear or branched non-conjugated diolefin having 6 to 20 carbon atoms. Specifically, 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene,
Polyenes such as 9-decadiene, 2,5-dimethyl-4-tert-butyl-2,6-heptadiene and 1,5,9-decatriene, and endomethylene cyclic dienes such as 5-vinyl-2-norbornene And the like. These α-olefins and non-conjugated dienes may be used alone or in combination of two or more. Content of α-olefin and / or non-conjugated diene The content of α-olefin and / or non-conjugated diene in the copolymer (B) is from 10 to 60% by weight, preferably from 20 to 5% by weight.
0% by weight. If it is less than 10% by weight, the impact strength will be reduced. If it exceeds 60% by weight, the rigidity of the resin composition is reduced. (3) Characteristic melt index (MI) of copolymer (B) The melt index of the copolymer (B) used in the present invention is 0.05 to 70 g / 10 minutes, preferably 0.1 to 70 g / 10 minutes.
50 g / 10 min, more preferably 0.1 to 40 g / 1
0 minutes. The measuring method was based on JIS-K-7210 (measuring conditions: load 2160 g, temperature 230 ° C.). Maximum melting point (Tm _max ) The maximum melting point (Tm _max ) of the copolymer (B) used in the present invention.
_max ) is 90 ° C or lower, preferably 85 ° C or lower, more preferably 80 ° C or lower. If the temperature exceeds 90 ° C., the impact strength decreases. The measuring method was as follows. A sheet having a thickness of 0.6 mm and a sample weight of about 10 mg was prepared, and a differential scanning calorimeter (DSC-7: Perkin-El) was prepared.
(manufactured by Mer. Co.) at 190 ° C. for 3 minutes, and then gradually cooled to 25 ° C. at a rate of 10 ° C./min for crystallization, and the sample was heated from 25 ° C. to 160 ° C. at a rate of 10 ° C.
/ Min to obtain a melting curve. The highest temperature among the peaks obtained at this time was defined as the highest melting point. Hexane-soluble component at 25 ° C. The hexane-soluble component at 25 ° C. of the copolymer (B) used in the present invention is 2.0% by weight or less, preferably 1.
8% by weight or less. If it exceeds 2.0% by weight, rigidity and impact strength decrease. The measuring method was as follows. 3 g of a sample pulverized at a low temperature was put into a cylindrical filter paper made of glass fiber (manufactured by Toyo Roshi Kaisha, Ltd .: 86R), and immersed in 200 ml of n-hexane in a 250 ml glass bottle for 6.5 hours in a 25 ° C constant temperature bath. Next, the cylindrical filter paper with the sample taken out was dried, a low molecular weight component was calculated from the weight loss, and the weight fraction of the component extracted with n-hexane was determined.
The amount of components soluble in hexane was used. (4) Production Method The copolymer (B) used in the present invention is not particularly limited, and can be produced by various methods. For example, a method using ethylene and at least one kind of α-olefin and / or a non-conjugated diene as a raw material can be exemplified. That is, ethylene may be used in combination with one or more other α-olefins, or ethylene may be used in combination with one or more non-conjugated dienes. Furthermore, for example, ethylene, at least one α-olefin and at least one non-conjugated diene can be used. Here, as the α-olefin, as described above,
Linear monoolefins such as 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene and 1-dodecene, 3-methylbutene-1,3-methylpentene-
1,4-methylpentene-1,2-ethylhexene-1
And mono-olefins substituted with an aromatic nucleus such as styrene.
Further, as the non-conjugated diene, 1,5-hexadiene,
Examples thereof include non-conjugated diolefins having a straight or branched chain having 6 to 20 carbon atoms, such as 1,8-nonadiene and 1,4-dimethyl-4-t-butyl-2,6-heptadiene. Further, a polyene such as 1,5,9-decatriene or an exomethylene cyclic diene such as 5-ethylidene-2-norbornene can be used. There is no limitation on the catalyst used.
Various things can be used. For example, (1)
(A) a transition metal compound, (b) a compound capable of forming an ionic complex by reacting with the transition metal compound, and (c) a catalyst mainly composed of an organoaluminum compound, (2) (a) a transition metal compound, (D) a catalyst mainly comprising an aluminum oxy compound and (c) an organic aluminum compound,
(3) Component (a) and / or component (b) as a main component,
The component (a) and / or the component (b) supported on the carrier (e), (4) the component (c) added to the component (3), (5) the component (a) and / or ( The component (d) is a main component, and the component (a) and / or the component (d) are supported on the component (e). (6) The component (c) is added to the component (5). it can. [0017] As (a) a transition metal compound in the present invention have the general formula ^{_{Q 1 a (C 5 H 5}} -ab R 1 b) (C 5 H 5-aC R 2 C) MX 1 Y 1 ··· ( ^{_{I) Q 2 a (C 5}} H 5-ad R 3 d) Z 1 MX 1 Y 1 ··· (II) or the general formula MX ² ₄ ··· (III) in suitably used a compound represented Can be. In the above general formulas (I) to (III), Q ¹
Binding group which crosslinks the two conjugated five-membered ring ligand _{(C 5 H 5-ab R} 1 b) and _{(C 5 H 5-ac R} 2 c), Q 2 is conjugated five-membered ring coordinated shows a bonding group which crosslinks the child _{(C 5 H 5-ad R} 3 d) and the Z group. As Q ¹ and Q ² , an alkyl group and a silyl group are preferable. a is 0, 1 or 2. _{Further, (C 5 H 5-ab} R 1 b), (C 5 H 5-ac
R ² _c ) and (C ₅ H _5-ad R ³ _d ) are conjugated five-membered ring ligands, and R ¹ , R ² and R ³ are each a hydrocarbon group, a halogen atom, an alkoxy group, and a silicon-containing group. A hydrocarbon group, a phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group or a boron-containing hydrocarbon group, and b, c and d are each an integer of 0 to 5 when a = 0, and when a = 1, , Each 0-4
When a = 2, an integer of 0 to 3 is shown. Here, the hydrocarbon group preferably has 1 to 20 carbon atoms. This hydrocarbon group may be bonded as a monovalent group to a cyclopentadienyl group which is a conjugated five-membered ring, and when there are a plurality of these, two of them are bonded to each other to form a cyclopentadienyl group. A ring structure may be formed together with a part of the pentadienyl group. On the other hand, M represents a transition metal of Groups 4 to 6 of the periodic table, and titanium, zirconium or hafnium is preferable. Z ¹ represents oxygen, sulfur, an alkoxy group or thioalkoxy group having 1 to 20 carbon atoms, or a phosphorus-containing hydrocarbon group having 1 to 40 carbon atoms. X ¹ and Y ^{1 each} represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms,
An alkoxy group, an amino group, a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms or a silicon-containing hydrocarbon group having 1 to 20 carbon atoms. X ² represents a halogen atom or an alkoxy group. As the compound (b) capable of forming an ionic complex by reacting with the transition metal compound, any compound capable of forming an ionic complex by reacting with the component (a) can be used. However, a compound comprising a cation and an anion having a plurality of groups bonded to an element, particularly a coordination complex compound comprising a cation and an anion having a plurality of groups bonded to an element can be preferably used. The (c) organoaluminum compound is represented by the following general formula (IV): R ⁴ _r AlQ _3-r (IV) (wherein R ⁴ has 1 to 20 carbon atoms, preferably 1 to 20 carbon atoms) 12
A hydrocarbon group such as an alkyl group, an alkenyl group or an arylalkyl group, Q represents a hydrogen atom, an alkoxy group having 1 to 20 carbon atoms or a halogen atom, and r is a number of 1 to 3. )). Also,
(D) The aluminum oxy compound is represented by the following general formula (V): (Wherein R ⁴ is the same as described above. S represents the degree of polymerization, and is usually an integer of 2 to 50, preferably 3 to 40). Formula (VI) (Wherein, R ⁴ is the same as described above. P represents the degree of polymerization and is usually an integer of 3 to 50, preferably 7 to 40). Can be. In the present invention, at least one of the catalyst components can be used, for example, supported on a solid inorganic or organic carrier (e) insoluble in a hydrocarbon solvent. For example, SiO ₂ , MgCl ₂ , Mg (OC ₂ H ₅ ) ₂ ,
Al ₂ O ₃ or the like can be suitably used. The polymerization method is not particularly limited, and any method such as a slurry polymerization method, a gas phase polymerization method, a bulk polymerization method, and a solution polymerization method may be used, but the slurry polymerization method and the gas phase polymerization method are preferred. 3. Additives In the composition of the present invention, if necessary, other powdery, granular, plate-like or other inorganic fillers, organic fillers, and inorganic fibers may be used as long as the object of the present invention is not impaired. Can be blended. As the inorganic filler, for example, a silica agent or an organic filler may be used such as diatomaceous earth, barium ferrite,
Oxides such as beryllium oxide, pumice and pumice balloons; hydroxides such as magnesium hydroxide, aluminum hydroxide and basic magnesium carbonate; carbonates such as calcium carbonate, magnesium carbonate, dolomite and dawsonite; calcium sulfate; barium sulfate; Sulfates or sulfites such as ammonium sulfate and calcium sulfite, talc, clay, mica, asbestos, glass balloons, glass beads, silicates such as calcium silicate, montmorillonite, bentonite, carbon black, graphite,
Carbons such as carbon hollow spheres, powdered, granular, plate-like inorganic fillers such as molybdenum sulfide, zinc borate, barium metaborate, calcium borate, and sodium borate; metal elements, metal compounds, alloys, etc. Examples include powdery or granular metal fillers, and powdery or granular ceramic fillers such as silicon carbide, silicon nitride, zirconia, aluminum nitride, and titanium carbide. Examples of the organic filler include shell fibers such as rice hulls, wood flour, cotton, jute, paper chips, cellophane chips, aromatic polyamide fibers, cellulose fibers, nylon fibers, polyester fibers, polypropylene fibers, and thermosetting resin powders. And the like. On the other hand, examples of the inorganic fiber include inorganic fibers such as glass fiber, carbon fiber, boron fiber, magnesium oxysulfate fiber, and magnesium hydroxide fiber; metal fibers made of stainless steel, brass, aluminum, nickel, and the like; metal whiskers; Ceramic whiskers made of potassium acid, silicon carbide, or the like can be used. Of these, magnesium oxysulfate fiber and magnesium hydroxide are particularly preferred. These inorganic fibers may be used alone or in combination of two or more. In the present invention, for the purpose of increasing the interface strength between the matrix resin and the filler, a chemical modifier such as a modified polyolefin can be blended if necessary. If necessary, various commonly used additives such as antioxidants, lubricants, coloring agents, stabilizers, ultraviolet absorbers, antistatic agents, flame retardants, plasticizers, nucleating agents, etc. can be added. . In particular, a composition having higher rigidity by using sodium benzoate, aluminum salt of di-p-tertiary butyl benzoic acid or dibenzylidene sorbitol known as a gelling agent alone or in combination as a nucleating agent for polypropylene. Can be manufactured. Further, other thermoplastic resins or rubbers may be blended within a range that does not impair the object of the present invention. 4. Preparation of Composition The composition of the present invention comprises a predetermined amount of an ethylene-propylene block copolymer as the component (A) and a copolymer of ethylene and an α-olefin and / or a non-conjugated diene as the component (B). Combine, blending various additives as needed,
It can be prepared by kneading with an extruder. There is no particular limitation on the extruder, for example, a screw extruder such as a single-screw extruder or a multi-screw extruder, an elastic extruder, a hydrodynamic extruder, a ram-type continuous extruder,
Non-screw extruders such as a roll-type extruder and a gear-type extruder can be mentioned, and among them, a screw extruder is preferable. EXAMPLES The present invention will be described more specifically with reference to the following examples. Example 1 Preparation of Methylaluminoxane Toluene solution of methylaluminoxane manufactured by Tosoh Agzo Co., Ltd. was distilled under reduced pressure to remove the solvent toluene. The solid residue thus obtained was further heat treated at 130 ° C. under a reduced pressure of 3 × 10 ⁻³ Torr for 5 hours. The thus obtained methylaluminoxane was redissolved in toluene. Ethylene / 1-octene copolymer (B)
30 liters of toluene was placed in a polymerization reactor purged with dry nitrogen,
2.0 liter of 1-octene was charged at room temperature. Next, 80 mmol of methylaluminoxane prepared above was added, and the temperature was raised to 65 ° C. After maintaining in this state for 30 minutes, pentamethylcyclopentadienyltitanium trimethoxide [Cp ^* Ti (OMe) ₃ ] 0.80 mmol
was added and the temperature was raised to 80 ° C. over 20 minutes. Thereafter, hydrogen was introduced at a partial pressure of 0.5 kg / cm ² G, and then ethylene was continuously introduced at a constant pressure of 4 kg / cm ² G for 60 minutes. After completion of the polymerization, 100 ml of isopropyl alcohol was added to stop the reaction, and the reactor was cooled and then depressurized and opened. The produced ethylene / 1-octene copolymer (B) was washed with methanol and then filtered and dried. Thus, the ethylene / 1-octene copolymer (B) (MI: 0.89 g / 10 min, Tm
_max : 65.8 ° C., hexane soluble matter: 0.92% by weight,
Density: 875 kg / m ³ , 1-octene content: 30.2
2600 g). Production of Ethylene / 1-octene Copolymer / Ethylene / Propylene Block Copolymer Composition 1200 g of the copolymer (B) obtained above was mixed with the ethylene / propylene block copolymer (A) (Idemitsu Petrochemical: Idemitsu Polypro J-750HP (MI: 15 g)
/ 10 min, ethylene content: 14.7% by weight)
g ((A) :( B) = 70: 30 by weight) and antioxidant (1,3,5-tris (3,5-di-t-butyl-4-hydroxy-benzyl) -s) -Triazine-2,
4,6- (1H, 3H, 5H) trione) (manufactured by ADEKA ARGUS: MARK AO-20) is 8 g (0.2 parts by weight based on 100 parts by weight of the composition (A) + (B)). ), And a single-screw extruder (manufactured by Yato Machine Co., Ltd .:
After melt-kneading with NVC-50), the strand was cut to obtain a pellet. A test piece was molded from this with a JSW-N100BII type injection molding machine (manufactured by Nippon Steel Works), and the physical properties of the obtained molded product were measured. The measuring method was as follows. (1) Flexural modulus: based on JIS-K-7203. (2) Notched Izod impact strength: JIS-K-7
110. The measurement temperature was set at 23 ° C and -30 ° C. Example 2 In Example 1, 800 g of an ethylene / 1-octene copolymer (B) was added,
Example 1 was repeated except that the amount of the propylene block copolymer (A) was changed to 3200 g. Example 3 In Example 1, 400 g of ethylene / 1-octene copolymer (B) was added.
Example 1 was repeated except that the amount of the propylene block copolymer (A) was changed to 3600 g. Comparative Example 1 In Example 1, instead of 1200 g of the ethylene / 1-octene copolymer (B),
Ethylene / 1-butene copolymer (manufactured by Nippon Synthetic Rubber Co .: E
BM12021P) (MI: 1.0 g / 10 min, Tm
_max : 70.3 ° C, hexane soluble: 0.82% by weight)
Was performed in the same manner as in Example 1 except that 1200 g of was used. Comparative Example 2 In Example 2, instead of 800 g of the ethylene / 1-octene copolymer (B), an ethylene / 1-butene copolymer (EB: manufactured by Nippon Synthetic Rubber Co., Ltd .: EB)
M12021P) (MI: 1.0 g / 10 min, Tm
_max : 70.3 ° C, hexane soluble: 0.82% by weight)
Was used in the same manner as in Example 2 except that 800 g was used. Comparative Example 3 In Example 1, instead of 1200 g of the ethylene / 1-octene copolymer (B),
Ethylene / 1-octene copolymer (manufactured by Idemitsu Petrochemical Co., Ltd .:
Moretec V-0398CN) (MI: 4.8 g / 10
Min, Tm _max : 117.6 ° C., hexane soluble: 2.5
(% By weight) except that 1200 g was used. As described above, the composition ratios of the components (A) and (B) used in Examples 1 to 3 and Comparative Examples 1 to 3,
Table 1 summarizes the types and characteristics of the α-olefin used as the component (B) and the physical properties (evaluation results) of the obtained composition. [Table 1] As described above, according to the present invention,
It is possible to provide a polypropylene-based resin composition having an excellent balance between physical properties of rigidity and impact resistance (particularly low-temperature impact strength).

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-53843 (JP, A) JP-A-6-192500 (JP, A) JP-A-58-23842 (JP, A) JP-A-60-1985 13838 (JP, A) JP-A-8-3384 (JP, A) JP-A-6-87986 (JP, A) JP-B-60-16982 (JP, B1) (58) Fields investigated (Int. ⁷ , DB name) C08L 53/00-53/02 C08L 23/00 -23/16

Claims (1)

(57) [Claim 1] A polypropylene resin composition comprising the following components (A) and (B) at the following composition ratios as main components. (A): 95 to 50% by weight of an ethylene / propylene block copolymer having the following properties: Melt index (MI): 1 to 70 g / 10 minutes Ethylene content: 25% by weight or less (B): Having the following properties and Ethylene ・ α
-5 to 50% by weight of olefin (C6 to C20) and / or non-conjugated diene copolymer Melt index (MI): 0.05 to 70 g / 1
0 minute maximum melting point (Tm _max ): 90 ° C or less Hexane soluble component at 25 ° C: 2.0% by weight or less