JP2008208305A - Polypropylene-based resin composition and its molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polypropylene-based resin composition which is low in luster and is excellent in surface impact characteristics, and to provide a molded article comprising the same. <P>SOLUTION: This polypropylene-based resin composition comprises 70 to 90 wt.% of the following propylenic polymer (A) and 10 to 30 wt.% of an inorganic filler (B), wherein the propylenic polymer (A) is a propylene-ethylene block copolymer which comprises 60 to 75 wt.% of a crystalline polypropylene portion comprising a propylene homopolymer, or a copolymer of propylene with ≤1 mol.% of ethylene or a ≥4C α-olefin and 25 to 40 wt.% of a propylene-ethylene random copolymer portion having a propylene/ethylene weight ratio of 75/25 to 35/65 and which satisfies specific requirements (1) and (2), and an injection molded article comprises the resin composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polyolefin resin composition and a molded body comprising the same. More specifically, the present invention relates to a polyolefin resin composition having low gloss and excellent surface impact characteristics, and a molded product thereof.

Polypropylene resin compositions are materials having excellent mechanical properties and the like, and are therefore used in a wide range of applications, for example, interior and exterior parts of automobiles and parts of electrical products.
For example, JP-A-9-157492 discloses a thermoplastic resin composition for the purpose of improving impact resistance, rigidity and moldability, having a homopropylene portion and an intrinsic viscosity of 2 to 5 dl / g. A propylene-ethylene block copolymer comprising a low ethylene concentration propylene-ethylene copolymer portion and a high ethylene concentration propylene-ethylene copolymer portion having an intrinsic viscosity of 4 to 6 dl / g; A thermoplastic resin composition comprising an ethylene-butene copolymer rubber of 30 g / 10 min, an MFR 0.1-20 g / 10 min ethylene-propylene copolymer rubber, and talc is described.

  Japanese Patent Application Laid-Open No. 2003-327642 discloses a propylene-ethylene block copolymer for the purpose of improving the balance of rigidity, hardness and moldability, toughness and low temperature impact resistance, comprising a crystalline polypropylene portion, ethylene Propylene-ethylene block comprising a propylene-ethylene random copolymer portion having a content of 20% by weight to less than 50% by weight and a propylene-ethylene random copolymer portion having an ethylene content of 50% by weight to 80% by weight A copolymer is described, and it is also described that an elastomer or an inorganic filler may be added to the propylene-ethylene block copolymer.

Japanese Patent Laid-Open No. 9-157492 JP 2003-327642 A

However, even in the polypropylene resin compositions described in the above publications and the like, it has been desired to further reduce the gloss and improve the surface impact characteristics.
Under such circumstances, an object of the present invention is to provide a polyolefin resin composition having a low gloss and excellent surface impact characteristics, and a molded product comprising the same.

As a result of the study, the present inventors have found that the present invention can solve the above problems, and have completed the present invention.
That is, one aspect of the present invention is
It is a polypropylene resin composition containing 70 to 90% by weight of the following propylene polymer (A) and 10 to 30% by weight of inorganic filler (B) (however, the total amount of the polypropylene resin composition is 100 %).
The propylene-based polymer (A) is a propylene homopolymer or a crystalline polypropylene portion of 60 to 75 weight which is a copolymer of propylene and ethylene having a content of 1 mol% or less or an α-olefin having 4 or more carbon atoms. And a propylene-ethylene random copolymer portion having a weight ratio of propylene to ethylene (propylene / ethylene (weight / weight)) of 75/25 to 35/65 and 25 to 40% by weight, and the following requirements ( 1) and a propylene-ethylene block copolymer satisfying the requirement (2) (provided that the total amount of the propylene-ethylene block copolymer is 100% by weight).
Requirement (1) The propylene-ethylene random copolymer portion is composed of a propylene-ethylene random copolymer component (EP-A) and a propylene-ethylene random copolymer component (EP-B). -A) intrinsic viscosity [η] EP-A is 1.5 dl / g or more and 8 dl / g or less, and ethylene content [(C2 ′) EP-A] is 20 wt% or more and less than 50 wt% (however, Component (EP-A) is 100% by weight), copolymer component (EP-B) has intrinsic viscosity [η] EP-B of 0.5 dl / g to 8 dl / g, ethylene content [ (C2 ′) EP-B] is 50% by weight or more and 80% by weight or less (provided that the total amount of component (EP-B) is 100% by weight).
Requirement (2) The melt flow rate (MFR) at 230 ° C. of the propylene polymer (A) is 5 to 120 g / 10 minutes.

Also, one aspect of the present invention is
Polypropylene resin composition containing the following propylene polymer (A) 69-89.9 wt%, inorganic filler (B) 10-30 wt%, and elastomer (C) 0.1-1 wt% (However, the total amount of the polypropylene resin composition is 100% by weight).
The propylene polymer (A) is
A propylene homopolymer or a crystalline polypropylene portion of 60 to 75% by weight, which is a copolymer of propylene and ethylene having a content of 1 mol% or less or an α-olefin having 4 or more carbon atoms, and a weight ratio of propylene and ethylene A propylene-ethylene random copolymer portion having a propylene / ethylene (weight / weight) of 75/25 to 35/65 and 25 to 40 % by weight, satisfying the following requirements (1) and (2) Propylene-ethylene block copolymer (however, the total amount of propylene-ethylene block copolymer is 100% by weight).
Requirement (1) The propylene-ethylene random copolymer portion is composed of a propylene-ethylene random copolymer component (EP-A) and a propylene-ethylene random copolymer component (EP-B). -A) intrinsic viscosity [η] EP-A is 1.5 dl / g or more and 8 dl / g or less, and ethylene content [(C2 ′) EP-A] is 20 wt% or more and less than 50 wt% (however, Component (EP-A) is 100% by weight), copolymer component (EP-B) has intrinsic viscosity [η] EP-B of 0.5 dl / g to 8 dl / g, ethylene content [ (C2 ′) EP-B] is 50% by weight or more and 80% by weight or less (provided that the total amount of component (EP-B) is 100% by weight).
Requirement (2) The melt flow rate (MFR) at 230 ° C. of the propylene polymer (A) is 5 to 120 g / 10 minutes.
The elastomer (C) comprises a copolymer elastomer (C-1) of ethylene and an α-olefin having 4 or more carbon atoms, a diene elastomer (C-2), and a vinyl aromatic compound-containing elastomer (C-3). It is at least one elastomer selected from the group.

  Another aspect of the present invention relates to a molded body made of the above polypropylene resin composition.

  According to the present invention, it is possible to obtain a polypropylene-based resin composition having a low gloss and excellent surface impact characteristics, and a molded body comprising the same.

  The propylene-based polymer (A) used in the present invention is a crystalline propylene homopolymer or a copolymer of propylene and ethylene having a content of 1 mol% or less or an α-olefin having 4 or more carbon atoms. Propylene-ethylene random copolymer portion of 25 to 40% by weight with a polypropylene part of 60 to 85% by weight and a weight ratio of propylene to ethylene (propylene / ethylene (weight ratio / weight ratio)) of 75/25 to 35/65 (However, the total amount of the propylene-ethylene block copolymer is 100% by weight).

  When the crystalline polypropylene part is less than 60% by weight (that is, when the propylene-ethylene random copolymer part exceeds 40% by weight), the rigidity and hardness are lowered, or the melt flow rate (MFR) is lowered. In some cases, sufficient moldability cannot be obtained, and when the crystalline polypropylene portion exceeds 75% by weight (that is, when the propylene-ethylene random copolymer portion is less than 25% by weight), the surface impact characteristics are deteriorated. There is a case.

  The crystalline polypropylene portion contained in the propylene-based polymer (A) used in the present invention is a propylene homopolymer, propylene and ethylene having a content of 1 mol% or less or an α-olefin having 4 or more carbon atoms. The crystalline polypropylene is a copolymer of the above (however, the total amount of the crystalline polypropylene portion is 100 mol%). If the content of ethylene or α-olefin having 4 or more carbon atoms exceeds 1 mol%, rigidity, heat resistance or hardness may be lowered.

The crystalline polypropylene part contained in the propylene-based polymer (A) used in the present invention is preferably a propylene homopolymer from the viewpoint of increasing rigidity, heat resistance or hardness, more preferably ¹³ C. -Propylene homopolymer having an isotactic pentad fraction calculated by NMR of 0.95 or more. Isotactic pentad fraction refers to the method published by A. Zambelli et al., Macromolecules, 6,925 (1973), i.e., in terms of pentad units in a polypropylene molecular chain measured using ¹³ C-NMR. Isotactic chain, in other words, the fraction of propylene monomer units at the center of a chain in which five propylene monomer units are continuously meso-bonded (however, the assignment of the NMR absorption peak is the Macromolecules, 8,687 published later) (Based on (1975)). Specifically, the isotactic pentad fraction is measured as the area fraction of the mmmm peak in the total absorption peak in the methyl carbon region of the ¹³ C-NMR spectrum. The isotactic pentad fraction of NPL standard substance CRM No. M19-14 Polypropylene PP / MWD / 2 of NATIONAL PHYSICAL LABORATORY, UK was measured by this method and found to be 0.944.

  The intrinsic viscosity [η] P of the crystalline polypropylene portion contained in the propylene polymer (A) used in the present invention is preferably 1. from the viewpoint of the balance between the fluidity at the time of melting and the toughness of the molded body. The molecular weight distribution (Q value, Mw / Mn) measured by gel permeation chromatography (GPC) is preferably 5 or more and less than 7, and more preferably 3 to 5.

  The weight ratio of propylene to ethylene (propylene weight / ethylene weight) in the propylene-ethylene random copolymer portion contained in the propylene-based polymer (A) used in the present invention is 75/25 to 35/65, preferably Is 70 / 30-40 / 60. If the composition ratio of propylene and ethylene deviates from the above range, sufficient impact resistance may not be obtained.

  The propylene-ethylene random copolymer portion contained in the propylene-based polymer (A) used in the present invention comprises a propylene-ethylene random copolymer component (EP-A) and a propylene-ethylene random copolymer component (EP -B).

  The ethylene content [(C2 ′) EP-A] of the propylene-ethylene random copolymer component (EP-A) is 20 wt% or more and less than 50 wt%, preferably 25 wt% or more and 45 wt% or less ( However, the total amount of the copolymer component (EP-A) is 100% by weight). If the ethylene content [(C2 ′) EP-A] is not within the above range, the rigidity may be lowered.

  The intrinsic viscosity [η] EP-A of the propylene-ethylene random copolymer component (EP-A) is 1.5 dl / g or more and 8 dl / g or less, preferably 2.5 dl / g or more and 8 dl / g or less. More preferably, it is 4 dl / g or more and 8 dl / g or less. In order to increase toughness and impact resistance, the intrinsic viscosity [η] EP-A is 1.5 dl / g or more, and suppresses the decrease in melt flow rate (MFR) and fluidity of the entire propylene polymer. Furthermore, the intrinsic viscosity [η] EP-A is 8 dl / g or less.

  The ethylene content [(C2 ′) EP-B] of the propylene-ethylene random copolymer component (EP-B) is 50 to 80% by weight, preferably 50 to 65% by weight (however, the copolymer component) The total amount of (EP-B) is 100% by weight). When the ethylene content [(C2 ′) EP-B] is not within the above range, the rigidity may be lowered or the gloss may be increased.

  The intrinsic viscosity [η] EP-B of the propylene-ethylene random copolymer component (EP-B) is 0.5 dl / g or more and 8 dl / g or less, preferably 2 dl / g or more and 3.5 dl / g or less. . When the intrinsic viscosity [η] EP-B is less than 0.5 dl / g, rigidity and hardness may decrease, and toughness and impact resistance may also decrease. When the intrinsic viscosity [η] EP-B exceeds 8 dl / g, the toughness and impact resistance may be lowered. In addition, in a propylene-based polymer having a large content of the propylene-ethylene random copolymer portion, the melt flow rate (MFR) of the entire propylene-based polymer may decrease, and the fluidity may decrease.

  The content of the propylene-ethylene random copolymer component (EP-A) contained in the propylene-based polymer (A) is preferably 3 to 15% by weight, of the propylene-ethylene random copolymer component (EP-B). The content is preferably 10 to 37% by weight. (However, the total amount of the propylene polymer (A) is 100% by weight, and the total of (EP-A) and (EP-B) satisfies 25 to 40% by weight.)

  The melt flow rate (MFR) of the propylene polymer (A) used in the present invention is 5 to 120 g / 10 minutes, preferably 10 to 100 g / 10 minutes. If it is less than 5 g / 10 minutes, the moldability may be deteriorated or the effect of preventing the generation of flow marks may be insufficient. If it exceeds 120 g / 10 minutes, the impact resistance may be lowered.

  The method for producing the propylene polymer (A) includes a propylene homopolymer, or a crystalline polypropylene portion which is a copolymer of propylene and ethylene having a content of 1 mol% or less or an α-olefin having 4 or more carbon atoms. Produced in the first step (referred to as the first segment), Propylene-ethylene random copolymer portion (EP-A, referred to as the second segment) in the second step, Propylene-ethylene random copolymer portion (EP-B, referred to as third segment) may be produced in the third step.

  And the method of manufacturing with a well-known polymerization method using a well-known polymerization catalyst is mentioned. Known polymerization catalysts include, for example, Ziegler catalysts and metallocene catalysts. Ziegler catalysts include (a) a solid catalyst component containing magnesium, titanium, halogen and an electron donor as essential components, and (b) an organic aluminum. And a catalyst system formed from a compound and (c) an electron donor component. The production method of this catalyst is described in detail in, for example, JP-A-1-319508, JP-A-7-216017, JP-A-10-212319, JP-A-2004-182876, and the like.

  Examples of known polymerization methods include bulk polymerization, solution polymerization, slurry weight, and gas phase polymerization. These polymerization methods can be either batch type or continuous type, and these polymerization methods may be arbitrarily combined. As a more specific production method, a polymerization tank consisting of at least three tanks in series in the presence of a catalyst system consisting of the above-mentioned solid catalyst component (a), organoaluminum compound (b) and electron donor component (c) is connected in series. And polymerizing the first segment in the first tank, transferring the resulting product to the second tank, polymerizing the second segment in the second tank, and No. 3 tank, the third segment is polymerized in the third tank, and a propylene polymer is continuously produced. From an industrial and economical viewpoint, a continuous gas phase polymerization method is preferred.

  The amount of the solid catalyst component (a), the organoaluminum compound (b) and the electron donor component (c) used in the above polymerization method and the method of supplying each catalyst component to the polymerization tank are determined by the known method of using the catalyst. Can be determined as appropriate.

  The polymerization temperature is usually −30 to 300 ° C., preferably 20 to 180 ° C. The polymerization pressure is usually normal pressure to 10 MPa, preferably 0.2 to 5 MPa. As the molecular weight regulator, for example, hydrogen can be used.

  In the production of the propylene-based polymer (A) used in the present invention, preliminary polymerization may be performed by a known method before the polymerization (main polymerization) is performed. As a known prepolymerization method, for example, a method of supplying a small amount of propylene in the presence of the solid catalyst component (a) and the organoaluminum compound (b) and carrying out in a slurry state using a solvent can be mentioned.

  Examples of the inorganic filler (B) used in the present invention include talc, mica, calcium carbonate, barium sulfate, magnesium carbonate, clay, alumina, silica, calcium sulfate, silica sand, carbon black, titanium oxide, magnesium hydroxide. , Zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium hydroxide, calcium sulfite, sodium sulfate, bentonite, graphite, fibrous magnesium oxysulfate, potassium titanate fiber, magnesium hydroxide fiber, aluminum borate fiber, silica Examples include calcium acid fiber, calcium carbonate fiber, carbon fiber, glass fiber, and metal fiber. From the viewpoint of obtaining good impact strength and good gloss of the molded article, talc, calcium carbonate, fibrous magnesium oxysulfate, and calcium silicate fiber are preferable, and talc or fibrous magnesium oxysulfate is more preferable. is there.

When the inorganic filler (B) is non-fibrous, the average particle diameter is usually 10 μm or less, preferably 5 μm or less. Here, the average particle diameter of the inorganic filler (B) was determined from the integral distribution curve of the sieving method measured by suspending in a dispersion medium such as water or alcohol using a centrifugal sedimentation type particle size distribution measuring device. It means a 50% equivalent particle diameter D50.
When the inorganic filler (B) is fibrous, the average fiber length is usually 5 μm or more, and the average fiber diameter is usually 0.2 to 2 μm. Preferably, the average fiber length is 10 μm or more.

  Further, the inorganic filler (B) may be used as it is without treatment. In order to improve the interfacial adhesion with the polypropylene resin and to improve the dispersibility with respect to the polypropylene resin, a silane coupling usually used. The surface may be treated with an agent, a titanium coupling agent or a surfactant. Examples of the surfactant include higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid salts and the like.

The elastomer (C) used in the present invention is an olefin elastomer (C-1) and / or a vinyl aromatic compound-containing elastomer (C-2).
The olefin elastomer (C-1) is a copolymer of ethylene and an α-olefin having 4 to 20 carbon atoms. Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, isobutene, 1 -Pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-octene , 1-nonene, 1-decene, 1-undecene, 1-dodecene and the like, and these may be used alone or in combination of two or more. 1-butene, 1-hexene and 1-octene are preferred.

The density of the olefin-based elastomer (C-1) is usually 0 from the viewpoint of enhancing the dispersibility with respect to the propylene block polymer (A) and increasing the impact strength of the resulting resin composition at room temperature or low temperature. a .85~0.885g / cm ^3, preferably 0.85~0.88g / cm ^3, more preferably 0.855~0.875g / cm ^3.
The MFR at 190 ° C. of the olefin elastomer (C-1) is usually from 0.1 to 30 g / 10 minutes, preferably from 0.5 to 20 g / 10 minutes, from the viewpoint of impact strength.

As a manufacturing method of an olefin type elastomer (C-1), the manufacturing method by a well-known polymerization method is mentioned using a well-known polymerization catalyst. Known polymerization catalysts include, for example, a Ziegler-Natta catalyst system comprising a vanadium compound, an organoaluminum compound and a halogenated ester compound, or at least one cyclopentadienyl anion skeleton on a titanium atom, a zirconium atom or a hafnium atom. Examples thereof include a so-called metallocene catalyst system in which a metallocene compound coordinated with a group having an alumoxane or boron compound is combined.
Known polymerization methods include, for example, a method of copolymerizing ethylene and α-olefin in an inert organic solvent such as a hydrocarbon compound, and a method of copolymerizing in ethylene and α-olefin without using a solvent. Can be mentioned.

  Examples of the vinyl aromatic compound-containing elastomer (C-2) include, for example, a block copolymer comprising a vinyl aromatic compound polymer block and a conjugated diene polymer block, and a double bond of the conjugated diene portion of the block copolymer. Is a block polymer in which the double bond of the conjugated diene moiety of the block copolymer is hydrogenated by 80% or more, more preferably 85% or more hydrogen. It is a block polymer that has been added.

  The molecular weight distribution of the vinyl aromatic compound-containing elastomer (C-2) is a molecular weight distribution determined from a weight average molecular weight (Mw) and a number average molecular weight (Mn) measured by gel permeation chromatography (GPC) method ( (Q value) is preferably 2.5 or less, and more preferably 2.3 or less.

  The average content of the vinyl aromatic compound contained in the vinyl aromatic compound-containing elastomer (C-2) is preferably 10 to 20% by weight, more preferably 12 to 19% by weight (however, vinyl aroma The total amount of the group compound-containing elastomer (C-2) is 100% by weight).

  The melt flow rate (MFR, JIS-K-6758, 230 ° C.) of the vinyl aromatic compound-containing elastomer (C-2) is preferably 1 to 15 g / 10 minutes, more preferably 2 to 13 g / 10 minutes. is there.

  Examples of the vinyl aromatic compound-containing elastomer (C-2) include styrene-ethylene-butene-styrene rubber (SEBS), styrene-ethylene-propylene-styrene rubber (SEPS), and styrene-butadiene rubber (SBR). , Block copolymers such as styrene-butadiene-styrene rubber (SBS) and styrene-isoprene-styrene rubber (SIS), or block copolymers obtained by hydrogenating these rubber components.

  A rubber obtained by reacting an olefin copolymer rubber such as ethylene-propylene-nonconjugated diene rubber (EPDM) with a vinyl aromatic compound such as styrene can also be suitably used. Further, at least two kinds of vinyl aromatic compound-containing elastomers may be used in combination.

  Examples of the method for producing the vinyl aromatic compound-containing elastomer (C-2) include a method in which a vinyl aromatic compound is bonded to an olefin copolymer rubber or a conjugated diene rubber by polymerization, reaction, or the like.

When the polypropylene resin composition of the present invention is a polypropylene resin composition containing a propylene polymer (A) and an inorganic filler (B),
The total amount of the polypropylene resin composition is 100% by weight, the content of the propylene polymer (A) is 70 to 90% by weight, and the content of the inorganic filler (B) is 10 to 30% by weight. Preferably, the content of the propylene polymer (A) is 75 to 90% by weight, and the content of the inorganic filler (B) is 10 to 25% by weight.

When the polypropylene resin composition of the present invention is a polypropylene resin composition containing a propylene polymer (A), an inorganic filler (B), and an elastomer (C),
The total amount of the polypropylene resin composition is 100% by weight, the content of the propylene polymer (A) is 69 to 89.9% by weight, and the content of the inorganic filler (B) is 10 to 30% by weight. The content of the elastomer (C) is 0.1 to 1% by weight.
Preferably, the content of the propylene polymer (A) is 74.5 to 89.8% by weight, the content of the inorganic filler (B) is 10 to 25% by weight, and the elastomer (C) is contained. The amount is 0.2 to 0.5% by weight.

When the content of the propylene polymer (A) is less than 69% by weight, the impact resistance may be insufficient, and when it exceeds 90% by weight, the rigidity may be lowered or the gloss may be increased. .
When the content of the inorganic filler (B) is less than 10% by weight, the rigidity may be insufficient, and when it exceeds 30% by weight, the impact resistance may be lowered.
When the content of the elastomer (C) exceeds 1% by weight, the surface impact characteristics may be deteriorated.

  Examples of the method for producing the polypropylene resin composition of the present invention include a method of kneading each component, and examples of the apparatus used for kneading include a single screw extruder, a twin screw extruder, a Banbury mixer, and a hot roll. . The kneading temperature is usually 170 to 250 ° C., and the time is usually 1 to 20 minutes. In addition, the kneading of each component may be performed at the same time or may be performed separately.

Examples of the method of kneading the components separately include the following methods (1) and (2).
(1) A method of kneading a propylene polymer (A) and an inorganic filler (B), adding an elastomer (C), and kneading.
(2) A method in which the propylene polymer (A) and the elastomer (C) are kneaded, and then the inorganic filler (B) is added and kneaded.
Moreover, you may add a propylene homopolymer (D) as needed at the time of kneading | mixing.

  In the polypropylene resin composition of the present invention, if necessary, an antioxidant, an ultraviolet absorber, a pigment, an antistatic agent, a copper damage inhibitor, a flame retardant, a neutralizing agent, a foaming agent, a lubricant, a plasticizer, You may mix | blend the nucleating agent, an anti-bubble agent, and the additive of a crosslinking agent.

The injection-molded article of the present invention is obtained by molding the polypropylene resin composition of the present invention by an injection molding method.
Examples of the use of the injection-molded article of the present invention include automotive parts, electrical / electronic product parts, building material parts, and the like, and preferably automotive parts.

The measurement method of physical property values is shown below.
(1) Melt flow rate (MFR, unit: g / 10 minutes)
The measurement was performed according to the method defined in JIS-K-6758. Unless otherwise specified, the measurement temperature is 230 ° C. and the load is 2.16 kg.

(2) Ethylene content (unit: wt%)
The ethylene content was determined by a calibration curve method using the absorbance of the characteristic absorption of methyl groups (—CH ₃ ) and methylene groups (—CH ₂ —) obtained by preparing press sheets and measuring infrared absorption spectra. .

(3) Intrinsic viscosity ([η], unit: dl / g)
Using a Ubbelohde viscometer, reduced viscosities were measured at three concentrations of 0.1, 0.2 and 0.5 g / dl. The intrinsic viscosity is calculated by the calculation method described in “Polymer Solution, Polymer Experiments 11” (published by Kyoritsu Shuppan Co., Ltd.), page 491. That is, the reduced viscosity is plotted against the concentration, and the concentration is extrapolated to zero. Obtained by extrapolation. Polypropylene was evaluated at a temperature of 135 ° C. using tetralin as a solvent.

(4) Molecular weight distribution (Q value)
It measured on the conditions shown below using the gel permeation chromatography (GPC).
GPC: Waters 150C type Column: Showa Denko Shodex 80 MA 2 Sample amount: 300 μl (polymer concentration 0.2 wt%)
Flow rate: 1 ml / min
Temperature: 135 ° C
Solvent: o-dichlorobenzene A standard curve of elution volume and molecular weight was prepared using standard polystyrene made by Toyo Soda. Using a calibration curve, the polystyrene-equivalent weight average molecular weight (Mw) and number average molecular weight (Mn) of the sample are obtained, and the Q value, that is, the weight average molecular weight / number average molecular weight (Mw / Mn) is obtained as a measure of the molecular weight distribution. It was.

(5) Isotactic pentad fraction The isotactic pentad fraction Measurements were made according to the method published and described by Zambelli et al., Macromolecules, 6, 925 (1973). That is, an isotactic chain of pentad units in a polypropylene molecular chain measured using ¹³ C-NMR, in other words, a propylene monomer at the center of a chain in which five propylene monomer units are continuously meso-bonded Find the unit fraction. However, the assignment of NMR absorption peaks was performed based on Macromolecules, 8, 687 (1975), which was subsequently published.
Specifically, the isotactic pentad fraction was measured as the area fraction of the mmmm peak in the total absorption peak in the methyl carbon region of the ¹³ C-NMR spectrum. By this method, NPL reference material CRM No. of British PHYSICAL LABORATORY It was 0.944 when the isotactic pentad fraction of M19-14 PolypropylenePP / MWD / 2 was measured.

(6) Weight ratio X of the propylene-ethylene random copolymer portion to the entire propylene-ethylene block copolymer
The weight ratio Xp of the polymer produced in the crystalline polypropylene part polymerization process, the weight ratio X1 of the polymer produced in the EP1 part polymerization process, and the weight ratio X2 of the polymer produced in the EP2 part polymerization process are calculated by the following equations: did.
Xp = ΔH2 / ΔHP
X1 = (ΔHP / ΔH1-1) × ΔH2 / ΔHP
X2 = 1-Xp-X1
ΔHP: heat of fusion of polymer after crystalline polypropylene part polymerization step (J / g)
ΔH1: heat of fusion of polymer after EP-1 part polymerization step (J / g)
ΔH2: heat of fusion of the polymer after the EP-2 part polymerization step (J / g)

(7) Ethylene content of propylene-ethylene random copolymer portion in propylene-ethylene block copolymer (unit: wt%)
The ethylene content of the propylene-ethylene random copolymer portion in the propylene-ethylene block copolymer was measured by the ethylene content (% by weight) in all block copolymers by infrared absorption spectroscopy, and calculated from the following formula.
(C2 ') EP = (C2') T / X
(C2 ′) T: ethylene content (% by weight) in all block copolymers
(C2 ′) EP: ethylene content of propylene-ethylene random copolymer portion (% by weight)

(7-1) Ethylene content [(C2 ′) EP-1] of first-stage copolymer part (EP-1) (unit: wt%)
[(C2 ′) EP-1] (% by weight) was determined in the same manner as (7) above using a sample taken from the polymerization tank after polymerizing the first-stage copolymer portion (EP-1). It was.

(7-2) Ethylene content of second-stage copolymer part (EP-2) [(C2 ′) EP-2] (unit: wt%)
It calculated | required from the following formula.
[(C2 ′) EP-2] = ((C2 ′) T − [(C2 ′) EP-1] × X1) / X2

(8) Intrinsic viscosity of propylene-ethylene random copolymer portion in propylene-ethylene block copolymer ([η] EP, unit: dl / g)
The intrinsic viscosity [η] EP of the propylene-ethylene random copolymer portion in the propylene-ethylene block copolymer is calculated from the following formula by measuring the intrinsic viscosity of each of the propylene homopolymer portion and the entire block copolymer: Calculated.
[Η] EP = [η] T / X− (1 / X−1) [η] P
[Η] P: Intrinsic viscosity of the propylene homopolymer part (dl / g)
[Η] T: Intrinsic viscosity of the entire block copolymer (dl / g)
In addition, the intrinsic viscosity [η] P of the propylene homopolymer portion which is the first segment of the propylene-ethylene block copolymer is from the inside of the polymerization tank after the production of the propylene homopolymer portion which is the first step. [Η] P was determined from the taken out propylene homopolymer.

(8-1) [η] EP-1
The intrinsic viscosity ([η] (1)) of the sample taken from the polymerization tank after polymerizing the copolymer part (EP-1) at the first stage was measured, and the first stage was obtained in the same manner as (8) above. The intrinsic viscosity [η] EP-1 of the copolymer part (EP-1) was determined.
[Η] EP-1 = [η] (1) / X (1) − (1 / X (1) −1) [η] P
[Η] P: Intrinsic viscosity of the propylene homopolymer portion (dl / g)
[Η] (1): Intrinsic viscosity (dl / g) of the entire propylene-ethylene block copolymer after EP-1 polymerization
X (1): Weight ratio of EP-1 to the entire propylene-ethylene block copolymer after EP-1 polymerization

(8-2) [η] EP-2
The intrinsic viscosity [η] EP-2 of the copolymer part (EP-2) polymerized in the second stage is that of the propylene-ethylene random copolymer part of the finally obtained propylene-ethylene block copolymer. It calculated | required from intrinsic viscosity [(eta)] EP, intrinsic viscosity [(eta)] EP-1 of the copolymer part (EP-1) of a 1st step | paragraph, and each weight ratio.
[Η] EP-2 = ([η] EP · X− [η] EP-1 · X1) / X2
X1: Weight ratio of EP-1 to the whole of the finally obtained propylene-ethylene block copolymer X2: Weight ratio of EP-2 to the whole of the finally obtained propylene-ethylene block copolymer

The evaluation of the injection-molded body was performed according to the following method.
(1) Flexural modulus (unit: MPa)
The measurement was performed according to the method defined in JIS-K-7203. A test piece molded by injection molding was used. The thickness of the test piece is 6.4 mm, and the bending elastic modulus is evaluated under the conditions of a span length of 100 mm and a load speed of 30 mm / min. The measurement temperature was 23 ° C.

(2) Izod impact strength (unit: KJ / m ² )
The measurement was performed according to the method defined in JIS-K-7110. A test piece molded by injection molding was used. The thickness of the test piece was 6.4 mm, and the impact strength with a notch was evaluated. The measurement temperature was 23 ° C.

(3) Gloss evaluation method (gross, unit:%)
It measured according to the 60 degree specular gloss measurement method in JIS Z8741 specular gloss measurement method. The thickness of the test piece was 3 mm, and the gloss was measured using Gloss-Meter GM-3D manufactured by Murakami Color Research Laboratory.

(4) High-speed impact test (HRIT)
A 100 × 100 × 3 (mm) flat plate test piece cut out from a 100 × 400 × 3 (mm) flat plate produced by injection molding using a high rate impact tester (RIT-8000 type) manufactured by Rheometrics (USA). Fixed with a 2-inch circular holder, an impact probe having a diameter of 1/2 inch (a radius of 1/4 inch of the tip spherical surface) was used, and the impact probe was applied to the test piece at a speed of 5 m / sec. The surface impact strength was evaluated by detecting the stress and calculating the area integral value.

The total energy (TE), which is the energy value required until the material breaks, was measured.
The unit is expressed in joules (J). Condition adjustment was performed by the thermostat attached to the apparatus. The test piece was put in a thermostat previously adjusted to a predetermined temperature and the condition was adjusted for 2 hours, and then the test was performed. This predetermined temperature was taken as the measurement temperature. This time, measurement was performed at 23 ° C.

Example 1
[Production of solid catalyst components]
The solid catalyst component used for the propylene polymer of the present invention was produced in the same manner as in Examples 3 (1) and (2) of JP-A No. 2004-182876.

[Production of propylene block polymer (A-1)]
1. Prepolymerization In an autoclave equipped with a stirrer, 25 mmol / L of triethylaluminum (hereinafter abbreviated as TEA) was added to hexane that had been sufficiently dehydrated and degassed, and cyclohexylethyldimethoxysilane (hereinafter abbreviated as CHEDMS) as an electron donor component was CHEDMS. /TEA=0.1 (mol / mol), and the solid catalyst component described in JP-A No. 2004-182876 is charged in the above order so that the content of Ti contained in the catalyst component is [TEA] / Ti = 5 The prepolymer was continuously supplied with propylene while maintaining the temperature ratio at 5 to 15 ° C. so that the polymer amount ratio per solid catalyst component (hereinafter abbreviated as PP / cat) was 2.5 (g / g). A slurry was obtained. The obtained prepolymer slurry was transferred to an autoclave equipped with a stirrer, and then sufficiently purified liquid butane was added and kept at a temperature of 10 ° C. or lower for storage.

2. Main polymerization (Production of P- (EP-B)-(EP-A))
A polymerization tank consisting of 5 tanks is arranged in series, and in the first, second and third tanks, continuous bulk polymerization of propylene homopolymer is performed, and when the replacement of the generated powder is completed, the powder held in the tank is removed. Then, the propylene-ethylene random copolymer (EP-B) was vapor-phase polymerized in the tank. Further, the obtained powder was transferred to the fifth tank in which the ratio of propylene-ethylene was adjusted, and propylene-ethylene copolymer (EP-A) was vapor-phase polymerized to obtain P- (EP-B)-(EP- A) A block copolymer having a structure was obtained.

In the 1st, 2nd, and 3rd tanks, a reactor internal temperature of 80 ° C. and a reactor internal pressure of 1.8 MPa were prepared in 1. under the conditions of maintaining 90% by volume of propylene and 10% by volume of hydrogen in the gas phase. Gas phase polymerization was continuously carried out while supplying TEA and CHEDMS using the prepolymer slurry as a solid catalyst component. The concentration in the obtained polymer is about [TEA] = 200 ppm, and polymerization is performed so that [CHEDMS] / [TEA] = 0.1 (mol / mol) and PP / cat = 20000 (g / g). Went. The average residence time was 3.5 hours. The intrinsic viscosity [η] _P of the obtained polymer was 0.91 dl / g.

  Next, in the fourth tank, the reactor internal temperature is 70 ° C., the reactor internal pressure is 1.6 MPa, and the propylene in the gas phase is 51 vol%, ethylene is 41 vol%, and hydrogen is 4.26 vol%. Then, in the fifth tank, at a reactor internal temperature of 70 ° C. and a reactor internal pressure of 1.2 MPa, 68% by volume of propylene in the gas phase part, 27% by volume of ethylene, and 2.37 of hydrogen. Gas phase polymerization was carried out under the condition of maintaining the volume%, and a P- (EP-B)-(EP-A) block copolymer was recovered. Total PP / cat = 30100 (g / g), the polymerization time in the fourth tank was 2.2 hr, and the polymerization time in the fifth tank was 2.1 hours.

The analysis results of the obtained polymer are shown in Table 1. The total intrinsic viscosity [η] _T of the obtained polymer is 1.56 dl / g, the EP-B content is 31.5 wt%, the EP-A content is 4.8 wt%, The ethylene content was 56.8% by weight, and the ethylene content in EP-A was 48.5% by weight. The intrinsic viscosity [η] EP-B of EP-B was 2.7 dl / g, and the intrinsic viscosity [η] EP-A of EP-A was 2.6 dl / g.

[Production of Propylene Polymer] (A-2)
By adjusting the hydrogen concentration in the 1st, 2nd and 3rd tanks, the volume ratio of propylene / ethylene / hydrogen in the 4th and 5th tanks, and the residence time in the same manner as in (A-1), a polypropylene polymer ( A-2) was produced. However, in A-2, it manufactured by making the volume ratio of the propylene / ethylene / hydrogen of 4th tank and 5th tank the same, and was a propylene-type polymer which has only EP-A.

[Production of Propylene Polymer] (A-3)
AZ864 manufactured by Sumitomo Chemical Co., Ltd. was used.

  The resulting propylene polymers (A-1) to (A-3) are shown in Table 1.

(B) Inorganic filler (B-1) Talc (MWHST, Hayashi Kasei Co., Ltd.) was used. The average particle size was 2.7 μm.

(C) Elastomer (C-1) Ethylene-1-octene copolymer rubber manufactured by DuPont Dow Elastomer Co., Ltd. was used. ENGAGE 8200 (density: 0.87 g / cm ³ , MFR (190 ° C.): 5 g / 10 min).

(D) Propylene homopolymer (D-1) R101 manufactured by Sumitomo Chemical Co., Ltd. was used. The molecular weight distribution (Q value) is 4.4, the intrinsic viscosity ([η] P) is 1.38 dl / g, the isotactic pentad fraction is 0.98, and the MFR (230 ° C.) is Propylene homopolymer which is 20 g / 10 min.

(D-2) U101E9 manufactured by Sumitomo Chemical Co., Ltd. was used. The molecular weight distribution (Q value) is 5.4, the intrinsic viscosity ([η] P) is 0.92 dl / g, the isotactic pentad fraction is 0.99, and the MFR (230 ° C.) is Propylene homopolymer which is 120 g / 10 min.

[Production of polypropylene resin composition]
The propylene copolymer (A) obtained by the above method, the inorganic filler (B), the elastomer (C), and the propylene homopolymer (D) are blended in the composition ratios shown in Table 2, and these are Henschel. After premixing uniformly with a mixer and tumbler, using a twin-screw kneading extruder (TEX44SS-31.5BW-2V type manufactured by Nippon Steel Works), the extrusion rate is 30 kg / hr, the screw rotation speed is 320 rpm, under vent suction. A polypropylene resin composition was produced. The obtained polypropylene resin composition is shown in Table 2.

[Manufacture of molded product for physical property evaluation]
The test piece for evaluating physical properties is produced under the following injection molding conditions. After drying the polypropylene resin composition with a hot air drier at 120 ° C. for 2 hours, using a Toshiba Machine IS150E-V type injection molding machine, a molding temperature of 180 ° C., a mold cooling temperature of 50 ° C., an injection time of 15 seconds, and a cooling time Injection molding was performed in 30 seconds. Table 3 shows the evaluation results of the obtained injection-molded body.

[Manufacture of compacts for high-speed surface impact tests]
As a test for high-speed surface impact, a mirror surface flat plate of 100 × 400 × 3 mm was used. It was produced under the following injection molding conditions. After drying the polypropylene resin composition with a hot air dryer at 120 ° C. for 2 hours, using a SE180D C510M type injection molding machine manufactured by Sumitomo Heavy Industries, Ltd., a molding temperature of 220 ° C., a mold cooling temperature of 50 ° C., an injection time of 15 seconds, Injection molding was performed with a cooling time of 30 sec. A high-speed surface impact test was performed on the obtained injection-molded product by the evaluation method (4). The results are shown in Table 3.

  In Comparative Example 1 that does not satisfy the structure of the propylene block polymer (A), the total energy TE until breakdown in the high-speed surface impact test was low and the surface impact characteristics were inferior. In Comparative Example 2, which did not satisfy the amount of elastomer (C) added, the total energy TE until breakdown in the high-speed surface impact test was low, the surface impact characteristics were inferior, and the gloss was high.

Claims (5)

It is a polypropylene resin composition containing 70 to 90% by weight of the following propylene polymer (A) and 10 to 30% by weight of inorganic filler (B) (however, the total amount of the polypropylene resin composition is 100 %).
The propylene-based polymer (A) is a propylene homopolymer or a crystalline polypropylene portion of 60 to 75 weight which is a copolymer of propylene and ethylene having a content of 1 mol% or less or an α-olefin having 4 or more carbon atoms. And a propylene-ethylene random copolymer portion having a weight ratio of propylene to ethylene (propylene / ethylene (weight / weight)) of 75/25 to 35/65 and 25 to 40% by weight, and the following requirements ( 1) and a propylene-ethylene block copolymer satisfying the requirement (2) (provided that the total amount of the propylene-ethylene block copolymer is 100% by weight).
Requirement (1) The propylene-ethylene random copolymer portion is composed of a propylene-ethylene random copolymer component (EP-A) and a propylene-ethylene random copolymer component (EP-B). -A) intrinsic viscosity [η] EP-A is 1.5 dl / g or more and 8 dl / g or less, and ethylene content [(C2 ′) EP-A] is 20 wt% or more and less than 50 wt% (however, Component (EP-A) is 100% by weight), copolymer component (EP-B) has intrinsic viscosity [η] EP-B of 0.5 dl / g to 8 dl / g, ethylene content [ (C2 ′) EP-B] is 50% by weight or more and 80% by weight or less (provided that the total amount of component (EP-B) is 100% by weight).
Requirement (2) The melt flow rate (MFR) at 230 ° C. of the propylene polymer (A) is 5 to 120 g / 10 minutes. Polypropylene resin composition containing the following propylene polymer (A) 69-89.9 wt%, inorganic filler (B) 10-30 wt%, and elastomer (C) 0.1-1 wt% (However, the total amount of the polypropylene resin composition is 100% by weight).
The propylene polymer (A) is
A propylene homopolymer or a crystalline polypropylene portion of 60 to 75% by weight, which is a copolymer of propylene and ethylene having a content of 1 mol% or less or an α-olefin having 4 or more carbon atoms, and a weight ratio of propylene and ethylene A propylene-ethylene random copolymer portion having a propylene / ethylene (weight / weight) of 75/25 to 35/65 and 25 to 40% by weight, satisfying the following requirements (1) and (2) Propylene-ethylene block copolymer (however, the total amount of propylene-ethylene block copolymer is 100% by weight).
Requirement (1) The propylene-ethylene random copolymer portion is composed of a propylene-ethylene random copolymer component (EP-A) and a propylene-ethylene random copolymer component (EP-B). -A) intrinsic viscosity [η] EP-A is 1.5 dl / g or more and 8 dl / g or less, and ethylene content [(C2 ′) EP-A] is 20 wt% or more and less than 50 wt% (however, Component (EP-A) is 100% by weight), copolymer component (EP-B) has intrinsic viscosity [η] EP-B of 0.5 dl / g to 8 dl / g, ethylene content [ (C2 ′) EP-B] is 50% by weight or more and 80% by weight or less (provided that the total amount of component (EP-B) is 100% by weight).
Requirement (2) The melt flow rate (MFR) at 230 ° C. of the propylene polymer (A) is 5 to 120 g / 10 minutes.
The elastomer (C) is at least one elastomer selected from the group consisting of a copolymer elastomer (C-1) of ethylene and an α-olefin having 4 or more carbon atoms, and a vinyl aromatic compound-containing elastomer (C-2). It is.   The intrinsic viscosity [η] EP-B of the propylene-ethylene random copolymer component (EP-B) contained in the propylene-based polymer (A) is 2 to 3.5 dl / g. Polypropylene resin composition.   The content of the propylene-ethylene random copolymer component (EP-A) contained in the propylene-based polymer (A) is 3 to 15% by weight, and the propylene-ethylene random copolymer component (EP-B) The polypropylene resin composition according to any one of claims 1 to 3, wherein the content is 10 to 37 wt% (provided that the total amount of the propylene polymer (A) is 100 wt%).   The molded object which consists of a polypropylene resin composition in any one of Claims 1-4.