JP2008274263A - Polypropylene-based resin composition and foamed molded product comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polypropylene-based resin composition which is excellent in flowability and can give molded products excellent in appearances, and to provide a foamed molded product comprising the same. <P>SOLUTION: This polypropylene-based resin composition comprises 100 pts.wt. [the total amount of (A) and (B) is 100 wt.%] of a resin composition comprising 40 to 99 wt.% of at least one propylene polymer (A) selected from the group consisting of propylene homopolymer (A-1) and the following propylene-ethylene block copolymer (A-2), and 1 to 60 wt.% of the following ethylene-α-olefin copolymer (B), and 0.1 to 20 pts.wt. of a petroleum resin (C). (A-2) The propylene-ethylene block copolymer in which [η]EP of the propylene-ethylene block copolymer component is 2 to 8 (dl/g), and (B) the ethylene-α-olefin copolymer in which the carbon atom number of the α-olefin is 4 to 20, and MI (190°C) is 1 to 40 g/10 min. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polypropylene resin composition and a foam-molded product comprising the same.

Conventionally, polypropylene resins have been used for automobile materials because of their high rigidity and excellent impact resistance.
For example, in JP-A-11-293058, as means for improving rigidity and impact resistance, polypropylene resin and two or more olefins selected from ethylene, propylene, and α-olefin, A thermoplastic resin composition comprising an olefin copolymer obtained by copolymerizing an olefin having a total carbon number of 6 or more and an inorganic filler is described.

  Japanese Patent Application Laid-Open No. 2001-192509 includes, as a means for improving flexibility and heat resistance, an amorphous olefin polymer having a tensile cutting strength of less than 2 MPa and a crystalline olefin resin. An olefin resin composition having a Shore A hardness of 85 or less is described.

Japanese Patent Laid-Open No. 11-293058 JP 2001-192509 A

However, also in the polypropylene resin composition described in the above-mentioned publications and the like, reduction of silver streaks generated when the resin composition is molded into a molded body has been demanded. Here, the silver streak is a short, whitened appearance defect caused by foaming. In molding, a continuous long appearance defect called radial corrugation extending radially from the gate portion may occur. Corrugation is an appearance defect that is not whitened, and is distinguished from silver streak.
In any case, these appearance defects affect the quality of the product, and it is required to reduce the occurrence thereof as much as possible.
Under such circumstances, an object of the present invention is to provide a polypropylene resin composition capable of obtaining a molded article having excellent fluidity and excellent molded article appearance (small silver streak and corrugation), and a foam molded article comprising the same. There is.

  As a result of intensive studies, the present inventor has found that the present invention can solve the above problems, and has completed the present invention.

That is, the present invention
Resin composition comprising the following component (A) 50 to 90% by weight, component (B) 5 to 20% by weight, and component (C) 5 to 30% by weight (however, component (A) and component (B) ) And 100% by weight of component (C) and (D) 0.005 to 10 parts by weight of organic peroxide and a polypropylene resin composition obtained by heat treatment, and this The present invention relates to a foam molded article made of a resin composition.
Component (A): At least one propylene polymer component (B) selected from the group consisting of propylene homopolymer (A-1) and propylene-ethylene copolymer (A-2): carbon number of α-olefin Propylene having a molecular weight distribution of 1 to 4, an intrinsic viscosity of 0.5 to 10 dl / g, a heat of fusion of 30 J / g or less, and an ethylene content of 60 mol% or less. Ethylene-α-olefin copolymer component (C): α-olefin has 4 to 20 carbon atoms, a density of 0.85 to 0.89 g / cm ³ , and a heat of fusion of 30 J / g or less. Ethylene-α-olefin copolymer

  ADVANTAGE OF THE INVENTION According to this invention, the polypropylene resin composition which can obtain the molded object with few silver streaks and corrugation, and the foaming molded object consisting thereof can be obtained.

[Propylene polymer (A)]
In the present invention, at least one propylene polymer (A) selected from the group consisting of a propylene homopolymer (A-1) and a propylene-ethylene copolymer (A-2) is used.
Examples of the propylene-ethylene copolymer (A-2) include a propylene-ethylene random copolymer (A-2-1) and a propylene-ethylene block copolymer (A-2-2). The propylene-ethylene block copolymer (A-2-2) is a copolymer composed of a propylene homopolymer component and a propylene-ethylene random copolymer component.

  The propylene polymer (A) is preferably a propylene homopolymer (A-1) or a propylene-ethylene block copolymer (A-2-2) from the viewpoint of rigidity, heat resistance or hardness of the molded product. .

The isotactic pentad fraction measured by ¹³ C-NMR of the propylene homopolymer (A-1) is preferably 0.95 or more, more preferably 0.98 or more.
The isotactic pentad fraction measured by ¹³ C-NMR of the propylene homopolymer component of the propylene-ethylene block copolymer (A-2-2) is preferably 0.95 or more, more preferably 0.8. 98 or more.

The isotactic pentad fraction is the fraction of the propylene monomer unit at the center of the isotactic chain in the pentad unit in the propylene polymer molecular chain. In other words, five propylene monomer units are consecutive. This is the fraction of propylene monomer units at the center of the meso-linked chain. The method for measuring the isotactic pentad fraction is as follows. Zambelli et al., Described in Macromolecules, 6, 925 (1973), that is, a method measured by ¹³ C-NMR. (However, the assignment of the NMR absorption peak is determined based on Macromolecules, 8, 687 (1975)).

Specifically, the ratio of the mmmm peak area to the absorption peak area of the methyl carbon region measured by ¹³ C-NMR spectrum is the isotactic pentad fraction. NPL reference material CRM No. of NATIONAL PHYSICAL LABORATORY measured by this method. The isotactic pentad fraction of M19-14 Polypropylene PP / MWD / 2 was 0.944.

Intrinsic viscosity ([η] _P ) measured in a tetralin solvent at 135 ° C. of the propylene homopolymer (A-1), 135 ° C. of the propylene homopolymer component of the block copolymer (A-2-2) Intrinsic viscosity ([η] _P ) measured in a tetralin solvent, and the intrinsic viscosity ([η]) of a random copolymer (A-2-1) measured in a tetralin solvent at 135 ° C. is 0. It is 7-5 dl / g, Preferably it is 0.8-4 dl / g.

  In addition, propylene homopolymer (A-1), propylene homopolymer component of block copolymer (A-2-2), and gel permeation chromatography of random copolymer (A-2-1) ( The molecular weight distribution (Q value, Mw / Mn) measured by GPC) is preferably 3 or more and 7 or less.

  The ethylene content contained in the propylene-ethylene random copolymer component of the block copolymer (A-2-2) is 20 to 65% by weight, preferably 25 to 50% by weight (provided that propylene-ethylene is used). The total amount of random copolymer components is 100% by weight).

The intrinsic viscosity ([η] _EP ) measured in a 135 ° C. tetralin solvent of the propylene-ethylene random copolymer component of the block copolymer (A-2-2) is 1.5 to 12 dl / g. Yes, preferably 2-8 dl / g, more preferably 3-8 dl / g.

  Content of the propylene-ethylene random copolymer component which comprises the said block copolymer (A-2-2) is 10 to 60 weight%, Preferably it is 10 to 40 weight%.

  The propylene homopolymer (A-1) has a melt index (MI) of 0.1 to 400 g / 10 minutes, preferably 1 to 300 g / 10 minutes. However, the measurement temperature is 230 ° C. and the load is 2.16 kg.

  The propylene-ethylene copolymer (A-2) has a melt index (MI) of 0.1 to 200 g / 10 minutes, preferably 5 to 150 g / 10 minutes. However, the measurement temperature is 230 ° C. and the load is 2.16 kg.

As a manufacturing method of the said propylene polymer (A), the method of manufacturing with a well-known polymerization method using a well-known polymerization catalyst is mentioned, for example.
Examples of the known polymerization catalyst used in the method for producing the propylene polymer (A) include (1) a solid catalyst component containing magnesium, titanium, halogen and an electron donor as essential components, and (2) organoaluminum. And a catalyst system comprising a compound and (3) an electron donor component. Examples of the method for producing this catalyst include the production methods described in JP-A-1-319508, JP-A-7-216017 and JP-A-10-212319.

  Examples of known polymerization methods used in the above production method include a bulk polymerization method, a solution polymerization method, a slurry polymerization method, and a gas phase polymerization method. These polymerization methods may be either batch type or continuous type, and these polymerization methods may be arbitrarily combined.

As a manufacturing method of said propylene-ethylene block copolymer (A-2-2), Preferably, it consists of said solid catalyst component (1), an organoaluminum compound (2), and an electron donor component (3). In the presence of a catalyst system, a polymerization tank comprising at least two tanks is arranged in series to produce a propylene homopolymer component of the propylene-ethylene block copolymer, and then the produced component is transferred to the next polymerization tank. In this polymerization tank, a propylene-ethylene random copolymer component is continuously produced to produce a propylene-ethylene block copolymer.
The amount of the solid catalyst component (1), the organoaluminum compound (2) and the electron donor component (3) used in the above production method and the method of supplying each catalyst component to the polymerization tank may be appropriately determined. .

  The polymerization temperature is -30 to 300 ° C, preferably 20 to 180 ° C. The polymerization pressure is normal pressure to 10 MPa, preferably 0.2 to 5 MPa. For example, hydrogen may be used as the molecular weight modifier.

  In the production of the propylene polymer (A), prepolymerization may be performed by a known method before carrying out the main polymerization. As a known prepolymerization method, for example, a method of supplying a small amount of propylene in the presence of the solid catalyst component (1) and the organoaluminum compound (2) and carrying out in a slurry state using a solvent can be mentioned.

[Propylene-ethylene-α-olefin copolymer (B)]
The α-olefin used in the propylene-ethylene-α-olefin copolymer (B) (hereinafter also simply referred to as copolymer (B)) used in the present invention is an α-olefin having 4 to 20 carbon atoms. Can be mentioned.
Examples of the α-olefin having 4 to 20 carbon atoms include a linear α-olefin and a branched α-olefin, and examples of the linear α-olefin include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1 -Octadecene, 1-nanodecene, 1-eicosene and the like. Examples of the branched α-olefin include 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-hexene and the like.

The propylene unit content contained in the copolymer (B) is 5 to 99 mol%, preferably 25 to 99 mol%, more preferably 35 to 99 mol%,
The ethylene unit content is 0-60 mol%, preferably 0-55 mol%,
The α-olefin unit content is 1 to 35 mol%, preferably 1 to 20 mol%, more preferably 1 to 10 mol%. (However, these propylene unit content, ethylene unit content, and α-olefin unit content are based on the total of these monomer units.)

The copolymer (B) preferably satisfies the relationship of the following formula.
0.1 <[y / (x + y)] ≦ 1.0
More preferably, 0.5 <[y / (x + y)] ≦ 1.0, and still more preferably 0.8 <[y / (x + y)] ≦ 1.0.
In the above formula, x represents the molar content of ethylene in (B), and y represents the total molar content of α-olefins having 4 to 20 carbon atoms in (B).

Examples of the method for producing the copolymer (B) include a method in which a predetermined monomer is polymerized using a metallocene catalyst by a slurry polymerization method, a solution polymerization method, a bulk polymerization method, a gas phase polymerization method, or the like.
Examples of the metallocene catalyst include, for example, Japanese Patent Application Laid-Open Nos. 3-163088, 4-268307, 9-12790, 9-87313, 11-80233, and special tables. Examples thereof include metallocene catalysts described in JP-A-10-508055.
As a method for producing a copolymer (B) using a metallocene catalyst, a method described in EP-A-1211287 is preferably mentioned.

  The intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. of the copolymer (B) is 0.5 to 10 dl / g, more preferably 0.9 to 5 dl / g, and still more preferably. 1.2 to 3 dl / g.

  The molecular weight distribution of the copolymer (B) is 1 to 4. The molecular weight distribution is the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn), and is measured by gel permeation chromatography (GPC) using standard polystyrene as the molecular weight standard substance. Is done.

  The heat of fusion of the copolymer (B) is 30 J / g or less, preferably 20 J / g or less, and more preferably 10 J / g or less. More preferably, it is 0 J / g.

[Ethylene-α-olefin copolymer (C)]
Examples of the ethylene-α-olefin copolymer (C) (hereinafter also simply referred to as copolymer (C)) used in the present invention include an ethylene-α-olefin random copolymer or a mixture thereof.

The density of the copolymer (C) is 0.85 to 0.89 g / cm ³ , preferably 0.85 to 0.88 g / cm ³ , more preferably 0.86 to 0.88 g / cm ³ . is there.

  The ethylene content contained in the copolymer (C) is preferably 20 to 95% by weight, more preferably 30 to 90% by weight. The α-olefin content is preferably 80 to 5% by weight, more preferably 70 to 10% by weight.

  The MI of the copolymer (C) (measurement temperature is 190 ° C., load is 2.16 kg) is 0.5 to 100 g / 10 min, preferably 1 to 50 g / 10 min, more preferably 10 to 10 g / 10 min. 40 g / 10 min.

  The heat of fusion of the copolymer (C) is 30 J / g or less, preferably 20 J / g or less, more preferably 10 J / g or less, and still more preferably 0 J / g.

  Examples of the α-olefin used in the copolymer (C) include α-olefins having 4 to 20 carbon atoms, such as 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, Examples include 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicocene. These α-olefins may be used alone or in combination of at least two kinds. The α-olefin is preferably an α-olefin having 4 to 12 carbon atoms such as 1-butene, 1-hexene and 1-octene.

  As a manufacturing method of a copolymer (C), the manufacturing method similar to the method used for manufacture of a copolymer (B) is mentioned. As a catalyst used for manufacture of a copolymer (C), the same metallocene catalyst as the catalyst used for manufacture of a copolymer (B) is mentioned.

  The content of the propylene polymer (A) is 50 to 90% by weight, preferably 55 to 85% by weight, and more preferably 60 to 80% by weight. The content of the propylene-ethylene-α-olefin copolymer (B) is 5 to 20% by weight, preferably 5 to 15% by weight, and more preferably 7 to 15% by weight. As content of ethylene-alpha-olefin random copolymerization (C), it is 5 to 30 weight%, Preferably, it is 10 to 30 weight%, More preferably, it is 13 to 25 weight%. However, the total amount of (A), (B) and (C) is 100% by weight.

[Organic peroxide (D)]
The organic peroxide (D) used in the present invention is, for example, an organic peroxide having a decomposition temperature of less than 120 ° C. with a half-life of 1 minute or a decomposition temperature of 120 ° C. or more with a half-life of 1 minute. Some organic peroxides can be mentioned. You may use these individually or in combination of 2 or more types.

  Examples of the organic peroxide having a decomposition temperature of less than 120 ° C. with a half-life of 1 minute include diacyl peroxide compounds and percarbonate compounds (compounds having a structure represented by the following formula (1) in the molecular skeleton). Examples thereof include (I) and alkyl perester compounds (compound (II) having a structure represented by the following formula (2) in the molecular skeleton).

Examples of the compound (I) having the structure represented by the above formula (1) include di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, bis (4-t-butylcyclohexyl) per Examples thereof include oxydicarbonate, diisopropyl peroxydicarbonate, t-butyl peroxyisopropyl carbonate, dimyristyl peroxycarbonate, and the like.
Examples of the compound (II) having a structure represented by the above formula (2) include 1,1,3,3-tetramethyl butyl neodecanoate, α-cumyl peroxy neodecanoate, t-butyl peroxy neodecanoate and the like. You may use these individually or in combination of 2 or more types.

  Examples of the organic peroxide having a decomposition temperature of 120 ° C. or more with a half-life of 1 minute include 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (4,4- Di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) cyclododecane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexano Ate, t-butyl peroxylaurate, 2,5 dimethyl-2,5-di (benzoylperoxy) hexane, t-butyl peroxyacetate, 2,2-bis (t-butylperoxy) butene, t- Butyl peroxybenzoate, n-butyl-4,4-bis (t-beroxy) valerate, di-t-butylberoxyisophthalate, Cumyl peroxide, α-α′-bis (t-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 1,3-bis (t -Butylperoxydiisopropyl) benzene, t-butylcumyl peroxide, di-t-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne- 3 etc. are mentioned. You may use these individually or in combination of 2 or more types.

The amount of the organic peroxide (D) added is 0.005 to 10 parts by weight, preferably 0.01 to 100 parts by weight of the resin composition containing (A), (B) and (C). -5 parts by weight, more preferably 0.01-1 part by weight.
In the present invention, the resin composition comprising the above (A), (B) and (C) (a resin composition containing an inorganic filler in some cases) and the organic peroxide are heat-treated.
The heat treatment may be kneading under heating as described later.

[Inorganic filler (E)]
The polypropylene resin composition according to the present invention may contain an inorganic filler (E). Examples of the inorganic filler (E) include carbon fiber, metal fiber, glass bead, mica, calcium carbonate, potassium titanate whisker, talc, bentonite, smectite, mica, sepiolite, wollastonite, allophane, imogolite, fibrous magnesium. Examples thereof include oxysulfate, barium sulfate, and glass flakes, and talc is preferable.

  As an average particle diameter of an inorganic filler (E), it is 0.01-50 micrometers, Preferably it is 0.1-30 micrometers, More preferably, it is 0.1-5 micrometers. Here, the average particle diameter of the inorganic filler (E) 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. % Equivalent particle diameter D50.

  The inorganic filler (E) may be used as it is without treatment, to improve the interfacial adhesive strength with the polypropylene resin composition, or to improve the dispersibility of the inorganic filler in the polypropylene resin composition. Therefore, the surface of the inorganic filler may be treated with various known silane coupling agents, titanium coupling agents, higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid salts or other surfactants. .

  As content of an inorganic filler (E), it is 0.1-60 weight part with respect to 100 weight part of polypropylene resin compositions containing (A), (B), and (C), Preferably, From the viewpoint of improving rigidity, it is 1 to 30 parts by weight, more preferably 5 to 20 parts by weight.

  MI (measurement temperature is 230 ° C., load is 2.16 kg) of the polypropylene resin composition of the present invention is 40 to 200 g / 10 minutes, preferably 40 to 150 g / 10 minutes, more preferably 40 to 120 g / minute. 10 minutes.

  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 170 to 250 ° C., and the time is 1 to 20 minutes. In addition, the kneading of each component may be performed at the same time or may be performed separately.

  The polypropylene resin composition of the present invention may contain additives as necessary, for example, neutralizers, antioxidants, light proofing agents, ultraviolet absorbers, copper damage preventing agents, lubricants, processing. Auxiliaries, plasticizers, dispersants, antiblocking agents, antistatic agents, nucleating agents, flame retardants, foaming agents, antifoaming agents, crosslinking agents, colorants, pigments and the like can be mentioned.

  Examples of the method for producing the molded product (including the foamed molded product) of the present invention include an injection molding method, an extrusion molding method, a rotational molding method, a vacuum molding method, a foam molding method, and a blow molding method.

The foam-molded article is obtained by adding a foaming agent to the polypropylene resin composition of the present invention and molding. As a foaming agent used by this invention, well-known foaming agents, such as a chemical foaming agent and a physical foaming agent, are mentioned.
Specific examples of the method for foam molding the polypropylene resin composition of the present invention include known methods such as an injection foam molding method, a press foam molding method, an extrusion foam molding method, and a stampable foam molding method.

  The foamed molded product of the present invention can be made into a decorative foamed molded product by bonding a skin material by a method such as insert molding or adhesion.

A known skin material can be used as the skin material. Specific examples of the skin material include a woven fabric, a non-woven fabric, a knitted fabric, a film or a sheet made of a thermoplastic resin or a thermoplastic elastomer. Further, a composite skin material in which sheets of polyurethane, rubber, thermoplastic elastomer or the like are laminated on these skin materials may be used.
A cushion layer can be further provided on the skin material. Examples of the material constituting the cushion layer include polyurethane foam, EVA foam, polypropylene foam, and polyethylene foam.

  Examples of the use of the molded article of the present invention include automobile interior parts or exterior parts, motorcycle parts, furniture and electrical product parts.

  Examples of automobile interior parts include instrument panels, trims, door panels, side protectors, console boxes, column covers, and the like. Examples of automobile exterior parts include bumpers, fenders, wheel covers, and the like. Examples of the parts include a cowling and a muffler cover.

Hereinafter, the present invention will be described with reference to examples and comparative examples.
In Examples or Comparative Examples, the following resins and additives were used.
(1) Propylene-ethylene block copolymer (A-1)
It was produced by a solvent polymerization method using the solid catalyst component described in Example 7 of JP-A-10-212319.
MI (230 ° C., 2.16 kg load): 130 g / 10 minutes Intrinsic viscosity [η] T of the entire propylene-ethylene block copolymer: 1.4 dl / g
Intrinsic viscosity [η] P of propylene homopolymer component: 0.8 dl / g
Weight ratio of propylene-ethylene random copolymer component to the whole copolymer: 12% by weight
Intrinsic viscosity [η] EP of propylene-ethylene random copolymer component: 6.0 dl / g
Ethylene unit content of propylene-ethylene random copolymer component: 30% by weight
(2) Propylene homopolymer (A-2)
It was produced by a gas phase polymerization method using the solid catalyst component described in Example 5 of JP-A-7-216017.
MI (230 ° C., 2.16 kg load): 20 g / 10 minutes (3) Propylene homopolymer (A-3)
It was produced by a solvent polymerization method using the solid catalyst component described in Example 7 of JP-A-10-212319.
MI (230 ° C., 2.16 kg load): 300 g / 10 min (4) Propylene-ethylene block copolymer (A-4)
It was produced by a gas phase polymerization method using a solid catalyst component prepared by the following method.
MI (230 ° C., 2.16 kg load): 30 g / 10 minutes Intrinsic viscosity [η] T of the entire propylene-ethylene block copolymer: 1.4 dl / g
Intrinsic viscosity [η] P of propylene homopolymer component: 1.06 dl / g
Weight ratio of propylene-ethylene random copolymer component to the whole copolymer: 20.5% by weight
Intrinsic viscosity [η] EP of propylene-ethylene random copolymer component: 2.8 dl / g
Ethylene unit content of propylene-ethylene random copolymer component: 37% by weight
The solid catalyst component used for the production of the copolymer (A-4) was prepared by the following method.
(1) Synthesis of solid component (a) 800 L of hexane, 6.8 kg of diisobutyl phthalate, 350 kg of tetraethoxysilane and 38.8 kg of tetrabutoxytitanium were charged into a reactor equipped with a nitrogen-substituted stirrer and stirred. Here, 900 L of a dibutyl ether solution (concentration 2.1 mol / l) of butyl magnesium chloride was added dropwise over 5 hours while keeping the temperature in the reactor at 7 ° C. After completion of the dropwise addition, the mixture was stirred at 20 ° C. for 1 hour and then filtered, and the obtained solid was repeatedly washed with 1100 L of toluene three times. The washed solid was added to toluene and dispersed to obtain 625 L of slurry. The resulting slurry was heated with stirring at 70 ° C. for 1 hour and then cooled to room temperature.
A part of the slurry was filtered, and the resulting solid component was dried under reduced pressure. The composition analysis of the obtained solid component revealed that the solid component contained 2.1% by weight of titanium atoms, 38.9% by weight of ethoxy groups, and 3.4% by weight of butoxy groups. Moreover, the valence of the titanium atom in this solid component was trivalent.

(2) Synthesis of solid catalyst component (activation 1)
After a 100 ml flask equipped with a stirrer, a dropping funnel and a thermometer was replaced with nitrogen, a slurry containing 8 g of the dry solid component obtained in (1) above was added, left to stand, and concentrated with the supernatant. Divided into slurry. The supernatant liquid was extracted so that the total volume of the remaining portion was 26.5 ml. A mixture of titanium tetrachloride (16.0 ml) and dibutyl ether (0.8 ml) was added at 40 ° C., and a mixture of 2.0 ml of phthalic acid chloride (hereinafter abbreviated as OPC) and 2.0 ml of toluene over 5 minutes. It was dripped. After completion of the dropwise addition, the reaction mixture was stirred at 115 ° C. for 4 hours. Thereafter, solid-liquid separation was performed at the same temperature, and the obtained solid was washed three times at 115 ° C. with 40 ml of toluene.

(Activation 2)
After washing, toluene was added to the obtained solid to obtain 26.5 ml of slurry. To this slurry, a mixture of 0.8 ml of dibutyl ether, 0.45 ml of diisobutyl phthalate and 6.4 ml of titanium tetrachloride was added and stirred at 105 ° C. for 1 hour. Thereafter, solid-liquid separation was performed at the same temperature, and the obtained solid was washed twice at 40 ° C. with 40 ml of toluene.

(Activation 3)
Next, toluene was added to the obtained solid to obtain 26.5 ml of slurry, which was further heated to 105 ° C. Thereto was added a mixture of 0.8 ml of dibutyl ether and 6.4 ml of titanium tetrachloride, and the mixture was stirred at 105 ° C. for 1 hour. Thereafter, solid-liquid separation was performed at the same temperature, and the obtained solid was washed twice at 40 ° C. with 40 ml of toluene.

(Activation 4)
Furthermore, toluene was added to the obtained solid to obtain 26.5 ml of a slurry, which was further heated to 105 ° C. Thereto was added a mixture of 0.8 ml of dibutyl ether and 6.4 ml of titanium tetrachloride, and the mixture was stirred at 105 ° C. for 1 hour. Thereafter, solid-liquid separation was performed at the same temperature, and the obtained solid was washed 6 times with 40 ml of toluene and 3 times with 40 ml of hexane at room temperature. This was dried under reduced pressure to obtain a solid catalyst component.
The solid catalyst component contained 1.6% by weight of titanium atoms, 7.6% by weight of diethyl phthalate, 0.8% by weight of ethyl normal butyl phthalate, and 2.5% by weight of diisobutyl phthalate.

(5) Propylene homopolymer (A-5)
Product name: FS2011DG3 manufactured by Sumitomo Chemical Co., Ltd.
MI (230 ° C., 2.16 kg load): 2.5 g / 10 min (6) Propylene-ethylene block copolymer (A-6)
It was produced by a solvent polymerization method using the solid catalyst component described in Example 5 of JP-A-7-216017.
MI (230 ° C., 2.16 kg load): 30 g / 10 minutes Intrinsic viscosity [η] T of the entire propylene-ethylene block copolymer: 1.5 dl / g
Intrinsic viscosity [η] P of propylene homopolymer component: 1.05 dl / g
Weight ratio of propylene-ethylene random copolymer component to the whole copolymer: 16% by weight
Intrinsic viscosity [η] EP of propylene-ethylene random copolymer component: 4.0 dl / g
Ethylene content of propylene-ethylene random copolymer component: 45% by weight

(7) Propylene-ethylene-1-butene copolymer (B)
(7-1) Production of propylene-1-butene copolymer (B-1) From the lower part of a 100 L-SUS polymerizer equipped with a stirrer, to which a jacket for circulating cooling water was attached, was used as a polymerization solvent. In Example 25 of JP-A-9-87313, hexane was used as a polymerization catalyst component at a rate of 100 L / hour, propylene at a rate of 24.00 Kg / hour, and 1-butene at a rate of 1.81 Kg / hour. Dimethylsilyl (tetramethylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride as described in Triphenylmethyltetrakis (pentafluorophenyl) borate at a rate of 0.005 g / hr The molecular weight at a rate of 0.298 g / hr and triisobutylaluminum at a rate of 2.315 g / hr. Hydrogen as an agent was continuously fed and copolymerized continuously at 45 ° C.

  After the polymerization reaction is stopped by adding a small amount of ethanol to the reaction mixture continuously withdrawn from the upper part of the polymerization vessel so that the reaction mixture in the polymerization vessel maintains an amount of 100 L, depolymerization and By washing with water and then removing the solvent with steam in a large amount of water, a propylene-1-butene copolymer (B-1) was obtained, which was dried under reduced pressure at 80 ° C. overnight. The production rate of the copolymer was 7.10 kg / hour. The structure of the obtained copolymer (B-1) is shown in Table 1.

(8) Amorphous olefin polymer masterbatch (B ′)
T3522 manufactured by Sumitomo Chemical Co., Ltd.
Amorphous olefin polymer masterbatch comprising 70 wt% of the amorphous olefin polymer (B-1) obtained above and 30 wt% of the propylene homopolymer (A-5) (MI is 2.6 g / 10 min).

(9) Elastomer (C)
(C-1) Ethylene-butene copolymer rubber Product name: CX5505 (manufactured by Sumitomo Chemical Co., Ltd.)
Density: 0.875 g / cm ³
MI (190 ° C., 2.16 kg load): 14 g / 10 minutes (C-2) ethylene-butene copolymer rubber Product name: GA801 (manufactured by Sumitomo Chemical Co., Ltd.)
Density: 0.920 g / cm ³
MI (190 ° C., 2.16 kg load): 20 g / 10 min (C-3) ethylene-butene copolymer rubber Product name: A6050 (manufactured by Mitsui Chemicals, Inc.)
Density: 0.863 g / cm ³
MI (190 ° C., 2.16 kg load): 6 g / 10 min

(10) Organic peroxide (D)
Product name: Parka Dox 14 manufactured by Kayaku Akzo

(11) Talc (E)
Product name: JR-46 (particle size = 2.7 μm) manufactured by Hayashi Kasei Co., Ltd.

(12) Talc master batch (E ')
Product name: MF110 (propylene-ethylene block copolymer (manufactured by Sumitomo Chemical Co., Ltd.)
A-6) talc masterbatch containing talc (E) and talc content of 70% by weight)

[Examples 1-6, Comparative Examples 1-8]
Each component shown in Table 1 was weighed in a predetermined amount, uniformly premixed with a tumbler, and then extruded at 200 ° C. using a twin-screw kneading extruder (TEX44SS 30BW-2V type manufactured by Nippon Steel Works). Propylene-based polymer fat composition pellets were produced by kneading and extruding in an amount of 30 to 50 kg / hr, screw rotation speed of 300 rpm and vent suction.
Using this pellet, injection foam molding was performed using an ES2550 / 400HL-MuCell (clamping force 400 ton) injection molding machine manufactured by Engel.
As a mold, the dimensions of the molded body are approximately 1.90 mm × 370 mm, the height is 45 mm, and the basic cavity clearance (initial plate thickness) is 1.5 mm when the mold is clamped. A box shape having a 6 mm portion (gate structure: direct gate) was used.
The cylinder temperature was set to 250 ° C. and the mold temperature was set to 50 ° C. After the mold was clamped, injection of the composition containing a foaming agent was started. After the composition was completely injected and filled into the mold cavity, the cavity wall surface of the mold was retreated by 2.0 mm to increase the cavity to foam the composition. The foamed composition was further cooled and solidified completely to obtain a foamed molded product. The foamed molded product was evaluated at a site 100 mm from the gate. The results are shown in Tables 2 and 3.

The measuring method of the physical property of the resin component and composition used by the Example and the comparative example was shown below.
(1) Melt index (MI, unit: g / 10 minutes)
It measured according to the method prescribed | regulated to JIS-K-6758.
The measurement was performed at 230 ° C. and a 2.16 kg load.

(2) Structural analysis of propylene-ethylene block copolymer (2-1) Intrinsic viscosity of propylene-ethylene block copolymer (2-1-a) Intrinsic viscosity of propylene homopolymer component: [η] _P
Intrinsic viscosity of the propylene homopolymer component of the propylene-ethylene block copolymer: [η] _P is the propylene homopolymer taken out from the polymerization tank after polymerization of the propylene homopolymer at the time of production. The [η] _{P of the} coalescence was determined by measurement.

(2-1-b) Intrinsic viscosity of propylene-ethylene random copolymer component: [η] _EP
The intrinsic viscosity of the propylene-ethylene random copolymer component of the propylene-ethylene block copolymer: [η] _EP is the intrinsic viscosity of the propylene homopolymer component: [η] _P and the intrinsic viscosity of the entire propylene-ethylene block copolymer. Viscosity: [η] _T was measured, and the weight ratio: X of the propylene-ethylene random copolymer component to the entire propylene-ethylene block copolymer was calculated from the following formula using X.
[η] _EP = [η] _T / X− (1 / X−1) [η] _P
[η] _P : intrinsic viscosity of propylene homopolymer component (dl / g)
[η] _T : intrinsic viscosity of the entire propylene-ethylene block copolymer (dl / g)

(2-1-c) Proportion of propylene-ethylene random copolymer component to the entire propylene-ethylene block copolymer: X
Weight ratio of propylene-ethylene random copolymer component to the entire propylene-ethylene block copolymer: X measures the heat of fusion of the propylene homopolymer component and the entire propylene-ethylene block copolymer. Obtained by calculation. The heat of fusion was measured by differential scanning thermal analysis (DSC).
X = 1− (ΔHf) _T / (ΔHf) _P
(ΔHf) _T : heat of fusion of the entire block copolymer (cal / g)
(ΔHf) P: heat of fusion of propylene homopolymer component (cal / g)

(3) Ethylene content of propylene-ethylene random copolymer component in propylene-ethylene block copolymer: (C2 ′) _EP
Ethylene content of propylene-ethylene random copolymer component of propylene-ethylene block copolymer: (C2 ') _EP measures the ethylene content (C2') _T of the entire propylene-ethylene block copolymer by infrared absorption spectroscopy. And obtained by calculation using the following equation.
(C2 ') _EP = (C2') _T / X
(C2 ′) _T : ethylene content of propylene-ethylene block copolymer as a whole (% by weight) (C2 ′) _EP : ethylene content of propylene-ethylene random copolymer component (% by weight) X: propylene-ethylene random copolymer Weight ratio of the combined component to the entire propylene-ethylene block copolymer

(4) Heat of fusion of copolymer (B) Measurement was performed under the following conditions using a differential scanning calorimeter (DSC RDC220 manufactured by Seiko Denshi Kogyo Co., Ltd.).
(I) About 5 mg of the sample was heated from room temperature to 200 ° C. at a rate of temperature increase of 30 ° C./min, and held for 5 minutes after completion of the temperature increase.
(Ii) Next, the temperature was decreased from 200 ° C. to −100 ° C. at a temperature decreasing rate of 10 ° C./min.
(Iii) After completion of the temperature decrease, the temperature was maintained for 5 minutes, and then the temperature was increased from −100 ° C. to 200 ° C. at a temperature increase rate of 10 ° C./min.
The peak observed in (iv) is the melting peak, and the heat of fusion was calculated from the peak area.

(5) Molecular weight distribution of copolymer (B) Using a gel permeation chromatograph (GPC) method, measurement was performed under the following conditions.
From the obtained results, a weight average molecular weight (Mw) and a number average molecular weight (Mn) were calculated, and a molecular weight distribution (Mw / Mn) was calculated.
Equipment: 150C ALC / GPC manufactured by Waters
Column: Showa Denko Corporation Shodex Packed Column A-80M 2 temperature: 140 ° C
Solvent: o-dichlorobenzene Elution solvent flow rate: 1.0 ml / min
Sample concentration: 1 mg / ml
Measurement injection volume: 400 μl
Molecular weight reference material: Standard polystyrene Detector: Differential refraction

(6) Fluidity The resin composition was molded at a resin temperature of 260 ° C. using a resin flow length measuring mold having a spiral flow path having a thickness of 2 mm, a width of 10 mm, and a length of 2000 mm. The flow length (mm) of the obtained molded product was measured, and the length was defined as the flow length.

(7) Appearance Evaluation of Foam Molded Body (7-1) Silver Streak A circle with a diameter of 60 mm shown in FIG. 1 at a site 100 mm away from the gate portion of the foamed molded resin composition obtained by foam molding. The range was evaluated visually and judged as shown below.
○: Silver streaks on the surface of the foamed molded product cannot be visually confirmed. Δ: Silver streaks are slightly noticeable. X: Silver streaks are conspicuous. (7-2) Corrugation (one type of silver streak of the appearance of the molded product)
The range within 100 mm from the gate portion of the foamed molded product of the propylene polymer composition obtained by foam molding was visually evaluated and judged as shown below.
○: Corrugation on the surface of the foamed molded product is hardly noticeable △: Corrugation is slightly noticeable ×: Corrugation is very noticeable

The perspective view of the foaming molding of the polypropylene resin composition produced in Example 1. FIG.

Explanation of symbols

1: Gate contact portion 2: Site where silver streak was evaluated

Claims (4)

Resin composition comprising the following component (A) 50 to 90% by weight, component (B) 5 to 20% by weight, and component (C) 5 to 30% by weight (however, component (A) and component (B) ) And 100% by weight of component (C) and a polypropylene resin composition obtained by heat-treating 0.005 to 10 parts by weight of organic peroxide (D).
Component (A): At least one propylene polymer component (B) selected from the group consisting of propylene homopolymer (A-1) and propylene-ethylene copolymer (A-2): carbon number of α-olefin Propylene having a molecular weight distribution of 1 to 4, an intrinsic viscosity of 0.5 to 10 dl / g, a heat of fusion of 30 J / g or less, and an ethylene content of 60 mol% or less. Ethylene-α-olefin copolymer component (C): α-olefin has 4 to 20 carbon atoms, a density of 0.85 to 0.89 g / cm ³ , and a heat of fusion of 30 J / g or less. Ethylene-α-olefin copolymer   The polypropylene according to claim 1, wherein 0.1 to 60 parts by weight of (E) inorganic filler is further blended with 100 parts by weight of the resin composition comprising the component (A), the component (B) and the component (C). -Based resin composition.   The organic peroxide (D) is an organic peroxide having a decomposition temperature of less than 120 ° C. with a half-life of 1 minute and / or an organic peroxide having a decomposition temperature of 120 ° C. or more with a half-life of 1 minute. The polypropylene resin composition according to claim 1 or 2, which is a product.   A foamed molded article obtained by foaming the polypropylene resin composition according to any one of claims 1 to 3.

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