JP6079346B2 - Propylene resin composition production method and molded article comprising the propylene resin composition - Google Patents

Description

  The present invention relates to a method for producing a propylene resin composition, a propylene resin composition produced by the production method, and a molded article comprising the propylene resin composition. More specifically, in the case of forming a molded body, a method for producing a propylene-based resin composition capable of obtaining a molded body having an excellent balance between rigidity and impact resistance at low temperature, and further having excellent elongation at break. The present invention relates to a propylene resin composition to be produced and a molded body comprising the propylene resin composition.

  Propylene resin is used for molding materials for various industrial parts such as automobile interior and exterior parts such as bumpers, instrument panels and garnishes, and home appliance parts such as TV cases.

  For example, Patent Document 1 discloses a propylene / ethylene block copolymer having a specific melt flow rate (MFR), a propylene homopolymer having a specific weight average molecular weight, a rubber having a specific MFR, and a specific A polypropylene resin composition is described which is composed of talc having an average particle diameter and is used for automobile exterior parts such as bumpers.

  Patent Document 2 discloses a composition comprising a polypropylene resin, a copolymer containing a portion composed of ethylene and an alpha olefin, and talc, wherein the MFR of the entire composition is in a specific range, and A resin composition that has a dispersion parameter of talc in a resin component in a specific range and is used as an exterior material for home appliances, office equipment and the like is described.

JP 2000-109639 A JP 2003-73508 A

However, the molded body made of the resin composition described in the above-mentioned patent documents has not yet been satisfactory with respect to the balance between rigidity and impact resistance at low temperature, and further about elongation at break.
Under such circumstances, the object of the present invention is to provide a propylene-based resin composition that, when formed into a molded body, can provide a molded body that is excellent in the balance between rigidity and impact resistance at low temperature, and further excellent in elongation at break. It is providing the manufacturing method of a thing, the propylene resin composition manufactured by this manufacturing method, and the molded object which consists of this propylene resin composition.

As a result of intensive studies, the present inventors have found that the present invention can solve the above problems, and have completed the present invention.
That is, the present invention
50 to 95% by mass of the following propylene resin (A),
The following propylene resin (B1) 0.05 to 25% by mass;
2.5 mass% to 49.5 mass% of the following propylene resin (B2) (however, the total amount of each mass of the propylene resin (A), the propylene resin (B1), and the propylene resin (B2) is 100 mass%) A propylene resin composition comprising
To a method for producing a propylene resin composition, which is produced by melt-kneading a multilayer pellet (B) composed of a sheath layer which is a propylene resin (B1) and a core layer which is a propylene resin (B2) and a propylene resin (A) It is related.
Propylene resin (A): The melt flow rate measured at 230 ° C. under a load of 2.16 kgf is 0.1 to 200 g / 10 min, and the intrinsic viscosity ([η] ^A _P ) measured in 135 ° C. tetralin is Propylene resin having a molecular weight distribution (Mw / Mn) of 3.0 or more and 0.8 to 7.0 dl / g.
Propylene resin (B1): Load 2.16 kgf, melt flow rate measured at 230 ° C. is 80 to 200 g / 10 min, and intrinsic viscosity ([η] ^B1 _P ) measured in 135 ° C. tetralin is 0. A propylene resin having a molecular weight distribution (Mw / Mn) of 3.0 or more and a content of a structural unit derived from propylene of 90% by mass or more of 8 to 1.2 dl / g.
Propylene resin (B2): obtained by melt-kneading propylene resin (a) having a load of 2.16 kgf and a melt flow rate of 0.1 to 100 g / 10 min measured at 230 ° C. and an organic peroxide (b) A propylene resin (B2),
The melt flow rate measured at a load of 2.16 kgf and 230 ° C. is 300 g / 10 min or more, and the intrinsic viscosity ([η] ^B2 _P ) measured in tetralin at 135 ° C. is 0.5 dl / g or more. A propylene resin having a molecular weight distribution (Mw / Mn) of less than 3.0 and a content of structural units derived from propylene of 90% by mass or more, less than 0 dl / g.

The present invention also provides:
The present invention relates to a propylene resin composition produced by the above-described method for producing a propylene resin composition, and a molded body comprising the propylene resin composition.

  According to the present invention, it is possible to produce a propylene-based resin composition that, when formed into a molded body, can provide a molded body that has an excellent balance between rigidity and impact resistance at low temperatures and that is excellent in elongation at break. A propylene resin composition produced by the production method and a molded body comprising the propylene resin composition can be obtained.

  The method for producing a propylene resin composition of the present invention comprises melt-kneading a multilayer pellet (B) composed of a sheath layer that is a propylene resin (B1) and a core layer that is a propylene resin (B2), and the propylene resin (A). To produce a propylene resin composition.

[Propylene resin composition]
As the propylene resin (A) used in the production method of the present invention,
Propylene homopolymer,
Random copolymers of propylene and other olefin monomers, or
A propylene polymerized material comprising a propylene polymer component and a copolymer component of propylene and another olefin and obtained by multistage polymerization is used. These may be used alone or in combination of two or more.

The same propylene resin as the propylene resin (A) is used as the propylene resin (B1) used for the sheath layer of the multilayer pellet (B) used in the production method of the present invention.
Specifically, a propylene homopolymer,
Random copolymers of propylene and other olefin monomers, or
A propylene polymerized material comprising a propylene polymer component and a copolymer component of propylene and another olefin and obtained by multistage polymerization is used. These may be used alone or in combination of two or more.

The propylene resin (B2) used for the core layer of the multilayer pellet (B) used in the production method of the present invention is a propylene resin obtained by melt-kneading the propylene resin (a) and the organic peroxide (b). And as said propylene resin (a), the propylene resin similar to the said propylene resin (A) or the said propylene resin (B1) is used.
Specifically, a propylene homopolymer,
Random copolymers of propylene and other olefin monomers, or
A propylene polymerized material comprising a propylene polymer component and a copolymer component of propylene and another olefin and obtained by multistage polymerization is used. These may be used alone or in combination of two or more.

[Propylene resin (A), propylene resin (B1), propylene resin (a)]
<Homopolymer>
The propylene homopolymer used as the propylene resin (A), the propylene resin (B1), or the propylene resin (a) is mainly composed of a polymer composed only of structural units derived from propylene, or a structural unit derived from propylene. Examples of such a polymer are structural units. In addition, having a structural unit derived from propylene as a main structural unit means that the content of the structural unit derived from propylene is at least 98% by mass or more with respect to 100% by mass of the total amount of the polymer. is there.

Random copolymers of propylene and other olefin monomers used as the propylene resin (A), propylene resin (B1), or propylene resin (a) are:
A propylene-ethylene random copolymer comprising a structural unit derived from propylene and a structural unit derived from ethylene,
A propylene-α-olefin random copolymer comprising a structural unit derived from propylene and a structural unit derived from an α-olefin having 4 or more carbon atoms, or
A propylene-ethylene-α-olefin random copolymer comprising a structural unit derived from propylene, a structural unit derived from ethylene, and a structural unit derived from an α-olefin having 4 or more carbon atoms.

The propylene polymer material used for the propylene resin (A), the propylene resin (B1), or the propylene resin (a) is:
Manufactured by multi-stage polymerization,
A propylene homopolymer component or a polymer component having a structural unit derived from propylene as a main structural unit, a structural unit derived from at least one olefin monomer selected from ethylene and an α-olefin having 4 or more carbon atoms, and propylene Is a propylene polymerized material comprising a copolymer component having a structural unit derived from.

As a manufacturing method of propylene resin (A), propylene resin (B1), or propylene resin (a), the manufacturing method which superposes | polymerizes an olefin monomer using a polymerization catalyst is mentioned.
Examples of the polymerization catalyst include a Ziegler type catalyst system, a Ziegler-Natta type catalyst system, a catalyst system comprising a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring and an alkylaluminoxane, or a cyclopentadienyl ring. Periodic table having a cyclopentadienyl ring in inorganic particles such as silica, clay minerals, catalyst systems composed of compounds and organoaluminum compounds that react with group 4 transition metal compounds and ionic complexes. Examples include a catalyst system in which a catalyst component such as a Group 4 transition metal compound, a compound that forms an ionic complex, and an organoaluminum compound is supported and modified, and in the presence of the above catalyst system, ethylene and propylene. Alternatively, a prepolymerization catalyst prepared by prepolymerizing an α-olefin having 4 or more carbon atoms may be used.
Examples of the catalyst system include JP-A-61-218606, JP-A-5-194485, JP-A-7-216071, JP-A-9-316147, JP-A-10-212319, Examples thereof include a catalyst system described in JP-A-2004-182981.

  Examples of the polymerization method include bulk polymerization, solution polymerization, slurry polymerization, and gas phase polymerization. Here, the bulk polymerization is a method of performing polymerization using a liquid olefin as a medium at the polymerization temperature, and the solution polymerization or slurry polymerization is an inert hydrocarbon such as propane, butane, isobutane, pentane, hexane, heptane, octane, etc. In this method, polymerization is performed in a solvent. Gas phase polymerization is a method in which a gaseous monomer is used as a medium, and the gaseous monomer is polymerized in the medium.

The polymerization method may be either batch (batch) or continuous. Moreover, either a single stage type using a single polymerization reaction tank or a multistage type in which a plurality of polymerization reaction tanks are connected in series may be used. Since it is economical, a continuous gas phase polymerization method or a bulk-gas phase polymerization method in which a bulk polymerization method and a gas phase polymerization method are continuously performed is preferable.
Various polymerization conditions (polymerization temperature, polymerization pressure, monomer concentration, catalyst input amount, polymerization time, etc.) depend on the target propylene resin (A), propylene resin (B1), or propylene resin (a). And may be determined as appropriate.

  In the production of the propylene resin (A), the propylene resin (B1), or the propylene resin (a), it is necessary to remove the residual solvent contained in the resin, the low molecular weight oligomer by-produced during the production, and the like. Accordingly, the resin may be dried at a temperature equal to or lower than the temperature at which the resin melts. Examples of the drying method include the methods described in JP-A Nos. 55-75410 and 2556553.

<Random copolymer>
As described above, the random copolymer of propylene and other olefin monomers used as the propylene resin (A), the propylene resin (B1), or the propylene resin (a),
A propylene-ethylene random copolymer comprising a structural unit derived from propylene and a structural unit derived from ethylene,
A propylene-α-olefin random copolymer comprising a structural unit derived from propylene and a structural unit derived from an α-olefin having 4 or more carbon atoms, or
A propylene-ethylene-α-olefin random copolymer comprising a structural unit derived from propylene, a structural unit derived from ethylene, and a structural unit derived from an α-olefin having 4 or more carbon atoms.

  Examples of the α-olefin having 4 or more carbon atoms used in the random copolymer include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene. 1-butene, 1-hexene and 1-octene are preferable.

As a propylene-α-olefin random copolymer comprising a structural unit derived from propylene and a structural unit derived from an α-olefin having 4 or more carbon atoms,
Examples thereof include a propylene-1-butene random copolymer, a propylene-1-hexene random copolymer, a propylene-1-octene random copolymer, and a propylene-1-decene random copolymer.

  As a propylene-ethylene-α-olefin random copolymer comprising a structural unit derived from propylene, a structural unit derived from ethylene, and a structural unit derived from an α-olefin having 4 or more carbon atoms, for example, propylene-ethylene- Examples include 1-butene random copolymer, propylene-ethylene-1-hexene random copolymer, propylene-ethylene-1-octene random copolymer, propylene-ethylene-1-decene random copolymer, and the like.

The content of the structural unit derived from ethylene contained in the propylene-ethylene random copolymer is preferably 0.1 to 40% by mass, more preferably 0.1 to 30% by mass, and still more preferably 2 ~ 15% by weight,
Content of the structural unit derived from propylene becomes like this. Preferably it is 99.9-60 mass%, More preferably, it is 99.9-70 mass%, More preferably, it is 98-85 mass%.
In addition, when using this propylene-ethylene random copolymer as a propylene resin (B1), content of the structural unit derived from propylene is as below-mentioned.

The content of the structural unit derived from the α-olefin contained in the propylene-α-olefin random copolymer is preferably 0.1 to 40% by mass, more preferably 0.1 to 30% by mass, More preferably, it is 2 to 15% by mass,
Content of the structural unit derived from propylene becomes like this. Preferably it is 99.9-60 mass%, More preferably, it is 99.9-70 mass%, More preferably, it is 98-85 mass%.
In addition, when using this propylene-ethylene random copolymer as a propylene resin (B1), content of the structural unit derived from propylene is as below-mentioned.

A structural unit derived from ethylene contained in a propylene-ethylene-α-olefin random copolymer comprising a structural unit derived from propylene, a structural unit derived from ethylene, and a structural unit derived from an α-olefin having 4 or more carbon atoms The total amount of the content of the structural unit derived from the α-olefin is preferably 0.1 to 40% by mass, more preferably 0.1 to 30% by mass, and even more preferably 2 to 2% by mass. 15% by weight,
Content of the structural unit derived from propylene becomes like this. Preferably it is 99.9-60 mass%, More preferably, it is 99.9-70 mass%, More preferably, it is 98-85 mass%.
In addition, when using this propylene-ethylene random copolymer as a propylene resin (B1), content of the structural unit derived from propylene is as below-mentioned.

<Propylene polymerized material>
Propylene polymer (A), propylene resin (B1), or propylene polymerized material of propylene and other olefin monomers used as propylene resin (a) is produced by multistage polymerization as described above.
At least selected from a propylene homopolymer component or a polymer component having a structural unit derived from propylene as a main structural unit (hereinafter referred to as polymer component (I)), ethylene and an α-olefin having 4 or more carbon atoms. A propylene copolymer material comprising a copolymer component (hereinafter referred to as polymer component (II)) having a structural unit derived from one olefin monomer and a structural unit derived from propylene.

When the polymer component (I) is a polymer component having a structural unit derived from propylene as a main structural unit, the structural component is derived from propylene, ethylene, and an α-olefin having 4 to 10 carbon atoms. A polymer component having a structural unit derived from at least one olefin monomer selected from the group, wherein the content of the structural unit derived from the olefin monomer is 0.01% by mass or more and less than 20% by mass (However, the mass of the polymer component (I) is 100% by mass).
The α-olefin having 4 to 10 carbon atoms is preferably 1-butene, 1-hexene or 1-octene, and more preferably 1-butene.

Examples of the polymer component having a structural unit derived from propylene as a main structural unit include, for example, a propylene-ethylene copolymer component, a propylene-1-butene copolymer component, a propylene-1-hexene copolymer component, and propylene. Examples include a -1-octene copolymer component, a propylene-ethylene-1-butene copolymer component, a propylene-ethylene-1-hexene copolymer component, and a propylene-ethylene-1-octene copolymer component.
The polymer component (I) is preferably a propylene homopolymer component, a propylene-ethylene copolymer component, a propylene-1-butene copolymer component, or a propylene-ethylene-1-butene copolymer component.

  The polymer component (II) is a copolymer component having a structural unit derived from at least one olefin monomer selected from ethylene and an α-olefin having 4 or more carbon atoms and a structural unit derived from propylene.

  When the polymer component (II) is a copolymer component having a structural unit derived from ethylene and a structural unit derived from propylene, the content of the structural unit derived from ethylene is 20 to 80% by mass. The content is preferably 20 to 60% by mass, more preferably 30 to 60% by mass (provided that the mass of the polymer component (II) is 100% by mass).

  When the polymer component (II) is a copolymer component having a structural unit derived from at least one olefin monomer selected from α-olefins having 4 or more carbon atoms and a structural unit derived from propylene, the number of carbon atoms Content of the structural unit derived from the at least 1 sort (s) of olefin monomer chosen from 4 or more alpha olefins is 20-80 mass%, Preferably it is 20-60 mass%, More preferably, it is 30-60 mass%. (However, the mass of the polymer component (II) is 100% by mass).

  A copolymer in which the polymer component (II) has a structural unit derived from ethylene, a structural unit derived from at least one olefin monomer selected from α-olefins having 4 or more carbon atoms, and a structural unit derived from propylene. When it is a component, the total content of the content of structural units derived from ethylene and the content of structural units derived from at least one olefin monomer selected from α-olefins having 4 or more carbon atoms is 20 to 80% by mass. It is preferably 20 to 60% by mass, more preferably 30 to 60% by mass (provided that the mass of the polymer component (II) is 100% by mass).

  Examples of the α-olefin having 4 to 10 carbon atoms constituting the polymer component (II) include the same α-olefin as the α-olefin having 4 to 10 carbon atoms constituting the polymer component (I). Is mentioned.

  Examples of the polymer component (II) include a propylene-ethylene copolymer component, a propylene-ethylene-1-butene copolymer component, a propylene-ethylene-1-hexene copolymer component, and propylene-ethylene-1-octene. Copolymer component, propylene-ethylene-1-decene copolymer component, propylene-1-butene copolymer component, propylene-1-hexene copolymer component, propylene-1-octene copolymer component, propylene-1 -Decene copolymer component, etc., preferably propylene-ethylene copolymer component, propylene-1-butene copolymer component, propylene-ethylene-1-butene copolymer component, more preferably propylene- It is an ethylene copolymer component.

  The content of the polymer component (II) in the propylene polymerized material composed of the polymer component (I) and the polymer component (II) is preferably 1 to 50% by mass, more preferably 1 to 40% by mass. Preferably, it is more preferably 10 to 40% by mass, and still more preferably 10 to 30% by mass (provided that the total mass of the propylene polymerized material is 100% by mass).

  When the polymer component (I) of the propylene polymer material composed of the polymer component (I) and the polymer component (II) is a propylene homopolymer component, examples of the propylene polymer material include (propylene)-(propylene- (Ethylene) copolymer material, (propylene)-(propylene-ethylene-1-butene) copolymer material, (propylene)-(propylene-ethylene-1-hexene) copolymer material, (propylene)-(propylene-ethylene-1) -Octene) copolymer material, (propylene)-(propylene-1-butene) copolymer material, (propylene)-(propylene-1-hexene) copolymer material, (propylene)-(propylene-1-octene) copolymer Materials, (propylene)-(propylene-1-decene) copolymer materials, and the like.

  In the case where the polymer component (I) of the propylene polymer material composed of the polymer component (I) and the polymer component (II) is a polymer component having a structural unit derived from propylene as a main structural unit, the polymer component Examples of the propylene polymerization material comprising (I) and the polymer component (II) include (propylene-ethylene)-(propylene-ethylene) copolymer material, (propylene-ethylene)-(propylene-ethylene-1-butene). Copolymer material, (propylene-ethylene)-(propylene-ethylene-1-hexene) copolymer material, (propylene-ethylene)-(propylene-ethylene-1-octene) copolymer material, (propylene-ethylene)-(propylene) -Ethylene-1-decene) copolymer material, (propylene-ethylene)-(propylene-1-butene) copolymer material, (pro Len-ethylene)-(propylene-1-hexene) copolymer material, (propylene-ethylene)-(propylene-1-octene) copolymer material, (propylene-ethylene)-(propylene-1-decene) copolymer material, (Propylene-1-butene)-(propylene-ethylene) copolymer material, (propylene-1-butene)-(propylene-ethylene-1-butene) copolymer material, (propylene-1-butene)-(propylene-ethylene) -1-hexene) copolymer material, (propylene-1-butene)-(propylene-ethylene-1-octene) copolymer material, (propylene-1-butene)-(propylene-ethylene-1-decene) copolymer material , (Propylene-1-butene)-(propylene-1-butene) copolymer material, (propylene-1-butene)-(propylene) -1-hexene) copolymer material, (propylene-1-butene)-(propylene-1-octene) copolymer material, (propylene-1-butene)-(propylene-1-decene) copolymer material, (propylene- 1-hexene)-(propylene-1-hexene) copolymer material, (propylene-1-hexene)-(propylene-1-octene) copolymer material, (propylene-1-hexene)-(propylene-1-decene) Examples include copolymers, (propylene-1-octene)-(propylene-1-octene) copolymer materials, (propylene-1-octene)-(propylene-1-decene) copolymer materials, and the like.

  The propylene polymerized material comprising polymer component (I) and polymer component (II) is preferably a (propylene)-(propylene-ethylene) copolymer material or (propylene)-(propylene-ethylene-1-butene) copolymer. Polymerized material, (propylene-ethylene)-(propylene-ethylene) copolymerized material, (propylene-ethylene)-(propylene-ethylene-1-butene) copolymerized material, (propylene-1-butene)-(propylene-1- Butene) copolymer material, more preferably (propylene)-(propylene-ethylene) copolymer material.

The intrinsic viscosity ([η] _I ) measured in 135 ° C. tetralin of the polymer component (I) is 0.1 to 5 dl / g, preferably 0.3 to 4 dl / g, more preferably 0.5-3 dl / g.

The intrinsic viscosity ([η] _II ) measured in 135 ° C. tetralin of the polymer component (II) is 1 to 20 dl / g, preferably 1 to 10 dl / g, more preferably 2 to 7 dl / g. It is.

The ratio of the intrinsic viscosity ([η] _II ) of the polymer component (II) to the intrinsic viscosity ([η] _I ) of the polymer component ( _I ) is preferably 1 to 20, more preferably 2 to 2. 10, more preferably 2-9.

The intrinsic viscosity (unit: dl / g) in the present invention is a value measured at a temperature of 135 ° C. using tetralin as a solvent by the following method.
Using a Ubbelohde viscometer, the reduced viscosity is measured at three points of concentrations of 0.1 g / dl, 0.2 g / dl and 0.5 g / dl. The intrinsic viscosity is a 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.
When the propylene resin (A), the propylene resin (B1), or the propylene resin (a) is a propylene polymer material obtained by multistage polymerization of the polymer component (I) and the polymer component (II), The intrinsic viscosity of the polymer component (I) or the polymer component (II) is determined from the polymer powder partially extracted from the polymerization tank, and the intrinsic viscosity values of the polymer component (I) and the polymer component (II) are obtained. Using the respective contents of the polymer component (I) and the polymer component (II), the intrinsic viscosity of the other polymer component is calculated.

In addition, a propylene polymerized material composed of the polymer component (I) and the polymer component (II) is obtained in which the polymer component (I) is obtained in the preceding polymerization step and the polymer component (II) is obtained in the subsequent step. In the case of a propylene polymer material produced by the method, the content of the polymer component (I) and the polymer component ( _II ), measurement of intrinsic viscosity ([η] _Total , [η] _I , [η] _II ) and The calculation procedure is as follows. The intrinsic viscosity ([η] _Total ) indicates the intrinsic viscosity of the entire propylene resin (A), propylene resin (B1), or propylene resin (a).

Intrinsic viscosity ([η] _I ) of the polymer component (I) obtained in the preceding polymerization step, intrinsic viscosity ([η] _Total ) measured by the above method of the propylene polymer material obtained after the subsequent polymerization step, propylene From the content of the polymer component (II) contained in the polymerization material, the intrinsic viscosity ([η] _II ) of the polymer component (II) is calculated from the following formula.
[Η] _II = ([η] _Total − [η] _I × XI) / XII
[Η] _Total : Intrinsic viscosity (dl / g) of the propylene-polymerized material obtained after the subsequent polymerization step
[Η] _I : Intrinsic viscosity (dl / g) of the polymer powder (polymer component (I)) extracted from the polymerization tank after the pre-stage polymerization step
XI: Mass ratio of the polymer component (I) to the total mass of the propylene polymerized material XII: Mass ratio of the polymer component (II) to the total mass of the propylene polymerized material Note that XI and XII are obtained from the mass balance at the time of polymerization.

The mass ratio (XII) of the polymer component (II) to the total mass of the propylene resin (A), propylene resin (B1), or propylene resin (a) is: propylene homopolymer component, propylene resin (A), propylene It is also possible to measure the heat of crystal fusion (of the entire resin) of each of the resin (B1) or the propylene resin (a), and obtain it by calculation using the following formula. The amount of heat of crystal melting can be measured by differential scanning thermal analysis (DSC).
XII = 1− (ΔHf) _Total / (ΔHf)
(ΔHf) _Total : heat of fusion (cal / g) of each of the propylene resin (A), propylene resin (B1), or propylene resin (a)
(ΔHf): heat of fusion of propylene homopolymer component (cal / g)

Content of structural unit derived from ethylene contained in propylene resin (A), propylene resin (B1), or polymer component (II) constituting propylene resin (a), α-olefin having 4 or more carbon atoms The content of the structural unit derived from or the total amount of these contents ((Cα ′) _II )
((Cα ′) _II ) is a structure derived from ethylene contained in each of the propylene resin (A), the propylene resin (B1), or the propylene resin (a) by the infrared absorption spectrum method. The content of the unit, the content of the structural unit derived from the α-olefin having 4 or more carbon atoms, or the total amount of these contents ((Cα ′) _Total ) is measured and obtained by calculation using the following formula.
(Cα ′) _II = (Cα ′) _Total / XII
(Cα ′) _Total : Propylene resin (A), propylene resin (B1), or the content of structural units derived from ethylene contained in each (total resin) of propylene resin (a), 4 carbon atoms Content of structural unit derived from the above α-olefin, or total amount (% by mass) of these contents
(Cα ′) _II : Content of structural unit derived from ethylene contained in polymer component (II), content of structural unit derived from α-olefin having 4 or more carbon atoms, or total of these contents Amount (mass%)

  The propylene polymerized material is obtained by producing the polymer component (I) in the first step and producing the polymer component (II) in the second step. As a manufacturing method, the manufacturing method which superposes | polymerizes an olefin monomer using the above-mentioned multistage polymerization using the above-mentioned polymerization catalyst is mentioned.

The isotactic pentad fraction (hereinafter referred to as [mmmm]) of the propylene resin (A), the propylene resin (B1), or the propylene resin (a) is determined by the tensile strength and the low temperature of the resin composition or its molded body. Is preferably 0.97 or more, and more preferably 0.98 or more from the viewpoint of improving the balance of impact resistance. In addition, as [mmmm] is closer to 1, the propylene resin (A), the propylene resin (B1), or the propylene resin (a) is a highly crystalline polymer having a molecular structure exhibiting high stereoregularity. Represents that.
Moreover, when it is a propylene resin (A), a propylene resin (B1), or a propylene resin (a), a random copolymer, or a propylene polymer material, it originates in the propylene contained in a random copolymer or a propylene polymer material The value measured for the chain of structural units is used.

<Propylene resin (A)>
The melt flow rate (hereinafter also referred to as MFR) of the propylene resin (A) used in the production method of the present invention is 0.1 to 200 g / 10 minutes, and increases the elongation at break and impact strength of the resulting molded product. In view of the above, it is preferably 0.5 to 200 g / 10 minutes, more preferably 10 to 100 g / 10 minutes, still more preferably 20 to 80 g / 10 minutes, and 30 to 50 g / 10 minutes. Even more preferably. In addition, MFR uses the value measured by load 2.16kgf and 230 degreeC according to JISK7210.

The intrinsic viscosity ([η] ^A _P ) measured in tetralin at 135 ° C. of the propylene resin (A) is 0.8 to 7.0 dl / g. From the viewpoint of fluidity of the resin composition, it is preferably 0.85 to 2.0 dl / g.

The molecular weight distribution (Mw / Mn) measured by GPC of the propylene resin (A) is 3.0 or more. From the viewpoint of the fluidity of the resin composition, it is preferably 3.5 dl / g or more.
Mw represents the weight average molecular weight of the propylene resin (A), and Mn represents the number average molecular weight of the propylene resin (A).

<Propylene resin (B1)>
The MFR of the propylene resin (B1) used for the sheath layer of the multilayer pellet (B) used in the production method of the present invention is 80 to 200 g / 10 minutes, and the viewpoint that the fluidity of the resin composition is not deteriorated or melting From the viewpoint that the tension is not lowered and the take-up property of the strand is not deteriorated, it is preferably 100 to 150 g / 10 minutes. In addition, MFR uses the value measured on the conditions similar to a propylene resin (A).

The intrinsic viscosity ([η] ^B1 _P ) measured in tetralin at 135 ° C. of the propylene resin (B1) is 0.8 to 1.2 dl / g. From the viewpoint of suppressing the decrease in toughness of the molded body and from the viewpoint of suppressing the deterioration of workability without decreasing the fluidity of the resin composition, it is preferably 0.85 to 1.1 dl / g.

  The molecular weight distribution (Mw / Mn) measured by GPC of the propylene resin (B1) is 3.0 or more. From the viewpoint of suppressing the decrease in tensile elongation at break of the molded product, it is preferably 3.2 or more, and more preferably 3.5 or more. Mw represents the weight average molecular weight of the propylene resin (B1), and Mn represents the number average molecular weight of the propylene resin (B1).

Content of the structural unit derived from the propylene contained in propylene resin (B1) is 90 mass% or more. (However, the total mass of the propylene resin (B1) is 100 mass%, and the content is measured by ¹³ C-NMR spectrum.) From the viewpoint of increasing the rigidity of the molded body, it is preferably 95 mass% or more. is there.

Propylene resin (B1) may contain the structural unit derived from the structural unit derived from ethylene other than the structural unit derived from propylene, and a C4-C20 alpha olefin. Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-hexene, 1-octene and the like.
Moreover, as a propylene resin (B1), each of a propylene homopolymer, a random copolymer, or a propylene polymerization material may be used independently, and at least 2 sort (s) may be used together. The propylene resin (B1) is preferably a propylene homopolymer.

<Propylene resin (a)>
The MFR of the propylene resin (a) used in the propylene resin (B2) constituting the core layer of the multilayer pellet (B) used in the production method of the present invention is 0.1 to 100 g / 10 min, and the molded body is broken. From the viewpoint of increasing the point elongation, it is preferably 0.2 to 10 g / 10 minutes, more preferably 0.3 to 5 g / 10 minutes, and further preferably 0.4 to 1.0 g / 10 minutes. is there. In addition, MFR uses the value measured on the conditions similar to a propylene resin (A).

[Multilayer pellet (B)]
The multilayer pellet (B) used in the production method of the present invention comprises a sheath layer made of the above-mentioned propylene resin (B1) and a core layer made of the propylene resin (B2) described later. The ratio of the mass of the sheath layer to the mass of the core layer constituting the multi-layer pellet (B) (sheath layer / core layer) is the viewpoint that the fluidity of the resin composition is not deteriorated, the melt tension is not reduced, From the viewpoint of not deteriorating the take-up property, it is preferably 50/50 to 1/99, more preferably 20/80 to 5/95, and further preferably 15/85 to 7/93.

  The MFR of the kneaded product obtained by melt-kneading the multilayer pellet (B) is preferably 300 g / 10 min or more, more preferably 350 g / 10 min or more, from the viewpoint of not deteriorating fluidity.

  In the sheath layer, the core layer, or both the sheath layer and the core layer of the multilayer pellet (B), an antioxidant, a neutralizing agent, a lubricant, an antistatic agent, a nucleating agent, and an ultraviolet ray preventing agent are optionally provided. Add additives such as flame retardants, fillers, plasticizers, foaming agents, foaming aids, dispersants, antiblocking agents, antifogging agents, antibacterial agents, crosslinking agents, crosslinking aids, organic porous powders, pigments, etc. You may do it.

  As a method for producing the multilayer pellet (B), the propylene resin (B1) constituting the sheath layer and the propylene resin (B2) constituting the core layer are respectively melted and supplied to the multilayer strand die apparatus, and the multilayer strand is obtained. The method of extruding, cooling, and cutting is mentioned.

  The method of supplying the propylene resin (B1) constituting the sheath layer or the propylene resin (B2) constituting the core layer to the multilayer strand die apparatus is different from each other in propylene resin (B1) and propylene resin (B2). A method of feeding from an extruder is preferred. Examples of the supply device include known extruders such as a feeder ruder, a cold feed extruder, and a twin screw taper extruder. The extruder may be a single screw extruder or a twin screw extruder.

The number of extruders to be used may be used according to the number of layers of the target multilayer pellet. In the case of a two-layer structure consisting of a core layer and a sheath layer, at least two extruders may be used. In the case of a three-layer structure composed of a core layer, a sheath layer, and another one layer, at least three extruders may be used.
The multilayer strand die apparatus is preferably a crosshead die, and a more preferable structure of the crosshead die is, for example, a crosshead die disclosed in detail in European Patent Publication No. EP1063070-A2.

<Propylene resin (B2)>
The propylene resin (B2) used for the core layer of the multilayer pellet (B) used in the production method of the present invention is a propylene obtained by melt-kneading the propylene resin (a) and the organic peroxide (b). Resin. The propylene resin (B2) has an MFR of 300 g / 10 min or more. From the viewpoint of the fluidity of the resin composition, it is preferably 350 g / 10 min or more. In addition, MFR uses the value measured on the conditions similar to a propylene resin (A).

The intrinsic viscosity ([η] ^B2 _P ) measured in tetralin at 135 ° C. of the propylene resin (B2) is 0.5 dl / g or more and less than 1.0 dl / g, and the viewpoint that the toughness of the molded article is not lowered. Alternatively, from the viewpoint of suppressing deterioration in fluidity of the resin composition and suppressing deterioration in workability, it is preferably 0.52 dl / g or more and 0.8 dl / g or less.

  The molecular weight distribution (Mw / Mn) measured by GPC of the propylene resin (B2) is less than 3.0, preferably from the viewpoint of ensuring sufficient toughness of the molded body and suppressing the decrease in tensile elongation at break. It is 2.8 or less, More preferably, it is 2.5 or less. Mw represents the weight average molecular weight of the propylene resin (B2), and Mn represents the number average molecular weight of the propylene resin (B2).

Content of the structural unit derived from the propylene contained in a propylene resin (B2) is 90 mass% or more. (However, the total mass of the propylene resin (B2) is 100 mass%, and the content is measured by ¹³ C-NMR spectrum.) From the viewpoint of increasing the rigidity of the molded body, it is preferably 95 mass% or more. is there.

  Among the components contained in the propylene resin (B2), the content of a component having a polystyrene-equivalent weight average molecular weight (Mw) measured by GPC of 21000 or less suppresses a decrease in toughness of the molded product, and further the resin composition Alternatively, from the viewpoint of reducing the amount of volatile components released from the molded body, it is preferably less than 5.0% by mass, more preferably 4.5% by mass or less, and further preferably 4.0% by mass. It is as follows.

<Organic peroxide (b)>
The organic peroxide (b) used for the production of the propylene resin (B2) used for the core layer of the multilayer pellet (B) preferably has a half-life of 1 minute from the viewpoint of promoting the decomposition of the resin. An organic peroxide having a decomposition temperature of 50 to 210 ° C. Further, an organic peroxide having an action of extracting a proton from the propylene resin (a) after generating radicals by decomposition is preferable.

  Examples of the organic peroxide having a decomposition temperature of 50 to 210 ° C. with a half-life of 1 minute include diacyl peroxide compounds, dialkyl peroxide compounds, peroxyketal compounds, alkyl perester compounds, and carbonate compounds. . A dialkyl peroxide compound, a diacyl peroxide compound, a carbonate compound, and an alkyl perester compound are preferable.

  Specific examples of the organic peroxide (b) include dicetyl peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, and bis (4-tert-butylcyclohexyl). ) Peroxydicarbonate, diisopropyl peroxydicarbonate, tert-butyl peroxyisopropyl carbonate, dimyristyl peroxycarbonate, 1,1,3,3-tetramethylbutyl neodecanoate, α-cumyl peroxyneodecano Ate, tert-butylperoxyneodecanoate, 1,1-bis (tert-butylperoxy) cyclohexane, 2,2-bis (4,4-di-tert-butylperoxycyclohexyl) propane, 1,1 -Bis (tert-butyl par Oxy) cyclododecane, tert-hexylperoxyisopropyl monocarbonate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxylaurate, 2,5-dimethyl-2,5-di (Benzoylperoxy) hexane, tert-butylperoxyacetate, 2,2-bis (tert-butylperoxy) butene, tert-butylperoxybenzoate, n-butyl-4,4-bis (tert-butylperoxy) ) Valerate, di-tert-butylperoxyisophthalate, dicumyl peroxide, α, α′-bis (tert-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (tert -Butylperoxy) hexane, 1,3-bis ( tert-butylperoxyisopropyl) benzene, tert-butylcumyl peroxide, di-tert-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne -3 and the like.

  The compounding quantity of an organic peroxide (b) is 0.001-10 mass parts with respect to 100 mass parts of propylene resin (a), Preferably it is 0.003-5 mass parts, More preferably, it is 0. 0.1 to 1.0 part by mass, and still more preferably 0.2 to 0.5 part by mass.

[Producing method of propylene resin composition]
The propylene resin composition is obtained by melt-kneading the propylene resin (A) and the multilayer pellet (B).
The melt kneading is preferably performed at 180 to 250 ° C. using a single screw or twin screw extruder.

The propylene resin composition produced by the above production method comprises 50 to 95% by mass of propylene resin (A), 0.05 to 25% by mass of propylene resin (B1), and 2.5% by mass of propylene resin (B2). -49.5 mass% (however, the total amount of each mass of a propylene resin (A), a propylene resin (B1), and a propylene resin (B2) is set to 100 mass%).
From the viewpoint of the balance between the rigidity and the impact property of the molded product, 60 to 80% by mass of propylene resin (A), 1 to 5% by mass of propylene resin (B1), and 40 to 20% by mass of propylene resin (B2). Is preferred.

[Elastomer (C)]
An elastomer (C) may be added to the production of the propylene resin composition of the present invention. Examples of the elastomer (C) include an olefin elastomer (C-1) and a vinyl aromatic-containing compound elastomer (C-2).
In addition, an elastomer (C) may be added to the propylene resin composition manufactured by the manufacturing method of the propylene resin composition which concerns on this invention, and may be added to the molded object which consists of a propylene resin composition.

  The elastomer (C) content used in the production method of the propylene resin composition of the present invention, or the elastomer contained in the molded product comprising the propylene resin composition produced by the production method of the present invention and the resin composition The content of (C) makes the impact strength of the molded article sufficient, and from the viewpoint of not deteriorating the rigidity, the propylene resin (A), the propylene resin (B1), and the propylene resin (B2) propylene resin composition. It is preferable that it is 1-100 mass parts with respect to 100 mass parts, It is more preferable that it is 10-70 mass parts, It is still more preferable that it is 20-50 mass parts.

<Olefin elastomer (C-1)>
The olefin elastomer (C-1) is a copolymer of ethylene and an α-olefin having 4 to 20 carbon atoms (provided that the ethylene content is 50% by mass or more).
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, Examples include 3-methyl-1-pentene, 4-methyl-1-pentene, 1-octene, 1-nonene, 1-decene, 1-undecene and 1-dodecene. 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 elastomer (C-1) measured according to JIS-K-7112 increases the dispersibility of the propylene resin (A), propylene resin (B1), or propylene resin (B2). Or from the viewpoint of increasing the impact strength of the molded article at room temperature or low temperature, it is 0.85 to 0.885 g / cm ³ , preferably 0.85 to 0.88 g / cm ³ , more preferably. 0.855 to 0.875 g / cm ³ .

  The MFR of the olefin-based elastomer (C-1) at 190 ° C. and a load of 2.16 kg is 0.1 to 30 g / 10 minutes from the viewpoint of increasing the impact strength of the molded product, preferably 0.5 to 20 g / 10 min.

As a manufacturing method of an olefin type elastomer (C-1), the method of manufacturing using a polymerization catalyst is mentioned. As a polymerization catalyst, for example,
(1) Ziegler-Natta catalyst comprising a vanadium compound, an organoaluminum compound and a halogenated ester compound,
(2) A catalyst (so-called metallocene catalyst) in which a metallocene compound in which a group having at least one cyclopentadienyl anion skeleton is coordinated to a titanium atom, a zirconium atom or a hafnium atom, and an alumoxane or boron compound
Etc.
Examples of the polymerization method include 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. .

<Vinyl aromatic-containing compound elastomer (C-2)>
The vinyl aromatic compound-containing elastomer (C-2) is an elastomer containing a vinyl aromatic compound monomer unit, and examples of the vinyl aromatic compound include styrene.
The average content of vinyl aromatic compound monomer units contained in the vinyl aromatic compound-containing elastomer (C-2) is preferably 10 to 20% by mass, more preferably 12 to 19% by mass ( However, the total amount of the vinyl aromatic compound-containing elastomer is 100% by mass).

  The MFR of the vinyl aromatic compound-containing elastomer (C-2) at 190 ° C. and a load of 2.16 kg is preferably 0.1 to 15 g / 10 minutes, and more preferably 1 to 13 g / 10 minutes.

  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.

  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 elastomer or a conjugated diene elastomer by polymerization or reaction.

As the vinyl aromatic compound-containing elastomer (C-2), for example,
(1) a block copolymer comprising a vinyl aromatic compound polymer block and a conjugated diene polymer block;
(2) a block polymer in which the double bond of the conjugated diene part of the block copolymer is hydrogenated;
(3) The elastomer etc. which are obtained by making an olefin copolymer elastomer and a vinyl aromatic compound react are mentioned.
Among these, it is preferable to use a block polymer in which the double bond of the conjugated diene portion of the block copolymer (2) is hydrogenated at least 80%, and a block polymer hydrogenated at least 85% is used. More preferably, it is used. These may be used alone or in combination of two or more.

  Examples of the block copolymer comprising the vinyl aromatic compound polymer block (1) and the conjugated diene polymer block are styrene-ethylene-butene-styrene elastomer (SEBS), styrene-ethylene-propylene-styrene elastomer. (SEPS), styrene-butadiene elastomer (SBR), styrene-butadiene-styrene elastomer (SBS), styrene-isoprene-styrene elastomer (SIS), and the like.

  Moreover, you may use the elastomer obtained by making an olefin copolymer elastomer (C-1) and a vinyl aromatic compound react as an elastomer (C). Examples of the elastomer (C) obtained by reacting the olefin copolymer elastomer (C-1) with a vinyl aromatic compound include olefin copolymer elastomers such as ethylene-propylene-nonconjugated diene elastomer (EPDM) and the like. Examples include elastomers obtained by reacting vinyl aromatic compounds such as styrene.

[Inorganic filler (D)]
You may use an inorganic filler (D) for the manufacturing method of the propylene resin composition of this invention. As an inorganic filler (D), a non-fibrous inorganic filler (D-1) or a fibrous inorganic filler (D-2) is mentioned.
In addition, an inorganic filler (D) may be added to the propylene resin composition manufactured by the manufacturing method of the propylene resin composition which concerns on this invention, or may be added to the molded object which consists of a propylene resin composition. Good.

The content of the inorganic filler (D) used in the production method of the propylene resin composition of the present invention, or the propylene resin composition produced by the production method of the present invention and a molded product comprising the resin composition. In view of the content of the inorganic filler (D), the rigidity of the molded body is sufficient, and the fluidity of the resin composition and the impact strength of the molded body are not deteriorated.
It is preferable that it is 1-50 mass parts with respect to 100 mass parts of propylene resin (A), propylene resin (B1), and a propylene resin (B2) propylene resin composition, and it is 10-30 mass parts. More preferred.

<Non-fibrous inorganic filler (D-1)>
Non-fibrous inorganic filler (D-1) includes 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 and the like. These may be used alone or in combination of two or more. Of these, talc is preferably used.

  The non-fibrous inorganic filler (D-1) may be used without treatment, and improves the interfacial adhesion with the propylene resin (A), the propylene resin (B1), or the propylene resin (B2), And in order to improve the dispersibility with respect to propylene resin (A), propylene resin (B1), or propylene resin (B2), the surface is treated with a silane coupling agent, a titanium coupling agent, or a surfactant. May be used. Examples of the surfactant include higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid salts and the like.

The average particle diameter of the non-fibrous inorganic filler (D-1) is 10 μm or less, preferably 5 μm or less. Here, the “average particle size” in the present invention is 50% obtained from an integral distribution curve of a 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 the equivalent particle diameter D50.
Examples of the non-fibrous inorganic filler include powder, flakes, and granules, and any form may be used.

<Fibrous inorganic filler (D-2)>
Examples of the fibrous inorganic filler (D-2) include fibrous magnesium oxysulfate, potassium titanate fiber, magnesium hydroxide fiber, aluminum borate fiber, calcium silicate fiber, calcium carbonate fiber, carbon fiber, and glass fiber. And metal fibers. These may be used alone or in combination of two or more. Among these, it is preferable to use fibrous magnesium oxysulfate and calcium silicate fiber, and it is more preferable to use fibrous magnesium oxysulfate.

  The fibrous inorganic filler (D-2) may be used without treatment, improves the interfacial adhesion with the propylene resin (A), the propylene resin (B1), or the propylene resin (B2), and In order to improve the dispersibility with respect to propylene resin (A), propylene resin (B1), or propylene resin (B2), the surface may be treated with a silane coupling agent or a higher fatty acid metal salt. Examples of the higher fatty acid metal salt include calcium stearate, magnesium stearate, zinc stearate and the like.

  The average fiber length measured by electron microscope observation of the fibrous inorganic filler (D-2) is 3 μm or more, preferably 3 to 20 μm, and more preferably 8 to 15 μm. Moreover, an aspect ratio is 10 or more, Preferably it is 10-30, More preferably, it is 12-25. And the average fiber diameter measured by electron microscope observation becomes like this. Preferably it is 0.2-1.5 micrometers, More preferably, it is 0.3-1.0 micrometer.

Examples of the use of the propylene resin composition produced by the production method of the present invention, or a molded article comprising the resin composition include, for example, vehicle parts, electric / electronic equipment parts, electric wires, building materials, agriculture / fisheries / horticulture Goods, chemical industrial goods, civil engineering materials, industrial / industrial materials, furniture, stationery, daily and miscellaneous goods, clothes, containers / packaging goods, toys, leisure goods, medical supplies, etc.
Examples of vehicle parts include automobile interior parts such as instrumental panels, doors, and pillars, and automobile exterior parts such as bumpers. Examples of the electric wire include a plastic cable, an insulated electric wire, and an electric wire protective material.
A method for molding the propylene resin composition is not particularly limited, but an injection molding method is preferably used.

Hereinafter, the present invention will be described in more detail based on examples. The components used in Examples and Comparative Examples are as follows.
(1) Propylene resin (a)
The following propylene homopolymer was used as the propylene resin (a) used for the propylene resin (B2) constituting the core layer of the multilayer pellet (B).
Molecular weight distribution (Mw / Mn): 3.3
Intrinsic viscosity ([η] P): 2.9 dl / g
Isotactic pentad fraction: 0.98
MFR (230 ° C.): 0.6 g / 10 min Content of structural unit derived from propylene: 99.7%

(2) Propylene resin (B1-1)
The following propylene homopolymer was used as the propylene resin (B1-1) constituting the sheath layer of the multilayer pellet (B).
Molecular weight distribution (Mw / Mn): 4.1
Intrinsic viscosity ([η] P): 0.95 dl / g
Isotactic pentad fraction: 0.98
MFR (230 ° C.): 120 g / 10 min Content of structural unit derived from propylene: 100%
(3) Propylene resin (B1-2)
The following propylene homopolymers were used as the propylene resins used in the comparative examples.
Molecular weight distribution (Mw / Mn): 4.1
Intrinsic viscosity ([η] P): 1.30 dl / g
Isotactic pentad fraction: 0.98
MFR (230 ° C.): 30 g / 10 minutes (4) Propylene resin (B1-3)
As the propylene resin used in the comparative example, the following propylene homopolymer (manufactured by Sanyo Chemical Industries, Ltd., low molecular weight polypropylene (Biscol 440P)) was used.
Molecular weight distribution (Mw / Mn): 4.3
Intrinsic viscosity ([η] P): 0.3 dl / g
MFR (230 ° C.): 5000 g / 10 minutes Polystyrene-converted weight average molecular weight Mw content of 21,000 or less (mass%): 31.4%
(5) Propylene resin (B1-4)
The following propylene homopolymer (manufactured by Sanyo Chemical Industries, Ltd., low molecular weight polypropylene (Biscol 660P)) was used as the propylene resin used in the comparative example.
Molecular weight distribution (Mw / Mn): 2.7
Intrinsic viscosity ([η] P): 0.12 dl / g
MFR (230 ° C.): 5000 g / 10 minutes Polystyrene-converted weight average molecular weight Mw content of 21,000 or less (mass%): 85.9%

(6) Propylene resin (A)
As the propylene resin (A), the following propylene-ethylene polymerized material (AGN450 manufactured by Philips Sumika Polypropylene Company) was used.
MFR (230 ° C.): 46 g / 10 minutes Intrinsic viscosity ([η] total): 1.31 dl / g
・ Propylene homopolymer component of copolymer material (polymer component (I))
Molecular weight distribution (Mw / Mn): 4.0
Intrinsic viscosity ([η] I): 1.0 dl / g
Isotactic pentad fraction: 0.97
・ Propylene-ethylene random copolymer component (polymer component (II))
Intrinsic viscosity ([η] II): 2.3 dl / g
Content of polymer component (II) relative to propylene-ethylene polymer material (BC-1): 19% by mass
Content of structural unit derived from ethylene contained in polymer component (II): 46% by mass

(7) Elastomer (R-1)
As the elastomer (R-1), the following ethylene-1-octene copolymer rubber (manufactured by DuPont Dow Elastomer Co., Ltd., ENGAGE 8842) was used.
Density: 0.857 g / cm ³
MFR (190 ° C.): 1 g / 10 min (8) Elastomer (R-2)
As the elastomer (R-2), the following ethylene-1-octene copolymer rubber (manufactured by DuPont Dow Elastomer, ENGAGE 8137) was used.
Density: 0.864 g / cm ³
MFR (190 ° C.): 13 g / 10 min (9) Talc (TALC)
As the inorganic filler, talc (MWHST, Hayashi Kasei Co., Ltd.) was used. The average particle size was 2.7 μm.
(10) Organic peroxide (b)
1,3-bis (tert-butylperoxyisopropyl) benzene manufactured by Kayaku Akzo Co., Ltd. was used as the organic peroxide (b).

The physical properties of the raw material components and the propylene resin composition were measured according to the methods shown below.
(1) Melt flow rate (MFR, unit: g / 10 minutes)
As the melt flow rate of the propylene resin, the value when measured under the conditions of a test load of 2.16 kgf and a test temperature of 230 ° C. according to JIS K 7210 (1995) was used.
As the melt flow rate of the elastomer, the value when measured under the conditions of a test load of 2.16 kgf and a test temperature of 190 ° C. according to JIS K 7210 (1995) was used.
(2) Flexural modulus (FM, unit: MPa)
Using a test piece having a thickness of 6.4 mm formed by injection molding, the flexural modulus at 23 ° C. was measured in accordance with ASTM D790.
(3) Elongation at break (UE, unit:%)
Using a test piece formed by injection molding and having a thickness of 3.2 mm, the elongation at break at 23 ° C. was measured according to ASTM D638. The pulling speed was 30 mm / min.
(4) Izod impact strength (Izod, unit: kJ / m ² )
The measurement was performed according to the method defined in JIS-K-7110. The thickness formed by injection molding was 3.2 mm, and the measurement temperature was measured at 23 ° C. and −15 ° C. using a notched test piece.
(5) Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn)
The weight average molecular weight (Mw) and the number average molecular weight (Mn) were determined by GPC under the following conditions, and the ratio (Mw / Mn) was calculated.
Model: Waters 150C type Column: TSK-GEL GMH6-HT 7.5φmm × 300mm × 3 Measurement temperature: 140 ° C.
Solvent: Orthodichlorobenzene Measurement concentration: 5mg / 5ml

[Production of multilayer pellets]
After uniformly premixing with a tumbler with the composition shown in Table 1, the core layer part is supplied to a twin screw extruder for core (TEX30: 30φmm manufactured by Nippon Steel), and the sheath layer part is a single sheath material. It supplied to the shaft extruder (VS40 by Ikegai Co., Ltd .: 40 (phi) mm, L / D = 25). Each extruder was supplied at a temperature of 250 ° C. to a core / sheath die (six caps) at a core / sheath ratio of 90/10 (mass% / mass%). Six extruded strands were passed through a water bath, cooled, and cut with a pelletizer to obtain two-layer pellets ((B-1) to (B-3)). Table 2 shows the MFR of the kneaded material obtained by melt-kneading the two-layer pellets.

[Examples 1-3, Comparative Examples 1-3]
After uniformly premixing with a tumbler with the composition shown in Table 3, the extrusion rate was 50 kg / hour and the cylinder set temperature was 200 using a twin-screw kneading extruder (TEX44αII-49BW-3V type manufactured by Nippon Steel Works). The propylene resin composition was manufactured by kneading and extruding at 200 ° C. and a screw rotation speed of 200 rpm under vent suction.
In Table 3, “mass%” means the total content of propylene resin (A) and multilayer pellet (B), or the total content of propylene resin (A) and propylene resin is 100 mass%. The “part by weight” is the sum of the contents of the propylene resin (A) and the multilayer pellet (B), or the sum of the contents of the propylene resin (A) and the propylene resin as 100 parts by weight. Value.

  The obtained propylene resin composition was injection-molded at a molding temperature of 220 ° C. and a mold temperature of 50 ° C. using a SE180DUZ type injection molding machine manufactured by Sumitomo Heavy Industries, and a specimen for evaluation of flexural modulus, elongation at break and Izod impact strength. Got. The physical properties of the resulting propylene resin composition are shown in Table 4 below.

Claims (2)

50 to 95% by mass of the following propylene resin (A),
The following propylene resin (B1) 0.05 to 25% by mass;
From 2.5 to 49.5% by mass of the following propylene resin (B2) (however, the total mass of each of the propylene resin (A), the propylene resin (B1), and the propylene resin (B2) is 100% by mass) A propylene resin composition
A method for producing a propylene resin composition, comprising a multilayer pellet (B) comprising a sheath layer which is a propylene resin (B1) and a core layer which is a propylene resin (B2) and a propylene resin (A).

Propylene resin (A): The melt flow rate measured at 230 ° C. under a load of 2.16 kgf is 0.1 to 200 g / 10 min, and the intrinsic viscosity ([η] ^A _P ) measured in 135 ° C. tetralin is Propylene resin having a molecular weight distribution (Mw / Mn) of 3.0 or more and 0.8 to 7.0 dl / g.
Propylene resin (B1): Load 2.16 kgf, melt flow rate measured at 230 ° C. is 80 to 200 g / 10 min, and intrinsic viscosity ([η] ^B1 _P ) measured in 135 ° C. tetralin is 0. A propylene resin having a molecular weight distribution (Mw / Mn) of 3.0 or more and a content of a structural unit derived from propylene of 90% by mass or more of 8 to 1.2 dl / g.
Propylene resin (B2): obtained by melt-kneading propylene resin (a) having a load of 2.16 kgf and a melt flow rate of 0.1 to 100 g / 10 min measured at 230 ° C. and an organic peroxide (b) Propylene resin (B2) having a melt flow rate of 300 g / 10 min or more measured at 230 ° C. under a load of 2.16 kgf and an intrinsic viscosity ([η] ^B2 _P ) measured in tetralin at 135 ° C. Propylene resin having 0.5 dl / g or more and less than 1.0 dl / g, a molecular weight distribution (Mw / Mn) of less than 3.0, and a content of structural units derived from propylene of 90% by mass or more .   The method for producing a propylene resin composition according to claim 1, wherein the ratio of the mass of the sheath layer to the mass of the core layer of the multilayer pellet (B) (sheath layer / core layer) is 50/50 to 1/99.