JP7015635B2 - Effervescent polypropylene composition - Google Patents

Description

The present invention relates to an effervescent polypropylene composition and a foam obtained by foaming the same.

Polypropylene foam has excellent physical properties and is therefore useful for applications such as automobiles. Since high rigidity and impact resistance are required for automobile parts from the viewpoint of safety and the like, a foamable polypropylene composition having improved physical properties and a foam thereof have been proposed. For example, Patent Document 1 discloses a polypropylene foam having an elastomer content of 5 to 13% by weight (Patent Document 1 Example). Further, Patent Document 2 discloses a foam having an elastomer content of 17 to 21% by weight (Patent Document 2 Example). The melt flow rate of the elastomer at 190 ° C. is 35 g / 10 minutes.

Japanese Unexamined Patent Publication No. 2004-82547 Patent No. 5580630

The foam disclosed in the above patent document does not have a sufficient balance between rigidity and impact resistance. Generally, when the amount of elastomer is increased, the impact resistance is improved but the rigidity is lowered, so that there is a trade-off relationship between the two. In view of such circumstances, it is an object of the present invention to provide a foamable polypropylene composition that provides a foam having an excellent balance between rigidity and impact resistance.

The inventors have found that the balance between the two can be optimized by using a specific amount of an elastomer having a specific melt flow rate and using a small amount of a plate-like inorganic filler, and completed the present invention. That is, the above problem is solved by the following invention.
(1) 35 to 75% by weight of a polypropylene composition composed of (A1-1) and (A1-2) as a component (A1).
(A1-1) Polypropylene 70-85% by weight
(A1-2) 15-30% by weight of propylene-ethylene copolymer containing 25-40% by weight of ethylene-derived units
0 to 30% by weight of polypropylene as a component (A2)
Elastomer as component (B) 18-35% by weight
A foaming composition containing a plate-like inorganic filler as a component (C) and a foaming agent as a component (D) in an amount of more than 1% by weight and less than 12% by weight.
The melt flow rate (190 ° C., load 21.18 N) of the component (B) is 1 to 10 g / 10 minutes.
The melt flow rate (230 ° C., load 21.18N) of the foaming agent-free composition comprising the components (A1), (A2), (B), and (C) is 40 to 60 g / 10 minutes. Effervescent polypropylene composition.
(2) The effervescent polypropylene composition according to (1), wherein the melt flow rate (230 ° C., load 21.18N) of the component (A1) is 50 to 120 g / 10 minutes.
(3) The effervescent polypropylene composition according to (1) or (2), wherein the xylene-soluble component of the component (A1) has an ultimate viscosity of 1 to 3 dl / g.
(4) The effervescent polypropylene composition according to any one of (1) to (3), wherein the melt flow rate (190 ° C., load 21.18 N) of the component (B) is 1 to 7 g / 10 minutes. ..
(5) The amount of xylene soluble content of the component (A2) at 25 ° C. is 6.0% by weight or less, and the melt flow rate (230 ° C., load 21.18N) is 5 to 2000 g / 10 minutes. The effervescent polypropylene composition according to any one of (1) to (4).
(6) The component (A1) is
(A) A solid catalyst containing an electron donor compound selected from magnesium, titanium, halogen, and succinate compounds as an essential component;
Any of (1) to (5), which is a polypropylene composition obtained by polymerizing propylene and ethylene using a catalyst containing (b) an organoaluminum compound and (c) an external electron donor compound. The effervescent polypropylene composition according to the above.
(7) 0.1 to 10 parts by weight of the foaming agent is contained in 100 parts by weight of the total amount of the components (A1), (A2), (B), and (C), (1) to ( 6) The effervescent polypropylene composition according to any one of 6).
(8) A foam obtained by foaming the effervescent polypropylene composition according to any one of (1) to (7) above.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a foamable polypropylene composition that gives a foam having an excellent balance between rigidity and impact resistance.

Hereinafter, the present invention will be described in detail. In the present invention, "X to Y" includes X and Y which are fractional values thereof.

1. 1. Effervescent Polypropylene Composition The effervescent polypropylene composition of the present invention includes:
Component (A1): Polypropylene composition If necessary, Component (A2): Polypropylene Component (B): Elastomer Component (C): Plate-like inorganic filler Component (D): Foaming agent

(1) Component (A1): Polypropylene Composition The polypropylene composition comprises (A1-1) polypropylene and (A1-2) a propylene-ethylene copolymer containing 25-40% by weight of ethylene-derived units. The weight ratio of the components (A1-1) and (A1-2) is 70 to 85:15 to 30. If the amount of the component (A1-2) exceeds this upper limit, the rigidity of the foam is lowered, and if it is less than the lower limit, the economic efficiency is lowered. From this point of view, the ratio is preferably 75 to 80:25 to 20.

The component (A1-2) is a propylene-ethylene copolymer and contains 25-40% by weight of ethylene-derived units. If the content of ethylene-derived units is less than the lower limit value or exceeds the upper limit value, the impact resistance of the foam is lowered. From this viewpoint, the content of ethylene-derived units is preferably 27 to 38% by weight.

The melt flow rate (230 ° C., load 21.18N) of the component (A1) is preferably 50 to 120 g / 10 minutes, more preferably 66 to 100 g / 10 minutes. If the MFR exceeds the upper limit value, the impact strength of the foam may decrease, and if it is less than the lower limit value, the fluidity of the effervescent polypropylene composition may decrease. Hereinafter, the melt flow rate measured under the relevant conditions is also simply referred to as “MFR”.

The ultimate viscosity (XSIV) of the xylene-soluble component (XS) of the component (A1) is also an index of the molecular weight of the non-crystalline component in the component (A1). XSIV is obtained by obtaining a component soluble in xylene at 25 ° C. and measuring the ultimate viscosity of the component by a conventional method. The XSIV of the component (A1) is preferably 1 to 3 dl / g, more preferably 1.5 to 2.5 dl / g. If the XSIV exceeds the upper limit, the appearance of the foam may be poor, and if it is less than the lower limit, the impact resistance of the foam may decrease.

The component (A1) may be produced by any method, but propylene which is a raw material of the component (A1-1) and a raw material monomer of the component (A1-2) are used as (a) magnesium, titanium, halogen, and internal electrons. It is preferably obtained by a method including a step of polymerizing using a solid catalyst containing a donor, (b) an organoaluminum compound, and (c) a catalyst containing an external electron donor compound. Examples of the internal electron donor compound include a phthalate compound, a succinate compound, and a diether compound. In the present invention, any of the internal electron donor compounds can be used, but a foam having an excellent balance between rigidity and impact resistance can be used. From the viewpoint of obtaining, a succinate compound is preferable. Succinate compounds give a wide molecular weight distribution. Generally, it is known that the molecular weight distribution can be increased by polymerizing in multiple steps, but a polypropylene composition polymerized using the catalyst is a pellet or powder blend of a polymer polymerized using another catalyst. It exhibits different characteristics from the polypropylene composition having the same molecular weight distribution obtained in the above process and the polypropylene composition having the same molecular weight distribution by further polymerizing in multiple stages. This is because the composition produced by using the catalyst is integrated with the high molecular weight component and the low molecular weight component in a state close to the molecular level, but the latter resin composition is not mixed in a state close to the molecular level. It is considered that this is because they seem to show the same molecular weight distribution. However, it is not realistic to express this in words in the claims. Hereinafter, the catalyst will be described.

1) Solid catalyst (component a)
The component (a) can be prepared by a known method, for example, by bringing the magnesium compound, the titanium compound and the internal electron donor compound into mutual contact. As described above, the succinate-based compound is preferable as the internal electron donor compound, and the compound refers to a succinic acid diester or a substituted succinic acid diester. Hereinafter, the succinate compound will be described in detail. The succinate compound preferably used in the present invention is represented by the following formula (I).

In the formula, the groups R ₁ and R ₂ are linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, or alkyl from C ₁ to C ₂₀ , which are the same or different from each other and may contain heteroatoms. Aryl groups; groups R ₃ to R ₆ are linear or branched alkyl, alkenyl, cycloalkyl, aryl, C ₁ to C ₂₀ that are the same or different from each other and contain hydrogen or, in some cases, heteroatoms. Groups R ₃ to R ₆ , which are arylalkyl or alkylaryl groups and are bonded to the same carbon atom or different carbon atoms, may be bonded together to form a ring.

R ₁ and R ₂ are preferably C ₁ to C ₈ alkyl, cycloalkyl, aryl, arylalkyl, and alkylaryl groups. Compounds in which R ₁ and R ₂ are selected from primary alkyls, particularly branched primary alkyls, are particularly preferred. Examples of suitable R ₁ and R ₂ groups are C ₁ to C ₈ alkyl groups, such as methyl, ethyl, n-propyl, n-butyl, isobutyl, neopentyl, 2-ethylhexyl. Ethyl, isobutyl, and neopentyl are particularly preferred.

One of the preferred groups of compounds represented by formula (I) is branched alkyl, cycloalkyl, aryl, arylalkyl, where R ₃ to R ₅ are hydrogen and R ₆ has 3 to 10 carbon atoms. , And an alkylaryl group. Preferred specific examples of such a monosubstituted succinate compound are diethyl-sec-butyl succinate, diethyl texyl succinate, diethyl cyclopropyl succinate, diethyl norbonyl succinate, diethyl perihydro succinate, diethyl. Trimethylsilyl succinate, diethyl methoxy succinate, diethyl-p-methoxyphenyl succinate, diethyl-p-chlorophenyl succinate, diethyl phenyl succinate, diethyl cyclohexyl succinate, diethyl benzyl succinate, diethyl cyclohexyl Methyl succinate, diethyl-t-butyl succinate, diethyl isobutyl succinate, diethyl isopropyl succinate, diethyl neopentyl succinate, diethyl isopentyl succinate, diethyl (1-trifluoromethyl ethyl) succinate , Diethylfluorenyl succinate, 1-ethoxycarbodiisobutylphenyl succinate, diisobutyl-sec-butyl succinate, diisobutyltexyl succinate, diisobutylcyclopropyl succinate, diisobutylnorbonyl succinate, diisobutylperihydro Succinate, diisobutyltrimethylsilyl succinate, diisobutylmethoxysuccinate, diisobutyl-p-methoxyphenyl succinate, diisobutyl-p-chlorophenyl succinate, diisobutylcyclohexyl succinate, diisobutylbenzyl succinate, diisobutylcyclohexylmethyl Succinate, diisobutyl-t-butyl succinate, diisobutylisobutyl succinate, diisobutylisopropyl succinate, diisobutylneopentyl succinate, diisobutylisopentyl succinate, diisobutyl (1-trifluoromethylethyl) succinate, Diisobutylfluorenyl succinate, geneopentyl-sec-butyl succinate, geneopentyltexyl succinate, geneopentylcyclopropyl succinate, geneopentylnorbonyl succinate, geneopentyl perihydrosuccinate , Zineopentyltrimethylsilyl succinate, geneopentylmethoxysuccinate, geneopentyl-p-methoxyphenyl succinate, geneopentyl-p-chlorophenyl succinate, geneopentylphenyl succinate, genine Opentyl cyclohexyl succinate, geneopentylbenzyl succinate, geneopentylcyclohexylmethylsuccinate, geneopentyl-t-butyl succinate, geneopentylisobutylsuccinate, geneopentylisopropylsuccinate, di Neopentyl Neopentyl succinate, geneopentyl isopentyl succinate, geneopentyl (1-trifluoromethylethyl) succinate, geneopentylfluorenyl succinate.

Another preferred group of compounds within the range of formula (I) is a linear C ₁ to C ₂₀ in which at least two groups from R ₃ to R ₆ differ from hydrogen and in some cases contain heteroatoms. Alternatively, it is selected from branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, or alkylaryl groups. A compound in which two groups different from hydrogen are bonded to the same carbon atom is particularly preferable. Specifically, it is a compound in which R ₃ and R ₄ are different groups from hydrogen, and R ₅ and R ₆ are hydrogen atoms. Preferred specific examples of such disubstituted succinates are diethyl-2,2-dimethylsuccinate, diethyl-2-ethyl-2-methylsuccinate, diethyl-2-benzyl-2-isopropylsuccinate, diethyl. -2-Cyclohexylmethyl-2-isobutylsuccinate, diethyl-2-cyclopentyl-2-n-butylsuccinate, diethyl-2,2-diisobutylsuccinate, diethyl-2-cyclohexyl-2-ethylsuccinate Nate, diethyl-2-isopropyl-2-methylsuccinate, diethyl-2-tetradecyl-2-ethylsuccinate, diethyl-2-isobutyl-2-ethylsuccinate, diethyl-2- (1-trifluoro) Methylethyl) -2-methylsuccinate, diethyl-2-isopentyl-2-isobutylsuccinate, diethyl-2-phenyl-2-n-butylsuccinate, diisobutyl-2,2-dimethylsuccinate, Diisobutyl-2-ethyl-2-methylsuccinate, diisobutyl-2-benzyl-2-isopropylsuccinate, diisobutyl-2-cyclohexylmethyl-2-isobutylsuccinate, diisobutyl-2-cyclopentyl-2-n- Butyl succinate, diisobutyl-2,2-diisobutyl succinate, diisobutyl-2-cyclohexyl-2-ethylsuccinate, diisobutyl-2-isopropyl-2-methylsuccinate, diisobutyl-2-tetradecyl-2- Ethyl succinate, diisobutyl-2-isobutyl-2-ethyl succinate, diisobutyl-2- (1-trifluoromethylethyl) -2-methyl succinate, diisobutyl-2-isopentyl-2-isobutyl succinate , Diisobutyl-2-phenyl-2-n-butyl succinate, geneopentyl-2,2-dimethylsuccinate, geneopentyl-2-ethyl-2-methylsuccinate, geneopentyl-2-benzyl-2-isopropyls Xinate, Gineopentyl-2-cyclohexylmethyl-2-isobutylsuccinate, Gineopentyl-2-cyclopentyl-2-n-butylsuccinate, Gineopentyl-2,2-diisobutylsuccinate, Gineopentyl-2-cyclohexyl-2 -Ethyl succinate, geneopentyl-2-isopropyl-2-methyl succinate, geneopentyl-2-tetradecyl-2-ethyl succine , Gineopentyl-2-isobutyl-2-ethylsuccinate, Gineopentyl-2- (1-trifluoromethylethyl) -2-methylsuccinate, Gineopentyl-2-isopentyl-2-isobutylsuccinate, Gineopentyl -2-Phenyl-2-n-butyl succinate.

Further, compounds in which at least two groups different from hydrogen are bonded to different carbon atoms are also particularly preferable. Specifically, it is a compound in which R ₃ and R ₅ are different groups from hydrogen. In this case, R ₄ and R ₆ may be hydrogen atoms or groups different from hydrogen, but it is preferable that one of them is a hydrogen atom (trisubstituted succinate). Preferred specific examples of such compounds are diethyl-2,3-bis (trimethylsilyl) succinate, diethyl-2,2-sec-butyl-3-methylsuccinate, diethyl-2- (3,3,3-). Trifluoropropyl) -3-methylsuccinate, diethyl-2,3-bis (2-ethylbutyl) succinate, diethyl-2,3-diethyl-2-isopropylsuccinate, diethyl-2,3-diisopropyl-2 -Methyl succinate, diethyl-2,3-dicyclohexyl-2-methyldiethyl-2,3-dibenzylsuccinate, diethyl-2,3-diisopropylsuccinate, diethyl-2,3-bis (cyclohexylmethyl) ) Succinate, diethyl-2,3-di-t-butyl succinate, diethyl-2,3-diisobutyl succinate, diethyl-2,3-dineopentyl succinate, diethyl-2,3-diiso Pentyl succinate, diethyl-2,3- (1-trifluoromethylethyl) succinate, diethyl-2,3-tetradecyl succinate, diethyl-2,3-fluorenyl succinate, diethyl-2-isopropyl -3-Isobutyl succinate, diethyl-2-tert-butyl-3-isopropyl succinate, diethyl-2-isopropyl-3-cyclohexyl succinate, diethyl-2-isopentyl-3-cyclohexyl succinate, diethyl -2-Tetradecyl-3-cyclohexylmethyl succinate, diethyl-2-cyclohexyl-3-cyclopentyl succinate, diisobutyl-2,3-diethyl-2-isopropylsuccinate, diisobutyl-2,3-diisopropyl-2 -Methyl succinate, diisobutyl-2,3-dicyclohexyl-2-methylsuccinate, diisobutyl-2,3-dibenzylsuccinate, diisobutyl-2,3-diisopropylsuccinate, diisobutyl-2,3- Bis (cyclohexylmethyl) succinate, diisobutyl-2,3-di-t-butylsuccinate, diisobutyl-2,3-diisobutylsuccinate, diisobutyl-2,3-dineopentyl succinate, diisobutyl-2, 3-Diisopentyl succinate, diisobutyl-2,3- (1-trifluoromethylethyl) succinate, diisobutyl-2,3-tetradecylsuccinate, diisobutyl-2,3-fluorenyl succinate , Diisobutyl-2-isopropyl-3-isobutylsuccinate, diisobutyl-2-tert-butyl-3-isopropylsuccinate, diisobutyl-2-isopropyl-3-cyclohexylsuccinate, diisobutyl-2-isopentyl-3- Cyclohexyl succinate, diisobutyl-2-tetradecyl-3-cyclohexylmethyl succinate, diisobutyl-2-cyclohexyl-3-cyclopentyl succinate, geneopentyl-2,3-bis (trimethylsilyl) succinate, geneopentyl-2,2- sec-butyl-3-methylsuccinate, geneopentyl-2- (3,3,3-trifluoropropyl) -3-methylsuccinate, geneopentyl-2,3-bis (2-ethylbutyl) succinate, geneopentyl- 2,3-diethyl-2-isopropylsuccinate, geneopentyl-2,3-diisopropyl-2-methylsuccinate, geneopentyl-2,3-dicyclohexyl-2-methylsuccinate, geneopentyl-2,3-di Benzyl succinate, geneopentyl-2,3-diisopropyl succinate, geneopentyl-2,3-bis (cyclohexylmethyl) succinate, geneopentyl-2,3-di-t-butyl succinate, geneopentyl-2,3- Diisobutyl succinate, geneopentyl-2,3-dineopentyl succinate, geneopentyl-2,3-diisopentyl succinate, geneopentyl-2,3- (1-trifluoromethylethyl) succinate, geneopentyl-2 , 3-Tetradecyl succinate, Dineopentyl-2,3-Fluorenyl succinate, Dineopentyl-2-isopropyl-3-isobutylsuccinate, Gineopentyl-2-tert-butyl-3-isopropylsuccinate, Gineopentyl -2-Isopropyl-3-cyclohexyl succinate, geneopentyl-2-isopentyl-3-cyclohexyl succinate, geneopentyl-2-tetradecyl-3-cyclohexylmethyl succinate, geneopentyl-2-cyclohexyl-3-cyclopentyl succinate Nate.

Among the compounds of the _formula (I), compounds in which some of the groups R3 to R6 _are bonded together to form a ring can also be preferably used. As such compounds, the compounds listed in Japanese Patent Publication No. 2002-542347, for example, 1- (ethoxycarbonyl) -1- (ethoxyacetyl) -2,6-dimethylcyclohexane, 1- (ethoxycarbonyl) -1-( Ethoxyacetyl) -2,51 dimethylcyclopentane, 1- (ethoxycarbonyl) -1- (ethoxyacetylmethyl) 2-1methylcyclohexane, 1- (ethoxycarbonyl) -1- (ethoxy (cyclohexyl) acetyl) cyclohexane Can be mentioned. In addition, cyclic succinate compounds such as diisobutyl 3,6-dimethylcyclohexane-1,2-dicarboxylic acid and diisobutyl cyclohexane-1,2-dicarboxylate as disclosed in International Publication No. 2009/069483 are also preferable. Can be used. As an example of other cyclic succinate compounds, the compounds disclosed in International Publication No. 2009/057747 are also preferred.

Among the compounds of the formula (I) _, when the groups R3 to R6 contain a heteroatom, the heteroatom may be a Group ₁₅ atom containing a nitrogen and phosphorus atom or a Group 16 atom containing an oxygen and sulfur atom. preferable. _Examples of the compound in which the groups R3 to R6 contain a group ₁₅ atom include compounds disclosed in JP-A-2005-306910. _On the other hand, examples of the compound in which the groups R3 to R6 contain a group ₁₆ atom include compounds disclosed in JP-A-2004-131537.

In addition to this, an internal electron donor that gives a molecular weight distribution equivalent to that of the succinate compound may be used. Examples of such an internal electron donor include the diphenyldicarboxylic acid ester described in JP2013-28704, the cyclohexene dicarboxylic acid ester described in JP2014-2016002, and JP2013-288705. Dicycloalkyldicarboxylic acid ester, diol dibenzoate described in Japanese Patent No. 4959920, 1,2-phenylenedibenzoate described in International Publication No. 2010/078494, and the like.

2) Organoaluminium compound (component b)
Examples of the organoaluminum compound of the component (b) include the following.
Trialkylaluminum such as triethylaluminum and tributylaluminum;
Trialkenyl aluminum such as triisoprenyl aluminum:
Dialkylaluminum alkoxides such as diethylaluminum ethoxide and dibutylaluminum butoxide;
Alkyl aluminum sesquialkoxides such as ethyl aluminum sesquiethoxydo and butylaluminum sesquibutoxide;

Partially halogenated alkylaluminum such as alkylaluminum dihalogenide such as ethylaluminum dichloride, propylaluminum dichloride, butylaluminum dibromid;
Dialkylaluminum hydrides such as diethylaluminum hydride, dibutylaluminum hydride;
Partially hydrogenated alkylaluminum such as alkylaluminum dihydrides such as ethylaluminum dihydrides and propylaluminum dihydrides;
Partially alkoxylated and halogenated alkylaluminum such as ethylaluminum ethoxychloride, butylaluminum butycyclolide, ethylaluminum ethoxybromid.

3) Electron donor compound (component c)
The electron donor compound of component (c) is generally referred to as an "external electron donor". As such an electron donor compound, an organosilicon compound is preferable. Preferred organosilicon compounds include:
Trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyl Dimethoxysilane, diphenyldiethoxysilane, biso-tolyldimethoxysilane, bism-tolyldimethoxysilane, bisp-tolyldimethoxysilane, bisp-tolyldiethoxysilane, bisethylphenyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane Silane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, Phenyltrimethoxysilane, γ-chlorpropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, texyltrimethoxysilane, n-butyltriethoxysilane, iso- Butyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlortriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, 2-norbornantrimethoxysilane , 2-norbornan triethoxysilane, 2-norbornan methyldimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxysilane, vinyltris (β-methoxyethoxysilane), vinyltriacetoxysilane, dimethyl Tetraethoxydisiloxane.

Among them, ethyltriethoxysilane, n-propyltriethoxysilane, n-propyltrimethoxysilane, t-butyltriethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-butylethyldimethoxysilane, t-butylpropyldimethoxysilane, t-butylt-butoxydimethoxysilane, t-butyltrimethoxysilane, i-butyltrimethoxysilane, isobutylmethyldimethoxysilane, i-butylsec-butyldimethoxysilane, ethyl (perhydroisoquinoline 2-) Il) dimethoxysilane, bis (decahydroisoquinolin-2-yl) dimethoxysilane, tri (isopropeniroxy) phenylsilane, texyltrimethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, vinyltri Butoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, i-butyl i-propyldimethoxysilane, cyclopentyl t-butoxydimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexyl i-butyldimethoxysilane, cyclopentyl i -Butyldimethoxysilane, cyclopentylisopropyldimethoxysilane, di-sec-butyldimethoxysilane, diethylaminotriethoxysilane, tetraethoxysilane, tetramethoxysilane, isobutyltriethoxysilane, phenylmethyldimethoxysilane, phenyltriethoxylan, bisp-tolyl Dimethoxysilane, p-tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylethyldimethoxysilane, 2-norbornantriethoxysilane, 2-norbornanmethyldimethoxysilane, diphenyldiethoxysilane, methyl (3,3,3-trifluoropropyl) Dimethoxysilane, ethyl silicate and the like are preferable.

4) Polymerization A known method can be used for the polymerization of the component (A1). For example, it is preferable to polymerize propylene as a raw material for the component (A1-1) and a raw material monomer for the component (A1-2) using two or more reactors. The polymerization may be carried out in a liquid phase, a gas phase or a liquid-gas phase. Further, a polymerizer having a gradient of monomer concentration and polymerization conditions may be used. In such a polymerizer, for example, one in which at least two polymerization regions are connected can be used, and the monomer can be polymerized by vapor phase polymerization. Specifically, in the presence of a catalyst, a monomer is supplied and polymerized in a polymerization region consisting of an ascending tube, and a monomer is supplied and polymerized by a descending tube connected to the ascending tube. The polymer product is recovered while circulating. This method comprises means to prevent the gas mixture present in the ascending tube from entering the descending tube in whole or in part. Further, a gas or liquid mixture having a composition different from that of the gas mixture existing in the ascending tube is introduced into the descending tube. As the above-mentioned polymerization method, for example, the method described in JP-A-2002-520426 can be applied.

(2) Component (A2): Polypropylene The effervescent polypropylene composition of the present invention contains 0 to 30% by weight of polypropylene as the component (A2). The component (A2) improves the rigidity and fluidity of the effervescent polypropylene composition. From this viewpoint, the amount of the component (A2) is preferably 0.1% by weight or more, more preferably about 3 to 21% by weight. The component (A2) is preferably a propylene homopolymer. Further, the amount of xylene-soluble content at 25 ° C., which is an index of the amorphous component, is preferably 6.0% by weight or less, more preferably 3.0% by weight or less, and 2.0% by weight. % Or less is more preferable. When the amount of xylene-soluble content at 25 ° C. exceeds the upper limit, the rigidity of the foam decreases. The MFR of the component (A2) is preferably 5 to 2000 g / 10 minutes, more preferably 7.5 to 70 g / 10 minutes. If the MFR exceeds the upper limit value, the impact resistance of the foam may decrease, and if it is less than the lower limit value, the fluidity of the effervescent polypropylene composition may decrease.

(3) Component (B): Elastomer The effervescent polypropylene composition of the present invention contains 18 to 35% by weight of an elastomer as component (B). Elastomer is a polymer with elasticity. The elastomer used in the present invention is different from the polymer of the component (A1-2). The component (B) improves the impact resistance, appearance, and scratch resistance of the foam. From this viewpoint, the amount of the component (B) is preferably 21 to 28% by weight. If the amount exceeds the upper limit, poor appearance and deterioration of scratch resistance may occur. If the amount is less than the lower limit, the impact resistance may decrease.

The melt flow rate of the elastomer under a load of 190 ° C. and 21.18 N (hereinafter, the melt flow rate measured under these conditions is also referred to as “MFR _{190 ° C.} ”) is 1 to 10 g / 10 minutes, but 1 to 7 g / 10 minutes is preferred. If the MFR _{190 ° C.} exceeds the upper limit value, the balance between the rigidity and the impact resistance of the foam may decrease, and if it is less than the lower limit value, the fluidity of the effervescent polypropylene composition may decrease.

Examples of the elastomer include a copolymer of ethylene and α-olefin. Examples of the α-olefin include α-olefins having 3 to 12 carbon atoms, and specifically, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene and the like are preferable. The elastomer preferably has a lower density than the polymers of the component (A1-1) and the component (A1-2). For example, the density of the elastomer is not limited, but is preferably 0.850 to 0.890 g / cm ³ , and more preferably 0.860 to 0.880 g / cm ³ . Such an elastomer can be prepared, for example, by polymerizing a monomer using a homogeneous catalyst such as metallocene or half metallocene as described in JP-A-2015-113363.

(4) Component (C): Plate-shaped Inorganic Filler The effervescent polypropylene composition of the present invention contains a plate-shaped inorganic filler in an amount of more than 1% by weight and less than 12% by weight as the component (C). The component (C) improves the rigidity and impact resistance of the foam. From this viewpoint, the amount of the component (C) is preferably 3 to 10% by weight. If the amount is equal to or more than the upper limit, the appearance may be poor and the scratch resistance may be deteriorated. If the amount is not more than the lower limit, the rigidity may decrease.

Examples of the plate-shaped inorganic filler include mica, clay, talc and the like, but talc is preferable because of its availability. The average particle size of the plate-shaped inorganic filler is preferably 1 to 10 μm, more preferably 3 to 7 μm. The average particle size is measured according to JIS Z 8825.

(5) Component (D): Foaming Agent The effervescent polypropylene composition of the present invention contains a foaming agent. As the foaming agent, either a decomposition type foaming agent or a solvent type foaming agent can be used. The decomposition type foaming agent is a compound that decomposes under the cylinder temperature condition of an injection molding machine to generate a gas such as carbon dioxide gas or nitrogen gas. As the decomposition type foaming agent, either an inorganic type or an organic type can be used. Further, a known foaming aid such as an organic acid that promotes the generation of gas may be used in combination.

Examples of the inorganic decomposition foaming agent include sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, ammonium nitrite, citric acid, sodium citrate and the like. Examples of the organic decomposition foaming agent include N-nitroso compounds such as N, N'-dinitrosoterephthalamide and N, N'-dinitrosopentamethylenetetramine; azodicarboxylicamide, azobisisobutyronitrile, and azocyclohexyl. Azo compounds such as nitrile, azodiaminobenzene, barium azodicarboxylate; benzenesulfonylhydrazide, toluenesulfonylhydrazide, p, p'-oxybis (benzenesulphenylhydrazide), diphenylsulphon-3,3'-disulfonylhydrazide and the like. Sulfonylhydrazide compounds; examples thereof include azoid compounds such as calcium azide, 4,4'-diphenyldisulfonyl azide, and p-toluene sulfonyl azide.

Among these effervescent agents, carbonates such as sodium bicarbonate or hydrogen carbonates are preferable from the viewpoint of having less impact on the environment, being safe, and stabilizing the effervescent cell, and in that case, an organic carboxylic acid. Is preferably used in combination as a foaming aid. The blending ratio of the carbonate or hydrogen carbonate to the organic carboxylic acid is preferably 10 to 70% by weight of the carbonate or hydrogen carbonate, and 30 to 90% by weight of the organic carboxylic acid.

The solvent-type foaming agent is a substance that functions as a foaming agent by injecting it into a composition containing no foaming agent from the cylinder portion of an injection molding machine and evaporating it in an injection molding die. Low-boiling aliphatic hydrocarbons such as propane, butane, neopentane, heptane, isohexane, hexane, isoheptane, and heptane, and low-boiling fluorine-containing hydrocarbons typified by freon gas can be used.

The foaming agent used in the effervescent polypropylene composition of the present invention can be added in the form of a foaming agent masterbatch using polyolefin as a carrier. Examples of the polyolefin include polypropylene, polyethylene, polystyrene and the like. In the present invention, the carrier contained in the masterbatch can also be regarded as a component of the foaming agent, assuming that the entire masterbatch of the foaming agent normally used in the art corresponds to the foaming agent. The amount of the foaming agent added is preferably 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the total amount of the components (A1), (A2), (B) and (C). The unit is more preferable. Further, within this range, the optimum amount is selected in consideration of the amount of generated gas, the foaming ratio, and the like. The foaming ratio is preferably 1.4 to 3, more preferably 1.5 to 2.8. From the effervescent polypropylene composition within this range, a resin foam having the same bubble diameter and uniformly dispersed bubbles can be obtained.

(6) Other components The effervescent polypropylene composition includes antioxidants, chlorine absorbers, heat stabilizers, light stabilizers, ultraviolet absorbers, internal lubricants, external lubricants, antiblocking agents, antistatic agents, and antifogging agents. In the field of agents, crystal nucleating agents, flame retardants, dispersants, copper damage inhibitors, neutralizing agents, plasticizers, bubble inhibitors, cross-linking agents, peroxides, oil spreads and other organic and inorganic pigments. Conventional additives commonly used may be added. The addition amount of each additive may be a known amount.

(7) Characteristics 1) MFR
The MFR of the effervescent polypropylene composition of the present invention is 40 to 60 g / 10 minutes, preferably 45 to 57 g / 10 minutes when it does not contain a foaming agent (hereinafter, also referred to as “non-effervescent polypropylene composition”). be. If the MFR exceeds the upper limit, the impact resistance of the foam is lowered, and if it is less than the lower limit, the fluidity of the foamable polypropylene composition is lowered.

2) Density The density of the non-effervescent polypropylene composition comprising the above (A1), (A2), (B), and (C) is preferably 0.91 to 0.98 g / cm ³ , more preferably 0.91. It is ~ 0.96 g / cm ³ .

3) Rigidity The flexural modulus of the non-foaming polypropylene composition is preferably 1000 MPa or more, more preferably 1200 MPa or more at 23 ° C.

4) Impact resistance The Charpy impact strength of the non-foaming polypropylene composition is preferably 30 kJ / m ² or more, more preferably 35 kJ / m ² or more at 23 ° C.

2. 2. Production Method When a decomposable foaming agent is used, the effervescent polypropylene composition of the present invention produces a non-effervescent polypropylene composition obtained by melt-kneading the components (A1) to (C) and, if necessary, an additive. It can be produced by dry-blending this with a foaming agent (component (D)). The dry blend may be melt-kneaded before molding in an extruder attached to a foam molding machine. As described above, a foaming agent masterbatch having a polyolefin as a carrier may be used as the foaming agent.

When a solvent-based foaming agent is used, the components (A1) to (C) and, if necessary, additives are melt-kneaded to prepare a non-foaming polypropylene composition, and the solvent-based foaming agent is prepared in the injection molding machine as described above. The effervescent polypropylene composition can be produced by mixing with. At this time, a foaming agent masterbatch using polyolefin or the like as a carrier may be added as a foaming agent.

3. 3. Molding A foam can be produced by foaming the effervescent polypropylene composition of the present invention. The foam is preferably produced by injection foam molding. Injection foam molding can be roughly divided into a method in which the volume of the cavity is not changed and a method in which the volume is changed. The former is a method in which the effervescent polypropylene composition is filled in the cavity of the mold, and the foaming agent is vaporized and foamed inside the molded product by reducing the pressure accompanying the shrinkage of the polymer. The latter is a method of foaming by core-backing the mold or moving a slide core or the like in the mold to expand the volume of the cavity during or after filling the cavity with the effervescent polypropylene composition. be. The injection conditions are preferably a cylinder temperature of 190 to 230 ° C., a mold temperature of 20 to 50 ° C., and an injection speed of 30 to 300 mm / sec.

The following materials were prepared.
(1) Ingredient (A1)
Production of Polypropylene Resin Composition 1 A solid catalyst in which Ti and diisobutyl phthalate as an internal donor were supported on MgCl ₂ was prepared by the method described in Example 5 of European Patent No. 728769. Next, using the solid catalyst, triethylaluminum (TEAL) as the organoaluminum compound, and dicyclopentyldimethoxysilane (DCPMS) as the external electron donor compound, the weight ratio of TEAL to the solid catalyst is 20, and the weight ratio of TEAL / DCPMS is 20. The contact was carried out at 12 ° C. for 24 minutes in an amount such that Prepolymerization was carried out by holding the obtained catalyst system in a suspended state in liquid propylene at 20 ° C. for 5 minutes.
The obtained prepolymer is introduced into the first-stage polymerization reactor of a polymerization apparatus equipped with a two-stage polymerization reactor in series to produce a propylene homopolymer (component (A1-1)) in the second stage. A propylene-ethylene copolymer (component (A1-2)) was produced in the polymerization reactor of the above. During the polymerization, the temperature and pressure were adjusted, and hydrogen was used as a molecular weight adjusting agent.
The ratio of the polymerization temperature to the reactants was as follows: in the first-stage reactor, the polymerization temperature and hydrogen concentration were 70 ° C. and 3.33 mol%, respectively, and in the second-stage reactor, the polymerization temperature and hydrogen concentration were C2 / (. C2 + C3) had a ratio of 80 ° C., 1.88 mol% and 0.21 mol, respectively. Further, the residence time distributions of the first stage and the second stage were adjusted so that the amount of the copolymer component was 30% by weight.
To 100 parts by weight of the obtained polypropylene polymer, 0.2 parts by weight of B225 manufactured by BASF as an antioxidant and 0.05 parts by weight of calcium stearate manufactured by Tannan Chemical Co., Ltd. as a neutralizing agent were blended. After stirring and mixing with a Henchel mixer for 1 minute, the mixture was melt-kneaded and extruded at a cylinder temperature of 200 ° C. using a twin-screw extruder (manufactured by Technobel Co., Ltd., model number KZW15TW-30MG) having a screw diameter of 15 mm. After cooling the strands in water, they were cut with a pelletizer to obtain pellets.
The obtained polypropylene resin composition (component (A1)) has MFR = 37 g / 10 minutes, component (A1-1): component (A1-2) = 70:30 (weight ratio), ethylene of a propylene-ethylene copolymer. The unit of origin was 27% by weight, and XSIV = 2.3 dL / g.

Production of Polypropylene Resin Composition 2 A solid catalyst in which Ti and diethyl-2,3- (diisopropyl) succinate as an internal donor compound are supported on MgCl ₂ is described in Example 1 of JP-A-7-2925. Prepared by the method described. Using a solid catalyst, triethylaluminum (TEAL) as an organoaluminum compound, and dicyclopentyldimethoxysilane (DCPMS) as an external electron donor compound, the mass ratio of TEAL to the solid catalyst is 18, and the mass ratio of TEAL / DCPMS is 10. The mixture was contacted at room temperature for 5 minutes in such an amount. Prepolymerization was carried out by holding the obtained catalyst system in a suspended state in liquid propylene at 20 ° C. for 5 minutes.
The obtained prepolymer is introduced into the first-stage polymerization reactor of a polymerization apparatus equipped with a two-stage polymerization reactor in series to produce a propylene homopolymer (component (A1-1)) in the second stage. A propylene-ethylene copolymer (component (A1-2)) was produced in the polymerization reactor of the above. During the polymerization, the temperature and pressure were adjusted, and hydrogen was used as a molecular weight adjusting agent.
The ratio of the polymerization temperature to the reactants was as follows: in the first-stage reactor, the polymerization temperature and hydrogen concentration were 70 ° C. and 1.83 mol%, respectively, and in the second-stage reactor, the polymerization temperature and hydrogen concentration were C2 / (. C2 + C3) had a ratio of 80 ° C., 2.45 mol% and 0.29 mol, respectively. Further, the residence time distributions of the first stage and the second stage were adjusted so that the amount of the copolymer component was 22% by weight.
Using the obtained polypropylene polymer, pellets of the polypropylene resin composition 2 were obtained in the same manner as in the polypropylene resin composition 1.
The obtained polypropylene resin composition (component (A1)) has MFR = 100 g / 10 minutes, component (A1-1): component (A1-2) = 78:22 (weight ratio), ethylene of a propylene-ethylene copolymer. The unit of origin was 35% by weight, and XSIV = 2.0 dl / g.

Production of Polypropylene Resin Composition 3 The polymerization temperature and hydrogen concentration of the first-stage reactor were set to 70 ° C. and 3.17 mol%, respectively, and the polymerization temperature and hydrogen concentration of the second-stage reactor were set to C2 / (C2 + C3). Polypropylene resin composition 1 except that the residence time distributions of the first and second stages were adjusted so that the amounts of the copolymer components were 15% by weight at 80 ° C., 1.61 mol% and 0.21 mol ratio, respectively. The polypropylene resin composition 3 was obtained in the same manner as above.
The obtained polypropylene resin composition (component (A1)) has MFR = 83.3 g / 10 minutes, component (A1-1): component (A1-2) = 85:15 (weight ratio), propylene-ethylene copolymer. Ethylene-derived unit = 27% by weight and XSIV = 2.5 dl / g.

(2) Ingredient (A2)
Polypropylene 1 (powdered polymer)
MFR = 1750 g / 10 minutes, xylene soluble content at 25 ° C. 2.3% by weight
Polypropylene 2 (pellets containing antioxidants and neutralizers)
MFR = 7.5 g / 10 minutes, xylene soluble content at 25 ° C. 1.5% by weight
Polypropylene 3 (pellets containing antioxidants and neutralizers)
MFR = 30 g / 10 minutes, xylene soluble content at 25 ° C. 1.5% by weight

(3) Ingredient (B)
Elastomer 1 (Dow Chemical Engage 8150)
MFR _{190 ° C} = 0.5 g / 10 minutes, density = 0.868 g / cm ³
Elastomer 2 (Dow Chemical Engage 8100)
MFR _{190 ° C} = 1.0 g / 10 minutes, density = 0.870 g / cm ³
Elastomer 3 (Dow Chemical Engage 8200)
MFR _{190 ° C} = 5.0 g / 10 minutes, density = 0.870 g / cm ³
Elastomer 4 (Toughmer A1050S manufactured by Mitsui Chemicals, Inc.)
MFR _{190 ° C} = 1.2 g / 10 minutes, density = 0.862 g / cm ³
Elastomer 5 (Dow Chemical Engage 8407)
MFR _{190 ° C} = 30 g / 10 minutes, density = 0.870 g / cm ³

(4) Ingredient (C)
Talc (UNI05 manufactured by Neolite Kosan Co., Ltd.) Average particle size = 5 μm

[Examples 1 to 8, Reference Examples 9 and 10]
(1) Non-foaming polypropylene composition Magnesium stearate is 0 as an additive to a total of 100 parts by weight of the component (A1), the component (A2), the component (B) and the component (C) shown in Table 1. .20 parts by weight, calcium stearate by 0.05 parts by weight, BASF B225 by 0.20 parts by weight, ADEKA Corporation ADEKA STAB LA-502XP by 0.20 parts by weight, glycerol monostearate by 0.20 parts by weight. After stirring and mixing with a Henshell mixer for 1 minute, melt-kneaded and extruded at a cylinder temperature of 200 ° C. using a twin-screw extruder (manufactured by JSW Co., Ltd., model number TEX-30α) with a screw diameter of 30 mm. .. After cooling the strands in water, they were cut with a pelletizer to obtain pellets. Next, the pellet was injection-molded into various test pieces using an injection molding machine (manufactured by FANUC Corporation, model number Roboshot S-2000i 100B). The molding conditions were a cylinder temperature of 200 ° C., a mold temperature of 40 ° C., and an injection speed of 200 mm / sec. Various physical properties of the non-foaming polypropylene composition thus produced were evaluated. The results are shown in Table 1. The evaluation method will be described later.

(2) Foaming agent To the above non-expandable polypropylene composition, 3 parts by weight of a foaming agent masterbatch (Polyslen EE65C manufactured by Eiwa Kasei Kogyo Co., Ltd.) was added and melt-kneaded by an extruder of an injection foam molding machine. Later, injection foam molding was performed to produce a foam in the shape of an automobile door part. The foaming agent masterbatch contains a degradable foaming agent and a polyolefin as a carrier. The evaluation results of the foam are shown in Table 1.

[Comparative Examples 1 to 9]
The components shown in Table 2 were used to prepare and evaluate non-foamable polypropylene compositions and foams for comparison in the same manner as in Examples. The results are shown in Table 2.

The non-foaming polypropylene composition of the present invention has excellent rigidity and impact resistance. In addition, the effervescent polypropylene composition exhibits excellent effervescence. From the above, it is clear that the effervescent polypropylene composition of the present invention provides a foam having an excellent balance between rigidity and impact resistance.

The method of measuring the physical property value is shown below.
[density]
It was measured according to JIS K 7112.
[MFR]
The measurement was performed in accordance with JIS K 7210 under the conditions of a temperature of 230 ° C. and a load of 21.18 N.
[MFR _{190 ° C} ]
According to JIS K 7210, the measurement was performed under the conditions of a temperature of 190 ° C. and a load of 21.18 N.

[Bending modulus]
The measurement was performed using a fully automatic testing machine AG-X (bending mode) manufactured by Shimadzu Corporation in accordance with JIS K6921-2.
Test speed: 10 mm / min Test temperature: 23 ° C

[Charpy impact strength]
The measurement was performed using a digital impact tester DG-UB type, which is a testing machine manufactured by Toyo Seiki Seisakusho Co., Ltd., in accordance with JIS K6921-2.

[XSIV]
2.5 g of the polymer was placed in a flask containing 250 mL of o-xylene (solvent) and stirred for 30 minutes at 135 ° C. using a hot plate and a reflux device while purging with nitrogen to completely dissolve the composition. After that, the mixture was cooled at 25 ° C. for 1 hour. The resulting solution was filtered using filter paper. 100 mL of the filtrate after filtration was collected, transferred to an aluminum cup or the like, evaporated to dryness at 140 ° C. while purging with nitrogen, and allowed to stand at room temperature for 30 minutes to obtain a xylene-soluble component (XS). The container was then maintained in an oven at 80 ° C. under vacuum until a constant weight was obtained, and then the weight of the polymer dissolved in xylene at room temperature was determined. The weight% of the polymer dissolved in xylene with respect to all the polymers was calculated and used as the amount of xylene soluble content at 25 ° C.
Using the above xylene-soluble component as a sample, the ultimate viscosity was measured in tetrahydronaphthalene at 135 ° C. using a Ubbelohde viscometer (SS-780-H1, manufactured by Shibayama Kagaku Kikai Seisakusho).
[Concentration of ethylene in the copolymer (component (A1-2)) in the polypropylene resin composition (component (A1)) and amount of copolymer]
A sample dissolved in a mixed solvent of 1,2,4-trichlorobenzene / dehydrogenated benzene was measured using Bruker's AVANCE III HD400 (13C resonance frequency 100 MHz) at a measurement temperature of 120 ° C, a flip angle of 45 degrees, and a pulse interval of 7 seconds. A 13C-NMR spectrum was obtained under the conditions of a sample rotation speed of 20 Hz and an integration number of 5000 times.

<Total ethylene content in polypropylene resin composition (component (A1))>
Using the spectra obtained above, the total ethylene of the polypropylene resin composition by the method described in the literature of Kakugo, Y.Naito, K.Mizunuma and T.Miyatake, Macromolecules, 15, 1150-1152 (1982). The amount (% by weight) was calculated.

<Ethylene concentration in copolymer (component (A1-2))>
The calculation was performed in the same manner as the total amount of ethylene except that the integrated intensity obtained by the following formula was used instead of the integrated intensity of Tββ obtained above, and the ethylene concentration in the copolymer was obtained.
T'ββ = 0.98 × Sαγ × A / (1-0.98 × A)
Here, A = Sαγ / (Sαγ + Sαδ)

<Amount of copolymer (component (A1-2)) in polypropylene resin composition (component (A1))>
It was calculated by the following formula.
Amount of copolymer (% by weight) = total ethylene content of polypropylene resin composition / (ethylene concentration in copolymer / 100)

[Liquidity]
We confirmed the presence or absence of short shots in injection molding of automobile door parts and evaluated them according to the following criteria.
A: Excellent, B: Good, C: Bad

[Foam characteristics]
Cross-sections of injection-molded products of automobile door parts were observed and evaluated according to the following criteria.
A: Excellent, B: Good, C: Bad

[exterior]
The swirl mark of the injection molded product of the automobile door part was visually judged and evaluated according to the following criteria.
A: Excellent, B: Good, C: Bad

[Scratch resistance]
A scratch test (5-finger method) on the surface of injection-molded products of automobile door parts was conducted and evaluated according to the following criteria.
A: Excellent, B: Good, C: Bad

Claims (9)

35-75% by weight of the polypropylene composition composed of (A1-1) and (A1-2) as the component (A1).
(A1-1) Polypropylene 70-85% by weight
(A1-2) 15-30% by weight of propylene-ethylene copolymer containing 25-40% by weight of ethylene-derived units
0 to 30% by weight of polypropylene as a component (A2)
23-28 % by weight of elastomer as component ( B)
Plate-like inorganic filler as component (C), 3 to 7% by weight
A foaming composition containing a foaming agent as the component (D).
The melt flow rate (190 ° C., load 21.18N) of the component (B) is 1 to 10 g / 10 minutes.
The melt flow rate (230 ° C., load 21.18N) of the foaming agent-free composition comprising the components (A1), (A2), (B), and (C) is 40 to 60 g / 10 minutes.
Effervescent polypropylene composition. The effervescent polypropylene composition according to claim 1, wherein the melt flow rate (230 ° C., load 21.18N) of the component (A1) is 50 to 120 g / 10 minutes. The effervescent polypropylene composition according to claim 1 or 2, wherein the xylene-soluble component of the component (A1) has an ultimate viscosity of 1 to 3 dl / g. The effervescent polypropylene composition according to any one of claims 1 to 3, wherein the melt flow rate (190 ° C., load 21.18 N) of the component (B) is 1 to 7 g / 10 minutes. Claim 1 in which the amount of xylene soluble content of the component (A2) at 25 ° C. is 6.0% by weight or less, and the melt flow rate (230 ° C., load 21.18N) is 5 to 2000 g / 10 minutes. The effervescent polypropylene composition according to any one of 4 to 4. The component (A1) is
(A) A solid catalyst containing an electron donor compound selected from magnesium, titanium, halogen, and succinate compounds as an essential component;
The polypropylene composition according to any one of claims 1 to 5, wherein (b) an organoaluminum compound; and (c) a polypropylene composition obtained by polymerizing propylene and ethylene using a catalyst containing an external electron donor compound. Effervescent polypropylene composition. With respect to 100 parts by weight of the total amount of the components (A1), (A2), (B), and (C).
The effervescent polypropylene composition according to any one of claims 1 to 6, which comprises 0.1 to 10 parts by weight of the effervescent agent. The component (A1) is
With 80-75% by weight of the above (A1-1) polypropylene,
It comprises a propylene-ethylene copolymer containing 20-25% by weight of the (A1-2) 25-40% by weight ethylene-derived unit.
The effervescent polypropylene composition according to any one of claims 1 to 7. A foam obtained by foaming the effervescent polypropylene composition according to any one of claims 1 to 8.