JPH11188823A - Polypropylene multilayer foam hollow molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the excellent appearance of a molded article with high surface gloss by allowing a substance consisting of polypropylene random copolymeric composition in its surface layer and a polypropylene copolymeric composition in its inner layer to foam with a chemical foaming agent. SOLUTION: A polypropylene random copolymeric composition X used for a skin layer has a melting point of 120-150 deg.C and a melt flow rate MFR in the range of 0.3-20. Also, a component (a) constituting a polypropylene copolymeric composition Y is an olefinic copolymer of an inherent viscosity ηE of 15-100 dl/g measured in 135 deg.C tetralin, and a component (b) is polypropylene having an inherent viscosity of ηP of 0.2-10 dl/g in 135 deg.C tetralin. The polypropylene composition Y consists of the component (a) of 0.01-5 pts.wt. and the component (b) of 100 pts.wt., MRF [230 deg.C; 21.18 N] is 0.1-10 g.10 min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polypropylene foam hollow molded article. More particularly, the present invention relates to a polypropylene foam hollow molded article having a high surface gloss and excellent appearance.

[0002]

2. Description of the Related Art In order to obtain effects such as heat insulation and sound absorption,
2. Description of the Related Art A hollow molded article is provided with a foam layer. Polypropylene has many excellent properties such as rigidity, impact resistance, heat-resistant rigidity, processability, chemical resistance, electrical properties, etc.In addition, it is hollow because the molded product is glossy and the appearance is beautiful It is widely used as a molded product. However, in the case of conventional polypropylene, when a foamed parison is blown in a mold by pressurized air, the foamed foam is crushed due to a low melt tension, and it is difficult to obtain a sufficiently foamed hollow molded product. It is. As a method for increasing the melt tension of polypropylene, a method in which an organic peroxide and a crosslinking aid are reacted with crystalline polypropylene in a molten state (JP-A-59-93711, JP-A-61-152754, etc.) A method of producing a gel-free polypropylene having a free-end long-chain branch by reacting a semi-crystalline polypropylene with a peroxide having a low decomposition temperature in the absence of oxygen (JP-A-2-298536). It has been disclosed. In the various compositions proposed above and their production methods, although the melt tension of polypropylene is improved to some extent, recycling to solve problems such as odor remaining due to the crosslinking aid and environmental problems is considered. There are problems such as lack of usability. As a technique related to a foamed hollow molded article, a method of blowing a foamed parison with a mold under special conditions (Japanese Patent Laid-Open No. 60-113)
30) A method in which a parison containing a foaming agent is blow-molded in an unfoamed state, and then the molded article is heated and foamed (Japanese Patent Laid-Open No.
-20322) and the like. The above method
There are problems such as complicated special molds and complicated processes.
Further, the surface of the foamed hollow molded article is not smooth due to the foam cells, the surface gloss is low, and the appearance needs to be improved in terms of aesthetic appearance. As described above, in the prior art, it is difficult to produce a polypropylene foam hollow molded article having a good foaming state and excellent appearance by a normal blow molding method.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a hollow polypropylene molded article having a high surface gloss and excellent appearance.

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object. As a result, a specific polypropylene random copolymer composition was used for the surface layer, and a small amount of a specific high intrinsic viscosity was used for the olefin polymerization catalyst in the inner layer. Hollow molding with high surface gloss and excellent foaming properties by using a polypropylene polymer composition with a large melt tension, in which propylene is polymerized using a catalyst pre-activated by supporting an olefin polymer having It was found that a product was obtained, and the present invention was completed.

The present invention has the following configurations (1), (2) and (3). (1) A multilayer foamed polypropylene foam molded article in which the skin layer has the following composition (X) and the inner layer has the following composition (Y) foamed with a chemical foaming agent. (X) a polypropylene random copolymer composition having a melting point of 120 to 150 ° C and a melt flow rate (hereinafter abbreviated as MFR) [230 ° C; 21.18N] of 0.3 to 20 (Y) 01 to 5 parts by weight and the following (b)
100 parts by weight, MFR 0.1 to 10 g / 10
(a) intrinsic viscosity [η] measured in tetralin at 135 ° C.
_E ] is 15 to 100 dl / g. (B) Intrinsic viscosity [η] measured in tetralin at 135 ° C.
_P ] is 0.2 to 10 dl / g. (2) In the above (1), the olefin polymer of (a) is the following (a '). (A ′) An ethylene homopolymer or an ethylene-olefin copolymer containing 50% by weight or more of ethylene polymer units having an intrinsic viscosity [η _E ] of 15 to 100 dl / g measured in tetralin at 135 ° C. (3) In the above (1) or (2), the olefin according to the olefin polymer or the ethylene-olefin copolymer is propylene, 1-butene, 1-pentene,
-Hexene, 1-octene, 1-decene, 4-methyl-
A polypropylene foam hollow molded article which is one or more selected from 1-pentene and 3-methyl-1-pentene.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The polypropylene random copolymer composition (X) used for the skin layer in the present invention will be described. The polypropylene random copolymer composition (X) used for the skin layer of the present invention is a composition comprising a random copolymer of propylene and ethylene or an α-olefin having 4 or more carbon atoms having a melting point of 120 to 150 ° C. And can be obtained by a known method using a Ziegler-Natta catalyst or the like. If the melting point is significantly lower than 120 ° C., the heat resistance of the obtained molded article is lowered, and the releasability from a mold during blow molding is lowered, which is not preferable. If the melting point is higher than 150 ° C., the effect of improving gloss is small, which is not preferable. MFR of the polypropylene random copolymer composition (X) used in the present invention is from 0.3 to 20, preferably from 0.5 to 20.
15, more preferably 1 to 10. When the MFR is significantly lower than 0.3, the improvement in gloss is small.
If the MFR exceeds 20, the releasability from the mold during molding deteriorates, which is not preferable. When a nucleating agent such as a sorbitol is added to the polypropylene random copolymer composition (X) used for the skin layer, a molded article having more excellent gloss and visual appearance can be obtained. To the polypropylene random copolymer composition (X) used for the skin layer, an elastomer such as polyethylene and EPR, an antioxidant, an ultraviolet absorber, an antistatic agent and the like are added as long as the effects of the present invention are not impaired. be able to.

The polypropylene polymer composition (Y) used in the present invention will be described. The olefin polymer of the component (a) constituting the polypropylene polymer composition (Y) used in the present invention is an olefin polymer having an intrinsic viscosity [η _E ] of 15 to 100 dl / g measured in tetralin at 135 ° C. And includes polyethylene within this intrinsic viscosity range, and has 50
Includes ethylene-olefin copolymers containing at least 1% by weight. Preferred are ethylene homopolymers or ethylene-olefin copolymers containing 70% by weight or more of ethylene polymerized units, and particularly preferred are ethylene homopolymers or ethylene-olefin copolymers containing 90% by weight or more of ethylene polymerized units. These polymers may be used alone or in combination of two or more. The intrinsic viscosity [η _E ] of the olefin polymer of the component (a) is 15 dl / g.
When the value is much lower than the above, the effect of improving the melt tension of the obtained polypropylene polymer composition (Y) becomes insufficient, and the foaming properties are poor. The upper limit of the intrinsic viscosity [η _E ] is not particularly limited. However, if the difference from the intrinsic viscosity [η _P ] of the polypropylene of the component (b) is too large, the polypropylene of the component (b) may be used as a composition. Since the dispersion of the olefin polymer of the component (a) therein tends to deteriorate, the melt tension does not increase as a result. Further, from the viewpoint of manufacturing efficiency, the upper limit is preferably set to a level not exceeding 100 dl / g. Accordingly, the intrinsic viscosity [η _E ] of the olefin polymer of the component (a) is in the range of 15 to 100 dl / g, preferably 17 to 50 dl / g. In addition, since the olefin polymer of the component (a) must have a high molecular weight up to 15 dl / g in intrinsic viscosity [η _E ] measured in tetralin at 135 ° C., ethylene polymer units are required from the viewpoint of high molecular weight efficiency. Is preferably contained by 50% by weight or more.
The olefin other than ethylene constituting the olefin polymer of the component (a) is not particularly limited, but may have 3 carbon atoms.
To 12 olefins are preferably used. Specific examples include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, and 3-methyl-1-pentene. May be not only one kind but also two or more kinds. Regarding the density of the olefin polymer of the component (a),
Although there is no particular limitation, specifically, 0.880 to 0.98
Those having about 0 g / cm ³ are preferable.

The component (b) constituting the polypropylene polymer composition (Y) used in the present invention is a propylene homopolymer, a propylene-olefin block copolymer containing 50% by weight or more of propylene polymer units, a propylene polymer. It is a propylene-olefin random copolymer containing 50% by weight or more of units. These polymers may be not only one kind but also a mixture of two or more kinds. A propylene-olefin copolymer in which the propylene polymerization unit is much less than 50% by weight is not preferable because the heat resistance of a hollow molded article using the obtained composition is reduced. The intrinsic viscosity [η _P ] of the polypropylene as the component (b) is 0.2 to 10
dl / g, preferably 0.5 to 8 dl / g. Intrinsic viscosity [η of the component (b) polypropylene
_{When P} ] is less than 0.2 dl / g, the mechanical properties of the obtained hollow molded article deteriorate, and when it exceeds 10 dl / g, the moldability of the obtained polypropylene polymer composition (Y) deteriorates. The olefin other than propylene copolymerized with propylene constituting the polypropylene of the component (b) is not particularly limited, but an olefin having 2 to 12 carbon atoms is preferably used. Specifically, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene,
-Decene, 4-methyl-1-pentene, 3-methyl-1
-Pentene, etc., and these olefins may be not only one kind but also two or more kinds. The stereoregularity of the component (b) polypropylene is not particularly limited, and any polypropylene that achieves the object of the present invention may be used as long as it is a crystalline polypropylene. In particular
^The isotactic pendad fraction (mmmm) measured by ¹³ C-NMR (nuclear magnetic resonance spectrum) is 0.80 to 0.80.
A polypropylene having a crystallinity of 0.99, preferably 0.85 to 0.99, particularly preferably 0.90 to 0.99 is used. Isotactic pendad fraction (m
mmm) is ¹³ C-NM proposed by A. Zambelli et al. (Macromolecules 6,925 (1973)).
R is the isotactic fraction in pentad units in the polypropylene molecular chain measured by R. A method for determining peak assignment in spectrum measurement is proposed by A. Zambelli et al. (Macromolecules 8,687
(1975)). Specifically, a mixed solution of o-dichlorobenzene / deuterated bromobenzene having a polymer concentration of 20% by weight = 8/2 by weight was used, and 67.2 was used.
It is determined by measuring at 0 MHz and 130 ° C. As a measuring device, for example, JEOL-GX270
An NMR measurement device (manufactured by JEOL Ltd.) is used.

[0008] The polypropylene polymer composition (Y) used in the present invention contains 0.01 to 5 parts by weight, preferably 0.02 to 2 parts by weight of the olefin polymer of the component (a).
Particularly preferably, it comprises 0.05 to 1 part by weight and 100 parts by weight of the component (b) polypropylene. When the olefin polymer of the component (a) is less than 0.01 part by weight, the effect of improving the melt tension of the obtained polypropylene polymer composition (Y) is small and the foamability is poor, and when it exceeds 5 parts by weight, the effect is increased. Is saturated, and the homogeneity of the obtained polypropylene polymer composition (Y) may be impaired. The MFR [230 ° C .; 21.18N] of the polypropylene polymer composition (Y) used in the present invention is 0.1 to 10
g / 10 min, preferably 0.1 to 8 g / 10 mi
n, more preferably 0.2 to 5 g / 10 min.
If the MFR [230 ° C .; 21.18 N] exceeds 10 g / 10 min, the drawdown becomes large and molding failure occurs. MFR [230 ° C .; 21.18N] is 0.1 g / 10
The load current of the blow molding machine is much lower than min.
The resin pressure is undesirably high. Further, the melt tension of the polypropylene polymer composition (Y) used in the present invention is:
It is preferably 3 to 30 cN, and if the melt tension is too large, the moldability of the composition is deteriorated, so that it is preferably 30 cN or less, while if it is too small, the drawdown becomes remarkable, and using a parison controller of a hollow molding machine. Also, since molding becomes extremely difficult due to uneven thickness of the molded article or cutting of the molten parison, 3 cN or more is preferable.
The melt tension of the polypropylene polymer composition (Y) used in the present invention is 230 ° C. (M)
S) and intrinsic viscosity [η] measured in tetralin at 135 ° C.
_T ] and log (MS)> 4.24 × log [η _T ] −1.05. The upper limit is not particularly limited, but if the melt tension is too high, the moldability of the composition deteriorates. Therefore, preferably 4.24 × log [η _T ] +0.50> log (MS)> 4.24 × log [η
_T ] -1.05, more preferably 4.24 × log [η _T ] +0.24> log (MS)> 4.24 × log [η
_T ] -1.05 Most preferably 4.24 × log [η _T ] +0.24> log (MS)> 4.24 × log [η
_T ] -0.93. Here, the melt tension at 230 ° C. is determined by heating the composition to 230 ° C. in an apparatus using a melt tension tester type 2 manufactured by Toyo Seiki Seisaku-sho, Ltd.
The molten composition was poured into a nozzle having a diameter of 2.095 mm by 20
It is a value (unit: cN) obtained by extruding into a 23 ° C. atmosphere at a speed of mm / min to form a strand, and measuring the tension of the thread-like composition when the strand is pulled at a speed of 3.14 m / min.

The method for producing the polypropylene polymer composition (Y) used in the present invention is not limited to the production method as long as the melt tension of the composition satisfies the above range. It can be easily produced by employing a method of polymerizing propylene or propylene with another olefin in the presence of a catalyst preactivated with one or more olefins.

As used herein, the term "pre-activation" refers to pre-activating the high molecular weight activity of the polyolefin production catalyst prior to carrying out the main polymerization of propylene or propylene with other olefins. This means that one or more olefins are preactivatedly polymerized in the presence of a catalyst for producing a polyolefin and supported on the catalyst. The preactivation catalyst used in producing the polypropylene polymer composition (Y) used in the present invention is a transition metal compound catalyst component containing at least a titanium compound, and 0.01 to 1 mol per mol of the transition metal atom. , 00
Periodic Table of 0 moles (1991 edition)
An organometallic compound [AL1] of a metal selected from the group consisting of metals belonging to Group 2 and Group 13, and 0 to 500 moles of an electron donor [Ed based on 1 mole of a transition metal atom;
1], and an intrinsic viscosity [η] of less than 15 dl / g measured in tetraline at 135 ° C. of 0.01 to 100 g per 1 g of the transition metal compound component supported on the catalyst. Polypropylene (B) for the main polymerization purpose and 0.01 to 5,000 g of 13 per 1 g of the transition metal compound catalyst component
The intrinsic viscosity [η] measured in tetralin at 5 ° C. is 15 to
An olefin polymer (A) having a weight ratio of 100 dl / g. In the preactivation catalyst, as the transition metal compound catalyst component, any of the known catalyst components mainly composed of a transition metal compound catalyst component containing at least a titanium compound proposed for polyolefin production can be used. Among them, a titanium-containing solid catalyst is preferably used for industrial production. As the titanium-containing solid catalyst component,
Titanium-containing solid catalyst component containing titanium trichloride composition as a main component (JP-B-56-3356, JP-B-59-28)
No. 573, JP-B-63-66323, etc.), titanium tetrachloride bearing magnesium compound, titanium,
A supported titanium-containing catalyst component containing magnesium, halogen, and an electron donor as essential components (Japanese Patent Application Laid-Open No. 62-104)
810, JP-A-62-104811, JP-A-62-104812, JP-A-57-63310
JP-A-57-63311, JP-A-58-63311
No. 83006, JP-A-58-138712) and the like have been proposed, and any of these can be used.

As the organometallic compound [AL1], the periodic table (1991 edition), Group 1, Group 2, Group 12, and Group 1
A compound having an organic group of a metal selected from the group consisting of metals belonging to Group 3, such as an organolithium compound, an organosodium compound, an organomagnesium compound, an organozinc compound, an organoaluminum compound, and the like; Can be used in combination with In particular, the general formula is AlR ₁ pR ₂ qX _3- (p + q) (where R
₁ and R ₂ are the same or different of a hydrocarbon group and an alkoxy group such as an alkyl group, a cycloalkyl group and an aryl group; X represents a halogen atom;
<Representing a positive number of p + q ≦ 3) can be suitably used. Specific examples of the organoaluminum compound include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, and tri-i.
-Butyl aluminum, tri-n-hexyl aluminum, tri-i-hexyl aluminum, trialkyl aluminum such as tri-n-octyl aluminum, diethyl aluminum chloride, di-n-propyl aluminum chloride, di-i-butyl aluminum chloride, Diethoxyaluminum monohalides such as diethylaluminum bromide and diethylaluminum iodide, dialkylaluminum hydrides such as diethylaluminum hydride, alkylaluminum sesquihalides such as ethylaluminum sesquichloride, monoalkylaluminum dihalides such as ethylaluminum dichloride and other diethoxys Alkoxyalkyl aluminum such as monoethyl aluminum can be mentioned, Mashiku uses trialkylaluminum and dialkylaluminum monohalide. These organoaluminum compounds can be used alone or in combination of two or more.

The electron donor [Ed1] is used as needed for the purpose of controlling the production rate and / or stereoregularity of the polyolefin. Electron donor [Ed
1] includes, for example, ethers, alcohols, esters, aldehydes, fatty acids, ketones, nitriles, amines, amides, ureas and thioureas, isocyanates, azo compounds, phosphines, phosphites , Phosphinite, hydrogen sulfide and organic compounds having any atom of oxygen, nitrogen, sulfur or phosphorus in the molecule such as thioethers, neoalcohols, silanols, etc. and having Si-OC bond in the molecule And organic silicon compounds. As ethers, dimethyl ether, diethyl ether, di-n-propyl ether, di-n-butyl ether, di-i-amyl ether, di-n-pentyl ether, di-n-hexyl ether, di-i-hexyl ether , Di-n-octyl ether, di-i-octyl ether, di-n-dodecyl ether, diphenyl ether, ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, etc., and alcohols such as methanol, ethanol, propanol, butanol, ぺTonnol, hexanol, octanol, 2-
Ethylhexanol, allyl alcohol, benzyl alcohol, ethylene glycol, glycerin and the like, and phenols such as phenol, cresol, xylenol, ethylphenol, naphthol and the like.
Esters include methyl methacrylate, methyl formate, methyl acetate, methyl butyrate, ethyl acetate, vinyl acetate, n-propyl acetate, i-propyl acetate, butyl formate, amyl acetate, n-butyl acetate, octyl acetate ,
Phenyl acetate, ethyl propionate, methyl benzoate,
Ethyl benzoate, propyl benzoate, butyl benzoate,
Octyl benzoate, 2-ethylhexyl benzoate, methyl toluate, ethyl toluate, methyl anisate,
Monocarboxylic acid esters such as ethyl anisate, propyl anisate, phenyl anisate, ethyl cinnamate, methyl naphthoate, ethyl naphthoate, propyl naphthoate, butyl naphthoate, 2-ethylhexyl naphthoate, and ethyl phenylacetate Aliphatic polycarboxylic acid esters such as diethyl succinate, diethyl methyl malonate, diethyl butyl malonate, dibutyl maleate, diethyl butyl maleate, monomethyl phthalate, dimethyl phthalate, diethyl phthalate, and di-phthalate. n-propyl, mono-n-butyl phthalate, di-n-butyl phthalate, di-i-butyl phthalate, di-n-heptyl phthalate, di-2-ethylhexyl phthalate, di-n-phthalate
-Octyl, i-diethyl phthalate, dipropyl i-phthalate, dibutyl i-phthalate, di-2-phthalic i-phthalate
Aromatic polycarboxylic acid esters such as ethylhexyl, diethyl terephthalate, dipropyl terephthalate, dibutyl terephthalate, and di-i-butyl naphthalenedicarboxylate are exemplified.

The aldehydes include acetaldehyde, propionaldehyde, benzaldehyde and the like, and the carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid,
Monocarboxylic acids such as oxalic acid, succinic acid, acrylic acid, maleic acid, valeric acid, and benzoic acid and acid anhydrides such as benzoic anhydride, phthalic anhydride, and tetrahydrophthalic anhydride are used as ketones such as acetone, methyl ethyl ketone,
Examples thereof include methyl-i-butyl ketone and benzophenone.

Examples of the nitrogen-containing compound include nitriles such as acetonitrile and benzonitrile, methylamine, diethylamine, tributylamine, triethanolamine, β (N, N-dimethylamino) ethanol, pyridine, quinoline, α-picoline, , 4,6-trimethylpyridine, 2,2,5,6-tetramethylpiperidine,
2,2,5,5, tetramethylpyrrolidine, N, N,
Amines such as N ′, N′-tetramethylethylenediamine, aniline, dimethylaniline, formamide, hexamethylphosphoric triamide, N, N, N ′, N ′,
Amides such as N "-pentamethyl-N'-β-dimethylaminomethylphosphoric triamide, octamethylpyrophosphoramide, ureas such as N, N, N ', N'-tetramethylurea, phenylisocyanate, toluyl Examples include isocyanates such as isocyanate and azo compounds such as azobenzene.

Examples of the phosphorus-containing compound include phosphines such as ethyl phosphine, triethyl phosphine, tri-n-octyl phosphine, triphenyl phosphine, triphenyl phosphine oxide, dimethyl phosphite,
Phosphines such as di-n-octylphosphine, triphenylphosphine and triphenylphosphine oxide, dimethyl phosphite, di-n-octyl phosphite, triethyl phosphite, tri-n-butyl phosphite and triphenyl phosphite; Phosphites are exemplified.

Examples of the sulfur-containing compound include thioethers such as diethylthioether, diphenylthioether, and methylphenylthioether; ethylthioalcohol;
thioalcohols such as n-propylthioalcohol and thiophenol; and further, as an organosilicon compound, trimethylsilanol, triethylsilanol,
Silanols such as triphenylsilanol, trimethylmethoxysilane, dime, rudimethoxysilane, methylphenyldimethoxysilane, diphenyldimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, trimethylethoxysilane, dimethyldiethoxysilane , Di-i-propyldimethoxysilane, di-i-butyldimethoxysilane, diphenyldiethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, ethyltriiso Propoxysilane, vinyltriacetoxysilane, cyclopentylmethyldimethoxysilane, cyclopentyltrimethoxysilane, dicyclopentyldimethoxy Silane, cyclohexyl methyl dimethoxy silane, cyclohexyl trimethoxy silane, dicyclohexyl dimethoxysilane, in the molecule such as 2-norbornyl methyl dimethoxy silane Si-O-C
An organic silicon compound having a bond may be used. These electron donors can be used alone or as a mixture of two or more.

In the preactivated catalyst, the olefin polymer (A) has an intrinsic viscosity [η] measured in tetralin at 135 ° C. of 15 to 100 dl / g, preferably 17 to 5 dl / g.
One or more olefin polymers in the range of 0 dl / g (preferably, ethylene homopolymer or ethylene polymer units are 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more (A copolymer of ethylene and an olefin having 3 to 12 carbon atoms), and finally constitutes the olefin polymer of the component (a) of the polypropylene polymer composition (Y) used in the present invention. Therefore, the intrinsic viscosity [η1] of the component (a) of the polypropylene polymer composition (Y) used in the present invention and the intrinsic viscosity [η2] of the olefin polymer (A) are [η1
] = [Η2].

The amount of the olefin polymer (A) supported per gram of the catalyst component of the transition metal compound is 0.01 to 5,000.
g, preferably 0.05 to 2,000 g, and more preferably 0.1 to 1,000 g. When the amount supported per 1 g of the transition metal compound catalyst component is less than 0.01 g, the effect of improving the melt tension of the polypropylene polymer composition (Y) finally obtained by the (co) polymerization is insufficient. If it exceeds 2,000 g, not only the improvement of these effects will not be remarkable, but also the homogeneity of the finally obtained polypropylene polymer composition (Y) may be unfavorably deteriorated.

On the other hand, polypropylene (B) has a temperature of 135 ° C.
Has an intrinsic viscosity [η] of 15 dl /
g of polypropylene having the same composition as that of component (b) for the purpose of main polymerization, and finally one of the polypropylene of component (b) of the polypropylene polymer composition (Y) used in the present invention. Incorporated as a department. The polypropylene (B) is a component that imparts dispersibility to the finally obtained polypropylene polymer composition (Y) of the olefin polymer (A). It is preferably smaller than the intrinsic viscosity of (A) and larger than the intrinsic viscosity of the finally obtained polypropylene polymer composition (Y). On the other hand, the supported amount of polypropylene (B) per 1 g of the transition metal compound catalyst component is preferably from 0.01 to 100 g, in other words, the range of 0.001 to 1% by weight based on the finally obtained polypropylene polymer composition. It is. If the supported amount of the polypropylene (B) is small, the dispersibility of the olefin polymer (A) in the target polypropylene polymer composition (Y) becomes insufficient, and if it is too large, the polypropylene weight of the olefin polymer (A) becomes small. Not only does the effect on the coalesced composition (Y) become saturated, but also the production efficiency of the preactivated catalyst decreases.

In the present improved configuration, the preactivated catalyst comprises:
In the presence of a catalyst for the production of polyolefin comprising a combination of the above-mentioned transition metal compound catalyst component containing at least a titanium compound, an organometallic compound [AL1] and an optional electron donor [Ed1], propylene or propylene for the purpose of this polymerization is used. And other olefins are prepolymerized to produce polypropylene, and then one or two
An olefin polymer (A) is produced by pre-activation polymerization of one or more kinds of olefins, and the olefin polymer (A) is produced by a pre-activation treatment in which the transition metal compound catalyst component carries the polypropylene (B) and the olefin polymer (A).

In this preactivation treatment, a transition metal compound catalyst component containing a titanium compound and 0.01 to 1,000 mol, preferably 0.05 to 500 mol of an organic metal are added to 1 mol of the transition metal in the catalyst component. 0 to 500 mol, preferably 0 to 100 mol, of the electron donor [Ed1] based on 1 mol of the transition metal in the compound [AL1] and the catalyst component
And used as a catalyst for polyolefin production.

The catalyst for producing a polyolefin is used in an amount of 0.001 to 1 in terms of transition metal atoms in a catalyst component per liter of polymerization volume of one or more olefins.
5,000 mmol, preferably 0.01 to 1,000
In the absence of a solvent or in a solvent up to 100 liters per 1 g of the transition metal compound catalyst component, 0.01 to 500 g of propylene or a mixture of propylene and other olefins for the purpose of this polymerization is supplied to prepare The polymerization is carried out to produce 0.01 to 100 g of polypropylene (B) per 1 g of the transition metal compound catalyst component. Then 0.01 g of one or more olefins
-10,000 g is supplied and preactivated polymerization is performed, and 0.01-5,000 g per 1 g of the transition metal compound catalyst component is used.
The polypropylene (B) and the olefin polymer (A) are coated and supported on the transition metal compound catalyst component by producing the olefin polymer (A).

In the present specification, the term “polymerization volume” refers to the volume of the liquid phase portion in the polymerization vessel in the case of liquid phase polymerization.
In the case of gas phase polymerization, it means the volume of the gas phase portion in the polymerization vessel. The amount of the transition metal compound catalyst component is used to maintain an efficient and controlled polymerization reaction rate of propylene.
It is preferably within the above range. On the other hand, if the amount of the organometallic compound [AL1] is too small, the (co) polymerization reaction rate will be too slow. It is not preferable because the amount of the organic metal compound [AL1] remaining in the polypropylene polymer composition increases. Further, if the amount of the electron donor [Ed1] is too large, the polymerization reaction rate is reduced. If the amount of the solvent used is too large, not only a large reaction vessel is required, but also it is difficult to efficiently control and maintain the polymerization reaction rate.

The preactivation treatment includes, for example, aliphatic hydrocarbons such as butane, pentane, hexane, heptane, octane, isooctane, decane and dodecane; alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclohexane; The reaction can be carried out in a liquid phase using an aromatic hydrocarbon such as xylene or ethylbenzene, an inert solvent such as a gasoline fraction or a hydrogenated diesel oil fraction, or an olefin itself as a solvent. It is also possible to do it in phase. The pre-activation treatment may be performed in the presence of hydrogen, but the intrinsic viscosity [η] is 15 to 1
In order to produce an olefin polymer (A) having a high molecular weight of 00 dl / g, it is preferable not to use hydrogen.
In the pre-activation treatment, the pre-polymerization conditions of propylene or a mixture of propylene and other olefins for the purpose of the main polymerization are such that polypropylene (B) is produced in an amount of 0.01 g to 100 g per 1 g of the transition metal compound catalyst component. Well, usually at a temperature of -40 ° C to 100 ° C, 0.1
It is performed under a pressure of 1 MPa to 5 MPa for 1 minute to 24 hours. The pre-activation polymerization conditions for the mixture with one or more olefins are such that the olefin polymer (A) is used in an amount of 0.01 to 5,000 per gram of the transition metal compound catalyst component.
g, preferably from 0.05 to 2,000 g, more preferably from 0.1 to 1,000 g, without any particular limitation, and is usually -40 ° C to 40 ° C, preferably- 40 ° C to 30 ° C, more preferably -40 ° C to
0.1MPa-5MP under relatively low temperature of about 20 ℃
a, preferably under a pressure of 0.2 MPa to 5 MPa, particularly preferably 0.3 MPa to 5 MPa, for 1 minute to 24 hours, preferably 5 minutes to 18 hours, particularly preferably 10 minutes to 12 hours.

After the pre-activation treatment, addition polymerization with propylene or a mixture of propylene and other olefins for the purpose of main polymerization is carried out by transition, in order to suppress a decrease in the main polymerization activity due to the pre-activation treatment. The reaction may be performed at a reaction amount of 0.01 to 100 g of polypropylene (C) per 1 g of the metal compound catalyst component. In this case, the amount of the organometallic compound [AL1], the electron donor [Ed1], the solvent, and the amount of propylene or a mixture of propylene and other olefins are the same as in the preactivated polymerization using one or more olefins. Within a range of 0.005 to 1 per mole of transition metal atom.
It is preferably carried out in the presence of 0 mol, preferably 0.01 to 5 mol of electron donor. As for the reaction conditions,
It is carried out at a temperature of 40 to 100 ° C. under a pressure of 0.1 to 5 MPa for 1 minute to 24 hours.

The organometallic compound [A] used for the addition polymerization
L1], the electron donor [Ed1], and the type of the solvent may be the same as those used in the preactivated polymerization using ethylene or a mixture of ethylene and another olefin.
For propylene or a mixture of propylene and another olefin, one having the same composition as for the purpose of the present polymerization is used. The intrinsic viscosity [η] of the polypropylene produced by the addition polymerization is in a range smaller than the intrinsic viscosity [η] of the olefin polymer (A), and finally, as a part of the polypropylene of the component (b) after the main polymerization. Incorporated.

The preactivated catalyst may be used as such or with an additional organometallic compound [AL2] and an electron donor [Ed2].
Can be used in the main polymerization of an olefin having 2 to 12 carbon atoms to obtain the desired polypropylene polymer composition (Y). The olefin main polymerization catalyst comprises a total of [AL1 + AL2] of the preactivated catalyst and the organometallic compound [AL1] in the activated catalyst with respect to 1 mol of the transition metal atom in the preactivated catalyst. ] 0.05-
The electron donor [Ed2] in the preactivated catalyst is used for 3,000 mol, preferably 0.1 to 1,000 mol and 1 mol of the transition metal atom in the activated catalyst.
1] and the total [Ed1 + Ed2] is from 0 to 5,000 mol, preferably from 0 to 3,000 mol. If the content of the organometallic compound [AL1 + AL2] is too small, the polymerization reaction rate in the main polymerization of propylene or propylene and other olefins is too slow. Not only is it inefficient and is not recognized, but also it is not preferable because the organometallic compound residue remaining in the finally obtained polypropylene polymer composition (Y) increases. Further, when the content of the electron donor [Ed1 + Ed2] is too large, the polymerization reaction rate is remarkably reduced.

The types of the organometallic compound [AL2] and the electron donor [Ed2] that are additionally used as necessary in the olefin main polymerization catalyst are as described above for the organometallic compound [AL1] and the electron donor [Ed1]. The same can be used. One type may be used alone, or two or more types may be used in combination. Further, they may be the same or different from those used in the pre-activation treatment. The catalyst for the main polymerization of olefin is a solvent, an unreacted olefin, an organometallic compound [AL
1] and a particle obtained by removing or decanting the electron donor [Ed1] and the like, or a suspension obtained by adding a solvent to the particle, and an additional organometallic compound [AL2 And, if desired, an electron donor [Ed2], and a powder or granules obtained by removing the solvent and unreacted olefin present by evaporation under reduced pressure or by an inert gas stream or the like. A suspension obtained by adding a solvent to the granules may be combined with an organometallic compound [AL2] and an electron donor [Ed2], if desired.

In the method for producing the polypropylene polymer composition (Y) used in the present invention, the amount of the preactivated catalyst or the catalyst for olefin main polymerization is determined by the amount of transition in the preactivated catalyst per liter of polymerization volume. It is used in an amount of 0.001 to 1,000 mmol, preferably 0.005 to 500 mmol, in terms of metal atoms. By setting the amount of the transition metal compound catalyst component in the above range, it is possible to maintain an efficient and controlled polymerization reaction rate of propylene or a mixture of propylene and a composition olefin. In the production of the polypropylene polymer composition (Y) used in the present invention, for the main polymerization of propylene or a mixture of propylene and another olefin, an olefin polymerization process known as the polymerization process can be used. Specifically, propane, butane, pentane, hexane, heptane, octane, isooctane, decane,
Aliphatic hydrocarbons such as dodecane, cyclopentane, cyclohexane, alicyclic hydrocarbons such as methylcyclohexane,
A slurry polymerization method in which olefins are polymerized in an aromatic hydrocarbon such as toluene, xylene, and ethylbenzene, and in an inert solvent such as a gasoline fraction or a hydrogenated diesel oil fraction. legal,
A gas phase polymerization method in which olefin polymerization is carried out in a gas phase, a liquid phase polymerization in which a polyolefin produced by polymerization is in a liquid state, or a polymerization process combining two or more of these processes can be used.

When using any of the above polymerization processes, the polymerization conditions include a polymerization temperature of 20 to 120 ° C., preferably 30 to 100 ° C., and particularly preferably 40 to 100 ° C.
° C, the polymerization pressure is 0.1 to 5 MPa, preferably in the range of 0.3 to 5 MPa, continuous, semi-continuous,
Alternatively, the polymerization time in the range of about 5 minutes to 24 hours is employed in a batch manner. By adopting the above polymerization conditions, the polypropylene as the component (b) can be produced with high efficiency and a controlled reaction rate. In a more preferred embodiment of the method for producing the polypropylene polymer composition (Y) used in the present invention, the polypropylene of the component (b) produced in the main polymerization and the finally obtained polypropylene polymer composition (Y) are used. MFR [230 ° C; 2
1.18N] is 0.1 to 10 g / 10 min, preferably 0.1 to 8 g / 10 min, and more preferably 0.2 to 5 g / 10 min.
g / 10 min, and in the obtained polypropylene polymer composition (Y), the olefin polymer (a) derived from the preactivated catalyst used is in the range of 0.01 to 5% by weight. Select polymerization conditions. Further, similarly to the known olefin polymerization method, the MFR of the obtained polymer can be adjusted by using hydrogen during the polymerization.

After the completion of the main polymerization, if necessary, a post-treatment step such as a catalyst deactivation treatment step, a catalyst residue removal step, and a drying step is carried out, and the desired polypropylene polymer composition having the desired high melt tension ( Y) is finally obtained.

In the method for producing the polypropylene polymer composition (Y) used in the present invention, a high molecular weight olefin polymer (A) is produced by a pre-activation step, and Since the method of uniformly dispersing in Y) is employed, the required amount of the preactivated catalyst can be adjusted collectively, while the main polymerization of propylene or propylene and other olefins is usually carried out using an existing process. Since it is sufficient to carry out the olefin polymerization, it is possible to maintain the same production amount as in the ordinary production of polyolefin. By adopting the production method using this preactivated catalyst,
Relationship between melt tension (MS) at 30 ° C. and intrinsic viscosity [η _T ] measured in tetralin at 135 ° C., MFR [2
30 ° C .; 21.18 N] can easily be obtained.

The polypropylene polymer composition (Y) used in the present invention contains, in addition to the above-mentioned components, antioxidants, neutralizing agents, weathering agents, ultraviolet absorbers, antistatic agents as stabilizers. As other additives, a colorant, a crystal nucleating agent, an inorganic powder, an ethylene-vinyl acetate copolymer, an ethylene-propylene crystalline random copolymer, a high-density polyethylene and the like can be blended within a range that does not impair the object of the present invention. As the chemical blowing agent used in the present invention,
Any chemical blowing agent known to be suitable for foaming various propylene or ethylene resins can be used. Typical of such blowing agents are, for example, azodicarbonamide, dinitropentamethylenetetramine, P, P'-oxybisbenzenesulfonylhydrazide, P, P'-oxybisbenzenesulfonyl semicarbazide, N, Foaming agents such as N'-dimethyl-N, N'-dinitrosoterephthalamide, baking soda and the like. As the foaming agent, one kind may be used alone, or a plurality of kinds may be mixed and used. The amount of the foaming agent to be used is 0.05 to 5 parts by weight, preferably 0.1 to 2 parts by weight, based on the polypropylene polymer composition (Y). If the amount of the foaming agent is less than 0.05 part by weight, the foaming ratio is too low to obtain a clear foam. If the amount is more than 5 parts by weight, the dispersion of the foaming agent is unfavorably deteriorated.

The foamed hollow molded article of the present invention is a molded article having a multilayer structure in which the surface layer is a polypropylene random copolymer composition (X) and the inner layer is a foamed polypropylene composition (Y) with a chemical foaming agent. The surface layer is preferably as thin as possible from the viewpoint of weight reduction which is a characteristic of the foamed product. Although the thickness of the surface layer cannot be determined unconditionally depending on the thickness of the molded product, it is considered that the standard is a minimum of 50 μm and about 15% of the thickness of the entire molded product. With a layer thinner than 50 μm, it is mechanically difficult to extrude a uniform surface layer, and there is a possibility that unevenness in gloss may occur due to thickness fluctuation.

As a method for obtaining the foamed hollow molded article of the present invention, a direct blow molding method and the like can be mentioned. As an example of the direct blow molding method, a multilayer blow molding machine capable of extruding a two-layer parison is used, and the polypropylene random copolymer composition (X) used in the present invention is used in an extruder for a surface layer, The composition obtained by mixing the polypropylene-based composition (X) and the chemical blowing agent used in the present invention is directly supplied to an inner layer extruder. The wall thickness is adjusted by adjusting the extrusion amount of each extruder, the two-layer parison is melt-extruded at an extrusion temperature of 180 to 230 ° C., and pre-blowing is performed as necessary, and the blow molding is maintained at 60 ° C. or less. Hold the parison in the mold and pressurized air (0.5 to 1MP)
A method of inflating the parison by blowing a) can be exemplified.

[0036]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited by these specific examples. The following methods were used to evaluate the characteristics used in the following examples and comparative examples. (1) Intrinsic viscosity [η]: The intrinsic viscosity in tetralin at 135 ° C. measured by an Ostwald viscometer (manufactured by Mitsui Toatsu Chemicals, Inc.) (unit: dl / g). (2) Melt tension (MS): The composition was heated to 230 ° C. in an apparatus using a melt tension tester type 2 manufactured by Toyo Seiki Seisaku-sho, Ltd., and the melted composition was 2.095 in diameter.
A value obtained by extruding into a 23 ° C. atmosphere at a speed of 20 mm / min into a strand at a speed of 20 mm / min into a strand, and measuring the tension of the thread-like composition when the strand is pulled at a rate of 3.14 m / min (unit: cN) . (3) MFR: Test condition 14 of JIS K7210 (2
30 ° C; 21.18N) (unit: g / 10
min). (4) Density: A test piece of 5 cm × 15 cm was cut out from the formed square bottle, and the thickness and weight were measured and calculated (unit: g / cc). (5) Foaming state: The state of the foaming cells in the cross section of the formed square bottle was visually observed. (6) Gloss: The gloss of a test piece cut out of a molded square bottle was measured according to the test conditions (60) of JIS K7105 (1981).
° Specular gloss) (unit%). The composition (Y) used in the inner layer, which was used in Examples and Comparative Examples, was produced by the following method. Table 1 shows the composition of the composition (Y).

[0037]

[Table 1]

Production of PP-1 (1) Preparation of catalyst component for transition metal compound In a stainless steel reactor equipped with a stirrer, decane 0.1.
3 liters, 48 g of anhydrous magnesium chloride, 170 g of n-butyl orthotitanate and 195 g of 2-ethyl-1-hexanol were mixed, and the mixture was heated to 130 ° C. while stirring.
The mixture was heated for a period of time to dissolve to form a uniform solution. This homogeneous solution was heated to 70 ° C., 18 g of di-i-butyl phthalate was added with stirring, and after 1 hour, 520 g of silicon tetrachloride was added over 2.5 hours to precipitate a solid.
For one hour. The solid was separated from the solution and washed with hexane to give a solid product. The total amount of solid product was 1,2
Mixed with 1.5 liters of titanium tetrachloride dissolved in 1.5 liters of dichloroethane, then di-i-phthalic acid
After adding 36 g of butyl and reacting with stirring at 100 ° C. for 2 hours, the liquid phase was removed by decantation at the same temperature, and 1.5 l of 1,2-dichloroethane and 1.5 l of titanium tetrachloride were added again. , 100 ° C
For 2 hours, washed with hexane and dried to obtain titanium 2.
A titanium-containing supported catalyst component (transition metal compound catalyst component) containing 8% by weight was obtained.

(2) Preparation of Preactivated Catalyst After replacing a stainless steel reactor having an inner volume of 5 liters with inclined blades with nitrogen gas, 2.8 liters of n-hexane was added.
Triethyl aluminum (organic metal compound (AL1))
After adding 4 mmol and 9.0 g of the titanium-containing supported catalyst component prepared in the preceding paragraph (5.26 mmol in terms of titanium atoms), 20 g of propylene was supplied, and prepolymerization was performed at -2 ° C for 10 minutes. Separately, when the polymer formed after the preliminary polymerization performed under the same conditions was analyzed, 2 g of propylene was converted to polypropylene (B) per 1 g of the titanium-containing supported catalyst component, and the polypropylene (B) was 135 ° C.
Has an intrinsic viscosity [η _B ] of 2.8 d measured in tetralin.
1 / g. After the completion of the reaction time, unreacted propylene is discharged out of the reactor, and the gas phase of the reactor is replaced with nitrogen once. Then, while maintaining the temperature in the reactor at -1 ° C, the pressure in the pressure reactor is reduced. Ethylene was continuously supplied to the reactor for 2 hours so that the pressure was maintained at 0.59 MPa, and preactivation polymerization was performed. Separately, as a result of analyzing the polymer formed after the preliminary polymerization performed under the same conditions, 24 g of the polymer was present per 1 g of the titanium-containing supported catalyst component, and 135 g of the polymer was present.
Intrinsic viscosity [η _T2 ] measured in tetralin at 31 ° C.
It was 4 dl / g. The amount of polyethylene (A) per gram of the titanium-containing supported catalyst component (W ₂ ) produced by the preactivation polymerization with ethylene is determined by the amount of the polymer produced per gram of the titanium-containing supported catalyst component after the preactivation treatment (W _T2). ) And 1 g of the supported catalyst component containing titanium after prepolymerization
It is determined by the following formula as a difference from the amount of the produced polypropylene (B) per unit (W ₁ ). W ₂ = W _T2 −W ₁ The intrinsic viscosity [η _A ] of the polyethylene (A) produced by preactivation with ethylene is the intrinsic viscosity [η _B ] of the polypropylene (B) produced by prepolymerization and the preliminary activity. It can be determined from the intrinsic viscosity [η _T2 ] of the polymer produced by the chemical treatment according to the following equation. [Η _A ] = ([η _T2 ] × W _T2 − [η _B ] × W ₁ ) / (W
_{T 2} −W ₁ ) = [η _E ] According to the above formula, the amount of polyethylene (A) produced by preactivated polymerization with ethylene is 22 g per 1 g of the titanium-containing supported catalyst component, and the intrinsic viscosity [η _E ] is 34.0 dl /.
g. After the reaction time, unreacted ethylene is discharged to the outside of the reactor, and the gas phase of the reactor is replaced with nitrogen once, and then di-i-propyldimethoxysilane (electron donor (E1) ) After adding 1.6 mmol, 20 g of propylene was supplied, and the mixture was kept at 1 ° C for 10 minutes to perform addition polymerization after the preactivation treatment. Separately, the analysis results of the polymer formed by the addition polymerization performed under the same conditions show that the intrinsic viscosity [η _{T3 of the} polymer containing 26 g of the polymer per 1 g of the titanium-containing supported catalyst component and measured in tetralin at 135 ° C. Is 29.2 dl / g, and the production amount (W ₃ ) of polypropylene (C) produced by addition polymerization calculated in the same manner as above is 2 g per 1 g of the titanium-containing supported catalyst component, and the intrinsic viscosity [η _d ] is 2.8 dl /
g. After completion of the reaction time, unreacted propylene is discharged outside the reactor, and the gas phase of the reactor is replaced with nitrogen once,
A pre-activated catalyst slurry for the main polymerization was obtained.

(3) Production of Polypropylene Composition (Main (Co) polymerization of Propylene) A stainless steel polymerization vessel equipped with a stirrer having an internal volume of 500 liters was replaced with nitrogen, and n-hexane 24 at 20 ° C.
0 liters, 780 mmol of triethylaluminum (organic metal compound (AL2)), 78 mmol of di-i-propyldimethoxysilane (electron donor (E2)), and を of the preactivated catalyst slurry obtained above It was charged into the polymerization vessel. Subsequently, 55 liters of hydrogen were introduced into the polymerization vessel, and the temperature was raised to 70 ° C.
Under the conditions described above, propylene was continuously supplied into the polymerization vessel for 2 hours while maintaining the gas phase pressure in the polymerization vessel at 0.79 MPa, to thereby perform main polymerization of propylene. After the polymerization time has elapsed,
One liter of methanol was introduced into the polymerization vessel, and the catalyst was deactivated at 70 ° C. for 15 minutes. Subsequently, after discharging the unreacted gas, the solvent was separated and the polymer b was dried to obtain a polymer having an intrinsic viscosity [η _r ] of 1.97 dl / g.
1 kg was obtained. The obtained polymer is a polypropylene composition having a polyethylene (A) content of 0.25% by weight by preactivated polymerization corresponding to the component (a), and (b)
The intrinsic viscosity [η _P ] of the component polypropylene is 1.97 d.
1 / g. The obtained polypropylene composition (Y)
Has a melt tension (MS) of 4.9 cN. This composition is designated as PP-1. Production of PP-2 In the production of PP-1, the preactivation treatment of (2) was omitted, and propylene was produced under the same conditions as (3) in the presence of the titanium-containing solid catalyst obtained in (1). The polymerization was carried out to produce a polypropylene composition (Y). This composition is referred to as PP-
Called 2. Production of PP-3

(1) Preparation of Catalyst Component for Transition Metal Compound Decane 3 was placed in a stainless steel reactor equipped with a stirrer.
7.5 liters, 7.14 kg of anhydrous magnesium chloride,
And 35.1 liters of 2-ethyl-1-hexanol were mixed and heated to 140 ° C. for 4 hours with stirring to dissolve to form a uniform solution. 1.67 kg of phthalic anhydride was added to the homogeneous solution, and the mixture was further stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride in the uniform solution.
After cooling the obtained homogeneous solution to room temperature (23 ° C.), the entire amount of the homogeneous solution was dropped into 200 liters of titanium tetrachloride kept at −20 ° C. over 3 hours. After the dropwise addition, the temperature was raised to 110 ° C. over 4 hours. When the temperature reached 110 ° C., 5.03 liters of di-i-butyl phthalate was added, and the reaction was carried out with stirring and maintaining at 110 ° C. for 2 hours. After completion of the reaction for 2 hours, the solid portion was collected by hot filtration, and the solid portion was resuspended with 275 liters of titanium tetrachloride.
The reaction was maintained at 0 ° C. for 2 hours. After the completion of the reaction, the solid portion was collected again by hot filtration, and sufficiently washed with n-hexane until no free titanium was detected in the washing solution. Subsequently, the solvent was separated by hot filtration, and the solid portion was dried under reduced pressure to obtain a titanium-containing supported catalyst component (transition metal compound catalyst component) containing 2.4% by weight of titanium hand.

(2) Preparation of Pre-Activated Catalyst After replacing a stainless steel reactor having an internal volume of 30 liters with inclined blades with nitrogen gas, 18 liters of n-hexane was added.
Triethyl aluminum (organic metal compound (AL1))
After adding 60 mmol and 150 g (75.16 mmol in terms of titanium atom) of the titanium-containing supported catalyst component adjusted in the preceding paragraph, 210 g of propylene was supplied, and -1 ° C.
For 20 minutes. Separately, when the polymer formed after the prepolymerization performed under the same conditions was analyzed, 1.2 g of polypropylene (B) was formed per 1 g of the titanium-containing supported catalyst component, and the polypropylene (B) was dissolved in tetralin at 135 ° C. The intrinsic viscosity [η _B ] measured at 2.7 was 2.7 dl / g. After the end of the reaction time, unreacted propylene is discharged outside the reactor, and the gas phase of the reactor is discharged once.
After purging with nitrogen, while keeping the temperature inside the reactor at -1 ° C,
Ethylene was continuously supplied to the reactor for 3 hours so that the pressure in the pressure reactor was maintained at 0.59 MPa, and preactivation polymerization was performed. Separately, as a result of analyzing the polymer formed after the prepolymerization performed under the same conditions, 33.2 g of the polymer was present per 1 g of the titanium-containing supported catalyst component, and the intrinsic viscosity of the polymer measured in tetralin at 135 ° C. [η
_T2 ] was 29.2 dl / g. The amount of polyethylene (A) per gram of the titanium-containing supported catalyst component (W ₂ ) produced by the preactivation polymerization with ethylene is determined by the amount of the polymer produced per gram of the titanium-containing supported catalyst component after the preactivation treatment (W _T2). ) And the amount of produced polypropylene (B) per 1 g of the titanium-containing supported catalyst component (W ₁ ) after the prepolymerization is determined by the following equation. W ₂ = W _T2 −W ₁ The intrinsic viscosity [η _A ] of the polyethylene (A) produced by preactivation with ethylene is the intrinsic viscosity [η _B ] of the polypropylene (B) produced by prepolymerization and the preliminary activity. It can be determined from the intrinsic viscosity [η _T2 ] of the polymer produced by the chemical treatment according to the following equation. [Η _A ] = ([η _T2 ] × W _T2 − [η _B ] × W ₁ ) / (W
_T2 -W ₁₎ = [eta _E] Polyethylene (A) the amount generated by the preactivation polymerization with ethylene according to the above equation, the titanium-containing supported catalyst component 1g per 32g, intrinsic viscosity [eta _E] is 30.2Dl /
g. After the reaction time, unreacted ethylene is discharged to the outside of the reactor, and the gas phase of the reactor is replaced with nitrogen once, and then di-i-propyldimethoxysilane (electron donor (E1) ) After adding 22.5 mmol, 385 g of propylene was supplied, and the mixture was kept at 0 ° C for 20 minutes to carry out addition polymerization after the preactivation treatment. After the completion of the reaction time, unreacted propylene was discharged outside the reactor, and the gas phase of the reactor was replaced with nitrogen once to obtain a preactivated catalyst slurry for main (co) polymerization. Separately, the analysis result of the polymer formed by the addition polymerization performed under the same conditions shows that the intrinsic viscosity measured in tetralin at 135 ° C. of the polymer exists in 35.4 g per 1 g of the titanium-containing supported catalyst component [ η _T3 ] is 27.6 dl / g, and polypropylene (C) produced by addition polymerization calculated in the same manner as above.
Weight of the product (W ₃₎ is per the titanium-containing supported catalyst component 1 g, 2.2 g, the intrinsic viscosity [ηc] was 2.8 dl / g.

(3) Production of Polypropylene Composition (Y) (Main (Co) polymerization of Propylene) Continuous horizontal gas phase polymerization reactor (length / diameter) equipped with a nitrogen-substituted, 110-liter internal volume stirrer = 3.7), 25 kg of a polypropylene powder were introduced, and the preactivated catalyst slurry was further added as a titanium-containing supported catalyst component at 0.61 g / h, triethylaluminum (organometallic compound (AL2)) and di-i-propyl. A 15 wt% n-hexane solution of dimethoxysilane (electron donor (E2)) was continuously supplied so that the molar ratio was 90 and 15 with respect to titanium atoms in the titanium-containing supported catalyst component, respectively. Further, the ratio of the hydrogen concentration in the polymerization vessel to the propylene concentration was 0.00
2 and then the pressure in the polymerization vessel is 1.7.
Propylene was respectively supplied into the polymerization vessel so as to maintain 7 MPa, and gas phase polymerization of propylene was continuously performed for 150 hours, thereby performing the polymerization step (I). Separately, the analysis result of the polymer obtained by the polymerization step performed under the same conditions showed that the MFR was 1.1 g / 10 minutes. Polymer 1
The intrinsic viscosity [η _T ] measured in tetralin at 35 ° C. was 2.39 dl / g. The intrinsic viscosity [η _P ] of the polypropylene in the polymerization step (I) was 2.32 dl / g. The polymer obtained above is converted into a polymerization vessel (II) at 60 ° C.
To maintain the hydrogen concentration ratio and the ethylene concentration ratio to the propylene concentration in the polymerization vessel at 0.003 and 0.2, and the pressure in the polymerization vessel is 1.57 MPa.
The polymerization step (II) was carried out while maintaining the supply of a. During the polymerization period, the level of polymer held in the polymerization vessel is 60
9.4 kg / polymer from the polymerization vessel so as to be% by volume.
h. The extracted polymer was contacted with a nitrogen gas containing 5% by volume of steam at 100 ° C. for 30 minutes to obtain a polymer having an intrinsic viscosity [μ _T ] of 2.69 dl / g. The content of polyethylene (A) produced by the preparative treatment in the polymer is 0.21% by weight and the propylene-ethylene block copolymer composition (b)
Had an intrinsic viscosity [μ _P ] of 2.63 dl / g. The resulting polypropylene composition (Y) had a melt tension (MS) of 6.0 cN. Polymerization step (I) and polymerization step (II)
The polymerization amount ratio of the copolymer was prepared by changing the reaction amount ratio of ethylene / propylene in advance, and this was used as a standard sample.
Making a calibration curve with infrared absorption spectrum, polymerization process (II)
Was calculated from the ethylene content in the whole polymer. This composition is converted to PP
-3. Production of PP-4 In the production of PP-3, a polymer was produced under the same conditions as in Example 2 except that preactivated polymerization with ethylene was not carried out. This composition was designated PP-4.
Called.

Example 1 Melting point 141 ° C., ethylene content 3.2% by weight, MFR
2.0 parts by weight of a polypropylene random copolymer, 2.0 parts by weight of tetrakis [methylene-3- (3′-5′-di-t)
-Butyl-4'-hydroxyphenyl) propionate] methane 0.1 part by weight, calcium stearate 0.1 part by weight.
The composition obtained by mixing 1 part by weight was mixed with a screw diameter of 40 mmφ
To the surface layer extruder, and tetrakis [methylene-3- (3′-5′-di-t) was added to 100 parts by weight of PP-1.
-Butyl-4'-hydroxyphenyl) propionate] methane 0.1 part by weight, calcium stearate 0.1 part by weight.
1 part by weight and 0.5 parts by weight of a blowing agent azodicarbonamide were mixed and supplied to an extruder for an inner layer having a screw diameter of 50 mmφ, and the extruding amount was adjusted so that the surface layer had a thickness of 100 μm. , 90mm x 195
A square bottle having a size of 45 mm and a weight of about 77 g was formed. Table 2 shows the properties of the molded product.

[0045]

[Table 2]

Example 2 The procedure of Example 1 was repeated except that 0.3 part by weight of the nucleating agent dibenzylidene sorbitol was added to 100 parts by weight of the polypropylene random copolymer used for the surface layer. Performed similarly. Table 2 shows the properties of the molded product.

Example 3 The procedure was as in Example 1, except that PP-3 was used for the inner layer and the parison was extruded at 210 ° C.
Table 2 shows the properties of the molded product.

Example 4 The procedure of Example 3 was repeated except that 0.3 part by weight of the nucleating agent dibenzylidene sorbitol was added to 100 parts by weight of the polypropylene random copolymer used for the surface layer. Performed similarly. Table 2 shows the properties of the molded product.

Comparative Example 1 The same procedure as in Example 1 was carried out except that PP-2 was used for the inner layer. Table 2 shows the properties of the molded product.

Comparative Example 2 The procedure of Example 1 was repeated, except that a polypropylene homopolymer having a melting point of 164 ° C. and an MFR of 2.3 was used for the surface layer. Table 2 shows the properties of the molded product.

Comparative Example 3 The same procedure as in Example 3 was carried out except that PP-4 was used for the inner layer. Table 2 shows the properties of the molded product.

Comparative Example 4 Tetrakis [methylene-3] was added to 100 parts by weight of PP-3.
-(3'-5'-di-tert-butyl-4'-hydroxyphenyl) propionate] 0.1 part by weight of methane, 0.1 part by weight of calcium stearate, and 0.5 part by weight of azodicarbonamide blowing agent are mixed. , Screw diameter 50mmφ
Was extruded at a temperature of 210 ° C. to form a single-layered square bottle having an outer shape of 90 mm × 195 mm × 45 mm and a weight of about 77 g. Table 2 shows the properties of the molded product. From the comparison between the examples in the table and the comparative examples, the foam molded product of the present invention has a high surface gloss, has a lower density, and has an excellent foaming state as compared with the foam molded product molded using conventional polypropylene. I understand.

[0053]

The polypropylene foam hollow molded article of the present invention has a high surface gloss and excellent appearance, is a foamed article having a uniform foaming and a small specific gravity as compared with a conventional polypropylene foamed article, and has heat insulation and sound absorption. It is suitable for applications requiring properties and the like.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08J 9/06 CES C08J 9/06 CES // B29K 23:00 B29L 9:00 22:00 C08L 23:12 23:14

Claims (3)

[Claims] 1. A multi-layer polypropylene foam hollow molded article having a skin layer comprising the following composition (X) and an inner layer comprising the following composition (Y) foamed with a chemical foaming agent. (X) a polypropylene random copolymer composition having a melting point of 120 to 150 ° C and a melt flow rate (hereinafter abbreviated as MFR) [230 ° C; 21.18N] of 0.3 to 20 (Y) 01 to 5 parts by weight and the following (b)
100 parts by weight, MFR 0.1 to 10 g / 10
(a) intrinsic viscosity [η] measured in tetralin at 135 ° C.
_E ] is 15 to 100 dl / g. (B) Intrinsic viscosity [η] measured in tetralin at 135 ° C.
_P ] is 0.2 to 10 dl / g 2. A polypropylene foam molded article according to claim 1, wherein the olefin polymer of (a) is the following (a ′). (A ′) intrinsic viscosity [η _E ] measured in tetralin at 135 ° C. is 15 to 100 dl /
g of an ethylene homopolymer or an ethylene-olefin copolymer containing 50% by weight or more of ethylene polymerization units. 3. The olefin according to claim 1, wherein the olefin according to the olefin polymer or the ethylene-olefin copolymer is propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-
A polypropylene foam hollow molded article which is one or more selected from methyl-1-pentene and 3-methyl-1-pentene.