JP2002241452A - Propylene-ethylene block copolymer composition and molded item obtained by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propylene-ethylene block copolymer composition which, though it does not contain a special additive, has high stiffness, impact strength, and swell ratio and a molded item obtained by using the same; especially, a propylene-ethylene block copolymer composition having high stiffness, impact strength, and swell ratio and excellent in foam-moldability, and a molded item obtained by using the same. SOLUTION: This propylene-ethylene block copolymer composition is obtained by conducting a polymerization step I and then polymerization step II by using a polyolefin production catalyst containing a transition metal compound catalyst component (A) at least containing titanium as a transition metal, an organometallic compound (B) which contains a metal selected from the group consisting of metals belonging to groups 1, 2, 12, and 13 of the 1991-edition periodic table, and is in an amount of 0.01-1,000 mol per mol of the transition metal atom, and an electron donor (C) in an amount of 0-1 mol per mol of the transition metal atom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-rigidity propylene / ethylene block copolymer composition, and more particularly, to a high-rigidity, high-impact-resistance, high-swell ratio copolymer composition; For molded products obtained using this, especially a copolymer composition excellent in foam moldability, and
It relates to a foam molded article obtained by using the same.

[0002]

2. Description of the Related Art Crystalline polypropylene (hereinafter sometimes referred to as polypropylene) is used as a general-purpose resin because of its excellent rigidity, hardness, tensile strength and heat resistance. However, there is a problem in that the impact resistance is insufficient, and it is unsuitable for applications subject to mechanical impact, particularly for applications used at low temperatures. Further, when compared with ABS resin or high impact polystyrene resin, not only impact resistance but also rigidity are inferior. In order to expand the use of polypropylene, and hence the demand, it is required to further improve not only the above-mentioned impact resistance but also the rigidity and to improve the drawdown resistance in blow molding. As a method of solving these problems, a method of random or block copolymerizing propylene with another α-olefin or ethylene is known.

[0003] However, the random copolymer obtained by such a method has insufficient improvement in low-temperature impact resistance as compared with polypropylene, and rigidity, strength, heat resistance, etc., increase as the ethylene content increases. It drops sharply.

[0004] On the other hand, while the impact resistance of the block copolymer is remarkably improved, the rigidity, hardness, heat resistance and the like are reduced. Numerous methods have been proposed as methods for improving these disadvantages of the block copolymer. For example, JP-A-50-115296 and JP-A-52-4588.
And JP-A-53-35879 propose a method for producing a block copolymer of propylene and ethylene by multi-stage polymerization. In addition, Japanese Patent Publication No. 47-8207 and 49
Nos. 13231 and 49-13514 propose an improved method of adding a third component to a catalyst. further,
JP-A-55-764, JP-A-54-152095 and JP-A-5-152095
JP-A-3-29390 and JP-B-55-8011 propose an improved method using a specific catalyst. However, any of the above proposals is an attempt to minimize the reduction in rigidity of the obtained block copolymer, and has not yet reached the rigidity equivalent to that of polypropylene. Also, Japanese Patent Application Laid-Open No. 58-201816 proposes a method for producing a high-rigidity propylene / ethylene block copolymer having a rigidity equal to or higher than that of polypropylene, but the resulting copolymer has an impact resistance. It was not satisfactory enough.

[0005] Polypropylene is generally excellent in surface quality such as heat resistance, smoothness and gloss, and is made into a product by various molding methods. The ratio is small and the drawdown resistance during blow molding is poor. In particular, when used as a material for large blow-molded articles, the swell ratio is small and the thickness is not uniform due to poor drawdown resistance, which causes problems such as warpage and sink marks in products. In addition, since the swell ratio is small, it is difficult to form it into a lining of home appliances by a vacuum forming method.
It was difficult to foam uniformly at a high foaming rate.

On the other hand, polyethylene has a larger swell ratio than polypropylene and is excellent in drawdown resistance. Among them, high-density polyethylene is particularly excellent in this property, and thus is frequently used as a material for blow molding or a material for foam molding, but has a drawback that heat resistance and surface quality are inferior. For this reason, it has been used as a material for blow molding and foam molding by blending with polypropylene. Recently, however, ethylene has been added to the molding material in order to impart paintability and high impact resistance to the molded product. Proposals have also been made to compound an α-olefin copolymer rubber or compound an inorganic filler for the purpose of imparting rigidity (Japanese Patent Laid-Open No. 3-1).
97542, JP-A-3-59049). However, due to the low melt flow rate of the blended high-density polyethylene and the low melt flow rate of the ethylene / α-olefin copolymer rubber, these molding materials have poor moldability (surface smoothness). In fact, it was not possible to obtain a satisfactory performance in terms of properties.

[0007]

SUMMARY OF THE INVENTION The present invention provides a propylene / ethylene block copolymer composition having high rigidity, high impact resistance and high swell ratio without adding a special additive, An object of the present invention is to provide a molded product obtained by using this. Particularly, an object of the present invention is to provide a propylene / ethylene block copolymer composition having high rigidity, high impact resistance, a high swell ratio, and excellent foam moldability, and a foam molded article obtained using the same. And

[0008]

The present invention comprises the following 1) to 7). 1) A transition metal compound catalyst component (A) containing at least titanium as a transition metal, a metal selected from the group consisting of metals belonging to Groups 1, 2, 12 and 13 of the 1991 edition of the periodic table And an organometallic compound (B) in a ratio of 0.01 to 1,000 mol per mol of the transition metal atom, and an electron donor (C) in a ratio of 0 to 1 mol per mol of the transition metal atom. A propylene / ethylene block copolymer composition obtained by performing a polymerization step II following a polymerization step I using a catalyst for producing a polyolefin containing (1) Polymerization Step I A propylene polymer having a molecular weight distribution (Mw / Mn) of 6 or less was converted to a propylene / ethylene block copolymer composition by weight using at least two tanks connected in series. And the melt flow rate of the propylene polymer obtained in the polymerization step I is defined as MFR (i), and the polymerization of the propylene polymer obtained in the polymerization vessel in each of the tanks is carried out. The maximum (MFR (h)) and minimum (MFR) of the melt flow rate
(L)) a step of polymerizing so that the relationship of the following formula (1) is satisfied. 0.1 ≦ Log (MFR (h) / MFR (l)) ≦ 1 Formula (1) (2) Polymerization Step II The melt flow rate (MFR (ii)) is set to 0.1 using at least one polymerization vessel. 001 g / 10 min, and the ethylene unit is 30 to 80 based on the weight of the copolymer.
Weight percent of the ethylene / α-olefin copolymer contained in the range of 50 to 5% by weight based on the weight of the propylene / ethylene block copolymer composition. A step of performing polymerization so that the melt flow rate (MFR (ii)) of the olefin copolymer and the melt flow rate (MFR (i)) of the propylene polymer satisfy the following formula (2). 3 ≦ Log (MFR (i) / MFR (ii)) ≦ 7 Equation (2)

2) The melt flow rate (MFR (T)) of the propylene / ethylene block copolymer composition is
The propylene / ethylene block copolymer composition according to the above 1), which is 0.1 to 100 g / 10 min. 3) The propylene / ethylene block copolymer composition according to 1) above, wherein MFR (h) and MFR (l) satisfy the relationship of the following formula (3). 0.2 ≦ Log (MFR (h) / MFR (l)) ≦ 0.5 Equation (3)

4) MFR (i) and MFR (ii) are
The propylene / ethylene block copolymer composition according to the above 1), which satisfies the relationship of the following formula (4). 4 ≦ Log (MFR (i) / MFR (ii)) ≦ 7 Formula (4) 5) The propylene according to 1), wherein the α-olefin to be copolymerized with ethylene in the polymerization step II is propylene. -An ethylene block copolymer composition. 6) A molded article obtained by using the propylene / ethylene block copolymer composition according to 1). 7) A foam molded article obtained by using the propylene / ethylene block copolymer composition described in 1) above

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION One component of a polyolefin production catalyst used for producing the propylene / ethylene block copolymer composition of the present invention is "a transition metal compound catalyst component (A) containing at least a titanium compound". (Or later,
As the transition metal compound catalyst component (may be referred to as (A)), a known catalyst component containing a transition metal compound catalyst component containing at least a titanium compound proposed for polyolefin production as a main component can be used, Among them, a titanium-containing solid catalyst component is preferably used for industrial production.

As the titanium-containing solid catalyst component, a titanium-containing solid catalyst component containing a titanium trichloride composition as a main component (JP-B-56-3356, JP-B-59-28573).
And JP-B-63-66323, and a titanium-containing supported catalyst component in which titanium tetrachloride is supported on a magnesium compound and contains titanium, magnesium, halogen, and an electron donor as essential components. -10481
0, Japanese Patent Application Laid-Open No. 62-104811, Japanese Patent Application Laid-Open
JP-A-2-104812, JP-A-57-63310, JP-A-57-63311, JP-A-58-830
No. 06, JP-A-58-138712, etc.), and any of these can be used.

As the organometallic compound (B), 1991
1st, 2nd, 12th, and 13th families of the periodic table
A compound having an organic group of a metal selected from the group consisting of metals belonging to the group, such as an organic lithium compound, an organic sodium compound, an organic magnesium compound, an organic zinc compound, and an organic aluminum compound can be given. In particular, the general formula ^{_{AlR 1 p R 2 q X 3-}} (p + q)
An organoaluminum compound represented by the following formula (1) can be preferably used. In the general formula, R ¹ and R ² independently represent a hydrocarbon group such as an alkyl group, a cycloalkyl group, an aryl group or the like, and an alkoxy group. X represents a halogen atom, and p and q represent positive numbers of 0 <p + q ≦ 3.

Specific examples of the organoaluminum compound include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, tri-i-butylaluminum, tri-n-hexylaluminum, tri-i-aluminum. Hexyl aluminum, trialkyl aluminum such as tri-n-octyl aluminum, diethyl aluminum chloride, di-n-propyl aluminum chloride, di-i
-Dialkylaluminum monohalides such as butylaluminum chloride, diethylaluminum bromide and diethylaluminum iodide, dialkylaluminum hydrides such as diethylaluminum hydride, alkylaluminum sesquihalides such as ethylaluminum sesquichloride, and monoalkylaluminum dihalides such as ethylaluminum dichloride And alkoxyalkylaluminum such as diethoxymonoethylaluminum. Preferred are trialkylaluminum and dialkylaluminum monohalides. These organoaluminum compounds can be used alone or in combination of two or more.

The electron donor (C) is used for controlling the production rate and / or stereoregularity of the polyolefin. Examples of the electron donor (C) include ethers, alcohols, phenols, esters, aldehydes, fatty acids, ketones, and the like. In addition, nitriles, amines, amides, urea or thioureas, isocyanates, azo compounds, phosphines, phosphites, phosphinites, hydrogen sulfide and thioethers, oxygen in molecules such as neoalcohols, Organic compounds having any of nitrogen, sulfur, and phosphorus, silanols, and organic silicon compounds having a Si—O—C bond in a molecule can be given.

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 and the like.

Examples of alcohols include methanol, ethanol, propanol, butanol, pentonol, hexanol, octanol, 2-ethylhexanol,
Allyl alcohol, benzyl alcohol, ethylene glycol, glycerin and the like can be mentioned.

Further, as phenols, phenol,
Cresol, xylenol, ethylphenol, naphthol and the like can be mentioned.

Esters include methyl methacrylate, methyl formate, methyl acetate, methyl butyrate, ethyl acetate, vinyl acetate, n-propyl acetate, i-propyl acetate, butyl formate, amyl acetate, and 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 , Diethyl succinate, methyl malonate Aliphatic polycarboxylic acid esters such as butyl, diethyl butylmalonate, dibutyl maleate and diethyl butylmaleate, monomethyl phthalate, dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate and mono-phthalate. n-butyl, di-n-butyl phthalate, di-i-butyl phthalate, di-n-heptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, -i-diethyl phthalate , −
i-dipropyl phthalate, -i-dibutyl phthalate,-
Aromatic polycarboxylic acid esters such as di-2-ethylhexyl i-phthalate, diethyl terephthalate, dipropyl terephthalate, dibutyl terephthalate, and di-i-butyl naphthalenedicarboxylate are exemplified.

The aldehydes include acetaldehyde, propionaldehyde, benzaldehyde and the like. Fatty acids include formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, succinic acid, acrylic acid, maleic acid,
Monocarboxylic acids such as valeric acid and benzoic acid, and acid anhydrides such as benzoic anhydride, phthalic anhydride and tetrahydrophthalic anhydride are exemplified. Examples of ketones include acetone, methyl ethyl ketone, 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,
N ', N'-tetramethylethylenediamine, aniline,
Amines such as dimethylaniline, formamide, hexamethylphosphoric triamide, N, N, N ', N', N "-pentamethyl-N'-β-dimethylaminomethylphosphoric triamide, octamethylpyrophosphoramide, etc. Amides, ureas such as N, N, N ', N'-tetramethylurea,
Examples include isocyanates such as phenyl isocyanate and toluyl 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, and 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; And phosphites.

Examples of the sulfur-containing compound include thioethers such as diethylthioether, diphenylthioether and methylphenylthioether, ethylthioalcohol,
and thioalcohols such as n-propylthioalcohol and thiophenol.

Examples of the organosilicon compound include silanols such as trimethylsilanol, triethylsilanol and triphenylsilanol, trimethylmethoxysilane, dimethyldimethoxysilane, methylphenyldimethoxysilane, diphenyldimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, Phenyltrimethoxysilane, trimethylethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, diphenyldiethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane Silane, ethyltriisopropoxysilane, vinyltriacetoxysilane, cyclopentylmethyl Organic silicon compounds having a Si-OC bond such as dimethoxysilane, cyclopentyltrimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexyltrimethoxysilane, dicyclohexyldimethoxysilane, and 2-norbornylmethyldimethoxysilane. No.

These electron donors can be used alone or
More than one kind can be mixed and used.

The transition metal compound catalyst component (A) is used in combination with the organometallic compound (B) and the electron donor (C) as a catalyst for producing a polyolefin to produce the propylene / ethylene block copolymer composition of the present invention. Preferably, it can be used as a catalyst which is preactivated by reacting a small amount of ethylene or α-olefin prior to the main polymerization.

The preactivation is carried out by reacting the organometallic compound (B) with one mole of titanium in the transition metal compound catalyst component (A).
Of ethylene or α-olefin at 0 to 50 ° C. for 1 minute to 20 hours with respect to 1 mol of titanium in the transition metal compound catalyst component (A).
Mole, preferably 0.3 to 3 moles. In addition to ethylene, α-olefins used for preactivation include propylene, butene-1, hexene-1, heptene-1, other linear monoolefins, 4-methyl-pentene-1, 2-methyl- Examples include branched monoolefins such as pentene-1, 3-methyl-butene-1, and styrene. These ethylenes and α-olefins may be used alone or as a mixture of two or more.

The preactivation with ethylene or α-olefin is carried out in an aliphatic or aromatic hydrocarbon solvent.
Alternatively, the reaction can be carried out in a liquefied olefin such as liquefied propylene and liquefied butene-1 without using a solvent. Also,
It can also be carried out in the gas phase of ethylene, propylene or the like.
Further, at the time of preactivation, an electron donor (C) may be used. After the completion of the preactivation, the solvent, the organometallic compound and the unreacted ethylene or α-olefin may be removed by filtration, decantation, or the like, or may be further dried and used as a powder.

The preactivated catalyst is subjected to a slurry polymerization method in a hydrocarbon solvent such as n-hexane, n-heptane, n-octane, benzene, and toluene, a bulk polymerization method in liquefied propylene, or The propylene / ethylene block copolymer composition of the present invention is used in a gas phase polymerization method, and further adopts a specific two-stage polymerization method, that is, a polymerization method in which a polymerization step II is performed subsequent to a polymerization step I described below. Can be suitably manufactured.

The polymerization step I is a step of producing a propylene polymer using at least two polymerization vessels connected directly.

When the polymerization step I is a slurry polymerization method, the polymerization temperature is usually 20 to 90 ° C., preferably 50 to 80 ° C., and the polymerization pressure is 0 to 5 MPa (gauge pressure). In the case of gas phase polymerization, the polymerization temperature is usually 20 to 150.
C. and a polymerization pressure of 0.2-5 MPa.
Hydrogen is usually used for controlling the molecular weight, and the MFR (i) of the propylene polymer is adjusted to the range of 0.1 to 1,000.

In the polymerization step I, the polymerization amount of the propylene polymer is from 50 to 95% by weight based on the total amount of the finally obtained propylene / ethylene block copolymer composition. If the polymerization amount is less than the above range, the rigidity of the product will be reduced, and if it is too large, the improvement in low-temperature impact strength may not be sufficiently achieved. The polymerization step I is carried out using two or more polymerization vessels connected in series, and the maximum value (MFR (h)) and minimum value (MFR (l)) of the melt flow rate of the polymer obtained in each tank are determined. The polymerization conditions of each polymerization vessel are set so that the ratio satisfies the relationship of 0.1 ≦ Log (MFR (h) / MFR (l)) ≦ 1. When the MFR ratio is less than 0.1, the rigidity of the product is reduced. When it exceeds 1, the tensile elongation and impact resistance of the finally obtained propylene / ethylene block copolymer composition are reduced. Might be. In the production of the propylene polymer in the polymerization step I, the ratio of the melt flow rate is within the range of the above formula, and within a range that does not reduce the rigidity of the finally obtained propylene / ethylene block copolymer composition. If so, the α-olefin other than ethylene or propylene may be copolymerized with propylene so as to be contained in the range of 0.1 to 5.0% by weight based on the weight of the propylene polymer. In addition to ethylene, α-olefins other than propylene suitable for copolymerization include 1-butene, 1-hexene, 4-methyl-1-pentene, and the like. As the propylene polymer produced in the polymerization step I, a propylene homopolymer is particularly preferred.

More preferably, the ratio between MFR (h) and MFR (l) satisfies the following equation. 0.2 ≦ Log (MFR (h) / MFR (l)) ≦ 0.
5

In the polymerization step I, the propylene polymer obtained in this step is used in a molecular weight distribution (weight average molecular weight (M.sub.M) measured by gel permeation chromatography (GPC).
The polymerization conditions are set so that the ratio (Mw / Mn) of w) to the number average molecular weight (Mn) is 6 or less. The M
If the w / Mn value is greater than 6, the resulting molded article may have reduced impact resistance and the appearance of the foam molded article may be impaired.

The propylene polymer obtained in the polymerization step I is supplied to the polymerization vessel in the polymerization step II while containing the catalyst component, and then an ethylene / α-olefin copolymer is produced. As the α-olefin to be copolymerized with ethylene, propylene, butene-1, hexene-1, heptene-1, other linear monoolefins, 4-methyl-pentene-1, 2-methyl-pentene-1,3- Examples include branched monoolefins such as methyl-butene-1 and styrene. The α-olefin may be used alone or as a mixture of two or more. Of these, propylene is preferred.

The polymerization step II is a step of producing an ethylene / α-olefin copolymer using at least one polymerization vessel. The polymerization temperature is from 20 to 80 ° C, preferably from 40 to 80 ° C.
It can be carried out by copolymerizing ethylene and an α-olefin at 70 ° C. and a pressure of 0 to 5 MPa. The method for supplying ethylene and α-olefin to the polymerization vessel and the method for polymerization are not limited. Hydrogen is usually used for controlling the molecular weight, and the hydrogen concentration in the polymerization vessel is 0 to 1
The polymerization can be carried out in the range of 0 mol%. In polymerization step II,
It is performed using one polymerization reactor or two or more polymerization reactors connected to each other.

In the polymerization step II, the ethylene unit content is in the range of 30 to 80% by weight, more preferably 40 to 70% by weight, based on the weight of the ethylene / α-olefin copolymer obtained in this step. %, The amount of monomer to be supplied is adjusted. If the content of the ethylene unit is larger or smaller than the above range, the rigidity and impact resistance of the finally obtained propylene / ethylene block copolymer composition may be inferior.

In the polymerization step II, based on the weight of the finally obtained propylene / ethylene block copolymer composition,
An ethylene / α-olefin copolymer occupying a proportion of 5 to 40% by weight is produced.

Further, in the polymerization step II, the melt flow rate (MFR (ii)) of the ethylene / α-olefin copolymer obtained in this step is changed to the melt flow rate (MFR) of the propylene polymer obtained in the polymerization step I. With respect to (i)), polymerization is performed so as to satisfy the relational expression of 3 ≦ log (MFR (i) / MFR (ii)) ≦ 7.

MFR (i) is an actually measured value obtained by actually measuring the propylene polymer obtained in the polymerization step I. On the other hand, the MFR (ii) is determined by the melt flow rate (MFR (T)) of the propylene / ethylene block copolymer composition after the completion of the polymerization step II and the polymerization step I when the total weight of the composition is 1. Can be calculated from the polymerization ratio (W1) and the polymerization ratio (W2) in the polymerization step II using the following relational expression. logMFR (T) = W1 × log (MFR (i)) +
W2 × log (MFR (ii))

Log (MFR (i) / MFR (ii))
Is smaller than 3 or larger than 7, the impact resistance and tensile elongation of the finally obtained propylene / ethylene block copolymer composition may be reduced.

More preferably, MFR (ii) satisfies the following expression with respect to MFR (i). 4 ≦ Log (MFR (i) / MFR (ii)) ≦ 7

Further, M of the copolymer obtained in the polymerization step II
FR (ii) is preferably smaller than 0.001 g / 10 min. MFR (ii) 0.001g / 10
If it is larger than min, the drawdown resistance of the propylene / ethylene block copolymer composition and the foaming performance during foam molding may be inferior.

The finally obtained propylene / ethylene block copolymer composition has a melt flow rate (MFR).
(T)) is preferably in the range of 0.1 to 100 g / 10 min, and more preferably in the range of 1 to 80 g / 10 min. If the MFR (T) is larger than 100 g / 10 min, the impact resistance may be reduced.

Since the propylene / ethylene block copolymer composition of the present invention has a high swell ratio, when used for blow molding, it has excellent drawdown resistance. As a result, especially when used as a molding material for a large blow molded article, the thickness becomes uniform, and the product is unlikely to warp or sink. In addition, since the swell ratio is large, it can be suitably molded to the lining of home electric appliances by a vacuum molding method. Furthermore, since it is excellent in foam moldability, it is suitable for producing foam molded articles.

The stiffness, heat resistance (heat stiffness, heat deformation temperature, etc.) and dimensional stability (mold shrinkage, warpage of the molded article) of the molded article obtained by using the propylene / ethylene block copolymer composition of the present invention. Inorganic filler can be blended with the high-rigidity propylene / ethylene block copolymer composition of the present invention for the purpose of improving the coating property and abrasion resistance, etc. within the range not impairing the object of the present invention. . Examples of the inorganic filler include talc, calcium carbonate, potassium titanate whisker, mica, glass fiber, barium sulfate and magnesium sulfate, and these may be used alone or in combination. Among the inorganic fillers, talc is preferable, the average particle size is 5 μm or less, preferably 2 μm or less, and the particle size component exceeding 10 μm is 5% by weight or less,
Preferably, talc of 1% by weight or less is more preferable in terms of impact resistance.

The propylene / ethylene block copolymer composition of the present invention is used for the purpose of improving the impact resistance, dimensional stability (linear expansion coefficient, warpage of the molded article, etc.) and coatability of the obtained molded article. A non-crystalline or low-crystalline ethylene / α-olefin copolymer, polyethylene (high-density polyethylene, low-density polyethylene, linear low-density polyethylene, etc.) or styrene-based elastomer within a range not to impair the object of the present invention. Can be blended.

For example, amorphous or low-crystalline ethylene
If it is an α-olefin copolymer, it is 1 to 2 with respect to 100 parts by weight of the propylene / ethylene block copolymer composition.
0 parts by weight, preferably 1 to 10 parts by weight can be blended. Examples of the amorphous or low-crystalline ethylene / α-olefin copolymer include an amorphous ethylene / propylene copolymer and an amorphous ethylene / 1-butene copolymer. Alpha olefin copolymers are preferred. The amorphous ethylene / α-olefin copolymer has a propylene content of 20 to 50% by weight, preferably 20 to 35% by weight, and a Mooney viscosity [ML1 + 4
(100 ° C)] is 5 to 60, preferably 10 to 50, and MFR (230 ° C: 21.18N) is 0.1 to 20 g.
/ 10 min, preferably 0.5 to 10 g / 10 min
Amorphous ethylene / propylene copolymers can be exemplified.

If necessary, an antioxidant, an antistatic agent, a coloring agent (pigment), a nucleating agent may be added to the propylene / ethylene block copolymer composition of the present invention within a range not to impair the object of the present invention. And at least one kind of various additives such as a slip agent, a release agent, a flame retardant, an ultraviolet absorber, a weathering agent, a plasticizer, a radical generator, and a foam nucleating agent.

[0050]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The analysis and measurement methods of various physical properties performed in the examples are shown below. (1) Melt flow rate (MFR): ASTM D-
Measurement was performed at a temperature of 230 ° C. and a load of 2.16 kg according to 1238. (Unit: g / 10 min) (2) Number average molecular weight (Mw), weight average molecular weight (M
w), molecular weight distribution (Mw / Mn): The sample was dissolved in orthodichlorobenzene at 135 ° C.
GPC (Gel Permination C) of type 0C
Chromatograph). As a column to be used, Tsk-gelGMH6- manufactured by Tosoh Corporation
T was used. (3) Ethylene unit content: determined by infrared absorption spectroscopy. (Unit: weight%) (4) The polymerization ratio (W1, W
2): A copolymer was prepared in advance in which the reaction amount ratio of ethylene / propylene was changed, and this was used as a standard sample.
Creating a calibration curve using the absorption peak of ^{700cm -1 ~750cm} -1 by infrared absorption spectrum using an IN ELMER Co. FT-IR, calculated ethylene / propylene reaction amount ratio of the polymerization step II, further the total polymer Was calculated from the ethylene content. (5) Flexural modulus: Measured according to JIS K7203. (Unit: MPa) (6) Tensile strength: Measured according to JIS K7113. (Unit: MPa) (7) Tensile elongation: Measured in accordance with JIS K7113. (Unit:%) (8) HDT: Measured in accordance with JIS K7207. (Unit: ° C) (9) Izod impact strength (II): JIS K711
0 was measured. (Unit: J / m)

(10) Foam Moldability The density of the foam molded article was measured according to JIS K6767. (Unit: g / cm ³ ). Expansion ratio: from the density of the resin composition d (g / cm ³⁾ and the foamed molded article of the density D (g / cm ³⁾ obtained by the following equation. Foaming ratio (unit: times) = d / D Average cell diameter: The cross section perpendicular to the thickness direction of the foamed molded product,
Take a picture with a microscope equipped with a camera and measure the area to 1.0cm
Measure the major axis and minor axis of all the bubbles in ² . The average of the major axis and the minor axis was defined as the cell diameter, and the average value of the measured total cell diameters was defined as the average cell diameter (unit: mm). Bubble uniformity: A foam having a foaming number of 3% or more of the average bubble diameter and having a foaming number of 10% or more is not allowed, and is represented by "x" and 10%
Less than good was indicated by "O".

(11) Swell ratio Using a “melt tension tester type 2” (manufactured by Toyo Seiki Seisaku-sho, Ltd.), the sample was heated to 230 ° C. in the apparatus, and the molten pellet was sprayed with a nozzle having a diameter (Do) of 2.095 mm. A strand obtained by extruding into a 23 ° C. atmosphere at a speed of 20 mm / min was sampled at a length of 3 cm, and the diameter (Ds) of the obtained strand was measured and calculated by the following equation. SR = Ds / Do

Example 1 (1) Preparation of Catalyst Preparation of Transition Metal Compound Catalyst Component (A) (Titanium-Containing Solid Catalyst Component) 150 g of magnesium ethoxide, 275 ml of 2
A mixture of ethylhexyl alcohol and 300 ml of toluene under a carbon dioxide atmosphere of 0.1 MPa;
After stirring at 3 ° C. for 3 hours, 400 ml of toluene and 400 ml of n-decane were further added. Hereinafter, this solution is referred to as a magnesium carbonate solution. 100 ml of toluene,
A mixture of 30 ml of chlorobenzene, 9 ml of tetraethoxysilane, 8.5 ml of titanium tetrachloride, and 100 ml of Isopar G (isoparaffinic hydrocarbon having an average carbon number of 10 and a boiling point of 156 to 176 ° C.) is stirred at 30 ° C. for 5 minutes. Then, 50 ml of the magnesium carbonate solution was added thereto. After stirring for 5 minutes, 22 ml of tetrahydrofuran was added, and the mixture was stirred at 60 ° C. for 1 hour. After stopping the stirring and removing the supernatant, the generated solid was washed with 50 ml of toluene. 100 ml of chlorobenzene and 100 ml of titanium tetrachloride were added to the obtained solid,
For 1 hour. Stop stirring, remove the supernatant,
250 ml of chlorobenzene, 100 m
l of titanium tetrachloride and 2.1 ml of di-n-butyl phthalate were added and stirred at 135 ° C for 1.5 hours. After removing the supernatant, 600 ml of toluene, 80 ml
The solid catalyst component was collected by sequentially washing with 0 ml of Isopearl G and 400 ml of n-hexane. The composition of the solid catalyst component was 2.3% by weight of titanium, 55% by weight of chlorine, 17% by weight of magnesium, and 7.5% by weight of di-n-butyl phthalate.

Pre-activation After replacing the stainless steel reactor having an inner volume of 50 L with a tilted blade type stirring device with nitrogen gas, 40 L of n-hexane was charged, and 75 g of the above solid composition and 13 g of triethylaluminum were added at room temperature. After that, 100 g of propylene
Feeding was performed over 0 minutes, and unreacted propylene and n-hexane were removed under reduced pressure to obtain 150 g of a preactivated catalyst.

<Polymerization Step I> First Stage Polymerization A 500 L internal stainless steel polymerization vessel equipped with a turbine-type stirring blade was replaced with nitrogen gas, and 250 L of n-hexane, 89 g of triethylaluminum, and di-i-propyldimethoxysilane were used. 27.4 g were charged, and then 15 g of the above preactivated catalyst was added. After the temperature in the vessel was raised to 70 ° C., propylene and hydrogen were supplied for 1 hour at the first stage while maintaining the total pressure at 0.8 MPa and the hydrogen / propylene molar ratio in the gas phase at 0.24. Polymerization was performed. After the reaction time, the supply of propylene and hydrogen was stopped, and the temperature in the reactor was reduced to 30
C., and propylene unreacted with hydrogen was released.
Next, a part of the polymerization slurry was extracted, and this sample was
This was used to determine the polymer yield per unit weight of the catalyst by measuring FR ₁ and measuring the Mg content in the polymer by inductively coupled plasma emission spectroscopy.

Second Stage Polymerization After the temperature in the polymerization reactor was raised to 70 ° C., the total pressure was increased to 1.0 MPa,
While maintaining the hydrogen / propylene molar ratio in the gas phase at 0.24, propylene and hydrogen were supplied for one hour to perform the second-stage polymerization. After the reaction time, the supply of propylene and hydrogen was stopped. The temperature in the vessel was cooled to 30 ° C., and propylene unreacted with hydrogen was released. Next, a part of the polymerization slurry was extracted, and the MFR was measured.
The g content was measured by inductively coupled plasma emission spectroscopy to determine the total polymer yield up to the second stage. Using the polymer yield of the first stage and the total polymer yield up to the second stage, 2
The polymer yield of the second stage was determined, and then the polymerization ratio (a) of the first stage and the polymerization ratio (b) of the second stage were determined. Further, the values of MFR ₁ and MFR were substituted into the following equation to determine MFR _{2 of} the polymer produced in the second stage. _{LogMFR = a × LogMFR 1 + (} 1-a) × Lo
gMFR ₂ a: polymerization ratio of the first stage, b: polymerization ratio of the second stage (b = 1
-A) MFR: MFR of the polymer extracted after completion of the second stage MFR ₁ : MFR of the polymer produced in the first stage, MFR ₂ : MFR of the polymer produced in the second stage

Third-stage polymerization After the temperature in the polymerization vessel was raised to 70 ° C., propylene and hydrogen were supplied while maintaining the total pressure at 1.2 MPa and the hydrogen / propylene molar ratio in the gas phase at 0.24. Then, after performing the third stage polymerization for 1 hour, the supply of propylene was stopped, and the temperature in the reactor was reduced to 3 hours.
After cooling to 0 ° C., propylene unreacted with hydrogen was released. Next, a part of the slurry was taken out, the MFR was measured, and the Mg content in the polymer was measured by inductively coupled plasma emission spectroscopy to obtain the total polymer yield up to the third stage. Using the polymer yields up to the second stage and the total polymer yields up to the third stage, the yield of the third stage and the polymerization ratio (a, b, c) of each stage were determined. Further, by substituting the values of MFR ₁ , MFR ₂ and MFR into the following equation, 3
The MFR _{3 of} the polymer formed in the step was determined. LogMFR = a × LogMFR ₁ + b × LogMFR ₂
+ C × LogMFR ₃ a + b + c = 1 a: polymerization ratio of first stage, b: polymerization ratio of second stage, c: 3
Stage polymerization ratio MFR: MFR of polymer extracted after completion of third stage MFR ₁ , MFR ₂ , MFR ₃ : MFR of polymer generated in each stage of first stage, second stage, third stage.

<Polymerization Step II> After the third reactor in the polymerization step I was completed, the temperature in the reactor was raised to 60 ° C.
Ethylene, propylene and hydrogen were continuously supplied for 2 hours so that the supply ratio of ethylene / propylene was 35% by weight and the hydrogen concentration in the gas phase was 0.4 mol%. The total supply of ethylene was 4.5 kg.
After the completion of the polymerization time, the supply of ethylene, propylene and hydrogen was stopped, and the temperature in the reactor was cooled to 30 ° C., after which unreacted ethylene and propylene were discharged. Then, 50 L of methanol was supplied into the polymerization vessel, the temperature in the vessel was raised to 60 ° C., and the mixture was stirred for 30 minutes. Then, 0.5 L of 20% by weight caustic soda water was further added, followed by stirring for 20 minutes and 100 L of pure water. Was added, and the temperature in the vessel was cooled to 30 ° C. After extracting the aqueous phase, add 300 L of pure water and stir for 10 minutes.
The aqueous phase was withdrawn. Next, the (hexane / polymer) slurry was extracted, filtered and dried to obtain a propylene / ethylene block copolymer composition. The obtained propylene
The ethylene block copolymer composition was analyzed, and the values are shown in Table 1.

Production of Pellets To 100 parts by weight of the propylene / ethylene block copolymer composition obtained above, 0.1 parts by weight of a phenolic heat stabilizer and 0.1 parts by weight of calcium stearate were added, and the mixture was stirred at high speed. Mixer (Henschel mixer: trade name)
At room temperature for 3 minutes, and the resulting mixture is
m were extruded into pellets. After conditioning the pellets at 23 ° C. for 72 hours, the swell ratio was measured as described above.

Production of Injection Molded Product Using an injection molding machine, a test piece was prepared from the above pellets under the conditions of a molten resin temperature of 230 ° C. and a mold temperature of 50 ° C. The test piece was subjected to a relative humidity of 50% and a room temperature of 2
After conditioning in a room at 3 ° C. for 72 hours, physical properties were measured. Table 1 shows the measurement results.

Production of foam molded article To 100 parts by weight of the pellet obtained above, 0.1 part by weight of sodium bicarbonate-citric acid was added as a foam nucleating agent.
Mixing was performed using a ribbon blender. The obtained mixture was melted at a resin temperature of 230 ° C. in the melting part and a resin temperature of 18 in the discharge part.
Feed to a single screw extruder with a diameter of 90 mm adjusted to 0 ° C,
From the middle of the barrel, n-butane gas as a foaming agent was injected into the molten resin at a rate of 1 part by weight per 100 parts by weight of the discharged resin, extruded into a cylindrical shape from a cylindrical die having a diameter of 120 mm, and cooled into a cylinder having a diameter of 300 mm. 1.5m thickness through mold
m was obtained. Evaluate the obtained foam molded product,
The results are shown in Table 1.

Comparative Example 1 A propylene / ethylene block copolymer composition was produced in the same manner as in Example 1 except that the gas phase hydrogen concentration in the polymerization step II was changed to 3 mol%, and physical properties were measured. The results are shown in Table 1. Since the value of MFR (ii) was larger than the value specified in the present invention, the swell ratio was small, the drawdown resistance was inferior, the foaming ratio of the foamed molded product was small, and the cell diameter was uneven.

Comparative Example 2 In the polymerization step I, the hydrogen / propylene molar ratio in the first stage was set at 0.
18, a polymerization time was changed to 3 hours, and a propylene / ethylene block copolymer composition was produced in the same manner as in Example 1 except that the second and third polymerization steps were omitted. went. The results are shown in Table 1. log (MFR
Since the value of (h) / (MFR (l)) was smaller than the value specified in the present invention, the rigidity of the molded product was inferior to that of Example 1.

Example 2 In the polymerization step I, the hydrogen / propylene molar ratio in the first, second, and third steps was changed to 0.08, and the gas phase hydrogen concentration in the polymerization step II was 0.5 mol. %, And a propylene / ethylene block copolymer composition was produced in the same manner as in Example 1 except that the total supply amount of ethylene was changed to 2 kg, and physical properties were measured. The results are shown in Table 1.

Comparative Example 3 In the polymerization step I, the hydrogen / propylene molar ratio in the first, second, and third stages was changed to 0.07, and the gas phase hydrogen concentration in the polymerization step II was changed to 3 mol%. A propylene / ethylene block copolymer composition was manufactured and the physical properties were measured in the same manner as in Example 2 except for the above. The results are shown in Table 1. Log which is the logarithm of the MFR ratio of the polymerization step I and the polymerization step II
Since (MFR (i) / MFR (ii)) was smaller than the value specified in the present invention, the rigidity, impact strength and tensile elongation were inferior to those of Example 2. Further, polymerization step II
Since the MFR (ii) of the copolymer obtained in the above was larger than the value specified in the present invention, the swell ratio was small, the expansion ratio of the foam molded article was small, and the cell diameter was not uniform.

[0066]

Industrial Applicability According to the present invention, a propylene / ethylene block copolymer composition having high rigidity, high impact resistance and high swell ratio without adding a special additive, and a propylene / ethylene block copolymer composition using the same are obtained. In particular, it is possible to provide a propylene / ethylene block copolymer composition having good foam moldability and a foam molded article obtained by using the same.

[0067]

[Table 1] Note: DIPDMS: di-i-propyldimethoxysilane, RE *: ethylene content in the portion polymerized in the polymerization step (II), TE *: ethylene content in the whole polymer, II *: Izod・ Impact

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method for producing a composition of the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Jun Shinozaki 5-1, Goi Kaigan, Ichihara City, Chiba Prefecture Chisso Petrochemical Co., Ltd. Polymer Research Laboratory (72) Inventor Yoshitaka Kobayashi 1 of 5 Goi Kaigan, Ichihara City, Chiba Prefecture Chisso Petrochemical Co., Ltd. Polymer Research Laboratory (72) Inventor Hiroyuki Maehara 5-1, Goi Kaigan, Ichihara City, Chiba Prefecture Chisso Petrochemical Co., Ltd. Polymer Research Laboratory F term (reference) 4F071 AA15 AA15X AA20 AA20X AA21 AA21X AA75 BB06 BC07 4F074 AA25C AB05 BA03 BA37 CA22 4J026 HA02 HA04 HA27 HA35 HA39 HA48 HA49 HB02 HB03 HB04 HB06 HB20 HB27 HB35 HB39 HB42 HB43 HB45 HB48 HE01 4J028 AA01A AB01A AC05A AC15A BA00B BCBBC BCBC BCBC BCBC CB27C CB43C CB44C CB47C CB52C CB53C CB54C CB63C CB64C CB66C CB68C CB 69C CB70C CB73C CB74C CB79C CB82C CB83C CB87C CB88C CB90C EA02 EB04 EB05 EB09 EB10 EC01 EC02 ED01 ED02 ED03 ED04 ED05 ED09 EF01 FA01 GA07 4J128 AA01 AB01 AC05 AC15 BA00A BA01B BB00A BB01B BC01B BC04B BC09B BC15B BC16B BC17B BC19B BC24B BC27B BC34B BC38B CB23C CB24C CB25C CB27C CB43C CB44C CB47C CB52C CB53C CB54C CB63C CB64C CB66C CB68C CB69C CB70C CB73C CB74C CB79C CB82C CB83C CB87C CB88C CB90C EA02 EB04 EB05 EB01 ED01 EC01 ED01 EC01 ED02

Claims (7)

[Claims] 1. A transition metal compound catalyst component (A) containing at least titanium as a transition metal, selected from the group consisting of metals belonging to Groups 1, 2, 12, and 13 of the 1991 edition of the periodic table. The organometallic compound (B) at a ratio of 0.01 to 1,000 mol per mol of the transition metal atom, and the electron donor at a ratio of 0 to 1 mol per mol of the transition metal atom. (C) A propylene / ethylene block copolymer composition obtained by performing a polymerization step II following a polymerization step I using a catalyst for producing a polyolefin containing (1) Polymerization Step I A propylene polymer having a molecular weight distribution (Mw / Mn) of 6 or less was converted to a propylene / ethylene block copolymer composition by weight using at least two tanks connected in series. In which the melt flow rate of the propylene polymer obtained in the polymerization step I is defined as MFR (i), and the propylene polymer obtained in the polymerization vessel in each tank is , Melt flow rate maximum (MFR (h)) and minimum (MFR (l))
Is a step of polymerizing so that the relationship of the following formula (1) is satisfied. 0.1 ≦ log (MFR (h) / MFR (l)) ≦ 1 Formula (1) (2) Polymerization Step II The melt flow rate (MFR (ii)) is set to 0.1 using at least one polymerization vessel. 001 g / 10 min, and the ethylene unit is 30 to 80 based on the weight of the copolymer.
Weight percent of the ethylene / α-olefin copolymer contained in the range of 50 to 5% by weight based on the weight of the propylene / ethylene block copolymer composition. A step of performing polymerization so that the melt flow rate (MFR (ii)) of the olefin copolymer and the melt flow rate (MFR (i)) of the propylene polymer satisfy the following formula (2). 3 ≦ Log (MFR (i) / MFR (ii)) ≦ 7 Equation (2) 2. A propylene / ethylene block copolymer composition having a melt flow rate (MFR (T)) of 0.1.
The propylene / ethylene block copolymer composition according to claim 1, wherein the composition is 1 to 100 g / 10 min. 3. The method according to claim 1, wherein the MFR (h) and the MFR (l) satisfy a relationship represented by the following equation (3).
The propylene / ethylene block copolymer composition according to the above. 0.2 ≦ Log (MFR (h) / MFR (l)) ≦ 0.5 Equation (3) 4. The propylene / ethylene block copolymer composition according to claim 1, wherein MFR (i) and MFR (ii) satisfy the relationship of the following formula (4). 4 ≦ Log (MFR (i) / MFR (ii)) ≦ 7 Equation (4) 5. An α copolymerized with ethylene in the polymerization step II.
2. The propylene / ethylene block copolymer composition according to claim 1, wherein the olefin is propylene. 6. A molded article obtained by using the propylene / ethylene block copolymer composition according to claim 1. 7. A foam molded article obtained by using the propylene / ethylene block copolymer composition according to claim 1.