JPH09157463A - Polyolefin composition and blow-molded product therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyolefin composition capable of giving blow-molded products extremely excellent in impact resistance, transparency, hard-to-whiten tendency and moldability. SOLUTION: This polyolefin composition 0.3-5g/10min in melt flow rate (230 deg.C; 21.18N) is obtained by blending 100 pts.wt. of a propylene-α-olefin block copolymer 130-160 deg.C in crystal melting point (Tm) composed of 80-95wt.% of propylene-α-olefin copolymer portion containing 0.1-5wt.% of an α-olefin and 20-5wt.% of propylene-α-olefin copolymer portion containing 15-34wt.% of ethylene and 0-25wt.% of >=4C α-olefin(s) with 20-1 pts.wt. of a low-density polyethylene 0.890-0.935g/cm<3> in density and 110-127 deg.C in crystal melting point (Tm).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyolefin composition and a hollow molded article using the polyolefin composition, and more specifically, a hollow molded article excellent in impact resistance, transparency, whitening property and moldability. And a hollow molded article using the polyolefin composition having excellent impact resistance, transparency, whitening property, and moldability.

[0002]

2. Description of the Prior Art Molded products using polyolefins, especially polypropylene, have many excellent properties such as rigidity, impact resistance, heat resistance, hygiene, non-toxicity to human body, resistance to water vapor transmission and moldability. Although it is widely used for molded hollow molded products, conventional hollow molded products using polyolefins do not simultaneously satisfy the surface gloss, transparency, and impact resistance demanded by the market. It was an important issue. As a solution to this problem, for example, as described in JP-A-53-79939, a composition comprising polypropylene or polyolefin and low density polyethylene is used to improve the transparency and impact resistance of a molded article. It has been known. However, the polypropylene or polyolefin shown here is a propylene polymer, an ethylene / propylene block copolymer and an ethylene / propylene random copolymer,
A composition comprising a propylene polymer and low-density polyethylene has not been sufficiently improved in impact resistance of a molded article using the composition, and a composition comprising an ethylene / propylene block copolymer and low-density polyethylene. Is not so improved that the transparency of a molded article using the composition is satisfied, and a composition comprising an ethylene / propylene random copolymer and low density polyethylene has a rigidity of a molded article using the composition. And the impact resistance is not improved at the same time. Further, in JP-A-3-181542, 90 to 99% by weight of an ethylene / propylene random copolymer having an ethylene content of 1 to 5% by weight and an ethylene content of 35 to 35% are disclosed.
65% by weight of ethylene / propylene random copolymerization part 1
The ethylene-propylene block copolymer consisting of 10 to 10% by weight has a density of 0.91 to 0.
A composition containing 1 to 12% by weight of an ethylene homopolymer of 93 g / cm ³ is described. However, when the ethylene content in the ethylene / propylene copolymer portion of the ethylene / propylene block copolymer blended in the composition is 35% by weight or more, the surface gloss and transparency of the molded article using the composition are increased. , Whitening resistance is not improved enough. Further, if the ethylene / propylene block copolymer contained in the composition has an ethylene / propylene random copolymer part having an ethylene content of 35 to 65% by weight of less than 5% by weight, a hollow molded article using the composition is obtained. The impact resistance of can not be satisfied.

[0003]

The object of the present invention is to improve the glossiness, impact resistance and transparency which are the remaining problems at the same time, while making the most of the excellent characteristics of molded products using polyolefin. To provide an olefin resin composition,
Another object is to provide a hollow molded product using the polyolefin composition.

[0004]

[Means for Solving the Problems] The constitution of the present invention will be described below. (1) 80-95% by weight of a propylene / α-olefin copolymerization part (E) having an α-olefin content of 0.1-5% by weight, and an ethylene content of 15-34% by weight, and a carbon number of 4 or more. A propylene / α-olefin block copolymer having a crystalline melting point (Tm) of 130 to 160 ° C. consisting of 20 to 5% by weight of a propylene / α-olefin copolymerization part (F) having an α-olefin content of 0 to 25% by weight Polymer (A) 1
The density is 0.890 to 0.935 g / 00 parts by weight.
The melt flow rate (230 ° C .; 21.18 N) obtained by blending 20 to 1 part by weight of low-density polyethylene (C) having a cm ³ and a crystal melting point (Tm) of 110 to 127 ° C. is 0.3.
~ 5g / 10min polyolefin composition (B)

(2) 0.1 to 0.8 parts by weight of a nucleating agent is added to 100 parts by weight of the block copolymer (A) described in 1 above or the polyolefin composition (B) described in 1 above. Melt flow rate (230 ° C; 2)
Polyolefin composition (D) having 1.18 N) of 0.3 to 5 g / 10 min

(3) The nucleating agent according to the above item 2 is a dibenzylidene sorbitol compound, an aromatic carboxylic acid metal salt (where the metal is aluminum or sodium) compound or a phosphate compound.
Polyolefin composition (D) described

(4) A hollow molded article using the block copolymer (A) described in 1 above, the polyolefin composition (B) described in 1 above or the polyolefin composition (D) described in 2 above.

(5) The propylene / α-olefin block copolymer (A) is the boiling n-pentane extraction ratio (W ¹ _ext ) and ethylene content (W ¹ ) of the propylene / α-olefin block copolymer (E). _c2 ) has a relationship of W ¹ _ext / W ¹ _c2 ≦ 0.90, and the intrinsic viscosity ([η] _PP ) of the propylene / α-olefin copolymer (E) measured in tetracycline at 135 ° C. 0.5 ≦ between the propylene / α-olefin copolymer (F) and the ultimate clay ([η] _RC ).
The hollow molded article according to 1 above, which uses the propylene / α-olefin block copolymer (A) according to 1 above, having a relationship of [η] _RC / [η] _PP ≦ 2.0.

(6) Ratio (W _RC ) of propylene / α-olefin copolymer (F) in propylene / α-olefin block copolymer (A) and cold xylene extraction rate (W).
_{RC (CXS))} between the _{(W RC (CXS)) /} (W RC) ≧ 0.95
The hollow molded article according to the above item 1 using the propylene / α-olefin block copolymer (A) according to the above item 1 having the relationship of

The details will be described below. The block copolymer (A) used in the present invention contains 80 to 95% by weight of a propylene / α-olefin random copolymerization part (E) having an α-olefin content of 0.1 to 5% by weight, and an ethylene content. Is 15 to 34% by weight, the content of α-olefin having 4 or more carbon atoms is 0 to 20% by weight, and the content of propylene / α-olefin copolymerization part (F) is 20 to 5% by weight, preferably the content of ethylene is 0. 80 to 95% by weight of a propylene / α-olefin copolymerization part (E) of 3 to 5% by weight, an ethylene content of 15 to 30% by weight, and a 1-butene content of 1 to 2
0% by weight of propylene / α-olefin copolymerization part (F)
20-5% by weight, preferably 0.5-ethylene content
4% by weight, 80-95% by weight of propylene / α-olefin copolymerization part (E) having a 1-butene content of 0.5-1% by weight, and an ethylene content of 15-30% by weight, 1-butene content A block copolymer having a crystal melting point (Tm) of 130 to 160 ° C. and comprising 20 to 5% by weight of a propylene / α-olefin copolymerization part (F) having an amount of 1 to 10% by weight.

Further, there are provided a polyolefin composition capable of obtaining a hollow molded article excellent in impact resistance, transparency, whitening property and moldability, and a polyolefin composition excellent in impact resistance, transparency, whitening property and moldability. The boiling n-pentane extraction rate (W ¹ _ext ) and ethylene content rate (W ¹ _c2 ) of the propylene / α-olefin copolymer (E) were obtained in that the hollow molded product used was obtained.
Preferably has a relationship of W ¹ _ext / W ¹ _c2 ≦ 0.90, more preferably W ¹ _ext / W ¹ _c2 ≦ 0.85, and has a propylene / α-olefin copolymer (E) of 135 ° C. Between the intrinsic viscosity ([η] _PP ) measured by tetracycline of [.eta.] And the intrinsic viscosity ([η] _RC ) of the propylene / α-olefin copolymer (F) measured by tetracycline at 135 ° C. is preferably 0.5. Propylene / α-olefin block copolymer having a relationship of ≦ [η] _RC / [η] _PP ≦ 2.0, more preferably 0.5 ≦ [η] _RC / [η] _PP ≦ 1.5 ( A) can be used.

Further, a polyolefin composition which gives a hollow molded article excellent in impact resistance, transparency, whitening resistance, and moldability, and a polyolefin composition excellent in impact resistance, transparency, whitening resistance, and moldability. In terms of obtaining a hollow molded article using the product, the ratio (W _RC ) of the propylene / α-olefin block copolymer (F) in the propylene / α-olefin block copolymer (A) and the cold xylene extraction rate ( W _{RC (CXS))} between the _{(W RC (CXS)) /} (W RC) ≧ 0.
The propylene / α-olefin block copolymer (A) having a relationship of 95 is preferable.

The block copolymer has a melt flow rate (230 ° C .; 21,18N) of 0.3 to 5 g / 10 mi.
n, preferably 0.5 to 3 g / 10 min, preferably 0.8 to 2 g / 10 min.

The intrinsic viscosity ([η] _RC ) of the propylene / α-olefin copolymer (F) measured in tetracycline at 135 ° C. is determined from the intrinsic viscosity ([η] _WHOLE ) of the block copolymer. , Calculated by the following formula. [Η] _RC = [[η] _WHOLE- (1-W _RC / 100)-
[Η] _PP ] / (W _RC / 100)

The xylene extraction rate _{(WRC (CXS)} ) of the propylene / α-olefin copolymer (F) was measured by measuring the cold xylene extraction rate (W _WHOLE ) of the propylene / α-olefin block copolymer (A). _(CXS) ) and propylene / α-olefin copolymer (E) (W _{PP (C XS)} ).

(W _{RC (CXS)} ) = (W _{WHOLE (CXS)} )-(1
-W _RC / 100) ・ (W _{PP (CXS)} )

The method for producing the block copolymer (A) is as follows:
Propylene as a main component and ethylene as a comonomer or α-olefin having 4 or more carbon atoms are relatively high by a known polymerization method using, for example, a Ziegler-Natta catalyst or a known highly active catalyst such as a reduction type or a supported type. Hydrogen concentration,
80 to 95% by weight of a propylene / α-olefin random copolymerization part having an α-olefin content of 0.5 to 5% by weight in slurry polymerization or gas phase polymerization under relatively low temperature conditions.
Polymerization, followed by a known polymerization method, a propylene / ethylene random copolymer having an ethylene content of 15 to 34% by weight or an ethylene component of less than 15 to 34% by weight, and an α-olefin such as 1-butene of 0 to 0% by weight. It can be obtained by polymerizing 20 to 5% by weight of a multi-component random copolymerization part consisting of 25% by weight of propylene / α-olefin. The melt flow rate can be adjusted by a known amount of hydrogen added.

As the highly active catalyst, a catalyst in which a titanium-containing solid catalyst component, an organoaluminum compound and an organosilicon compound are combined can be exemplified.

The crystalline melting point (Tm) used herein means that a 10 mg sample is heated at 20 ° C. in a nitrogen atmosphere using a scanning differential calorimeter.
The peak temperature of the endothermic curve accompanying the melting of the crystal obtained by raising the temperature at a rate of / min is shown. Crystal melting point (Tm) of propylene / α-olefin block copolymer is 160 ° C
A hollow molded article using a composition containing more than 10% has a high hardness, but the impact resistance, gloss and transparency are deteriorated. In addition, the hardness of hollow moldings using a composition containing a crystalline melting point (Tm) of less than 130 ° C is lowered, and the surface of the hollow moldings is easily scratched in the molding and handling steps of the hollow molding, and the defective rate is high. Increase and productivity decreases.

In the present invention, the block copolymer (A) may contain a low density polyethylene (C) in order to further improve the transparency and gloss of the hollow molded article. The low density polyethylene (C) is linear low density polyethylene (LLDPE) or polyethylene obtained by radical polymerization by a high pressure method. Among them, linear low-density polyethylene (LLDPE) is preferable because it has excellent compatibility with the block copolymer (A). The low melting point polyethylene (C) has a crystal melting point (Tm) of 110 to 127 ° C, preferably 115 to 123 ° C. The density was in 0.890~0.935g / cm ^3, preferably 0.895~0.922g / cm ^3, preferably 0.9
It is from 00 to 0.915 g / cm ³ . Hollow molded articles using a composition containing polyethylene having a density of 0.935 or more are not preferable because the transparency and the whiteness are increased and the coloring property and vividness of the color pigment are decreased.

The low density polyethylene (C) has a melt flow rate (190 ° C .; 21.18 N) of 0.5 to 30 g.
/ 10 min, preferably 1 to 15 g / 10 mi
n, preferably 2 to 10 g / 10 min. Melt flow rate (190 ° C; 21.18N) is 0.5 g /
Low-density polyethylene of less than 10 min or more than 30 g / 10 min is not suitable because of poor compatibility with the block copolymer (A). The blending amount of the low-density polyethylene (C) is 20 to 1 part by weight, preferably 20 to 2 parts by weight, and preferably 15 to 3 parts by weight, based on 100 parts by weight of the block copolymer (A). . A hollow molded article using a composition blended in an amount of more than 20 parts by weight is likely to be scratched on the surface of the hollow molded article in the molding step and the handling step, resulting in an increase in defective rate and a decrease in productivity. The method for producing the low-density polyethylene comprises ethylene as a main component, butene-1, hexene-
For example, it is possible to obtain a polyethylene copolymer obtained by polymerizing an α-olefin such as 1 using a Ziegler-Natta catalyst or the like, or an ethylene homopolymer.

In the present invention, a nucleating agent may be added to the block copolymer (A) or the polyolefin composition (B) in order to further improve the surface gloss of the hollow molded article. Among the nucleating agents, dibenzylidene sorbitol compounds, aromatic carboxylic acid metal salt (where metal is aluminum or sodium) compounds or phosphate compounds are preferable.

Examples of the dibenzylidene sorbitol compounds include 1,3,2,4-dibenzylidene sorbitol, 1,3-benzylidene-2,4-p-methylbenzylidene sorbitol, and 1,3-benzylidene-2.
4-p-ethylbenzylidene sorbitol, 1.3-p
-Methylbenzylidene-2,4-benzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-benzylidene sorbitol, 1.3-p-methylbenzylidene-2,4-p-ethylbenzylidene sorbitol, 1
-3-p-Ethylbenzylidene-2,4-p-methylbenzylidene sorbitol, 1,3,2,4-di (p-methylbenzylidene) sorbitol, 1,3,2,4-di (p-ethylbenzylidene) Sorbitol 1,3,2
-4-di (pn-propylbenzylidene) sorbitol, 1,3,2,4-di (pi-propylbenzylidene) sorbitol, 1,3,2.4-di (pn-butylbenzylidene) Sorbitol, 1,3,2,4-di (ps-butylbenzylidene) sorbitol, 1
3,2,4-di (pt-butylbenzylidene) sorbitol, 1,3,2,4-di (2 ', 4'-dimethylbenzylidene) sorbitol, 1,3,2,4-di (p-
Methoxybenzylidene) sorbitol, 1, 3, 2.4
-Di (p-ethoxybenzylidene) sorbitol, 1 ·
3-benzylidene-2,4-p-chlorobenzylidene sorbitol, 1.3-p-chlorobenzylidene-2.4
-P-methylbenzylidene sorbitol, 1.3-p-
Chlorbenzylidene-2,4-p-ethylbenzylidene sorbitol, 1.3-p-methylbenzylidene-2.
4-p-chlorobenzylidene sorbitol, 1.3-p
-Ethylbenzylidene-2,4-p-chlorobenzylidene sorbitol, 1,3,2,4-di (p-chlorobenzylidene) sorbitol and the like can be exemplified, and particularly 1-
3,2.4-Dibenzylidene sorbitol, 1,3,2
-4-di (p-methylbenzylidene) sorbitol, 1
・ 3,2,4-di (p-ethylbenzylidene) sorbitol, 1,3-p-chlorobenzylidene-2,4-p-
Methylbenzylidene sorbitol and 1.3,2.4-
Di (p-chlorobenzylidene) sorbitol is preferred. These compounds may be used alone, or two or more compounds may be used in combination.

Examples of the aromatic carboxylic acid metal salt compounds include benzoic acid, o-toluic acid, m-toluic acid, p-toluic acid, pt-butylbenzoic acid and pt.
-Amylbenzoic acid, pt-octylbenzoic acid, o-methoxybenzoic acid, m-methoxybenzoic acid, anisic acid, naphthoic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, mellitic acid, salicylic acid , Acetylsalicylic acid and 3,5-di-t-butyl-4-
Examples thereof include aluminum salt or sodium salt of hydroxybenzoic acid. Especially 3,5-di-t-butyl-4
-The aluminum and sodium salts of hydroxybenzoic acid are preferred.

Examples of the phosphate compound include sodium-2,2'-methylene-bis (4,6-
Di-t-butylphenyl) phosphate, sodium-2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, lithium-2,2'-methylene-bis (4,6-) Di-t-butylphenyl) phosphate, lithium-2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate,
Sodium-2,2'-ethylidene-bis (4-i-propyl-6-t-butylphenyl) phosphate, lithium-2,2'-methylene-bis (4-methyl-6-)
t-butylphenyl) phosphate, lithium-2,
2'-methylene-bis (4-ethyl-6-t-butylphenyl) phosphate, calcium-bis [2,2 '
-Thiobis (4-methyl-6-t-butylphenyl) phosphate], calcium-bis [2,2'-thiobis (4-ethyl-6-t-butylphenyl) phosphate], calcium-bis [2,2] 2'-thiobis (4,
6-di-t-butylphenyl) phosphate], magnesium-bis [2,2'-thiobis (4,6-di-t]
-Butylphenyl) phosphate], magnesium-
Bis [2,2'-thiobis (4-t-octylphenyl) phosphate], sodium-2,2'-butylidene-bis (4,6-di-methylphenyl) phosphate, sodium-2,2'- Butylidene-bis (4
6-di-t-butylphenyl) phosphate, sodium-2,2'-t-nonylidene-bis (4,6-di-
Methylphenyl) phosphate, sodium-2,2
′ -T-nonylidene-bis (4,6-di-t-butylphenyl) phosphate, calcium-bis [2,2 ′
-Methylene-bis (4,6-di-t-butylphenyl)
Phosphate], magnesium-bis [2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate], barium-bis [2,2'-methylene-
Bis (4,6-di-t-butylphenyl) phosphate], sodium-2,2'-methylene-bis (4-methyl-6-t-butylphenyl) phosphate], sodium-2,2'- Methylene-bis (4-ethyl-6)
-T-butylphenyl) phosphate], sodium- (4,4'-dimethyl-6,6'-di-t-butyl-
2,2'-biphenyl) phosphate, calcium-
Bis [(4,4'-dimethyl-6,6'-di-t-butyl-2,2'-biphenyl) phosphate,] Sodium-2,2'-ethylidene-bis (4-s-butyl-)
6-t-Butylphenyl) phosphate, sodium-2,2'-methylene-bis (4,6-di-methylphenyl) phosphate, sodium-2,2'-methylene-bis (4,6-di-) Ethylphenyl) phosphate, potassium-2,2'-ethylidene-bis (4,6-
Di-t-butylphenyl) phosphate, calcium-bis [2,2'-ethylidene-bis (4,6-di-t)
-Butylphenyl) phosphate], magnesium-
Bis [2,2'-ethylidene-bis (4,6-di-t-
Butylphenyl) phosphate], barium-bis [2,2′-ethylidene-bis (4,6-di-t-butylphenyl) phosphate], aluminum-tris [2,2′-methylene-bis (4,4) 6-di-t-butylphenyl) phosphate], aluminum-tris [2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate], sodium-bis (4
-T-butylphenyl) phosphate, sodium-
Bis (4-t-methylphenyl) phosphate, sodium-bis (4-t-ethylphenyl) phosphate, sodium-bis (4-i-propylphenyl) phosphate, sodium-bis (4-t-octylphenyl) ) Phosphate, potassium-bis (4-t-butylphenyl) phosphate, calcium-bis (4
-T-butylphenyl) phosphate, magnesium-bis (4-t-butylphenyl) phosphate, lithium-bis (4-t-butylphenyl) phosphate and aluminum-bis (4-t-butylphenyl)
Phosphate and the like can be exemplified. These compounds can be used alone, and two or more compounds can be used in combination.

Further, the block copolymer (A) of the present invention,
For the polyolefin composition (B) and the polyolefin composition (D), in addition to the above-mentioned components, an antioxidant,
A weather resistance agent, an ultraviolet absorber, an antistatic agent, a colorant, a metal soap, an olefin elastomer and an ethylene / propylene random copolymer can be blended within a range not impairing the object of the present invention. However, when polyethylene with a density of more than 0.935 is blended, 1 is added to the composition.
Must be limited to parts by weight or less.

The melt flow rate (230 ° C .; 21.18) of the polyolefin composition (B), the polyolefin composition (C) and the polyolefin composition (D) of the present invention.
N) is 0.3 to 5 g / 10 min. Melt flow rate (230 ° C; 21.18N) is 0.3g / 10m
A composition of less than in has a high melt viscosity at the time of blow molding, and thus melt fracture occurs, and the resulting hollow molded article has unfavorable surface gloss and transparency. 5g / 1
A composition exceeding 0 min has a low melt viscosity at the time of blow molding, which causes a drastic drawdown, makes it difficult to obtain a hollow molded product having a uniform thickness, and increases the defective rate, resulting in a decrease in productivity.

The polyolefin composition (B) and the polyolefin composition (D) of the present invention are obtained by blending the above-mentioned respective components. For blending each of these components, a conventional mixer such as a mixer with a high-speed stirrer such as a Henschel mixer (trade name) and a super mixer (trade name), a ribbon blender, and a tumbler may be used. When melt-kneading is required, a usual single-screw extruder or twin-screw extruder is used. The kneading temperature is 200 to 300 ° C, preferably 230 to 270 ° C.

The present invention comprises a block copolymer (A), a polyolefin composition (B) and a polyolefin composition (D).
It is possible to obtain a hollow molded article using. The hollow molded article is a molded article excellent in transparency, surface gloss, and whitening resistance.

As a method for obtaining the hollow molded article, there is a direct blow molding method. Specifically, the block copolymer (A), the polyolefin composition (B) and the polyolefin composition (D) are put into an extruder of a direct blow molding machine to melt-extrude the parison, and immediately maintain it at 50 ° C or lower. It is sandwiched between the blow molding dies and the inside is filled with air (air pressure is 0.049 to 0.098 MPa).
It can be illustrated by blowing to obtain a hollow molded article.

The hollow molded article of the present invention may be a container. Since the container has excellent transparency, surface gloss and impact resistance, it is excellent as a storage container for liquid foods, daily necessities (liquid soap etc.), general industrial products and the like. As a method for obtaining the container, specifically, a mold for molding the blow molding machine may be changed to a mold for molding the container. It can be advantageously used for various purposes.

[0032]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The properties used in the following examples and comparative examples were evaluated by the following methods. (1) The crystal melting point (Tm) is represented by the peak temperature (unit: ° C) of the endothermic curve accompanying the melting of the crystal, and is 10 mg in a nitrogen atmosphere using a scanning differential calorimeter (abbreviation: DSC). The sample was measured at room temperature (23 ° C) at a temperature rising rate of 20 ° C / min. (2) 230 ° C melt flow rate (abbreviation MFR-
) Is the test condition 14 of JIS K7210 (1976).
(230 ° C., 21.18 N). (Unit: g / 10min)

(3) 190 ° C. Melt flow rate (abbreviation MFR−) was measured based on JIS K7210 (1976) test condition 14 (190 ° C., 21.18 N). (Unit: g / 10 min) (4) The density was measured based on the D method (density gradient tube method) under the test conditions of JIS K7112 (1980). (Unit: g / cm ³ )

(5) The glossiness is JIS K7105 (19
81) The test conditions (60 degree specular gloss) were measured. (Unit:%) (6) Transparency is measured based on the test method of ASTM D1003 from the center of the body of the hollow molded product (thickness 0.8 m
m) was taken and the Haze value (cloudiness) was measured. The smaller this value, the better the transparency.

(7) The scratch resistance was evaluated by observing the surface of the hollow molded products after rubbing them together. Evaluation results E and G
And P have the following meanings. E: Scratches are hardly observed; G: Slight scratches are generated but practically no problem; P: Scratches are noticeable.

(8) As for impact resistance, 10 hollow moldings were prepared which were filled with 600 cc of water and sealed, and left in a low temperature room at 5 ° C. for 8 hours or more, and then repeated from a height of 1 m onto a concrete pavement surface 10 It was dropped once and the state of destruction was observed and evaluated. The evaluation results A to E have the following meanings. A: The hollow molded article was not cracked at all after repeated 10 drops. B: 80% or more of the hollow molded product is not cracked by repeatedly dropping 10 times. C: The hollow molded article was not cracked at all by repeated 5 drops, and 1
Everything is broken by 0 times. D: 50% or more of the hollow molded product is broken by repeatedly dropping up to 5 times. E: All of the hollow molded products are broken by repeating 1 to 3 times.

(9) The whiteness was evaluated by visually observing the hue of the hollow molded article. The evaluation results A and B have the following meanings. A: A product having a whiteness similar to that of polypropylene (comparative polypropylene: Chisso Polypro XF1800). B: A product having a whiteness similar to that of high-density polyethylene (comparative high-density polyethylene: Chissopolyech B504).

(10) As for the whitening resistance, a measurement sample (50 × 50 × 0.8 mm) was taken from the center of the body of the hollow molded product, and a hammer having a 1/4 ″ R tip on the surface side of the hollow molded product. Using 5
An impact of 00 g × 50 cm is applied to judge the degree of whitening. A: When the whitened area is extremely small and less than 10 mm ² . B: When the whitened area is 10 to 15 mm ² . C: When the whitened area is 15 to 20 mm ² . D: When the whitened area exceeds 20 mm ² .

The abbreviations of the polymers used in the following Examples and Comparative Examples are as follows. PP: 89.6 parts by weight of ethylene / propylene random copolymerization part (a) having an ethylene content of 1.6% by weight and 10.4 parts by weight of ethylene / propylene random copolymerization part (b) having an ethylene content of 25% by weight Section, MFR is 1.07
g / 10 min, a block copolymer having a crystal melting point (Tm) of 152 ° C. Further details are shown in Table 1 below.

[0040]

[Table 1]

PP: 92 parts by weight of ethylene / propylene random copolymerization part having an ethylene content of 1.1% by weight (c) and 11 parts by weight of ethylene / propylene random copolymerization part having an ethylene content of 31% by weight (d) , A block copolymer having an MFR of 1.2 g / 10 min and a crystal melting point (Tm) of 156 ° C. Further details are shown in Table 2 below.

[0042]

[Table 2]

PP: 89 parts by weight of ethylene / propylene random copolymer part having an ethylene content of 2.4% by weight and propylene / α-olefin random having an ethylene content of 24% by weight and a 1-butene content of 22% by weight. Copolymerization part 1
1 part by weight, MFR is 1.2 g / 10 min, and the block copolymer has a crystal melting point (Tm) of 142 ° C.

PP: 90 parts by weight of ethylene / propylene random copolymerization part (e) having an ethylene content of 1.5% by weight and 10 parts of propylene / α-olefin random copolymerization part (f) having an ethylene content of 45% by weight Parts by weight, MFR
Is 0.96 g / 10 min, the crystal melting point (Tm) is 152
C block copolymer. Further details are shown in Table 3 below.

[0045]

[Table 3]

PP: ethylene content of 2.5% by weight,
An ethylene / propylene random copolymer having an MFR of 1.0 g / 10 min and a crystal melting point (Tm) of 147 ° C. )

PE (MFR 0.8 g / 10 mi
n, density 0.900 g / cm ³ , and crystalline melting point (Tm) of 115 ° C. linear low density polyethylene)

PE (MFR 8 g / 10 min, density 0.920 g / cm ³ , crystal melting point (Tm) 122
℃ linear low density polyethylene)

PE (MFR is 6.5 g / 10 mi
n, density 0.952 g / cm ³ , linear melting point (Tm) 130 ° C. linear low density polyethylene)

Nucleating agent (sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate)

(Examples 1 to 9 and Comparative Examples 1 to 4) PP
, PP, PP, PP, PP, 100 parts by weight of PE, PE, and a nucleating agent are mixed in the amount shown in Table 4 below, and tris (2,
4-di-t-butylphenyl) phosphate 0.05
Parts by weight, tetrakis [methylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate)] methane 0.
05 parts by weight and 0.1 part by weight of calcium stearate were blended, mixed using a Henschel mixer, melt-kneaded and extruded by an extruder set at 250 ° C. to obtain a pelletized composition.

The pelletized composition was fed to an extruder of a blow molding machine [SN50A (Plastic Co.)] to obtain 1
The parison is extruded at 90 ° C, and the parison is set at a mold temperature of 3
Blow molding was performed in a mold for blow molding at 0 ° C. to form a hollow molded product (a container having an average wall thickness of 0.8 mm and an internal volume of 600 ml). Table 4 shows the characteristics of the hollow molded article.

[0053]

[Table 4]

Examples 1 to 3 shown in Table 4 are PP, PP and hollow molded articles using PP which are the block copolymer (A), and have high glossiness, low haze and white feeling without any problem. It also has excellent scratch resistance and impact resistance. On the other hand, Comparative Example 1 is a hollow molded article using PP having a propylene / α-olefin random copolymerization portion having an ethylene content of more than 34% by weight, and has a low glossiness and a high haze.
Furthermore, the whiteness of the molded product is very close to that of the molded product using high-density polyethylene, and it is not suitable for applications where it is required to confirm the content liquid of the hollow molded product from the outside.

Comparative Example 2 is a hollow molded product having PP which is an ethylene / propylene random copolymer and is not preferable because of its low impact resistance. Examples 4 to 8 are hollow moldings using the polyolefin composition (B) in which the block copolymer (A) PP, PP and PP and the low density polyethylene (C) PE and are blended. These hollow molded products were further improved in the glossiness and haze of the hollow molded products shown in Examples 1 to 3, and the hollow molded products having a more excellent commercial value were obtained. Comparative Example 3 is a hollow-molded product using a composition in which the low-density polyethylene (C) PE in an amount of more than 20 parts by weight was added to 100 parts by weight of the block copolymer (A) PP. As compared with the hollow molded article of No. 3, the deterioration of the scratch resistance due to the decrease of the surface hardness and the decrease of the impact resistance due to the decrease of the strength of the pinch-off part or the weld part were observed.

Comparative Example 4 is a hollow molded article using a composition in which PP which is a block copolymer (A) and PE which is a low density polyethylene having a density of more than 0.935 g / cm ³ are used. As compared with the hollow molded product of No. 4, a decrease in transparency and whiteness was observed. Example 9 is a hollow molded article using a polyolefin composition (D) obtained by adding a nucleating agent to PP which is a block copolymer (A),
The glossiness and haze of the hollow molded products shown in Examples 1 to 3 were further improved, and hollow molded products having a further excellent commercial value were obtained.

The polyolefin composition of the present invention gives a hollow molded article which is extremely excellent in impact resistance, transparency, whitening property and moldability, and a hollow molded article using the polyolefin composition of the present invention is impact resistant. It has the effects of being extremely excellent in the properties, transparency, whitening resistance, and moldability.

Claims (6)

[Claims] 1. A propylene / α-olefin copolymerization part (E) 80 having an α-olefin content of 0.1 to 5% by weight.
To 95% by weight, an ethylene content of 15 to 34% by weight, and an α-olefin content of 4 or more carbon atoms of 0 to 25% by weight, a propylene / α-olefin copolymerization part (F) 20.
˜5 wt% crystalline melting point (Tm) 130-160
The density is 0.890 to 0.9 with respect to 100 parts by weight of the propylene / α-olefin block copolymer (A) at 0 ° C.
35 g / cm ³ , crystal melting point (Tm) 110-127 ° C.
Melt flow rate (230 ° C; 21.18N) obtained by blending 20 to 1 part by weight of low density polyethylene (C)
Of 0.3 to 5 g / 10 min polyolefin composition (B) 2. The block copolymer (A) according to claim 1.
Alternatively, the polyolefin composition (B) 1 according to claim 1.
Melt flow rate (230 ° C .; 21.18;
N) 0.3 to 5 g / 10 min polyolefin composition (D) 3. The polyolefin according to claim 3, wherein the nucleating agent according to claim 2 is a dibenzylidene sorbitol compound, an aromatic carboxylic acid metal salt (where the metal is aluminum or sodium) compound or a phosphate compound. Composition (D) 4. A hollow molded article using the block copolymer (A) according to claim 1, the olefin resin composition (B) according to claim 1 or the polyolefin composition (D) according to claim 2. 5. The boiling n-pentane extraction ratio (W ¹ _ext ) and ethylene content ratio (W ¹ _c2 ) of the propylene / α-olefin block copolymer (A) are the propylene / α-olefin block copolymer (E). ) Has a relationship of W ¹ _ext / W ¹ _c2 ≦ 0.90 and is 1 of the propylene / α-olefin copolymer (E).
0.5 ≦ [η] between the intrinsic viscosity ([η] _PP ) measured in tetracycline at 35 ° C. and the limiting clay ([η] _RC ) of the propylene / α-olefin copolymer (F).
The hollow molded article according to claim 1, which uses the propylene / α-olefin block copolymer (A) according to claim 1, having a relationship of _RC / [η] _PP ≦ 2.0. 6. A ratio of the propylene / α-olefin copolymer (F) in the propylene / α-olefin block copolymer (A) (W _RC ) and a cold xylene extraction rate (W _{RC (CXS)} ). Between (W _{RC (CXS)} ) / (W _RC ) ≧ 0.
The hollow molded article according to claim 1, wherein the propylene / α-olefin block copolymer (A) according to claim 1 having a relationship of 95 is used.