JP2002187996A - Propylene resin composition and hollow molded container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a propylene resin composition which is excellent in the balance of impact resistance, rigidity and transparency and is also excellent in the strength at welded positions and in its appearance and to provide a hollow molded container made of this composition. SOLUTION: The propylene resin composition comprises 70-90 wt.% of a propylene block copolymer and 30-10 wt.% of an ethylene resin. The composition has a die swell ratio at 210 deg.C and 1216 s-1 of not more than 1.70, and satisfies formula (1) among its Izot impact value (unit: kJ/m2) at 0 deg.C, its flexural modulus (unit: MPa) at 23 deg.C and its haze value (unit: %); Izot impact value (×) flexural modulus/haze value >=200 (1). A hollow molded container and a multi-layered hollow molded container are made of this propylene resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a propylene-based resin composition. More specifically, the present invention relates to a propylene-based resin composition in which welds hardly occur at a resin confluence, and which has an excellent balance between impact resistance, rigidity, and transparency. The propylene-based resin composition of the present invention is particularly suitable for producing a container (hollow molded container) by a hollow molding method.

[0002]

2. Description of the Related Art Polypropylene resins are used in detergents,
It is one of the resins widely used as containers for articles exemplified by beverages, foods, and medicines. Almost all of these containers are formed by a hollow molding method widely used as a method for manufacturing a thermoplastic resin container. The blow molding method is classified into a direct blow molding method using a hot parison and an injection stretch blow molding method using a hot parison or a cold parison. The direct blow molding method is superior to the injection stretch blow molding method in terms of molding stability and molding equipment cost, and many polypropylene resin containers are molded by the direct blow molding method. A polypropylene resin container formed by the direct blow molding method easily causes weld at a resin confluence portion in a die of a blow molding machine, and the weld portion lowers the strength of the container and deteriorates the appearance.

[0003] Polypropylene resin is excellent in heat resistance, rigidity and transparency, but has a drawback of poor impact resistance. Therefore, as a composition having improved impact resistance without impairing the excellent transparency of the polypropylene resin, a composition comprising a polypropylene resin, a linear low-density polyethylene, and an ethylene-α-olefin copolymer elastomer ( A composition comprising a polypropylene resin and an ethylene-α-olefin copolymer polymerized using a metallocene catalyst (see JP-A-9-31264) is known. I have.

[0004]

However, the hollow molded container made of the composition described in the above-mentioned publication has reached a level at which the balance of impact resistance, rigidity and transparency expressed by drop strength can be satisfied. In addition, there is a problem that the strength of the weld portion is insufficient. As a composition in which the strength of the weld portion of the polypropylene resin container is improved, a propylene polymer, a wide-molecular-weight distribution linear low-density polyethylene, a narrow-molecular-weight distribution linear low-density polyethylene, and an ethylene-α-olefin copolymer A composition comprising a coalesced elastomer (see JP-A-11-152379) is known, but a container satisfying the balance between rigidity and transparency of the container has not been obtained even if the strength of the weld portion is improved. Was. An object of the present invention is to provide a propylene-based resin composition having an excellent balance between impact resistance, rigidity, and transparency, and having excellent weld portion strength and appearance, and a hollow molded container made of the composition.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on the development of a propylene-based resin composition having an excellent balance of impact resistance, rigidity and transparency, and having excellent weld strength and appearance. Was. As a result, a propylene-based resin composition having a specific composition in which the Izod impact resistance value, the flexural modulus, and the haze value satisfy a specific relational expression and the die swell ratio is equal to or less than a certain value fulfills the object of the present invention. This led to the completion of the present invention. That is, the present invention comprises 70 to 90% by weight of a propylene block copolymer and 30 to 10% by weight of an ethylene-based resin.
The die swell ratio at 6 s ^-1 is 1.70 or less;
Izod impact value at 0 ° C (unit: kJ / m ² )
And a propylene-based resin composition in which the relationship between the flexural modulus at 23 ° C. (unit: MPa) and the haze value (unit:%) satisfies the following formula (1), and a hollow molding comprising the propylene-based resin composition The present invention relates to a container and a multilayer hollow molded container. Izod impact value × flexural modulus / haze value ≧ 200 (1)

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The propylene resin composition of the present invention is a resin composition comprising a propylene block copolymer as a main component and a propylene block copolymer and an ethylene resin. Polymer 70 ~
90% by weight, preferably 72 to 89% by weight, more preferably 75 to 88% by weight, and 30 to 10% by weight, preferably 28 to 11% by weight, and more preferably 2 to 11% by weight of the ethylene resin.
5 to 12% by weight of the resin composition. here,
The total amount of both components is 100% by weight.

[0007] The propylene block copolymer is
It means a copolymer obtained in the following steps. First step: The total amount of the polymer component (component A) in which propylene alone or propylene and ethylene has a content of a repeating unit derived from ethylene of 0 to 2% by weight (component A and component B below) 70-90% by weight of the total amount
A process of polymerizing until Second step: In the presence of the component A produced in the first step, propylene and ethylene are mixed with a propylene-ethylene copolymer component having a content of a repeating unit derived from ethylene of 15 to 50% by weight ( A step of copolymerizing until the amount of the (B component) becomes 10 to 30% by weight of the total amount of the polymer (the total amount of the A component and the B component).

The content of the component A in the propylene block copolymer is preferably 75 to 89% by weight, more preferably 80 to 88% by weight, and the content of the repeating unit derived from ethylene in the component A Is preferably 1% by weight
It is as follows. In addition, B in the propylene block copolymer
The content of the component is preferably 25 to 11% by weight, more preferably 20 to 12% by weight, and the content of the repeating unit derived from ethylene in the component B is preferably 2 to 12% by weight.
0 to 45% by weight, more preferably 25 to 40% by weight. Preferred propylene block copolymer is 230 ° C.
Is a propylene block copolymer having a melt flow rate (MFR) of 2 g / 10 min or less, preferably 0.5 to 1.8 g / 10 min, more preferably 0.8 to 1.6 g / 10 min.

The above-mentioned ethylene-based resin is a thermoplastic ethylene homopolymer containing 50% by weight or more of a repeating unit derived from ethylene, ethylene and 3 carbon atoms.
~ 18 alpha-olefins, or copolymerization of ethylene with at least one other monomer. As the α-olefin, propylene, butene-1,
4-methylpentene-1, hexene-1, octene-
1, decene-1. Conjugated dienes (eg butadiene and isoprene) as other monomers,
Non-conjugated dienes (eg, 1,4 pentadiene), acrylic acid, acrylates (eg, methyl acrylate and ethyl acrylate), methacrylic acid, methacrylates (eg, methyl methacrylate and ethyl methacrylate)
And vinyl acetate.

Examples of the ethylene resin include low-density polyethylene; ultra-low-density polyethylene; medium-density polyethylene; high-density polyethylene; ethylene-propylene copolymer, ethylene-butene-1 copolymer, and ethylene-4-methylpentene-1. Copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer, ethylene-
A copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms, such as a decene-1 copolymer; a copolymer of ethylene and a conjugated diene (eg, butadiene or isoprene); a copolymer of ethylene and a non-conjugated diene (eg, 1, Copolymers of ethylene with acrylic acid, methacrylic acid or vinyl acetate; and these resins, for example, α, β-unsaturated carboxylic acids and derivatives thereof (eg, acrylic acid and Methyl acrylate) or a resin modified (eg, graft-modified) with an alicyclic carboxylic acid or a derivative thereof (eg, maleic anhydride).

As preferred ethylene resins, the following resins (1) to (3) and mixtures thereof can be exemplified. (1) Ethylene-α-olefin copolymer (E1) obtained by polymerizing ethylene and α-olefin in the presence of a metallocene catalyst (2) Ultra-low density polyethylene (E2) (3) Ethylene-α-olefin copolymer (E1), ultra-low-density polyethylene (E2), low-density polyethylene (E3) and ethylene-
Resin mixture comprising at least one ethylene resin selected from the group consisting of α-olefin copolymer (E4)

The ethylene-α-olefin copolymer (E1) has a density of 0.890 to 0.930 g / cm.
^3, which is a copolymer of ethylene and an α-olefin having ³ to 18 carbon atoms. A preferred upper limit of the density is 0.929 g / cm ³ , and a more preferred upper limit is 0.92 g / cm ³ .
8 g / cm ³ . Examples of the α-olefin include propylene, butene-1, pentene-1, hexene-1, 4-methyl-1-pentene, octene-1, decene-1, dodecene-1, tetradecene-1, hexadecene-1, Octadecene-1 and the like. Ethylene-
The melt flow rate (MFR) at 190 ° C. of the α-olefin copolymer (E1) is preferably 0.05 to
50 g / 10 min, more preferably 0.1 to 40 g / 10
Min, and still more preferably 1 to 30 g / 10 min.

The ethylene-α-olefin copolymer (E
As a preferred production method of 1), ethylene and an α-olefin are polymerized by a gas phase polymerization method in the presence of a polymerization catalyst (metallocene catalyst) comprising a transition metal compound having a group having a cyclopentadiene-type anion skeleton. (For example, JP-A-3-234).
No. 717 gazette)

[0014] The ultra-low density polyethylene (E2), a density of less than ^{0.880g / cm 3 ~0.910g / cm 3} , ethylene and carbon atoms a copolymer of 3 to 18 of the α- olefin means. The density is preferably 0.88
2 to 0.909 g / cm ³ , more preferably 0.885
０．９0.908 g / cm ³ . Examples of the α-olefin include the same α-olefin as in the case of the ethylene-α-olefin copolymer (E1). MFR of very low density polyethylene (E2) at 190 ° C
Is preferably 0.05 to 50 g / 10 min, more preferably 0.1 to 40 g / 10 min, and still more preferably 1 to 3
0 g / 10 minutes.

[0015] The low density polyethylene (E3), density refers to polyethylene having 0.915~0.930g / cm ^3. The density is preferably between 0.916 and 0.9
29 g / cm ³ , more preferably 0.918 to 0.92
8 g / cm ³ . Low density polyethylene (E3)
It can be produced by polymerizing ethylene by a high-pressure radical polymerization method. Low density polyethylene (E3)
MFR at 190 ° C. is preferably 0.05 to 5
0 g / 10 min, more preferably 0.1 to 40 g / 10
Min, more preferably 1 to 30 g / 10 min.

The ethylene-α-olefin copolymer (E
4) is the ethylene-α-olefin copolymer (E
Density other than 1) is 0.910 to 0.930 g / cm ³
Of ethylene and an α-olefin having 3 to 18 carbon atoms. The density is preferably 0.912 to
0.929 g / cm ³ , more preferably 0.915 to
0.928 g / cm ³ . Examples of the α-olefin include the same α-olefin as in the case of the ethylene-α-olefin copolymer (E1). The MFR of the ethylene-α-olefin copolymer (E4) at 190 ° C. is preferably 0.05 to 50 g / 10
Min, more preferably 0.1 to 40 g / 10 min, and still more preferably 1 to 30 g / 10 min. The method for producing the ethylene-α-olefin copolymer (E4) is not particularly limited. Excludes the manufacturing method. Examples of the production method include a production method in which ethylene and an α-olefin are polymerized in the presence of a conventional solid catalyst (multi-site catalyst) (for example, JP-A-7-31).
No. 6220).

The value of the die swell ratio at 210 ° C. and 1216 s ⁻¹ is preferably 1.3 to 1.68, more preferably 1.2 to 1.66. When the value of the die swell ratio exceeds 1.70, a weld portion is easily generated at a resin confluence portion in a molding machine and a mold, which is not preferable.
The method for measuring the die swell ratio and the method for evaluating the weld portion will be described later.

The value of the left side of the equation (1) (Izod impact resistance × flexural modulus / haze value) is 200 or more, preferably 25 or more.
It is 0-5000, more preferably 300-3000. If the value on the left side is less than 200, it is difficult to obtain a propylene-based resin composition having an excellent balance between low-temperature impact resistance, rigidity, and transparency. The method of measuring the Izod impact value, flexural modulus and haze value will be described later.

The propylene block copolymer or ethylene resin used in the present invention can further improve the transparency of the propylene resin composition of the present invention or form a molding cycle for obtaining a molded article from the resin composition. May be used in combination with a crystal nucleating agent from the viewpoint of the effect of shortening. The amount of the crystal nucleating agent used is generally 0.01 to 0.5 part by weight with respect to 100 parts by weight of the resin composition.
If the amount is more than 5 parts by weight, the effect is saturated and extra cost may be required.

Examples of the crystal nucleating agent include a sorbitol nucleating agent, an organic phosphate nucleating agent, a carboxylic acid metal salt nucleating agent, a polymer nucleating agent, and an inorganic compound. Specific examples include 1,3,2,4-dibenzylidene sorbitol, 1,3,2,4-di- (p-methylbenzylidene)
Sorbitol, 1,3-p-chlorobenzylidene-2,
4-p-methylbenzylidene sorbitol, sodium-bis- (4-tert-butylphenyl) phosphate,
Potassium-bis- (4-tert-butylphenyl) phosphate, sodium-2,2′-ethylidene-bis (4,6-di-tert-butylphenyl) phosphate,
Sodium-2,2'-methylene-bis (4,6-di-
(t-butylphenyl) phosphate, pt-butyl aluminum benzoate, aluminum adipate, sodium benzoate, polyvinylcycloalkane, talc, mica, calcium carbonate, etc., but are not limited thereto. Do not mean. Further, two or more of these crystal nucleating agents may be used in combination.

The propylene block copolymer or ethylene resin used in the present invention may be appropriately selected from inorganic fillers such as talc, calcium carbonate, mica, etc., as long as the object of the present invention is not impaired. Inhibitors, heat stabilizers, weathering agents, lubricants, ultraviolet absorbers, antistatic agents, antiblocking agents, antifogging agents, antifoaming agents, dispersants, flame retardants, antibacterial agents, fluorescent brighteners, crosslinking agents, crosslinking Additives such as auxiliaries; dyes,
It may be used in combination with another component exemplified by a coloring agent such as a pigment.

The method for producing the resin composition of the present invention is not particularly limited. Examples of the production method include a method in which each component is melt-kneaded with a known kneader to produce a resin composition. Examples of the kneading machine include a single-screw kneading extruder, a multi-screw kneading extruder, a kneader, and a Banbury mixer. Melt kneading conditions are not particularly limited as long as the molten resin is not degraded by shearing, heating temperature, heat generated by shearing or the like during kneading. From the viewpoint of preventing the deterioration of the molten resin, it is effective to appropriately set the heating temperature or to add an antioxidant or a heat stabilizer.

Various molded articles can be obtained by molding the resin composition of the present invention according to a known molding technique. Molding techniques include, for example, injection molding, compression molding, injection compression molding, T-die film molding, stretched film molding, inflation film molding, sheet molding, calendar molding, air pressure molding, vacuum molding, pipe molding, profile extrusion molding, hollow molding Molding, injection hollow molding, injection stretch hollow molding,
Lamination molding and the like can be mentioned.

By molding the resin composition of the present invention with a known hollow molding machine, a hollow molded container can be manufactured. For example, the resin composition is extruded from an extruder to obtain a molten parison, the parison is set in a mold having a desired container shape of a hollow molding machine, and then a compressed gas is blown into the parison until the inner wall of the mold. By expanding and then cooling, a hollow molded container can be manufactured.

Further, the resin composition of the present invention is molded by a known hollow molding machine, whereby silk screen printing,
It is also possible to manufacture a hollow molded container surface-modified with offset printing, shrink labels, stretch labels, in-mold labels, and the like. For example, by means of air suction or the like, a label is previously mounted in a mold having a desired container shape, and a molten parison obtained by extruding the resin composition from an extruder is set here. By blowing a compressed gas into the mold to inflate it to the inner wall of the mold and then cooling it, a hollow molded container with an in-mold label can be manufactured. The thus obtained hollow molded container with an in-mold label is a particularly preferable container having an excellent appearance since there is no step between the label surface and the container surface.

Further, using the resin composition of the present invention,
It is also possible to produce a multilayer hollow molded container composed of more than one layer. As a multi-layer hollow molded container, (i) ground glass comprising an outer layer made of a resin composition obtained by blending an ethylene-propylene random copolymer and a low-pressure high-density polyethylene, and an inner layer made of the resin composition of the present invention. A two-layer hollow-molded container having a natural appearance, and (ii) a three-layer having excellent gas barrier properties, wherein the outer layer and the inner layer are made of the resin composition of the present invention, and the intermediate layer is made of an ethylene-vinyl alcohol copolymer. Hollow molded container.

[0027] The multilayer hollow molded container may have a layer made of recycled resin obtained by pulverizing burrs generated during the hollow molding. This recycled resin may be used in combination with another resin.

The hollow molded container obtained from the propylene-based resin composition of the present invention can be used for hair washing, hair conditioning, cosmetics, detergents, etc.
Containers for liquid daily necessities such as fungicides; Containers for liquid foods such as soft drinks, water and seasonings; Containers for other chemicals;
It can be widely used as a container for industrial liquids.

[0029]

Hereinafter, the present invention will be described based on examples.
The present invention is not limited by these examples. The evaluation methods used in the examples and comparative examples are as follows.

1. Melt flow rate (MFR) The propylene block copolymer and the propylene-based resin composition are used under the condition 14 (Condition Nu.
It was measured at 230 ° C. according to the method of mber 14). The ethylene resin was measured at 190 ° C. according to JIS K6760.

2. Density was measured according to JIS K6760.

3. Die swell ratio (DS) Using a capillary viscometer (trade name CAPIROGRAPH-1B manufactured by Toyo Seiki Co., Ltd.) having a capillary with a diameter of 1 mm and a length of 40 mm, the JIS K7199 was used.
At a temperature of 210 ° C. and a shear rate of 1216 s ⁻¹ .

4. Evaluation of Weld Part The weld part of the container obtained by direct blow molding was visually observed and evaluated according to the following criteria. ：: No weld line is generated. ×: Weld line occurred. It can be confirmed visually.

5. Izod impact value (unit: kJ / m
² ) According to JIS K7110, place 2 in a thermostat at 0 ° C.
It measured about the test piece left still for 4 hours or more.

6. Flexural modulus (unit: MPa) Measured according to JIS K7106.

7. Haze value (unit:%) The haze value was measured according to JIS K7105 using a 1 mm thick resin-made press sheet prepared according to JIS K6758.

The polymers used in the examples and comparative examples are as follows. 1. Propylene block copolymer Propylene block copolymer (a): Sumitomo Chemical Co., Ltd.
Is a copolymer whose product name is Nobrene. The copolymer is composed of the components A and B described above, and the content of the repeating unit derived from ethylene in the component A is 0.
% By weight, the content of the repeating unit derived from ethylene in the B component was 38% by weight, the ratio of the B component in the copolymer was 15.5% by weight, and the MFR was 1.3 g / 10 minutes. .

Propylene block copolymer (b): a copolymer manufactured by Sumitomo Chemical Co., Ltd. under the trade name Nobrene AH561. The copolymer is composed of the components A and B described above.
The content of the repeating unit derived from ethylene in the component A is 0% by weight, the content of the repeating unit derived from ethylene in the component B is 38% by weight, and the content of the B in the copolymer is 38% by weight. The ratio of the components was 17.0% by weight, and the MFR was 3.0 g / 10 minutes.

2. Ethylene-based resin Ethylene-based resin (a): Sumitomo Chemical Industries, Ltd. trade name: Sumikasen EFV401, ethylene-hexene-
1 copolymer. This resin was produced with a metallocene catalyst and had a density of 0.902 g / cm ³ , MF
R was 4.0 g / 10 minutes.

Ethylene resin (b): Ethylene-butene-1 copolymer (trade name: Exelen VL VL400, manufactured by Sumitomo Chemical Co., Ltd. (ultra low density polyethylene))
Having a density of 0.900 g / cm ³ and an MFR of 5.
It was 0 g / 10 minutes.

Ethylene resin (c): A high-pressure low-density polyethylene manufactured by Sumitomo Chemical Co., Ltd. under the trade name of Sumikasen L405, having a density of 0.923 g / cm.
^3. MFR was 3.7 g / 10 min.

Ethylene resin (d): a high-pressure method low-density polyethylene having a trade name of Sumikasen G801 manufactured by Sumitomo Chemical Co., Ltd., having a density of 0.918 g / cm.
^3. MFR was 20 g / 10 min.

3. Other Polymers Propylene-ethylene random copolymer (a): a copolymer manufactured by Sumitomo Chemical Co., Ltd. under the trade name of Noblen S131, wherein the content of repeating units derived from ethylene is 5% by weight. , MFR was 1.3 g / 10 min.

Propylene homopolymer (a): a polymer manufactured by Sumitomo Chemical Co., Ltd. under the trade name of Noblen YE101, having an MFR of 1.0 g / 10 min.

Example 1 80 parts by weight of a propylene block copolymer (a) and 20 parts by weight of an ethylene-based resin (a) were mixed at a temperature of 250 ° C. using a single screw extruder having a screw diameter of 65 mm. The mixture was melt-kneaded at a rotation speed of 100 rpm (see Table 1. The mixing ratio is part by weight) to obtain a propylene-based resin composition. The die swell ratio of the obtained propylene-based resin composition was 1.64 (see Table 3). The propylene resin composition has an MFR of 1.6 g / 10 minutes, an Izod impact value of 72 kJ / m ² , and a flexural modulus of 810 MP.
a, the haze value is 82%, and therefore, the Izod impact value × flexural modulus / haze value is 72 × 810/82 =
711 (see Table 4). The propylene-based resin composition was extruded with a blow molding machine (NB3B type) manufactured by Nippon Steel Works having a screw diameter of 50 mm and a die temperature of 2 kg / h.
Extruded at 30 ° C. into a hot parison. After sandwiching the hot parison in a mold temperature-controlled to 15 ° C.,
kg / cm ² air is blown in for 12 seconds and the weight is 30
g, side thickness is about 0.7mm, capacity is 500ml,
A narrow-mouth elliptical hollow container was manufactured. No weld line was generated in this hollow molded container, and the balance between transparency, rigidity, and drop strength (impact resistance) was excellent.

Example 2 A propylene block copolymer (a), an ethylene-based resin (b), and an ethylene-based resin (c) were mixed in the same proportions as shown in Table 1 in the same manner as in Example 1. The mixture was melt-kneaded to obtain a propylene-based resin composition. Tables 3 and 4 show the physical properties of the resin composition obtained by the measurement in the same manner as in Example 1. Weld lines did not occur in the hollow molded containers made of these compositions, and the balance between transparency, rigidity and drop strength (impact resistance) was excellent.

[Comparative Example 1] Only a propylene block copolymer (a) (see Table 2; the mixing ratio is part by weight) was used in Example 1.
The mixture was melt-kneaded in the same manner as described above to obtain a kneaded product. The results obtained by evaluating the kneaded material in the same manner as in Example 1 are shown in Tables 3 and 4, respectively. When a hollow molded container was formed from the kneaded material in the same manner as in Example 1, no weld line was generated, but the obtained hollow molded container was inferior in transparency and impact resistance.

Comparative Example 2 A propylene block copolymer (b) and an ethylene-based resin (c) were melt-kneaded in the mixing ratio shown in Table 2 in the same manner as in Example 1 to obtain a kneaded product. Obtained. The results obtained by evaluating the kneaded material in the same manner as in Example 1 are shown in Tables 3 and 4, respectively. When a hollow molded container was formed from the kneaded material in the same manner as in Example 1, no weld line was generated, but the obtained hollow molded container was inferior in transparency and impact resistance.

Comparative Example 3 A propylene-ethylene random copolymer (a), an ethylene-based resin (b), and an ethylene-based resin (c) were mixed in the same proportions as in Example 1 in the proportions shown in Table 2. The mixture was melt-kneaded by the method to obtain a kneaded product. The results obtained by evaluating the kneaded material in the same manner as in Example 1 are shown in Tables 3 and 4, respectively. When a hollow molded container was molded from the kneaded material in the same manner as in Example 1, no weld line was generated, but the obtained hollow molded container was inferior in transparency, rigidity, and impact resistance. .

Comparative Example 4 Propylene homopolymer (a)
, And an ethylene-based resin (b) and an ethylene-based resin (c) were melt-kneaded in the proportions shown in Table 2 in the same manner as in Example 1 to obtain a resin composition. The results obtained by evaluating the resin composition in the same manner as in Example 1 are shown in Tables 3 and 4, respectively. When a hollow molded container was molded from the resin composition in the same manner as in Example 1, a weld line was generated, and the obtained hollow molded container was poor in impact resistance.

[Comparative Examples 5 to 7] The propylene block copolymer (a) and one or two ethylene resins selected from the ethylene resins (b) to (d) were blended as shown in Table 2. Melt kneading was performed in the same manner as in Example 1 to obtain a resin composition. The results obtained by evaluating the resin composition in the same manner as in Example 1 are shown in Tables 3 and 4, respectively.
When a hollow molded container was molded from each of the obtained resin compositions in the same manner as in Example 1, the weld portion evaluation was as shown in Table 3, and the obtained hollow molded container had transparency, rigidity, and impact resistance. Gender.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

[Table 4]

[0056]

EFFECT OF THE INVENTION Propylene block copolymer (main component)
A propylene-based resin according to the present invention, wherein the swell ratio is equal to or less than a certain value, and the Izod impact value, the flexural modulus and the haze value satisfy the formula (1). The composition is a resin composition having an excellent balance of impact resistance (particularly low-temperature impact resistance), rigidity and transparency, and having good weld strength and appearance, and is particularly preferably used for the production of a hollow molded container. .

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) C08L 23:04) C08L 23:04) (72) Inventor Tatsuhiro Nagamatsu 5-1, Anesaki Beach, Ichihara-shi, Chiba Sumitomo Chemical F-term in the company (reference) 4F071 AA15X AA18 AA19 AA20X AA21X AA75X AA76X AA88 AF17Y AF20Y AF23Y AF32Y AH05 BA01 BB06 BC04 4F100 AK04A AK06A AK07A AK64 AK65 AL01A AL02A01B01A01 J03A03B BB053 BB062 BB063 BB072 BB073 BB082 BB083 BB102 BB103 BB152 BB153 BP021 DE236 DJ036 DJ046 EC036 EC066 EG076 FD206

Claims (10)

[Claims] 1. A propylene block copolymer comprising 70 to 90% by weight and an ethylene-based resin 30 to 10% by weight,
The die swell ratio at 210 ° C. and 1216 s ⁻¹ is 1.
70 or less, and the relationship between the Izod impact value at 0 ° C. (unit: kJ / m ² ), the flexural modulus at 23 ° C. (unit: MPa), and the haze value (unit:%) is expressed by the following formula (1). A propylene-based resin composition that satisfies the following. Izod impact value × flexural modulus / haze value ≧ 200 (1) 2. The propylene block copolymer has a temperature of 230 ° C.
The propylene-based resin composition according to claim 1, wherein the propylene-based resin composition has a melt flow rate of 2 g / 10 minutes or less. 3. The propylene resin composition according to claim 1, wherein the ethylene resin is an ethylene-α-olefin copolymer obtained by polymerizing ethylene and an α-olefin in the presence of a metallocene catalyst. 4. The propylene resin composition according to claim 1, wherein the ethylene resin is an ultra low density polyethylene. 5. An ethylene-based resin comprising: an ethylene-α-olefin copolymer obtained by polymerizing ethylene and an α-olefin in the presence of a metallocene catalyst; an ultra-low-density polyethylene, a low-density polyethylene; The propylene resin composition according to claim 1, which is a resin mixture comprising at least one ethylene resin selected from the group consisting of ethylene-α-olefin copolymers. 6. The low-density polyethylene is a low-density polyethylene produced by a high-pressure radical polymerization method.
The propylene-based resin composition according to the above. 7. The propylene resin composition according to claim 1, which contains 0.01 to 0.5 parts by weight of a crystal nucleating agent based on 100 parts by weight of the propylene resin composition. 8. A hollow molded container comprising the propylene resin composition according to claim 1. 9. The hollow molded container according to claim 8, wherein the hollow molded container is a hollow molded container with an in-mold label. 10. A multilayer blow-molded container having at least one layer comprising the propylene resin composition according to claim 1.