JPH10139977A - Polyolefin resin composition for container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which can give an injection-molded container having impact resistance, reduced in tendency of whitening and having a streak- free surface, by mixing a polypropylene resin being a propylene/ethylene crystalline block copolymer with a high-density polyethelenic resin and a lubricant. SOLUTION: This composition is obtained by adding various additives to a composition comprising 100 pts.wt. propylene/ethylene block copolymer having an ethylene content of 5-20wt.% and an MFR of 20-70, 25-100 pts.wt. ethylene homopolymer, an ethylene-based ethylene/propylene or ethylene/butene-1 crystalline copolymer or a mixture thereof each having an MFR of 10-45 and 0.3-3.0 pts.wt. lubricant being zinc stearate, calcium stearate, magnesium stearate, montan acid wax having a dropping point of 80-105 deg.C, a PE wax having a dropping point of 100-128 deg.C or a PP wax having a dropping point of 150-160 deg.C, and the resulting mixture is melt-kneaded and pelletized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polyolefin resin composition having impact resistance, hardly causing whitening, and providing a container having an excellent surface appearance. More specifically, a composition in which a high-density polyethylene resin having a specific melt flow rate and a specific lubricant are mixed in a specific mixing ratio in a polypropylene resin, and a container is formed by an injection molding method using the composition. The resulting container has impact resistance, the surface appearance is free of stripes generated by injection molding, and the impacted portion is hardly whitened when the container is subjected to an impact (hereinafter, referred to as low (Referred to as whitening property).

[0002]

2. Description of the Related Art A polyolefin resin composition for forming a container is a crystalline copolymer of propylene as a main component and a propylene / ethylene copolymer having a melt flow rate of 5 g / 10 minutes or less. A resin composition in which ethylene-propylene rubber or styrene-butadiene rubber is blended with a coalesced or crystalline copolymer is known. The melt index (MI _PP ) is 1 to
5g / 10min polypropylene-based resin 50-90% by weight
An inorganic powder having an average particle size of 10 μm or less is mixed with 100 parts by weight of a mixture of a polyethylene resin having a melt index (MI _PE ) of 0.05 g / 10 minutes or less, and -3.0 ≦ log (MI A low gloss resin composition for blow molding, which satisfies the relationship of _PE / MI _PP ) ≦ −1.3, is disclosed in Japanese Patent Publication No. Hei 6-13625, in which 100 parts by weight of a polypropylene resin, weight average molecular weight / Japanese Patent Application Laid-Open No. 62-277450 discloses a polyolefin resin composition comprising 3 to 250 parts by weight of a polyethylene resin having a number average molecular weight of 16 or more and a melting index of 0.2 or less.

However, in order to obtain a container molded product having a good surface appearance by the injection molding method, if the above-mentioned known resin composition for molding a container obtained by mixing a polyethylene resin with a polypropylene resin is used, the resulting container can be manufactured at a low cost. Although the whitening property is good, the resin composition for the container has a low melt flow rate, so that injection molding is impossible, or if,
Even when injection molding is possible by high-pressure injection, a striped pattern is generated on the surface of the obtained molded product, and a container by an injection molding method having an excellent surface appearance cannot be obtained. By injection molding method,
In order to obtain a container molded article having low whitening property and excellent impact resistance, a resin composition obtained by mixing a polypropylene resin having a high melt flow rate and a polyethylene resin having a high melt flow rate is required. Because the crystallization rate of polypropylene resin and polyethylene resin is different, striped pattern due to resin flow unevenness occurs on the molded product surface,
There is a disadvantage that a container molded product having an excellent surface appearance cannot be obtained.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have found that a polyolefin resin composition which can be obtained by injection molding to obtain a container molded product having impact resistance, low whitening property and no striped appearance defect. Diligent research on things. As a result, when a polyolefin resin composition in which a specific amount of a high-density polyethylene resin and a specific amount of a specific lubricant are blended with a specific polypropylene resin, the container has an impact resistance and a low whitening property when molded by an injection molding method. The present invention has been found to be a resin composition capable of obtaining a container having an excellent surface appearance without a stripe pattern, and the present invention has been completed based on this finding. As is apparent from the above description, an object of the present invention is to provide a container molded article by an injection molding method which has impact resistance, low whitening property, and excellent surface appearance without a stripe pattern on the molded article surface. It is an object of the present invention to provide a polyolefin resin composition for a container from which a molded container having the following formula is obtained.

[0005]

According to the present invention, a melt flow rate (230 ° C. 21.18 N) of 20 to 70 g / 10
Flow rate (190 ° C. 21.18N) 10 to 45 g / 10
Of a high-density polyethylene resin in a ratio of 25 to 100 parts by weight and a lubricant in a ratio of 0.3 to 3.0 parts by weight.

The polypropylene resin used in the present invention has a melt flow rate (230 ° C., 21.18 N) of 20 to 7
It is a polypropylene-based resin of 0 g / 10 minutes, and is a crystalline block copolymer of propylene and ethylene with propylene as a main component. The ethylene content in the crystalline block copolymer is preferably from 5 to 20% by weight.

The high-density polyethylene resin used in the present invention has a melt flow rate (190 ° C. 21.18 N) of 10%.
A high-density polyethylene resin of about 45 g / 10 min, preferably 20 to 40 g / 10 min, comprising crystalline ethylene homopolymer, ethylene as a main component, and ethylene and propylene or ethylene and butene-1. It is a crystalline ethylene copolymer or a mixture thereof. When a high-density polyethylene resin having a melt flow rate (190 ° C. 21.18 N) of less than 10 g / 10 minutes is used, the melt fluidity is reduced and the melt flow rate (190 ° C. 21.18 N) is reduced.
When a high-density polyethylene resin having N) of 45 g / 10 min or more is used, the effect of low whitening property cannot be expected. The mixing ratio of the high-density polyethylene resin used in the present invention is 25 to 100 parts by weight with respect to 100 parts by weight of the polypropylene resin. If a product is not obtained, and if it exceeds 100 parts by weight, the surface gloss of the obtained molded product is reduced.

[0008] The lubricant used in the present invention is zinc stearate, calcium stearate, magnesium stearate, and has a drop point of 80 in Test Method ASTM D566.
Montanic acid wax at ~ 105 ° C, dropping point 100 ~ 128
° C and PE wax at a dropping point of 150 to 160 ° C.
The ratio is 0.3 to 3.0 parts by weight, preferably 0.5 to 1.5 parts by weight, based on 0 parts by weight. If the compounding ratio is less than 0.3 parts by weight, the effect of preventing the stripe pattern during injection molding is small, and even if the compounding ratio is 3.0 parts by weight or more, there is no further improvement in the surface appearance improving effect.

The polyolefin resin composition for containers according to the present invention contains ethylene-propylene rubber, styrene-butadiene rubber, polyvinyl acetate, ethylene-vinyl acetate copolymer and partially saponified as long as the effects of the present invention are not impaired. Materials, inorganic fillers (talc, mica, glass fiber,
Radical generators such as wollastonite, zeolite, calcium carbonate, magnesium hydroxide, etc., light stabilizers, antioxidants, antiblocking agents, antistatic agents, clarifying agents, nucleating agents, and various coupling agents (silanes) System, titanate system, boron system, aluminate system) can be used in combination.

The polyolefin resin composition for containers of the present invention has a melt flow rate (230 ° C. 21.18 N) of 20.
Polypropylene-based resin, melt flow rate (190 ° C. 21.18N) of 10 to 45 g / min.
A predetermined amount of the high-density polyethylene resin for 10 minutes, the specific lubricant and the above-mentioned various additives is added using a usual mixing device, for example, a Henschel mixer (trade name), a super mixer, a ribbon blender, a tumbler mixer, a Banbury mixer, or the like. Mixing, single or twin screw extruder,
It can be obtained by melt-kneading with a roll or the like at a melt-kneading temperature of 160 to 300 ° C, preferably 180 to 250 ° C, and pelletizing.

[0011]

EXAMPLES The present invention will now be described specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. The evaluation method used in the examples and comparative examples was based on the following method. 1) Melt flow rate (230 ° C 21.18N):
Complies with JIS K6758. 2) Melt flow rate (190 ° C. 21.18N):
Conforms to JIS K6760. 3) Whitening diameter: A test piece having a length of 50 mm, a width of 50 mm, and a thickness of 2 mm is prepared by an injection molding method, and the test piece has an outer diameter of 50 m.
m, placed on a stainless steel cylinder with an inner diameter of 44 mm, placed a hammer with a tip of 1/4 inch R at the center of the test piece, dropped a load of 500 g from a height of 1 m onto the hammer, and maximized whitening caused by impact. The diameter was measured with a vernier caliper to obtain the whitening diameter. 4) Whitening property: The maximum diameter of whitening is preferably 15 mm or less.
6 mm or more was evaluated as defective. 5) Surface appearance: 400 mm long prepared by injection molding
The test piece having a width of 80 mm and a thickness of 2 mm was evaluated by observing the presence or absence of melt fracture and stripe pattern.

Examples 1-4, Comparative Examples 1-4 Melt flow rates (23) were used as polypropylene resins.
0 ° C. 21.18 N) A melt flow rate (190 ° C. 21.18 N) 10 g / 1 is added to 100 parts by weight of propylene-ethylene block copolymer pellets at 20 g / 10 min.
0-minute ethylene homopolymer pellets and zinc stearate (hereinafter referred to as lubricant A) as a lubricant were added to the first
Put in the tumbler mixer at the mixing ratio shown in the table,
After mixing for minutes, the mixture was extruded at a melt kneading temperature of 220 ° C. using a single screw extruder having a diameter of 45 mm, and pelletized. In addition, as Comparative Examples 1 to 4, as a polypropylene resin, a melt flow rate (230 ° C. 21.1) was used.
8N) Ethylene homopolymer pellets at a melt flow rate (190 ° C. 21.18N) of 10 g / 10 minutes were added to 100 parts by weight of propylene-ethylene block copolymer pellets at 20 g / 10 minutes, as described in Table 1 below. After mixing in a tumbler mixer at the mixing ratio of 10 minutes,
Melt kneading, extrusion, and pelletizing were performed according to Examples 1 to 4. Predetermined test pieces were prepared using the pellets obtained in each of the examples and comparative examples, and the whitening diameter, whitening property, and surface appearance were evaluated. The results are summarized in the first
It is shown in the table.

[0013]

[Table 1]

Examples 5-8, Comparative Examples 5-8 Melt flow rates (23
0 ° C. 21.18 N) 100 g of propylene-ethylene block copolymer pellets at 70 g / 10 min, melt flow rate (190 ° C. 21.18 N) 10 g / 1.
The 0-minute ethylene homopolymer pellets and the lubricant A were placed in a tumbler mixer at the mixing ratio shown in Table 2 below and mixed for 10 minutes, and then the mixture was melted using a single-screw extruder having a diameter of 45 mm. The mixture was extruded at a kneading temperature of 220 ° C. and pelletized. Further, as Comparative Examples 5 to 8, the melt flow rate (230 ° C.) was used as the polypropylene resin.
21.18 N) 70 g / 10 min propylene-ethylene block copolymer pellets (100 parts by weight), melt flow rate (190 ° C. 21.18 N) 10 g / 10 min ethylene homopolymer pellets, described in Table 2 below After mixing for 10 minutes in a tumbler mixer at the mixing ratio described in Example 1, melt kneading, extrusion and pelletizing were performed according to Examples 5 to 8. Predetermined test pieces were prepared using the pellets obtained in each of the examples and comparative examples, and the whitening diameter, whitening property, and surface appearance were evaluated. The results are summarized in Table 2.

[0015]

[Table 2]

Comparative Examples 9-11 Melt flow rates (23) were used as polypropylene resins.
Comparative Example 9 had a melt flow rate (190 ° C. 21.1) based on 100 parts by weight of a propylene-ethylene block copolymer pellet at 20 g / 10 min (0 ° C. 21.18 N).
8N) 10 g / 10 minutes of ethylene homopolymer pellets were added without adding lubricant A at a ratio of 1 part by weight. Comparative Example 10 had a melt flow rate (190 ° C. 21.18 N) of 10 g /
Comparative Example 11 used a melt flow rate (190 ° C. 21.18N) of 10 g / 10 min. Of ethylene homopolymer pellets at a rate of 120 parts by weight. Part and lubricant A
Was placed in a tumbler-mixer at a ratio of 1 part by weight, mixed for 10 minutes, and then melt-kneaded, extruded and pelletized according to Examples 1-4.

Comparative Examples 12 to 14 Melt flow rates (23) were used as polypropylene resins.
Comparative Example 12 has a melt flow rate (190 ° C. 21.18 N) of 70 g / 10 min with respect to 100 parts by weight of pellets of the propylene-ethylene block copolymer.
18N) Comparative Example 13 with 1 part by weight of lubricant A without addition of ethylene homopolymer pellets of 10 g / 10 min.
Is 10 g of melt flow rate (190 ° C 21.18N)
Comparative Example 14 used an ethylene homopolymer pellet having a melt flow rate (190 ° C. 21.18 N) of 10 g / 10 min. Parts by weight of the lubricant A and 1 part by weight of the lubricant A, respectively.
After mixing for 10 minutes, the mixture was melt-kneaded, extruded and pelletized according to Examples 1-4.

Comparative Examples 15 to 17 As the polypropylene resin, a melt flow rate (23
Comparative Example 15 has a melt flow rate (190 ° C. 21.18 N) of 20 g / 10 min with respect to 100 parts by weight of propylene-ethylene block copolymer pellets.
18N) Comparative Example 16 with 1 part by weight of lubricant A without adding ethylene homopolymer pellets of 45 g / 10 min.
Then melt flow rate (190 ° C 21.18N) 45
In Comparative Example 17, the melt flow rate (190 ° C. 21.18 N) was 45 g / 10 g in 20 parts by weight of the ethylene homopolymer pellets and 1 part by weight of the lubricant A.
Of ethylene homopolymer pellets at a ratio of 120 parts by weight and lubricant A at a ratio of 1 part by weight were placed in a tumbler-mixer, mixed for 10 minutes, and then melt-kneaded and extruded according to Examples 1-4. , Pelletized.

Comparative Examples 18 to 20 As the polypropylene resin, a melt flow rate (23
Comparative Example 18 has a melt flow rate (190 ° C. 21.18 N) of 70 g / 10 min and 100 parts by weight of propylene-ethylene block copolymer pellets.
18N) Comparative Example 19 without adding ethylene homopolymer pellets of 45 g / 10 min.
Is 45g melt flow rate (190 ° C 21.18N)
Comparative Example 20 was prepared by mixing ethylene homopolymer pellets at a melt flow rate (190 ° C. 21.18N) of 45 g / 10 min at 120 parts by weight of 20 parts by weight of ethylene homopolymer pellets at 1/10 minutes and lubricant A at 1 part by weight. Parts by weight of the lubricant A and 1 part by weight of the lubricant A, respectively.
After mixing for 10 minutes, the mixture was melt-kneaded, extruded and pelletized according to Examples 1-4.

A predetermined test piece was prepared using each of the pellets obtained in Comparative Examples 9 to 20, and the whitening diameter, whitening property, and surface appearance were evaluated. About the result, Comparative Examples 9-1
6 is shown in Table 3, and Comparative Examples 17 to 20 are shown in Table 4.

[0021]

[Table 3]

[0022]

[Table 4]

Examples 9 and 10 As the polypropylene resin, the melt flow rate (23
Example 9 is a melt flow rate (190 ° C 21.1) based on 100 parts by weight of propylene-ethylene block copolymer pellets at 0 ° C 21.18 N) 20 g / 10 min.
8N) Example 1 with 25 parts by weight of 10 g / 10 min ethylene homopolymer pellets and 1 part by weight of calcium stearate (hereinafter referred to as lubricant B) as a lubricant.
0 is a melt flow rate (190 ° C. 21.18 N) 10
g / 10 minutes of ethylene homopolymer pellets and 100 parts by weight of calcium stearate as lubricant B were placed in a tumbler-mixer at a ratio of 1 part by weight, and mixed for 10 minutes. It was melt-kneaded, extruded, and pelletized.

Examples 11 and 12 As the polypropylene resin, the melt flow rate (23
Example 11 is a melt flow rate (190 ° C. 21.18 N) of 20 g / 10 min with respect to 100 parts by weight of propylene-ethylene block copolymer pellets.
18N) 25 parts by weight of 10 g / 10 min ethylene homopolymer pellets and 1 part by weight of magnesium stearate (hereinafter referred to as lubricant C) as a lubricant, Example 12 shows a melt flow rate (190 ° C. 21.18 N). ) 1
100 g of ethylene homopolymer pellets of 0 g / 10 min and 100 g of lubricant C were put in a tumbler-mixer at a ratio of 1 pbw, mixed for 10 min, and then melt-kneaded according to Examples 1-4. Extruded and pelletized.

Examples 13 and 14 Melt flow rates (23) were used as polypropylene resins.
Example 13 has a melt flow rate (190 ° C. 21.18 N) of 70 g / 10 min with respect to 100 parts by weight of propylene-ethylene block copolymer pellets.
18N) 25 parts by weight of 10 g / 10 min ethylene homopolymer pellets and 1 part by weight of lubricant B, Example 14 had a melt flow rate (190 ° C. 21.18 N) 1.
100 g of an ethylene homopolymer pellet of 0 g / 10 min and 100 g of a lubricant B were added to a tumbler-mixer at a ratio of 1 pbw and mixed for 10 minutes, and then melt-kneaded according to Examples 1-4. Extruded and pelletized.

Examples 15 and 16 As a polypropylene resin, a melt flow rate (23
Example 15 is a melt flow rate (190 ° C. 21.18 N) based on 100 parts by weight of propylene-ethylene block copolymer pellets at 70 g / 10 min.
18N) 5 parts by weight of 10 g / 10 min ethylene homopolymer pellets and 1 part by weight of lubricant C
6 is a melt flow rate (190 ° C. 21.18 N) 10
g / 10 minutes of the ethylene homopolymer pellets in a ratio of 100 parts by weight of the lubricant C and 1 part by weight of the lubricant C were placed in a tumbler mixer, mixed for 10 minutes, and then melt-kneaded according to Examples 1 to 4, Extruded and pelletized.

Examples 17 and 18 Melt flow rates (23) were used as polypropylene resins.
Example 17 shows a melt flow rate (190 ° C. 21.18 N) of melt flow rate (190 ° C. 21.18 N) per 100 parts by weight of propylene-ethylene block copolymer pellets of 20 g / 10 min.
18N) 45 g / 10 min of ethylene homopolymer pellets in a ratio of 25 parts by weight and lubricant A in a ratio of 1 part by weight. In Example 18, the melt flow rate (190 ° C. 21.18 N) 4
100 parts by weight of the ethylene homopolymer pellets of 5 g / 10 minutes and 1 part by weight of the lubricant A were put in a tumbler mixer, mixed for 10 minutes, and then melt-kneaded according to Examples 1-4. Extruded and pelletized.

Examples 19 and 20 Melt flow rates (23) were used as polypropylene resins.
Example 19 is a melt flow rate (190 ° C. 21.18 N) of 100 g of a propylene-ethylene block copolymer pellet at 70 g / 10 min.
18N) 45 g / 10 min of ethylene homopolymer pellets at 25 parts by weight and lubricant A at 1 part by weight. Example 20 had a melt flow rate (190 ° C. 21.18 N) 4.
100 parts by weight of the ethylene homopolymer pellets of 5 g / 10 minutes and 1 part by weight of the lubricant A were put in a tumbler mixer, mixed for 10 minutes, and then melt-kneaded according to Examples 1 to 4. Extruded and pelletized.

Using the respective pellets obtained in Examples 9 to 20, predetermined test pieces were prepared, and the whitening diameter, whitening property,
The surface appearance was evaluated. The results are shown in Examples 9 to
13 is shown in Table 4, and Examples 14 to 20 are shown in Table 5.

[0030]

[Table 5]

Examples 21 to 23 As the polypropylene resin, a melt flow rate (23
Example 21 is a melt flow rate (190 ° C. 21.18 N) based on 100 parts by weight of propylene-ethylene block copolymer pellets of 20 g / 10 min.
18N) 25 g by weight of ethylene homopolymer pellets at 10 g / 10 min and 0.5 by weight of lubricant A, Example 22 had a melt flow rate (190 ° C. 21.18).
N) 10 g / 10 min ethylene homopolymer pellets
In Example 23, the melt flow rate (190 ° C. 21.18N) 1 was 5 parts by weight and the lubricant A was 2.0 parts by weight.
25 g by weight of 0 g / 10 min ethylene homopolymer pellets and 3.0 parts by weight of Lubricant A were placed in a tumbler mixer, mixed for 10 minutes, and then melted according to Examples 1-4. Kneaded, extruded and pelletized.

Examples 24-26 Melt flow rates (23
Example 24 shows a melt flow rate (190 ° C. 21.18 N) based on 100 parts by weight of propylene-ethylene block copolymer pellets at 70 g / 10 min.
18N) 25 parts by weight of 10 g / 10 min ethylene homopolymer pellets and 0.5 part by weight of lubricant A, Example 25 had a melt flow rate (190 ° C. 21.18).
N) 10 g / 10 min ethylene homopolymer pellets
In Example 26, the melt flow rate (190 ° C. 21.18 N) 1 was 5 parts by weight and the lubricant A was 2.0 parts by weight.
25 g of ethylene homopolymer pellets of 0 g / 10 min and 3.0 g of lubricant A were added to a tumbler-mixer at a ratio of 3.0 parts by weight and mixed for 10 minutes, and then melt-kneaded according to Examples 1-4. Extruded and pelletized.

Examples 27 and 28 Melt flow rates (23) were used as polypropylene resins.
Example 27 is a melt flow rate (190 ° C. 21.18 N) of 20 g / 10 min with respect to 100 parts by weight of propylene-ethylene block copolymer pellets.
18N) 25 parts by weight of ethylene-propylene copolymer pellets at 10 g / 10 min and 1.0 part by weight of lubricant A, Example 28 had a melt flow rate (190 ° C.
1.18N) 100 g of ethylene-propylene copolymer pellets of 10 g / 10 min and 1.0 g of lubricant A were placed in a tumbler-mixer at a ratio of 1.0 part by weight and mixed for 10 minutes. Melt kneading, extrusion, and pelletizing were performed according to the method described in No. 4.

A predetermined test piece was prepared using each of the pellets obtained in Examples 21 to 28, and the whitening diameter, whitening property, and surface appearance were evaluated. The results are shown in Table 5 for Examples 21 to 22, and Table 6 for Examples 23 to 28.

[0035]

[Table 6]

As is clear from Tables 1 and 2, the container molded products obtained in Examples 1 to 8 using the container resin composition of the present invention have low whitening properties and excellent surface appearance. However, Comparative Examples 1 to 1 without a lubricant outside the scope of the present invention
The container molded product of No. 8 has low whitening property, but the surface appearance is poor, and Comparative Examples 9 to 20 shown in Tables 3 and 4 contain the lubricant of the present invention. In Nos. 9 and 10, since the compounded amount of the high-density polyethylene was not more than the range of the present invention, the surface appearance of the obtained molded product was good, but no low whitening property was obtained. Since the amount exceeds the range of the present invention, the obtained molded article has a good low whitening property but deteriorates the surface appearance. Comparative Examples 12 and 1
Comparative Examples 1 and 3 are a combination of a high-density polyethylene resin having a melt flow rate (230 ° C. 21.18 N) of 70 g / 10 min and a melt flow rate (190 ° C. 21.18 N) of 10 g / 10 min.
5, 16 and 17 are melt flow rates (230 ° C. 2
1.18 N) 20 g / 10 min polypropylene resin and melt flow rate (190 ° C. 21.18 N) 45 g /
The combination of high-density polyethylene resin for 10 minutes, Comparative Examples 18, 19, and 20 were melt flow rates (230 ° C. 2
1.18N) 70 g / 10 min polypropylene resin and melt flow rate (190 ° C. 21.18 N) 45 g /
Although a combination of a high-density polyethylene resin for 10 minutes was used, the results were the same as those of Comparative Examples 9, 10, and 11, and a molded article having low whitening property and good surface appearance was not obtained.

In Examples 9, 10, 11, and 12 in Table 4, even if the type of lubricant is changed, the whitening property is low and the surface appearance is good as long as it is within the compounding range of the present invention. In Examples 13, 14, 15, and 16 of Table 5, the melt flow rates (23
0 ° C. 21.18 N) Even if a polypropylene resin of 70 g / 10 min was used, the effect was not changed.
As is apparent from 8, 19, and 20, even if a high-density polyethylene resin having a melt flow rate (190 ° C. 21.18 N) of 45 g / 10 minutes is used, the effects of the present invention are not impaired. Six tables of Examples 21, 22, 23,
If the lubricant is within the range of the present invention at 24, 25, and 26, even if the melt flow rate of the polypropylene resin is changed, it has low whitening properties and good surface appearance. In Examples 27 and 28, the ethylene copolymer was used. It was confirmed that the effect of the present invention was not impaired even when used.

[0038]

According to the present invention, when the resin composition for a container is used,
A container molded product having a low whitening property and a good surface appearance can be obtained. The composition of the present invention can be used for a variety of travel bags, attache cases, automobile shoe storage cases, costume cases, refrigerator vegetable cases, automobiles, home appliances, and the like. It is suitable for manufacturing injection-molded containers such as parts transport containers and agricultural transport containers.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 23:00 B29L 22:00

Claims (5)

[Claims] 1. A melt flow rate (230 ° C. 21.1)
8N) 20-70 g / 10 min polypropylene resin 10
0 parts by weight and a melt flow rate (190 ° C. 21.18)
N) A polyolefin resin composition for containers comprising 25 to 100 parts by weight of a high-density polyethylene resin of 10 to 45 g / 10 min and 0.3 to 3.0 parts by weight of a lubricant. 2. The polyolefin resin composition for a container according to claim 1, wherein the polypropylene resin is a crystalline block copolymer of propylene and ethylene as a main component. 3. The high-density polyethylene resin is an ethylene homopolymer or a copolymer containing ethylene as a main component and ethylene and propylene or butene-1.
The polyolefin resin composition for containers according to the above. 4. The polyolefin resin composition for containers according to claim 1, wherein the lubricant is one or more selected from zinc stearate, calcium stearate and magnesium stearate. 5. A container obtained by molding the polyolefin resin composition for a container according to claim 1 by an injection molding method.