JP2001181455A - Resin composition for blow molding and cow molded container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition for blow molding having excellent impact resistance and a blow molded container comprising the composition and excellent in impact resistance. SOLUTION: The composition is obtained by comprising (A) 98-70 wt.% propylene polymer resin and (B) 2-30 wt.% ethylene polymer resin, the resin composition for blow molding is obtained by including (C) 0.02-1.0 pts.wt. higher fatty acid derivative per 100 pts.wt. composition mentioned above and the blow molded container is obtained by using the resin composition for blow molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for hollow molding and a hollow molded container comprising the resin composition.
More specifically, the present invention relates to a resin composition for hollow molding excellent in impact resistance and suitable for uses such as foodstuffs, daily necessities, and medical use, and a hollow molded container made of the resin composition.

[0002]

2. Description of the Related Art Propylene polymer resins are excellent in mechanical properties, moldability, appearance and the like, and are widely used for containers and the like by injection molding, extrusion molding, hollow molding and the like. Above all, hollow molded containers are often used for containers for foodstuffs, containers for daily miscellaneous goods, medical infusion containers and the like. Properties required for a hollow molded container for such use include impact resistance that does not crack even when the container is dropped. However, with the recent enforcement of the Containers and Packaging Recycling Law and the like, the demand for reducing the weight of bottles is increasing, and if the thickness of the bottles is reduced to reduce the weight, the impact resistance is not always sufficient.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin composition for hollow molding having excellent impact resistance and a hollow molded container comprising the resin composition and having excellent impact resistance. .

[0004]

That is, the present invention relates to a composition comprising (A) 98 to 70% by weight of a propylene polymer resin and (B) 2 to 30% by weight of an ethylene polymer resin; The present invention relates to a resin composition for hollow molding containing (C) 0.02 to 1.0 part by weight of a higher fatty acid derivative per part by weight. Further, the present invention relates to a hollow molded container using the resin composition for hollow molding. Hereinafter, the present invention will be described in detail.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The propylene polymer resin (A) used in the present invention is a resin obtained by polymerizing propylene, and is not particularly limited. Examples thereof include a propylene homopolymer resin and a propylene-ethylene random copolymer. Copolymer resins, propylene-ethylene-α-olefin ternary random copolymer resins, propylene-ethylene block copolymer resins, and propylene-ethylene-α-olefin ternary block copolymer resins. Here, the α-olefin is an α-olefin having 4 to 20 carbon atoms, and examples thereof include 1-butene, 1-hexene, 1-octene, and 1-decene.

The propylene polymer resin (A) used in the present invention is preferably a propylene-ethylene random copolymer resin or a propylene-ethylene block copolymer resin, and more preferably a propylene-ethylene random copolymer resin. is there.

The content of the ethylene unit in the propylene polymer resin (A) used in the present invention is not particularly limited, but is preferably 8% by weight or less. If it exceeds 8% by weight, the rigidity and the heat-resistant rigidity decrease, so that it is not so preferable. Further, the content of ethylene units of the propylene-ethylene random copolymer resin used for a hollow molded container particularly requiring impact resistance and transparency is preferably 2 to 7% by weight, more preferably 4 to 6% by weight. %, Particularly preferably 5.1 to 5.8% by weight.

The propylene polymer resin (A) used in the present invention preferably has an MFR of 4.0 g / 10
Min, more preferably 2.5 g / 10 min or less, particularly preferably 1.0 to 1.8 g / 10 min.
If it exceeds 4.0 g / 10 minutes, drawdown tends to occur during parison extrusion, and moldability deteriorates, which is not preferred.

The method for producing the propylene polymer resin (A) used in the present invention is not particularly limited.
For example, a known polymerization process using a catalyst described in JP-A-7-216017, for example, a gas phase polymerization, a slurry polymerization, a bulk polymerization, a liquid phase-gas phase polymerization and the like can be mentioned. The polymerization process is preferably a gas phase polymerization process.

The (B) ethylene polymer resin used in the present invention is a resin obtained by polymerizing ethylene, and is not particularly limited. Examples thereof include low-density polyethylene, linear low-density polyethylene, and metallocene linear low-density. Examples thereof include an ethylene-based polymer such as polyethylene, extremely low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-based plastomer, and ethylene-based elastomer, or an ethylene-α-olefin copolymer. Here, the α-olefin is an α-olefin having 4 to 20 carbon atoms, and examples thereof include 1-butene, 1-hexene, 1-octene, and 1-decene.

In the present invention, the (B) ethylene polymer resin used particularly when transparency is required includes linear low-density polyethylene, metallocene-based linear low-density polyethylene, ultra-low-density polyethylene, ethylene-based plastomer And ethylene-α-olefin copolymers such as ethylene-based elastomers.

The MFR of the ethylene polymer resin (B) used in the present invention is not particularly limited, but is preferably 1 to 20 g / 10 minutes. If the amount is less than 1 g / 10 minutes, the dispersibility in the (A) propylene polymer resin deteriorates,
The effect of improving the impact resistance may be reduced, which is not preferable. If it exceeds 20 g / 10 minutes, the impact resistance of the (B) ethylene polymer resin itself may be reduced, and the effect of improving the impact resistance may be reduced. It is more preferably from 2 to 10 g / 10 minutes, and particularly preferably from 3 to 8 g / 10 minutes.

In the present invention, the density of the ethylene polymer resin (B) used when transparency is particularly required is preferably 0.870 to 0.915 g / cm ³ . Less than 0.870 g / cm ³ or 0.915 g
If it exceeds / cm ³ , the difference in the refractive index from the propylene polymer resin (A) becomes large, and the transparency may be deteriorated. More preferably 0.880
0.910 g / cm ³ , particularly preferably 0.8
90 to 0.907 g / cm ³ .

In the present invention, a metallocene linear low-density polyethylene is particularly preferably used as the (B) ethylene polymer resin used when transparency and elution resistance are required. A preferred method for producing a metallocene linear low-density polyethylene is described in, for example,
-234717, ethylene and an α-olefin are polymerized by a gas phase polymerization method in the presence of a polymerization catalyst (metallocene catalyst) using a transition metal compound having a group having a cyclopentadiene-type anion skeleton. Can be exemplified.

The (C) higher fatty acid derivative used in the present invention is not particularly restricted but includes, for example, lubricating agents such as erucamide, oleamide, beheninamide, stearamide, butyl stearate, etc .; Antistatic agents such as fatty acid monoglyceride having 14 to 18 and diglyceride thereof, fatty acid diethanolamine having 12 to 18 carbon atoms, and fatty acid diethanolamide having 12 to 18 carbon atoms are exemplified.

The (C) higher fatty acid derivative used in the present invention is preferably a derivative of an aliphatic carboxylic acid having 12 or more carbon atoms, more preferably a derivative of 1 carbon atom.
Derivatives of 8 or more aliphatic carboxylic acids. Fatty acids having a large number of carbon atoms (i.e., higher fatty acids) are preferred because they have good affinity with the (B) ethylene polymer resin and have a large effect of improving impact resistance. As the aliphatic carboxylic acid mentioned here, a saturated aliphatic carboxylic acid is preferable. Further, as the acid derivative here, an acid amide or an acid ester is preferable, and an acid amide is more preferable. A particularly preferred (C) higher fatty acid derivative is erucamide.

When the total amount of (A) the propylene polymer resin and (B) the ethylene polymer resin in the resin composition for blow molding of the present invention is 100% by weight, the respective amounts are (A) 98 to 98%. 70% by weight and (B) 2 to 30% by weight. When the amount of the (B) ethylene polymer resin is less than 2% by weight, the effect of improving the impact resistance of the composition is small.
Not preferred. On the other hand, if the content exceeds 30% by weight, the composition becomes too soft, and the rigidity and heat-resistant rigidity decrease, which is not preferable. It is more preferably 5 to 20% by weight, particularly preferably 10 to 15% by weight.

In the resin composition for blow molding of the present invention,
When the composition comprising (A) a propylene polymer resin and (B) an ethylene polymer resin is 100 parts by weight,
(C) The amount of the higher fatty acid derivative is 0.02 to 1.0 part by weight. If the amount is less than 0.02 part by weight, the effect of improving the impact resistance is small, so that it is not preferable. If the amount exceeds 1.0 part by weight, bleeding to the surface of the hollow molded container increases, which may cause stickiness or whitening, which is not preferable. The (C)
Is more preferably 0.03 to 0.50 part by weight, particularly preferably 0.04 to 0.30 part by weight, and most preferably 0.15 to 0.25 part by weight.

The resin composition for hollow molding of the present invention contains additives such as a neutralizing agent, an antioxidant, a heat stabilizer, and an ultraviolet absorber, or an organic phosphoric acid as long as the object of the present invention is not impaired. Salts, aluminum salts of aromatic carboxylic acids, sorbitol, nucleating agents such as polyvinylcycloalkane, and inorganic fillers such as talc, calcium carbonate, mica,
A coloring agent such as a pigment may be blended.

As a method for mixing the resin composition for hollow molding of the present invention and for compounding the above-mentioned various additives, a known kneader can be used. Known kneaders, for example,
Examples thereof include a single-screw kneading extruder, a multi-screw kneading extruder, and a Banbury mixer, but are not limited to these methods.

The melt-kneading conditions at this time are preferably set so as not to cause deterioration of the molten resin due to shearing, high-temperature heating and shearing heat during kneading. To prevent deterioration of the molten resin, appropriate temperature setting and adjustment are performed so that the resin pressure does not increase. However, increasing the amount of additives such as an antioxidant and a heat stabilizer is also effective.

Various molded articles can be obtained by subjecting the resin composition for hollow molding of the present invention to hollow molding. As a method of manufacturing a hollow molding container, for example, the copolymer is extruded from an extruder to obtain a molten parison, and the parison is set in a mold having a desired container shape of the hollow molding machine. Is blown to expand the inner wall of the mold, and then cooled to produce a hollow molded container.

Further, by molding the resin composition for hollow molding of the present invention with a known hollow molding machine, a hollow surface-modified with silk screen printing, offset printing, shrink label, stretch label, in-mold label, or the like. Molded containers can also be manufactured.

Further, using the resin composition for hollow molding of the present invention, a multilayer hollow molded container comprising two or more layers can be produced. For example, the outer layer and the inner layer are made of the resin composition for hollow molding of the present invention, the intermediate layer is an ethylene-vinyl alcohol copolymer, and a layer for bonding the intermediate layer and the inner and outer layers is optionally made of modified polypropylene. A multilayer hollow molded container having at least three layers or more having excellent barrier properties, or an outer layer comprising a resin composition obtained by blending a conventional propylene polymer resin and high-density polyethylene, and an inner layer comprising the hollow molded container of the present invention. And a two-layer multi-layer hollow molded container having a frosted glass appearance made of a resin composition for use.

The above-mentioned multilayer hollow-molded container may have a layer made of recycled resin obtained by pulverizing burrs generated during the hollow molding. The recycled resin may be combined with another resin.

The hollow molded container obtained from the resin composition for hollow molding of the present invention comprises a sauce, ketchup, seasoning, water,
Widely used in containers for foodstuffs such as soft drinks, containers for daily necessities such as cosmetics, detergents, shampoos, haircuts, disinfectants, medical infusion containers such as saline, and industrial liquid containers. Although it can be used and its use is not limited, it is particularly preferable to use it for food containers such as sauces, ketchups and seasonings, and medical infusion containers such as physiological saline.

[0027]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the invention. The evaluation methods used in Examples and Comparative Examples are described below.

(1) Melt Flow Rate (MFR) Condition 14 of JIS K7210 (Condition Number 1)
According to the method of 4), at 230 ° C. for propylene polymer resin and 190 ° C. for ethylene polymer resin
Was measured respectively.

(2) Ethylene Unit Content Polymer Handbook (1995, published by Kinokuniya Bookstore)
The measurement was performed by infrared spectroscopy according to the method described on page 616 et seq.

The polymers used in the examples and comparative examples are as follows. (A) Propylene polymer resin A propylene-ethylene random copolymer resin powder produced by the following production method was used. 0.08 parts by weight of calcium stearate with respect to 100 parts by weight of the powder,
0.05 parts by weight of hydrodalcite, 0.20 parts by weight of Irganox 1010 (manufactured by Ciba Geigy) and 0.05 parts by weight of erucamide were added and mixed, and the mixture was heated at 230 ° C.
The MFR of the propylene-ethylene random copolymer resin pellets obtained by melt-kneading at 230 ° C. was 1.5.
g / 10 minutes, and the content of ethylene units determined by infrared spectroscopy was 5.3% by weight.

(1) Synthesis of solid catalyst component After replacing a 200 LSUS reaction vessel equipped with a stirrer with nitrogen, 80 L of hexane and 6.55 of tetrabutoxytitanium were used.
Mol, 2.8 mol of diisobutyl phthalate, and 98.9 mol of tetraethoxysilane, to obtain a uniform solution.
Next, 51 L of a diisobutyl ether solution of butylmagnesium chloride having a concentration of 2.1 mol / L was gradually dropped over 5 hours while maintaining the temperature in the reaction vessel at 5 ° C. After completion of the dropwise addition, the mixture was further stirred at room temperature for 1 hour, then subjected to solid-liquid separation at room temperature, and washed three times with 70 L of toluene. Then
After toluene was added so that the slurry concentration was 0.2 kg / L, 47.6 mol of diisobutyl phthalate was added,
The reaction was performed at 95 ° C. for 30 minutes. After the reaction, solid-liquid separation was performed, and the resultant was washed twice with toluene. Next, 3.13 mol of diisobutyl phthalate, 8.9 mol of butyl ether and 274 mol of titanium tetrachloride were added, and the mixture was reacted at 105 ° C. for 3 hours. After the completion of the reaction, the mixture was subjected to solid-liquid separation at the same temperature, and then washed twice with 90 L of toluene at the same temperature. Then, after adjusting the slurry concentration to 0.4 kg / L, 8.9 mol of butyl ether and 137 mol of titanium tetrachloride were added, and
The reaction was performed at 5 ° C. for 1 hour. After completion of the reaction, the mixture was separated into solid and liquid at the same temperature, and washed three times with 90 L of toluene at the same temperature.
Further, after washing three times with 70 L of hexane, the solid was dried under reduced pressure to obtain 11.4 kg of a solid catalyst component. The solid catalyst component contains 1.8% by weight of titanium atom, 20.1% by weight of magnesium atom,
It contained 8.4% by weight of phthalic acid ester, 0.3% by weight of ethoxy group and 0.2% by weight of butoxy group, and had good particle properties without fine powder.

(2) Pre-activation of solid catalyst component n-hexane 1.5 L, triethylaluminum 37.5 mmol, t-butyl- n-
Preliminary activation was performed by adding 3.75 mmol of propyldimethoxysilane and 12 g of the above solid catalyst component, and continuously supplying 30 g of propylene over 30 minutes while maintaining the temperature in the vessel at 5 to 15 ° C.

(3) Polymerization of Propylene-Ethylene Random Copolymer Resin In a SUS 2000 L polymerization tank, propylene, ethylene and hydrogen are supplied under the conditions of a polymerization temperature of 80 ° C. and a polymerization pressure of 1.76 MPa. While continuously supplying 50 mmol / h of triethylaluminum, 5 mmol / h of t-butyl-n-propyldimethoxysilane and 0.7 g / h of a preactivated solid catalyst component, propylene-ethylene random copolymerization was carried out. By continuing continuously, 25.5 kg / h of a copolymer resin powder was obtained. At this time, the amount of the copolymer resin produced was the solid catalyst component 1
g / hour and 36,000 g / hour, and the intrinsic viscosity of the copolymer resin was 2.3 dl / g.

(B) Ethylene polymer resin Sumikasen EFV401 manufactured by Sumitomo Chemical Co., Ltd.
(Product name) was used. This resin was an ethylene-hexene-1 copolymer produced with a metallocene catalyst, and had a density of 0.905 g / cm ³ and an MFR of 4.0 g / 10 minutes.

(C) Higher fatty acid derivatives  Neutron S manufactured by Nippon Seika Co., Ltd. (trade name:
New-S) was used. This compound is erucic acid
It is an amide, which is solid (powder) at normal temperature and has a melting point of 85 ° C.
Was.

Example 1 90% by weight of the (A) propylene-ethylene random copolymer resin powder and (B)
(C) 0.20 parts by weight of New-S, 0.08 parts by weight of calcium stearate, 0.05 parts by weight of hydrotalcite, and Irganox (trade name), where 100 parts by weight of 10% by weight of Sumikacene E FV401 is blended. 1010 (manufactured by Ciba-Geigy) 0.2 part by weight was further added and blended, and the screw diameter was 65 mmφ, and the
Using a single screw extruder having a screw ratio of 32 and a full flight screw shape, the mixture was melt-kneaded under a nitrogen atmosphere at 230 ° C. and a screw rotation speed of 100 rpm to obtain pellets of the resin composition for hollow molding. Using this pellet, a hollow forming machine (NB3
(Type B), a hot parison was extruded at an extrusion rate of 10 kg / h and a die temperature of 210 ° C. Heat the hot parison at 15 ° C
After being clamped by a temperature-controlled mold, pressure 6 kg / c
m ² air was blown in for 15 seconds to produce a narrow-bore hollow molded bottle having a weight of 30 g, a side thickness of about 0.7 mm, and a capacity of 500 ml. After filling this bottle with 500 g of pure water and conditioning at 5 ° C. for 12 hours or more,
From a height of 2.0 m, the bottle was allowed to fall naturally onto the concrete block ten times in the vertical direction, and immediately thereafter, was naturally dropped ten times repeatedly in the horizontal direction. If the water broke down on the way or the bottle was pushed and water leaked, the drop was stopped there. Drop a total of 10 bottles,
Eight were unbroken after the tenth round and four were unbroken after the tenth round. When the impact energy at that time was calculated according to the following equation, it was 15.9 J / number. (Impact energy) = (weight of water) x (fall height) x
(Total number of drops during the test) ÷ (Number)

Example 2 A resin composition pellet was obtained in the same manner as in Example 1 except that the amount of (C) New-S was changed to 0.10 parts by weight, and a hollow molded bottle was manufactured in the same manner. . A bottle drop impact test was performed using this bottle, and a total of 10 bottles were dropped. Five bottles were not broken after finishing 10 times and three bottles were not broken after finishing 10 times. The calculated impact energy at that time was 11.8 J / times.

Example 3 A resin composition pellet was obtained in the same manner as in Example 1 except that the amount of (C) New-S was changed to 0.05 part by weight, and a hollow molded bottle was manufactured in the same manner. . Using this bottle, a bottle drop impact test was performed. A total of 10 bottles were dropped, and 6 bottles were not broken after finishing 10 times, and 3 bottles were not broken after finishing 10 times. When the impact energy at that time was calculated, it was 12.9 J / times.

Comparative Example 1 (C) Resin composition pellets were obtained in the same manner as in Example 1 except that New-S was not blended.
Similarly, a hollow molded bottle was manufactured. A bottle drop impact test was performed using this bottle, and a total of 10 bottles were dropped.
The book was indestructible. The calculated impact energy at that time was 9.5 J / number.

[0040]

[Table 1]

[0041]

According to the present invention, a container excellent in impact resistance can be provided by using the resin composition for hollow molding according to the present invention, and a container having the conventional impact resistance maintained even when the container is made thin. Can be provided.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tatsuhiro Nagamatsu 5-1, Anesaki Beach, Ichihara City, Chiba Prefecture Sumitomo Chemical Co., Ltd. F-term (reference) 3E033 BA13 BA15 BA16 BB01 BB04 BB05 CA03 CA18 FA02 GA02 4J002 BB032 BB052 BB121 BB141 BB151 BB152 BP021 EH056 EN106 EN116 EP016 FD010 FD106 FD176 GG01

Claims (4)

[Claims] (A) 98 to 70% by weight of a propylene polymer resin, and (B) 2 to 30% by weight of an ethylene polymer resin.
And a resin composition for hollow molding, comprising (C) 0.02 to 1.0 part by weight of a higher fatty acid derivative per 100 parts by weight of the composition. 2. The resin composition for hollow molding according to claim 1, wherein the higher fatty acid derivative is an aliphatic carboxylic acid derivative having 12 or more carbon atoms. 3. The resin composition according to claim 1, wherein the acid derivative is an acid amide or an acid ester. 4. A hollow molded container comprising the resin composition for hollow molding according to claim 1, 2 or 3.