JP2004051744A - Composition for hollow container for halogen-based detergent and hollow container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a hollow container for a halogen-based detergent, made of a high-density polyethylene which has excellent chemical resistance to the halogen-based detergent, blow moldability and rigidity. <P>SOLUTION: The composition for the hollow container for the halogen-based detergent comprises the high-density polyethylene which is obtained by using an ion polymerization catalyst by a multistage polymerization of two ore more stages in different hydrogen concentrations, has 0.05-2g/10 minute MFR, 13-20 Q value, 0.950-0.970g/cm<SP>3</SP>density and ≤0.5 double bond in 1,000 carbon atoms, ≥40 hour constant strain environmental stress cracking property and ≥5kJ/m<SP>2</SP>Izod impact strength. <P>COPYRIGHT: (C)2004,JPO

Description

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【表２】

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a hollow container excellent in chemical resistance, which is suitable for a halogen-based detergent, and more specifically, is excellent in blow moldability, capable of reducing rigidity and weight, and excellent in chemical resistance to a halogen-based detergent. The present invention relates to a composition for a hollow container suitable for a halogen-based detergent and a hollow container.
[0002]
[Prior art]
In recent years, plasticization of detergent containers has been actively promoted, and polyolefin resins are generally used as plastic materials from the viewpoint of achieving low price, high strength, good weather resistance, good chemical resistance and environmental protection. ing.
[0003]
Among the polyolefin resins, high-density polyethylene is a resin suitable as a resin for blow molding. In particular, polyethylene having a relatively wide molecular weight distribution, a large melt tension, and good uniform stretchability is used.
[0004]
On the other hand, various detergents such as laundry, shampoo, rinse and kitchen detergent are used as detergents. Among them, halogen-based detergents containing halogen such as chlorine have been widely used as mold removers for bathrooms, detergents for sinks, etc. for sterilization, bleaching, and enhancement of detergency.
[0005]
However, although halogen-based detergents are very useful as detergents, they significantly lower the chemical resistance of resins compared to ordinary non-halogen-based detergents, and have a higher resistance to halogen-based detergents when compared with other polyolefins. Even with high-density polyethylene having excellent chemical properties, chemical cracking is likely to occur, and it is necessary to take measures such as keeping the halogen concentration in the halogen-based detergent low or increasing the material thickness.
[0006]
The present inventors have conducted intensive studies on the durability when a high-density polyethylene container is used as a halogen-based detergent, and in particular, as to why the chemical cracking is likely to occur. It turned out that there is.
[0007]
First, the first factor is cracking due to insufficient impact resistance of the material, and in this case, it is accompanied by material deterioration. The second factor is stress cracking due to commonly known surfactants. The third factor is that hypohalous acid ions generated by the dissociation of the halogen water penetrate from the inner surface of the high-density polyethylene container and are decomposed into radical oxygen and halogen to oxidize and degrade the resin in the container, or cause halogenation. It is to deteriorate.
[0008]
In order to improve these factors based on the concept of the conventional polymer technology, the following structure is required as a polymer. That is, as a preferable molecular structure for preventing stress cracking due to a surfactant, it is necessary to increase the molecular weight of the polymer and increase the copolymerization amount of the α-olefin. The reason for this is to increase the number of tie molecules that connect the crystals and to reduce the stress load by giving the material flexibility. On the other hand, as a preferable molecular structure against degradation by hypohalite ions, in order to reduce penetration of hypohalite ions, the copolymerization amount of α-olefin is small, crystallinity is high, and radical In order to reduce the reaction with oxygen, it is necessary to reduce the tertiary carbon structure in the polymer generated by copolymerizing a double bond in the polymer with an α-olefin.
[0009]
Further, as a preferable molecular structure against cracking due to insufficient impact resistance of the material and cracking due to insufficient impact resistance of the material, it is necessary that the polymer has a high molecular weight and a uniform molecular weight distribution.
[0010]
Due to the existence of these three different deterioration mechanisms, only a method for improving environmental stress cracking resistance (Environmental Stress Cracking Resistance), which has been conventionally evaluated as a measure of chemical resistance by a surfactant, is not sufficient for halogenated detergents. Chemical resistance including container drop cannot be improved, and rigidity, stress cracking resistance due to surfactant, and deterioration resistance due to hypohalite ion require polymer structures that are contradictory. No improvement was possible.
[0011]
[Problems to be solved by the invention]
An object of the present invention is to provide a high-density polyethylene hollow container suitable for halogen-based detergents, which is excellent in chemical resistance to halogen-based detergents, and excellent in blow moldability and rigidity.
[0012]
[Means for Solving the Problems]
Therefore, the present inventors have studied diligently to solve the above-mentioned problems, and solve the above contradictory problems by using a specific high-density polyethylene, have excellent blow moldability, have high rigidity, and have a light weight. This has led to the development of a composition for hollow containers suitable for halogen-based detergents and a container suitable for halogen-based detergents, which is possible and has excellent chemical resistance to halogen-based detergents.
[0013]
That is, the present invention provides an MFR of 0.05 to 2 g / 10 min and a Q value of 13 to 20 obtained by performing two or more stages of multi-stage polymerization using an ionic polymerization catalyst and different hydrogen concentrations. Having a density of 0.950 to 0.970 g / cm³0.5 double bonds or less per 1000 carbons, constant strain environmental stress cracking of 40 hours or more, Izod impact strength of 5 kJ / m²It is intended to provide a composition for a hollow container suitable for a halogen-based detergent, comprising a high-density polyethylene as described above.
[0014]
Further, the present invention provides a high-density polyethylene, which is a homopolymer of ethylene polymerized using a Ziegler catalyst system or a copolymer of ethylene and an α-olefin other than ethylene, wherein the polymerization reaction is performed in two steps. In one stage, the homopolymerization of ethylene is carried out to produce 50 to 70% by weight of the total amount of the produced polymer, and in another stage, a hydrogen concentration different from the hydrogen concentration in the one stage is obtained. And homopolymerization of ethylene or copolymerization of ethylene and an α-olefin other than ethylene to obtain a (co) polymer having an intrinsic viscosity [η] = 3.5 to 8.2 of 30 to 50% of the total polymer production amount. % Of the above-mentioned composition for a hollow container for a halogen-based detergent, which is obtained by producing the polymer by weight, and the intrinsic viscosity [η] of the homopolymer obtained in one stage is 0.5 to 0.7, and the like. At the stage of Providing the above composition for hollow containers suitable for halogen-based detergents, wherein the intrinsic viscosity [η] of the homopolymerization of ethylene or the copolymer of ethylene and α-olefin other than ethylene is 3.5 to 8.2. It is.
[0015]
Furthermore, the present invention provides a hollow container for a halogen-based detergent characterized by being formed by the composition according to any one of the above, and the above-described halogen obtained by blending a light-shielding pigment with high-density polyethylene. An object of the present invention is to provide a hollow container suitable for a detergent.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
[I] Halogen detergent
1. Surfactants used in halogen-based detergents
The detergent suitable for storage by the hollow container of the present invention is a halogen-based detergent, and as the surfactant used for the halogen-based detergent, an anionic surfactant, a nonionic surfactant, a cationic surfactant, One or two or more surfactants selected from amphoteric surfactants.
[0017]
Examples of the anionic surfactant include soaps such as sodium laurate, sodium myristate, sodium palmitate, and sodium stearate, alkylbenzenesulfonate, alkylnaphthalenesulfonate, alkylsulfonate, α-olefinsulfonic acid Salt, dialkyl sulfosuccinate, α-sulfonated fatty acid salt, N-methyl-N-oleyltaurine (Igepon @ T), petroleum sulfonate, alkyl sulfate, sulfated oil, polyoxyethylene alkyl phenyl ether sulfate, poly Oxyethylene alkyl ether sulfate, polyoxyethylene styrenated phenyl ether sulfate, alkyl phosphate, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl phenyl ether phosphate, naphthalenesul And a formaldehyde condensate of sulfonic acid.
[0018]
Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polystyryl ether, polyoxyethylene-polyoxypropylene glycol (including block and random), polyoxyethylene- Polyoxypropylene alkyl ethers, fatty acid partial esters of polyhydric alcohols (various monoglyces, sugar esters, sorbitan esters (Span), etc.), polyoxyethylene fatty acid esters (Myrj, etc.), polyglycerin fatty acid esters, polyoxyethylated castor oil, Examples thereof include fatty acid diethanolamide, polyoxyethylene alkylamine, triethanolamine fatty acid partial ester, and trialkylamine oxide.
[0019]
Examples of the cationic surfactant include primary, secondary, and tertiary fatty acid amine salts such as monoalkylamine, dialkylamine, and trialkylamine hydrochlorides, tetraalkylammonium salts, trialkylbenzylammonium salts, and alkylpyridium. Quaternary ammonium salts such as salts, 2-alkyl-1-alkyl-1-hydroxyethylimidazolium salts, N, N-dialkylmonophorium salts, and polyethylenepolyamine fatty acid amide salts thereof.
[0020]
Examples of the amphoteric surfactant include N, N-dimethyl-N-alkyl-N-carboxymethylammonium betaine, N, N-dialkylaminoalkylenecarboxylate, N, N-trialkyl-N-sulfoalkyleneammonium betaine, N, N-dialkyl-N, N-bispolyoxyethylene ammonium sulfate betaine, 2-alkyl-1-carboxymethyl-1-hydroxyethylimidazolium betaine, and the like.
[0021]
These surfactants are used alone or in combination as necessary, and are usually used as a mixture of a surfactant and water. The mixing ratio of the surfactant and water is usually 0.1 to 30% by weight, and water is often mixed in the range of 70 to 99.9% by weight from the viewpoint of detergency.
[0022]
2. Halogen used in halogen-based detergents
Examples of the halogen used in the halogen-based detergent according to the present invention include fluorine, chlorine, bromine and iodine, and industrially inexpensive chlorine is usually used.
[0023]
These halogens are obtained by directly dissolving fluorine, chlorine, bromine and iodine in a detergent solution, by adding these halogens in an aqueous solution in which water is dissolved in water in advance, or by dissolving an alkalizing agent in the aqueous halogen solution to form hypochlorous acid. There is a method of adding as an alkali halide aqueous solution.
[0024]
The concentration of these halogens is appropriately selected depending on the purpose of the detergent, but is often mixed in the range of 10 ppm to 5% by weight based on the entire halogen-based detergent.
[0025]
3. Alkaline agent used for halogenated detergents
It is preferable to add an alkalizing agent to the halogen-based detergent in order to prevent the halogen dissolved in water from dissociating and disappearing due to heat and light.As the alkalizing agent used for the halogen-based detergent, sodium hydroxide, And / or potassium hydroxide. The reason for this is that it has versatility, is inexpensive, and has excellent halogen stabilizing effects. The appropriate concentration of the alkalinizing agent varies depending on the amount of halogen in the halogen-based detergent, but is mixed in the range of 0.05 to 5% by weight based on the entire halogen-based detergent.
[II] High density polyethylene
1. Types of high density polyethylene
Examples of the high-density polyethylene used in the present invention include a homopolymer of ethylene and a copolymer of ethylene and an α-olefin. Examples of the α-olefin include propylene, butene-1, pentene-1, and hexene-. 1,4-methyl-pentene-1, octene-1 and the like.
[0026]
Examples of the catalyst for the polymerization of ethylene and α-olefin include an ionic polymerization catalyst such as a Ziegler catalyst, a chromium-based catalyst, and a metallocene catalyst. Among them, a Ziegler catalyst is preferable. In the present invention, the Ziegler catalyst system means a catalyst system comprising a solid catalyst component containing titanium and halogen and an organoaluminum compound. Generally, a so-called supported Ziegler catalyst to which a magnesium compound is added is used.
[0027]
As a polymerization method of the high-density polyethylene used in the present invention, a general-purpose process such as a slurry method, a solution method, and a gas phase method can be applied. Alternatively, a polymer having two or more components having different characteristics can be obtained. By this polymerization method, a material for a hollow container excellent in blow moldability, rigidity, and chemical resistance to a halogen-based detergent, which is the object of the present invention, can be obtained.
[0028]
2. MFR of high density polyethylene
The MFR (melt flow rate) of the high-density polyethylene used in the present invention is a value measured according to JIS-K7210 (190 ° C., 2.16 kg load). This MFR is 0.05 to 2 g / 10 min, preferably 0.1 to 1.5 g / 10 min. If the MFR is less than the above range, extrusion becomes difficult during molding, and the outer surface of the resin becomes rough.
[0029]
On the other hand, when the MFR exceeds the above range, there is a problem that the resistance to environmental stress cracking and the drop strength are reduced, and a drawdown phenomenon in which the resin sags during molding occurs, making molding difficult.
[0030]
As a method of adjusting the MFR, it can be adjusted by a general method such as changing the hydrogen concentration during polymerization and the polymerization temperature, and the higher the hydrogen concentration and the higher the polymerization temperature, the higher the MFR.
[0031]
3. Q value of high density polyethylene
The Q value of the polyethylene resin used in the present invention is determined as a ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC). Value. The smaller the value, the more uniform the molecular weight and the narrower the molecular weight distribution.
[0032]
This Q value is 13-20, preferably 15-20. When the Q value is less than the above range, not only the drawdown property is deteriorated in view of MFR, but also the bulge (swell) of the molten parison becomes small, and it becomes difficult to form a container having a handle structure. In addition, when the Q value is small, the environmental stress crack resistance also decreases.
[0033]
On the other hand, if the Q value exceeds the above range, the impact strength is inferior and the drop strength decreases.
[0034]
The specific measurement of the Q value can be performed under the following conditions.
[0035]
GPC device: ISOC-ALC / GPC manufactured by Waters
Column: GMHHR-H (S) HT manufactured by Tosoh Corporation 60 cm x 1
Solvent: O-dichlorobenzene
Solution concentration: 5 mg / 3.4 ml
Sample preparation: Adjusted to 5 mg / 3.4 ml solution using o-dichlorobenzene
Then dissolve at 140 ° C for 1 to 3 hours.
[0036]
Measurement temperature: 140 ° C
Flow velocity: 1m / min
Standard material: Monodisperse polystyrene manufactured by Tosoh Corporation
Calibration curve order: 1st order
PP molecular weight: PS x 0.639
When the multi-stage polymerization is carried out using the same catalyst, it can be adjusted by a method of changing the difference between the molecular weight on the low molecular weight side and the molecular weight on the high molecular weight side by carrying out the multi-stage polymerization.
[0037]
This Q value can be obtained by performing multi-stage polymerization under different hydrogen concentration conditions. In order to obtain the Q value of the present invention, the intrinsic viscosity [η] of the homopolymer obtained in one step is 0.5 to 0.7, and the homopolymerization of ethylene obtained in the other step or ethylene and ethylene other than ethylene. The intrinsic viscosity [η] of the copolymer with α-olefin is in the range of 3.5 to 8.2.
[0038]
4. High density polyethylene density
The density of the polyethylene resin used in the present invention is a density measured according to JIS-K6760. This density is 0.950-0.970 g / cm³0.955 to 0.970 g / cm³And more preferably 0.960 to 0.970 g / cm³It is. When the density is low, the environmental stress crack resistance is improved, but the resin is easily deteriorated by the halogen-based detergent, so that the chemical resistance to the halogen-based detergent is reduced and the rigidity is also reduced.
[0039]
On the other hand, if the density exceeds the above range, the drop strength may decrease, and the density is 0.970 g / cm.³Larger ones are practically difficult to manufacture.
[0040]
The density can be adjusted by changing the amount of α-olefin to be copolymerized with ethylene. The higher the amount of α-olefin, the lower the density.
[0041]
5. Double bond in high density polyethylene
The amount of double bond of the polyethylene resin used in the present invention is determined using an infrared spectrophotometer.
963cm wave number transformer^-1, Terminal vinyl bond 910cm wave number^-1, A vinylidene bond with a wave number of 888 cm^-1Is the total value of the trans bond, the terminal vinyl bond, and the vinylidene bond determined from the absorbance at the time. This measurement and the conversion formula from the absorbance to the number per 1000 carbons are described in C = C on page 594 of “New Edition Polymer Analysis Handbook” by The Japan Society for Analytical Chemistry, published by Kinokuniya Shoten Co., Ltd. in 1995. Determined by unsaturated bond. Specifically, it was calculated from the following equation 1.
[0042]
Transformer (pcs / 1000C) = 0.083A / ρ · t Equation 1
Terminal vinyl (pcs / 1000C) = 0.114A / ρ · t Formula 2
Vinylidene (pieces / 1000C) = 0.09A / ρ · t Equation 3
In this equation, A is the absorbance and ρ is the density (g / cm³) And t are thickness (mm).
[0043]
The double bond amount, which is the total value of these trans bond, terminal vinyl bond, and vinylidene bond, is 0.5 or less, preferably 0.4 or less, more preferably 0.3 or less per 1000 carbons. is there. If the amount of the terminal vinyl bond is large, the deterioration due to the halogen-based detergent tends to occur. The adjustment of the amount of double bond can be performed by a method of selecting a polymerization catalyst and changing the amount of hydrogen for adjusting the molecular weight.
[0044]
Examples of the catalyst having a small amount of terminal vinyl bond include a metallocene catalyst and a Ziegler catalyst.These catalysts have a high degree of polymerization of the polymer. Depends on what you can do.
[0045]
On the other hand, in the case of a chromium-based catalyst obtained by calcining silica with pure chromium oxide, chromium acetate, or the like, the degree of polymerization of the polymer is low. There is a problem that the amount of binding increases. However, when using a modified catalyst such as a chromium-based catalyst obtained by co-catalyzing titanium and chromium, or a chromium-based catalyst organically modified, a small amount of hydrogen is required to adjust the MFR. As a result, the amount of terminal vinyl bond is often intermediate between a pure chromium-based catalyst and a Ziegler catalyst.
[0046]
Further, when the amount of the ultra-low molecular weight component is large, the number of terminals increases with respect to the average molecular weight, and as a result, the amount of double bonds tends to increase.
[0047]
When a Ziegler catalyst is used, the amount of terminal vinyl bonds is relatively small, but when an α-diolefin is used as an olefin to be copolymerized with ethylene, a double bond is formed.amountUndesirably increases.
[0048]
6. Constant strain environmental stress cracking of high density polyethylene.
The constant strain environmental stress cracking property of the high-density polyethylene used in the present invention is a value measured according to JIS-K6760 using a 10 wt% aqueous solution of Igepearl specified in ASTM-D1693 as a test solution. The constant strain environmental stress cracking time is 40 hours or more, preferably 60 hours or more, and more preferably 100 hours or more. When the constant strain environmental stress cracking time is less than the above range, the chemical cracking lowers the chemical resistance.
[0049]
As a method for adjusting the constant strain environmental stress cracking property, there are a method of changing the molecular weight, a method of changing the amount of the ultrahigh molecular component, a method of changing the amount of α-olefin to be copolymerized with ethylene, and the like. The higher the molecular weight, the higher the amount of the superpolymer component, and the lower the density by increasing the amount of α-olefin to be copolymerized with ethylene, the higher the constant strain environmental stress cracking property. As a method other than this, it is better to use hexene-1, 4-methyl-pentene-1, octene-1 or the like having 6 or 8 carbon atoms as the type of α-olefin to be copolymerized with ethylene, It is preferable because the existence probability of the tie molecules connecting the crystals increases and the constant strain environmental stress cracking property increases.
[0050]
7. Izod impact strength of high density polyethylene
In the present invention, the drop strength of the container needs to take into account the resistance to impact deformation. In particular, in the case of the drop strength of high-density polyethylene, a material with a certain degree of rigidity has better deformation resistance, and the lower the rigidity, the higher the impact strength tends to be when the rigidity is higher than the tensile impact strength that is superior in impact resistance. It is a preferable method to make a judgment based on the observed Izod impact strength.
[0051]
The Izod impact strength of the high-density polyethylene used in the present invention is a value measured according to JIS-K7110. Specifically, a sheet having a thickness of 4 mmt was prepared according to the test piece preparation conditions of JIS-K6760, and the condition was adjusted according to the test piece condition adjustment conditions. The specimen inserted by processing is used as a test piece. Then, it is measured using an Izod tester in a room adjusted to a temperature of 23 ° C. and a humidity of 50%.
[0052]
This Izod impact strength is 5 kJ / m²Or more, preferably 6 kj / m²That is all. When the Izod impact strength is low, even if the chemical resistance to the halogen-based detergent is good, there is a problem in actual use because the container is easily broken when the container is dropped in actual use.
[0053]
The method of adjusting the Izod impact strength can be adjusted by increasing the molecular weight of the polymer or narrowing the molecular weight distribution. However, these methods require caution because blow molding causes surface roughness and a drawdown phenomenon, which makes molding difficult, and reduces the environmental stress cracking resistance to surfactants. Furthermore, when the container filled with the halogen-based detergent is dropped, the Izod impact strength is low. Become.
[0054]
[III] Preferred high density polyethylene
1. Preferred high density polyethylene polymerization
The high-density polyethylene used in the present invention can be obtained by polymerizing ethylene or ethylene and another α-olefin using a chromium-based catalyst, a metallocene catalyst, or a Ziegler catalyst. A preferred high-density polyethylene can be obtained by performing ethylene homopolymerization or copolymerizing ethylene with another α-olefin in two steps while using a Ziegler catalyst and changing the hydrogen concentration.
[0055]
2. Preferred Ziegler catalyst for the polymerization of high density polyethylene
The Ziego catalyst system used in the present invention is a catalyst system comprising a solid catalyst component containing magnesium, titanium and halogen and an organoaluminum compound.
[0056]
Examples of such a catalyst system include those described in JP-A-49-119980, JP-A-49-58189, JP-A-50-142689, and JP-A-56-61406. No.
[0057]
Specifically, a reaction product of an oxygen-containing organic compound of magnesium, an oxygen-containing compound of titanium, and an aluminum halide, a reaction product of an oxygen-containing organic compound of magnesium with a titanium halide, a magnesium halide, and a titanium halide And a hydrocarbon-insoluble solid product obtained from a reaction mixture of a solid complex comprising an organic donor and an organoaluminum compound, or a compound represented by the general formula Mg (OR¹)_mX¹ _2-m(Where R¹Represents an alkyl group, an aryl group or a cycloalkyl group;¹Represents a halogen atom, m represents 1 or 2) and a compound represented by the general formula Ti (OR²)_nX² _dn(Where R²Represents an alkyl, aryl or cycloalkyl group;²Represents a halogen atom, and n is 1, 2 or 3) in an inert hydrocarbon solution containing a compound represented by the general formula AlR³ _pX³ _3-p(Where R³Represents an alkyl, aryl or cycloalkyl group;³Represents a halogen atom, and p represents a number of 0 <p <3), and a catalyst system comprising an organic aluminum and a solid catalyst component obtained by adding and reacting the compound. These catalyst systems are more advantageous than other catalysts such as titanium trichloride-alkyl aluminum catalyst and titanium tetrachloride-trialkoxy vanadyl-alkyl aluminum catalyst in terms of polymerization activity and coloring.
[0058]
Among these catalyst systems, a reaction between an oxygen-containing organic compound of magnesium, an oxygen-containing organic compound of titanium, and an aluminum halide compound described in JP-A-56-61406, which has a particularly high degree of freedom in activity and molecular weight distribution controllability. A catalyst system comprising a product and an organoaluminum compound is preferable, and more preferably, a solid catalyst component containing magnesium, titanium and halogen has a general formula of Mg (OR⁴)_mX⁴ _2-m(Where R⁴Represents an alkyl group, an aryl group or a cycloalkyl group;⁴Represents a halogen atom, m represents 1 or 2) and a compound represented by the general formula Ti (OR²)_nX² _4-n(Where R²Represents an alkyl, aryl or cycloalkyl group;²Represents a halogen atom, and n is 1, 2 or 3) in an inert hydrocarbon solution containing a compound represented by the general formula AlR³ _pX³ _3-p(Where R³Represents an alkyl, aryl or cycloalkyl group;³Represents a halogen atom, and p represents a number of 0 <p <3), and a catalyst system comprising an organic aluminum and a solid catalyst component obtained by adding and reacting the compound.
[0059]
3. Preferred polymerization ratio of high density polyethylene
In the preferred high-density polyethylene used in the present invention, the production ratio of the polymer in another step is set to 30 to 50% by weight of the total amount of the produced polymer.
[0060]
When the polymerization generation ratio is less than the above range, the two components of the homopolymer in one stage and the polymer in the other stage are controlled so that the difference in molecular weight is increased, so that the two components are dispersed even when melt-mixed. However, the appearance of the container becomes poor, and the appearance of the container becomes poor, and the Izod impact strength also decreases. On the other hand, when this polymerization generation ratio exceeds the above range, the environmental stress cracking resistance decreases.
[0061]
4. Intrinsic viscosity of a homopolymer in one stage of a preferred high-density polyethylene, or a homopolymer of ethylene or a copolymer of ethylene and an α-olefin other than ethylene obtained in another stage
Intrinsic viscosity [η] of one-stage homopolymer of preferred high-density polyethylene used in the present invention or a homopolymer of ethylene or a copolymer of ethylene and α-olefin other than ethylene obtained in another stage Is a value obtained by dissolving the pellet in tetralin at 130 ° C. and measuring the intrinsic viscosity [η] using an Ubbelohde viscometer.
[0062]
The intrinsic viscosity [η] of the homopolymer obtained in one step used in the present invention is preferably from 0.5 to 0.7. When the intrinsic viscosity is less than the above range, even if these two components are melt-mixed, the dispersion is poor, and the appearance of the container becomes poor and fisheye, resulting in poor appearance of the container. On the other hand, if the intrinsic viscosity exceeds the above range, the environmental stress cracking resistance decreases.
[0063]
The intrinsic viscosity [η] of the homopolymerization of ethylene or the copolymer of ethylene and an α-olefin other than ethylene obtained in another stage is preferably 3.5 to 8.2. If the intrinsic viscosity is less than the above range, the environmental stress cracking resistance decreases. On the other hand, when the intrinsic viscosity exceeds the above range, even if these two components are melt-mixed, dispersion becomes poor, resulting in bumps and fish eyes, resulting in poor container appearance.
[0064]
[IV] Formulation of resin
1. Compound
In the high-density polyethylene used in the present invention, a burr resin generated at the time of blow molding and a compounding component can be blended according to various purposes within a range not significantly impairing the effects of the present invention. As these additional components, a crystallization nucleating agent, an antioxidant, a neutralizing agent, a weather resistance improving agent, an anti-foaming agent, a dispersing agent, an antistatic agent, which is used as an ordinary additive or compounding agent for polyolefins, Lubricants, molecular weight regulators (peroxides, etc.), heat stabilizers, light stabilizers, ultraviolet absorbers, lubricants, anti-fog agents, anti-blocking agents, slip agents, flame retardants, conductivity-imparting agents, crosslinking agents, crosslinking Examples include auxiliary agents, metal deactivators, antibacterial agents, various auxiliary agents such as fluorescent whitening agents, and other various resins and elastomers, fillers, coloring agents, and the like.
[0065]
2. Preferred phenolic antioxidants
It is preferable to add a phenolic antioxidant to the high-density polyethylene used in the present invention in order to prevent oxidative deterioration due to a halogen-based detergent. 5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, octadecyl-3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl- 2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 3,9-bis [2- [3- (3-t-butyl- -Hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10 tetraoxaspiro [5,5] undecane, 1,3,5-tris (4-t-butyl -3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid. Among these, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate which has a high molecular weight from the viewpoint of volatilization and extraction into a drug, and has low volatility and excellent extraction resistance. And 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene.
[0066]
The compounding amount of the phenolic antioxidant is 0.005 to 0.5 part by weight, preferably 0.01 to 0.2 part by weight, per 100 parts by weight of the high-density polyethylene. If the amount is less than 0.005 part by weight, the oxidation resistance of the product is not sufficient. On the other hand, if the amount exceeds 0.5 part by weight, not only is it uneconomical, but also there are problems of chemical contamination, discoloration, and bleeding. Not preferred.
[0067]
3. Preferred neutralizer
In the high-density polyethylene used in the present invention, it is preferable to add an inorganic neutralizing agent having a high neutralizing effect in order to prevent halogenation deterioration due to a halogen-based detergent. And at least one neutralizing agent selected from hydrotalcite and metal hydroxide salts, and may be used alone or in combination of two or more.
[0068]
Specific hydrotalcites do not contain hydrated basic carbonates such as magnesium, calcium, zinc, aluminum and bismuth or water of crystallization, and include natural products and synthetic products. As a natural product, Mg₆Al₂(OH)₁₆CO₃・ 4H₂O-structures. In addition, as a synthetic product, Mg_0.7Al_0.3(OH)₂(CO₃)_0.15・ 0.54H₂O, Mg_4.5Al₂(OH)₁₃CO₃・ 3.5H₂O, Mg_4.2Al₂(OH)_12.4CO₃, Zn₆Al₂(OH)₁₆CO₃・ 4H₂O, Ca₆Al₂(OH)₁₆CO₃・ 4H₂O, Mg₁₄Bi₂(OH)_29.6・ 4.2H₂O and the like.
[0069]
Specific examples of the metal hydroxide salts include magnesium hydroxide, aluminum hydroxide, and lithium aluminum composite hydroxide salts.
[0070]
The compounding amount of these neutralizing agents is 0.005 to 0.5 parts by weight, preferably 0.01 to 0.2 parts by weight, per 100 parts by weight of the high-density polyethylene. If the amount is less than 0.005 parts by weight, the effect of preventing corrosion of a mold, a molding machine, and the like is not sufficient. I do.
[0071]
4. Sunscreen
It is preferable to use a light-shielding agent for the high-density polyethylene used in the present invention. Examples of preferable light-shielding agents include common colorants such as titanium oxide and carbon black, and rutile-type titanium oxide is more preferable from the viewpoint of light-shielding effect and deterioration resistance.
[0072]
The compounding amount of these light-shielding agents is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the high-density polyethylene. If the amount is less than 0.1 part by weight, the light-shielding effect is not sufficient.
[0073]
5. Mixing method
As a method of mixing the high-density polyethylene used in the present invention, the high-density polyethylene obtained by polymerization is melt-kneaded together with additives. In the present invention, the high-density polyethylene is controlled so that the molecular weight difference between the two components of the homopolymer at one stage and the (co) polymer at the other stage is large, so that the dispersion is relatively poor. The kneading is preferably performed under the condition that the specific energy, which is a kneading degree index of the melt kneader, is 0.1 to 0.35 kW · H / kg, preferably 0.2 to 0.3 kW · H / kg.
[0074]
As a method of satisfying the specific energy value, a twin-screw kneader capable of increasing the specific energy value than a single-shaft machine is preferable. Models such as LCM of Kobe Steel Co., Ltd. and CIM of Japan Steel Works Co., Ltd. Is more preferable because it can be easily adjusted.
[0075]
Examples of the method of compounding the additives, resins, and the like mentioned in the compound include a method of directly blending the compound with the high-density polyethylene using a melt kneader or a method of dry blending pellets with a blow molding machine. Can be However, when dry blending the additive, it is preferable to use a masterbatch pellet in which the additive has a high concentration in advance.
[0076]
Examples of the mixer or kneader used for the mechanical mixing or the melt kneading include, for example, a Henschel mixer, a super mixer, a V blender, a tumbler mixer, a ribbon blender, a Banbury mixer, a kneader blender, a Brabender plastograph, a roll, and a single screw. Extrusion granulators, twin screw extrusion granulators and the like can be mentioned. The melting and kneading temperature is generally from 100 to 300 ° C.
[0077]
[V] Blow molding
1. Blow molding method
As a method for molding the container used in the present invention, a general blow molding method can be applied. Specifically, a single-head or multi-head direct extrusion blow molding machine, a rotor-type blow molding machine that continuously extrudes a large number of dies while rotating, or an accumulation-type blow that intermittently extrudes and extrudes resin once It may be a molding machine or a combination of the structures of a multilayer blow molding machine capable of forming two or more layers. However, in the case of multilayer blow, it is necessary to use the high-density polyethylene used in the present invention for the inner layer from the viewpoint of chemical resistance to a halogen-based detergent.
[0078]
The molding conditions may be general conditions used for high-density polyethylene. Specifically, a molding temperature of 160 to 280 ° C. and a blow pressure of 3 to 10 Kg / cm²The bottle has a cooling time of 5 to 30 seconds and a bottle capacity of about 100 to 20 liters.
[0079]
2. Container capacity and weight
The container used in the present invention aims at high rigidity and light weight. In order to exhibit this effect, application to a thin-walled product is preferable. Specifically, the relationship between the weight (g) and the capacity preferably satisfies the following equation (4).
[0080]
Weight ≦ 0.6 × (capacity) 2/3 Equation 4
Further, it is more preferable that the following formula 5 is satisfied.
Weight ≦ 0.5 × (capacity) 2/3 Equation 5.
[0081]
3. Barrier resin
In the container of the present invention, a barrier resin can be used between the innermost resin and the outermost resin from the viewpoint of preventing oxidation of the contents and escape of the contents. Examples of the barrier resin include an ethylene-vinyl alcohol copolymer, a polyvinyl alcohol resin, and a polyamide resin, and an ethylene-vinyl alcohol copolymer having excellent oxygen barrier properties is particularly preferable.
[0082]
Further, since these barrier resins have poor compatibility with polyethylene, it is preferable to use a maleic acid-modified polyethylene adhesive resin on both surfaces of the barrier resin. The thickness of the barrier resin is preferably 5 to 50 μm, and the thickness of the adhesive layer resin is preferably 10 μm or less.
[0083]
4. Container drop strength
The drop strength of the container of the present invention needs to be at a level that does not cause any problem during actual use. As a guide, a consumer purchases a container fully filled with a halogenated detergent, and a person in winter can use his / her hand. It is important that they do not break when dropped from the reach. A specific condition that satisfies this requirement is that a halogen-based detergent is fully filled, stored at room temperature for one month, and then dropped at a temperature of 0 ° C. from a height of 2 m without breaking.
[0084]
Specifically, the above-mentioned halogen-based detergent (polyoxyethylene alkylphenyl ether sulfate 5% by weight, sodium hypochlorite 0.01% by weight, potassium hydroxide 0.5%) was placed in a two-type 500 cc bottle container of JIS-Z1703. The mixture is filled up to the mouth with a halogen-based detergent obtained by dissolving a weight percent in tap water and mixed, sealed, and stored outdoors for one month under sunlight. Next, the condition is adjusted in a low-temperature room at a temperature of 0 ° C. for 24 hours, and the bottle is preferably dropped vertically 10 times from a height of 2 m so that the bottom surface of the bottle hits the floor surface, and is preferably not broken.
[0085]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. The methods for evaluating the physical properties of the polyethylene resin and the quality of the container are as follows.
[0086]
1. Evaluation of the physical properties
1) MFR
The MFR was measured according to JIS-K7210 using an MFR meter under the conditions of a temperature of 190 ° C. and a load of 2.16 kg.
[0087]
2) Q value
The ratio of the weight average molecular weight to the number average molecular weight was measured under the following conditions using a gel permeation chromatograph (GPC: Gel @ Permeation @ Chromatography).
[0088]
GPC device: ISOC-ALC / GPC manufactured by Waters
Solvent: O-dichlorobenzene
Measurement temperature: 140 ° C
Flow rate: 1m / min
Standard material: monodisperse polystyrene manufactured by Tosoh Corporation.
[0089]
3) Density
The pellets were melted by a hot compression molding machine at a temperature of 160 ° C. and then cooled at a rate of 25 ° C./min to form a sheet having a thickness of 2 mmt. After the sheet was conditioned for 48 hours in a room at a temperature of 23 ° C., it was placed in a density gradient tube and the density was measured.
[0090]
4) Double bond amount
The pellets were melted by a hot compression molding machine at a temperature of 160 ° C. and then cooled at a rate of 25 ° C./min to form a sheet having a thickness of 0.5 mmt. The absorbance of this sheet was measured at a wavelength of 963 cm-1, 910 cm-1, and 888 cm-1 using an IR-100 general-purpose infrared spectrophotometer manufactured by JASCO Corporation.
[0091]
From the absorbance, the measured density, and the thickness of the measurement sheet, the amount of double bonds was calculated.
[0092]
5) Intrinsic viscosity [η]
The pellet was dissolved in tetralin at 130 ° C. using an Ubbelohde viscometer to measure the intrinsic viscosity [η]. In the case of two-stage polymerization, the intrinsic viscosity of the second stage was calculated from the intrinsic viscosity of the first stage and the whole and the polymerization ratio by a simple average formula.
[0093]
6) Olsen flexural rigidity
After the pellets were melted by a hot compression molding machine at a temperature of 160 ° C, the temperature was lowered at a rate of 25 ° C / min to form a sheet having a thickness of 2 mmt. This sheet was conditioned in a room at a temperature of 23 ° C. for 48 hours, and then punched out with a dumbbell blade so as to have a length of 85 mm and a width of 15 mm to obtain a test piece.
[0094]
Next, a cantilever bending stress was measured at 60 deg / min with a stiffness meter manufactured by Toyo Seiki Co., Ltd., based on JIS-K7106, at a span of 30 mm, a grip portion of 30 mm, and a total bending moment of 6 kgf · cm. .
[0095]
7) Izod impact strength
A 2 mm sheet adjusted for use in the Olsen bending stiffness test was formed into a shape having a length of 80 mm and a width of 10 mm, and a notch was cut into a tip radius of 0.25 mm by cutting to obtain a test piece.
[0096]
Next, the absorbed energy was measured with a load of 30 kg using an Izod tester manufactured by Toyo Seiki Co., Ltd. in accordance with JIS-K7110, and the Izod impact strength value was determined from the cross-sectional area of the test piece.
[0097]
8) Fisheye
A 0.8 mm thick sheet produced by pressing at 190 ° C. is melted and stretched twice in length and width to obtain a 0.2 mm thick film. In this film, the number of fish eyes having a diameter of 0.5 mm or more is determined. evaluated.
[0098]
9) Crack time for constant strain environmental stress
After the pellets were melted by a hot compression molding machine at a temperature of 160 ° C, the temperature was lowered at a rate of 25 ° C / min to form a sheet having a thickness of 2 mmt. The sheet was conditioned in a room at a temperature of 23 ° C. for 48 hours, and then punched out with a dumbbell blade so as to have a length of 38 mm and a width of 13 mm, thereby obtaining a test piece.
[0099]
Next, a notch having a length of 19.1 mm and a depth of 0.30 mm was inserted into the test piece with a razor blade, and the test piece was bent and inserted into a holder having an inner width of 11.75 mm, and 10 wt% of Igepearl (Antarox Co630) was previously prepared. % Aqueous solution was immersed in a test tube at 50 ° C., and the time required for the test piece to generate 50% cracks was measured. In addition, Igepearl used here is nonylphenoxypoly (ethyleneoxy) ethanol described in ASTM D1693. This product is also known as polyoxyethylene nonyl phenyl ether.
[0100]
2. Container performance evaluation
1) Chemical resistance of container
Halogen system in which 5% by weight of polyoxyethylene alkyl phenyl ether sulfate, 0.01% by weight of sodium hypochlorite, and 0.5% by weight of potassium hydroxide are dissolved and mixed in tap water in a two-type 500 cc bottle container of JIS-Z1703. After 50 cc of the detergent was put in the container and sealed, the container was placed in an oven at a temperature of 65 ° C., and the time required to break the bottle was measured.
[0101]
2) Drop test of container
The above-mentioned halogen-based detergent was filled up to the mouth with two kinds of 500 cc bottles of JIS-Z1703, sealed, and stored outdoors for one month under sunlight. Next, the condition was adjusted in a low-temperature room at a temperature of 0 ° C. for 24 hours, and the bottle was dropped 10 times vertically from a height of 2 m so that the bottom surface of the bottle hit the floor surface.
[0102]
The results of the drop test were evaluated as "x" when the sample was broken once, "x" when the sample was not split even 10 times, and "△" when the sample was broken not up to 10 times.
[0103]
Example 1
1. Preparation of solid catalyst
Mg (OC₂H₅)₂115g and Ti (OC₄H₉)₃Cl @ 151g and n-C₄H₉37 g of OH was mixed at 150 ° C. for 6 hours to homogenize. After cooling, a predetermined amount of benzene was added to make a homogeneous solution. Next, 457 g of ethyl aluminum sesquichloride was added dropwise at a predetermined temperature, and the mixture was stirred for 1 hour. Further washing with n-hexane was repeated to obtain 220 g of a solid catalyst.
[0104]
2. Polymerization of ethylene
A 2,000-liter stainless steel autoclave is charged with 1,000-liter n-hexane and 0.32 mol of diethylaluminum chloride as a cocatalyst, and heated to 90 ° C. When the specified temperature is reached, the gauge pressure is 12 kg / cm²Of hydrogen, and then ethylene was supplied at a gauge pressure of 4 kg / cm through a catalyst supply pipe containing 20 g of the catalyst obtained in the above item 1.²Supplied.
[0105]
After maintaining the total pressure at a predetermined value and continuing the reaction until the supplied ethylene integration amount reached 205 kg, the reactor was cooled and the gas phase gas was purged. A part of the slurry was sampled and subjected to the measurement of the molecular weight of the produced polymer in the first stage. The sampled polymer weighed 10 g after drying. Then, the autoclave was maintained at 65 ° C. and hydrogen was supplied at a gauge pressure of 1 kg / cm.²Then, ethylene is supplied so as to have an ethylene / hydrogen molar ratio of 0.8, and the polymerization is carried out while maintaining the total pressure until the cumulative amount of ethylene reaches 40% by weight of the total produced polymer. Was performed. When a predetermined amount of ethylene was reached, ethyl alcohol was supplied to terminate the polymerization. After polymer separation, the polymer slurry was dried under a nitrogen atmosphere to obtain 340 kg of a powdery polymer.
[0106]
3. Pelletizing powder
To the powdery polymer obtained above, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, which is a phenol antioxidant, was added in an amount of 0.1%. 1 part by weight, 0.1 part by weight of hydrotalcite DHT4A manufactured by Kyowa Chemical Industry Co., Ltd., which is a neutralizing agent, was mixed and mixed with a Henschel mixer, and heated to 230 ° C. The mixture was melt-kneaded with an extruder having a flight screw at a specific energy of 0.2 kW · H / kg to obtain a pellet-shaped resin composition. It should be noted that 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene is phenolic I and hydrotalcite DHT4A is a neutralizing agent D. And described in Table 1.
[0107]
4. Preparation of light-blocking agent master batch
This melt-kneaded pellet resin was mixed with 40 wt% of rutile-type titanium oxide and 2 wt% of calcium stearate with a hot roll at 160 ° C. for 3 minutes to produce a pelletized light-shielding agent master batch.
[0108]
5. Blow molding
The light-blocking agent masterbatch pellets were dry-blended with the melt-kneaded pellet resin so that the final titanium oxide concentration was 2 wt%, and a small direct blow molding machine TL5543L manufactured by Tahara Co., Ltd. was used at a temperature of 200 ° C. and a screw rotation of 30 rpm. Under a condition of a die diameter of 21.8 mm and a core diameter of 18.9 mm, cooling water of 30 ° C. was passed through two kinds of 500 cc bottle molds of JIS-Z1703 and cooled for 10 seconds to form a bottle container weighing 30 g.
[0109]
6. Evaluation of the physical properties
Using the above sample, the first-stage intrinsic viscosity, the second-stage intrinsic viscosity, MFR, Q value, density, terminal vinyl bond, rigidity, fisheye, constant strain environmental stress cracking time, blow moldability, resistance of containers with halogen-based detergent A chemical test and a drop test of the container were performed. Table 1 shows the results.
[0110]
Example 2
As the polymerization conditions for the high-density polyethylene, the hydrogen concentration in the second stage was increased and the molecular weight in the second stage was reduced, and the polymerization amount in the first stage was reduced to 55 wt% and the polymerization ratio in the first stage was 55 wt%. It carried out like Example 1 except having set the polymerization ratio of the eye to 45 wt%. Table 1 shows these polymerization conditions and evaluation results.
[0111]
Example 3
The polymerization was carried out in the same manner as in Example 1 except that butene-1 was fed in the second stage to lower the density as the polymerization conditions for high-density polyethylene. Table 1 shows these polymerization conditions and evaluation results.
[0112]
Example 4
As the polymerization conditions for high-density polyethylene, increasing the hydrogen concentration in the first stage and decreasing the molecular weight in the first stage, and increasing the hydrogen concentration in the second stage and decreasing the molecular weight in the second stage, Example 3 was carried out in the same manner as in Example 3 except that the polymerization amount in the first stage was reduced to 50% by weight of the polymerization ratio in the first stage and 50% by weight in the second stage. Table 1 shows these polymerization conditions and evaluation results.
[0113]
Example 5
Example 1 was carried out in the same manner as in Example 1 except that the weight of the bottle was increased to 40 g. Table 1 shows these polymerization conditions and evaluation results.
[0114]
Comparative Example 1
As the polymerization conditions for high-density polyethylene, the hydrogen concentration in the second stage was reduced and the molecular weight in the second stage was increased, and the polymerization amount in the first stage was increased to increase the polymerization ratio in the first stage to 75 wt% and the second stage. It carried out like Example 1 except having set the polymerization ratio of the eye to 25 wt%. Table 2 shows these polymerization conditions and evaluation results.
[0115]
Comparative Example 2
As the polymerization conditions for high-density polyethylene, the hydrogen concentration in the second stage was increased to reduce the molecular weight in the second stage, and the polymerization amount in the first stage was reduced to 47% by weight to reduce the polymerization amount in the first stage. It carried out like Example 1 except having set the polymerization ratio of the eye to 53 wt%. Table 2 shows these polymerization conditions and evaluation results.
[0116]
Comparative Example 3
The polymerization was performed in the same manner as in Example 1 except that the same catalyst as in Example 1 was used instead of the one-step continuous copolymerization with propylene as the polymerization conditions for high-density polyethylene. Table 2 shows these polymerization conditions and evaluation results.
[0117]
Comparative Example 4
The polymerization conditions of the high-density polyethylene were carried out except that it was changed to a one-step continuous copolymerization product with butene-1 using a Phillips catalyst obtained by calcining chromium acetate on silica and that polymerization was carried out without adding hydrogen. Performed as in Example 1. Table 2 shows these polymerization conditions and evaluation results.
[0118]
Comparative Example 5
Comparative Example 4 was carried out in the same manner as in Comparative Example 4 except that the same Phillips catalyst as in Comparative Example 4 was used as the polymerization condition for the high-density polyethylene to change to a one-step continuous copolymer with hexene-1. Table 2 shows these polymerization conditions and evaluation results.
[0119]
Example 6
Example 1 was carried out in the same manner as in Example 1 except that the light-shielding agent was not added. Table 2 shows these polymerization conditions and evaluation results.
[0120]
Example 7
Example 1 was carried out in the same manner as in Example 1 except that all the additives of Example 1 were not added. Table 2 shows these polymerization conditions and evaluation results.
[0121]
Example 8
1,3,5-Trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, which is a phenol antioxidant used in Example 1, was converted to 2,6-di- It carried out like Example 1 except having changed into -t-butyl-4-hydroxytoluene. Table 2 shows these polymerization conditions and evaluation results.
[0122]
In addition, 2,6-di-t-butyl-4-hydroxytoluene was referred to as phenol B and described in Table 1.
[0123]
【The invention's effect】
The present invention has excellent rigidity and markedly improves the chemical resistance to halogen-based detergents, so that it is possible to reduce the wall thickness, which has been conventionally difficult to reduce the weight, and has excellent blow moldability and container performance, and thus has an industrial value. Can be used as a hollow container suitable for halogen detergents.
[0124]
[Table 1]

[0125]
[Table 2]

Claims (5)

An MFR of 0.05 to 2 g / 10 min, a Q value of 13 to 20, and a density of 0.950 obtained by performing two or more stages of multi-stage polymerization using an ionic polymerization catalyst and different hydrogen concentrations. 0.970 g / cm ³ , less than 0.5 double bonds per 1000 carbons, constant strain environmental stress cracking of 40 hours or more, and Izod impact strength of 5 kJ / m ² or more. A composition for a hollow container suitable for a halogen-based detergent. High-density polyethylene is a homopolymer of ethylene or a copolymer of ethylene and another α-olefin other than ethylene polymerized using a Ziegler catalyst system, wherein the polymerization reaction is performed in two steps, In the stage, ethylene homopolymerization is performed to produce 50 to 70% by weight of the total amount of the polymer produced, and in another stage, ethylene homopolymerization or ethylene polymerization is performed under a hydrogen concentration different from the hydrogen concentration in one stage. Copolymerization of ethylene and an α-olefin other than ethylene is performed to form a (co) polymer having an intrinsic viscosity [η] of 3.5 to 8.2 by 30 to 50% by weight based on the total amount of the produced polymer. 2. The composition for a hollow container for a halogen-based detergent according to claim 1, which is obtained. Intrinsic viscosity [η] of the homopolymer obtained in one stage is 0.5 to 0.7, and homopolymerization of ethylene obtained in the other stage or the limit of a copolymer of ethylene and an α-olefin other than ethylene The composition for hollow containers for halogen-based detergents according to claim 1 or 2, wherein the viscosity [η] is 3.5 to 8.2. A hollow container suitable for a halogen-based detergent, which is formed of the composition according to claim 1. The hollow container for a halogen-based detergent according to claim 4, wherein a light-shielding pigment is blended with high-density polyethylene.