JPH11292933A - Container for highly pure chemical - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject container having excellent mechanical strengths such as excellent impact resistance and excellent environmental stress crack resistance characteristics, having easy handleability, scarcely oozing impurity particles into a chemical stored in the container and suitable for storing the highly pure chemical by using specific polyethylene as a component material. SOLUTION: The container for a highly pure chemical is produced from a polyethylene which comprises ethylene homopolymer or the copolymer of ethylene with an α-(3-20C) olefin and has a melt flow rate I2 of 0.05-50 g/10 min at a temperature of 190 deg.C under a load of 2.16 kg, a density of 0.910-0.975 g/cm<3> , an Mw/Mn ratio of 3-6 measured by gel permeation chromatography(GPC), a melt flow rate ratio of 16-30, and an A value of -0.5 to 0.01 in a least square method approximate linear relational equation (A and C are each a constant) between an elusion temperature (Ti/ deg.C) and the maximum mol.wt. [Mmax (Ti)] of eluted components at the elution temperature in the correlation of mol.wt.-elution temperature-eluted amount measured by the cross fractionation measurement(CFC) using a warming elusion fractionation method and GPC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container suitable for storing high-purity chemicals made of polyethylene.

[0002]

2. Description of the Related Art Polyethylene containers are lightweight, have excellent mechanical strength, are excellent in chemical resistance, are sanitary, are easy to mold, and are inexpensive. Therefore, molding methods such as blow molding and injection blow molding are used. Is shaped as a container by
Although widely used, in recent years, its usage has increased in the field of high-purity medicine containers used in the semiconductor industry, the liquid crystal industry, and the like, or in the field of medical containers for storing medical drugs. The contents to be filled in high-purity chemical containers include sulfuric acid, nitric acid,
Etching and cleaning chemicals such as aqueous hydrogen peroxide, hydrofluoric acid, and ammonium fluoride; methyl alcohol, ethyl alcohol, isobutyl alcohol, and ethylene glycol used for semiconductor processes and liquid crystal displays.
Examples include high-purity solvent-based resists such as acetone, ethyl acetate, toluene, dimethylformamide, ethylene glycol acetate, methoxypropyl acetate, and butyl cellosolve, and diluting solvents.On the other hand, the content to be filled in a medical container is methyl alcohol. And high-purity solvents used for medicinal purposes such as sterilization, disinfection, and raw materials for pharmaceuticals such as ethyl alcohol and isopropyl alcohol.

[0003] Containers filled with these high-purity chemicals must be able to store the stored high-purity chemicals with high purity, so that chemical resistance is required. Stiffness and excellent mechanical properties such as impact resistance and environmental stress cracking resistance (ESCR). For this reason, among the polyethylene containers, relatively high-density polyethylene (having a density of about 0.935 g / cm ³ or more) excellent in chemical resistance and impact resistance is expected as a material of the high-purity chemical container. . However, during storage and storage of high-purity chemicals in polyethylene containers, impure fine particles often leach out of the containers into the chemicals, thereby deteriorating the purity of the chemicals. For this reason, there are problems that the quality and yield of semiconductors and liquid crystals are significantly affected, and that the storage period of chemicals is shortened.

[0004] The "cleanness" required for high-purity chemical containers and medical containers generally means "particulates" that have leached out of the material of the container during storage for a long time in the container. The cleanliness is higher as the number of fine particles is smaller. The degree of cleanliness is determined by forming an inspection container, storing ultrapure water in the inspection container for a certain period of time, and determining how many fine particles with a particle size of 0.2 μm or more exist in 1 ml of water stored in the resin container. Is calculated and obtained. Generally, in order to improve the quality and yield of semiconductors and liquid crystals, a cleanness of 500 / ml or less is required, but in recent years the demand for cleanness has been increasing more and more. The causes of the generation of fine particles in the contents filled in the polyethylene container include (1) the residue of the catalyst used during the polymerization, (2) a neutralizing agent, an antioxidant, and an antistatic agent blended in the polyethylene. Various additive components such as UV inhibitors, (3) wax components contained in polyethylene, (4) low-density low molecular weight components contained in polyethylene, and the like are considered, but the mechanism is still insufficient. Not disclosed.

Attempts to improve the cleanliness of polyethylene containers include JP-A-62-39444, JP-A-62-178342, and JP-A-63-5444.
No. 4, JP-A-1-208155, JP-A-5-208
177,693, JP-A-7-330074,
JP-A-8-113678, JP-A-8-17555
No. 5 publication. In these publications, as a method of suppressing the generation of fine particles from a polyethylene container, the container is made to have a two-layer structure, the type and amount of an additive component to be mixed with polyethylene are controlled, and the inner surface of the container is made of fluorine. It describes processing or controlling the molecular weight distribution of polyethylene as a raw material and the content of wax components.

[0006] However, among the factors listed above that may cause the generation of fine particles, those relating to the polymerization catalyst residue and wax component or low-density low-molecular weight component in polyethylene are essentially polymerization catalysts and polymerization processes. In order to reduce the generation of fine particles based on these factors, there is a limit in improvement by controlling the structure of the container, processing the inner surface of the container, and controlling the blending of additives, and it is a material. The polyethylene itself needs to be improved. In recent years, metallocene catalysts have made it possible to produce polyethylene with high activity. Since the polyethylene has a narrow molecular weight distribution and can obtain an ethylene / α-olefin copolymer having a uniform composition distribution of constituent molecules,
It is considered to be extremely promising for obtaining a polyethylene container having excellent cleanliness. Japanese Patent Application Laid-Open No. 9-77921 discloses a technology relating to a polyethylene resin composition having high cleanliness using a metallocene polyethylene having a density of 0.910 to 0.940 g / cm ³ ,
A composition having a density of 0.940 g / cm ³ or more is not exemplified, and the same publication further describes that metallocene polyethylene having a high density has reduced transparency and high-speed fracture resistance.

As described above, although there is a high need for a polyethylene container having high cleanliness and excellent mechanical strength such as impact resistance and ESCR, a polyethylene container exhibiting satisfactory performance is not yet available. At present it has not been obtained. In particular, for high-density polyethylene containers, improvements in cleanliness and mechanical strength are strongly desired.

[0008]

DISCLOSURE OF THE INVENTION The present invention has a high mechanical strength such as impact resistance and ESCR, is easy to handle, and has very little leaching of impurity particles into stored chemicals. An object of the present invention is to provide a polyethylene container suitable for storing pure chemicals.

[0009]

Means for Solving the Problems The inventor of the present invention uses a specific polyethylene having a controlled polymer molecular structure and molecular weight distribution as a constituent material of a container to obtain a machine having rigidity, impact resistance, ESCR characteristics and the like. The present inventors have found that a polyethylene container having an extremely small amount of fine particles, which serves as a measure of mechanical properties and cleanliness, can be obtained, and completed the present invention.

That is, the polyethylene container of the present invention comprises:
(1) An ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and (2) a melt flow rate value (I ₂ ) under a condition of a load of 2.16 kg and a temperature of 190 ° C. 0.05 g / 10 min or more and 50 g / 10 min or less, and (3) a density of 0.9 g / min.
10g / cm ³ or more 0.975g / cm ³ or less,
(4) The Mw / Mn value determined by gel permeation chromatography (GPC) measurement is 3 or more and 6 or less, and (5) the melt flow rate ratio (MI
R) is 16 or more and 30 or less. (6) In the correlation of molecular weight-elution temperature-elution amount determined by cross-fractionation measurement (CFC) between the elevated temperature elution fractionation and gel permeation chromatography, A least squares approximation linear relationship between the elution temperature (Ti / ° C.) expressed by (1) and the maximum molecular weight (Mmax (Ti)) of the elution component at the elution temperature,

[0011]

[Formula 4] log (Mmax (Ti)) = A * Ti + C (1) (where A and C are constants in the above formula (1)), the constant A is represented by the following relational expression (2):

[0012]

This is a high-purity chemical container made of polyethylene satisfying the following formula: -0.5 ≦ A ≦ 0.01 (2)

The polyethylene which is the material of the polyethylene container of the present invention can be produced by a vessel-type slurry polymerization method using a supported geometrically constrained single-site catalyst. The reason why the polyethylene container of the present invention can achieve a dramatic improvement in the balance between clean performance and mechanical characteristics as compared with the container according to the prior art is that polyethylene as a material is supported using a geometrically constrained single-site catalyst. It is produced by a vessel type slurry polymerization method and has the following three characteristics. The first characteristic is that the polyethylene obtained by the above method is extremely excellent in cleanliness as compared with conventional polyethylene. The polyethylene is (1)
Due to its high catalytic activity, the content of transition metals belonging to Group 4 of the periodic table (Ti, Zr, Hf) contained in polyethylene is reduced to 10 p.
pm or less, preferably 3 ppm or less, more preferably 1 ppm or less.
(2) low wax content due to narrow molecular weight distribution, and (3) low content of low-density low molecular weight components due to high uniformity of polymer structure. For example, the amount of fine particles leached from the container into the contents can be extremely reduced. The expression of this first characteristic is largely due to the single-site catalyst, but in addition, it is characterized by adopting a slurry polymerization method as a polymerization method of polyethylene. That is, in the slurry polymerization method, a process of separating the polymerized polyethylene powder from the polymerization solvent can be introduced by a separation device such as a centrifugal separator in a process. It is possible to efficiently remove low molecular weight components, catalyst residue components and the like. As the polyethylene used in the polyethylene container of the present invention, polyethylene obtained by washing and purifying the polymerization powder with a solvent as described above can be preferably used, and the polyethylene obtained by the method can be used in another solution method or gas method. As compared with the metallocene-based polyethylene obtained by the above process, it is possible to further reduce the residual amount in the polymer such as the wax component, the low-density low-molecular-weight component, or the catalyst residue component. The second characteristic is that when the value of the constant A in the above formula (1) is the following relational formula (2),

[0014]

[Formula 6] -0.5 ≦ A ≦ 0.01 (2) Preferably, the following relational expression (3):

[0015]

[Formula 7] -0.4 ≦ A ≦ −0.001 (3) In the formula (1), when the constant A is negative (minus), it indicates that when the polyethylene is a copolymer, more comonomer is introduced into the high molecular weight component of the copolymer. Polyethylene having such a comonomer distribution has an improved tie molecular density, and thus has improved impact resistance, ESCR characteristics and fatigue resistance characteristics.

On the other hand, when the constant A is positive (plus), the copolymer has a structure in which a large amount of comonomer is introduced into the low molecular weight component of the copolymer. Therefore, the ESCR properties, impact resistance and fatigue resistance properties are insufficient. Become. In the case of polyethylene obtained using a conventional Ziegler-Natta type catalyst, the constant A is usually positive (plus) because a large amount of comonomer is introduced on the low molecular weight component side. Also, in the case of general metallocene polyethylene, the constant A is often positive.
In the case of a homopolymer, it is difficult to accurately measure the value of the constant A, but the value of the constant A is almost equal to zero.

A third feature is that the polyethylene as the material of the container is controlled to an optimum molecular weight distribution in order to balance rigidity, impact resistance and ESCR characteristics at a high level. That is, the polyethylene used in the present invention has a Mw / Mn value of 3 to 3 based on a GPC measurement method described later.
6, which is narrower than that of the polyethylene obtained using the conventional Ziegler-Natta type catalyst, and is slightly wider than that of the general metallocene polyethylene. Polyethylenes having such molecular weight distribution characteristics are extremely advantageous for maintaining a high level of balance between stiffness, impact resistance and ESCR properties.

The superiority of the cleanliness and mechanical strength of the polyethylene container of the present invention will be specifically described in a later example. However, the polyethylene container of the present invention uses a supported geometrically constrained single-site catalyst. This is achieved by utilizing the characteristics of polyethylene produced by a vessel polymerization method using a vessel.
Hereinafter, the present invention will be described in detail. The polyethylene according to the present invention is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.

Here, the α-olefin having 3 to 20 carbon atoms includes propylene, 1-butene, 1-pentene,
1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1
-Hexadecene, 1-octadecene, 1-eicosene and the like, and these are used as one kind or a combination of two or more kinds. Among them, preferred are 1-butene, 1-pentene, 1-hexene and 1-octene, and particularly preferred are 1-pentene, 1-hexene and 1-octene. When the polyethylene used in the present invention is a copolymer, it has a specific molecular structure in which more comonomers are introduced into components on the high molecular weight side, which are generally difficult to obtain with a conventional Ziegler-Natta (ZN) type catalyst. In order to obtain polyethylene having this structure, 1-pentene, 1-hexene, 4-methyl-
More preferably, 1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene are used as comonomers.

The content of α-olefin in polyethylene is 0.05 to 2.0 mol%, preferably 0.1 to 2.0 mol%.
1.5 mol%. Here, the α-olefin content refers to the total content of α-olefins other than ethylene.
When the amount of the α-olefin exceeds 2.0 mol%, the density of the obtained polyethylene is too low and is out of the range of the present invention. The α-olefin content (unit: mol%) was determined by adding about 30 mg of the copolymer in a sample tube of usually 10 mmφ using a product name of α-400 manufactured by JEOL Datum Co., Ltd.
ml of orthodichlorobenzene / d6-benzene = 1 /
13C of a sample uniformly dissolved in 4 to 1/5 mixed solvent
The NMR spectrum is measured at a measurement temperature of 135 ° C.

2.16 of the polyethylene according to the present invention
Melt flow rate value (I
₂ ) is 0.05g / 10min or more and 50g / 10mi
n or less. If I ₂ is less than 0.05 g / 10 min, the fluidity of the polyethylene becomes insufficient, and the moldability becomes difficult. On the other hand, if I ₂ exceeds 50 g / 10 min, the fluidity is too high, and it is difficult to form a container by ordinary blow molding or rotational molding. I ₂ is 0.1 g /
It is preferably from 10 min to 40 g / 10 min, more preferably from 0.3 g / 10 min to 30 g / 10 min.
min, particularly preferably 0.5 g / 10 mi
It is n or more and 20 g / 10 min or less. The melt flow rate value is measured according to ASTM D1238 by adding 1,000 ppm of an antioxidant, and the MFR values shown in the present specification below are all values measured by the same method.

The density of the polyethylene according to the present invention is 0.910 g / cm ³ or more and 0.975 g / cm ³ or less. If the density is less than 0.910 g / cm ³ ,
The rigidity of the container is insufficient, and the number of generated fine particles increases, and the cleanness decreases. On the other hand, when the density is 0.975
If it exceeds g / cm ³ , the mechanical strength of the container becomes insufficient. Density is 0.930 g / cm ³ or more and 0.970 g / c
m ³ or less, more preferably 0.940 g /
cm ³ or more 0.965 g / cm ³ or less, particularly preferably 0.945 g / cm ³ or more 0.963 g / cm ³ or less.

The densities shown in this specification are all measured by measuring the sample under nitrogen at 120 ° C. for 1 hour, gradually cooling to room temperature (about 23 ° C.) over 1 hour, and then measuring the density gradient. You. The polyethylene according to the present invention has an Mw / Mn value determined by gel permeation chromatography (GPC) of 3 or more and 6 or less.
In the polyethylene container of the present invention, as the Mw / Mn value of the polyethylene used is smaller, the impact resistance is improved, and the number of fine particles generated in the container can be suppressed low, so that the cleanness is also improved. However, if the Mw / Mn value is less than 3, the ultimate density of polyethylene is low, so that it is difficult to increase the rigidity of the container, and E
It is not preferable because the SCR is lowered and the fluidity is further lowered, so that molding processing becomes difficult. On the other hand, Mw / Mn
If the value exceeds 6, the number of generated fine particles in the container increases, the cleanness decreases, and the impact resistance of the container also decreases.

That is, the molecular weight distribution of the polyethylene according to the present invention is characterized in that the balance between the cleanliness of the container and the mechanical strength is in an extremely preferable range.
The preferred range of the / Mn value is 3.2 or more and 5.5 or less, and more preferably 3.5 or more and 5 or less. The polyethylene according to the present invention can be produced by a Bessel type slurry polymerization method using a supported geometrically constrained single-site catalyst described later. When polyethylene is produced by the polymerization method, Mw / M of polyethylene is used.
The n value ranges from 3 to 6.

The Mw / Mn value of the ethylene polymer of polyethylene obtained by the polymerization method varies depending on the average residence time of the polymerization slurry in the reactor, the polymerization pressure, the polymerization temperature, the comonomer concentration, and the like. It increases with increasing residence time, increases with decreasing polymerization pressure, increases with increasing superposition temperature, and decreases with the addition of comonomer. Here, the average residence time of the polymerization slurry inside the reactor is defined as a value obtained by dividing the total amount of the slurry liquid inside the reactor by the amount of the slurry liquid passing through the reactor per unit time. The polymerization pressure is the total pressure inside the reactor (kgf / cm ² , gauge pressure).

When the polyethylene according to the present invention is produced by a slurry polymerization method using a supported geometry-constrained single-site catalyst, the average residence time of the polymerization slurry in the reactor is 0.5 to 8 hours,
It is preferably within a range from 0.8 hours to 7 hours, more preferably from 1 hour to 6 hours.
The polymerization pressure inside the reactor was 1 kgf / cm ²
30 kgf / cm ² or less, preferably 3 kgf / c
m ² or more 25 kgf / cm ² or less, more preferably 5k
It is preferably in the range of not less than gf / cm ^{2 and not} more than 20 kgf / cm ² . The polymerization temperature inside the reactor is 40 ° C. or higher and 110 ° C. or lower, preferably 50 ° C. or higher and 10 ° C. or lower.
It is preferably in the range of 0 ° C. or less, more preferably 55 ° C. or more and 90 ° C. or less.

[0027] The Mw / Mn value of the ethylene polymer is determined by GPC.
The GPC measurement in the present invention is performed under the following conditions. [Apparatus] ALC / GPC 150- manufactured by Waters
Type C [Measurement conditions] Column: AT-807S (1) manufactured by Showa Denko KK and GMH-HT6 (2) manufactured by Tosoh Corporation connected in series Mobile phase: Trichlorobenzene (TCB) Column temperature: 140 C Flow rate: 1.0 ml / min Sample concentration: 20 to 30 mg (PE) / 20 ml (TC
B) Melting temperature; 140 ° C. Inflow: 500-1,000 ml Detector; Differential refractometer

[Measurement sample] A melt-kneaded material containing 1,000 ppm of an antioxidant (such as BHT) or a strand obtained by MFR measurement. Further, the polyethylene according to the present invention has a melt flow rate ratio (MIR) of 16 or more. 30 or less. Here, the MIR is the MFR under a 21.6 kg load at 190 ° C. as I ₂₀ , and the MFR under a 2.16 kg load at the same temperature as I ₂₀
MIR = I ₂₀ / I ₂ when _2, and is a measure of melt flowability. That is, it means that the larger the MIR, the better the moldability. In general, the molecular weight distribution of a linear polyethylene increases as the MIR increases. In the polyethylene according to the present invention, the MIR
If the ratio is less than 16, the molding processability deteriorates, which is not preferable. On the other hand, if it exceeds 30, the number of generated fine particles in the container increases, the cleanliness becomes insufficient, and the impact resistance of the container also decreases. The MIR is preferably 18 or more and 28 or less, more preferably 20 or more and 26 or less.

Further, the polyethylene according to the present invention is:
In the correlation of molecular weight-elution temperature-elution amount determined by cross-separation measurement (CFC) between temperature-elution fractionation and gel permeation chromatography, elution temperature (Ti / ° C) expressed by the following equation (1) And a least squares approximation linear relational expression of the maximum molecular weight (Mmax (Ti)) of the eluted component at the elution temperature,

[0030]

[Formula 8] log (Mmax (Ti)) = A * Ti + C (1) (where A and C are constants in the above formula (1)), the constant A is represented by the following relational expression (2):

[0031]

[Formula 9] -0.5 ≦ A ≦ 0.01 (2) Preferably, the following relational expression (3):

[0032]

[Formula 10] -0.4 ≦ A ≦ −0.001 (3) is satisfied. As described above, when the constant A is a negative value, the polyethylene is more likely to have a tie molecule in which more comonomer is introduced on the high molecular weight side of the polyethylene, and the mechanical properties of the container are further improved. . In the polyethylene according to the present invention, the range of the constant A is more preferably

[0033]

[Formula 11] -0.3 ≦ A ≦ −0.002, more preferably

[0034]

[Formula 12] -0.35 ≦ A ≦ −0.003, and particularly preferably,

[0035]

[Formula 13] -0.2 ≦ A ≦ −0.005. It is substantially difficult to polymerize a polymer having a constant A smaller than -0.5 (negatively large) with a single catalyst system. The above constant A is defined as the logarithmic maximum molecular weight (log (Mmax (Ti))) at the elution temperature (Ti / ° C.) and T
It is obtained from the plot of i, and the Mmax value when the amount of the eluted component at the elution temperature Ti is 1 wt% or less, and the Mm value of the eluted component at the lowest and highest elution temperatures.
The ax value is obtained excluding.

Polyethylene obtained by slurry polymerization using a supported-type geometrically-constrained single-site catalyst often satisfies the relationship of the above formula (2). ) Is not always obtained, and is listed below (1).
When produced under the polymerization conditions shown in (4) to (4), it is possible to obtain a polyethylene in which the constant A of the formula (1) is more negative, that is, the polyethylene having improved mechanical performance. (1) When obtaining a polyethylene having a larger weight average molecular weight. (2) When the α-olefin which is a comonomer is a so-called higher olefin such as 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene and the like. (3) When the polymerization temperature is lower (40 to 90 ° C.) (4) When the polymerization pressure is lower (1 to 20 kg / c)
m ² ) The cross-separation measurement (CFC) between the temperature-elution fractionation and gel permeation chromatography performed in the present invention is performed under the following conditions.

[Apparatus] CFC T-150A type manufactured by Dia Instruments Co., Ltd. [Measurement conditions] GPC column: AD806MS manufactured by Showa Denko KK
Mobile phase; dichlorobenzene (DCB) Column temperature; 140 ° C. Flow rate: 1.0 ml / min Sample concentration: 20 to 30 mg (PE) / 20 ml (DC
B) Dissolution temperature; 140 ° C. TREF column packing material; glass beads Sample solution injection amount: 5 ml TREF column cooling rate; 1 ° C./min (cooled from 140 ° C. to 0 ° C.) TREF column heating rate; 1 ° C./min (0 14 degrees Celsius
Temperature rises to 0 ° C) Detector: Magna IR Spectrometer Model 550 manufactured by Nicolt Co., Ltd.

[Measurement Sample] A melt-kneaded product containing 1,000 ppm of an antioxidant (such as BHT) or a strand obtained by MFR measurement Next, a catalyst system and a production method for obtaining the polyethylene used in the present invention will be described. . The polyethylene according to the present invention is at least η-bonded to (a) a carrier substance, (b) an organoaluminum compound, (c) a borate compound having active hydrogen, and (d) a cyclopentadienyl or substituted cyclopentadienyl group. It can be produced by a vessel-type slurry polymerization method using a supported geometry-constrained single-site catalyst prepared from a titanium compound.

The carrier substance (A) may be either an organic carrier or an inorganic carrier. As an organic carrier,
(1) α-olefin polymer having 2 to 10 carbon atoms, for example, polyethylene, polypropylene, polybutene-1,
Ethylene / propylene copolymer, ethylene / butene-1
Copolymer, ethylene / hexene-1 copolymer, propylene / butene-1 copolymer, propylene / divinylbenzene copolymer, (2) aromatic unsaturated hydrocarbon polymer such as polystyrene, styrene / divinylbenzene copolymer Examples of the polymer include (3) a polar group-containing polymer such as polyacrylate, polymethacrylate, polyacrylonitrile, polyvinyl chloride, polyamide, and polycarbonate. As the inorganic carrier, (4) a porous oxide, for example, SiO ₂ , Al ₂ O
_{3, MgO, TiO 2, B} 2 O 3, CaO, ZnO, B
_{aO, ThO 2, SiO 2 -MgO} , SiO 2 -Al 2
_{O 3, SiO 2 -MgO, SiO} 2 -V 2 O 5 or the like,
(5) Inorganic halogen compounds, for example, MgCl ₂ , Al
(6) inorganic carbonates and sulfates such as Cl ₃ and MnCl ₂ ,
Nitrates such as Na ₂ CO ₃ , K ₂ CO ₃ , CaCO
₃ , MgCO ₃ , Al ₂ (SO ₄ ) ₃ , BaSO ₄ , K
(6) hydroxides such as NO ₃ and Mg (NO ₃ ) ₂ , for example, Mg (OH) ₂ , Al (OH) ₃ , Ca (OH) ₂
Etc. can be exemplified. The most preferred carrier material among the above-listed simple substances is silica (SiO ₂ ). The particle size of the carrier material can be conveniently selected, but is generally from 1 to 3000 μm, preferably from 5 to 2,000 μm.
μm, and more preferably 10 to 1,000 μm.

The carrier material is treated with an organoaluminum compound (a) before use. Preferred organic aluminum compounds include trimethyl aluminum, triethyl aluminum, tripropyl aluminum, triisopropyl aluminum, triisobutyl aluminum, trihexyl aluminum, trioctyl aluminum,
Alkyl aluminum hydrides such as tridecyl aluminum, diethyl aluminum monochloride, diisobutyl aluminum monochloride, ethyl aluminum dichloride, dimethyl aluminum chloride, diethyl aluminum hydride, diisobutyl aluminum hydride, diethyl aluminum ethoxide, dimethyl aluminum methoxide, dimethyl aluminum phenoxide, etc. And organic aluminum oxy compounds (alumoxane) such as aluminum alkoxide, methylalumoxane, ethylalumoxane, isobutylalumoxane, and methylisobutylalumoxane. Of these, trialkyl aluminum, aluminum alkoxide and the like are preferably used. Most preferred are trimethylaluminum, triethylaluminum and triisobutylaluminum.

Further, in the supported catalyst used in the production of polyethylene according to the present invention, a borate compound (C) having active hydrogen is used. This borate compound is an activator that converts (d) into a cation by reacting with (c) a titanium compound (d) η-bonded to a cyclopentadienyl or substituted cyclopentadienyl group, which is the main catalyst. The group (TH) having an active hydrogen in the borate compound may form a chemical bond or a physical bond with the carrier when the borate compound (c) is carried on the carrier material (a). it can. A complex represented by the following formula (7) is formed by a borate compound (c) having active hydrogen and a titanium compound (d) η-bonded to a cyclopentadienyl or substituted cyclopentadienyl group.

[0042]

[B ^- Qn (Gq (TH) r) z] A ⁺ (7) In the above formula (7), B represents boron, and G represents a multi-bond hydrocarbon radical. . Preferred examples of the multibonded hydrocarbon (G) include alkylene, arylene, ethylene, and alkenylene radicals each having 1 to 20 carbon atoms. Preferred examples of G include phenylene, bisphenylene, naphthalene, methylene, and the like. Ethylene, 1,3-propylene, 1,4-butadiene, p
Phenylenemethylene can be mentioned. The multibond radical G has an r + 1 bond, ie, one bond bonds to the borate anion, and the other bond of G bonds to the (TH) group. T represents O, S, NR, or PR;
Represents a hydrocarbenyl radical, a trihydrocarbenylsilyl radical, a trihydrocarbenylgermanium radical, or a hydride. q is 1 or more, and preferably 1. As the TH group,
—OH, —SH, —NRH, or —PRH, wherein R is a C1 to C18, preferably C1 to C10, hydrocarbenyl radical or hydrogen. Preferred R groups include alkyl, cycloalkyl, allyl, allylalkyl or alkylallyl having 1 to 18 carbon atoms. -OH, -S
H, -NRH or -PRH is, for example, -C (O),
-OH, -C (S), -SH, -C (O) -NRH, and C (O) -PRH may be used. The most preferred group having active hydrogen is an -OH group. Q is hydride,
Dihydrocarbylamide, preferably dialkylamide, halide, hydrocarbyloxide, alkoxide, allyloxide, hydrocarbyl, substituted hydrocarbyl radical and the like. Here, n + z is 4.

[B ⁻ Qn (Gq (T−
H) r) z], for example, triphenyl (hydroxyphenyl) borate, diphenyl-di (hydroxyphenyl) borate, triphenyl (2,4-dihydroxyphenyl) borate tri (p-tolyl) (hydroxyphenyl) borate, tris -(Pentafluorophenyl) (hydroxyphenyl) borate, tris- (2,
4-dimethylphenyl) (hydroxyphenyl) borate, tris- (3,5-dimethylphenyl) (hydroxyphenyl) borate, tris- (3,5-di-trifluoromethylphenyl) (hydroxyphenyl) borate, tris- ( Pentafluorophenyl) (2-hydroxyethyl) borate, tris- (pentafluorophenyl) (4-hydroxybutyl) borate, tris-
(Pentafluorophenyl) (4-hydroxy-cyclohexyl) borate, tris- (pentafluorophenyl) (4- (4′-hydroxyphenyl) phenyl) borate, tris- (pentafluorophenyl) (6-hydroxy-2naphthyl) Borate, bis (hydrogenated taloalkyl) methylammonium tris (pentafluorophenyl) (4-hydroxyphenyl) borate and the like, most preferably tris (pentafluorophenyl) (4-hydroxyphenyl)
Borate, bis (hydrogenated taloalkyl) methylammonium tris (pentafluorophenyl) (4-hydroxyphenyl) borate. Further, the —OH group of the borate compound is replaced with —NHR (where R
Are substituted with methyl, ethyl, t-butyl).

Examples of the counter cation of the borate compound include a carbonium cation, a tropylium cation, an ammonium cation, an oxonium cation, a sulfonium cation, and a phosphonium cation. In addition, metal cations and organic metal cations that are easily reduced by themselves are also included. Specific examples of these cations include:
Triphenylcarbonium ion, diphenylcarbonium ion, cycloheptatrinium, indenium,
Triethylammonium, tripropylammonium,
Tributyl ammonium, dimethyl ammonium, dipropyl ammonium, dicyclohexylammonium,
Trioctylammonium, N, N-dimethylammonium, diethylammonium, 2,4,6-pentamethylammonium, N, N-dimethylbenzylammonium, di- (i-propyl) ammonium, dicyclohexylammonium, triphenylphosphonium, triphosphonium , Tridimethylphenylphosphonium, tri (methylphenyl) phosphonium, triphenylphosphonium ion, triphenyloxonium ion, triethyloxonium ion, pyridinium, silver ion,
Gold ion, platinum ion, copper ion, palladium ion,
Mercury ions, ferrocenium ions and the like can be mentioned. Of these, ammonium ions are particularly preferred.

Further, in the supported catalyst used in the production of polyethylene according to the present invention, a titanium compound having η-bonded to a cyclopentadienyl or substituted cyclopentadienyl group represented by the following formula (8): Is used.

[0046]

(Equation 15) In the above formula (8), Ti is a titanium atom in an oxidation state of +2, +3, +4, Cp is a cyclopentadienyl or substituted cyclopentadienyl group that is η-bonded to titanium,
X ₁ is an anionic ligand, and X ₂ is a neutral conjugated diene compound. n + m is 1 or 2, and Y is-
O-, -S-, -NR-, or -PR-;
Represents SiR ₂ , CR ₂ , SiR ₂ —SiR ₂ , CR ₂ C
R ₂ , CR = CR, CR ₂ SiR ₂ , GeR ₂ , BR ₂
Wherein R is selected from hydrogen, hydrocarbyl, silyl, germium, cyano, halo or combinations thereof and combinations thereof having up to 20 non-hydrogen atoms. The substituted cyclopentadienyl group includes one or more C ₁ to C ₂₀ hydrocarbyl,
₁ to C ₂₀ halohydrocarbyl, halogen or C
Cyclopentadienyl substituted with _one to C ₂₀ hydrocarbyl substituted Group 14 metalloid group, indenyl, tetrahydroindenyl, fluorenyl or octa-fluorenyl and the like, preferably substituted with an alkyl group of C ₁ -C ₆ A cyclopentadienyl group. X ₁ ,
As X ₂ , for example, n is 2,
If m is 0 and the oxidation number of titanium is +4, X ₁ is selected from methyl and benzyl. If n is 1, m is 0 and the oxidation number of titanium is +3, X ₁ is 2- (N , N-dimethyl)
If the oxidation number of aminobenzyl and titanium is +4, X ₁ is 2-butene-1,4-diyl, and n is 0.
If m is 1 and the oxidation number of titanium is +2, X ₂ is 1,
4-diphenyl-1,3-butadiene or 1,3-
Pentadiene is chosen.

The supported geometrically constrained single-site catalyst used for obtaining the polyethylene according to the present invention can be obtained by supporting component (a), component (c) and component (d) on component (a). The method of supporting the component (d) from the component (a) is optional, but generally, the components (a), (c) and (d) are dissolved in an inert solvent in which each can be dissolved. And after mixing with component (a), distilling off the solvent, component (a), component (c)
And dissolving the component (d) in an inert solvent, and then concentrating the solid to the extent that no solid precipitates out, and adding an amount of the component (a) capable of holding the entire amount of the next concentrated liquid in the particles, A)
A method in which the component (a) and the component (c) are first supported, and then the component (d) is supported.
And a method of successively supporting the component (d) and the component (c), a method of supporting the component (a), the component (a), the component (c) and the component (d) by co-milling, and the like.

The components (c) and (d) used in the preparation of the supported geometrically constrained single-site catalyst are generally solids, and the component (a) has a pyrophoric property. The components may be diluted with an inert solvent before loading. Inert solvents used for this purpose include, for example, aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclopentane Hydrogen; aromatic hydrocarbons such as benzene, toluene, and xylene; and halogenated hydrocarbons such as ethyl chloride, chlorobenzene, and dichloromethane, and mixtures thereof. Such an inert hydrocarbon solvent is desirably used after removing impurities such as water, oxygen, and sulfur using a desiccant, an adsorbent, or the like.

In the preparation of the above catalyst, component (A) 1
(A) is 1 × 10 ⁻⁵ to 1 × 10 ⁻¹ mol, preferably 1 × 10 ⁻⁴ mol to 5 × 1 in terms of Al atom.
0 ^{- 2} mol, (c) is 1 × 10 ^-7 mol 1 × 10 ^-3 mol, preferably 5 × 10 ^-4 mol 5 × 10 ^-7 mol,
(D) is used in the range of 1 × 10 ^-7 mol to 1 × 10 ^-3 mol, preferably 5 × 10 ^-7 mol to 5 × 10 ^-4 mol. The amount of each component used and the method of loading are determined by activity, economy, powder characteristics, scale in the reactor, and the like. The obtained supported catalyst may be washed by a method such as decantation or filtration using an inert hydrocarbon solvent for the purpose of removing the organoaluminum compound, borate compound, and titanium compound that are not supported on the support. it can. A series of operations such as dissolution, contact, and washing performed in the above catalyst preparation are selected for each unit operation.
It is recommended to carry out at a temperature in the range of 0 ° C. or more and 150 ° C. or less. A more preferred range of such temperatures is 0 ° C or higher and 1 ° C or higher.
90 ° C. or less. In the preparation of the catalyst, a series of operations for obtaining a solid catalyst is preferably performed in a dry inert atmosphere.

The above-described supported geometrically constrained single-site catalyst can be stored in a slurry state dispersed in an inert hydrocarbon solvent, or can be dried and stored in a solid state. The polyethylene according to the present invention can be produced by a Vessel type slurry polymerization method. At the time of polymerization, a polymerization solvent, ethylene, a comonomer α-
Polyethylene is produced by continuously supplying the system with the olefin, hydrogen, and supported catalyst to the reactor.
The supply rates of the solvent, ethylene, comonomer, and hydrogen are conveniently adjusted according to the molecular weight and density of the target polyethylene. As the solvent used in the slurry method, an inert hydrocarbon solvent is preferable, and in particular, isobutane, isopentane, heptane, hexane, octane and the like can be used, and hexane and isobutane are particularly preferable.

In the polymerization, the polyethylene according to the present invention can be produced by using only a supported catalyst. However, in order to prevent poisoning of a solvent or a reaction system, an organic aluminum compound is added as an additional component. It is also possible to use. As the organoaluminum compound to be used, the above-mentioned organoaluminum compounds can be preferably used, and most preferably, trimethylaluminum,
Triethyl aluminum and triisobutyl aluminum. Polyethylene according to the present invention, if necessary, antioxidants, light stabilizers, antistatic agents, lubricants, antiblocking agents, organic or inorganic pigments, other polyolefin resins, such as polyolefin resins, usually used for polyolefin The agent can be added within a range that does not impair the performance of the container. The method of blending these additives in polyethylene is not particularly limited, but, for example, a method of directly adding them in the granulation process of pellets after polymerization, a single-screw or multi-screw extruder, a Banbury mixer, a kneader, a roll Melt kneading using a known kneading apparatus, such as a method of preparing a high-concentration master batch in advance and dry-blending it when forming a container.

The method for producing the polyethylene container of the present invention is not particularly limited, but it can be produced by, for example, blow molding, injection blow molding or rotational molding. In addition, the container of the present invention can be a multilayer container. In this case, the above-mentioned polyethylene can be used for the inner layer, and another polyolefin-based resin can be used for the outer layer. In blow molding, a resin is melted by an extruder and extruded into a cylindrical parison having a single-layer or multilayer structure. The extruded parison is sandwiched between metal molds, blown with a pressurized gas from a blow pin, and cooled. Also,
In injection blow molding, a preform obtained by injection molding is sandwiched between molds, and blown with a pressurized gas from a blow pin, followed by cooling. In the case of rotational molding, the resin powder is put into a mold, heated externally while rotating the mold, the resin is melted and adhered to the inside of the mold, and after cooling, the molded product is taken out. .

In the present invention, it is particularly preferable that the polyethylene as a raw material has the following physical property values. The polyethylene according to the present invention has a ratio of the elution amount of 80 ° C. or less based on the CFC measurement to the total elution amount of 10 w
It is preferably at most t%. Polyethylene produced by a supported, geometrically constrained single-site catalyst has a narrow composition distribution and is produced by a slurry polymerization method, so it is possible to exert the function of washing the polymerization powder with a polymerization solvent in the process. The content of the wax component, the low-density low molecular weight component and the catalyst residue can be extremely reduced, which is extremely convenient for improving the cleanliness. Is preferably 10 wt% or less, more preferably 8 wt% or less, and still more preferably 6 wt% or less.

In the polyethylene according to the present invention, the content of the transition metal of Group 4 of the periodic table contained in the polyethylene is preferably 10 ppm or less. Here, transition metals of Group 4 of the periodic table include Ti, Zr, and Hf.
Is shown. If the content in one or more of these polyethylenes exceeds 10 ppm, not only is the cleanliness of the container lowered, but also the container is colored and deterioration during processing is notable, which is not preferable. The content of the transition metal of Group 4 of the periodic table in polyethylene is more preferably 3 ppm or less, particularly preferably 1 ppm or less. Further, the polyethylene according to the present invention has a neutralizer, an antioxidant, and a light stabilizer each having a content of 100 pp.
m or less is preferable. In the present invention, in order to enhance the cleanliness of the container, it is particularly preferable to use these additives without blending them, but it is also possible to use them as needed. However, since the neutralizing agent, antioxidant, and light stabilizer are leached out of the container into the chemical solution and cause the generation of fine particles, the control of the addition amount is important.

The neutralizing agent is used as a chlorine catcher contained in polyethylene. Examples of the neutralizing agent include stearates of alkaline earth metals such as calcium, magnesium and barium. 100p neutralizer content
If it exceeds pm, the cleanliness of the container is undesirably reduced. Incidentally, the polyethylene obtained by the slurry polymerization method using the supported-type geometrically constrained single-site catalyst according to the present invention, it is also possible to exclude the halogen component from the catalyst component, in this case, the neutralizing agent Not required. Antioxidants include dibutylhydroxytoluene, pentaerythyl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t- Butyl-
A phenolic antioxidant such as 4-hydroxyphenyl) propionate may be mentioned, but if the content of the antioxidant exceeds 100 ppm as in the case of the neutralizing agent, it is not preferable because the cleanliness of the container is reduced.

As the light stabilizer, 2- (5-methyl-
2-hydroxyphenyl) benzotriazole, 2-
Benzotriazole-based light stabilizers such as (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, bis (2,2,6,6-tetramethyl-4-piperidine) sebacate, Poly [$ 6-
(1,1,3,3-tetramethylbutyl) amino-1,
3,5-triazine-2,4-diyl {(2,2,
Hindered amine light stabilizers such as 6,6-tetramethyl-4-piperidyl) imino {hexamethylene} (2,2,6,6-tetramethyl-4-piperidyl) imino}. When the content of the light stabilizer is more than 100 ppm like the agent and the antioxidant, the cleanliness of the container is undesirably reduced.

The content of the additives contained in the polyethylene was determined by extracting the polyethylene, which is a container material, by Soxhlet extraction using tetrahydrofuran (THF) for 8 hours, and separating the extract by liquid chromatography.
It can be determined by quantification. The equipment used is LC-10A series (manufactured by Shimadzu Corporation) and the column is S
TR-ODSII (manufactured by Shimadzu Corporation), solvent used was THF, and detector was UV-VISSPD-10AVP (manufactured by Shimadzu Corporation) or RID-10A (manufactured by Shimadzu Corporation).

[0058]

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Physical properties of the following polyethylene (1) to (3) are 19
It carried out according to the method shown below from the test plate prepared by compression molding at 0 degreeC. (1) Density (d, unit: g / cm ³ ) According to ASTM-D1505, density gradient tube method (23
° C). (2) Charpy impact test (Charpy, unit: kg
f · cm / cm ² ) In accordance with JIS-K7111, the shape of a test piece was measured at 23 ° C. and −20 ° C. with a No. 1 EA type. (3) Bending ESCR (b-ESCR, unit: hr) Based on JIS-K6760. Water temperature of constant temperature water tank is 50
° C. As a test solution, a 10 wt% aqueous solution of Antalox CO630 manufactured by Lion Corporation was used. (4) Cleanness Using a blow molding machine with a 50 mm diameter screw, a round container having a capacity of 200 ml was molded at a cylinder temperature of 180 ° C. and a mold temperature of 20 ° C.

100 ml of ultrapure water (trade name: Trepure LV-10T (manufactured by Toray Industries, Inc.)) is placed in the molded container.
It was shake-washed for 15 seconds and drained. This shaking wash is 5
Repeated times. 5 ml was collected from the fifth washing water, and the number of fine particles having a size of 0.2 μm or more leached therein was measured by a particle counter (KL-22, manufactured by Rion Co., Ltd.). The number of fine particles contained in the water is obtained by the following equation (9), and this is defined as the cleanness.

[0060]

Formula 16: Number of fine particles in water (pieces / ml) = {count number (pieces) × water quantity of ultrapure water 100 (ml)} / {sampling quantity 5 (ml) × container capacity 200 (ml)} (9) 100 ml of ultrapure water was newly added to the molding container, shaken for 15 seconds, and left as it was at room temperature for one week. The water that had passed for one week was left as it was and shaken again for 15 seconds, and the water in the shaken container was allowed to stand for 20 minutes. 5 ml was collected from the water left standing for 20 minutes, and the number of fine particles of 0.2 μm or more leached into the water was counted in the same manner as described above. (5) Bottle ESCR (unit: hr) Using a hollow molding machine with a 50 mm diameter screw, 500 is molded at a cylinder temperature of 190 ° C and a mold temperature of 40 ° C.
ml round bottle (weight 42g), manufactured by Lion Corporation,
50 ml of a 10 wt% aqueous solution of Liponox NC-140 (trade name) was placed in an oven at 60 ° C., and the time until cracks occurred in the bottle was measured. The bottle internal pressure was 0.8 kgf / cm ² (gauge pressure). (6) Bottle drop impact test 500 molded at a cylinder temperature of 190 ° C. and a mold temperature of 40 ° C. using a hollow molding machine with a 50 mm diameter screw.
A 15 ml bottle is filled with water at 15 ° C., stoppered, the bottle is dropped on the concrete surface from the bottom, and the drop height at which the bottle bursts (the height from the concrete surface) , Maximum height 8 m). The measurement was performed on ten samples, and the height at which at least two burst was used as the measured value.

(Preparation Example of Supported Geometric Constrained Single-Site Catalyst) Heat-treated at 500 ° C. for 3 hours in a nitrogen stream 20
0 g of silica powder (trade name: P-10, manufactured by Fuji Silysia K.K.) is stirred in 5 liters of hexane. Subsequently, 20.1 g dissolved in 296 ml of toluene
(17.6 mmol) of bis (hydrogenated taloalkyl) methylammonium tris (pentafluorophenyl) (4-hydroxyphenyl) borate is gradually added with stirring, and after the dropwise addition, the mixture is further stirred for 30 minutes. Thereafter, 400 ml of a 1 M triethylaluminum hexane solution was added to the silica slurry solution,
Stir at room temperature for 30 minutes. Thereafter, the resultant is washed five times by decantation using hexane at 23 ° C. to remove excess triethylaluminum and the like. Then 0.2
18M titanium (N-1,1-dimethylethyl) dimethyl [1- (1,2,3,4,5, -eta) -2,
3,4,5-tetramethyl-2,4-cyclopentadien-1-yl) silanamate [(2-) N]-(η ⁴
60 ml of an ISOPAR ^™ E (manufactured by Exxon Chemical Co.) solution (deep violet color) of
Stir for an additional 3 hours. By the above operation, a green solid catalyst system is obtained.

[0062]

EXAMPLES Example 1 Hexane, ethylene, 1-butene, hydrogen, and the supported catalyst obtained in the above catalyst preparation example were continuously supplied to a Bessel type reactor equipped with a stirrer, and polyethylene ( Ethylene / 1-butene copolymer). The temperature of the reactor was 70 ° C., and the total pressure in the reactor was 10 kgf / cm ² . The average residence time of the polymerization slurry in the reactor was 1.7 hours. The polymerization product in the form of a slurry was continuously guided from the reactor to a centrifugal separator, and after the slurry was concentrated, a polyethylene powder was obtained through a further drying step.

The obtained polyethylene powder was subjected to a twin screw extruder (JSW TEX-44CMT, manufactured by Nippon Steel Corporation).
Was melt-kneaded under the conditions of a screw rotation speed of 150 rpm and a barrel set temperature of 210 ° C., and pelletized to obtain polyethylene pellets. When kneading,
No neutralizer, antioxidant, or light stabilizer was added at all. Table 1 shows the measured values of various physical properties of the obtained polyethylene.
Example 1 is shown. The value of the correlation coefficient A between the elution temperature and the peak top molecular weight based on the CFC measurement of the obtained polyethylene was -0.003.

Further, the Charpy impact strength and bending ESCR values of the obtained polyethylene, and containers prepared by blow molding using the polyethylene, and the results of various physical properties thereof are shown in Example 1 of Table 2. The obtained container has a particle count of 72 particles / ml in water after one week, which means that the container is extremely excellent in cleanliness and also has excellent characteristics regarding the bottle ESCR and the bottle drop impact strength. (Example 2) 1- used as a comonomer in Example 1
The butene was changed to 1-hexene, and polyethylene (ethylene / 1-hexene copolymer) was obtained by the method shown in Example 1.

The obtained polyethylene powder was used in Example 1.
In the same manner as in the above, polyethylene pellets were formed using a twin screw extruder. As in Example 1, no neutralizing agent, antioxidant, and light stabilizer were added during kneading. Various measured values of physical properties of the obtained polyethylene are shown in Example 2 of Table 1. The value of the correlation coefficient A between the elution temperature and the peak top molecular weight based on the CFC measurement of the obtained polyethylene was -0.007. Although the polyethylene uses 1-hexene as a comonomer component, compared to the case of Example 1 using 1-butene as a comonomer,
The value of the correlation coefficient A is negatively large.

Further, the Charpy impact strength and bending ESCR values of the obtained polyethylene, and containers prepared by blow molding using the polyethylene, and the results of various physical properties thereof are shown in Example 2 of Table 2. The obtained container has a particle count of 58 particles / ml in water after one week, and is extremely excellent in cleanliness. Even more surprisingly, it can be seen that the polyethylene has significantly improved bending ESCR performance. Comparative Example 1 An ethylene / 1-butene copolymer was prepared by a slurry polymerization method in the same manner as in Example 1 except that a Ziegler-Natta type solid catalyst in which 2 wt% of titanium was supported on a magnesium chloride solid surface was used as a catalyst. I got

The obtained polyethylene powder was used in Example 1.
In the same manner as in the above, polyethylene pellets were formed using a twin screw extruder. As in Example 1, no neutralizing agent, antioxidant, and light stabilizer were added during kneading. The measured values of various physical properties of the obtained polyethylene are shown in Comparative Example 1 of Table 1. The value of the correlation coefficient A between the elution temperature and the peak top molecular weight based on the CFC measurement of the obtained polyethylene was 0.021. The measurement results of various physical properties of the obtained polyethylene are shown in Comparative Example 1 of Table 2. (Comparative Example 2) Measurement results of various physical properties of an ethylene / 1-octene copolymer (trade name: Affinity HF1030) obtained by solution polymerization commercially available from Dow Chemical Company are shown in Comparative Examples 2 of Tables 1 and 2. .

Comparative Example 3 The same procedure as in Example 1 was repeated except that a supported catalyst comprising a combination of a bis (cyclopentadienyl) zirconium-type metallocene catalyst and alumoxane was used as a catalyst. A 1-butene copolymer was obtained. The obtained polyethylene powder was formed into polyethylene pellets using a twin-screw extruder in the same manner as in Example 1. As in Example 1, no neutralizing agent, antioxidant, and light stabilizer were added during kneading. The measured values of various physical properties of the obtained polyethylene are shown in Comparative Example 3 in Table 1. The value of the correlation coefficient A between the elution temperature and the peak top molecular weight based on the CFC measurement of the obtained polyethylene was 0.005.

The measurement results of various physical properties of the obtained polyethylene are shown in Comparative Example 3 in Table 2. (Example 3) Example 1 Ethylene-1-butene copolymer used as the inner layer, the high-density polyethylene as the outer layer (Asahi Chemical Industry Co., Ltd. B870, I _2: 0.35g /
10 min, density: 0.960 g / cm ³ ), inner layer thickness 0.5 mm, outer layer thickness 1.0 mm, container capacity 500 m using a multilayer blow molding machine (manufactured by Placo).
1 container was prepared. The results of examining various physical properties of the obtained multilayer blown container are shown in Example 3 of Table 2. The obtained container has a particle count of 55 particles / ml in water after one week, and is extremely excellent in cleanliness. (Comparative Example 4) A multilayer blow container was produced in the same manner as in Example 3 except that the ethylene / 1-butene copolymer used in Comparative Example 1 was used as an inner layer. The results of examining various physical properties of the obtained multilayer blown container are shown in Comparative Example 4 in Table 2.

[0070]

[Table 1]

[0071]

[Table 2] FIG. 1 shows an ethylene homopolymer (b) used as a material for the container of the present invention, an ethylene homopolymer (a) obtained by a conventional Ziegler-Natta type catalyst, and a commonly used bis (cyclopentane). FIG. 3 is a graph showing the relationship between the density of ethylene homopolymer (c) obtained from a metallocene catalyst of the (dienyl) zirconium type and I ₂ . According to this, it is understood that the ethylene homopolymer (b) according to the present invention has a higher density than the ethylene homopolymer (c) obtained from an ordinary metallocene catalyst and is suitable as a material for a highly rigid container.

[0072]

The container for high-purity chemicals made of polyethylene according to the present invention has an extremely high degree of cleanliness, and furthermore has high rigidity and ESC.
Because of its excellent R and impact resistance, it is suitable as a container for storing high-purity reagents for industrial or medical use.

Further, the demand for clean polyethylene containers has been increasing more and more in recent years due to the tendency toward no additives, and suitable containers for satisfying the needs, for example, general food containers. Can be used.

[Brief description of the drawings]

FIG. 1 shows an ethylene homopolymer (b) used as a material for the container of the present invention, an ethylene homopolymer (a) obtained by a conventional Ziegler-Natta type catalyst, and a commonly used bis (cyclopentadienyl). FIG. _{2 is} a graph showing the relationship between the density of ethylene homopolymer (c) obtained from a zirconium-type metallocene catalyst and I ₂ .

Claims (7)

[Claims] 1. An ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and (2) a load of 2.16 kg and a temperature of 19
Melt flow rate value (I ₂ ) under 0 ° C. condition is 0.05 g
/ 10 min or more and 50 g / 10 min or less,
(3) A density of 0.910 g / cm ³ or more and 0.975 g /
cm ³ or less, and (4) M determined by gel permeation chromatography (GPC) measurement.
w / Mn value is 3 or more and 6 or less; (5) melt flow rate ratio (MIR) is 16 or more and 30 or less;
In the correlation of molecular weight-elution temperature-elution amount determined by cross fractionation measurement (CFC) between the temperature-elution fractionation and gel permeation chromatography, the elution temperature (Ti / ° C) expressed by the following equation (1) ) And the least squares approximation linear relational expression of the maximum molecular weight (Mmax (Ti)) of the eluted component at the elution temperature, Equation (1): log (Mmax (Ti)) = A * Ti + C (1) In the above formula (1), A and C are constants, and the constant A is a polyethylene satisfying the following relational expression (2): -0.5 ≦ A ≦ 0.01 (2) Container for high purity chemicals. 2. The polyethylene, wherein the value of A in the above formula (1) satisfies the following relational formula (3): ## EQU3 ## -0.4 ≦ A ≦ −0.001 (3) The container according to claim 1, wherein: 3. The container according to claim 1, wherein the comonomer used for the polyethylene is one of 1-pentene, 1-hexene, and 1-octene. 4. The container according to claim 1, wherein the polyethylene is a polyethylene polymerized by a slurry polymerization method using a supported-type single-site catalyst. 5. The polyethylene, wherein the ratio of the amount of elution at 80 ° C. or lower to the total amount of elution in the CFC measurement is 10 watts.
The container according to any one of claims 1 to 4, wherein the content is not more than t%. 6. The periodic table No. 4 contained in polyethylene.
The container according to any one of claims 1 to 5, wherein the content of the group III transition metal is 10 ppm or less. 7. The method according to claim 1, wherein the content of each of the neutralizing agent, antioxidant, and light stabilizer determined in the polyethylene by the liquid chromatography is 100 ppm or less. The container according to any one of the above.