JP2006299067A - Blow molded container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blow-molded container having a good medicine resistance and forming less fine particles into a medicine. <P>SOLUTION: This blow-molded container uses a polyethylene-based resin satisfying the following (A) to (D) conditions. (A) Having ≥890 kg/m<SP>3</SP>and ≤980 kg/m<SP>3</SP>density. (B) The number of ≥6C long chain branches is ≥0.01 and ≤3 based on 1,000 carbon atoms. (C) A melt strength (MS<SB>190</SB>) (mN) measured at 190°C and MFR (g/10 min, 190°C) under 2.16 kg load satisfy formula (1): MS<SB>190</SB>>22 x MFR<SP>-0.88</SP>---(1), and also the melt strength (MS<SB>160</SB>) (mN) measured at 160°C and MFR (g/10 min, 190°C) under 2.16 kg load satisfy formula (2): MS<SB>160</SB>>110-110xlog (MFR)---(2), and (D) The number of peaks of an endothermic curve obtained in a rising temperature measurement by a differential scanning type calorimeter is only one. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a blow container using a polyethylene resin. More specifically, in the semiconductor device industry field, the precision industrial parts field, etc., for example, suitable for high-purity chemical containers used for cleaning parts, especially when the skin of the product is good and filled with high-purity chemicals, The present invention relates to a blow container in which the mechanical strength is less decreased with time and the generation of fine particles in the chemical is small.

  In general, food containers such as detergent bottles, beverage bottles and edible oil bottles, large containers such as drum cans and industrial cans, and blow containers such as kerosene cans and fuel containers such as gasoline tanks are manufactured by a hollow molding method. In the hollow molding method, the resin is melted by an extruder and extruded into a cylindrical parison, and the parison is expanded and deformed by blowing a pressurized gas from a blow pin with the extruded parison sandwiched between molds. It is cooled after being shaped into the cavity shape. These hollow molding methods can be widely applied to hollow molded products such as bottles, gasoline tanks with complex shapes, drum cans, and panel-shaped molded products. It is widely used because the molding cost is low.

  The demand for blow containers, particularly high-purity chemical containers, is rapidly increasing with the recent remarkable development of the electronics industry. High-purity chemicals are used as chemicals indispensable for the manufacture of electronic circuits such as large-scale and integrated LSIs. For example, sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, ammonium fluoride for wafer cleaning / etching, wiring / insulating film etching, jig cleaning, developer, resist dilution, resist stripping solution, drying, etc. , Hydrogen peroxide, isopropyl alcohol, xylene, TMAH (tetramethylammonium hydroxide), methanol, acetic acid, phosphoric acid, aqueous ammonia, PGMEA (propylene glycol methyl ether acetate), DMSO (dimethyl sulfoxide), NMP (N-methyl) 2-pyrrolidone), ECA (ethyl carbamate), ethyl lactate and the like are used. Conventionally, polyethylene resins have been used as container materials for these high-purity chemicals in terms of chemical resistance, impact resistance, price, and the like. However, in containers made of polyethylene, fine particles, which are impurities, leached from the container into the chemical, often during storage and storage of high-purity chemicals, impairing the purity of the chemicals and reducing the mechanical strength of the containers over time. There was a thing. As a method for solving this problem, a method for controlling the kind and amount of additive component to be blended with polyethylene (for example, refer to Patent Document 1), molecular weight distribution of raw material polyethylene and content of wax component A control method (see, for example, Patent Document 2) is known.

  However, the polymerization catalyst residues and wax components in polyethylene or low-density low molecular weight components are essentially dependent on the polymerization catalyst and the polymerization process, so the generation of fine particles based on these factors is reduced. In order to achieve this, there is a limit to improvement by structural control such as double-layering of containers and blending control of additives, and it is necessary to improve the raw material polyethylene itself.

  In addition, when a large product is hollow-molded, a phenomenon that the parison hangs down due to its own weight (drawdown) tends to occur. In order to reduce this drawdown, it is necessary to use a resin having a sufficiently high melt viscosity and melt tension. Conventionally, a method of increasing the molecular weight has been taken to improve the drawdown resistance of polyethylene, but the melt viscosity becomes high, the extrusion characteristics (extrusion amount, parison surface state) deteriorate, and the parison fusion property is poor. Therefore, there is a problem that the pinch-off shape is deteriorated. As a method for solving this problem, a multistage polymerization method (for example, see Patent Document 3), a method for adding a crosslinking agent (for example, see Patent Document 4), and mixing two-component polyethylene at a specific ratio. A method (see, for example, Patent Document 5) is known.

  In recent years, instead of an accumulator type molding machine conventionally used in large hollow molding machines, a continuous extrusion type hollow molding machine with few staying parts has begun to be used. Compared to the accumulator method, a continuous extrusion type hollow molding machine takes a long time to extrude the parison, easily causes the parison to be drawn down, and is required to have a resin having more excellent draw-down resistance. For this reason, the polyethylene improved by the above conventional method or the like has insufficient drawdown resistance to obtain a large blow product.

JP 7-330074 A Japanese Patent Laid-Open No. 8-113678 JP-A-55-152735 Japanese Patent Publication No. 2-52654 JP-A-6-299909

  An object of the present invention is to provide a blow container having improved product appearance, chemical resistance and cleanliness, which are disadvantages of conventional polyethylene blow containers, and capable of being enlarged.

The present invention has been found as a result of intensive studies on the above-described object. That is, this invention relates to the blow container characterized by consisting of the polyethylene-type resin which satisfy | fills the requirements of following (A)-(D).
(A) The density is 890 kg / m ³ or more and 980 kg / m ³ or less,
(B) The number of long-chain branches having 6 or more carbon atoms is 0.01 to 3 per 1,000 carbon atoms,
(C) Melt tension (MS ₁₉₀ ) (mN) measured at 190 ° C. and MFR (g / 10 min, 190 ° C.) with a load of 2.16 kg are represented by the following formula (1)
MS ₁₉₀ > 22 × MFR ^−0.88 (1)
The melt tension (MS ₁₆₀ ) (mN) measured at 160 ° C. and the MFR (g / 10 min, 190 ° C.) with a load of 2.16 kg satisfy the following formula (2),
MS ₁₆₀ > 110-110 × log (MFR) (2)
(D) There is one peak of the endothermic curve obtained in the temperature rise measurement by the differential scanning calorimeter. The present invention will be described in detail below.

Density of the polyethylene resin constituting the blow molded container of the present invention, a value measured by a density gradient tube method in conformity with JIS K6922-1 (1997), is 890 kg / ^{m 3} or more 980 kg / ^{m 3} or less. If it is less than 890 kg / m ³ , chemical resistance may decrease because components that are likely to be dissolved in the chemical increase, and if it exceeds 980 kg / m ³ , stress cracking resistance and chemical resistance may decrease.

The weight-average molecular weight (M _w ) in terms of linear polyethylene of the polyethylene resin constituting the blow container of the present invention is 10,000 or more and 1,000,000 or less, preferably 20,000 or more and 700,000 or less. More preferably, it is 25,000 or more and 300,000 or less. When _Mw is less than 10,000, the melt tension becomes too small and the drawdown is severe and molding cannot be performed. If it exceeds 1,000,000, the melt viscosity is too high and the extrusion load is large, and the appearance (surface skin) of the blow container may be impaired.

  The MFR at 190 ° C. and a load of 2.16 kg of the polyethylene resin constituting the blow container of the present invention is 0.005 to 10 g / 10 minutes, preferably 0.05 to 5 g / 10 minutes. If it is less than 0.005 g / 10 minutes, the melt viscosity is too high and the extrusion load is large, and the appearance (surface skin) of the blow container may be impaired. If it exceeds 10 g / 10 minutes, the melt tension becomes too small, and the drawdown cannot be severely molded.

The number of long-chain branches of the polyethylene resin constituting the blow container of the present invention is 0.01 or more and 1,000 or less per 1,000 carbon atoms. If the number is less than 0.01, it is extremely difficult to perform hollow molding, and thus there is a possibility that a blow container cannot be obtained. Moreover, when it exceeds three, there exists a possibility that an ethylene-type resin layer may become a blow container inferior in intensity | strength. The number of long-chain branches is the number of branches of hexyl groups or more (6 or more carbon atoms) detected by ¹³ C-NMR measurement.

The melt tension (MS ₁₉₀ ) (mN) measured at 190 ° C. and the MFR (g / 10 min, 190 ° C.) with a load of 2.16 kg of the polyethylene resin constituting the blow container of the present invention are expressed by the following formula (1).
MS ₁₉₀ > 22 × MFR ^−0.88 (1)
And preferably the following formula (1 ′)
MS ₁₉₀ > 30 × MFR ^−0.88 (1 ′)
More preferably, the following formula (1 ″)
MS ₁₉₀ > 5 + 30 × MFR ^−0.88 (1 ″)
It is in the relationship shown by. When the formula (1) is not satisfied, the melt tension becomes low and it becomes extremely difficult to perform hollow molding, so there is a possibility that a blow container cannot be obtained.

Further, the melt tension (MS ₁₆₀ ) (mN) measured at 160 ° C. and the MFR (g / 10 min, 190 ° C.) with a load of 2.16 kg of the polyethylene resin constituting the blow container of the present invention are expressed by the following formula (2 )
MS ₁₆₀ > 110-110 × log (MFR) (2)
And preferably the following formula (2 ′)
MS ₁₆₀ > 130-110 × log (MFR) (2 ′)
More preferably, the following formula (2 ″)
MS ₁₆₀ > 150-110 × log (MFR) (2 ″)
It is in the relationship shown by. When the formula (2) is not satisfied, it is extremely difficult to perform hollow molding, and thus there is a possibility that a blow container cannot be obtained.

  The polyethylene resin constituting the blow container of the present invention has one endothermic curve peak obtained in the temperature rise measurement by a differential scanning calorimeter (DSC), and the blow container obtained thereby is elastic. The temperature dependence of the rate is small and the heat resistance is excellent. The endothermic curve is obtained by inserting 5 to 10 mg of sample into an aluminum pan and raising the temperature with DSC. Note that the temperature rise measurement is performed by previously leaving at 230 ° C. for 3 minutes, then lowering the temperature to −10 ° C. at 10 ° C./min, and then raising the temperature to 150 ° C. at a rate of 10 ° C./min .

The polyethylene resin constituting the blow container of the present invention has a shrinkage factor (g ′ value) evaluated by gel permeation chromatography (GPC) / intrinsic viscometer of 0.1 or more and less than 0.9, further 0 It is preferable that the ratio is 1 or more and 0.7 or less, which reduces the draw down when the polyethylene resin is hollow-molded, so that a large blow container can be molded. The shrinkage factor (g ′ value) in the present invention is a parameter representing the degree of long-chain branching, and the intrinsic viscosity of the polyethylene-based resin at an absolute molecular weight three times the weight average molecular weight (M _w ) is completely different from the branching. It is the ratio of the intrinsic viscosity at the same molecular weight of the non-high density polyethylene (abbreviated as HDPE). Further, the relationship between the g ′ value and the contraction factor (g value) evaluated by the GPC / light scatterometer is preferably the formula (3), more preferably the formula (3 ′). As a result, the yield of the blow container is further reduced. In addition, g value is a ratio of the root mean square of the inertial radius of this polyethylene-type resin in the absolute molecular weight 3 times _Mw , and the mean square of the inertial radius in the same molecular weight of HDPE without a branch.

0.2 <log (g ′) / log (g) <1.3 (3)
0.5 <log (g ′) / log (g) <1.0 (3 ′)
Further, between the g value in an absolute molecular weight three times the _{M w (g 3M)} and g values of the absolute molecular weight of 1 × _{M w (g M),} formula (4), preferably of formula (4 ') More preferably, the relationship represented by the formula (4 ″) is desirable in order to reduce the drawdown.

0 <g _3M / g _M ≦ 1 (4)
0 <g _3M / g _M ≦ 0.9 (4 ′)
0 <g _3M / g _M ≦ 0.8 (4 ″)
The polyethylene resin constituting the blow container of the present invention has an ethylene polymer having a vinyl group at the terminal obtained by polymerizing ethylene, or a terminal obtained by copolymerizing ethylene and an olefin having 3 or more carbon atoms. An ethylene copolymer having a vinyl group,
(E) M _n is 2,000 or more,
(F) It is desirable to be obtained by polymerizing ethylene and optionally an olefin having 3 or more carbon atoms in the presence of a macromonomer having M _w / M _n of 2 or more and 5 or less. The macromonomer is an olefin polymer having a vinyl group at the terminal, preferably an ethylene polymer having a vinyl group at the terminal obtained by polymerizing ethylene, or copolymerizing ethylene and an olefin having 3 or more carbon atoms. Is an ethylene copolymer having a vinyl group at the terminal, and more preferably, long-chain branches (ie, detected by ¹³ C-NMR measurement) among branches other than those derived from olefins having 3 or more carbon atoms. A linear ethylene polymer or linear ethylene copolymer having a vinyl group at the terminal, which is less than 0.01 per 1,000 main chain methylene carbon atoms.

  Examples of the olefin having 3 or more carbon atoms include propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, α-olefin such as vinylcycloalkane, norbornene, Examples include cyclic olefins such as norbornadiene, dienes such as butadiene or 1,4-hexadiene, and styrene. Two or more of these olefins can be mixed and used.

When an ethylene polymer having a vinyl group at the terminal or an ethylene copolymer having a vinyl group at the terminal is used as the macromonomer, the number average molecular weight (M _n ) in terms of linear polyethylene is 2,000 or more. , Preferably it is 5,000 or more, More preferably, it is 10,000 or more. The weight average molecular weight (M _w ) in terms of linear polyethylene is 4,000 or more, preferably 10,000 or more, more preferably more than 15,000. The ratio of the weight average molecular weight (M _w ) to M _n (M _w / M _n ) is 2 or more and 5 or less, preferably 2 or more and 4 or less, more preferably 2 or more and 3.5 or less. . The following general formula (5)
Z = [X / (X + Y)] × 2 (5)
(Where X is the number of vinyl ends per 1,000 main chain methylene carbons of the macromonomer, and Y is the number of saturated ends per 1,000 main chain methylene carbons of the macromonomer.)
The ratio (Z) between the number of vinyl ends and the number of saturated ends represented by is from 0.25 to 1, preferably from 0.50 to 1. X and Y are determined by ¹ H-NMR, ¹³ C-NMR, FT-IR, or the like. For example, in ¹³ C-NMR, the presence and amount of vinyl end can be confirmed by peaks at 114 ppm and 139 ppm at the vinyl end and 32.3 ppm, 22.9 ppm and 14.1 ppm at the saturated end.

  The production method of the macromonomer in the present invention is not particularly limited, but when producing an ethylene polymer having a vinyl group at the terminal or an ethylene copolymer having a vinyl group at the terminal as the macromonomer, for example, Group 3 of the periodic table A method of polymerizing ethylene using a catalyst containing a metallocene compound containing a transition metal selected from Group 4, Group 5 and Group 6 as a main component can be used. Examples of the cocatalyst include organoaluminum compounds, proton acid salts, Lewis acid salts, metal salts, Lewis acids and clay minerals.

  The polyethylene resin constituting the blow container of the present invention uses, for example, a catalyst containing, as a main component, a metallocene compound containing a transition metal selected from Group 3, Group 4, Group 5 and Group 6 of the periodic table. Obtained by polymerizing ethylene and optionally an olefin having 3 or more carbon atoms in the presence of a macromonomer. Moreover, a cocatalyst can be used similarly to manufacture of a macromonomer.

  The polymerization temperature is in the range of -70 to 300 ° C, preferably 0 to 250 ° C, more preferably 20 to 150 ° C. The ethylene partial pressure is in the range of 0.001 to 300 MPa, preferably 0.005 to 50 MPa, and more preferably 0.01 to 10 MPa. Further, hydrogen may be present as a molecular weight regulator in the polymerization system.

  In the present invention, when ethylene and an olefin having 3 or more carbon atoms are polymerized in the presence of a macromonomer, the ethylene / olefin having 3 or more carbon atoms (molar ratio) is 1 to 200, preferably 3 to 100, and more preferably. 5 to 50 can be used.

  Polyethylene resin constituting the blow container of the present invention is not added, or used for polyolefins, such as antioxidants, weathering stabilizers, antistatic agents, lubricants, antiblocking agents, organic / inorganic pigments, etc. as necessary Additives to be added may be added. The method of mixing the above-mentioned additives in the resin is not particularly limited. For example, a method of directly adding in the pellet granulation step after polymerization, or a high concentration master batch is prepared in advance, Examples thereof include a method of dry blending at the time of molding.

  The production method of the blow container of the present invention is not particularly limited, but there are an accumulator type and continuous extrusion type extrusion blow molding method, an injection blow molding method, an extrusion stretch blow molding method, an injection stretch blow molding method and the like. Can be mentioned. Examples of the parison method include a cold parison method and a hot parison method, and are not particularly limited. For example, the polyethylene resin of the present invention is put into a blow molding machine (made by Placo) having a 65 mmφ extrusion screw set at 200 ° C., a parison is extruded at a screw rotation speed of 20 rpm, and a mold set at 25 ° C. is used. It is obtained by sandwiching and blowing air from a blow pin and cooling for 18 seconds.

  Moreover, when using the blow container of this invention as a high purity chemical | medical agent container, it can be made into a single layer or a multilayer. In this case, the constitution of the layer is not particularly limited, but it is effective to use the present polyethylene resin for the innermost layer.

  The blow container of the present invention is suitable for cleaning and etching of parts in the field of semiconductor devices and precision industrial parts, etc., as well as a container of a high purity solvent required for medical use and food use, and a large blow container of 50 L or more. Used.

  The blow container of the present invention has a better skin than conventional polyethylene containers, and when filled with high-purity chemicals, it has excellent chemical properties and can stably maintain its mechanical strength for a long period of time. In the semiconductor device field, the precision industrial parts field, etc., it is suitably used for a container of a solvent having a high purity and a large container required for medical use and food, etc., as well as cleaning and etching of parts.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

  Preparation of modified hectorite, preparation of a catalyst for producing a macromonomer, production of a macromonomer, production of polyethylene and solvent purification were all carried out under an inert gas atmosphere. As the preparation of modified hectorite, the preparation of a catalyst for producing a macromonomer, the production of a macromonomer, the solvent used for the production of polyethylene, all of the solvents previously purified, dried and deoxygenated in a known manner were used. Diphenylsilanediylbis (cyclopentadienyl) zirconium dichloride and diphenylmethylene (1-cyclopentadienyl) (2,7-di-t-butyl-9-fluorenyl) zirconium dichloride were synthesized and identified by known methods. Was used. A hexane solution (0.714M) of triisobutylaluminum was manufactured by Tosoh Finechem Corporation.

  Furthermore, various physical properties of the polyethylene resins in Examples and Comparative Examples were measured by the methods shown below.

-Molecular weight and molecular weight distribution-
The weight average molecular weight (M _w ) and number average molecular weight (M _n ) were measured by gel permeation chromatography (GPC). Tosoh Co., Ltd. HLC-8121GPC / HT is used as the GPC device, Tosoh Co., Ltd. TSKgel GMHhr-H (20) HT is used as the column, the column temperature is set to 140 ° C., and 1 is used as the eluent. The measurement was performed using 2,4-trichlorobenzene. A measurement sample was prepared at a concentration of 1.0 mg / mL, and 0.3 mL was injected and measured. The calibration curve of molecular weight is calibrated using a polystyrene sample having a known molecular weight. In addition, _Mw and _Mn were calculated | required as a value of linear polyethylene conversion.

-Contraction factor (g 'value)-
The shrinkage factor (g ′ value) is the [η] at 3 times the absolute molecular weight of _Mw determined by the method of measuring [η] of polyethylene resin fractionated by GPC, at the same molecular weight of HDPE without any branching. The value divided by [η]. Tosoh Co., Ltd. HLC-8121GPC / HT is used as the GPC apparatus, Tosoh Co., Ltd. TSKgel GMHhr-H (20) HT is used as the column, the column temperature is set to 145 ° C., and 1 is used as the eluent. Measurement was performed using 2,4-trichlorobenzene. A measurement sample was prepared at a concentration of 2.0 mg / mL, and 0.3 mL was injected and measured. As a viscometer, a capillary differential pressure viscometer 210R + manufactured by Viscotek was used.

~ Shrink factor (g value) ~
The shrinkage factor (g value) was determined by a method of measuring the radius of inertia of a polyethylene resin fractionated by GPC by light scattering. This is a value obtained by dividing the root mean square of the radius of inertia at an absolute molecular weight 3 times _Mw of the polyethylene resin used in the resin cap of the present invention by the root mean square of the same molecular weight of HDPE having no branches. As the light scattering detector, a multi-angle light scattering detector DAWV EOS manufactured by Wyatt Technology was used, and the wavelength of 690 nm was 29.5 °, 33.3 °, 39.0 °, 44.8 °, 50.7. °, 57.5 °, 64.4 °, 72.3 °, 81.1 °, 90.0 °, 98.9 °, 107.7 °, 116.6 °, 125.4 °, 133.2 Measurements were made at detection angles of °, 140.0 °, and 145.8 °.

~ Z value ~
The terminal structure of a macromonomer such as a vinyl terminal or a saturated terminal was measured by ¹³ C-NMR using a JNM-ECA400 type nuclear magnetic resonance apparatus manufactured by JEOL Ltd. The solvent is tetrachloroethane -d _2. The number of vinyl ends was determined from the average value of peaks at 114 ppm and 139 ppm as the number per 1,000 main chain methylene carbons (chemical shift: 30 ppm). Similarly, the number of saturated terminals was determined from the average value of peaks at 32.3 ppm, 22.9 ppm, and 14.1 ppm. From this vinyl terminal number (X) and saturated terminal number (Y), Z = [X / (X + Y)] × 2 was determined.

~density~
The density was measured by a density gradient tube method in accordance with JIS K6922-1 (1997).

~ MFR ~
MFR was measured at 190 ° C. under a load of 2.16 kg in accordance with JIS K6922-1 (1997).

~ HLMFR ~
HLMFR was measured at 190 ° C. under a load of 21.6 kg in accordance with JIS K6922-1 (1997). It measured about the polyethylene-type resin which MFR is too low and cannot be measured.

~ Number of long chain branches ~
The number of long chain branches of the polyethylene resin was measured by ¹³ C-NMR using a JNM-GSX270 type nuclear magnetic resonance apparatus manufactured by JEOL Ltd.

~ Melting tension (MS) ~
The polyethylene resin used for the measurement of melt tension (MS) is pre-added with 1,500 ppm Irganox 1010 ^TM (manufactured by Ciba Specialty Chemicals) and 1,500 ppm Irgafos 168 ^TM (manufactured by Ciba Specialty Chemicals) as heat stabilizers. Then, using an internal mixer (trade name: Labo Plast Mill, manufactured by Toyo Seiki Seisakusho Co., Ltd.), kneaded for 3 minutes at 190 ° C. and 30 rpm in a nitrogen stream. The melt tension (MS) is a capillary viscometer (Toyo Seiki Seisakusho, trade name: Capillograph) with a barrel diameter of 9.55 mm, a length (L) of 8 mm, a diameter (D) of 2.095 mm, and an inflow angle of 90 °. A die was mounted and measured. For MS, the temperature was set to 160 ° C. or 190 ° C., the piston lowering speed was set to 10 mm / min, the stretch ratio was set to 47, and the load (mN) required for take-up was MS.

~ Number of endothermic peaks ~
Measurement was performed using DSC (trade name: DSC-7, manufactured by Perkin Elmer). 5-10 mg of polyethylene-based resin is inserted into an aluminum pan, placed on the DSC, then heated to 230 ° C. at a temperature increase rate of 80 ° C./min, and left at 230 ° C. for 3 minutes. Thereafter, the temperature is cooled to −10 ° C. at a rate of temperature decrease of 10 ° C./min, and the temperature is increased / decreased from −10 ° C. to 150 ° C. at a rate of temperature increase of 10 ° C./min. The number of endothermic curves observed at the time of temperature increase was evaluated.

~ 100L container molding and its evaluation ~
Using a blow molding machine (manufactured by Nippon Steel Works) having a 115 mmφ extrusion screw, a drum having a cylinder temperature of 220 to 230 ° C., a thickness of 5 mm, and a container volume of 100 L was molded, and moldability and drop strength were measured.

~ Moldability ~
Those that can be molded by the above molding were marked with ◯, and those that could not be molded were marked with ×.

~ Drop strength ~
The 100L container obtained by the above molding was filled with the following chemicals, left at 50 ° C. for 1 month, then taken out, washed with water, then filled with water until it was full and sealed. Thereafter, the container was dropped vertically from a height of 3 m with the bottom of the container down, and a drop test of 10 containers was performed. The following chemicals were used. The case where no crack was observed by visual observation was marked with ○, and the case where crack was generated even with one container was marked with ×.

Hydrogen peroxide solution: Mitsubishi Gas Chemical Co., Ltd. Special grade reagent hydrogen peroxide solution (31%)
Hydrofluoric acid: Special grade reagent hydrofluoric acid (46%) manufactured by Kishida Chemical Co., Ltd.
Sulfuric acid: Wako Pure Chemical Industries special grade sulfuric acid (98%)
-Molding of 500mL container and its evaluation-
Using a three-type three-layer blow molding machine (Placo) with a 65 mmφ extrusion screw, a 0.2 μm filter is attached to the blowing air port, the cylinder temperature is 160 to 180 ° C., the thickness is 1.5 mm, and the container A container with a volume of 500 mL was molded, and the surface roughness and the number of fine particles were measured.

~ Surface roughness of molded parts ~
The surface roughness Ra value (μm) on the inside of the container obtained by the above molding was measured using a digital microscope (Ultra Deep Shape Measurement Microscope VK-8550 manufactured by Keyence Corporation).

-Measurement of the number of fine particles-
The container obtained by the above molding was thoroughly washed with the following chemicals filtered through a 0.1 μm filter, and then filled with chemicals. This was left standing at 40 ° C. for a certain period, and then the number of fine particles of 0.5 μm or more was measured with a liquid fine particle counter series 4100 manufactured by HIAC / ROYCO. All operations were performed in a Class 1000 clean room.

Pure water Hydrogen peroxide water: Mitsubishi Gas Chemical Co., Ltd. Special grade reagent hydrogen peroxide water (31%)
Hydrofluoric acid: Special grade reagent hydrofluoric acid (46%) manufactured by Kishida Chemical Co., Ltd.
Sulfuric acid: Wako Pure Chemical Industries special grade sulfuric acid (98%)
Example 1
[Preparation of modified hectorite]
After adding 60 mL of ethanol and 2.0 mL of 37% concentrated hydrochloric acid to 60 mL of water, 6.55 g (0.022 mol) of N, N-dimethyloctadecylamine was added to the resulting solution and heated to 60 ° C. An N, N-dimethyloctadecylamine hydrochloride solution was prepared. To this solution was added 20 g of hectorite. The suspension was stirred at 60 ° C. for 3 hours, the supernatant was removed, and then washed with 1 L of 60 ° C. water. Then, it dried at 60 degreeC and 10 < ^-3 > torr for 24 hours, and the modified | denatured hectorite with an average particle diameter of 5.2 micrometers was obtained by grind | pulverizing with a jet mill. As a result of elemental analysis, the amount of ions per gram of modified hectorite was 0.85 mmol.

[Preparation of catalyst for macromonomer production]
8.0 g of the above modified hectorite is suspended in 29 mL of hexane, 46 mL of hexane solution of triisobutylaluminum (0.714M) is added, and the mixture is stirred for 1 hour at room temperature, whereby contact formation of the modified hectorite and triisobutylaluminum occurs. I got a thing. On the other hand, 151 mg (320 μmol) of diphenylsilanediylbis (cyclopentadienyl) zirconium dichloride dissolved in toluene was added and stirred overnight at room temperature to obtain a catalyst slurry (100 g / L).

[Manufacture of macromonomer]
To a 10 L autoclave, 6,000 mL of hexane and 5.0 mL of a hexane solution of triisobutylaluminum (0.714 mol / L) were introduced, and the internal temperature of the autoclave was raised to 85 ° C. To this autoclave, 0.88 mL of the catalyst slurry was added, and ethylene was introduced until the partial pressure reached 1.2 MPa to initiate polymerization. During the polymerization, ethylene was continuously introduced so that the partial pressure was kept at 1.2 MPa. The polymerization temperature was controlled at 85 ° C. 90 minutes after the start of the polymerization, the internal temperature was lowered to 50 ° C. and the internal pressure of the autoclave was depressurized to 0.1 MPa. Then, nitrogen was introduced into the autoclave until the pressure became 0.6 MPa, and the pressure was depressurized and replaced with nitrogen. This operation was repeated 5 times. _{Mn of} this macromonomer extracted from the autoclave was 14,400 and _Mw / _Mn was 3.02. When the terminal structure of the macromonomer was analyzed by ¹³ C-NMR, the number of vinyl terminals and the number of saturated terminals were determined. The ratio (Z) was Z = 0.65. In ¹³ C-NMR, 0.41 methyl branches per 1,000 carbon atoms and 0.96 ethyl branches per 1,000 carbon atoms were detected. Furthermore, long chain branching was not detected in ¹³ C-NMR.

[Production of polyethylene]
To a 10 L autoclave containing the macromonomer produced above, 1.4 mL of a hexane solution (0.714 mol / L) of triisobutylaluminum and diphenylmethylene (1-cyclopentadienyl) (2,7-di-t-butyl) -9-Fluorenyl) zirconium dichloride 7 μmol was introduced, and the internal temperature of the autoclave was raised to 60 ° C., followed by stirring for 30 minutes. Subsequently, after raising the internal temperature of the autoclave to 90 ° C., an ethylene / hydrogen mixed gas (1,000 ppm of hydrogen) was introduced until the partial pressure became 0.3 MPa to initiate polymerization. During the polymerization, an ethylene / hydrogen mixed gas was continuously introduced so that the partial pressure was maintained at 0.3 MPa. The polymerization temperature was controlled at 90 ° C. After 230 minutes from the start of polymerization, the internal pressure of the autoclave was released, and the contents were suction filtered. After drying, 1,008 g of polymer was obtained. The obtained polyethylene has an MFR of 0.3 g / 10 min, a density of 955 kg / m ³ , M _w of 13.1 × 10 ⁴ , M _w / M _n of 5.7, and the number of long chain branches of 0.03. / 1,000 carbon. Other physical properties are shown in Tables 1-3.

  The obtained polyethylene was molded into a 100 L drum using a blow molding machine (manufactured by Nippon Steel Works) having a 115 mmφ extrusion screw, and the moldability and the drop strength were measured.

  Next, the obtained polyethylene was molded into a container having a cylinder temperature of 160 to 180 ° C., a thickness of 1.5 mm, and a container volume of 500 mL using a three-kind three-layer blow molding machine (Placo). Using this container, the surface roughness and the number of fine particles were measured. The results are shown in Tables 4 to 5, and it is understood that the chemical resistance is excellent and the number of fine particles is small.

Example 2
The polyethylene obtained in Example 1 is used as the innermost layer, and high-density polyethylene (Nipolon Hard 8300A manufactured by Tosoh Corporation, MFR = 0.35 g / 10 min, density = 955 kg / m ³ ) is used for the intermediate layer and the outer layer. A container was molded in the same manner as in Example 1, and the moldability, surface roughness, drop test, and number of fine particles were measured. The results are shown in Tables 4 to 5, and it is understood that the chemical resistance is excellent and the number of fine particles is small.

Comparative Example 1
Using a commercially available high-density polyethylene (RS1000 manufactured by Nippon Polyethylene Co., Ltd., MFR = 0.1 g / 10 min, density 953 kg / m ³ ), a container is molded in the same manner as in Example 1, and moldability and surface roughness are obtained. A drop test was performed and the number of fine particles was measured. The results are shown in Tables 1 to 5, but the product appearance (surface skin) and chemical resistance are inferior.

Comparative Example 2
Using a commercially available high-density polyethylene (Nippon Polyethylene Co., Ltd. HB217R, HLMFR = 5 g / 10 min, density 946 kg / m ³ ), a container is molded in the same manner as in Example 1, and the moldability, surface roughness, drop The test and the number of fine particles were measured. The results are shown in Tables 1 to 5, but the product appearance (surface skin) and chemical resistance are inferior.

Claims (9)

A blow container comprising a polyethylene resin that satisfies the following requirements (A) to (D).
(A) The density is 890 kg / m ³ or more and 980 kg / m ³ or less,
(B) The number of long-chain branches having 6 or more carbon atoms is 0.01 to 3 per 1,000 carbon atoms,
(C) Melt tension (MS ₁₉₀ ) (mN) measured at 190 ° C. and MFR (g / 10 min, 190 ° C.) with a load of 2.16 kg are represented by the following formula (1)
MS ₁₉₀ > 22 × MFR ^−0.88 (1)
The melt tension (MS ₁₆₀ ) (mN) measured at 160 ° C. and the MFR (g / 10 min, 190 ° C.) with a load of 2.16 kg satisfy the following formula (2),
MS ₁₆₀ > 110-110 × log (MFR) (2)
(D) There is one peak of the endothermic curve obtained in temperature rise measurement with a differential scanning calorimeter. An ethylene polymer having a vinyl group at a terminal obtained by polymerizing ethylene, or an ethylene copolymer having a vinyl group at a terminal obtained by copolymerizing ethylene and an olefin having 3 or more carbon atoms;
(E) M _n is 2,000 or more,
(F) The polyethylene-based resin according to claim 1 obtained by polymerizing ethylene and optionally an olefin having 3 or more carbon atoms in the presence of a macromonomer having M _w / M _n of 2 or more and 5 or less. A blow container characterized by that. The blow container according to claim 1 or 2, wherein (A ') a polyethylene resin having a density of 940 kg / m ³ or more and 980 kg / m ³ or less is used. At least 1 type of resin layer consists of the polyethylene-type resin in any one of Claims 1-3, The multilayer blow container characterized by the above-mentioned. A high-purity chemical container comprising the polyethylene resin according to any one of claims 1 to 3. A high-purity chemical multilayer container comprising the polyethylene resin according to any one of claims 1 to 3. The high-purity chemical container according to any one of claims 5 to 6, wherein the high-purity chemical is hydrogen peroxide, hydrofluoric acid, or sulfuric acid. A large blow container having an internal volume of 50 L or more made of the polyethylene-based resin according to claim 1. A large-sized multilayer blow container having an internal volume of 50 L or more made of the polyethylene-based resin according to claim 1.