JPH0649287A - Ethylenic polymer composition - Google Patents

Abstract

PURPOSE:To provide an ethylenic polymer composition comprising three components consisting of specific ethylene homopolymers, specified ethylene-alpha- olefin copolymers, etc., wide in its mol.wt. distribution, and excellent in the balance between its melt elasticity, flow characteristics, etc. CONSTITUTION:The objective composition comprises (A) ultra-high mol.wt. ethylene homopolymer or ethylene-alpha-olefin copolymer having an intrinsic viscosity (eta1) of 9-45dl/g, a density (d) of 0.890-0.935g/cm<3>, (B) ethylene homopolymer having eta2 of 0.3-3.0dl/g, a (d2) of 0.890-0.980g/cm<3>, an area ratio (S1) of equation I between an area under the curved line in the elusion temperature range of >=90 deg.C and an area under the curved line in the elusion temperature range of 25-90 deg.C in the graph of the elusion temperature-elusion amount curved line, and an o-dichlorobenzene soluble content of <=W1wt.% of equation II at 25 deg.C, etc., and (C) an ethylene-alpha-3-18C olefin copolymer having eta2 of <1.2-9.0dl/g, an area ratio (S2) of equation III, and a soluble content (W2) of equation IV, the total amount of the components being 100wt.%, and has eta of 1.0-6.0dl/g, d of 0.890-0.970g/cm<3>, and an N-value of formula V of 1.7-3.0.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is excellent in melt elasticity (melt tension, die swell ratio, etc.), flow characteristics (processing characteristics, etc.), mechanical characteristics (impact resistance, tensile strength, etc.), and has an extremely high molecular weight distribution. With respect to a wide ethylene polymer composition,
In particular, it relates to an ethylene polymer composition suitable for large hollow molded products such as gasoline tanks and extruded products such as large diameter pipes because of its excellent flow properties and mechanical properties at low temperatures, and large melt tension and die swell ratio. .

[0002]

2. Description of the Related Art Heretofore, a method of broadening the molecular weight distribution of an ethylene / α-olefin copolymer has been reported for the purpose of improving flow characteristics (for example, JP-A-57-21409 and JP-B-63-47741). However, melt elasticity and mechanical properties, especially mechanical properties at low temperatures, are not improved by merely broadening the molecular weight distribution in this way, but rather greatly decrease. In addition, regarding the improvement of mechanical properties and flow properties, the short chain branching degree of the high molecular weight component of the ethylene / α-olefin copolymer consisting of the high molecular weight component and the low molecular weight component was specified and Attempts have been made to improve not only mechanical properties and fluidity but also environmental stress crack resistance (ESCR) by introducing a large number of branches (Japanese Patent Laid-Open No. 54-10044, Japanese Patent Publication No. 64-7096).
Issue). However, even in these cases, the mechanical properties, especially the mechanical properties at low temperature and the melt elasticity are not satisfactory. Further, in JP-A-2-305811,
For the purpose of improving impact resistance, ESCR, and pinch-off fusion bondability, a method of specifying the polymerization conditions of the catalyst and the two-stage polymerization has been proposed, but this method is slightly improved in terms of ESCR and melt elasticity. However, it is insufficient to improve the mechanical properties, especially at low temperatures. In addition, a polyethylene composition for blow molding, which has improved drawdown resistance, die swell and ESCR (Japanese Patent Laid-Open No. Sho 5)
9-89341, JP-A-60-20946, etc.)
Is disclosed, and a three-step polymerization method has been proposed as a method for improving the drawbacks of the two-step polymerization method (Japanese Patent Publication No. 59-1072).
4, JP-A Nos. 62-25105 and 62-25106.
No. 62-25107, No. 62-25108,
62-25109, etc.). Even in these cases, the improvement of the melt elasticity and the flow characteristics is still insufficient, and the mechanical characteristics are not improved especially at low temperatures.

[0003]

In view of the above points, the present invention is directed to melt elasticity (melt tension, die swell ratio, etc.),
An ethylene polymer composition that has an excellent balance of physical properties such as flow characteristics (processing characteristics) and mechanical characteristics (impact resistance, tensile strength, etc.), and has an extremely wide molecular weight distribution. It is an object of the present invention to provide a composition suitable for large hollow molded products such as gasoline tanks and extruded molded products such as large diameter pipes because of its excellent physical properties and large melt tension and die swell ratio.

[0004]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in view of the above-mentioned objects, the inventors have found that they are ultra-high molecular weight components, high molecular weight components and have a very wide distribution of short-chain branches between molecules. Ethylene / α-olefin copolymers and specific ethylene / α with extremely wide distribution of short chain branches between molecules
-By blending a low molecular weight component consisting of an olefin copolymer or an ethylene homopolymer having no short chain branching, excellent balance of various physical properties such as melt elasticity, flow properties and mechanical properties, especially flow properties and low temperature The present invention has been accomplished by finding that an ethylene polymer composition having excellent mechanical properties at the time is obtained. That is, the present invention includes (I)
Ultrahigh molecular weight ethylene homopolymers or ethylene / α-olefin copolymers 1 to 50 satisfying (a) and (b)
% By weight, (a) intrinsic viscosity (η ₁ ) 9 to 45 dl / g, (b) density (d ₁ ) 0.890 to 0.935 g / cm ³ , (II) (c) to
Ethylene homopolymer or ethylene / α that satisfies (f)
-Olefin copolymer 5 to 94% by weight, (c) intrinsic viscosity (η ₂ ) 0.3 to 3.0 dl / g, (d) density (d ₂ ) 0.890
˜0.980 g / cm ³ , (e) In the elution temperature-elution amount curve by the continuous temperature elution fractionation method, the ratio of the area Ib at the elution temperature of 25 to 90 ° C. to the area Ia under the curve at the elution temperature of 90 ° C. or more. S (Ib / Ia) is S ₁ or less calculated from the following equation, S ₁ = 20 η ₂ ⁻¹ exp [−50 (d ₂ −0.900)] (f) 25 ° C. ortho-dichlorobenzene soluble content W% by weight is W ₁ or less calculated from the formula, W ₁ = 100 η ₂ ^−0.5 exp [−50 η ₂ ^0.5 (d ₂ −0.900)], and (III) ethylene and carbon number 3 satisfying the following (g) to (j): 5 to 94% by weight of a copolymer of 18 to 18 with α-olefin, (g) intrinsic viscosity (η ₃ ) of 1.2 dl / g or more and less than 9.0 dl / g, (h) density (d ₃ ) of 0.9. 890 to 0.940 g / cm ³ , (i)
In the elution temperature-elution amount curve by the continuous temperature elution fractionation method, the ratio S (Ib / I) of the area Ib at the elution temperature of 25 to 90 ° C to the area Ia under the curve at the elution temperature of 90 ° C or more.
a) is S ₂ or less calculated from the following equation, S ₂ = 20η ₃ ⁻¹ exp [−50 (d ₃ −0.900)] (j) 25 ° C. ortho-dichlorobenzene soluble content W weight% is calculated from the following equation. that W ₂ or more, made of _{W 2 = 20exp (-η 3)} , and wherein component (I), the sum is 100% by weight of (II) and (III), of each component (I) ~ (III) A mixture having different intrinsic viscosities, each having an intrinsic viscosity of 1.0 to 6.0 dl / g and a density of 0.890.
The present invention provides an ethylene polymer composition having an N-value of 1.7 to 3.0 calculated from 0.970 g / cm ³ and the following formula.

[0005]

[Equation 2]

The details of the present invention will be described below. The ultrahigh molecular weight component (I) of the present invention is an ethylene homopolymer or an ethylene / α-olefin copolymer, and as the α-olefin of the copolymer, those having 3 to 18 carbon atoms are used. Particularly, those having 4 to 10 carbon atoms are preferable from the viewpoint of mechanical properties. Specifically, 1-butene, 1-pentene,
1-hexene, 4-methyl-1-pentene, 1-octene, 1-nonene, 1-decene and the like can be mentioned. Α-
Two or more olefins may be used in combination without any problem.

The above-mentioned ultrahigh molecular weight component (I), an ethylene homopolymer or an ethylene / α-olefin copolymer, is
(a) Intrinsic viscosity (η ₁ ) is 9 to 45 dl / g, preferably 10
It is preferably 40 dl / g, more preferably 12 to 40 dl / g. When η ₁ is less than 9 dl / g, the melt elasticity and mechanical properties of the obtained composition are poor, and when it is more than 45 dl / g, the molding processability is deteriorated, such as the surface roughness of the molded product and fish eyes. . The components (I) (b) Density (d ₁₎ is in the range of 0.890~0.935g / cm ^3, is preferably 0.890~0.930g / cm ³ is used. Those having d ₁ of less than 0.890 g / cm ³ are not preferable because they are difficult to produce and cause stickiness of the obtained composition. On the other hand, when d ₁ exceeds 0.935 g / cm ³ , the mechanical properties of the composition, particularly at low temperature, are deteriorated, which is not preferable.

The component (II) of the present invention is an ethylene homopolymer or an ethylene / α-olefin copolymer. As the α-olefin of the ethylene / α-olefin copolymer, those having 3 to 18 carbon atoms are used as in the case of the component (I), preferably 4 to 10 carbon atoms, and particularly 1- Butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-nonene, 1-
Decene and the like are preferable in terms of mechanical properties and the like. It should be noted that two or more α-olefins may be used in combination.

The intrinsic viscosity (η ₂ ) of component (II) (c) is in the range of 0.3 to 3.0 dl / g, preferably 0.6 to 3.0.
It is in the range of 0 dl / g. When η ₂ is less than 0.3 dl / g, the mechanical properties of the obtained composition, particularly at low temperature, are poor, and when it exceeds 3.0 dl / g, the flow properties are deteriorated, and therefore, in any case. Not preferable. The components (II) (d) Density (d ₂₎ is in the range of 0.890~0.980g / cm ^3, preferably in the range of 0.900~0.975g / cm ³ is used.
Those having d ₂ of less than 0.890 g / cm ³ are not preferable because they are difficult to produce and cause stickiness of the obtained composition. On the other hand, when it exceeds 0.980 g / cm ³ , not only is it difficult to produce, but also the mechanical properties of the obtained composition deteriorate, which is also not preferable.

The above regarding the component (II) used in the present invention
The condition (e) is that the high branching component containing many short chain branches dissolves in the solvent at a low temperature, but the low branching component containing few short chain branches does not dissolve in the solvent unless it is at a high temperature. , The branch distribution is quantitatively defined. That is, L. Wild et al.'S continuous elevated temperature elution fractionation method (Temperature Rising Elution Fract
ionation (TREF) ； Journal of Polymer Science: Polymer
r Physics Edition, Vol. 20, 441-455 (1982)), in the elution temperature-elution amount curve, between the area Ia under the curve at an elution temperature of 90 ° C or higher and the same area Ib at an elution temperature of 25 to 90 ° C. It is necessary for a specific relationship to be established, and in the present invention, the area ratio S = Ib / I shown in the schematic diagram of FIG.
The value of a must be less than or equal to S ₁ obtained from the following equation. S ₁ = 20 η ₂ ^-1 exp [−50 (d ₂ −0.900)] When the value of S exceeds S ₁ , the branch distribution becomes almost uniform, resulting in mechanical properties, especially at low temperature. The extremely effective high branching component is relatively decreased, which is not preferable.

Component (II) (f) 25 ° C. used in the present invention
The ortho-dichlorobenzene-soluble content is so low that the elution temperature is too low to be quantified by the continuous temperature-rising elution fractionation method described above.
It represents the amount of a component having an extremely large amount of branching, and needs to be a specific value corresponding to the intrinsic viscosity and the density. However, this also indicates the presence of a non-useful low molecular weight component, which should be eliminated as much as possible. For this purpose, the same soluble content W% by weight must be W ₁ or less obtained from the following equation. It is preferably W ₃ or less. W ₁ = 100 η ₂ ^-0.5 exp [−50 η ₂ ^0.5 (d ₂ −0.900)] W ₃ = 90 η ₂ ^−0.5 exp [−50 η ₂ ^0.5 (d ₂ −0.900)] When the value of W is W ₁ or more, it is extremely high. It shows that in addition to the components having a large amount of branching, there is a non-useful low-molecular weight component, resulting in poor mechanical properties, especially at low temperatures.

The ethylene / α-olefin copolymer of the component (III) of the present invention is a copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms as in the case of the components (I) and (II). And preferably having 4 to 10 carbon atoms in terms of mechanical properties and the like. Specific examples include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-nonene, 1-decene. It should be noted that two or more α-olefins may be used in combination.

The (g) intrinsic viscosity (η ₃ ) of the above component (III) is in the range of 1.2 dl / g or more and less than 9.0 dl / g, preferably 1.4 to 8.5 dl / g. More preferably 1.6 to 8.0
It is in the range of dl / g. When η ₃ is less than 1.2 dl / g, the melt elasticity and mechanical properties of the obtained composition are inferior, while 9.0 d
If it exceeds l / g, the molding processability will deteriorate, such as the surface roughness of the molded product and the generation of fish eyes.

The (h) density (d ₃ ) of the component (III) is 0.
Range is used 890~0.940g / cm ^3, preferably in the range of 0.900~0.935g / cm ^3. d ₃ is 0.8
If it is less than 90 g / cm ³ , it is not preferable because it is difficult to manufacture and causes stickiness of the obtained composition. On the other hand, when it exceeds 0.940 g / cm ³ , mechanical properties deteriorate.

The component (III) used in the present invention is the above-mentioned (i)
As shown in (e) of the component (II), the area ratio S of the elution temperature-elution amount curve in the continuous temperature rising elution fractionation method was
The value of = Ib / Ia must be S ₂ or less obtained from the following equation. S ₂ = 20 η ₃ ^-1 exp [−50 (d ₃ −0.900)] When the value of S exceeds S ₂ , the branch distribution becomes almost uniform, resulting in mechanical characteristics, especially at low temperature. The extremely effective high branching component is relatively decreased, which is not preferable.

Component (III) (j) 25 used in the present invention
As described above, since the elution temperature is too low, the ortho-dichlorobenzene-soluble component is a component having an extremely high degree of branching that cannot be quantified by the continuous temperature-rising elution fractionation method as described above, and therefore, the specific temperature is not less than a certain value. It is necessary to be. That is, the same soluble content W% by weight must be W ₂ or more obtained from the following equation. It is preferably W ₄ or more. W ₂ = 20exp (−η ₃ ) W ₄ = 22exp (−η ₃ ) If the value of W is less than W ₂ , the highly effective high branching component is too small for mechanical properties, especially at low temperatures. And is not preferable as described above.

The proportions of the components (I), (II) and (III) in the present invention are 1 to 50% by weight of the component (I), 5 to 94% by weight of the component (II) and 5 to 94 of the component (III). weight%
And preferably (I) 5 to 40% by weight, (I
I) 5 to 90% by weight and (III) 5 to 90% by weight, provided that the total amount of components (I), (II) and (III) is 1
It is 00% by weight, and these compounding ratios are selected according to the performance required for the composition. Among the above components, since the component (I) plays an important role in the present invention, it is preferable to select the blending ratio of the composition in consideration of the characteristics of the component (I). When the amount of the component (I) is less than 1% by weight, melt elasticity and mechanical properties, particularly mechanical properties at low temperature, are insufficient, while when it exceeds 50% by weight, flow properties become poor. In addition, from component (I) to component (IV)
It is essential that the intrinsic viscosities of are different from each other,
If this is not satisfied, the mechanical properties at low temperature, which is one of the objects of the present invention, cannot be improved.

The ethylene polymer composition of the present invention is obtained by blending the components (I), (II) and (III) as described above, and the intrinsic viscosity of the composition is 1.0 to 6.0 dl / g,
It is preferably 1.5 to 5.0 dl / g. Intrinsic viscosity is 1.0
If it is less than dl / g, the melt viscosity and mechanical properties, especially at low temperature, are insufficient, while if it exceeds 6.0 dl / g, the flow properties are poor, so both are not preferable. Density of the composition is 0.890~0.970g / cm ^3, preferably 0.900~0.970g / cm ^3.
If the density is less than 0.890 g / cm ^3, it is difficult to produce and the composition becomes sticky, and if it exceeds 0.970 g / cm ³ , the mechanical properties are low. Further, it is necessary that the N-value of the composition is 1.7 to 3.0, and preferably 1.7 to 2.8. When the N-value is less than 1.7, the high speed moldability is low, and when it exceeds 3.0, melt fracture tends to occur.

There is no particular limitation on the method for producing the ethylene polymer composition of the present invention. For example, after the components (I), (II) and (III) are each independently produced by one-step polymerization, they may be mixed by a known method, or by two-step or more multi-step polymerization, It may be produced by a known polymerization method. In the case of producing by the former mixing, a known method such as a method of kneading with a single-screw or twin-screw extruder or a Banbury mixer, or a solution mixing method can be used.

The latter method by multi-stage polymerization is one in which the polymerization is carried out using a plurality of reactors. For example, in the case of two-stage polymerization, the first stage reactor is charged with the component (I). An ethylene polymer composition is prepared by maintaining the polymerization conditions for production, maintaining the second stage reactor under the polymerization conditions of component (II), and continuously flowing the polymer produced in the first stage to the second stage. Can be manufactured. In this case, the components (I) and (II) may be produced in any reactor,
The number of stages is not particularly limited. In any of the above cases, the reaction form is not particularly limited, and the slurry method,
Various methods such as a gas phase method, a solution method and a high pressure ion method can be used.

The polymerization catalyst is also not particularly limited, and for example,
Any of a Ziegler type catalyst mainly composed of a transition metal such as titanium and / or vanadium, a Phillips type catalyst mainly composed of a chromium-based catalyst, a Kaminsky type catalyst mainly composed of a metallocene and the like can be used. Among the catalysts, a Ziegler type catalyst having a high activity, which is supported on a solid support, is particularly preferable, and the details thereof will be described below.

The highly active Ziegler type catalyst is an inorganic solid support such as magnesium metal, magnesium hydroxide, magnesium carbonate, magnesium oxide, various aluminas, silica, silica-alumina, magnesium chloride or the like, or magnesium and silicon, aluminum or calcium. Double salts containing selected elements, double oxides, hydrous carbonates, hydrous silicates, etc., and further these inorganic solid carriers are treated or reacted with oxygen-containing compounds, sulfur-containing compounds, hydrocarbons, halogen-containing substances. As a solid component, an inorganic solid carrier such as a metal oxide, a transition metal compound, for example, a metal halide such as titanium, vanadium, zirconium, or chromium supported thereon, an alkoxy halide, an oxide, or a halogenated oxide is used. , An organic compound of a Group I-IV metal, preferably Or Combinations of aluminum organometallic compounds of, or of these further α-
Pretreated by contacting with olefin, etc., and usually has a catalytic activity of 50 g-polymer / g-catalyst · hr · kg / cm ² -olefin pressure or higher, preferably 100 g-polymer / g-catalyst · hr · kg / cm ^2- Olefin pressure or higher. Among the above, a highly active Ziegler type catalyst containing magnesium halide is particularly preferable.

In the ethylene polymer composition of the present invention, other olefinic polymers, rubbers or the like, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, antistatic agents are included within the scope of the present invention. Well-known additives such as anti-fog agents, anti-blocking agents, processing aids, color pigments, cross-linking agents, foaming agents, inorganic / organic fillers, flame retardants and the like can be blended and used.

[0024]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto. First,
The test methods used in the present invention are shown. (1) Intrinsic viscosity [η] was measured in a decalin solution at 135 ° C. (2) Density Density gradient tube method (23
(° C). (3) Continuous temperature rising elution fractionation method (TREF) As described above, the method of L. Wild et al. Was followed. The details of the measuring method are as follows. [Measurement Method] 5 ml of an orthodichlorobenzene solution prepared by heating and dissolving the sample at 135 ° C. to a concentration of 0.05% by weight was injected into a 8.5 liter stainless steel column filled with Celite 545. After 4 ℃ / min
The sample is deposited on the surface of Celite by cooling to 25 ° C at a cooling rate of. Next, while ortho-dichlorobenzene is flown through this column at a constant rate of 1 ml / min, the temperature is raised at a constant rate of 50 ° C./hr to elute the samples sequentially. At this time, with respect to the sample eluted in the solvent, the absorption at a wave number of 2925 cm ⁻¹ of the asymmetric stretching vibration of methylene was detected by an infrared detector,
By recording, the relationship between the elution temperature and the elution amount, that is, the composition distribution is obtained. (4) Area ratio (S) by continuous temperature rising elution fractionation method As described above and in FIG. (5) Orthodichlorobenzene-soluble matter (W) at 25 ° C. 0.5 g of a sample was added to 20 ml of orthodichlorobenzene (O).
In DCB), heat at 135 ° C. for 2 hours to completely dissolve the sample and then cool to 25 ° C. in 2 hours. This solution was left overnight at 25 ° C, then filtered through a Teflon filter to collect the filtrate, and the absorption of the methylene asymmetric stretching vibration at a wave number of 2950 cm ^-1 was measured with an infrared spectrophotometer. The sample concentration in the filtrate is quantified by the calibration curve obtained. (6) N-value Using a Koka type flow tester (manufactured by Shimadzu Corporation), extruding from a die of 2 mmφ × 40 mm at a resin temperature of 210 ° C., and appearance at low test pressure of 20 kg / cm ² and high test pressure of 150 kg / cm ^2. The shear rate of is calculated and calculated by the following equation 3.

[Equation 3] (7) High load melt flow rate (HLMFR) Measured in accordance with JIS K6760. (Measurement temperature 190
(° C, load 21.6 kg) (8) Tensile yield strength (YTS) According to JIS K6760. (Pulling speed 50mm / mi
n, test piece thickness 2 mm) (9) Tensile impact value (TIS) Measured in accordance with ASTM D1822. (Test piece thickness 1.
5 mm) (10) Izod impact value (IIS) Based on JIS K7110, measured at -40 ° C by the following method. A sheet having a thickness of 3 mm is produced from the sample by pressing. The shape of the test piece is No. 2A. The sample is adjusted at 23 ° C. and humidity of 50% for 88 hours, held in a low temperature room controlled at −40 ° C. for about 3 hours, and then measured at −40 ° C. in the low temperature room. Five test pieces are prepared, and the average value of five measurements is used. (11) Melt tension (MT) Measured with a melt tension tester manufactured by Toyo Seiki Co., Ltd. (Measurement temperature: 190 ° C.) (12) Die swell ratio (DSR) A sample is extruded at a temperature of 210 ° C. using a high-performance flow tester, and the ratio between the strand diameter and the die inner diameter is determined.
The shear rate was measured at an extrusion rate corresponding to 100 sec ^-1 . (13) Critical shear rate (γc) It was measured by a capillary rheometer manufactured by INTESCO. (Measurement temperature 190 ° C.) (14) Environmental stress crack resistance (ESCR) The value of F ₅₀ of constant strain ESCR according to JIS K6760 is obtained.

[Production of Components (I), (II) and (III)] First, titanium tetrachloride is supported on a solid carrier containing anhydrous magnesium chloride as one component using a stirring reactor having an internal volume of 50 liters. 1 in a nitrogen atmosphere using the solid catalyst prepared above and a co-catalyst of triethylaluminum (TEA).
Stage polymerization was carried out to prepare polymer A1 and A2 of component (I) and polymer B1 to B3 of component (II). Table 1 shows the polymerization conditions and the physical properties of the obtained polymer.

[0026]

[Table 1]

Using a stirring type reactor having an internal volume of 70 liters and using the same catalyst system as described above, one-stage polymerization was continuously carried out under the polymerization conditions shown in Table 2 to obtain a polymer (C1) of component (III).
C3 was produced. At this time, the total polymerization pressure of the reactor is 8.8.
Polymerization was carried out while keeping the liquid volume at ˜9.2 kg / cm ² G and 50 liters. The results of evaluating the physical properties of these polymers are shown in Table 2.

[0028]

[Table 2]

Next, using an autoclave having an internal volume of 2 liters and using the same catalyst as described above, 1
Stage polymerization was carried out to produce polymers C4 to C7 of component (III). Table 3 shows the polymerization conditions and the physical properties of the obtained polymer.

[0030]

[Table 3]

[Preparation of Composition] Of the above-mentioned polymer, the component (I) and the component (II) were mixed and prepared by the solution mixing method under the following blending conditions. <Blend conditions> Atmosphere: Nitrogen Solvent: Xylene (4.5 liters) Sample amount: Total 200g Temperature: 200 ° C Time: 2 hours Deposition solvent: -20 ° C Methanol (8 liters) Cleaning solvent: Hexane Cleaning: Until xylene odor disappears Drying: From room temperature to 110 ° C Polymer recovery rate: Almost 100% Further, the above mixture and the polymer of the component (III) are placed under a nitrogen atmosphere, the total amount of the sample is 70 g, the rotation speed is 20 rpm, and the kneading time is Mixing was carried out for 7 minutes at a kneading temperature of 160 ° C. to obtain the compositions of Examples and Comparative Examples.

<Examples 1 to 6> Table 4 shows the blending ratios of the compositions of Examples and the evaluation results of the physical properties.

[0033]

[Table 4]

<Comparative Examples 1 to 6> Table 5 shows the blending ratios of the compositions of Comparative Examples and the evaluation results of the physical properties.

[0035]

[Table 5]

Next, FIG. 2 shows a schematic diagram in which the molecular weight is further added as a parameter to the elution temperature-elution amount curve by TREF shown in FIG. 1 and the elution amount is represented by contour lines.
In the figure, when the examples and the comparative examples are compared in the range where the molecular weight is 10,000 or more, for example, the composition of the example has a lower elution temperature in a region where the molecular weight is larger than that of the composition of the comparative example. It can be seen that the component, that is, the component having many short-chain branches (25 ° C. ortho-dichlorobenzene-soluble component) is contained in a larger amount. It is presumed that this component is the main factor for improving the mechanical properties and ESCR at low temperature of the composition of the present invention.

[0037]

The ethylene polymer composition of the present invention comprises a specific ethylene / α-olefin copolymer which is an ultra-high molecular weight component, a high molecular weight component and has an extremely wide distribution of short chain branches between molecules, and Obtained by blending a low molecular weight component consisting of a specific ethylene / α-olefin copolymer having a very wide short chain branch distribution between molecules or an ethylene homopolymer having no short chain branch, melt elasticity, flow characteristics, It is a composition having an extremely wide molecular weight distribution with excellent balance of mechanical properties and the like, and specifically has the following features. (1) Excellent mechanical properties at low temperature such as low temperature Izod impact value and cold resistance. (2) Since it has excellent melt elasticity such as melt tension and die swell ratio, and excellent flow characteristics such as critical shear rate,
Good moldability such as high-speed moldability. As a result of having the above-mentioned advantages, it is used for various films, sheets, pipes, hollow containers, various coating materials, foaming materials, etc., but since it has extremely excellent melt elasticity, it is a composition for large hollow containers such as gasoline tanks. Is useful as

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between an elution temperature and an elution amount by a continuous temperature rising elution fractionation method (TREF).

FIG. 2 is a contour map of elution temperature-molecular weight-elution amount of a composition. (A) Example 1, (b) Comparative Example 1

Claims (1)

[Claims] (I) 1 to 50% by weight of an ultrahigh molecular weight ethylene homopolymer or ethylene / α-olefin copolymer satisfying the following (a) and (b), (a) intrinsic viscosity (η ₁ ) 9-45 dl / g, (b) density (d ₁ ) 0.890-0.
935 g / cm ³ , (II) 5 to 94% by weight of an ethylene homopolymer or an ethylene / α-olefin copolymer satisfying the following (c) to (f), (c) intrinsic viscosity (η ₂ ) 0.3 ˜3.0 dl / g, (d) Density (d ₂ ) 0.890 to 0.980 g / cm ³ , (e) Elution temperature-elution amount curve by continuous temperature elution fractionation method Elution temperature 25 for area Ia under the curve
The ratio S (Ib / Ia) of the area Ib at ˜90 ° C. is less than or equal to S ₁ calculated from the following equation: S ₁ = 20η ₂ ⁻¹ exp [−50 (d ₂ −0.900)] (f) 25 ° C. Chlorobenzene soluble content W weight% is W ₁ or less calculated from the following formula, W ₁ = 100 η ₂ ^−0.5 exp [−50 η ₂ ^0.5 (d ₂ −0.900)], and (III) the following (g) to (j) ) And ethylene having 3 carbon atoms
A copolymer with an α-olefin of 5 to 94% by weight,
(g) Intrinsic viscosity (η ₃ ) of 1.2 dl / g or more and less than 9.0 dl / g,
(h) Density (d ₃ ) 0.890 to 0.940 g / cm ³ , (i) Elution temperature-elution amount curve by continuous temperature elution fractionation method,
The ratio S (Ib / Ia) of the area Ib at the elution temperature of 25 to 90 ° C. to the area Ia under the curve at the elution temperature of 90 ° C. or more is S ₂ or less calculated from the following equation: S ₂ = 20 η ₃ ⁻¹ exp [ −50 (d ₃ −0.900)] (j) 25 ° C. ortho-dichlorobenzene-soluble component W weight% is W ₂ or more calculated from the following formula, W ₂ = 20exp (−η ₃ ), and the component (I ), (II) and (III) are 100% by weight, and the components (I) to (III) have different intrinsic viscosities from each other, and the intrinsic viscosity of the mixture is 1.0 to 6 0.0dl / g, density 0.890
An ethylene polymer composition having an N-value of 1.7 to 3.0 calculated from 0.970 g / cm ³ and the following formula 1. [Equation 1]