JPS6026049A - Polyethylene composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having excellent moldability, impact resistance, etc. and suitable for use in the production of a thin film, etc., by blending polyethylene obtd. by polymn. in the presence of a Ziegler catalyst, with polyethylene composed of both high-molecular and low-molecular moieties. CONSTITUTION:85-50wt% polyethylene (A) which is obtd. by (co)polymerizing ethylene by a two-stage polymn. method and is composed of a low-molecular moiety having an MW of 5,000-50,000 and a high-molecular moiety having an MW of 100,000-1,500,000 in the weight ratio of the low-molecular moiety to the high-molecular moiety of 70/30-30/70 and in which the ratio of the MW of the high-molecular moiety to that of the low-molecular moiety is 7-200, is mixed with 15-50wt% polyethylene (B) having an MW of 90,000-500,000, obtd. by (co) polymerization in the presence of a Ziegler catalyst to obtain the desired polyethylene compsn. having a melt index of 0.001-10g/10min.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a polyethylene composition having excellent molding processability and physical properties of molded articles, including molding processability such as melt extensibility, melt viscoelasticity, thin film processability, and physical properties such as impact resistance. This invention relates to a polyethylene composition suitable for excellent film forming, stretch forming, etc. applications.

For polyethylene film applications, etc., the thread stitch is relatively S.
++<, polymers with a relatively wide molecular weight distribution are suitable17.

As a method for producing polyethylene with a wide molecular tjt distribution,
Several methods have been proposed:

One method is to use high molecular weight polyethylene and low molecular weight BL
: s? +) A method of mixing with ethylene has been proposed ( lN? Publication No. 45-3215, Special Publication No. 4.5-2
20 (17, Japanese Patent Publication No. 54-100444, Japanese Patent Application Publication No. 1983-100444
-100445, JP-A-54-161657, JP-A-5
5-60542, JP-A-55-6 (1543, /1.+
1″ 1987-57841, JP-A 57-133136
).

In addition, as another method, a multistage polymerization method of two or more stages has been attempted (Sr Komei 46-11349, Japanese Patent Publication No. 48-4
27+6, JP-A-51-47079, JP-A-52-19
788).

The inventors of the present application have looked in detail at the polyethylene produced by -l-, Ml blind b% polymerization, and polymerization, and have confirmed that the extrudability is excellent due to the wide molecular h1. Although it is possible, it has been found that it has several drawbacks, such as low strength and melt extensibility, a certain point in thin film processability, and insufficient impact resistance on the surface of the thin film.

The present invention improves these drawbacks of polyethylene, which is composed of a low molecular weight part and a high molecular weight part, and has excellent processability and physical properties, and is particularly suitable for thin film applications, stretching applications, etc.
The present invention provides a +51J ethylene composition.

That is, the present invention is a polyethylene composition consisting of polyethylene FA) and (+3) selected from the group of ethylene homopolymers and copolymers of ethylene and α-olefin, (1) polyethylene (A) is Molecular weight is 0.5 to 5
10,000 low molecular weight part (A-T, ) and molecular weight 10 to 150
It consists of 10,000 polymer M parts (A-11), (A-I-r
The molecular weight of ) / (A-T, ) is 7 to 200, and the ratio of a pair of (A-T・) to (A-■+) is 70:30 to 30: 70, and (II
) Polyethylene (B) is polymerized using a Ziegler type catalyst, and the molecular weight of (11) is from 90,000 to 500,000, and the amount of (B) in the hV product is from 15% by weight to 50% by weight.
% by weight, and (Ill) the melt index of the composition is 0.001
g/l0m1n.

to 10 g/10 m1n.

According to the present invention, it has excellent f+ melt extensibility, thin film processability, and thin film impact resistance, which has a wide range of application in the T industry, and is particularly suitable for film molding, W stretching molding, etc. A polyethylene composition is then deposited.

The present invention will be explained in detail below.

Polyethylene (A) which is a constituent component of the present invention (B)
It is selected from the group of homopolymers of ethylene and copolymers of ethylene and alpha-olefins.

The .alpha.-olefin used in the reaction has 3 to 145 carbon atoms, and includes, for example, propylene, budene, pentene, hexene, 4-methylpentene-1, octene, and decene.

Polyethylene (A) is a polymer consisting of a low molecular weight part (A, -T,) and a high molecular weight part (A-n), but A
-T.

The molecular weight (MWA-+,) is from 5,000 to 50,000,
The molecular weight (MWh-u) of A-H is 100,000 to 150
Ten thousand. When MWA-■ is less than 50,000, the uniform dispersibility and physical properties of each component deteriorate12, while when it is more than 50,000, it becomes difficult to widen the molecular weight distribution within an appropriate range of molecular %° of the composition. Processability deteriorates. More preferably, it is from 10,000 to 40,000. On the other hand, if MWA-H is less than 100,000, the molecular weight of the composition decreases and the impact resistance also decreases. If it exceeds 1,500,000 yen, fish eyes will occur, and the dispersibility of each component in the composition will decrease, resulting in poor processability and physical properties.

More preferably, it is 150,000 to 1,000,000.

In addition, the ratio between MWA-H and MWA-1 (MWA-1(
/ M W^-1,) is 7 to 200, and if it is less than 7, the molecular weight distribution is narrow and processability is low, making it difficult to obtain the excellent physical properties of the present invention. On the other hand, even if it exceeds 200, there are no advantages in improving moldability and physical properties, and there are also disadvantages in manufacturing. More preferably, it is 10-150.

The density of doop ζ, A-T, is 091~o, 9 parts g/-, and the density of A-T-1 Il''J, (1,91~0.97
It is g~. In particular, the density of A-11 is lower than that of A, -L and polyethylene 01), and 091
~0.95 g/cn? In the case of , both processability such as extrudable film formability and physical properties such as impact resistance are excellent.

A −L (7) amount vs. A, − in polyethylene (A)
The amount of H ranges from 70:30 to 30:70, preferably from 60:40 to 40:60.

When the amount of A-T, dimension or A-H exceeds 70, the molecular acid distribution becomes narrow and the processability and physical properties are poor.

The polyethylene (A) can be produced by mixing the low molecular weight part and the core high molecular weight part prepared in advance, or by two-stage polymerization of the low molecular weight part and the high molecular weight part. Industrially, a two-stage polymerization method is preferred.

Polyethylene (11) &rl its molecule im: (Mwn
) ranges from 90,000 to 50 power. In order to improve the balance between moldability and physical properties of the composition, a particularly desirable embodiment is that the MWB is 10 to 400,000 force and the MWR/MW^-
L is 2 or more, and MW A-11/M W I+ is 1.5 or more.

The density is 0.91 to 0.98 g/'+J, but particularly favorable densities exceed o94 g/- (1,417 g to
It is as follows.

If the density is low, the rigidity and tensile strength of the composition will decrease, which is not preferable.

However, the amount of polyethylene (13) in the composition is in the range of 15 to 50%, preferably 17% or more.
It is 5chi shuncho. When M of (+1) is less than 15, workability and impact strength are not sufficiently improved. On the other hand, if it exceeds 50, the molecular weight distribution of the composition becomes narrow, the processability and properties of the film deteriorate, and the characteristics of the polyethylene composition of the present invention are impaired.

Said 71 seriethylene (A) N1, Ziegler type catalyst,
It is combined with a transition metal catalyst such as a chromium compound catalyst. Both the low molecular weight part and the high molecular weight part of
Particularly preferred are those polymerized using transition metal catalysts of the same type, and those polymerized using transition metal catalysts of the f+li class in which one part of the low molecular weight and one part of the polymer part are different from each other. Both the low molecular weight part and the high molecular weight part were produced using a magnesium compound-based Ziegler type catalyst.

The polyethylene fB) iJ: is produced using a Ziegler type catalyst, but particularly preferred is one produced using a magnesium compound-based Ziegler type catalyst which can omit the decatalyst step. Polyethylene made by magnesium compound-based Ziegler type
13) is characterized by a relatively narrow molecular weight distribution, which increases the effects aimed at in the present application.

As the magnesium compound-based Ziegler type catalyst, any system based on organic magnesium or inorganic magnesium can be used. For example, magnesium chloride, hydroxymagnesium chloride, magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesium alkoxide, organic acid salts of ma-9-gnesium, or complexes of these with electron-donating compounds such as alcohols and organic acid esters. , or a mixture thereof, an organomagnesium compound having a carbon-magnesium bond, such as dialkylmagnesium, alkylmagnesium chloride, argylmagnesium alkoxide, alkylmagnesium siloxide,
Or complexes of these organomagnesium compounds and electron donors such as ethers, or complexes of these organomagnesium components and halides, such as hydrochloric acid, chlorinated hydrocarbons, silicon tetrachloride, tin tetrachloride! A reaction product is used as a magnesium component, and a catalyst comprising a component obtained by reacting this with titanium and/or a nonadium compound and an organometallic compound is used.

Particularly preferred catalysts in the present invention include, for example, (1) the general formula Mau g/R'pR"qXr
Y* (In the formula, α is 0 ← a number larger than 10, p+
q+r+ll is a number that spans 0 and is greater than 0, and p+q-1
-r〇〇〇〇〇〇〇〇　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　, A hydrocarbon group having the same number of carbon atoms, X and Y are groups with the same brightness,
Halogen, OR3+ O8i It,' 11.511
'+NR' represents a group R8+ SR9, R,"l
R'+Tt511L'1Tt71R' is hydrogen atomic size/moss hydrocarbon group, Rp is hydrocarbon group); and (II) titanium containing at least one nitrogen atom, or S sodium compound and (II) AI, n1s+, n e 1S
n 11” e s S b halide compound (1
) to (lii), (1) and (11) or (1)
It consists of a solid catalyst component [A] formed by reacting (0) and (lil) and an organometallic compound [H'3.

For organometallic compounds ['B] and [-, periodic table 1~■
Of the compounds of the above group, complexes containing organoaluminum compounds and organomagnesium are particularly preferred.

The reaction between the catalyst component [A] and the organometallic compound [B] acid component is as follows:
It is also possible to add both components into the polymerization system and carry out the reaction as the polymerization progresses under the polymerization conditions, or it may be carried out in advance prior to the polymerization. In addition, the reaction ratio of the catalyst components is 1 to 3 [B] components to 1 g of [A] component (] (+
It is preferable to carry out the reaction within the range of 1 (l m+no/). Instead of the catalyst component [A'l, an inorganic Mg compound supported on a T1 compound may be used.

Among these catalytic yarns, the catalytic yarns are particularly desirable because they can omit the decatalyzing process for a second purpose.
-36788.52-36790.52-36791.
52-36792.52-5 (1070, 52-367
94, 52-36795, 52-36796, 52-3
6915, 52-36917, 53-6010, JP 50-21876.5 (1-31835, 50-720
44, 50-78619, 5140696.

The polyethylene fA) and (Ii) are produced by methods such as suspension polymerization, solution polymerization, and gas phase polymerization.

It is industrially preferable to produce the polyethylene (^)tJi by two-stage polymerization. However, several two-stage polymerization methods have already been proposed. Examples of preferred methods used in the present invention are as follows:1. I will clarify.

The polymerization is carried out in a saturated hydrocarbon having 4 to 10 carbon atoms. The 111th order of It combination is (A-r,)-(A-1-
T) or (A-II)-(A-:r,).

For simplicity, the pattern (AT,)-(A-r+) will be explained with reference to the drawings.

The low molecular acid part (A-L) has a polymerization pressure of 1 to 30 kg/
cJa.

Preferably, the polymerization temperature is 101 a in 3 to 25, and the polymerization temperature is 60
-100°C, preferably 70-90°C. The high molecular weight part (A-H) has a polymerization pressure of 05 to 30 Kg/1y.
The polymerization temperature is 40-110°C, preferably 60-90°C.

In the polymerization vessel (1), ethylene, hexano, hydrogen, catalyst components, etc. are supplied from the line (2), and low molecular weight polyethylene (A-L) is polymerized. The slurry in the polymerization vessel (1) is led to a flash 12 ram (3) to remove unreacted ethylene and hydrogen. The removed ethylene and hydrogen are pressurized by a compressor (4) and returned to the polymerization vessel (1). On the other hand, the slurry in the flash P ram (3) is introduced into the second stage polymerization vessel (6) by the pump (5).

In the polymerization vessel (6), ethylene, comonomer, hexano, catalyst components, etc. are supplied from the line (7), and high molecular weight polyethylene (A-H) is polymerized, and the polymer in the polymerization vessel [6] is converted into a product. It is taken out after a post-processing process.

13- In the above explanation, 7-1y11 is one of the typical +I11+ of the present invention, and in some cases it is
), the high molecular weight part (A, -n) is polymerized, and the low molecular weight part -f-1:*[fA-T,) is polymerized in the polymerization vessel (6). But that's fine.

In this case, it is possible to omit the flash ram 3 11. Furthermore, the contents of the polymerization vessel may be circulated from the polymerization vessel (6) in the wandering stage to the polymerization vessel (1) in the preceding stage.

Such a flow sheet allows polyethylene (
The polymerization of A) can be carried out.

The polyethylene (A) and (+1) are mixed and kneaded to form the desired polyknee silk composition.

As for the mixing method of polyethylene (A) and 01), usual methods such as powder state, slurry state, pell/tub state, etc. are used. When mixing, at a temperature of 150 to 300℃,
- It is carried out in a screw or twin screw extruder, kneader, etc.

In this way 1. The melt index (hereinafter referred to as MI) of the polyethylene composition manufactured by Fl17 is 0,
OO1q/l11mIn, to 10 g/l 0m
1n, depending on the application. especially,
For a film composition that has excellent overall processability and physical properties, MI is -14 = ItQ]g/I+1mi, to 1g/]
8 of 00m1n! It is surrounded by i'l, and the density is fl,!
l: (ranging from 51!/- to 0.965 g/-.

The polyethylene composition Vl2, a heat stabilizer, anti-corrosion cutting,
Items that can be added to or blended with polyolefins, such as absorbers, face washes, anti-static IF, agents, lubricants, fillers, other resins, thermoplastic resins, rubber, etc.
! iii, can be used as required.

However, it is also possible to mix foaming agents into foam molding.

1] Detailed in J 10 1. As stated above, the polyethylene composition obtained by the present invention has the following characteristics.

(1) It has a good balance of processing properties such as flow properties when melted, melt extensibility, and melt viscoelasticity, and also has excellent physical properties such as stiffness, impact resistance, tensile strength, and surface gloss.

(2) 6, which was previously thought to be difficult in film applications.
It is possible to process very thin films of less than 1 Miku at ultra-high speeds of 100 m/m and 1.1 mm.

(3) The molded product has high rigidity, impact resistance, and environmental stress cracking resistance, and all of these lvr properties are practically excellent. In particular, it provides excellent impact resistance for thin-walled molded products.

(4) It has excellent physical properties and processability, making it easy to make thin-walled molded products. Therefore, it is suitable for the era of resource saving and energy saving.

(5) Easy to manufacture.

(6) It can also be applied to various molding applications such as hollow molding, extrusion, injection, rotation, and foaming.

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited in any way by these Examples.

Symbols, measurement methods, and measurement conditions shown in Examples and Comparative Examples.

(1) MT: Melt index, ASTM
D-1238, 1:S, temperature 190℃, load 2.1
Value measured under the conditions of 6-.

(R) MIR: Load 21.6 under Ml measurement conditions
9, and the value is divided by MT to mean the quotient, which is one measure of molecular weight distribution, and the larger the value, the broader the molecular weight distribution.

(Il+) Molecular weight (MW): 1 using decalin solution
Intrinsic viscosity (η) measured at 35°C and Journal Op. Formula described in Limersience Vol. 36, p. 91 (1957), η-6,8X 10""MW'・67 to M
I hit W.

Note that all molecular weights in the present invention are determined by this method.

GV) Density: Measured according to ASTM D-1505.

(■) Melt extensibility; using a melt tension tester made by Toyo Seiki ■, melt extrusion of the resin at a temperature of 150°C? I:f
The quotient is the maximum drawing speed at which the strand P can be stretched without breaking, divided by the linear velocity at which the strand 13 exits from the nozzle.

G) Film molding processability; 50 adjustment screw, 75
A blown film forming machine with a diameter of 1" mm was used, the temperature was 190℃, the blow ratio was 3.5 times, and the take-up speed was 105.
Mold the film at a rate of m/min and determine the minimum moldable thickness.

(1×) Impact resistance of film: the above film forming machine,
Measurement is performed using a 12 micron thick film obtained by molding under the following conditions.

Example 1-1 (]) Synthesis of M (medium) for polyethylene^) and 01) Trichlorosilane (118i fj/3) ] mol/e hexane solution , was kept at 50°C.The composition A/!Mg
,,o(o2H!,)2. .

(n 041-Tg )(5((1('14L1g)
q, 5 organoaluminium-magnesilano, complex 1
A mol/P hexane solution 21 was added dropwise with stirring over 2 hours (17), and the reaction was further allowed to proceed at this temperature for 2 hours. Generation l~
The active component was precipitated twice with 2 parts of hexane, and washed with 1 part of hexane. Titanium tetrachloride 2/ was added to the slurry containing this solid component, and after reacting at 130°C for 2 hours,
The solid 9 was isolated 17 and washed with hexane until no free halogen was detected. This solid catalyst contained 1-7 titanium and 21 titanium.

(2) Production of polyethylene (A) by two-stage reaction
tl'j polymerization 1-2/ in the polymerization vessel (1). The polymerization temperature was 83°C, and the polymerization pressure was I: ] I Kg/cn? 1.3 mmo/! ('I' i
At the speed of atomic reference)/+(,, 20 nnnne (
Triethylaluminum is supplied at a rate of /Hr (based on metal atoms) and purified hexane is supplied at a rate of 40 //Hr.
,′! 1. Polymerization was carried out by supplying 7 NM3/Hr of ethylene, a molecular weight regulator, and 1 to 1 mol of hydrogen such that the hydrogen concentration in the gas phase was about 90 mol. The polymer slurry content in the polymerization vessel (1) is brought to a pressure of IKq/crlG.

The slurry is led to a flash drum (3) at a temperature of 75° C., and after separating unreacted ethylene and hydrogen, the slurry is introduced into a polymerization reactor (6) under increased pressure using a slurry pump (5). In the polymerization vessel (6), polymerization is carried out at a temperature of 78° C. and a pressure of 5 Kg/lri G.

Polymerization vessel (6) 11-1, internal volume 250/. 7.5 mmo/(
purified hexane at a rate of 401
/11r, ethylene was fed at a rate of 7 and 1 NM3/ITr, respectively, and hydrogen and butene-1 were introduced so that the concentration in the gas phase was about 1 molar and about 25 molar, respectively, to carry out the polymerization. I did it. Two-stage polymerization was carried out in this way, and the polyethylene (A) powder obtained from the polymerization vessel (6) had an MI of 0, 141471 Omtn, and a density of 0.956 g/-.

In addition, from the results of a separate experiment conducted under similar conditions, the low molecular weight portion (Δ-1,) of polyethylene (A) polymerized in the first stage polymerization vessel (1) has a molecular weight of is about 13,000, density is about 0.974 gh2. High molecular weight part (A-11) of l-polyethylene (8) polymerized in the second stage polymerization vessel (2) i'a: molecular weight is about 620,000, The density is estimated to be approximately 0.939 g/h2, respectively.

(3) Production of polyethylene (II) Polyethylene (fl) was produced by homopolymerization using a 1 hour reactor with a reaction volume of 200/ml. Polymerization temperature is 83℃
, ■ "Combined LE force 1d: l] Control 11. was applied to Kf/ノ ().

The catalyst used was the same as polyethylene (A), hydrogen was used as a molecular weight regulator, 1-butene was used as a comonomer, the molecular chain was 130,000, and the density was 0.
950 g/lJ, MI i, -1-, 0,6R/10
Manufacture polyethylene (+3) of mIn, Mll't 33 1. Noko.

(4) Production and evaluation of polyethylene compositions As described above 1
．． Manufacture 1. Polyethylene (A) and 03) were mixed in a ratio of 78:22 using one mold needle, and then the mixture was mixed with an antibacterial agent [7], 800 ppm of di-tert-butylhydroxytoluene, and 800 ppm of tetrakis [7].
Methylene-3-(3',5'-di-t-butyl-4I-
Hydroxyphenyl) propionate comethane 14 old) I'Pms o'22 Calcium stearate 23 o
Oppm i: Added and in a Henschel mixer,
Mix for 10 minutes to make a powdery mixture, knead this mixture at a temperature of 220°C using a Farrell FOM, then extrude this kneaded product using a single screw extruder at a temperature of 250°C, and pelletize it. A polyethylene composition was produced. As shown in Table 1, this polyethylene composition exhibits excellent moldability and physical properties.

Example 1-2 Polyethylene (A) and (B) produced in Example 1-1
) A polyethylene composition was produced in the same manner as in Example 1-1, except that the amount of polyethylene was changed to the amount shown in Table 1.

Its performance is shown in Table 1.

Comparative Example 1-1 The performance of Comparative Example 1-1 was evaluated in the same manner as in Example 1-1, except that only the polyethylene (A) produced in Example 1-1 was used.

Comparative Example 1-2 In Example 1-1, the performance was evaluated in the same manner as in Example 1-1, except that the blending amount was changed as shown in Table 1.

Example 2-1 (1) Production of polyethylene (A) Using the catalyst used in Example 1-1, the polymerization vessel, polymerization temperature, and pressure used to polymerize polyethylene (+1) in Example 1-1 Then, the low molecular weight part (A-r, ) and the high molecular weight part (A-H) of polyethylene (4) were separately polymerized. (A-T, ) and (A-H) both used butene-1 as a comonomer, and the molecular weight regulator was Example 1-1.
Similarly, hydrogen was used.

The produced (A-1,) has a molecular weight of approximately 30,000 and a density of 0.9.
63g fake, (A-n) has a molecule l゛ of about 450,000 and a density of 0.
．． It was 935 g.

(2) Synthesis of catalyst for polyethylene (■3)
138 g of butylmagnesium and 19 g of triethylaluminum and 21 g of n-hebutane were introduced into a bamboo battering tank with a size of 4/2, and reacted at 80°C for 2 hours, resulting in a composition of AlMg6(02115)3.
(Rho 04H9) +2 A J machine aluminum-magnesium inscription is synthesized. This complex 4 (l Ommo/
? (54 g) of n-hebutane solution containing 80 (l
mj! and titanium tetrachloride 400 mmof! n containing
- 800 ml of the hebutane solution was replaced with dry nitrogen to remove moisture and oxygen (7), and then reacted at -20°C for 4 hours with oval stirring. The intermediate hydrocarbon-insoluble solid was isolated, and the hebutane solution was Washing with water gave 106 g of solid.

+3) 71? In the production of polyethylene (13), the solid catalyst prepared as in H[j and triethylaluminum were used as catalysts, octene-1 was used as a comonomer, hydrogen was used as a molecular weight regulator, and polyethylene of Example 1-1 was prepared. Polyethylene (13) as shown below was polymerized using the polymerization vessel used to make the following polyethylene (13) at a polymerization temperature +0+ and pressure. That is, the molecular weight is 220,000, the density is 0. g 45 g/cn? ,
λiIO, 11g/l0m1n, , MTR55 (4) Production and evaluation of polyethylene compositions (A-L) and (
A-11) and polyethylene (B) in Table 2.
Then, as a stabilizer, 800 ppm of diterlyzotylhydroxytoluene, 1500 ppm of 1n-octadecyl-β-(4'-hydroxy-3'15'-di-1-ditylphenyl)propionate.
, 250Qppm addition of Sudearin calcium 1 ~,
Next, the mixture was sufficiently stirred and mixed with a Henschel mixer 17, and this mixture was mixed with a Farrell FOM at a temperature of 220°C 7. The kneaded product was then extruded with a single-screw extruder at a temperature of 260°C, pelletized, and made into polyethylene. 11 compositions!
! ! Construction 1. Ta. 1 sheet of this polyethylene composition
As shown in Table 2, both form 57 processability and physical properties show very good performance.

Example 2-2 In Example 2-1, (A-L), (A-IT
) The procedure was the same as in Example 2-1, except that the blending ratio of sea urchin (13) was changed to 1:sea urchin as shown in Table 2.

Comparative Examples 2-1 to 2-2 The same procedure as Example 2-1 was carried out except that (AT, ) and (A-■) were blended as shown in Table 2.

24- 25- 26-

[Brief explanation of drawings]

Drawing d is a flow sheet showing an example of two-stage polymerization according to an embodiment of the present invention. 1%W “Applicant Asahi Kasei Industrial Co., Ltd. 27-Drawing

Claims (5)

[Claims] (1) Homopolymers of ethylene and ethylene α-
Polyethylene selected from the group of olefin copolymers (
Consisting of A) and ■), (1) Polyethylene (A) has a molecular weight of 0.5 to 5.
Low molecular weight needle (A-I,) and molecular weight from 100,000 to 15
Consisting of 00,000 high molecular weight parts (A, -H), (A-u)
Molecule 1! The molecule l of l/(A-T, ) is 7~2()0
The amount of (A-1,) to (-11) is in the range of 70:30 to 30:70, and the amount of polyethylene (A-1,) in the composition is 70:30 to 30:70. ) is in the range of 85 to 501 polyethylene, (1) polyethylene (11) is polymerized using a fl-1 Ziegler type catalyst, and its molecular weight is from 90,000 to 50,
The amount of polyethylene (B) in the composition it: t ranges from 5% to 50% by weight, and (IN) the melt index of the composition is 0.001 g
/lf1min. A polyethylene composition characterized in that it is 10 g/+amin or more, and I or less. (2) The polyethylene composition according to claim 1, in which the polyethylene (A) is produced by a two-stage 111 combination. (3) Polyethylene composition 1 according to claim 1 or 2, wherein polyethylene (A) and (11) are produced using a magnesium compound-based Ziegler type catalyst. (4) The molecular weight of polyethylene (11) is 100,000 to 4
00,000, and ・j′? Molecule of polyethylene (B) bt/(
A-1-) molecule 1° is 2 or more, and (A-H) molecule f/polyethylene (n) has a molecular weight of 1.5 or more, Claim 1.2 or 3 polyethylene composition of (5) Density of polyethylene (1() exceeds 094 and 0
．． 97 g/(M”) of the polyethylene composition according to claim 1.2.3 or 4.