JPS5838738A - Polyolefin composition - Google Patents

Abstract

PURPOSE:A composition, consisting of two high-density high-molecular weight and low-density low-molecular weight ethylene-alpha-olefin copolymers having improved transparency without deteriorating the density thereof, and suitable for films. CONSTITUTION:A composition, having 0.1-10g/10min melt index and 0.910- 0.935g/cm<3> density, and prepared by incorporating (A) 10-60pts.wt. ethylene-alpha- olefin copolymer having 0.915-0.945g/cm<3> density (rhoA), 70,000-700,000 viscosity- average molecular weight (MA) and 2-10 weight-average molecular weight/ number-average molecular weight ratio with (B) 40-90pts.wt. ethylene-alpha-olefin copolymer having 0.905-0.930g/cm<3> density (rhoB), rhoB<=rhoA, 10,000-100,000 viscosity-average molecular weight (MA), 2-10 (MA/MB) and 2-10 weight-average molecular weight/number-average molecular weight. Preferably, the alpha-olefin in the components (A) and (B) is a >=4C alpha-olefin, e.g. butene-1 or pentene-1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a relatively high density, high molecular weight ethylene-α-olefin copolymer and a relatively low density, low molecular weight ethylene-α-olefin copolymer.
The present invention relates to a polyolefin composition with excellent transparency, which is composed of an α-olefin comonomer.

The low-density ethylene-α-olefin copolymer obtained (generally by low-pressure polymerization using a Ziegler-Natsuta catalyst) is
Compared to low-density polyethylene obtained by the high-pressure radical method, it is superior in terms of tear strength and impact strength, especially in film applications, but it is equivalent to or inferior in transparency.

In the case of an ethylene-α-olefin copolymer, transparency can be improved to some extent by increasing the number of mono-α-olefins to be co-merged to form a monomer with a lower density.

However, when considering practicality as a film, problems such as a decrease in the amphoteric nature of the film due to a decrease in density or stickiness of the film due to the lifetime of the low molecular weight polymer containing a large amount of α-olefin occur. A method of improving transparency without reducing density was desired.

In view of the above-mentioned circumstances, the present inventor, Hiro, has conducted a study to obtain a low-pressure process low-density ethylene-α-olefin monomer that is superior not only in strength but also in transparency to high-pressure process low-density polyethylene. , arrived at the present invention.

That is, the gist of the present invention is that the melt index is 0. /~/Of// 0 minutes, density O0 1O~θ, ri j j t / C4 polyolefin composition - a comonomer of ethylene and other α-olefins specified by the following characteristic values ( A) 10-
A polyolefin composition comprising 40 parts by weight and (B) 4tO to 0klk parts.

ni) 11&(ρmu)θ, ri/J~θ, ta das
t/cd.

Viscosity average molecule: m (M) 20,000 to 200,000,] 1-weight average molecular weight/number average molecular weight λ to i.

(B) Density (ρ1)θ, riOj −0, YjO
f/Cd, ρB≦Im, viscosity average molecular weight (Ml)/
10,000 to 700,000, Mmu/MB-λ to 70% 1 cap average molecular weight/
Number average molecular weight - ~i.

exists in

Next, the present invention will be explained in detail, but in the following clarification,
Melt index is based on MU8TMD-/2JJ”/
It is the measured load pressure value at 0℃, λ, and itkg load, and the density is A8TM D /! 0' x M
"" ((y) is the intrinsic viscosity, M is the viscosity average molecule k). This is the value obtained by calculating the average molecular weight per cell jt/Th average molecular weight from the molecular weight distribution graph.

The polyolefin composition according to the present invention comprises the following comonomer (A
)/θ ~ 6θ] Lj 11 parts and co) 1 in combination) 4tO
~ri OMJi part 9, melt index 0. /
~10 fl/10 min, area is Oori/θ~0.2 Jjt
/cd.

copolymer) has a density (ρ, ) of θ, ri/j~θ, 2+1
Ethylene and other α-olefins with a viscosity average molecular weight of 1t/ai, a viscosity average molecular weight of 20,000 to 200,000, *m3F average molecular weight/#average molecular weight of C or less, and a MW/M ratio of -~IO It is a copolymer with The α-olefin contained as a comonomer of ethylene in the copolymer (A) is preferably butene-7, pentene-11, hexene-/
, 4t-methylpentene-/, octene-7, decene-
There are no α-olefins with a number of atoms greater than 7, etc.
These comonomer components may be of type J or higher,
Its content is 0. /~101 lid% is dangerous.

The copolymer (B) has a density (ρB) of 0. θj -0, 3θt7cii, and ρ1≦ρ, and the viscosity average molecular weight (Ml) is 10,000 to /Q0,000, and Mm/lock 1 =
1-10. Preferably J-4%My/Ml is -~1
It is a copolymer of ethylene and other α-olefins. In copolymer [F]), ethylene (1) 3
%/Y- include the same α-olefins as those in K in the copolymer, but the content is preferably 3 to 3θ weight %.

In the polyolefin composition of the present invention, copolymer color)
and a copolymer (if the composition ratio is outside the above range, a composition with the desired high transparency cannot be obtained, so this is not preferred).

If the melt index is higher than the upper range 1, the film strength will decrease, and if it is lower, the moldability will decrease, which is undesirable. Also, if the density is higher than the above range, the transparency and strength will deteriorate. If the pressure is low enough, the film may be sticky.
An opening due to lack of rigidity occurs.

In the copolymer (A) or (b), if the density is lower than the stated value, problems such as stickiness of the film or lack of rigidity as a film arise.

Co-1 combination (A) or (B) In 4C, first t14
When the wrinkle average molecular weight is smaller than the above value, the JIK strength when the composition is used as a film decreases, and the JIK strength is lower than the above value.
If the cracks are large, the moldability deteriorates, which is not preferable.

In the copolymer (A) or C), Mv/Mw is 1
If it exceeds 0, the Kfi clarity and strength will decrease when the film is used as a binder, which is not preferable.

Furthermore, if the relationship between the densities or the viscosity average molecular weight of the copolymers (A) and (B) is outside the above range, a composition with high transparency cannot be obtained when used as a film.

The polyolefin composition of the present invention can be obtained by separately producing the copolymers (A) and (B) and then mixing them together, but the copolymers (A) and I) can be obtained in one step. It can also be obtained by manufacturing.

For the method of mixing copolymers←) and (b), special K1
1lll@, any known method can be applied. For example, a solution mixing method in which the copolymer (→ and (B) are each spread over one layer of solvent Ki, mixed, and precipitated.
(Continuous engineering ntena1ve Mlx
er, 1FCM (IParred 0ontinuo
Examples include a continuous melt-kneading method using a single screw extruder, and a patch-type melt-kneading method using a Banbury company. Among these, mixing using a Banbury mixer is preferable from the viewpoint of uniformity of the blended polymer.

In addition, in order to produce the polyolein composition of the present invention by a one-step polymerization reaction, ethylene and other α-
A co-1 polymer (A) or (B) is obtained by co-1 polymerization with an olefin, and then the resulting co-1 polymer is combined with ethylene and other α-
It can be introduced into the second reaction zone together with the olefin to produce copolymers) or Fi←). It is preferable that the composition obtained by this method is then kneaded. The composition obtained by this method is easily homogenized, and can be homogenized by a continuous kneading method using a single screw extruder or the like.

As mentioned above, the polyolefin group a- of the present invention has superior tear toughness and high impact strength, as well as transparency compared to high-pressure process low density polyethylene, and is suitable for plastic and film applications. It can be suitably used.

Next K, j1! However, the present invention is not limited to the following examples which do not exceed the gist of the present invention.

In the following examples, the film haze value as a measure of transparency was measured using a Nippon Denshoku digital turbidity meter NDH-
Measurement was performed using a Model 10D in accordance with ASTM D-1003.

Falling weight impact strength as film strength is AEITM-D
-/702. However, 1.Here, the falling height of the hoko is defined as aotx.

The film was produced by the blown film method under the following conditions.

Extruder: Oimg diameter (manufactured by Thermoplastics Industries) Extruder screw Full flight screw (L7'D
-J/, compression ratio 3.0) Production Finish A 30mfi circular die, clearance/, -Phoenix temperature 'l * C2# CS die head, die all 210℃ -Rotation speed /θOrpm Frost line -0 country blow-up ratio - Film thickness DaOμ Viscosity average molecular weight (abbreviated as Mi) was measured according to the method described above.

My / MNlj Molecular distribution was determined by gel permeation chromatography under the above conditions as #j constant [7] and calculated from the distribution. 1 Molecular weight distribution is obtained by calculating the M:M:if of the chromatographic count number to the viscosity average molecular weight of the fractionated polyethylene, and then using this calibration line.
The distribution was calculated using

Machine: Manufactured by Shinji Waters -〇θ type romatograph solvent: 20-dichlorobenzene
Ram: Polystyrene GMS (manufactured by Toyo Soda Co., Ltd., trademark) 9 Main stream speed: /cc/min Polyethylene #M-ren□2 〇, 2! Heavy violet% Preparation amount:, 2CC Melt index (abbreviated as M) FiAsTMD-/
Observations were made under 2JIK base at 0°C and under 4I#. tlLIi3'jli ratio (abbreviated as PR) is ASTM
Measured using MU8TM D-/jOj.

Production side of copolymer (1) or (B) Copolymer having the physical properties shown in Table 7 was produced using either the catalyst system (a) or (b) below.

0) Magnesium diethyl) JOmtoo 1% tri-n-butoxymonochlorotitanium/Ommol and 10 mmol of butanol were mixed and stirred at /4tθ°C for 4 hours to form a homogeneous solution. Then, the temperature was lowered to 60° C., and benzene/j OCC was added to form a homogeneous solution.

Next, at 40°C, ethylaluminum sesquichloride 1
0 mmol was injected into the chest for 20 minutes, and then incubated at 60℃ for 7 days.
Stir for hours.

The resulting precipitate was washed with normal hexane and dried for 1fL to obtain a solid powder polymerization catalyst (a).

(Synthesis of MfCl, i, jT HF) Using a Soxhlet extractor, reflux extraction was carried out with commercially available anhydrous MyCt, /ot & tetrahydrofuran-jθ11/ for -20 hr. Ta.

(Synthesis of TiO4.jTHF) In the same manner as above, commercially available 'riaz was extracted to obtain a light blue powder of TiC4.jTHF.

Mf0 synthesized earlier in a flask in which the element has been substituted in advance
4, /i T HIt / 3. ! mmol was charged and then dehumidified and deoxygenated 'rHFjj- was injected.

MfOl-,・/,! The THF powder dissolved immediately and a colorless solution was obtained. Similarly, in another flask, the previously synthesized TiO4-j Tl1F /, j j m
mol of THFJQm, which was then dehumidified and deoxidized.
was injected to obtain a purplish-brown homogeneous solution.

Both of the above solutions were mixed and reacted at 6θ°C for 7 hours. After the reaction, purified normal hexane-6θd was added with stirring at room temperature.
When the mixture was slowly added dropwise over 0 minutes, a pale sky blue precipitate was formed. The obtained precipitate was thoroughly washed with purified normal hexane to obtain a normal hexane slurry. At this time, 43% of [Mf 4- Ti ] in the nos slurry is θ, /
To this n-hexane slurry, which was mol/-l-hexane, diethylaluminum chloride-j and Om1llo1 were added dropwise with stirring at room temperature, and the mixture was reacted at tj'c for 7 hours. After cooling, the mixture was thoroughly washed with n-hexane to obtain a solid catalyst component (b) of J/f.

Copolymerization of α-olefin with partial pressure of ethylene using a Fijt autoclave and using butane as a polymerization solvent. was charged, and the ethylene partial pressure was 3.0Ic9/-11. At the beginning of the conversion, JLI!
A predetermined amount of the comonomer shown in L/Table was introduced into the reactor via a lid, and the combination was carried out at 10° C. under the hydrogen partial pressure shown in Table 7. The characteristic values of the obtained ethylene-α-olefin copolymer are shown in the jig/table.

Example 7~Da, and Comparative Example/~- The copolymer (A) (Mu/~Muro) produced earlier and the copolymer (B) (B/~B4) were mixed in the proportions shown in the m1 table. , a Banbury epsilon mixer or a solution.

The results of measuring the physical properties of the obtained polyolefin composition are shown in Table 1.

The details of the mixing method are as follows.

Mixing using a Banbury mixer: The co-electrolyte (A) and (B) are mixed to a predetermined heavy electric ratio, and the total amount of the co-electrolyte (A) and (B) is 2409.

This mixed powder was charged into a Banbury mixer, and the mixture was thoroughly purged with nitrogen. Knead at a rotation speed of -00 rpm, a shear rate of 4 at a rate of 10 BeQ-', and a time of 3 minutes.

#Mixing with liquid: Copolymer (A) and (total amount of 30o
Turn the temperature to r and place in a pressurized stirring hinoki.

Toluene as solvent3. ! Prepare l. The inside of the stirring tank was replaced with nitrogen, and the temperature was raised to /lθ°C while stirring.

Stir at 110° C. for 1 hour to blend the polymer. After cooling to below the boiling point, the mixture is precipitated into 0 Jl of methanol to obtain a polymer.

Example! jt stainless steel autoclave r (butane 2, j l
and catalyst ←) 4tOwIg were charged. The temperature was raised to ♂θ℃, hydrogen was introduced into the reactor, and then triethylaluminum θ, 6 mmol, and l-butene/If were introduced together with ethylene [5, the total pressure was set to /kg/dck. .

Ethylene absorption was observed as ethylene was introduced, but ethylene was additionally introduced to carry out the polymerization reaction so as to maintain the total pressure at /4t#/cdGK. The total amount of fabric was determined from the cumulative amount of ethylene supplied and the amount of butene consumed.

After 120 minutes, when the yield was 310 f, the ethylene supply was stopped, the 1st cup of the 7th stage was stopped, and the transition was made to the 1st batch of the -2nd stage. N f/l! In order to maintain the pressure at f/j, j kg/7 G, ethylene was supplied and the polymerization reaction was subsequently carried out. When the sum of the supply volume S of ethylene and the consumption amount of butene in the first stage and the second stage reached 10309, the polymerization was stopped by injection of ethanol.

The obtained polymer powder was divided into jOIJIρ, L/D-12,
Dalmage screw extrusion Shin (DaOr, pom.

Temperature 0. /60'C, C, /10°C, D=/0°C) and pelletized sample was molded into a film and its physical properties were measured. The results are shown in the Kawara table.

In addition, in this two-stage 1 combination, M knee o, θj ri 1My-/r, can plate θ, ri 319/Crd as the copolymer (A), and M knee as the copolymer (B). s, r,
Mvm! ,/10,000, e degree 0. A composition consisting of an ethylene-α-olefin co-Toa composite with a ratio f/- was obtained.

Comparative Example 3 Stripes/Copolymer powder obtained under the polymerization conditions shown in the table 0-/
The physical properties of the product K, which was pelletized using the extruder used in Example J, were measured. The results are shown in Table J.

Comparative Examples A film was formed using commercially available high-pressure low-density polyethylene, and the physical properties were measured.The results are shown in Table 1.

Claims (1)

[Claims] (1) A polyolefin composition having a melt index of 0.7 to 101710 minutes, a density of go, yio to θ, and a ratio of J j t / Cd, which contains ethylene and other α-olefins specified by the following characteristic values. Polymer (41
0 to 20 parts by weight of (B)yO). (Chograph 31 (71,) 0.ta l!~O0ri4tj
f/cm, viscosity average molecular weight (Mmu) 70,000-200,000, lkl average molecular weight/number average molecular cap λ~l0 (B) Density (ρB) θ, 9 0 j -0, ta j Of/ca! , ρ1≦I'As viscosity average molecule 11("n)/10,000~100,0001Mmu/MIIslI-~
101 Iris cover average molecular weight/number average molecular weight -~/θ