JP2000063438A - Olefin copolymer and molded article using this copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ethylene-produced catalyst using a single-site catalyst.
Without lowering the strength of the α-olefin copolymer,
Olefin copolymer with improved bubble stability during inflation molding such as air cooling and melt parison stability during direct blow molding of ethylene-α-olefin copolymer produced by single-site catalyst in a simple and low-cost method And to provide molded articles such as inflation molding and blow molding using the copolymer. SOLUTION: Melt tension obtained by treating an ethylene-α-olefin copolymer produced from a single-site catalyst having a specific density, a melt flow rate, a melt flow rate ratio and a separation amount distribution with a radical generator is from 0.5 to 0.5%.
20 g of an olefin copolymer and a molded product such as inflation molding or blow molding using the olefin copolymer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a bubble stability during air-cooled inflation molding in which an ethylene-α-olefin copolymer produced with a single-site catalyst is modified or treated with a radical generator, or direct blow molding. TECHNICAL FIELD The present invention relates to an olefin copolymer having improved melt parison stability and a molded article such as inflation molding or blow molding using the copolymer.

[0002]

2. Description of the Related Art Ethylene-α-olefin copolymers produced by single-site catalysts such as metallocene catalysts are
As a material for films, containers, etc., it is lighter in weight, easier to dispose of, and better in chemical resistance than conventional glass containers.
It is widely used because of its excellent mechanical properties.

Ethylene-α produced with metallocene catalysts
-As a modification relating to the melt tension of the olefin copolymer,
Japanese Unexamined Patent Publication (Kokai) No. 6-172448 discloses, as an olefin polymer having a high melt tension, [I] [A] a transition metal compound catalyst component, and [B] a periodic table group I to group II.
A prepolymerized catalyst obtained by prepolymerizing an organometallic compound catalyst component containing a metal selected from Group I with an olefin and a polyene compound in an amount of 0.01 to 2000 g per 1 g of the [A] transition metal compound catalyst component. , [II] A polymer obtained by polymerizing or copolymerizing an olefin containing ethylene as an essential component in the presence of an organometallic compound catalyst component containing a metal selected from Groups I to III of the periodic table. To
An olefin-based polymer characterized by being irradiated with radiation is disclosed.

Further, in JP-A-6-172450, an olefin polymer having a high melt tension is selected from [A] a transition metal compound catalyst component and [B] a periodic table group I to group III. (I) ethylene and (ii) an aliphatic and / or alicyclic polyene having olefinic double bonds at both ends in the presence of an olefin polymerization catalyst formed from an organometallic compound catalyst component containing a metal A copolymer obtained by copolymerizing a compound with the compound (i) containing a structural unit derived from ethylene in an amount of 50 to 99.99 mol% is irradiated with radiation. An olefin-based copolymer is disclosed.

[0005]

The ethylene-α-olefin copolymer produced by a metallocene catalyst has a small melt tension because it does not have long-chain branching so much. Therefore, if the molecular weight is increased in order to increase the melt tension of the ethylene-α-olefin copolymer produced by the metallocene catalyst, the viscosity at the time of molding increases, the motor load of the processing machine increases, and the die Melt fracture may occur when the molten resin is discharged from the gap.

As a method of increasing the melt tension,
In some cases, the composition is improved by a composition of a metallocene-catalyzed ethylene-α-olefin copolymer and a high-pressure low-density polyethylene resin. However, the composition of the metallocene-catalyzed ethylene-α-olefin copolymer and the high-pressure low-density polyethylene resin shows that the metallocene-catalyzed ethylene-ethylene such as tensile strength at break and impact strength.
The characteristics of the α-olefin copolymer may be deteriorated.

The present invention is a simple and low-cost method for producing ethylene-α-olefin copolymers produced by a single-site catalyst without lowering the strength of the ethylene-α-olefin copolymer produced by a single-site catalyst. Provide an olefin copolymer having improved bubble stability during inflation molding such as air-cooling and melt parison stability during direct blow molding, and molded products such as inflation molding and blow molding using this copolymer. The purpose is to

[0008]

According to the present invention, an ethylene-α-olefin copolymer produced from a single site catalyst having the following characteristics (A) is treated with a radical generator to obtain a melt tension of 0.5 to 20 g. It relates to an olefin copolymer.

(A) Ethylene-α-olefin copolymer: (A-1) Density (d) = 0.895-0.950 (g /
^{cm 3) (A-2)} 190 ℃, melt flow rate at 2.16Kg load _{(MFR 2. 16) = 0.1~100 (} g / 1
0 min) (A-3) 190 ℃ , melt flow rate in 10.0Kg load (MFR _{10 .0)} and 190 ° C., 2.16 Kg
Ratio with melt flow rate (MFR _2.16 ) under load (MFR _10.0 ) / (MFR _2.16 ) = 5-10 (A-4) Molecular weight distribution (Mw / Mn) = 2.0-4.0

More preferably, the present invention is characterized by treating 100 parts by weight of an ethylene-α-olefin copolymer produced from a single site catalyst with 0.01 to 0.5 parts by weight of a radical generator. It relates to an olefin copolymer.

Further, the present invention relates to a molded product using the above olefin copolymer.

More preferably, the present invention provides a molded article,
The present invention relates to a molded product obtained by inflation molding or blow molding.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, an ethylene-α-olefin copolymer produced from a single-site catalyst having the following characteristics (A) is treated with a radical generator or modified to obtain a melt tension of 0.5 to 20 g. , Preferably 0.
5 to 10 g, more preferably 1 to 10 g, particularly preferably 1 to 7 g of olefin copolymer.

(A) Ethylene-α-olefin copolymer: (A-1) Density (d) = 0.895-0.950 (g /
^{cm 3) (A-2)} 190 ℃, melt flow rate at 2.16Kg load _{(MFR 2. 16) = 0.1~100 (} g / 1
0 minutes), preferably 0.1 to 50 (g / 10 minutes), more preferably 0.5 to 20 (g / 10 minutes) (A-3) 190 ° C, melt flow rate (MFR) at 10.0 Kg load. _10.0) and 190 ℃, 2.16Kg
Ratio with melt flow rate (MFR _2.16 ) under load (MFR _10.0 ) / (MFR _2.16 ) = 5-10 (A-4) Molecular weight distribution (Mw / Mn) = 2.0-4.0

The above-mentioned olefin copolymer comprises 100 parts by weight of an ethylene-α-olefin copolymer produced from a single-site catalyst, 0.01 to 0.5 parts by weight of a radical generator, and 0.01 to 0. 2 parts by weight, especially 0.01-
Olefin copolymer treated with 0.1 parts by weight is preferred. Further, 100 parts by weight of an ethylene-α-olefin copolymer produced from a single-site catalyst is added to 0.01 to 0.5 parts by weight of a radical generator, further 0.01 to 0.2 parts by weight, and particularly 0.01 to 0 part. An olefin copolymer treated in the coexistence of 1 part by weight with a stabilizer such as calcium stearate or an antioxidant such as a hindered phenol-based or phosphorus-based antioxidant is preferable.

The above-mentioned olefin copolymer is produced from a single-site catalyst in the presence of a glycidyl compound or a compound containing a polar group such as maleic anhydride and an ethylene bond or a polar group and an ethyne bond. Ethylene
It does not include those obtained by treating the α-olefin copolymer with a radical generator.

Further, the olefin copolymer of the present invention is
It is an olefin copolymer suitable for inflation molding and blow molding, and a molded product can be produced by inflation molding or blow molding.

In particular, the olefin copolymer of the present invention can stably produce a molded product having a thickness of 5 to 500 μm by inflation molding and a molded product having a thickness of 0.5 to 5 mm by blow molding.

The above radical generator is described in US Pat.
The dicumyl compounds described in No. 751270, azo type decomposable radical generators, peroxide type radical generators and the like can be used.

The ethylene-α-olefin copolymer (A) is produced by copolymerizing ethylene and an α-olefin having 3 to 10 carbon atoms in the presence of a single site catalyst.

Examples of the α-olefin having 3 to 10 carbon atoms include propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, octene-1 and the like.

The repeating unit derived from the α-olefin in the ethylene / α-olefin copolymer is
Usually, it is preferably in the range of 10 mol% or less, more preferably in the range of 0.1 to 5 mol%, and particularly preferably 0.1.
It is contained in the range of 4 mol%. α-olefin is
The ethylene-α-olefin copolymer may be used alone or in combination of two or more kinds.

As the single-site catalyst, a combination of a metallocene compound of a transition metal of Group IV or V of the periodic table with an organoaluminum compound and / or an ionic compound is used.

As the group IV or V transition metal of the periodic table, titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V) and the like are preferable.

The metallocene compound is a compound bridged by at least one cyclopentadienyl group, a substituted cyclopentadienyl group, hydrocarbyl silicon, etc., and a cyclopentadienyl group bridged by oxygen, nitrogen and phosphorus atoms. Any known metallocene compound having the above as a ligand can be used.

Specific examples of these metallocene compounds include dimethylsilyl (2,4-dimethylcyclopentadienyl) (3 ', 5'-dimethylcyclopentadienyl) zirconium dichloride and dimethylsilyl (2.
Silicon-bridged metallocene compounds such as 4-dimethylcyclopentadienyl) (3 ', 5'-dimethylcyclopentadienyl) hafnium dichloride, ethylenebisindenylzirconium dichloride, ethylenebisindenylhafnium dichloride, ethylenebis (methyl) Examples thereof include indenyl-based zirconium dichloride, ethylenebis (methylindenyl) hafnium dichloride, and other indenyl-based crosslinkable metallocene compounds.

The organoaluminum compound used in combination with the above metallocene compound has a general formula (-A
A linear or cyclic polymer represented by l (R) O-) n (R is a hydrocarbon group having 1 to 10 carbon atoms, and includes a group partially substituted with a halogen atom and / or an RO group. .N
Is the degree of polymerization and is 5 or more, preferably 10 or more)
And specific examples thereof include methylalumoxane, ethylalumoxane, and isobutylethylalumoxane, in which R is a methyl, ethyl, or isobutyl group, respectively.

Further, other organic aluminum compounds include trialkylaluminum, dialkylhalogenoaluminum, sesquialkylhalogenoaluminum, alkenylaluminum, dialkylhydroaluminum, sesquialkylhydroaluminum and the like.

The ionic compound is represented by the general formula: C ⁺ .A
^And C ⁺ is an oxidizing cation of an organic compound, an organometallic compound, or an inorganic compound, or a Bronsted acid composed of a Lewis base and a proton, and reacts with the anion of a metallocene ligand to form a cation of metallocene. Can be generated. As specific examples thereof, Japanese Patent Laid-Open No. Hei 4
It is possible to use those described in JP-A-253711, JP-A-4-305585, JP-A-5-507756 and JP-A-5-502906.

Particularly, an ionic compound of a tetrakis (pentafluorophenyl) borate anion and a triphenylcarbonium cation or a dialkylanilinium cation is preferable. These ionic compounds can be used in combination with the above-mentioned organoaluminum compound.

As a method for copolymerizing ethylene and α-olefin with the above single-site catalyst, various well-known methods can be adopted, and fluidized bed gas phase polymerization or agitation gas phase polymerization in an inert gas can be adopted. Polymerization, slurry polymerization in an inert solvent, bulk polymerization using a monomer as a solvent and the like can be mentioned.

With respect to 100 parts by weight of the above-mentioned (A) ethylene-α-olefin copolymer, for the purpose of improving moldability, transparency, and glossiness, high-pressure low-density polyethylene, high-density polyethylene, the above single-site catalyst Manufactured in (A)
Ethylene-α excluding ethylene-α-olefin copolymer
-A polyethylene polymer such as an olefin copolymer may be added in an amount of preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and particularly 20 parts by weight or less.

The polyethylene-based polymer may be a homopolymer or an ethylene-α-olefin copolymer of ethylene and a small amount of α-olefin. For example, ethylene and alumina or silica-Phillips method obtained by polymerizing using a catalyst such as chromium oxide supported on alumina, standard method obtained by polymerizing using a catalyst such as molybdenum oxide supported on alumina, Examples thereof include polyethylene and ethylene-α-olefin copolymers obtained by polymerizing using a Ziegler type catalyst composed of a transition metal compound and an organometallic compound.

As the high-pressure low-density polyethylene, those produced by high-pressure radical polymerization can be used.

The above high-pressure low-density polyethylene includes
In addition to ethylene homopolymers, copolymers with other monomers such as ethylene-vinyl acetate copolymers can be used. When an ethylene-vinyl acetate copolymer is used, the repeating unit derived from vinyl acetate in the copolymer is
Usually, it is preferably 20 wt% or less.

The above-mentioned (A) ethylene-α-olefin copolymer, olefin copolymer, or a molded article using this copolymer is a higher fatty acid, erucic acid amide, oleic acid amide, or ethylene, depending on the application. Higher aliphatic amides such as bisoleic acid amide and ethylene bis-erucic acid amide, lubricants and slip agents such as metallic soap and glycerin ester, PMMA fine particles, aluminosilicate, anti-blocking agents such as diatomaceous earth, phenolic, phosphorus, B
Antioxidants such as HT, UV absorbers such as benzophenone, benzotriazole and HALS, flame retardants such as aluminum hydroxide, magnesium hydroxide, phosphorus-based and halogen-based, talc, zeolite, silica, calcium carbonate, barium sulfate, mica , Inorganic / organic fillers such as carbon black, azo type, phthalocyanine type, quinacridone type,
Pigments such as iron oxide and ultramarine, antistatic agents, and surfactants can be added.

With respect to 100 parts by weight of the (A) ethylene-α-olefin copolymer, 0.05 to 1 part by weight of the antiblocking agent and 0.05 to 0.
It is preferable to add 5 parts by weight.

[0038]

EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

The characteristic values were measured as follows. (A) Method for measuring characteristics of ethylene-α-olefin copolymer and olefin copolymer [1] Density: 190 according to JIS K7112
The strand obtained at the time of MFR measurement at 2.16 Kg load at 0 ° C. was heat-treated at 100 ° C. for 1 hour and gradually cooled to room temperature over 1 hour, and a sample was measured using a density gradient tube. [2] Melt flow rate (MFR _2.16 ): JIS
19 using a melt indexer in accordance with K7210
It was determined by measuring the weight of the resin extruded in a strand shape at 0 ° C. under a load of 2.16 Kg for 10 minutes. [3] Melt flow rate ratio (MFR _10.0 / MFR
_2.16 ): 10.0K in the same manner as in the above [2]
It is a value obtained by dividing the resin weight (MFR _10.0 ) determined by g load by the resin weight (MFR _2.16 ) determined in [2] above.

[4] Molecular weight distribution: The molecular weight distribution (Mw / Mn) of the ethylene-α-olefin copolymer composition was measured by gel permeation chromatography (GPC). The measuring method is shown below. (1) Measuring device: WATERS 150CV was used. (2) Measurement sample: The polymer was dissolved in a solvent (o-dichlorobenzene) at a temperature of 145 ° C and a concentration of 1 mg / ml. (3) Molecular weight distribution measurement: measurement sample of the above (2) 0.
4 ml was injected into two GPC columns AT-806MS, solvent o-dichlorobenzene, temperature 145 ° C, 1.0.
The flow rate was ml / min. The measurement by GPC was performed for 35 minutes. The polymer concentration in the solution separated by the GPC column was measured by a differential refractometer (RI). The molecular weight is
Converted according to polystyrene standard. (4) Data processing: The data processing is VAX-STATI.
ON3100 was used. G obtained by the measurement in (3) above
When a baseline is drawn on the PC chromatogram, the area is integrated using the data processing software attached to the device, and the number average molecular weight (Mn), weight average molecular weight (Mw), Mw / Mn
Is calculated automatically. The GPC chromatogram is specified on the screen of the device as the size of the figure, with the horizontal axis being 125 mm per measurement time of 20 minutes, and the vertical axis being the total integrated elution amount being 100.
Performed at 13 mm per 20.

[5] Melt tension: Resin temperature was measured using Capirograph 1C manufactured by Toyo Seiki Seisaku-sho, Ltd.
190 ° C, extrusion speed 10 mm / min, winding speed 20 m /
Minutes, the nozzle diameter was 2.09 mmφ, and the nozzle length was 8 mm.

Evaluation Method of Film Molded Product [1] Haze: The haze was measured according to JIS K7105. [2] Gloss: Measured according to JIS K7105 45 °. [3] Tensile Yield Strength: Based on JIS K7127, it was performed under the conditions of a No. 4 test piece, a chuck distance of 60 mm, and a pulling speed of 500 mm / min. [4] Tensile strength at break: Based on JIS K7127, it was performed under the conditions of a No. 4 test piece, a chuck distance of 60 mm, and a pulling speed of 500 mm / min. [5] Tensile secant elastic modulus: Measured according to JIS K7127
In accordance with, pulling speed 5mm / min, chuck distance 40
mm. The tensile secant elastic modulus was obtained from the stress at the time of 2% deformation. [6] Tear strength: According to JIS K7128 B method (Emendorf method), the No. 1 test method was used. [7] Impact Drilling Strength: A film impact tester manufactured by Toyo Seiki was used, and a 1-inch hemisphere was used as an impact head. [8] Fish eye: Polymer pellets made of Uniplus T-die film molding machine (screw diameter 30 mmφ
L / D = 24, compression ratio 3.5, full flight type), and melted to form 6 layers of screen mesh (# 60/80 /
120/120/80/60) and then, using an air knife and a cooling roll (mirror finish, surface temperature 40 ° C.), a sheet polymer sample having a film thickness of 50 μm was prepared at a take-up speed of 8 m / min. . 0.1 mm observed on a sheet-shaped polymer sample 50 mmφ using a defect inspection device (CCD line sensor system) manufactured by Hutech
The number of fish eyes having a size exceeding 100 was measured. The number of fish eyes was shown by a numerical value calculated by calculating the number of fish eyes in 50 mmφ measured per 1 m ² . [9] Film moldability: Stability was evaluated by visually observing the bubble-melted portion from the die exit to the frost line during air-cooled inflation molding. ◯: There is no pulsation or vibration-like tremor, ×: There is pulsation or vibration-like tremor, and the fold diameter size of the film tube changes.

The characteristics of the ethylene-α-olefin copolymer and the high-pressure low-density polyethylene used are shown in Table 1.

[0044]

[Table 1]

(Examples 1 to 3) Production of olefin copolymer from ethylene-α-olefin copolymer Ethylene-α-olefin copolymer shown in Table 1 and radical generator were blended in the weights shown in Table 2. Later, calcium stearate: 500 ppm, IRGANOX 1076:
1500ppm [Ciba Specialty Chemicals Co., Ltd., chemical name octadecyl-3- (3,5-di-
t-Butyl-4-hydroxyphenyl) propionate] and IRGAFOS 168: 1000 ppm
[Ciba Specialty Chemicals Co., Ltd., chemical name Tris (2,4-di-t-butylphenyl) phosphite] was added, and melt kneading was performed at a temperature of 210 ° C. using a single-screw extruder with a vent. To produce pellets of olefin copolymer.

[0046]

[Table 2]

(Examples 4 to 6) Pellets of the olefin copolymers of Examples 1 to 3 were produced at a temperature of 200 ° C and a thickness of 50 µm using an air-cooled inflation molding apparatus using a 50 mmφ extruder. The obtained film molded product was evaluated, and the results are shown in Table 3.

Reference Example 1 Calcium stearate: 500 ppm, IRGANOX 1076: 15 on polyethylene A produced from the single site catalyst shown in Table 1.
00ppm [Ciba Specialty Chemicals Co., Ltd., chemical name octadecyl-3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate] and IRGAFOS 168: 1000 ppm [Ciba.
Specialty Chemicals Co., Ltd., chemical name Tris (2,4-di-t-butylphenyl) phosphite] was added, and using a vented single-screw extruder, 21
Melt kneading was carried out at a temperature of 0 ° C. to produce olefin copolymer pellets.

Reference Example 2 70 parts by weight of polyethylene A produced from the single-site catalyst shown in Table 1 and 30 parts by weight of polyethylene B, which is a high-pressure low-density polyethylene, were added to calcium stearate: 350 ppm, IRGA.
NOX 1076: 1050ppm [Ciba Specialty Chemicals Co., Ltd., chemical name: octadecyl-
3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and IRGAFOS 168:
700 ppm [Ciba Specialty Chemicals Co., Ltd., chemical name Tris (2,4-di-t-butylphenyl) phosphite] was added, and melt kneading was performed at a temperature of 210 ° C. using a vented single-screw extruder. Then, pellets of the olefin copolymer were produced.

Comparative Examples 1-2 Reference Examples 1-2 shown in Table 2
The olefin copolymer pellets of No. 2 were heated to 200 mm using an air-cooled inflation molding apparatus using a 50 mmφ extruder.
A film having a thickness of 50 μm was produced at a temperature of ° C. The obtained film molded product was evaluated, and the results are shown in Table 3.

[0051]

[Table 3]

[0052]

EFFECT OF THE INVENTION The olefin copolymer of the present invention is a simple and low-cost method without lowering the strength such as the tensile yield strength of the ethylene-α-olefin copolymer produced by a single-site catalyst. It is an improvement in bubble stability during inflation molding such as air cooling of an ethylene-α-olefin copolymer produced with a single-site catalyst and melt parison stability during direct blow molding. Furthermore, this olefin copolymer can provide a molded product such as inflation molding or blow molding.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29K 23:00 B29L 7:00 F term (reference) 4F208 AA03A AA03C AA03E AG01 AG07 AR15 AR17 AR18 LG01 4F210 AA03A AA03C AA03E AG01 AG07 AR15 AR17 AR18 QA01 QK01 4J002 BB051 FD010 FD050 FD070 FD090 FD130 FD170 4J100 AA02P AA03Q AA04Q AA07Q AA16Q AA17Q AA19Q CA04 DA04 DA12 DA42 FA10 JA58

Claims (4)

[Claims] 1. An ethylene-α-olefin copolymer produced from a single-site catalyst having the following characteristics (A) is treated with a radical generator to obtain a melt tension of 0.5 to
20 g of olefin copolymer. (A) Ethylene-α-olefin copolymer: (A-1) Density (d) = 0.895 to 0.950 (g /
^{cm 3) (A-2)} 190 ℃, melt flow rate at 2.16Kg load _{(MFR 2. 16) = 0.1~100 (} g / 1
0 min) (A-3) 190 ℃ , melt flow rate in 10.0Kg load (MFR _{10 .0)} and 190 ° C., 2.16 Kg
Ratio with melt flow rate (MFR _2.16 ) under load (MFR _10.0 ) / (MFR _2.16 ) = 5-10 (A-4) Molecular weight distribution (Mw / Mn) = 2.0-4.0 2. The olefin according to claim 1, wherein 100 parts by weight of an ethylene-α-olefin copolymer produced from a single-site catalyst is treated with 0.01 to 0.5 part by weight of a radical generator. Copolymer. 3. A molded product using the olefin copolymer according to claim 1. 4. The molded product according to claim 3, which is a molded product obtained by inflation molding or blow molding.