JP7828750B2 - Ethylene-nonconjugated polyene copolymer - Google Patents

Description

This invention relates to an ethylene-non-conjugated polyene copolymer suitable for obtaining molded articles with a high melting point (Tm), good mechanical strength, and an excellent balance of processability and mechanical strength.

Polyolefins (olefin polymers), such as polyethylene and polypropylene, are attracting increasing attention in various industries as part of their efforts to create a circular economy through the 3Rs (Reduce, Reuse, Recycle). They require less energy to produce, are lightweight, and are highly recyclable. Polyolefins are used in a wide range of fields, including daily necessities, kitchenware, packaging films, home appliances, machine parts, electrical components, and automotive parts.

It is widely known that the density of polyethylene (ethylene-based polymer) can be adjusted by the copolymerization amount of α-olefin copolymerized with ethylene (for example, Patent Document 1). By appropriately adjusting the copolymerization amount of α-olefin, amorphous ethylene-α-olefin copolymers, linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE) with a wide density range of 875 to 970 kg/ ^m³ are manufactured and sold.

Japanese Patent Publication No. 2009-197225

The objective of this invention is to obtain an ethylene-based polymer with a high density while having a melting point (Tm) equivalent to that of an ethylene-α-olefin copolymer.

This invention relates to an ethylene-non-conjugated polyene copolymer (X) comprising a constituent unit (A) derived from ethylene and a constituent unit (B) derived from a non-conjugated polyene, characterized by satisfying all of the following requirements (1) to (5).

Ethylene-non-conjugated polyene copolymer (X)
(1) The content of constituent units derived from non-conjugated polyenes is in the range of 0.01 to 10 mol% [where the sum of (A) and (B) is 100 mol%].
(2) The intrinsic viscosity [η] measured in decalin at 135°C is in the range of 1.0 to 2.0 dl/g.
(3) The density is in the range of 920 to 950 kg/ ^m³ .
(4) The melting point (Tm) measured by DSC is in the range of 100 to 130°C.
(5) The P value [η*(ω=0.1)/η*(ω=100)] obtained by melt viscoelasticity measurement is in the range of 5 to 100.

The ethylene-non-conjugated diene copolymer of the present invention exhibits better processability (moldability) compared to polyethylene with a similar density. The resulting molded articles have a high melting point (Tm), good mechanical strength, and an excellent balance between processability and mechanical strength.

<Ethylene-nonconjugated polyene copolymer (X)>
The ethylene-non-conjugated polyene copolymer (X) of the present invention (hereinafter sometimes referred to as "polymer (X)") is an ethylene-based copolymer that satisfies all of the following requirements (1) to (5).

<Requirement (1)>
The content of constituent units derived from non-conjugated polyenes is in the range of 0.01 to 10 mol%, preferably 0.05 to 8 mol% (where the sum of (A) and (B) is 100 mol%).

The non-conjugated polyene constituting the copolymer (X) of the present invention is a cyclic or linear non-conjugated polyene. Examples of cyclic non-conjugated polyenes include 5-ethylidene-2-norbornene (ENB), dicyclopentadiene, 5-vinyl-2-norbornene (VNB), norbornadiene, and methyltetrahydroindene. Examples of linear non-conjugated polyenes include 1,4-hexadiene, 7-methyl-1,6-octadiene, 8-methyl-4-ethylidene-1,7-nonadien, and 4-ethylidene-1,7-undecadien. These non-conjugated polyenes can be used individually or in combination of two or more.

Among these non-conjugated polyenes, ENB and VNB are preferred.
Specific examples of the copolymer (X) of the present invention include ethylene-ENB copolymer, ethylene-VNB copolymer, and ethylene-ENB-VNB copolymer.

The molar amount (mol%) of copolymer (X) of the present invention was determined by intensity measurement using a ^1H -NMR spectrometer. Details of the measurement conditions are described in International Publication No. 2015/122415.

<Requirement (2)>
The intrinsic viscosity [η] measured in decalin at 135°C is in the range of 1.0 to 2.0 dl/g, preferably 1.4 to 1.7 dl/g. Copolymers (X) having an intrinsic viscosity [η] within the above range exhibit excellent processability.

<Requirement (3)>
The density is in the range of 920 to 950 kg/ ^m³ , preferably 930 to 940 kg/ ^m³ . Molded articles obtained from copolymers (X) with a density in the above range have excellent mechanical strength.
The density of copolymer (X) was measured in water at 23°C by liquid weighing method in accordance with JIS Z8807:2012.

<Requirement (4)>
The melting point (Tm) measured by DSC is in the range of 100 to 130°C, preferably 100 to 125°C. Molded articles obtained from copolymers (X) with a melting point (Tm) in the above range have excellent mechanical strength.

The melting point (Tm) of copolymer (X) was measured by the following method.
Using a differential scanning calorimeter (DSC), approximately 5 mg of the sample was sealed in an aluminum pan and heated from room temperature to 200°C at a rate of 10°C/min. The sample was then held at 200°C for 3 minutes to completely melt it. Next, it was cooled to 30°C at a rate of 10°C/min and held at 30°C for 3 minutes. Finally, the sample was heated again to 230°C at a rate of 10°C/min. The peak temperature detected during the second heating test was defined as the melting point (Tm).

<Requirement (5)>
The P value [η*(ω=0.1)/η*(ω=100)] determined by melt viscoelasticity measurement is in the range of 5 to 100, preferably 6 to 50, and more preferably 6 to 30.

The P-value is an indicator of processability. Copolymers (X) whose P-values meet the above range exhibit high fluidity and high shape retention in the molten state during molding processes such as extrusion molding, injection molding, film molding, inflation molding, blow molding, extrusion blow molding, injection blow molding, press molding, vacuum molding, powder slush molding, calendering, and foam molding.

In this invention, the "complex viscosity η*" used to measure the P value was determined using an Ares viscoelasticity measuring device (manufactured by Rheometric Scientific) as a rheometer. The complex viscosity η*(ω=0.01) at frequencies ω=0.01 rad/s, ω=0.1 rad/s, ω=10 rad/s, and ω=100 rad/s (all in units of Pa·sec) were measured under conditions of 190°C and 1.0% strain. From these results, the P value (η*(ω=0.1)/η*(ω=100)), which is the ratio of the complex viscosities of η*(ω=0.1) and η*(ω=100), was calculated.

The copolymer (X) of the present invention satisfies all of the above requirements (1) to (5), thereby enabling the production of a molded article with good moldability and excellent mechanical strength.
The copolymer (X) of the present invention, in addition to the above requirements (1) to (5),
The copolymer (X) of the present invention has a melt flow rate (MFR) measured in accordance with JIS K7210 at a temperature of 190°C and a load of 2.16 kg, which is typically in the range of 0.1 to 1.5 g/10 min, preferably 0.2 to 1.0 g/10 min.

<Method for producing ethylene-nonconjugated polyene copolymer (X)>
The copolymer (X) of the present invention can be produced by copolymerizing ethylene and a non-conjugated polyene in the presence of a polymerization catalyst system containing [bis(4-methylphenyl)methylene( ^η5 -cyclopentadienyl)( ^η5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride (metallocene compound (a)), which is a type of metallocene compound.

≪Polymerization catalyst containing metallocene compound (a)≫
Polymerization catalysts that can be suitably used in the production of copolymer (X) of the present invention include those containing the above-mentioned metallocene compound (a) and capable of copolymerizing monomers.

Preferably, the polymerization catalyst comprises (a) a metallocene compound, (b) at least one compound selected from (b-1) an organometallic compound, (b-2) an organoaluminum oxy compound, and (b-3) a compound that reacts with the metallocene compound (a) to form an ion pair (hereinafter also referred to as "ionized ionic compound"), and optionally (c) a particulate support. Each component will be described in detail below.

≪Compound (b)≫
The compound (b) is at least one compound selected from (b-1) organometallic compounds, (b-2) organoaluminum oxy compounds, and (b-3) ionized ionic compounds, and preferably includes at least the organometallic compound (b-1).

(b-1) Organometallic compounds As the organometallic compounds (b-1), for example, organometallic compounds of groups 1 and 2 and groups 12 and 13 of the periodic table, such as those shown in the following general formulas [VII] to [IX], can be used.

(b-1a) General formula: R ^a _m Al (OR ^b ) _n H _p X _q ... [VII]
An organoaluminum compound represented by formula [VII] (wherein ^Ra and R ^b may be the same or different, and represent a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4; X represents a halogen atom; m is a number where 0 < m ≤ 3, n is a number where 0 ≤ n < 3, p is a number where 0 ≤ p < 3, and q is a number where 0 ≤ q < 3, and m + n + p + q = 3).

Examples of such compounds include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, and tri-n-octylaluminum, tricycloalkylaluminum, isobutylaluminum dichloride, diethylaluminum chloride, ethylaluminum dichloride, ethylaluminum sesquichloride, methylaluminum dichloride, dimethylaluminum chloride, and diisobutylaluminum hydride.

(b-1b) General formula: M ² AlR ^a ₄ ...[VIII]
A complex alkylate of a Group 1 metal of the periodic table and aluminum, represented by formula [VIII] (wherein ^M2 represents Li, Na, or K, and ^Ra is a hydrocarbon group having 1 to 15, preferably 1 to 4, carbon atoms).
Examples of such compounds include LiAl _{( C2H5} ) ₄ and LiAl _{( C7H15} ) ₄ .

(b-1c) General formula: R ^a R ^b M ³ ...[IX]
A dialkyl compound having a Group 2 or Group 12 metal of the periodic table, represented by formula [IX] (wherein ^Ra and R ^b may be the same or different, and represent a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4, and M ³ is Mg, Zn, or Cd).

Among the organometallic compounds (b-1) listed above, organoaluminum compounds such as triethylaluminum, triisobutylaluminum, and tri-n-octylaluminum are preferred. Furthermore, such organometallic compounds (b-1) may be used individually or in combination of two or more.

(b-2) Organoaluminum oxy compound The organoaluminum oxy compound (b-2) may be a conventionally known aluminoxane, or it may be a benzene-insoluble organoaluminum oxy compound as exemplified in Japanese Patent Application Publication No. 2-78687.

Conventionally known aluminoxanes can be produced by methods such as those described below, and are usually obtained as solutions in a hydrocarbon solvent.
(1) A method of reacting the adsorbed water or crystal water with the organoaluminum compound by adding an organoaluminum compound such as trialkylaluminum to a suspension of a hydrocarbon medium containing a compound or salt containing crystal water, such as magnesium chloride hydrate, copper sulfate hydrate, aluminum sulfate hydrate, nickel sulfate hydrate, or cerium chloride hydrate. (2) A method of directly reacting an organoaluminum compound such as trialkylaluminum with water, ice, or water vapor in a medium such as benzene, toluene, ethyl ether, or tetrahydrofuran.
(3) A method of reacting organoaluminum compounds such as trialkylaluminum with organotin oxides such as dimethyltin oxide and dibutyltin oxide in a medium such as decane, benzene, or toluene.

Furthermore, the aluminoxane may contain small amounts of organometallic components. Alternatively, after removing the solvent or unreacted organoaluminum compounds from the recovered aluminoxane solution by distillation, the solution may be redissolved in a solvent or suspended in a poor solvent for the aluminoxane.

Examples of organoaluminum compounds used in the preparation of aluminoxanes include those similar to those exemplified as organoaluminum compounds belonging to (b-1a) above.

Of these, trialkylaluminum and tricycloalkylaluminum are preferred, and among them, trimethylaluminum and triisobutylaluminum are particularly preferred.
The organoaluminum compounds described above can be used individually or in combination of two or more.

Furthermore, one embodiment of the organoaluminum oxy compound (b-2) used in the present invention, which is a benzene-insoluble organoaluminum oxy compound, is preferably one in which the Al component that dissolves in benzene at 60°C is typically 10% by weight or less, preferably 5% by weight or less, and particularly preferably 2% by weight or less, relative to 100% by weight of benzene, in terms of Al atoms; that is, it is preferably insoluble or sparingly soluble in benzene.

The organoaluminum oxy compound (b-2) used in this invention may also include an organoaluminum oxy compound containing boron represented by the following general formula [X].

(In formula [X], ^R1 represents a hydrocarbon group having 1 to 10 carbon atoms, and ^R2 to ^R5 may be the same or different from each other, and represent a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 10 carbon atoms.)

The boron-containing organoaluminum oxy compound represented by the general formula [X] is,
General formula: R ¹ -B(OH) ₂ ...[XI]
It can be produced by reacting an alkylboronic acid represented by formula [XI] (wherein R ¹ represents the same group as R ¹ in the general formula [X]) with an organoaluminum compound in an inert solvent under an inert gas atmosphere at a temperature of -80°C to room temperature for 1 minute to 24 hours.

Examples of alkylboronic acids represented by the general formula [XI] include methylboronic acid, ethylboronic acid, isopropylboronic acid, n-propylboronic acid, n-butylboronic acid, isobutylboronic acid, n-hexylboronic acid, cyclohexylboronic acid, phenylboronic acid, 3,5-difluorophenylboronic acid, pentafluorophenylboronic acid, and 3,5-bis(trifluoromethyl)phenylboronic acid.

Among these, methylboronic acid, n-butylboronic acid, isobutylboronic acid, 3,5-difluorophenylboronic acid, and pentafluorophenylboronic acid are preferred. These can be used individually or in combination of two or more.

Examples of organoaluminum compounds to be reacted with such alkylboronic acids include those similar to those exemplified as organoaluminum compounds belonging to (b-1a) above. Of these, trialkylaluminum and tricycloalkylaluminum are preferred, and trimethylaluminum, triethylaluminum, and triisobutylaluminum are particularly preferred.
The organoaluminum oxy compounds (b-2) described above can be used individually or in combination of two or more.

(b-3) Ionized Ionic Compounds Examples of the ionized ionic compounds (b-3) include Lewis acids, ionic compounds, borane compounds, and carborane compounds described in Japanese Patent Publication No. 1-501950, Japanese Patent Publication No. 1-502036, Japanese Patent Publication No. 3-179005, Japanese Patent Publication No. 3-179006, Japanese Patent Publication No. 3-207703, Japanese Patent Publication No. 3-207704, USP 5321106, etc. Furthermore, heteropoly compounds and isopoly compounds can also be mentioned. Such ionized ionic compounds (b-3) can be used individually or in combination of two or more.

Specifically, examples of Lewis acids include compounds represented by _BR3 (where R is a phenyl group or fluorine, which may have substituents such as fluorine, a methyl group, or a trifluoromethyl group), such as trifluoroborone, triphenylborone, tris(4-fluorophenyl)borone, tris(3,5-difluorophenyl)borone, tris(4-fluoromethylphenyl)borone, tris(pentafluorophenyl)borone, tris(p-tolyl)borone, tris(o-tolyl)borone, and tris(3,5-dimethylphenyl)borone.

Examples of ionic compounds include those represented by the following general formula [XII].

(In formula [XII], R1 ⁺ can be H ⁺ , a carbonium cation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptyltrienyl cation, or a ferrocenium cation having a transition metal. ^R2 to ^R5 may be the same or different from each other, and are organic groups, preferably aryl groups or substituted aryl groups.)

Specifically, examples of the aforementioned carbonium cations include trisubstituted carbonium cations such as triphenylcarbonium cation, tri(methylphenyl)carbonium cation, and tri(dimethylphenyl)carbonium cation.

Specifically, the ammonium cations mentioned above include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, tributylammonium cation, and tri(n-butyl)ammonium cation;
N,N-dialkylanilinium cations such as N,N-dimethylanilinium cation, N,N-diethylanilinium cation, and N,N,2,4,6-pentamethylanilinium cation;
Examples include di(isopropyl)ammonium cations and dialkylammonium cations such as dicyclohexylammonium cations.

Specifically, examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tri(methylphenyl)phosphonium cation, and tri(dimethylphenyl)phosphonium cation.

As R1 ⁺ , carbonium cations and ammonium cations are preferred, and triphenylcarbonium cations, N,N-dimethylanilinium cations, and N,N-diethylanilinium cations are particularly preferred.

Furthermore, examples of ionic compounds include trialkylsubstituted ammonium salts, N,N-dialkylanilinium salts, dialkylammonium salts, and triarylphosphonium salts.

Specific examples of trialkyl-substituted ammonium salts include, for example, triethylammonium tetra(phenyl)boron, tripropylammonium tetra(phenyl)boron, tri(n-butyl)ammonium tetra(phenyl)boron, trimethylammonium tetra(p-tolyl)boron, trimethylammonium tetra(o-tolyl)boron, tri(n-butyl)ammonium tetra(pentafluorophenyl)boron, tripropylammonium tetra(o,p-dimethylphenyl)boron, tri(n-butyl)ammonium tetra(N,N-dimethylphenyl)boron, tri(n-butyl)ammonium tetra(p-trifluoromethylphenyl)boron, tri(n-butyl)ammonium tetra(3,5-ditrifluoromethylphenyl)boron, and tri(n-butyl)ammonium tetra(o-tolyl)boron.

Examples of N,N-dialkylanilinium salts include, for example, N,N-dimethylanilinium tetra(phenyl)boron, N,N-diethylanilinium tetra(phenyl)boron, and N,N,2,4,6-pentamethylanilinium tetra(phenyl)boron.

Examples of dialkylammonium salts include, for instance, di(1-propyl)ammonium tetra(pentafluorophenyl)boron and dicyclohexylammonium tetra(phenyl)boron.

Furthermore, other ionic compounds include triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, ferrocenium tetra(pentafluorophenyl)borate, triphenylcarbenium pentaphenylcyclopentadienyl complex, N,N-diethylanilinium pentaphenylcyclopentadienyl complex, and boron compounds represented by the following formulas [XIII] or [XIV]. In the following formulas, Et represents an ethyl group.

Specific examples of borane compounds include decaborane; salts of anions such as bis[tri(n-butyl)ammonium]nonaborate, bis[tri(n-butyl)ammonium]decaborate, bis[tri(n-butyl)ammonium]undecaborate, bis[tri(n-butyl)ammonium]dodecaborate, bis[tri(n-butyl)ammonium]decachlorodecaborate, and bis[tri(n-butyl)ammonium]dodecachlorododecaborate; and salts of metal borane anions such as tri(n-butyl)ammonium bis(dodecahydridedodecaborate)cobaltate (III) and bis[tri(n-butyl)ammonium]bis(dodecahydridedodecaborate)nickelate (III).

Specifically, examples of carborane compounds include 4-carbanonaborane, 1,3-dicarbanonaborane, 6,9-dicarbadecaborane, dodecahydride-1-phenyl-1,3-dicarbanonaborane, dodecahydride-1-methyl-1,3-dicarbanonaborane, undecahydride-1,3-dimethyl-1,3-dicarbanonaborane, 7,8-dicarbowndecaborane, 2,7-dicarbowndecaborane, and undecahydride-7,8-dimethyl-7,8 -Dicarboundecaporane, dodecahydride-11-methyl-2,7-dicarboundecaporane, tri(n-butyl)ammonium 1-carbadecaborate, tri(n-butyl)ammonium-1-carboundecaporate, tri(n-butyl)ammonium-1-carbadodecaborate, tri(n-butyl)ammonium-1-trimethylsilyl-1-carbadecaborate, tri(n-butyl)ammonium bromo-1-carbadodecaborate, tri(n-butyl ) Ammonium-6-carbadecaborate, tri(n-butyl)ammonium-7-carboundadecaborate, tri(n-butyl)ammonium-7,8-diccarboundadecaborate, tri(n-butyl)ammonium-2,9-diccarboundadecaborate, tri(n-butyl)ammonium dodecahydride-8-methyl-7,9-diccarboundadecaborate, tri(n-butyl)ammonium undecahydride-8-ethyl-7,9-diccarboundadecaborate Salts of anions such as tri(n-butyl)ammonium undecahydride-8-butyl-7,9-dicalbound decaborate, tri(n-butyl)ammonium undecahydride-8-allyl-7,9-dicalbound decaborate, tri(n-butyl)ammonium undecahydride-9-trimethylsilyl-7,8-dicalbound decaborate, and tri(n-butyl)ammonium undecahydride-4,6-dibromo-7-carbound decaborate;
Tri(n-butyl)ammonium bis(nonahydride-1,3-dicarbanonaborate)cobaltate (III), tri(n-butyl)ammonium bis(undekahydride-7,8-dicarbanonaborate)ferrate (III), tri(n-butyl)ammonium bis(undekahydride-7,8-dicarbanonaborate)cobaltate (III), tri(n-butyl)ammonium bis(undekahydride-7,8-dicarbanonaborate)nickelate (III), tri(n-butyl)ammonium bis(undekahydride-7,8-dicarbanonaborate)copperate (III), tri(n-butyl)ammonium bis(undekahydride-7,8-dicarbanonaborate)goldate (III), tri(n-butyl)ammonium bis(nonahydride-7,8-dimethyl-7,8-dicarbanonaborate)ferric acid Examples include salts of metal carborane anions such as salt (III), tri(n-butyl)ammonium bis(nonahydride-7,8-dimethyl-7,8-dicarboundecaborate)chromate (III), tri(n-butyl)ammonium bis(tribromooctahydride-7,8-dicarboundecaborate)cobaltate (III), tris[tri(n-butyl)ammonium]bis(undekahydride-7-carboundecaborate)chromate (III), bis[tri(n-butyl)ammonium]bis(undekahydride-7-carboundecaborate)manganate (IV), bis[tri(n-butyl)ammonium]bis(undekahydride-7-carboundecaborate)cobaltate (III), and bis[tri(n-butyl)ammonium]bis(undekahydride-7-carboundecaborate)nickelate (IV).

Heteropoly compounds consist of atoms selected from silicon, phosphorus, titanium, germanium, arsenic, and tin, and one or more atoms selected from vanadium, niobium, molybdenum, and tungsten. Specifically, this includes, but is not limited to, salts of these acids with metals from Group 1 or 2 of the periodic table, specifically lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, triphenylethylamine, and other organic salts.

Among the ionized ionic compounds (b-3), the above-mentioned ionic compounds are preferred, and among them, triphenylcarbenium tetrakis(pentafluorophenyl)borate and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate are more preferred.

In this invention, when a metallocene catalyst containing the above-mentioned metallocene compound (a), an organometallic compound such as triisobutylaluminum (b-1), an organoaluminum oxy compound such as methylaluminoxane (b-2), and an ionized ionic compound such as triphenylcarbenium tetrakis (pentafluorophenyl) borate (b-3) is used as the polymerization catalyst, extremely high polymerization activity can be achieved in the production of copolymer (X).

(c) Particulate carrier The particulate carrier (c) used as necessary in the present invention is an inorganic compound or an organic compound, which is a solid in the form of granules or fine particles.

Preferred inorganic compounds include porous oxides, inorganic halides, clays, clay minerals, or ion-exchangeable layered compounds. Specific examples of these are those described in Publication No. WO2015/122495.

The clay, clay minerals, and ion-exchangeable layered compounds used in this invention may be used as is, or after being subjected to treatments such as ball milling or sieving. They may also be used after being newly treated with water adsorption or heat dehydration. Furthermore, they may be used individually or in combination of two or more.

Of these, clay or clay minerals are preferred, with montmorillonite, vermiculite, hectorite, teniolite, and synthetic mica being particularly preferred.
Examples of organic compounds include granular or particulate solids with particle sizes ranging from 10 to 300 μm. Specifically, examples include (co)polymers produced mainly from α-olefins having 2 to 14 carbon atoms, such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene, or (co)polymers produced mainly from vinylcyclohexane and styrene, and their modified products.

The polymerization catalyst used in this invention comprises a metallocene compound (a), at least one compound (b) selected from organometallic compounds (b-1), organoaluminum oxy compounds (b-2), and ionized ionic compounds (b-3), and a support (c) as needed, and may also optionally include a specific organic compound component (d).

(d) Organic compound component In the present invention, the organic compound component (d) is used as needed to improve polymerization performance and the physical properties of the resulting polymer. Examples of such organic compounds include, but are not limited to, alcohols, phenolic compounds, carboxylic acids, phosphorus compounds, and sulfonates.

<<Method and conditions for producing copolymer (X)>>
The copolymer (X) of the present invention is produced by copolymerizing ethylene with a non-conjugated polyene.
When copolymerizing such monomers, the method of use and the order of addition of each component constituting the polymerization catalyst mentioned above can be arbitrarily selected, but the following methods (1) to (5) are examples.
(1) A method of adding metallocene compound (a) alone to a polymerizer.
(2) A method of adding metallocene compound (a) and compound (b) to a polymerizer in any order.
(3) A method of adding a catalyst component in which a metallocene compound (a) is supported on a carrier (c) and compound (b) to a polymerizer in any order.
(4) A method of adding a catalyst component in which compound (b) is supported on a support (c) and a metallocene compound (a) to a polymerizer in any order.
(5) A method of adding a catalyst component, in which metallocene compound (a) and compound (b) are supported on a support (c), to a polymerizer.

In each of the methods described in (2) to (5) above, at least two of the metallocene compound (a), compound (b), and carrier (c) may be in contact with each other beforehand.
In the methods described in (4) and (5) above, in which compound (b) is supported, unsupported compound (b) may be added in any order as needed. In this case, compound (b) may be the same as or different from compound (b) supported on the carrier (c).

Furthermore, the solid catalyst component in which metallocene compound (a) is supported on the above-mentioned support (c), and the solid catalyst component in which metallocene compound (a) and compound (b) are supported on the support (c), may have the olefin prepolymerized, and the catalyst component may be further supported on the prepolymerized solid catalyst component.

The copolymer (X) of the present invention can be suitably obtained by copolymerizing ethylene and a non-conjugated polyene in the presence of the polymerization catalyst described above.
When polymerizing ethylene and non-conjugated polyene using the polymerization catalyst described above, the metallocene compound (a) is used in an amount that is typically ^10⁻¹² to ^10⁻² moles, preferably ^10⁻¹⁰ to ^10⁻⁸ moles, per liter of reaction volume.

Compound (b-1) is used in an amount such that the molar ratio [(b-1)/M] of compound (b-1) to the total transition metal atoms (M) in the metallocene compound (a) is typically 0.01 to 50,000, preferably 0.05 to 10,000. Compound (b-2) is used in an amount such that the molar ratio [(b-2)/M] of aluminum atoms in compound (b-2) to the total transition metals (M) in the metallocene compound (a) is typically 10 to 50,000, preferably 20 to 10,000. Compound (b-3) is used in an amount such that the molar ratio [(b-3)/M] of compound (b-3) to the transition metal atoms (M) in the metallocene compound (a) is typically 1 to 20, preferably 1 to 15.

In the present invention, the method for producing copolymer (X) can be carried out using either a liquid-phase polymerization method such as solution polymerization or suspension polymerization, or a gas-phase polymerization method, and is not particularly limited, but it is preferable to have a step of obtaining the polymerization reaction solution described below.

The step of obtaining the polymerization reaction solution involves using an aliphatic hydrocarbon as the polymerization solvent and copolymerizing ethylene and a non-conjugated polyene in the presence of the metallocene compound (a) to obtain the polymerization reaction solution of copolymer (X).

Examples of polymerization solvents include aliphatic hydrocarbons and aromatic hydrocarbons. Specifically, these include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene, and xylene; and halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane. These can be used individually or in combination of two or more. Furthermore, the olefin itself can be used as the solvent. Of these, hexane is preferred from the viewpoint of separation and purification from the resulting copolymer (A).

Furthermore, the polymerization temperature is typically in the range of -50 to +200°C, preferably 0 to +150°C, and more preferably +70 to +110°C. While this depends on the target molecular weight and polymerization activity of the metallocene catalyst system used, higher temperatures (above +70°C) are desirable from the viewpoint of catalytic activity, copolymerizability, and productivity.

The polymerization pressure is typically atmospheric pressure to 10 MPa gauge pressure, preferably 1.1 to 5 MPa gauge pressure, and more preferably 1.2 to 2.0 MPa gauge pressure. The polymerization reaction can be carried out using batch, semi-continuous, or continuous methods. Furthermore, polymerization can be carried out in two or more stages with different reaction conditions. In this invention, it is preferable to employ a method in which ethylene and non-conjugated polyene are continuously supplied to the reactor for copolymerization.

The reaction time (or average residence time if copolymerization is carried out by a continuous process) varies depending on conditions such as catalyst concentration and polymerization temperature, but is typically 0.5 minutes to 5 hours, preferably 5 minutes to 3 hours, and more preferably 10 minutes to 2 hours.

The molecular weight of the resulting copolymer (X) can be adjusted by introducing hydrogen into the polymerization system or by changing the polymerization temperature. Furthermore, it can also be adjusted by the amount of compound (b) used. Specific examples include triisobutylaluminum, methylaluminoxane, and diethylzinc. When adding hydrogen, an appropriate amount is approximately 0.001 to 100 NL per kg of olefin.

In the present invention, it is preferable to include a step (2) in which a catalyst deactivator is added after a step (1) in which copolymerization is carried out in the presence of the polymerization catalyst.
Alcohols can be used as the catalyst deactivator, with methanol or ethanol being preferred, and ethanol being particularly preferred.

In step (2) above, by adding the catalyst deactivator in an amount preferably 0.05 to 3.0 mol, more preferably 0.06 to 2.5 mol, and even more preferably 0.08 to 2.0 mol relative to the organometallic compound (b-1), a small amount of catalyst modified by the catalyst deactivator such as ethanol is generated, and the low molecular weight components are appropriately polymerized. As a result, a copolymer (X) with a moderately broad molecular weight distribution can be obtained. On the other hand, if too much catalyst deactivator is added, almost no modified catalyst is generated, and the polymerization of low molecular weight components hardly occurs, so the molecular weight distribution of the resulting copolymer (X) tends to be narrow. Furthermore, if no catalyst deactivator is added, or if too little is added, a large amount of modified catalyst is generated, and a large amount of low molecular weight components are polymerized, so the content of low molecular weight components in the resulting copolymer (X) tends to be too high.

<Applications of ethylene-nonconjugated polyene copolymer (X)>
The copolymer (X) of the present invention can be used in various known molded articles.
The copolymer (X) of the present invention may optionally contain various additives commonly used in polyolefins, such as heat stabilizers, weather stabilizers, ultraviolet absorbers, light stabilizers, inorganic fillers such as talc, calcium carbonate, metal powders, titanium dioxide, and zinc oxide, waxes, lubricants, slip agents, nucleating agents, antiblocking agents, antistatic agents, antifogging agents, pigments, dyes, dispersants, flame retardants, flame retardant aids, plasticizers, and compatibilizers, to the extent that they do not impair the objectives of the present invention.

<Molded body>
The molded article of the present invention contains the copolymer (X) of the present invention. Specific examples of methods for producing the molded article (molding method) include conventionally known methods for molding polyolefins, such as known thermoforming methods including extrusion molding, injection molding, film molding, inflation molding, blow molding, extrusion blow molding, injection blow molding, press molding, vacuum molding, powder slush molding, calendering, and foam molding.

The molded article made from the copolymer (X) of the present invention also exhibits excellent mechanical properties.
Specific examples of molded products include those used in a wide range of applications, from household goods such as daily necessities and recreational items to general industrial and industrial products. Examples include home appliance materials and parts, communication equipment parts, electrical components, electronic components, automobile parts, other vehicle parts, ship and aircraft materials, mechanical mechanism parts, building materials, civil engineering components, agricultural materials, power tool parts, food containers, films, sheets, and fibers.

The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.
The symbols (a) to (w) shown in Examples 1 to 3 represent the quantities of each unit shown in Table 1 below.

[Examples 1-3]
Dehydrated and purified n-hexane (C6) was supplied at a rate of (a) L/h to one feed port of a 136 L continuous polymerizer, and from the other feed port, a hexane solution of [bis(4-methylphenyl)methylene( ^η5 -cyclopentadienyl)( ^η5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride (ZD) (b) mmol/L at a rate of (c) L/h, a hexane solution of triisobutylaluminum (4 mmol/L) (d) L/h, a hexane slurry of triphenylcarbenium tetrakis(pentafluorophenyl) borate (CB-3) (e) mmol-B/L) at a rate of (f) L/h, VNB (g) g/h, and ENB (h) g/h were continuously supplied [Total hexane (T-C6): (i) L/h]. Simultaneously, ethylene (C2) was continuously supplied to another supply port of the polymerizer at a rate of (j) kg/h and hydrogen at a rate of (k) NL/h, and continuous solution polymerization was carried out under conditions of polymerization temperature: 1°C, total pressure (m) MPaG, and residence time (n) minutes.

The hexane solution of the ethylene-non-conjugated polyene copolymer (X) produced in the polymerizer was continuously discharged through an outlet provided on the side wall of the polymerizer and led to a connecting pipe whose jacket section was heated with 8 kg/ ^cm² of steam. The hexane solution of ethylene-non-conjugated polyene copolymer (X), heated to approximately 170°C in the steam-jacketed connecting pipe, was continuously supplied to the flash tank through a double-walled pipe heated with 10 kg/ ^cm² of steam, by adjusting the opening of a liquid level control valve provided at the end of the connecting pipe to maintain a solution volume of approximately 28 L in the polymerization tank. Immediately after the liquid level control valve, a supply port for the injection of methanol, a catalyst deactivator, was provided, and a 1.0 vol% hexane diluted solution was injected at a rate of 12 L/h and merged with the hexane solution. During transfer to the flash tank, the solution temperature and pressure adjustment valve opening were set to maintain a pressure of 0.05 MPaG in the flash tank and a steam temperature of 180°C in the flash tank.

As a result, ethylene-non-conjugated polyene copolymer (X) was obtained at a production rate of (p) kg/h. The polymerization miles of ethylene-non-conjugated polyene copolymer (X) were (q) kg/mol-Zr, the [η] of ethylene-non-conjugated polyene copolymer (X) was (r) dl/g, the MFR was (s) g/10 min, the melting point (Tm) was (t) °C, the density was (u) kg/ ^m³ , the VNB content was (v) mol% (mol%), and the ENB content was (w) mol% (mol%).

The physical properties of the polymers obtained in the examples and reference examples were measured using the following measurement methods.
(1) Tensile properties A 4 mm thick sheet was prepared by press molding, and Type 1B test specimens were punched out. The tensile yield stress, tensile fracture strain, and tensile fracture stress were measured in accordance with JIS K7161 and JIS K7162.
(2) Durometer hardness (D hardness)
A 4 mm thick sheet was produced by press molding, a Type 1B test specimen was punched out, and the hardness (D) was measured in accordance with JIS K7215.

[Reference example 1]
As the linear low-density polyethylene (LLDPE), ethylene-1-hexene copolymer [product name Ultzex 2022F, manufactured by Prime Polymer Co., Ltd.] (UZ2022F) was used.
The results are shown in Table 1.

As is clear from Table 1, the ethylene-non-conjugated polyene copolymer (X) shown in Examples 1-3 has a higher P value, higher fluidity in molding processes, and better shape retention in the molten state compared to the LLDPE shown in the Reference Example. Furthermore, despite having a melting point (Tm) equivalent to or lower than the LLDPE shown in the Reference Example, the ethylene-non-conjugated polyene copolymer (X) shown in Examples 1-3 exhibits higher tensile fracture stress due to its higher P value.

Claims (3)

A method for producing an ethylene-nonconjugated polyene copolymer (X),
The process includes copolymerizing ethylene and a non-conjugated polyene in the presence of a polymerization catalyst system containing [bis(4-methylphenyl)methylene(η5 ^- cyclopentadienyl)(η5 ^- octamethyloctahydrodibenzofluorenyl)]zirconium dichloride.
The ethylene-non-conjugated polyene copolymer (X) comprises a constituent unit (A) derived from ethylene and a constituent unit (B) derived from a non-conjugated polyene, and is characterized by satisfying all of the following requirements (1) to (5) :
A method for producing an ethylene-nonconjugated polyene copolymer (X).
( 1) The content of constituent units derived from non-conjugated polyenes is in the range of 0.01 to 10 mol% [where the sum of (A) and (B) is 100 mol%].
(2) The intrinsic viscosity [η] measured in decalin at 135°C is in the range of 1.0 to 2.0 dl/g.
(3) The density is in the range of 920 to 950 kg/ ^m³ .
(4) The melting point (Tm) measured by DSC is in the range of 100 to 130°C.
(5) The P value [η*(ω=0.1)/η*(ω=100)] obtained by melt viscoelasticity measurement at 190°C is in the range of 5 to 100. A method for producing the copolymer (X) according to claim 1, characterized in that the non-conjugated polyene of the ethylene-non-conjugated polyene copolymer (X) is selected from 5-vinyl-2-norbornene and 5-ethylidene-2-norbornene. A method for producing the copolymer (X) according to claim 1 or 2, characterized in that the ethylene-non-conjugated polyene copolymer (X) contains 1.0 mol% or less of structural units derived from α-olefins having 3 or more carbon atoms.