Polyethylene composition and process for producing same

• US 20040214953A1
• Filed: 04/27/2004
• Published: 10/28/2004
• Est. Priority Date: 04/28/2003
• Status: Active Grant

• Current Assignee: Tosoh Corporation
• Original Assignee: Tosoh Corporation
• Inventors: Yamada, Satoru, Yamaguchi, Masayuki, Yano, Akihiro, Inatomi, Kei, Wakabayashi, Yasutake
• Granted Patent: US 7,678,866 B2
• Time in Patent Office: Days
• US Class Current: 525/240
• CPC Class Codes: C08F 210/02 Ethene
• CPC Class Codes: C08F 290/042 Polymers of hydrocarbons as defined in group C08F10/00
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 23/08 Copolymers of ethene C08L23/16 takes precedence
• CPC Class Codes: C08L 2314/06 Metallocene or single site catalysts
• CPC Class Codes: C08L 2666/06 Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof
• CPC Class Codes: Y10S 526/903 Monomer polymerized in presence of transition metal containing catalyst and hydrocarbon additive affecting polymer properties of catalyst activity

Abstract

A polyethylene composition prepared by polymerizing ethylene and an optional olefin with ≧3 carbon atoms in the presence of a macromonomer, is provided. The macromonomer is a vinyl-terminated ethylene polymer prepared by polymerizing ethylene and an optional olefin with ≧3 carbon atoms, and the macromonomer has (A) Mn≧5,000, and Mw/Mn=2-5. The polyethylene composition comprises (C) branched polyethylene prepared by copolymerizing ethylene, the macromonomer and an optional olefin with ≧3 carbon atoms, and the macromonomer. The polyethylene composition has (D) a density of 0.890-0.980 g/cm³, (E) Mw=30,000-10,000,000, (F) Mw/Mn=2-30, (G) a long chain branch frequency of 0.01-3 per 1,000 C atoms, and (H) a shrinking factor (g′ value) of 0.1-0.9 as measured by GPC/intrinsic-viscosity. The polyethylene composition can be finely divided particles having (P) a powder bulk density of 0.15-0.50 g/cm³.

Claims

1. A polyethylene composition which is prepared by polymerizing ethylene and an optional olefin having at least three carbon atoms in the presence of a macromonomer, wherein the macromonomer is an ethylene polymer having a terminal vinyl group, prepared by polymerizing ethylene, or an ethylene copolymer having a terminal vinyl group, prepared by copolymerizing ethylene and an olefin having at least three carbon atoms, and

the macromonomer is characterized by having:

(A) a number average molecular weight (Mn) of at least 5,000, and

(B) a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn), in the range of 2 to 5; and

the polyethylene composition is characterized by comprising;

(C) based on the weight of the polyethylene composition, 1% to 99% by weight of branched polyethylene which is a copolymer derived from ethylene, the macromonomer and an optional olefin having at least three carbon atoms, and 1% to 99% by weight of the macromonomer, and

the polyethylene composition is further characterized by having;

(D) a density in the range of 0.890 g/cm³ to 0.980 g/cm

(E) a weight average molecular weight (Mw) in the range of 30,000 to 10,000,000,

(F) a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn), in the range of 2 to 30,

(G) a frequency of long chain branches in the range of 0.01 to 3 per 1,000 carbon atoms, and

(H) a shrinking factor (g′

value) as determined by a combination of gel permeation chromatography (GPC) and on-line intrinsic viscosity measurements, in the range of at least 0.1 but smaller than 0.9.

2. The polyethylene composition according to claim 1, which is prepared by polymerizing ethylene and an optional olefin having at least three carbon atoms in the presence of a macromonomer, wherein the macromonomer is an ethylene polymer having a terminal vinyl group, prepared by polymerizing ethylene, or an ethylene copolymer having a terminal vinyl group, prepared by copolymerizing ethylene and an olefin having at least three carbon atoms, and

the macromonomer is characterized by having:

(A) a Mn of at least 5,000, and

(B) a Mw/Mn ratio in the range of 2 to 5; and

the polyethylene composition is characterized by comprising;

(C′

) based on the weight of the polyethylene composition, 30% to 80% by weight of branched polyethylene which is a copolymer derived from ethylene, the macromonomer and an optional olefin having at least three carbon atoms, and 20% to 70% by weight of the macromonomer, and

the polyethylene composition is further characterized by having;

(D) a density in the range of 0.890 g/cm³ to 0.980 g/cm³,

(E) a Mw in the range of 30,000 to 10,000,000,

(F′

) a Mw/Mn ratio in the range of 2 to 8,

(G) a frequency of long chain branches in the range of 0.01 to 3 per 1,000 carbon atoms, and

(H) a g′

value in the range of at least 0.1 but smaller than 0.9.

3. The polyethylene composition according to claim 1, wherein the macromonomer is a linear ethylene polymer having a terminal vinyl group, prepared by polymerizing ethylene and an optional olefin having at least three carbon atoms, and

the macromonomer is further characterized by having:

(J) a Z value in the range of 0.25 to 1 as defined by the following equation (1);

Z=[X/(X+Y)]×

2 

 

(1)

wherein X is frequency of vinyl terminal groups per 1,000 methylene carbon atoms in the main chain of macromonomer, and Y is frequency of saturated terminal groups per 1,000 methylene carbon atoms in the main chain of macromonomer.

4. The polyethylene composition according to claim 1, which is further characterized by satisfying the following relationship (2):

(K)0.2<

log(g′

)/log(g)<

1.3 

 

(2)

wherein g is a shrinking factor (g value) as determined by a combination of gel permeation chromatography (GPC) and light scattering measurements.

5. The polyethylene composition according to claim 1, which is further characterized by having:

(L) a flow activation energy (Ea) in the range of 30 kJ/mol to 100 kJ/mol.

6. The polyethylene composition according to claim 1, which is further characterized by satisfying the following relationship (3):

(M)MS₁₉₀>

22×

MFR<sup>−

0.88</sup> 

 

(3)

wherein MS₁₉₀ is a melt strength (MS) (mN) as measured at a temperature of 190°

C., and MFR is a melt flow rate (g/10 min.) as measured under a load of 2.16 kg and at a temperature of 190°

C.

7. The polyethylene composition according to claims 1, which is further characterized by satisfying the following relationship (27):

(M′

)MS₁₆₀>

110−

110×

log(MFR) 

 

(27)

wherein MS₁₆₀ is a melt strength (MS) (mN) as measured at a temperature of 160°

C., and MFR is a melt flow rate (g/10 min.) as measured under a load of 2.16 kg and at a temperature of 190°

C.

8. The polyethylene composition according to claim 1, which is further characterized by having:

(N) a non-linear parameter (λ

) for elongation viscosity in the range of 1.2 to 100.

9. The polyethylene composition according to claim 1, which is further characterized by satisfying the following formula (4):

(O)log(DR)>

5−

1.33×

log(MS₁₆₀) 

 

(4)

wherein DR is a maximum drawing ratio and MS₁₆₀ is a melt strength (MS) as measured at a temperature of 160°

C.

18. A process for producing the polyethylene composition as claimed in claim 1, which comprises polymerizing ethylene and an optional olefin having at least three carbon atoms in the presence of the macromonomer and a catalyst comprising as the main ingredient a metallocene compound [ingredient (d)] represented by the following general formula (5):

19. The process for producing the polyethylene composition according to claim 18, wherein the catalyst comprising as the main ingredient the metallocene compound [ingredient (d)], further comprises (b) a modified clay compound.

20. The producing process according to claim 19, wherein the modified clay compound [ingredient (b)] is a modified clay compound which has been treated with an organic compound represented by the following general formula (17):

[R¹³_kGH]⁺[A] 

 

(17)

wherein G is an element selected from those of group 15 or 16 of the periodic table, R¹³ independently represents a hydrogen atom or a substituent including a hydrocarbon group having 1 to 30 carbon atoms, provided that at least one of R¹³s is a hydrocarbon group having 1 to 30 carbon atoms, wherein each R¹³ may be bound to another R¹³;

when G is an element selected from those of group 15, k is 3, and, when G is an element selected from those of group 16, k is 2; and

[A]⁻

is a counter anion.

10. A particulate polyethylene composition which is prepared by polymerizing ethylene and an optional olefin having at least three carbon atoms in the presence of a macromonomer, wherein the macromonomer is an ethylene polymer having a terminal vinyl group, prepared by polymerizing ethylene, or an ethylene copolymer having a terminal vinyl group, prepared by copolymerizing ethylene and an olefin having at least three carbon atoms, and

the macromonomer is characterized by having:

(A) a number average molecular weight (Mn) in the range of 1,000 to 50,000, and

(B) a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn), in the range of 2 to 5; and

the polyethylene composition is characterized by comprising;

(C) based on the weight of the polyethylene composition, 1% to 99% by weight of branched polyethylene which is a copolymer derived from ethylene, the macromonomer and an optional olefin having at least three carbon atoms, and 1% to 99% by weight of the macromonomer, and

the polyethylene composition is further characterized by having;

(D) a density in the range of 0.890 g/cm³ to 0.980 g/cm

(E) a weight average molecular weight (Mw) in the range of 30,000 to 10,000,000,

(F) a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn), in the range of 2 to 30,

(G) a frequency of long chain branches in the range of 0.01 to 3 per 1,000 carbon atoms, and

(H) a shrinking factor (g′

value) as determined by a combination of gel permeation chromatography (GPC) and on-line intrinsic viscosity measurements, in the range of at least 0.1 but smaller than 0.9, and

(P) a powder bulk density in the range of 0.15 g/cm³ to 0.50 g/cm³.

11. The particulate polyethylene composition according to claim 10, wherein the macromonomer is a linear ethylene polymer having a terminal vinyl group, prepared by polymerizing ethylene and an optional olefin having at least three carbon atoms, and

the macromonomer is further characterized by having:

(J) a Z value in the range of 0.25 to 1 as defined by the following equation (1);

Z=[X/(X+Y)]×

2 

 

(1)

wherein X is frequency of vinyl terminal groups per 1,000 methylene carbon atoms in the main chain of macromonomer, and Y is frequency of saturated terminal groups per 1,000 methylene carbon atoms in the main chain of macromonomer.

12. The particulate polyethylene composition according to claim 10, which is further characterized by satisfying the following relationship (2):

(K)0.2<

log(g′

)/log(g)<

1.3 

 

(2)

wherein g is a shrinking factor (g value) as determined by a combination of gel permeation chromatography (GPC) and light scattering measurements.

13. The particulate polyethylene composition according to claim 10, which is further characterized by having:

(L) a flow activation energy (Ea) in the range of 30 kJ/mol to 100 kJ/mol.

14. The particulate polyethylene composition according to claim 10, which is further characterized by satisfying the following relationship (3):

(M)MS₁₉₀>

22×

MFR<sup>−

0.88</sup> 

 

(3)

wherein MS₁₉₀ is a melt strength (MS) (mN) as measured at a temperature of 190°

C., and MFR is a melt flow rate (g/10 min.) as measured under a load of 2.16 kg and at a temperature of 190°

C.

15. The particulate polyethylene composition according to claims 10, which is further characterized by satisfying the following relationship (27):

(M′

)MS₁₆₀>

110−

110×

log(MFR) 

 

(27)

wherein MS₁₆₀ is a melt strength (MS) (mN) as measured at a temperature of 160°

C., and MFR is a melt flow rate (g/10 min.) as measured under a load of 2.16 kg and at a temperature of 190°

C.

16. The polyethylene composition according to claim 10, which is further characterized by having:

(N) a non-linear parameter (λ

) for elongation viscosity in the range of 1.2 to 100.

17. The polyethylene composition according to claim 10, which is further characterized by satisfying the following formula (4):

(O)log(DR)>

5−

1.33×

log(MS₁₆₀) 

 

(4)

wherein DR is a maximum drawing ratio and MS₁₆₀ is a melt strength (MS) as measured at a temperature of 160°

C.

21. A process for producing the particulate polyethylene composition as claimed in claim 10, which comprises:

step I wherein ethylene and an optional olefin having at least 3 carbon atoms are polymerized in a slurry state in the presence of a catalyst to prepare the macromonomer;

said catalyst comprising;

(a) a metallocene compound [ingredient (a)] represented by the following general formula (11);

wherein M is a transition metal of group 3, 4, 5 or 6 of the periodic table;

X¹ independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms, which may contain a silicon, nitrogen or oxygen atom;

x is an integer of 0 to 3 which varies depending upon the valence of M¹;

R¹ and R² are ligands represented by the following general formula (12), (13) or (14);

wherein R⁴ independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms, which may contain a silicon, nitrogen or oxygen atom;

said ligands R¹ and R² form a sandwich structure together with M¹;

R³ is a group represented by the following general formula (15);

wherein R⁵ independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms, which may contain a silicon, nitrogen or oxygen atom, and two R⁵s may be bonded with each other to form a ring together with Y¹ to which the two R⁵s are bonded;

Y¹ is an atom of group 14 of the periodic table;

1 is an integer of 1 to 5; and

R³ has a function of crosslinking R¹ with R²;

(b) a modified clay compound [ingredient (b)]; and

(c) an optional organoaluminum compound [ingredient (c)] represented by the following general formula (16);

AlR⁶₃ 

 

(16)

wherein R⁶ independently represents a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 20 carbon atoms, or an aryl, aryloxy, arylalkyl, arylalkoxy, alkylaryl or alkylaryloxy group having 6 to 20 carbon atoms, provided that at least one of R⁶s is an alkyl group having 1 to 20 carbon atoms; and

step II wherein a catalyst is added to a reaction mixture containing the macromonomer as produced in step I; and

subsequently, ethylene, the macromonomer as produced in step I, and an optional olefin having at least three carbon atoms are copolymerized in a slurry state in the presence of the added catalyst;

said catalyst added comprising as the main ingredient a metallocene compound [ingredient (d)] represented by the following general formula (5);

wherein M² is a transition metal of group 3, 4, 5 or 6 of the periodic table;

X² independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms, which may contain a silicon, nitrogen or oxygen atom;

y is an integer of 0 to 3 which varies depending upon the valence of M²;

R⁷ is a ligand represented by the following general formula (6), (7) or (8);

wherein R¹⁰ independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms, which may contain a silicon, nitrogen or oxygen atom;

R⁸ is a ligand represented by the following general formula (9);

wherein R¹¹ independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms, which may contain a silicon, nitrogen or oxygen atom;

said ligands R⁷ and R⁸ form a sandwich structure together with M²;

R⁹ is a group represented by the following general formula (10);

wherein R¹² independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms, which may contain a silicon, nitrogen or oxygen atom;

Y² is an atom of group 14 of the periodic table; and

m is an integer of 1 to 5; and

R⁹ has a function of crosslinking R⁷ with R⁸.

22. The producing process according to claim 21, wherein the modified clay compound [ingredient (b)] is a modified clay compound which has been treated with an organic compound represented by the following general formula (17):

[R¹³_kGH]⁺[A]⁻

 

 

(17)

wherein G is an element selected from those of group 15 or 16 of the periodic table, R¹³ independently represents a hydrogen atom or a substituent including a hydrocarbon group having 1 to 30 carbon atoms, provided that at least one of R¹³ s is a hydrocarbon group having 1 to 30 carbon atoms, wherein each R¹³ may be bound to another R¹³;

when G is an element selected from those of group 15, k is 3, and, when G is an element selected from those of group 16, k is 2; and

[A]⁻

is a counter anion.

23. The producing process according to claim 21, wherein the catalyst comprising the metallocene compound [ingredient (d)] as the main catalytically active ingredient, further comprises:

(i) an optional aluminum compound [ingredient (e)] represented by the following general formula (18), (19) or (20);

AlR¹⁴₃ 

 

(18)

wherein R¹⁴ independently represents a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 20 carbon atoms, or an aryl, aryloxy, arylalkyl, arylalkoxy, alkylaryl or alkylaryloxy group having 6 to 20 carbon atoms, provided that at least one of R¹⁴ s is an alkyl group having 1 to 20 carbon atoms;

R¹⁵ independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms; and

q is an integer of 2 to 60; and

(ii) an optional compound [ingredient (f)] represented by the following general formula (21), (22), (23) or (24);

[HR¹⁶][E(Ar)₄] 

 

(21) [JR¹⁷_o][E(Ar)₄] 

 

(22) [D][E(Ar)₄] 

 

(23) E(Ar)₄ 

 

(24)

wherein H is proton;

E is a boron atom or an aluminum atom;

R¹⁶ is a Lewis base selected from the group consisting of an aliphatic amine, an aromatic amine and a phosphine;

R¹⁷ is a Lewis base selected from the group consisting of an aliphatic amine, an aromatic amine and a phosphine, or a cyclopentadienyl group which may be substituted;

J is a lithium, iron or silver atom;

D is a carbonium cation or a tropylium cation;

Ar independently represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, which is selected from alkyl groups, aryl groups, aralkyl groups, aryl groups having a halogen substituent, aryl groups having a hydrocarbon group substituent, aryl groups having a hetero atom-containing hydrocarbon group as a substituent, aralkyl groups having a halogen substituent, aralkyl groups having a hydrocarbon group as a substituent, aralkyl groups having a hetero atom-containing hydrocarbon group as a substituent, aryl groups having as a substituent a silyl group having a hydrocarbon group, aryl groups having as a substituent a silyl group having a hetero atom-containing hydrocarbon group, aralkyl groups having as a substituent a silyl group having a hydrocarbon group, and aralkyl groups having as a substituent a silyl group having a hetero atom-containing hydrocarbon group, and o is an integer of 0, 1 or 2.