Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
1999-08-20
2001-10-16
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S227000, C526S348200, C526S348500, C526S348600
Reexamination Certificate
active
06303713
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a catalyst for olefin polymerization, a process for olefin polymerization using said catalyst, an ethylene/&agr;-olefin copolymer, a graft modified ethylene/&agr;-olefin copolymer and an ethylene copolymer composition. More particularly, the invention relates to a catalyst for olefin polymerization which is capable for producing an olefin polymer excellent in transparency, mechanical strength and moldability, to a process for olefin polymerization using said catalyst, to an ethylene/&agr;-olefin copolymer of high moldability which is capable for giving a film having higher transparency and mechanical strength as compared with films obtained from conventionally known ethylene copolymers, and to a graft modified ethylene/&agr;-olefin copolymer and an ethylene copolymer composition both having high moldability and high adhesion strength to metals or polar resins and from which a film having higher transparency and mechanical strength as compared with films obtained from conventionally known ethylene copolymers or ethylene copolymer compositions can be produced.
BACKGROUND OF THE INVENTION
Ethylene copolymers have heretofore been molded by various molding methods, and used in many fields. The requirement for the characteristics of the ethylene copolymers differs depending on the molding methods and uses. For example, when an inflation film is molded at a high speed, it is necessary to select an ethylene copolymer having a high melt tension compared with its molecular weight in order to stably conduct high speed molding without fluctuation or tearing of bubbles. An ethylene copolymer is required to have similar characteristics in order to prevent sag or tearing in blow molding, or to suppress width shortage to the minimum range in T-die molding.
By the way, Japanese Patent L-O-P Nos. 90810/1981 and 106806/1985 propose a method for improving moldability by improving the melt tension and die swell ratio of ethylene polymers obtained by using Ziegler type catalysts, especially a titanium type catalyst.
The ethylene polymers obtained by using a titanium catalyst, however, especially the low density ethylene polymers generally have problems such as their broad composition distribution and stickiness of their molded articles such as films.
Of the ethylene polymers prepared by using the Ziegler type catalysts, those obtained by using chromium type catalysts are relatively excellent in melt tension but has a defect of poor heat stability. This is thought to be caused by that the chain terminals of the ethylene polymers prepared by using the chromium type catalysts tend to become unsaturated bonds.
It is known that the ethylene polymers obtained by using a metallocene catalyst from among the Ziegler type catalysts have merits such as a narrow composition distribution and a low stickiness of their molded articles such as films. However, it is described in, for example Japanese Patent L-O-P. No. 35007/1985, that an ethylene polymer obtained by using a zirconocene compound formed from a cyclopentadienyl derivative contains one terminal unsaturated bond per molecule, and hence this ethylene polymer is presumably poor in heat stability similarly to the above-mentioned ethylene polymer obtained by using the chromium type catalyst.
Accordingly, it will industrially be of great value to provide a catalyst for olefin polymerization or a process for olefin polymerization, by which an olefin copolymer, particularly an ethylene copolymer, having good heat stability, high mechanical strength and a narrow composition distribution can be prepared.
By the way, ethylene copolymers generally have no polar group in the molecule and inherently non-polar, so that they are insufficient in adhesion strength to highly polar materials such as metals and polar resins. For these reasons, when such ethylene copolymers are used by bonding them with the highly polar materials, it is necessary to subject the surface of the ethylene copolymer to a flame treatment, a corona discharge treatment, a primer treatment or the like, and hence resulting in a problem of complicated operation.
Accordingly, it will also industrially be of great value to provide an ethylene copolymer or an ethylene copolymer composition, which has high melt tension, good heat stability and high mechanical strength and shows sufficient adhesion strength to highly polar materials.
OBJECT OF THE INVENTION
It is, therefore, an object of the present invention to provide a catalyst for olefin polymerization which is capable for producing an olefin polymer excellent in transparency, mechanical strength and moldability, and to provide a process for olefin polymerization using said catalyst. It is another object of the invention to provide an ethylene/&agr;-olefin copolymer of good moldability which is capable for giving a film having higher transparency and mechanical strength as compared with films obtained from conventionally known ethylene copolymers, and to provide a graft modified ethylene/&agr;-olefin copolymer and an ethylene copolymer composition both having good moldability and high adhesion strength to metals or polar resins and from which a film having higher transparency and mechanical strength as compared with films obtained from conventionally known ethylene copolymers or ethylene copolymer compositions can be produced.
SUMMARY OF THE INVENTION
The first catalyst for olefin polymerization according to the present invention is a catalyst for olefin polymerization, comprising:
(a) an organoaluminum oxy-compound,
(b-I) at least one kind of a transition metal compound represented by the following formula [I]:
ML
1
X
[I]
wherein M is a transition metal atom selected from Group IVB of the periodic table, L
1
is a ligand coordinating to the transition metal atom M, at least two of L
1
are groups selected from a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group and a substituted cyclopentadienyl group having at least one substituent group selected from a hydrocarbon group of 3 to 10 carbon atoms, L
1
other than the (substituted) cyclopentadienyl group is a hydrocarbon group of 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom, and X is a valence of the transition metal atom M, and
(b-II) at least one kind of a transition metal compound represented by the following formula [II]:
ML
2
X
[II]
wherein M is a transition metal atom selected from Group IVB of the periodic table, L
2
is a ligand coordinating to the transition metal atom, at least two of L
2
are substituted cyclopentadienyl groups having 2-5 substituent groups selected from a methyl group and an ethyl group, L
2
other than the substituted cyclopentadienyl group is a hydrocarbon group of 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atom or a hydrogen atom, and X is a valence of the transition metal atom M.
The second catalyst for olefin polymerization according to the present invention is a catalyst for olefin polymerization, comprising:
(a) an organoaluminum oxy-compound,
(b-I) at least one kind of a transition metal compound represented by the above formula [I],
(b-II) at least one kind of a transition metal compound represented by the above formula [II], and
(c) an organoaluminum compound.
The third catalyst for olefin polymerization according to the present invention is a catalyst for olefin polymerization, comprising:
a carrier,
(a) an organoaluminum oxy-compound,
(b-I) at least one kind of a transition metal compound represented by the above formula [I], and
(b-II) at least one kind of a transition metal compound represented by the above formula [II],
said organoaluminum oxy-compound (a), said transition metal compound (b-I) and said transition metal compound (b-II) being supported on the carrier.
The fourth catalyst for olefin polymerization according to the present inve
Inagaki Hajime
Ohta Seiji
Takahashi Mamoru
Todo Akira
Tsutsui Toshiyuki
Cheung William
Mitsui Chemicals Inc
Wu David W.
LandOfFree
Graft modified ethylene &agr;-olefin copolymer obtained by... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Graft modified ethylene &agr;-olefin copolymer obtained by..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Graft modified ethylene &agr;-olefin copolymer obtained by... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2611168