Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-02-16
2001-03-13
Cain, Edward J. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
active
06201090
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a propylene-ethylene block copolymer in which ethylene-propylene copolymer segments of a uniform rubber-like elastomer component are dispersed in the matrix of propylene homopolymer segments having high stereospecificity. Precisely, the invention relates to a propylene-ethylene block copolymer which is characterized in that ethylene-propylene copolymer segments of not a mixture of plural rubber-like elastomers each having a different degree of hardness but a uniform rubber-like elastomer component are dispersed in the matrix of propylene homopolymer segments of that type.
The invention also relates to a propylene-ethylene block copolymer in which copolymer segments having a large proportion of ethylene-propylene copolymer fragments are dispersed in the matrix of propylene homopolymer segments having high stereospecificity. Precisely, the invention relates to a propylene-ethylene block copolymer which is characterized in that copolymer segments having a small proportion of crystalline polyethylene fragments relative to the ethylene content thereof and therefore having a large proportion of ethylene-propylene copolymer fragments relative to the same are dispersed in the matrix of propylene homopolymer segments of that type.
2. Description of the Related Art
Various studies for improving propylene-ethylene block copolymers have heretofore been made, which are specifically directed to the improvement in the physical balance of rigidity and impact resistance of the copolymers. One good approach thereto is to investigate the copolymers from the aspect of their solid structure morphology. Briefly, propylene-ethylene block copolymers are composed of propylene homopolymer segments that constitute the matrix of the copolymers and ethylene-propylene copolymer segments of a rubber-like elastomer dispersed in the matrix. To improve their properties, the influence of the solid structure of the copolymers on the strength characteristic thereof is first analyzed for various factors of the copolymers, including the proportion of the constituent segments thereof, and also the molecular weight and the stereospecificity of each constituent segment, and thereafter the thus-analyzed data are reflected on polymer designing and are further fed back to the technique of producing the intended polymers.
As a result of various studies to that effect, it has be en clarified that, in propylene-ethylene copolymers, the molecular weight of the ethylene-propylene copolymer segments constituting the rubber-like elastomer component has governing influences on the physical balance of rigidity and impact resistance of the copolymers.
In that situation, however, it is further desired to develop propylene-ethylene block copolymers having more improved impact resistance.
SUMMARY OF THE INVENTION
The object of the present invention is to provide propylene-ethylene block copolymers having an improved physical balance of rigidity and impact resistance.
We, the present inventors have assiduously studied for the purpose of attaining the object as above, and have completed the invention. Specifically, the invention is to provide propylene-ethylene block copolymers mentioned below.
[1] A propylene-ethylene block copolymer characterized by the following (a), (b) and (c):
(a) its melt flow rate (MFR) (at 230° C. under a load of 2.16 kg) falls between 0.01 and 1000 g/10 min;
(b) the room-temperature xylene-insoluble component thereof, as measured through
13
C-NMR, has a stereospecificity index [mmmm] fraction of not smaller than 98.9%; and
(c) the room-temperature xylene-soluble component thereof is characterized by the following (c1), (c2) and (c3):
(c1) its amount falls between 3 and 50% by weight;
(c2) the T1 relaxation time component thereof, as measured through pulse NMR, is of a single relaxation component; and
(c3) the ethylene content thereof, x % by weight, as measured through
13
C-NMR, and the T1 relaxation time for it, y (milliseconds), as measured through pulse NMR, satisfy the following relational formula (I):
y≦
0.0014
x
3
−0.0897
x
2
−1.0593
x+
231.6 (I).
[2] The propylene-ethylene block copolymer of above [1], of which the melt flow rate (MFR) (at 230° C. under a load of 2.16 kg) falls between 0.3 and 300 g/10 min.
[3] The propylene-ethylene block copolymer of above [2], which is produced through polymerization in the presence of a catalyst that comprises (A) a solid catalyst component formed from (a) a magnesium compound, (b) a titanium compound, (c) an electron donor, and optionally (d) a silicon compound, (B) an organoaluminium compound, and optionally (C) the third component of an electron-donating compound.
[4] The propylene-ethylene block copolymer of above [2], which is produced through polymerization in the presence of a catalyst that comprises (A) a solid catalyst component as prepared by contacting (a) a magnesium compound and (b) a titanium compound with each other in the presence of (c) an electron donor, at a temperature falling between 120 and 150° C., followed by washing them with an inert solvent at a temperature falling between 100 and 150° C., (B) an organoaluminium compound, and (C) the third component of an electron-donating compound.
[5] The propylene-ethylene block copolymer of above [2], which is produced through polymerization in the presence of a catalyst that comprises (A) a solid catalyst component as prepared by contacting (a) a magnesium compound and (b) a titanium compound with each other in the presence of (c) an electron donor and (d) a silicon compound, at a temperature falling between 120 and 150° C., followed by washing them with an inert solvent at a temperature falling between 100 and 150° C., (B) an organoaluminium compound, and (C) the third component of an electron-donating compound.
[6] A propylene-ethylene block copolymer characterized by the following (a), (b) and (c′):
(a) its melt flow rate (MFR) (at 230° C. under a load of 2.16 kg) falls between 0.01 and 1000 g/10 min;
(b) the room-temperature xylene-insoluble component thereof, as measured through
13
C-NMR, has a stereospecificity index [mmmm] fraction of not smaller than 98.9%; and
(c′) the room-temperature xylene-soluble component thereof is characterized by the following (c1) and (c4):
(c1) its amount falls between 3 and 50% by weight; and
(c4) the ethylene content thereof, x % by weight, as measured through
13
C-NMR, and the ratio by weight of the crystalline polyethylene segments to the total of the ethylene-propylene copolymer segments and the crystalline polyethylene segments, z (%), as obtained from the TEM (transmission electron microscope) image of the propylene-ethylene block copolymer, satisfy the following relational formula (II):
z≦
0.016
x
2
−0.069
x−
1.34 (II).
[7] The propylene-ethylene block copolymer of above [6], of which the melt flow rate (MFR) (at 230° C. under a load of 2.16 kg) falls between 0.3 and 300 g/10 min.
[8] The propylene-ethylene block copolymer of above [7], which is produced through polymerization in the presence of a catalyst that comprises (A) a solid catalyst component formed from (a) a magnesium compound, (b) a titanium compound, (c) an electron donor, and optionally (d) a silicon compound, (B) an organoaluminium compound, and optionally (C) the third component of an electron-donating compound.
[9] The propylene-ethylene block copolymer of above [7], which is produced through polymerization in the presence of a catalyst that comprises (A) a solid catalyst component as prepared by contacting (a) a magnesium compound and (b) a titanium compound with each other in the presence of (c) an electron donor, at a temperature falling between 120 and 150° C., followed by washing them with an inert solvent at a temperature falling between 100 and 150
Miyazaki Sueto
Ota Tsuyoshi
Sato Kazuo
Sumitomo Takashi
Cain Edward J.
Idemitsu Petrochemical Co. Ltd.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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