Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Organic compound containing
Utility Patent
1997-04-14
2001-01-02
Wu, David W. (Department: 1713)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Organic compound containing
C526S127000, C526S160000, C526S943000, C556S011000, C556S012000, C556S013000, C556S019000, C556S020000, C556S043000, C556S051000, C556S052000, C556S053000, C502S153000
Utility Patent
active
06169052
ABSTRACT:
DESCRIPTION
The invention relates to a process for the preparation of copolymers of polycyclic olefins in which ring opening does not occur.
It is known that polycyclic olefins can be pulverized by means of various Ziegler catalysts. The polymerization proceeds, depending on the catalyst, via ring opening (cf. U.S. Pat. No. 4,178,424) or opening of the double bond (cf. EP-A 156 464, EP-A 283 164 and EP-A 203 799).
The disadvantage of ring-opening polymerization is that the polymer obtained contains double bonds, which can result in chain crosslinking and thus considerably restrict the processibility of the material by extrusion or injection molding.
Polymerization with opening of the double bond results, in the case of cyclic olefins, in a relatively slow polymerization rate (conversion rate).
A certain increase in the reaction rate has been achieved by using soluble metallocene compounds, such as bis(cyclopentadienyl)zirconium dichloride (cf. JP 61/221,206).
Catalysts which can be used for cyclic olefins are stereorigid chiral metallocene compounds, such as, for example, ethylenebis(indenyl)zirconium dichloride (cf. EP-A 283,164) or dimethylsilylbis(indenyl)zirconium dichloride (cf. ZA 90/5308), the polymerization taking place with retention of the ring.
The glass transition temperatures of amorphous polymers correlate with the rates of incorporation of the comonomers into the polymer. For example, the glass transition temperature of norbornene-ethylene copolymers increases by from 4 to 5 Kelvin per mol percent of norbornene in the polymer. The glass transition temperature is an indirect measure of the heat resistance.
Experiments have shown that the incorporation ratios achieved when conventional metallocene catalysts are used are very sensitive to the reaction parameters such as monomer concentration, pressure and temperature.
In batchwise polymerization, the chemical homogeneity of the products is very conversion-dependent.
In continuous processes, a relatively long start-up period is necessary before steady-state reaction conditions are achieved. The chemically non-homogeneous products produced in this phase do not generally meet the specifications required for commercial products.
In both cases, low sensitivity of the catalysis to changes in the reaction parameters is desirable in order to save time and waste and to achieve higher space-time yields.
Random copolymers are characterized by a random distribution of the comonomers units in the polymer chain. This has the consequence of a relatively great fluctuation in the density of the material than in homopolymers or alternating copolymers. However, density fluctuations increase the proportion of scattered light and reduce the transparency. Applications in which, such as in optical fibers, extremely high demands are made on the optical transparency are thus restricted. Here too, chemically homogeneous products are therefore very desirable.
The term chemical homogeneity is taken to mean a virtually constant incorporation ratio of the monomers into the copolymer—via the respective polymer chain and via the total number of chains formed (over the polymerization time). Thus, the chemical homogeneity increases to the extent at which the structure of the copolymers approaches an alternating monomer sequence from a random sequence.
The object was therefore to find a process for the preparation of cycloolefin copolymers which, based on polymerization via the double bond, gives chemically homogeneous copolymers at a high space-time yield and in which, at the same time, changes in the reaction parameters have less effect on the chemical homogeneity of the products than in known processes.
It has been found that this object can be achieved by means of specific metallocene catalysts.
REFERENCES:
patent: 3268627 (1966-08-01), Emrick
patent: 3305538 (1967-02-01), Natta et al.
patent: 3364190 (1968-01-01), Emrick
patent: 4178424 (1979-12-01), Tenney
patent: 4261880 (1981-04-01), Fujii et al.
patent: 4411821 (1983-10-01), Howard, Jr.
patent: 4497906 (1985-02-01), Hanji et al.
patent: 4530914 (1985-07-01), Ewen et al.
patent: 4658078 (1987-04-01), Slaugh et al.
patent: 4701432 (1987-10-01), Welborn, Jr.
patent: 4794096 (1988-12-01), Ewen
patent: 4797162 (1989-01-01), Spietschka et al.
patent: 4849487 (1989-07-01), Kaminsky et al.
patent: 4931417 (1990-06-01), Miya et al.
patent: 4948856 (1990-08-01), Minchak et al.
patent: 5003019 (1991-03-01), Ishimaru et al.
patent: 5017714 (1991-05-01), Welborn
patent: 5036034 (1991-07-01), Ewen
patent: 5086134 (1992-02-01), Antberg et al.
patent: 5087677 (1992-02-01), Brekner et al.
patent: 5093483 (1992-03-01), Springer et al.
patent: 5162278 (1992-11-01), Razavi
patent: 5176941 (1993-01-01), Peuckert et al.
patent: 5416228 (1995-05-01), Ewen et al.
patent: 5436305 (1995-07-01), Alt et al.
patent: 5451649 (1995-09-01), Zenk et al.
patent: 201 7192 (1990-11-01), None
patent: 0 128 046 (1984-12-01), None
patent: 0 129 368 (1984-12-01), None
patent: 0156464 (1985-02-01), None
patent: 0203 799 (1986-05-01), None
patent: 0 283 164 (1988-09-01), None
patent: 316 155 (1988-11-01), None
patent: 0 344 887 (1989-12-01), None
patent: 0 351 392 (1990-01-01), None
patent: 399 347 (1990-05-01), None
patent: 61-221206 (1986-10-01), None
patent: 87/00299 (1987-01-01), None
patent: 87/03604 (1987-06-01), None
patent: 90/5308 (1991-04-01), None
Ewen et al.,J. Am. Chem. Soc., “Syndiospecific Propylene Polymerizations with Group 4 Metallo-cenes”, vol. 110, pp. 6255-6256 (1988).
Ewen,J. Am. Chem. Soc., “Mechanisms of StereochemicalControl in Propylene Polymerizations with Soluble Group 4B Metallocene/Methylalumoxane Catalysts”, vol. 106, pp. 6355-6364 (1984).
Ewen et al.,American Chemical Society, “Crystal Structures and Stereospecific Propylene Polymerizations with Chiral Hafnium Metallocene Catalysts”, vol. 109, pp. 6544-6545 (1987).
Buschermohle, Maria, Dissertation, “Experiments on the Sterio block polymerization of propylene with homogeneous Ziegler-Natta catalysts”, Hamburg, Germany (1987).
Ewen et al.,Makromol. Chem. Makromol Symp., “Metallocene/Polypropylene Structural Relationships: Implications on Polymerization and StereochemicalControl Mechanisms”, 48/49, pp. 253-295 (1991).
Klouras et al.,Monatshefte f{umlaut over (u)}r Chemie, “Ringsubstituierte [1]Titanocenophane”, vol. 112, pp. 887-907 (1981).
Randall,Journal of Polymer Science, Polymer Physics Edition, “Carbon-13-Nuclear Magnetic Resonance Quantitative Measurements of Average Sequence Lengths fo Like Stereochemical Additions in Polypropylene and Polystyrene”, vol. 14, pp. 2083-2094 (1976).
Antberg Martin
Brekner Michael-Joachim
Osan Frank
Rohrmann J{umlaut over (u)}rgen
Choi Ling-Siu
Connolly Bove & Lodge & Hutz LLP
Targor GmbH
Wu David W.
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