Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Compositions to be polymerized by wave energy wherein said...
Patent
1997-04-23
1998-07-07
Berman, Susan W.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Compositions to be polymerized by wave energy wherein said...
522 66, 522 28, 522 29, 522184, 522185, 522186, 522188, C08G 6108, C08F 250
Patent
active
057769974
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a process for the polymerization of cyclical olefins by photochemical ring-opening metathesis polymerization using catalytic amounts of a molybdenum, tungsten, titanium, niobium or tantalum catalyst in which a silylmethyl group and at least one halogen are bonded to the metal, and to compositions comprising these olefins together with a catalytic amount of this catalyst.
Thermally induced ring-opening metathesis polymerization using catalytic amounts of metal catalysts has already been known for a relatively long Ivin, K. J., Olefin Metathesis 1-12, Academic Press, London (1983)!. Polymers which can be prepared in this way are prepared industrially and are commercially obtainable. On the other hand, only little has become known on photochemically induced ring-opening metathesis polymerization and as yet there have been no commercial applications.
It is known from U.S. Pat. No. 4,060,468 to carry out an olefin metathesis polymerization by introducing a two-component mixture of a metal salt chosen from salts of tungsten, molybdenum, rhenium and tantalum and a substituted phenol or benzyl alcohol as cocatalysts into a reaction vessel with the monomeric olefin and then irradiating the entire reaction mixture with UV light. Only cyclical and acyclical hydrocarbons without functional groups or substituents are mentioned as olefins. Separate storage of the catalyst components and the process step of mixing the catalyst components directly before the actual reaction make the known process industrially expensive and cumbersome. Letters 52:4589-4592 (1977)! describe the catalyst system W(CO).sub.6 /CCl.sub.4, which, after irradiation with UV light, can be employed for metathesis polymerization of cyclopentene and norbornene. Metal carbonyls are volatile and toxic, so that their use necessitates expensive safety precautions for physiological reasons. Furthermore, a free-radical addition reaction with formation of monomeric 1-chloro-2-trichloromethyl-cycloalkanes is observed as a competing reaction. Mol. Catal. 15:245-270 (1982)! that a tungsten pentacarbonyl-carbene complex of the formula ##STR1## is a thermal catalyst for ring-opening metathesis polymerization of dimethylnorbornene and, together with phenylacetylene as a cocatalyst, is also a photocatalyst system for the same polymerization. This catalyst system has the serious disadvantage that, as a ready-to-use formulation, it has only a low storage stability, the carbonyl compound is physiologically unacceptable and the tolerance towards functional groups in cycloolefins is too low. in Inorganic Chemistry 39:3-73 (1991)! describe molybdenum- and tungsten-alkylidene complexes which by themselves are only weak but together with Lewis acids are active thermal catalysts for the polymerization of cycloolefins.
The known catalysts which can be activated photochemically thus always require a cocatalyst, which means that the quality of the polymers prepared can vary greatly as a result of the chosen nature and sequence of the reagents.
Polymers of cyclical olefins can be prepared by photochemical ring-opening metathesis polymerization by the known processes only with a high expenditure and in an economically unsatisfactory manner. The lack of storage stability, which allows mixing of the components only directly before the preparation, the lack of tolerance towards functionalized cyclical olefins and the need to use two components as the catalyst system are found to be particular disadvantages. There is therefore a need to provide a generally usable process, which is improved from industrial, economic and ecological aspects, for the preparation of polymers from cyclical olefins by photochemical ring-opening metathesis polymerization.
WO 93/13171 describes air- and water-stable one-component and two-component catalysts based on molybdenum compounds and tungsten compounds containing carbonyl groups and ruthenium compounds and osmium compounds with at least one polyene ligand for the thermal metathesis polymerization and a photoactivated me
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Hafner Andreas
Muhlebach Andreas
Van Der Schaaf Paul Adriaan
Berman Susan W.
Ciba Specialty Chemicals Corporation
Hall Luther A. R.
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