DE2231995B2 - PROCESS FOR THE PRODUCTION OF HOMO- AND COPOLYMERS OF THE POLYALKENAMER CLASS - Google Patents

Description

The invention relates to a process for the preparation of homo- and copolymers of the polyalkenamer class by polymerizing a norbornene, which has an esterified hydroxyl or carboxyl group, a halogen atom or a nitrile group in the 5-position or via an alkylene radical with the Contains 5-position connected, where optionally the 5-position is an alkyl group as a further substituent with 1 to 6 carbon atoms, in the presence of a metallic catalyst system in the liquid phase.

Polyalkenamers belong to a class of polymers which are formed from cyclic olefins by ring opening are generated by polymer molecules between double-bonded carbon atoms, the latter then combine separately with similar carbon atoms of other ring-opened monomer molecules, in order to saturate each other's free valences by creating new double bonds and therefore extended ones Molecular chains are formed.

It is known to use norbornene derivatives using metal catalysts such as ruthenium, iridium and / or to polymerize osmium compounds (GB-PS 12 30 597, J. of Poly. Science A, 895-905 (1965) and Polymer Letters Vol. 3, 1049-52 (1965)). However, these known noble metal catalysts allow just an economically extremely costly process.

The object of the invention is a process for the preparation of homopolymers and copolymers of the polyalkenamer class with high yields, the process being carried out in a simple and economical manner is feasible.

The invention relates to a process for the preparation of homopolymers and copolymers of the polyalkenamer class by polymerizing a norbornene, which has an esterified hydroxyl or carboxyl group, a halogen atom or a nitrile group in the 5-position or via an alkyl radical in the 5-position contains connected, where appropriate the 5-SteIhng may have as a further substituent an alkyl group with 1 to 6 carbon atoms, in the presence of a metallic catalyst system in the liquid phase, characterized in that the catalyst system one is used which is produced by reacting halides of tungsten, molybdenum or tantalum with alcohols and organometallic compounds of a metal from group la, Ma, Hb or IHa des

Periodic table is obtained.

The ethylene radical is preferably methylene. Suitable tungsten halides are particularly WCI ₅ , WCI ₆ . WOCi ₄ and WO ₂ Cl ₂ . Suitable molybdenum halides include molybdenum pentahalide MoCl ₅ . Suitable tantalum halides are TaOs and TaBr ₅ . Preferred arganometallic compounds are aluminum alkyl hydrides and alkyl halides of the general formula AlR ₁ Xy, in which * + y = 3; and χ is 1,2 [or 3; and R is lower alkyl, for example ethyl, isopropyl, isobutyl or n-hexyl; and X (if present) is hydrogen, or preferably halogen, for example chloride. Analogous Mg, Be and Zn compounds can be used as alternatives to the organic aluminum compounds. The proportion of organometallic compound which is incorporated into the catalyst is advantageously greater on a molar basis than the proportion of the W, Mo or Ta halide, for example such that the A !: W atomic ratio is at least 2: 1, preferably at least 4: 1 and especially around 10: 1

amounts to.

Optionally, according to the invention, the catalyst system and / or the polymerization reaction can be prepared or carried out in a suitable organic solvent, for example a cycloaliphatic or aromatic hydrocarbon (for example benzene or toluene). The polymerization reaction is conveniently carried out at or near ambient temperature, but a wide temperature range is permissible. Practically, one will select a temperature usually in the range of -30 to + 50 °, although the temperature advantageously slightly example 55 is higher, up to 7O ⁰ C, when products are desired, with lower molecular weight. The preparation of lower molecular weight polymers is also promoted by incorporating a controlled, small amount of a chain terminating acyclic monoolefin, e.g., octene-1, into the reaction medium. The polymerization can optionally be carried out with a copolymerizable cyclic olefin, in particular a cyclic monoolefin.

The esterified hydroxyl or carboxyl group -OCOR or -COOR advantageously has an alkyl radical R with 1 to 6 carbon atoms. Norbornene compounds which can be used as monomers according to the invention are expediently prepared by addition reaction between cyclopentadiene and corresponding mono-olefinically unsaturated compounds, for example vinyl compounds, alkyl vinyl compounds and allyl compounds, as is described, for example, in British Patent 11 23 878.

The following examples illustrate the invention:

example 1

50 g of 5-acetoxy-2-norbornene are diluted in a flask under a nitrogen blanket with 100 cm ^{3 of} benzene. 5 m-moles of tungsten hexachloride dissolved in 100 cm ^{3 of} benzene and 5 m-moles of ethanol dissolved in 50 cm ^{3 of} benzene are then added and the contents of the flask are flushed with nitrogen to remove the HCl which is produced by reaction between WCU and Ethanol is released. 50 m-mol of ethyl chloride (a reaction product of ethyl chloride with aluminum) dissolved in 50 cm ^{3 are then added}

hydrogenated isobutene trimers added. The subsequent polymerization reaction is allowed to proceed for 20 minutes (initial temperature 20 "C, final temperature 25" C) and the reaction is then terminated by adding 50 cm ^{3 of} a mixture of 1 g of 2,2'-methylene-bis- [4,4 ' -dimethyl-6,6 '- (l-methylcyclohexyl)] phenol (antioxidant), 3 g of ethanolamine, 20 g of ethanol and 100 cm ^{3 of} benzene are added. The yield of polymers! is 38 g (96%) of the molecular weight 68800 ± 1%. The polymer is soluble in benzene, toluene and carbon tetrachloride.

Example 2

30 g of 5-acetoxy-2-norbornene are dissolved in 470 cm ^{3 of} benzene in a flask under a nitrogen blanket. 1 m-Mon! Tungsten hexachloride is dissolved in 20 cm ^{3 of} benzene and 1 m-mol of ethanol, dissolved in 20 cm ^{3 of} benzene, and 1 m-mol of ethanol, dissolved in 10 cm ^{3 of} benzene, are then added and the contents of the flask are flushed with nitrogen to remove HCl to remove which is released by the reaction between WCIe and the ethanol. Then 2 m-mol of ethylaluminum sesquichloride, dissolved in 2 cm ^{3 of} hydrogenated isobutenirimer, are added. The following polymerization reaction is allowed to proceed for 120 minutes (initial temperature 2O ⁰ C) and then the reaction is terminated by adding thereto of 10 cm ³ of a mixture of 1 g of 2,2'-methylene-bis [4,4-dimethyl-6,6 '- (1-methylcyclohexyl)] phenol (antioxidant), 3 g of ethanolamine, 20 g of ethanol and 100 cm ^{3 of} benzene. The yield of polymer is 15.2 g (52%). The polymer is soluble in benzene, toluene and carbon tetrachloride.

Example 3

The procedure of Example 1 is carried out using 2-norbornene-5- »iitrile instead of the 5-acetoxy-2-norbornens repeated. However, the polymerization reaction time is in this case 120 minutes. The yield of polymer is of the order of 50%. The polymer is in benzene, Toluene, carbon tetrachloride and the other common solvents are insoluble.

Example 4

The procedure of Example 2 is followed using the norbornene compound, which by addition reaction between methyl methacrylate and cyclopentadiene, namely des Methyl ester of 2-norbornene-5-methyl-5-carboxylic acid. The polymerization reaction time is here 45 minutes and the polymer yield (soluble in benzene) is on the order of 73%.

Example 5

Example 4 is carried out using the ethyl ester of 2-norbornene-5-carboxylic acid as monomers repeated. A 76% yield of polymer is obtained, which in benzene and carbon tetrachloride is soluble.

Example 6

Example 3 is carried out using 2-norbornene-5-chloride as the monomer in place of the Nitrile repeated. Again a ring-opened polymer is obtained.

Example 7

100 g of 5-acetoxy-2-norbornene are diluted in a flask under a nitrogen poister with 400 cm ^{3 of} toluene. 8 m-moles of tungsten hexachloride dissolved in 100 cm ^{3 of} benzene and 8 m-moles of ethanol dissolved in 50 cm ^{3 of} benzene are then added and the contents of the flask are flushed with nitrogen to remove the HCl which is produced by the reaction between WCl _b and ethanol is released. Thereafter, 40 m-mol of ethyl acetate, dissolved in 40 cm ^{3 of} hydrogenated isobutene trimers, are added. The following polymerization reaction is allowed to proceed for 20 minutes at a temperature of 6O ⁰ C and then it is ended by adding 50 cm ^{3 of} a mixture of 1 g of 2,2'-methylene-bis- [4,4'-dimethyl-6, 6 '- (1-methylcyclohexyl)] phenol (antioxidant), ethanolamine (3 g), ethanol (20 g) and benzene (100 cm ³ ). The resulting polymer is recovered in 60% yield and it has an inherent viscosity of 1.3.

Example 8

Example 7 is repeated with the only difference that the reaction mixture contains 20 m-mol of octene-1 having. The resulting polymer has an inherent viscosity of 0.32, which is the chain termination effect of the incorporated acyclic monoolefin is demonstrated.

In all examples, the polymers are positively identified as those of the polyalkene class (ie open ring) according to analytical techniques, which include nuclear magnetic resonance spectroscopy,
so

Claims (1)

Claim: Process for the production of homo- and copolymers of the polyalkeramer class by polymerization a norbornene, which is an esterified hydroxyl or carboxyl group, a halogen atom or a nitrile group in the 5-position or connected to the 5-position via an alkylene radical contains, the 5-position optionally being an alkyl group with 1 to 6 as a further substituent May have carbon atoms in the presence of a metallic catalyst system in the liquid phase, characterized in that the catalyst system used is one which is characterized by '5 Conversion of halides of tungsten, molybdenum or tantalum with alcohols and organometallic Compounds of a metal of group Ia, Ma, Ub or IHa of the periodic table is obtained. 20th