AU463583B2 - Process for the preparation of polypentenamers - Google Patents

Description

13.699

The polymerisation of cyclopentene with tungsten and molybdenum compounds in combination with organometallic compounds and hydride compounds of metals of the Main Groups I to III of the Periodic Table is known but the yields and reaction velocities obtained have so far been insufficient. Although oxygen-containing and sulphur-containing cocatalyst compounds provide better yields, no industrial process can be based on these systems because it is inadvisable to use solvents in such a process in order to prevent long induction periods and low yields. The use of solvents is necessary in industrial polymerisation processes of the Ziegler-Natta type in order to prevent gel formation. Gel formations leads to the formation of-deposits on cooled surfaces which necessitates time-consuming cleaning operations. The use of solvents is further necessary in order to control the temperature and to maintain adequate flow by keeping up low viscosities.

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6-99 P/ According to the present invention, there is

provided a process for producing cyclopentene polymers

or copolymers, -whereincyclopentene alone, or cyclopentene

with up to 30% by weight, based thereon, of another cyclic

unsaturated mnoer, is respectively polymerised or co-

polymerised at*-15 to +15C in the presence of a catalyst

made from

a) tungsten hexachloride,

b) an alkyl or aryl tin hydride and

c) a cocatalyst compound containing -OH or -0-0-

groups.

Unlike the prior art acknowledged above, the instant

process does not involve compounds of metals of the Main

Groups I to III of the Periodic Table. The present process is preferably carried out in an inert organic solvent,

bulk polymerisation (although it does not provide any

particular advantages) being also possible.

Turning to the catalyst featured in the process,

suitable tin alkyl or aryl hydrides for producing

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the catalyst of the invention are compounds of the formula S3na H x 4-x in which R represents an alkyl radical containing 1 to carbon atoms, a cycloalkyl radical containing 3 to 8 carbon atoms or an aryl radical, and x is 1,2 or 3. The aryl radicals are preferably phenyl, naphthyl or diphenyl.

Aliphatic alkyl tin hydrides of the formula

SnR H

in which R represents an alkyl group having 1-20 carbon

atoms, e.g. ethyl, propyl, i-butyl, hexyl, dodecyl are

most preferred.

Alkyl and aryl tin hydrides are known compounds.

Compounds which contain-OH or -O-O-groups are used as cocatalysts These compounds (which exclude nitro compounds) may also contain halogen. Examples of such compounds are epoxides, aldehydes, alcohols or

hydroperoxides such as ethanol, cyclohexanol, chloroethanol, chlorophenols, cyclopentenyl hydroperoxide, ethylene oxide, chloral and benzaldehyde.

The amount of tungsten hexachloride used is gnerally C.2 to 5 Iillimol, preferably 0.2 to 0.8 millimol

per 100 g of cyclopentene (and, if desired, other monomers). The malar ratio of tungsten to tin should be between

1: C.1 and 1 5, preferably between 1 0.2 and 1 0.6. The quantity of cocatalysts depends the particular substances

used. The molar ratio of tungsten to cocatalyst is

generally 1 0.2 to 1 1 in the case of OH and 0-0

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compounds. IThe catalysts are normally prepared by introducing

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catalyst components into a suitable solvent under exclusion of air and maisture at temperatures between about -30 and +15 C.

Solvents to be used are the same solvents which are suitable for the polymerisation step. During catalyst preparation the cmnomer (or monomers) can be present but need not be present.

The sequence of introducing the catalyst constituents is in

principle arbitrary, however it is preferred to introduce the

tungsten hexachloride first very oftn and for convenience as

a solution in a solvent as described below) followed by the 0 cocatalyst. These steps aremostly carried out at 10 to 25 C.

Subsequently the tin alkyl or aryl hydride is added (also conveniently as a solution in one of the solvents for the

polymerisation). Preferably for this step the temperature is

between about -30 and OOC.

Polymerisation:

If the process is carried out as a solution polymerisation,

e.g. aliphatic, cycloaliphatic or aromatic hydrocarbons may be used as solvents. Aromatic solvents such as toluene are preferred. Petroleum hydrocarbon fractions, cyclohexane and benzene are other examples of suitable solvents. The concentratior

of cyclopentene (and other monomers, if any) in these solvents should be about 5 to 25 preferably 15 to 20 According to the invention, cyclopentene may be polymerised

alone, but other cyclic unsaturated monomers may also be

copolymerised in quantities of up to 30 by weight based on

cyclopentene. It is preferable to use 0.05 to 5 based on

cyclopentene weight. Suitable comonomers are, in particular other olefines, preferably bicyclic or polycyclic olefines, such as dicyclopentadiene, norbornene and norbornadiene. The polymerisation process. is generally carried out by

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the introducing a solution of the cyclopentene in one of and adding solvents mentioned above into a reaction vessel to the the catalyst components or a separately prepared catalyst gas solution. It is preferable to work under a protective atmospheric oxygen, atmosphere in order to exclude moisture and Atmosphericpres- for example an atmosphere of nitrogen or argon. be carried out sureis-generally employed but.the process may also proceeds at under elevated pressure. Polymerisation generally 0 +15 to -150 C. temperatures of between 50 and *30 C, Preoferabl The reaction takes from about 1 to 24 hours. the Before the polymers are isolated at the end of with reaction, it is advantageous to stop polymerisation about 5 based on the amount of monomer used, of a proton active compound such as formic acid or methanol. at It is advisable to add a complex forming compound remaining the same time which prevents catalyst residues from Diamines in the polymer after the polymer has been worked up. are and aminoalcohols such as ethylene diamine or aminoethanol suitable for this purpose. excess The polymer can be isolated by precipitation with an 3 to 5 times the amount of polymer solution) of a lower butyl cresol, alcohol in which an age resister such as ditertiary 8-phenyl naphthylamine or the like has been dissolved before precipitation. Alternatively, the solution may be introduced In this into boiling water and the solvent removed with steam. case, the age resister can be added with the polymerisation inhibitor to the polymer solution. The polymers thus isolated which are still moist with water or alcohol may be freed from residues of the coagulation medium in a circulating air oven or in a drying screw.

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13.699170 The polymerisation and working up process may, of course, be carried out continuously. The polymers obtained are polypentenamers with a high trans double bond content. The trans content is generally above 90 in most cases between 90 and 98%. It can be determined from the infrared spectrum of the products. Trans- polypentenamers are rubber-like substances. In the following Examples, only dry apparatus and reagents are used and the processes are carried out under a protective gas atmosphere of pure nitrogen.

Example 1 1000 g of anhydrbus toluene which is free from air and 200 g of anhydrous cyclopentene are placed in an anhydrous, air-free autoclave which is equipped with a stirrer which has no packing gland and a thermometer and these materials are covered with purest nitrogen. 1 mmol of WCl dissolved in g of toluene, followed by 0.5 mmol of cyclopentenyl hydroperoxide are introduced at room temperature with the exclusion of air. After cooling to -100C, 0.3 mmol of tin triethylhydride dissolved in 50 g of toluene are introduced with a syringe. The temperature is kept between 0 and by external cooling. After 2 hours, the reaction is stopped by the addition of 10 g of ethanolamine, and 1.5 g of 4-methyl- 2,5 -ditertiary butylphenol are added. The polymer is isolated by introducing the viscous solution into 5 times its quantity of methanol and the polymer obtained is dried in a circulating air cupboard. The yield is 58% of the theoretical, the trans bond content 93.8%.

A3 described in Example 1, cyclopentene is polymerised

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with a combination of 1 mmol of WC1 6 0.5 mmol of ethanol and 0.4 mmol of tin dibutyldihydride. The yield obtained after 4 hours is 61% of the theoretical, the trans bond content 91.2%.

Example 3 Cyclopentene is polymerised with 1.2 mmol of WC1 6 which had been reacted with 1.2 mmol of ethanol before polymerisation, and with 1,8 mmol of tin triethylhydride by the method described

in Example 1. The yield is 54; of the theory, the trans bond content is 92.8%.

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Claims (4)

13.699 The claims defining the invention are as follows:

1. Process for producing cyclopentene polymers or

copolymers, wherein cyclopentene alone, or cyclopentene

with up to 30% by weight, based thereon, of another

cyclic unsaturated monomer, is respectively polymerised

or copolymerised at -15 to +15°C in the presence of a catalyst made from

a) tungsten hexachloride, b) an alkyl or aryl tin hydride and

c) a cocatalyst compound containing -OH or -0-0- groups.

2. Process according to claim 1, wherein up to 304 by weight of a bicyclic or polycyclic olefine (based on

cyclopentene) is copolymerised with cyclopentene.

3. Process according to claim 1, wherein polymerisation is carried out in an inert organic solvent,

4. Process according to claim 1, wherein the alkyl or aryl tin hydride is a compound of the formula

Snx 4-x in which H represents an alkyl radical having 1 to

carbon atoms, a cycloalkyl radical having 3 to 8 carbon atoms or an aryl radical, and x is 1, 2 or 3.

Catalyst composition for polymerising cyclopentene consisting of

a) tungsten hexachloride, b) an alkyl or aryl tin hydride and

c) a cocatalyst compound containing OH or -O-O-groupg.

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Catalyst composition according to claim 7 consisting of a) 1 Mol of tungsten hexachloride, b) 0.1 to 5 mols of a tin compound of the formula

wherein R represents an alkyl radical having 1 to

carbon atoms, a cycloalkyl radical having 3 to 8 carbon atoms or an aryl radical and x is 1, 2 or 3, c) 0.1 to 7 mols of a cocatalyst. 1 4. Process for producing cyclopentene polymers or copolymers substantially as herein described with reference to any one of the foregoing examples thereof.

9. Catalyst composition for polymerising cyclopenteDe substantially .as herein described with reference to any one 6f the foregoing examples thereof.

Deted this 9th day of April, 1970.

FARBENFABRIKEN BAYER AKTIENGESELLCHAPT 3y its Patent Attorneys,

ARTHUR S. CAVE CO.