DE2552616A1 - Catalyst for polyalkenamer prepn - consisting of mixture of organo-silicon compound, organo-tungsten halide, and organo-aluminium compound - Google Patents

Abstract

Polyalkenamers having a high content of cis double bonds useful e.g. for shoe soles, tyres and belts are prepd. by polymerising cyclooctene or 1,5-cyclooctadiene in the presence of a catalyst system consisting of (A) an organosilicon cpd. of formula R4-nSi(Y)n (where R is alkyl, alkenyl or aryl; Y is alkylidenyl, alkoxy, aryloxy, or aralkoxy; and n is at least 2), (B) a tungsten halide of formula Rm-n WXn (where X is chlorine or bromine; R is alkoxy, aryloxy, haloalkoxy, alkaryloxy or acetylacetonyl; m is 6 when X is chlorine, and is 5 when X is bromine; and n is 3-6), and (C) an organoaluminium cpd. of formula AlR1R2R3 (where R1-3 are each alkyl, aralkyl or halogen). Polymers contg. ca. 90% cis double bonds are obtd. and the catalyst has a high activity.

Description

Process for the preparation of polyalkenamers with a high cis-

Content The invention relates to a process for the preparation of polyoctenamers with high cis content and polybutenamers with high cis content and copolymers thereof by ring-opening polymerizations of cyclooctene and / or 1,5-cyclooctadiene using a catalyst system composed of (A) an organosilicon compound, (B) a tungsten halide salt and (C> an organoaluminum compound.

Ring-opening polymerization is to be understood as meaning a process which, when carried out, cycloolefins in the presence of an olefin double conversion catalyst (metathesis catalyst) form polyalkenamers having a high molecular weight.

It should be noted that in polyalkenamers, which are based on the ring-opening polymerization Decrease of cycloolefins, the repeating polymer segments the same Number of carbon atoms and double bonds like the polymerized cycloolefin contain. This phenomenon is in contrast to addition polymers, which consist of acyclic Olefins and diolefins are produced in which the polymer segments a Contain fewer double bonds than the olefin or diolefin monomer used.

Recently, there is a need for high cis polybutadiene and high cis polyisoprene made by polymerizing butadiene or isoprene, arose because these elastomers with a high cis content certain desired ones Possess properties.

The polymer obtained by ring-opening polymerization of 1,5-cyclooctadiene, which can be referred to as polyoctadienameres (I) or polybutenameres (11), is predominantly that same high 1,4-content polybutadiene made by addition polymerization of butadiene. However, one important difference should be noted. High 1,4-content polybutadiene contains at least some vinyl side chain units as a result of the occurrence of some "1,2-addition" (in addition to normal 1,4-addition) during the addition polymerization of the 1,3-butadiene monomer. However, such vinyl units are completely absent in the polybutenamer (11) due to the mechanism inherent in ring-opening polymerizations of cycloolefins, according to which the formation of such side groups cannot occur.

In the known ring-opening polymerization process of cycloolefins and cyclodiolefins occur slightly less than 90 of the vinylene (-CH = CH-) units of the Polymer products in the cis configuration. One of the advantages of the invention is that by applying the methods described, polyalkenamers (i.e. polyoctenamers and polybutenamers) can be obtained which cis-vinylene contents of approximately 90% or more.

According to the invention, at least one cycloolefin selected from the group consisting of cyclooctene and 1,5-cyclooctadiene is polymerized using a catalyst system which consists of (A) an organosilicon compound of the formula 'R4-nsi (Y) n // wherein R is any Is hydrocarbyl such as alkyl, alkenyl, or aryl, and Y can be selected from the group consisting of vinyl, alkylidenyl, alkoxy, aryloxy, and aralkoxy, where n is at least 2, (B) a tungsten halide of the general formula in which X is chlorine or bromine and R is selected from the group consisting of alkoxy, haloalkoxy, aryloxy, alkaryloxy and acetylacetonyl radicals, where m is 6 when X = Cl or 5 when X is = Br, and where n 'can also mean 3 up to and including 6, and (C) an organoaluminum compound of the formula in which the substituents R1, R2 and R3 independently of one another represent an alkyl or aralkyl group or a halogen atom.

In the case of the compounds (C), it is preferable that they be at least have an aluminum-carbon bond.

Representative examples of compounds of the formula Ri ~ nSi 1 or for component (A) of the catalyst system are diphenyldivinylsilane, diallyldivinylsilane, Diethyldipropylidenylsilane, dimethyldiethoxysilane, benzyltrivinylsilane and tetravinylsilane. Vinyl or alkylidenyl radicals represent a preferred class of group Y.

Representative examples of compounds of the formula Rm-n'WXn '/ or component (B) of the catalyst system are tungsten hexachloride, phenoxy tungsten tachloride, (2-chloroethoxy) tungsten tachloride, ethoxy tungsten tetrabromide, di- (2-chlorophenoxy) tungsten tetrachloride, Triethoxy tungsten trichloride and acetylacetonyl tungsten tachloride.

Some of these tungsten salts can be modified by modifying WCl6 or WBr5 made with materials that contain OH groups such as alcohols or phenols will. This modification appears to be the mode of operation of the catalyst system in this respect to improve than in some cases the catalyst a higher rate of polymerization conditional, while in other cases the formation of a gel in the finished polymer prevented or suppressed. For example, it has been found that if lower alkyl alcohols or phenols, such as ethyl alcohol, halogen-substituted ethyl alcohols, i.e. trifluoroethanol, or even propyl or butyl alcohol of the tungsten hexachloride compound added in molar amounts of from 1 to about 4 moles of the alcohol per mole of tungsten the catalyst exhibits one or more of these advantages.

Representative examples of compounds of the formula or the component (C) of the catalyst system are trialkylaluminum compounds such as triethylaluminum, triisobutylaluminum or the like, dialkylaluminum halides such as diethylaluminum chloride, diethylaluminum bromide or the like, mixtures of dialkylaluminum halides and alkylaluminum dihalides, such as alkylaluminum aluminum dihalides, such as ethylaluminum aluminum dihalides, such as ethyl chloride aluminum dihalides, such as ethyl chloride aluminum dihalides, such as ethyl aluminum dihalide, and the like, ethyl aluminum dihalide, and the like, ethyl aluminum dihalide.

The main action of the organosilicon component (A) of the catalyst system can easily be determined by comparing the cis-vinylene content of the resulting polymers when using this component compare with the content resulting from the combination of (B) and (C) of the catalyst in the absence of (A). In some cases, for example when (B) and (C) in combination alone a polymer with one cis double bond content of only 21%, has the addition of (A) to the monomer solution before using the same (B) / (C) combination, with otherwise identical conditions be observed, the formation of a polymer with a cis double bond content of more than 92%. Although it is not yet known for sure why component (A) is critical with regard to the stereoselectivity of the catalyst system is, it is believed that these silicon compounds are called in a certain way Chelating agents act and as such modify the active tungsten catalyst component.

The basis for this assumption is based in part on the finding that the number of Y substituents, as described above in connection with (A) must be at least 2. For example, it was found that although divinyldiphenylsilane is very effective in the system, monovinylsilanes are only marginally effective when used in amounts the same Allow concentrations of vinyl groups.

The polymerizations according to the invention can be in solution or in bulk be performed. If the polymerization is carried out in solution, then solvents, which do not adversely affect the polymerization are required. Such Solvents that meet this requirement are liquid aromatic Hydrocarbons such as benzene, chlorobenzene or toluene, as well as liquid aliphatic ones Compounds such as pentane, hexane, cyclohexane or the like.

It has been found to have good results in practicing the invention can be obtained when the molar ratio between the three catalyst components (A), (B) and (C) as defined above are as follows: molar ratio (A) / (B) between 0.1 / 1 and 3/1 and molar ratio (C) / (B) between 1/1 and 10/1. In particular, a molar ratio (A) / (B) becomes from 0.5 / 1 to 1.25 / 1 and a molar ratio (C) / (B) from 1/1 to 4/1 are preferred.

The catalysts used according to the invention are mixed by mixing the components produced by known methods.

For example, the catalysts can be prepared according to the "Vorbildengs" or in situ method getting produced. The 'education' method is carried out in such a way that that the catalyst components interact with each other prior to exposure to any of the catalyst components on the cyclic monomers used to carry out the polymerization reaction be mixed. When performing the in situ method, the catalyst components separately added to the cyclic monomers in the polymerization mixture. To the The latter method is preferred for carrying out the invention. The preferred order is in that the silicon compound (A) is added crushed, followed by the addition of the tungsten halide (B) and then finally the aluminum component (C).

The amount of used to carry out the polymerization reactions Catalyst can fluctuate within a wide range of concentrations and depends on a number of factors, such as the purity of the reactants, the desired reaction times and the temperature maintained. The polymerization reactions can can be carried out successfully when the amount of catalyst is approximately 1 Part by weight of component (B) per 2500 parts by weight of the monomer used is, the molar ratios (A) / (B) and (C) / (B) adjusted accordingly will.

The temperatures at which the polymerization reactions are carried out also vary within a wide range from extreme low temperatures, such as -40 "C, up to high temperatures, such as 1500C. The temperatures are therefore not critical. However, for practicing the invention it is generally it is preferable to carry out the reaction at a temperature between -10 and about 250C. Even if the cis / trans ratio of the double bond content of the polymer product not drastically by changing temperatures within the preferred range changes, it was nevertheless found that in general a somewhat higher cis double bond content in the polymer is achieved when the polymerizations at the lower end of the Temperature range, while all other factors remain the same.

The molecular weight of the homo- and copolymers according to the invention can be controlled in a conventional manner by adding small amounts of acyclic olefins to the respective polymerization batches. The process according to which a molecule is cleaved in the double conversion of a -CH = CH-vinylene main chain double bond and the vinylene-CH = CH- of the added acyclic olefin can be represented as follows: A notable feature of the catalyst system of the invention is that during the course of a particular polymerization the cis / trans ratio of the double bond content of the polymer generally remains fairly constant. This means that there is little change in the "cis content" of the final polymer product when this content is compared, for example, to a sample of the polymer taken after a 5% conversion of the monomer to the polymer. In addition, there is generally no noticeable decrease in the cis double bond content of the polymer if the polymerization is not stopped for prolonged periods of time after the conversion of the monomer into the polymer has ended. These phenomena show that the addition of the organosilicon compound, as defined according to the invention, to the catalyst system makes the combination of (A), (B) and (C) of this system a real cis-directing catalyst when it is used for the ring-opening polymerization of cyclooctene and / or 1,5-cyclooctadiene is used.

As has already been mentioned, the main difference is between the polybutenamer, which is formed by the ring-opening polymerization of 1,5-cyclooctadiene and polybutadiene that by addition polymerization from 1,3-butadiene, the complete absence of any vinyl side chain units in the first mentioned connection. Therefore, the polymers made from 1,5-cyclooctadiene obtained by the process according to the invention, actually "vinyl-free" Polybutadiene rubbers with a high cis-1,4 content.

The polymers produced according to the invention can be used as rubbers use to make various elastomeric articles, for example Rubber articles, shoe soles and heels, industrial tapes and automobile tires. They can be reinforced with carbon black and made with various materials, such as rubber pigments and fillers, are pigmented. They can also be used in a conventional manner Using sulfur vulcanization methods to be crosslinked or vulcanized or crosslinked in a conventional manner by exposure to ionizing radiation will.

The following examples illustrate the invention without restricting it. Unless otherwise stated, all parts and percentages relate on weight.

The monomer solutions are used to carry out the following examples prepared in such a way that a 20% solution of a freshly distilled cycloolefin in n-hexane is passed through a column filled with silica gel and aluminum oxide is filled.

The polymerizations are carried out in previously dried 120 ml bottles carried out, which included 50 ml samples of the monomer solution passed through the column Nitrogen can be supplied. Self-locking, rubber-lined Closures are used to close the bottles.

The tungsten halide catalyst derivatives (A) are made in the manner manufactured, that 0.05m benzene solutions of WCl6 with 1-3 times the molar equivalents of an alcohol or phenol (as indicated below), the solutions being treated with Purge with nitrogen for a few minutes until all of the HCl gas is removed.

All catalyst components are added to the monomer solutions in the bottles fed through a syringe passing through the self-sealing, lined with rubber Cover to be pushed.

When octene-2 is used as a molecular weight regulator, then it is added in a similar manner prior to the addition of the catalyst.

The percentage of the cis double bond content of each sample becomes determined by the relationship (100 minus percentage trans double bond content). The percentage of trans double bond content is obtained from the infrared absorbance determined at 967 cm 1, which in the case of each sample was determined using 1- or 2% solutions in CS2 is determined.

Example 1 A comparative bottle containing 50 ml of a Contains 20% by weight solution of 1,5-cyclooctadiene (COD) in n-hexane 0.4 ml of a 0.05 M solution of (CF3CH2OH) 3.WCl6 and 0.4 ml of a 0.2 M solution of Ethyl aluminum dichloride (RAD) added. After 2 hours the polymerization is Finished with a small amount of isopropanol, whereupon the polymer cement dried will. A 96% yield of the polybutenamer rubber is obtained Analysis shows a cis double bond content of 21%.

Example 2 A bottle containing 50 ml of a 20% solution of COD in n-hexane contains, 0.45ml of a 0.05 m solution of divinyldiphenylsilane, 0.4 ml of the (CF3CH2OH) 3-WC16 solution and 0.4 ml of the AADC solution were added. After 2 The polymerization is ended and the sample after that described in Example 1 is completed Method dried. A 93% yield of the polybutenamer rubber is found. An analysis shows that the cis double bond content is 92%.

Example 3 According to the method described in Example 2, 50 ml of the 1,5-COD monomer solution with 0.45 ml of a 0.05 M solution of dimethoxydiphenylsilane, 0.4 ml of the (CF3CH2OH) 3.WCl6 solution and 0.4 ml of the ÄADC solution. After a In a similar work-up method, a rubber falls in a 94% yield a cis double bond content of 86%.

Example 4 According to the method described in Example 2, 50 ml of the 1,5-COD monomer solution with 0.45 ml of a 0.05 M solution of tetravinylsilane, 0.4 ml of the (CF3CH2OH) 3.WCl6 solution and 0.4 ml of the ADC solution. A similar Working up gives a rubber with a cis double bond content in 91% yield of 94%.

Example 5 In a comparative bottle containing 50 ml of the 1,5-COD monomer solution contains 0.4 ml of a 0.05 M solution of (CH3Cff2OH) 3.WCl6 and 0.4 ml of the 0.2 m ADC solution given. After 4 hours, the reaction solution is according to that in Example ; described way worked up. A rubber is obtained in 96% yield with a cis double bond content of 78%.

Example 6 Following the procedure described in Example 2 are 50 ml of the 1,5-COD monomer solution with 0.4 ml of a 0.05 M solution of tetravinylsilane, 0.4 ml of the (CH3CH2OH) 3.WCl6 solution and 0.4 ml of the ÄADC solution. After a Similar work-up gives a rubber with a 95% yield cis double bond content of 93.5 t.

Example 7 In a comparative bottle containing 50 ml of a 20% strength by weight n-hexane solution of cyclooctene (CO) containing 700 ppm octene-2, will be 0.5 ml of a 0.05 M (CH3CH2OH) 3.WCl6 solution and 0.45 ml of a 0.2 M ÄADC solution given. After 45 minutes, the reaction is ended and the rubber after the in Example 1 described method isolated. A polyoctenamer is obtained in 93% yield with a cis double bond content of 75.5% Example 8 In a bottle containing 50 ml of a 20% strength by weight n-hexane solution of cyclooctene is 0.55 ml of a 0.05M divinyldiphenylsilane, 0.5 ml of a 0.05M (CH3CH2OH) 3.1iCl6 and 0.45 ml of a 0.2 m ÄADC is added. After 90 minutes, the polymerization is terminated, whereupon the polymer is isolated in the manner described. A 63% yield is obtained a rubber with a cis double bond content of 96.5%.

Example 9 Following the procedure described in Example 8 are 50 ml of the cyclooctene solution with 0.55 ml of a 0.01 m (C6H5) 2Si (OCH3) 2, 0.5 ml of a (CF.3CH2OH) 3.WCl6 and 0.45 ml of a 0.2 M ÄADC. With a similar one Work-up method can be used to isolate a rubber in a 30% yield The cis vinylene content of the rubber is 91.4%.

The results of Examples 1 to 9 are summarized in Table I.

Table I Solution a-polymerizations b, c of cycloolefinend R2 # Examples Monomeric R4-nSi (Z) n (A) R (m-n ') WXn'e (B) R1-Al-R3 (C) vinylene units cis 1 1,5-COD (NH3CH2O) 3 (WCl) 3e EtAlCl2 21% (comparison) 2 "(C6H5) 2Si (CH = CH2) 2" "90% 3" (C6H5) 2Si (OCH3) 2 "" 86% 4 "(CH2 = CH) 4Si" "94% 5 (CH3CH2O) 3WCl3" 78% (comparison) 6 "(CH2 = CH) 4Si "" 93.5% 7 Cyclo- (CF3CH2O) 3WCl3 "75.5% (comparison) octene 8" (C6H5) 2Si (CH = CH2) 2 "" 96.5% 9 "(C6H5) 2Si (OCH3) 2f" "91.4% a) 20% solutions in n-hexane, b) 24 ° C, c) Molar ratios (A) / (B) / (C) = approx. 1.25 / 1/4, unless otherwise stated, d) Weight ratio of monomer / (B) = approx. 2300/1, e) certain average numbers the substituents per W atom, f) (A) / (B) / (C) = 0.5 / 1/4.

In the following examples the polymerization reactions are polymerizations in bulk performed using undiluted 1,5-COD, which is cleaned in the same way as the COD related to the above-mentioned hexane-dilute monomer solutions has been used.

Example 10 In a comparative bottle containing 22 g of the 1,5-COD monomer 0.6 ml of a 0.05 M solution of C6H5OH.WCl6 and 0.4 ml of a 0.2 m solution of dietylaluminum chloride (DÄAC) given.

The polymerization is ended after 1 hour. The drying takes place as in the case of the solution polymers described above.

A rubber with a cis double bond content is obtained in a 96% yield of 59%.

Example 11 In a bottle containing 22 g of the 1,5-COD monomer, add 0.6 ml of a 0.05 M solution of tetravinylsilane, 0.6 ml of the 0.05 M C6H5OH.WCl6 solution and added 0.4 ml of the DÄAC solution. After 1 hour the polymerization is ended, whereupon the cement is dried. A rubber is obtained in a 75% yield, which has a cisβ double bond content of 96%.

In the definitions of the substituents of components (A), (B) and (C) contain the mentioned alkyl, alkenyl, alkylidene and alkoxy groups preferably 1 to 4 carbon atoms, the same applies to the side chains of the aryl radicals, the are preferably phenyl radicals.

Claims (8)

Claims Ij; A process for the preparation of polyalkenamers with a high cis content, characterized in that a cycloolefin selected from the group consisting of cyclooctene and 1,5-cyclooctadiene is polymerized using a catalyst system consisting of (A) an organosilicon compound of Formula R4-nSi (Y) n, where R is a hydrocarbon radical selected from the group consisting of alkyl, alkenyl or aryl groups, and Y is selected from the group consisting of vinyl, alkylidenyl, Alkoxy, aryloxy and aralkoxy radicals, and n is at least 2, (B) a tungsten halide salt of the general formula Man n, WXn ,, wherein X is chlorine or bromine and R is selected from the group consisting of alkoxy, aryloxy , Haloalkoxy, alkaryloxy and acetylacetonyl radicals, where m is 6 when X is chlorine and m is 5 when X is bromine, and further where n 'can be 3 up to and including 6, and (C) an organoaluminum compound of the formula in which R1, R2 and R3 independently of one another represent an alkyl or aralkyl radical or a halogen atom. 2. The method according to claim 1, characterized in that the used Organosilicon compound contains a vinyl radical. 3. The method according to claim 1, characterized in that the used Organoaluminum compound consists of ethylaluminum dichloride. 4. The method according to claim 1, characterized in that the used Tungsten halide salt consists of a tungsten hexachloride 3-ethyl alcohol complex. 5. The method according to claim 1, characterized in that the used Organosilicon compound consists of tetravinylsilane. 6. The method according to claim 1, characterized in that the used Organosilicon compound consists of diphenyldivinylsilane. 7. The method according to claim 1, characterized in that the used Organosilicon compound from diphenyldivinylsilane, the organoaluminum compound from ethyl aluminum dichloride and the tungsten halide salt from tungsten hexachloride, modified with 3 moles of ethyl alcohol. 8. The method according to claim 1, characterized in that the used Organosilicon compound made from tetravinylsilane, the organoaluminum compound made from Ethyl aluminum dichloride and the tungsten halide salt of tungsten hexachloride, modified with 3 moles of ethyl alcohol.