Description of Related Art Cyclic Olefin Copolymers. COC, are polymeric materials of high interest. They are particularly attractive because their properties can easily be varied and the materials be used in various articles ranging from elastomers to High Perfomance Engineering Plastics.

A further avantage of these materials is that they can be made using existing polyethylene or polypropylene polymerization reactors.

The COC's are commercially prepared by copolymerizing cyclic monomers. such as norbornene or substituted norbornenes. with olefinic comonomers, in particular lower alkenes or styrene. The copolymerization reactions are typically carried out in the presence of catalysts. Thus. tetracyclododecene is copolymerized with ethylene using vanadium- type Ziegler-Natta catalysts (Mitsui Chemical's APEL). Metallocene catalyst have been also used for the copolvmerization of norbornene with ethylene (commercially available products are Mitsui Chemical's APO and Ticona's TOPAS). Soft elastomeric types of polyolefins are obtained by Idemitsu Kosan by copolymerization of small amounts of norbornene with ethylene. Furthermore. the use of metallocenes for homopolymerization of norbornene as well as for catalytic copolymerization of substituted norbornenes with ethylene. propylene and styrene is known in the art. Other Single Site Catalysts, like

palladium and nickel catalysts, have been used in homo-and copolymerization of norbornene and substituted norbornenes. Engineering types of COC are made by ring- opening methathesis polymerization (ROMP) of substituted norbornenes (commercially available products are represented by BF Goodrich's TELENE OP. Nippon Zeon's ZEONEX and Japan Synthetic Rubber's ARTON). The ROMP-technique can also be employed from manufacturing elastomers (Huls'VESTENAMER polycyclooctene and Atochem's NORSOREX polynorbornene) as well as RIM thermosets (BF Goodrich's TELENE RIM).

However, the future of the COC-polymers depends to a high degree on the availability and price of the cyclic monomers.

All the cyclic monomers used in the art and presented above are made from raw-materials obtainable from the petrochemical industry and originating in a non-renewable source, i. e. oil. Norbornene and tetracyclododecene are made from dicyclopentadiene and ethylene both of which come from the ethylene cracker. The reaction is carried out by subjecting the feed to a Diels-Alder process which is hazardous. There is only one producer (Atochem) of norbornene and tetracyclododecene in the world and a capacity increase is very unlikely.

Substituted norbornenes can also be produced with a Diels-Alder process from dicyclo- pentadiene and vinyl-monomers or unsaturated aliphatic compounds. Diels-Alder reactions between cyclopentadiene and assymetrical unsaturated chemical compounds such as styrene and indene (Patent Application PCT/FI97/00169) as well as allylbenzene. 4- phenylbutene-1. vinylpyridine vinylcyclohexane etc.. can easily be carried out at increased temperatures with or without a solvent.

EP Patent Application No. 0 157 222 discloses a process of producing alkylidene- norbornenes by reacting cyclopentadienes with conjugated dienes in the presence of a catalyst comprising titanium containing compounds and lithium aluminium hydrie.

Under the conditions of the processes of the prior art side reactions such as dimerization and trimerization of cyclopentadiene occur and the amount of side products increases with increasing temperature (150 to 220 °C) and time (2 to 3 h). In these cases. mixtures of

endo-and exo-diastereomers are obtained and the exo/endo ratio has significant effects on the polymerization processes and the technical properties of the polymers.

Furthermore. Diels-Alder reactions between cyclopentadiene and symmetrical unsaturated chemical compounds, such as 2-butene. 3-hexene. stilbene. cyclopentene. cyclooctene. norbomene, anthracene. have led to low conversions or no reaction at all.

As apparent from the above. new alternative routes to norbornene and tetracyclododecene are urgently needed due to technical reasons as well as the supply situation.

Brief Summarv of the Invention It is an object of the present invention to eliminate the problems of the prior art and to provide a process for synthesizing norbornene and derivatives thereof while avoiding side reactions and the formation of a mixture of endo-and exo-stereoisomers.

It is another object of the present invention to provide cyclic olefin copolymers using the monomers produced by the present invention.

These and other objects. together with the avantages thereof over known processes. which shall become apparent from the specification which follows. are accomplished by the invention as hereinafter described and claimed.

The present invention is based on subjecting cyclopentadiene and a dienophile to a Diels- Alder reaction in the presence of a heterogeneous. porous catalyst. In the art heterogeneous catalysts like zeolites, montmorillonites and silicagel have been used in Diels-Alder reactions as such but only emploving dienophiles containing oxygen. nitrogen or other elements which attract electrons. Now it has surprisingly been found that by carrying out the Diels-Alder reaction between a cyclopentadiene and a dienophile in the presence of a porous heterogenous catalyst, such as activated NaY-zeolite. the synthesis temperature can be kept low (room temperature) and the time very short (a few minutes). The monomers prepared can advantageously be used for the production of cyclic olefin copolymers.

In particular, the process for producing norbornene and substituted norbornenes is characterized by what is stated in the characterizing part of claim 1.

The COC compounds prepared from the present monomers are characterized by what is stated in the characterizing part of claim 23.

At the reaction conditions and with the catalysts of the present invention, the product is very pure (mainly the raw-materials and the main product) and also symmetrical unsaturated chemical compounds can be used as dienophiles with conversions of commercial significance. Dimerization of cyclopentadiene is efficiently prevented. The heterogeneous catalysts used in the present invention are therefore suitable for making multicycloolefinic compounds like cvclooctylnorbornene from cyclooctene and cyclopentadiene and tetracyclododecene from norbornene and cyclopentadiene. The tricycloolefinic and in particular the tetracycloolefinic compunds increase the stiffness of polymers more efficiently than the bicycloolefinic compounds when used as monomers.

Higher glass-transition temperatures are obtained and in copolymers lower incorporations can be used.

Detailed Description of the Invention Next. the invention will be described more closely with the aid of a detailed description and referring to a number of working examples.

The present invention comprises reacting cyclopentadiene with a dienophile in the presence of a porous heterogeneous catalyst. Any porous heterogeneous catalyst capable of catalysing a Diels-Alder reaction of the two main reactants at ambient or slightly increased temperature (generally up to about 50 °C) can be used. It is preferred to use a catalyst comprising a molecular sieve structure which means that is is capable of discriminating action towards the species present in the reaction mixture by adsorbing some molecules and rejecting others. This molecular sieve action will reduce the extent of undesired side reactions. as explained in greater detail below.

The particularly preferred heterogeneous catalyst used in the present invention is a zeolite,

in particular a zeolite having the general formula Nf (AlO,) x (SiO.) \. zHnO wherein M is hydrogen or a cation and v. x. y and z are integers each having a value from 1 to 24 The ratio between y and x is advantageously greater than 1. preferably about 1.5 to 3. i. e. the zeolite is of"X"or"Y"type. preferably of the latter. As known in the art these kinds of structure have large cages joined by smaller openings which determine the size of the adsorbing molecule which can gain access (molecular sieve action). The effective pore diameter is determined bv the cation balancing the negative charge of the structure.

Typically, the pore diameter increases when potassium is changed for sodium and sodium is changed for calcium. The zeolites are natural or synthetic.

In the process of the invention the preferred zeolite is a Y-zeolite (such as faujasite), e. g. in the Na form. The NaY-zeolite has been found to be very suitable for the Diels-Alder reaction between cyclopentadiene and cyclooctene. although the scope of the present invention is not limited to NaY-zeolite or zeolites in general. The main product is obtained inside the pores but there is not room enough for the side-reactions like dimerization and trimerization of cyclopentadiene. When using another dienophile than cyclooctene another pore size and/or chemical composition of the heterogeneous catalyst might be different when optimum conditions are looked for. Using suitable, porous heterogeneous catalysts also the diastereomers of substituted norbornenes (exo and endo) can be made selectively.

It should be noted that when substituted norbornenes are used as monomers in COC's the exo-diastereomer is preferable in some polymerization processes and for some applications whereas the endo-diastereomer is preferable for other ones.

In addition to the above mentioned crvstalline aluminosilicate zeolites and their ionexchanged modifications. other suitable catalysts include borosilicates. ferrosilicates and/or aluminosilicates. However, the invention is not limited to the above-named catalyst grades alone, but rather. all porous, solid phase catalysts that catalyze a Diels-Alder reaction between cyclopentadiene and a dienophile are suited for use according to the

invention.

Within the scope of the present invention and in conclusion of what has been stated above. in particular for cvclopentadiene porous''solid catalvsts stand for compounds having an <BR> <BR> <BR> average pore size typically in the range of about 5 to 20 A. preferably about 10 to 15 As explained in connection with zeolites, the porous catalysts should have an average pore size so that the catalyst is capable of discriminating between the desired and undesired products. In particular. the pore size should be such that reactants and the products, the norbornene and its derivatives, fit into the pores. but not the products of side-reactions. e. e. dimers and trimers of cyclopentadiene or the corresponding cyclic diene used as reactant.

Thus, preferably the pores should be generally smaller than the size of the dimer molecules.

The NaY-zeolites used in the examples below contain spherical cavities (pores) having a diameter of about 12 A (11.8 A) connected bv about 7 A (7.4 A) circular windows (openings) and they have found to be very suitable for catalysing the present reaction.

The reaction between the cyclopentadiene (or generally a cyclic diene) and the dienophile is carried out using a liquid reaction medium. The molar ratio of the reactants is equimolar or an excess of the dienophile compound is used. The reaction temperature is about 5 to 150 °C in particular about 10 to 60 °C and the reaction time is 0.01 min to 48 hours. preferably about 0.1 min to 24 hours. In particular. the synthesis time is 0.1 to 60 min. depending on the amounts of reactants. After the reaction the product is separated from the reaction mixture by, e. g., extraction. Preferably the extraction is carried out with a liquid extraction agent such as a non-polar chlorinated hvdrocarbon.

Preferably, the cyclic diene comprises dicyclopentadiene or cyclopentadiene. Most suitably dicyclopentadiene is cracked immediately before the reaction to form cyclopentadiene, for example. by feeding the reagent into the reaction mixture through a pipe with heated mantle. The cyclopentadiene is preferably added gradually as a function of time and/or along the reactor train.

Norbornene is prepared « y reacting the cyclic diene with ethylene. When substituted norbornene derivatives are prepared, the suitable dienophilic compounds include unsaturated aliphatic or aromatic compounds. The unsaturated aliphatic compound can be

selected from the group consisting of propylene and C4-Cs olefins and dienes. The unsaturated aromatic compound can be selected from the group consisting of styrene. indene. vinvlpyridine. stilbene. allylbenzene. 4-phenyl-butene-1. anthracene and their derivatives. Further. cyclic olefines (such as cyclopentene. cyclohexene. cyclooctene and derivatives thereof, norbomene. trimethyinorbomene. apopinene and derivatives thereof). linear dienes (in particular 1.2-butadiene). acrvlic acid and methacrylic acid and esters thereof (for examples methylacrylate). and unsaturated silanes (for example. vinyl- trimethoxysilane) can be used.

.-\s noted above. norbornene can be used as a dienophile for preparing tetracyclic olefinic compounds, such as tetracyclododecene. However, bicycloolefinic compounds can be used instead of norbomene. the future availability of which is questionable. Such bicycloolefinic compounds which can replace norbornene as raw-materials in the process of the invention are a-pinne apopinene (obtained from a-pinne by eliminating the methylgroup in a- position). (iso) bornene (obtained from (iso) bornylesters), trimethylnorbornene (obtained from a-pinene, P-pinene, camphene through hydrochlorination of the double bond-E-2- elimination) etc. These bicyclo-olefinic compounds also have the advantage of being obtained from natural, renewable sources.

In the working examples given below. the amount of the catalyst is rather high compared to the amount of reactants and the product needs to be extracted out of the pores of the catalyst. However, because very short reaction times are needed continuous processes can be used to carry out the invention in an efficient and economical manner. If liquid dienophiles like cyclooctene are used these can be employed in excess (used as a solvent for cyclopentadiene and the product) in the Diels-Alder synthesis and at the same time or <BR> <BR> <BR> <BR> later as the extraction solvent. Usuallv the excess is about I to 200 %. in particular about 5 to 30 %. of the equimolar mount. The dienophile can be used alone or together with another solvent in the synthesis and/or the extraction stages.

According to a preferred embodiment, the reactor configuration used comprises one or several tube reactors in series and/or parallell with fixed or moving (screw conveying) beds of catalyst which are extracted intermittently or simultaneously. The process of the invention is. however, not limited to fixed and moving bed tube reactors, but any reactors

and their combinations in which high mounts of catalyst can be used in the Diels-Alder synthesis. extraction and eventually reactivation can be used. Stirred autoclaves and/or loops as single reactors or in cascade can be used in anv combination. It is also possible to make the Diels-Alder synthesis in gas phase using for instance the fludized bed reactor.

This is especially suitable for low boiling point dienophiles like ethylene. propylene and C4-Cx olefins cyloolefins. dienes and cyclic dienes as well as styrene.

No matter what kinds of reactors are used it is advantageous to use the dienophile as a solvent and add cyclopentadiene gradually (as a function of time or further down the reactor train) at the same speed as it is consumed. In this wav the formation of by-products is minimized and the separation is simple (only the product and the dienophile).

The substituted norbornene can be homopolymerized of copolymerized with ethylene. propylene, styrene and/or carbon monoxide. Polymerization or copolymerization can be carried out with an addition polymerization method. The addition polymerization can be done with a Ziegler-Natta catalyst (vanadium based), a metallocene catalyst, a palladium- catalyst, nickel/palladium-catalyst or a single site catalyst.

The substituted norbornene can also be polymerized or copolymerized with a ring-opening polymerization method (ROMP).

When the substituted norbornenes are made thermally a mixture of endo-and exo- diastereomers is always obtained. Under certain conditions the dienophile can also dimerize in high yields. This applies to norbornene as well as to substituted norbornenes even if the pore size of the catalyst needs to be bigger. The dimers of norbornene and/or substituted norbornenes can be used as additives in polyolefins in order to improve their water vapour barrier in the same way as hydrogenated dicyclopentadiene is used today (Hercules).

Tetracyclododecene is used in Mitsui Chemical's vanadium-based Ziegler-Natta catalyzed APEL and in Nippon Zeon's ring-opening polymerized Zeonex. Conventionally, tetracyclododecene is obtained as a byproduct in very small amounts when making norbornene. It is difficult to separate and its future availability is very questionable. It is

therefore an important feature and avantage of the present invention that tetracyclo- dodecene can be made independently of the production of norbornene.

The fundamental characteristics of the COC's manufactured according to the invention are thermoplastic/elastomeric. thermoplastic/conventional plastic. thermoplastic/engineering plastic ; thermoset/elastomeric thermoset/rigid plastic (RIM). Any known processing method can be used for manufacturing the final products.

The following non-limiting examples illustrate the invention: Example 1 A reactor was charged with 1.7 g NaY-zeolite. 0.11 ml cis-cyclooctene and 0.06 ml cyclopentadiene. The zeolite had been activated by drying in vacuum at 190 °C for 4 h.

The mixture was shaken vigorously and allowed to stand at 21 °C overnight. The product was extracted with dichloromethane at 21 °C. The conversion to a Diels-Alder product of Formula I was. based on MS-GC-analysis. 3.4 %.

Example 2 1.7 g NaY-zeolite. 0.1 I ml cis-cyclooctene and 0.06 mi cyclopentadiene were charged into a reactor. The zeolite had been activated by drying in vacuum at 190 °C for 4 h. The mixture was shaken vigorously and allowed to stand at 50 °C overnight. The product was extracted with dichloromethane at 21 °C. The conversion to Diels-Alder product according to MS-GC-analysis was 3.6 %.

Example 3 A reactor was charged with 1.7 g NaY-zeolite. 0.095 ml cis-cyclooctene and 0.07 ml cyclopentadiene. The zeolite was activated by drying in vacuum at 190 °C for 4 h. The mixture was shaken vigorously and allowed to stand at 21 °C overnight. The product was extracted with dichloromethane at 21 °C. Conversion to Diels-Alder product was 2.7% Example 4 NaY-zeolite (1.7 g), 0.11 ml cis-cyclooctene and 0.06 mi cyclopentadiene were charged into a reactor. The zeolite was activated by drying in vacuum at 190 °C for 4 h. The <BR> <BR> <BR> mixture was shaken vigorously and allowed to stand at 21 °C. Total reaction time was 5 h.

The product was extracted with dichloromethane at 21°C. Conversion to Diels-Alder product according to MS-GC-analysis was 3.7 % Example 5 A reactor was charged with 1.7 g NaY-zeolite, 0.11 ml cis-cyclooctene and 0.06 ml cyclopentadiene. The zeolite was activated by drying in vacuum at 190 °C for 4 h. The mixture was shaken vigorously and allowed to stand at 21 °C. Total reaction time was 2 h.

The product was extracted with dichloromethane at 21°C. Conversion to Diels-Alder product according to MS-GC-analysis was 4.8 %.

Example 6 A reactor was charged with 1.7 g NaY-zeolite, 0.11 ml cis-cyclooctene and 0.06 ml cyclopentadiene. The zeolite was activated by drying in vacuum at 190 °C for 4 h. The mixture was shaken vigorously and allowed to stand at 21 °C. Total reaction time was 1 h.

The product was extracted with dichloromethane at 21 °C. Conversion to Diels-Alder product according to MS-GC-analysis was 5.0 %.

Example 7 A reactor was charged with 1.7 g NaY-zeolite. 0. 1 1 ml cis-cvclooctene and 0.06 mi cyclopentadiene. The zeolite was activated by drying in vacuum at 190 °C for 4 h. The mixture was shaken vigorously and allowed to stand at 21 °C. Total reaction time was 30 minutes. The product was extracted with dichloromethane at 21°C. Conversion to Diels- Alder product according to MS-GC-analysis was 2.0 % Example 8 A reactor was cnarged with 1.7 g NaY-zeolite. 0.11 ml cis-cyclooctene and 0.06 ml cyclopentadiene. The zeolite was activated by drying in vacuum at 190 °C for 4 h. The mixture was shaken vigorously and allowed to stand at 21 °C. Total reaction time was 5 minutes. The product was extracted with dichloromethane at 21 °C. Conversion to Diels- Alder product according to MS-GC-analysis was 1.6 % Example 9 Into a reactor were charged 1.7 g NaY-zeolite, 0.11 ml cis-cyclooctene and 0.06 ml cyclopentadiene. The zeolite was activated by drying in vacuum at 190 °C for 4 h. The mixture was shaken vigorously and allowed to stand at 21 °C. Total reaction time was 1 h.

Extraction of the product was carried out with cis-cyclooctene at 21 °C. Conversion to Diels-Alder product according to MS-GC-analysis was 3.5 % Example 10 A reactor was charged with 1.7 g NaY-zeolite. 0.11 ml cis-cyclooctene and 0.06 ml cyclopentadiene. The zeolite was activated by drying in vacuum at 190 °C for 4 h. The mixture was shaken vigorously and allowed to stand at 21 °C. Total reaction time was 60 minutes. Extraction of the product was carried out with cis-cyclooctene at 70 °C.

Conversion to Diels-Alder product according to MS-GC-analysis was 8.2 %.

Example 11 A reactor was charged with 1.7 g NaY-zeolite. 0.15 ml cis-stilbene and 0.06 ml syklopentadiene. The zeolite was activated by drying in vacuum at 190 °C for 4 h. The mixture was shaken vigorously and allowed to stand at 21 °C. Total reaction time was 1 h.

Extraction of the product was carried out with dichlormethane at 21 °C. According to MS- GC-analysis. conversion to a Diels-Alder product of Formula II was 0.3 %.

Example 12 Norbornene (0.17 g) was dissolved in 0.1 g cyclopentadiene. A reactor was charged with 0.17 ml of this mixture and 1.7 g NaY-zeolite. The zeolite was activated by drying in vacuum at 190 °C for 4 h. The mixture was shaken vigorously and allowed to stand at 21 °C. Total reaction time was 1 h. Extraction of the product was carried out with dichloromethane at 21°C. Conversion to Diels-Alder product (fig 3) according to MS-GC- analysis was 1.0 %.