Process for the preparation of polytriazines from aromatic polycyanates

ABSTRACT OF THE DISCLOSURE

This invention is a process for the preparation of polytriazines comprising contacting aromatic polycyanates in the presence of a catalytic amount of a 5 metal salt of a carboxylic acid at a temperature between 20״c and 200^ec. The process is characterized in that the catalyst is a cobalt salt of a C^ carboxylic acid.

30,830A״F

A PROCESS FOR THE PREPARATION OF POLYTRIAZINES FROM AROMATIC POLYCYANATES

Ai .i

This invention relates to a process for the. preparation.of polytriazines. More specifically, it relates to novel catalysts for the preparation of p_o1_ytriazines from aromatic polycyanates.

it is known from sundermann et al., U.S. Patent 4,094,852, June 13, 1978, that aromatic cyanates can be polymerized to prepare polytriazine polymers. Such polymers are prepared by contacting the aromatic cyanates with suitable catalysts at elevated temperatures. It is taught that suitable catalysts include acids, bases, salts, nitrogen and phosphorus compounds, for example, Lewis acids such, as Alcl₃, BF_3״ Feel , Tici Znc1₂, SnCl₄; proton acids such as HC1, .H^oJ aromatic hydroxy compounds such as phenol, p-nitrophenol, pyrocatechol, dihydroxy naphthalene, sodium hydroxide, sodium methylate, sodium phenolate, trimethylamine, * triathylamme, tributyl amine, diazobicyclo-( 2,2,2 )-octane, quinoline, isoquinoline, tetrahydroisoquinoline, tetraethyl. ammonium chloride, pyridine-N-oxide, tributylphosphine, pho6pholine-h³-l-oxa-l-phenyl, zinc octoate, tin octoate, zinc naphthenate and mixtures thereof.

30,830A-F

-I״'Oehmke, U.S. Patent 3,694,410, September 26,

1972, teaches that chelates of metal ions of the nonionic type or the ionic type, with 1 to 6 or more chelate rings, can catalyze the preparation of polytri5 azines from aromatic polycyanates.

It is desirable to use a catalyst in the preparation of polytri azines from aromatic polycyanates . j in which the polymerization time is short.

This invention is a process for the prepa- ration of polytriazines comprising contacting aromatic polycyanates in the presence of a catalytic amount of a metal salt of a carboxylic acid at a temperature between 20®C and 2d0°c, characterized in that the catalyst is a cobalt salt of a C_g_₂₀ carboxylic acid.

¹⁵ The polytriazines of this invention can be used as cure-in-place resins or fabricated in the form of shaped articles, where thermal stability, chemical inertness and solvent resistance is desirable or required.

Catalysts for the preparation of polytria20 zines from aromatic polycyanates which afford shorter polymerization times than heretofore known have been discovered. These catalysts are cobalt salts of C carboxylic acids. Preferable catalysts are cobalt*²⁰salts of C_6-10 carboxylic acids and most preferred are cobalt octoate and cobalt naphthenate, cobalt naphthenate is prepared by treating cobaltous hydroxide or cobaltous acetate with naphthenic acid. Naphthenic acid is saturated fatty acids derived from the gas-oil fraction of petroleum by extraction with caustic soda solution and subsequent acidification.

30,830A-F ־3The amount of the catalyst which is suitable for this use is that amount which catalyzes the preparetion of polytriazines from aromatic polycyanates to the desired degree, a suitable range includes between

0.001 and 5 percent by weight of the aromatic polycyanates.

A preferable range includes between 0.01 and 1 percent by weight of the aromatic polycyanates. A more preferable range includes between 0.01 and 0.1 percent by weight of the aromatic polycyanates.

^{10 Theee} catalysts are useful in the preparation of polytriazines from any aromatic polycyanate. Desirable aromatic polycyanates include those represented by the formula Ar|OCN)_n (I).wherein Ar represents an aromatic radical or an aromatic radical interrupted by one or more bridge members, and n is a number of from 1 to 7.

In one embodiment, the aromatic polycyanates preferably used correspond.to the following general formula: »

<img file="IL73238A_D0001.tif" />

(II) wherein each R may be the same or different and represents hydrogen, halogen, straight or branched ^Cl‘^C20 ³¹¹¹?¹׳ Phenyl, two adjacent radicals R on the same nucleus may together form a carbocyclic

30,S30A-F

5- or 6-membered ring, two adjacent radicals R may, together with a hetero atom (0, s, N), form a 5or 6-membered heterocyclic ring, alkoxy radicals having from 1 to 4 carbon atoms,, or alkoxy carbpnyl radicals having from 1 to 4 carbon atoms in the alkyl group;

R׳ has the same meaning as R or represents the group (OCN)^ (R)_b

A represents a direct bond, a c_f c alkylene group optionally substituted by alkyl or phe nyl, a cycloaliphatic or aromatic 5- or 6-membered ring optionally interrupted by oxygen, a sulfonyl group (-S0₂-), a carbonyl dioxide group, (-0C0-) or a carbonyl group;

a represents a number of from 1 to 5 when e£l, and a nuxnber of from 2 to 5 when e0־;

b represents 5-a when eil and 6-(a+d) when e=0;

c represents 5-d;

d represents a number of from 0 to 5; and e represents 0, 1, 2 or 3,

30,830a-F

-5with the proviso that the sum of a and d is always a number from 2 to 5.

More preferably, the symbols in general formula (II) have the following meanings:

R is hydrogen, fluorine, chlorine or bromine, ^C1 ^c4 alkyl, methoxy, ethoxy, methoxy carbonyl, ethoxy carbonyl or butoxy carbonyl;

A is a direct bond, oxygen, a sulfonyl group, a carbonyl group, a carbonyl dioxide group, a methylene group, ethylene group, 2,2-propylene group ?^H3 (-C-)

CH₃ or a cyclohexylene radical;

a is the number 1 when βέΐ, and the number 2 when e=0;

» b is the number 1 or 2, and most preferably 2° the, number 1;

c is the number 1 or 2, and most preferably the number 1;

d is the number 0 or 1; and e is the number 0, 1, 2 or 3, with the pro25 vise that a*d=2.

The following compounds are specifically mentioned as examples of compounds within one or more of the formulas noted above; 1,3- _and 1,4-dicyanatobenzene, 2-tert-butyl-l,4-dicyanatobenzene, 2,4-dimethyl-l,3-di30 cyanatobenzene, 2,5-di-tert-butyl-l,4-dicyanatobenzene,

30,930A-F tetramethyl-1,4-dicyanatobenzene, 2,4,6-trimethyl-1,3-dicyanatobenzene, 4-chloro-1,3-dicyanatobenzene, 1,3-,

1,4 , 1,5 , 1,6-, 1,7-, 1,8-,. 2,6- or 2,7-dicyanatonaphthalene, 1,3,5-tricyanatobenzene; 4,4'-dicyanatodiphenyl, 2,2'-dicyanatodiphenyl, 3,3’,5,5'-tetramethyl-4,4׳-dicyanatodiphenyl, 3,3 ., 5,5' -tetrachloro-4,4' -dicyanatodiphenyl.,

3,3 ,5,5'-tetrachloro-2,2'-dicyanatodiphenyl, 2,2',6,6'-tetrachl_Oro-4,4 *-dicyanatodiphenyl, 4,4'-bis-[(3-cyanato)-phenoxy]-diphenyl, 4,4'-bis-[(4-cyanato)-phenoxy]-diphenyl; 2,2 ' -dicyanato-1,1 י -binaphthyl; '׳

4,4׳-dicyanatodiphenyl ether, 3,3 ', 5,5'-tetramethyl-4,4׳-dicyanatodiphenyl ether, 3,3',5,5'-tetrachloro-4,4'-dicyanatodiphenyl ether, 4,4'-bi_B-[p-_cyanatophenoxy]-diphenyl ether, 4,4'-bis-[p-cyanatophenylisopropyl]- -diphenyl ether, 4,4'-bis-(p-cyanatophenoxy]-benzene, 4,4'-bis-[m-cyanatophenoxy]-diphenyl ether, 4,4.-bis“£4-(4-cyanatophenoxy)-phenyl sulfone]-diphenyl ether; 4,4'-dicyanatodiphenyl sulfone, 3,35,5,׳’-tetramethyL. 4,4־'-dicyanatodiphenyl sulfone, 3,3.,5,5׳-tetrachloro-4,4.-dicyanatodiphenyl sulfone, 4,4 י-bis-[p-cyanatophenylisopropyl]-diphenyl sulfohe, 4,4'-bis-[(4-cyanato)״pbenoxy]-diphenylsulfone, 4,4׳-bis-[(3-cyanato)-phenoxyj-diphenyl sulfone, 4,4'-bis-[4-(4-cyanatophenylisopropyl)-phenoxy]-diphenyl sulfone, 4,4י-bis-[4-cyanatophenyl sulfone)-phenoxy]-diphenyl sulfone, 44׳'-bis-[4-(4-cyanato)-diphenoxy]~diphenyl sulfone, 4,4׳-dicyanatodiphenyl methane!, 4,4'-bis-[p-_Cyanatophenyl]-diphenyl methane, 2,2-bis-(p-j:y_anatophenyl)-propane, ²*2-b1s-(3,5-dimethyl-4-cyanatbphenyl)-propane, 2,2-bis3,5)־־-dichloro-4-cyanatophenyl )-propane, 1,1-bis35

-[p-cyanatophenyl]-cyclohexane, bis-[2-cyanato-l-naphthyl]-methane, 1,2-bis-[p-cyanatophenyl]-1,1,2,2-tetramethyl ethane, 4,4'-dicyanatobenzophenone, 4,4׳-bis-(4-cyanato)-phenoxybenzophenone, 1,4-bis-[p-cyanato Phenylisopropyl]-benzene, 2,2 5,5,׳'-tetracyanatodiphenyl

30,830A~F sulfone; and polycyanic acid esters of novolaks (reaction .products of phenol or alkyl- or halogen-substituted phenols with formaldehyde in acid solution) having from 3 to 5 OCN 'groups.

Aromatic polycyanates are known compounds and may be prepared by the procedure disclosed in Sundermann et al., U.S. Patent 4,094,852.

In another preferred embodiment, the aromatic cyanates include polyaromatic cyanates which correspond 10 to the formula (NCO4_g E— ¹?״t <?>t ך <v>_t

B---- E--־ B-----E — (OCN) r jx (OCN) s

IV wherein:

B is a C_?1_₂₀ polycyclic aliphatic radical;

. D is any nonactive hydrogen-containing substituent;

E is an aromatic radical;

g, r and 8 are independently in each occurrence the integers 0, 1, 2, or 3; with the proviso that the sum of q, r and s is greater than or equal to 2;

t independently in each occurrence an integer of between 0 and 4; and x is a number between 0 and 5.

Aromatic radical, refers herein to any radical containing an aromatic group. Examples of aromatic 30 radicals include benzene, naphthalene, phenanthracene,

30,830A-F anthracene, or biaromatic radicals, or two or more aromatic radicals bridged‘by alkylene moieties. Preferable aromatic radicals include benzene, naphthalene, biphenyl, binaphthyl, or diphenylalkylene radicals. A 5 more preferred aromatic radical is a benzene radical.'

Polycyclic aliphatic radical refers herein to any aliphatic radical which contains two or more cyclic rings. The polycyclic aliphatic radicals may contain ' one or more double or triple bonds. Preferred polycyclic 10 aliphatic radicals correspond to the formulas

<img file="IL73238A_D0002.tif" />

<img file="IL73238A_D0003.tif" />

<img file="IL73238A_D0004.tif" />

<img file="IL73238A_D0005.tif" />

<img file="IL73238A_D0006.tif" />

30,830A-F

XVI, wherein:

Ο Ο

Υ is -CHj, -S-, -S- or -S- ;

W ' and D¹ is alkyl.

B is more preferably a radical which correspends to one of the formulas V, VI, VII, VIII, IX, χ, Xi or XVI with radicals corresponding to formulas V, VI, VII, viii or xvi being even more preferred, and radicals cotresponding to formula V being most preferred.

D is any substituent which can be substituted on an organic, hydrocarbon radical, with the exception that the substituent cannot contain an active hydrogen atom. Substituents within the scope of this invention are well-known to those skilled in the art. Active hydrogen atom means herein a hydrogen atom which is bonded to an oxygen, sulfur or nitrogen atom. Examples of substituents within the scope of ס include alkyl, alkenyl, alkynyl, aryl, alkaryl aralkyl, halo, alkoxy, nitro, carboxylate; sulfone, sulfide or carbonate moieties, Preferred substituents are alkyl, ^Cl-10 nitro, and halo moieties, with alkyl, alkynyl, bromo and chloro moieties being most preferred.

30,830A-F

Preferably, q, r and s are independently 1 or 2, and are most preferably 1,' Preferably, t is independently an. integer of 0, 1 or 2, more preferably 0 or 1, and most preferably 0. Preferably, χ is between about 0 ana 2 inclusive, and more preferably between about 0 and 1 inclusive.

The polyaromatic cyanates of this invention usually exist as a mixture of many isomers. Further, these polyaromatic cyanates usually are found as a mixture of compounds in which x is between 0 and 5. Usually the number given for x in a particular mixture is an average number.

In one preferred embodiment the polyaromatic cyanates correspond to the formula '

<img file="IL73238A_D0007.tif" />

wherein X is a real number of between 0 and 5, inclusive.

The polyaromatic cyanate esters are generally 20 prepared by contacting a suitable polyaromatic phenol with cyanogen chloride, in the presence of a tertiary amine. it is preferable to prepare the cyanogen chloride in situ by contacting a solution of chlorine in a chlorinated hydrocarbon solvent with an aqueous solu25 tion of an alkali metal cyanide. The reaction mixture

30,830A-F separates into an organic layer of the chlorinated hydrocarbon containing the cyanogen chloride and an alkali metal chloride metal cyanide and chlorine of between 1.0:1.0 and 1.0:1.0 and 1.0:1.05; and excess of either may excess and excess aqueous layer containing the salt. Generally, the alkali are reacted in a molar ratio 1.0:1.15, preferably between most preferably 1.0:1.0. An result in undesirable consequences, that is, chlorine may later react with the phenol, alkali metal cyanide may result in a lower product purity. This contacting is done at a temperature of 0 c or below, preferably less than -15°C. Above 0®C the cyanogen chloride will trimerize. Preferable solvents for the chlorine are the aliphatic chlorinated hydrocarbons, such as, for example, methyl chloride, chloroform, or 1,1,1-trichloroethane. The preferred alkali metal cyanide is sodium cyanide.

The aqueous layer and organic layer are then separated. The separation of the organic layer from 20 the aqueous layer is advantageous as the presence of the aqueous layer in further.processing adversely affects the purity of the polyaromatic cyanates eventually prepared.

The organic layer containing the cyanogen chloride is then contacted with a polycyclic bridged hydroxy-substituted polyaromatic compound dissolved in a suitable solvent in the presence of a tertiary amine.

Polycyclic bridged hydroxy-substituted polyaromatic compounds useful in this process correspond to the formula

30,830A-F

-12⁽?’t Γ⁽?^;t <?>t 1 ^(1,)t ^<d)(H0,g E--B--- έ--B---- EL ^<i8)r jx (OK).

*3 wherein E, B, D, q, r, s, t and x are as defined hereinbefore.

In one. preferred embodiment the polycyclic bridged hydroxy-substituted polyaromatic compounds cor 10 respond to the formula

<img file="IL73238A_D0008.tif" />

wherein x is as defined hereinbefore. The polycyclic 15 bridged hydroxy-substituted polyaromatic compounds used usually exist as a mixture of isomers. Further, the polycyclic bridged hydroxy-substituted polyaromatic compounds are found as a mixture of compounds in which x is between 0 and 5. Usually the number given for x is an average number. The solvents used for the polycyclic bridged hydroxy-substituted polyaromatic compounds are secondary alcohols, tertiary alcohols, or chlorinated hydrocarbons. Preferred solvents are secondary alcohols or aliphatic chlorinated hydrocarbons, 25 with isopropyl alcohol and methylene chloride most preferred.

The process is preferably done at a temperature of 0°c or below, more preferably -15’c or below.

30,830A-F

For complete conversion of the hydroxy moieties on the aromatic radicals to cyanate moieties, at least 1 mole of cyanogen chloride for each hydroxy equivalent is needed. It is preferable to use an excess of 10 mole percent of cyanogen chloride for each hydroxy equivalent to insure complete conversion.

The tertiary amine acts as a hydrochloride acceptor, and as a result a tertiary amine hydrochloride salt is a by-product of the process. Generally, at least one mole of tertiary amine for each hydroxy equivalent is used. Hydroxy equivalent refers herein to the average molecular weight of the polycyclic ' bridged hydroxy-substituted polyaromatic compound divided by the average number of hydroxy moieties per molecule.

The polyaromatic cyanates can be recovered from the reaction solution in the following manner. The reaction mixture is first contacted with a dilute aqueous solution of base, such as a bicarbonate, to remove the excess cyanogen chloride. Then the reaction mixture is contacted with water to remove the tertiary ־amine hydrogen chloride salt. Thereafter, the reaction solution is contacted with a dilute aqueous acid solution to neutralize any base present. A 1 to 20 weight percent solution of hydrochloride, phosphoric or sulfuric acid can be used, preferably a 5 to 10 weight percent solution. The reaction solution is then contacted with water to remove any impurities which may be present. The reaction solution is dried over a dessicant to remove the water, and the solvent is stripped off.

30,830A-F ־13The polyaromatic cyanate recovered is of sur pnsmgly high purity and can be used directly to prepare p.olytriazines.

The polycyclic bridged hydroxy-substituted polyaromatic ־־»pound־ useful in this invention can be prepared by reacting an aromatic compound, containing at least one aromatic hydroxy moiety and one position on the aromatic ring which can be alkylated, with an unsaturated polycyclic aliphatic compound under 10 conditions such that a polycyclic bridged hydroxy-substituted polyaromatic compound useful in this invention is prepared.

suitable substituted aromatic hydroxy compounds which ־an be employed herein include any such compounds which contain one or two aromatic rings, at east one phenolic hydroxyl group and at least one ortho or para ring position with respect to a hydroxyl 9roup available for alkylation.

Particularly suitable hydroxy-substituted aromatic compounds which can be employed herein include, Tor example, phenol, ־hlorophenol, bromophenol, methylPhenol, hydroquinone, catechol, resorcinol, guaiacol, isopropylphenol, ethylphenol, isobutylphenol, octylphenol.

pyrogallol, phloroglucinol, i propylphenol, t-butylphenol, nonylphenol, cus.ylph.nol, p-phenylphenol, o-phenylphenol m-pheny phenol, bisphenol A, dihydroxydipheny! sulfone.

and mixtures thereof.

The hydroxy-substituted polyaromatic compound ¹'’דל״״־^ס’ ^the Ρ־־ΙΥ־11־7־ aliphatic compound optionally in the presence of a solvent

30,830A-F

Preferred solvents include chlorinated hydrocarbons, aliphatic hydrocarbons, aromatic hydrocarbons and nitro-substituted hydrocarbons. In general the hydroxy-substituted polyaromatic compound is contacted with 5 the unsaturated polycyclic aliphatic compound in a mole ratio of between 20.0:1.0 and 1.0:1.0, preferably between 10.0:1.0 and 1.5:1.0.

These reactants are preferably contacted in the presence of a catalyst.

^{10 Acid} catalysts which can be employed herein include, for example, Lewis acids, alkyl, aryl and aralkyl sulfonic acids, and disulfonic acids of diphenyloxide and alkylated diphenyloxide, sulfuric acid, and mixtures thereof. Preferable catalysts are such Lewis

IS acids as bf₃ gas, organic complexes of boron trifluoride such as those complexes formed with phenol, cresol, ethanol, and acetic acid. Also Lewis acids include, for example, aluminum chloride,, zinc chloride, and stannic chloride. Also catalysts include, for example,. activated clays, silica, and eilica-alumina complexes.

^In preparing the compounds which contain an average of more than one phenolic hydroxyl group and more than one aromatic ring per molecule, the reaction between the phenolic hydroxyl-containing compounds and 25 the unsaturated hydrocarbons can be conducted at temperatures of from 33’c to 270’c, preferably from 33^eC to 210°C.

In the formula ArfOCN)_n׳ n is preferably an integer of the value of 2 or greater.

30,830A-F

The products prepared by the process disclosed herein are polytriazines, which in the simplest terms can be represented by the formula

ArO

אי־־/

Arp

Where »1,1, the product 1־ a trimer of the aromatic cyanates. .whera n is 2 _Or greater, cross-linked polymers are prepared in which a basic unit is a triazine such as the one shown above.

The polymers prepared by this invention can be homopolymers as well as copolymers formed from two or more of the aromatic polycyanates. One or more monocyanates, wherein n is one, can be used in combination with one or more polycyanates in order to produce polytriazinas with modified properties. Such modified properties may be solubility, glass transition temper-’ ature, moisture resistance and impact resistance.

This process can be used to prepare completely cured polymers, which are essentially free of cyanate functionalities, and partially cured prepolymers, such prepolymers are cyanate group-containing polytriazines of liquid, wax-like or solid consistency and are soluble in organic solvents. These prepolymers are highly stable in storage. These prepolymers may be later converted to high molecular weight polytriazines when exposed to polymerization conditions. Prepolymers are

30,630A-F prepared to permit easy handling of _a resin prior to final use. Further, these prepolymers are useful _ia ' production of coatings on such substrates as metals ceramics, glass and earthenware, end as impregnating lacquers or laminating resins.

In the preparation of the polytriazines, aro»at!־ polycyanates are contacted in the presence of a catalytic amount of one of ths novel catalysts disclosed 1־ in ’ ^ίβ”^ΡεΓ״υ“ ^Of ^d ־.00־, optionally in the pre.־־״־ of a solvent. Preferable temperatures are between 80°C and 180«c.

The prepolymers are prepared by the same process, except either a lower temperature or a lower amount of catalyst is used,. so that thd aromatic IS Pdycyanates do not completely polymerise.

The rate of polymerisation is dependent upon the temperature and the catalyst amount. As either, or both, increase, the rate of polymerisation increases. At higher temperatures, a lower amount of catalyst is necessary for the desired amount of polymerization than is necessary at lower temperatures.

The solvent can be any compound which dis^P°^ly־yan«« ״><« not interfere with.the reaction, suitable solvent, include aromatic hydrocarbons, alcohols and ketones.

The polyfunctions! aromatic polycyanate־ may be combined with the powder-form or fibrous fillers

30,830A-F ־17or reinforcing materials either before or after heat treatment of the aromatic polycyanates and by basically any method. For example, it is possible, to impregnate powder-form or fibrous fillers or reinforcing materials such as quartz sand or glass cloths, with the aromatic cyanates, optionally in solution. Examples of the solvents which may be used for this purpose and which, generally, have to be removed again afterwards, are inert solvents such as methylene chloride, acetone, methyl ethyl ketone, xylene, ethyl acetate benzene, toluene, tetrahydrofuran, chlorobenzene, dibutyl ether, dimethyl formamide and tetramethylene sulfone.

. Suitable fillers and reinforcing materials are, generally, in any powder form and/or fibfous products, for example, of the type commonly used in the production of moldings based on unsaturated polyester resins or epoxide resins. Examples of products such as these are, primarily, granular fillers such as quartz powder, ground shale, asbestos powder, powdered corundum,־ chalk, iron powder, aluminum powder, sand, gravel and other fillers of this kind, also inorganic or organic fibers, more especially glass fibers in the.usual textile forms of fibers, filaments, rovings, yarns, nonwovens, and mats and cloths, in this connection, amino silane-based finishes have proven to be particularly effective, it is also possible to use corresponding textile structures of organic, preferably synthetic fibers, (polyamides, polyesters) or on the basis of quartz, carbon, metals, etc., as well as monocrystals (whiskers).

The end products combined with fillers or reinforcing materials may be used in particular in vessei and pipe construction by the winding technique, in

30,830A-F

18-19electrical engineering, in mold construction and tool making and also in the construction of heavily stressed components, in the lightweight construction of vehicles iri aeronautical and astronautical engineering.

^{5 T}^^e following examples are included to further illustrate the invention and are not intended to limit the scope of the invention or claims.

Procedure

Aromatic polycyanate samples (2 to 4 g)' were 10 poured into aluminum weighing dishes and the exact weight of each sample was determined. Methyl ethyl ketone (5-10 ml) was added to dissolve the aromatic polycyanate. A weighed amount of catalyst was added to each dish and the excess solvent was air evaporated.

Approximately 1-gram samples of the abovedescribed mixture were removed from the dishes and placed on the gel plate, which was set at 177®C. The gel time was then determined for each mixture. Actual gel times were determined to be the time required for 20 aromatic polycyanate to polymerize to a point at which it could no longer be remelted on the gel plate. Shorter gel times indicate higher catalytic activity.

Example 1

The gel times of the cyanate compound derived 25 from the bisphenol of dicyclopentadiene, which has a structure represented by the formula;

<img file="IL73238A_D0009.tif" />

30,830A-F using various catalysts were determined. The results are compiled in Table I.

TABLE I .

<td></td><td></td><td> Catalyst</td><td> Catalyst</td><td></td>

<td></td><td></td><td> Concen-</td><td> Concen-</td><td></td>

<td></td><td></td><td> tration</td><td> tration</td><td> Gel Time</td>

<td></td><td> catalyst</td><td> (PPm)</td><td rowspan="2"></td><td> (min,)</td>

<td></td><td rowspan="2"> None</td><td></td><td rowspan="2"> &gt;&gt;60.0</td>

<td></td><td></td><td></td>

<td> 10</td><td> Cobalt octoate</td><td> 800 400</td><td> 0.08 0.04</td><td> 0.5 2.75</td>

<td></td><td></td><td> 200</td><td> 0.02</td><td> 8.25</td>

<td></td><td></td><td> 120</td><td> 0.012</td><td> 21.0</td>

<td></td><td> Cobalt naph-</td><td> 800</td><td> 0.08</td><td> דל.</td>

<td> 15</td><td> thenate,</td><td> 400</td><td> 0.04 .</td><td> £ »Z 6.7</td>

<td></td><td></td><td> 200</td><td> 0.02</td><td> 20.0</td>

<td></td><td> Zinc octoate Tin octoate Lead octoate</td><td> 400 800 800</td><td> 0.04 0.08 0.08</td><td> 12.5 &gt;40.0 5.5</td>

<td> 20</td><td> Cobalt acetylacetbnate</td><td> 800 400</td><td> 0.08 0.04</td><td> 13.25 24.25</td>

<td></td><td></td><td> 200</td><td> 0.02</td><td> &gt;45.0</td>

<td> , «</td><td> Zinc acetyl״</td><td> 800</td><td> 0.08</td><td> 5 5</td>

<td></td><td> acetonate</td><td> 400</td><td> 0.04</td><td> 19.0’</td>

<td></td><td> Nickel acetyl-</td><td rowspan="2"> 1,600</td><td rowspan="2"> 1.06</td><td rowspan="2"> &gt;25.0'</td>

<td> 25</td><td> acetonate</td>

<td></td><td> Novelac</td><td> 70,000</td><td> 70.0</td><td> 4.5</td>

Example 2

The gel times for the polymerization of the aromatic polycyanate compound represented by the struc 30 ture;

30,830A-F

<img file="IL73238A_D0010.tif" />

using various catalysts were determined.' The results are compiled in Table II.

TABLE II

Catalyst

None

Cobalt naphthenate

Catalyst Catalyst

Concen- Concentration tration Gel Time iWt. %} J min.) >120.0

0,004 5.65

<td> Cobalt acetylacetonate</td><td> 100</td><td> 0.010</td><td> 35.0</td>

<td> 15 Cobalt chloride</td><td> 540</td><td> 0.054</td><td> 16.1</td>

Example 3

Gel times for the polymerization of the dicyanate of bisphenol a, which has a structure represented by the formula:

<img file="IL73238A_D0011.tif" />

30,830a~F

-22using various catalysts were determined. * The results are compiled in Table III.

TABLE in

<td> 5</td><td colspan="2"> Catalyst</td><td colspan="2"> Catalyst</td>

<td></td><td> catalyst</td><td> Concentration _lppm)</td><td> Concen״ tration %)</td><td> Gel Time (min.)</td>

<td></td><td> Cobalt octoate</td><td> 100</td><td> 0.01</td><td> • 14.2</td>

<td></td><td> Cobalt naphthenate ׳</td><td> 100</td><td> 0.01</td><td> 12.5</td>

<td> 10</td><td> Zinc octoate</td><td> 100</td><td> 0.,01</td><td> 29.8</td>

<td></td><td> Cobalt acetylacetonate</td><td> 100</td><td> 0.01</td><td> 46.8</td>

<td></td><td> Cobalt chloride</td><td> 2,133</td><td> 2.0133</td><td> 2.16</td>

The above .examples demonstrate that cobalt ectoate and cobalt naphthenate are better catalyst־ for this process than those taught in the references cited above, in fact, catalytic activity of cobalt octoate and cobalt napthenate is 3 to 10 times more than that of the catalysts described in the references discussed

30,830A-F