AU609580B2 - Flame resistant polyaromatic cyanate resins with improved thermal stability - Google Patents

Description

Signatre~s)O dociarant(s) To: The Commissioner of Patents Agent: Phillips, Ornionde Fitzpatrick wz THE DOW CHEMICAL COMPANY RICHARD G. WATERMAN General Patent Counsel Note INoiegakipntioflsl ,ther witness requilred,

II-

VR

^09A% DATE 11/08/89 APPLN. I PCI? OP I 30'422 89 INTERNATIONAL APPLICATi. AOJP DATE 07/09/89 PCT NUMBER PCI/US88/O'467 6 (51) International Patent Classification 4 (11) International Publication N umber: WO 89/ 06665 C08G 73/00 Al (43) International Publication Date: 27 July 1989 (27.07.89) (21) International Application Numbell: PCT/US88/04676 (22) International Filing Date: 28 December 1988 (28.12.88) (31)I Priority Anulication Number: 142,983 (811~ Designated States: AU, BR, JP, KR.

Published With international search report.

(32) Priority Date: (33) Priority Country: 12 January 1988 (12,01,88) us (71) Applicznt: THE DOW CHEMICAL COMPANY [US/ US]; 2030 Dow Center Abbott Road, Midland, MI 48640 (US).

(72) Inventors: BOGAN, Gary, W, 242 Corkwood, Lake Jackson, TX 77566 MONNERAT, Georgia, A, 303 Caladium, Lake Jackson, TX 77566 (US), (74) Agent: DAMOCLES, N~mia, C. The Dow Chemical Company, PO. Box 1967, Midland, MI 48641-1967

(US),

TY'

(54) Title: FLAME RESISTANT POLYAROMATIC CYANATE RESINS WITH IMPROVED THERMAL STABILI- (57) AbstractT Halogen-contai~ning hydrocarbon phenol cyanate resins are prepared by reacting the product resulting from reacting a hydrocarbon phenol resin with a metahialogenated hydroxymethyl phenol with a cyanogen halide. A mixture comprising disclosed, thehalgenconaifinghydocabon phenol cyanate resins and halogen-free hydrocarbon phenol cyanate resins is also

IIIIIII.

i i I: WO 89/06665 pCUS88/04676 -1- FLAME RESISTANT POLYAROMATIC CYANATE RESINS WITH IMPROVED THERMAL STABILITY The present invention concerns polyaromatic cyanate resins which are flame resistant and which exhibit improved thermal stability.

Aromatic cyanate esters derived from bisphenol A exhibit high glass transition temperatures, but suffer from high dielectric constants and vulnerability to moisture attack. Aromatic oyanate esters derived 1 from hydrocarbon (dicyclopentadienyl) phenols offer improved moisture resistance and electrical properties, but lack flame retardancy required in many electrical laminate applications. It would therefore be desirable to have hydrocarbon phenol cyanate resins which exhibit some flame retardanoy.

One aspect of the present invention pertains to 4h hydrocarbon phenol cyanate resins on represented by the following formula I K i* z-t WO 89/06665 PCT/US88/04676 -2- FORMULA I O-C N 0-C N

O-C=N

R

m m

R

R'

wherein each R is independently hydrogen or an alkyl group having from 1 to 10 carbon atoms; each m independently has a value from 1 to 6; each m' has an average value from zero to 4; each R' is independently hydrogen or a group represented by the following formula II; FORMULA II X R"

-CH

2 O-0C N X

R"

wherein each R" is independently an alkyl group having from 1 to 4 carbon atoms; each X is a halogen; with the proviso that at least one R' group is a group represented by formula II.

Another aspect of the present invention pertains to a mixture comprising

I

WO 89/06665 pCrUS88/04676 -3at least one hydrocarbon phenol cyanate resin represented by the following formula FORMULA I 0-C N 0-C N wherein each R is independently hydros-n or an alkyl group having from 1 to 10 carbon atoms; each m independently has a value from 1 to 6; m' has an average value from zerc to 4; each R' is independently hydrogen or a group represented by the following formula II FORMULA II X R" O-C -CH2 -C N wherein each R" is independently an alkyl group having from 1 to 4 carbon atoms; each X is a halogen; with the proviso that at least one R' grouo is a group represented by formula II; and WO a9/06665 PCT/US88/04676 -4at least one halogen-free hydrocarbon phenol cyanate resin represented by the following formula III FORMULA

III

-CN O-C N O-C N O-C~ N

R

4mm m' wherein each R is independently hydrogen or an alkyl group having from 1 to 10 carbon atoms; each m independently has a value from 1 to 6; m' has an average value from zero to 4; wherein component is present in an amount of from 1 to 99 percent by weight and component is present in an amount of from 99 to 1 percent by weight based upon the combined weight of components and Another aspect of the present invention pertains to a curable composition comprising a hydrocarbon phenol cyanate resin represented by formula I or a mixture of hydrocarbon phenol cyanate resins represented by formulas I and III with a curing quantity of a suitable curing agent.

Another aspect of the present invention pertains to the product resulting from curing the aforemen'iioied curable composition.

i 'r I- U~L WO 89/06665 PCT/US88/04676 A further aspect of the present invention pertains to a process for preparing a hydrocarbon phenol cyanate resin represented by formula I.

The halogen-containing hydrocarbon phenol cyanate resins of the present invention can be prepared by reacting hydrocarbon phenol resin with a hydroxymethyl or halomethyl metahalogenated phenol.

This reaction is suitably conducted at a temperature of from 30°C to 180°C, more suitably from 500C to 160 0

C,

most suitably from 80°C to 150°C for a time sufficient to complete the reaction, usually from 1 to 30, more usually from 2 to 15, most usually, from 3 to 10 hours.

The higher the temperature, the shorter the reaction time; likewise, the lower the temperature, the longer the reaction time. If desired, the reaction can be conducted in the presence of solvents such as, for example, aromatic hydrocarbons, aromatic or aliphatic ketones, halogenated hydrocarbons, aliphatic hydrocarbons and combinations thereof. Particularly suitable such solvents include, for example, toluene, methyl isobutyl ketone, ethylene dichloride, octane and combinations thereof.

Hydrocarbon phenol resins can be prepared by reacting dicyclopentadiene or oligomers thereof with an aromatic hydroxyl-containing compound. This reaction can suitably be conducted at temperatures of from to 1650C, more suitably from 500C to 1000C, most suitably from 60°C to 90°C for a time sufficient to complete the addition of the dicyclopentadiene to the reaction mixture, usually from 0.25 to 8, more usually, from to 4, most usually, from 1 to 2 hours. This is usually followed by a reaction digestion period which can be suitably conducted at temperatures of from 140°C to .I 1 WO 89/06665 PCT/US88/046 7 6 -6- 200°C, more suitably from 145°C to 175°C and most suitably from 145°C to 155°C for a time sufficient to complete the reaction, usually from 0.5 to 6, more usually from 1 to 5, most usually from 2 to 4 hours.

The higher the temperature, the shorter the reaction time; likewise, the lower the temperature, the longer the reaction time. If desired, the reaction can be conducted in the presence of solvents such as, for example, aprotic solvents such as aliphatic and aromatic hydrocarbons, chlorinated hydrocarbons and combinations thereof. Particularly suitable such solvents include, for example, toluene, methylene chloride, carbon tetrachloride and combinations thereof.

Metahalogenated phenols can be prepared by reacting bromine or other reactive halogen with mesitol (2,4,6-trimethyl phenol) or other suitable phenol. The resulting halomethyl metahalogenated phenol can then be reacted with the hydrocarbon phenol resins or, optionally, hydrolyzed to the corresponding hydroxymethyl metahalogenated phenol which can then be reacted with the hydrocarbon phenol resins. The reaction of halogen with substituted phenol can suitably be conducted in an inert solvent at temperatures of from 30 0 to 100 0 C, more suitably from to 90°C, and most suitably from 500C to 800C, depending upon the reflux temperature of the reaction solvent chosen. Suitable solvents include, for example, katones, alcohols, halogenated hydrocarbons, aliphatic or aromatic hydrocarbons, esters and combinations thereof. Particularly suitable solvents S include, for example, methylene chloride, carbon f i il_ WO 89/06665 PCT/US88/04676 -7tetrachloride, dichloromethane, cyclohexane and combinations thereof.

Hydrolysis of the halomethyl metahalogenated phenol to the corresponding hydroxymethyl metahalogenated phenol can be accomplished by reacting the halomethyl metahalogenated phenol with water in the presence of a suitable inert solvent. This reaction can suitably be conducted at temperatures of from to 100°C, more suitably from 40°C to 90°C, and most suitably from 50°C to 80°C, depending upon the reflux temperature of the reaction solvent chosen. Suitable solvents include those which are completely miscible with water or have a high water solubility and which are not reactive toward ether formation. Particularly suitable solvents include, for example, dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, 2methoxyethyl acetate, ethylene glycol dimethyl ether, dioxane, N-methyl-pyrrolidone, tetrahydrofuran, acetone and combinations thereof.

The hydrocarbon phenol cyanate resins can be prepared by reacting the product resulting from reacting a hydrocarbon phenol resin with a metanalogenated hydroxymethyl phenol with a cyanogen halide, such as, for example cyanogen chloride or cyanogen bromide or a combination thereof in the presence of a base such as triethyl amine or other trialkyl amine. Such suitable basic catalysts are disclosed in British Patent 1,007,790. This reaction can suitably be conducted at temperatures of from to 65C, more suitably from -20°C to 100C, most suitably from -20°C to -15 0 C for a time sufficient to complete the reaction, usually from 0.5 to 8, more usually from 1 to 6, most usually, from 1.5 to 3 hours. The higher WO 89/06665 PCT/US88/04 6 7 6 -8the temperature, the shorter the reaction time; likewise, the lower the temperature, the longer the reaction time. If desired, the reaction can be conducted in the presence of solvents such as, for example, aliphatic ketones, secondary or tertiary alcohols, chlorinated aliphatic hydrocarbons, chlorinated aromatic hydrocarbons, aliphatic hydrocarbons, aromatic hydrocarbons and combinations thereof. Particularly suitable such solvents include, for example, methylene chloride, acetone, isopropyl alcohol and combinations thereof.

Suitable hydrocarbon phenol resins which can be employed herein include, for example, those represented 1 by the following formula IV FORMULA IV OH OH

R

R R m wherein each R is independently hydrogen or an alkyl group having suitably from 1 to 10, more suitably from 1 to 6, most suitably from 1 to 2 carbon atoms; each m independently has a value suitably from 1 to 6, more suitably from 1 to 3, most suitably from 1 to 2; m' has an average value suitably from zero to 4, more suitably from zero to 2, most suitably from zero to 1.

Particularly suitable hydrocarbon phenol resins include those disclosed by Donald L. Nelson in U.S. Patent those disclosed by Donald L. Nelson in U.S. Patent L i_ WO 89/06665 PCT/US88/0467 6 -9- 4,390,680; by Bebhart'et al in U.S. Patent 3,557,239; and by Vegter et al. in U.S. Patent 31536,734.

Suitable hydroxymethyl or halomethyl metahalogenated phenols which' can be employed herein include those represented by the following formula V FORMULA V XRi X'-CH2 OH xR1 ,wherein each R" is independently an alkyl group having suitably from 1 to 14, rmori suitably from 1 to 2, most suitably 1, carbon atom(s-); each X is a halogen, preferably ohlorine or bromine, most preferably bromine; and X' is a hydroxyl group, chlorine or bromine. Particularly suitable hydroxymethyl or halornethyl metaha],ogenated phenols include, for example, 3,5-dibromo- 1 4-hydroxymethyl.-2,6-dimethy.

phenol, 3 t 5-d 1 rorc-'4-hydroxymethyl-2,6-di ethyl phen~ol, 3,5-dibrorno-4-chloromethyl-2,6-ditmethyl phenol, dibromo-14-chloromethyl-2,6-diethy, phenol, 4-bromomethyl-2,6-dimethy. phenol, 3v5-dibromo-4bromomethyl-2,6-diethyl phenol, 3,5-dichloro-4hydroxymethyl-2,6-dimethyl phenol, 3,5-dichloro-4hydroxymethyl-2,6-di ethyl phenol, 3$5-dlchloro-4chloromethyl-2,6-dlmethyl phenol, 3,5-dichloro-4chloromethyl-2,6-diethyl phenol, 3,5-dichloro-14bromomethyl-2,6-direthyl phenols 3,5-dichloro-4- L I A WO 89/06665 pCT/US88/04676 bromomethyl-2,6-diethyl phenol, and combinations thereof.

The mixture of hydrocarbon phenol cyanate resins represented by formulas I and III can be employed in quantities which provide suitably from 1 to 99, more suitably from 10 to 90, most Puitably from to 85 percent of the resin represented by formula I and from 99 to 1, more suitably from 90 to 10, most suitably from 85 to 15 percent of the resin represented by formula III based uron the combined weight of the resins represented by formulas I and III, Suitable curing agents or catalysts which can be employed herein include acids, bases, salts, nitrogen and phosphorus compounds, for example, Lewis acids such as AIC13, BF3, FeCl3, Ti~l4,? ZnCJ2, SnC14,* proton acids such as HCl, HWOO4 aromatic hydroxyl containing, compounds such as phenol, alkyl phenols, pnJitrophenol, pyrocatechol, dihydroxy naphthalene; sodium hydroxcidet sodium methylate, sodium phenolate, trimethylamine, triethyJlamine, trIbutylamine, diazobicyclo.-(2,402)-.Odtane, quinoline, isoquinoline, tetrahydroisoq uinoline, tetraethyl. ammonium chloride, pyricline-N-oxide, tributylphosphine, phospholine-L.

3 -1oxa-l-phenyl; transition metal salts, carboxylates, and complexes such, as zinc octoate, tin ootoate, zinc naphthenate, cobalt salts Of C6..20 carboxylic acids and mixtures thereof, Preferable curing agents or catalysts are the cobalt salts Of C6-20 carboxylic acids, with cobalt naphthenatet and cobalt octoate being most preferred, or cobalt acetylaoetonate.

The curIng, agent or catalyst is employed In any quantity which can cure the, hydrocarbon polyphenyl WO 89/06665 PCT/US88/0467 6 -11cyanate resins. Suitable amounts of curing agents or catalysts include, from 0.001 to 10, more suitably from 0.02 to 0.5, most suitably from 0.025 to 0.2, percent by weight of the curing agent or catalyst based upon the weight of the hydrocarbon polypheny., cyanate resin(s) to be cured. The level of curing agent or catalyst desired is dependent on he choice of curing agent and the desired cure time.

If desired, accelerators for the curing agent can be employed such as, for example, alkyl phenols such as octyl phenol, nonyl phenol and combinations thereof.

The pojyfunctional aromatic polycyanates can be combined in a solid or molten state, or optionally in solution with the powder-form or fibrous fillers, dyes, pigments, or reinforcing materials. 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 can 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, tetramethylene sulfone and combinations thereof.

Suitable fillers and reinforcing materials are, generally, in powder and/or fibrous form, for example, of the type commonly used in the production of moldings based on unsaturated polyester resins or epoxy resins.

Examples of products such as these are, primarily, wherein each R is independently hydrogen or an alkyl group havinig from 1 to 10 carbon atoms; each m independently has a value from 1 to 6; m' has an average value ;rom zero to 4 each R' is independently /2 WO 89/06665 PCT/US88/04676 -12granular fillers such as quartz powder, ground shale, powdered corundum, chalk, iron powder, aluminum powder, sand, gravel and other fillers of this kind, also inorganic or organic fibers, more especially glass fibers, rayon fibers, nylon fibers, graphite fibers or combinations thereof in the usual textile forms of fibers, filaments, rovings, yarns, nonwovens, mats and cloths. It is also possible to use corresponding textile structures of organic, preferably synthetic, fibers (polyamides, polyesters) as well as textile structures formed from quartz, carbon, and metal fibers, as well as monoorystals (whiskers).

These additives are provided in functionally equivalent amounts, the pigments and/or dyes are added in quantities which will provide the composition with the desired color; however, they are suitably employed in amounts similar to those employed with epoxy resins and polyester resins, suitably in amounts of from to 90, more suitably fro i 10 to 80, most suitably from 20 to 75 peroerft by weight based upon the combined weight of the pigment and/or dyes and the polyfunctional aromatiu cyanate.

The fillers can be employed in amounts similar to those employed with epoxy resins and polyester resins, suitably from 5 to 90, more suitably from 10 to 80, most suitably from 20 to percent by weight based upon ethe combined weight of the filUer and the polyfunctional aromatic oyanate.

The following examples are illustrative of the invention, WO 89/06665 PCT/US88/04676 -13- EXAMPLE 1 A. Preparation of dicyclopentadiene phenol resin.

Molten phenol (1333 lbs., 604.65 kg, 6425.6 OH equiv.) was agitated in a stainless steel reactor while boron trifluoride gas (3 lbs., 1.36 kg) was introduced.

Dicyclopentadiene (187 lbs., 84.8 kg, 641.4 equiv.) was added slowly over a period of about 111 minutes, while maintaining the reaction temperature at about 68 0 C 85°C. The temperature of the reaction mixture was then increased to 145°C for three hours. Unreacted phenol was removed by vacuum distillation at temperatures from 145°C to 180 0 C and pressures from 1-11 psia (6.9-75.8 kPa). The entire process required 806 minutes, during which time a steam distillation was employed for about minutes. The product which was recovered had an average functionality of about 2.18 and a phenolic equivalent weight of about 164.

SB Preparation of metahalogenated phenol.

3,5-dibro.-2,6-dimethyl-4-hydroxymethyl phenol was prepared in the following manner.

Preparation of 4-bromomethyl-3,5-dibromo-2,6dimethyl phenol (tribromomesitol).

A 136.2 gram portion of 2,4,6-trimethyl phenol (1 mole) was dissolved in 2 liters of carbon tetrachloride. Using a water bath for cooling, 230 ml of bromine (4.5 moles) was added at 20°C to 26'C over a period of 15 minutes. Hydrogen bromide gas was given off during the bromine addition, and a slurry of dibromo-2,4,6-trimethylphenol was obtained. The temperature was increased to 70 C to 75°C, and in the process, a solution was obtained. The solution was WO 89/06665 PCT/US88/046 7 6 -14held at that temperature for 2 hours. The unreacted bromine was removed by distillation with the aid of 1 liter of carbon tetrachloride. When 1 liter of solvent remains with the product, the solution was cooled to 25°C. The light brown solid obtained was filtered and dried under a vacuum for 5 hours. A yield of 260 g was obtained, which was analyzed by gas chromatography as 99 percent tribromomesitol, Hydrolysis of tribromomesitol to 2,6-dimethyl-4-hydroxymethyl phenol.

The p-oduct of above, 260 g, was dissolved in about 650 g of acetone at room temperature. About 520 g of water was added over a period of about 1.5 hours. The mixture was gradually heated to reflux (580C) over a period of about hours. The reflux was maintained for an additional hours. The white precipitate that forms was isolated by filtration at 250C, and then vacuum dried at 600C.

The yield was 92.8 percent, and the product contained 87 percent of the desired product, 3,5-dibromo-4hydroxymethyl-2,6-dimethyl phenol, and 13 percent dibromo-2,6-dimethyl-4-hydroxymethyl phenyl ether by- 2 5 Sproduct.

C. Preparation of condensation product of dicyclopentadiene phenol resin and meta brominated phenolic compound.

In a reaction flask equipped with a ,mechanical stirrer, 330 grams (2 equiv.) of the dicyclopentadiene phenol resin from A above were melted at 1300C. To this were added 166.7 grams (0.5 equiv.) of the product from above containing 4-hydroxymethyl-2,6-dimethyl phenol. After stirring WO 89/06665 PCT/US88/04676 for about 1.5 hours at a temperature of 129°C to 130'C, 160 grams of toluene were added. While maintaining the temperature at 113 0 C to 119°C, the reaction mixture was 3tirred for about 6 hours, during which time the toluene/water azeotrope was removed overhead. The residual toluene and water were removed from the product by vacuum stripping on a rotoevaporator for about 1 hour at 140 0 C at 8 to 9 mm Hg. The resulting product had a Mettler softening point of 113.6 0

C.

D. Cyanation of condensation product from C.

A solution designated as A was prepared by dissolving 149.2 grams of cyanogen bromide in 800 ml of methylene chloride in a reaction flask at -10 0 C. A solution designated as B was prepared by dissolving 227.3 g of the condensation product from C above and 135.2 grams of triethylamine in 350 ml of methylene chloride. While maintaining the temperature at between -10 0 C and -220C, Solution B was added dropwise to Solution A over a period of about 1.5 hours. Then an additional 6.2 grams of triethylamine was added over a period of about 2 minutes. The cooling was then removed and the reaction mixture allowed to digest while slowly warming to ambient temperature (about 23 0

C)

over a period of 1 hour. The reaction mixture was washed by extracting once with 400 ml of deionized water, twioe with 100 ml of 0.2 N HC, and eight additional times with 300-400 ml portions of deionized water. The remaining organic phase was dried over MgSO4 and filtered through filter paper. The reaction solvent was removed by vacuum stripping on a rotoevaporator. Two hundred grams of cyanated product WO 89/06665 PCT/US88/0467 6 -16having a calculated cyanate equivalent weight of about 210 was recovered.

E. Curing.

The cyanated bromine-containing product from D above was blended with a halogen-free cyanated dicyclopentadiene phenol resin having an average functionality of about 2.27 and a calculated cyanate equivalent weight of about 190 so as to achieve a blended product containing 12 percent bromine by weight. The blending was conducted as follows: Fifty-five grams of the halogen-free cyanated dicyclopentadiene phenol resin and 200 grams of the bromine-containing cyanated product from D above were melted and blended at about 130°C. To this blend was added 300 ppm by weight of cobalt as a 1 percent solution of Co(III) acetylacetonate in divinylbenzene.

The catalyzed mixture was cured in a mold for 1 hour at 175 0 C, 2 hours at 225°C and 1 hour at 240 0

C.

The above blended product designated as Sample A was subjected to testing to determine the properties thereof. The properties of the halogen-free cyanated dicyclopentadiene phenol resin cured with cobalt (III) acetylacetonate in divinylbenzene as described above was also determined for comparative purposes. This cured product is designated as sample B. The results are given in the following Table.

WO 89106665 PCT/US88/046 76 -17- PROPERTY Sample A Sample B* Tgl, 00 289 250 Coefficient of Thermal Expansion 2 ppm/OC 52.4 8000 49.9 50.3 57.9 53.2 100.0 53.9 53.6 1 10 0 C 54.7 53.1 12000 52.,9 52.8 1300C 50.8 51.5 14000C 53.4 55.1 15000 57.7 52.2 1600C 555.9 55.6 17000C 60.2 56.9 18000 54.4 59.3 19000C 56.8 59.0 2000C 62.1 614.9 21000 61.6 67.8 22000 60.1 57.9 23000 61.0 66.7 24000 63.9 79.2 25000 55.0 89.0 26000 60.2 156.0 27000 67.1 165.0 28000 73.4 150.0 29000 86.6 158.0 30000 82.9-- 31000C 61.5-- 3200C 81.8-- 33000 109.0-- Thermal Decompositon 3 00 3914 410 Dielectric Constant 0 2100 ,07 2.91 Dissipation Factor 210C 0.00434 0.00287 Moisture Pickup 4 percent Wt. gain 2.34 1.71 Flame RetardancyS, No UL 94 rating I V-.0 Rating WO 89/06665 PCT/US88/04676 -18- FOOTNOTES TO TABLE Not an example of the present invention.

1 The glass transition temperature, Tg, was determined by Thermomedhanical Analysis.

2 The coefficient of thermal expansion was a volumetric determination obtained by Thermomechanical Analysis and the results are parts per million by volume per degree centigrade.

3 The thermal decomposition temperature was determined by Thermogravimetric Analysis.

4 The moisture pickup test was conducted for 500 hours at 121°C under 15 psig (103 kPa) steam pressure.

The flame retardancy rating was determined by the Underwriters Laboratory UL 94 Burn Test.

i' I L I i I:

Claims (9)

1. A hydrocarbon phenol cyanate resin represented by the following formula I FORMULA I 0-C N 0-C N 0-C N R m m' R' R wherein each R is independently hydrogen or an alkyl group having from 1 to 10 carbon atoms; each m independently has a value from 1 Vt 6; m' has an average value from zero to 4; each R' is independently hydrogen or a group represented by the following formula II I WO 89/06665 PCT/US88/04676 FORMULA II CH2 0-C N wherein each R" is independently an alkyl group having from 1 to 4 carbon atoms; each X is a halogen; with the proviso that at least one R' group is a group represented by formula II.

2. A hydrocarbon phenol cyanate resin of Claim 1 wherein R is hydrogen, R" is methyl, and X is bromine.

3. A hydrocarbon phenol cyanate resin mixture comprising at least one hydrocarbon phenol cyanate resin represented by the following formula I i_ S r WO 89/06665 PCT/US88/04676 -21- FORMULA I 0-C N 0-C N wherein each R is independently hydrogen or an alkyl group having from 1 to 10 carbon atoms; each m independently has a value from 1 to 6; each m' has an average value from zero to 4; each R' is independently hydrogen or a group represented by the following formula II; FORMULA II CH2 0-C- N wherein each R" is independently an alkyl group having from 1 to 4 carbon atoms; each X is a halogen; with the proviso that at least one R' group is a group represented by formula II; and at least one halogen-free hydrocarbon phenol Oyanate resin represented by the following formula III I I WO 89/06665 PCT/US88/04676 -22- FORMULA III -C N O-C N 0-C N R RR m m' m wherein each R is independently hydrogen or an alkyl group having from 1 to 10 carbon atoms; each m independently has a value from 1 to 6; m' has an average value from zero to 4; and wherein component is present in an amount of from 1 to 99 percent by weight and component is present in an amount of from 99 to 1 percent by weight based upon the combined weight of components and r lfu-or

4. A hydrocarbon phenol oyanate resinlof Claim 3 wherein in components and R is hydrogen, R" is methyl and X is bromine. A curable composition comprising a hydrocarbon phenol cyanate resin of Claim 1 with a curing quantity of a suitable curing agent or catalyst.

6. The product resulting from curing the composition of Claim

7. A process for preparing a hydrocarbon phenol cyanate resin which comprises reacting a reaction product resulting from reacting WO 89/06665 PCT/LJS8804676 -23- a hydrocarbon phenol resin represented by the following formula IV FORMULA IV wherein each R is independently hydrogen or an alkyl 1 group having from 1 to 10 carbon atoms; each m independently has value from 1 to 6; m' has an average value from zero to 4, with a hydroxymethyl or halomethyl metahalogenated phenol represented by the following formula CH 2 wherein each R" is independently an alkyl group having from 1 to 4 carbon atom(s); each X is a halogen, and X' is a hydroxyl group, chlorine or bromine, with a cyanogen halide in the presence of a basic catalyst. I I 24

8. A hydrocarbon phenol cyanate resin as claimed in claim 1 or claim 3 substantially as hereinbefore descrzibed with reference to the Examples.

9. A process as claimed in claim 7 substantially as hereinbefore described with reference to the Exampl~es. DATED: 24 January, 1991 PHILLIPS ORt4ONDE FITZPATRICK Attorneys for: THBE DOW CHEMICAL COMPANY *6 6 S S S. S 5* 6 56 66 S S 6 S 6S 60 9 S 6 S *956 S* 5O S 6 S *55506 6 S 60*9 SS 55 05 Se *6 INTERNATIONAL SEARCH REPORT International Application No, PCTi/US88/04676 1, CLASSIFICATION OF SUB3JECT MATTER (I1 several classification symbols apply, indicate all)6 According to Internationel Patenit Clarification (IPC) or to both National Classiication and IPC INT. CL4: C08G 73/00 II. FIELDS SEARCHED Minimum Documentation Searched7 U.S. 528/392, 422, 425 Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included in the Fields Searcheda Ill. DOCUMENTS CONSIDERED TO BE RELEVANT Category Citation of Document, ii it indication, where appropriate, ot the relevant passages 12 Relevant to Claim No, 13 A US, A, 4,097,455 (BtJRKHPJ= ET AL) 27 JUNE 1978; 1-7 SEE THE ENTIRE DOUMT A US, A, 4,751,323 (MO ET. AL) 14 JUNE 1988; 1-7 SEE THE ENTIRE DOCUINT. Spetial categories of cited documents,, t IT" later document published after the international r. ?Ig date geneal sateol l~ ar ~hch ~not or priority date and not in conflict with the application but document defining the gnrlsaeothafvicisot cited to understand the principle or theory undertying the considered to be oI llarticiqlar relevance Invention "El earlier document but published on or after the international 11P document of par~,ctiar televan,.el) the claimed. invention filing dale cannot. be considered novel or cannot be considered to

111.11 ddeument which may throw doubts on priority claimls) or involve an Inventive step which is cited to establish the publication date of another "Yi" document cPt particular relevance, the claimed inention citation or other special ites1son specified) cannot be Wwndered to involve art inventive step when the I'0" document referring to an oral disclo-sure, tI e, e;htbltlon or document is cointined with one or more other such docur other renvers manta, such combination being obvious teC. a person oftilled OP" dlocuinient published prior to the, interr5Ions) filinq date but in, the art, later than the priority date tlairried I' document member of the. same patent family IV, CERTIFICATION Date ol the Actual Comhpletion~ of the International Search IDate of. Mailing o1 this International Search Report 23 FESRUAY 19859A 'Inv__ 18 9 International, SeatChIng AijthofiQ~ F~~itS tswd "hso4 (A*0l47Y ixitERE01SAutoie A Offce