GB2038835A

GB2038835A - Curable Resin Compositions

Info

Publication number: GB2038835A
Application number: GB7919617A
Authority: GB
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1978-11-22
Filing date: 1979-06-05
Publication date: 1980-07-30
Also published as: JPS6146002B2; JPS5571706A; DE2953349A1; JPS60186539A; NL7904171A; FR2449702A1; GB2038835B; FR2449702B1; FR2455618A1; FR2455618B1

Abstract

Curable organic resin compositions, such as epoxy resins, ca are provided, based on the use of a diaryliodonium salt-redox catalyst curing system. The curable composition comprises a cationically polymerisable organic resin 1 to 35% by weight of a mixture of a diaryliodonium salt, a copper salt and an Sn<2+> salt, an activated ???-hydroxy compound or a mixture thereof. The curable compositions can provide flexible or rigid organic resin foam when used with a volatile organic solvent as a result of exothermic heat of cure.

Description

SPECIFICATION Curable Organic Resin Compositions and Foaming Method The present invention relates to curable organic resin compositions which employ a diaryliodonium-redox catalyst system of copper salt in combination with stannous salts or an activated (hydroxy compound. More particularly, the present invention relates to organic resin foam and method of foaming.

As shown in U.K. Patent Application No. 47634/78, aromatic iodonium salts can be employed in combination with organic acids or copper salts to facilitate the heat cure of various organic materials, such as epoxy resins. Valuable results also can be achieved if reducing agents such as thiophenol are used in combination with aryl onium salts to facilitate the termal cure of epoxy resins. Surprisingly, in the absence of such cocatalysts, the cure of cationically polymerizable organic materials, such as epoxy resins, with an aromatic iodonium salt can require temperatures exceeding 2000C over an extended period of time. U.K.Patent Application No. 48110/78 shows that if a diaryliodonium salt of the formula [(R)a (R1)b l]+[Y]-, (1) is employed with a redox catalyst comprising a mixture of copper salt and ascorbic acid or a derivative thereof with a cationically polymerizable organic material, e.g. an epoxy resin, the cure of the organic material can be achieved without the use of external heat, where R is a monovalent aromatic organic radical, R' is a divalent aromatic organic radical, Y is a non-nucleophilic anion defined below, a is a whole number equal to 1 or 2, b is a whole number equal to O or 1, and when a is 0, b is 1, and when b is 0, a is 2. If an organic solvent is utilized with the cationically polymerizable organic material and the diaryliodonium salt-redox catalyst curing system, exothermic heat of reaction can generate an organic foam.Equally good results may be obtained by using an Sn++ salt or an activated hydroxy compound in lieu of the ascorbic acid.

There is provided by the present invention, curable compositions comprising: (A) a cationically polymerizable organic resin, and (B) 1% to 35% by weight of the curable composition of a catalyst consisting essentially of (i) a diaryl iodonium salt of formula (1), (ii) 0.5 to 10 parts, per part of (i), of a copper salt, and (iii) 0.5 part to 10 parts, per part of (i) an Sn+2, compound, an activated hydroxy compound, or a mixture thereof.

Anions included by Y of formula (I) are, for example, MQd, where M is a metal or metalloid, Q is a halogen radical and d is an integer having a value of from about 4-6 inclusive. Besides epoxy resins, formula (I) iodonium salts also have been found to be useful in curing cyclic ethers, lactones, lactams and cyclic acetals, etc., where the iodonium salts also can have non-nucleophilic counterions such as perchlorate, CF3S03- and CeH4S03-. Again, the cationically polymerizable material can be a phenolformaldehyde, urea-formaldehyde or melamine-formaldehyde resin, Y of formula (I) also can include in addition to MQd and other non-nucleophilic counterions previously recited, halide counterions such as Cl, Br, F and I as well as for example a nitrate or a phosphate.

Radicals included by R of formula (I) can be the same or different aromatic 'carbocyclic or heterocyclic radicals having from 6 to 20 carbon atoms, which can be substituted with from 1 to 4 monovalent radicals selected from C1,~8) alkoxy, phenyl, chlorophenyl, nitrophenyl, methoxyphenyl, pyridyl. Radicals included by R1 are divalent radicals such as

Zcan -0-,

--(CH,O),,-,

R2 is C(18) alkyl or C(6~,3) aryl and n is an integer equal to 1-8 inclusive.Metals or metaloids included by M of formula (I) are transition metals such as Sb, Fe, Sn, Bi, Al, Ga, In, Ti, Zr, Sc, V, Cr, Mn, Cs, rare earth elements such as the lanthanides, for example, Cd, Pr, Nd, actinides, such as Th, Pa, U, Np, and metalloids such as B, P, As. Complex anions included by MQd-(d-e} are, for example, BF4-, PF6-, Ass6~, SbF6-, FeCI4-, SnCI6-, SbCI6-, BiCI5=.

Halonium salts included by formula (I) are, for example,

There is also provided by the present invention a foaming method which comprises (1) agitating a curable composition comprising, (C) a cationically polymerizable organic material, (D) 1% to 35% by weight of the curable composition of a mixture of (iv) a diaryliodonium salt of formula (I), (v) 0.5 part to 10 parts, per part of (iv), of a copper salt and (vi) 0.5 part to 10 parts, per part of (iv), of a member selected from an Sn+2 compound salt, an activated hydroxy compound and mixtures thereof.

(E) 1% to 30% by weight of (C), (D) 8 (E) of a volatile inert organic solvent, and (2) thereafter allowing the ingredients of the resulting mixture to react resulting in the production of exothermic heat and the simultaneous vaporization of the organic solvent and the cure of the cationically curable organic resin.

Copper I and II salts included by the redox system of the present invention are, for example, carboxylic acid and mineral acid copper salts such as Cu(ll) benzoate, Cu(ll) citrate, Cu(ll) formate, Cu(ll) acetate, Cu(ll) stearate, Cu(ll) oleate, Cu(ll) carbonate; Cu(l) bromide; Cu(l) chloride; Cu(l) gluconate. Tin (Sn+2) compounds which can be used are, for example, Sn+2 carboxylic acid salts, e.g., stannous octoate, stannous stearate, stannous laurate, stannous citrate, stannous oxalate, stannous benzoate.Among the hydroxy compounds there are included ketones such as acyloins and benzoins,

In addition to (hydroxy ketones other activated ct-hydroxy compounds which can be used with copper salts as defined above, are included by the following formula,

where R3 is a C(120) alkyl radical, or Cm6~20) aryl radical and X is a monovalent radical selected from the class of nitro, halo, sulfone, CO2R4, cyano,

-CCl3 and CHCl2, where R4 is selected from hydrogen and R3.

The diaryliodonium salts of formula (I) and methods for making them are shown in Crivello U.S.

Patent 3,981,897. Additional methods for making such diaryliodonium salts are shown by F. M.

Beringer, R. A. Falk, M. Karmal, J. Lillien, G. Masullo, M. Mausner, E. Sommers, J. Am. Chem. Soc., 81 342 (1958) and I. Mason, Nature, 139 150 (1937); I. Mason and E. Race, J. Am. Chem. Soc., 1718 (1937).

Included by the cationically polymerizable materials which can be employed in the curable compositions of the present invention are, for example, epoxy resins which include any monomeric, dimeric or oligomeric or polymeric epoxy material containing one or a plurality of epoxy functional groups. For example, those resins which result from the reaction of bisphenol-A (4,4'isopropylidenediphenol) and epichlorhydrin, or by the reaction of low molecular weight phenolformaldehyde resins (Novolak resins) with epichlorohydrin, can be used alone or in combination with an epoxy containing compound as a reactive diluent. Such diluents as phenyl glycidyl ether, 4-vinylcyclohexene dioxide, limonene dioxide, 1,2-cyclohexene oxide, glycidyl acrylate, glycidyl methacrylate, styrene oxide, allyl glycidyl ether, etc., may be added as viscosity modifying agents.

In addition, the range of these compounds can be extended to include polymeric materials containing terminal or pedant epoxy groups. Examples of these compounds are vinyl copolymers containing glycidyl acrylate or methacrylate as one of the comonomers. Other classes of epoxy containing polymers amenable to cure using the above catalysts are epoxy-siloxane resins, epoxy-polurethanes and epoxy-polyesters. Such polymers usually have epoxy functional groups at the ends of their chains. Epoxy-siloxane resins and method for making are more particularly shown by E. P.

Plueddemann and G. Fanger. J. Am. Chem. Soc. 81 2632-5 (1959). As described in the literature, epoxy resins can also be modified in a number of standard ways such as reactions with amines, carboxylic acids, thiols, phenols, alcohols, etc., as shown in Patents 2,935,488; 3,235,620; 3,369,055; 3,379,653; 3,398,21 1; 3,403,199; 3,563,8503,567,797; 3,677,995, etc. Further examples of epoxy resins which can be used are shown in the Encyclopedia of Polymer Science and Technology, Vol. 6, 1967, Interscience Publishers, New York, pp. 209-271.

Additional examples of the cationically polymerizable materials are, for example, vinyl organic monomers, vinyl organic prepolymers, cyclic organic ethers, cyclic organic esters, cyclic organic sulfides, organo silicon cyclics. There are included, for example, styrene, vinyl acetamide, a-methyl styrene, isobutyl vinylether, n-octyl vinylether, acrolein, 1 ,1-diphenylethylene, -pinene, vinyl arenes such as 4-vinyl biphenyl, 1-vinylpyrene, 2-vinyl fluorene, acenaphthalene, 1 and 2-vinyl naphthalene; 9-vinyl carbazole, vinyl pyrrolidone, 3-methyl-1-butene; vinyl cycloaliphatics such as vinylcyclohexane, vinyl cyclopropane, 1 -phenylvinylcyclopropane; dienes such as isobutylene, isoprene, butadiene, 1,4pentadiene.

Some of the vinyl organic prepolymers which can be used to make the polymerizable compositions of the present invention are, for example, CH2=CHO(CH2CH20)mCH=CH2, where m is a positive integer having a value up to about 1000 or higher; multi-functional vinylethers, such as 1 ,2,3-propane trivinyi ether, trimethylolpropane trivinyl ether, prepolymers having the formula,

and low molecular weight polybutadiene having a viscosity of from 200 to 1 0,000 centipoises at 250C, etc. Products resulting from the cure of such compositions can be used as potting resins, crosslinked coatings, printing inks and other applications typical of thermosetting or network resins.

A further category of the organic materials which can be used to make the polymerizable compositions are cyclic ethers which are convertible to thermoplastics. Included by such cyclic ethers are, for example, oxetanes such as 3,3-bis-chloromethyloxetane, alkoxyoxetanes as shown by Schroeter Patent 3,673,216, assigned to the same assignee as the present invention; oxolanes such as tetrahydrofuran, oxepanes, oxygen containing spiro compounds, trioxane, dioxolane.

in addition to cyclic ethers, there are also included cyclic esters such as p-lactones, for example propiolactone, cyclic amines, such as 1 ,3,3-trimethylazetidine and organosilicone cyclics, for example, materials included by the formula,

where R" can be the same or different monovalent organic radicals such as methyl or phenyl and q is an integer equal to 3 to 8 inclusive. An example of an organosilicon cyclic is hexamethyl trisiloxane, octamethyl tetrasiloxane, etc. The products made in accordance with the present invention are high molecular weight oils and gums.

Included by the thermosetting organic condensation resins of formaldehyde which can be used in the practice of the present invention are, for example, urea type resins, such as [CH2=NCONH2jx . H20, [CH2=NCONH2]XCH3COOH, [CH2=NCoNHCH2NHCONHCH2OH]x; phenol-formaldehyde type resins, such as

where r and s are integers having a value 1 or greater;

In addition, there can be used melamine thiourea resins, melamine, or urea aldehyde resins, cresol-formaldehyde resins and combinations with other carboxy, hydroxyl, amino and mercapto containing resins, such as polyesters, alkyds and polysulfides.

In particular instances, depending upon the compatability of the halonium salt with the organic material, the halonium salt can be dissolved or dispersed in an organic solvent such as nitromethane, acetonitrile, methylene chloride, etc., prior to its incorporation into the organic material. Experience has shown that the proportion of halonium salt to organic material can vary widely inasmuch as the salt is substantially inert, unless activated. Effective results can be achieved, for example, if a proportion of at least 0.1% by weight of halonium salt is employed, based on the weight of polymerizable composition.

Higher or lower amounts can be used, however, depending upon factors such as the nature of organic material, polymerization time desired, etc.

In the practice of the invention, the curable compositions can be made by effecting contact between the diaryliodonium salt, the cationically polymerizable organic resin and the redox system of the copper salt and the Sn+2 or hydroxy compound. In certain situations, a volatile organic solvent also can be utilized in combination with the aforementioned ingredients to produce a foam, based on the vaporization of the organic solvent due to the generation of exothermic heat of reaction while the cationically polymerizable organic Iresin is curing.

It has been found that contact between the various ingredients of the curable mixture of the present invention can be effected if the diaryliodonium salt is contacted with the redox catalyst in the presence of the cationically polymerizable organic material. For example, the diaryliodonium salt can be combined with an epoxy resin to produce a stable mixture while the redox catalyst can separately be employed in combination with an epoxy resin which also has infinite shelf stability. In instances where a foam is desired, a volatile organic solvent can be combined with either of the aforementioned stable mixtures or can be introduced separately during the mixing of the respective mixtures.Suitable volatile organic solvents which can be employed to produce rigid or flexible foams in the practice of the present invention are, for example, acetone, hexane, trichlorofluoromethane, n-pentane, 2-methylhexane, dichloromethane, 1,1,2-trichlorotrifluoroethane, methyl alcohol, ethyl alcohol, methyl ethyl ketone. In addition to such volatile solvents, there are also included thermally unstable compounds such as ethylene carbonate, ammonium nitrite, benzoyl peroxide, cyclohexanone peroxide, methyl ethyl ketone peroxide, 2,2'-azobis(2-methylpropionitrile), azobisformamide.

The foamabie mixture can be injection molded into suitable receptacles, such as refrigerator doors and the like to provide for the production of insulating foams. Thorough mixing of the ingredients has been found to facilitate the production of a uniform foam which can be achieved by the employment of a mechanical stirrer or agitator, as generally utilized in the art.

In instances where a flexible foam is desired, the above described epoxy resin can be combined with polycaprolactones or any hydroxy terminated polyester to render the foams made in accordance with the present invention more flexible. Typical hydroxy terminated polycaprolactones are Niax polyols, manufactured by the Union Carbide Corporation. There can be utilized from 1 to 60 parts of the hydroxy terminated polyester per part of the epoxy resin and preferably from 1 to 50 parts, included by the hydroxy terminated polyester which can be employed in the practice of the present invention to flexibilize cured epoxy resin films or foams are compounds of the formula,

where t is an integer having an average value of from 1 to 100.

As previously indicated, the curable compositions of the present invention also can be used in coating applications and in the production of rigid or flexible films. In addition to the cationically polymerizable organic resin which includes any of the aforementioned epoxy resins, as well as the organic cyclics as previously defined, as well as additives, such as caprolactones for flexibilizing the films and foams made therefrom, there also can be combined with such ingredients fillers in a proportion by weight of from 0 to 500 parts of such filler per 100 parts of the cationically polymerizable organic resin. Suitable fillers include, for example, talc, alumina, sand, silica, ground quartz, wood flour, carbon black, glass fibers, mica, barium sulfate, titanium dioxide.

In addition, the above curable compositions may include additives to enhance surface properties and to control foam cell size. Among such additives are polyalkylene oxide surfactants and silicone fluids.

In order that those skilled in the art will be better able to practice the present invention, the following examples are given by way of illustration and not by way of limitation. All parts are by weight.

Example 1 There were added 3 parts of stannous octoate and 3 parts of diphenyliodonium hexafluorophosphate to 100 parts of 3,4-epoxycyclohexyl methyl-3',4'-epoxycyclohexane carboxylate (CY 179, ERL422 1) and the resulting mixture was thoroughly stirred. There was then added to the mixture, 0.05 part of a 12% solution of copper naphthenate to the resulting mixture while it was rapidly ,stirred. The mixture hardened and became rigid at room temperature within two minutes.

The above procedure is repeated, except that the mixture prior to hardening is poured into a silicone mold. There is obtained a finished part within two minutes conforming to the shape of the mold.

Example 2 Several 10 part aliquots were prepared from a mixture of 70 parts of the epoxy resin of Example 1 and 30 parts of hydroxyl terminated polyester resin (Rucoflex F2018, Hooker Chemical Company).

Various amounts of diphenyl iodonium hexafluorophosphate, copper naphthenate and stannous octoate were added to each of the 10 part aliquots. After each of the respective mixtures were thoroughly stirred they were allowed to stand at room temperature to determine how long it took for the mixtures to gel. The results are shown in Table I which shows the parts of the various ingredients used in the mixture, and "Cu(Naphth)2,, is copper naphthenate, and "Sn(Oct)2" is stannous octoate.

Table I (C8Hs)2l+pF6 Cu(Naphth)2 Sn (Oct)2 Gel Time (min) 3 0.15 3 7.5 3 0.30 3 5.0 3 0.45 3 3.5 3 0.60 3 3.2 3 0.60 6 2.5 The above results show improved epoxy resin cure rate with increasing copper and tin salt concentration.

Example 3 There was added to a mixture of 70 parts of Epon 828, a diglycidyl ether of bisphenol-A, and 30 parts of Rucoflex F201 8 hydroxy terminated ester, which was divided into 10 part aliquots. Various parts of stannous octoate, copper naphthenate in mineral oil and various diphenyliodonium hexafluoroarsenate salts were used per each 10 part aliquot. The mixtures were stirred and allowed to stand at room temperature to determine cure time.The following results are shown in Table II, where "GT" is gel time, Cu+2 is copper naphthenate and Sn+2 is stannous octoate: Table II

lodonium Salt (0.3 part) Sn+2 Cu+2 GT (Min ()2+IAsF6 - 0.6 .072 3.4 ZAsF6- 0.3 .054 9 (CH3{9) +iAsF6 0.3 .054 9.75 (1)2 ZAsF6 0.3 .054 10 Example 4 A mixture of 100 parts of ERL422 1, which is the epoxy resin utilized in Example 1, 30 parts of acetone, 6 parts of a 50% solution of diphenyliodonium hexafluoroarsenate in propylene carbonate, 3 parts of stannous octoate and 0.5 part of a 12% solution of copper naphthenate, along with 0.1 part of Cabosil fume silica was vigorously stirred in a container. The resulting stirred mixture was then allowed to stand at room temperature. In approximately 4 minutes, a vigorous polymerization occurred along with the production of a voluminous low density foam which quickly became rigid. The above foam is useful as a thermal insulator.

Example 5 There was added to 91 parts of the epoxy resin of Example 4, to 6 parts of a 50% solution of diphenyiiodonium hexafluoroarsenate in propylene carbonate and 3 parts of stannous octoate. The resulting mixture was vigorously stirred and divided into 10 part aliquots to which various copper compounds were added respectively in 0.1 part amounts. The resulting mixtures were then stirred and allowed to rest under atmospheric conditions.Table Ill shows the gel time obtained in minutes which were obtained from each of the mixtures containing a particular copper compound: Table Ill Copper Compound Gel Time (min) copper naphthenate 0.8 copper benzoate 1 5.5 copper salicylate 1 2.4 copper acetylacetonate 1 6.4 copper stearate 47.5 The above results show that the effectiveness of copper compounds as redox catalysts can vary widely.

Example 6 A mixture was stirred consisting of 5 parts of epichlorohydrin, 0.25 part of diphenyliodonium hexafluoroarsenate, 0.2703 part of stannous octoate and 0.025 part of copper benzoate. Exothermic polymerization was immediately observed and after 5 minutes the mixture was poured into about 100 parts of methanol. There was obtained about 3 parts of polyepichlorohydrin rubber.

Example 7 A mixture of 100 parts of ERL4221, the epoxy resin of Example 1, 3 parts of diphenyliodonium hexafluorophosphate, 3 parts of benzoin and 0.1 part of copper naphthenate as a 12% dispersion in mineral oil were thoroughly stirred together. The mixture was quickly poured into a silicone mold at 350C. The mixture was found to harden within 5 minutes resulting in the production of a finished part which was removed from the mold.

Example 8 A mixture of 5 parts of E-caprolactone, 0.21 part of diphenyliodonium hexafluoroarsenate, 0.093 part of benzoin and 0.21 part of copper benzoate was placed in a sealed container. The seaied mixture was then heated at 500C for 30 minutes in a water bath and thereafter poured into 100 parts of methanol. A product precipitated which was filtered, washed with methanol and then dried. There was obtained 4.4 parts, or an 88% yield of polycaprolactone based on method of preparation.

Example 9 The procedure of Example 8 was repeated, except that -caprolactone was replaced with 2chloroethylvinyl ether. After the mixture was allowed to stand for 1 hour at room temperature, rapid exothermic polymerization occurred. There was obtained a low molecular weight poly-2chloroethylvinyl ether, based on method of preparation.

Example 10 There was added with stirring to a mixture of 70 parts of ERL4221 and 0.1 part of copper naphthenate as a 12% solution of mineral oil, 3 parts of benzoin and 3 parts of diphenyliodonium hexafluorophosphate dissolved in about 25 parts of acetone. The resulting mixture was thoroughly stirred and then allowed to rest under atmospheric conditions. Within 5 minutes, rapid polymerization occurred along with simultaneous vaporization of the acetone resulting the production of a low density closed cell rigid foam. It is found that the resulting foam is useful as a thermal insulator.

The above procedure was repeated except that addition to the above ingredients there was initially utilized in the mixture 30 parts of a hydroxy terminated polyester (Hooker Company Rucoflex R201 8). There was obtained a flexible foam which was found to be suitable for furniture and automotive padding.

Example 11 A solution of 91 parts of ERL4221 epoxy resin, 3 parts of benzoin and 3 parts of diphenyliodonium hexafluoroarsenate was divided into 10 aliquots. There was then added to each 10 part aliquot at 40-450C, increments of copper naphthenate as a 12% solution in mineral oil. Each of the resulting mixtures was thoroughly stirred and gel times were noted. The following results were obtained, where the amounts of copper naphthenate are shown in parts: Table IV Copper Naphthenate (parts) Gel Time 0.05 5 min, 35 sec 0.15 5min,18sec 0.30 6 min, 5 sec 0.45 6 min, 28 sec 0.60 7 min, 21 sec The above results show that catalytic amounts of copper naphthenate achieve optimum gel times which increase as the concentration of the copper naphthenate increases.

Example 12 A solution of 91 parts of ERL422 1 epoxy resin, 3 parts of diphenyliodonium hexafluoroarsenate and 3 parts of propylene carbonate and 0.1 part of copper naphthenate as a 12% mineral oil solution was divided into 10 aliquots. Various benzoin compounds were then evaluated and 0.1 part levels utilizing the aforementioned 10 part aliquots. The following gel times were recorded at 250C.

Benzoin Gel Time O OH OC-cHO C-CH e 22 min, 7 sec o OH Cl Or C-CH O )- Cl 75 min o OH o) 14 C-CH 4 14 min, 40 sec O OH CH30 -(orC-CH-O C-CH &commat; OCH3 43 min, 26 sec OH > or OCH3 15 min, O I OCH3 l5min,8sec Cl OCH3 O OH CH3 &commat; OC-CHO CH3 min, 50 sec Stearoin > 60 min Example 13 A mixture of 91 parts of the ERL422 1 epoxy resin, 1 part of a copper naphthenate as a 1 2% solution in mineral oil and 3 parts of benzoin was divided into 10 part aliquots. Various diaryliodonium salts were then evaluated for effectiveness by utilizing them in the respective aliquots at a 0.3 part level. The following gel times were recorded: Diaryliodonium Salt Gel Time (C8Hs)21+AsF- 5 min, 44 sec (p-CH2-C6H4)2l$AsFJ 7 min, 53 sec (p-t-but-C6H4)2l+AsF6 6 min, 27 sec (p-Cl-C8H4)2I+AsF6 8 min, 17 sec (pCH3-C8H4)2 l+SbF6 5 min, 1 sec (CH3-C6H4) 21+ PF6- 5 min, 26 sec

Claims

1. A curable composition comprising (A) a cationically polymerizable organic resin, and (B) 1% to 35% by weight of the curable composition of mixture of (i) a diaryliodonium salt of the formula, [(R)8(R1 )bl]+[Y], where R is a monovalent aromatic organic radical, R1 is a divalent aromatic organic radical, Y is a non-nucleophilic anion, a is O or 2, b is O or 1 and when b is 0, a is equal to 2, and when a is0, his equal to 1, and (ii) 0.5 parts to 10 parts, per part of (i), of copper salt, (iii) 0.5 parts to 10 parts, per part of (i), of an Sn+2 salt, an activated (*-hydroxy compound or a mixture thereof.

2. A curable composition as claimed in claim 1, where the cationically polymerizable organic resin is a phenolformaldehyde resin.

3. A curable composition as claimed in claim 1 or claim 2 where the copper salt is copper benzoate.

4. A curable composition as claimed in any one of the preceding claims having up to 10% by weight of a volatile organic solvent.

5. A curable composition as claimed in any one of claims 1 to 4 wherein (iii) is an Sn+2 salt.

6. A curable composition as claimed in any one of the preceding claims wherein the Sn+2 salt is stannous octoate.

7. A curable composition as claimed in any one of the preceding claims wherein the activated a- hydroxy compound is an a-hydroxy carbonyl.

8. A curable composition as claimed in any one of claims 1 to 6 wherein the activated hydroxy compound is benzoin.

9. A curable composition comprising (C) a cationically polymerizable organic resin, and (D) 1% to 35% by weight of the curable composition of a mixture of (iv) a diaryliodonium salt of the formula, [(R)a(R1)bl]+c[MQd] (d e}, where R is a monovalent aromatic organic radical, R1 is a diva lent aromatic organic radical, M is a metal or metalloid, Q is a halogen radical, a is O or 2, b is O or 1, and when a is 0, b is 1, and when be is 0, a, is 2, c=d-e, e equals the valency of M, and is an integer equal to 2 to 7 inclusive and d > e is an integer having a value up to 8, and (v) 0.5 part to 10 parts, per part of (iv) of a copper salt, (vi) 0.5 part to 10 parts, per part of (iv), of an Sn+2 salt, an activated hydroxy compound, or a mixture thereof.

10. A curable composition as claimed in claim 8, where the cationically polymerizable organic resin is an epoxy resin.

1 A curable composition as claimed in claim 10 where the cationically polymerizable organic material is a vinyl organic prepolymer.

12. A curable composition as claimed in any one of claims 9 to 11 where the copper salt is copper benzoate.

13. A curable composition as claimed in any one of claims 9 to 12 where the diaryliodonium salt is diphenyliodonium hexafluoroarsenate.

14. A composition as claimed in any one of claims 9 to 13 having up to 60% by weight of hydroxy terminated polyester.

1 5. A curable composition as claimed in any one of claims 9 to 14 having up to 10% by weight of a volatile organic solvent.

16. A method of foaming a curable composition which comprises (1) agitating the curable composition comprising, (E) a cationically polymerizable organic material and (F) 1% to 35% by weight of the curable composition of a mixture of (vii) a diaryliodonium salt of the formula, [(R)a(R')bl]+[Y]-, where R is a monovalent aromatic organic radical, R' is a divalent aromatic organic radical, Y is a non-nucleophilic anion, a is O or 2, b is O or 1, such that when a is 0, b is and b is 0, a is, (viii) 0.5 part to 10 parts, per part of (vii), of an Sn+2 salt, an activated hydroxy compound or a mixture thereof.

(ix) 0.5 parts to 10 parts, per part of (vii) of an Sn+2 salt, an activated hydroxy compound or a mixture thereof, and (G) 1% to 30% by weight of (E), (F) and (G) of a volatile inert organic solvent, and (2) allowing the ingredients of the resulting mixture to react resulting in the production of exothermic heat and the simultaneous vaporization of the organic solvent and the cure of the cationically curable organic resin.

1 7. A method as claimed in claim 1 6 wherein the cationically polymerizable organic resin is a epoxy resin.

1 8. A method as claimed in claim 16, wherein the cationically polymerizable organic resin is a mixture of an epoxy resin and a hydroxy terminated polyester.

1 9. A method as claimed in claim 16 wherein the cationically polymerizable organic resin is a phenolformaldehyde.

20. A rigid epoxy foam resulting from the vaporization of an organic solvent during the cure of a curable epoxy resin mixture.

21. A flexible epoxy foam resulting from the vaporization of an organic solvent during the cure of a curable epoxy resin mixture.

22. A rigid phenol formaldehyde foam resulting from the vaporization of an organic solvent during the cure of a curable phenolformaldehyde mixture.

23. A curable composition as claimed in claim 1 substantially as hereinbefore described in any one of the examples.

24. A method of foaming a curable composition as claimed in claim 16 substantially as hereinbefore described in Example 4.

25. A foamed composition when produced by a method as claimed in any one of claims 1 6 to 19 and 24.

New Claims filed on 20 February 1980.

New or Amended Claims:

1. A curable composition comprising (A) a cationically polymerizable organic resin, and (B) 1% to 35% by weight of the curable composition of mixture of (i) a diaryliodonium salt of the formula, [(R)a(R')bl]+[Y]-, where R is a monovalent aromatic organic radical, R' is a divalent aromatic organic radical, Y is a non-nucleophilic anion, a is O or 2, b is O or 1 and when b is 0, a is equal to 2, and when a is 0, b is equal to 1, and (ii) 0.5 part of 10 parts, per part of (i), of copper salt, copper salicylate or copper acetylacetonate, (iii) 0.5 part to 10 parts, per part of (i), of an Sn+2 salt, an activated a-hydroxy compound or a mixture thereof.

4. A curable composition as claimed in claim 1 or claim 2 wherein the compound (ii) is copper salicylate.

5. A curable composition as claimed in claim 1 or claim 2 where the compound (ii) is copper acetylacetonate,

6. A curable composition as claimed in any one of the preceding claims having up to 10% by weight of a volatile organic solvent.

7. A curable composition as claimed in any one of the preceding claims wherein (iii) is an Sn+2 salt.

8. A curable composition as claimed in any one of the preceding claims wherein the Sn+2 salt is stannous octoate.

9. A curable composition as claimed in any one of the preceding claims wherein the activated a- hydroxy compound is an hydroxy carbonyl.

10. A curable composition as claimed in any one of claims 1 to 8 wherein the activated ahydroxy compound is benzoin.

11. A curable composition comprising (C) a cationically polymerizable organic resin, and (D) 1% to 35% by weight of the curable composition of a mixture of (iv) a diaryliodonium salt of the formula, [(R)a(R )bl]c[MQd] ( )t where R is a monovalent aromatic organic radical, R' is a divalent aromatic organic radical, M is a metal or metalloid, Q is a halogen radical, a is O or 2, b is O or 1, and when a is 0, b is 2, and when b is 0, a is 1, c=d-e, e equals the valency of M, and is an integer equal to 2 to 7 inclusive and d > e is an integer having a value up to 8, and (v) 0.5 part to 10 parts, per part of (iv) of a copper salt, copper salicylate or copper acetylacetonate, (vi) 0.5 part to 10 parts, per part of (iv), of an Sn+2 salt, an hydroxyl carbonyl compound, or a mixture thereof.

12. A curable composition as claimed in claim 1 where the cationically polymerizable organic resin is an epoxy resin.

13. A curable composition as claimed in claim 11 where the cationically polymerizable organic material is a vinyl organic prepolymer.

14. A curable composition as claimed in any one of claims 9 to 11 where the copper salt is copper benzoate.

1 5. A curable composition as claimed in any one of claims 9 to 11 wherein the compound (ii) is copper salicylate.

1 6. A curable composition as claimed in any one of claims 9 to 11 wherein the compound (ii) is copper acetylacetonate.

1 7. A curable composition as claimed in any one of claims 11 to 1 6 where the diaryliodonium salt is diphenyliodonium hexafluoroarsenate.

18. A composition as claimed in any one of claims 11 to 1 7 having up to 60% by weight of hydroxy terminated polyester.

19. A curable composition as claimed in any one of claims 11 to 18 having up to 10% by weight of a volatile organic solvent.

20. A method of foaming a curable composition which comprises (1) agitating the curable composition comprising, (E) a cationically polymerizable organic material and (F) 1% to 35% by weight of the curable composition of a mixture of (vii) a diaryliodonium salt of the formula, [(R)a(R1 )bl]+[Y], where R is a monovalent aromatic organic radical, R' is a divalent aromatic organic radical, Y is a non-nucleophilic anion, a is O or 2, b is O or 1, such that when a is 0, b is 2 and when b isO,ais 1, (viii) 0.5 part to 10 parts, per part of (vii), of an Sn+2 salt, an activated a-hydroxy compound or a mixture thereof, and (G) 1% to 30% by weight of (E), (F) and (G) of a volatile inert organic solvent, and (2) allowing the ingredients of the resulting mixture to react resulting in the production of exothermic heat and the simultaneous vaporization of the organic solvent and the cure of the cationically curable organic resin.

21. A method as claimed in claim 20 wherein the cationically polymerizable organic resin is an epoxy resin.

22. A method as claimed in claim 20 wherein the cationically polymerizable organic resin is a mixture of an epoxy resin and a hydroxy terminated polyester.

23. A method as claimed in claim 20 wherein the cationically polymerizable organic resin is a phenolformaldehyde.

24. A rigid epoxy foam resulting from the vaporization of an organic solvent during the cure of a curable epoxy resin mixture.

25. A flexible epoxy foam resulting from the vaporization of an organic solvent during the cure of a curable epoxy resin mixture.

26. A rigid phenol formaldehyde foam resulting from the vaporization of an organic solvent during the cure of a curable phenolformaldehyde mixture.

27. A curable composition as claimed in claim 1 substantially as hereinbefore described in any one of the examples.

28. A method of foaming a curable composition as claimed in claim 20 substantially as hereinbefore described jn Example 4.

29. A foamed composition when produced by a method as claimed in any one of claims 20 to 23 and 28.