CA1134537A

CA1134537A - Polymerisation by means of sulfoxonium salts

Info

Publication number: CA1134537A
Application number: CA000354166A
Authority: CA
Inventors: George E. Green; Edward Irving
Original assignee: Ciba Geigy Investments Ltd
Current assignee: BASF Schweiz AG
Priority date: 1979-06-19
Filing date: 1980-06-17
Publication date: 1982-10-26
Also published as: US4299938A; EP0022081A1; EP0022081B1; DE3061890D1; ES8105343A1; ES492540A0

Abstract

ABSTRACT
Substances (I) capable of being converted into higher-molecular weight materials under the influence of a cationic catalyst, such as 1,2-epoxides, aminoplasts, vinyl monomers or prepolymers, or phenoplasts, are so converted by exposure to actinic irradiation or by heating in the presence of as aryloxysulphoxonium salt formula II
where either R6 and R7 separately denote lower alkyl (optionally sub-stituted by halogen and interrupted in the chain by -O- or -SO2-), or an aryl or aryloxy group, or R6 and R7 together denote a divalent group forming with the S atom a heterocyclic radical; R8 denotes a aryl group; M denotes an atom of a metal or metalloid; X denotes a halogen atom; and n is 4, 5, or 6 for instance, p-chlorophenoxy-p-tolyl-p-phenoxysulphoxonium hexaflourophosphate and 1-phenoxy-1-oxidotetrahydrothiophenium tetraflourborate.
When I is an epoxide resin or a resol resin, it may be photopolymerised by means of II and subsequently crosslinked with a latent heat-curing agent.

Description

i~ 34~3 ~

- 2 -THIS INVENTION relates to compositions co~prising a cationically-pol~merisable material and an aryloxysulpho~onil~ salt. It also relates to the pol~merisation of such compositions by means o actinic radiation and to the optional fur~her crosslinking of photopolymerised products so obtained by ~eans of heat in the presence of heat-curing agents, to the polymerisation of such compositions by the effect of heat alone, and to the use of the compositions as surface coatings, in printing plates, in printed circuits, and in reinforced composites, and as adhesives~
For a number of reasons, it has become desirable to induce - polymerisation of organic materials by means of actinic radiation.
Employing photopolymerisation procedures may, for example, avoid the use of organic solvents with their attendant risks of toxicity, fla~ability, and pollution, and the cost of recovering the solvent.
Photop~lymerisatio~ enables insolubilisation of the resin composition to be restricted to defined areas, i.e., those which have been irradiated, and so permits the produc~ion of printed circuits and printing plates or allows the bonding of substrates to be confined to required zones. Further, in production processes, irradiation procedures are often more rapid than those involving heating and a consequential cooling step.
It has been known for some years that certain aromatic diazoniu~ salts undergo decom~osition on exposure to actini~
radiation and that, if the salt is mixed T~ith a cationically-~5 polymerisable substance, then the Lewis Acid which is generated . - ,. ' `
'- ~

3~

_ situ on irradiation induces poly~erisation (see, for ~xa~ple, British Pa~ent Specification No. 1 321 263). Ho~ever, the diazoniu~
salts are not en~irely satisfactory: t~e po~-life of the mixture of diaæonium salt and cationically-polymerisabls substance is ofte~
too short, particularly in daylight, and secondly, nitrogen is generated during liberation of the Lewqs Acid ~atalyst, which evolution of gas restricts the range of processes in which the catalysts may successfully be e ployed.
Numerous proposals have therefore been made for the replacement of these diazoniu~ salts by others which, while liberating an acid catalyst on irradiation~ do not also evolve nitrogen: particularly in~ensively studied have been onium salts of sulphur/and iodonium salts.
Thus, it has recently been disclosed, in British Patent Specification No. 1 516 511 and its United States equivalent, No. 4 058 401, that a mono-1,2-epoxide, an çpoxide resin (i.e., a substance containing on average more than one 1~2-epoxide group), or a mi2ture thereof, may be polymerised or cured by means of a radiation-sensitive aromatic oni~m sal~ of oxygen, sulphur, selenium, or tellurium present in an amount capable of effec~ing the polymerisation or cure of the epoxide (or polyepoxide) by release of a Br~nsted Acid catalyst when e~posed to radiant energy, The only such salts described in the Specification are of the formula [ (R)a(R )b(R )cxl ~Qe ~ I

where R denotes a monovalent aromatic radical, Rl denotes an alkyl, cycloalkyl, or substituted alkyl group, S R2 denotes a polyvalent aliphatic or aroma~ic radical fo~ing a heterocyclic or fused ring structure, X denotes o~ygen, sulphur, selenium, or tellurium, M denotes an atom of a metal or metalloid, such as antimony, iron, tin, bismuth, aluminlum, gallium, indium, titanium, ~irconium, scandium, vanadium, chromium, manganese, boron, phosphorus, or arsenic, Q denotes a halogen radical, a denotes 0, 1, 2, or 3, b denotes 0, 1, or 2, L5 c denotes 0 or 1, the sum of a ~ b ~ c being 3 or the ~alency of X, ~ :
d denotes (e~f), f is the valency of M, and is an integer of f~om 2 to 7, and e is more than f and is an integer of up ~o 8.
Shortly afterwards, in British Patent Specification No. 1 518 141, and also in its corresponding United States Patent No. 4 058 400, the same paten~ee disclosed that monomeric or prepolymeric, cationically polymerisable organic materials free -from any 1,2-epoxide group, selected from ~inyl monomers, vinyl prepolymers, cyclic ethers, cyclic esters, cycli.c sulphides, cyclic amines, and organosilicon cyclics, can also be polymerised by exposing ~hem to radiant energy in the presence of an effective amount of a radiation--sensitive onium salt S of the Group VIA elements listed above. The only onium salts described are likewise of formula I above.
Still more recently, in its United States Patent No. 4 102 687, the same patentee disclosed that the curing of urea-formaldehyde resins, melamine-formaldehyde resins, and phenol-formaldehyde resins could be initiated by exposing them to llltraviolet radiation in the presence of a Group VIA onium salt, curing being completed by heating.
Again, only the onium salts of formula I are mentioned.
Subsequent disclosures of this patentee concerning onium salts of sulphur have been confined to sulphonium salts.
Thus, British Patent Specification ~o. 1 535 492 describes the use of radia~ion-sensitive sulphonium salts of arylsulphonic, haloarylsulpho~ic, alkylsulphonic, and haloalkylsulphonic acids for the cationic polymerisation of epoxide resins, vinyl monomers and prepolymers, cyclic organic ethers, cyclic organic esters~ cyclic organic sulphides, cyclic a~ines, and cyclic organic silicon compounds.
Its United Sta~es Patent No. 4 139 385 discloses the use of sulphonium and other salts in the curing of polyolefins by means of polythiols. A polyethylenically unsaturated co~pound, such as diallyl phthalate, diallyl maleate, or triallyl cyanurate, is mixed with a polythiol, such as trimethylolpropane trithioglycollate or 3~

pentaerythieol tetra(3-mercaptopropionate) and, e.g., triphenylsulphonium he~afluoroarsenate or tetrafluoroborate, and then exposed to ultraviolet light. The salts used as catalysts are all of the formula ~ ~ [ ] (k-m~

or ~(R)c(R2) or _ _ + ~ ~ (k-m~-(R)~(R )g(RS)hZ l ~ ¦ IV

where R denotes a monovalent aromatic radical, Rl denotes a divalent aromatic radical~
R denotes a polyvalent aliphatic or aromatic radical forming a heterocyclic or fused ring structure, l; R4 denotes an alkyl, alkoxy, cycloalkyl, or subs~ituted alkyl radical, R5 denotes a polyvalent radical forming an aromatic, heterocyclic or fused ring s~ructure, M denotes an atom of a metal or a metalloid, X denotes a halogen radicals Z denotes a nitrogen, phosphorus, arsenic, bismuth~ or anti~ony at~m, a denotes O or 2, b denotes O or 1, where a + b ~ 2 or tne valency of iodine, ~-c denates O or 3, d denotes O or 2, _.
e denotes O or l, such that (c ~ d ~ e) ~ 3 or the va}ency of sulphur, f is an integer of from O to 4, -g is 0, 1, or 2, h is 0, 1, or 2, such that (f ~ g + h~ = 4 or the valency of Z, i is k - m, m is ~he valency of M, being 2 to 7, and k is an integer of re ~han 1 but not more than 8.
-~ts West German Offenlegungsschrift No. 2 833 648 disclosesthat triarylsulphonium salts of formula [ (R~ [ d~ V

can be used to initiate the curing, on irradiation, of an aliphatically unsaturated composi~ion containing a 1,2-epoxide '.

:: .

group, such as ~lycidyl acrylate, or a mixture of an epoxide resin with an aliphatically-unsaturated substance such as methyl methacrylate, a polyes~er, or styrene. I~ formula V -R denotes an aromatic hydrocarbon or heterocyclic group of 6 to 13 carbon atoms, which may be substitu~ed, R denotes a divalent aromatic hydrocarbon or heterocyclic group, which may be subs~ituted, a is l or 3, b is 0 or 1, S has a valency of 3, which may be satisfiad by R alone or b~ a combination of k and Rl, M denotes an atom of a metal or metalloid, Q denotes a halogen radical, and d is 4, S, or 6.
Its ~nited States Patent No. 4 136 102 describes various sulphonium salts containing a he~afluorophosphate, he~afluoroarseu~te, or he2afluoroantimonate anion and their use in curing epoxide resins.
They are s~ated to be also useful for the polymerisation of a variety of unspecified cyclic organic and cyclic organo-silicon compounds.
Its West German Offenlegungsschrift No. 2 730 725 discloses the photo-induced curing, by means of aromatic onium salts7 o epoxide resin compositions which also contain a polyvinyl acetal. The only onium salts of sulphur indicated are ~hose of formula I.
Its United States Paten~ 4 081 276 describes a process for the formation of photoresist images, especially for printed circuit 3~

production, wherein a layer of a photoinitiator is e~posed to radiant energy and then contacted with a cationically polymerisable material~
e.g., an epoxide resin. Again, the only onium salts of sulphur cited are those of formula I above.
Another pate~tee has described, in Belgian Patent No. 845 746 the photopolymerisation, using as catalyst an aromatic sulphoni.um salt or an aro~atic iodonium salt, of mi~tures comprising a compound having an epo~ide functionality of more than 1.5 epo~ide groups per molecule and a compound having hydro~y functionality of at least one.
This second patentee describes, in United States Patent No.

4 090 936, photohardenable liquid compositions comprising (a) an organic compound having an average epo~ide functionality i~ the range of about 1 to 1.3, (b) from about 3 to 502 by weight, calculated on the weight of (a), of an organic polymer which is compatible with ~a) and has a glass transition temperature in the range of about -20 C to 105C, being a polymer derived from at least one acrylate or methacrylate monomer, or a copolymer of styrene and allyl alcohol, or a polyvinyl butyral polymer, and ~c) an aromatic complex salt photoinitiator which is an onium salt of a Group VA or Group VIA element or a haloniwm salt. The only onium salts of sulphur indicated are sulphonium sal~s.
Another disclosure of this second patentee, United States Patent No. 4 069 054, relates to photopolymerisable compositions containing a cationically polymerisable monomer, an aromatic sulphonium compound, . ~

- 10 ~
and an aromatic ~ertiary amine, aro~atic tertiary diamine, or an arcmatic polycyclic compound as a sensitiser.
An ar~matic sulphonium salt, namely triphenylsulphonium hexafluorophosphate~ has been used c~mmercially for t1ne photo-polymerisation of epoxide resins.
We have now surprisingly found that cationlcally polymerisable materials can be photopolymerised by means of aryloxysulphoxoniu~ salts.
~se of these salts as catalysts generally results in ~aster photo-polymerisation than if thc sulphoni~m or iodonium salts of the prior art are used. Further, contrary to what ~ould be expected from the teachings of United States Patent No. 4 102 687, we have found that u~ea-fo~maldehyde resins may be cured either by irradiation or by ~e applicai~on o~ heat.
A further ad-vantage of the aryloxysulpho~onium salts is that compositions containing them, unlike those containing co~ventional sulphonium salts as catalysts, do not liberate obnoxious mercaptan odours on irradiation.
This invention accordingly provides co~positions comprising a) a compound, or mixture of compounds, capable o~ beina tranformed into a higher-mo~ecular weight material under the influence of a cationic catalyst, b) an effective amount of an aryloxysulphoxonium salt of ~he formula R6 ,~ o ~ +

-where either R6 and R7 each denote i) an alkyl group of 1 to 6 carbon atoms, which may be substituted by a halogen atom a~d which may be interrupted i.n the

5 chain by an ether oxygen atom or a sulphonyl group, ii) an aryl group of 6 to 15 carbon atoms, or iii) an aryloxy group o 6 to 15 carbon atoms, or R6 and R7 together denote a divalent gro-up of 4 to 10 carbon ~ ~:
atoms, forming with the.indicated sulphur atom a heterocyclic radical, R8 denotes an aryl group of 6 to 15 carbon atoms, M denotes an atom o a metal or metalloid9 X denotes a halogen atom, preferably af fluorine or of chlorine, and ~ : :
n is 4, 5, or 6 and is one more than the valency of M.
Another ~spect of this invention provides a process for the transformation into a higher-molecular weight material Qf a compound or mixture of cwmpounds capable of being converted into a higher-molecular weight material under the influence of a cationic catalyst, comprising subjecting a said composition of this inven~ion to actinic radiation.
We have further found that cationically polymerisable materials may also be polymerised by heating compositions o ~his învention.
~ccordingly, a further aspect of this i~ventio~ provides a process for the transformation into a higher-molecular weight material of a compound or mixture of compounds capable of being con~erted into a higherqmolecular weight material under the inluence o a ca~ionic catalyst, which co~prises heating a said composition of this invention.
Preferably R and R7, when taken ssparatelg, are each an aryl or aryloxy group of 6 to 11 carbon ato~s, or taken together rorm a mono-cyclic chain co~posed only of carbon and hydrogen atoms. More preferably R de~otes a phenyl or naphthyl group, optionally substituted by one or two alkyl ~roups of 1 to 4 carbon atoms each or by one or two fluori~e, chlorine, or bromine atoms. More. preferably, too, R denotes a phenyl, phenoxy, naphthyl, or- naphthyloxy group, optionally substituted by one or two alkyl groups of 1 to 4 carbon atoms each or by one or two fluorine, ehlorine, or bromine atoms.
When R6 and R7 together denote a divale~t group 3 more preferably this is a group ~CH2~4.
R8 more preferàbly denotes a phenyl or naphthyl group, optionally substltuted by one or two alkyl or alkoxy grollps of 1 ~o 4 carbon atoms each, by one or ~wo nitro groups, or by one or two fluorine, chlorine, or bromine atoms.
M preerably denotes an atom of boron, phosphorus, arsenic, ant~mony, or bismuth, especially boron or phosphorus.
The anion MXn may be, e.g., hexachlorobismu~hate, but it is preferably hexafluoroantimonate, hexafluoroarsenate, hexafluoro-phosphate, or tetrafluoroborate.
Specific examples of suitable sulphoxonium salts are:-3~ `

- 13 ~
diphenylphenoxysulpho~onium hexafluorophosphate, phenyldiphenoxy-sulphoxonium hexafluorophosphate, methyldiphenoxysulphoxonit~
he~afluorophosphate9 ~-~olylpheno~y-p-tolyloxysulphoxonium hexafluorophosphate, ethyl(ethylsulphonylmethyl)-~-tolyloxy- .
sulphoxoniu~ hexafluorophosphate, o-chlorophenoxy p-tolyl~
phenoxysulphoxoniu~ hexafluorophosphate, l~phenoxy-l-oxido-tetrahydrothiophenium hexa1uorophosphate, l-phenoxy-l-o~ido-tetrahydrothiophenium tetrafluoroborate, and l-phenoxy-l-Qxido-tetrahydrothiophenium hexafllloroan~imonat~.
Salts of ormula VI are, in general, known (see Chalkey, Snodin, Stevens, and Whiting, J._Chem. Soc. (C), 1970, 682--6) and are obtainable by decomposition of ~he corresponding arenediaæonium salt of ormula R N2 ~Xn VII

in the presence o an excess of the appropriate sulphone or aryl ester of an alkanesulphonic acid or arenesulphonic acid of formula \ S ~ VIII
R7 ~ 0 where R6, R7, R8, M, X, and n have the meanings previously assigned9 such as dimethyl sulphone, tetrahydro~hiophen~ dioxide, phenyl i3'`~

14 ~

methanesulphonate, or phenyl benzenesulphonate.
The amount of b) employed is sufficient to induce polymerisation of a) on exposure of the composition to actinic radiation or on heating it. Usually, from 0.1 to 7.5, especially from 0.5 to 6, S parts by weight of b) are employed per 100 parts by ~eight of component a).
Co~ponent a) is preferably a 1,2-epoxide, a vinyl monomer or prepoly~er, an aminoplast, or a phenoplast. It may be, for exa~ple, a mo~o-1,2-epoxide, such as epichlorohydrin, propylene oxide, or a ~
glycidyl ether of a monohydric alcohol or phenol, such as n-butyl glycidyl ether or phenyl glycidyl ether; it may also be, e.g., a glycidyl ester such as glycidyl acrylate or methacrylate.
Preferably it is an epoxide resin, especially those containing at least one group of formula O
- C~ - C - CE I~
R9 Rl RlI

directly attached to an atom of oxygen, where either R9 and R
each represent a hydrogen atom, in which case R10 denotes a hydrogen atom or a methyl group, or R9 and Rll together represent -CE2CH2-, in which case R denotes a hydrogen atom.
As examples of such resins may be mentioned polyglycidyl and poly(~-methylglycidyl) esters obtainable by reaction of a compound 3~g~ -~ 15 ~

containing two or more carb~ylic acid ~roups per molecule with epichlorohydrin, glycerol dichlorohydrin, or ~ethylepichlorohydrin in the presence of an 21kali. Such polyglycidyl esters may be derived frcm aliphatic polycarbo~ylic acids9 e.g., succinic acid, ~lutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, or dimerised or trimerised linoleic acid; from cycloaliphat;c polycarboxylic acids such as tetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, hexahydrophthalic acid9 a~d 4-methylhexahydrophthalic acid; and from aromatic polycarbo~ylic acids such as phthalic acid, isophthalic acid, and terephthalic acid. Other suitable polyglycidyl esters are obtainable by Yinyl polymerisation of glycidyl esters of vinylic acids, especially glycidyl acrylate and glycidyl methacrylate.

Further examples are polyglycidyl and poly(~-methylglycidyl) ethers obtainable by reaction of a compound containing at least two free alcohoLic hydroxyl and/or phenolic hydroxyl groups per molecule with the appropriate epichlorohydrin under alkaline conditions o~, alternatively, in the presence of an acidic catalyst and subsequent treab~ent with alkali. These ethers may be made ~rom acyclic alcohols such as ethylene glycol, diethylene glycol, and higher poly(oxyethyle~e) glycols, propane-1,2-diol nd poly(oxypropylene) glycols, propane-1,3 diol, poly~oxytetra~ethylene~
glycols9 pentane-1,5-diol, hex~ne-2,4,6-~riol, glycerol, 1,1,1-trimethylolpropane, pentaerythritol, sorbitol, and poly(epichlorohydrin);

3~

rom cycloaliphatic alcohols such as resorcitol, quinitol, bis~4-hydro~7cyclohexyl~methane, 2,2-bis(4-hydroxycyclohexyl~propane, and l,l-bis(hydroxymethyl)cyclohex-3-ene; and from alcohols having aro~atic nuclei, such as NlN-bis~2-hydroxyathyl)miline and p,~'-bis(2-hydroxyethylamino)diphenylmethane~ Or they may be made from mononuclear phenols, such as resorcinol and hydroquinone, a~d from polynuclear phenols, such as bis(4-hydroxyphenyl)methane, 4,4'-dihydroxydiphenyl, bis(4-hydroxyphenyl) sulphone, 1,1,2,2-te~rakis(4-hydroxyphenyl)ethane, 292-bis(4-hydroxyphenyl)propane, (otherwise known as bisphenol A), 2,2-bis(3,5-dibromo-4-hydroxy-phenyl)propane, and novolaks formed from aldehydes such as formaldehyde, acetaldehyde, chloral, and furfuraldehyde, with phenol itself, and phenol substituted in the ring by chlorine atwms or by alkyl groups each c taining up to nine carbon ato~s, such as 4-chlorophenol, 2-methylphenol, and 4-ter~.butyl~henol.

Poly(~-glycidyl) c~mpounds ~ay also be used; e.g., N-glycidyl derivatives of amines such as aniline, _-butylamine, bis(4-amillo-phenyl)methane~ and bis(4-methylaminophenyI)methane triglycidyl isocyanurate; and N,N'-diglycidyl derivati~es of cyclic aIkylene ureas, such as ethyleneurea and 1,3-propyleneurea, and of hydantoins such as 5,5'~dimethylhyda~oin. In general, however, they are not preferred.

. C"~3 ~

Poly~S-glycidyl) comæounds may al50 be used, e.g., ti~S-glycidyl) deriva~ivas of dithiols such a~ e~ha~e-1,2-dith-iol and bis(4-mercaptomethylpnenyl) ether, buc ~hey also are ~o~ preferred.
Examples of epaxide resins havin~ groups o~E for wla I~ where R9 and Rll conjointly denote a -CH2C~- group are bis(2,3-epoxy- ~:
cyclop~n~yl) ether, 2,3-epoxycyclopentyl glycidyl ether, ant 1,2-bis(2,3-epoxycyclope~tyloxy)ethane.
Epoxide resins having the 1,2-epoxide groups aetached to di~fere~ kinds of hetero atomC may be employed, e.g., ~he glycidyl ether-glycidyl ester of salicylic acid.
Epoxide resins in which some or all of the epoxide groups are ~ot terminal may also be employed, such as vinylcyclohexene dioxide, limonene dio~ide, dicyclopen~adiene dioxide, 4-oxatetra-c~clo [ 6.2 1.02~7.0,3'5 ] u~dec-9-yl glycidyl ethe., 1,2-bis(4-oxatetracyclo ~6.2~1.02'7Ø '5 3 u~dec 9-yloxy)ethane, 3,4-epoxycyclohex71methyl 3',4'-epoxycyclohexanecarboxylate and i~s

6,6'-dimethyl deri~ative, ethylene glycol bis(3,4-epo~ycyclohexan2-carbo~yla~e), 3-(3,4-epoxycyclohexyl)-8,9-epoxy-2,4-dioxaspiro-r5~ undecane, and epoxidised butadienes or copoly~ers of butadiene with ethylenic compounds such as styre~e and vinyl acetatP
If desired, a mixture ~f epo~ide resins may be used.
Especially preferred epoxide resins used in this invention are diglycidyl ethers, which may h~ve been advancod, of dihydric phenols such as 2,2-bis(4-hydroxyphanyl)propane and bis(4-hydro~y-phenyl)methane and of dihydrie alcohols such as butane-1,4-diol.

3r;

l8 ~
If desired, the epoxide resin may be co-cured with a polyhydric alcohol, i.e., a compound having at least t~o alcoholic hydroxyl, preferably primary, groups per molecule~ Preerably the polyhydric alcohol is present in a quantity sufficient ~o supply from 0.5 to 1.5, especially 0.75 to 1.259 alcoholic hydroxyl groups per 1,2-epoxide group of the epoxide resin. The polyhydric alcohol preferably cont~ins, in addition ~o the alcoholic hydroxyl groups, only carbon, hydrogen, and, optionally, oxygen present as ether oxygen, acetal or carbonyloxy g~oups, and halogen atoms_ It is further preferred that the polyhydric alcohol have a molecular weight of at least 100 and particularly more than 1000. Examples of suitable polyhydric alcohols are poly(oxyethylene) glycols, polytoxypropylene) glycols, poly(oxytetra~ethyle~e) glycols, polyepichlorohydrins, poly(oxyethylene)-, poly(oxypropylene)-, and poly(oxytetramethylene) triols, obtainable by polymerisation of ethylene oxide, propylene oxide~ or tetrahydrofuran in the presence o~ glycerol or 1,1,1Itrimethylolpropane, hydroxyl-terminated polycaprolactones, copolymers of styrene with allyl alcohoI, polyvinyl alcohols, hydroxypropylcellulose, hydroxyl-containing pol~vinyl acetals, and partial esters of cellulose, e.g., a cellulose acetate butyrate.

Vinyl nomers and prepolymers which may be polymerised include 9 tyrene, a-me~thylstyre~e, allylbenæese, divinylbenzene, vi~ylcyclohexane, 4-vinylcyclohex-1-ene, N-vinylpyrrolidin-2-one, N-vinylcarbazole, acrolein, isoprene, bu~adiene, piperylene, vinyl S acetate, and vinyl ethers such as l butyl vinyl ether, methyl vinyl ether, trime~hylolpropane trivinyl ether, glycerol trivinyl ether, vinyl ethers of ethylene glycol a~d poly(oxyethylene glycols), and cyclic vinyl ethers having at least two cyclic vinyl ether groups each forming part of a 3,4-dihydro-2H-pyran nucleus, such as 3,4-dihydro-2H-pyran-~-ylmethyl 3,4-dihydro-2H-pyran-2-carboxylate and its prepolymers. The preferred vinyl co~ounds are vinyl ethers of aliphatic monohydric alcohols and 3,4-dihydro-2H-pyran-2~ylmethyl 3,4-dihydro-2H-pyran-2-carboxylate and its prepoly~ers.
The aminoplasts preferred as component a) containS per molecule, at least two groups of formula -CH20R directly attache.d to an amidic or thioamidic ni~rogen atom or atoms, where R12 denotes a hydrogen atom, an alkyl group of 1 to 4 carbon atoms, or an acetyl group. Examples of such aminoplasts are the N-hydroxy-methyl, N-me~hoxymethyl, N-butoxymethyl, and N-acetoxymethyl derivatives of the following amides and amide-like subs~ances.
1. Urea, thiourea, and the cyclic ureas having the formula .... , . .. .. , ... . .. ... . . ~ . . .. ~. . .. . .. ... . .. .. . . . .. .
'~ ' ''' ~

:

L.~ 7 / \ X
W~
\ /

i~ which R13 denotes oxygen or sulphur and R14 denotes either a group of formula HC ~ C~
Xl E~ NH
\C

or a divalent group which may be subetituted by methyl, methoxy, or hydroxy groups, and which may be interrupted by -CO-, -O-, or -N(RI5)-, where R15 deno~es an alkyl or hydroxyalXyl group containing up to 4 carbon atoms, said divalent group containing 2 to 4 carbon atoms other than those in any ~ethyl or methoxy subs~tituents or interrupti~g -CO- or N~R )- groups.
~ xamples of such cyclic ureas are ethyleneurea (imidazolidin-2 one), dihydroxyethyleneurea (4,5-dihydroxyi~idazolidin-2-one), hydantoin, uron (~etrahydro-oxadiazin~4-one), 132~propyleneurea (4-methylimidazolidin-2-one), 1,3-propyleneurea thexahydro-2H-pyrimid 2-one), hydroxypropyleneurea (5-hydroxyhexahydro-2H-pyrimid-~ 2-one), dimethylpropyleneurea (5,5-dimethyLhexahydro-2H-pyrimld--, .

:

~ ~1 ~
~-one), dimethylhydroxypropyleneurea and dimethylmethoxy-propyleneurea (4-hydroxy- and 4-methoxy-5,5-dimethrlhexahydro-2H-pyrimid-~-one), 5-ethyltriazin-2-one/and 5-(2-hydroxyethyl)-triazin-2-one.
II. Carbama~es and dic~rbamates of aliphatic monohydric and dihydric alcohols containing up to four carbon ~toms, e.g., methyl~
ethyl, isopropyl, 2-hydro~yethyl, 2-~ethoxyethyl, 2-hydroxy-n~
propyl and 3-hydroxy-n-propyl carbamates, and ethylene and 1,4-butylene dicarbamates.
III. Melamine and other polyamino-1,3-triazines such as aceto~
guanamine, benzoguanamine9 and adipoguanamine.
If desired, aminoplasts con~aining both N-hydroxymethyl and N~alkoxymethyl, or N-hydroxymethyl and N-acetoxy~ethyl~groups may be uset (for example, a hexamethylol~elamine in which 1 to 3 of the hydroxyl groups have bee~ etherified with methyl groups~.
The preferred amirioplasts are condensation products of urea, uron, hydantoin, or melamine with formaldehyde, and the partially or fully etherified products of such condensation products with an aliphatic monohydric alcohol of 1 to 4 carbon atoms.
The preferred phenoplasts are resols made-from a phenol and an aldehyde. Suitahle phenols include phenol itself, resorcinol, 2,2-bls(p-hydroxyphenyl)propane, p-chlorophenol, a phenol substituted by one or two alkyl groups, each of 1 to 9 carbon atoms, such as o-, m-, and ~-cresol, the xylenols, p-tertiary butylphenol~ p-nonylphenol, and phenyl~rsubstituted phenols3 especially p-phenylphenol. ~he 31~

aldehyde which is condensed with the phenol is preferably f ormaldehyde, but other aldehydes such as acetaldehyde and furfuraldehyde may also bc used. If de~ired, a mixture of such curable phenol~aldehyde resins may be used.
The preferred resols are condensation products of phenol, r chlorophenol, resorcinol, or o , -, or p-cresol wqth ~ormaldehyde.
Preferably the compositions of this in~e~tion9 when they are to be photopolymerised, also contain a sensitiser. We have ~ound that~
by incorporation of suitable sensitisers, the speed of curing is yet further increased, thereby permitting the use of even shorter exposure times a~d/or of less powerful sources o irradiation.
Further, the se~sitivity to visible light is enhanced. Sensitisers other than dyes have been fou~d the more effective, particularly arom~tic polycyclic compounds having at least three fused benzene rings and having an ionisation energy of less than about~7.5 ev.
Suitable such sensitisers are described in United States Patent Specification No. 4 069 054, and include anthrace~e, rubrene, perylene, phenanthrene, fluoranthene, and pyrene. We prefer to include fr~m 0.1 to 2%, and especially from 0.25 to 0.75%, by weight of the sensitiser, calculated on the weight of a).
In the photopolymerising step actinic radiation of wa~elength from 200 to 600 nm is preferably used~. uitable sources of actinic radiation include carbon arcs, mercury vapour arcs, fluorescent lamps with phosphors emitting ultraviolet light, argon and xenon glow lamps, tungsten~ lamps, and photographic flood lamps. Of these, .
.~ ~

__ ~, _ . ,_ .. , __ _. .... _ . ._ . . ___.. _ ., . .... _ _ . _ .. _ _ _ .... _ .. __ . . .,~_~ __ . . . . . ~

:
' ' ' ~

~:~.34 ~3 ~

- 23 ~

mercury vapour arcs, particularly sun lamps, Il~lorescent sun lamps, and metal halide lamp~ are most suitable. The time required for the exposure will depend upon a variety of factors which include, for example, the indi~idual polymerisable substrate used, the type o light source, and its distance from the irradiated material.
Suitable times may be readily determined by those f ~iliar with photopolymerisation techniques. I~l as in the process described below, it is necessary that the product so photopoLymerised must still be curable on heating with the heat-curing agent admi~ed therewith, then, o course, irradiation is carried out at a temperature below that at which substantial heat-curing of the photopolymerised product by means of that heat-curing ageDt would occur.
Whe~ the compositions or this invention are to be polymerised substantially by means of hea~ alone, they are preferably heated to a temperature of from 100 to 175C, and preferably for from 3 to 20 minutes.
The compositions of this invention may be used as surface coatings. They may be applied to a substrate such as steel, aluminium, copper`, cadmlum, zinc, paper, or wood, preferably as a \ liquid, and irradia~ed or heated. By photopolymerising part of ! the coating, as by irradiation through a mask, those sections which have not been e posed may be washed with a solvent to remove ~ the unpolymerised portions while leaving the photopolymerised, 25~ insoluble portions in place. Thus the compositions of tnis invention ~?~3~3P~,J

may be used in the production of printing plates and printed circuits.
Methods of producing printi~g plates and printed circuîts from photopolymerisable compositions are well known (see~ e.g., our British Patent Specificatlon No. 1 495 746), S The compositions may also be used as adhesives. A layer o~
the composition may be sandwiched between two surfaces o~ objects, a~ least one of which is transparent to ~he actinic radiation, e.g., of glass, when photopolymerisation is to be employed~ then the assembly is heated, or irradiated and, if desired, heated to complete the polymerisation.
The compositions are also useful in the production of fibre~
reinforced composites, including sheet moulding compounds.
They may be applied directly, in liquid form, to reinforcing fibres (including strands, filaments, and whiskers), ~hich may be in the form of woven or nonwoven cloth, unidirectional lengths, or chopped strands, especially glass, boron, stainless steel, tungsten, al~mina, silicon carbide, asbestos, potassium titanate whiskers, an aromatic polyamide such as poly(m-phenylene isophthalamide), poly(~-phenylene terephthalamide), or poly(~benzamide), polyethylene, polypropylene, or carbon.
The fibre-rPinforced composite may be made by a batch process, the fibrous reinforcing materlal being laid on a film of the photopolymerised composition, which is advantageously under slight tension, when a second such film may, if desired, be laid on top, and then the assembly is pressed while being heated It may also 3 ~

- 25 ~

be made continuously, such as by contactlng the ibrous reinforcing material with a film of the photopolymerised composition, then, if desired, placing a second such film on the reverse face o the fibrous reinforcing material and applying heat and pressure. More conveniently, two such films, preferably suppor~ed on the reverse side by belts or strippable sheets, are applied simultaneousl~ to the fibrous rein~orcing material so as to contact each e~posed face.
When two such films are applied, they may be the same or different.
Multilayer composites may be made by heating lmder pressure interleaved films and layers of one or more fibrous reinforcing materials~ When unidirectional fibres are used as the reinforce~ent material, successive layers of them may be oriented to form cross-ply structures.
With the fibrous reinforcing material there may be used additional types of reinforcement such as a foil of metal (e.g., aluminium, steel, or ei~anium) or a sheet of a plas~ics material (e.g., an aromatic or aliphatic polyamide, a polyimide, a polysulpho~e, or a polycarbonate) or of a rubber (e.g., a neoprene or acryloni~rile rubber).
Alternatively, a mi~ture of the reinforcing fibres and a compositio~ of this invention is heated to form a composite directly.
In the production of sheet moulding compounds, a composition of this inven~ion, together with the chopped strand reinforcing m~terlal and any o~her components, is exposed to irradia~ion in layers through supporting sheets or is heated.

,~ .

3~

The polymerisable composition is preerably applied 50 that ~he composite contains 3 total o ~rom 20 to 80% by ~eight of the saicl c~mposition and, correspondingly, 80 to 20Z by weight of the rein~orcement. More preferably, a ~otal of 30 to 50~ by weight of the composition is employed The composi~ions of this invention are useftll in the production of put~ies and fillers. They ~ay be used as dip-coati~gs, an article to be coated being dipped in the liquid composition, withdrawn, and the adhering coating being heated, or being irradiated to photo-polymerise (and hence solidify it~ and subsequently, if desired,being heated We have ou~d that it is possible, using arylo~ysulphoxonium salts, ~o cure epoxide resins and phenoplasts i~ two stages; the resin is first con~erted in~o the partially cured B-stage by e~posing it to actinic radiation in the presence of an aryloxysulphoxonium salt and a la~ent, heat-activated crosslinking agent for the epoxide resin or phenoplast, and, in a second stage, the partially cured c~mposition is heated so that curing is completed by means of the heat-activated crosslinking agent. Thus, a liquid or sem~liquid c~mposition may be prepared, ~hich may then be shaped or used to impregnate a substrate while being irradialed to solidify it; then the solidified body is heated when desired, to complete the cure of the resin According, therefore, to another e~bodîment of this invention, an epoxide resin or a phenoplast is irradiated in the presence of .

3~

an amount o~ a~ aryloxysulphoxoniu~ salt of formula ~I effective for ~he polymerisation of the epoxide resin or phenoplast and of a curing amount of a latent heat-curing agent ~or the epo~ide resin or phenoplast to form a B-stage product, and, when desired, curing of the composition is completed by heating it.
A further embodiment comprises a composition containing an epoxide resin or a phenoplast, an amount of an aryloxysulphoxoni~
salt of formula VI effective for polymerisation of the said epoxide resin or phenoplast on exposure of the compositio~ to actinic radiation9 and a curing amount of a late~t heat-curing agent for the epoxide resin or phenoplast.
Suitable heat-activated crosslinking agents for the epoxide resin compositions include polycarboxylic acid anhydrides, comple~es of ~mines, especially primary or tertiary aliphatic 2mines such as ethylamine, trimethyla~ine, and n-oc~yldimethylami~e, with boron trifluoride or boron trichloride, and latent boron difluoride chelates.
Aromatic polyamines and i~ida~oles are usually not preferred, because indifferen~ results are obtained, possibly due to reaction between the acid catalyst liberated and the amine. Dicya~diamine can be used successfully, providing it is in rela~ively coarse particles.
Suitable heat-ae~ivated crosslinking agents for resols include hexamethylenetetramine and paraform.
The temperature and dura~ion of heating required for the thermal curing after photopolymerisation, and the proportions of heat-activated curing agent~ are readily found by routine 3~

- 28 ~

exper~mentation and e~sily derlvable from wha~ is already well known concerning the heat-curing of epoxide resins and phenol-aldehyde resols.
Compositions containin~ resins having epoxide groups or phenolic S hydroxyl groups thrcugh which they can be heat-cured ater photopolymerisation are partlcularly use~ul in the production of multilayer printed circuits.
Conventionally, a multilayer printed circuit is prepared fro~
several double~sided printed circuit boards of copper, stacked one on ~op of another and separated from each other by insulating sheets, usually of glass fibre impreg~ated with an epoæide resin or a phenol-formaldehyde resin i~ the B-stage. I~ a heat-curing agent lS

not a~m~Yed with the la~er of photopolymerisahle resin in th~ circuit board, it can be incorporated in the insul~ting layers whlch alternate with the pla~es, these layers conveniently being of an epo~ide resi~ or phenol-formaldehyde resin prepreg, sufficient of the heat-curi~g agent contained in the prepreg, providing the latter is not too thic~, migrates to induce crosslinking of the photopolymerised epoxide resin or phenol~formaldehyde resin. ~he stack is heated and compressed to bond the layers together, Conve~tional photopolymerisable materials, however, do not farm strong bonds either with copper or with resin-impregnated glass fibre sheets ~ stack which is bonded with the photopolymer still covering the copper lS therefore inherently weak and in use can become delaminated. It is therefore normal practlce to remove the residual photopoly~er after the etching stage, either by ~eans of - - :

. . . . . . . . . . . .. ... .. . . .. . . . . . .. ... . . . . .. ..... .

., ;3'7 powerful solvents or by a mechanical me~hod, 8,g., by means of brushes. Such a stripping process can da~age the copper of the prin~ed circuit or the surface of the la~inate on which the circuit rests, and so there is a need for a method whi.ch would avoid the necessity of removing the photopolymerised material prior to bonding the boards together. The presence of residual crosslinking groups in the compositions of this invention means that` crosslinking ca~
occur when the boards are bonded, resulting in good adhesion to the copper and to the resin-impregnated glass fibre substrate, so avoiding the necessity jus~ referred to; also, products with a higher glass transition temperature are obtained.
Another application i~volving heat-curing after photopolymerisation of the compositions of this invention is in filament winding. Thus, a continuous tow of ibrous reinforcement is impregnated wi~h a composition containing a latent heat-curing agent and then wound arou~d a mandrel or former while e~posing the winding to actinic radiation. Such filament windings still have a degree of fle~ibility, permit~ing the mandrel or former to be removed more readily than ~hen 2 rigid winding is formed in one step. When required, the winding is heated to crosslink the composi~ion.
In a further such applica-tion, a layer of the compositio~ in liauid form is irradiated until it solidifies, producing a film adhesive, which is then placed between, and in contact wi-th, two surfaces which are to be bonded together, and the assembly is heated to complete crosslinking of the composition. The fiLm may be provided on one face with a s~rippable backing sheet, e.g.~ of ~ 30 -a polyolefin or a polyester, or of cellulosic paper ha~ing a coating of a silicone re.lease agent. Manipulation of t:he assembly is often easier if the film has a tacky surface~ This ~ay be produced by coating the film with a substance which if7 tacky at room temperature S but which crosslinks to a hard, insoluble, infusible resin under the.conditions of heat employed ~o co~plete crosslinking of the composition. ~owever, an adequate degree of tackiness often exists without additional treatment, especi~lly if polymerisation of the composition has not proceeded too ar. Suitable ~dherends include metals such as iron, zinc, copper, nickel, and aluminium, ceramics, glass, and rubbers.
The following Examples illustrate the invention. Unless other~ise indicated, parts are by ~eight.
: Aryloxysulphoxonium salts employed in these Examples were prepared as described by Chalkley et al., loc~cit.

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- 31 ~
EXA~ELE 1 A curable composition was prepared by forming a mixture of 50 parts of 2,2-bis~4-Olycidyloxphenyl)propane, 30 parts of 3,4-epoxycyclohexylmethyl 3,4~epoxycyclohexanecarboxylate, 20 parts of 1,4-bistglycidyloxy~butane~and 2 parts o phenoxyF~-tolyl-r .tolyloxysulphoxonium hexafluorophosphate; A film 10 ym thick of this composition was drawn on tinplate and e~posed to ultraviolet irradiation by passing once through a 'Mini-cure' apparat~s (Primarc Ltd.~ containing two medium pressure mercury arc lamps ( 80 w per cm) and operating at a belt speed of 30 metres per minute. The resin cured to a hard, solvent-resistant film in less than three seconds, i.e., it withstood more than twenty rubs with a cotto~
wool swab which had bee~ soaked in acetone.
EXAMPTF! 2 A portion of the curable compositlon prepared in Example 1 was applied to a l mm thick glass plate to a thickness of 10 ~m.
Another plate of glass was placed on top of the ~irst, and ehe assembly was exposed to irradiation from a Primarc 80 w per cm medium pressure mercury arc lamp at a distance of 8 cm.
After an exposure time of 5 seconds the glass plates were permanently bonded together.
EX~MPLE 3 There were added 2 parts of phenoxy-p-tolylF~-tolyluxy-sulphoxonium hexa~luorophosphate to 100 parts~ o~ 3,4-dihydro-2H-pyran 2~ylmethyl 3,4-dihydro-2H-pyran 2-carboxylate. After the components had been mixed thoroughly~ the mixture was applied as a film 10 ~m thick to tinplate. Exposure of this for 5 seconds to the irradiation from a 80 w per cm medium pressure ~$~i3'~

- 3~ -mercury arc lamp at a distance of 8 cm produced a hard, tack-free coating.
~XA~PLE 4 .
There ~ere added 2 parts of phenoxy-p-tol~yl-p-tolyloxy-sulphoxoni~m he~a1uorophosphate to 100 parts Oe a commercially available phenol-formaldehyde resol having a P:~ ratio of 1:1.6.
Irradiation of the mixture as a 10 ~m ilm under the conditions described in Ex~mple 3 produced a hard clear fllm after 5 seconds.

,_ _ There were added 2 parts of phenoxy-p-tolyl-~tolyloxy-sulp~oxonium hexafluorophosphate to 100 parts of a commercially-available, highly condensed, urea-formaldehyde resin of urea:
formaldehyde ratio 1:1.4. Irradiation of the mixture as a 10 ~m film under the conditions described in Example 3 produced a tack-free coating after 5 seconds. ~hen the sulpho~onium salt was omitted, the resin remained tacky on irradiation and could readily be removed by wiping or with water.

~ portion of a composition comprising 2 parts of phenoxy-p- -tolyl-p=tolyloxysulphoxonium hexafluorophosphate and 100 parts of 2,2-bis~4~glycidyloxyphenyl)propane was applied as a lO ~m film to tinplate. This layer was exposed to the irradiation fro~ a 400 w high pressure metal halide ~uartz lamp (providing radiation predominantly in the 365 m~ band) at a distance of 22 cm. After 5 minutes' exposure, a slightly tacky film was produced which became tack-free on standing for a further 5 minutes. To another portion of the above mixture was added 0.5% of pyrene. Exposure of this mixture as a 10 ~m film to the same irradiation conditions .. .. .. .. , .. . . ... , .. , .. ., ~ .. ., .. , ~

~ 33 - ~
as the mixture without pyrene produced a tack-free coa~ing after 45 s~conds' irradiation. This film could not be remo~ed wlth acetone.

Irradiation o~ a maxture co~prising 2 parts of l-pheno~y-l-oxidoeetrahydrothiophenium hexafluorophosphate and 100 parts of 2,2-bis(4-glycidyloxyphenyl~2ropane as a film lO ~m thick under the conditions described in Example 2 produced a tack-free coating after 20 seconds' irradiation.

The procedure of Example 7 was repeated7 using in place of the hexafluorophosphate 2 g of l-Rhenox~ Q~idotetrahydrothiophenium tetrafluoroborate. A tack-free coat;ng was obtained after irradiation for one minute.

- -There was added 1 part of-p-chloropheno~y-p-tolylphenoxy-sulphQxonium hexafluorophosphate to I00 part~ of 3,4-epoxycyclo-h~æylmethyl 3,4-epoxycyclohexanecarboxylate. Exposure of the mixture as a 10 ~m film to irradiation under the conditians described in Example 2 produced a hard, sol~ent-resis~ant coating after less than 1 second's irradiation.

E~AMPLE 10 A mixture of 1 par~ of phenyldiphenoxysulpnoxonium hexafluorophosphate and 100 parts of 2,2-bis(4-glycidyloxyphenyl)-propane was exposed as a 10 ~m film to lrradia~ion u~der theconditions described in Example 2, producing a hard, solvent-resistant coa-ting after less than 1 second's irradia~ion.

, - 3~

E,Y~u~IPLE 11 -There was added 1 part of methyldiphenoxysulphoxonium hexafluorophosphate to 100 parts of 2,2-~is(4-glycidylox~phenyl) propane. ~ollowing the procedura of Example ~ a fully cured coating was obtained after 5 seconds~ irradiati.on.
E~A~PLE 12 Ex~mple 11 wa.s repeated, using, however, 1 part o diphenyl-phe~oxysulphoxonium heæ~fluorophosphate instead of the methyl~
diphenoxy analogue. ~ hard, cured, adherent film ~as formed after 10 seconds' exposura .
E~A*PLE 13 The procedure of Example 2 ~as followed, using a coating lO~m thick of a mixture comprising 2 parts of l-phenoxy-l-oxidotetrahydrothiophenium hexafluoroantimonate and 100 parts of 2,2-bis(4-glycidyloxyphenyl)propane. A tac~-free coating was produced after irradiation for 10 seco~ds.
EgAMPLE 14 . .
The procedure of Example 1 was repeated e~cept that the t'Mini-CY-re" apparatus was operated at a belt speed of 90 metres per minute. The resin cured to a hard, solvent-resistant coating within 19 ~econds.
To a~other portion of the above composition was added 0.5%
of pyrene. Expcsure of this mixture to the same irratiatio~
conditions produced a tac~-free coating after only 10 seconds.

- .

' ~3~

` .

A liquid composition was prepared by forming a mix~ure of 7~
parts of 2,~-bis(4-glycidyloxyphenyl)propane, 25 parts of a poly-glycidyl ether of a phenol-formaldehyde novolak having an spoxide 5 content o 5.6 equiv./kg, 4 parts of the boron trichloride-complex of n-octyldimethylamine, and 2 parts o p-chlorophenoxy-p-tolylphenoxy-sulphoxonium hexafluorophosphate. This curable CO~positiQn was used to make a prepreg by impregnating glass cloth (square weave) with it and then exposing both sides to the irradiation fro~ a 80 w per c~ medium pressure mercury arc lamp at a distance of 8 cm or 5 seconds. A 6-ply glass cloth laminate was prepared by pressing six 10 cm-square pieces of the prepreg at 120 for 1 hour at a pressure of 2.1 MN/m2. This laminate, which consisted of 58% o~
~lass, had an interla~anar shear strçngth of 448 MN/m2.

EXA~PLE 16 A solution of 1 g of the diglycidyl ether of 2,2-bis(p-hydroxy-phenyl)propane (having an epoxide content of 5.3 equiv./kg), 4 g of the tetraglycidyl ether of 1,1,2,2-te~ra(p-hydroxyphenyl)ethane (having an epoxide con~ent of 5.2 equiv./kg), 5 g of a diglycidyl ether of 2,2-bis(p-hydroxyphenyl)propane which had been advanced with a bromine-containing phenol to a so~tening point of about 50C
and had an epoxide content of 2 equiv./kg, and 0.1 g of p-chloro-phenoxy~p-tolylphenoxysulphoxonium hexafluorophosphate in 10 g of a cyclohexanone was prepared. A copper-clad laminate was coated with this composition and the solvent was allowed to evaporate, ~,"

lea~ing a film ~bout 10 ~ thick. This film was irradiatecl for lO
minutes through a negative llsing a 500 w medium pressure mercury lamp at a distance of 22 cm. Ater irradiation the ;mage was developed in toluene, washing away the unexposed areas to leave a good relief image on tne copper. The uncoated copper areas were then etched using an aqueous solution of ferric chloride ~41% w/w FeC13) at 35C, leaving the coated areas intact.

This E~ample illustrate the co-curing of an epoxide resin with ;~
a polyhydric alcohol on irradiation.
A cow~osition comprising 100 parts of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 100 parts of a commercially available styrene-allyl alcohol copolymer of hydroxyl content 3.56 equlv./kg, ~;
("RJ100" of Monsanto Chemical Co.), a~d 2 parts of r chlorophenoxy-p-tolylphe~oxysulphoxonium hexafluorophosphate was applied as a coating 10 ~m thick on ti~plate and exposed to irradiation from a medlum-pressure mercury arc lamp t80 w per cm). A tack-free flexible coating was formed in 2 seconds.

In this Example, the efficacy of catalysts of the present inven~ion in inducing photopolymerisation is compared with that of prior art catalysts.

~34~

- ~7 -Co~poSitionS were prepared from 2 parts of catalys~, 50 parts of 2,2-bis(4-glycidyloxyphenyl)propane, 30 parts o~
3,4-epoxycyclohex~lmethyl 3~4-epoxycyclohexanecarbo~ylate~ and 20 parts of 1~4-di~lycidyloxybuta~e. Films 10 ~m thick were drawn on tinplate and e~posed to ultraviolet irradia~ion by : passing twice through a "Minicure" unit ( as described in Example 1) which operated at a belt-speed of 60 metres/~inute. The irradiation ~imes needed for the coatiugs to become tack-free are given in the following Table.

Composition Catalyst time to become ~ack fr ee (seconds) _ . _ _ __ .. _.. _.. . , _ _ a phenoxy-p-tolyl-p-tolyloxy-sulphoxonium hexafluorophosphate 7 b phenyldiphen~xysulphoxonium hexafluorophosphate 13 c triphe~ylsulphoniu~ hexafluoro-phosphate 42 d 3,3'-dinitrodiphenyliodonium ~ hexafluorophosphate 45 Triphenylsulphonium hexafluorophosphate has, as stated above, been employed commercially In the photopolyme~sation of epoxide resins.
Of iodonium salts proposed in the patent literature mentioned above as also suitable for photopol}~erislng epoxide resins9 3,3'-dinitrodiphenyliodonium hexafluorophospha~e was shown, in unpublishedexperiments of the present inventors, to be one of the ~ore active~

.____,_ _ _ _ _ _ ._ ._____ _. _ . __ __ .. _ __ _ __.. _., _ _.. __.__._.. _. _ __ _ .. ~ _ _ _~_ _ ... ~ . ___ _ _.. __ .. _ .__ ~___. ... _ _ ___ . ~_ ._ _ __ _.. _ ._ .. _ _ __ _ _ _ _ .. _ _. _ ___ . __ __ . _ _ ~ _ _ _ ___ ~ ~ __ _ _ ~5~__. __ _ . _ _ . __ . -- _ ~3~

The superiority of tha sulphoxo~ium salts used in co~positions a and b o~er those of the prior art is clearly demonstrated.
EXArPL~ 19 This, aud succeeding Examples, illustrate thermal curing of compositions of this invention.
l-Pheno~y-l-oxidotetrahydrothiophenium hexafluorophosphate (2 parts) was milled with 98 parts of 2,2-bis(4-glycid~loxyphenyl)-propane. A 15 g - sa~ple of the mixture was still fluid and had not gelled af~er being hea~ed at 60C for 24 hours; 15 g - samples heated at 110C and at lS0C cured in 17 minutes and 6 mi~lutes respectively, showing the compositions to be latent (i.e., to have long storage lives in the uncured state at about room temperature but to cure rapldly on hea~ing ~t elevated temperature).

A composition eomprising 2 parts of phenyldiphenoxysulphoæonium hexafluorophosphate and 98 parts of 3,4-epoæycyclohexyl~ethyl 3,4-epo~ycyclohe~anecarboxylate was applied as a film 10 ~m thick on tinplate and heated at 120C for 15 minutes. A hard, tack-free coating was obtained.
E~AMPLE 21 A mixture or 2 parts of l-phenoxy-l-oxidotetrahydrothiophenIu~
hexafluorophosphate and 98 parts oî the phenol-formaldehyde resol employed in Example 4 was heated, as a layer 10 ym thick on tinplate, for 15 minutes a~ 110 C. A hard coa~ing, resistant to acetone, was produced.

.. ~ ~ _ ~ .. _.. _ .. , _ . _ ., ,. , _ . . _ . . . ~. , ~ .. ,, _ ,_, . .. _ . _ , .. .. _ . _ _ .. . . . _ _ .. , .. . ,_ . _, __ . _ . . .. .
.
: ' :

Claims

1. Compositions comprising a) a compound, or mixture of compounds, capable of being transformed into a higher-molecular weight material under the in-fluence of a cationic catalyst, and b) an effective amount of an aryloxysulphoxonium salt of the formula where either R6 and R7 each denote i) an alkyl group of 1 to 6 carbon atoms, which may be sub-stituted by a halogen atom and which may be interrupted in the chain by an ether oxygen atom or a sulphonyl group, ii) an aryl group of 6 to 15 carbon atoms, or iii) an aryloxy group of 6 to 15 carbon atoms, or R6 and R7 together denote a divalent group of 4 to 10 carbon atoms forming with the indicated sulphur atom a heterocyclic radical, R8 denotes an aryl group of 6 to 15 carbon atoms, M denotes an atom of a metal or metalloid, X denotes a halogen atom, and n is 4, 5, or 6 and is one more than the valency of M.

2. A composition according to claim 1, wherein R6 and R7 are each an aryl or aryloxy group of 6 to 11 carbon atoms.

3. A composition according to claim 1, wherein R6 and R7 together form a monocyclic chain composed only of carbon and hydrogen atoms.

4. A composition according to claim 1, where R8 denotes a phenyl or naphthyl group, optionally substituted by one or two alkyl or alkoxy groups of 1 to 4 carbon atoms each, by one or two nitro groups, or by one or two fluorine, chlorine or bromine atoms.

5. A composition according to claim 1, wherein M denotes an atom of boron, phosphorus, arsenic, antimony, or bismuth and X denotes fluorine or chlorine.

6. A composition according to claim 1, wherein b) is diphenylphenoxysulfoxonium hexafluorophosphate, diphenyldiphenoxy-sulfoxonium hexafluorophosphate, methyldiphenoxysulfoxonium hexafluorophosphate, p-tolylphenoxy-p-tolyloxysulfoxonium hexafluorophosphate, ethyl(ethylsulfonylmethyl)-p-tolyloxysulfoxonium hexafluorophosphate, p-chlorophenoxy-p-tolylphenoxysulfoxonium hexafluorophosphate, 1-phenoxy-1-oxidotetrahydrothiophenium hexafluo-rophosphate, 1-phenoxy-1-oxidotetrahydrothiophenium tetrafluoroborate, or 1-phenoxy-1-oxidotetrahydrothiophenium hexafluoroantimonate.

7. A composition according to claim 1, wherein a) is a 1,2-epoxide, a vinyl monomer or prepolymer, an aminoplast, or a phenoplast.

8. A composition according to claim 1, wherein a) is an epoxide resin or a resol resin made from a phenol and an aldehyde.

9. A composition according to claim 1, containing 0.1 to 7.5 parts by weight of b) per 100 parts by weight of a).

10. A composition according to claim 8, which also contains a curing amount of a latent heat-curing agent for the epoxide resin or for the resol resin.