CA1216998A

CA1216998A - Photopolymerization compositions comprising amine- substituted photosensitizers and n-heterocyclic compounds bearing an n-oxy substituent

Info

Publication number: CA1216998A
Application number: CA000376470A
Authority: CA
Inventors: Donald P. Specht; Samir Y. Farid
Original assignee: Eastman Kodak Co
Current assignee: Kodak Graphics Holding Inc
Priority date: 1980-09-10
Filing date: 1981-04-29
Publication date: 1987-01-20
Also published as: FR2489982A1; FR2489982B1; GB2083832B; DE3135399A1; JPS5783501A; GB2083832A

Abstract

PHOTOPOLYMERIZATION COMPOSITIONS COMPRISING AMINE-SUBSTITUTED
PHOTOSENITIZERS AND N-HETEROCYCLIC COMPOUNDS BEARING
AN N-OXY SUBSTITUENT

Abstract A co-initiator composition for use in an improved photopolymerization composition, element and method is dis-closed. The co-initiator comprises an amine photosensitizer and an N-heterocyclic compound containing from 5 to 14 nuclear atoms and bearing an N-oxy substiuent, such compound being responsive in the presence of the photo-excited form of said photosensitizer to form a free radical.

Description

PHOTOPOLYMERIZATION COMPOSITIONS CO~PRISING AMINE-~U~STITUTED
____ _______ __ HOTOSEN~SITIZERS AND_N-H _EROCYCLIC COMPOUNDS BEARING
AN N-OXY SUBSTITUENT
Introduction 1) Field of ~he Invention _ This invention relate~ to compo~itions used to photoinitiate the polymerization of addition-polymerizable compounds containing ethylenic unsatur~tion.

2~ _ack~round of the Invention Mixed photoinitiator~, hereinafter "co-ini~i~tor~", have been disclosed for use with addition-polymerizable mono-mers. Co-initiators usually compri~e two compounds, 9 light sensitive compound u~ually identified a6 & photosensitizer, and an activator compound. The activator is substantially insensitive to activa~ing radiation ~or the co-initi~tor com-position; but, in the presence of the excited pho~osensi-tizer, the ac~ivator is believed ~o contribute to the forma-tion of a free radical. The known classes of such 2ctivator6 include amines, ~ulfinic acid ~nd sulfinic acid esters, ~ul-fone5, ~- and B-dicarbonyl~ such as bornanedione ~nd acetylacetone, phosphines, phosphites, 6tannates, and hexa-arylbi-imidazoles.
An early exsmple of an effective co initi~t~r com-position is ~ichler's ketone as the photosensitizer, admixed with benzophenone as the activat~r, e3~ ~ as described in U.S. Patent No. 3,682,641. This composition has lcng been considered an industry standard. nore recently, a number of aromatic carbonyl compounds have been disclosed ~ useful photosensitizers with amine activator6 to ~orm co~initi-

3~ ators. Such compositions are de~cribed in Ledwith, J. Oil Col. Chem. Assoc~, 59, p. 157 and especi~l~y pp. 162-164 (1976). The carbonyls specifically identified are phenones, including cyclic ketones, ~uch as benzophenone, fluorenones, anthraquinones and anthrone~.
Although such co-initiators have been highly effee-tive, most of them are not responsive to vi~ible light, thu6 requiring UV radiation. Some co-initiators have been found to have a spectral response in the vi~ible wavelength~, ~` ~

but their speed has been so DlUCh leS5 than the speed of industry standards such as Michler's ketone and benzophenone that they have not been aceeptable.
Thus there has been a long existing need for the developmen~ of a co-initiator composi~ion that not only is responsive to visible light radiation, but also has a speed comparable to or better than the speed of conventional UY-responsive co-initiators.
3) Related Applications Commonly vwned U.S. Patent 4,366,228, issued Deoember 28, 1982,by Specht et al, entitled "Photopolymeri-zable Compositions Featuring Novel Co-Initia~ors" discloses and claims 3-ketocoumarins in combination with activators, such as amines, in general.
1~ SU~MARY OF THE INVENTION
This invention features a composition for improved photopolymeriza~ion and a method of photopolymerizati~n using co-initiator compositions containing an amine photosensitizer and an activator, as described hereinafter. The composition is effective to provide increased photopolymeriz~tion light sensitivity, i.e., speed, compared to the speeds obtained when using these ac~ivators with comparable nOn-amine photo-sensitizers.
More specifically, there is provided a composition comprising an amine photosensitizer and an N-heterocyclic compound containing from 5 to 14 nuclear atoms and bearing an N-oxy substituent, said compound being responsive in the presence of the photo-excited form of the photosensitizer tG
form a free radical.
Such a composi~ion, when added to an addition-poly-merizable compound, act~ as a co-initiator to provide an improved photopolymerizable composition and a photopolymeri-zation method having improved speeds.
Other features of the invention will become apparent upon reference to the following "Description o the Preferred Embodiments".
Description of the Preferred ~mbodiments -The term "addition-polymerizable" or "addition ; -, ,, .C~

polymeriza~ion" refers to the chain reac~ion thst occur6 wherein 8 single photon cause~ the addition of more ~han one recurring unit to a growing polymer, in contras~ with single-event crosslinking wherein a single photon creates genera]ly only one crosslink event. Without being limited to speciflc chanisms, addition polymerization achievable with this in-vention preferably involves the production of re2 radicals.
The ~erm "photosensitizer" broadly includes both materials which are operable ~o 6ensitize single-even~ crosslinking of photopolymers as well as tho~e, such as ~he present "co-ini-tiator compositions"9 which sensitize only addi~ion polymeri-zation of simple compounds or polymer~.
As used herein, with regard to the photosensitizers, "carbocyclic", "aryll', "aromaticl', "heterocyclic", "alkyl", and "alkoxy" include substituted as well as unsubstituted carbocyclic, aryl, aromatic, heterocyclic, ~lkyl snd ~lkoxy, respectively, unless o$herwise specified. Suitable sub-stituents include alkoxy containing from 1 to about 5 c~rbon atoms, such as methoxy, ethoxy, propo8y, butoxy, ~nd the ~0 like; sulfonates, such ~6 fluorosulfonate and the like;
cyano; dialkylamino such as dimethylamino, diethylamino ~od the like; halo such 85 chloro, bromo and the like; nitro;
hydroxy; and alkyl of from 1 to about 5 carbon ~tom6, ~ch methyl, ethyl, propyl and ~he like. Also, alkenyl includes aryl- or alkyl-substituted al~enyl, for example, styryl, cinnamylidenemethyl, 2-(2-thienyl~vinyl and the like.
Th;s invention is based upon the discovery that the N-heterocyclic compounds hereinafter described will functa~n as activators in a co-initiator composition. Furthermore, it has been discovered that when used with Pmine photo-sensitizers, these compounds produce unexpectedly high speed~
compared to speeds achieved when they are used with non-amine photosensitizers. Thus, the photopolymerizable composition of the invention comprises an addition-polymerizable compound containing ethylenic unsaturation, and a co-initiator com-position comprising an admixture o~ an amine photosensitizer such as an amine substituted 3-ketocoumarin, and a photo-polymerization ac~ivator as se~ forth in the Summary.

-4--As used herein, and in keeping with standard nomen-claeure practice, amines such as amine photosensitizers include heterocyclic compounds containing an uncharged nitrogen attached to three separate atoms, and do not include, for example, pyridine or pyridinium compound~.
Any compound containing ethylenic unsaturation which i6 addition polymerizable is useful in the invention. Pre-ferred are simple compounds containin~ ethylenic unsatura~
tion, as well as polymers having end ~roups or pendant groups containing ethylenic unsaturation. For example, the phrase "addition-polymerizable compounds" includes polymers having recurrin~ units with the structure OC CT~C~
..
o wherein R is any polymer backbone-forming grOup and T is hydro~en or methylO
Examples of useful addition-polymerizable compounds containing ethylenic unsaturation include monomeric acrylates, acrylamides, methacrylates, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, N-vinyl compounds, styrenes and crotonates. ~any examples of each of these classes are well known, e.g., as listed in British Patent Specification No. 1,534,137, published November 29, 1978, Still other useful addition-polymerizable compounds are listed in V.S. Pat. No. 3,759~807, issued on September 18, 1973, such 8S acrylonitrile and the like.
Hi~hly preferred as addition-polymerizable compounds are the acrylate compounds as a class. Acrylates for years have been used in photopolymerization and a wide variety have been identified in the literature. Particularly useful examples include alkyl acrylate~ con~aining from 1 ~o abou~
10 and most preferably 1 to about 5 carbon atoms in the alkyl portion, such as methyl acrylate, ethyl methacrylate and the like; pentaerythritol tri and tetraacrylates and meth-acrylates; esters of polyols including glycol diacrylates and ' ' dimethacrylates, such ~ tripropylene ~lycol ~iacrylates, tetraethylene glycol diacrylate, triethylene glycol dimeth-acrylate, and the like; ~lkanediol di~crylates ~uch ~s hexanediol diacrylates and the like; polyether sliacryl~tes ~uch as that obtainable from UCB, a divi6ion of Chimique Chaussee de Charleroi, Brussels, Bel~ium under the trade nsme "Ebecryl 210"; and mixtures of the above. Particularly pre-ferred are diacrylate~ and mixtures of te~raacrylste~ and tetramethacrylaees .
Of the two components of the co-initiator com-position, the one which preferably predominates ~s the light-absorbing component is the photosensitizer. That i~, pref-erably greater than about 50% of the activating radiationD
and in some case6, all of ~he radiation, is absorbed by the photosensitizer. Examples of useful amine photosen~itizer~
include those having as substituents on an aromatic or heterocyclic rin~, dialkylamino containin~ from 1 to 5 carbon atoms, for example, dimethylamino, diethylamino, and the like; piperidinyl; N-pyrrolidinyl; morpholino and the like, or substituen~s that together form as a fu~ed ring on ~aid aromatic or heterocyclic rin~, ,^
~ N'~
~
Preferred amine photosensitizer~ are carbonyl-contsining com-pounds with significant electron-donating ~ubstituents, and high extinction coefficient. ~ost preferred are keto-coumarins, and particularly ~ho6e having the formul~

3~wherein Rl i~ alkyl or alkenyl having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, l-butenyl and thc like; or a carbocyclic or heterocyclic group having 5 to ?0 ~Z~

carbon and hetero nuclear ~toms; and R2D R3 ~nd R4 ~re the same or different and are each hydro~en; dialkyl~mino containin~ from 1 to &bout 5 carbon atoms ~n the alkyl portion, such as dimethylamino, dîe~hylamino, flnd the lik~;
N-pyrrolidinyl; piperidinyl; ~nd morphol~no; provided th~t ~t least one of R2, R3, snd R4 is an ~mine; or R2-R4, when taken together, comprise the non-metallic atoms th t form, as a fused substituent on the coum~rin rin~, the rings ~ -~,J O
Examples of heterocyclic groups for Rl include benzofuryl, thienyl, furyl, pyridyl and the like~ 3-Coumarinyl groups 15 are additional preferred examples of such he~erocyclic groups.
Also highly preferred are amine-substi~uted 3-keto-coumarins having polar moieties or substituents, ~uch ~s ionic moieties, and especially ~hose contsining water- andlor alcohol-soluble moieties. Useful example~ include, attached 20 to the keto group in the 3-po~ition, heterocyclic onium salt groups, e.g., pyridinium salt, imidazolium salts ~nd the like, and groups containin~ 601ubilizing substituents such as a carboxylate salt, sulfonate 6alt, quaternized N>N,N-trisub-stituted amino, e.~,, an N-phenylene-N,N,N-trimethylaMmonium 25 chloride, ~nd the like. Examples of ~uch sub~tituent~
attached to the coumarin rings include groups containing sub-stituents such ~s carboxy, earboxyslkyl, c~rboxyaryl, ~ulfo, sulfoalkyl, sulfoaryl and the monovalent metal or ammonium (including tetraor~anoammonium~ salts of 6aid carboxy ~nd 30 sulfo substituents, and quaternary ammonium ~alt groups ~uch 8 S are noted in the previous sentence.
The 3-ketocoumarins of this invention ~re particu-larly useful with broad spectral light ~ources ~uch ~s xenon and halogen lamps, or with limited wavelength ~ources cuch a~
35 mercury lamps having emission spectra st 366, 405, 43S and 547 nm, or lasers emitting at 457 nm, 48B nm or 515 nm.
Other examples of useful amine photosensitizer~
include thiazoline and selenazoline photosensitizers of the ~ 7--type described in U.S. Patent No. 4,062,686.
The following is a partial list of amine photo-sensitizer.s that are hi~hly useful a~ one of the componen~s of the co-initiator compo~ition of the invention:
3-(2-benzo~uroyl)-7-diethylaminocoumarin;
3-(2-benzofuroyl)-7-(1 pyrrolidinyl)coumarin;
7-dimethylamino-3-thenoylcoumarin;
3-(o-methoxybenzoyl)-7-diethylaminocoumarin;
3-(p-dimethylaminobenzoyl)-7-diethylaminocoumarin;
3,3'-carbonylbis(7-diethylaminocoumarin);
7-diethylamino-3-[3 (2-thienyl)acryloyl]coumarin;
3~ furoyl)-7-diethylaminocoumarin;
3-(p-diethylaminocinnamoyl)-7-diethylaminocoumarin;
3 (4-morpholinocinnamoyl~-7 diethylaminocoumarin;
9-(7-diethylamino-3-coumarinoyl)-1,2,4,5-tetrahydro-3H,6H,lOH[l]benzopyrano[6,7,8-i,j]quinolizine-10-one; which has the ~tructure:

N ~ O O ~ ~
.J N~e~5)~2 ; 9-(7-di-n-propylamino-3-coumarinoyl)-1,2,4,5 tetrahydro-3H,6H,lOH[l]benzopyrano[6,7,8-i,j]quinolizine-10-one;
9-(4-diethylaminocinnamoyl)-1,2,4,5-tetrahydro-3H,6H, lOH[l]benzopyrano~6,7,8-i,j]guinolizine-10-one;
7-dime~hylamino-3-[3-(2-thienyl)acryloyl]coumarin;
9-[3-(2-thienyl)acryloyl]-1,2,4,5-tetrahydro-3H,6H,lOH[l~-3 benzopyrano[6,7,8-i,j~quinolizine-10-one;
7-diethylamino-3-~4-dimethylaminocinnamylideneacetyl~-coumarin;
9-[3-(9-julolidyl)acryloyl]-1,2,4,5 tetrahydro-3H,6H,lOH[l]benzopyrano[6,7,8-i,j]quinolizine-10-one;
3-cinnamoyl-7-diethylaminocoumarin;
7-diethylamino-3-~4-morpholinocinnamoyl)coumarin;
7-diethylamino-3-(4-ethoxycinnamoyl)coumarin;
3-(4-bromocinnamoyl)-7-diethylsminocoumarin;

7-diethylamino-3-[3-(4~methoxy-1-naphthyl)acryloyl]-coumarin;
7 diethylamino-3-cinnamylideneacetylcoumarin;
9-[3-(2-thienyl)acryloyl~-1,2,4,5-te~rahydro-3~,6H,lOH-[l]benzopyrano[6,7,8-i,j]quinolizine-10-one;
7-diethylamino-3-(3-fluorosulfonylbenzoyl)coumarin;
3-(4-cyanobenzoyl)-7-diethylaminocoumarin;
3-benzoyl-7-dimethylaminocoumarin;
3-benzoyl-7-diethylaminocoumarin;
3-benzoyl-7-pyrrolidinylcoumarin;
3-(4-iodobenzoyl)-7-dimethylaminocoumarin;
3-(4-iodobenzoyl)-7-diethylaminocoumarin;
7-dimethylamino-3-(4-dimethylaminobenzoyl)coumarin;
7-diethylamino-3-(4-nitrobenzoyl~coumarin;
7-diethylamino~3-(2-thenoyl)coumarin;
7-pyrrolidinyl-3-(2-thenoyl)coumarin;
7-diethylamino-3-(2-furoyl)coumarin, 7-diethylamino-3-(2-methoxybenzoyl3coumarin;
2-(p-pyrrolidinylbenzylidene)-1,3-indanedione;
Michler's ketone;
2-[bis(2-furoyl)methylene]-1-methylnaphtho[1,2-d~thiazoline;
2-[(2-thenoyl)methylene3-1-methylnaphtho[1,2-d]thiazoline;
2-benzoylmethylene-1-ethylnaphtho[1,2-d]thiazoline;
2-[bis(2-furoyl)methylene~-2-methylbenzothiazoline;
2,5-bis(4-diethylaminobenzylidene~cyclopentanone;
4'-dimethylaminochalcone; and 2-(2-thenoylmethylene)-3-methylnaphtho[2,1-d]thiazoline.
A mixture of two or more of any of the above photo-sensitizers is also useful.
Conventional methods are used to prepare ~hese photosensitizers. For example, useful preparations of keto-coumarins are disclosed in the aforesaid U.S. Patent No.
4,147,552.
In accordance with one aspect of the invention, the free-radical photopolymerization activator used with the photosensitizer described above comprises an N-heterocyclic ~ compound of the type noted in t~e Summary. Useful examples include those having a formula selected from the following s b) ~1 ~3 1 ~6 1~6 ~ 3 oR6 wherein R5 is alkyl of 1 to 3 oarbon atom~, such as methyl, ethyl and the like; or ~ryl of from 6 ~o 10 carbon ~toms, such 8S phenyl ~nd naphthyl; R6 is slkyl of from 1 to 3 20 carbon atoms ~uch as methyl, ethyl, propyl, ~nd isopropyl;
snd ~ is an anion such ~s fluorobor~te.
Useful examples for these ~tructures include N-methoxy-4-phenylpyridinium fluoroborate and N-methoxy-4-methylpyridinium fluoroborate; N,N,0-triacylhydr~xylsmines con~aining an imide ring, for example the compound6 li6ted in col. 5 of ~.S. Patent No. 3,359,109, snd p2rticularly ; N-benzoyloxy phthalimides ~uch as N-~2,4-dichlorobenzoyloxy3-phthalimide and N-(cyanobenzoyloxy)phthalimide; N-~henoyloxy~
phthalimide; and N-benzenesulfonyloxyphthalimide ~nd 6ub-3o stituted equivalent~ such as N (4-chlorobenzenesulfonyloxy)-., 1,8-naphthalimide; and N-alkoxy N-heterocyclic compounds ,^, described in UOS. Patent No. 3,615,568. Specific ex~mples of the compounds of said U.S. P~tent No. 3~615,568 include '~ 2 ~ -~nilinovinyl-l-methoxypyr;dinium p-toluenesulfonate;
1-methoxy-2-methylpyridinium p-toluenesulfonate;
l-methoxy-4-methylpyridinium p-toluene~ulfonate;
anhydro-2-methyl-1-(3 ~ulfopropoxy)pyridinium hydroxide;
l-ethoxy-2-methylpyridinium tetrafluoroborate;

~10 -l-benzyloxy-2-~ethylpyridinium bromide;
l-ethoxy-2-methylquinolinium tetra1uoroborate;
l,l'-ethylenedioxybispyridinium dibrsmide;
l-acetoxy-2-(4-dimethylaminostyryl)pyridinium perchlorate;
1-benzoyloxy-2-(4-dimethylflminostyryl)pyridinium perchlorflte;
-1,3-dimethyl-5-[(1-methoxy-2(1H)-pyridylidene)ethylidene~
thiobarbituric flcid;
3-ethyl-5-[(l-methoxy-2(lH)-pyridylidene)e~hylidene3rhodanine;
1~3-diethyl-5-[(l-methoxy-2~lH)-pyridylidene)ethylidene~
barbituric acid;
2-(3,3-dicyanoalkylidene)-1methoxy-1,2-dihydropyridine;
2-[(1-methoxy-2(1H)-pyridylidene)-ethylidenelbenzo[b]-thio-phen-3(2H)-one-l,l-dioxide;
3-cyano-5-[(1-methoxy-2~1H)-pyridylidene)ethylidene3-4-phenyl-2~5H)-furanone;
N-ethoxy-2-picolinium iodide;
; N-ethoxy-2-picolinium hexafluorophosphate; and N-methoxy-2-snilinovinylpyridinium paratoluenesulfonate.
Still other examples of useful N-hetetocyclic ~cti vators are the ~ubstantially colorless M-alkoxy heterocyclic compounds described in U.S. Patent No. Re 27,925 and par-~icularly ~he following compounds selected rom Table I
- thereof:
l-methoxy-2-methylpyridinium p-toluenesulfonate;
1-methoxy-2-methylpyridinium p-toluenesulfonaee;
anhydro-2-me~hyl~ 3-sulfopropoxy3pyridinium hydroxide;
l-ethoxy-2-methylpyridinium tetrsfluoroborate;
l-benzyloxy-2-methylpyridinium bromide borate;
l-ethoxy-2-methylquinolinium tetrafluoroborate;
. 30 l,l'-ethylenedioxybispyridinium dibromide;
- l,l'-trimethylenedioxybispyridinium dibromide;
~ 1,1'-tetramethylenedioxybis(2-methylpyridinium)dibromide;
- 1,1'-tetramethylenedioxybis(4-methylpyridinium)dibromide;
~t l,l'-tetramethylenedioxybispyridinium dibromide;
l,l'-pentamethylenedioxybispyridinium dibromide;
l-acetoxy-2-(4-dimethylaminostyryl)pyridinium perchlorate; and l-benzoyloxy-2-(4-dimethylamino~tyryl)pyridinium perchlorate.
The amount of photosensitizer used does not appear ~6~6~
-~1 to be critical~ Preferably ~t i~ present in the range of about .0002 to about 0.2 mmole per gram of dry solids con-tent. Actual preferred examples tested were in the range of from ~bout 0.005 to abnut 0~015 mmole per gr~m.
Of course, a 6ufficient amoun~ of the activ~tor mu~t be present to allow interaction between the excited photo-sensitizer and the activ~tor. Preferably, the amount of interaction, and therefore the amount of activator required, is that which gives a respectable speed, which means herein, a speed, when exposed to a medium pressure Hg lamp, that is at least about one-fifth that obtained for the same composition except that the co-initiator i~ Michler'~ ketone and benzophenone in a 1 tv B mole ratio (0.1 millimole to 0.8 millimole). The activator is ~enerally present in amounts between about 0.005 and about 2.0 mmole per gram of dry solids, and preferably between sbout 0.05 and ~bout 0.2.
Most preferably, i~ is present in an amount tha~ i6 ten times the amount of the photosensitizer.
The unexpectednes~ of the ~peeds produced by the 20 activator6 of this invention iB best understood by comparing their performance, when used with an amine photosensitizer, ~o their performance when used with a comparable non-~mine photosensitizer. In fact, in many instances the ~peeds pro-duced in the latter case are 60 610w that it might be ques 25 tioned whether the N-heterocyclic compounds of this invention can even be considered to be useful activators when used wieh ~uch non-amine photosensitizers. Yet, the ~peeds obtained with amine photosensitizers have been found in many cases to be much superior to the speeds produced in the ~ame com-30 position when using the co-initiator ~ichler'~ ketone ~nd r benzophenone, long considered to be an industry ~tandard.
~ Still further, this behavior of the N heterocyclic compounds, ; when used with ~mine photosensitizers, ;6 even more striking when it is realized that ~ome other clas6es of activators 35 useful in co-initiator compositions tend to give better 6peed results when used with non-~mine photosensitizer6, than with comparable amine photosensitizers.
~ In certain uses, ~ binder is optionally added to the composition. The polymerizable compound is generally present from ~bout 5 to about 100 weight percent of the mix~ure of that compound and the binder.
The dry thickness of the composition ~ ~ariable.
When applied to a support, the dry thicknes~ i6 gener311y

5 between aboue 1 micron and sbout 1 mm, and i~ prefer~bly b~tween ~bout 20 and about 120 microns. The composition of the invention i~ applied to a ~upport by a wide variety of techniques such as spray-coating, whirler-coatin~, curtain-coating? roll-coating, ~nd the like, ~11 of which are ~.on-10 ventional.
A coating of the compo6ition i~ carrie~ out by selectin~ any suitable ~olven~ for preparing a dope of the composition to be coated on a support. Useful examples include dichloromethane, acetone, benzene, ~lcohols, ether6, 15 toluene, and the like. The choice will depend, of cour6e, upon the polymerizable compound ~nd the activator selected as well as upon other components that mi~ht be included, e.g., polymeric binders r The support for the composition, if nece sary or 20 desired, includes 8 variety of known 6upports, including photo~raphic ~upports. Preferred useful supports include polymeric film, wood fiber- e.~., paper, ~etallic sheet ~nd foil, ~lass ~nd ceramic ~upporting element~. Such 6upport6 are often provided with one or more subbing layer6 to enh~nce 25 the adhe6ive, ~nti6ta~ic, dimensional, abr~siv2, hardne~, frictional, and/or other properties of the ~upport 6urface as desired.
. Example6 of useful polymeric film 6upports sre films .~ of cellulo~e nitrate and cellulose ester~ ~uch a~ cellulo6e -~ 3 triacetate and diacetste, polystyrene, polyamides, homo- and r copolymers of vinyl chloride, poly(vinyl acetal), poly-~, carbonate, homo- and copolymer of olefins, such a8 poly-ethylene and polypropylene, and polyesters of dibasic !' aromatic carboxylic acid~ with divalent ~lcohols, such ~6 35 poly(ethylene terephthalste).
Useful paper supports are those which sre parti~lly acetylated or coated with baryta ~nd/or a polyolefin, par-ticularly a polymer of an ~-olefin containing 2 to 10 carbon stoms, ~uch 8S polyethylene, polypropylene, copolymers @~

of ethylene and propylene and the like.
Further details of useful supports will be found in Research_Disclosure, Vol. 176, Publication No. 17643, Para.
XVII (Dec. 1978), published by Industrisl Opportunities L~d., Ho~ewell, Havant, Hampshire, PO9 lEF, United Kin~dom, The compositions of ~he invention have utility in a wide variety of applications. For example, one embodiment of ehe invention is an element comprising a support bearing the photopolymerizable composition of the invention, preferably along with a polymeric binder. Particularly preferred sup-ports are metallic foil such as copper. Such an element is useful in microelectronics and photofabrication, wherein the foil is etched into desired configurations. In such a use, the photopolymerizable composition of the invention, together with a compatible binder, acts as a negative resist that i5 exposed and developed to form, for example, annular-shaped spacers for beam leads that are etched out of the metal foil using a positive-working resist for the beam lead portions of the metal. Certain examples of such a use are described in 20 U.S. Patent No. 3,795,043 issued on March 5, 1974. As used herein, a binder is "compatible" if it forms with the co-initiator composition a single-phase coating, when dried, and does not interfere with the photoaddition polymerization cap-ability of the composition.
When binders are desired as an additional component, they are preferably selected from addition polymers, e.g., homopolymers, copolymers and terpolymers of vinyl, especially acrylic monomers; or condensation polymers, e.g., polyesters, polyamides and polysulfonamides, mixtures of the above, and the like. Such binders are not needed, however, even in resist applications, when the polymerizable compound and co-initiator composition are film-forming in and of them-selves, e.g., when the polymerizable compound is of a relatively high molecular weight such as an oligomer or a polymer.
Plasticizers are optionally included in the photo-,,. ~
,, polymerizable composi~ions of the invention for ~pecific pur-poses or applications. However~ in ~ome C8SeS bet~er ~peed~
are obtained by omitting them.
Additionally, the photopolymerizable compo~i~ions cf the invention ~re u~eful to manufActure polymeric coating~ ~
and other articles of manufacture that are uniformly, rather than ima~ewise, exposed to activating radiation.
Examples The following examples further ill~tra~e the nature of the invention.
Examples 1-3 To demon6trate the unexpected speed result6 noted above for the co-initiator composieion of the present inven-tion containing amine photosen~itizer~ ~nd the N-heterocyclic activator~ descr;bed above, compared to the relative per-formance of these activators when used with non-amine photo 6ensitlzers, dopes were prepared using the followin~ com-position:
ketocoumarin of Table I 0~08 millimole (m~) activator of Table I 0.8 m~
(in 2 ml of ethanol or dichloromethane, for N-phenylglycine or ethyl p-dimethylaminoben~oa~e, respectively~
This was added to 13 ml of a dope compri~ing:
Pentaerythritol ~etraacrylate 45.0 g Pentaerythritol tetramethacrylate 60.0 g t-Butyl 4-hydroxy-5-methyl- 1.05 g ~ phenyl ~ulfide (~tabilizer) '.'t Poly(methyl methacrylate-co- 120 g 3 butyl me~hacrylate-co~
acrylic acid) (34:63:3) ~vail-able from Rohm & Haas under the trademark "Acryloid B48N"
Poly(methyl meehacrylate) avail- 120 g able from Rohm & Haas under the trademark "Acryloid A-ll"
Dibutyl phthalate (plasticizer) 50.4 g Dichloromethane 601vent 535.2 g In the examples using ~-phenylglycine (NPG), the NPG
was purified prior to making the composition by recrystalliz-ing it from toluene.
Each dope solution was placed in an ultrasonic bath as an aid to attaining complete solution. The solution was coated at a wet thickness of 300 microns on a copper ~upport on a coating block maintained at 18C~ After 5 minutes, the temperature of the block was raised to 66C for 10 minutes.
The coa~ing was then placed in an oven at 90C for 10 minutes.
Test strips were exposed for 180 seconds through a KodakT'f T-14 step table~ and a polypropylene cover sheet using a "Colight Xposer I"~M device, which uses a 400W medium-pressure mercury lamp. The exposed test strips were developed for 55 seconds in a processing tank containing l,l,l-trichloro 15 ethane, rinsed for 5 seconds with fresh 1,191~trichloro-ethane, rinsed with water9 and dried.
All speeds were determined by examining the last solid step produced after development, compared to such a step produced by a control formulation. The control ini-20 tially was the preceding formulation, except using 0.1 mmoleMichler's ketone and 0.8 mmole of benzophenone as the co-initiator. This control in turn was verified by comparing a large number of replicates of the control against the speed of e~hyl p-dimethylaminobenzoate (DMAB) used in admixture 2~ with 3,3'-carbonylbis(5,7-di-n propoxycoumarin), hereinafter Control B', to determine that the speed of Con~rol B' relative to Michler's ketone benæophenone is 3.5. There-after, all tests were made by comparing the developed results against the speed of Control B' rather than that of Michler's 3 ketone-benzophenone, for the reason that comparisons are dif-ficult when the relative speed is much faster than that of the control that is being used. The final speed results are stated in Table I compared to ~ichler's ketone-benzophenone as the co-initiator because the latter composition is usually 35 regarded as the conventional industry standard.
Thus, in contrast for example to D~AB that performs best with an alkoxy-substituted photosensitizer ~compare Con-~rol A and Example 1), the activators of this invention per-: -, . . ~

form best when used with amine photo6ensitizer~. This behavior is totally unexpected in light of the fact that the speed obtained when used with alkoxy~substitu~ed photo-sensitizers would hardly 6uggest thst these N-heterocycliC
5 compounds will function as significant act:lva~ors in any com-bination.

3o .

o,~
I
I
~:t ~ ~
~ ~ o X ~o o .c ~ ~
o C ~D I
E; ~ E ~~ o c~ _~ ~
. . o Z P~-~ ~ o C~l ~o ~ ~;
~ C
_, g F.
W ._ X ~
* ~ ~ C: ~o ~ o a~ ~ c~
o C~
P~ ~ U ~: r C~
* ~ ~ X O O
u~ ~ ~ ~ ~ ~ ~ Z ~7 Z ~ Q) O
O
~: ~ ;Q
J- ~ ~-r~
3 , J~ ~O
~~ tJ
V~ ~ C
,Q ~ ~ ~ ~ O
ca ~ ~ ~C~ ~c: co ~ ss~ ~C d E-~ ~.c ~4 . . . . . ~D J~
~ tn v ~~U~ ~ In ~ ~ C

QO
. I
' :~
O
. . . U
O ~ ~ Z ~
ao X ~ I C
I' V ~ O I ~ ~ O ~ ~ t-- ~ O
NE;~ O r~ ` Ei ~ I C
_ ~ O :~ 6 ~ ~--I
Ll ~C p. i~ CJ t~
rl I O I I O 0 ~1 ~ O O
G I ~ r ~ O X
~) O~ 1 0 Ei ~ IJ~ O~
~o ~W U a 1~ V ~ tD ~U Ei O ~ ! ~ O
v5) 6 O~ ) ~ ~ ~ ~ t- ~i I ~ `~ Ei ~
I ^ It~ O I J~ rl I V
~4.J
'P a) V ~ ~ ~
l~ C
_~ ~ ~ ~ ~ ~ C~
_~ O ;~ o ~ ~ m - 3~ ~ C' ~ 1~' 6 a~
Ei ~ ~ Ei 6 ~ Ei L~ O O O X

_x mples 4-20 The proced~re of Example 1 wa6 repeated, except that the photosensitizer and the activator were ~elected a~ indi cated in Table II, at 0.08 mM and 0O8 mM, respectively.

-2~

3o Table II
Example Photosensitizer Activator Relative Speed 4 3-(p-dimethylamino- N-methoxy-4- 1.5 benzoyl)-7-diethyl- phenylpyridinium aminocoumarin fluoroborate 3,3'-carbonylbis- N-methoxy-4- 0.8 (7-diethylamino- methylpyridinium coumarin) fluoroborate 10 ,~ ? ~ .

6 R=C2Hs N-methoxy-4- 1.6 Ar=phenyl phenylpyridinium fluoroborate

7 R=CH3, N methoxy-4- 1.7 Ar=2-benzo~uroyl phenylpyridinium fluoroborate

8 R=C2H5 " 2.1 Ar=2-thienyl

9 R=CH3 1.6 Ar=p-methoxy-phenyl R=C2Hs, Ar= 1.6 p-thiomethoxyphenyl 11 R=C2H5~ Ar=
naphthyl 12 2-(2-thenoyl- 1.8 methylene) 3-methyl-naphtho-2,1-d-thiazoline 13 4'-dimethylchalcone " 0.38 14 3-(2-benzofurvyl)- " 3.7 7-diethylamino-coumarin 3-(2-benzofuroyl)-7- 4.3 (l-pyrrolidinyl~
coumarin 16 7-diethylamino-3- " 2.6 (4-diethylamino-3 cinnamoyl)coumarin 17 Michler's ketone " 1.2 18 2-[bis(2-furoyl)- " 1.9 methylene]-l-methyl-naphtho[l,~-d]-thiazoline 19 2-(p-pyrrolidinyl- 0.77 benzylidene)-1,3-indanedione 2,5-bis(4-diethyl- " 103 aminobenzylidene) cyclopentanone Table II _on~inued) Rela~iVe Example Photosensitizer Activ~tor Speed Control 2,5-(bis(4-ethoxy- N-methoxy-4- 0.1 D benzylidene)cyclo- phenylpyridinium pentanone fl~orobor~te 1 Compared to a ~peed of 1.0 or ~ichler'~ ketone plus benzo--phenone.
A comparison of Example 20 against Control D lndicate~
again the importance of the photosensitiæer being an amine photose~sit~zer.

2~

3o ~21-Exam les 21-23 - Other Act~vator~
P _ _ The procedure of Ex~mple 1 wa~ repeated, except th~t the photo~ensitizer and the ~ctivator were ~elected ~ indi 5 c~ted in Table III, at 0.08 mM and 0.8 mM, respectively.

Rel~tive Example Photosensitizer Ac~ivstor Speedl_ Control 3-(2-benzofuroyl~-7- N-(4-n;trobenzoyl~ none E diethylaminocoumarin oxy)phth~limide

10 21 3-(2-benzofuroyl)~7- N-(2,4-dichloro- 0.45 diethylaminocoumarin benzoyloxy)phthal-imide 22 3-(2-benzofuroyl)~7- N-~p-cyanobenzoyl0.45 diethylaminocoumarin oxy)phthalimide 23 " N-thenoyloxy- 0.45 phthalimide ' Compared to a speed of 1.0 for Michler'~ ketone plu~ benzo-phenone.
Control E demonstrated thst not ~11 N-heterocyclic compound~
bearing an N-oxy substituent will respond to ~n excited photosen~itizer to produce a free radical or to provide ~
6peed when used with ~n addieion-polymerizable composition, that is at least ~bout 1/5 that obtained u~in~ ~ichler'~
ketone and benzophenone as the co-;niti~tor.
I'he invention has been described in detail with p~r-ticular reference to preferred embodiment~ thereof, but it will be understood that variations and modifications c~n be 3o effected within the 6pirit and ~cope of the invention.

3~

Claims

WHAT IS CLAIMED IS:

1. A composition comprising a photosensitizer com-prising a coumarin having an absorptive maximum between about 350 and about 550 nm, and the structure wherein R1 is selected from the group consisting of alkyl or alkenyl having 1 to 12 carbon atoms and a carbocyclic, heterocyclic, or quaternized heterocyclic group having 5 to 20 carbon and hetero nuclear atoms;
and R2, R3, and R4 are the same or different and are hydrogen, dialkylamino containing from 1 to 5 carbon atoms in the alkyl portion, N-pyrrolidinyl, piperidinyl, morpholino, or when taken together, R2, R3 and R4 com-prise the non-metallic atoms that form as a fused substituent on the coumarin ring, provided that at least one of R2, R3, and R4 is an amine, and an N-heterocyclic compound containing from to 14 nuclear atoms and bearing an N-oxy substituent, said compound being a) responsive in the presence of the photo-excited form of said photosensitizer to form a free radical, and b) capable, when coated and dried together with an addition-polymerizable compound to form a layer, and then exposed to a medium pressure mercury light source, of providing a speed that is at least about one-fifth that of the same layer coated, dried and exposed identically except that Michler's ketone and benzophenone in a mole ratio of 1 to 8 is used in lieu of said photosensitizer and said N-heterocyclic compound.

2. In a photopolymerizable composition comprising an addition-polymerizable compound and a co-initiator com-position comprising a photosensitizer comprising a coumarin having an absorptive maximum between about 350 and about 550 nm, and the structure wherein R1 is selected from the group consisting of alkyl or alkenyl having 1 to 12 carbon atoms and a carbocyclic, heterocyclic, or quaternized heterocyclic group having 5 to 20 carbon and hetero nuclear atoms;
and R2, R3, and R4 are the same or different and are hydrogen, dialkylamino containing from 1 to 5 carbon atoms in the alkyl portion, N-pyrrolidinyl, piperidinyl, morpholino, or when taken together, R2, R3 and R4 com-prise the non-metallic atoms that form as a fused substituent on the coumarin ring, provided that at least one of R2, R3, and R4 is an amine, and a photorolymerization activator responsive in the presence of the photo-excited form of said photo-sensitizer to form a free radical;
the improvement wherein said activator is an N-heterocyclic compound containing from 5 to 14 nuclear atoms and bearing an N-oxy substituent, said N-heterocyclic com-pound and said photosensitizer being present in an amount sufficient to provide to said composition in a coated and dried state, and when exposed to a medium pressure mercury light source, a speed that is at least about one-fifth that of the same composition coated, dried and exposed identically except that the co-initiator consists of Michler's ketone and benzophenone in a mole ratio of 1 to 8 in lieu of said photosensitizer and said N-heterocyclic compound.

3. A composition as defined in claim 1 or 2, wherein said N-heterocyclic compound is an N-alkoxyphenyl pyridinium salt.

4. A composition as defined in claim 1 or 2, wherein said N-heterocyclic compound is N-methoxy-4-phenyl pyridinium fluoroborate.

5. A composition as defined in claim 1 or 2, wherein said N-heterocyclic compound is an N,N-0-triacyl-hydroxylamine containing an imide ring.

6. A composition as defined in claim 1 Or 2, wherein said N-heterocyclic compound is an N-benzoyloxy-phthalimide.

7. A composition as defined in claim 1 or 2, wherein said coumarin includes a polar substituent, whereby said coumarin is soluble in polar solvents.

8. A composition as defined in claim 1 or 2, wherein said photosensitizer is selected from the group con-sisting of 3-(2-benzofuroyl)-7-diethylsminocoumarin;
3-(2-benzofuroyl)-7-(1-pyrrolidinyl)coumarin;
7-dimethylamino-3-thenoylcoumarin;
3-benzoyl-7-diethylaminocoumarin;
3-(o-methoxybenzoyl)-7-diethylaminocoumarin;
3-(p-dimethylaminobenzoyl)-7-diethylaminocoumarin;
3,3'-carbonylbis(7-diethylaminocoumarin);
7-diethylamino-3-[3-(2-thienyl)acryloyl]coumarin;
3-(2-furoyl)-7-diethylaminocoumarin;
3-(p-diethylaminocinnamoyl)-7-diethylaminocoumarin;
3-(4-morpholinocinnamoyl)-7-diethylaminocoumarin;
9-(7-diethylamino-3-coumarinoyl)-1,2,4,5-tetrahydro-3H,6H,10H[1]benzopyrano[6,7,8 i,j]quinolizine-10-one;
9-(7-di-n-propylamino-3-coumarinoyl)-1,2,4,5-tetrahydro-3H,6H, 10H[l]benzopyrano[6,7,8-i.j]quinolizine-10-one;

9-(4-diethylaminocinnamoyl)-1,2,4,5-tetrahydro-3H,6H, 10H[1]benzopyrano[6,7,8-i.j]quinolizine-10-one;
7-dimethylamino-3-[3-(2-thienyl)acryloyl]coumarin;
9-[3-(2-thienyl)acryloyl]-1,2,4,5-tetrahydro-3H,6H,10H[1]-benzopyrano[6,7,8-i,j]quinolizine-10-one;
7-diethylamino-3-(4-dimethylaminocinnamylideneacetyl)coumarin;
9-[3-(9-julolidyl)acryloyl]-1,2,4,5-tetrahydro-3H,6H,10H[1]-benzopyrano[6,7,8-i,j]quinolizine-10-one;
3-cinnamoyl-7-diethylaminocoumarin;
7-diethylamino-3-(4-morpholinocinnamoyl)coumarin;
7-diethylamino-3-(4-ethoxycinnamoyl)coumarin;
3-(4-bromocinnamoyl)-7-diethylaminocoumarin;
7-diethylamino-3-[3-(4-methoxy-1-naphthyl)acryloyl]coumarin;
7-diethylamino-3-cinnamylideneacetylcoumarin;
9-[3-(2-thienyl)acryloyl]-1,2,4,5-tetrahydro-3H,6H,10H-[1]benzopyrano[6,7,8-i,j]quinolizine-10-one;
7-diethylamino-3-(3-fluorosulfonylbenzoyl)coumarin;
3-(4-cyanobenzoyl)-7-diethylaminocoumarin;
3-benzoyl-7-dimethylaminocoumarin;
3-benzoyl-7-diethylaminocoumarin;
3-benzoyl-7-pyrrolidinylcoumarin;
3-(4-iodobenzoyl)-7-dimethylaminocoumarin;
3-(4-iodobenzoyl)-7-diethylaminocoumarin;
7-dimethylamino-3-(4-dimethylaminobenzoyl)coumarin;
7-diethylamino-3-(4-nitrobenzoyl)coumarin;
7-diethylamino-3-(2-thenoyl)coumarin;
7-pyrrolidinyl-3-(2-thenoyl)coumarin;
7-diethylamino-3-(2-furoyl)coumarin;
7-diethylamino-3-(2-methoxybenzoyl)coumarin;
2-(p-pyrrolidinylbenzylidene)-1,3-indanedione;
Michler's ketone;
2-[bis(2-furoyl)methylene]-1-methylnaphtho[1,2-d]-thiazoline;
2-[(2-thenoyl)methylene]-1-methylnaphtho[1,2-d]-thiazoline;
2-benzoylmethylene-1-ethylnaphtho[1,2-d]thiazoline;

2 [bis(2-furoyl)methylene] 2-methylbenzothiazoline;
2,5-bis(4-diethylaminobenzylidene)cyclopentanone;
4'-dimethylaminochalcone; and 2-(2-thenoylmethylene)-3-methylnaphtho[2,1-d]thiazoline.

9. A composition as defined in claim 2, wherein said polymerizable compound is an acrylate.

10. An element comprising a composition as defined in claim 1 or 2, on a support.

11. A composition comprising an amine 3-keto-coumarin and an N-heterocyclic compound containing from 5 to 14 nuclear atoms and bearing an N-oxy substituent, said compound being a) responsive in the presence of the photo-excited form of said ketocoumarin to form a free radical, and b) capable, when coated and dried together with an addition-polymerizable compound to form a layer, and then exposed to a medium pressure mercury light source, of providing a speed that is at least about one-fifth that of the same layer coated, dried and exposed identically except that Michler's ketone and benzophenone in a mole ratio of 1 to 8 is used in lieu of said ketocoumarin and said N-heterocyclic compound.

12. In a method of photopolymerizing a composition by exposing it to activating radiation, the composition com-prising an addition-polymerizable compound and a co-initiator composition comprising a photosenitizer comprising a coumarin having an absorptive maximum between about 350 and about 550 nm, and the structure wherein R1 is selected from the group consisting of alkyl or alkenyl having 1 to 12 carbon atoms and a carbocyclic, heterocyclic, or quaternized heterocyclic group having 5 to 20 carbon and hetero nuclear atoms;

and R2, R3, and R4 are the same or different and are hydrogen, dialkylamino containing from 1 to 5 carbon atoms in the alkyl portion, N-pyrrolidinyl, piperidinyl, morpholino, or when taken together, R2, R3 and R4 com-prise the non-metallic atoms that form as a fused substituent on the coumarin ring, provided that at least one of R2, R3, and R4 is an amine, and a photopolymerization activator responsive in the presence of the photo-excited form of said photo-sensitizer to form a free radical;
the improvement wherein said activator is an N-heterocyclic compound containing from 5 to 14 nuclear atoms and bearing an N-oxy substituent, said N-heterocyclic com-pound and said photosensitizer being present in an amount sufficient to provide to said composition in a coated and dried state, and when exposed to a medium pressure mercury light source, a speed that is at least about one-fifth that of the same composition coated dried and exposed identically except that the co-initiator consists of Michler's ketone and benzophenone in a mole ratio of 1 to 8 in lieu of said amine photosensitizer and said N-heterocyclic compound.

13. A method of increasing the speed of a radiation-responsive composition comprising an addition-polymerizable compound and a co-initiator composition comprising a photosensitizer and a photopolymerization activator responsive in the presence of the photo-excited form of said photosensitizer to form a free radical, said method comprising the step of selecting, as the photo-sensitizer, a coumarin having an absorptive maximum between about 350 and about 550 nm, and the structure wherein R1 is selected from the group consisting of alkyl or alkenyl having 1 to 12 carbon atoms and a carbocyclic, heterocyclic, or quaternized heterocyclic group having 5 to 20 carbon and hetero nuclear atoms;
and R2, R3, and R4 are the same or different and are hydrogen, dialkylamino containing from 1 to 5 carbon atoms in the alkyl portion, N-pyrrolidinyl, piperidinyl, morpholino, or when taken together, R2, R3 and R4 com-prise the non-metallic atoms that form as a fused substituent on the coumarin ring, provided that at least one of R2, R3, and R4 is an amine, and as the activator, an N-heterocyclic compound containing from 5 to 14 nuclear atoms and bearing an N-oxy substituent, said N-heterocyclic compound and said photosensitizer being present in an amount sufficient to provide to said composition in a coated and dried state, and when exposed to a medium pressure mercury light source, a speed that is at least about one-fifth that of the same composition coated, dried and exposed identically except that the co-initiator consists of Michler's ketone and benzophenone in a mole ratio of 1 to 8 in lieu of said photosensitizer and said N-heterocyclic compound.