Specified Rate-affecting Material Is Heterocyclic Patents (Class 522/16)
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Patent number: 5049481Abstract: A photopolymerizable composition comprising (i) a polymerizable compound having an addition polymerizable unsaturated bond, (ii) a compound represented by formula (Ia): ##STR1## a compound represented by formula (Ib): ##STR2## or a compound represented by formula (Ic): ##STR3## wherein A represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, an alkyl- or aryl-substituted nitrogen atom, or a dialkyl-substituted carbon atom; Y.sup.1 represents a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group, an acyl group, an alkoxycarbonyl group, or a substituted alkoxycarbonyl group; R.sup.1 and R.sup.2 each represents a hydrogen atom, an alkyl group having from 1 to 18 carbon atoms, or an alkyl group having from 1 to 18 carbon atoms which is substituted with R.sup.3 O--, ##STR4## or a halogen atom (i.e., F, Cl, Br, and I), wherein R.sup.Type: GrantFiled: December 26, 1989Date of Patent: September 17, 1991Assignee: Fuji Photo Film Co., Ltd.Inventors: Yasuo Okamoto, Tadahiro Sorori
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Patent number: 5034429Abstract: A photopolymerizable composition comprising (a) an addition polymerizable compound having a boiling point of 100.degree. C. or high under an atmospheric pressure, (b) a photoinitiator, and (c) a benzene derivative can provide a cured film having high strength suitable for producing, e.g. printed circuit boards.Type: GrantFiled: June 2, 1988Date of Patent: July 23, 1991Assignee: Hitachi Chemical Co., Ltd.Inventors: Makoto Kaji, Nobuyuki Hayashi, Futami Kaneko
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Patent number: 5026740Abstract: The invention relates to the use of a new class of sulphurated derivatives of aromatic-aliphatic or aliphatic ketones as a) polymerization or crosslinking photoinitiators for transparent or pigmented mixtures containing ethylenically unsaturated photopolymerizable compounds, in particular for obtaining polyacrylates, b) photochemically releasable latent acid catalysts, useful for crosslinking systems polycondensable by acid catalysis, of the type comprising etherified aminoplasts together with compounds containing hydroxyl, carboxyl, amido, amino and other functionalities.Said sulphurated derivatives enable manufactured articles to be obtained with exceptionally clear color while maintaining photochemical reactivity at high levels.Type: GrantFiled: July 15, 1988Date of Patent: June 25, 1991Assignee: Fratelli Lamberti S.p.A.Inventors: Giuseppe Li Bassi, Luciano Cadona, Carlo Nicora
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Patent number: 5019482Abstract: A photosensitive composition comprising:(a) a polymer(b) 1 to 20% by weight, based on the weight of polymer (a), of a compound having a terminal ethylenically unsaturated group;(c) 0.1 to 20% by weight, based on the weight of polymer (a), of an oxime ester compound(d) 0.01 to 10% by weight, based on the weight of polymer (a), of a coumarin compound having a wave length of the absorption peak of 330 to 550 nm; has high photosensitivity to an actinic light of a wave length of 400 to 500 nm and is capable of forming heat-resistant images, patterns or films.Type: GrantFiled: August 5, 1988Date of Patent: May 28, 1991Assignee: Asahi Kasei Kogyo Kabushiki KaishaInventors: Hideo Ai, Nobuhiko Suga, Satoshi Ogitani, Hideaki Takahashi, Akihiko Ikeda
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Patent number: 5015555Abstract: Improved photosensitive compositions contain a heterocyclic triazole or its hydrate such as 1-hydroxy benzotriazole hydrate.Type: GrantFiled: May 27, 1988Date of Patent: May 14, 1991Assignee: E. I. Du Pont de Nemours and CompanyInventor: Kenneth I. Lazaar
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Patent number: 5011755Abstract: The present invention relates to compositions comprising(a) a titanocene photoinitiator of the formula I ##STR1## (b) a 3-ketocoumarin of the formula II ##STR2## in which both R.sup.1, R.sup.2 and R.sup.3 are as defined in claim 1, R.sup.4 is a radical of the formula V ##STR3## R.sup.5 is C.sub.1 -C.sub.20 alkyl, cycloalkyl having 5-7 ring carbon atoms, phenyl or naphthyl which are unsubstituted or substituted by one to three C.sub.1 -C.sub.6 alkyl groups, C.sub.1 -C.sub.6 alkoxy groups or halogen atoms or by one diphenylamino or C.sub.1 -C.sub.6 dialkylamino group, or is C.sub.7 -C.sub.9 aralkyl, a radical --(CH.dbd.CH).sub.a --C.sub.6 H.sub.5 or a radical of the formula V, a is 1 or 2, preferably 1, and R.sup.10, R.sup.11, R.sup.12, R.sup.13 and R.sup.14 independently of one another are hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 alkoxy, phenyl, tolyl, xylyl or benzyl, and R.sup.11 can additionally also be a group --NR.sup.15 R.sup.16 or --OR.sup.15, wherein R.sup.15 and R.sup.Type: GrantFiled: January 30, 1990Date of Patent: April 30, 1991Assignee: Ciba-Geigy CorporationInventors: Ottmar Rohde, Armin Schaffner, Martin Riediker, Kurt Meier
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Patent number: 5009982Abstract: A photosetting liquid ink composition developable with a dilute alkaline aqueous solution and comprising (A) a resin curable with an activated energy ray, obtained by the reaction of a saturated or unsaturated polybasic acid anhydride with a product of the reaction of a novolak type epoxy compound and an unsaturated monocarboxylic acid, (B) a photopolymerization initiator, and (C) a diluent can be used for the production of an etching resist or a solder resist in the manufacture of a printed circuit. This composition, when combined with a thermosetting component, produces a photosetting and thermosetting liquid ink composition.Type: GrantFiled: June 6, 1988Date of Patent: April 23, 1991Assignee: Taiyo Ink Manufacturing Co., Ltd.Inventors: Yuichi Kamayachi, Syoji Inagaki
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Patent number: 4997745Abstract: A photosensitive composition comprising a trihalomethyl-s-triazine compound and a photosensitizer, wherein the photosensitizer being a dye having a reduction potential not more than 0.10 volt higher than the reduction potential of the trihalomethyl-s-triazine compound, and a photopolymerizable composition employing the photosensitive composition.Type: GrantFiled: August 11, 1989Date of Patent: March 5, 1991Assignee: Fuji Photo Film Co., Ltd.Inventors: Kouichi Kawamura, Hirotaka Matsumoto, Jun Yamaguchi
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Patent number: 4992547Abstract: The photopolymerizable mixture described contains(A) at least one ethylenically unsaturated photopolymerisable compound,(B) a photoinitiator of the formula I ##STR1## and (C) a photosensitiser from the group of aromatic carbonyl compounds having a triplet energy of 225-310 kJ/mol, for example xanthones, thioxianthones, coumarins, phthalimides, phenones and the like.Ar is phenyl substituted in the 4-position by a substituted amino group, R.sup.1 and R.sup.2 are alkyl, R.sup.3 and R.sup.4 are alkyl or alkoxyalkyl, or R.sup.3 and R.sup.4 together are 3-oxapentamethylene. Said sensitisers (C) raise the activity of said photoinitiators (B) without shortening the shelf life of the mixtures. The photocurable mixtures are used especially as binders for printing inks or paints.Type: GrantFiled: June 14, 1988Date of Patent: February 12, 1991Assignee: Ciba-Geigy CorporationInventors: Godwin Berner, Kurt Meier, Kurt Dietliker, Rinaldo Husler
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Patent number: 4962011Abstract: Novel photopolymerizable recording materials suitable in particular for producing photoresist layers and lithographic printing plates are composed of one or more photopolymerizable, olefinically unsaturated organic compounds, optionally a polymeric binder, a photopolymerization initiator, a color-forming system composed of a color former and a photooxidant, a certain benzotriazole compound as a sensitizer and optionally further additive and/or auxiliary substances.Type: GrantFiled: May 17, 1988Date of Patent: October 9, 1990Assignee: BASF AktiengesellschaftInventors: Reinhard Aldag, Peter Neumann, Andreas Boettcher, Thomas Bluemel, Friedrich Seitz
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Patent number: 4954415Abstract: A photoinitiator composition comprising a compound which absorbs actinic radiation and directly or indirectly generates free radicals, and an O-acylthiohydroxamate compound or an N-alkoxypyridine thione; photohardenable compositions containing that photoinitiator composition; and photosensitive materials employing same.Type: GrantFiled: March 9, 1989Date of Patent: September 4, 1990Assignee: The Mead CorporationInventors: Paul D. Davis, Gary B. Schuster, Jacqueline G. Truini, Al Fentiman
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Patent number: 4942112Abstract: Solid photopolymerizable compositions and photosensitive elements are provided that are useful in preparing optical elements, and especially holograms. The composition contains a polymeric binder, a liquid ethylenically unsaturated monomer, and a photoinitiator system. Typical compositions have a refractive index modulation of at least 0.005 when measured per the specified test.Type: GrantFiled: January 15, 1988Date of Patent: July 17, 1990Assignee: E. I. Du Pont de Nemours and CompanyInventors: Bruce M. Monroe, William K. Smothers
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Patent number: 4940649Abstract: Novel photopolymerizable recording materials suitable in particular for producing photoresist layers and lithographic printing plates are composed of one or more photopolymerizable, olefinically unsaturated organic compounds, optionally a polymeric binder, a photopolymerization initiator, a color-forming system composed of a color former and a photooxidant, a certain 4-phenylpyridine as sensitizer and optionally further additive and/or auxiliary substances.Type: GrantFiled: May 17, 1988Date of Patent: July 10, 1990Assignee: BASF AktiengesellschaftInventors: Reinhard Aldag, Peter Neumann, Andreas Boettcher, Thomas Bluemel, Friedrich Seitz, Friedrich-Wilhelm Raulfs
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Patent number: 4940647Abstract: The invention comprises a photopolymerizable mixture comprising as the essential constituents a polymeric binder, a compound capable of forming a polymer by free-radical initiated polymerization, a photoinitiator, a leuco dye and a leuco dye stabilizer having at least one epoxy group. The mixture has a better shelf life in the dark than known compositions and is preferably used in the preparation of dry photoresists.Type: GrantFiled: October 6, 1988Date of Patent: July 10, 1990Assignee: Hoechst AktiengesellschaftInventors: Hans-Dieter Frommeld, Hartmut Wiezer
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Patent number: 4935330Abstract: A photopolymerizable mixture containing one or more ethylenically unsaturated, photopolymerizable or photocrosslinkable compounds and a photopolymerization initiator which comprises a combination of an aromatic carbonyl compound of the type stated in claim 1 and an s-triazine compound containing one or more halogen-substituted methyl groups, photosensitive recording elements which possess a photopolymerizable recording layer consisting of these photopolymerizable mixtures, and a process for the production of lithographic printing plates using these recording elements.Type: GrantFiled: November 14, 1989Date of Patent: June 19, 1990Assignee: BASF AktiengesellschaftInventors: Gerhard Hofmann, Reiner Hoffman, Harald Lauke, Wilhelm Weber, Reinhold J. Leyrer
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Patent number: 4900763Abstract: Vehicles for ultraviolet radiation-curable ceramic enamels comprising (a) acrylate- or methacrylate- modified oligomers; (b) monofunctional acrylate- or methacrylate-modified monomers; (c) pentafunctional acrylate or methacrylate-modified monomers; and (d) a photoinitiator system for said polymerizable components; and the enamels prepared therefrom comprising glass enamels and the vehicles as described.Type: GrantFiled: February 26, 1988Date of Patent: February 13, 1990Assignee: Ciba-Geigy CorporationInventor: Douglas J. Kraushaar
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Patent number: 4891301Abstract: Abstract of the disclosure: Novel photopolymerizable recording materials suitable in particular for producing photoresist layers and lithographic printing plates are composed of one or more photopolymerizable, olefinically unsaturated organic compounds, a photopolymerization initiator, a color-forming system composed of a color former and a photooxidant, novel 4-quinazolone compounds as sensitizers of the formula (I) ##STR1##Type: GrantFiled: May 17, 1988Date of Patent: January 2, 1990Assignee: BASF AktiengesellschaftInventors: Reinhard Aldag, Peter Neumann, Andreas Boettcher, Thomas Bluemel, Friedrich Seitz
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Patent number: 4856670Abstract: An improved transfer printing ink for printing indicia on impervious surfaces, such as glass, is comprised of a liquid resin component comprising one or more liquid acrylate monomers, one or more polyfunctional acrylate monomers, one or more polymeric binders and one or more photoinitiators. The transfer ink also is comprised of a solid component comprising one or more pigment materials and a particulate glass frit mixture. The glass frit mixture consists of a pluality of wetting agents and a frit flux. The wetting agents melt at an elevated temperature to fuse the pigments and the frit flux to the glass.Type: GrantFiled: January 12, 1988Date of Patent: August 15, 1989Assignee: RCA Licensing Corp.Inventors: Kenneth W. Hang, Wayne M. Anderson
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Patent number: 4843110Abstract: A light curing composition for dental restoration comprises (a) a polymerizable compound containing at least one ethylenically unsaturated double-bond, (b) at least one photo-polymerization initiator selected from ketal base compounds defined hereinafter, (c) at least one photopolymerization initiator selected from thioxanthone base compounds defined hereinafter, (d) a reducing agent and (e) a filler.Type: GrantFiled: September 11, 1986Date of Patent: June 27, 1989Assignee: G-C Dental Industrial CorporationInventors: Takao Kubota, Tetsuro Sakuma, Ryoji Nakazato
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Patent number: 4839401Abstract: A light curable pit and fissure sealant composition comprises 2,2-propane-bis [3-(4-phenoxy)-1,2-dihydroxy-propane-1- methacrylate] and triethylene glycol dimethacrylate in a 55:45 weight ratio, a polymerization initiator, titanium dioxide as an opaquing agent, and DEA-EMA of at least 95 percent purity as the polymerization accelerator. Optionally, up to 50% filler can be used.Type: GrantFiled: September 30, 1986Date of Patent: June 13, 1989Assignee: Jeneric/Pentron, Inc.Inventor: Samuel Waknine
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Patent number: 4826888Abstract: A photopolymerizable composition comprising a vinyl monomer, a mercaptocarboxylic acid/.alpha.-diketone photopolymerization initiator and a storage stabilizer. The composition may admit of a filler, and exhibits excellent mechanical strength, storage stability, color and resistance to coloring, and availability.Type: GrantFiled: April 2, 1986Date of Patent: May 2, 1989Assignee: Mitsubishi Rayon Co., Ltd.Inventors: Isao Sasaki, Nobuhiro Mukai, Hitoshi Ige
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Patent number: 4772534Abstract: A light-sensitive composition containing a novel light-sensitive s-triazine compound represented by the formula (I) as a free radical-generating agent is disclosed. The s-triazine compound responds radiation in the range of the near ultraviolet to visible light, shows high sensitivity for photolysis and, therefore, the compositon has high light-sensitivity.Type: GrantFiled: September 5, 1986Date of Patent: September 20, 1988Assignee: Fuji Photo Film Co., Ltd.Inventors: Kouichi Kawamura, Hirokazu Kondo, Yoshimasa Aotani
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Patent number: 4755450Abstract: Spectral sensitizing dyes which sensitize photoinitiators and disperse in aqueous solutions are desirable in photosensitive systems where precise color rendition is important.Type: GrantFiled: April 22, 1986Date of Patent: July 5, 1988Assignee: Minnesota Mining and Manufacturing CompanyInventors: James F. Sanders, David B. Olson
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Patent number: 4740450Abstract: An image reproducing material which comprises a support and at least a photosensitive resin layer and scratch resistance layer borne on the support, said scratch resistance layer containing a compound represented by AmBn, wherein A is mono- or divalent, straight or branched C.sub.11-20 aliphatic hydrocarbon; B is hydrogen, hydroxyl, amino, nitrile, aldehyde, carboxyl, or alkylamide, alkylester, ammonium salt or a periodic table group I-IV metal salt of a carboxylic acid; m is an integer of 1 to 3; and n is 1 or 2. A process for preparing the image reproducing material as well as a process for preparing an image reproduced material by using the image reproducing material are also described.Type: GrantFiled: January 8, 1987Date of Patent: April 26, 1988Assignee: Toyo Boseki Kabushiki KaishaInventors: Nobuyuki Tamaoki, Yoshio Katoh, Akitada Osako, Toshihiko Kajima, Shinichi Tanaka
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Photopolymerizable composition and photopolymerizable recording material containing said composition
Patent number: 4737445Abstract: In photopolymerizable composition that contains, as the essential constituents,(a) a polymeric binder,(b) a polymerizable compound, and,(c) as the photoinitiator, a 2,3-dihydro-1H-cyclopenta(b)quinoline represented the formula ##STR1## in which R.sup.1 is a substituted or unsubstituted m-valent, carbocyclic aromatic or heterocyclic aromatic radical,R.sup.2 is a hydrogen atom, an alkyl group, an aryl group, an aralkyl group or an aralkenyl group,R.sup.3 and R.sup.4 are identical or different, and each denotes a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group,n is 0 or 1, andm is 1 or 2,the photoinitiator possesses an excellent initiating action, resulting in high image resolution.Type: GrantFiled: October 21, 1986Date of Patent: April 12, 1988Assignee: Hoechst AktiengesellschaftInventors: Hans-Dieter Frommeld, Heike Ziemke -
Patent number: 4710523Abstract: Acylphosphine oxide compounds of the general formula ##STR1## where R.sup.1 is alkyl, cyclohexyl, cyclopentyl, aryl which is unsubstituted or substituted by halogen, alkyl or alkoxy, or an S-containing or N-containing five-membered or six-membered heterocyclic radical,R.sup.2 has one of the meanings of R.sup.1 (but R.sup.1 and R.sup.2 may be identical or different) or is alkoxy, aryloxy or aralkoxy, or R.sup.1 and R.sup.2 together form a ring andR.sup.3 is an at least disubstituted phenyl, pyridyl, furyl or thienyl radical which carries, at least at the two carbon atoms adjacent to the linkage point of the carbonyl group, the substituents A and B, which may be identical or different, and each of which is alkyl, alkoxy or alkylthio of 1 to 6 carbon atoms, cycloalkyl of 5 to 7 carbon atoms, phenyl or halogen, or R.sup.3 is .alpha.-naphthyl substituted by A and B at least in the 2- and 8-positions or is .beta.Type: GrantFiled: January 18, 1984Date of Patent: December 1, 1987Assignee: BASF AktiengesellschaftInventors: Peter Lechtken, Ingolf Buethe, Manfred Jacobi, Werner Trimborn
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Patent number: 4707431Abstract: This invention relates to an optical information recording medium comprising a substrate provided at least with an underlayer and a recording layer thereon, said underlayer being prepared by curing a light-curable composition containing a reducing agent, a photo-polymerization initiator and acrylate monomer and/or methacrylate monomer and/or their corresponding oligomer.Type: GrantFiled: October 25, 1985Date of Patent: November 17, 1987Assignee: Ricoh Co., Ltd.Inventor: Masaakira Umehara
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Patent number: 4696888Abstract: Light-sensitive compounds are described which have the formula ##STR1## wherein R.sup.1 and R.sup.2 denote H or alkyl, R.sup.3 and R.sup.4 denote H or 4,6-bis-trichloromethyl-s-triazin-2-yl, R.sup.5 and R.sup.6 denote H or halogen, alkyl, alkenyl or alkoxy, and Ar denotes a mononuclear to trinuclear aromatic group.These compounds are suitable as photoinitiators for free-radical polymerizations or as photolytic acid donors for acid-cleavable compounds, and for cross-linking and color formation reactions. They are distinguished by a high sensitivity in various spectral ranges.Type: GrantFiled: July 30, 1986Date of Patent: September 29, 1987Assignee: Hoechst AktiengesellschaftInventor: Gerhard Buhr
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Patent number: 4680249Abstract: Improved adhesion to a substrate is obtained employing a photopolymerizable composition containing a carboxy benzotriazole.Type: GrantFiled: May 28, 1986Date of Patent: July 14, 1987Assignee: E. I. Du Pont de Nemours and CompanyInventor: Gregory C. Weed
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Patent number: 4657942Abstract: A photopolymerizable composition is described, comprising an addition polymerizable compound having at least two ethylenically unsaturated bonds in the molecule, at least one photopolymerization initiator, and at least one of 2-mercapto-5-substituted thiadiazole compounds represented by formulae (I) and (II) ##STR1## wherein R represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted alkylthio group, or a substituted or unsubstituted aralkylthio group; and R' represents a substituted or unsubstituted alkylene group. The composition has a remarkably good photosensitivity.Type: GrantFiled: January 27, 1986Date of Patent: April 14, 1987Assignee: Fuji Photo Film Co., Ltd.Inventors: Masayuki Iwasaki, Minoru Maeda, Sadao Fujikura
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Patent number: 4599155Abstract: There is disclosed a resin composition comprising(A) a spiro ortho ester compound and/or a spiro ortho carbonate compound;(B) an aluminum compound; and(C) a silanol compound or a silicon compound which is capable of generating a silanol group;the amounts of components (B) and (C) being within the range of 0.001 to 10% by weight and 0.1 to 20% by weiht, based on the amount of component (A), respectively.The resin composition of this invention is excellent in volumetric shrinkage performance at curing operation and is good in storability. Therefore, the cured product can be used for a wide variety of industrially valuable applications, such as an ink, a coating, an adhesive, a surface coating, an encapsulation and an electrical insulating material.Type: GrantFiled: September 21, 1984Date of Patent: July 8, 1986Assignee: Kabushiki Kaisha ToshibaInventors: Shuichi Suzuki, Moriyasu Wada, Shuzi Hayase
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Patent number: 4585876Abstract: Novel xanthones and thioxanthones of the formula I ##STR1## in which A, X, Y, Z, E and E' are as defined in patent claim 1, are described. A is preferably --S-- and E and E' are preferably bonded in the ortho-position relative to one another. The compounds (I) are suitable, for example, as sensitizers for photocrosslinkable polymers or photocurable compositions, or for use in mixtures with polymers with H donor groups for image formation, in particular electrically conductive coatings and patterns, by means of electroless deposition of metals.Type: GrantFiled: November 14, 1983Date of Patent: April 29, 1986Assignee: Ciba-Geigy CorporationInventors: Walter Fischer, Jurgen Finter, Hans Zweifel
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Patent number: 4582862Abstract: Compounds of the formula I, II or III ##STR1## in which Ar is a sulfur-containing aromatic radical, R.sup.1 and R.sup.2 are a monovalent hydrocarbon radical which is substituted or unsubstituted or R.sup.1 and R.sup.2 together form alkylene, oxaalkylene or azaalkylene, R.sup.3 is a direct bond or a divalent hydrocarbon radical, X is a monovalent amino group and X' is a divalent amino or diamino group, are excellent photoinitiators for the photocuring of colored, in particular pigmented, compositions containing an olefinically unsaturated, photopolymerizable binder.Type: GrantFiled: February 22, 1983Date of Patent: April 15, 1986Assignee: Ciba-Geigy CorporationInventors: Godwin Berner, Rinaldo Husler, Rudolf Kirchmayr
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Patent number: 4576976Abstract: Disclosed is a process for the photopolymerization of vinyl compounds and of photopolymerizable materials containing vinyl compounds and products produced thereby which are especially useful for dental materials. The process utilizes at least one photosensitizer of the formula ##STR1## wherein X is selected from the group consisting of CO, C(R.sup.1)(R.sup.2) and C(R.sup.3)(OR.sup.4); wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 are each selected from the group consisting of hydrogen and a hydrocarbon radical;n is 0 or 1; andA is selected from hydrocarbon radicals which may be substituted and which may be bonded together with the proviso that when n is 1 and X is C(R.sup.1)(R.sup.2), and when n is 0, A is an aromatic radical; andat least one reducing agent of formula (I) or (II) ##STR2## wherein Y is selected from oxygen, sulfur or the group NR.sup.1 where R.sup.Type: GrantFiled: March 7, 1984Date of Patent: March 18, 1986Assignee: Kulzer & Co., GmbHInventor: Roland Schaefer
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Patent number: 4576975Abstract: Michler's ketone analogs and salts thereof, which are photosensitizers in water-soluble photoinitiator systems used to induce polymerization in free-radically-curable, ethylenically-unsaturated materials, are disclosed. The Michler's ketone analogs have the formula: ##STR1## wherein each R is an alkyl group of 1 to 8 carbon atoms,R.sup.1 is an alkylene group having 1 to 8 carbon atoms,Z is R.sup.1 COOH or R.sup.1 H, andn is an integer having a value of 1 or 2.The photoinitiator systems are useful in imaging systems, and additionally contain a free radical initiator compound selected from iodonium salts, biimidazoles, trialkylphosphites, alkyl peroxides, benzyl halides, alkyl nitrates, and the benzophenones other than (a).Type: GrantFiled: December 18, 1984Date of Patent: March 18, 1986Assignee: Minnesota Mining and Manufacturing CompanyInventor: Laurence W. Reilly, Jr.