Abstract: 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.

Abstract: Titanocenes containing two 5-membered cyclodienyl groups, for example cyclopentadienyl, and one or two 6-membered carbocyclic or 5- or 6-membered heterocyclic aromatic rings which are substituted by a fluorine atom in at least one of the two ortho-positions to the titanium-carbon bond and contain, as a further substituent, unsubstituted or substituted 1-pyrryl, are suitable as photoinitiators for radiation-induced polymerization of ethylenically unsaturated compounds.

Abstract: Liquid, photocurable coating compositions containing nitrile copolymers. Such compositions comprises from about 10 percent to about 60 percent by weight of a high nitrile copolymer, containing at least about 70 percent by weight of a nitrile polymer; from about 30 percent to 90 percent by weight of a photopolymerizable solvent for the high nitrile copolymer, wherein the photopolymerizable solvent is selected from the group consisting of N-vinyl pyrrolidone, cyanoethylacrylate, styrene, N,N-dimethylacylamide, N,N-methylenebisacrylamide, gamma-butyrolactone and combinations thereof, and from about 0.1 percent to about 10 percent by weight of a photoinitiator soluble in the photopolymerizable solvent for curing the high nitrile copolymer with the incorporation of at least 50 percent by weight of the solvent therein upon exposure to ultraviolet radiation, having a wavelength of from about 2000 .ANG. to 14,000 .ANG.

Abstract: An adhesive for surface mounting devices comprising a polymerizable prepolymer, a reactive diluent, and a polymerization initiator, the adhesive further comprising as a chelating agent an aminopolycarboxylic acid having at least one hydroxyethyl group bound to the nitrogen atom thereof or an alkali metal salt thereof, and as a curing accelerator cupferron or a metallic salt thereof.

Abstract: 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.

Abstract: A photopolymeric composition having improved sensitivity to a visible light ray which comprises:(a) at least one ethylenic unsaturated compound which is non-gaseous at a normal temperature;(b) at least one metallic arene compound;(c) a compound selected from the group consisting of p-aminophenyl unsaturated detone compounds, pyridine derivatives or salts thereof, xanthene or thioxanthene compounds and mixtures thereof; and optionally(d) a compound selected from the group consisting of phenylglycine derivatives, cyclic diketone compounds and mixtures thereof.

Abstract: A dental adhesive composition containing as major components:(a) at least one isocyanate-group-containing urethane prepolymer,(b) at least one isocyanate-group-containing silane compound,(c) at least one radical-polymerizable unsaturated monomer, and(d) at least one initiator selected from the group consisting of redox polymerization initiators and photopolymerization initiatorsis disclosed.This composition is excellent in bonding properties when it is used to bond a living dental tissue with a restoring material such as a metal, organic polymer, and ceramic. Also, this adhesive composition does not require a troublesome pretreatment of the restoring material with an etching agent such as phosphoric acid when the restorating material is required to bond to the living tissue.

Abstract: A photopolymerizable dental composition, which comprises:(A) an organic composite filler obtained by polymerizing at least one carboxylic acid monomer of the formula: ##STR1## wherein R.sub.1 is a hydrogen atom, a C.sub.1 -C.sub.15 alkyl group, a --COOY group, a halogen atom, or a phenyl group or a derivative thereof; R.sub.2 is a hydrogen atom, a C.sub.1 -C.sub.15 alkyl group, a --COOZ group, a halogen atom, or a phenyl group or a derivative thereof; R.sub.3 is a hydrogen atom, a C.sub.1 -C.sub.15 alkyl group, a halogen atom, or a phenyl group or a derivative thereof; and each of X, Y and Z is a hydrogen atom, NH.sub.4 or an alkali metal atom; or the formula: ##STR2## wherein each of R.sub.4 and R.sub.5 is a hydrogen atom, a C.sub.1 -C.sub.

Abstract: Epoxy functional organopolysiloxanes are compatibilized with onium salt photocatalysts by modifying a controlled number of epoxy groups by esterification with carboxylic acids.

Abstract: A photo-curable epoxy resin type composition which comprises (a) an epoxy resin, (b) at least one compound selected from the group consisting of (i) a compound having a group, other than an imido group, which is represented by the formula --CONH and (ii) an aromatic amine, (c) an organic metal compound, where said metal is selected from the group consisting of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminum and zirconium; and (d) an organic silicon compound having at least one group selected from the group consisting of a peroxysilyl group and an o-nitrobenzyloxy group capable of forming a silanol group by irradiation with light. The photo-curable epoxy resin type composition according to this invention is capable of readily curing by light (ultraviolet ray in particular) and also capable of heat curing at a temperature of 150.degree. C.

Abstract: A high speed visible light sensitive photopolymerizable composition useful for printing plates comprising(a) at least one free radically polymerizable monomer having at least one ethylenically unsaturated group,(b) an ethylenically unsaturated free radically polymerizable oligomer having carboxyl groups substituted thereon,(c) a visible light sensitizing initiator system for free radical polymerization comprising an initiator selected from diaryl iodonium salts, halogenated triazines, and triaryl iodonium salts which are photoinitiating electron acceptor compounds having a reduction potential in the range 0.0 to -1.5 eV, spectrally sensititzed with at least one merocyanine sensitizer containing a constrained alkylamino group, preferably a julolidinyl group.

Abstract: Titanocenes with, for example, .pi.-cyclopentadienyl ligands in which one or two carbo- or heterocyclic aromatic rings are bonded to the titanium, the aromatic rings being substituted by fluorine in at least one of the two ortho-positions relative to the matal-carbon bond and being substituted by at least one free or etherified or esterified polyoxaalkylene radical, are suitable as photoinitiators for the photopolymerization of ethylenically unsaturated substrates.

Abstract: A biologically compatible adhesive dental primer that is shelf stable as a single component adhesive and includes a mixture of an adhesive promoting and polymerizable monomer system having a free radical polymerizable monomer or prepolymer having ethylenic unsaturation and a phosphorus containing adhesion promoter which is free from halogen atoms bonded directly to a phosphorus atom, and optionally a free radical polymerization catalyst, and an accelerator for the catalyst.

Abstract: Disclosed is a photopolymerizable composition which is very sensitive to visible light. The composition comprises a polymerizable compound and a photopolymerization initiator wherein the photopolymerization initiator comprises (A) a particular xanthene, coumarin or merocianine dyestuff, (B) a diaryliodonium salt and (C) a compound having the formula; R(n)--D--CH.sub.

Abstract: There is provided a photo-curable coating composition comprising (a) a photo-curable monomer of polymer and (b) a compound having a blocked isocyanate group and at least one ethylenically unsaturated group.

Abstract: 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.

Abstract: Photopolymerizable compositions comprising:(1) at least one vinyl monomer capable of undergoing free radical polymerization,(2) a visible light or ultraviolet light responsive photoinitiator system comprising:(a) a diaryliodonium salt,(b) a pigment, insoluble in the photopolymerizable composition, said pigment also serving as a sensitizer,(c) one or more electron donating compounds, and, optionally,(3) adjuvants.The three component photoinitiator system of this invention can increase, by several orders of magnitude, the rate of ultraviolet light or visible light photocuring of vinyl monomers.

Abstract: Free radical polymerizable compositions contain a sulfonium salt which is tethered to at least one of an electron donor and a sensitizer, and a polymerizable monomer, demonstrate substantially enhanced photosensitivity. This invention also provides layered structures comprising a substrate coated with a free radical polymerizable composition containing a sulfonium salt which is tethered to at least one of an electron donor and a sensitizer, and the polymerized layered structures. A method for the preparation of certain tethered sulfonium salts is described.

Abstract: A device, e.g., an electrical or electromechanical assembly, comprising a housing with a mechanism disposed therein which is potted by a cured mass of a self-leveling liquid composition. The composition comprises an actinic radiation cured first resin component and a subsequently cured second resin component which is non-cured under the actinic radiation conditions effective for curing the first resin component. Also disclosed is an appertaining method of making such devices.Depending on the depth of the composition which is to be cured in the housing, it may be desirable to utilize the self-leveling liquid composition as either a single homogeneous mixture of the first and second resin components, or, where the depth of the housing is greater than the depth of UV penetration, as a cured mass wherein the first resin component is in a separate and discrete resin layer overlying a lower resin layer containing the second resin component but not the first resin component.

Abstract: Compositions which cure by UV radiation in less than one second are obtained by mixing an alkenyl containing polydiorganosiloxane, a mercapto functional crosslinker of the mercapto functional polyorganosiloxane or mercapto organic compounds, a photosensitizer, a viscosity stabilizer, and optionally a reinforcing agent. These compositions can be packaged in one container and can be used as the primary coating for optical fibers.

Abstract: A photocurable ethylenically unsaturated liquid coating composition consisting essentially of: 1- polyethylenically unsaturated material in which the ethylenically unsaturated groups are polymerizable groups which are not (meth)acrylate groups; 2- a polyamine resin; and 3- an hydroxyalkyl phenone photoinitiator to speed the cure. The photocure rate is also speeded by combining a tertiary amine-functional acrylic copolymer, an allyl-functional resin, and a maleate-functional resin in a weight ratio of about 15-65/5-45/30-70. In preferred practice both expedients are used to maximize the cure speed.

Abstract: Novel systems for bonding a polyarylate substrate to another polyarylate substrate or to a polycarbonate substrate, at least one of the substrates being transparent, employing a visible light curable adhesive composition consisting essentially of:(1) at least one member of the group consisting of monofunctional acrylic monomers, polyfunctional acrylic monomers, and polyfunctional polyester acrylate oligomers;(2) N-vinyl pyrrolidone;(3) at least one low molecular weight aliphatic urethane acrylate polymer; and(4) a catalyst or photoinitiator activatable by visible light.The invention is particularly directed to the bonding of component parts of automotive headlamp assemblies, at least one component of which comprises a polyarylate.

Abstract: 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.

Abstract: Radiation-curable coating compositions particularly adapted for the single coat coating of optical fibers are disclosed. These comprise (1) from 65% to 85% of a diethylenic-terminated polyurethane, which may contain urea groups, the polyurethane being based on a diisocyanate having an average molecular weight of from 400 to 5000; and (2) from 5% to 25% of an ether of a C.sub.2 -C.sub.4 alkylene glycol monoester of a monoethylenically unsaturated monocarboxylic acid, the ether being selected from the group consisting of ethoxyethyl, dicyclopentenyl, phenyl, and mixtures thereof. Ethoxyethoxyethyl acrylate is particularly preferred. A triacrylate ester, such as trimethylol propane triacrylate, is also desirably present.

Abstract: A photopolymerizable dental composition, which comprises:(A) an organic composite filler obtained by polymerizing a sulfonic acid or sulfonate monomer of the formula: ##STR1## wherein R.sub.1 is a hydrogen atom, a C.sub.1 -C.sub.20 alkyl group, a phenyl group or a derivative thereof, or a halogen atom; ##STR2## wherein each of R.sub.2 and R.sub.3 is a hydrogen atom or a C.sub.1 -C.sub.15 alkyl group, R.sub.4 is a C.sub.1 -C.sub.15 alkylene group, m is an integer of from 1 to 20 and n is an integer of from 0 to 20; and Y is a hydrogen atom, NH.sub.4 or an alkali metal atom, and at least one radical polymerizable vinyl monomer in a polymerization system in which an inorganic compound is dispersed;(B) a monomer mixture comprising 2,2-bis[4-(methacryloxyethoxy)phenyl]propane, at least one hexa-functional urethane (meth)acrylate of the formula: ##STR3## wherein X is ##STR4## wherein n is an integer of from 1 to 10, and each of R.sub.1 and R.sub.

Abstract: A photopolymerizable composition comprises a polyfunctional monomer, a photopolymerization initiator, an organic halogen compound and a 3,6-diaminofluoran derivative. The 3,6-diaminofluoran has the formula (I): ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group or a heterocyclic group, R.sup.1 and R.sup.2 (also R.sup.3 and R.sup.4 may form a heterocyclic ring in conjunction with the adjoining nitrogen atom, provided that at least two of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are aryl groups, or at least one group of the group containing R.sup.1 and R.sup.2 and the group containing R.sup.3 and R.sup.4 forms in conjunction with the adjoining nitrogen atom a heterocyclic ring; each of R.sup.5, R.sup.6 and R.sup.

Abstract: A photosensitive composition comprising:(a) a compound of the formula ##STR1## (b) an ethylenically unsaturated compound capable of free radical initiated addition polymerization;(c) a polymeric binder; and(d) a free radical generating system activatable by actinic radiation which comprises a hexaarylbiimidazole and a chain transfer agent.A single step process for forming a light-stable hologram using this photosensitive composition is also disclosed.

Abstract: 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.

Abstract: Photoinitiator compositions are disclosed which contain 3,3'-carbonyl bis(7-diethylaminocoumarin); an alkyl ester of a p-dialkylamino benzoic acid; and either camphorquinone or a 2,4,5-triphenylimidazolyl dimer. Photoinitiators are also provided which contain 3,3'-carbonyl bis(7-diethylaminocoumarin); an alkyl ester of a p-dialkylamino benzoic acid; camphorquinone and a 2,4,5-triphenylimidazolyl dimer. These latter photoinitiators are particularly useful in photopolymerizable compositions which are polymerized by exposure to visible laser light.

Abstract: Photopolymerizable compositions comprising:(1) at least one vinyl monomr capable of undergoing free radical polymerization,(2) a visible light or ultraviolet light responsive photoinitiator system comprising:(a) a diaryliodonium salt,(b) a pigment, insoluble in the photopolymerizable composition, said pigment also serving as a sensitizer,(c) one or more electron donating compounds, and, optionally,(3) adjuvants.The three component photoinitiator system of this invention can increase, by several orders of magnitude, the rate of ultraviolet light or visible light photocuring of vinyl monomers.

Abstract: Disclosed is a coating composition which crosslinks upon exposure to ultraviolet radiation. The coating composition comprises: (A) from 1 to 5 percent of a saturated, chlorinated polymeric material selected from the group consisting of (1) a chlorinated polyolefin containing about 5 to 75 percent by weight of chlorine and having a number average molecular weight of about 5,000-50,000, (2) a chlorinated polyolefin containing carboxylic anhydride groups and about 5 to 25 percent by weight of chlorine and having a number average molecular weight of about 5,000-50,000, and (3) a mixture thereof; (B) from 20 to 80 percent of a radiation sensitive monomer having at least two addition polymerizable unsaturated bonds; (C) from 0.1 to 5.0 percent of a photopolymerization initiator; and (D) from 80 to 20 percent of an acrylic addition polymer having at least one amino group and having a number average molecular weight of about 8,000-70,000.

Abstract: The invention is directed to a photosensitive polymer composition capable of being electrophoretically depositable as an adherent, uniform photosensitive film on a conductive surface. The photosensitive polymer composition useful for electrodeposition is formed from an aqueous solution or emulsion of at least one polymer having charged carrier groups, a photoinitiator and a source of unsaturation for crosslinking the resulting film upon exposure to actinic radiation. The photosensitive film formed from the photosensitive polymer composition is aqueous developable and resistant to strong inorganic acids and strong bases. The photosensitive polymer composition is useful in the preparation of printed circuit boards, lithographic printing plates, cathode ray tubes, as well as in chemical milling, solder resist and planarizing layer applications.

Abstract: Disclosed is a photopolymerizable composition which is very sensitive to visible light. The composition comprises a polymerizable compound and a photopolymerization initiator wherein the photopolymerization initiator comprises (A) a particular xanthene, coumarin or merocianine dyestuff, (B) a diaryliodonium salt and (C) a compound having the formula;R(n)--D--CH.sub.

Abstract: This invention provides hardenable compositions useful as construction media for a wide range of applications. Particular utility is found in the dental and medical arts where such compositions are highly suitable for the formation and construction of denture base, denture baseplates, denture liners, denture repair, custom trays, veneering for crowns and bridgework, artificial teeth, veneers and repair for natural teeth, and tooth restorative fillings. Such materials having improved impact strengths and elastic moduli when hardened are disclosed which include rubber-modified polymer.

Abstract: A microfilled dental composite containing from about 30% to about 60% filler. The filler being sub-micron hydrophobic silica particles of about 0.01-0.04 micrometers in diameter. The filler is dispersed in ethoxylated bisphenol A dimethacrylate resin containing suitable aliphatic dimethacrylate diluents up to about 40% by weight and curing agents effecting curing.

Abstract: 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.

Abstract: A photosetting polymer composition comprises:a base polymer comprising a denatured copolymer which is produced by reacting a copolymer of maleic anhydride and an unsaturated hydrocarbon compound with a specific aminocarboxylic acid, an alcohol or a cellosolve derivative, and a glycidyl (meth)acrylate compound under specific conditions;5-500 weight parts of a photopolymerizable monomer per 100 weight parts of the base polymer; and1-50 weight parts of a photopolymerization initiator per 100 weight parts of the base polymer.

Abstract: 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.

Abstract: An active energy beam-curable type resin composition, which comprises (A) a graft copolymer comprising a main chain composed mainly of structural units of monomers containing one (meth)acryloyl group and a dicyclopentenyl derivative group represented by the following general formula (I): ##STR1## wherein Z represents a five-membered ring given by ##STR2## and R.sub.1 and R.sub.

Abstract: An active energy ray-curable resin composition comprises (A) a graft copolymerized polymer comprising graft chains composed mainly of structural units derived from at least one monomer selected from the group consisting of (a) hydroxyl containing (meth)acrylic monomers, (b) amino or alkylamino containing (meth)acrylic monomers, (c) carboxyl containing (meth)acrylic or vinyl monomers, (d) N-vinylpyrrolidone, (e) vinylpyridine or its derivatives and (f) (meth)acrylic amide derivatives represented by the general formula (II) shown below: ##STR1## (wherein R.sub.1 is hydrogen or methyl group and R.sub.2 is hydrogen or an alkyl or acyl group having 1 to 4 carbon atoms which may have hydroxyl group added to trunk chains composed mainly of structural units compsiting at least one monomer selected from the group consisting of the monomer represented by the general formula (I) shown below: ##STR2## (wherein R.sub.1 to R.sub.

Abstract: 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.

Abstract: A conformal coating composition is made from a mixture of acrylamide functional polydimethylsiloxane, a methacrylate functional/dialkoxy polydiorganosiloxane, reactive diluent including isobornyl acrylate, cyclohexyl acrylate, and 2-ethylhexyl acrylate; a photoinitiator combination of 2-hydroxy-2-methylphenylpropanone and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholenopropanone, an amine including dimethylethanolamine and diisopropylethylamine, and an organic titanate. The composition has a viscosity of from 0.07 to 0.2 Pa.s at 25.degree. C. and cures by exposure to ultraviolet radiation and to atmospheric moisture, i.e. a dual curing composition. This composition cures too fast by exposure to ultraviolet radiation in the presence of nitrogen resulting in a distorted surface and therefore for coating printed circuit boards it is recommended that it be cured in air so that the rate of cure is reduced and no surface distortions are formed.

Abstract: A combined chemical-light-polymerization type composition for dental restoration consists of a formulation A composed mainly of a. an ethylenically polymerizable unsaturated compound, b. a photopolymerization initiator and c. a reducing agent, and a formulation B composed mainly of d. a filler and e. an organic perioxide. The formulations A and B are separately packaged and designed to be mixed for use.

Abstract: A biologically compatible adhesive that is shelf stable as a single component adhesive and includes a mixture of an adhesive promoting and polymerizable monomer system having a free radical polymerizable monomer or prepolymer having ethylenic unsaturation and a phosphorus containing adhesion promoter which is free from halogen atoms bonded directly to a phosphorus atom, a free radical polymerization catalyst, and an accelerator for the catalyst, the accelerator selected from the group consisting of sulfinic acid or salt thereof, amine or amine salt and mixtures thereof.

Abstract: 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 compound as defined herein, (c) at least one photo-polymerization initiator selected from anthraquinone base compounds as defined herein, (d) a reducing agent and (e) a filler.

Abstract: This invention describes the use of some Mannich bases as photosensitizers for iodonium salts for use in the initiation of free radical polymerization of vinyl monomers. These Mannich bases are unexpectedly more efficient as photosensitizers than are the conventional photosensitizers.

Abstract: Radiation sensitive compositions comprising acrylic or methacrylic acid esters with decreased oxygen inhibition attained by use of minor amounts of N,N'-diorgano dicarboxamide additives. The acrylated ester compositions are suitable for ultraviolet curable coatings.

Abstract: Upon imagewise exposure, a photopolymerizable composition which contains(a) a polymeric binder;(b) a compound that has at least one terminal ethylenic double bond and a boiling temperature, at standard pressure, of above 100.degree. C., and that can form a polymer by polymerization initiated by a free-radical process;(c) a photoinitiator;(d) a leuco base of a triarylmethane dye; and(e) a photochromic spiro-indolino-benzopyran compound represented by the formula ##STR1## wherein R denotes a hydrogen atom or a C.sub.1 -to-C.sub.16 alkyl group,R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different, and each denotes a hydrogen or a halogen atom, a C.sub.1 -to-C.sub.4 alkyl or alkoxy group, or a nitro group, andR.sup.5, R.sup.6, R.sup.7 and R.sup.8 are identical or different, and each denotes a hydrogen or a halogen atom, a nitro or an amino group, a C.sub.1 -to-C.sub.5 alkyl or alkoxy group, or a C.sub.6 -to-C.sub.

Abstract: Compositions which cure by UV radiation in less than one second are obtained by mixing an alkenyl containing polydiorganosiloxane, a mercapto functional crosslinker of the mercapto functional polyorganosiloxane or mercapto organic compounds, a photosensitizer, a viscosity stabilizer, and optionally a reinforcing agent. These compositions can be packaged in one container and can be used as the primary coating for optical fibers.

Abstract: A novel 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 photo-polymerization initiator selected from benzoin alkyl ether base compounds defined hereinafter, (d) a reducing agent and (e) a filler.