Abstract: Photopolymerizable compositions that include free radically active and cationically active functional groups, and methods for polymerizing such compositions, in which the onset of cationic polymerization is controllably delayed to extend the time between formation of a moldable gel and formation of a hardened solid.

Abstract: The present invention relates to a radiation-curable binder BM consisting of a copolymer which is composed of: A) from 80 to 99% by weight of a hydroxyl-containing polyether acrylate and/or polyester acrylate A), which optionally contains a mono-, di- and/or polyamine AA) as adduct, and of B) from 1 to 20% by weight of benzophenonetetracarboxylic acid, its anhydrides and/or its esters. The invention additionally relates to processes for the preparation of the binder BM and to the use of the binders BM in radiation-curable coating compositions.

Abstract: New initiators which are suitable for cationic polymerization have the following structure: ##STR1## such that following apply: R.sup.1 and R.sup.2 are alkyl or cycloalkyl or they, together with the S atom, form a heterocyclic ring,R.sup.3 is H or alkyl,R.sup.4, R.sup.5, R.sup.6, and R.sup.7 are H, alkyl, or alkoxy,X.sup.-- is a non-nucleophilic anion.Reaction resin mixtures with initiators of this type contain, in addition to a cationically polymerizable monomer and/or oligomer, 0.01 to 10% by mass of the initiator.

Abstract: A photopolymerizable composition comprising i) an addition polymerizable compound having an ethylenically unsaturated double bond, ii) a sensitizing dye represented by the following formula (I) and iii) a titanocene compound: ##STR1## wherein A.sup.1 and A.sup.2 each represents a carbon atom or a hetero atom, Q.sup.1 represents a nonmetallic atom group necessary for forming a heterocyclic ring together with A.sup.1, A.sup.2 and the carbon atoms adjacent thereto, R.sup.1 and R.sup.2 each represents a hydrogen atom, an alkyl group or an aryl group and R.sup.1 and R.sup.2 may be combined with each other to form a ring, X.sup.1 and X.sup.2 each represents a cyano group or a substituted carbonyl group and X.sup.2 and X.sup.2 may be combined with each other to form a ring, and n represents 0, 1 or 2.

Abstract: A photocurable composition comprising an ultraviolet radical polymerization initiator, a cationic dye with absorptions in the visible light region, a quaternary boron salt and optionally a polymerization accelerator, is irradiated with ultraviolet light and visible light either simultaneously or separately, to achieve adequate hardening in air of both the surface and the interior of the cured product, and to provide a cured product with an excellent appearance and without production of coloring substances derived from the polymerization initiator.

Abstract: Compounds of formula I, II or III ##STR1## X is a divalent radical; Y is C.sub.1 -C.sub.6 aklylene, cyclohexylene or a direct bond;Ar.sub.1 is an aromatic radical as defined in claim 1,R.sub.1 and R.sub.2 are each independently the other, inter alia, a radical of formula ##STR2## in which p is zero or 1, or a radical of formula ##STR3## R.sub.3 is, inter alia, hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.12 cycloalkyl or phenyl-C.sub.1 -C.sub.3 alkyl;R.sub.4 is, inter alia, C.sub.1 -C.sub.12 cycloalkyl, phenyl-C.sub.1 -C.sub.3 alkyl or phenyl;or an acid addition salt of a compound of formula I, II or III;are useful as photosensitive base catalysts in base crosslinking compositions.

Abstract: The present invention provides a visible laser-curable resist composition which contains at least one radical-protecting compound selected from a phosphorous acid ester compound and an aromatic compound having N,N-dimethylamino group bonded to the carbon atom forming the aromatic ring and which is free from the hindrance of curing caused by deactivation of radical by oxygen and has excellent curability, and a process for formation of a resist pattern using the above composition.

Abstract: Photocurable, addition polymerizable compositions contain an epoxy resin and a photoinitiator system containing (a) an epoxy resin and (b) a photoinitiator system comprising: (i) an iodonium salt; (ii) a visible light sensitizer; and (iii) an electron donor compound, wherein the photoinitiator system has a photoinduced potential of at least about 0 mV relative to a standard solution of 2.9.times.10.sup.-5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5.times.10.sup.-5 moles/g camphorquinone in 2-butanone. The compositions cure on exposure to light in the visible spectrum and are useful in a variety of applications, including dental adhesives and composites.

Abstract: A method of preparing an adhesive composition that includes exposing a free-radically polymerizable pre-adhesive composition to a monochromatic radiation source having a peak intensity at a wavelength falling within the range of about 250 nanometers to about 600 nanometers to polymerize the pre-adhesive composition and form the adhesive composition.

Abstract: Photocurable, addition polymerizable compositions contain an epoxy resin and a photoinitiator system containing (a) an epoxy resin and (b) a photoinitiator system comprising: (i) an iodonium salt; (ii) a visible light sensitizer; and (iii) an electron donor compound, wherein the photoinitiator system has a photoinduced potential of at least about 0 mV relative to a standard solution of 2.9.times.10.sup.-5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5.times.10.sup.-5 moles/g camphorquinone in 2-butanone. The compositions cure on exposure to light in the visible spectrum and are useful in a variety of applications, including dental adhesives and composites.

Abstract: Photocurable addition-polymerizable compositions containing a free-radically-polymerizable monomer and a photoinitiator system containing i) an arylidonium salt, ii) a sensitizing compound, and iii) an electron donor having an oxidation potential that is greater than zero and less than or equal to that of p-dimethyoxybenzene (1.32 volts vs. S.C.E.). The compositions cure rapidly and deeply under ultraviolet or visible light.

Abstract: Provided by the invention is an ultraviolet-curable silicone-based releasing agent suitable for use as a coating agent on the back surface of a pressure-sensitive adhesive tape and releasable protective sheet on a pressure-sensitive adhesive label with an advantage that the coating layer thereof is curable by ultraviolet irradiation in an atmosphere which is not completely free from oxygen having an inhibiting effect on the curing reaction of the coating layer contributing to cost reduction for the production of pressure-sensitive adhesive tapes and labels. The releasing composition comprises, in addition to a radical-polymerizable organopolysiloxane having (meth)acryloxyalkyl groups and a photopolymerization initiator, a tertiary amine compound such as isoamyl 4-dimethylamino benzoate and 2-ethylhexyl 4-dimethylamino benzoate in a limited amount.

Abstract: A free-radical curable polish composition is described. The composition can be applied and cured as an ultra thin film on finished surfaces to provide enhanced chemical and mar resistance. The composition comprises an aqueous emulsion including an olefin-functional polymer or an olefin-functional prepolymer, and a silicone or silicone copolymer preferably with photoinitiators for UV and EB cure. The polish/emulsion can be applied, for example, to wet the surface of nitrocellulose lacquer wood finishes. The polish wet surface is first wiped to remove excess polish and thereafter exposed to UV radiation to provide a thin, polymerized protective film.

Abstract: The invention describes a dental composition, delivery system and method for making temporary crowns and bridges in which the composition comprises two free-radical polymerizable pastes, one a catalyst paste and the other a base paste, wherein the catalyst paste comprises at least one polymerizable monomer, at least one polymerization initiator which is a peroxide oxidizing agent, at least one first polymerization inhibitor and a filler, and wherein the base paste comprises at least one polymerizable monomer, at least one polymerization accelerator, at least one second polymerization inhibitor, at least one non-polymerizable plasticizer and a filler. These catalyst and base pastes are stored in a dual cartridge from which they can be dispensed with a dispenser, preferably in a 1:1 volume ratio, and can be mixed in a static mixer to form a moldable polymerizing material, which is then applied to a prepared area of one or more teeth in a patient's mouth to form a crown or a bridge.

Abstract: In accordance with the present invention, there are provided highly sensitive, water-developable photoreactive resin compositions useful for the preparation of printing plates. Due to the high sensitivity of invention resin compositions, they are particularly useful for preparation of digitally imaged printing plates. Printing plates prepared employing invention compositions are characterized as having excellent exposure sensitivity, the capability of rapidly curing upon exposure, excellent retention of fine details, and excellent colorless performance. Moreover, printing plates prepared employing invention compositions have good clarity and flexibility, excellent washout properties, and retain such properties over extended periods of storage. Once photopolymerized, printing plates of the invention have excellent physical properties, enabling their use in many very demanding flexographic applications.

Abstract: The present invention relates to novel compositions that contain an activator system that comprises a photoactivator, acid generator and chain extender. Methods and articles of manufacture that comprise such compositions are also provided. In a preferred aspect, the compositions are photoimageable.

Abstract: Powder coatings are described which are curable by means of exposure to radiation, typically ultraviolet radiation, in a form suitable for deposition onto substrates, typically by means of electrostatic deposition. It is expected that such powder coatings would be particularly useful in coating heat sensitive substrates since the necessity for heating the powder coating to elevated temperatures is not necessary to effect cure. Free radical curing coatings are described using specific chemical formulations of acrylourethane resins, unsaturated polyester resins and mixtures thereof in combination with morpholino containing photoinitiators, phenol containing photoinitiators, and ketal containing photoinitiators.

Abstract: An improved barrier or drug delivery system which is highly adherent to the surface to which it is applied is disclosed, along with methods for making the barrier. The barrier can be prepared by staining tissue with a photoinitiator, applying a solution containing a polymerizable barrier material solution and a photoinitiator to the tissue, and polymerizing the polymer solution on exposure to light. The resulting polymer adheres strongly to the tissue surface, and also forms a gel in the rest of the applied volume. The polymerizable barrier materials are highly useful for sealing tissue surfaces and junctions against leaks of fluids. The method can be used to adhere preformed barriers to tissue or other surfaces, or to adhere tissue surfaces to each other. Tissue surfaces can be adhered to each other to repair wounds. In addition to photochemical initiators, non-photochemical initiators and combinations of chemical initiators and photochemical initiators can be used.

Abstract: Provided is a radiation-curable, optical glass fiber coating composition containing at least one radiation-curable oligomer or monomer, and at least one chromophoric indicator selected so as to be susceptible to destruction of its chromophoric characteristic upon exposure to radiation and present in an amount which becomes substantially colorless when exposed to a level of radiation sufficient to cure said radiation-curable, optical glass fiber coating composition, wherein said at least one chromophoric indicator has a color which is distinguishable from a base color of said radiation-curable, optical glass fiber coating composition in cured form. The invention also provides a method of making the coating composition. The invention further provides a coated optical glass fiber and a method of making a coated optical glass on a fiber drawing tower. Also provided is a cable and telecommunications system.

Abstract: Compounds of the formulaRG--A--INwherein IN is a photoinitiator basic structure A is a spacer group and RG is a functional reactive group can be employed as coreactive photoinitiators for photo-polymerization of systems containing ethylenically unsaturated compounds.

Abstract: A free-radical polish composition is described. The composition can be applied and cured as an ultra thin film on finished surfaces to provide enhanced chemical and mar resistance. The composition comprises an aqueous emulsion including an olefin-functional polymer having low glass transition temperature or an olefin-functional prepolymer, and a silicone or silicone copolymer preferably with photoinitiators for UV and EB cure. The polish/emulsion can be applied, for example, to wet the surface of nitrocellulose lacquer wood finishes. The polish wet surface is first wiped to remove excess polish and thereafter exposed to UV radiation to provide a thin, polymerized permanent protective film on the polished surface.

Abstract: A marking composition comprising an energy ray curing resin, a leuco dye and a color developer both of which are low in solubility in toluene, which composition is capable of forming a vivid black color on irradiation with laser beams, and a laser marking method for forming a clear-cut black-colored mark by using the above composition.

Abstract: Compositions containing conductivity enhancers, which are capable of being coated onto a substrate by means of electrostatic assistance. The compositions comprise one or more free-radically curable monomer(s), and one or more non-volatile conductivity enhancer(s), having cationic and anionic portions, which are soluble in the monomer(s) and which do not interfere with free-radical polymerization, wherein said anionic portion is a non-coordinating organophilic carbon-containing anion. The compositions may further comprise one or more initiator(s), one or more dissociation enhancing agent(s), cross-linking agent(s), cationically polymerizable monomer(s), cationic initiator(s), leveling agents, oligomer(s) or polymer(s), preferably co-reactive, and other additives or adjuvants to impart specific properties to the cured coating.

Abstract: An N-aryl-.alpha.-amino acid (I), which is a novel compound, is effective as a photoinitiator. The photoinitiator composition including this photoinitiator is effective for improving photosensitive properties of photosensitive materials containing poly(amic acid) and an addition polymerizable compound used for pattern formation. Further, a photoinitiator composition (A) comprising an N-aryl-.alpha.-amino acid (I) or (I'), a 3-substituted coumarin (II) and/or an azabenzalcyclohexanone (III), or a photoinitiator composition (B) comprising an N-aryl-.alpha.-amino acid (I) or (I'), a 3-substituted coumarin (II) and a titanocene (IV), or a photoinitiator composition (C) comprising a 3-substituted coumarin (II), a titanocene (IV) and an oxime ester (V), is effective for improving photosensitive properties of photosensitive materials containing poly(amic acid) and an addition polymerizable compound used for pattern formation.

Abstract: Radiation curable compositions having improved moisture resistance with at least one acrylic monomer, silica, at least one initiator for ultraviolet radiation-induced curing of said composition, an effective amount of at least one ultraviolet light absorber, an effective amount of at least one hindered amine light stabilizer to inhibit ultraviolet radiation-induced degradation of said composition, and an effective amount of at least one acrylic functional siloxane additive to provide a surface energy of said composition having a contact angle of water greater than about 80.degree.. When employed as coatings for resinous articles, such as polycarbonate, and cured, said compositions provide improved weatherability and moisture resistance.

Abstract: The specification describes techniques for the manufacture of optical gratings in optical fibers. The grating pattern is written into the core of the fiber without removing the fiber coating. Coating compositions with high transparency to the actinic (writing) radiation but which are UV curable are described in detail. The coating compositions contain a UV photoinitiator that absorbs sufficient UV radiation to effectively cure the polymer but is relatively transparent to UV radiation used for writing the grating. The photoinitiator is one or more compounds selected from a specified group of aliphatic and cycloaliphatic ketones.

Abstract: Primer/bonding-resin compositions include certain hydrophilic monomers, reactive diluent monomers, high viscosity adhesive resins and photo-initiator systems, all provided in a one-component solution containing ethanol or acetone or other suitable solvents. Methods of use of such compositions include a single step application for priming and imparting enhanced adhesion between dental substrates and dental restoratives or components.

Abstract: A photopolymerizable composition comprising an addition polymerizable compound having at least one ethylenically unsaturated double bond and a photopolymerization initiator system, wherein the photopolymerization initiator system comprises:(a) a titanocene compound, and(b) at least one coumarin compound of the following formula (I): ##STR1## wherein (i) each of R.sup.1, R.sup.2 and R.sup.5 is a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, each of R.sup.3 and R.sup.4 is an alkyl group, provided that at least one of R.sup.3 and R.sup.4 is a C.sub.4-16 alkyl group, or (ii) R.sup.1 is a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and at least one set of R.sup.2 and R.sup.3, and R.sup.4 and R.sup.5, is connected to form an alkylene group substituted by a lower alkyl group, provided that when they do not form the connecting group, each of R.sup.2 and R.sup.5 is a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and each of R.sup.3 and R.sup.

Abstract: The denture base relining resin comprises a powder component that is a methacrylate ester polymer powder with benzoyl peroxide added thereto and a liquid component that comprises a combination of methyl methacrylate, a methacrylate and a monomer having a specific structure with at least one compound selected from 4-dimethylaminobenzoate and 4,4'-dimethylaminobenzophenone, a specific tertiary amine and a polymerization inhibitor, all incorporated in said liquid component at specific ratios.

Abstract: An active energy ray-curable resin composition comprises:(i) a linear polymer having a glass transition temperature at least equal to 50.degree. C. and a weight-average molecular weight of at least about 3.0.times.10.sup.4 ; and(ii) a resin obtained by esterifying, with an unsaturated carboxylic acid, a part of epoxy groups present in an epoxy resin comprising at least one compound having at least two epoxy groups in a molecule.

Abstract: The present invention relates to a photopolymerizable composition comprising squarylium compound represented by the formula (I): ##STR1## wherein R represents lower alkyl having 2 to 8 carbon atoms, a radical generator and an addition-polymerizable compound having at least one ethylenic unsaturated double bond.

Abstract: Resin compositions useful for filament winding applications comprising an epoxy component including at least one polyepoxide resin curable by heat, an olefinicially unsaturated monomer component including at least one polyolefinically unsaturated monomer curable by actinic radiation, at least one photoinitiator which is not a peroxide, at least one organic peroxide, and a heat activated curing agent for epoxides. The compositions have a viscosity less than about 2000 centipoise (cps) and are capable of retaining this viscosity for at least about 2 hours at a temperature of from about ambient temperature to about 60.degree. C. The resins are capable of being immobilized by actinic radiation exposure and further heat cured without substantial resin drip. One or more organic peroxides are employed, selected from the group of organic peroxides having 10 hour decomposition half lives at temperatures of from about 50.degree. C. to less than about 104.degree. C.

Abstract: An ultraviolet curing resin for an optical disk according to the present invention which includes: a multiacrylate-functional monomer selected from the group consisting of multiacrylate-functional monomers and multimethacrylate-functional monomers and mixtures of the foregoing monomers; a difunctional monomer selected from the group consisting of diacrylate-functional monomers, dimethacrylate-functional monomers and mixtures of the foregoing monomers; a diluent; an adhesion promoter; and a photopolymerization initiator. The ultraviolet curing resin may also include a surface tension adjusting agent.

Abstract: Primer/bonding-resin compositions include certain hydrophilic monomers, reactive diluent monomers, high viscosity adhesive resins and photo-initiator systems, all provided in a one-component solution containing ethanol or acetone or other suitable solvents. Methods of use of such compositions include a single step application for priming and imparting enhanced adhesion between dental substrates and dental restoratives or components.

Abstract: There are disclosed herein a visible light sensitizer for a photopolymerizing initiator and/or a photocrosslinking agent which comprises a thiobarbituric acid derivative compound of the general formula (A) or (B): ##STR1## a photopolymerizable and/or a photocrosslinkable composition in which the thiobarbituric acid derivative compound is used, and a hologram recording medium in which the composition is used.

Abstract: Photocurable addition-polymerizable compositions containing a free-radically-polymerizable monomer and a photoinitiator system containing i) an arylidonium salt, ii) a sensitizing compound, and iii) an electron donor having an oxidation potential that is greater than zero and less than or equal to that of p-dimethyoxybenzene (1.32 volts vs. S.C.E.). The compositions cure rapidly and deeply under ultraviolet or visible light.

Abstract: An optical disc comprises two facing disc units, at least one of which has a recording layer formed on its surface facing to the other disc unit. The disc units are bonded together by a layer of adhesive which may be a room-temperature curing thermosetting adhesive having a glass transition temperature higher than the upper limit of the range of temperatures of environments in which the disc may be used. Alternatively, the adhesive may be a room-temperature curing two-pack epoxy adhesive which comprises a bisphenol epoxy resin base agent and a modified aliphatic polyamine curing agent, and which has a viscosity of 100-1000 cps, a pot life of one hour or more, a cure shrinkage of 1.0% or less, a water absorption, after curing, of 0.2% or less, and a Shore hardness, after curing, of 80-90.

Abstract: A gloss coating composition comprising radiation curable oligomers and monomers, and photosensitizers in a homogeneous mixture having a viscosity in the range of 4500 to 8000 cps; wherein the presence of the photosensitizers causes polymerization of the radiation curable oligomers and monomers when exposed to an ultraviolet light source. The coating composition is applied to at least one surface of a substrate and exposed to an ultraviolet light source resulting in curing of the composition onto the substrate surface without substantial penetration into the substrate surface forming a gloss coated substrate.

Abstract: A pyran derivative has a structure ofR.sup.2 R.sup.3 C.dbd.(C.sub.5 H.sub.2 R.sup.1 O)--(CH.dbd.CH).sub.n --C.sub.6 H.sub.2 R.sup.6 R.sup.7 --NR.sup.4 R.sup.5wherein n is 3 or 4; R.sup.1 is a proton, alkyl or phenyl group; each of R.sup.2 and R.sup.3 is independently a cyano, alkoxycarbonyl having an alkyl, acyl having an alkyl, aracyl having phenyl, sulfonyl, aryl, or aryloxy; each of R.sup.4 and R.sup.5 is an alkyl group; and each of R.sup.6 and R.sup.7 is a proton, provided that R.sup.4 and R.sup.5 are alkyl groups, and a pair of R.sup.4 and R.sup.6 as well as a pair of R.sup.5 and R.sup.7 can be bonded to each other to form a heterocycle.A photosensitive composition comprises a polymerizable compound, a polymerization initiator and a photosensitizer which is the pyran derivative. A photosensitive resin composition comprises a crosslinkable polymer, a crosslinking agent and the photosensitizer.

Abstract: A curable silicone composition comprising an addition reaction product of an organopolysiloxane having amino groups at both ends of its molecule and a vinyl group-containing isocyanate, and a moisture-curing or anaerobic-curing catalyst and a photopolymerization catalyst.The silicone composition has high photocurability and moisture- or anaerobic-curability, easy to manufacture and easy to handle.

Abstract: Aminoketone-substituted coumarin sensitizers having quaternary amine substituents are described which have very high photosensitivity, and are useful in moderate pH aqueous-developable printing plates. The aminoketone-substituted coumarin sensitizers are described by the formula: ##STR1## wherein R.sub.1 and R.sub.2 each represent an alkyl group having 1 to 6 carbon atoms, and R.sub.3 and R.sub.4 each represent hydrogen; or at least one of R.sub.1 and R.sub.3 or R.sub.2 and R.sub.4 together represent an alkylene group having 2 to 4 carbon atoms,R.sub.5 represents an alkyl group having 1 to 6 carbon atoms or H,R.sub.6 represents an alkylene group having 1 to 16 carbon atoms, an oxyalkylene group having form 1 to 16 carbon atoms, or a poly(oxyalkylene) group in which said alkylene group has 2 to 4 carbon atoms and the number of oxygen atoms is a positive integer less than or equal to four,R.sub.7, R.sub.8, and R.sub.9 each independently represent an alkyl group having 1 to 6 carbon atoms, or any two of R.sub.

Abstract: Novel photosensitive compositions based on azlactone derived polymers are described. The polymers have a hydroearbyl backbone and pendant peptide groups with free-radically polymerizable functionality attached thereto, said polymer further comprising at least one oxyacid group or salt thereof, and optionally quaternary ammonium salt groups. A high speed durable printing plate having a mild pH aqueous developability is disclosed which incorporates these polymers in combination with a photoinitiator. The polymers are also useful as proofing films in graphic arts applications.

Abstract: A coating material crosslinkable by radiation comprising a) an olefinic unsaturated ester of an epoxy novolac resin, b) a binder formed by reaction of an epoxy compound having more than one epoxide group per molecule with at least one carboxylic acid in a molar ratio of epoxy groups per carboxyl group of 1:0.5 to 0.9 and subsequent reaction of the resulting reaction product with at least one unsaturated isocyanate ester formed by reaction of a compound with at least two isocyanate groups with a member of the group consisting of hydroxyl containing acrylic acid, methacrylic acid and cyanacrylic acid esters, c) at least one latent hardener, d) at least one photoinitiator e) 80-120% by weight of fillers and (f) additives, adjuvants and solvents and protective films formed with them.

Abstract: An adhesive system capable of use to secure two substrates to one another. The adhesive system uses a resin and a hardener which are encased in a polymerized, integral film.

Abstract: Aminoketone-substituted coumarin sensitizers having tethered tertiary amino groups are described which have extremely good photosensitivity. The sensitizers of the instant invention have the formula: ##STR1## wherein R.sub.1 and R.sub.2 each represent an alkyl group having 1 to 6 carbon atoms, and R.sub.3 and R.sub.4 each represent hydrogen; or at least one of R.sub.1 and R.sub.3 or R.sub.2 and R.sub.4 together represent an alkylene group having 2 to 4 carbon atoms,R.sub.5 represents an alkyl group having 1 to 6 carbon atoms or H,R.sub.6 represents an alkylene group having 1 to 6 carbon atoms, andR.sub.7 and R.sub.8 each independently represent an alkyl group having 1 to 6 carbon atoms, both of R.sub.7 and R.sub.8 taken together represent an alkylene group having 4 to 6 carbon atoms, or R.sub.5 or R.sub.6 taken together with R.sub.7 or R.sub.8 represent a five, six, or seven membered heterocyclic ring group.

Abstract: The invention relates to acyl-(2'-hydroxydiphenyl-2-yl)-phosphinic acid salts of formula (I) ##STR1## in which each of the radicals R.sup.1, R.sup.2 and R.sup.3 may be included singly or multiply and in which R.sup.1 and R.sup.2 are mutually independently hydrogen, an alkyl or alkoxy radical with 1 to 6 carbon atoms or halogen with an atomic number of 9 to 35; R.sup.3 means the same as R.sup.1 or R.sup.2 ; Ar is an aromatic hydrocarbon radical with 6 to 10 carbon atoms; and Me is a cation of at least one alkaline metal or N(R.sup.4).sub.4 + in which the radicals R.sup.4 are the same or different and stand for an alkyl radical with 1 to 6 carbon atoms. The invention also relates to a process for producing these compounds (I) and their use as photoinitiators in photopolymerisable materials, preferably on an aqueous basis.

Abstract: An adhesive composition for being applied to at least one of thread contact faces of screw members so as to stick said thread contact faces to each other in engaging the screw members with each other for the purpose of locking and sealing the engaged screw members, in which micro-capsules enclosing at least a reactive monomer of a reactive adhesive composition comprising said monomer, a polymerization initiator of the aforesaid monomer and/or an activator of the aforesaid polymerization initiator is dispersed in a binder comprising a photo-hardening resin composition.

Abstract: A photopolymerizable composition comprises: (i) a polymerizable compound carrying an addition-polymerizable unsaturated bond; (ii) a methine compound; (iii) at least one compound selected from the group consisting of: (a) compounds having carbon-halogen bonds, (b) aromatic onium salts, (c) organic peroxides, (d) thio compounds, (e) hexaaryl-biimidazoles, (f) ketooxime esters, and (g) compounds represented by the following general formula (III): ##STR1## wherein R.sup.6, R.sup.7, R.sup.8 and R.sup.9 may be the same or different and each represents a substituted or unsubstituted alkyl, aryl, alkenyl, alkynyl or heterocyclic group, provided that at least two of R.sup.6, R.sup.7, R.sup.8 and R.sup.9 may be bonded together to form a ring structure and that at least one of them represents an alkyl group; and Z.sup.+ represents an alkali metal cation or a quaternary ammonium cation. The composition has a high sensitivity to a wide range of actinic light rays extending from ultraviolet to visible light.

Abstract: A modelling liquid used for building up dental porcelain, comprising:(A) a photopolymerizable compound having at least one ethylenically unsaturated double bond,(B) a photopolymerization initiator,(C) a reducing agent, and(D) a polymerization inhibitor.

Abstract: Disclosed is a photocurable composition comprising (a) a radical-polymerizable monomer, (b) an .alpha.-ketocarbonyl compound and (c) a derivative of mercaptobenzimidazole, mercaptobenzothiazole or mercaptobenzoxazole or an aromatic amine nucleus-substituted with an electron-attractive group. This composition has a high photocuring speed at a temperature close to normal temperature and gives a cured product excellent in various physical properties. This composition is valuable as a dental adhesive or resin.