Abstract: A photopolymerizable composition which is capable of successfully ensuring both high sensitivity and excellent storage stability is provided as a radical photopolymerization-system composition which is highest in the sensitivity and very promising out of the image-forming techniques. The photopolymerizable composition comprises a polymerizable group-containing compound having a specific structure set forth below wherein X1 and X2 each independently represent a group containing a hetero atom wherein the hetero atom is in the &agr;-position or a halogen atom and a photopolymerization initiator.

Abstract: The present invention provides a polymerizable composition comprising (a) an alicyclic alkane having at least one oxetanyl group and at least one epoxy group within the same molecule and (b) a compound capable of initiating cationic polymerization under irradiation of an active energy ray and/or under heat exhibits high activity in the photo- or heat-cationic ring-opening polymerization exhibiting high activity, e.g., rapid polymerizability, rapid curability, under irradiation of an active energy ray and/or under heat. The present invention also provides a polymerization product thereof.

Abstract: A thermally-stable cationic photoinitiator capable of flash vaporization under vacuum and temperature conditions of an available flash-evaporation chamber is selected. The photoinitiator is mixed with a cation-polymerizable monomer and/or oligomer of interest and the mixture is flash evaporated and condensed in conventional manner as a film on a cold substrate. The resulting vacuum-deposited, homogeneous layer is cured with a high-energy radiation source that causes the cationic photoinitiator to liberate acidic species that catalyze the crosslinking of the monomer/oligomer compounds in its deposited film form. As a result of the homogeneous, pinhole-free nature of the vacuum deposition process, the thin-film polymer product does not suffer from the disadvantages attendant to prior-art atmospheric processes for cationically-cured polymers.

Abstract: Photopolymerizable compositions are provided which are the reaction products of a vinyl ether, a photoinitiator system comprising an iodonium salt, a visible light sensitizer, and an electron donor compound. These monomeric/oligomeric compositions may also include epoxides, polyols, spiroorthocarbonates. One embodiment of the present invention is a polymerizable composition comprised of a vinyl ether, a spiroorthocarbonate, and a photoinitiator system. Another embodiment of the present invention is a polymerizable composition comprised of a vinyl ether, an epoxide, a polyol, and a photoinitiator system. Still another embodiment of the present invention is a polymerizable composition comprised of a vinyl ether, an epoxide, a polyol, a spiroorthocarbonate, and a photoinitiator system. Still further, another embodiment of the present invention is certain novel spiroorthocarbonate compounds. Each of these novel spiroorthocarbonate compounds include at least one epoxy group as a substituent.

Abstract: This invention is to provide a kind of photothermosetting component, which was composed of a base resin (A), a photopolymerizable photomonomer or photooligomer (B), a photoinitiator (C), an epoxide compound containing at least two epoxy groups (D), and an organic solvent. A base resin (A) is composed of containing at least two epoxy groups of epoxide compound (a), containing at least two double bonds of unsaturated monobasic acid (b), a saturated or unsaturated dibasic acid (c), and a saturated or unsaturated acid anhydride (d) according to the typical ratio. This photothermosetting component was coating on the substrate, and then dried by baking, exposed by light, developed, irradiated by ultraviolet light or heated, and cured to form a solder mask.

Abstract: Adhesives useful in applying articles, such as tapes, labels, signs, decals, emblems, car moldings, protective or optical films, etc., to surfaces to which articles normally do not adhere well, such as surfaces containing fluorine and polycarbonate, for example. The adhesives include a copolymer of one or more monoethylenically unsaturated alkyl (meth)acrylate monomers, one or more monoethylenically unsaturated secondary or tertiary amide-functional monomers, and optionally one or more acidic monomers.

Abstract: Selectively colorable compositions and a method for forming selectively colored polymeric bodies using such compositions are disclosed. In accordance with the invention, a selectively colorable polymerizable composition comprising a leucobase color former is irradiated with light of a particular wavelength and specific intensity for a specified duration. Exposure to actinic radiation cures the composition and activates the color former. Exposure to higher dosages of actinic radiation can bleach the composition. The irradiation dosage can be varied to selectively color the polymeric body whereby the resultant color of any particular area depends on the exposure dose received at that location. By varying the dose, a polymeric body can be prepared having distinctly colored elements at specific locations.

Abstract: Hydrogels of polymerized and crosslinked macromers comprising hydrophilic oligomers having biodegradable monomeric or oligomeric extensions, which biodegradable extensions are terminated on free ends with end cap monomers or oligomers capable of polymerization and cross linking are described. The hydrophilic core itself may be degradable, thus combining the core and extension functions. Macromers are polymerized using free radical initiators under the influence of long wavelength ultraviolet light, visible light excitation or thermal energy. Biodegradation occurs at the linkages within the extension oligomers and results in fragments which are non-toxic and easily removed from the body. Preferred applications for the hydrogels include prevention of adhesion formation after surgical procedures, controlled release of drugs and other bioactive species, temporary protection or separation of tissue surfaces, adhering of sealing tissues together, and preventing the attachment of cells to tissue surfaces.

Abstract: Low viscosity, radiation curable fluid formulations that can be used advantageously as radiation curable, inks. The formulations are easily prepared for use in ink jet systems. The viscosity of the compositions is low enough so that conventional solvent is not required in order to satisfy the requisite low ink jet viscosity specifications. After curing, the compositions form durable, weatherable, abrasion resistant, printed images on a wide variety of porous and nonporous substrates. The formulations are very suitable for outdoor printing applications, especially for printing outdoor graphics onto a variety of surfaces, including vinyl or other polymer films commonly used for signage, retroreflective signage or other retroreflective items.

Abstract: One embodiment of the present invention is a method for synthesizing superabsorbent polyacrylate polymers comprising the steps of providing an acrylate monomer, a multifunctional monomer, and free radical initiator in the absence of a solvent; mixing the acrylate monomer, multifunctional monomer, and free radical initiator to create a solvent free solution; and subjecting the solvent free solution to radiation to create a cross-linked polymer. The product created by this method is also a part of the present invention.

Abstract: The invention relates to a polymerizable, cross-linkable composition which contains: (A) 1-99.99 wt.-% of at least one conversion product of OH-functional (meth)acrylates with (i) oligomers from unsaturated rings or heterocyclic rings and maleic anhydride and/or with (ii) at least one ring-shaped polycarboxylic acid with at least 4 ring-carbon atoms and/or the anhydrides thereof with a saturated ring system, at least 4 carboxyl groups, and 0 or 1 heterocyclic ring atoms from the group N, O, S, whereby at least one carboxyl group and/or anhydride group of the above described substance groups is reacted with unsaturated polymerizable groups; (B) 0 to 98.99 wt.-% of one or more polymerizable, unsaturated organic compounds with at least one CH2═C(R10)—COO-group, whereby R10 represents H or methyl; (C) 0.01 to 5 wt.-% initiators and optional activators; (D) 0 to 90 wt.-% common solvents; (E) 10 to 90 wt.

Abstract: The invention relates to: 4-methylene-1,3-dioxolanes of the general formula (I) 1

Abstract: A photocurable resin composition suitable for photo-fabrication. The resin composition capable of being promptly cured by photo-irradiation, thereby reducing fabricating time and providing cured products having excellent mechanical strength and minimized shrinkage during curing to ensure high dimensional accuracy. The composition includes (A) an oxetane compound, (B) an epoxy compound, and (C) a cationic photo-initiator.

Abstract: Enhancement of the rates of cationic polymerizations initiated by onium salts has been achieved through the use of oligomeric and polymeric electron-transfer photosensitizers derived from a polymerizable compound substituted with a polynuclear aromatic group, including epoxides, oxetanes, and ethylenically unsaturated compounds. The polymerizable compound is substituted with residues derived from anthracene, naphthalene, perylene, pyrene, fluorene, carbazole, indole, benzocarbazole, acridone, phenothiazine, and thianthrene, particularly carbazole.

Abstract: Solvent-free and water-free radiation-curable primers based on hydroxy-functional prepolymers and cycloaliphatic epoxides or based on hydroxy-functional prepolymers and olefinically unsaturated compounds or based on epoxides and vinyl ethers together with cationic or free-radical initiators may be applied in the same manner as conventional commercial solvent-free laminating adhesives and, for many coatings, allow subsequent in-line coating without there being any need to evaporate solvent or water from the primer coating.

Abstract: The present invention relates to a process for the production of three-dimensional articles by stereolithography using a radiation-curable composition comprising a mixture of at least one cationically polymerizable compound and/or at least one free radical polymerizable compound, at least one filler material and at least one photoinitiator for cationic and/or radical polymerization. An organic viscosity stabilizer material may be brought into contact with the composition to substantially delay or prevent undesirable viscosity increase and subsequently premature polymerization. A filler material is optionally added to the composition in an effective amount to at least delay or prevent a significant increase in viscosity and polymerization. The process is particularly suitable for stabilizing resins in stereolithography baths.

Abstract: Photopolymerizable compositions are provided which are the reaction products of a vinyl ether, a photoinitiator system comprising an iodonium salt, a visible light sensitizer, and an electron donor compound. These monomeric/oligomeric compositions may also include epoxides, polyols, spiroorthocarbonates. One embodiment of the present invention is a polymerizable composition comprised of a vinyl ether, a spiroorthocarbonate, and a photoinitiator system. Another embodiment of the present invention is a polymerizable composition comprised of a vinyl ether, an epoxide, a polyol, and a photoinitiator system. Still another embodiment of the present invention is a polymerizable composition comprised of a vinyl ether, an epoxide, a polyol, a spiroorthocarbonate, and a photoinitiator system.

Abstract: Describes polymerizing with actinic radiation a cationically polymerizable organic composition comprising (a) at least one polyfunctional thiirane having at least two groups represented by the following general formula I, 1

Abstract: There is disclosed a cation-polymerizable coating composition characterized by containing (A) a cation-polymerizable binder component consisting of (a) an epoxy group-containing compound and, as necessary, (b) an oxetane compound, (B) a modified dimethylsilicone oil with a number average molecular weight of 500-1,000,000 having a hydroxyl group(s) bonded directly to a silicon atom, a hydrolyzable functional group(s) bonded directly to a silicon atom and capable of forming a hydroxyl group(s) bonded directly to a silicon atom by hydrolysis, or a carboxyl group(s), and (C) a cation-polymerization initiator which forms a cation by irradiation or by heating. Said coating composition is suitable particularly for coating cans capable of forming a coating film having excellent adhesivity, processibility, hardness, initial lubricity and lubricity after the retort treatment.

Abstract: The present invention is directed to a photocatalytic composition which comprises at least one compound selected from a group consisting of polycyclic aromatic compounds and carbazole derivatives, both of which contain as substitutes at least any of hydroxy group, optionally-substituted aralkyloxy group or alkoxy group and having an UV absorption spectrum at a wavelength longer than 330 nm, and at least one aryl onium salt selected from a group consisting of diphenylalkylsul fonium salts, dinaphthylalkylsulfonium salts, triphenylsulfonium salts, diphenyliodonium salts, phenylnaphthyliodonium salts and dinaphthyliodonium salts, those which perform as a catalyst for cationic photopolymerization. The photocatalytic composition according to the present invention can be cured by admixing it with a cationically-polymerizable compound in the presence of an actinic radiation, such as light, electron beam and X-ray.

Abstract: Disclosed is an ultraviolet-curable cellulosic coating composition comprising cellulose acetate, diepoxy compound and photo cationic polymerization catalyst. The objective is to provide a novel ultraviolet-curable cellulosic coating composition capable of forming a film excellent in the adherence to polar substrate, solvent resistance, gloss and impact resistance.

Abstract: There are provided a photosensitive polymer having a copolymer of alkyl vinyl ether and a resist composition containing the same.

Abstract: The invention concerns a novel method for preparing non-toxic resins crosslinkable under radiation in the presence of an initiator system. Said resins are prepared from compositions of an organic and/or silicon type comprising monomers, oligomers and/or polymers with organofunctional groups, and are cross-linked in the presence of an initiator system consisting of an onium salt with low toxicity whereof the cationic structure is [(CH(CH3)2—C6H4—)—I—(—R1)]+(I).

Abstract: Polymerizable and hydrolysable oxetane silanes and in particular silicic acid condensates which can be prepared therefrom are described, which exhibit only a low volume shrinkage on polymerization and produce polymers with high mechanical strength and therefore can be used above all as dental material or constituent thereof.

Abstract: The invention relates to a photosensitive resin composition for rapid prototyping comprising: a. about 30 wt. % to about 70 wt. % of at least two epoxy resins, at least one of these resins is solid at room temperature and comprises aromatic groups, and at least one of these resins is liquid, having a viscosity at 25° C. lower than about 1,000 Pa.s, b. about 15 wt. % to about 50 wt. % of at least one multifunctional acrylate compound c. about 5 wt. % to about 30 wt. % of a hydroxyfunctional compound d. about 1 wt. % to about 6 wt. % cationic photoinitiator e. about 1 wt. % to about 6 wt. % free radical photoinitiator. The invention further relates to a process for the manufacturing of 3-dimensional objects, known as rapid prototyping, wherein the photosensitive resin composition is used.

Abstract: A curing process for cationically polymerisable monomers, which comprises applying a composition comprising: (a) at least one cationically polymerisable monomer, (b) as photoinitiator at least one iodonium salt containing an SbF6, PF6 or BF4 anion, (c) one pigment, and (d) at least one sensitiser, to a substrate, irradiating it with light having a wavelength of 200-600 nm and then heat-postcuring it, is distinguished by little yellowing of the cured formulation.

Abstract: Disclosed are compounds of the formulas which are useful as monomers in photopolymerizable compositions. Also disclosed are methods of polymerizing these monomers, and polymers produced thereby.

Abstract: An actinic radiation curable, cationic polymerizable, ink and coating composition having greatly enhanced reactivity, and reduced viscosity and are low in odor comprised of an aqueous solution containing a cationic polymerizable compound such as an cycloaliphatic epoxy compound, a water compatible hydroxy functional cyclic ether compound, particularly, an epoxy or oxetane compound, and water.

Abstract: UV-hardenable and thermally hardenable epoxy resins for the underfilling process in electrical and electronic components are provided. A new casting resin component has an increased storage stability at room temperature of at least 6 months and improved characteristics for the underfilling process including faster hardening and lower viscosity. Filler material with a maximum grain size of 20 &mgr;m and a siloxane component are provided in addition to the casting resin formulation.

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: There is disclosed an ultraviolet-curing coating composition for cans comprising (A) 10-85 parts by weight of a compound having alicyclic epoxy group(s) in the molecule, (B) 5-60 parts by weight of a compound having an oxetane ring of a specific structure, (C) 5-60 parts by weight of a compound having an oxetane ring and hydroxyl group in the molecule, (D) 5-60 parts by weight of a compound having either at least two oxetane rings or oxetane ring(s) and epoxy group(s) in the molecule, and (E) 0.01-20 parts by weight of a cation-polymerization initiator, which generates a cation when irradiated with ultraviolet rays, per 100 parts by weight of the total amount of the compounds (A), (B), (C) and (D); and a process for producing a coated metal can by coating this coating composition and curing by irradiation with ultraviolet rays.

Abstract: A cationically polymerizable pigmented composition comprising (A) a cationically polymerizable binder component containing at least one resin or compound selected from the group consisting of (A-1) a cationically polymerizable acrylic resin consisting of a copolymer of (a) a (meth) acrylic ester monomer having C.sub.6-31 aliphatic hydrocarbon group, (b) a polymerizable unsaturated monomer containing a polymerizable unsaturated group and at least one cationically polymerizable moiety selected from the group consisting of an epoxy group and an oxetane ring, and optionally (c) other polymerizable unsaturated monomer, and (A-2) a fatty acid-modified epoxy compound containing C.sub.6-32 aliphatic hydrocarbon group and epoxy group, (B) a cationic polymerization initiator initiating polymerization by irradiation or heating, and (C) a color pigment.

Abstract: A radiation curable coating composition is provided and includes an effective amount of cationic photoinitiator, in combination with a charge transfer complex, the charge transfer complex comprising at least one electron withdrawing reactant component and at least one electron donating reactant component free radically reactive therewith, the electron withdrawing reactant component comprising an unsaturated nitrogen containing compound and the electron donating reactant component comprising an unsaturated compound having at least one vinyl ether group, the electron donating reactant component may be separate from or structurally incorporated within the electron withdrawing reactant component and an effective amount of a cationic photoinitiator. A photopolymerization process employing the composition is also provided.

Abstract: A photocationically curable composition and a process for producing the same are provided. The composition comprises, as the essential component, a condensation product having an oxetanyl group, which is a condensation product of a hydrolyzate of an organic silane compound having an oxetanyl group and being represented by the formula below, or of a mixture of said organic silane compound and a reactive silicone having a siloxane linkage-forming group: ##STR1## wherein R.sup.0 means an organic functional group having an oxetanyl group, and X means a hydrolyzable group. The composition forms cured coating films of high surface hardness, and is useful as hard coating agents.

Abstract: A method for preparing a film suitable for use as the light-modulating unit of an SPD light valve, which film comprises a cross-linked polymer matrix having droplets of a liquid light valve suspension distributed in the cross-linked polymer matrix. The light valve suspension comprises particles suspended in a liquid suspending medium. The method comprises admixing a UV cross-linkable liquid oligomer or polymer and the liquid light valve suspension, emulsifying the resulting admixture to form an emulsion of the liquid light valve suspension in the UV cross-linkable liquid oligomer or polymer, and cross-linking the UV cross-linkable liquid oligomer or polymer while the mixture is in the form of a thin layer of the emulsion by exposing the layer to UV radiation or to an electron beam, such that the film is not damaged due to such exposing. The oligomer or polymer and the particles are free of deleterious effects on one another.

Abstract: The invention relates to compositions which undergo cationic curing with visible light, comprising:(a) 0.01 to 8 wt. % of at least one diaryliodonium compound,(b) 0.01 to 8 wt. % of at least one .alpha.-dicarbonyl compound,(c) 10.0 to 99.9 wt. % of at least one compound containing epoxide groups and/or oxetane groups,(d) 0 to 85 wt. % of modifiers, such as fillers, dyestuffs, pigments, flow improvers, thixotropic agents, polymeric thickeners, additives having an oxidizing action, stabilizers and retardants, characterized in that they additionally comprise(e) 0.001 to 5 wt. % of at least one aromatic amine.The compositions have a low intrinsic color, cure with little smell and, after curing, give compositions with very good mechanical properties.

Abstract: A coating composition which comprises (A) an actinic radiation curable resin, which is the ring-opening addition reaction product of (a) a polyester resin having hydroxyl functionality and (b) a compound having both a cyclic ether group and a (meth)acryloyl group, and preferably (B) at least one compound having at least one radical-polymerizable unsaturated group in a molecule. The composition also preferably comprises (C) a photopolymerization initiator and (D) photosensitizer. A process for obtaining the composition and the coating of metal substrates are also disclosed, as well as coated metal substrates that are particularly useful as cans for beverages, soft drinks, juices, and other food products. The coating compositions and the resulting cured coatings and coated substrates exhibit improved processability, adhesivity, hardness, mar resistance, appearance and retort resistance.

Abstract: Process for producing coatings or moldings by radiation curing, which involves using high-energy light to irradiate radiation-curable compositions containing 1-100% by weight, based on the total amount of free-radically or cationically polymerizable compounds, of compounds A) containing at least one cationically polymerizable 2,3-dihydrofuran group.

Abstract: The invention relates to a coating composition comprising (a) a radiation-curable binder composition comprising an unsaturated compound having at least one maleate, fumerate, itaconate, citraconate or mesaconate group; (b) an unsaturated vinylether compound and a compound which forms a strong exciplex with (a) or (b); that is otherwise free of a photoinitiating compound.

Abstract: Process for producing coatings or moldings by radiation curing, which involves using high-energy light to irradiate radiation-curable compositions containing 1-100% by weight, based on the total amount of free-radically or cationically polymerizable compounds, of compounds A) containing at least one cationically polymerizable 2,3-dihydrofuran structure.

Abstract: An ionic compound comprising at least one group A.sup.+ X.sup.-, comprising:a cationic group A.sup.+ selected from the group consisting of biaryliodonium, arylsulfonium, arylacylsulfonium, diazonium and organometallic cations comprising a transition metal complexed with at least one unsaturated cyclic compound comprising 4-12 carbon atoms, said cationic group being part of a polymer chain; whereinX.sup.- is an imide anion, [FSO.sub.2 NSO.sub.2 R'.sub.F ].sup.- or [R.sub.F CH.sub.2 OSO.sub.2 NSO.sub.2 R'.sub.F ].sup.- or [(R.sub.F).sub.2 CHOSO.sub.2 NSO.sub.2 R'.sub.F ].sup.-, or a methylide anion [FSO.sub.2 C(Q)SO.sub.2 R'.sub.F ].sup.-, or a [R.sub.F CH.sub.2 OSO.sub.2 C(Q)SO.sub.2 R'.sub.F ].sup.- or [(R.sub.F).sub.2 CHOSO.sub.2 C(Q)SO.sub.2 R'.sub.F ].sup.31 .

Abstract: A liquid, radiation curable composition is disclosed that includes a reactive diluent to lower initial application viscosity without substantial reduction of cure rate. The composition of the present invention comprises: (a) an unsaturated polyester polymer; (b) a non-polymerized, cocurable polyfunctional vinyl ether component; and (c) a reactive diluent which is an unsaturated dioic acid ester having the following structural formula: ##STR1## wherein at least one of R.sup.1 and R.sup.2 is a group that includes an oxygen with a carbon adlacent thereto and an abstractable hydrogen attached to the carbon.

Abstract: A photocurable resin composition suitable for photo-fabrication. The resin composition capable of being promptly cured by photo-irradiation, thereby reducing fabricating time and providing cured products having excellent mechanical strength and minimized shrinkage during curing to ensure high dimensional accuracy. The composition includes (A) an oxetane compound, (B) an epoxy compound, and (C) a cationic photo-initiator.

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

Abstract: A heat-activatable adhesive comprising an acrylic copolymer, which copolymer comprises a monomer consisting of an acrylate or methacrylate ester of a non-tertiary alkyl alcohol having a Tg of about 0.degree. C. or lower; a monomer consisting of an acrylate or methacrylate ester of an alcohol having a Tg of at least about 5.degree. C.; and a functional monomer. Selected embodiments include a retroreflective article comprising a film having a substantially flat surface and a structured surface, the structured surface comprising a plurality of precisely shaped projections, a colored layer disposed on the structured surface and adhered thereto in a plurality of discrete locations, and a heat-activatable adhesive layer disposed on the colored layer.

Abstract: An active energy ray-curable resin composition, particularly an active energy ray-curable coating composition, both comprising:(A) a resin having oxetane functional groups and epoxy groups in the molecule, and(B) a photo-induced cationic polymerization initiator.

Abstract: Process for the photocatalytic polymerization of a cyclical olefin or at least two different cyclical olefins in the presence of a metal compound as the catalyst, which is characterized in that a photochemical ring-opening metathesis polymerization is carried out in the presence of a catalytic amount of at least one carbene-free, bivalent-cationic ruthenium or osmium compound which contains at least one phosphine group, at least one photolabile ligand, and optionally neutral ligands bonded to the metal atom, a total of 2 or 3 ligands being bonded, and which contains acid ions for balancing the charge. The process can also be carried out by first carrying out the irradiation and ending the polymerization by heating. The process is suitable, for example, for the preparation of thermoplastics shaping compounds and the production of coatings and images in relief.

Abstract: A visible-light photopolymerizable composition comprising a) a cationically polymerizable epoxy resin, b) a hydroxyl-containing material c) an aryliodonium salt and d) a visible light sensitizer that is an alpha-dicarbonyl compound having an extinction coefficient less than about 1000. Particularly preferred compositions of the present invention are dental materials.

Abstract: Process for the photocatalytic polymerization of a cyclic olefin or at least two different cyclic olefins in the presence of a metal compound as catalyst, which comprises carrying out a photochemical ring-opening metathesis polymerization in the presence of a catalytic amount of at least one heat-stable niobium(V) or tantalum(V) compound which contains at least two methyl groups or two monosubstituted methyl groups bound to the metal, the substituent containing no hydrogen atom in the .alpha.-position.The process can also be carried out by first performing the irradiation and completing the polymerization by heating. The process is suitable, for example, for the preparation of thermoplastic molding materials, coatings and relief images.