13542 results about "Photoinitiator" patented technology

The invention provides a ceramic slurry preparation and 3D (three dimensional) printing light curing molding method. 25-85vol% of ceramic powder and 15-75vol% of an optical resin premix solution are mainly involved, and the method includes: A), preparation of the optical resin premix : namely stirring a low polymer, a reactive diluent, a photoinitiator, a dispersing agent, a photosensitizer and a sensitizer according to a certain proportion under intermediate speed for 0.5-3 hours to enable the components to be mixed evenly; B), placing the premix solution and the ceramic powder in a ball mill according to certain volume for ball-milling for 5-15 hours to prepare the ceramic slurry high in solid content and low in viscosity; subjecting the ceramic slurry to curing molding layer by layer gradually on a 3D light curing molding machine to obtain a ceramic green body prior to aftertreatment of drying, degreasing, sintering and the like to obtain ceramic part. The method is high in preparation molding precision and free of molds to prepare complex structure parts, the ceramic product can reach more than 92% in density, 320-1750MPa in flexural strength and 1800-4500MPa in compression strength.

Blends of oligomeric urethane multi(meth)acrylate; optionally at least one other monomer selected from the group consisting of acrylic monomers, styrenic monomers and ethylenically unsaturated nitrogen heterocycles, preferably a polyol multi(meth)acrylate; and nanoparticles of an ethylenically unsaturated, preferably (meth)acrylic-functionalized, titanium or zirconium compound can be cured by ultraviolet radiation in contact with a photoinitiator to produce optical resinous articles having high refractive indices, haze ratings of at most 5% and other properties which may be tailored according to the desired use.

A polymerizable composition includes at least one monomer, a photoinitiator capable of initiating polymerization of the monomer when exposed to light, and a phosphor capable of producing light when exposed to radiation (typically X-rays). The material is particularly suitable for bonding components at ambient temperature in situations where the bond joint is not accessible to an external light source. An associated method includes: placing a polymerizable adhesive composition, including a photoinitiator and energy converting material, such as a down-converting phosphor, in contact with at least two components to be bonded to form an assembly; and, irradiating the assembly with radiation at a first wavelength, capable of conversion (down-conversion by the phosphor) to a second wavelength capable of activating the photoinitiator, to prepare items such as inkjet cartridges, wafer-to-wafer assemblies, semiconductors, integrated circuits, and the like.

A method for manufacturing optical fiber ribbon containing optical fibers having colored layers. The color is provided in a secondary coating composition that is cured prior to application of a matrix material for forming the optical fiber ribbon. The secondary coating composition includes a photoinitiator that is relatively insensitive to oxygen, and the environment to which the secondary coating composition is exposed is limited by removing the boundary layer of air surrounding the secondary coating composition prior to the application of the matrix material thereto.

Radiation-curable silsesquioxane resin materials are employed for micro- and nanolithography. The resin materials can include a radiation-curable silsesquioxane resin and a photo-initiator having low viscosity. The low viscosity of the liquid system allows imprinting with low pressure and low temperature; e.g. room temperature. The resist's dry etching resistance is increased and the cured film is more easily separated from the mask. Due to its high modulus after cure, the material allows the fabrication of micro- and nano-features having high aspect ratios while providing a high throughput. Various pattern sizes, for example, ranging from tens of microns to as small as a few nanometers, may be achieved with the UV-curable material system.

A curable composition comprises epoxy resin preparable by reaction of epichlorohydrin with at least one of bisphenol A or bisphenol F, polyfunctional (meth)acrylate, dicyandiamide and photoinitiator. The curable composition is useful for preparing treated backings and coated abrasive articles.

Liquid radiation curable resins for additive fabrication comprising an R-substituted aromatic thioetber triaryl sulfonmm tetrakis(pentafluorophenyl)borate cationic photoinitiator is disclosed. A process for using the liquid radiation curable resins for additive fabrication and three-dimensional articles made from the liquid radiation curable resins for additive fabrication are also disclosed.

A new photopolymerizable material allows single-step, fast recording of volume holograms with properties that can be electrically controlled. Polymer-dispersed liquid crystals (PDLCs) in accordance with the invention preferably comprise a homogeneous mixture of a nematic liquid crystal and a multifunctional pentaacrylate monomer in combination with photoinitiator, coinitiator and cross-linking agent. Optionally, a surfactant such as octancic acid may also be added. The PDLC material is exposed to coherent light to produce an interference pattern inside the material. Photopolymerization of the new PDLC material produces a hologram of clearly separated liquid crystal domains and cured polymer domains. Volume transmission gratings made with the new PDLC material can be electrically switched between nearly 100% diffraction efficiency and nearly 0% diffraction efficiency. By increasing the frequency of the switching voltage, switching voltages in the range of 50 Vrms can be achieved. The optional use of a surfactant allows low switching voltages at lower frequencies than without a surfactant. In an alternative embodiment, a PDLC material in accordance with the invention can be utilized to form reflection gratings, including switchable reflection gratings. In still further embodiments, a PDLC material in accordance with the invention can be used to form switchable subwavelength gratings. By further processing, static transmission, reflection, and subwavelength PDLC materials can be formed. In addition, PDLC materials in accordance with the present invention can be used to form switchable slanted transmission gratings suitable for switchable optical coupling and reconfigurable optical interconnects.

The invention relates to the photoinitiator technical field, in particular to an oxime ester photoinitiator and a preparation method thereof. A carbazole oxime ester photoinitiator has a structural general formula as the right formula, R=formula (1), n=0-5, m=3 or 4, R radical is aliphatic ketone with cyclane, the cyclane is cycloaliphatic ring from cyclopropane to cyclooctane, branched-chain aliphatic hydrocarbon connects the cyclane and the ketone, and the chain usually has 0-6 carbon atoms. The carbazole oxime ester photoinitiator with the structure is a brand-new compound with good photoinitiator performance, and solves the problem of poor sensitivity, thermal stability and solubility of the existing carbazole oxime ester photoinitiators.

Curable pressure sensitive adhesive compositions comprising an acrylate copolymer, a mono-acrylate oligomer, a multi-acrylate oligomer having from 2 to 5 acrylate functional groups per molecule, and a photoinitiator, the adhesive exhibiting pressure sensitive adhesive characteristics and forms at least a semi-interpenetrating polymer network when cured; wherein the semi-IPN has an average molecular weight between crosslinks (M_c) greater than about 3000, and the cured adhesive has a peel strength greater than about 40 N/dm. Embodiments of the adhesive compositions, when cured, are optically clear and resistant to heat and moisture.

Method and apparatus for making [and coating] a plastic lens is provided. [Oxygen barrier containing photoinitiator is used to cure incompletely cured lens portions. Radiation pulses are used to control lens curing rate. Lens is postcured while in a mold cavity using a conductive heat source.] More particularly, the invention relates to applying alternating periods of ultraviolet light to lens forming composition. Such composition is cured while controlling the rate of heat generation and/or dissipation via manipulation of the duration of the radiation or the cooling in the curing chamber. The ultraviolet light is directed toward the lens forming composition which is preferably disposed in a mold cavity formed by two mold members. The ultraviolet light may be directed in pulses or continuously.

A method of multiphoton photosensitizing a photoreactive composition comprises irradiating the composition with light sufficient to cause simultaneous absorption of at least two photons, thereby inducing at least one acid- or radical-initiated chemical reaction where the composition is exposed to the light. The composition comprises: (a) at least one reactive species that is capable of undergoing such reaction; and (b) at least one multi-component, multiphoton photoinitiator system.

Acrylate-terminated poly(beta-amino esters) are cross-linked to form materials useful in the medical as well as non-medical field. The polymeric starting material is combined with a free radical initiator, either a thermal initiator or a photoinitiator, and the mixture for cross-linking is heated or exposed to light depending on the initiator used. The resulting materials due to the hydrolysable ester bond in the polymer backbone are biodegradable under physiological conditions. These cross-linked materials are particular useful as drug delivery vehicles, tissue engineering scaffolds, and in fabricating microdevices. The materials may also be used as plastics, coating, adhesives, inks, etc. The cross-linked materials prepared exhibit a wide range of degradation times, mass loss profiles, and mechanical properties. Therefore, the properties of the material may be tuned for the desired use. The high-throughput approach to preparing a library of cross-linked poly(beta-amino esters) allows for the rapid screening and design of degradable polymers for a variety of applications.

Method of ejecting or depositing a substance includes depositing at least one substance that includes first and second photoinitiators onto a substrate, causing the first photoinitiator to react by irradiating the substance with at least one light, and causing the second photoinitiator to react by irradiating the substance with at least one light. Substance ejecting or depositing system including a substrate, an applicator that deposits a substance that includes first and second photoinitiators onto a substrate, and at least one light usable to irradiate the substance to cause the first and/or second photoinitiators to react.

Transmission and reflection type holograms may be formed utilizing a novel polymer-dispersed liquid crystal (PDLC) material and its unique switching characteristics to form optical elements. Applications for these switchable holograms include communications switches and switchable transmission, and reflection red, green, and blue lenses. The PDLC material of the present invention offers all of the features of holographic photopolymers with the added advantage that the hologram can be switched on and off with the application of an electric field. The material is a mixture of a polymerizable monomer and liquid crystal, along with other ingredients, including a photoinitiator dye. Upon irradiation, the liquid crystal separates as a distinct phase of nanometer-size droplets aligned in periodic channels forming the hologram. The material is called a holographic polymer-dispersed liquid crystal (H-PDLC).

Method of fabricating an optical element. A photodefinable composition is provided that includes (i) a hydrophobic, photodefinable polymer, said photodefinable polymer having a glass transition temperature in the cured state of at least about 80° C.; and (ii) a multiphoton photoinitiator system comprising at least one multiphoton photosensitizer and preferably at least one phtoinitiator that is capable of being photosensitized by the photosensitizer. One or more portions of the composition are imagewise exposed to the electromagnetic energy under conditions effective to photodefinably form at least a portion of a three-dimensional optical element.

This invention provides novel methods for the formation of biocompatible membranes around biological materials using photopolymerization of water soluble molecules. The membranes can be used as a covering to encapsulate biological materials or biomedical devices, as a “glue” to cause more than one biological substance to adhere together, or as carriers for biologically active species. Several methods for forming these membranes are provided. Each of these methods utilizes a polymerization system containing water-soluble macromers, species, which are at once polymers and macromolecules capable of further polymerization. The macromers are polymerized using a photoinitiator (such as a dye), optionally a cocatalyst, optionally an accelerator, and radiation in the form of visible or long wavelength UV light. The reaction occurs either by suspension polymerization or by interfacial polymerization. The polymer membrane can be formed directly on the surface of the biological material, or it can be formed on material, which is already encapsulated.

The invention relates to an ultraviolet curing color decorative coating, the components of the coating and the parts by weight thereof are as follows: 5 to 25 parts of epoxy acrylate prepolymer, 5 to 30 parts of polyurethane acrylate prepolymer, 2 to 10 parts of polyester acrylate prepolymer, 15 to 70 parts of acrylate monomer, 1 to 10 parts of photoinitiator, 1 to 35 parts of pigment, 0.5 to 10 parts of dispersant and 0.1 to 2 parts of auxiliary agent, the acrylate monomer is a mixture of the monomer with bifunctionality and the monomer with high functionality, wherein, the mixture ratio of the monomer with high bifunctionality to the monomer with bifunctionality is 1: 0.3 to 8. Compared with an ultraviolet curing transparent varnish, the ultraviolet curing color decorative coating has stronger decorative effect and almost the same curing speed, paint film hardness, adhesion, paint film gloss, and the like; and compared with a traditional solvent based colored paint, the ultraviolet curing color decorative coating does not contain volatile organic solvent, thereby avoiding the pollution and greatly improving the production efficiency. The ultraviolet curing color decorative coating is applicable to the decoration of plastics, wood materials, metals and other base materials.