摘要:
An acrylic oligomer useful in a two stage curing coating composition having a weight average molecular weight of 100 to 3000, a polydispersity of 1.01 to 1.7 and one or more reactive functionalities reactive with isocyanate groups and having 7.0 to 40.0 weight percent, based on the weight of the acrylic oligomer, of hydroxyl moieties wherein at least 40.0 to 70.0 weight percent of the hydroxyl moieties are provided by hydroxy butyl acrylate and the remaining hydroxyl moieties are provided by fast reacting hydroxyl constituents of hydroxy ethyl acrylate, hydroxy ethyl methacrylate or any mixtures thereof and by slow reacting hydroxyl constituents of secondary hydroxyl containing hydroxy propyl acrylate and secondary hydroxyl containing hydroxy propyl methacrylate and any mixtures thereof.
摘要:
The invention is directed to a two-stage cure coating composition comprising a two component composition of a binder and a crosslinking component; the binder comprises an acrylic polymer having a weight average molecular weight of 3,000 to 50,000 and hydroxyl moieties in the range of 7.0 to 40.0 weight percent, based on the weight of the acrylic polymer; wherein at least 40.0 weight percent of the hydroxyl moieties are provided by hydroxy butyl acrylate; and the crosslinking component comprises an organic polyisocyanate; and the first stage curing of a finish of the composition on a substrate forms a water spot free finish within 90 minutes of application and the composition has a pot life of less than a 2 second rise in Zahn cup viscosity in 150 minutes; and the invention also is directed to a method of producing a finish on a substrate utilizing the two component coating composition which comprises forming a two stage cure coating composition by mixing together the above described binder component and a cross-linking component; applying a layer of the coating composition over the substrate; first stage curing the layer on the substrate to a water spot free finish; and second stage curing the first stage cured layer on the substrate into a finish having excellent appearance and excellent physical properties.
摘要:
The instant invention pertains to a method and a fluid composition for producing contact lenses with relatively high edge quality and with relatively high precision and fidelity in reproducing a desired lens design. The method of the invention involves: a mold which has a first mold half with a first molding surface and a second mold half with a second molding surface, wherein the first and second mold halves are configured to receive each other such that the cavity is formed between the first and second molding surfaces which define the opposite two surfaces of a contact lens to be produced; a spatial limitation of actinic radiation to define the edge of the contact lens to be produced; and addition of a radical scavenger in a fluid composition comprising a lens-forming material to reduce substantially the crosslinking/polymerizing, caused by diffused, scattered and/or reflected incident actinic radiation, of the fluid composition outside of and around the spatial limitation of actinic radiation.
摘要:
The instant invention pertains to a method and a fluid composition for producing contact lenses with improved lens quality and with increased product yield. The method of the invention involves adding a non-crosslinkable hydrophilic polymer into a fluid composition including a lens-forming material in an amount sufficient to reduce an averaged mold separation force by at least about 40% in comparison with that without the non-crosslinkable hydrophilic polymer and to provide a disparity of about 10 N or less in mold separation force. The non-crosslinkable hydrophilic polymer has a limited miscibility with the lens-forming material low enough to successfully and timely form an intact interfacial film with a sufficient thickness at an interface between the mold and the fluid composition therein, and has a structure that minimizes entanglement of the non-crosslinkable hydrophilic polymer in the interfacial film with the polymer matrix of the formed lens.
摘要:
The invention provides a continuous-flow process for producing a polymeric material. The process of the invention comprises the steps of: introducing at least two solutions, each comprising one or more reactants, into a microreactor to mix the two solutions to form a reacting solution, wherein the one or more reactants are selected from the group consisting of a monomer, an initiator, a coupling agent, a prepolymer, a macromer, and mixtures thereof; feeding continuously the reacting solution into a flow-through polymerization reactor in a coil form, wherein the flow-through polymerization reactor is capable of providing a residence time sufficient for (co)polymerizing the reactants to form a polymer with a desired polydispersity, wherein the flow-through polymerization reactor is immersed in an ultrasonic bath to minimize or substantially eliminate unwanted high-molecular-weight fractions of the polymer.
摘要:
The present invention provides a water-soluble crosslinkable polyurea prepolymer. The crosslinkable polyurea prepolymer of the invention is prepared by reacting an amine- or isocyanate-capped polyurea with a multifunctional compound having at least one one ethylenically unsaturated group and a function group coreactive with the capping amine or isocyanate groups of the amine- or isocyanate-capped polyurea. The amine- or isocyanate-capped polyurea is a copolymerization production of: (a) at least one poly(oxyalkylene)diamine, (b) optionally at least one organic di- or poly-amine, (c) optionally at least one diisocyanate, and (d) at least one polyisocyanate. The crosslinkable polyurea prepolymer of the invention can find use in economically producing contact lenses which have durable, highly elastic soft contact lenses with desired physical properties. In addition, the present invention provides method for making a medical device, preferably an ophthalmic device, more preferably a contact lens.