摘要:
An electrocaloric element for a heat transfer system includes an electrocaloric material of a copolymer of (i) vinylidene fluoride, and (ii) an addition polymerization monomer that is larger than vinylidene fluoride and includes a substituent more electronegative than chlorine. Electrodes are disposed on opposite surfaces of the electrocaloric material, and an electric power source is configured to provide voltage to the electrodes. The system also includes a first thermal flow path between the electrocaloric material and a heat sink, and a second thermal flow path between the electrocaloric material and a heat source.
摘要:
An exemplary polymerizable thermosetting composition includes the reaction product of (a) allyl alcohol; (b) a cyclic polyol selected from the group consisting of a cycloaliphatic polyol having at least one secondary hydroxyl group, a heterocyclic polyol having primary and/or secondary hydroxyl groups, and mixtures thereof; (c) ethyleneglycol bischloroformate; and (d) optionally, at least one linear or branched aliphatic polyol having two to six hydroxyl groups. The allyl alcohol (a) is present in an amount of 0.4 to 1.99 equivalents of OH to 1 equivalent chloroformate, and the cyclic polyol (b) is present in an amount of 0.01 to 0.6 equivalents of OH to 1 equivalent of chloroformate. A reaction product, a polymerizate including the polymerizable thermosetting composition, and an optical article including the polymerizable thermosetting composition are also provided.
摘要:
Photochromic matrix compositions and tie layer compositions useful for the preparation of photochromic polycarbonate lenses are disclosed. The tie layer compositions facilitate adhesion of the photochromic matrix composition to the polycarbonate lens. The photochromic matrix compositions can contain a flexible hydrophilic dimethacrylate monomer, one or more hydrophobic monomers, a flexible hydrophobic multi(meth)acrylate monomer, one or more urethane methacrylate oligomers, and one or more photochromic dyes. The tie layer compositions can contain one or more methacrylate monomers, a (meth)acrylated oligomer with a polycarbonate backbone, one or more urethane methacrylate oligomers, and a solvent or solvent mixture. Methods of preparing photochromic polycarbonate lenses are also disclosed, involving the serial application of the tie layer composition, then the photochromic matrix composition to the lens.
摘要:
Disclosed herein is a polycarbonate comprising a terminal olefin group of the formula wherein R1 is a C1-C40 hydrocarbon that can be unsubstituted or substituted with a halogen, olefin, ether, ketone, or C4-C30 polyoxyalkylene functionality in which the alkylene groups contain 2 to 6 carbon atoms, R2 to R4 are each independently a hydrogen or a C1-C40 hydrocarbon that can be unsubstituted or substituted with a halogen, olefin, ether, ketone, or a C4-C30 polyoxyalkylene functionality in which the alkylene groups contain 2 to 6 carbon atoms, and optionally wherein any two of R1 to R4 together form a monocyclic, bicyclic, or tricyclic ring system optionally substituted with a heteroatom in each ring.
摘要:
Novel monomers of the general formula ##STR1## where b is 0 or 1, a is 1, 2, 3 or 4, R.sup.2 is a monovalent alkyl radical and R is an organic radical. The novel monomers may be employed to produce novel copolymers useful as hydrogel, soft non-hydrogel and/or rigid gas permeable contact lens materials.
摘要:
A process for forming a polymerizable, liquid, substantially gel-free, poly(allyl carbonate)-functional prepolymer composition comprises heating a neat composition comprising at least one poly(allyl carbonate)-functional monomer and free radical initiator having a ten-hour half-life temperature of at least 85.degree. C. at temperatures in the range of from 5 Celsius degrees below the ten-hour half-life temperature of the free radical initiator to 150.degree. C., to form a reaction mixture having an increased 25.degree. C. viscosity in the range of from 25 to 10,000 centipoises and an ethylenic double bond utilization of at least 3 percent; and over a period of less than 90 minutes cooling the reaction mixture to a temperature at least 20 Celsius degrees below the ten-hour half-life temperature of the initiator.
摘要:
A network polymer that contains:(a) a plurality of polymer chains which are derived from one or more ethylenically-unsaturated monomer(s), and(b) at least one linking group which links the polymer chains and which contains anhydride, carbonate, or uretidinedione moieties.The network polymer and other network polymers which contain similar dissociating groups are useful in curable formulations which contain a curable compound that contains:(a) a central moiety, and(b) a plurality of reactive groups which are bonded to the central moiety and which react with acid, hydroxyl, or isocyanate moieties liberated by dissociation of the anhydride, carbonate, or uretidinedione moieties.The curable composition builds viscosity more slowly and more controllably during curing than equivalent systems which do not contain the network polymer. It is useful in coatings and other uses for curable compositions.
摘要:
The method includes disposing a liquid monomer or a monomer mixture and a photosensitive initiator into a mold cavity defined by mold members and directing ultraviolet light to act on the lens forming material in the cavity to produce a lens therefrom. The mold members are cooled by air.
摘要:
A photopolymerizable resin is formed from between about 50% to 90% by weight of a polymerizable base component, between about 1% and 20% by weight of a cross-linker, between about 0.5% and 6% by weight of a photoinitiator, and between about 0.5% and 20% by weight of a viscosity control agent. Preferably the resin has a viscosity above 25 and below 130 centistokes at 68.degree. F. In a preferred embodiment, the resin includes between about 0.5% and 3.0% by weight of fumed silica or fine mesh silica as a viscosity control agent, and is cured under the combined influence of heat and actinic radiation to form a clear, hard, plastic optic having a refractive index of greater than or equal to 1.50 and a scratch resistance greater than or equal to 1.0 in a Bayer abrader and hazemeter. A method and apparatus for forming improved ophthalmic lenses is also included.
摘要:
Method, for making a plastic lens. The method includes disposing a liquid monomer or a monomer mixture and a photosensitive initiator into a mold cavity and directing ultraviolet light to act on the lens forming material in the cavity to produce a lens therefrom.