Zms, Llc.

Nano-tex, Inc.

University of California

Michael R Houston

David S Soane

Toshiaki Hino

Roger T Howe

Roya Maboudian

Uthara Srinivasan

This invention is directed to a processing approach for the rapid and efficient in-situ polymerization of specially prepared precursor mixtures to achieve near-net-shape production of objects/articles with exact dimensions. The process relies on the use of polymerizable compositions comprised of a mixture of a dead polymer, a reactive plasticizer and, optionally, an initiator, which compositions are semi-solid-like prior to curing and induce low shrinkage upon curing as a result of their partially polymerized nature prior to processing. The partially polymerized nature of the precursor mixtures also allows extremely impact-resistant objects/articles to be fabricated. Other desirable engineering property attributes can similarly be achieved via the judicious blending of starting ingredients in formulating the polymerizable (curable) mixtures.

Near-net-shape polymerization process and materials suitable for use therewith

This disclosure describes a processing approach for the rapid and efficient in-situ polymerization of specially prepared precursor mixtures to achieve near-net-shape production of objects/articles with exact dimensions. The process relies on the use of polymerizable compositions comprised of a mixture of a reactive plasticizer and an initiator, optionally also including a dead polymer, which compositions are semi-solid-like and induce little shrinkage upon curing as a result of their partially polymerized nature prior to processing. The articles of the invention have a surface and an interior core, the composition of the surface material being distinct from the composition of the core material while at the same time the surface and the core are an integral, monolithic entity. In addition, the articles are dimensionally stable and exhibit high fidelity replication.

Precision integral articles

This disclosure describes a processing approach for the rapid and efficient in-situ polymerization of specially prepared precursor mixtures to achieve near-net-shape production of objects/articles with exact dimensions. The process relies on the use of polymerizable compositions comprised of a mixture of a dead polymer, a reactive plasticizer and an initiator, which compositions are semi-solid-like prior to curing and induce low shrinkage upon curing as a result of their partially polymerized nature prior to processing. The partially polymerized nature of the precursor mixtures also allows extremely impact-resistant objects/articles to be fabricated. Other desirable engineering property attributes can similarly be achieved via the judicious blending of starting ingredients in formulating the polymerizable (curable) mixtures.

This invention is directed to a process for the rapid in-situ curing of polymerizable materials to provide macromolecular networks and articles of manufacture that are &ldquo;morphology-trapped&rdquo;; that is, they exhibit a fixed phase morphology and/or molecular orientation that is locked in by the curing step. The process includes the steps of mixing together a dead polymer, a reactive plasticizer and an initiator to give a polymerizable composition; further processing the mixture in order to achieve a desired phase morphology and/or molecular orientation of the polymeric constituents; shaping the polymerizable composition into a desired geometry; and exposing the polymerizable composition to a source of polymerizing energy, without mixing, to give a final product with the desired phase morphology and/or molecular orientation locked in place. The phase morphology and molecular orientation present just prior to cure of the polymerizable composition is subsequently trapped or locked in place by the curing step so that further changes in morphology are hindered or prevented.

Morphology trapping and materials suitable for use therewith

This invention is directed to a process for the rapid in-situ curing of polymerizable materials to provide macro-molecular networks and articles of manufacture that are &ldquo;morphology-trapped&rdquo;; that is, they exhibit a fixed phase morphology and/or molecular orientation that is locked in by the curing step. The process includes the steps of mixing together a dead polymer or a prepolymer, a reactive plasticizer or a diulent, and an initiator to give a polymerizable composition; further processing the mixture in order to achieve a desired phase morphology and/or moelcular orientation of the polymeric constitutents; shaping the polymerizable composition into a desired geometry; and exposing the polymerizable composition to a source of polymerizing energy, without mixing to give a final product with the desired phase morphology and/or moelcular orientation locked in place. The phase morphlogy and molecular orientation present just prior to cure of the polymerizable composition is subsequently trapped or locked in place by the curing step to that further changes in morphology are hindered or prevented.

The present invention is directed to thermo-expandable microspheres and to the expanded microballoons, microcellular foam or foamed composite material that results upon heating the microspheres. The thermo-expandable microsphere of the present invention is characterized by having a polymeric wall surrounding one or more pockets or particles of blowing agent or propellant within the microsphere. The polymeric wall may have reactive functional groups on its surface to give a fusible microsphere. When the microspheres are heated, they expand to form microballoons comprising polymeric shells surrounding one or more internal gaseous voids, and when the microspheres are expanded while in contact with each other, a microcellular foam may be formed. The foam consists of a plurality of microballoons fused together, optionally aided by functional groups present on the surface of the heated microspheres that act to crosslink the material. When microspheres are mixed with a matrix, which can optionally react with functional groups on the microsphere surface, and the resulting combination is heated, the microspheres expand to give a foamed composite material in which the microballoons may be fused or chemically crosslinked to the matrix.

Microcellular foams, their method of production, and uses and products thereof

Method for synthesizing thermo-expandable polymeric microspheres

The invention is directed to a method for making composite articles, including optical lenses, which includes the steps of obtaining a substrate; placing a semi-solid-like polymerizable composition in contact with at least one of the front or back surface of the substrate; compressing or heating the resulting semi-solid/substrate sandwich between two mold halves, where the mold contacting the semi-solid polymerizable material has a desired surface geometry; and exposing the semi-solid/substrate sandwich to a source of polymerizing energy. The resulting composite article has the desirable characteristics of the substrate but is also easily fabricated as a result of the semi-solid molding process. Also included within the present invention is a composite article comprising a substrate portion and at least one layer of a cured resin bonded to the substrate portion, the cured resin comprising an interpenetrating crosslinked polymer network of reactive plasticizer within a dead polymer. In one embodiment, the reactive plasticizer polymer network is further crosslinked to the dead polymer. The composite article exhibits dimensional stability and high-fidelity replication of an internal mold cavity.

Precision composite article

The invention is directed to a method for making composite optical lenses, which includes the steps of obtaining an optical lens &ldquo;core&rdquo;; placing a semi-solid-like polymerizable composition in contact with at least one of the front or back surface of the core; compressing or heating the resulting semi-solid/core sandwich between two mold halves, where the mold contacting the semi-solid polymerizable material has a desired surface geometry; and exposing the semi-solid/core sandwich to a source of polymerizing energy. The resulting composite lens has the desirable characteristics of the core but is also easily fabricated with both toroidal curves and multi-focal pockets as a result of the semi-solid molding process. Also included within the present invention is a composite optical lens comprising a core portion and at least one layer of a cured resin bonded to the core portion, the cured resin comprising an interpenetrating crosslinked polymer network of reactive plasticizer within an entangled dead polymer. In one embodiment, the reactive plasticizer polymer network is further crosslinked to the dead polymer. The composite lens exhibits dimensional stability and high-fidelity replication of an internal mold cavity. The final lens may be a multi-vision lens and further may incorporate astigmatic corrections.

Precision composite lens

The present invention is directed to thermo-expandable fibers and to the expanded hollow fibers or microtubes, microcellular foam or foamed composite material that results upon heating the expandable fibers. The thermo-expandable fiber of the present invention is characterized by having a polymeric wall surrounding one or more pockets or particles of blowing agent or propellant within the fiber. The polymeric wall may have reactive functional groups on its surface to give a fusible fiber. When the expandable fibers are heated, they expand to form hollow fibers or microtubes comprising polymeric shells surrounding one or more internal gaseous voids, and when the fibers are expanded while in contact with each other, a microcellular foam may be formed. The foam consists of a plurality of hollow fibers fused together, optionally aided by functional groups present on the surface of the heated fibers that act to crosslink the material. When expandable microspheres are mixed with a matrix, which can optionally react with functional groups on the fiber surface, and the resulting combination is heated, the fibers expand to give a foamed composite material in which the hollow fibers or microtubes may optionally be fused or chemically crosslinked to the matrix.

Growing community of inventors

Berkeley, CA, United States of America

Michael R Houston