Abstract: The present application relates generally to tubes, such as thin walled catheter liners with small wall thicknesses (e.g., less than 1 mm), including crosslinked fluoropolymers, e.g., crosslinked poly(tetrafluoroethylene). The disclosure further provides methods of manufacturing such tubes and systems for manufacturing such tubes.

Abstract: A polytetrafluoroethylene resin comprising polytetrafluoroethylene having a two-dimensional branched structure in the molecule is produced by exposing polytetrafluoroethylene to an ionizing radiation at a dose of no more than 10 kGy.

Abstract: Preparation methods of an anisotropic conductive adhesive film are provided. One of the preparation methods includes heating a solid-state light-curing resin, a solid-state thermosetting resin and a solid-state elastomer to form a mixture. A liquid-state light curing active monomer and plasticizer are added to the mixture. A leveling agent, antioxidant and insulating nanoparticles are added separately to the mixture. Conductive particles are added to the mixture. A light curing agent, latent heat curing agent and coupling agent are added to the mixture to produce a light-beat dual curing anisotropic conductive adhesive. The conductive adhesive is coated on a plastic film base material to form a semi-finished product. The semi-finished product is cured and dried to form a cured conductive adhesive layer, so that an anisotropic conductive adhesive film is produced. The anisotropic conductive adhesive layer is cut, and the anisotropic conductive adhesive film is rolled.

Abstract: The present invention relates to a method of surface cross-linking superabsorbent polymer particles using UV irradiation. The superabsorbent polymer particles for use in the method of the present invention have a relatively high degree of neutralization. Bronsted acids are selectively applied onto the surface of the superabsorbent polymer particles to selectively facilitate a relatively high number of protonated carboxyl groups at the surface of the superabsorbent polymer particles while the relatively high degree of neutralization in the core of the superabsorbent polymer particles remains substantially unaffected.

Abstract: A plastic is converted from an initial condition with a higher density into a foamed condition with a lower density using a blowing agent, wherein the plastic is cross-linked prior to foaming by means of a first cross-linking agent and during the foaming by means of at least one second cross-linking agent.

Abstract: A process for preparing polypropylene and its copolymers of high melt strength while is kept melt index suitable for processing is described, the polypropylene and its copolymers being modified by grafting with high molecular weight portions and crosslinking with free radicals, both modifications being promoted by high energy ionizing radiation used at low doses in the presence of an atmosphere that contains crosslinking promoting gases, the polypropylene and its copolymers optionally containing stabilizing substances dispersed in the amorphous phase.

Abstract: The invention pertains to dielectric films for the production of microelectronic devices. A spin-on glass film is produced by depositing a silazane polymer containing composition film onto a substrate and then exposing the film to electron beam radiation. The electron beam exposing step is conducted by overall exposing the dielectric layer with a wide, large beam of electron beam radiation from a large-area electron beam source.

Abstract: A process for producing water-soluble, cationic polyelectrolytes is described, wherein the polymerization of the water-soluble monomers is initiated at low temperatures using a combination of UV light, photoinitiator and a redox system, and is characterized in that the redox system is capable of initiating the polymerization only at temperatures higher than or equal to 20° C. The polymers have a high molecular weight and a low content of residual monomer.

Abstract: Disclosed is a method of polymerizing vinyl chloride or vinylidene chloride monomer. A mixture is prepared of (1) a monomer selected from the group consisting of vinyl chloride, vinylidene chloride, and mixtures thereof with up to about 20 wt % of a comonomer, (2) supercritical carbon dioxide, subcritical carbon dioxide, or liquid carbon dioxide in a weight ratio to the monomer of about 0.5 to about 5; and (3) about 0.1 to about 1 phr of a free radical initiator that is soluble in said supercritical carbon dioxide or a solution of said a free radical initiator in a solvent that is miscible with the carbon dioxide. The mixture is heated to a temperature of about 40 to about 70° C. to polymerize the monomer.

Abstract: Fibers as a reinforcing substrate are impregnated with the particles of polytetrafluoroethylene and pressed into a shape at the melting point of polytetrafluoroethylene. Alternatively, the reinforcing substrate sandwiched between polytetrafluoroethylene sheets is pressed into a shape at the melting point of polytetrafluoroethylene. In either case, the shaped article is then exposed to an ionizing radiation in an oxygen-free atmosphere at the melting point of polytetrafluoroethylene. The inherent characteristics of the polytetrafluoroethylene, i.e., heat resistance, chemical resistance, abrasion resistance and lubricity, are retained and yet radiation resistance and resin transparency are imparted.

Abstract: Disclosed is a process which comprises reacting a polymer of the general formula ##STR1## or ##STR2## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR3## B is one of several specified groups, such as or mixtures thereof, and n is an integer representing the number of repeating monomer units, with a halomethylethyl ether, a hydrohalic acid, and acetic acid in the presence of a halogen-containing Lewis acid catalyst, thereby forming a halomethylated polymer.

Abstract: A product having reduced friction and improved abrasion resistance comprises a formed resin containing at least one fluorine-containing polymer which is exposed to an ionizing radiation. The formed resin may include from 1 to 100 weight percent of the fluorine-containing polymer in the form of powder, and from 99 to 0 percent of a high molecule polymer which is not exposed to the ionizing radiation. The fluorine-containing polymer is preferably exposed to the ionizing radiation for a total dose of from 1 KGy to 10 MGy in the absence of oxygen at a temperature not lower than the melting point of a starting fluorine-containing polymer.

Abstract: A process for making oxidized olefins is disclosed. Specifically, the process comprises providing an olefin and oxygen in combination in a reaction medium comprising carbon dioxide, and then oxidizing the olefin in the reaction medium to make the oxidized olefin. Preferably, a perfluoropolyether is produced by the process.

Abstract: Disclosed is a process which comprises reacting a polymer of the general formula ##STR1## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR2## B is one of several specified groups, such as ##STR3## or mixtures thereof, and n is an integer representing the number of repeating monomer units, with an acetyl halide and dimethoxymethane in the presence of a halogen-containing Lewis acid catalyst and methanol, thereby forming a haloalkylated polymer. In a specific embodiment, the haloalkylated polymer is then reacted further to replace at least some of the haloalkyl groups with photosensitivity-imparting groups. Also disclosed is a process for preparing a thermal ink jet printhead with the aforementioned polymer.

Abstract: A photopolymerizable composition is described, comprising components (i) a compound having at least one addition-polymerizable ethylenically unsaturated bond, (ii) a compound represented by the following formula (I): ##STR1## and (iii) an activating agent which generates an active radical upon light irradiation in the co-presence of component (ii). The substituents in formula (I) are defined in the specification.

Abstract: A process is provided comprising crosslinking of a derivative of a linear alternating copolymer of carbon monoxide and one or more olefinically unsaturated compounds, which copolymer has a ratio of weight average molecular weight to number average molecular weight of more than 1, and which derivative is obtainable by treating the linear alternating copolymer with formaldehyde and/or a precursor of formaldehyde, a thermoset resin obtainable by such process and a coating based on such thermoset resin.

Abstract: Process for preparing hydrogen-containing fluoropolymers, wherein the corresponding olefinic monomers are (co) polymerized in an organic suspending medium in the presence of a radical photoinitiator and of ultraviolet-visible radiation at a temperature of from -60.degree. C. to +30.degree. C. Hydrogen-containing fluoropolymers are thus obtained having high second melting temperature and high maximum operating temperature, using as initiators non-hazardous products, which can be easily handled and kept also at room temperature.

Abstract: Modified PTFE is produced by exposing a starting PTFE to an ionizing radiation for a total dose of at least 100 kGy in the absence of oxygen at a temperature not lower than the crystal melting point of the starting PTFE. The thus modified PTFE is improved in radiation resistance and has rubber characteristics.

Abstract: A water-isoluble hydrogel, obtained by cross-linking a polyvinyl alcohol by itself, a polyvinyl pyrrolidone by itself, and a polyvinyl alcohol and a polyvinyl pyrrolidone as a pair by exposure to radiation to a cross-linking degree enough for occlusion therein of 50 to 99% by weight of water and they freezing and thawing the product of said cross-linking, production thereof, and an untrasonic transmission medium using the hydrogel.

Abstract: In one embodiment this invention provides an optical medium which consists of a microdispersion of liquid crystal droplets in a synthetic resin matrix. A preferred invention optical medium exhibits a Kerr effect, and can transmit propagating light waves with low scattering loss under waveguiding conditions.

Abstract: A method of biomolecule immobilization is described in which the biomolecule itself or, alternatively, a monomer-conjugated biomolecule, is grafted with free monomer onto a hydrophilic, solid-phase, polymeric substrate which has been pre-irradiated with ionizing radiation. The pre-irradiation step is carried out, preferably at -78.degree. C. in air, while the grafting step is carried out at 0.degree. C. in a substantially oxygen-free atmosphere. The technique is applicable to immobilization of a wide variety of biomolecules, such as enzymes, catalysts, hormones, lectins, drugs, vitamins, antibodies, antigens, nucleic acids, DNA and RNA segments, pesticides, dyes and fertilizers. The products may be used for therapeutic or diagnostic applications or bioseparations.

Abstract: Monodisperse, polymeric microspheres are formed by injecting uniformly shaped droplets of radiation polymerizable monomers, preferably a biocompatible monomer, having covalent binding sites such as hydroxyethylmethacrylate, into a zone, impressing a like charge on the droplet so that they mutually repel each other, spheroidizing the droplets within the zone and collecting the droplets in a pool of cryogenic liquid. As the droplets enter the liquid, they freeze into solid, glassy microspheres, which vaporizes a portion of the cryogenic liquid to form a layer. The like-charged microspheres, suspended within the layer, move to the edge of the vessel holding the pool, are discharged, fall and are collected. The collected microspheres are irradiated while frozen in the cryogenic liquid to form latent free radicals. The frozen microspheres are then slowly thawed to activate the free radicals which polymerize the monomer to form evenly-sized, evenly-shaped, monodisperse polymeric microspheres.

Abstract: Hydrophilic monomers in a supercooled, transparent state, are polymerized in the presence of water. The polymers have low levels of residual monomers and exhibit good mechanical strength. The process provides materials useful as contact lenses.

Abstract: A mixture of a specified siloxanylalkyl ester monomer and a specified vinyl monomer is polymerized by exposure to an ionizing radiation at low temperatures and the resulting polymer is worked with a lathe cut to form a contact lens. The contact lens obtained is free from any optical distortion, has good dimensional stability and exhibits high oxygen permeability. In a preferred embodiment, a monomer mixture comprising a siloxanylalkyl ester, a methacrylate or acrylate, N-vinylpyrrolidone, and a small amount of a dimethacrylate or diacrylate is exposed to a total dose of 1.times.10.sup.5 -5.times.10.sup.6 roentgens at a low temperature (-80.degree. C. to -20.degree. C. and at a dose rate of 8.times.10.sup.4 -2.times.10.sup.6 roentgens per hour, and the resulting polymer is worked into a contact lens by a suitable forming process involving cutting, grinding and polishing operations.

Abstract: A method of biomolecule immobilization is described in which the biomolecule itself or, alternatively, a monomer-conjugated biomolecule, is grafted with free monomer onto a hydrophilic, solid-phase, polymeric substrate which has been pre-irradiated with ionizing radiation. The pre-irradiation step is carried out, preferably at -78.degree. C. in air, while the grafting step is carried out at 0.degree. C. in a substantially oxygen-free atmosphere. The technique is applicable to immobilization of a wide variety of biomolecules, such as enzymes, catalysts, hormones, lectins, drugs, vitamins, antibodies, antigens, nucleic acids, DNA and RNA segments, pesticides, dyes and fertilizers. The products may be used for therapeutic or diagnostic applications or bioseparations.

Abstract: A novel polymer and polymer treatment method are provided. The method involves irradiation of a polymer under non-gelling conditions at a temperature above the polymer melting temperature and in the absence of oxygen. The polymer is characterized by a unique long chain Y-branched molecular structure.