Ionizing radiation crosslinkable pressure sensitive adhesive precursors containing hydrocarbon tackifiers and having an acid content of no more than 3% by weight. The precursors can be exposed to a source of ionizing radiation, for example, one or both of an electron beam or gamma radiation, for an exposure time sufficient to receive an energy dose sufficient to at least partially crosslink the adhesive precursor, thereby forming a pressure sensitive adhesive. Methods of using ionizing radiation to crosslink a crosslinkable pressure sensitive adhesive precursor are also disclosed.

Provided are methods for surface-modifying a rubber vulcanizate or a thermoplastic elastomer, the methods forming a surface with a chemically fixed lubricant instead of resin coating which has drawbacks, such as that the coating is, for example, removed or peeled during the movement within a vessel, whereby the lubricity is reduced. The present invention relates to a method for surface-modifying an object of a rubber vulcanizate or a thermoplastic elastomer, the method including step 1 of forming polymerization initiation points on a surface of the object, and step 2 of radically polymerizing a deliquescent monomer starting from the polymerization initiation points by irradiation with ultraviolet light having a wavelength within the range of 300 to 400 nm, to grow polymer chains on the surface of the object.

An electrical or electronic device comprising a polymeric coating, formed by exposing;the device to pulsed plasma comprising a compound of formula (I),

##STR00001##

where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined in the specification, for a sufficient period of time to allow a polymeric layer to form on the surface of the electrical or electronic device. Devices of this type are protected from contamination by liquids, in particular environmental liquids.

An electrical or electronic device comprising a polymeric coating, formed by exposing;the device to pulsed plasma comprising a compound of formula (I),

##STR00001##

where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined in the specification, for a sufficient period of time to allow a polymeric layer to form on the surface of the electrical or electronic device. Devices of this type are protected from contamination by liquids, in particular environmental liquids.

An apparatus and a method for surface coating by means of grid control and plasma-initiated gas-phase polymerization. The method comprises: dividing a vacuum chamber into a discharging cavity and a processing chamber by using a metal grid mesh, the metal grid mesh being insulated from the vacuum chamber; separately feeding carrier gas and monomer steam into the discharging cavity and the processing chamber through different pipes, putting a substrate to be processed in the processing chamber, and generating in the discharging cavity plasma that continuously discharges; and applying pulse positive bias to the metal grid mesh, to release the plasma into the processing chamber to initiate monomer polymerization.

An apparatus and a method for surface coating by means of grid control and plasma-initiated gas-phase polymerization. The method comprises: dividing a vacuum chamber into a discharging cavity and a processing chamber by using a metal grid mesh, the metal grid mesh being insulated from the vacuum chamber; separately feeding carrier gas and monomer steam into the discharging cavity and the processing chamber through different pipes, putting a substrate to be processed in the processing chamber, and generating in the discharging cavity plasma that continuously discharges; and applying pulse positive bias to the metal grid mesh, to release the plasma into the processing chamber to initiate monomer polymerization.

A method of treating an elastomer packaging element (10), in particular a stopper for medical or pharmaceutical use, the packaging element (10) having a bottom portion (11) that is to penetrate into a neck (21) of a container (20) and a top portion (12) that is to co-operate in sealed manner with a top surface (22) of said neck (21) of the container (20). The top surface of the top portion (12) is treated by a plasma-assisted polymerization method at atmospheric pressure using a plasma flame created at atmospheric pressure and into which a monomer is injected, the monomer polymerizing on the top surface in order to form a coating (18).

A system and method for light stimulation within a medium. The system has a reduced-voltage x-ray source configured to generate x-rays from a peak applied cathode voltage at or below 105 kVp, and a plurality of energy-emitting particles in the medium which, upon radiation from the x-ray source, radiate at a first lower energy than the x-ray source to interact with at least one photoactivatable agent in the medium. The method introduces the plurality of energy-emitting particles into the medium, radiates the energy-emitting particles in the medium with x-rays generated from a peak applied cathode voltage at or below 105 kVp; and emits a lower energy than the x-ray source to interact with the medium or with at least one photoactivatable agent in the medium.

Provided is a coated optical fiber excellent in both characteristics of the microbending loss resistance and the low-temperature characteristic. The coated optical fiber 1 comprises an optical fiber 10 that has a cladding layer composed of glass formed on an outer periphery of a glass core, a primary coating layer 20 that coats an outer periphery of the optical fiber 10, and a secondary coating layer 30 that coats an outer periphery of the primary coating layer 20, wherein the primary coating layer 20 has a Young's modulus of 1.2 MPa or less, the secondary coating layer 30 has a Young's modulus of 700 MPa or more, and the primary coating layer 20 contains tin in a content of 70 ppm or less.

The present invention provides a visible light photoinitiating system for preparing a holographic photopolymer material with high-diffraction efficiency. The photoinitiating system comprises a photosensitizer and a co-initiator, and its mechanism is that the photosensitizer transforms from ground state to excited state after absorbing photons, and then interacts with the co-initiator through transfer of electrons and protons, which produces an alkyl (or aryl) free radical R and a ketyl radical K; wherein the free radical R initiates the addition polymerization of monomers that are capable of free radical polymerization, whereas the radical K inhibits the chain propagation of the macromolecular free radicals to a certain degree due to the steric hindrance effect, and thus delays the gelation time of the photopolymerization, which helps to increase the phase separation between the polymer and the functional components. A holographic photopolymer material with high-diffraction efficiency can be obtained by employing this visible light photoinitiating system.