Raychem Limited

Bernard J Lyons

David A Horsma

Robert Smith-Johannsen

Peter H Van Konynenburg

Marlin N Schuetz

Wendell W Moyer

David A Vroom

Eugene F Lopez

David D Nyberg

Lester T Toy

Travers K Cammack, Ii

Leon Conrad Glover, Jr

Young J Kim

An electron beam accelerator has an accelerator tube consisting essentially of metal and ceramic components which are fused directly to each other and a transmission window generally rectangular in shape when viewed in the direction of the electron beam and is convex towards the vacuum chamber with a radius of curvature which is at most twice the width of the rectangle when measured in the absence of a pressure differential across the window. The electron beam accelerator is particularly suitable for use as a liquid material processor. The preferred transmission window of the accelerator of the invention can withstand energy transfer rates of at least 1500 watts per gram of the window material to which the energy is transferred. Certain embodiments are especially suitable for irradiating fluids to higher doses or for irradiating liquids containing suspended solids or slurries. A mobile transporter enabling relocation of the liquid material processor between process sites is also described.

Apparatus and methods for electron beam irradiation

A particle accelerator has a transmission window formed of a thin homogeneous foil having a predetermined thickness and having a predetermined length, and when laid fiat as a sheet having a transverse dimension. The window is formed to have a locus of a curve in cross section along the transverse dimension such that a radius of curvature of at least a portion of the curve in cross section is less than the length of the transverse dimension. Longitudinal channel and tubular shapes are preferred. Window cooling by gaseous and liquid fluid flows is also described. A transmission window assembly and a particle beam accelerator having an efficient rugged accelerator tube structure are also described. As one example, a liquid material processor and processing method employs either the curved window or a conventional window and advantageously directs liquid material onto the window to cool it, while a particle beam passing through the window enters the liquid material and changes it chemically in a predetermined manner. A mobile transporter enabling relocation of the liquid material processor between process sites is also described.

Transmission window for particle accelerator

Novel conductive polymer compositions which exhibit useful PTC behavior are produced by cross-linking processes. By correlating the polymer, the conductive filler dispersed therein, and the cross-linking conditions, PTC compositions having desired resistance/temperature characteristics can be prepared. In particular the cross-linking can be carried out so as to provide compositions having a switching temperature around the cross-linking temperature. The invention is applicable to both elastomeric and thermoplastic polymers, and provides for the first time a method of making PTC compositions exhibiting useful PTC behavior from elastomers.

PTC compositions and devices comprising them

A self-regulating heating article comprising a layer of material exhibiting a positive temperature coefficient of resistance (PTC) and said PTC layer having at least partially contiguous therewith at least one layer of constant wattage output material. The article operates such that when connected to an electric power source, the current flows through at least a portion of the thickness of the PTC layer and of the constant wattage layer.

Layered self-regulating heating article

A self-regulating heating article comprising a layer of material exhibiting a positive temperature coefficient of resistance (PTC) and said PTC layer having at least partially contiguous therewith at least one layer of constant wattage output material. The article operates such that when connected to an electric power source, the current flows through at least a portion of the thickness of the PTC layer and of the constant wattage layer. In a preferred embodiment, upon heating the article, a change in dimensions as well as activation of an adhesive occurs.

PTC Compositions and devices comprising them

Conductive polymer compositions which have improved voltage stability and which preferably exhibit PTC behavior. The compositions comprise a carbon black dispersed in a crystalline copolymer of an olefin and at least 10% by weight of an olefinically unsaturated comonomer containing a polar group. The carbon black has a particle size greater than 18 millimicrons, preferably greater than 30 millimicrons, a d-spacing greater than 360 and a surface area which is less than

Conductive polymer compositions, and to devices comprising such

New high voltage insulating compositions are disclosed. The compositions comprise a polymer (e.g. a polysiloxane, epoxide resin or a polymer of one or more olefins or substituted olefins), an antitracking additive (e.g. an alumina hydrate), and certain organic polymerizable phosphorus-containing compounds which have been found to provide the compositions with greatly improved resistance to erosion by high voltage stress. The phosphorus-containing compounds include phosphonates, phosphates, phosphites, phosphinates, phosphonites, phosphinites, phosphine oxides and sulfides, and phosphines, and salts and complexes thereof. The phosphorus-containing compound can react in situ with the polymer or other ingredients of the composition.

High voltage insulating compositions containing organic polymerizable

The voltage stability of crosslinked compositions of fluorocarbon polymers and conductive carbon black that exhibit a positive temperature coefficient of resistance can be improved by incorporating into the composition prior to its crosslinking an effective amount of a polymerizable polyethylenically unsaturated monomer such as, for example, triallylisocyanurate.

Voltage stable positive temperature coefficient of resistance

An improved antioxidant composition, especially suitable for irradiated or fire-retardant plastics, comprising a mixture of a hydroxy aromatic compound containing sulfur and organic phosphonate compounds.

Antioxidant comprising a hydroxy aromatic compound containing sulfur and

For incorporation in normally oxidizable polymers, polymeric antioxidants characterized by repeating hindered bisphenolic units, the average number of said units per polymeric chain in said composition being from about 2 to 10, preferably about 2 to 7, most preferably about 2 to 4. The antioxidants are prepared by oxidative coupling of appropriate bisphenols, as by reaction with a ferricyanide coupling agent. Polymer-antioxidant combinations formed according to the invention have excellent high temperature oxidative stability, high resistance to polymer damage by massive doses of ionizing radiation and the antioxidant does not release significant amounts of condensable species when subjected simultaneously to conditions of high vacuum and elevated temperatures.

Compositions of antioxidants of reduced volatility

Hydroxy aromatic compound containing sulfur and an organic phosphonate

An irradiation cross-linked polymer composition having improved oxidation resistance is disclosed. Improved oxidation resistance is obtained by utilizing an organic phosphite which is relatively insoluble and unreactive under irradiation conditions so as to be unaffected by the irradiation.

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Atherton, CA, United States of America

Bernard J Lyons