摘要:
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.
摘要:
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.
摘要:
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 than1.2S+e.sup.S/50where S is the DBP absorption of the carbon black. The carbon black is preferably present in amount at least 15% by weight of the composition. Particularly useful devices including such compositions are self-regulating heaters.
摘要翻译:导电聚合物组合物具有改进的电压稳定性并且优选表现出PTC行为。 组合物包含分散在烯烃和至少10重量%的含有极性基团的烯属不饱和共聚单体的结晶共聚物中的炭黑。 炭黑的粒度大于18毫微子,优选大于30毫微子,d间距大于360,表面积小于1.2S + eS / 50,其中S是炭黑的DBP吸收。 炭黑优选以组合物的至少15重量%的量存在。 包括这种组合物的特别有用的装置是自调节加热器。
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
In general, multiple embodiments of a catheter/fistula needle to bloodline connection assurance device, which secures and strengthens a connection between an extension tube end of a catheter or fistula needle and a bloodline are provided. A first embodiment of the assurance device is configured to be compatible with any industrial catheter/fistula needle female luer connector and is specifically configured for use with a bloodline connector having locking clips which are biased slightly outwardly from the bloodline connector. The first embodiment of the assurance device is cylindrical and includes clamshell halves that open rotatably about at least one hinge. The first embodiment of the assurance device includes an upper, threaded portion and a lower housing portion. The interior wall of the upper portion defines a plurality of barbs configured to engage with distal or moveable ends of the locking clips. Each locking clip is biased slightly outwardly to enable the distal or moveable end of the locking clip to fit between two respective barbs. The barbs are spaced as close together as possible to prevent any axial movement of the bloodline connector when the assurance device is engaged about the mated connectors.
摘要:
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.
摘要:
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.