Abstract: This invention relates to a self-limiting electrical heating element comprising resistance components having a positive temperature coefficient and a zero temperature coefficient, arranged in a layered structure with two electrodes placed diagonally within or in contact with two ZTC layers separated by a PTC layer.

Abstract: A method for making a water and fire resistant building material of a layered, shaped and hardened composition of one or more absorbant components, magnesia cement, chemically active fumed silica, alkali silicate, one or several inorganic fillers, one or several lignin sulphonates, eventually ethyl silicate, whereby the final product is built up of a two binder system, one of fumed silica, alkali silicate and optionally magnesium oxide and the other of magnesia cement and a lignin sulphonate salt. The method of producing the product includes forming a dual layered binder system having a very short press time.

Abstract: Self-regulating articles, particularly heaters, containing two spaced-apart elongate electrodes which are joined together by a melt-extruded element composed of a conductive polymer. The conductive polymer is a dispersion of carbon black in a crystalline polymer, has a resistivity at room temperature of R ohm-cm, and contains L % by weight of carbon black, L being not greater than about 15, and L and R being such that2L+5 log.sub.10 R.ltoreq.45.

Abstract: The application concerns a water and fire resistant building material consisting of a layered, shaped and hardened composition of one or more absorbant components, magnesia cement, chemically active fumed silica, alkali silicate, one or several inorganic fillers, one or several lignin sulphonates, eventually ethyl silicate, whereby the final product is built up of a two binder system, one consisting of fumed silica, alkali silicate and possibly magnesium oxide and the other consisting of magnesia cement and a lignin sulphonate salt. The application also concerns the method of producing the product. The procedure is characterized by forming a dual layered binder system and by having a very short press time.

Abstract: 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.

Abstract: The invention relates to a process for forming a cement composition which comprises mixing hydratable cement particles, water and an oil-in-water suspension wherein the oil droplets of the suspension are surrounded by colloidal particles having a zeta potential of between about +18 and -18 millivolts, and allowing the mixture to cure.

Abstract: Stable suspensions of oil and water are provided by surrounding the droplets of the suspended phase by colloidal particles to form an aggregate particle having a zeta potential between about +18 and -18 millivolts.A process for forming such stable suspensions of water and oil by adding to one of the liquid phases an anionic agent and a cationic agent to produce colloidal particles having a zeta potential between about +18 and -18 millivolts, then adding the other liquid phase to form the suspension.

Abstract: Novel aqueous inorganic particle slurries, wherein some of the particles have had their charge potential altered to a sufficient extent to prevent segregation or settling of the particles, are described, along with a method for their preparation. The method of forming slurries of negatively charged particles comprises treating some of the particles with a cationic agent to reduce their charge and mixing these treated particles with the remainder of the particles to form a thick, cream-like flowable composition of a thixotropic nature. When slurries of positively charged particles are to be formed, an anionic agent is used instead of a cationic agent.

Abstract: Composite inorganic articles are produced by bringing two separate inorganic slurries, each containing different ceramic materials, into contact with each other, simultaneously freezing the slurries while in contact with each other to form a unified frozen structure, thawing and drying the structure, and firing the unified structure.

Abstract: 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.

Abstract: A composite useful as a ski sole comprising polyethylene particles in a polyethylene film, the former having a greater hardness or higher melt index than the latter, which is capable of renewably forming fibrils extending from a surface thereof under the abrasion characteristic of skiing conditions. The particles may have been treated with a material which is incompatible with or reduces the adhesion to the film-forming polyethylene.

Abstract: 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.

Abstract: Composite inorganic articles are produced by bringing two separate inorganic slurries, each containing different ceramic materials, into contact with each other, simultaneously freezing the slurries while in contact with each other to form a unified frozen structure, thawing and drying the structure, and firing the unified structure.

Abstract: Process of freezing organic particulate suspensions containing freeze-sensitive inorganic colloidal sols to form uniform porous substrates and of freezing biological material while in contact with a hydrophobic liquid.

Abstract: A process for producing magnesium oxychloride hydrate cements which involves forming a mixture of water, magnesium chloride hydrate and magnesium oxide in which a minor portion of the magnesium oxide is treated to render it initially substantially unreactive with the magnesium chloride hydrate but capable of slowly reacting with the magnesium chloride hydrate after the initial exotherm reaction of the reactive portion of the magnesium oxide with the magnesium chloride hydrate.

Abstract: 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.

Abstract: Graphite compositions in which the majority of the flake-like particles have at least two substantially hydrophobic surfaces or areas and at least one substantially hydrophilic area of sufficient hydrophilicity to retain the water dispersibility of the graphite compositions and which are used as coatings on hydrophobic surfaces, such as polyethylene, ski soles, sound and video tapes, telephone cables and so forth.

Abstract: Described herein are self-regulating conductive articles comprised of an extruded length of polymeric material containing not more than about 15% by weight conductive carbon black, the resistivity of the extrudate following prolonged exposure to temperatures in excess of the crystalline melting point or range of the polymeric matrix in which the black content satisfies the equation:2L+5 log.sub.10 R.ltoreq.45.Wherein L is percent by weight black and R is resistivity of the extrudate expressed in ohm-cm. The articles exhibit room temperature resistivity in the range from about 5 to 100,000 ohm-cm and may be employed, e.g., in heat tracing and thermostating applications.

Abstract: Aqueous particulate slurries or suspensions containing a small amount of a freeze sensitive ceramic sol are frozen by supercooling the aqueous slurry prior to freezing. The process includes the use of lithium ions in the slurries with or without supercooling.

Abstract: Water resistant magnesium oxychloride hydrate (Sorel cement) compositions and processes for producing the same. The processes comprise the addition of an ethyl silicate and/or a premix of magnesium chloride and magnesium oxide to the magnesium oxychloride hydrate reaction mixture (MgCl.sub.2 +MgO) followed by the subsequent reaction and curing thereof.