Abstract: CBN abrasive grains contain 0.01% by weight or more of Si and, the majority of the surfaces of its grains consist of {111} planes. In the method for producing CBN abrasive grains, a C source, an Si source, and at least one member selected from the group consisting of alkali hydride, alkali-earth hydride, and a synthetizing catalyst of CBN which may be the alkali hydride and alkali-earth hydride, are mixed together with HBN and are subjected to the treatment.

Abstract: A cutting element for a rotary drill bit comprises a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof. The front layer is thinner than the backing layer, at least in the vicinity of the cutting edge of the cutting element.

Abstract: A metal wire-containing polymeric laminate tape is continuously produced by superimposing a pair of primary cross-linked, electro-insulating thermoplastic polymer tapes side by side along the longitudinal axes thereof under tension, while a plurality of metal wires are interposed, under tension, in parallel to each other, between the primary tapes along the longitudinal axes thereof; by heating the resultant precursory laminate tape up to a temperature of from 10.degree. to 120.degree. C. above the melting point of the corresponding thermoplastic polymer, which is not cross-linked; by pressing the heated precursory laminate tape by using a pair of elastic pressing rolls, whereby the primary tapes are heat-bonded together to provide a body of laminate matrix within which the metal wires are embedded; and, optionally, by cooling the resultant laminate tape.

Abstract: Magnesium or calcium carboxylate used as an adhesion control agent for plasticized polyvinylbutyral sheeting by incorporating into the sheeting after water removal and prior to extrusion.

Abstract: Intumescent flame-retardant coating composition consisting substantially of a film-forming agent, an ammonium polyphosphate, one or more substances which are carbonizable under the action of heat, a dispersant, and optionally a filler. The coating composition additionally contains an ammonium polyphosphate activator weighing 0.5 to 50% of the weight of ammonium polyphosphate. The activator is constituted by at least one salt which contains water of crystallization which is liberated upon the composition being heated to about 35.degree. C.