Abstract: An electrical choke comprises a magnetic amorphous metal core having, in combination, a distributed gap and a discrete gap. The amorphous metal is an iron based, rapidly solidified alloy. The distributed gap configuration is achieved by subjecting the magnetic core to a heat treatment, causing partial crystallization of the amorphous alloy. Such partial volume crystallization reduces the permeability of the magnetic core from several thousands to a value ranging from 200 to 800. The discrete gap is introduced by cutting the core and inserting a spacer. Depending on the width of the gap and the value of the annealed permeability, effective permeabilities in the range of 200 to 40 can be achieved. Advantageously, the reduced permeability magnetic core maintains its initial permeability under DC bias field excitation and exhibits low core loss, making it especially suited for use in power factor correction applications.

Abstract: A high-strength polymer-modified polyol comprises a polyol and from 40 to 80% by weight of the reaction product of a polyisocyanate and a tertiary-N-polyolamine based on the combined weight of the polyol and reaction product.Also included are methods of forming the polymer-modified polyol; a polymer-modified polyol obtained by dilution of the high strength polymer-modified polyol; the use of the polymer-modified polyols in the manufacture of polyurethane products and the polyurethane products so obtained.The polymer-modified polyols are particularly useful for preparing highly resilient flexible foams.

Abstract: A polymer-modified polyol comprises a dispersion in a first polyol which has a molecular weight of at least 1000, an average functionality of more than 2, and a Hydroxyl Number of less than 150, of the reaction product of a polyisocyanate and a second polyol which is either (a) a polyethylene glycol having a molecular weight of up to 600 or (b) a polyol, which is not a polyethylene glycol, and which has a molecular weight of less than 250 and is free from nitrogen atoms.A method of forming the polymer-modified polyol, its use in the manufacture of polyurethane products and the polyurethane products so obtained, are included.The dispersions are particularly useful for preparing highly resilient flexible foams.