Mechanism of Chemical Reactions Involved in Magnetic Coatings

  • R. S. Tu


The major binders in magnetic coatings are high molecular weight thermoplastic polyurethane and low molecular weight polyisocyanate. This paper reviews the stoichiometry and kinetics of the isocyanate reactions involved in a typical formulation. It was concluded that the dominant reaction is the condensation of the -NCO groups and water in the formulation with the formation of polyurea as an inter-penetrating network in the polyurethane matrix. The degree of crosslinking of the polyurethane molecules was insignificant.


Magnetic Tape Frame Durability Melamine Formaldehyde Resin Major Binder Polyurethane Matrix 
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    Union Carbide, “Chemical and Plastic Physical Properties”, 1979–80 Edition (F-44086C, 2/79–40M).Google Scholar
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    Mobay, “Chemistry for Coatings (3/76)”.Google Scholar
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    J. Curtis, MTD Project Report, “Isocyanate Reaction Chemistry in Magnetic Tape Formulation — IV”, May 20, 1981.Google Scholar

Copyright information

© Plenum Press, New York 1989

Authors and Affiliations

  • R. S. Tu
    • 1
  1. 1.Magnetic Tape DivisionAmpex CorporationRedwood CityUSA

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