×

Magnetic recording medium supported on aromatic polyamide

  • US 4,112,187 A
  • Filed: 04/19/1976
  • Issued: 09/05/1978
  • Est. Priority Date: 12/28/1973
  • Status: Expired due to Term
First Claim
Patent Images

1. Magnetic recording medium comprising a layer of magnetizable material and a flexible support material prepared from a high molecular weight p-oriented polycarbonamide consisting of at least about 70 mole % of recurring units of a formula selected from the group consisting of:

  • ##STR4## and mixtures thereof, wherein;

    X, Y, X'"'"' and Y'"'"' are monovalent radicals attached to a nuclear carbon and are selected from the group consisting of hydrogen, halogen, nitro and alkyl and alkoxy having from 1 to 3 carbon atoms, 0-30 mole % of other copolymeric units whenever present constituting such recurring units as m-phenylene ##STR5## urethane (--NHCOO--), urea (--NHCONH--), ester (--COO--), hydrazide (--CONHNH--), ether (--O--), and aliphatic hydrocarbon groups (C1 -C3),said flexible material having a tensile modulus in excess of 800 kg/mm2 and up to 20,000 kg/mm2 at least in one direction, a water adsorption of less than 2.0 wt. % at 25°

    C and 75% relative humidity and a hydroscopic linear expansion coefficient of less than 1.0 ×

    10-5 mm/mm/% at least in one direction.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×