For Typing Plural Copies Simultaneously With Ribbon(s) (e.g., Duplicate Typing) Patents (Class 400/204)
Including holder for short length of ribbon (Class 400/205)
Using plural ribbons (e.g., additional ribbon(s) (Class 400/206)
  • Stabilizer for electron doner-acceptor carbonless copying systems
    Patent number: 4372582
    Abstract: A stabilizing agent for use in electron donor-acceptor carbonless copying systems. The stabilizing agent is 2,2'-methylene-bis(4-methyl-6-t-butyl phenol). Systems in which the stabilizing agent is useful comprise a color-forming composition comprising at least one leuco dye which is fadeable or discolorable after development, a color-developing composition comprising an acidic coreactant material capable of reacting with the color-forming composition to provide colored products, and the stabilizing agent. The stabilizing agent prevents discoloration or fade of images produced by reaction of the color-forming composition with the color-developing composition.
    Type: Grant
    Filed: March 30, 1981
    Date of Patent: February 8, 1983
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Thomas C. Geisler
  • Imaging compositions
    Patent number: 4334015
    Abstract: A composition capable of forming colored complexes with transition metal salts is provided which comprises an aromatic substituted hydrazone carried in an organic cosolvent vehicle. When employed in the art of carbonless paper the aromatic substituted hydrazone and the transition metal salt complex to form yellow colored images. The invention provides means for producing dark, black, neutral images by the reaction of the aromatic substituted hydrazones and conventional dithiooxamide complexing compounds, both carried in an organic cosolvent vehicle, with transition metal salts.
    Type: Grant
    Filed: May 23, 1979
    Date of Patent: June 8, 1982
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Dean R. Yarian