| 摘要 |
997, 362. Thermographic copying material and process. MINNESOTA MINING & MANUFACTURING CO. Jan. 3,1962 [Jan. 3,1961], No. 10700/65. Divided out of 997,361. Heading G2C. A copy sheet or copysheet combination, which forms a visible image when heated but can be desensitized by exposure to ultra-violet radiation, contains (1) a normally solid organic salt of nickel, cobalt or copper and (2) N, N<SP>1</SP>-bis-furfuryl-dithiooxamide or N, N<SP>1</SP>-bis-carboxyamyl-dithiooxamide. Copies may be made by placing an original in contact with the copy sheet or combination, irradiating with infra-red while in contact, and subsequently desensitizing the copy by exposure to ultraviolet, or by exposing a copy sheet to ultra-violet through a transparent original bearing opaque markings, and subsequently heating to develop colour in the areas not so desensitized. The two reagents may be disposed in a single layer, in separate layers on a single carrier, or in separate layers on separate carriers. The reagent (1) may be nickel stearate or behenate. The reagents may be dispersed in a thin film of a resinous or polymeric film-forming binder in the form of a self-sustaining film, or as a coating on a backing of film, paper or the like. The Specification includes a list of suitable binders. The sheets may also include pigments, fillers, plasticizers, dyes, waxes and resins. |
