| 摘要 |
1424459 Print ribbon INTERNATIONAL BUSINESS MACHINES CORP 19 July 1973 [3 Aug 1972 (2)] 34532/73 Addition to 1316534 Heading D2B A method of typing and subsequently erasing typed characters comprises the steps of using a typewriter mechanism to type characters by transferring discrete areas of an ink layer from a print ribbon onto a record medium and subsequently using the typewriter mechanism to strike an adhesive ribbon against erroneously typed characters on the record medium, and is characterised in that the print ribbon comprises a substrate film having an ink layer comprising from 25 to 53.7% by wt. of a hard non-waxy polyamide resin, 15 to 35% by wt. of a mineral oil, 0 to 25% by wt. of one or more fatty acid esters and from 12.2 to 35% by wt. of pigment insoluble in the other constituents of the ink layer. The invention also comprises print ribbons for use in the above method comprising a substrate film having an ink layer comprising from 25 to 35% by wt. of a hard non-waxy polyamide resin, 15 to 30% by wt. of mineral oil, 25 to 35% by wt. of one or more fatty acid esters, and 25 to 35% by wt. of pigment insoluble in the other constituents of the layer. The substrate film may be a high-density polyethylene film. The ink layer may also include an epoxy resin and/or a synthetic wax. The pigment may be carbon black or an organic dye. Exemplified fatty acid esters include isopropyl palmitate, butyl stearate, and coconut oil. |
