Browse Prior Art Database

Reagents for Removal of Imidazoline in Resistive Ribbon Ink

IP.com Disclosure Number: IPCOM000040166D
Original Publication Date: 1987-Oct-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

Beach, BL: AUTHOR [+3]

Abstract

Resistive ribbon thermal transfer printing employs ribbons having a resistive, support layer, often of polycarbonate; a thin aluminum interlayer; and an ink outer layer, which is transferred by heat generated in the ribbon itself. U.S. Patent 4,384,797 is illustrative. When the ink layer comprises an amine-terminated polyamide, imidazoline functionalities can be formed as an impurity, which can decompose polycarbonate of the support layer. To avoid such damage, the imidazoline groups are removed by treating the polyamide prior to use with diphenyl carbonate as a sacrificial reagent. The imidazoline formation stems from a ring closure reaction between the amine end group and the amide hydrogen of the polyamide, as seen in Fig. 1.

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Reagents for Removal of Imidazoline in Resistive Ribbon Ink

Resistive ribbon thermal transfer printing employs ribbons having a resistive, support layer, often of polycarbonate; a thin aluminum interlayer; and an ink outer layer, which is transferred by heat generated in the ribbon itself. U.S. Patent 4,384,797 is illustrative. When the ink layer comprises an amine-terminated polyamide, imidazoline functionalities can be formed as an impurity, which can decompose polycarbonate of the support layer. To avoid such damage, the imidazoline groups are removed by treating the polyamide prior to use with diphenyl carbonate as a sacrificial reagent. The imidazoline formation stems from a ring closure reaction between the amine end group and the amide hydrogen of the polyamide, as seen in Fig. 1.

(Image Omitted)

These imidazoline groups can decompose polycarbonate, causing printing ribbons using polycarbonate as the substrate resin to break. The imidazoline groups are selectively removed by adding a sacrificial reaction site to the coating solution. One such additive is diphenyl carbonate. By adding diphenyl carbonate to the coating solution, all of the imidazoline present will react with the carbonate before it is coated and thus the imidazoline can not react with the polycarbonate substrate. This sacrificial reaction is shown in Fig. 2. Imidazoline is reduced to essentially zero after 7 hours in solution with dipheny carbonate.

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