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(11) | EP 1 091 262 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Toner supply roll and production method therefore |
| (57) A toner supply roll comprises a shaft (1) and a soft polyurethane sponge layer (2)
provided on an outer circumferential surface of the shaft, wherein not less than 90%
of cell walls defining boundaries between respective adjacent cells have openings.
The soft polyurethane sponge layer of the toner supply roll is of an open-cell foam
structure in which the cells are three-dimensionally connected to one another via
the openings in the cell walls, so that air contained in the sponge layer smoothly
flows out when the sponge layer is depressed. Therefore, the sponge layer has a lower
hardness than a soft polyurethane sponge layer of a closed-cells foam structure. Since
not less than 90% of the cell walls defining the boundaries between the respective
adjacent cells have openings, toner fluidity can properly be maintained. Therefore,
the toner supply roll can minimise degradation of the toner during prolonged use and
stably maintain toner scrapability and toner supplying capability, thereby ensuring
formation of high quality images for an extended period of time. |