| 摘要 |
An ink retaining flexible polyurethane foam is prepared by reacting a polyether polyol with from 20 to 50 parts by weight, based on the weight of polyol, of a polyisocyanate component having one or a mixture of toluene diisocyanates, such that the 2,4 isomer of toluene diisocyanate includes no more than seventy-five percent by weight of the polyisocyanate component, preferably no more than seventy two and one half percent by weight. The foam has pore sizes in the range of 70 to 88 pores per inch in an uncompressed state. The foam is reticulated to improve liquid holding capacity, and, depending upon pore size, felted to compression ratios from 1 to 2 up to from 1 to 20. The foam absorbs and retains ink, and is resistant against attack from ink, emitting less than 2.0% solvent extractables, preferably less than 1.1% solvent extractables.
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