| 摘要 |
Urethane and oligourethane derivatives and corresponding uses and methods of producing watermarks using the offset printing technique. The invention relates to compounds having general formula (R—CO—NH—X—NH—CO—O—(-A-O—CO—NH—X′—NH—CO—O—)n—R′(I) where, for example, R and R′are C3-C18 alkyl radicals or the radical from the dimer diol when loosing an OH group, X and X′are radicals from an aliphatic diisocyanate, A is a C3-C18 alkylen radical, n is 0 or 1. The molecular weight of the compound is less than 2000 and the NCO value is equivalent to 0. The invention also relates to compositions containing this compound, to methods for producing watermarks using this compound and to uses of these compounds to produce watermarks both in laminar cellulosic materials and in laminar textile materials. |
