| 摘要 |
The invention describes a graft polymer based on a graft base which contains a polymer comprising diol components and diisocyanate components which has at least two urethane groups in the molecule, onto which graft base have been grafted polymer chains comprising units of vinyl esters of carboxylic acids, having 3 to 20 carbon atoms, and/or hydrolysis products thereof, and optionally units of other ethylenically unsaturated monomers or hydrolysis products thereof and which are additionally esterified in the melt in homogeneous phase with an acylating reagent, in particular with carboxylic anhydrides. The product is insoluble in water, but soluble in aqueous alcohol solution and can be used as a binder in light-curable mixtures for the preparation of relief printing plates. Also described is a process for the preparation of the graft polymers mentioned above, in which on catalyst is used and consequently a colorless product results. The product is obtained from the homogeneous phase. |
