On the Comultiplication in Quantum Affine Algebras

We express the comultiplication of the generators in Drinfelds second realization of the quantum affine algebra U_q(sl_2^), induced by the comultiplication of the generators in the Drinfeld-Jimbo realization of U_q(sl_2^) in terms of generating functions. Then we find explicit expressions for the comultiplication of the generators.