In these compositions, one or more nitrogen organic compounds are selected from the group consisting of reaction products of ethylene urea and formaldehyde, reaction products of ethylene thiourea and formaldehyde, and 1,3,5-triazine derivatives represented by the formula: ##STR6## wherein X is morpholino or piperidino, Y is a two valence group of piperazine, and n is an integer of 2 to 50.