Compounds useful in making crosslinkable polymers having the formula (I): ##STR1## wherein R is hydrogen or methyl; R.sup.1 is cyano or ##STR2## wherein R.sup.2 is alkyl; Z is --X--R.sup.3 --X-- or ##STR3## wherein each --X-- is --O-- or --NR.sup.4 --, provided at least one --X-- is --NR.sup.4 -- wherein R.sup.4 is hydrogen or alkyl, R.sup.3 is divalent hydrocarbon and D.sub.1 and D.sub.2 together are the carbon atoms necessary to complete a 5 to 7 membered ring. These compounds can be homopolymerized or copolymerized with each other or with polymerizable ethylenically unsaturated monomers to give crosslinkable polymers. Such polymers can be purified by conventional purification techniques such as dialysis, diafiltration, ultrafiltration without losing their capability of crosslinking. The resulting purified polymers are particularly useful in photographic materials as gelatin extenders, binders or polymeric color couplers.
有用于制备可交联聚合物的化合物,其具有以下式子(I):##STR1##
其中R为氢或甲基;R.sup.1为
氰基或##STR4##
其中R.sup.2为烷基;Z为--X--R.sup.3--X--或##STR5##
其中每个--X--为--O--或--NR.sup.4--,至少有一个--X--为--NR.sup.4--,其中R.sup.4为氢或烷基,R.sup.3为二价碳氢化合物,且D.sub.1和D.sub.2共同形成5至7成员环所需的碳原子。这些化合物可以与彼此或与可聚合的
乙烯基不饱和单体共聚合,以产生可交联的聚合物。这样的聚合物可以通过常规的纯化技术(如透析、透过滤、超滤)进行纯化,而不失去其交联能力。所得到的纯化聚合物在摄影材料中特别有用,作为明胶扩展剂、粘合剂或聚合色偶。