A photographic element having thereon a barrier layer comprising a chill-gelable polymer comprising:
(a) 30 to 97 weight percent of polymerized N-alkyl-substituted acrylamide,
(b) 3 to 25 weight percent of polymerized crosslinking monomer having at least two addition-polymerizable groups per molecule and
(c) the remainder of the copolymer (if any) being made up by one or more other polymerized monomers,
with the proviso that said other monomers (c) comprise less than 5 weight percent of cationic monomers, less than 15 weight percent of free acid monomers, and less than 3 weight percent of metal or ammonium salts of acid monomers. The barrier layer is particularly useful as a process timing layer in color image transfer film units.
                            一种照相元件,其上有一层阻隔层,阻隔层由可冷凝胶聚合物组成,该聚合物包括
(a) 30 至 97 重量百分比的聚合 N-烷基取代
丙烯酰胺、
(b) 3 至 25 重量百分比的聚合交联单体,每个分子至少有两个可加成聚合的基团, 以及
(c) 共聚物的其余部分(如有)由一种或多种其他聚合单体组成、
但上述其他单体(c)中
阳离子单体的重量百分比小于 5%,
游离酸单体的重量百分比小于 15%,酸单体的
金属盐或
铵盐的重量百分比小于 3%。阻隔层特别适用于彩色图像转印胶片装置中的加工定时层。