Photographic colour diffusion transfer materials containing timing layers.

摘要

A photographic colour diffusion transfer material containing an acid layer and a timing layer whose break-down time varies with changes in temperature thus enabling temperature dependence profiles to be matched wherein the timing layer comprises an addition block copolymer comprising blocks of polymerised styrene or a substituted styrene and blocks of a homo-or co-polymer which is alkali-permeable or which becomes alkali-permeable after contact with alkali.