Amorphous polyester adhesives for photographic materials comprising phthalic acid, linear and branched aliphatic glycol components

摘要

Disclosed herein are heat-activatable adhesive compositions comprising an amorphous condensation polymer which is characterized by having an acid component comprising a phthalic acid derivative and a glycol component comprising from about 15 to about 85 mole percent of (1) a linear aliphatic glycol having the structure HO-R-H wherein R is either: <IMAGE> or -CH2CH2O-n wherein n is an integer from 2 to 4; and from about 85 to about 15 mole percent of (2) a branched aliphatic glycol having the structure: <IMAGE> wherein R1 and R2 are alkyl. These polyester adhesives are further characterized as being soluble in halogenated solvents, having glass transition temperatures within the range of about -30 DEG C. to about 50 DEG C., and having high bonding strengths at elevated temperatures. They have been found useful in a variety of photographic materials, and particularly in photographic film units.