Vylon GK150 Non-crystalline copolyester Toyobo Vylon Polyester ADHESIVE Highly polymerized copolyester resin that can be dissolved by general purpose organic solvents. For its dissolution property, this product is used for a variety of solution type adhesives. Acid added type of GK140 Acid added highly polymerized copolyester resin. Used in adhesives for flexible printed circuit board.