A new class of hydroxyl terminated silicon phthalocyanine (SiPc) derivatives was prepared by capping dihydroxy SiPc with a variety of compounds containing two or more hydroxyl groups. The unique feature of these polyhydroxy SiPc derivatives is their function as crosslinkers that allows their processability into polyurethane films on reacting with isophorone diisocyanate. The films possess high impact resistance, thermostability at 125°C for over 10 h, and low absorption in the visible region. Solid polymeric films incorporating over 20% (w/w) of Pc rings were prepared without phase segregation. The kinetic parameters of polymerization, such as reaction conversion versus time and temperature, heat of reaction (ΔH), activation energy (ΔE), and reaction order (n) were investigated. Some of the polyhydroxy SiPc derivatives exhibit very high solubility in common organic solvents and possess adequate optical transparency for use as nonlinear optical materials in vision protection against laser light. © 1996 John Wiley & Sons, Inc.