A b r organics limited [abrol] founded in 1991 is the manufacturer of different types of polyimide resins. Abron br720 is used for preparing laminates and some of the specifications:
Prepare a 45 - 50 % solution of abron br720 in dry nmp/ dmf/ dmac.
Use this solution to impregnate glass-fiber fabrics and then dry at 1600c for 10 minutes to obtain a b-stage prepregs.
Stack required number of the b-stage prepregs between aluminum foils/mylar sheets.
Place the stack between heated press plates at a temperature of 1200c.
Immediately apply a pressure of 210 psi to 800 psi depending upon the thickness.
Increase the temperature progressively to 1800c in 30 minutes for stack not thicker than 3/8 in.
Cure the laminate at 1800c for 1 -2 hrs.
Remove the laminate from the hot press at 1000c and post cure it for 16 - 24 hours at 2500c
