Patent ID: 8344092

Claim:
A bischloroformate compound production method of producing a bischloroformate compound represented by a formula (1) below, the method comprising: mixing a dihydric phenol compound represented by a formula (2) below, a phosgene compound, and an aliphatic tertiary amine together using a hydrophobic organic solvent to produce bischloroformate represented by the formula (1), the bischloroformate having an average number of repeating units (n) of 1.99 or less, the average number of repeating units (n) being calculated by an equation (1) below: where Ar of the formulae (1) and (2) is a divalent aromatic group; and Average Number of Repeating Units ( n )=1+( Mav−M 1)/ M 2 (Equation 1) where Mav is (2×1000/(CF value)), M2 is (M1−98.92), M1 is a molecular weight of the bischloroformate compound when n=1 in the formula (1), the CF value (N/kg) is (CF number/concentration), the CF number (N) is a chlorine molecule number of the bischloroformate compound represented by the formula (1) contained in a 1 L reaction solution, the concentration (kg/L) is calculated from an amount of a solid resulting from condensation of the 1 L reaction solution, and 98.92 is a total atomic weight of two chlorine atoms, one oxygen atom and one carbon atom that exist outside n repeating units in the formula (1).