PURPOSE: To permit selective transmission of infrared rays in a wavelength region radiated by flame by forming, a film in which glass frit and BaTiO3 are dispersed uniformly in polyamide.
CONSTITUTION: Film is formed from glass frit (A) and BaTiO3 (B) dispersed unoformly in polyamide (C). Glass frit having low melting point which transmit infrared rays n 3.3W5.7 micron band selectively is desirable as the component A, and Nylon 6 which transmits infrared rays in 3.6W5.9 micron band is desirable as the component C. When a mixture of the above described three components in an appropriate compositional ratio (e.g. 30W55wt% A, 3W10wt% B, residual wt% C) is formed into a film, a flexible filter is obtd. Since the obtd. Filter selectively transmits infrared rays in a wavelength band including 4.3 micron wavelength radiated from flame, the filter is usable as a material for a flame sensor.
YANAGIDA TOMOYOSHI
TOKUDA HIROSHI
FUKASE TOSHIMITSU
